diff options
| author | Rui Paulo <rpaulo@FreeBSD.org> | 2015-03-24 00:00:59 +0000 |
|---|---|---|
| committer | Rui Paulo <rpaulo@FreeBSD.org> | 2015-03-24 00:00:59 +0000 |
| commit | 52bff0d770d4359f702d9922b8608ad23351ea89 (patch) | |
| tree | a54637781398b630824152ae05672536c0fa8341 | |
| download | src-52bff0d770d4359f702d9922b8608ad23351ea89.tar.gz src-52bff0d770d4359f702d9922b8608ad23351ea89.zip | |
Import lua 5.3.0.vendor/lua/5.3.0
Notes
Notes:
svn path=/vendor/lua/dist/; revision=280405
svn path=/vendor/lua/5.3.0/; revision=280406; tag=vendor/lua/5.3.0
| -rw-r--r-- | Makefile | 114 | ||||
| -rw-r--r-- | README | 6 | ||||
| -rw-r--r-- | doc/contents.html | 619 | ||||
| -rw-r--r-- | doc/logo.gif | bin | 0 -> 4232 bytes | |||
| -rw-r--r-- | doc/lua.1 | 111 | ||||
| -rw-r--r-- | doc/lua.css | 105 | ||||
| -rw-r--r-- | doc/luac.1 | 118 | ||||
| -rw-r--r-- | doc/manual.css | 27 | ||||
| -rw-r--r-- | doc/manual.html | 10789 | ||||
| -rw-r--r-- | doc/osi-certified-72x60.png | bin | 0 -> 3774 bytes | |||
| -rw-r--r-- | doc/readme.html | 371 | ||||
| -rw-r--r-- | src/Makefile | 197 | ||||
| -rw-r--r-- | src/lapi.c | 1270 | ||||
| -rw-r--r-- | src/lapi.h | 24 | ||||
| -rw-r--r-- | src/lauxlib.c | 972 | ||||
| -rw-r--r-- | src/lauxlib.h | 256 | ||||
| -rw-r--r-- | src/lbaselib.c | 520 | ||||
| -rw-r--r-- | src/lbitlib.c | 230 | ||||
| -rw-r--r-- | src/lcode.c | 954 | ||||
| -rw-r--r-- | src/lcode.h | 87 | ||||
| -rw-r--r-- | src/lcorolib.c | 168 | ||||
| -rw-r--r-- | src/lctype.c | 55 | ||||
| -rw-r--r-- | src/lctype.h | 95 | ||||
| -rw-r--r-- | src/ldblib.c | 437 | ||||
| -rw-r--r-- | src/ldebug.c | 643 | ||||
| -rw-r--r-- | src/ldebug.h | 40 | ||||
| -rw-r--r-- | src/ldo.c | 717 | ||||
| -rw-r--r-- | src/ldo.h | 46 | ||||
| -rw-r--r-- | src/ldump.c | 214 | ||||
| -rw-r--r-- | src/lfunc.c | 151 | ||||
| -rw-r--r-- | src/lfunc.h | 54 | ||||
| -rw-r--r-- | src/lgc.c | 1159 | ||||
| -rw-r--r-- | src/lgc.h | 138 | ||||
| -rw-r--r-- | src/linit.c | 68 | ||||
| -rw-r--r-- | src/liolib.c | 757 | ||||
| -rw-r--r-- | src/llex.c | 602 | ||||
| -rw-r--r-- | src/llex.h | 86 | ||||
| -rw-r--r-- | src/llimits.h | 242 | ||||
| -rw-r--r-- | src/lmathlib.c | 404 | ||||
| -rw-r--r-- | src/lmem.c | 99 | ||||
| -rw-r--r-- | src/lmem.h | 69 | ||||
| -rw-r--r-- | src/loadlib.c | 786 | ||||
| -rw-r--r-- | src/lobject.c | 470 | ||||
| -rw-r--r-- | src/lobject.h | 540 | ||||
| -rw-r--r-- | src/lopcodes.c | 124 | ||||
| -rw-r--r-- | src/lopcodes.h | 295 | ||||
| -rw-r--r-- | src/loslib.c | 356 | ||||
| -rw-r--r-- | src/lparser.c | 1647 | ||||
| -rw-r--r-- | src/lparser.h | 120 | ||||
| -rw-r--r-- | src/lprefix.h | 45 | ||||
| -rw-r--r-- | src/lstate.c | 346 | ||||
| -rw-r--r-- | src/lstate.h | 223 | ||||
| -rw-r--r-- | src/lstring.c | 182 | ||||
| -rw-r--r-- | src/lstring.h | 46 | ||||
| -rw-r--r-- | src/lstrlib.c | 1430 | ||||
| -rw-r--r-- | src/ltable.c | 650 | ||||
| -rw-r--r-- | src/ltable.h | 53 | ||||
| -rw-r--r-- | src/ltablib.c | 357 | ||||
| -rw-r--r-- | src/ltm.c | 143 | ||||
| -rw-r--r-- | src/ltm.h | 75 | ||||
| -rw-r--r-- | src/lua.c | 611 | ||||
| -rw-r--r-- | src/lua.h | 485 | ||||
| -rw-r--r-- | src/lua.hpp | 9 | ||||
| -rw-r--r-- | src/luac.c | 449 | ||||
| -rw-r--r-- | src/luaconf.h | 735 | ||||
| -rw-r--r-- | src/lualib.h | 58 | ||||
| -rw-r--r-- | src/lundump.c | 277 | ||||
| -rw-r--r-- | src/lundump.h | 33 | ||||
| -rw-r--r-- | src/lutf8lib.c | 255 | ||||
| -rw-r--r-- | src/lvm.c | 1182 | ||||
| -rw-r--r-- | src/lvm.h | 58 | ||||
| -rw-r--r-- | src/lzio.c | 78 | ||||
| -rw-r--r-- | src/lzio.h | 67 |
73 files changed, 35199 insertions, 0 deletions
diff --git a/Makefile b/Makefile new file mode 100644 index 000000000000..7fa91c858bb1 --- /dev/null +++ b/Makefile @@ -0,0 +1,114 @@ +# Makefile for installing Lua +# See doc/readme.html for installation and customization instructions. + +# == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT ======================= + +# Your platform. See PLATS for possible values. +PLAT= none + +# Where to install. The installation starts in the src and doc directories, +# so take care if INSTALL_TOP is not an absolute path. See the local target. +# You may want to make INSTALL_LMOD and INSTALL_CMOD consistent with +# LUA_ROOT, LUA_LDIR, and LUA_CDIR in luaconf.h. +INSTALL_TOP= /usr/local +INSTALL_BIN= $(INSTALL_TOP)/bin +INSTALL_INC= $(INSTALL_TOP)/include +INSTALL_LIB= $(INSTALL_TOP)/lib +INSTALL_MAN= $(INSTALL_TOP)/man/man1 +INSTALL_LMOD= $(INSTALL_TOP)/share/lua/$V +INSTALL_CMOD= $(INSTALL_TOP)/lib/lua/$V + +# How to install. If your install program does not support "-p", then +# you may have to run ranlib on the installed liblua.a. +INSTALL= install -p +INSTALL_EXEC= $(INSTALL) -m 0755 +INSTALL_DATA= $(INSTALL) -m 0644 +# +# If you don't have "install" you can use "cp" instead. +# INSTALL= cp -p +# INSTALL_EXEC= $(INSTALL) +# INSTALL_DATA= $(INSTALL) + +# Other utilities. +MKDIR= mkdir -p +RM= rm -f + +# == END OF USER SETTINGS -- NO NEED TO CHANGE ANYTHING BELOW THIS LINE ======= + +# Convenience platforms targets. +PLATS= aix bsd c89 freebsd generic linux macosx mingw posix solaris + +# What to install. +TO_BIN= lua luac +TO_INC= lua.h luaconf.h lualib.h lauxlib.h lua.hpp +TO_LIB= liblua.a +TO_MAN= lua.1 luac.1 + +# Lua version and release. +V= 5.3 +R= $V.0 + +# Targets start here. +all: $(PLAT) + +$(PLATS) clean: + cd src && $(MAKE) $@ + +test: dummy + src/lua -v + +install: dummy + cd src && $(MKDIR) $(INSTALL_BIN) $(INSTALL_INC) $(INSTALL_LIB) $(INSTALL_MAN) $(INSTALL_LMOD) $(INSTALL_CMOD) + cd src && $(INSTALL_EXEC) $(TO_BIN) $(INSTALL_BIN) + cd src && $(INSTALL_DATA) $(TO_INC) $(INSTALL_INC) + cd src && $(INSTALL_DATA) $(TO_LIB) $(INSTALL_LIB) + cd doc && $(INSTALL_DATA) $(TO_MAN) $(INSTALL_MAN) + +uninstall: + cd src && cd $(INSTALL_BIN) && $(RM) $(TO_BIN) + cd src && cd $(INSTALL_INC) && $(RM) $(TO_INC) + cd src && cd $(INSTALL_LIB) && $(RM) $(TO_LIB) + cd doc && cd $(INSTALL_MAN) && $(RM) $(TO_MAN) + +local: + $(MAKE) install INSTALL_TOP=../install + +none: + @echo "Please do 'make PLATFORM' where PLATFORM is one of these:" + @echo " $(PLATS)" + @echo "See doc/readme.html for complete instructions." + +# make may get confused with test/ and install/ +dummy: + +# echo config parameters +echo: + @cd src && $(MAKE) -s echo + @echo "PLAT= $(PLAT)" + @echo "V= $V" + @echo "R= $R" + @echo "TO_BIN= $(TO_BIN)" + @echo "TO_INC= $(TO_INC)" + @echo "TO_LIB= $(TO_LIB)" + @echo "TO_MAN= $(TO_MAN)" + @echo "INSTALL_TOP= $(INSTALL_TOP)" + @echo "INSTALL_BIN= $(INSTALL_BIN)" + @echo "INSTALL_INC= $(INSTALL_INC)" + @echo "INSTALL_LIB= $(INSTALL_LIB)" + @echo "INSTALL_MAN= $(INSTALL_MAN)" + @echo "INSTALL_LMOD= $(INSTALL_LMOD)" + @echo "INSTALL_CMOD= $(INSTALL_CMOD)" + @echo "INSTALL_EXEC= $(INSTALL_EXEC)" + @echo "INSTALL_DATA= $(INSTALL_DATA)" + +# echo pkg-config data +pc: + @echo "version=$R" + @echo "prefix=$(INSTALL_TOP)" + @echo "libdir=$(INSTALL_LIB)" + @echo "includedir=$(INSTALL_INC)" + +# list targets that do not create files (but not all makes understand .PHONY) +.PHONY: all $(PLATS) clean test install local none dummy echo pecho lecho + +# (end of Makefile) diff --git a/README b/README new file mode 100644 index 000000000000..32fb68e77e31 --- /dev/null +++ b/README @@ -0,0 +1,6 @@ + +This is Lua 5.3.0, released on 06 Jan 2015. + +For installation instructions, license details, and +further information about Lua, see doc/readme.html. + diff --git a/doc/contents.html b/doc/contents.html new file mode 100644 index 000000000000..e59e4215eee3 --- /dev/null +++ b/doc/contents.html @@ -0,0 +1,619 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<HTML> +<HEAD> +<TITLE>Lua 5.3 Reference Manual - contents</TITLE> +<LINK REL="stylesheet" TYPE="text/css" HREF="lua.css"> +<META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1"> +<STYLE TYPE="text/css"> +ul { + list-style-type: none ; + list-style-position: outside ; +} +</STYLE> +</HEAD> + +<BODY> + +<HR> +<H1> +<A HREF="http://www.lua.org/"><IMG SRC="logo.gif" ALT="" BORDER=0></A> +Lua 5.3 Reference Manual +</H1> + +<P> +The reference manual is the official definition of the Lua language. +For a complete introduction to Lua programming, see the book +<A HREF="http://www.lua.org/pil/">Programming in Lua</A>. + +<P> +<A HREF="manual.html">start</A> +· +<A HREF="#contents">contents</A> +· +<A HREF="#index">index</A> +<HR> +<SMALL> +Copyright © 2015 Lua.org, PUC-Rio. +Freely available under the terms of the +<A HREF="http://www.lua.org/license.html">Lua license</A>. +</SMALL> + +<H2><A NAME="contents">Contents</A></H2> +<UL style="padding: 0"> +<LI><A HREF="manual.html">1 – Introduction</A> +<P> +<LI><A HREF="manual.html#2">2 – Basic Concepts</A> +<UL> +<LI><A HREF="manual.html#2.1">2.1 – Values and Types</A> +<LI><A HREF="manual.html#2.2">2.2 – Environments and the Global Environment</A> +<LI><A HREF="manual.html#2.3">2.3 – Error Handling</A> +<LI><A HREF="manual.html#2.4">2.4 – Metatables and Metamethods</A> +<LI><A HREF="manual.html#2.5">2.5 – Garbage Collection</A> +<UL> +<LI><A HREF="manual.html#2.5.1">2.5.1 – Garbage-Collection Metamethods</A> +<LI><A HREF="manual.html#2.5.2">2.5.2 – Weak Tables</A> +</UL> +<LI><A HREF="manual.html#2.6">2.6 – Coroutines</A> +</UL> +<P> +<LI><A HREF="manual.html#3">3 – The Language</A> +<UL> +<LI><A HREF="manual.html#3.1">3.1 – Lexical Conventions</A> +<LI><A HREF="manual.html#3.2">3.2 – Variables</A> +<LI><A HREF="manual.html#3.3">3.3 – Statements</A> +<UL> +<LI><A HREF="manual.html#3.3.1">3.3.1 – Blocks</A> +<LI><A HREF="manual.html#3.3.2">3.3.2 – Chunks</A> +<LI><A HREF="manual.html#3.3.3">3.3.3 – Assignment</A> +<LI><A HREF="manual.html#3.3.4">3.3.4 – Control Structures</A> +<LI><A HREF="manual.html#3.3.5">3.3.5 – For Statement</A> +<LI><A HREF="manual.html#3.3.6">3.3.6 – Function Calls as Statements</A> +<LI><A HREF="manual.html#3.3.7">3.3.7 – Local Declarations</A> +</UL> +<LI><A HREF="manual.html#3.4">3.4 – Expressions</A> +<UL> +<LI><A HREF="manual.html#3.4.1">3.4.1 – Arithmetic Operators</A> +<LI><A HREF="manual.html#3.4.2">3.4.2 – Bitwise Operators</A> +<LI><A HREF="manual.html#3.4.3">3.4.3 – Coercions and Conversions</A> +<LI><A HREF="manual.html#3.4.4">3.4.4 – Relational Operators</A> +<LI><A HREF="manual.html#3.4.5">3.4.5 – Logical Operators</A> +<LI><A HREF="manual.html#3.4.6">3.4.6 – Concatenation</A> +<LI><A HREF="manual.html#3.4.7">3.4.7 – The Length Operator</A> +<LI><A HREF="manual.html#3.4.8">3.4.8 – Precedence</A> +<LI><A HREF="manual.html#3.4.9">3.4.9 – Table Constructors</A> +<LI><A HREF="manual.html#3.4.10">3.4.10 – Function Calls</A> +<LI><A HREF="manual.html#3.4.11">3.4.11 – Function Definitions</A> +</UL> +<LI><A HREF="manual.html#3.5">3.5 – Visibility Rules</A> +</UL> +<P> +<LI><A HREF="manual.html#4">4 – The Application Program Interface</A> +<UL> +<LI><A HREF="manual.html#4.1">4.1 – The Stack</A> +<LI><A HREF="manual.html#4.2">4.2 – Stack Size</A> +<LI><A HREF="manual.html#4.3">4.3 – Valid and Acceptable Indices</A> +<LI><A HREF="manual.html#4.4">4.4 – C Closures</A> +<LI><A HREF="manual.html#4.5">4.5 – Registry</A> +<LI><A HREF="manual.html#4.6">4.6 – Error Handling in C</A> +<LI><A HREF="manual.html#4.7">4.7 – Handling Yields in C</A> +<LI><A HREF="manual.html#4.8">4.8 – Functions and Types</A> +<LI><A HREF="manual.html#4.9">4.9 – The Debug Interface</A> +</UL> +<P> +<LI><A HREF="manual.html#5">5 – The Auxiliary Library</A> +<UL> +<LI><A HREF="manual.html#5.1">5.1 – Functions and Types</A> +</UL> +<P> +<LI><A HREF="manual.html#6">6 – Standard Libraries</A> +<UL> +<LI><A HREF="manual.html#6.1">6.1 – Basic Functions</A> +<LI><A HREF="manual.html#6.2">6.2 – Coroutine Manipulation</A> +<LI><A HREF="manual.html#6.3">6.3 – Modules</A> +<LI><A HREF="manual.html#6.4">6.4 – String Manipulation</A> +<UL> +<LI><A HREF="manual.html#6.4.1">6.4.1 – Patterns</A> +<LI><A HREF="manual.html#6.4.2">6.4.2 – Format Strings for Pack and Unpack</A> +</UL> +<LI><A HREF="manual.html#6.5">6.5 – UTF-8 Support</A> +<LI><A HREF="manual.html#6.6">6.6 – Table Manipulation</A> +<LI><A HREF="manual.html#6.7">6.7 – Mathematical Functions</A> +<LI><A HREF="manual.html#6.8">6.8 – Input and Output Facilities</A> +<LI><A HREF="manual.html#6.9">6.9 – Operating System Facilities</A> +<LI><A HREF="manual.html#6.10">6.10 – The Debug Library</A> +</UL> +<P> +<LI><A HREF="manual.html#7">7 – Lua Standalone</A> +<P> +<LI><A HREF="manual.html#8">8 – Incompatibilities with the Previous Version</A> +<UL> +<LI><A HREF="manual.html#8.1">8.1 – Changes in the Language</A> +<LI><A HREF="manual.html#8.2">8.2 – Changes in the Libraries</A> +<LI><A HREF="manual.html#8.3">8.3 – Changes in the API</A> +</UL> +<P> +<LI><A HREF="manual.html#9">9 – The Complete Syntax of Lua</A> +</UL> + +<H2><A NAME="index">Index</A></H2> +<TABLE WIDTH="100%"> +<TR VALIGN="top"> +<TD> +<H3><A NAME="functions">Lua functions</A></H3> +<P> +<A HREF="manual.html#6.1">basic</A><BR> +<A HREF="manual.html#pdf-_G">_G</A><BR> +<A HREF="manual.html#pdf-_VERSION">_VERSION</A><BR> + +<A HREF="manual.html#pdf-assert">assert</A><BR> +<A HREF="manual.html#pdf-collectgarbage">collectgarbage</A><BR> +<A HREF="manual.html#pdf-dofile">dofile</A><BR> +<A HREF="manual.html#pdf-error">error</A><BR> +<A HREF="manual.html#pdf-getmetatable">getmetatable</A><BR> +<A HREF="manual.html#pdf-ipairs">ipairs</A><BR> +<A HREF="manual.html#pdf-load">load</A><BR> +<A HREF="manual.html#pdf-loadfile">loadfile</A><BR> +<A HREF="manual.html#pdf-next">next</A><BR> +<A HREF="manual.html#pdf-pairs">pairs</A><BR> +<A HREF="manual.html#pdf-pcall">pcall</A><BR> +<A HREF="manual.html#pdf-print">print</A><BR> +<A HREF="manual.html#pdf-rawequal">rawequal</A><BR> +<A HREF="manual.html#pdf-rawget">rawget</A><BR> +<A HREF="manual.html#pdf-rawlen">rawlen</A><BR> +<A HREF="manual.html#pdf-rawset">rawset</A><BR> +<A HREF="manual.html#pdf-require">require</A><BR> +<A HREF="manual.html#pdf-select">select</A><BR> +<A HREF="manual.html#pdf-setmetatable">setmetatable</A><BR> +<A HREF="manual.html#pdf-tonumber">tonumber</A><BR> +<A HREF="manual.html#pdf-tostring">tostring</A><BR> +<A HREF="manual.html#pdf-type">type</A><BR> +<A HREF="manual.html#pdf-xpcall">xpcall</A><BR> + +<P> +<A HREF="manual.html#6.2">coroutine</A><BR> +<A HREF="manual.html#pdf-coroutine.create">coroutine.create</A><BR> +<A HREF="manual.html#pdf-coroutine.isyieldable">coroutine.isyieldable</A><BR> +<A HREF="manual.html#pdf-coroutine.resume">coroutine.resume</A><BR> +<A HREF="manual.html#pdf-coroutine.running">coroutine.running</A><BR> +<A HREF="manual.html#pdf-coroutine.status">coroutine.status</A><BR> +<A HREF="manual.html#pdf-coroutine.wrap">coroutine.wrap</A><BR> +<A HREF="manual.html#pdf-coroutine.yield">coroutine.yield</A><BR> + +<P> +<A HREF="manual.html#6.10">debug</A><BR> +<A HREF="manual.html#pdf-debug.debug">debug.debug</A><BR> +<A HREF="manual.html#pdf-debug.gethook">debug.gethook</A><BR> +<A HREF="manual.html#pdf-debug.getinfo">debug.getinfo</A><BR> +<A HREF="manual.html#pdf-debug.getlocal">debug.getlocal</A><BR> +<A HREF="manual.html#pdf-debug.getmetatable">debug.getmetatable</A><BR> +<A HREF="manual.html#pdf-debug.getregistry">debug.getregistry</A><BR> +<A HREF="manual.html#pdf-debug.getupvalue">debug.getupvalue</A><BR> +<A HREF="manual.html#pdf-debug.getuservalue">debug.getuservalue</A><BR> +<A HREF="manual.html#pdf-debug.sethook">debug.sethook</A><BR> +<A HREF="manual.html#pdf-debug.setlocal">debug.setlocal</A><BR> +<A HREF="manual.html#pdf-debug.setmetatable">debug.setmetatable</A><BR> +<A HREF="manual.html#pdf-debug.setupvalue">debug.setupvalue</A><BR> +<A HREF="manual.html#pdf-debug.setuservalue">debug.setuservalue</A><BR> +<A HREF="manual.html#pdf-debug.traceback">debug.traceback</A><BR> +<A HREF="manual.html#pdf-debug.upvalueid">debug.upvalueid</A><BR> +<A HREF="manual.html#pdf-debug.upvaluejoin">debug.upvaluejoin</A><BR> + +<P> +<A HREF="manual.html#6.8">io</A><BR> +<A HREF="manual.html#pdf-io.close">io.close</A><BR> +<A HREF="manual.html#pdf-io.flush">io.flush</A><BR> +<A HREF="manual.html#pdf-io.input">io.input</A><BR> +<A HREF="manual.html#pdf-io.lines">io.lines</A><BR> +<A HREF="manual.html#pdf-io.open">io.open</A><BR> +<A HREF="manual.html#pdf-io.output">io.output</A><BR> +<A HREF="manual.html#pdf-io.popen">io.popen</A><BR> +<A HREF="manual.html#pdf-io.read">io.read</A><BR> +<A HREF="manual.html#pdf-io.stderr">io.stderr</A><BR> +<A HREF="manual.html#pdf-io.stdin">io.stdin</A><BR> +<A HREF="manual.html#pdf-io.stdout">io.stdout</A><BR> +<A HREF="manual.html#pdf-io.tmpfile">io.tmpfile</A><BR> +<A HREF="manual.html#pdf-io.type">io.type</A><BR> +<A HREF="manual.html#pdf-io.write">io.write</A><BR> + +<A HREF="manual.html#pdf-file:close">file:close</A><BR> +<A HREF="manual.html#pdf-file:flush">file:flush</A><BR> +<A HREF="manual.html#pdf-file:lines">file:lines</A><BR> +<A HREF="manual.html#pdf-file:read">file:read</A><BR> +<A HREF="manual.html#pdf-file:seek">file:seek</A><BR> +<A HREF="manual.html#pdf-file:setvbuf">file:setvbuf</A><BR> +<A HREF="manual.html#pdf-file:write">file:write</A><BR> + +</TD> +<TD> +<H3> </H3> +<P> +<A HREF="manual.html#6.7">math</A><BR> +<A HREF="manual.html#pdf-math.abs">math.abs</A><BR> +<A HREF="manual.html#pdf-math.acos">math.acos</A><BR> +<A HREF="manual.html#pdf-math.asin">math.asin</A><BR> +<A HREF="manual.html#pdf-math.atan">math.atan</A><BR> +<A HREF="manual.html#pdf-math.ceil">math.ceil</A><BR> +<A HREF="manual.html#pdf-math.cos">math.cos</A><BR> +<A HREF="manual.html#pdf-math.deg">math.deg</A><BR> +<A HREF="manual.html#pdf-math.exp">math.exp</A><BR> +<A HREF="manual.html#pdf-math.floor">math.floor</A><BR> +<A HREF="manual.html#pdf-math.fmod">math.fmod</A><BR> +<A HREF="manual.html#pdf-math.huge">math.huge</A><BR> +<A HREF="manual.html#pdf-math.log">math.log</A><BR> +<A HREF="manual.html#pdf-math.max">math.max</A><BR> +<A HREF="manual.html#pdf-math.maxinteger">math.maxinteger</A><BR> +<A HREF="manual.html#pdf-math.min">math.min</A><BR> +<A HREF="manual.html#pdf-math.mininteger">math.mininteger</A><BR> +<A HREF="manual.html#pdf-math.modf">math.modf</A><BR> +<A HREF="manual.html#pdf-math.pi">math.pi</A><BR> +<A HREF="manual.html#pdf-math.rad">math.rad</A><BR> +<A HREF="manual.html#pdf-math.random">math.random</A><BR> +<A HREF="manual.html#pdf-math.randomseed">math.randomseed</A><BR> +<A HREF="manual.html#pdf-math.sin">math.sin</A><BR> +<A HREF="manual.html#pdf-math.sqrt">math.sqrt</A><BR> +<A HREF="manual.html#pdf-math.tan">math.tan</A><BR> +<A HREF="manual.html#pdf-math.tointeger">math.tointeger</A><BR> +<A HREF="manual.html#pdf-math.type">math.type</A><BR> +<A HREF="manual.html#pdf-math.ult">math.ult</A><BR> + +<P> +<A HREF="manual.html#6.9">os</A><BR> +<A HREF="manual.html#pdf-os.clock">os.clock</A><BR> +<A HREF="manual.html#pdf-os.date">os.date</A><BR> +<A HREF="manual.html#pdf-os.difftime">os.difftime</A><BR> +<A HREF="manual.html#pdf-os.execute">os.execute</A><BR> +<A HREF="manual.html#pdf-os.exit">os.exit</A><BR> +<A HREF="manual.html#pdf-os.getenv">os.getenv</A><BR> +<A HREF="manual.html#pdf-os.remove">os.remove</A><BR> +<A HREF="manual.html#pdf-os.rename">os.rename</A><BR> +<A HREF="manual.html#pdf-os.setlocale">os.setlocale</A><BR> +<A HREF="manual.html#pdf-os.time">os.time</A><BR> +<A HREF="manual.html#pdf-os.tmpname">os.tmpname</A><BR> + +<P> +<A HREF="manual.html#6.3">package</A><BR> +<A HREF="manual.html#pdf-package.config">package.config</A><BR> +<A HREF="manual.html#pdf-package.cpath">package.cpath</A><BR> +<A HREF="manual.html#pdf-package.loaded">package.loaded</A><BR> +<A HREF="manual.html#pdf-package.loadlib">package.loadlib</A><BR> +<A HREF="manual.html#pdf-package.path">package.path</A><BR> +<A HREF="manual.html#pdf-package.preload">package.preload</A><BR> +<A HREF="manual.html#pdf-package.searchers">package.searchers</A><BR> +<A HREF="manual.html#pdf-package.searchpath">package.searchpath</A><BR> + +<P> +<A HREF="manual.html#6.4">string</A><BR> +<A HREF="manual.html#pdf-string.byte">string.byte</A><BR> +<A HREF="manual.html#pdf-string.char">string.char</A><BR> +<A HREF="manual.html#pdf-string.dump">string.dump</A><BR> +<A HREF="manual.html#pdf-string.find">string.find</A><BR> +<A HREF="manual.html#pdf-string.format">string.format</A><BR> +<A HREF="manual.html#pdf-string.gmatch">string.gmatch</A><BR> +<A HREF="manual.html#pdf-string.gsub">string.gsub</A><BR> +<A HREF="manual.html#pdf-string.len">string.len</A><BR> +<A HREF="manual.html#pdf-string.lower">string.lower</A><BR> +<A HREF="manual.html#pdf-string.match">string.match</A><BR> +<A HREF="manual.html#pdf-string.pack">string.pack</A><BR> +<A HREF="manual.html#pdf-string.packsize">string.packsize</A><BR> +<A HREF="manual.html#pdf-string.rep">string.rep</A><BR> +<A HREF="manual.html#pdf-string.reverse">string.reverse</A><BR> +<A HREF="manual.html#pdf-string.sub">string.sub</A><BR> +<A HREF="manual.html#pdf-string.unpack">string.unpack</A><BR> +<A HREF="manual.html#pdf-string.upper">string.upper</A><BR> + +<P> +<A HREF="manual.html#6.6">table</A><BR> +<A HREF="manual.html#pdf-table.concat">table.concat</A><BR> +<A HREF="manual.html#pdf-table.insert">table.insert</A><BR> +<A HREF="manual.html#pdf-table.move">table.move</A><BR> +<A HREF="manual.html#pdf-table.pack">table.pack</A><BR> +<A HREF="manual.html#pdf-table.remove">table.remove</A><BR> +<A HREF="manual.html#pdf-table.sort">table.sort</A><BR> +<A HREF="manual.html#pdf-table.unpack">table.unpack</A><BR> + +<P> +<A HREF="manual.html#6.5">utf8</A><BR> +<A HREF="manual.html#pdf-utf8.char">utf8.char</A><BR> +<A HREF="manual.html#pdf-utf8.charpattern">utf8.charpattern</A><BR> +<A HREF="manual.html#pdf-utf8.codepoint">utf8.codepoint</A><BR> +<A HREF="manual.html#pdf-utf8.codes">utf8.codes</A><BR> +<A HREF="manual.html#pdf-utf8.len">utf8.len</A><BR> +<A HREF="manual.html#pdf-utf8.offset">utf8.offset</A><BR> + +<H3><A NAME="env">environment<BR>variables</A></H3> +<A HREF="manual.html#pdf-LUA_CPATH">LUA_CPATH</A><BR> +<A HREF="manual.html#pdf-LUA_CPATH_5_3">LUA_CPATH_5_3</A><BR> +<A HREF="manual.html#pdf-LUA_INIT">LUA_INIT</A><BR> +<A HREF="manual.html#pdf-LUA_INIT_5_3">LUA_INIT_5_3</A><BR> +<A HREF="manual.html#pdf-LUA_PATH">LUA_PATH</A><BR> +<A HREF="manual.html#pdf-LUA_PATH_5_3">LUA_PATH_5_3</A><BR> + +</TD> +<TD> +<H3><A NAME="api">C API</A></H3> +<P> +<A HREF="manual.html#lua_Alloc">lua_Alloc</A><BR> +<A HREF="manual.html#lua_CFunction">lua_CFunction</A><BR> +<A HREF="manual.html#lua_Debug">lua_Debug</A><BR> +<A HREF="manual.html#lua_Hook">lua_Hook</A><BR> +<A HREF="manual.html#lua_Integer">lua_Integer</A><BR> +<A HREF="manual.html#lua_KContext">lua_KContext</A><BR> +<A HREF="manual.html#lua_KFunction">lua_KFunction</A><BR> +<A HREF="manual.html#lua_Number">lua_Number</A><BR> +<A HREF="manual.html#lua_Reader">lua_Reader</A><BR> +<A HREF="manual.html#lua_State">lua_State</A><BR> +<A HREF="manual.html#lua_Unsigned">lua_Unsigned</A><BR> +<A HREF="manual.html#lua_Writer">lua_Writer</A><BR> + +<P> +<A HREF="manual.html#lua_absindex">lua_absindex</A><BR> +<A HREF="manual.html#lua_arith">lua_arith</A><BR> +<A HREF="manual.html#lua_atpanic">lua_atpanic</A><BR> +<A HREF="manual.html#lua_call">lua_call</A><BR> +<A HREF="manual.html#lua_callk">lua_callk</A><BR> +<A HREF="manual.html#lua_checkstack">lua_checkstack</A><BR> +<A HREF="manual.html#lua_close">lua_close</A><BR> +<A HREF="manual.html#lua_compare">lua_compare</A><BR> +<A HREF="manual.html#lua_concat">lua_concat</A><BR> +<A HREF="manual.html#lua_copy">lua_copy</A><BR> +<A HREF="manual.html#lua_createtable">lua_createtable</A><BR> +<A HREF="manual.html#lua_dump">lua_dump</A><BR> +<A HREF="manual.html#lua_error">lua_error</A><BR> +<A HREF="manual.html#lua_gc">lua_gc</A><BR> +<A HREF="manual.html#lua_getallocf">lua_getallocf</A><BR> +<A HREF="manual.html#lua_getextraspace">lua_getextraspace</A><BR> +<A HREF="manual.html#lua_getfield">lua_getfield</A><BR> +<A HREF="manual.html#lua_getglobal">lua_getglobal</A><BR> +<A HREF="manual.html#lua_gethook">lua_gethook</A><BR> +<A HREF="manual.html#lua_gethookcount">lua_gethookcount</A><BR> +<A HREF="manual.html#lua_gethookmask">lua_gethookmask</A><BR> +<A HREF="manual.html#lua_geti">lua_geti</A><BR> +<A HREF="manual.html#lua_getinfo">lua_getinfo</A><BR> +<A HREF="manual.html#lua_getlocal">lua_getlocal</A><BR> +<A HREF="manual.html#lua_getmetatable">lua_getmetatable</A><BR> +<A HREF="manual.html#lua_getstack">lua_getstack</A><BR> +<A HREF="manual.html#lua_gettable">lua_gettable</A><BR> +<A HREF="manual.html#lua_gettop">lua_gettop</A><BR> +<A HREF="manual.html#lua_getupvalue">lua_getupvalue</A><BR> +<A HREF="manual.html#lua_getuservalue">lua_getuservalue</A><BR> +<A HREF="manual.html#lua_insert">lua_insert</A><BR> +<A HREF="manual.html#lua_isboolean">lua_isboolean</A><BR> +<A HREF="manual.html#lua_iscfunction">lua_iscfunction</A><BR> +<A HREF="manual.html#lua_isfunction">lua_isfunction</A><BR> +<A HREF="manual.html#lua_isinteger">lua_isinteger</A><BR> +<A HREF="manual.html#lua_islightuserdata">lua_islightuserdata</A><BR> +<A HREF="manual.html#lua_isnil">lua_isnil</A><BR> +<A HREF="manual.html#lua_isnone">lua_isnone</A><BR> +<A HREF="manual.html#lua_isnoneornil">lua_isnoneornil</A><BR> +<A HREF="manual.html#lua_isnumber">lua_isnumber</A><BR> +<A HREF="manual.html#lua_isstring">lua_isstring</A><BR> +<A HREF="manual.html#lua_istable">lua_istable</A><BR> +<A HREF="manual.html#lua_isthread">lua_isthread</A><BR> +<A HREF="manual.html#lua_isuserdata">lua_isuserdata</A><BR> +<A HREF="manual.html#lua_isyieldable">lua_isyieldable</A><BR> +<A HREF="manual.html#lua_len">lua_len</A><BR> +<A HREF="manual.html#lua_load">lua_load</A><BR> +<A HREF="manual.html#lua_newstate">lua_newstate</A><BR> +<A HREF="manual.html#lua_newtable">lua_newtable</A><BR> +<A HREF="manual.html#lua_newthread">lua_newthread</A><BR> +<A HREF="manual.html#lua_newuserdata">lua_newuserdata</A><BR> +<A HREF="manual.html#lua_next">lua_next</A><BR> +<A HREF="manual.html#lua_numbertointeger">lua_numbertointeger</A><BR> +<A HREF="manual.html#lua_pcall">lua_pcall</A><BR> +<A HREF="manual.html#lua_pcallk">lua_pcallk</A><BR> +<A HREF="manual.html#lua_pop">lua_pop</A><BR> +<A HREF="manual.html#lua_pushboolean">lua_pushboolean</A><BR> +<A HREF="manual.html#lua_pushcclosure">lua_pushcclosure</A><BR> +<A HREF="manual.html#lua_pushcfunction">lua_pushcfunction</A><BR> +<A HREF="manual.html#lua_pushfstring">lua_pushfstring</A><BR> +<A HREF="manual.html#lua_pushglobaltable">lua_pushglobaltable</A><BR> +<A HREF="manual.html#lua_pushinteger">lua_pushinteger</A><BR> +<A HREF="manual.html#lua_pushlightuserdata">lua_pushlightuserdata</A><BR> +<A HREF="manual.html#lua_pushliteral">lua_pushliteral</A><BR> +<A HREF="manual.html#lua_pushlstring">lua_pushlstring</A><BR> +<A HREF="manual.html#lua_pushnil">lua_pushnil</A><BR> +<A HREF="manual.html#lua_pushnumber">lua_pushnumber</A><BR> +<A HREF="manual.html#lua_pushstring">lua_pushstring</A><BR> +<A HREF="manual.html#lua_pushthread">lua_pushthread</A><BR> +<A HREF="manual.html#lua_pushvalue">lua_pushvalue</A><BR> +<A HREF="manual.html#lua_pushvfstring">lua_pushvfstring</A><BR> +<A HREF="manual.html#lua_rawequal">lua_rawequal</A><BR> +<A HREF="manual.html#lua_rawget">lua_rawget</A><BR> +<A HREF="manual.html#lua_rawgeti">lua_rawgeti</A><BR> +<A HREF="manual.html#lua_rawgetp">lua_rawgetp</A><BR> +<A HREF="manual.html#lua_rawlen">lua_rawlen</A><BR> +<A HREF="manual.html#lua_rawset">lua_rawset</A><BR> +<A HREF="manual.html#lua_rawseti">lua_rawseti</A><BR> +<A HREF="manual.html#lua_rawsetp">lua_rawsetp</A><BR> +<A HREF="manual.html#lua_register">lua_register</A><BR> +<A HREF="manual.html#lua_remove">lua_remove</A><BR> +<A HREF="manual.html#lua_replace">lua_replace</A><BR> +<A HREF="manual.html#lua_resume">lua_resume</A><BR> +<A HREF="manual.html#lua_rotate">lua_rotate</A><BR> +<A HREF="manual.html#lua_setallocf">lua_setallocf</A><BR> +<A HREF="manual.html#lua_setfield">lua_setfield</A><BR> +<A HREF="manual.html#lua_setglobal">lua_setglobal</A><BR> +<A HREF="manual.html#lua_sethook">lua_sethook</A><BR> +<A HREF="manual.html#lua_seti">lua_seti</A><BR> +<A HREF="manual.html#lua_setlocal">lua_setlocal</A><BR> +<A HREF="manual.html#lua_setmetatable">lua_setmetatable</A><BR> +<A HREF="manual.html#lua_settable">lua_settable</A><BR> +<A HREF="manual.html#lua_settop">lua_settop</A><BR> +<A HREF="manual.html#lua_setupvalue">lua_setupvalue</A><BR> +<A HREF="manual.html#lua_setuservalue">lua_setuservalue</A><BR> +<A HREF="manual.html#lua_status">lua_status</A><BR> +<A HREF="manual.html#lua_stringtonumber">lua_stringtonumber</A><BR> +<A HREF="manual.html#lua_toboolean">lua_toboolean</A><BR> +<A HREF="manual.html#lua_tocfunction">lua_tocfunction</A><BR> +<A HREF="manual.html#lua_tointeger">lua_tointeger</A><BR> +<A HREF="manual.html#lua_tointegerx">lua_tointegerx</A><BR> +<A HREF="manual.html#lua_tolstring">lua_tolstring</A><BR> +<A HREF="manual.html#lua_tonumber">lua_tonumber</A><BR> +<A HREF="manual.html#lua_tonumberx">lua_tonumberx</A><BR> +<A HREF="manual.html#lua_topointer">lua_topointer</A><BR> +<A HREF="manual.html#lua_tostring">lua_tostring</A><BR> +<A HREF="manual.html#lua_tothread">lua_tothread</A><BR> +<A HREF="manual.html#lua_touserdata">lua_touserdata</A><BR> +<A HREF="manual.html#lua_type">lua_type</A><BR> +<A HREF="manual.html#lua_typename">lua_typename</A><BR> +<A HREF="manual.html#lua_upvalueid">lua_upvalueid</A><BR> +<A HREF="manual.html#lua_upvalueindex">lua_upvalueindex</A><BR> +<A HREF="manual.html#lua_upvaluejoin">lua_upvaluejoin</A><BR> +<A HREF="manual.html#lua_version">lua_version</A><BR> +<A HREF="manual.html#lua_xmove">lua_xmove</A><BR> +<A HREF="manual.html#lua_yield">lua_yield</A><BR> +<A HREF="manual.html#lua_yieldk">lua_yieldk</A><BR> + +</TD> +<TD> +<H3><A NAME="auxlib">auxiliary library</A></H3> +<P> +<A HREF="manual.html#luaL_Buffer">luaL_Buffer</A><BR> +<A HREF="manual.html#luaL_Reg">luaL_Reg</A><BR> +<A HREF="manual.html#luaL_Stream">luaL_Stream</A><BR> + +<P> +<A HREF="manual.html#luaL_addchar">luaL_addchar</A><BR> +<A HREF="manual.html#luaL_addlstring">luaL_addlstring</A><BR> +<A HREF="manual.html#luaL_addsize">luaL_addsize</A><BR> +<A HREF="manual.html#luaL_addstring">luaL_addstring</A><BR> +<A HREF="manual.html#luaL_addvalue">luaL_addvalue</A><BR> +<A HREF="manual.html#luaL_argcheck">luaL_argcheck</A><BR> +<A HREF="manual.html#luaL_argerror">luaL_argerror</A><BR> +<A HREF="manual.html#luaL_buffinit">luaL_buffinit</A><BR> +<A HREF="manual.html#luaL_buffinitsize">luaL_buffinitsize</A><BR> +<A HREF="manual.html#luaL_callmeta">luaL_callmeta</A><BR> +<A HREF="manual.html#luaL_checkany">luaL_checkany</A><BR> +<A HREF="manual.html#luaL_checkinteger">luaL_checkinteger</A><BR> +<A HREF="manual.html#luaL_checklstring">luaL_checklstring</A><BR> +<A HREF="manual.html#luaL_checknumber">luaL_checknumber</A><BR> +<A HREF="manual.html#luaL_checkoption">luaL_checkoption</A><BR> +<A HREF="manual.html#luaL_checkstack">luaL_checkstack</A><BR> +<A HREF="manual.html#luaL_checkstring">luaL_checkstring</A><BR> +<A HREF="manual.html#luaL_checktype">luaL_checktype</A><BR> +<A HREF="manual.html#luaL_checkudata">luaL_checkudata</A><BR> +<A HREF="manual.html#luaL_checkversion">luaL_checkversion</A><BR> +<A HREF="manual.html#luaL_dofile">luaL_dofile</A><BR> +<A HREF="manual.html#luaL_dostring">luaL_dostring</A><BR> +<A HREF="manual.html#luaL_error">luaL_error</A><BR> +<A HREF="manual.html#luaL_execresult">luaL_execresult</A><BR> +<A HREF="manual.html#luaL_fileresult">luaL_fileresult</A><BR> +<A HREF="manual.html#luaL_getmetafield">luaL_getmetafield</A><BR> +<A HREF="manual.html#luaL_getmetatable">luaL_getmetatable</A><BR> +<A HREF="manual.html#luaL_getsubtable">luaL_getsubtable</A><BR> +<A HREF="manual.html#luaL_gsub">luaL_gsub</A><BR> +<A HREF="manual.html#luaL_len">luaL_len</A><BR> +<A HREF="manual.html#luaL_loadbuffer">luaL_loadbuffer</A><BR> +<A HREF="manual.html#luaL_loadbufferx">luaL_loadbufferx</A><BR> +<A HREF="manual.html#luaL_loadfile">luaL_loadfile</A><BR> +<A HREF="manual.html#luaL_loadfilex">luaL_loadfilex</A><BR> +<A HREF="manual.html#luaL_loadstring">luaL_loadstring</A><BR> +<A HREF="manual.html#luaL_newlib">luaL_newlib</A><BR> +<A HREF="manual.html#luaL_newlibtable">luaL_newlibtable</A><BR> +<A HREF="manual.html#luaL_newmetatable">luaL_newmetatable</A><BR> +<A HREF="manual.html#luaL_newstate">luaL_newstate</A><BR> +<A HREF="manual.html#luaL_openlibs">luaL_openlibs</A><BR> +<A HREF="manual.html#luaL_optinteger">luaL_optinteger</A><BR> +<A HREF="manual.html#luaL_optlstring">luaL_optlstring</A><BR> +<A HREF="manual.html#luaL_optnumber">luaL_optnumber</A><BR> +<A HREF="manual.html#luaL_optstring">luaL_optstring</A><BR> +<A HREF="manual.html#luaL_prepbuffer">luaL_prepbuffer</A><BR> +<A HREF="manual.html#luaL_prepbuffsize">luaL_prepbuffsize</A><BR> +<A HREF="manual.html#luaL_pushresult">luaL_pushresult</A><BR> +<A HREF="manual.html#luaL_pushresultsize">luaL_pushresultsize</A><BR> +<A HREF="manual.html#luaL_ref">luaL_ref</A><BR> +<A HREF="manual.html#luaL_requiref">luaL_requiref</A><BR> +<A HREF="manual.html#luaL_setfuncs">luaL_setfuncs</A><BR> +<A HREF="manual.html#luaL_setmetatable">luaL_setmetatable</A><BR> +<A HREF="manual.html#luaL_testudata">luaL_testudata</A><BR> +<A HREF="manual.html#luaL_tolstring">luaL_tolstring</A><BR> +<A HREF="manual.html#luaL_traceback">luaL_traceback</A><BR> +<A HREF="manual.html#luaL_typename">luaL_typename</A><BR> +<A HREF="manual.html#luaL_unref">luaL_unref</A><BR> +<A HREF="manual.html#luaL_where">luaL_where</A><BR> + +<H3><A NAME="library">standard library</A></H3> +<P> +<A HREF="manual.html#pdf-luaopen_base">luaopen_base</A><BR> +<A HREF="manual.html#pdf-luaopen_coroutine">luaopen_coroutine</A><BR> +<A HREF="manual.html#pdf-luaopen_debug">luaopen_debug</A><BR> +<A HREF="manual.html#pdf-luaopen_io">luaopen_io</A><BR> +<A HREF="manual.html#pdf-luaopen_math">luaopen_math</A><BR> +<A HREF="manual.html#pdf-luaopen_os">luaopen_os</A><BR> +<A HREF="manual.html#pdf-luaopen_package">luaopen_package</A><BR> +<A HREF="manual.html#pdf-luaopen_string">luaopen_string</A><BR> +<A HREF="manual.html#pdf-luaopen_table">luaopen_table</A><BR> +<A HREF="manual.html#pdf-luaopen_utf8">luaopen_utf8</A><BR> + +<H3><A NAME="constants">constants</A></H3> +<A HREF="manual.html#pdf-LUA_ERRERR">LUA_ERRERR</A><BR> +<A HREF="manual.html#pdf-LUA_ERRFILE">LUA_ERRFILE</A><BR> +<A HREF="manual.html#pdf-LUA_ERRGCMM">LUA_ERRGCMM</A><BR> +<A HREF="manual.html#pdf-LUA_ERRMEM">LUA_ERRMEM</A><BR> +<A HREF="manual.html#pdf-LUA_ERRRUN">LUA_ERRRUN</A><BR> +<A HREF="manual.html#pdf-LUA_ERRSYNTAX">LUA_ERRSYNTAX</A><BR> +<A HREF="manual.html#pdf-LUA_HOOKCALL">LUA_HOOKCALL</A><BR> +<A HREF="manual.html#pdf-LUA_HOOKCOUNT">LUA_HOOKCOUNT</A><BR> +<A HREF="manual.html#pdf-LUA_HOOKLINE">LUA_HOOKLINE</A><BR> +<A HREF="manual.html#pdf-LUA_HOOKRET">LUA_HOOKRET</A><BR> +<A HREF="manual.html#pdf-LUA_HOOKTAILCALL">LUA_HOOKTAILCALL</A><BR> +<A HREF="manual.html#pdf-LUA_MASKCALL">LUA_MASKCALL</A><BR> +<A HREF="manual.html#pdf-LUA_MASKCOUNT">LUA_MASKCOUNT</A><BR> +<A HREF="manual.html#pdf-LUA_MASKLINE">LUA_MASKLINE</A><BR> +<A HREF="manual.html#pdf-LUA_MASKRET">LUA_MASKRET</A><BR> +<A HREF="manual.html#pdf-LUA_MAXINTEGER">LUA_MAXINTEGER</A><BR> +<A HREF="manual.html#pdf-LUA_MININTEGER">LUA_MININTEGER</A><BR> +<A HREF="manual.html#pdf-LUA_MINSTACK">LUA_MINSTACK</A><BR> +<A HREF="manual.html#pdf-LUA_MULTRET">LUA_MULTRET</A><BR> +<A HREF="manual.html#pdf-LUA_NOREF">LUA_NOREF</A><BR> +<A HREF="manual.html#pdf-LUA_OK">LUA_OK</A><BR> +<A HREF="manual.html#pdf-LUA_OPADD">LUA_OPADD</A><BR> +<A HREF="manual.html#pdf-LUA_OPBAND">LUA_OPBAND</A><BR> +<A HREF="manual.html#pdf-LUA_OPBNOT">LUA_OPBNOT</A><BR> +<A HREF="manual.html#pdf-LUA_OPBOR">LUA_OPBOR</A><BR> +<A HREF="manual.html#pdf-LUA_OPBXOR">LUA_OPBXOR</A><BR> +<A HREF="manual.html#pdf-LUA_OPDIV">LUA_OPDIV</A><BR> +<A HREF="manual.html#pdf-LUA_OPEQ">LUA_OPEQ</A><BR> +<A HREF="manual.html#pdf-LUA_OPIDIV">LUA_OPIDIV</A><BR> +<A HREF="manual.html#pdf-LUA_OPLE">LUA_OPLE</A><BR> +<A HREF="manual.html#pdf-LUA_OPLT">LUA_OPLT</A><BR> +<A HREF="manual.html#pdf-LUA_OPMOD">LUA_OPMOD</A><BR> +<A HREF="manual.html#pdf-LUA_OPMUL">LUA_OPMUL</A><BR> +<A HREF="manual.html#pdf-LUA_OPPOW">LUA_OPPOW</A><BR> +<A HREF="manual.html#pdf-LUA_OPSHL">LUA_OPSHL</A><BR> +<A HREF="manual.html#pdf-LUA_OPSHR">LUA_OPSHR</A><BR> +<A HREF="manual.html#pdf-LUA_OPSUB">LUA_OPSUB</A><BR> +<A HREF="manual.html#pdf-LUA_OPUNM">LUA_OPUNM</A><BR> +<A HREF="manual.html#pdf-LUA_REFNIL">LUA_REFNIL</A><BR> +<A HREF="manual.html#pdf-LUA_REGISTRYINDEX">LUA_REGISTRYINDEX</A><BR> +<A HREF="manual.html#pdf-LUA_RIDX_GLOBALS">LUA_RIDX_GLOBALS</A><BR> +<A HREF="manual.html#pdf-LUA_RIDX_MAINTHREAD">LUA_RIDX_MAINTHREAD</A><BR> +<A HREF="manual.html#pdf-LUA_TBOOLEAN">LUA_TBOOLEAN</A><BR> +<A HREF="manual.html#pdf-LUA_TFUNCTION">LUA_TFUNCTION</A><BR> +<A HREF="manual.html#pdf-LUA_TLIGHTUSERDATA">LUA_TLIGHTUSERDATA</A><BR> +<A HREF="manual.html#pdf-LUA_TNIL">LUA_TNIL</A><BR> +<A HREF="manual.html#pdf-LUA_TNONE">LUA_TNONE</A><BR> +<A HREF="manual.html#pdf-LUA_TNUMBER">LUA_TNUMBER</A><BR> +<A HREF="manual.html#pdf-LUA_TSTRING">LUA_TSTRING</A><BR> +<A HREF="manual.html#pdf-LUA_TTABLE">LUA_TTABLE</A><BR> +<A HREF="manual.html#pdf-LUA_TTHREAD">LUA_TTHREAD</A><BR> +<A HREF="manual.html#pdf-LUA_TUSERDATA">LUA_TUSERDATA</A><BR> +<A HREF="manual.html#pdf-LUA_USE_APICHECK">LUA_USE_APICHECK</A><BR> +<A HREF="manual.html#pdf-LUA_YIELD">LUA_YIELD</A><BR> +<A HREF="manual.html#pdf-LUAL_BUFFERSIZE">LUAL_BUFFERSIZE</A><BR> + +</TD> +</TR> +</TABLE> + +<HR> +<SMALL CLASS="footer"> +Last update: +Tue Dec 9 21:26:07 BRST 2014 +</SMALL> +<!-- +Last change: updated for Lua 5.3.0 (final) +--> + +</BODY> +</HTML> diff --git a/doc/logo.gif b/doc/logo.gif Binary files differnew file mode 100644 index 000000000000..2f5e4ac2e742 --- /dev/null +++ b/doc/logo.gif diff --git a/doc/lua.1 b/doc/lua.1 new file mode 100644 index 000000000000..411531b9ed6e --- /dev/null +++ b/doc/lua.1 @@ -0,0 +1,111 @@ +.TH LUA 1 "$Date: 2014/12/10 15:55:45 $" +.SH NAME +lua \- Lua interpreter +.SH SYNOPSIS +.B lua +[ +.I options +] +[ +.I script +[ +.I args +] +] +.SH DESCRIPTION +.B lua +is the standalone Lua interpreter. +It loads and executes Lua programs, +either in textual source form or +in precompiled binary form. +(Precompiled binaries are output by +.BR luac , +the Lua compiler.) +.B lua +can be used as a batch interpreter and also interactively. +.LP +The given +.I options +are handled in order and then +the Lua program in file +.I script +is loaded and executed. +The given +.I args +are available to +.I script +as strings in a global table named +.BR arg . +If no options or arguments are given, +then +.B "\-v \-i" +is assumed when the standard input is a terminal; +otherwise, +.B "\-" +is assumed. +.LP +In interactive mode, +.B lua +prompts the user, +reads lines from the standard input, +and executes them as they are read. +If the line contains an expression or list of expressions, +then the line is evaluated and the results are printed. +If a line does not contain a complete statement, +then a secondary prompt is displayed and +lines are read until a complete statement is formed or +a syntax error is found. +.LP +At the very start, +before even handling the command line, +.B lua +checks the contents of the environment variables +.B LUA_INIT_5_3 +or +.BR LUA_INIT , +in that order. +If the contents is of the form +.RI '@ filename ', +then +.I filename +is executed. +Otherwise, the string is assumed to be a Lua statement and is executed. +.SH OPTIONS +.TP +.BI \-e " stat" +execute statement +.IR stat . +.TP +.B \-i +enter interactive mode after executing +.IR script . +.TP +.BI \-l " name" +execute the equivalent of +.IB name =require(' name ') +before executing +.IR script . +.TP +.B \-v +show version information. +.TP +.B \-E +ignore environment variables. +.TP +.B \-\- +stop handling options. +.TP +.B \- +stop handling options and execute the standard input as a file. +.SH "SEE ALSO" +.BR luac (1) +.br +The documentation at lua.org, +especially section 7 of the reference manual. +.SH DIAGNOSTICS +Error messages should be self explanatory. +.SH AUTHORS +R. Ierusalimschy, +L. H. de Figueiredo, +W. Celes +.\" EOF diff --git a/doc/lua.css b/doc/lua.css new file mode 100644 index 000000000000..3199a2b6e8fc --- /dev/null +++ b/doc/lua.css @@ -0,0 +1,105 @@ +html { + background-color: #F8F8F8 ; +} + +body { + border: solid #a0a0a0 1px ; + border-radius: 20px ; + padding: 26px ; + margin: 16px ; + color: #000000 ; + background-color: #FFFFFF ; + font-family: Helvetica, Arial, sans-serif ; + text-align: justify ; +} + +h1, h2, h3, h4 { + font-family: Verdana, Geneva, sans-serif ; + font-weight: normal ; + font-style: normal ; +} + +h2 { + padding-top: 0.4em ; + padding-bottom: 0.4em ; + padding-left: 0.8em ; + padding-right: 0.8em ; + background-color: #D0D0FF ; + border-radius: 8px ; + border: solid #a0a0a0 1px ; +} + +h3 { + padding-left: 0.5em ; + border-left: solid #D0D0FF 1em ; +} + +table h3 { + padding-left: 0px ; + border-left: none ; +} + +a:link { + color: #000080 ; + background-color: inherit ; + text-decoration: none ; +} + +a:visited { + background-color: inherit ; + text-decoration: none ; +} + +a:link:hover, a:visited:hover { + color: #000080 ; + background-color: #D0D0FF ; + border-radius: 4px; +} + +a:link:active, a:visited:active { + color: #FF0000 ; +} + +h1 a img { + vertical-align: text-bottom ; +} + +hr { + border: 0 ; + height: 1px ; + color: #a0a0a0 ; + background-color: #a0a0a0 ; + display: none ; +} + +table hr { + display: block ; +} + +:target { + background-color: #F8F8F8 ; + padding: 8px ; + border: solid #a0a0a0 2px ; + border-radius: 8px ; +} + +.footer { + color: gray ; + font-size: x-small ; +} + +input[type=text] { + border: solid #a0a0a0 2px ; + border-radius: 2em ; + background-image: url('images/search.png') ; + background-repeat: no-repeat ; + background-position: 4px center ; + padding-left: 20px ; + height: 2em ; +} + +pre.session { + background-color: #F8F8F8 ; + padding: 1em ; + border-radius: 8px ; +} diff --git a/doc/luac.1 b/doc/luac.1 new file mode 100644 index 000000000000..33a4ed00acef --- /dev/null +++ b/doc/luac.1 @@ -0,0 +1,118 @@ +.\" $Id: luac.man,v 1.29 2011/11/16 13:53:40 lhf Exp $ +.TH LUAC 1 "$Date: 2011/11/16 13:53:40 $" +.SH NAME +luac \- Lua compiler +.SH SYNOPSIS +.B luac +[ +.I options +] [ +.I filenames +] +.SH DESCRIPTION +.B luac +is the Lua compiler. +It translates programs written in the Lua programming language +into binary files containing precompiled chunks +that can be later loaded and executed. +.LP +The main advantages of precompiling chunks are: +faster loading, +protecting source code from accidental user changes, +and +off-line syntax checking. +Precompiling does not imply faster execution +because in Lua chunks are always compiled into bytecodes before being executed. +.B luac +simply allows those bytecodes to be saved in a file for later execution. +Precompiled chunks are not necessarily smaller than the corresponding source. +The main goal in precompiling is faster loading. +.LP +In the command line, +you can mix +text files containing Lua source and +binary files containing precompiled chunks. +.B luac +produces a single output file containing the combined bytecodes +for all files given. +Executing the combined file is equivalent to executing the given files. +By default, +the output file is named +.BR luac.out , +but you can change this with the +.B \-o +option. +.LP +Precompiled chunks are +.I not +portable across different architectures. +Moreover, +the internal format of precompiled chunks +is likely to change when a new version of Lua is released. +Make sure you save the source files of all Lua programs that you precompile. +.LP +.SH OPTIONS +.TP +.B \-l +produce a listing of the compiled bytecode for Lua's virtual machine. +Listing bytecodes is useful to learn about Lua's virtual machine. +If no files are given, then +.B luac +loads +.B luac.out +and lists its contents. +Use +.B \-l \-l +for a full listing. +.TP +.BI \-o " file" +output to +.IR file , +instead of the default +.BR luac.out . +(You can use +.B "'\-'" +for standard output, +but not on platforms that open standard output in text mode.) +The output file may be one of the given files because +all files are loaded before the output file is written. +Be careful not to overwrite precious files. +.TP +.B \-p +load files but do not generate any output file. +Used mainly for syntax checking and for testing precompiled chunks: +corrupted files will probably generate errors when loaded. +If no files are given, then +.B luac +loads +.B luac.out +and tests its contents. +No messages are displayed if the file loads without errors. +.TP +.B \-s +strip debug information before writing the output file. +This saves some space in very large chunks, +but if errors occur when running a stripped chunk, +then the error messages may not contain the full information they usually do. +In particular, +line numbers and names of local variables are lost. +.TP +.B \-v +show version information. +.TP +.B \-\- +stop handling options. +.TP +.B \- +stop handling options and process standard input. +.SH "SEE ALSO" +.BR lua (1) +.br +The documentation at lua.org. +.SH DIAGNOSTICS +Error messages should be self explanatory. +.SH AUTHORS +R. Ierusalimschy, +L. H. de Figueiredo, +W. Celes +.\" EOF diff --git a/doc/manual.css b/doc/manual.css new file mode 100644 index 000000000000..ca613cd9fb11 --- /dev/null +++ b/doc/manual.css @@ -0,0 +1,27 @@ +h3 code { + font-family: inherit ; + font-size: inherit ; +} + +pre, code { + font-size: 12pt ; +} + +span.apii { + float: right ; + font-family: inherit ; + font-style: normal ; + font-size: small ; + color: gray ; +} + +p+h1, ul+h1 { + font-style: normal ; + padding-top: 0.4em ; + padding-bottom: 0.4em ; + padding-left: 16px ; + margin-left: -16px ; + background-color: #D0D0FF ; + border-radius: 8px ; + border: solid #000080 1px ; +} diff --git a/doc/manual.html b/doc/manual.html new file mode 100644 index 000000000000..5ed8f0692217 --- /dev/null +++ b/doc/manual.html @@ -0,0 +1,10789 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<html> + +<head> +<title>Lua 5.3 Reference Manual</title> +<link rel="stylesheet" type="text/css" href="lua.css"> +<link rel="stylesheet" type="text/css" href="manual.css"> +<META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1"> +</head> + +<body> + +<hr> +<h1> +<a href="http://www.lua.org/"><img src="logo.gif" alt="" border="0"></a> +Lua 5.3 Reference Manual +</h1> + +by Roberto Ierusalimschy, Luiz Henrique de Figueiredo, Waldemar Celes +<p> +<small> +Copyright © 2015 Lua.org, PUC-Rio. +Freely available under the terms of the +<a href="http://www.lua.org/license.html">Lua license</a>. +</small> +<hr> +<p> + +<a href="contents.html#contents">contents</A> +· +<a href="contents.html#index">index</A> + +<!-- ====================================================================== --> +<p> + +<!-- $Id: manual.of,v 1.146 2015/01/06 11:23:01 roberto Exp $ --> + + + + +<h1>1 – <a name="1">Introduction</a></h1> + +<p> +Lua is an extension programming language designed to support +general procedural programming with data description +facilities. +Lua also offers good support for object-oriented programming, +functional programming, and data-driven programming. +Lua is intended to be used as a powerful, lightweight, +embeddable scripting language for any program that needs one. +Lua is implemented as a library, written in <em>clean C</em>, +the common subset of Standard C and C++. + + +<p> +As an extension language, Lua has no notion of a "main" program: +it only works <em>embedded</em> in a host client, +called the <em>embedding program</em> or simply the <em>host</em>. +The host program can invoke functions to execute a piece of Lua code, +can write and read Lua variables, +and can register C functions to be called by Lua code. +Through the use of C functions, Lua can be augmented to cope with +a wide range of different domains, +thus creating customized programming languages sharing a syntactical framework. +The Lua distribution includes a sample host program called <code>lua</code>, +which uses the Lua library to offer a complete, standalone Lua interpreter, +for interactive or batch use. + + +<p> +Lua is free software, +and is provided as usual with no guarantees, +as stated in its license. +The implementation described in this manual is available +at Lua's official web site, <code>www.lua.org</code>. + + +<p> +Like any other reference manual, +this document is dry in places. +For a discussion of the decisions behind the design of Lua, +see the technical papers available at Lua's web site. +For a detailed introduction to programming in Lua, +see Roberto's book, <em>Programming in Lua</em>. + + + +<h1>2 – <a name="2">Basic Concepts</a></h1> + +<p> +This section describes the basic concepts of the language. + + + +<h2>2.1 – <a name="2.1">Values and Types</a></h2> + +<p> +Lua is a <em>dynamically typed language</em>. +This means that +variables do not have types; only values do. +There are no type definitions in the language. +All values carry their own type. + + +<p> +All values in Lua are <em>first-class values</em>. +This means that all values can be stored in variables, +passed as arguments to other functions, and returned as results. + + +<p> +There are eight basic types in Lua: +<em>nil</em>, <em>boolean</em>, <em>number</em>, +<em>string</em>, <em>function</em>, <em>userdata</em>, +<em>thread</em>, and <em>table</em>. +<em>Nil</em> is the type of the value <b>nil</b>, +whose main property is to be different from any other value; +it usually represents the absence of a useful value. +<em>Boolean</em> is the type of the values <b>false</b> and <b>true</b>. +Both <b>nil</b> and <b>false</b> make a condition false; +any other value makes it true. +<em>Number</em> represents both +integer numbers and real (floating-point) numbers. +<em>String</em> represents immutable sequences of bytes. + +Lua is 8-bit clean: +strings can contain any 8-bit value, +including embedded zeros ('<code>\0</code>'). +Lua is also encoding-agnostic; +it makes no assumptions about the contents of a string. + + +<p> +The type <em>number</em> uses two internal representations, +one called <em>integer</em> and the other called <em>float</em>. +Lua has explicit rules about when each representation is used, +but it also converts between them automatically as needed (see <a href="#3.4.3">§3.4.3</a>). +Therefore, +the programmer may choose to mostly ignore the difference +between integers and floats +or to assume complete control over the representation of each number. +Standard Lua uses 64-bit integers and double-precision (64-bit) floats, +but you can also compile Lua so that it +uses 32-bit integers and/or single-precision (32-bit) floats. +The option with 32 bits for both integers and floats +is particularly attractive +for small machines and embedded systems. +(See macro <code>LUA_32BITS</code> in file <code>luaconf.h</code>.) + + +<p> +Lua can call (and manipulate) functions written in Lua and +functions written in C (see <a href="#3.4.10">§3.4.10</a>). +Both are represented by the type <em>function</em>. + + +<p> +The type <em>userdata</em> is provided to allow arbitrary C data to +be stored in Lua variables. +A userdata value represents a block of raw memory. +There are two kinds of userdata: +<em>full userdata</em>, +which is an object with a block of memory managed by Lua, +and <em>light userdata</em>, +which is simply a C pointer value. +Userdata has no predefined operations in Lua, +except assignment and identity test. +By using <em>metatables</em>, +the programmer can define operations for full userdata values +(see <a href="#2.4">§2.4</a>). +Userdata values cannot be created or modified in Lua, +only through the C API. +This guarantees the integrity of data owned by the host program. + + +<p> +The type <em>thread</em> represents independent threads of execution +and it is used to implement coroutines (see <a href="#2.6">§2.6</a>). +Lua threads are not related to operating-system threads. +Lua supports coroutines on all systems, +even those that do not support threads natively. + + +<p> +The type <em>table</em> implements associative arrays, +that is, arrays that can be indexed not only with numbers, +but with any Lua value except <b>nil</b> and NaN. +(<em>Not a Number</em> is a special numeric value used to represent +undefined or unrepresentable results, such as <code>0/0</code>.) +Tables can be <em>heterogeneous</em>; +that is, they can contain values of all types (except <b>nil</b>). +Any key with value <b>nil</b> is not considered part of the table. +Conversely, any key that is not part of a table has +an associated value <b>nil</b>. + + +<p> +Tables are the sole data-structuring mechanism in Lua; +they can be used to represent ordinary arrays, sequences, +symbol tables, sets, records, graphs, trees, etc. +To represent records, Lua uses the field name as an index. +The language supports this representation by +providing <code>a.name</code> as syntactic sugar for <code>a["name"]</code>. +There are several convenient ways to create tables in Lua +(see <a href="#3.4.9">§3.4.9</a>). + + +<p> +We use the term <em>sequence</em> to denote a table where +the set of all positive numeric keys is equal to {1..<em>n</em>} +for some non-negative integer <em>n</em>, +which is called the length of the sequence (see <a href="#3.4.7">§3.4.7</a>). + + +<p> +Like indices, +the values of table fields can be of any type. +In particular, +because functions are first-class values, +table fields can contain functions. +Thus tables can also carry <em>methods</em> (see <a href="#3.4.11">§3.4.11</a>). + + +<p> +The indexing of tables follows +the definition of raw equality in the language. +The expressions <code>a[i]</code> and <code>a[j]</code> +denote the same table element +if and only if <code>i</code> and <code>j</code> are raw equal +(that is, equal without metamethods). +In particular, floats with integral values +are equal to their respective integers +(e.g., <code>1.0 == 1</code>). +To avoid ambiguities, +any float with integral value used as a key +is converted to its respective integer. +For instance, if you write <code>a[2.0] = true</code>, +the actual key inserted into the table will be the +integer <code>2</code>. +(On the other hand, +2 and "<code>2</code>" are different Lua values and therefore +denote different table entries.) + + +<p> +Tables, functions, threads, and (full) userdata values are <em>objects</em>: +variables do not actually <em>contain</em> these values, +only <em>references</em> to them. +Assignment, parameter passing, and function returns +always manipulate references to such values; +these operations do not imply any kind of copy. + + +<p> +The library function <a href="#pdf-type"><code>type</code></a> returns a string describing the type +of a given value (see <a href="#6.1">§6.1</a>). + + + + + +<h2>2.2 – <a name="2.2">Environments and the Global Environment</a></h2> + +<p> +As will be discussed in <a href="#3.2">§3.2</a> and <a href="#3.3.3">§3.3.3</a>, +any reference to a free name +(that is, a name not bound to any declaration) <code>var</code> +is syntactically translated to <code>_ENV.var</code>. +Moreover, every chunk is compiled in the scope of +an external local variable named <code>_ENV</code> (see <a href="#3.3.2">§3.3.2</a>), +so <code>_ENV</code> itself is never a free name in a chunk. + + +<p> +Despite the existence of this external <code>_ENV</code> variable and +the translation of free names, +<code>_ENV</code> is a completely regular name. +In particular, +you can define new variables and parameters with that name. +Each reference to a free name uses the <code>_ENV</code> that is +visible at that point in the program, +following the usual visibility rules of Lua (see <a href="#3.5">§3.5</a>). + + +<p> +Any table used as the value of <code>_ENV</code> is called an <em>environment</em>. + + +<p> +Lua keeps a distinguished environment called the <em>global environment</em>. +This value is kept at a special index in the C registry (see <a href="#4.5">§4.5</a>). +In Lua, the global variable <a href="#pdf-_G"><code>_G</code></a> is initialized with this same value. +(<a href="#pdf-_G"><code>_G</code></a> is never used internally.) + + +<p> +When Lua loads a chunk, +the default value for its <code>_ENV</code> upvalue +is the global environment (see <a href="#pdf-load"><code>load</code></a>). +Therefore, by default, +free names in Lua code refer to entries in the global environment +(and, therefore, they are also called <em>global variables</em>). +Moreover, all standard libraries are loaded in the global environment +and some functions there operate on that environment. +You can use <a href="#pdf-load"><code>load</code></a> (or <a href="#pdf-loadfile"><code>loadfile</code></a>) +to load a chunk with a different environment. +(In C, you have to load the chunk and then change the value +of its first upvalue.) + + + + + +<h2>2.3 – <a name="2.3">Error Handling</a></h2> + +<p> +Because Lua is an embedded extension language, +all Lua actions start from C code in the host program +calling a function from the Lua library. +(When you use Lua standalone, +the <code>lua</code> application is the host program.) +Whenever an error occurs during +the compilation or execution of a Lua chunk, +control returns to the host, +which can take appropriate measures +(such as printing an error message). + + +<p> +Lua code can explicitly generate an error by calling the +<a href="#pdf-error"><code>error</code></a> function. +If you need to catch errors in Lua, +you can use <a href="#pdf-pcall"><code>pcall</code></a> or <a href="#pdf-xpcall"><code>xpcall</code></a> +to call a given function in <em>protected mode</em>. + + +<p> +Whenever there is an error, +an <em>error object</em> (also called an <em>error message</em>) +is propagated with information about the error. +Lua itself only generates errors whose error object is a string, +but programs may generate errors with +any value as the error object. +It is up to the Lua program or its host to handle such error objects. + + +<p> +When you use <a href="#pdf-xpcall"><code>xpcall</code></a> or <a href="#lua_pcall"><code>lua_pcall</code></a>, +you may give a <em>message handler</em> +to be called in case of errors. +This function is called with the original error message +and returns a new error message. +It is called before the error unwinds the stack, +so that it can gather more information about the error, +for instance by inspecting the stack and creating a stack traceback. +This message handler is still protected by the protected call; +so, an error inside the message handler +will call the message handler again. +If this loop goes on for too long, +Lua breaks it and returns an appropriate message. + + + + + +<h2>2.4 – <a name="2.4">Metatables and Metamethods</a></h2> + +<p> +Every value in Lua can have a <em>metatable</em>. +This <em>metatable</em> is an ordinary Lua table +that defines the behavior of the original value +under certain special operations. +You can change several aspects of the behavior +of operations over a value by setting specific fields in its metatable. +For instance, when a non-numeric value is the operand of an addition, +Lua checks for a function in the field "<code>__add</code>" of the value's metatable. +If it finds one, +Lua calls this function to perform the addition. + + +<p> +The keys in a metatable are derived from the <em>event</em> names; +the corresponding values are called <em>metamethods</em>. +In the previous example, the event is <code>"add"</code> +and the metamethod is the function that performs the addition. + + +<p> +You can query the metatable of any value +using the <a href="#pdf-getmetatable"><code>getmetatable</code></a> function. + + +<p> +You can replace the metatable of tables +using the <a href="#pdf-setmetatable"><code>setmetatable</code></a> function. +You cannot change the metatable of other types from Lua +(except by using the debug library (<a href="#6.10">§6.10</a>)); +you must use the C API for that. + + +<p> +Tables and full userdata have individual metatables +(although multiple tables and userdata can share their metatables). +Values of all other types share one single metatable per type; +that is, there is one single metatable for all numbers, +one for all strings, etc. +By default, a value has no metatable, +but the string library sets a metatable for the string type (see <a href="#6.4">§6.4</a>). + + +<p> +A metatable controls how an object behaves in +arithmetic operations, bitwise operations, +order comparisons, concatenation, length operation, calls, and indexing. +A metatable also can define a function to be called +when a userdata or a table is garbage collected (<a href="#2.5">§2.5</a>). + + +<p> +A detailed list of events controlled by metatables is given next. +Each operation is identified by its corresponding event name. +The key for each event is a string with its name prefixed by +two underscores, '<code>__</code>'; +for instance, the key for operation "add" is the +string "<code>__add</code>". +Note that queries for metamethods are always raw; +the access to a metamethod does not invoke other metamethods. +You can emulate how Lua queries a metamethod for an object <code>obj</code> +with the following code: + +<pre> + rawget(getmetatable(obj) or {}, "__" .. event_name) +</pre> + +<p> +For the unary operators (negation, length, and bitwise not), +the metamethod is computed and called with a dummy second operand, +equal to the first one. +This extra operand is only to simplify Lua's internals +(by making these operators behave like a binary operation) +and may be removed in future versions. +(For most uses this extra operand is irrelevant.) + + + +<ul> + +<li><b>"add": </b> +the <code>+</code> operation. + +If any operand for an addition is not a number +(nor a string coercible to a number), +Lua will try to call a metamethod. +First, Lua will check the first operand (even if it is valid). +If that operand does not define a metamethod for the "<code>__add</code>" event, +then Lua will check the second operand. +If Lua can find a metamethod, +it calls the metamethod with the two operands as arguments, +and the result of the call +(adjusted to one value) +is the result of the operation. +Otherwise, +it raises an error. +</li> + +<li><b>"sub": </b> +the <code>-</code> operation. + +Behavior similar to the "add" operation. +</li> + +<li><b>"mul": </b> +the <code>*</code> operation. + +Behavior similar to the "add" operation. +</li> + +<li><b>"div": </b> +the <code>/</code> operation. + +Behavior similar to the "add" operation. +</li> + +<li><b>"mod": </b> +the <code>%</code> operation. + +Behavior similar to the "add" operation. +</li> + +<li><b>"pow": </b> +the <code>^</code> (exponentiation) operation. + +Behavior similar to the "add" operation. +</li> + +<li><b>"unm": </b> +the <code>-</code> (unary minus) operation. + +Behavior similar to the "add" operation. +</li> + +<li><b>"idiv": </b> +the <code>//</code> (floor division) operation. + +Behavior similar to the "add" operation. +</li> + +<li><b>"band": </b> +the <code>&</code> (bitwise and) operation. + +Behavior similar to the "add" operation, +except that Lua will try a metamethod +if any operator is neither an integer +nor a value coercible to an integer (see <a href="#3.4.3">§3.4.3</a>). +</li> + +<li><b>"bor": </b> +the <code>|</code> (bitwise or) operation. + +Behavior similar to the "band" operation. +</li> + +<li><b>"bxor": </b> +the <code>~</code> (bitwise exclusive or) operation. + +Behavior similar to the "band" operation. +</li> + +<li><b>"bnot": </b> +the <code>~</code> (bitwise unary not) operation. + +Behavior similar to the "band" operation. +</li> + +<li><b>"shl": </b> +the <code><<</code> (bitwise left shift) operation. + +Behavior similar to the "band" operation. +</li> + +<li><b>"shr": </b> +the <code>>></code> (bitwise right shift) operation. + +Behavior similar to the "band" operation. +</li> + +<li><b>"concat": </b> +the <code>..</code> (concatenation) operation. + +Behavior similar to the "add" operation, +except that Lua will try a metamethod +if any operator is neither a string nor a number +(which is always coercible to a string). +</li> + +<li><b>"len": </b> +the <code>#</code> (length) operation. + +If the object is not a string, +Lua will try its metamethod. +If there is a metamethod, +Lua calls it with the object as argument, +and the result of the call +(always adjusted to one value) +is the result of the operation. +If there is no metamethod but the object is a table, +then Lua uses the table length operation (see <a href="#3.4.7">§3.4.7</a>). +Otherwise, Lua raises an error. +</li> + +<li><b>"eq": </b> +the <code>==</code> (equal) operation. + +Behavior similar to the "add" operation, +except that Lua will try a metamethod only when the values +being compared are either both tables or both full userdata +and they are not primitively equal. +The result of the call is always converted to a boolean. +</li> + +<li><b>"lt": </b> +the <code><</code> (less than) operation. + +Behavior similar to the "add" operation, +except that Lua will try a metamethod only when the values +being compared are neither both numbers nor both strings. +The result of the call is always converted to a boolean. +</li> + +<li><b>"le": </b> +the <code><=</code> (less equal) operation. + +Unlike other operations, +The less-equal operation can use two different events. +First, Lua looks for the "<code>__le</code>" metamethod in both operands, +like in the "lt" operation. +If it cannot find such a metamethod, +then it will try the "<code>__lt</code>" event, +assuming that <code>a <= b</code> is equivalent to <code>not (b < a)</code>. +As with the other comparison operators, +the result is always a boolean. +</li> + +<li><b>"index": </b> +The indexing access <code>table[key]</code>. + +This event happens when <code>table</code> is not a table or +when <code>key</code> is not present in <code>table</code>. +The metamethod is looked up in <code>table</code>. + + +<p> +Despite the name, +the metamethod for this event can be either a function or a table. +If it is a function, +it is called with <code>table</code> and <code>key</code> as arguments. +If it is a table, +the final result is the result of indexing this table with <code>key</code>. +(This indexing is regular, not raw, +and therefore can trigger another metamethod.) +</li> + +<li><b>"newindex": </b> +The indexing assignment <code>table[key] = value</code>. + +Like the index event, +this event happens when <code>table</code> is not a table or +when <code>key</code> is not present in <code>table</code>. +The metamethod is looked up in <code>table</code>. + + +<p> +Like with indexing, +the metamethod for this event can be either a function or a table. +If it is a function, +it is called with <code>table</code>, <code>key</code>, and <code>value</code> as arguments. +If it is a table, +Lua does an indexing assignment to this table with the same key and value. +(This assignment is regular, not raw, +and therefore can trigger another metamethod.) + + +<p> +Whenever there is a "newindex" metamethod, +Lua does not perform the primitive assignment. +(If necessary, +the metamethod itself can call <a href="#pdf-rawset"><code>rawset</code></a> +to do the assignment.) +</li> + +<li><b>"call": </b> +The call operation <code>func(args)</code>. + +This event happens when Lua tries to call a non-function value +(that is, <code>func</code> is not a function). +The metamethod is looked up in <code>func</code>. +If present, +the metamethod is called with <code>func</code> as its first argument, +followed by the arguments of the original call (<code>args</code>). +</li> + +</ul> + + + + +<h2>2.5 – <a name="2.5">Garbage Collection</a></h2> + +<p> +Lua performs automatic memory management. +This means that +you do not have to worry about allocating memory for new objects +or freeing it when the objects are no longer needed. +Lua manages memory automatically by running +a <em>garbage collector</em> to collect all <em>dead objects</em> +(that is, objects that are no longer accessible from Lua). +All memory used by Lua is subject to automatic management: +strings, tables, userdata, functions, threads, internal structures, etc. + + +<p> +Lua implements an incremental mark-and-sweep collector. +It uses two numbers to control its garbage-collection cycles: +the <em>garbage-collector pause</em> and +the <em>garbage-collector step multiplier</em>. +Both use percentage points as units +(e.g., a value of 100 means an internal value of 1). + + +<p> +The garbage-collector pause +controls how long the collector waits before starting a new cycle. +Larger values make the collector less aggressive. +Values smaller than 100 mean the collector will not wait to +start a new cycle. +A value of 200 means that the collector waits for the total memory in use +to double before starting a new cycle. + + +<p> +The garbage-collector step multiplier +controls the relative speed of the collector relative to +memory allocation. +Larger values make the collector more aggressive but also increase +the size of each incremental step. +You should not use values smaller than 100, +because they make the collector too slow and +can result in the collector never finishing a cycle. +The default is 200, +which means that the collector runs at "twice" +the speed of memory allocation. + + +<p> +If you set the step multiplier to a very large number +(larger than 10% of the maximum number of +bytes that the program may use), +the collector behaves like a stop-the-world collector. +If you then set the pause to 200, +the collector behaves as in old Lua versions, +doing a complete collection every time Lua doubles its +memory usage. + + +<p> +You can change these numbers by calling <a href="#lua_gc"><code>lua_gc</code></a> in C +or <a href="#pdf-collectgarbage"><code>collectgarbage</code></a> in Lua. +You can also use these functions to control +the collector directly (e.g., stop and restart it). + + + +<h3>2.5.1 – <a name="2.5.1">Garbage-Collection Metamethods</a></h3> + +<p> +You can set garbage-collector metamethods for tables +and, using the C API, +for full userdata (see <a href="#2.4">§2.4</a>). +These metamethods are also called <em>finalizers</em>. +Finalizers allow you to coordinate Lua's garbage collection +with external resource management +(such as closing files, network or database connections, +or freeing your own memory). + + +<p> +For an object (table or userdata) to be finalized when collected, +you must <em>mark</em> it for finalization. + +You mark an object for finalization when you set its metatable +and the metatable has a field indexed by the string "<code>__gc</code>". +Note that if you set a metatable without a <code>__gc</code> field +and later create that field in the metatable, +the object will not be marked for finalization. +However, after an object has been marked, +you can freely change the <code>__gc</code> field of its metatable. + + +<p> +When a marked object becomes garbage, +it is not collected immediately by the garbage collector. +Instead, Lua puts it in a list. +After the collection, +Lua goes through that list. +For each object in the list, +it checks the object's <code>__gc</code> metamethod: +If it is a function, +Lua calls it with the object as its single argument; +if the metamethod is not a function, +Lua simply ignores it. + + +<p> +At the end of each garbage-collection cycle, +the finalizers for objects are called in +the reverse order that the objects were marked for finalization, +among those collected in that cycle; +that is, the first finalizer to be called is the one associated +with the object marked last in the program. +The execution of each finalizer may occur at any point during +the execution of the regular code. + + +<p> +Because the object being collected must still be used by the finalizer, +that object (and other objects accessible only through it) +must be <em>resurrected</em> by Lua. +Usually, this resurrection is transient, +and the object memory is freed in the next garbage-collection cycle. +However, if the finalizer stores the object in some global place +(e.g., a global variable), +then the resurrection is permanent. +Moreover, if the finalizer marks a finalizing object for finalization again, +its finalizer will be called again in the next cycle where the +object is unreachable. +In any case, +the object memory is freed only in the GC cycle where +the object is unreachable and not marked for finalization. + + +<p> +When you close a state (see <a href="#lua_close"><code>lua_close</code></a>), +Lua calls the finalizers of all objects marked for finalization, +following the reverse order that they were marked. +If any finalizer marks objects for collection during that phase, +these marks have no effect. + + + + + +<h3>2.5.2 – <a name="2.5.2">Weak Tables</a></h3> + +<p> +A <em>weak table</em> is a table whose elements are +<em>weak references</em>. +A weak reference is ignored by the garbage collector. +In other words, +if the only references to an object are weak references, +then the garbage collector will collect that object. + + +<p> +A weak table can have weak keys, weak values, or both. +A table with weak keys allows the collection of its keys, +but prevents the collection of its values. +A table with both weak keys and weak values allows the collection of +both keys and values. +In any case, if either the key or the value is collected, +the whole pair is removed from the table. +The weakness of a table is controlled by the +<code>__mode</code> field of its metatable. +If the <code>__mode</code> field is a string containing the character '<code>k</code>', +the keys in the table are weak. +If <code>__mode</code> contains '<code>v</code>', +the values in the table are weak. + + +<p> +A table with weak keys and strong values +is also called an <em>ephemeron table</em>. +In an ephemeron table, +a value is considered reachable only if its key is reachable. +In particular, +if the only reference to a key comes through its value, +the pair is removed. + + +<p> +Any change in the weakness of a table may take effect only +at the next collect cycle. +In particular, if you change the weakness to a stronger mode, +Lua may still collect some items from that table +before the change takes effect. + + +<p> +Only objects that have an explicit construction +are removed from weak tables. +Values, such as numbers and light C functions, +are not subject to garbage collection, +and therefore are not removed from weak tables +(unless their associated values are collected). +Although strings are subject to garbage collection, +they do not have an explicit construction, +and therefore are not removed from weak tables. + + +<p> +Resurrected objects +(that is, objects being finalized +and objects accessible only through objects being finalized) +have a special behavior in weak tables. +They are removed from weak values before running their finalizers, +but are removed from weak keys only in the next collection +after running their finalizers, when such objects are actually freed. +This behavior allows the finalizer to access properties +associated with the object through weak tables. + + +<p> +If a weak table is among the resurrected objects in a collection cycle, +it may not be properly cleared until the next cycle. + + + + + + + +<h2>2.6 – <a name="2.6">Coroutines</a></h2> + +<p> +Lua supports coroutines, +also called <em>collaborative multithreading</em>. +A coroutine in Lua represents an independent thread of execution. +Unlike threads in multithread systems, however, +a coroutine only suspends its execution by explicitly calling +a yield function. + + +<p> +You create a coroutine by calling <a href="#pdf-coroutine.create"><code>coroutine.create</code></a>. +Its sole argument is a function +that is the main function of the coroutine. +The <code>create</code> function only creates a new coroutine and +returns a handle to it (an object of type <em>thread</em>); +it does not start the coroutine. + + +<p> +You execute a coroutine by calling <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>. +When you first call <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>, +passing as its first argument +a thread returned by <a href="#pdf-coroutine.create"><code>coroutine.create</code></a>, +the coroutine starts its execution, +at the first line of its main function. +Extra arguments passed to <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> are passed +as arguments to the coroutine's main function. +After the coroutine starts running, +it runs until it terminates or <em>yields</em>. + + +<p> +A coroutine can terminate its execution in two ways: +normally, when its main function returns +(explicitly or implicitly, after the last instruction); +and abnormally, if there is an unprotected error. +In case of normal termination, +<a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> returns <b>true</b>, +plus any values returned by the coroutine main function. +In case of errors, <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> returns <b>false</b> +plus an error message. + + +<p> +A coroutine yields by calling <a href="#pdf-coroutine.yield"><code>coroutine.yield</code></a>. +When a coroutine yields, +the corresponding <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> returns immediately, +even if the yield happens inside nested function calls +(that is, not in the main function, +but in a function directly or indirectly called by the main function). +In the case of a yield, <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a> also returns <b>true</b>, +plus any values passed to <a href="#pdf-coroutine.yield"><code>coroutine.yield</code></a>. +The next time you resume the same coroutine, +it continues its execution from the point where it yielded, +with the call to <a href="#pdf-coroutine.yield"><code>coroutine.yield</code></a> returning any extra +arguments passed to <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>. + + +<p> +Like <a href="#pdf-coroutine.create"><code>coroutine.create</code></a>, +the <a href="#pdf-coroutine.wrap"><code>coroutine.wrap</code></a> function also creates a coroutine, +but instead of returning the coroutine itself, +it returns a function that, when called, resumes the coroutine. +Any arguments passed to this function +go as extra arguments to <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>. +<a href="#pdf-coroutine.wrap"><code>coroutine.wrap</code></a> returns all the values returned by <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>, +except the first one (the boolean error code). +Unlike <a href="#pdf-coroutine.resume"><code>coroutine.resume</code></a>, +<a href="#pdf-coroutine.wrap"><code>coroutine.wrap</code></a> does not catch errors; +any error is propagated to the caller. + + +<p> +As an example of how coroutines work, +consider the following code: + +<pre> + function foo (a) + print("foo", a) + return coroutine.yield(2*a) + end + + co = coroutine.create(function (a,b) + print("co-body", a, b) + local r = foo(a+1) + print("co-body", r) + local r, s = coroutine.yield(a+b, a-b) + print("co-body", r, s) + return b, "end" + end) + + print("main", coroutine.resume(co, 1, 10)) + print("main", coroutine.resume(co, "r")) + print("main", coroutine.resume(co, "x", "y")) + print("main", coroutine.resume(co, "x", "y")) +</pre><p> +When you run it, it produces the following output: + +<pre> + co-body 1 10 + foo 2 + main true 4 + co-body r + main true 11 -9 + co-body x y + main true 10 end + main false cannot resume dead coroutine +</pre> + +<p> +You can also create and manipulate coroutines through the C API: +see functions <a href="#lua_newthread"><code>lua_newthread</code></a>, <a href="#lua_resume"><code>lua_resume</code></a>, +and <a href="#lua_yield"><code>lua_yield</code></a>. + + + + + +<h1>3 – <a name="3">The Language</a></h1> + +<p> +This section describes the lexis, the syntax, and the semantics of Lua. +In other words, +this section describes +which tokens are valid, +how they can be combined, +and what their combinations mean. + + +<p> +Language constructs will be explained using the usual extended BNF notation, +in which +{<em>a</em>} means 0 or more <em>a</em>'s, and +[<em>a</em>] means an optional <em>a</em>. +Non-terminals are shown like non-terminal, +keywords are shown like <b>kword</b>, +and other terminal symbols are shown like ‘<b>=</b>’. +The complete syntax of Lua can be found in <a href="#9">§9</a> +at the end of this manual. + + + +<h2>3.1 – <a name="3.1">Lexical Conventions</a></h2> + +<p> +Lua is a free-form language. +It ignores spaces (including new lines) and comments +between lexical elements (tokens), +except as delimiters between names and keywords. + + +<p> +<em>Names</em> +(also called <em>identifiers</em>) +in Lua can be any string of letters, +digits, and underscores, +not beginning with a digit. +Identifiers are used to name variables, table fields, and labels. + + +<p> +The following <em>keywords</em> are reserved +and cannot be used as names: + + +<pre> + and break do else elseif end + false for function goto if in + local nil not or repeat return + then true until while +</pre> + +<p> +Lua is a case-sensitive language: +<code>and</code> is a reserved word, but <code>And</code> and <code>AND</code> +are two different, valid names. +As a convention, +programs should avoid creating +names that start with an underscore followed by +one or more uppercase letters (such as <a href="#pdf-_VERSION"><code>_VERSION</code></a>). + + +<p> +The following strings denote other tokens: + +<pre> + + - * / % ^ # + & ~ | << >> // + == ~= <= >= < > = + ( ) { } [ ] :: + ; : , . .. ... +</pre> + +<p> +<em>Literal strings</em> +can be delimited by matching single or double quotes, +and can contain the following C-like escape sequences: +'<code>\a</code>' (bell), +'<code>\b</code>' (backspace), +'<code>\f</code>' (form feed), +'<code>\n</code>' (newline), +'<code>\r</code>' (carriage return), +'<code>\t</code>' (horizontal tab), +'<code>\v</code>' (vertical tab), +'<code>\\</code>' (backslash), +'<code>\"</code>' (quotation mark [double quote]), +and '<code>\'</code>' (apostrophe [single quote]). +A backslash followed by a real newline +results in a newline in the string. +The escape sequence '<code>\z</code>' skips the following span +of white-space characters, +including line breaks; +it is particularly useful to break and indent a long literal string +into multiple lines without adding the newlines and spaces +into the string contents. + + +<p> +Strings in Lua can contain any 8-bit value, including embedded zeros, +which can be specified as '<code>\0</code>'. +More generally, +we can specify any byte in a literal string by its numerical value. +This can be done +with the escape sequence <code>\x<em>XX</em></code>, +where <em>XX</em> is a sequence of exactly two hexadecimal digits, +or with the escape sequence <code>\<em>ddd</em></code>, +where <em>ddd</em> is a sequence of up to three decimal digits. +(Note that if a decimal escape sequence is to be followed by a digit, +it must be expressed using exactly three digits.) + + +<p> +The UTF-8 encoding of a Unicode character +can be inserted in a literal string with +the escape sequence <code>\u{<em>XXX</em>}</code> +(note the mandatory enclosing brackets), +where <em>XXX</em> is a sequence of one or more hexadecimal digits +representing the character code point. + + +<p> +Literal strings can also be defined using a long format +enclosed by <em>long brackets</em>. +We define an <em>opening long bracket of level <em>n</em></em> as an opening +square bracket followed by <em>n</em> equal signs followed by another +opening square bracket. +So, an opening long bracket of level 0 is written as <code>[[</code>, +an opening long bracket of level 1 is written as <code>[=[</code>, +and so on. +A <em>closing long bracket</em> is defined similarly; +for instance, +a closing long bracket of level 4 is written as <code>]====]</code>. +A <em>long literal</em> starts with an opening long bracket of any level and +ends at the first closing long bracket of the same level. +It can contain any text except a closing bracket of the same level. +Literals in this bracketed form can run for several lines, +do not interpret any escape sequences, +and ignore long brackets of any other level. +Any kind of end-of-line sequence +(carriage return, newline, carriage return followed by newline, +or newline followed by carriage return) +is converted to a simple newline. + + +<p> +Any byte in a literal string not +explicitly affected by the previous rules represents itself. +However, Lua opens files for parsing in text mode, +and the system file functions may have problems with +some control characters. +So, it is safer to represent +non-text data as a quoted literal with +explicit escape sequences for non-text characters. + + +<p> +For convenience, +when the opening long bracket is immediately followed by a newline, +the newline is not included in the string. +As an example, in a system using ASCII +(in which '<code>a</code>' is coded as 97, +newline is coded as 10, and '<code>1</code>' is coded as 49), +the five literal strings below denote the same string: + +<pre> + a = 'alo\n123"' + a = "alo\n123\"" + a = '\97lo\10\04923"' + a = [[alo + 123"]] + a = [==[ + alo + 123"]==] +</pre> + +<p> +A <em>numerical constant</em> (or <em>numeral</em>) +can be written with an optional fractional part +and an optional decimal exponent, +marked by a letter '<code>e</code>' or '<code>E</code>'. +Lua also accepts hexadecimal constants, +which start with <code>0x</code> or <code>0X</code>. +Hexadecimal constants also accept an optional fractional part +plus an optional binary exponent, +marked by a letter '<code>p</code>' or '<code>P</code>'. +A numeric constant with a fractional dot or an exponent +denotes a float; +otherwise it denotes an integer. +Examples of valid integer constants are + +<pre> + 3 345 0xff 0xBEBADA +</pre><p> +Examples of valid float constants are + +<pre> + 3.0 3.1416 314.16e-2 0.31416E1 34e1 + 0x0.1E 0xA23p-4 0X1.921FB54442D18P+1 +</pre> + +<p> +A <em>comment</em> starts with a double hyphen (<code>--</code>) +anywhere outside a string. +If the text immediately after <code>--</code> is not an opening long bracket, +the comment is a <em>short comment</em>, +which runs until the end of the line. +Otherwise, it is a <em>long comment</em>, +which runs until the corresponding closing long bracket. +Long comments are frequently used to disable code temporarily. + + + + + +<h2>3.2 – <a name="3.2">Variables</a></h2> + +<p> +Variables are places that store values. +There are three kinds of variables in Lua: +global variables, local variables, and table fields. + + +<p> +A single name can denote a global variable or a local variable +(or a function's formal parameter, +which is a particular kind of local variable): + +<pre> + var ::= Name +</pre><p> +Name denotes identifiers, as defined in <a href="#3.1">§3.1</a>. + + +<p> +Any variable name is assumed to be global unless explicitly declared +as a local (see <a href="#3.3.7">§3.3.7</a>). +Local variables are <em>lexically scoped</em>: +local variables can be freely accessed by functions +defined inside their scope (see <a href="#3.5">§3.5</a>). + + +<p> +Before the first assignment to a variable, its value is <b>nil</b>. + + +<p> +Square brackets are used to index a table: + +<pre> + var ::= prefixexp ‘<b>[</b>’ exp ‘<b>]</b>’ +</pre><p> +The meaning of accesses to table fields can be changed via metatables. +An access to an indexed variable <code>t[i]</code> is equivalent to +a call <code>gettable_event(t,i)</code>. +(See <a href="#2.4">§2.4</a> for a complete description of the +<code>gettable_event</code> function. +This function is not defined or callable in Lua. +We use it here only for explanatory purposes.) + + +<p> +The syntax <code>var.Name</code> is just syntactic sugar for +<code>var["Name"]</code>: + +<pre> + var ::= prefixexp ‘<b>.</b>’ Name +</pre> + +<p> +An access to a global variable <code>x</code> +is equivalent to <code>_ENV.x</code>. +Due to the way that chunks are compiled, +<code>_ENV</code> is never a global name (see <a href="#2.2">§2.2</a>). + + + + + +<h2>3.3 – <a name="3.3">Statements</a></h2> + +<p> +Lua supports an almost conventional set of statements, +similar to those in Pascal or C. +This set includes +assignments, control structures, function calls, +and variable declarations. + + + +<h3>3.3.1 – <a name="3.3.1">Blocks</a></h3> + +<p> +A block is a list of statements, +which are executed sequentially: + +<pre> + block ::= {stat} +</pre><p> +Lua has <em>empty statements</em> +that allow you to separate statements with semicolons, +start a block with a semicolon +or write two semicolons in sequence: + +<pre> + stat ::= ‘<b>;</b>’ +</pre> + +<p> +Function calls and assignments +can start with an open parenthesis. +This possibility leads to an ambiguity in Lua's grammar. +Consider the following fragment: + +<pre> + a = b + c + (print or io.write)('done') +</pre><p> +The grammar could see it in two ways: + +<pre> + a = b + c(print or io.write)('done') + + a = b + c; (print or io.write)('done') +</pre><p> +The current parser always sees such constructions +in the first way, +interpreting the open parenthesis +as the start of the arguments to a call. +To avoid this ambiguity, +it is a good practice to always precede with a semicolon +statements that start with a parenthesis: + +<pre> + ;(print or io.write)('done') +</pre> + +<p> +A block can be explicitly delimited to produce a single statement: + +<pre> + stat ::= <b>do</b> block <b>end</b> +</pre><p> +Explicit blocks are useful +to control the scope of variable declarations. +Explicit blocks are also sometimes used to +add a <b>return</b> statement in the middle +of another block (see <a href="#3.3.4">§3.3.4</a>). + + + + + +<h3>3.3.2 – <a name="3.3.2">Chunks</a></h3> + +<p> +The unit of compilation of Lua is called a <em>chunk</em>. +Syntactically, +a chunk is simply a block: + +<pre> + chunk ::= block +</pre> + +<p> +Lua handles a chunk as the body of an anonymous function +with a variable number of arguments +(see <a href="#3.4.11">§3.4.11</a>). +As such, chunks can define local variables, +receive arguments, and return values. +Moreover, such anonymous function is compiled as in the +scope of an external local variable called <code>_ENV</code> (see <a href="#2.2">§2.2</a>). +The resulting function always has <code>_ENV</code> as its only upvalue, +even if it does not use that variable. + + +<p> +A chunk can be stored in a file or in a string inside the host program. +To execute a chunk, +Lua first <em>loads</em> it, +precompiling the chunk's code into instructions for a virtual machine, +and then Lua executes the compiled code +with an interpreter for the virtual machine. + + +<p> +Chunks can also be precompiled into binary form; +see program <code>luac</code> and function <a href="#pdf-string.dump"><code>string.dump</code></a> for details. +Programs in source and compiled forms are interchangeable; +Lua automatically detects the file type and acts accordingly (see <a href="#pdf-load"><code>load</code></a>). + + + + + +<h3>3.3.3 – <a name="3.3.3">Assignment</a></h3> + +<p> +Lua allows multiple assignments. +Therefore, the syntax for assignment +defines a list of variables on the left side +and a list of expressions on the right side. +The elements in both lists are separated by commas: + +<pre> + stat ::= varlist ‘<b>=</b>’ explist + varlist ::= var {‘<b>,</b>’ var} + explist ::= exp {‘<b>,</b>’ exp} +</pre><p> +Expressions are discussed in <a href="#3.4">§3.4</a>. + + +<p> +Before the assignment, +the list of values is <em>adjusted</em> to the length of +the list of variables. +If there are more values than needed, +the excess values are thrown away. +If there are fewer values than needed, +the list is extended with as many <b>nil</b>'s as needed. +If the list of expressions ends with a function call, +then all values returned by that call enter the list of values, +before the adjustment +(except when the call is enclosed in parentheses; see <a href="#3.4">§3.4</a>). + + +<p> +The assignment statement first evaluates all its expressions +and only then the assignments are performed. +Thus the code + +<pre> + i = 3 + i, a[i] = i+1, 20 +</pre><p> +sets <code>a[3]</code> to 20, without affecting <code>a[4]</code> +because the <code>i</code> in <code>a[i]</code> is evaluated (to 3) +before it is assigned 4. +Similarly, the line + +<pre> + x, y = y, x +</pre><p> +exchanges the values of <code>x</code> and <code>y</code>, +and + +<pre> + x, y, z = y, z, x +</pre><p> +cyclically permutes the values of <code>x</code>, <code>y</code>, and <code>z</code>. + + +<p> +The meaning of assignments to global variables +and table fields can be changed via metatables. +An assignment to an indexed variable <code>t[i] = val</code> is equivalent to +<code>settable_event(t,i,val)</code>. +(See <a href="#2.4">§2.4</a> for a complete description of the +<code>settable_event</code> function. +This function is not defined or callable in Lua. +We use it here only for explanatory purposes.) + + +<p> +An assignment to a global name <code>x = val</code> +is equivalent to the assignment +<code>_ENV.x = val</code> (see <a href="#2.2">§2.2</a>). + + + + + +<h3>3.3.4 – <a name="3.3.4">Control Structures</a></h3><p> +The control structures +<b>if</b>, <b>while</b>, and <b>repeat</b> have the usual meaning and +familiar syntax: + + + + +<pre> + stat ::= <b>while</b> exp <b>do</b> block <b>end</b> + stat ::= <b>repeat</b> block <b>until</b> exp + stat ::= <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b> +</pre><p> +Lua also has a <b>for</b> statement, in two flavors (see <a href="#3.3.5">§3.3.5</a>). + + +<p> +The condition expression of a +control structure can return any value. +Both <b>false</b> and <b>nil</b> are considered false. +All values different from <b>nil</b> and <b>false</b> are considered true +(in particular, the number 0 and the empty string are also true). + + +<p> +In the <b>repeat</b>–<b>until</b> loop, +the inner block does not end at the <b>until</b> keyword, +but only after the condition. +So, the condition can refer to local variables +declared inside the loop block. + + +<p> +The <b>goto</b> statement transfers the program control to a label. +For syntactical reasons, +labels in Lua are considered statements too: + + + +<pre> + stat ::= <b>goto</b> Name + stat ::= label + label ::= ‘<b>::</b>’ Name ‘<b>::</b>’ +</pre> + +<p> +A label is visible in the entire block where it is defined, +except +inside nested blocks where a label with the same name is defined and +inside nested functions. +A goto may jump to any visible label as long as it does not +enter into the scope of a local variable. + + +<p> +Labels and empty statements are called <em>void statements</em>, +as they perform no actions. + + +<p> +The <b>break</b> statement terminates the execution of a +<b>while</b>, <b>repeat</b>, or <b>for</b> loop, +skipping to the next statement after the loop: + + +<pre> + stat ::= <b>break</b> +</pre><p> +A <b>break</b> ends the innermost enclosing loop. + + +<p> +The <b>return</b> statement is used to return values +from a function or a chunk +(which is an anonymous function). + +Functions can return more than one value, +so the syntax for the <b>return</b> statement is + +<pre> + stat ::= <b>return</b> [explist] [‘<b>;</b>’] +</pre> + +<p> +The <b>return</b> statement can only be written +as the last statement of a block. +If it is really necessary to <b>return</b> in the middle of a block, +then an explicit inner block can be used, +as in the idiom <code>do return end</code>, +because now <b>return</b> is the last statement in its (inner) block. + + + + + +<h3>3.3.5 – <a name="3.3.5">For Statement</a></h3> + +<p> + +The <b>for</b> statement has two forms: +one numeric and one generic. + + +<p> +The numeric <b>for</b> loop repeats a block of code while a +control variable runs through an arithmetic progression. +It has the following syntax: + +<pre> + stat ::= <b>for</b> Name ‘<b>=</b>’ exp ‘<b>,</b>’ exp [‘<b>,</b>’ exp] <b>do</b> block <b>end</b> +</pre><p> +The <em>block</em> is repeated for <em>name</em> starting at the value of +the first <em>exp</em>, until it passes the second <em>exp</em> by steps of the +third <em>exp</em>. +More precisely, a <b>for</b> statement like + +<pre> + for v = <em>e1</em>, <em>e2</em>, <em>e3</em> do <em>block</em> end +</pre><p> +is equivalent to the code: + +<pre> + do + local <em>var</em>, <em>limit</em>, <em>step</em> = tonumber(<em>e1</em>), tonumber(<em>e2</em>), tonumber(<em>e3</em>) + if not (<em>var</em> and <em>limit</em> and <em>step</em>) then error() end + <em>var</em> = <em>var</em> - <em>step</em> + while true do + <em>var</em> = <em>var</em> + <em>step</em> + if (<em>step</em> >= 0 and <em>var</em> > <em>limit</em>) or (<em>step</em> < 0 and <em>var</em> < <em>limit</em>) then + break + end + local v = <em>var</em> + <em>block</em> + end + end +</pre> + +<p> +Note the following: + +<ul> + +<li> +All three control expressions are evaluated only once, +before the loop starts. +They must all result in numbers. +</li> + +<li> +<code><em>var</em></code>, <code><em>limit</em></code>, and <code><em>step</em></code> are invisible variables. +The names shown here are for explanatory purposes only. +</li> + +<li> +If the third expression (the step) is absent, +then a step of 1 is used. +</li> + +<li> +You can use <b>break</b> and <b>goto</b> to exit a <b>for</b> loop. +</li> + +<li> +The loop variable <code>v</code> is local to the loop body. +If you need its value after the loop, +assign it to another variable before exiting the loop. +</li> + +</ul> + +<p> +The generic <b>for</b> statement works over functions, +called <em>iterators</em>. +On each iteration, the iterator function is called to produce a new value, +stopping when this new value is <b>nil</b>. +The generic <b>for</b> loop has the following syntax: + +<pre> + stat ::= <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b> + namelist ::= Name {‘<b>,</b>’ Name} +</pre><p> +A <b>for</b> statement like + +<pre> + for <em>var_1</em>, ···, <em>var_n</em> in <em>explist</em> do <em>block</em> end +</pre><p> +is equivalent to the code: + +<pre> + do + local <em>f</em>, <em>s</em>, <em>var</em> = <em>explist</em> + while true do + local <em>var_1</em>, ···, <em>var_n</em> = <em>f</em>(<em>s</em>, <em>var</em>) + if <em>var_1</em> == nil then break end + <em>var</em> = <em>var_1</em> + <em>block</em> + end + end +</pre><p> +Note the following: + +<ul> + +<li> +<code><em>explist</em></code> is evaluated only once. +Its results are an <em>iterator</em> function, +a <em>state</em>, +and an initial value for the first <em>iterator variable</em>. +</li> + +<li> +<code><em>f</em></code>, <code><em>s</em></code>, and <code><em>var</em></code> are invisible variables. +The names are here for explanatory purposes only. +</li> + +<li> +You can use <b>break</b> to exit a <b>for</b> loop. +</li> + +<li> +The loop variables <code><em>var_i</em></code> are local to the loop; +you cannot use their values after the <b>for</b> ends. +If you need these values, +then assign them to other variables before breaking or exiting the loop. +</li> + +</ul> + + + + +<h3>3.3.6 – <a name="3.3.6">Function Calls as Statements</a></h3><p> +To allow possible side-effects, +function calls can be executed as statements: + +<pre> + stat ::= functioncall +</pre><p> +In this case, all returned values are thrown away. +Function calls are explained in <a href="#3.4.10">§3.4.10</a>. + + + + + +<h3>3.3.7 – <a name="3.3.7">Local Declarations</a></h3><p> +Local variables can be declared anywhere inside a block. +The declaration can include an initial assignment: + +<pre> + stat ::= <b>local</b> namelist [‘<b>=</b>’ explist] +</pre><p> +If present, an initial assignment has the same semantics +of a multiple assignment (see <a href="#3.3.3">§3.3.3</a>). +Otherwise, all variables are initialized with <b>nil</b>. + + +<p> +A chunk is also a block (see <a href="#3.3.2">§3.3.2</a>), +and so local variables can be declared in a chunk outside any explicit block. + + +<p> +The visibility rules for local variables are explained in <a href="#3.5">§3.5</a>. + + + + + + + +<h2>3.4 – <a name="3.4">Expressions</a></h2> + +<p> +The basic expressions in Lua are the following: + +<pre> + exp ::= prefixexp + exp ::= <b>nil</b> | <b>false</b> | <b>true</b> + exp ::= Numeral + exp ::= LiteralString + exp ::= functiondef + exp ::= tableconstructor + exp ::= ‘<b>...</b>’ + exp ::= exp binop exp + exp ::= unop exp + prefixexp ::= var | functioncall | ‘<b>(</b>’ exp ‘<b>)</b>’ +</pre> + +<p> +Numerals and literal strings are explained in <a href="#3.1">§3.1</a>; +variables are explained in <a href="#3.2">§3.2</a>; +function definitions are explained in <a href="#3.4.11">§3.4.11</a>; +function calls are explained in <a href="#3.4.10">§3.4.10</a>; +table constructors are explained in <a href="#3.4.9">§3.4.9</a>. +Vararg expressions, +denoted by three dots ('<code>...</code>'), can only be used when +directly inside a vararg function; +they are explained in <a href="#3.4.11">§3.4.11</a>. + + +<p> +Binary operators comprise arithmetic operators (see <a href="#3.4.1">§3.4.1</a>), +bitwise operators (see <a href="#3.4.2">§3.4.2</a>), +relational operators (see <a href="#3.4.4">§3.4.4</a>), logical operators (see <a href="#3.4.5">§3.4.5</a>), +and the concatenation operator (see <a href="#3.4.6">§3.4.6</a>). +Unary operators comprise the unary minus (see <a href="#3.4.1">§3.4.1</a>), +the unary bitwise not (see <a href="#3.4.2">§3.4.2</a>), +the unary logical <b>not</b> (see <a href="#3.4.5">§3.4.5</a>), +and the unary <em>length operator</em> (see <a href="#3.4.7">§3.4.7</a>). + + +<p> +Both function calls and vararg expressions can result in multiple values. +If a function call is used as a statement (see <a href="#3.3.6">§3.3.6</a>), +then its return list is adjusted to zero elements, +thus discarding all returned values. +If an expression is used as the last (or the only) element +of a list of expressions, +then no adjustment is made +(unless the expression is enclosed in parentheses). +In all other contexts, +Lua adjusts the result list to one element, +either discarding all values except the first one +or adding a single <b>nil</b> if there are no values. + + +<p> +Here are some examples: + +<pre> + f() -- adjusted to 0 results + g(f(), x) -- f() is adjusted to 1 result + g(x, f()) -- g gets x plus all results from f() + a,b,c = f(), x -- f() is adjusted to 1 result (c gets nil) + a,b = ... -- a gets the first vararg parameter, b gets + -- the second (both a and b can get nil if there + -- is no corresponding vararg parameter) + + a,b,c = x, f() -- f() is adjusted to 2 results + a,b,c = f() -- f() is adjusted to 3 results + return f() -- returns all results from f() + return ... -- returns all received vararg parameters + return x,y,f() -- returns x, y, and all results from f() + {f()} -- creates a list with all results from f() + {...} -- creates a list with all vararg parameters + {f(), nil} -- f() is adjusted to 1 result +</pre> + +<p> +Any expression enclosed in parentheses always results in only one value. +Thus, +<code>(f(x,y,z))</code> is always a single value, +even if <code>f</code> returns several values. +(The value of <code>(f(x,y,z))</code> is the first value returned by <code>f</code> +or <b>nil</b> if <code>f</code> does not return any values.) + + + +<h3>3.4.1 – <a name="3.4.1">Arithmetic Operators</a></h3><p> +Lua supports the following arithmetic operators: + +<ul> +<li><b><code>+</code>: </b>addition</li> +<li><b><code>-</code>: </b>subtraction</li> +<li><b><code>*</code>: </b>multiplication</li> +<li><b><code>/</code>: </b>float division</li> +<li><b><code>//</code>: </b>floor division</li> +<li><b><code>%</code>: </b>modulo</li> +<li><b><code>^</code>: </b>exponentiation</li> +<li><b><code>-</code>: </b>unary minus</li> +</ul> + +<p> +With the exception of exponentiation and float division, +the arithmetic operators work as follows: +If both operands are integers, +the operation is performed over integers and the result is an integer. +Otherwise, if both operands are numbers +or strings that can be converted to +numbers (see <a href="#3.4.3">§3.4.3</a>), +then they are converted to floats, +the operation is performed following the usual rules +for floating-point arithmetic +(usually the IEEE 754 standard), +and the result is a float. + + +<p> +Exponentiation and float division (<code>/</code>) +always convert their operands to floats +and the result is always a float. +Exponentiation uses the ISO C function <code>pow</code>, +so that it works for non-integer exponents too. + + +<p> +Floor division (<code>//</code>) is a division +that rounds the quotient towards minus infinite, +that is, the floor of the division of its operands. + + +<p> +Modulo is defined as the remainder of a division +that rounds the quotient towards minus infinite (floor division). + + +<p> +In case of overflows in integer arithmetic, +all operations <em>wrap around</em>, +according to the usual rules of two-complement arithmetic. +(In other words, +they return the unique representable integer +that is equal modulo <em>2<sup>64</sup></em> to the mathematical result.) + + + +<h3>3.4.2 – <a name="3.4.2">Bitwise Operators</a></h3><p> +Lua supports the following bitwise operators: + +<ul> +<li><b><code>&</code>: </b>bitwise and</li> +<li><b><code>|</code>: </b>bitwise or</li> +<li><b><code>~</code>: </b>bitwise exclusive or</li> +<li><b><code>>></code>: </b>right shift</li> +<li><b><code><<</code>: </b>left shift</li> +<li><b><code>~</code>: </b>unary bitwise not</li> +</ul> + +<p> +All bitwise operations convert its operands to integers +(see <a href="#3.4.3">§3.4.3</a>), +operate on all bits of those integers, +and result in an integer. + + +<p> +Both right and left shifts fill the vacant bits with zeros. +Negative displacements shift to the other direction; +displacements with absolute values equal to or higher than +the number of bits in an integer +result in zero (as all bits are shifted out). + + + + + +<h3>3.4.3 – <a name="3.4.3">Coercions and Conversions</a></h3><p> +Lua provides some automatic conversions between some +types and representations at run time. +Bitwise operators always convert float operands to integers. +Exponentiation and float division +always convert integer operands to floats. +All other arithmetic operations applied to mixed numbers +(integers and floats) convert the integer operand to a float; +this is called the <em>usual rule</em>. +The C API also converts both integers to floats and +floats to integers, as needed. +Moreover, string concatenation accepts numbers as arguments, +besides strings. + + +<p> +Lua also converts strings to numbers, +whenever a number is expected. + + +<p> +In a conversion from integer to float, +if the integer value has an exact representation as a float, +that is the result. +Otherwise, +the conversion gets the nearest higher or +the nearest lower representable value. +This kind of conversion never fails. + + +<p> +The conversion from float to integer +checks whether the float has an exact representation as an integer +(that is, the float has an integral value and +it is in the range of integer representation). +If it does, that representation is the result. +Otherwise, the conversion fails. + + +<p> +The conversion from strings to numbers goes as follows: +First, the string is converted to an integer or a float, +following its syntax and the rules of the Lua lexer. +(The string may have also leading and trailing spaces and a sign.) +Then, the resulting number is converted to the required type +(float or integer) according to the previous rules. + + +<p> +The conversion from numbers to strings uses a +non-specified human-readable format. +For complete control over how numbers are converted to strings, +use the <code>format</code> function from the string library +(see <a href="#pdf-string.format"><code>string.format</code></a>). + + + + + +<h3>3.4.4 – <a name="3.4.4">Relational Operators</a></h3><p> +Lua supports the following relational operators: + +<ul> +<li><b><code>==</code>: </b>equality</li> +<li><b><code>~=</code>: </b>inequality</li> +<li><b><code><</code>: </b>less than</li> +<li><b><code>></code>: </b>greater than</li> +<li><b><code><=</code>: </b>less or equal</li> +<li><b><code>>=</code>: </b>greater or equal</li> +</ul><p> +These operators always result in <b>false</b> or <b>true</b>. + + +<p> +Equality (<code>==</code>) first compares the type of its operands. +If the types are different, then the result is <b>false</b>. +Otherwise, the values of the operands are compared. +Strings are compared in the obvious way. +Numbers follow the usual rule for binary operations: +if both operands are integers, +they are compared as integers; +otherwise, they are converted to floats +and compared as such. + + +<p> +Tables, userdata, and threads +are compared by reference: +two objects are considered equal only if they are the same object. +Every time you create a new object +(a table, userdata, or thread), +this new object is different from any previously existing object. +Closures with the same reference are always equal. +Closures with any detectable difference +(different behavior, different definition) are always different. + + +<p> +You can change the way that Lua compares tables and userdata +by using the "eq" metamethod (see <a href="#2.4">§2.4</a>). + + +<p> +Equality comparisons do not convert strings to numbers +or vice versa. +Thus, <code>"0"==0</code> evaluates to <b>false</b>, +and <code>t[0]</code> and <code>t["0"]</code> denote different +entries in a table. + + +<p> +The operator <code>~=</code> is exactly the negation of equality (<code>==</code>). + + +<p> +The order operators work as follows. +If both arguments are numbers, +then they are compared following +the usual rule for binary operations. +Otherwise, if both arguments are strings, +then their values are compared according to the current locale. +Otherwise, Lua tries to call the "lt" or the "le" +metamethod (see <a href="#2.4">§2.4</a>). +A comparison <code>a > b</code> is translated to <code>b < a</code> +and <code>a >= b</code> is translated to <code>b <= a</code>. + + + + + +<h3>3.4.5 – <a name="3.4.5">Logical Operators</a></h3><p> +The logical operators in Lua are +<b>and</b>, <b>or</b>, and <b>not</b>. +Like the control structures (see <a href="#3.3.4">§3.3.4</a>), +all logical operators consider both <b>false</b> and <b>nil</b> as false +and anything else as true. + + +<p> +The negation operator <b>not</b> always returns <b>false</b> or <b>true</b>. +The conjunction operator <b>and</b> returns its first argument +if this value is <b>false</b> or <b>nil</b>; +otherwise, <b>and</b> returns its second argument. +The disjunction operator <b>or</b> returns its first argument +if this value is different from <b>nil</b> and <b>false</b>; +otherwise, <b>or</b> returns its second argument. +Both <b>and</b> and <b>or</b> use short-circuit evaluation; +that is, +the second operand is evaluated only if necessary. +Here are some examples: + +<pre> + 10 or 20 --> 10 + 10 or error() --> 10 + nil or "a" --> "a" + nil and 10 --> nil + false and error() --> false + false and nil --> false + false or nil --> nil + 10 and 20 --> 20 +</pre><p> +(In this manual, +<code>--></code> indicates the result of the preceding expression.) + + + + + +<h3>3.4.6 – <a name="3.4.6">Concatenation</a></h3><p> +The string concatenation operator in Lua is +denoted by two dots ('<code>..</code>'). +If both operands are strings or numbers, then they are converted to +strings according to the rules described in <a href="#3.4.3">§3.4.3</a>. +Otherwise, the <code>__concat</code> metamethod is called (see <a href="#2.4">§2.4</a>). + + + + + +<h3>3.4.7 – <a name="3.4.7">The Length Operator</a></h3> + +<p> +The length operator is denoted by the unary prefix operator <code>#</code>. +The length of a string is its number of bytes +(that is, the usual meaning of string length when each +character is one byte). + + +<p> +A program can modify the behavior of the length operator for +any value but strings through the <code>__len</code> metamethod (see <a href="#2.4">§2.4</a>). + + +<p> +Unless a <code>__len</code> metamethod is given, +the length of a table <code>t</code> is only defined if the +table is a <em>sequence</em>, +that is, +the set of its positive numeric keys is equal to <em>{1..n}</em> +for some non-negative integer <em>n</em>. +In that case, <em>n</em> is its length. +Note that a table like + +<pre> + {10, 20, nil, 40} +</pre><p> +is not a sequence, because it has the key <code>4</code> +but does not have the key <code>3</code>. +(So, there is no <em>n</em> such that the set <em>{1..n}</em> is equal +to the set of positive numeric keys of that table.) +Note, however, that non-numeric keys do not interfere +with whether a table is a sequence. + + + + + +<h3>3.4.8 – <a name="3.4.8">Precedence</a></h3><p> +Operator precedence in Lua follows the table below, +from lower to higher priority: + +<pre> + or + and + < > <= >= ~= == + | + ~ + & + << >> + .. + + - + * / // % + unary operators (not # - ~) + ^ +</pre><p> +As usual, +you can use parentheses to change the precedences of an expression. +The concatenation ('<code>..</code>') and exponentiation ('<code>^</code>') +operators are right associative. +All other binary operators are left associative. + + + + + +<h3>3.4.9 – <a name="3.4.9">Table Constructors</a></h3><p> +Table constructors are expressions that create tables. +Every time a constructor is evaluated, a new table is created. +A constructor can be used to create an empty table +or to create a table and initialize some of its fields. +The general syntax for constructors is + +<pre> + tableconstructor ::= ‘<b>{</b>’ [fieldlist] ‘<b>}</b>’ + fieldlist ::= field {fieldsep field} [fieldsep] + field ::= ‘<b>[</b>’ exp ‘<b>]</b>’ ‘<b>=</b>’ exp | Name ‘<b>=</b>’ exp | exp + fieldsep ::= ‘<b>,</b>’ | ‘<b>;</b>’ +</pre> + +<p> +Each field of the form <code>[exp1] = exp2</code> adds to the new table an entry +with key <code>exp1</code> and value <code>exp2</code>. +A field of the form <code>name = exp</code> is equivalent to +<code>["name"] = exp</code>. +Finally, fields of the form <code>exp</code> are equivalent to +<code>[i] = exp</code>, where <code>i</code> are consecutive integers +starting with 1. +Fields in the other formats do not affect this counting. +For example, + +<pre> + a = { [f(1)] = g; "x", "y"; x = 1, f(x), [30] = 23; 45 } +</pre><p> +is equivalent to + +<pre> + do + local t = {} + t[f(1)] = g + t[1] = "x" -- 1st exp + t[2] = "y" -- 2nd exp + t.x = 1 -- t["x"] = 1 + t[3] = f(x) -- 3rd exp + t[30] = 23 + t[4] = 45 -- 4th exp + a = t + end +</pre> + +<p> +The order of the assignments in a constructor is undefined. +(This order would be relevant only when there are repeated keys.) + + +<p> +If the last field in the list has the form <code>exp</code> +and the expression is a function call or a vararg expression, +then all values returned by this expression enter the list consecutively +(see <a href="#3.4.10">§3.4.10</a>). + + +<p> +The field list can have an optional trailing separator, +as a convenience for machine-generated code. + + + + + +<h3>3.4.10 – <a name="3.4.10">Function Calls</a></h3><p> +A function call in Lua has the following syntax: + +<pre> + functioncall ::= prefixexp args +</pre><p> +In a function call, +first prefixexp and args are evaluated. +If the value of prefixexp has type <em>function</em>, +then this function is called +with the given arguments. +Otherwise, the prefixexp "call" metamethod is called, +having as first parameter the value of prefixexp, +followed by the original call arguments +(see <a href="#2.4">§2.4</a>). + + +<p> +The form + +<pre> + functioncall ::= prefixexp ‘<b>:</b>’ Name args +</pre><p> +can be used to call "methods". +A call <code>v:name(<em>args</em>)</code> +is syntactic sugar for <code>v.name(v,<em>args</em>)</code>, +except that <code>v</code> is evaluated only once. + + +<p> +Arguments have the following syntax: + +<pre> + args ::= ‘<b>(</b>’ [explist] ‘<b>)</b>’ + args ::= tableconstructor + args ::= LiteralString +</pre><p> +All argument expressions are evaluated before the call. +A call of the form <code>f{<em>fields</em>}</code> is +syntactic sugar for <code>f({<em>fields</em>})</code>; +that is, the argument list is a single new table. +A call of the form <code>f'<em>string</em>'</code> +(or <code>f"<em>string</em>"</code> or <code>f[[<em>string</em>]]</code>) +is syntactic sugar for <code>f('<em>string</em>')</code>; +that is, the argument list is a single literal string. + + +<p> +A call of the form <code>return <em>functioncall</em></code> is called +a <em>tail call</em>. +Lua implements <em>proper tail calls</em> +(or <em>proper tail recursion</em>): +in a tail call, +the called function reuses the stack entry of the calling function. +Therefore, there is no limit on the number of nested tail calls that +a program can execute. +However, a tail call erases any debug information about the +calling function. +Note that a tail call only happens with a particular syntax, +where the <b>return</b> has one single function call as argument; +this syntax makes the calling function return exactly +the returns of the called function. +So, none of the following examples are tail calls: + +<pre> + return (f(x)) -- results adjusted to 1 + return 2 * f(x) + return x, f(x) -- additional results + f(x); return -- results discarded + return x or f(x) -- results adjusted to 1 +</pre> + + + + +<h3>3.4.11 – <a name="3.4.11">Function Definitions</a></h3> + +<p> +The syntax for function definition is + +<pre> + functiondef ::= <b>function</b> funcbody + funcbody ::= ‘<b>(</b>’ [parlist] ‘<b>)</b>’ block <b>end</b> +</pre> + +<p> +The following syntactic sugar simplifies function definitions: + +<pre> + stat ::= <b>function</b> funcname funcbody + stat ::= <b>local</b> <b>function</b> Name funcbody + funcname ::= Name {‘<b>.</b>’ Name} [‘<b>:</b>’ Name] +</pre><p> +The statement + +<pre> + function f () <em>body</em> end +</pre><p> +translates to + +<pre> + f = function () <em>body</em> end +</pre><p> +The statement + +<pre> + function t.a.b.c.f () <em>body</em> end +</pre><p> +translates to + +<pre> + t.a.b.c.f = function () <em>body</em> end +</pre><p> +The statement + +<pre> + local function f () <em>body</em> end +</pre><p> +translates to + +<pre> + local f; f = function () <em>body</em> end +</pre><p> +not to + +<pre> + local f = function () <em>body</em> end +</pre><p> +(This only makes a difference when the body of the function +contains references to <code>f</code>.) + + +<p> +A function definition is an executable expression, +whose value has type <em>function</em>. +When Lua precompiles a chunk, +all its function bodies are precompiled too. +Then, whenever Lua executes the function definition, +the function is <em>instantiated</em> (or <em>closed</em>). +This function instance (or <em>closure</em>) +is the final value of the expression. + + +<p> +Parameters act as local variables that are +initialized with the argument values: + +<pre> + parlist ::= namelist [‘<b>,</b>’ ‘<b>...</b>’] | ‘<b>...</b>’ +</pre><p> +When a function is called, +the list of arguments is adjusted to +the length of the list of parameters, +unless the function is a <em>vararg function</em>, +which is indicated by three dots ('<code>...</code>') +at the end of its parameter list. +A vararg function does not adjust its argument list; +instead, it collects all extra arguments and supplies them +to the function through a <em>vararg expression</em>, +which is also written as three dots. +The value of this expression is a list of all actual extra arguments, +similar to a function with multiple results. +If a vararg expression is used inside another expression +or in the middle of a list of expressions, +then its return list is adjusted to one element. +If the expression is used as the last element of a list of expressions, +then no adjustment is made +(unless that last expression is enclosed in parentheses). + + +<p> +As an example, consider the following definitions: + +<pre> + function f(a, b) end + function g(a, b, ...) end + function r() return 1,2,3 end +</pre><p> +Then, we have the following mapping from arguments to parameters and +to the vararg expression: + +<pre> + CALL PARAMETERS + + f(3) a=3, b=nil + f(3, 4) a=3, b=4 + f(3, 4, 5) a=3, b=4 + f(r(), 10) a=1, b=10 + f(r()) a=1, b=2 + + g(3) a=3, b=nil, ... --> (nothing) + g(3, 4) a=3, b=4, ... --> (nothing) + g(3, 4, 5, 8) a=3, b=4, ... --> 5 8 + g(5, r()) a=5, b=1, ... --> 2 3 +</pre> + +<p> +Results are returned using the <b>return</b> statement (see <a href="#3.3.4">§3.3.4</a>). +If control reaches the end of a function +without encountering a <b>return</b> statement, +then the function returns with no results. + + +<p> + +There is a system-dependent limit on the number of values +that a function may return. +This limit is guaranteed to be larger than 1000. + + +<p> +The <em>colon</em> syntax +is used for defining <em>methods</em>, +that is, functions that have an implicit extra parameter <code>self</code>. +Thus, the statement + +<pre> + function t.a.b.c:f (<em>params</em>) <em>body</em> end +</pre><p> +is syntactic sugar for + +<pre> + t.a.b.c.f = function (self, <em>params</em>) <em>body</em> end +</pre> + + + + + + +<h2>3.5 – <a name="3.5">Visibility Rules</a></h2> + +<p> + +Lua is a lexically scoped language. +The scope of a local variable begins at the first statement after +its declaration and lasts until the last non-void statement +of the innermost block that includes the declaration. +Consider the following example: + +<pre> + x = 10 -- global variable + do -- new block + local x = x -- new 'x', with value 10 + print(x) --> 10 + x = x+1 + do -- another block + local x = x+1 -- another 'x' + print(x) --> 12 + end + print(x) --> 11 + end + print(x) --> 10 (the global one) +</pre> + +<p> +Notice that, in a declaration like <code>local x = x</code>, +the new <code>x</code> being declared is not in scope yet, +and so the second <code>x</code> refers to the outside variable. + + +<p> +Because of the lexical scoping rules, +local variables can be freely accessed by functions +defined inside their scope. +A local variable used by an inner function is called +an <em>upvalue</em>, or <em>external local variable</em>, +inside the inner function. + + +<p> +Notice that each execution of a <b>local</b> statement +defines new local variables. +Consider the following example: + +<pre> + a = {} + local x = 20 + for i=1,10 do + local y = 0 + a[i] = function () y=y+1; return x+y end + end +</pre><p> +The loop creates ten closures +(that is, ten instances of the anonymous function). +Each of these closures uses a different <code>y</code> variable, +while all of them share the same <code>x</code>. + + + + + +<h1>4 – <a name="4">The Application Program Interface</a></h1> + +<p> + +This section describes the C API for Lua, that is, +the set of C functions available to the host program to communicate +with Lua. +All API functions and related types and constants +are declared in the header file <a name="pdf-lua.h"><code>lua.h</code></a>. + + +<p> +Even when we use the term "function", +any facility in the API may be provided as a macro instead. +Except where stated otherwise, +all such macros use each of their arguments exactly once +(except for the first argument, which is always a Lua state), +and so do not generate any hidden side-effects. + + +<p> +As in most C libraries, +the Lua API functions do not check their arguments for validity or consistency. +However, you can change this behavior by compiling Lua +with the macro <a name="pdf-LUA_USE_APICHECK"><code>LUA_USE_APICHECK</code></a> defined. + + + +<h2>4.1 – <a name="4.1">The Stack</a></h2> + +<p> +Lua uses a <em>virtual stack</em> to pass values to and from C. +Each element in this stack represents a Lua value +(<b>nil</b>, number, string, etc.). + + +<p> +Whenever Lua calls C, the called function gets a new stack, +which is independent of previous stacks and of stacks of +C functions that are still active. +This stack initially contains any arguments to the C function +and it is where the C function pushes its results +to be returned to the caller (see <a href="#lua_CFunction"><code>lua_CFunction</code></a>). + + +<p> +For convenience, +most query operations in the API do not follow a strict stack discipline. +Instead, they can refer to any element in the stack +by using an <em>index</em>: +A positive index represents an absolute stack position +(starting at 1); +a negative index represents an offset relative to the top of the stack. +More specifically, if the stack has <em>n</em> elements, +then index 1 represents the first element +(that is, the element that was pushed onto the stack first) +and +index <em>n</em> represents the last element; +index -1 also represents the last element +(that is, the element at the top) +and index <em>-n</em> represents the first element. + + + + + +<h2>4.2 – <a name="4.2">Stack Size</a></h2> + +<p> +When you interact with the Lua API, +you are responsible for ensuring consistency. +In particular, +<em>you are responsible for controlling stack overflow</em>. +You can use the function <a href="#lua_checkstack"><code>lua_checkstack</code></a> +to ensure that the stack has enough space for pushing new elements. + + +<p> +Whenever Lua calls C, +it ensures that the stack has space for +at least <a name="pdf-LUA_MINSTACK"><code>LUA_MINSTACK</code></a> extra slots. +<code>LUA_MINSTACK</code> is defined as 20, +so that usually you do not have to worry about stack space +unless your code has loops pushing elements onto the stack. + + +<p> +When you call a Lua function +without a fixed number of results (see <a href="#lua_call"><code>lua_call</code></a>), +Lua ensures that the stack has enough space for all results, +but it does not ensure any extra space. +So, before pushing anything in the stack after such a call +you should use <a href="#lua_checkstack"><code>lua_checkstack</code></a>. + + + + + +<h2>4.3 – <a name="4.3">Valid and Acceptable Indices</a></h2> + +<p> +Any function in the API that receives stack indices +works only with <em>valid indices</em> or <em>acceptable indices</em>. + + +<p> +A <em>valid index</em> is an index that refers to a +real position within the stack, that is, +its position lies between 1 and the stack top +(<code>1 ≤ abs(index) ≤ top</code>). + +Usually, functions that can modify the value at an index +require valid indices. + + +<p> +Unless otherwise noted, +any function that accepts valid indices also accepts <em>pseudo-indices</em>, +which represent some Lua values that are accessible to C code +but which are not in the stack. +Pseudo-indices are used to access the registry +and the upvalues of a C function (see <a href="#4.4">§4.4</a>). + + +<p> +Functions that do not need a specific stack position, +but only a value in the stack (e.g., query functions), +can be called with acceptable indices. +An <em>acceptable index</em> can be any valid index, +including the pseudo-indices, +but it also can be any positive index after the stack top +within the space allocated for the stack, +that is, indices up to the stack size. +(Note that 0 is never an acceptable index.) +Except when noted otherwise, +functions in the API work with acceptable indices. + + +<p> +Acceptable indices serve to avoid extra tests +against the stack top when querying the stack. +For instance, a C function can query its third argument +without the need to first check whether there is a third argument, +that is, without the need to check whether 3 is a valid index. + + +<p> +For functions that can be called with acceptable indices, +any non-valid index is treated as if it +contains a value of a virtual type <a name="pdf-LUA_TNONE"><code>LUA_TNONE</code></a>, +which behaves like a nil value. + + + + + +<h2>4.4 – <a name="4.4">C Closures</a></h2> + +<p> +When a C function is created, +it is possible to associate some values with it, +thus creating a <em>C closure</em> +(see <a href="#lua_pushcclosure"><code>lua_pushcclosure</code></a>); +these values are called <em>upvalues</em> and are +accessible to the function whenever it is called. + + +<p> +Whenever a C function is called, +its upvalues are located at specific pseudo-indices. +These pseudo-indices are produced by the macro +<a href="#lua_upvalueindex"><code>lua_upvalueindex</code></a>. +The first value associated with a function is at position +<code>lua_upvalueindex(1)</code>, and so on. +Any access to <code>lua_upvalueindex(<em>n</em>)</code>, +where <em>n</em> is greater than the number of upvalues of the +current function (but not greater than 256), +produces an acceptable but invalid index. + + + + + +<h2>4.5 – <a name="4.5">Registry</a></h2> + +<p> +Lua provides a <em>registry</em>, +a predefined table that can be used by any C code to +store whatever Lua values it needs to store. +The registry table is always located at pseudo-index +<a name="pdf-LUA_REGISTRYINDEX"><code>LUA_REGISTRYINDEX</code></a>, +which is a valid index. +Any C library can store data into this table, +but it must take care to choose keys +that are different from those used +by other libraries, to avoid collisions. +Typically, you should use as key a string containing your library name, +or a light userdata with the address of a C object in your code, +or any Lua object created by your code. +As with variable names, +string keys starting with an underscore followed by +uppercase letters are reserved for Lua. + + +<p> +The integer keys in the registry are used +by the reference mechanism (see <a href="#luaL_ref"><code>luaL_ref</code></a>) +and by some predefined values. +Therefore, integer keys must not be used for other purposes. + + +<p> +When you create a new Lua state, +its registry comes with some predefined values. +These predefined values are indexed with integer keys +defined as constants in <code>lua.h</code>. +The following constants are defined: + +<ul> +<li><b><a name="pdf-LUA_RIDX_MAINTHREAD"><code>LUA_RIDX_MAINTHREAD</code></a>: </b> At this index the registry has +the main thread of the state. +(The main thread is the one created together with the state.) +</li> + +<li><b><a name="pdf-LUA_RIDX_GLOBALS"><code>LUA_RIDX_GLOBALS</code></a>: </b> At this index the registry has +the global environment. +</li> +</ul> + + + + +<h2>4.6 – <a name="4.6">Error Handling in C</a></h2> + +<p> +Internally, Lua uses the C <code>longjmp</code> facility to handle errors. +(Lua will use exceptions if you compile it as C++; +search for <code>LUAI_THROW</code> in the source code for details.) +When Lua faces any error +(such as a memory allocation error, type errors, syntax errors, +and runtime errors) +it <em>raises</em> an error; +that is, it does a long jump. +A <em>protected environment</em> uses <code>setjmp</code> +to set a recovery point; +any error jumps to the most recent active recovery point. + + +<p> +If an error happens outside any protected environment, +Lua calls a <em>panic function</em> (see <a href="#lua_atpanic"><code>lua_atpanic</code></a>) +and then calls <code>abort</code>, +thus exiting the host application. +Your panic function can avoid this exit by +never returning +(e.g., doing a long jump to your own recovery point outside Lua). + + +<p> +The panic function runs as if it were a message handler (see <a href="#2.3">§2.3</a>); +in particular, the error message is at the top of the stack. +However, there is no guarantee about stack space. +To push anything on the stack, +the panic function must first check the available space (see <a href="#4.2">§4.2</a>). + + +<p> +Most functions in the API can raise an error, +for instance due to a memory allocation error. +The documentation for each function indicates whether +it can raise errors. + + +<p> +Inside a C function you can raise an error by calling <a href="#lua_error"><code>lua_error</code></a>. + + + + + +<h2>4.7 – <a name="4.7">Handling Yields in C</a></h2> + +<p> +Internally, Lua uses the C <code>longjmp</code> facility to yield a coroutine. +Therefore, if a C function <code>foo</code> calls an API function +and this API function yields +(directly or indirectly by calling another function that yields), +Lua cannot return to <code>foo</code> any more, +because the <code>longjmp</code> removes its frame from the C stack. + + +<p> +To avoid this kind of problem, +Lua raises an error whenever it tries to yield across an API call, +except for three functions: +<a href="#lua_yieldk"><code>lua_yieldk</code></a>, <a href="#lua_callk"><code>lua_callk</code></a>, and <a href="#lua_pcallk"><code>lua_pcallk</code></a>. +All those functions receive a <em>continuation function</em> +(as a parameter named <code>k</code>) to continue execution after a yield. + + +<p> +We need to set some terminology to explain continuations. +We have a C function called from Lua which we will call +the <em>original function</em>. +This original function then calls one of those three functions in the C API, +which we will call the <em>callee function</em>, +that then yields the current thread. +(This can happen when the callee function is <a href="#lua_yieldk"><code>lua_yieldk</code></a>, +or when the callee function is either <a href="#lua_callk"><code>lua_callk</code></a> or <a href="#lua_pcallk"><code>lua_pcallk</code></a> +and the function called by them yields.) + + +<p> +Suppose the running thread yields while executing the callee function. +After the thread resumes, +it eventually will finish running the callee function. +However, +the callee function cannot return to the original function, +because its frame in the C stack was destroyed by the yield. +Instead, Lua calls a <em>continuation function</em>, +which was given as an argument to the callee function. +As the name implies, +the continuation function should continue the task +of the original function. + + +<p> +As an illustration, consider the following function: + +<pre> + int original_function (lua_State *L) { + ... /* code 1 */ + status = lua_pcall(L, n, m, h); /* calls Lua */ + ... /* code 2 */ + } +</pre><p> +Now we want to allow +the Lua code being run by <a href="#lua_pcall"><code>lua_pcall</code></a> to yield. +First, we can rewrite our function like here: + +<pre> + int k (lua_State *L, int status, lua_KContext ctx) { + ... /* code 2 */ + } + + int original_function (lua_State *L) { + ... /* code 1 */ + return k(L, lua_pcall(L, n, m, h), ctx); + } +</pre><p> +In the above code, +the new function <code>k</code> is a +<em>continuation function</em> (with type <a href="#lua_KFunction"><code>lua_KFunction</code></a>), +which should do all the work that the original function +was doing after calling <a href="#lua_pcall"><code>lua_pcall</code></a>. +Now, we must inform Lua that it must call <code>k</code> if the Lua code +being executed by <a href="#lua_pcall"><code>lua_pcall</code></a> gets interrupted in some way +(errors or yielding), +so we rewrite the code as here, +replacing <a href="#lua_pcall"><code>lua_pcall</code></a> by <a href="#lua_pcallk"><code>lua_pcallk</code></a>: + +<pre> + int original_function (lua_State *L) { + ... /* code 1 */ + return k(L, lua_pcallk(L, n, m, h, ctx2, k), ctx1); + } +</pre><p> +Note the external, explicit call to the continuation: +Lua will call the continuation only if needed, that is, +in case of errors or resuming after a yield. +If the called function returns normally without ever yielding, +<a href="#lua_pcallk"><code>lua_pcallk</code></a> (and <a href="#lua_callk"><code>lua_callk</code></a>) will also return normally. +(Of course, instead of calling the continuation in that case, +you can do the equivalent work directly inside the original function.) + + +<p> +Besides the Lua state, +the continuation function has two other parameters: +the final status of the call plus the context value (<code>ctx</code>) that +was passed originally to <a href="#lua_pcallk"><code>lua_pcallk</code></a>. +(Lua does not use this context value; +it only passes this value from the original function to the +continuation function.) +For <a href="#lua_pcallk"><code>lua_pcallk</code></a>, +the status is the same value that would be returned by <a href="#lua_pcallk"><code>lua_pcallk</code></a>, +except that it is <a href="#pdf-LUA_YIELD"><code>LUA_YIELD</code></a> when being executed after a yield +(instead of <a href="#pdf-LUA_OK"><code>LUA_OK</code></a>). +For <a href="#lua_yieldk"><code>lua_yieldk</code></a> and <a href="#lua_callk"><code>lua_callk</code></a>, +the status is always <a href="#pdf-LUA_YIELD"><code>LUA_YIELD</code></a> when Lua calls the continuation. +(For these two functions, +Lua will not call the continuation in case of errors, +because they do not handle errors.) +Similarly, when using <a href="#lua_callk"><code>lua_callk</code></a>, +you should call the continuation function +with <a href="#pdf-LUA_OK"><code>LUA_OK</code></a> as the status. +(For <a href="#lua_yieldk"><code>lua_yieldk</code></a>, there is not much point in calling +directly the continuation function, +because <a href="#lua_yieldk"><code>lua_yieldk</code></a> usually does not return.) + + +<p> +Lua treats the continuation function as if it were the original function. +The continuation function receives the same Lua stack +from the original function, +in the same state it would be if the callee function had returned. +(For instance, +after a <a href="#lua_callk"><code>lua_callk</code></a> the function and its arguments are +removed from the stack and replaced by the results from the call.) +It also has the same upvalues. +Whatever it returns is handled by Lua as if it were the return +of the original function. + + + + + +<h2>4.8 – <a name="4.8">Functions and Types</a></h2> + +<p> +Here we list all functions and types from the C API in +alphabetical order. +Each function has an indicator like this: +<span class="apii">[-o, +p, <em>x</em>]</span> + + +<p> +The first field, <code>o</code>, +is how many elements the function pops from the stack. +The second field, <code>p</code>, +is how many elements the function pushes onto the stack. +(Any function always pushes its results after popping its arguments.) +A field in the form <code>x|y</code> means the function can push (or pop) +<code>x</code> or <code>y</code> elements, +depending on the situation; +an interrogation mark '<code>?</code>' means that +we cannot know how many elements the function pops/pushes +by looking only at its arguments +(e.g., they may depend on what is on the stack). +The third field, <code>x</code>, +tells whether the function may raise errors: +'<code>-</code>' means the function never raises any error; +'<code>e</code>' means the function may raise errors; +'<code>v</code>' means the function may raise an error on purpose. + + + +<hr><h3><a name="lua_absindex"><code>lua_absindex</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_absindex (lua_State *L, int idx);</pre> + +<p> +Converts the acceptable index <code>idx</code> into an absolute index +(that is, one that does not depend on the stack top). + + + + + +<hr><h3><a name="lua_Alloc"><code>lua_Alloc</code></a></h3> +<pre>typedef void * (*lua_Alloc) (void *ud, + void *ptr, + size_t osize, + size_t nsize);</pre> + +<p> +The type of the memory-allocation function used by Lua states. +The allocator function must provide a +functionality similar to <code>realloc</code>, +but not exactly the same. +Its arguments are +<code>ud</code>, an opaque pointer passed to <a href="#lua_newstate"><code>lua_newstate</code></a>; +<code>ptr</code>, a pointer to the block being allocated/reallocated/freed; +<code>osize</code>, the original size of the block or some code about what +is being allocated; +and <code>nsize</code>, the new size of the block. + + +<p> +When <code>ptr</code> is not <code>NULL</code>, +<code>osize</code> is the size of the block pointed by <code>ptr</code>, +that is, the size given when it was allocated or reallocated. + + +<p> +When <code>ptr</code> is <code>NULL</code>, +<code>osize</code> encodes the kind of object that Lua is allocating. +<code>osize</code> is any of +<a href="#pdf-LUA_TSTRING"><code>LUA_TSTRING</code></a>, <a href="#pdf-LUA_TTABLE"><code>LUA_TTABLE</code></a>, <a href="#pdf-LUA_TFUNCTION"><code>LUA_TFUNCTION</code></a>, +<a href="#pdf-LUA_TUSERDATA"><code>LUA_TUSERDATA</code></a>, or <a href="#pdf-LUA_TTHREAD"><code>LUA_TTHREAD</code></a> when (and only when) +Lua is creating a new object of that type. +When <code>osize</code> is some other value, +Lua is allocating memory for something else. + + +<p> +Lua assumes the following behavior from the allocator function: + + +<p> +When <code>nsize</code> is zero, +the allocator must behave like <code>free</code> +and return <code>NULL</code>. + + +<p> +When <code>nsize</code> is not zero, +the allocator must behave like <code>realloc</code>. +The allocator returns <code>NULL</code> +if and only if it cannot fulfill the request. +Lua assumes that the allocator never fails when +<code>osize >= nsize</code>. + + +<p> +Here is a simple implementation for the allocator function. +It is used in the auxiliary library by <a href="#luaL_newstate"><code>luaL_newstate</code></a>. + +<pre> + static void *l_alloc (void *ud, void *ptr, size_t osize, + size_t nsize) { + (void)ud; (void)osize; /* not used */ + if (nsize == 0) { + free(ptr); + return NULL; + } + else + return realloc(ptr, nsize); + } +</pre><p> +Note that Standard C ensures +that <code>free(NULL)</code> has no effect and that +<code>realloc(NULL,size)</code> is equivalent to <code>malloc(size)</code>. +This code assumes that <code>realloc</code> does not fail when shrinking a block. +(Although Standard C does not ensure this behavior, +it seems to be a safe assumption.) + + + + + +<hr><h3><a name="lua_arith"><code>lua_arith</code></a></h3><p> +<span class="apii">[-(2|1), +1, <em>e</em>]</span> +<pre>void lua_arith (lua_State *L, int op);</pre> + +<p> +Performs an arithmetic or bitwise operation over the two values +(or one, in the case of negations) +at the top of the stack, +with the value at the top being the second operand, +pops these values, and pushes the result of the operation. +The function follows the semantics of the corresponding Lua operator +(that is, it may call metamethods). + + +<p> +The value of <code>op</code> must be one of the following constants: + +<ul> + +<li><b><a name="pdf-LUA_OPADD"><code>LUA_OPADD</code></a>: </b> performs addition (<code>+</code>)</li> +<li><b><a name="pdf-LUA_OPSUB"><code>LUA_OPSUB</code></a>: </b> performs subtraction (<code>-</code>)</li> +<li><b><a name="pdf-LUA_OPMUL"><code>LUA_OPMUL</code></a>: </b> performs multiplication (<code>*</code>)</li> +<li><b><a name="pdf-LUA_OPDIV"><code>LUA_OPDIV</code></a>: </b> performs float division (<code>/</code>)</li> +<li><b><a name="pdf-LUA_OPIDIV"><code>LUA_OPIDIV</code></a>: </b> performs floor division (<code>//</code>)</li> +<li><b><a name="pdf-LUA_OPMOD"><code>LUA_OPMOD</code></a>: </b> performs modulo (<code>%</code>)</li> +<li><b><a name="pdf-LUA_OPPOW"><code>LUA_OPPOW</code></a>: </b> performs exponentiation (<code>^</code>)</li> +<li><b><a name="pdf-LUA_OPUNM"><code>LUA_OPUNM</code></a>: </b> performs mathematical negation (unary <code>-</code>)</li> +<li><b><a name="pdf-LUA_OPBNOT"><code>LUA_OPBNOT</code></a>: </b> performs bitwise negation (<code>~</code>)</li> +<li><b><a name="pdf-LUA_OPBAND"><code>LUA_OPBAND</code></a>: </b> performs bitwise and (<code>&</code>)</li> +<li><b><a name="pdf-LUA_OPBOR"><code>LUA_OPBOR</code></a>: </b> performs bitwise or (<code>|</code>)</li> +<li><b><a name="pdf-LUA_OPBXOR"><code>LUA_OPBXOR</code></a>: </b> performs bitwise exclusive or (<code>~</code>)</li> +<li><b><a name="pdf-LUA_OPSHL"><code>LUA_OPSHL</code></a>: </b> performs left shift (<code><<</code>)</li> +<li><b><a name="pdf-LUA_OPSHR"><code>LUA_OPSHR</code></a>: </b> performs right shift (<code>>></code>)</li> + +</ul> + + + + +<hr><h3><a name="lua_atpanic"><code>lua_atpanic</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf);</pre> + +<p> +Sets a new panic function and returns the old one (see <a href="#4.6">§4.6</a>). + + + + + +<hr><h3><a name="lua_call"><code>lua_call</code></a></h3><p> +<span class="apii">[-(nargs+1), +nresults, <em>e</em>]</span> +<pre>void lua_call (lua_State *L, int nargs, int nresults);</pre> + +<p> +Calls a function. + + +<p> +To call a function you must use the following protocol: +first, the function to be called is pushed onto the stack; +then, the arguments to the function are pushed +in direct order; +that is, the first argument is pushed first. +Finally you call <a href="#lua_call"><code>lua_call</code></a>; +<code>nargs</code> is the number of arguments that you pushed onto the stack. +All arguments and the function value are popped from the stack +when the function is called. +The function results are pushed onto the stack when the function returns. +The number of results is adjusted to <code>nresults</code>, +unless <code>nresults</code> is <a name="pdf-LUA_MULTRET"><code>LUA_MULTRET</code></a>. +In this case, all results from the function are pushed. +Lua takes care that the returned values fit into the stack space. +The function results are pushed onto the stack in direct order +(the first result is pushed first), +so that after the call the last result is on the top of the stack. + + +<p> +Any error inside the called function is propagated upwards +(with a <code>longjmp</code>). + + +<p> +The following example shows how the host program can do the +equivalent to this Lua code: + +<pre> + a = f("how", t.x, 14) +</pre><p> +Here it is in C: + +<pre> + lua_getglobal(L, "f"); /* function to be called */ + lua_pushliteral(L, "how"); /* 1st argument */ + lua_getglobal(L, "t"); /* table to be indexed */ + lua_getfield(L, -1, "x"); /* push result of t.x (2nd arg) */ + lua_remove(L, -2); /* remove 't' from the stack */ + lua_pushinteger(L, 14); /* 3rd argument */ + lua_call(L, 3, 1); /* call 'f' with 3 arguments and 1 result */ + lua_setglobal(L, "a"); /* set global 'a' */ +</pre><p> +Note that the code above is <em>balanced</em>: +at its end, the stack is back to its original configuration. +This is considered good programming practice. + + + + + +<hr><h3><a name="lua_callk"><code>lua_callk</code></a></h3><p> +<span class="apii">[-(nargs + 1), +nresults, <em>e</em>]</span> +<pre>void lua_callk (lua_State *L, + int nargs, + int nresults, + lua_KContext ctx, + lua_KFunction k);</pre> + +<p> +This function behaves exactly like <a href="#lua_call"><code>lua_call</code></a>, +but allows the called function to yield (see <a href="#4.7">§4.7</a>). + + + + + +<hr><h3><a name="lua_CFunction"><code>lua_CFunction</code></a></h3> +<pre>typedef int (*lua_CFunction) (lua_State *L);</pre> + +<p> +Type for C functions. + + +<p> +In order to communicate properly with Lua, +a C function must use the following protocol, +which defines the way parameters and results are passed: +a C function receives its arguments from Lua in its stack +in direct order (the first argument is pushed first). +So, when the function starts, +<code>lua_gettop(L)</code> returns the number of arguments received by the function. +The first argument (if any) is at index 1 +and its last argument is at index <code>lua_gettop(L)</code>. +To return values to Lua, a C function just pushes them onto the stack, +in direct order (the first result is pushed first), +and returns the number of results. +Any other value in the stack below the results will be properly +discarded by Lua. +Like a Lua function, a C function called by Lua can also return +many results. + + +<p> +As an example, the following function receives a variable number +of numerical arguments and returns their average and their sum: + +<pre> + static int foo (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + lua_Number sum = 0.0; + int i; + for (i = 1; i <= n; i++) { + if (!lua_isnumber(L, i)) { + lua_pushliteral(L, "incorrect argument"); + lua_error(L); + } + sum += lua_tonumber(L, i); + } + lua_pushnumber(L, sum/n); /* first result */ + lua_pushnumber(L, sum); /* second result */ + return 2; /* number of results */ + } +</pre> + + + + +<hr><h3><a name="lua_checkstack"><code>lua_checkstack</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_checkstack (lua_State *L, int n);</pre> + +<p> +Ensures that the stack has space for at least <code>n</code> extra slots. +It returns false if it cannot fulfill the request, +either because it would cause the stack +to be larger than a fixed maximum size +(typically at least several thousand elements) or +because it cannot allocate memory for the extra space. +This function never shrinks the stack; +if the stack is already larger than the new size, +it is left unchanged. + + + + + +<hr><h3><a name="lua_close"><code>lua_close</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void lua_close (lua_State *L);</pre> + +<p> +Destroys all objects in the given Lua state +(calling the corresponding garbage-collection metamethods, if any) +and frees all dynamic memory used by this state. +On several platforms, you may not need to call this function, +because all resources are naturally released when the host program ends. +On the other hand, long-running programs that create multiple states, +such as daemons or web servers, +will probably need to close states as soon as they are not needed. + + + + + +<hr><h3><a name="lua_compare"><code>lua_compare</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>int lua_compare (lua_State *L, int index1, int index2, int op);</pre> + +<p> +Compares two Lua values. +Returns 1 if the value at index <code>index1</code> satisfies <code>op</code> +when compared with the value at index <code>index2</code>, +following the semantics of the corresponding Lua operator +(that is, it may call metamethods). +Otherwise returns 0. +Also returns 0 if any of the indices is not valid. + + +<p> +The value of <code>op</code> must be one of the following constants: + +<ul> + +<li><b><a name="pdf-LUA_OPEQ"><code>LUA_OPEQ</code></a>: </b> compares for equality (<code>==</code>)</li> +<li><b><a name="pdf-LUA_OPLT"><code>LUA_OPLT</code></a>: </b> compares for less than (<code><</code>)</li> +<li><b><a name="pdf-LUA_OPLE"><code>LUA_OPLE</code></a>: </b> compares for less or equal (<code><=</code>)</li> + +</ul> + + + + +<hr><h3><a name="lua_concat"><code>lua_concat</code></a></h3><p> +<span class="apii">[-n, +1, <em>e</em>]</span> +<pre>void lua_concat (lua_State *L, int n);</pre> + +<p> +Concatenates the <code>n</code> values at the top of the stack, +pops them, and leaves the result at the top. +If <code>n</code> is 1, the result is the single value on the stack +(that is, the function does nothing); +if <code>n</code> is 0, the result is the empty string. +Concatenation is performed following the usual semantics of Lua +(see <a href="#3.4.6">§3.4.6</a>). + + + + + +<hr><h3><a name="lua_copy"><code>lua_copy</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void lua_copy (lua_State *L, int fromidx, int toidx);</pre> + +<p> +Copies the element at index <code>fromidx</code> +into the valid index <code>toidx</code>, +replacing the value at that position. +Values at other positions are not affected. + + + + + +<hr><h3><a name="lua_createtable"><code>lua_createtable</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void lua_createtable (lua_State *L, int narr, int nrec);</pre> + +<p> +Creates a new empty table and pushes it onto the stack. +Parameter <code>narr</code> is a hint for how many elements the table +will have as a sequence; +parameter <code>nrec</code> is a hint for how many other elements +the table will have. +Lua may use these hints to preallocate memory for the new table. +This pre-allocation is useful for performance when you know in advance +how many elements the table will have. +Otherwise you can use the function <a href="#lua_newtable"><code>lua_newtable</code></a>. + + + + + +<hr><h3><a name="lua_dump"><code>lua_dump</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>int lua_dump (lua_State *L, + lua_Writer writer, + void *data, + int strip);</pre> + +<p> +Dumps a function as a binary chunk. +Receives a Lua function on the top of the stack +and produces a binary chunk that, +if loaded again, +results in a function equivalent to the one dumped. +As it produces parts of the chunk, +<a href="#lua_dump"><code>lua_dump</code></a> calls function <code>writer</code> (see <a href="#lua_Writer"><code>lua_Writer</code></a>) +with the given <code>data</code> +to write them. + + +<p> +If <code>strip</code> is true, +the binary representation is created without debug information +about the function. + + +<p> +The value returned is the error code returned by the last +call to the writer; +0 means no errors. + + +<p> +This function does not pop the Lua function from the stack. + + + + + +<hr><h3><a name="lua_error"><code>lua_error</code></a></h3><p> +<span class="apii">[-1, +0, <em>v</em>]</span> +<pre>int lua_error (lua_State *L);</pre> + +<p> +Generates a Lua error, +using the value at the top of the stack as the error object. +This function does a long jump, +and therefore never returns +(see <a href="#luaL_error"><code>luaL_error</code></a>). + + + + + +<hr><h3><a name="lua_gc"><code>lua_gc</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>int lua_gc (lua_State *L, int what, int data);</pre> + +<p> +Controls the garbage collector. + + +<p> +This function performs several tasks, +according to the value of the parameter <code>what</code>: + +<ul> + +<li><b><code>LUA_GCSTOP</code>: </b> +stops the garbage collector. +</li> + +<li><b><code>LUA_GCRESTART</code>: </b> +restarts the garbage collector. +</li> + +<li><b><code>LUA_GCCOLLECT</code>: </b> +performs a full garbage-collection cycle. +</li> + +<li><b><code>LUA_GCCOUNT</code>: </b> +returns the current amount of memory (in Kbytes) in use by Lua. +</li> + +<li><b><code>LUA_GCCOUNTB</code>: </b> +returns the remainder of dividing the current amount of bytes of +memory in use by Lua by 1024. +</li> + +<li><b><code>LUA_GCSTEP</code>: </b> +performs an incremental step of garbage collection. +</li> + +<li><b><code>LUA_GCSETPAUSE</code>: </b> +sets <code>data</code> as the new value +for the <em>pause</em> of the collector (see <a href="#2.5">§2.5</a>) +and returns the previous value of the pause. +</li> + +<li><b><code>LUA_GCSETSTEPMUL</code>: </b> +sets <code>data</code> as the new value for the <em>step multiplier</em> of +the collector (see <a href="#2.5">§2.5</a>) +and returns the previous value of the step multiplier. +</li> + +<li><b><code>LUA_GCISRUNNING</code>: </b> +returns a boolean that tells whether the collector is running +(i.e., not stopped). +</li> + +</ul> + +<p> +For more details about these options, +see <a href="#pdf-collectgarbage"><code>collectgarbage</code></a>. + + + + + +<hr><h3><a name="lua_getallocf"><code>lua_getallocf</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_Alloc lua_getallocf (lua_State *L, void **ud);</pre> + +<p> +Returns the memory-allocation function of a given state. +If <code>ud</code> is not <code>NULL</code>, Lua stores in <code>*ud</code> the +opaque pointer given when the memory-allocator function was set. + + + + + +<hr><h3><a name="lua_getfield"><code>lua_getfield</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>int lua_getfield (lua_State *L, int index, const char *k);</pre> + +<p> +Pushes onto the stack the value <code>t[k]</code>, +where <code>t</code> is the value at the given index. +As in Lua, this function may trigger a metamethod +for the "index" event (see <a href="#2.4">§2.4</a>). + + +<p> +Returns the type of the pushed value. + + + + + +<hr><h3><a name="lua_getextraspace"><code>lua_getextraspace</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void *lua_getextraspace (lua_State *L);</pre> + +<p> +Returns a pointer to a raw memory area associated with the +given Lua state. +The application can use this area for any purpose; +Lua does not use it for anything. + + +<p> +Each new thread has this area initialized with a copy +of the area of the main thread. + + +<p> +By default, this area has the size of a pointer to void, +but you can recompile Lua with a different size for this area. +(See <code>LUA_EXTRASPACE</code> in <code>luaconf.h</code>.) + + + + + +<hr><h3><a name="lua_getglobal"><code>lua_getglobal</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>int lua_getglobal (lua_State *L, const char *name);</pre> + +<p> +Pushes onto the stack the value of the global <code>name</code>. +Returns the type of that value. + + + + + +<hr><h3><a name="lua_geti"><code>lua_geti</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>int lua_geti (lua_State *L, int index, lua_Integer i);</pre> + +<p> +Pushes onto the stack the value <code>t[i]</code>, +where <code>t</code> is the value at the given index. +As in Lua, this function may trigger a metamethod +for the "index" event (see <a href="#2.4">§2.4</a>). + + +<p> +Returns the type of the pushed value. + + + + + +<hr><h3><a name="lua_getmetatable"><code>lua_getmetatable</code></a></h3><p> +<span class="apii">[-0, +(0|1), –]</span> +<pre>int lua_getmetatable (lua_State *L, int index);</pre> + +<p> +If the value at the given index has a metatable, +the function pushes that metatable onto the stack and returns 1. +Otherwise, +the function returns 0 and pushes nothing on the stack. + + + + + +<hr><h3><a name="lua_gettable"><code>lua_gettable</code></a></h3><p> +<span class="apii">[-1, +1, <em>e</em>]</span> +<pre>int lua_gettable (lua_State *L, int index);</pre> + +<p> +Pushes onto the stack the value <code>t[k]</code>, +where <code>t</code> is the value at the given index +and <code>k</code> is the value at the top of the stack. + + +<p> +This function pops the key from the stack, +pushing the resulting value in its place. +As in Lua, this function may trigger a metamethod +for the "index" event (see <a href="#2.4">§2.4</a>). + + +<p> +Returns the type of the pushed value. + + + + + +<hr><h3><a name="lua_gettop"><code>lua_gettop</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_gettop (lua_State *L);</pre> + +<p> +Returns the index of the top element in the stack. +Because indices start at 1, +this result is equal to the number of elements in the stack; +in particular, 0 means an empty stack. + + + + + +<hr><h3><a name="lua_getuservalue"><code>lua_getuservalue</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int lua_getuservalue (lua_State *L, int index);</pre> + +<p> +Pushes onto the stack the Lua value associated with the userdata +at the given index. + + +<p> +Returns the type of the pushed value. + + + + + +<hr><h3><a name="lua_insert"><code>lua_insert</code></a></h3><p> +<span class="apii">[-1, +1, –]</span> +<pre>void lua_insert (lua_State *L, int index);</pre> + +<p> +Moves the top element into the given valid index, +shifting up the elements above this index to open space. +This function cannot be called with a pseudo-index, +because a pseudo-index is not an actual stack position. + + + + + +<hr><h3><a name="lua_Integer"><code>lua_Integer</code></a></h3> +<pre>typedef ... lua_Integer;</pre> + +<p> +The type of integers in Lua. + + +<p> +By default this type is <code>long long</code>, +(usually a 64-bit two-complement integer), +but that can be changed to <code>long</code> or <code>int</code> +(usually a 32-bit two-complement integer). +(See <code>LUA_INT</code> in <code>luaconf.h</code>.) + + +<p> +Lua also defines the constants +<a name="pdf-LUA_MININTEGER"><code>LUA_MININTEGER</code></a> and <a name="pdf-LUA_MAXINTEGER"><code>LUA_MAXINTEGER</code></a>, +with the minimum and the maximum values that fit in this type. + + + + + +<hr><h3><a name="lua_isboolean"><code>lua_isboolean</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isboolean (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a boolean, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_iscfunction"><code>lua_iscfunction</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_iscfunction (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a C function, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_isfunction"><code>lua_isfunction</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isfunction (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a function +(either C or Lua), and 0 otherwise. + + + + + +<hr><h3><a name="lua_isinteger"><code>lua_isinteger</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isinteger (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is an integer +(that is, the value is a number and is represented as an integer), +and 0 otherwise. + + + + + +<hr><h3><a name="lua_islightuserdata"><code>lua_islightuserdata</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_islightuserdata (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a light userdata, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_isnil"><code>lua_isnil</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isnil (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is <b>nil</b>, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_isnone"><code>lua_isnone</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isnone (lua_State *L, int index);</pre> + +<p> +Returns 1 if the given index is not valid, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_isnoneornil"><code>lua_isnoneornil</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isnoneornil (lua_State *L, int index);</pre> + +<p> +Returns 1 if the given index is not valid +or if the value at this index is <b>nil</b>, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_isnumber"><code>lua_isnumber</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isnumber (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a number +or a string convertible to a number, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_isstring"><code>lua_isstring</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isstring (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a string +or a number (which is always convertible to a string), +and 0 otherwise. + + + + + +<hr><h3><a name="lua_istable"><code>lua_istable</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_istable (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a table, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_isthread"><code>lua_isthread</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isthread (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a thread, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_isuserdata"><code>lua_isuserdata</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isuserdata (lua_State *L, int index);</pre> + +<p> +Returns 1 if the value at the given index is a userdata +(either full or light), and 0 otherwise. + + + + + +<hr><h3><a name="lua_isyieldable"><code>lua_isyieldable</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_isyieldable (lua_State *L);</pre> + +<p> +Returns 1 if the given coroutine can yield, +and 0 otherwise. + + + + + +<hr><h3><a name="lua_KContext"><code>lua_KContext</code></a></h3> +<pre>typedef ... lua_KContext;</pre> + +<p> +The type for continuation-function contexts. +It must be a numerical type. +This type is defined as <code>intptr_t</code> +when <code>intptr_t</code> is available, +so that it can store pointers too. +Otherwise, it is defined as <code>ptrdiff_t</code>. + + + + + +<hr><h3><a name="lua_KFunction"><code>lua_KFunction</code></a></h3> +<pre>typedef int (*lua_KFunction) (lua_State *L, int status, lua_KContext ctx);</pre> + +<p> +Type for continuation functions (see <a href="#4.7">§4.7</a>). + + + + + +<hr><h3><a name="lua_len"><code>lua_len</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void lua_len (lua_State *L, int index);</pre> + +<p> +Returns the length of the value at the given index. +It is equivalent to the '<code>#</code>' operator in Lua (see <a href="#3.4.7">§3.4.7</a>) and +may trigger a metamethod for the "length" event (see <a href="#2.4">§2.4</a>). +The result is pushed on the stack. + + + + + +<hr><h3><a name="lua_load"><code>lua_load</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int lua_load (lua_State *L, + lua_Reader reader, + void *data, + const char *chunkname, + const char *mode);</pre> + +<p> +Loads a Lua chunk without running it. +If there are no errors, +<code>lua_load</code> pushes the compiled chunk as a Lua +function on top of the stack. +Otherwise, it pushes an error message. + + +<p> +The return values of <code>lua_load</code> are: + +<ul> + +<li><b><a href="#pdf-LUA_OK"><code>LUA_OK</code></a>: </b> no errors;</li> + +<li><b><a name="pdf-LUA_ERRSYNTAX"><code>LUA_ERRSYNTAX</code></a>: </b> +syntax error during precompilation;</li> + +<li><b><a href="#pdf-LUA_ERRMEM"><code>LUA_ERRMEM</code></a>: </b> +memory allocation error;</li> + +<li><b><a href="#pdf-LUA_ERRGCMM"><code>LUA_ERRGCMM</code></a>: </b> +error while running a <code>__gc</code> metamethod. +(This error has no relation with the chunk being loaded. +It is generated by the garbage collector.) +</li> + +</ul> + +<p> +The <code>lua_load</code> function uses a user-supplied <code>reader</code> function +to read the chunk (see <a href="#lua_Reader"><code>lua_Reader</code></a>). +The <code>data</code> argument is an opaque value passed to the reader function. + + +<p> +The <code>chunkname</code> argument gives a name to the chunk, +which is used for error messages and in debug information (see <a href="#4.9">§4.9</a>). + + +<p> +<code>lua_load</code> automatically detects whether the chunk is text or binary +and loads it accordingly (see program <code>luac</code>). +The string <code>mode</code> works as in function <a href="#pdf-load"><code>load</code></a>, +with the addition that +a <code>NULL</code> value is equivalent to the string "<code>bt</code>". + + +<p> +<code>lua_load</code> uses the stack internally, +so the reader function must always leave the stack +unmodified when returning. + + +<p> +If the resulting function has upvalues, +its first upvalue is set to the value of the global environment +stored at index <code>LUA_RIDX_GLOBALS</code> in the registry (see <a href="#4.5">§4.5</a>). +When loading main chunks, +this upvalue will be the <code>_ENV</code> variable (see <a href="#2.2">§2.2</a>). +Other upvalues are initialized with <b>nil</b>. + + + + + +<hr><h3><a name="lua_newstate"><code>lua_newstate</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_State *lua_newstate (lua_Alloc f, void *ud);</pre> + +<p> +Creates a new thread running in a new, independent state. +Returns <code>NULL</code> if it cannot create the thread or the state +(due to lack of memory). +The argument <code>f</code> is the allocator function; +Lua does all memory allocation for this state through this function. +The second argument, <code>ud</code>, is an opaque pointer that Lua +passes to the allocator in every call. + + + + + +<hr><h3><a name="lua_newtable"><code>lua_newtable</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void lua_newtable (lua_State *L);</pre> + +<p> +Creates a new empty table and pushes it onto the stack. +It is equivalent to <code>lua_createtable(L, 0, 0)</code>. + + + + + +<hr><h3><a name="lua_newthread"><code>lua_newthread</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>lua_State *lua_newthread (lua_State *L);</pre> + +<p> +Creates a new thread, pushes it on the stack, +and returns a pointer to a <a href="#lua_State"><code>lua_State</code></a> that represents this new thread. +The new thread returned by this function shares with the original thread +its global environment, +but has an independent execution stack. + + +<p> +There is no explicit function to close or to destroy a thread. +Threads are subject to garbage collection, +like any Lua object. + + + + + +<hr><h3><a name="lua_newuserdata"><code>lua_newuserdata</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void *lua_newuserdata (lua_State *L, size_t size);</pre> + +<p> +This function allocates a new block of memory with the given size, +pushes onto the stack a new full userdata with the block address, +and returns this address. +The host program can freely use this memory. + + + + + +<hr><h3><a name="lua_next"><code>lua_next</code></a></h3><p> +<span class="apii">[-1, +(2|0), <em>e</em>]</span> +<pre>int lua_next (lua_State *L, int index);</pre> + +<p> +Pops a key from the stack, +and pushes a key–value pair from the table at the given index +(the "next" pair after the given key). +If there are no more elements in the table, +then <a href="#lua_next"><code>lua_next</code></a> returns 0 (and pushes nothing). + + +<p> +A typical traversal looks like this: + +<pre> + /* table is in the stack at index 't' */ + lua_pushnil(L); /* first key */ + while (lua_next(L, t) != 0) { + /* uses 'key' (at index -2) and 'value' (at index -1) */ + printf("%s - %s\n", + lua_typename(L, lua_type(L, -2)), + lua_typename(L, lua_type(L, -1))); + /* removes 'value'; keeps 'key' for next iteration */ + lua_pop(L, 1); + } +</pre> + +<p> +While traversing a table, +do not call <a href="#lua_tolstring"><code>lua_tolstring</code></a> directly on a key, +unless you know that the key is actually a string. +Recall that <a href="#lua_tolstring"><code>lua_tolstring</code></a> may change +the value at the given index; +this confuses the next call to <a href="#lua_next"><code>lua_next</code></a>. + + +<p> +See function <a href="#pdf-next"><code>next</code></a> for the caveats of modifying +the table during its traversal. + + + + + +<hr><h3><a name="lua_Number"><code>lua_Number</code></a></h3> +<pre>typedef double lua_Number;</pre> + +<p> +The type of floats in Lua. + + +<p> +By default this type is double, +but that can be changed to a single float. +(See <code>LUA_REAL</code> in <code>luaconf.h</code>.) + + + + + +<hr><h3><a name="lua_numbertointeger"><code>lua_numbertointeger</code></a></h3> +<pre>int lua_numbertointeger (lua_Number n, lua_Integer *p);</pre> + +<p> +Converts a Lua float to a Lua integer. +This macro assumes that <code>n</code> has an integral value. +If that value is within the range of Lua integers, +it is converted to an integer and assigned to <code>*p</code>. +The macro results in a boolean indicating whether the +conversion was successful. +(Note that this range test can be tricky to do +correctly without this macro, +due to roundings.) + + +<p> +This macro may evaluate its arguments more than once. + + + + + +<hr><h3><a name="lua_pcall"><code>lua_pcall</code></a></h3><p> +<span class="apii">[-(nargs + 1), +(nresults|1), –]</span> +<pre>int lua_pcall (lua_State *L, int nargs, int nresults, int msgh);</pre> + +<p> +Calls a function in protected mode. + + +<p> +Both <code>nargs</code> and <code>nresults</code> have the same meaning as +in <a href="#lua_call"><code>lua_call</code></a>. +If there are no errors during the call, +<a href="#lua_pcall"><code>lua_pcall</code></a> behaves exactly like <a href="#lua_call"><code>lua_call</code></a>. +However, if there is any error, +<a href="#lua_pcall"><code>lua_pcall</code></a> catches it, +pushes a single value on the stack (the error message), +and returns an error code. +Like <a href="#lua_call"><code>lua_call</code></a>, +<a href="#lua_pcall"><code>lua_pcall</code></a> always removes the function +and its arguments from the stack. + + +<p> +If <code>msgh</code> is 0, +then the error message returned on the stack +is exactly the original error message. +Otherwise, <code>msgh</code> is the stack index of a +<em>message handler</em>. +(In the current implementation, this index cannot be a pseudo-index.) +In case of runtime errors, +this function will be called with the error message +and its return value will be the message +returned on the stack by <a href="#lua_pcall"><code>lua_pcall</code></a>. + + +<p> +Typically, the message handler is used to add more debug +information to the error message, such as a stack traceback. +Such information cannot be gathered after the return of <a href="#lua_pcall"><code>lua_pcall</code></a>, +since by then the stack has unwound. + + +<p> +The <a href="#lua_pcall"><code>lua_pcall</code></a> function returns one of the following constants +(defined in <code>lua.h</code>): + +<ul> + +<li><b><a name="pdf-LUA_OK"><code>LUA_OK</code></a> (0): </b> +success.</li> + +<li><b><a name="pdf-LUA_ERRRUN"><code>LUA_ERRRUN</code></a>: </b> +a runtime error. +</li> + +<li><b><a name="pdf-LUA_ERRMEM"><code>LUA_ERRMEM</code></a>: </b> +memory allocation error. +For such errors, Lua does not call the message handler. +</li> + +<li><b><a name="pdf-LUA_ERRERR"><code>LUA_ERRERR</code></a>: </b> +error while running the message handler. +</li> + +<li><b><a name="pdf-LUA_ERRGCMM"><code>LUA_ERRGCMM</code></a>: </b> +error while running a <code>__gc</code> metamethod. +(This error typically has no relation with the function being called.) +</li> + +</ul> + + + + +<hr><h3><a name="lua_pcallk"><code>lua_pcallk</code></a></h3><p> +<span class="apii">[-(nargs + 1), +(nresults|1), –]</span> +<pre>int lua_pcallk (lua_State *L, + int nargs, + int nresults, + int msgh, + lua_KContext ctx, + lua_KFunction k);</pre> + +<p> +This function behaves exactly like <a href="#lua_pcall"><code>lua_pcall</code></a>, +but allows the called function to yield (see <a href="#4.7">§4.7</a>). + + + + + +<hr><h3><a name="lua_pop"><code>lua_pop</code></a></h3><p> +<span class="apii">[-n, +0, –]</span> +<pre>void lua_pop (lua_State *L, int n);</pre> + +<p> +Pops <code>n</code> elements from the stack. + + + + + +<hr><h3><a name="lua_pushboolean"><code>lua_pushboolean</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>void lua_pushboolean (lua_State *L, int b);</pre> + +<p> +Pushes a boolean value with value <code>b</code> onto the stack. + + + + + +<hr><h3><a name="lua_pushcclosure"><code>lua_pushcclosure</code></a></h3><p> +<span class="apii">[-n, +1, <em>e</em>]</span> +<pre>void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n);</pre> + +<p> +Pushes a new C closure onto the stack. + + +<p> +When a C function is created, +it is possible to associate some values with it, +thus creating a C closure (see <a href="#4.4">§4.4</a>); +these values are then accessible to the function whenever it is called. +To associate values with a C function, +first these values must be pushed onto the stack +(when there are multiple values, the first value is pushed first). +Then <a href="#lua_pushcclosure"><code>lua_pushcclosure</code></a> +is called to create and push the C function onto the stack, +with the argument <code>n</code> telling how many values will be +associated with the function. +<a href="#lua_pushcclosure"><code>lua_pushcclosure</code></a> also pops these values from the stack. + + +<p> +The maximum value for <code>n</code> is 255. + + +<p> +When <code>n</code> is zero, +this function creates a <em>light C function</em>, +which is just a pointer to the C function. +In that case, it never raises a memory error. + + + + + +<hr><h3><a name="lua_pushcfunction"><code>lua_pushcfunction</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>void lua_pushcfunction (lua_State *L, lua_CFunction f);</pre> + +<p> +Pushes a C function onto the stack. +This function receives a pointer to a C function +and pushes onto the stack a Lua value of type <code>function</code> that, +when called, invokes the corresponding C function. + + +<p> +Any function to be registered in Lua must +follow the correct protocol to receive its parameters +and return its results (see <a href="#lua_CFunction"><code>lua_CFunction</code></a>). + + +<p> +<code>lua_pushcfunction</code> is defined as a macro: + +<pre> + #define lua_pushcfunction(L,f) lua_pushcclosure(L,f,0) +</pre><p> +Note that <code>f</code> is used twice. + + + + + +<hr><h3><a name="lua_pushfstring"><code>lua_pushfstring</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>const char *lua_pushfstring (lua_State *L, const char *fmt, ...);</pre> + +<p> +Pushes onto the stack a formatted string +and returns a pointer to this string. +It is similar to the ISO C function <code>sprintf</code>, +but has some important differences: + +<ul> + +<li> +You do not have to allocate space for the result: +the result is a Lua string and Lua takes care of memory allocation +(and deallocation, through garbage collection). +</li> + +<li> +The conversion specifiers are quite restricted. +There are no flags, widths, or precisions. +The conversion specifiers can only be +'<code>%%</code>' (inserts the character '<code>%</code>'), +'<code>%s</code>' (inserts a zero-terminated string, with no size restrictions), +'<code>%f</code>' (inserts a <a href="#lua_Number"><code>lua_Number</code></a>), +'<code>%L</code>' (inserts a <a href="#lua_Integer"><code>lua_Integer</code></a>), +'<code>%p</code>' (inserts a pointer as a hexadecimal numeral), +'<code>%d</code>' (inserts an <code>int</code>), +'<code>%c</code>' (inserts an <code>int</code> as a one-byte character), and +'<code>%U</code>' (inserts a <code>long int</code> as a UTF-8 byte sequence). +</li> + +</ul> + + + + +<hr><h3><a name="lua_pushglobaltable"><code>lua_pushglobaltable</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>void lua_pushglobaltable (lua_State *L);</pre> + +<p> +Pushes the global environment onto the stack. + + + + + +<hr><h3><a name="lua_pushinteger"><code>lua_pushinteger</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>void lua_pushinteger (lua_State *L, lua_Integer n);</pre> + +<p> +Pushes an integer with value <code>n</code> onto the stack. + + + + + +<hr><h3><a name="lua_pushlightuserdata"><code>lua_pushlightuserdata</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>void lua_pushlightuserdata (lua_State *L, void *p);</pre> + +<p> +Pushes a light userdata onto the stack. + + +<p> +Userdata represent C values in Lua. +A <em>light userdata</em> represents a pointer, a <code>void*</code>. +It is a value (like a number): +you do not create it, it has no individual metatable, +and it is not collected (as it was never created). +A light userdata is equal to "any" +light userdata with the same C address. + + + + + +<hr><h3><a name="lua_pushliteral"><code>lua_pushliteral</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>const char *lua_pushliteral (lua_State *L, const char *s);</pre> + +<p> +This macro is equivalent to <a href="#lua_pushlstring"><code>lua_pushlstring</code></a>, +but can be used only when <code>s</code> is a literal string. +It automatically provides the string length. + + + + + +<hr><h3><a name="lua_pushlstring"><code>lua_pushlstring</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>const char *lua_pushlstring (lua_State *L, const char *s, size_t len);</pre> + +<p> +Pushes the string pointed to by <code>s</code> with size <code>len</code> +onto the stack. +Lua makes (or reuses) an internal copy of the given string, +so the memory at <code>s</code> can be freed or reused immediately after +the function returns. +The string can contain any binary data, +including embedded zeros. + + +<p> +Returns a pointer to the internal copy of the string. + + + + + +<hr><h3><a name="lua_pushnil"><code>lua_pushnil</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>void lua_pushnil (lua_State *L);</pre> + +<p> +Pushes a nil value onto the stack. + + + + + +<hr><h3><a name="lua_pushnumber"><code>lua_pushnumber</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>void lua_pushnumber (lua_State *L, lua_Number n);</pre> + +<p> +Pushes a float with value <code>n</code> onto the stack. + + + + + +<hr><h3><a name="lua_pushstring"><code>lua_pushstring</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>const char *lua_pushstring (lua_State *L, const char *s);</pre> + +<p> +Pushes the zero-terminated string pointed to by <code>s</code> +onto the stack. +Lua makes (or reuses) an internal copy of the given string, +so the memory at <code>s</code> can be freed or reused immediately after +the function returns. + + +<p> +Returns a pointer to the internal copy of the string. + + +<p> +If <code>s</code> is <code>NULL</code>, pushes <b>nil</b> and returns <code>NULL</code>. + + + + + +<hr><h3><a name="lua_pushthread"><code>lua_pushthread</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int lua_pushthread (lua_State *L);</pre> + +<p> +Pushes the thread represented by <code>L</code> onto the stack. +Returns 1 if this thread is the main thread of its state. + + + + + +<hr><h3><a name="lua_pushvalue"><code>lua_pushvalue</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>void lua_pushvalue (lua_State *L, int index);</pre> + +<p> +Pushes a copy of the element at the given index +onto the stack. + + + + + +<hr><h3><a name="lua_pushvfstring"><code>lua_pushvfstring</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>const char *lua_pushvfstring (lua_State *L, + const char *fmt, + va_list argp);</pre> + +<p> +Equivalent to <a href="#lua_pushfstring"><code>lua_pushfstring</code></a>, except that it receives a <code>va_list</code> +instead of a variable number of arguments. + + + + + +<hr><h3><a name="lua_rawequal"><code>lua_rawequal</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_rawequal (lua_State *L, int index1, int index2);</pre> + +<p> +Returns 1 if the two values in indices <code>index1</code> and +<code>index2</code> are primitively equal +(that is, without calling metamethods). +Otherwise returns 0. +Also returns 0 if any of the indices are not valid. + + + + + +<hr><h3><a name="lua_rawget"><code>lua_rawget</code></a></h3><p> +<span class="apii">[-1, +1, –]</span> +<pre>int lua_rawget (lua_State *L, int index);</pre> + +<p> +Similar to <a href="#lua_gettable"><code>lua_gettable</code></a>, but does a raw access +(i.e., without metamethods). + + + + + +<hr><h3><a name="lua_rawgeti"><code>lua_rawgeti</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int lua_rawgeti (lua_State *L, int index, lua_Integer n);</pre> + +<p> +Pushes onto the stack the value <code>t[n]</code>, +where <code>t</code> is the table at the given index. +The access is raw; +that is, it does not invoke metamethods. + + +<p> +Returns the type of the pushed value. + + + + + +<hr><h3><a name="lua_rawgetp"><code>lua_rawgetp</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int lua_rawgetp (lua_State *L, int index, const void *p);</pre> + +<p> +Pushes onto the stack the value <code>t[k]</code>, +where <code>t</code> is the table at the given index and +<code>k</code> is the pointer <code>p</code> represented as a light userdata. +The access is raw; +that is, it does not invoke metamethods. + + +<p> +Returns the type of the pushed value. + + + + + +<hr><h3><a name="lua_rawlen"><code>lua_rawlen</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>size_t lua_rawlen (lua_State *L, int index);</pre> + +<p> +Returns the raw "length" of the value at the given index: +for strings, this is the string length; +for tables, this is the result of the length operator ('<code>#</code>') +with no metamethods; +for userdata, this is the size of the block of memory allocated +for the userdata; +for other values, it is 0. + + + + + +<hr><h3><a name="lua_rawset"><code>lua_rawset</code></a></h3><p> +<span class="apii">[-2, +0, <em>e</em>]</span> +<pre>void lua_rawset (lua_State *L, int index);</pre> + +<p> +Similar to <a href="#lua_settable"><code>lua_settable</code></a>, but does a raw assignment +(i.e., without metamethods). + + + + + +<hr><h3><a name="lua_rawseti"><code>lua_rawseti</code></a></h3><p> +<span class="apii">[-1, +0, <em>e</em>]</span> +<pre>void lua_rawseti (lua_State *L, int index, lua_Integer i);</pre> + +<p> +Does the equivalent of <code>t[i] = v</code>, +where <code>t</code> is the table at the given index +and <code>v</code> is the value at the top of the stack. + + +<p> +This function pops the value from the stack. +The assignment is raw; +that is, it does not invoke metamethods. + + + + + +<hr><h3><a name="lua_rawsetp"><code>lua_rawsetp</code></a></h3><p> +<span class="apii">[-1, +0, <em>e</em>]</span> +<pre>void lua_rawsetp (lua_State *L, int index, const void *p);</pre> + +<p> +Does the equivalent of <code>t[k] = v</code>, +where <code>t</code> is the table at the given index, +<code>k</code> is the pointer <code>p</code> represented as a light userdata, +and <code>v</code> is the value at the top of the stack. + + +<p> +This function pops the value from the stack. +The assignment is raw; +that is, it does not invoke metamethods. + + + + + +<hr><h3><a name="lua_Reader"><code>lua_Reader</code></a></h3> +<pre>typedef const char * (*lua_Reader) (lua_State *L, + void *data, + size_t *size);</pre> + +<p> +The reader function used by <a href="#lua_load"><code>lua_load</code></a>. +Every time it needs another piece of the chunk, +<a href="#lua_load"><code>lua_load</code></a> calls the reader, +passing along its <code>data</code> parameter. +The reader must return a pointer to a block of memory +with a new piece of the chunk +and set <code>size</code> to the block size. +The block must exist until the reader function is called again. +To signal the end of the chunk, +the reader must return <code>NULL</code> or set <code>size</code> to zero. +The reader function may return pieces of any size greater than zero. + + + + + +<hr><h3><a name="lua_register"><code>lua_register</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>void lua_register (lua_State *L, const char *name, lua_CFunction f);</pre> + +<p> +Sets the C function <code>f</code> as the new value of global <code>name</code>. +It is defined as a macro: + +<pre> + #define lua_register(L,n,f) \ + (lua_pushcfunction(L, f), lua_setglobal(L, n)) +</pre> + + + + +<hr><h3><a name="lua_remove"><code>lua_remove</code></a></h3><p> +<span class="apii">[-1, +0, –]</span> +<pre>void lua_remove (lua_State *L, int index);</pre> + +<p> +Removes the element at the given valid index, +shifting down the elements above this index to fill the gap. +This function cannot be called with a pseudo-index, +because a pseudo-index is not an actual stack position. + + + + + +<hr><h3><a name="lua_replace"><code>lua_replace</code></a></h3><p> +<span class="apii">[-1, +0, –]</span> +<pre>void lua_replace (lua_State *L, int index);</pre> + +<p> +Moves the top element into the given valid index +without shifting any element +(therefore replacing the value at the given index), +and then pops the top element. + + + + + +<hr><h3><a name="lua_resume"><code>lua_resume</code></a></h3><p> +<span class="apii">[-?, +?, –]</span> +<pre>int lua_resume (lua_State *L, lua_State *from, int nargs);</pre> + +<p> +Starts and resumes a coroutine in a given thread. + + +<p> +To start a coroutine, +you push onto the thread stack the main function plus any arguments; +then you call <a href="#lua_resume"><code>lua_resume</code></a>, +with <code>nargs</code> being the number of arguments. +This call returns when the coroutine suspends or finishes its execution. +When it returns, the stack contains all values passed to <a href="#lua_yield"><code>lua_yield</code></a>, +or all values returned by the body function. +<a href="#lua_resume"><code>lua_resume</code></a> returns +<a href="#pdf-LUA_YIELD"><code>LUA_YIELD</code></a> if the coroutine yields, +<a href="#pdf-LUA_OK"><code>LUA_OK</code></a> if the coroutine finishes its execution +without errors, +or an error code in case of errors (see <a href="#lua_pcall"><code>lua_pcall</code></a>). + + +<p> +In case of errors, +the stack is not unwound, +so you can use the debug API over it. +The error message is on the top of the stack. + + +<p> +To resume a coroutine, +you remove any results from the last <a href="#lua_yield"><code>lua_yield</code></a>, +put on its stack only the values to +be passed as results from <code>yield</code>, +and then call <a href="#lua_resume"><code>lua_resume</code></a>. + + +<p> +The parameter <code>from</code> represents the coroutine that is resuming <code>L</code>. +If there is no such coroutine, +this parameter can be <code>NULL</code>. + + + + + +<hr><h3><a name="lua_rotate"><code>lua_rotate</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void lua_rotate (lua_State *L, int idx, int n);</pre> + +<p> +Rotates the stack elements from <code>idx</code> to the top <code>n</code> positions +in the direction of the top, for a positive <code>n</code>, +or <code>-n</code> positions in the direction of the bottom, +for a negative <code>n</code>. +The absolute value of <code>n</code> must not be greater than the size +of the slice being rotated. + + + + + +<hr><h3><a name="lua_setallocf"><code>lua_setallocf</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void lua_setallocf (lua_State *L, lua_Alloc f, void *ud);</pre> + +<p> +Changes the allocator function of a given state to <code>f</code> +with user data <code>ud</code>. + + + + + +<hr><h3><a name="lua_setfield"><code>lua_setfield</code></a></h3><p> +<span class="apii">[-1, +0, <em>e</em>]</span> +<pre>void lua_setfield (lua_State *L, int index, const char *k);</pre> + +<p> +Does the equivalent to <code>t[k] = v</code>, +where <code>t</code> is the value at the given index +and <code>v</code> is the value at the top of the stack. + + +<p> +This function pops the value from the stack. +As in Lua, this function may trigger a metamethod +for the "newindex" event (see <a href="#2.4">§2.4</a>). + + + + + +<hr><h3><a name="lua_setglobal"><code>lua_setglobal</code></a></h3><p> +<span class="apii">[-1, +0, <em>e</em>]</span> +<pre>void lua_setglobal (lua_State *L, const char *name);</pre> + +<p> +Pops a value from the stack and +sets it as the new value of global <code>name</code>. + + + + + +<hr><h3><a name="lua_seti"><code>lua_seti</code></a></h3><p> +<span class="apii">[-1, +0, <em>e</em>]</span> +<pre>void lua_seti (lua_State *L, int index, lua_Integer n);</pre> + +<p> +Does the equivalent to <code>t[n] = v</code>, +where <code>t</code> is the value at the given index +and <code>v</code> is the value at the top of the stack. + + +<p> +This function pops the value from the stack. +As in Lua, this function may trigger a metamethod +for the "newindex" event (see <a href="#2.4">§2.4</a>). + + + + + +<hr><h3><a name="lua_setmetatable"><code>lua_setmetatable</code></a></h3><p> +<span class="apii">[-1, +0, –]</span> +<pre>void lua_setmetatable (lua_State *L, int index);</pre> + +<p> +Pops a table from the stack and +sets it as the new metatable for the value at the given index. + + + + + +<hr><h3><a name="lua_settable"><code>lua_settable</code></a></h3><p> +<span class="apii">[-2, +0, <em>e</em>]</span> +<pre>void lua_settable (lua_State *L, int index);</pre> + +<p> +Does the equivalent to <code>t[k] = v</code>, +where <code>t</code> is the value at the given index, +<code>v</code> is the value at the top of the stack, +and <code>k</code> is the value just below the top. + + +<p> +This function pops both the key and the value from the stack. +As in Lua, this function may trigger a metamethod +for the "newindex" event (see <a href="#2.4">§2.4</a>). + + + + + +<hr><h3><a name="lua_settop"><code>lua_settop</code></a></h3><p> +<span class="apii">[-?, +?, –]</span> +<pre>void lua_settop (lua_State *L, int index);</pre> + +<p> +Accepts any index, or 0, +and sets the stack top to this index. +If the new top is larger than the old one, +then the new elements are filled with <b>nil</b>. +If <code>index</code> is 0, then all stack elements are removed. + + + + + +<hr><h3><a name="lua_setuservalue"><code>lua_setuservalue</code></a></h3><p> +<span class="apii">[-1, +0, –]</span> +<pre>void lua_setuservalue (lua_State *L, int index);</pre> + +<p> +Pops a value from the stack and sets it as +the new value associated to the userdata at the given index. + + + + + +<hr><h3><a name="lua_State"><code>lua_State</code></a></h3> +<pre>typedef struct lua_State lua_State;</pre> + +<p> +An opaque structure that points to a thread and indirectly +(through the thread) to the whole state of a Lua interpreter. +The Lua library is fully reentrant: +it has no global variables. +All information about a state is accessible through this structure. + + +<p> +A pointer to this structure must be passed as the first argument to +every function in the library, except to <a href="#lua_newstate"><code>lua_newstate</code></a>, +which creates a Lua state from scratch. + + + + + +<hr><h3><a name="lua_status"><code>lua_status</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_status (lua_State *L);</pre> + +<p> +Returns the status of the thread <code>L</code>. + + +<p> +The status can be 0 (<a href="#pdf-LUA_OK"><code>LUA_OK</code></a>) for a normal thread, +an error code if the thread finished the execution +of a <a href="#lua_resume"><code>lua_resume</code></a> with an error, +or <a name="pdf-LUA_YIELD"><code>LUA_YIELD</code></a> if the thread is suspended. + + +<p> +You can only call functions in threads with status <a href="#pdf-LUA_OK"><code>LUA_OK</code></a>. +You can resume threads with status <a href="#pdf-LUA_OK"><code>LUA_OK</code></a> +(to start a new coroutine) or <a href="#pdf-LUA_YIELD"><code>LUA_YIELD</code></a> +(to resume a coroutine). + + + + + +<hr><h3><a name="lua_stringtonumber"><code>lua_stringtonumber</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>size_t lua_stringtonumber (lua_State *L, const char *s);</pre> + +<p> +Converts the zero-terminated string <code>s</code> to a number, +pushes that number into the stack, +and returns the total size of the string, +that is, its length plus one. +The conversion can result in an integer or a float, +according to the lexical conventions of Lua (see <a href="#3.1">§3.1</a>). +The string may have leading and trailing spaces and a sign. +If the string is not a valid numeral, +returns 0 and pushes nothing. +(Note that the result can be used as a boolean, +true if the conversion succeeds.) + + + + + +<hr><h3><a name="lua_toboolean"><code>lua_toboolean</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_toboolean (lua_State *L, int index);</pre> + +<p> +Converts the Lua value at the given index to a C boolean +value (0 or 1). +Like all tests in Lua, +<a href="#lua_toboolean"><code>lua_toboolean</code></a> returns true for any Lua value +different from <b>false</b> and <b>nil</b>; +otherwise it returns false. +(If you want to accept only actual boolean values, +use <a href="#lua_isboolean"><code>lua_isboolean</code></a> to test the value's type.) + + + + + +<hr><h3><a name="lua_tocfunction"><code>lua_tocfunction</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_CFunction lua_tocfunction (lua_State *L, int index);</pre> + +<p> +Converts a value at the given index to a C function. +That value must be a C function; +otherwise, returns <code>NULL</code>. + + + + + +<hr><h3><a name="lua_tointeger"><code>lua_tointeger</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_Integer lua_tointeger (lua_State *L, int index);</pre> + +<p> +Equivalent to <a href="#lua_tointegerx"><code>lua_tointegerx</code></a> with <code>isnum</code> equal to <code>NULL</code>. + + + + + +<hr><h3><a name="lua_tointegerx"><code>lua_tointegerx</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_Integer lua_tointegerx (lua_State *L, int index, int *isnum);</pre> + +<p> +Converts the Lua value at the given index +to the signed integral type <a href="#lua_Integer"><code>lua_Integer</code></a>. +The Lua value must be an integer, +or a number or string convertible to an integer (see <a href="#3.4.3">§3.4.3</a>); +otherwise, <code>lua_tointegerx</code> returns 0. + + +<p> +If <code>isnum</code> is not <code>NULL</code>, +its referent is assigned a boolean value that +indicates whether the operation succeeded. + + + + + +<hr><h3><a name="lua_tolstring"><code>lua_tolstring</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>const char *lua_tolstring (lua_State *L, int index, size_t *len);</pre> + +<p> +Converts the Lua value at the given index to a C string. +If <code>len</code> is not <code>NULL</code>, +it also sets <code>*len</code> with the string length. +The Lua value must be a string or a number; +otherwise, the function returns <code>NULL</code>. +If the value is a number, +then <code>lua_tolstring</code> also +<em>changes the actual value in the stack to a string</em>. +(This change confuses <a href="#lua_next"><code>lua_next</code></a> +when <code>lua_tolstring</code> is applied to keys during a table traversal.) + + +<p> +<code>lua_tolstring</code> returns a fully aligned pointer +to a string inside the Lua state. +This string always has a zero ('<code>\0</code>') +after its last character (as in C), +but can contain other zeros in its body. + + +<p> +Because Lua has garbage collection, +there is no guarantee that the pointer returned by <code>lua_tolstring</code> +will be valid after the corresponding Lua value is removed from the stack. + + + + + +<hr><h3><a name="lua_tonumber"><code>lua_tonumber</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_Number lua_tonumber (lua_State *L, int index);</pre> + +<p> +Equivalent to <a href="#lua_tonumberx"><code>lua_tonumberx</code></a> with <code>isnum</code> equal to <code>NULL</code>. + + + + + +<hr><h3><a name="lua_tonumberx"><code>lua_tonumberx</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_Number lua_tonumberx (lua_State *L, int index, int *isnum);</pre> + +<p> +Converts the Lua value at the given index +to the C type <a href="#lua_Number"><code>lua_Number</code></a> (see <a href="#lua_Number"><code>lua_Number</code></a>). +The Lua value must be a number or a string convertible to a number +(see <a href="#3.4.3">§3.4.3</a>); +otherwise, <a href="#lua_tonumberx"><code>lua_tonumberx</code></a> returns 0. + + +<p> +If <code>isnum</code> is not <code>NULL</code>, +its referent is assigned a boolean value that +indicates whether the operation succeeded. + + + + + +<hr><h3><a name="lua_topointer"><code>lua_topointer</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>const void *lua_topointer (lua_State *L, int index);</pre> + +<p> +Converts the value at the given index to a generic +C pointer (<code>void*</code>). +The value can be a userdata, a table, a thread, or a function; +otherwise, <code>lua_topointer</code> returns <code>NULL</code>. +Different objects will give different pointers. +There is no way to convert the pointer back to its original value. + + +<p> +Typically this function is used only for debug information. + + + + + +<hr><h3><a name="lua_tostring"><code>lua_tostring</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>const char *lua_tostring (lua_State *L, int index);</pre> + +<p> +Equivalent to <a href="#lua_tolstring"><code>lua_tolstring</code></a> with <code>len</code> equal to <code>NULL</code>. + + + + + +<hr><h3><a name="lua_tothread"><code>lua_tothread</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_State *lua_tothread (lua_State *L, int index);</pre> + +<p> +Converts the value at the given index to a Lua thread +(represented as <code>lua_State*</code>). +This value must be a thread; +otherwise, the function returns <code>NULL</code>. + + + + + +<hr><h3><a name="lua_touserdata"><code>lua_touserdata</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void *lua_touserdata (lua_State *L, int index);</pre> + +<p> +If the value at the given index is a full userdata, +returns its block address. +If the value is a light userdata, +returns its pointer. +Otherwise, returns <code>NULL</code>. + + + + + +<hr><h3><a name="lua_type"><code>lua_type</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_type (lua_State *L, int index);</pre> + +<p> +Returns the type of the value in the given valid index, +or <code>LUA_TNONE</code> for a non-valid (but acceptable) index. +The types returned by <a href="#lua_type"><code>lua_type</code></a> are coded by the following constants +defined in <code>lua.h</code>: +<a name="pdf-LUA_TNIL"><code>LUA_TNIL</code></a>, +<a name="pdf-LUA_TNUMBER"><code>LUA_TNUMBER</code></a>, +<a name="pdf-LUA_TBOOLEAN"><code>LUA_TBOOLEAN</code></a>, +<a name="pdf-LUA_TSTRING"><code>LUA_TSTRING</code></a>, +<a name="pdf-LUA_TTABLE"><code>LUA_TTABLE</code></a>, +<a name="pdf-LUA_TFUNCTION"><code>LUA_TFUNCTION</code></a>, +<a name="pdf-LUA_TUSERDATA"><code>LUA_TUSERDATA</code></a>, +<a name="pdf-LUA_TTHREAD"><code>LUA_TTHREAD</code></a>, +and +<a name="pdf-LUA_TLIGHTUSERDATA"><code>LUA_TLIGHTUSERDATA</code></a>. + + + + + +<hr><h3><a name="lua_typename"><code>lua_typename</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>const char *lua_typename (lua_State *L, int tp);</pre> + +<p> +Returns the name of the type encoded by the value <code>tp</code>, +which must be one the values returned by <a href="#lua_type"><code>lua_type</code></a>. + + + + + +<hr><h3><a name="lua_Unsigned"><code>lua_Unsigned</code></a></h3> +<pre>typedef ... lua_Unsigned;</pre> + +<p> +The unsigned version of <a href="#lua_Integer"><code>lua_Integer</code></a>. + + + + + +<hr><h3><a name="lua_upvalueindex"><code>lua_upvalueindex</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_upvalueindex (int i);</pre> + +<p> +Returns the pseudo-index that represents the <code>i</code>-th upvalue of +the running function (see <a href="#4.4">§4.4</a>). + + + + + +<hr><h3><a name="lua_version"><code>lua_version</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>const lua_Number *lua_version (lua_State *L);</pre> + +<p> +Returns the address of the version number stored in the Lua core. +When called with a valid <a href="#lua_State"><code>lua_State</code></a>, +returns the address of the version used to create that state. +When called with <code>NULL</code>, +returns the address of the version running the call. + + + + + +<hr><h3><a name="lua_Writer"><code>lua_Writer</code></a></h3> +<pre>typedef int (*lua_Writer) (lua_State *L, + const void* p, + size_t sz, + void* ud);</pre> + +<p> +The type of the writer function used by <a href="#lua_dump"><code>lua_dump</code></a>. +Every time it produces another piece of chunk, +<a href="#lua_dump"><code>lua_dump</code></a> calls the writer, +passing along the buffer to be written (<code>p</code>), +its size (<code>sz</code>), +and the <code>data</code> parameter supplied to <a href="#lua_dump"><code>lua_dump</code></a>. + + +<p> +The writer returns an error code: +0 means no errors; +any other value means an error and stops <a href="#lua_dump"><code>lua_dump</code></a> from +calling the writer again. + + + + + +<hr><h3><a name="lua_xmove"><code>lua_xmove</code></a></h3><p> +<span class="apii">[-?, +?, –]</span> +<pre>void lua_xmove (lua_State *from, lua_State *to, int n);</pre> + +<p> +Exchange values between different threads of the same state. + + +<p> +This function pops <code>n</code> values from the stack <code>from</code>, +and pushes them onto the stack <code>to</code>. + + + + + +<hr><h3><a name="lua_yield"><code>lua_yield</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>int lua_yield (lua_State *L, int nresults);</pre> + +<p> +This function is equivalent to <a href="#lua_yieldk"><code>lua_yieldk</code></a>, +but it has no continuation (see <a href="#4.7">§4.7</a>). +Therefore, when the thread resumes, +it continues the function that called +the function calling <code>lua_yield</code>. + + + + + +<hr><h3><a name="lua_yieldk"><code>lua_yieldk</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>int lua_yieldk (lua_State *L, + int nresults, + lua_KContext ctx, + lua_KFunction k);</pre> + +<p> +Yields a coroutine (thread). + + +<p> +When a C function calls <a href="#lua_yieldk"><code>lua_yieldk</code></a>, +the running coroutine suspends its execution, +and the call to <a href="#lua_resume"><code>lua_resume</code></a> that started this coroutine returns. +The parameter <code>nresults</code> is the number of values from the stack +that will be passed as results to <a href="#lua_resume"><code>lua_resume</code></a>. + + +<p> +When the coroutine is resumed again, +Lua calls the given continuation function <code>k</code> to continue +the execution of the C function that yielded (see <a href="#4.7">§4.7</a>). +This continuation function receives the same stack +from the previous function, +with the <code>n</code> results removed and +replaced by the arguments passed to <a href="#lua_resume"><code>lua_resume</code></a>. +Moreover, +the continuation function receives the value <code>ctx</code> +that was passed to <a href="#lua_yieldk"><code>lua_yieldk</code></a>. + + +<p> +Usually, this function does not return; +when the coroutine eventually resumes, +it continues executing the continuation function. +However, there is one special case, +which is when this function is called +from inside a line hook (see <a href="#4.9">§4.9</a>). +In that case, <code>lua_yieldk</code> should be called with no continuation +(probably in the form of <a href="#lua_yield"><code>lua_yield</code></a>), +and the hook should return immediately after the call. +Lua will yield and, +when the coroutine resumes again, +it will continue the normal execution +of the (Lua) function that triggered the hook. + + +<p> +This function can raise an error if it is called from a thread +with a pending C call with no continuation function, +or it is called from a thread that is not running inside a resume +(e.g., the main thread). + + + + + + + +<h2>4.9 – <a name="4.9">The Debug Interface</a></h2> + +<p> +Lua has no built-in debugging facilities. +Instead, it offers a special interface +by means of functions and <em>hooks</em>. +This interface allows the construction of different +kinds of debuggers, profilers, and other tools +that need "inside information" from the interpreter. + + + +<hr><h3><a name="lua_Debug"><code>lua_Debug</code></a></h3> +<pre>typedef struct lua_Debug { + int event; + const char *name; /* (n) */ + const char *namewhat; /* (n) */ + const char *what; /* (S) */ + const char *source; /* (S) */ + int currentline; /* (l) */ + int linedefined; /* (S) */ + int lastlinedefined; /* (S) */ + unsigned char nups; /* (u) number of upvalues */ + unsigned char nparams; /* (u) number of parameters */ + char isvararg; /* (u) */ + char istailcall; /* (t) */ + char short_src[LUA_IDSIZE]; /* (S) */ + /* private part */ + <em>other fields</em> +} lua_Debug;</pre> + +<p> +A structure used to carry different pieces of +information about a function or an activation record. +<a href="#lua_getstack"><code>lua_getstack</code></a> fills only the private part +of this structure, for later use. +To fill the other fields of <a href="#lua_Debug"><code>lua_Debug</code></a> with useful information, +call <a href="#lua_getinfo"><code>lua_getinfo</code></a>. + + +<p> +The fields of <a href="#lua_Debug"><code>lua_Debug</code></a> have the following meaning: + +<ul> + +<li><b><code>source</code>: </b> +the name of the chunk that created the function. +If <code>source</code> starts with a '<code>@</code>', +it means that the function was defined in a file where +the file name follows the '<code>@</code>'. +If <code>source</code> starts with a '<code>=</code>', +the remainder of its contents describe the source in a user-dependent manner. +Otherwise, +the function was defined in a string where +<code>source</code> is that string. +</li> + +<li><b><code>short_src</code>: </b> +a "printable" version of <code>source</code>, to be used in error messages. +</li> + +<li><b><code>linedefined</code>: </b> +the line number where the definition of the function starts. +</li> + +<li><b><code>lastlinedefined</code>: </b> +the line number where the definition of the function ends. +</li> + +<li><b><code>what</code>: </b> +the string <code>"Lua"</code> if the function is a Lua function, +<code>"C"</code> if it is a C function, +<code>"main"</code> if it is the main part of a chunk. +</li> + +<li><b><code>currentline</code>: </b> +the current line where the given function is executing. +When no line information is available, +<code>currentline</code> is set to -1. +</li> + +<li><b><code>name</code>: </b> +a reasonable name for the given function. +Because functions in Lua are first-class values, +they do not have a fixed name: +some functions can be the value of multiple global variables, +while others can be stored only in a table field. +The <code>lua_getinfo</code> function checks how the function was +called to find a suitable name. +If it cannot find a name, +then <code>name</code> is set to <code>NULL</code>. +</li> + +<li><b><code>namewhat</code>: </b> +explains the <code>name</code> field. +The value of <code>namewhat</code> can be +<code>"global"</code>, <code>"local"</code>, <code>"method"</code>, +<code>"field"</code>, <code>"upvalue"</code>, or <code>""</code> (the empty string), +according to how the function was called. +(Lua uses the empty string when no other option seems to apply.) +</li> + +<li><b><code>istailcall</code>: </b> +true if this function invocation was called by a tail call. +In this case, the caller of this level is not in the stack. +</li> + +<li><b><code>nups</code>: </b> +the number of upvalues of the function. +</li> + +<li><b><code>nparams</code>: </b> +the number of fixed parameters of the function +(always 0 for C functions). +</li> + +<li><b><code>isvararg</code>: </b> +true if the function is a vararg function +(always true for C functions). +</li> + +</ul> + + + + +<hr><h3><a name="lua_gethook"><code>lua_gethook</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_Hook lua_gethook (lua_State *L);</pre> + +<p> +Returns the current hook function. + + + + + +<hr><h3><a name="lua_gethookcount"><code>lua_gethookcount</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_gethookcount (lua_State *L);</pre> + +<p> +Returns the current hook count. + + + + + +<hr><h3><a name="lua_gethookmask"><code>lua_gethookmask</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_gethookmask (lua_State *L);</pre> + +<p> +Returns the current hook mask. + + + + + +<hr><h3><a name="lua_getinfo"><code>lua_getinfo</code></a></h3><p> +<span class="apii">[-(0|1), +(0|1|2), <em>e</em>]</span> +<pre>int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar);</pre> + +<p> +Gets information about a specific function or function invocation. + + +<p> +To get information about a function invocation, +the parameter <code>ar</code> must be a valid activation record that was +filled by a previous call to <a href="#lua_getstack"><code>lua_getstack</code></a> or +given as argument to a hook (see <a href="#lua_Hook"><code>lua_Hook</code></a>). + + +<p> +To get information about a function you push it onto the stack +and start the <code>what</code> string with the character '<code>></code>'. +(In that case, +<code>lua_getinfo</code> pops the function from the top of the stack.) +For instance, to know in which line a function <code>f</code> was defined, +you can write the following code: + +<pre> + lua_Debug ar; + lua_getglobal(L, "f"); /* get global 'f' */ + lua_getinfo(L, ">S", &ar); + printf("%d\n", ar.linedefined); +</pre> + +<p> +Each character in the string <code>what</code> +selects some fields of the structure <code>ar</code> to be filled or +a value to be pushed on the stack: + +<ul> + +<li><b>'<code>n</code>': </b> fills in the field <code>name</code> and <code>namewhat</code>; +</li> + +<li><b>'<code>S</code>': </b> +fills in the fields <code>source</code>, <code>short_src</code>, +<code>linedefined</code>, <code>lastlinedefined</code>, and <code>what</code>; +</li> + +<li><b>'<code>l</code>': </b> fills in the field <code>currentline</code>; +</li> + +<li><b>'<code>t</code>': </b> fills in the field <code>istailcall</code>; +</li> + +<li><b>'<code>u</code>': </b> fills in the fields +<code>nups</code>, <code>nparams</code>, and <code>isvararg</code>; +</li> + +<li><b>'<code>f</code>': </b> +pushes onto the stack the function that is +running at the given level; +</li> + +<li><b>'<code>L</code>': </b> +pushes onto the stack a table whose indices are the +numbers of the lines that are valid on the function. +(A <em>valid line</em> is a line with some associated code, +that is, a line where you can put a break point. +Non-valid lines include empty lines and comments.) + + +<p> +If this option is given together with option '<code>f</code>', +its table is pushed after the function. +</li> + +</ul> + +<p> +This function returns 0 on error +(for instance, an invalid option in <code>what</code>). + + + + + +<hr><h3><a name="lua_getlocal"><code>lua_getlocal</code></a></h3><p> +<span class="apii">[-0, +(0|1), –]</span> +<pre>const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n);</pre> + +<p> +Gets information about a local variable of +a given activation record or a given function. + + +<p> +In the first case, +the parameter <code>ar</code> must be a valid activation record that was +filled by a previous call to <a href="#lua_getstack"><code>lua_getstack</code></a> or +given as argument to a hook (see <a href="#lua_Hook"><code>lua_Hook</code></a>). +The index <code>n</code> selects which local variable to inspect; +see <a href="#pdf-debug.getlocal"><code>debug.getlocal</code></a> for details about variable indices +and names. + + +<p> +<a href="#lua_getlocal"><code>lua_getlocal</code></a> pushes the variable's value onto the stack +and returns its name. + + +<p> +In the second case, <code>ar</code> must be <code>NULL</code> and the function +to be inspected must be at the top of the stack. +In this case, only parameters of Lua functions are visible +(as there is no information about what variables are active) +and no values are pushed onto the stack. + + +<p> +Returns <code>NULL</code> (and pushes nothing) +when the index is greater than +the number of active local variables. + + + + + +<hr><h3><a name="lua_getstack"><code>lua_getstack</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>int lua_getstack (lua_State *L, int level, lua_Debug *ar);</pre> + +<p> +Gets information about the interpreter runtime stack. + + +<p> +This function fills parts of a <a href="#lua_Debug"><code>lua_Debug</code></a> structure with +an identification of the <em>activation record</em> +of the function executing at a given level. +Level 0 is the current running function, +whereas level <em>n+1</em> is the function that has called level <em>n</em> +(except for tail calls, which do not count on the stack). +When there are no errors, <a href="#lua_getstack"><code>lua_getstack</code></a> returns 1; +when called with a level greater than the stack depth, +it returns 0. + + + + + +<hr><h3><a name="lua_getupvalue"><code>lua_getupvalue</code></a></h3><p> +<span class="apii">[-0, +(0|1), –]</span> +<pre>const char *lua_getupvalue (lua_State *L, int funcindex, int n);</pre> + +<p> +Gets information about a closure's upvalue. +(For Lua functions, +upvalues are the external local variables that the function uses, +and that are consequently included in its closure.) +<a href="#lua_getupvalue"><code>lua_getupvalue</code></a> gets the index <code>n</code> of an upvalue, +pushes the upvalue's value onto the stack, +and returns its name. +<code>funcindex</code> points to the closure in the stack. +(Upvalues have no particular order, +as they are active through the whole function. +So, they are numbered in an arbitrary order.) + + +<p> +Returns <code>NULL</code> (and pushes nothing) +when the index is greater than the number of upvalues. +For C functions, this function uses the empty string <code>""</code> +as a name for all upvalues. + + + + + +<hr><h3><a name="lua_Hook"><code>lua_Hook</code></a></h3> +<pre>typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar);</pre> + +<p> +Type for debugging hook functions. + + +<p> +Whenever a hook is called, its <code>ar</code> argument has its field +<code>event</code> set to the specific event that triggered the hook. +Lua identifies these events with the following constants: +<a name="pdf-LUA_HOOKCALL"><code>LUA_HOOKCALL</code></a>, <a name="pdf-LUA_HOOKRET"><code>LUA_HOOKRET</code></a>, +<a name="pdf-LUA_HOOKTAILCALL"><code>LUA_HOOKTAILCALL</code></a>, <a name="pdf-LUA_HOOKLINE"><code>LUA_HOOKLINE</code></a>, +and <a name="pdf-LUA_HOOKCOUNT"><code>LUA_HOOKCOUNT</code></a>. +Moreover, for line events, the field <code>currentline</code> is also set. +To get the value of any other field in <code>ar</code>, +the hook must call <a href="#lua_getinfo"><code>lua_getinfo</code></a>. + + +<p> +For call events, <code>event</code> can be <code>LUA_HOOKCALL</code>, +the normal value, or <code>LUA_HOOKTAILCALL</code>, for a tail call; +in this case, there will be no corresponding return event. + + +<p> +While Lua is running a hook, it disables other calls to hooks. +Therefore, if a hook calls back Lua to execute a function or a chunk, +this execution occurs without any calls to hooks. + + +<p> +Hook functions cannot have continuations, +that is, they cannot call <a href="#lua_yieldk"><code>lua_yieldk</code></a>, +<a href="#lua_pcallk"><code>lua_pcallk</code></a>, or <a href="#lua_callk"><code>lua_callk</code></a> with a non-null <code>k</code>. + + +<p> +Hook functions can yield under the following conditions: +Only count and line events can yield +and they cannot yield any value; +to yield a hook function must finish its execution +calling <a href="#lua_yield"><code>lua_yield</code></a> with <code>nresults</code> equal to zero. + + + + + +<hr><h3><a name="lua_sethook"><code>lua_sethook</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void lua_sethook (lua_State *L, lua_Hook f, int mask, int count);</pre> + +<p> +Sets the debugging hook function. + + +<p> +Argument <code>f</code> is the hook function. +<code>mask</code> specifies on which events the hook will be called: +it is formed by a bitwise or of the constants +<a name="pdf-LUA_MASKCALL"><code>LUA_MASKCALL</code></a>, +<a name="pdf-LUA_MASKRET"><code>LUA_MASKRET</code></a>, +<a name="pdf-LUA_MASKLINE"><code>LUA_MASKLINE</code></a>, +and <a name="pdf-LUA_MASKCOUNT"><code>LUA_MASKCOUNT</code></a>. +The <code>count</code> argument is only meaningful when the mask +includes <code>LUA_MASKCOUNT</code>. +For each event, the hook is called as explained below: + +<ul> + +<li><b>The call hook: </b> is called when the interpreter calls a function. +The hook is called just after Lua enters the new function, +before the function gets its arguments. +</li> + +<li><b>The return hook: </b> is called when the interpreter returns from a function. +The hook is called just before Lua leaves the function. +There is no standard way to access the values +to be returned by the function. +</li> + +<li><b>The line hook: </b> is called when the interpreter is about to +start the execution of a new line of code, +or when it jumps back in the code (even to the same line). +(This event only happens while Lua is executing a Lua function.) +</li> + +<li><b>The count hook: </b> is called after the interpreter executes every +<code>count</code> instructions. +(This event only happens while Lua is executing a Lua function.) +</li> + +</ul> + +<p> +A hook is disabled by setting <code>mask</code> to zero. + + + + + +<hr><h3><a name="lua_setlocal"><code>lua_setlocal</code></a></h3><p> +<span class="apii">[-(0|1), +0, –]</span> +<pre>const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n);</pre> + +<p> +Sets the value of a local variable of a given activation record. +Parameters <code>ar</code> and <code>n</code> are as in <a href="#lua_getlocal"><code>lua_getlocal</code></a> +(see <a href="#lua_getlocal"><code>lua_getlocal</code></a>). +<a href="#lua_setlocal"><code>lua_setlocal</code></a> assigns the value at the top of the stack +to the variable and returns its name. +It also pops the value from the stack. + + +<p> +Returns <code>NULL</code> (and pops nothing) +when the index is greater than +the number of active local variables. + + + + + +<hr><h3><a name="lua_setupvalue"><code>lua_setupvalue</code></a></h3><p> +<span class="apii">[-(0|1), +0, –]</span> +<pre>const char *lua_setupvalue (lua_State *L, int funcindex, int n);</pre> + +<p> +Sets the value of a closure's upvalue. +It assigns the value at the top of the stack +to the upvalue and returns its name. +It also pops the value from the stack. +Parameters <code>funcindex</code> and <code>n</code> are as in the <a href="#lua_getupvalue"><code>lua_getupvalue</code></a> +(see <a href="#lua_getupvalue"><code>lua_getupvalue</code></a>). + + +<p> +Returns <code>NULL</code> (and pops nothing) +when the index is greater than the number of upvalues. + + + + + +<hr><h3><a name="lua_upvalueid"><code>lua_upvalueid</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void *lua_upvalueid (lua_State *L, int funcindex, int n);</pre> + +<p> +Returns a unique identifier for the upvalue numbered <code>n</code> +from the closure at index <code>funcindex</code>. +Parameters <code>funcindex</code> and <code>n</code> are as in the <a href="#lua_getupvalue"><code>lua_getupvalue</code></a> +(see <a href="#lua_getupvalue"><code>lua_getupvalue</code></a>) +(but <code>n</code> cannot be greater than the number of upvalues). + + +<p> +These unique identifiers allow a program to check whether different +closures share upvalues. +Lua closures that share an upvalue +(that is, that access a same external local variable) +will return identical ids for those upvalue indices. + + + + + +<hr><h3><a name="lua_upvaluejoin"><code>lua_upvaluejoin</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void lua_upvaluejoin (lua_State *L, int funcindex1, int n1, + int funcindex2, int n2);</pre> + +<p> +Make the <code>n1</code>-th upvalue of the Lua closure at index <code>funcindex1</code> +refer to the <code>n2</code>-th upvalue of the Lua closure at index <code>funcindex2</code>. + + + + + + + +<h1>5 – <a name="5">The Auxiliary Library</a></h1> + +<p> + +The <em>auxiliary library</em> provides several convenient functions +to interface C with Lua. +While the basic API provides the primitive functions for all +interactions between C and Lua, +the auxiliary library provides higher-level functions for some +common tasks. + + +<p> +All functions and types from the auxiliary library +are defined in header file <code>lauxlib.h</code> and +have a prefix <code>luaL_</code>. + + +<p> +All functions in the auxiliary library are built on +top of the basic API, +and so they provide nothing that cannot be done with that API. +Nevertheless, the use of the auxiliary library ensures +more consistency to your code. + + +<p> +Several functions in the auxiliary library use internally some +extra stack slots. +When a function in the auxiliary library uses less than five slots, +it does not check the stack size; +it simply assumes that there are enough slots. + + +<p> +Several functions in the auxiliary library are used to +check C function arguments. +Because the error message is formatted for arguments +(e.g., "<code>bad argument #1</code>"), +you should not use these functions for other stack values. + + +<p> +Functions called <code>luaL_check*</code> +always raise an error if the check is not satisfied. + + + +<h2>5.1 – <a name="5.1">Functions and Types</a></h2> + +<p> +Here we list all functions and types from the auxiliary library +in alphabetical order. + + + +<hr><h3><a name="luaL_addchar"><code>luaL_addchar</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>void luaL_addchar (luaL_Buffer *B, char c);</pre> + +<p> +Adds the byte <code>c</code> to the buffer <code>B</code> +(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>). + + + + + +<hr><h3><a name="luaL_addlstring"><code>luaL_addlstring</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l);</pre> + +<p> +Adds the string pointed to by <code>s</code> with length <code>l</code> to +the buffer <code>B</code> +(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>). +The string can contain embedded zeros. + + + + + +<hr><h3><a name="luaL_addsize"><code>luaL_addsize</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>void luaL_addsize (luaL_Buffer *B, size_t n);</pre> + +<p> +Adds to the buffer <code>B</code> (see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>) +a string of length <code>n</code> previously copied to the +buffer area (see <a href="#luaL_prepbuffer"><code>luaL_prepbuffer</code></a>). + + + + + +<hr><h3><a name="luaL_addstring"><code>luaL_addstring</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>void luaL_addstring (luaL_Buffer *B, const char *s);</pre> + +<p> +Adds the zero-terminated string pointed to by <code>s</code> +to the buffer <code>B</code> +(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>). + + + + + +<hr><h3><a name="luaL_addvalue"><code>luaL_addvalue</code></a></h3><p> +<span class="apii">[-1, +?, <em>e</em>]</span> +<pre>void luaL_addvalue (luaL_Buffer *B);</pre> + +<p> +Adds the value at the top of the stack +to the buffer <code>B</code> +(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>). +Pops the value. + + +<p> +This is the only function on string buffers that can (and must) +be called with an extra element on the stack, +which is the value to be added to the buffer. + + + + + +<hr><h3><a name="luaL_argcheck"><code>luaL_argcheck</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>void luaL_argcheck (lua_State *L, + int cond, + int arg, + const char *extramsg);</pre> + +<p> +Checks whether <code>cond</code> is true. +If it is not, raises an error with a standard message (see <a href="#luaL_argerror"><code>luaL_argerror</code></a>). + + + + + +<hr><h3><a name="luaL_argerror"><code>luaL_argerror</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>int luaL_argerror (lua_State *L, int arg, const char *extramsg);</pre> + +<p> +Raises an error reporting a problem with argument <code>arg</code> +of the C function that called it, +using a standard message +that includes <code>extramsg</code> as a comment: + +<pre> + bad argument #<em>arg</em> to '<em>funcname</em>' (<em>extramsg</em>) +</pre><p> +This function never returns. + + + + + +<hr><h3><a name="luaL_Buffer"><code>luaL_Buffer</code></a></h3> +<pre>typedef struct luaL_Buffer luaL_Buffer;</pre> + +<p> +Type for a <em>string buffer</em>. + + +<p> +A string buffer allows C code to build Lua strings piecemeal. +Its pattern of use is as follows: + +<ul> + +<li>First declare a variable <code>b</code> of type <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>.</li> + +<li>Then initialize it with a call <code>luaL_buffinit(L, &b)</code>.</li> + +<li> +Then add string pieces to the buffer calling any of +the <code>luaL_add*</code> functions. +</li> + +<li> +Finish by calling <code>luaL_pushresult(&b)</code>. +This call leaves the final string on the top of the stack. +</li> + +</ul> + +<p> +If you know beforehand the total size of the resulting string, +you can use the buffer like this: + +<ul> + +<li>First declare a variable <code>b</code> of type <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>.</li> + +<li>Then initialize it and preallocate a space of +size <code>sz</code> with a call <code>luaL_buffinitsize(L, &b, sz)</code>.</li> + +<li>Then copy the string into that space.</li> + +<li> +Finish by calling <code>luaL_pushresultsize(&b, sz)</code>, +where <code>sz</code> is the total size of the resulting string +copied into that space. +</li> + +</ul> + +<p> +During its normal operation, +a string buffer uses a variable number of stack slots. +So, while using a buffer, you cannot assume that you know where +the top of the stack is. +You can use the stack between successive calls to buffer operations +as long as that use is balanced; +that is, +when you call a buffer operation, +the stack is at the same level +it was immediately after the previous buffer operation. +(The only exception to this rule is <a href="#luaL_addvalue"><code>luaL_addvalue</code></a>.) +After calling <a href="#luaL_pushresult"><code>luaL_pushresult</code></a> the stack is back to its +level when the buffer was initialized, +plus the final string on its top. + + + + + +<hr><h3><a name="luaL_buffinit"><code>luaL_buffinit</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void luaL_buffinit (lua_State *L, luaL_Buffer *B);</pre> + +<p> +Initializes a buffer <code>B</code>. +This function does not allocate any space; +the buffer must be declared as a variable +(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>). + + + + + +<hr><h3><a name="luaL_buffinitsize"><code>luaL_buffinitsize</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz);</pre> + +<p> +Equivalent to the sequence +<a href="#luaL_buffinit"><code>luaL_buffinit</code></a>, <a href="#luaL_prepbuffsize"><code>luaL_prepbuffsize</code></a>. + + + + + +<hr><h3><a name="luaL_callmeta"><code>luaL_callmeta</code></a></h3><p> +<span class="apii">[-0, +(0|1), <em>e</em>]</span> +<pre>int luaL_callmeta (lua_State *L, int obj, const char *e);</pre> + +<p> +Calls a metamethod. + + +<p> +If the object at index <code>obj</code> has a metatable and this +metatable has a field <code>e</code>, +this function calls this field passing the object as its only argument. +In this case this function returns true and pushes onto the +stack the value returned by the call. +If there is no metatable or no metamethod, +this function returns false (without pushing any value on the stack). + + + + + +<hr><h3><a name="luaL_checkany"><code>luaL_checkany</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>void luaL_checkany (lua_State *L, int arg);</pre> + +<p> +Checks whether the function has an argument +of any type (including <b>nil</b>) at position <code>arg</code>. + + + + + +<hr><h3><a name="luaL_checkinteger"><code>luaL_checkinteger</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>lua_Integer luaL_checkinteger (lua_State *L, int arg);</pre> + +<p> +Checks whether the function argument <code>arg</code> is an integer +(or can be converted to an integer) +and returns this integer cast to a <a href="#lua_Integer"><code>lua_Integer</code></a>. + + + + + +<hr><h3><a name="luaL_checklstring"><code>luaL_checklstring</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>const char *luaL_checklstring (lua_State *L, int arg, size_t *l);</pre> + +<p> +Checks whether the function argument <code>arg</code> is a string +and returns this string; +if <code>l</code> is not <code>NULL</code> fills <code>*l</code> +with the string's length. + + +<p> +This function uses <a href="#lua_tolstring"><code>lua_tolstring</code></a> to get its result, +so all conversions and caveats of that function apply here. + + + + + +<hr><h3><a name="luaL_checknumber"><code>luaL_checknumber</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>lua_Number luaL_checknumber (lua_State *L, int arg);</pre> + +<p> +Checks whether the function argument <code>arg</code> is a number +and returns this number. + + + + + +<hr><h3><a name="luaL_checkoption"><code>luaL_checkoption</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>int luaL_checkoption (lua_State *L, + int arg, + const char *def, + const char *const lst[]);</pre> + +<p> +Checks whether the function argument <code>arg</code> is a string and +searches for this string in the array <code>lst</code> +(which must be NULL-terminated). +Returns the index in the array where the string was found. +Raises an error if the argument is not a string or +if the string cannot be found. + + +<p> +If <code>def</code> is not <code>NULL</code>, +the function uses <code>def</code> as a default value when +there is no argument <code>arg</code> or when this argument is <b>nil</b>. + + +<p> +This is a useful function for mapping strings to C enums. +(The usual convention in Lua libraries is +to use strings instead of numbers to select options.) + + + + + +<hr><h3><a name="luaL_checkstack"><code>luaL_checkstack</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>void luaL_checkstack (lua_State *L, int sz, const char *msg);</pre> + +<p> +Grows the stack size to <code>top + sz</code> elements, +raising an error if the stack cannot grow to that size. +<code>msg</code> is an additional text to go into the error message +(or <code>NULL</code> for no additional text). + + + + + +<hr><h3><a name="luaL_checkstring"><code>luaL_checkstring</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>const char *luaL_checkstring (lua_State *L, int arg);</pre> + +<p> +Checks whether the function argument <code>arg</code> is a string +and returns this string. + + +<p> +This function uses <a href="#lua_tolstring"><code>lua_tolstring</code></a> to get its result, +so all conversions and caveats of that function apply here. + + + + + +<hr><h3><a name="luaL_checktype"><code>luaL_checktype</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>void luaL_checktype (lua_State *L, int arg, int t);</pre> + +<p> +Checks whether the function argument <code>arg</code> has type <code>t</code>. +See <a href="#lua_type"><code>lua_type</code></a> for the encoding of types for <code>t</code>. + + + + + +<hr><h3><a name="luaL_checkudata"><code>luaL_checkudata</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>void *luaL_checkudata (lua_State *L, int arg, const char *tname);</pre> + +<p> +Checks whether the function argument <code>arg</code> is a userdata +of the type <code>tname</code> (see <a href="#luaL_newmetatable"><code>luaL_newmetatable</code></a>) and +returns the userdata address (see <a href="#lua_touserdata"><code>lua_touserdata</code></a>). + + + + + +<hr><h3><a name="luaL_checkversion"><code>luaL_checkversion</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void luaL_checkversion (lua_State *L);</pre> + +<p> +Checks whether the core running the call, +the core that created the Lua state, +and the code making the call are all using the same version of Lua. +Also checks whether the core running the call +and the core that created the Lua state +are using the same address space. + + + + + +<hr><h3><a name="luaL_dofile"><code>luaL_dofile</code></a></h3><p> +<span class="apii">[-0, +?, <em>e</em>]</span> +<pre>int luaL_dofile (lua_State *L, const char *filename);</pre> + +<p> +Loads and runs the given file. +It is defined as the following macro: + +<pre> + (luaL_loadfile(L, filename) || lua_pcall(L, 0, LUA_MULTRET, 0)) +</pre><p> +It returns false if there are no errors +or true in case of errors. + + + + + +<hr><h3><a name="luaL_dostring"><code>luaL_dostring</code></a></h3><p> +<span class="apii">[-0, +?, –]</span> +<pre>int luaL_dostring (lua_State *L, const char *str);</pre> + +<p> +Loads and runs the given string. +It is defined as the following macro: + +<pre> + (luaL_loadstring(L, str) || lua_pcall(L, 0, LUA_MULTRET, 0)) +</pre><p> +It returns false if there are no errors +or true in case of errors. + + + + + +<hr><h3><a name="luaL_error"><code>luaL_error</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>int luaL_error (lua_State *L, const char *fmt, ...);</pre> + +<p> +Raises an error. +The error message format is given by <code>fmt</code> +plus any extra arguments, +following the same rules of <a href="#lua_pushfstring"><code>lua_pushfstring</code></a>. +It also adds at the beginning of the message the file name and +the line number where the error occurred, +if this information is available. + + +<p> +This function never returns, +but it is an idiom to use it in C functions +as <code>return luaL_error(<em>args</em>)</code>. + + + + + +<hr><h3><a name="luaL_execresult"><code>luaL_execresult</code></a></h3><p> +<span class="apii">[-0, +3, <em>e</em>]</span> +<pre>int luaL_execresult (lua_State *L, int stat);</pre> + +<p> +This function produces the return values for +process-related functions in the standard library +(<a href="#pdf-os.execute"><code>os.execute</code></a> and <a href="#pdf-io.close"><code>io.close</code></a>). + + + + + +<hr><h3><a name="luaL_fileresult"><code>luaL_fileresult</code></a></h3><p> +<span class="apii">[-0, +(1|3), <em>e</em>]</span> +<pre>int luaL_fileresult (lua_State *L, int stat, const char *fname);</pre> + +<p> +This function produces the return values for +file-related functions in the standard library +(<a href="#pdf-io.open"><code>io.open</code></a>, <a href="#pdf-os.rename"><code>os.rename</code></a>, <a href="#pdf-file:seek"><code>file:seek</code></a>, etc.). + + + + + +<hr><h3><a name="luaL_getmetafield"><code>luaL_getmetafield</code></a></h3><p> +<span class="apii">[-0, +(0|1), <em>e</em>]</span> +<pre>int luaL_getmetafield (lua_State *L, int obj, const char *e);</pre> + +<p> +Pushes onto the stack the field <code>e</code> from the metatable +of the object at index <code>obj</code> and returns the type of pushed value. +If the object does not have a metatable, +or if the metatable does not have this field, +pushes nothing and returns <code>LUA_TNIL</code>. + + + + + +<hr><h3><a name="luaL_getmetatable"><code>luaL_getmetatable</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int luaL_getmetatable (lua_State *L, const char *tname);</pre> + +<p> +Pushes onto the stack the metatable associated with name <code>tname</code> +in the registry (see <a href="#luaL_newmetatable"><code>luaL_newmetatable</code></a>). +If there is no metatable associated with <code>tname</code>, +returns false and pushes <b>nil</b>. + + + + + +<hr><h3><a name="luaL_getsubtable"><code>luaL_getsubtable</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>int luaL_getsubtable (lua_State *L, int idx, const char *fname);</pre> + +<p> +Ensures that the value <code>t[fname]</code>, +where <code>t</code> is the value at index <code>idx</code>, +is a table, +and pushes that table onto the stack. +Returns true if it finds a previous table there +and false if it creates a new table. + + + + + +<hr><h3><a name="luaL_gsub"><code>luaL_gsub</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>const char *luaL_gsub (lua_State *L, + const char *s, + const char *p, + const char *r);</pre> + +<p> +Creates a copy of string <code>s</code> by replacing +any occurrence of the string <code>p</code> +with the string <code>r</code>. +Pushes the resulting string on the stack and returns it. + + + + + +<hr><h3><a name="luaL_len"><code>luaL_len</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>lua_Integer luaL_len (lua_State *L, int index);</pre> + +<p> +Returns the "length" of the value at the given index +as a number; +it is equivalent to the '<code>#</code>' operator in Lua (see <a href="#3.4.7">§3.4.7</a>). +Raises an error if the result of the operation is not an integer. +(This case only can happen through metamethods.) + + + + + +<hr><h3><a name="luaL_loadbuffer"><code>luaL_loadbuffer</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int luaL_loadbuffer (lua_State *L, + const char *buff, + size_t sz, + const char *name);</pre> + +<p> +Equivalent to <a href="#luaL_loadbufferx"><code>luaL_loadbufferx</code></a> with <code>mode</code> equal to <code>NULL</code>. + + + + + +<hr><h3><a name="luaL_loadbufferx"><code>luaL_loadbufferx</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int luaL_loadbufferx (lua_State *L, + const char *buff, + size_t sz, + const char *name, + const char *mode);</pre> + +<p> +Loads a buffer as a Lua chunk. +This function uses <a href="#lua_load"><code>lua_load</code></a> to load the chunk in the +buffer pointed to by <code>buff</code> with size <code>sz</code>. + + +<p> +This function returns the same results as <a href="#lua_load"><code>lua_load</code></a>. +<code>name</code> is the chunk name, +used for debug information and error messages. +The string <code>mode</code> works as in function <a href="#lua_load"><code>lua_load</code></a>. + + + + + +<hr><h3><a name="luaL_loadfile"><code>luaL_loadfile</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>int luaL_loadfile (lua_State *L, const char *filename);</pre> + +<p> +Equivalent to <a href="#luaL_loadfilex"><code>luaL_loadfilex</code></a> with <code>mode</code> equal to <code>NULL</code>. + + + + + +<hr><h3><a name="luaL_loadfilex"><code>luaL_loadfilex</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>int luaL_loadfilex (lua_State *L, const char *filename, + const char *mode);</pre> + +<p> +Loads a file as a Lua chunk. +This function uses <a href="#lua_load"><code>lua_load</code></a> to load the chunk in the file +named <code>filename</code>. +If <code>filename</code> is <code>NULL</code>, +then it loads from the standard input. +The first line in the file is ignored if it starts with a <code>#</code>. + + +<p> +The string <code>mode</code> works as in function <a href="#lua_load"><code>lua_load</code></a>. + + +<p> +This function returns the same results as <a href="#lua_load"><code>lua_load</code></a>, +but it has an extra error code <a name="pdf-LUA_ERRFILE"><code>LUA_ERRFILE</code></a> +if it cannot open/read the file or the file has a wrong mode. + + +<p> +As <a href="#lua_load"><code>lua_load</code></a>, this function only loads the chunk; +it does not run it. + + + + + +<hr><h3><a name="luaL_loadstring"><code>luaL_loadstring</code></a></h3><p> +<span class="apii">[-0, +1, –]</span> +<pre>int luaL_loadstring (lua_State *L, const char *s);</pre> + +<p> +Loads a string as a Lua chunk. +This function uses <a href="#lua_load"><code>lua_load</code></a> to load the chunk in +the zero-terminated string <code>s</code>. + + +<p> +This function returns the same results as <a href="#lua_load"><code>lua_load</code></a>. + + +<p> +Also as <a href="#lua_load"><code>lua_load</code></a>, this function only loads the chunk; +it does not run it. + + + + + +<hr><h3><a name="luaL_newlib"><code>luaL_newlib</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void luaL_newlib (lua_State *L, const luaL_Reg l[]);</pre> + +<p> +Creates a new table and registers there +the functions in list <code>l</code>. + + +<p> +It is implemented as the following macro: + +<pre> + (luaL_newlibtable(L,l), luaL_setfuncs(L,l,0)) +</pre><p> +The array <code>l</code> must be the actual array, +not a pointer to it. + + + + + +<hr><h3><a name="luaL_newlibtable"><code>luaL_newlibtable</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void luaL_newlibtable (lua_State *L, const luaL_Reg l[]);</pre> + +<p> +Creates a new table with a size optimized +to store all entries in the array <code>l</code> +(but does not actually store them). +It is intended to be used in conjunction with <a href="#luaL_setfuncs"><code>luaL_setfuncs</code></a> +(see <a href="#luaL_newlib"><code>luaL_newlib</code></a>). + + +<p> +It is implemented as a macro. +The array <code>l</code> must be the actual array, +not a pointer to it. + + + + + +<hr><h3><a name="luaL_newmetatable"><code>luaL_newmetatable</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>int luaL_newmetatable (lua_State *L, const char *tname);</pre> + +<p> +If the registry already has the key <code>tname</code>, +returns 0. +Otherwise, +creates a new table to be used as a metatable for userdata, +adds to this new table the pair <code>__name = tname</code>, +adds to the registry the pair <code>[tname] = new table</code>, +and returns 1. +(The entry <code>__name</code> is used by some error-reporting functions.) + + +<p> +In both cases pushes onto the stack the final value associated +with <code>tname</code> in the registry. + + + + + +<hr><h3><a name="luaL_newstate"><code>luaL_newstate</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>lua_State *luaL_newstate (void);</pre> + +<p> +Creates a new Lua state. +It calls <a href="#lua_newstate"><code>lua_newstate</code></a> with an +allocator based on the standard C <code>realloc</code> function +and then sets a panic function (see <a href="#4.6">§4.6</a>) that prints +an error message to the standard error output in case of fatal +errors. + + +<p> +Returns the new state, +or <code>NULL</code> if there is a memory allocation error. + + + + + +<hr><h3><a name="luaL_openlibs"><code>luaL_openlibs</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>void luaL_openlibs (lua_State *L);</pre> + +<p> +Opens all standard Lua libraries into the given state. + + + + + +<hr><h3><a name="luaL_optinteger"><code>luaL_optinteger</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>lua_Integer luaL_optinteger (lua_State *L, + int arg, + lua_Integer d);</pre> + +<p> +If the function argument <code>arg</code> is an integer +(or convertible to an integer), +returns this integer. +If this argument is absent or is <b>nil</b>, +returns <code>d</code>. +Otherwise, raises an error. + + + + + +<hr><h3><a name="luaL_optlstring"><code>luaL_optlstring</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>const char *luaL_optlstring (lua_State *L, + int arg, + const char *d, + size_t *l);</pre> + +<p> +If the function argument <code>arg</code> is a string, +returns this string. +If this argument is absent or is <b>nil</b>, +returns <code>d</code>. +Otherwise, raises an error. + + +<p> +If <code>l</code> is not <code>NULL</code>, +fills the position <code>*l</code> with the result's length. + + + + + +<hr><h3><a name="luaL_optnumber"><code>luaL_optnumber</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number d);</pre> + +<p> +If the function argument <code>arg</code> is a number, +returns this number. +If this argument is absent or is <b>nil</b>, +returns <code>d</code>. +Otherwise, raises an error. + + + + + +<hr><h3><a name="luaL_optstring"><code>luaL_optstring</code></a></h3><p> +<span class="apii">[-0, +0, <em>v</em>]</span> +<pre>const char *luaL_optstring (lua_State *L, + int arg, + const char *d);</pre> + +<p> +If the function argument <code>arg</code> is a string, +returns this string. +If this argument is absent or is <b>nil</b>, +returns <code>d</code>. +Otherwise, raises an error. + + + + + +<hr><h3><a name="luaL_prepbuffer"><code>luaL_prepbuffer</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>char *luaL_prepbuffer (luaL_Buffer *B);</pre> + +<p> +Equivalent to <a href="#luaL_prepbuffsize"><code>luaL_prepbuffsize</code></a> +with the predefined size <a name="pdf-LUAL_BUFFERSIZE"><code>LUAL_BUFFERSIZE</code></a>. + + + + + +<hr><h3><a name="luaL_prepbuffsize"><code>luaL_prepbuffsize</code></a></h3><p> +<span class="apii">[-?, +?, <em>e</em>]</span> +<pre>char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz);</pre> + +<p> +Returns an address to a space of size <code>sz</code> +where you can copy a string to be added to buffer <code>B</code> +(see <a href="#luaL_Buffer"><code>luaL_Buffer</code></a>). +After copying the string into this space you must call +<a href="#luaL_addsize"><code>luaL_addsize</code></a> with the size of the string to actually add +it to the buffer. + + + + + +<hr><h3><a name="luaL_pushresult"><code>luaL_pushresult</code></a></h3><p> +<span class="apii">[-?, +1, <em>e</em>]</span> +<pre>void luaL_pushresult (luaL_Buffer *B);</pre> + +<p> +Finishes the use of buffer <code>B</code> leaving the final string on +the top of the stack. + + + + + +<hr><h3><a name="luaL_pushresultsize"><code>luaL_pushresultsize</code></a></h3><p> +<span class="apii">[-?, +1, <em>e</em>]</span> +<pre>void luaL_pushresultsize (luaL_Buffer *B, size_t sz);</pre> + +<p> +Equivalent to the sequence <a href="#luaL_addsize"><code>luaL_addsize</code></a>, <a href="#luaL_pushresult"><code>luaL_pushresult</code></a>. + + + + + +<hr><h3><a name="luaL_ref"><code>luaL_ref</code></a></h3><p> +<span class="apii">[-1, +0, <em>e</em>]</span> +<pre>int luaL_ref (lua_State *L, int t);</pre> + +<p> +Creates and returns a <em>reference</em>, +in the table at index <code>t</code>, +for the object at the top of the stack (and pops the object). + + +<p> +A reference is a unique integer key. +As long as you do not manually add integer keys into table <code>t</code>, +<a href="#luaL_ref"><code>luaL_ref</code></a> ensures the uniqueness of the key it returns. +You can retrieve an object referred by reference <code>r</code> +by calling <code>lua_rawgeti(L, t, r)</code>. +Function <a href="#luaL_unref"><code>luaL_unref</code></a> frees a reference and its associated object. + + +<p> +If the object at the top of the stack is <b>nil</b>, +<a href="#luaL_ref"><code>luaL_ref</code></a> returns the constant <a name="pdf-LUA_REFNIL"><code>LUA_REFNIL</code></a>. +The constant <a name="pdf-LUA_NOREF"><code>LUA_NOREF</code></a> is guaranteed to be different +from any reference returned by <a href="#luaL_ref"><code>luaL_ref</code></a>. + + + + + +<hr><h3><a name="luaL_Reg"><code>luaL_Reg</code></a></h3> +<pre>typedef struct luaL_Reg { + const char *name; + lua_CFunction func; +} luaL_Reg;</pre> + +<p> +Type for arrays of functions to be registered by +<a href="#luaL_setfuncs"><code>luaL_setfuncs</code></a>. +<code>name</code> is the function name and <code>func</code> is a pointer to +the function. +Any array of <a href="#luaL_Reg"><code>luaL_Reg</code></a> must end with a sentinel entry +in which both <code>name</code> and <code>func</code> are <code>NULL</code>. + + + + + +<hr><h3><a name="luaL_requiref"><code>luaL_requiref</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void luaL_requiref (lua_State *L, const char *modname, + lua_CFunction openf, int glb);</pre> + +<p> +If <code>modname</code> is not already present in <a href="#pdf-package.loaded"><code>package.loaded</code></a>, +calls function <code>openf</code> with string <code>modname</code> as an argument +and sets the call result in <code>package.loaded[modname]</code>, +as if that function has been called through <a href="#pdf-require"><code>require</code></a>. + + +<p> +If <code>glb</code> is true, +also stores the module into global <code>modname</code>. + + +<p> +Leaves a copy of the module on the stack. + + + + + +<hr><h3><a name="luaL_setfuncs"><code>luaL_setfuncs</code></a></h3><p> +<span class="apii">[-nup, +0, <em>e</em>]</span> +<pre>void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup);</pre> + +<p> +Registers all functions in the array <code>l</code> +(see <a href="#luaL_Reg"><code>luaL_Reg</code></a>) into the table on the top of the stack +(below optional upvalues, see next). + + +<p> +When <code>nup</code> is not zero, +all functions are created sharing <code>nup</code> upvalues, +which must be previously pushed on the stack +on top of the library table. +These values are popped from the stack after the registration. + + + + + +<hr><h3><a name="luaL_setmetatable"><code>luaL_setmetatable</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void luaL_setmetatable (lua_State *L, const char *tname);</pre> + +<p> +Sets the metatable of the object at the top of the stack +as the metatable associated with name <code>tname</code> +in the registry (see <a href="#luaL_newmetatable"><code>luaL_newmetatable</code></a>). + + + + + +<hr><h3><a name="luaL_Stream"><code>luaL_Stream</code></a></h3> +<pre>typedef struct luaL_Stream { + FILE *f; + lua_CFunction closef; +} luaL_Stream;</pre> + +<p> +The standard representation for file handles, +which is used by the standard I/O library. + + +<p> +A file handle is implemented as a full userdata, +with a metatable called <code>LUA_FILEHANDLE</code> +(where <code>LUA_FILEHANDLE</code> is a macro with the actual metatable's name). +The metatable is created by the I/O library +(see <a href="#luaL_newmetatable"><code>luaL_newmetatable</code></a>). + + +<p> +This userdata must start with the structure <code>luaL_Stream</code>; +it can contain other data after this initial structure. +Field <code>f</code> points to the corresponding C stream +(or it can be <code>NULL</code> to indicate an incompletely created handle). +Field <code>closef</code> points to a Lua function +that will be called to close the stream +when the handle is closed or collected; +this function receives the file handle as its sole argument and +must return either <b>true</b> (in case of success) +or <b>nil</b> plus an error message (in case of error). +Once Lua calls this field, +the field value is changed to <code>NULL</code> +to signal that the handle is closed. + + + + + +<hr><h3><a name="luaL_testudata"><code>luaL_testudata</code></a></h3><p> +<span class="apii">[-0, +0, <em>e</em>]</span> +<pre>void *luaL_testudata (lua_State *L, int arg, const char *tname);</pre> + +<p> +This function works like <a href="#luaL_checkudata"><code>luaL_checkudata</code></a>, +except that, when the test fails, +it returns <code>NULL</code> instead of raising an error. + + + + + +<hr><h3><a name="luaL_tolstring"><code>luaL_tolstring</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>const char *luaL_tolstring (lua_State *L, int idx, size_t *len);</pre> + +<p> +Converts any Lua value at the given index to a C string +in a reasonable format. +The resulting string is pushed onto the stack and also +returned by the function. +If <code>len</code> is not <code>NULL</code>, +the function also sets <code>*len</code> with the string length. + + +<p> +If the value has a metatable with a <code>"__tostring"</code> field, +then <code>luaL_tolstring</code> calls the corresponding metamethod +with the value as argument, +and uses the result of the call as its result. + + + + + +<hr><h3><a name="luaL_traceback"><code>luaL_traceback</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void luaL_traceback (lua_State *L, lua_State *L1, const char *msg, + int level);</pre> + +<p> +Creates and pushes a traceback of the stack <code>L1</code>. +If <code>msg</code> is not <code>NULL</code> it is appended +at the beginning of the traceback. +The <code>level</code> parameter tells at which level +to start the traceback. + + + + + +<hr><h3><a name="luaL_typename"><code>luaL_typename</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>const char *luaL_typename (lua_State *L, int index);</pre> + +<p> +Returns the name of the type of the value at the given index. + + + + + +<hr><h3><a name="luaL_unref"><code>luaL_unref</code></a></h3><p> +<span class="apii">[-0, +0, –]</span> +<pre>void luaL_unref (lua_State *L, int t, int ref);</pre> + +<p> +Releases reference <code>ref</code> from the table at index <code>t</code> +(see <a href="#luaL_ref"><code>luaL_ref</code></a>). +The entry is removed from the table, +so that the referred object can be collected. +The reference <code>ref</code> is also freed to be used again. + + +<p> +If <code>ref</code> is <a href="#pdf-LUA_NOREF"><code>LUA_NOREF</code></a> or <a href="#pdf-LUA_REFNIL"><code>LUA_REFNIL</code></a>, +<a href="#luaL_unref"><code>luaL_unref</code></a> does nothing. + + + + + +<hr><h3><a name="luaL_where"><code>luaL_where</code></a></h3><p> +<span class="apii">[-0, +1, <em>e</em>]</span> +<pre>void luaL_where (lua_State *L, int lvl);</pre> + +<p> +Pushes onto the stack a string identifying the current position +of the control at level <code>lvl</code> in the call stack. +Typically this string has the following format: + +<pre> + <em>chunkname</em>:<em>currentline</em>: +</pre><p> +Level 0 is the running function, +level 1 is the function that called the running function, +etc. + + +<p> +This function is used to build a prefix for error messages. + + + + + + + +<h1>6 – <a name="6">Standard Libraries</a></h1> + +<p> +The standard Lua libraries provide useful functions +that are implemented directly through the C API. +Some of these functions provide essential services to the language +(e.g., <a href="#pdf-type"><code>type</code></a> and <a href="#pdf-getmetatable"><code>getmetatable</code></a>); +others provide access to "outside" services (e.g., I/O); +and others could be implemented in Lua itself, +but are quite useful or have critical performance requirements that +deserve an implementation in C (e.g., <a href="#pdf-table.sort"><code>table.sort</code></a>). + + +<p> +All libraries are implemented through the official C API +and are provided as separate C modules. +Currently, Lua has the following standard libraries: + +<ul> + +<li>basic library (<a href="#6.1">§6.1</a>);</li> + +<li>coroutine library (<a href="#6.2">§6.2</a>);</li> + +<li>package library (<a href="#6.3">§6.3</a>);</li> + +<li>string manipulation (<a href="#6.4">§6.4</a>);</li> + +<li>basic UTF-8 support (<a href="#6.5">§6.5</a>);</li> + +<li>table manipulation (<a href="#6.6">§6.6</a>);</li> + +<li>mathematical functions (<a href="#6.7">§6.7</a>) (sin, log, etc.);</li> + +<li>input and output (<a href="#6.8">§6.8</a>);</li> + +<li>operating system facilities (<a href="#6.9">§6.9</a>);</li> + +<li>debug facilities (<a href="#6.10">§6.10</a>).</li> + +</ul><p> +Except for the basic and the package libraries, +each library provides all its functions as fields of a global table +or as methods of its objects. + + +<p> +To have access to these libraries, +the C host program should call the <a href="#luaL_openlibs"><code>luaL_openlibs</code></a> function, +which opens all standard libraries. +Alternatively, +the host program can open them individually by using +<a href="#luaL_requiref"><code>luaL_requiref</code></a> to call +<a name="pdf-luaopen_base"><code>luaopen_base</code></a> (for the basic library), +<a name="pdf-luaopen_package"><code>luaopen_package</code></a> (for the package library), +<a name="pdf-luaopen_coroutine"><code>luaopen_coroutine</code></a> (for the coroutine library), +<a name="pdf-luaopen_string"><code>luaopen_string</code></a> (for the string library), +<a name="pdf-luaopen_utf8"><code>luaopen_utf8</code></a> (for the UTF8 library), +<a name="pdf-luaopen_table"><code>luaopen_table</code></a> (for the table library), +<a name="pdf-luaopen_math"><code>luaopen_math</code></a> (for the mathematical library), +<a name="pdf-luaopen_io"><code>luaopen_io</code></a> (for the I/O library), +<a name="pdf-luaopen_os"><code>luaopen_os</code></a> (for the operating system library), +and <a name="pdf-luaopen_debug"><code>luaopen_debug</code></a> (for the debug library). +These functions are declared in <a name="pdf-lualib.h"><code>lualib.h</code></a>. + + + +<h2>6.1 – <a name="6.1">Basic Functions</a></h2> + +<p> +The basic library provides core functions to Lua. +If you do not include this library in your application, +you should check carefully whether you need to provide +implementations for some of its facilities. + + +<p> +<hr><h3><a name="pdf-assert"><code>assert (v [, message])</code></a></h3> + + +<p> +Calls <a href="#pdf-error"><code>error</code></a> if +the value of its argument <code>v</code> is false (i.e., <b>nil</b> or <b>false</b>); +otherwise, returns all its arguments. +In case of error, +<code>message</code> is the error object; +when absent, it defaults to "<code>assertion failed!</code>" + + + + +<p> +<hr><h3><a name="pdf-collectgarbage"><code>collectgarbage ([opt [, arg]])</code></a></h3> + + +<p> +This function is a generic interface to the garbage collector. +It performs different functions according to its first argument, <code>opt</code>: + +<ul> + +<li><b>"<code>collect</code>": </b> +performs a full garbage-collection cycle. +This is the default option. +</li> + +<li><b>"<code>stop</code>": </b> +stops automatic execution of the garbage collector. +The collector will run only when explicitly invoked, +until a call to restart it. +</li> + +<li><b>"<code>restart</code>": </b> +restarts automatic execution of the garbage collector. +</li> + +<li><b>"<code>count</code>": </b> +returns the total memory in use by Lua in Kbytes. +The value has a fractional part, +so that it multiplied by 1024 +gives the exact number of bytes in use by Lua +(except for overflows). +</li> + +<li><b>"<code>step</code>": </b> +performs a garbage-collection step. +The step "size" is controlled by <code>arg</code>. +With a zero value, +the collector will perform one basic (indivisible) step. +For non-zero values, +the collector will perform as if that amount of memory +(in KBytes) had been allocated by Lua. +Returns <b>true</b> if the step finished a collection cycle. +</li> + +<li><b>"<code>setpause</code>": </b> +sets <code>arg</code> as the new value for the <em>pause</em> of +the collector (see <a href="#2.5">§2.5</a>). +Returns the previous value for <em>pause</em>. +</li> + +<li><b>"<code>setstepmul</code>": </b> +sets <code>arg</code> as the new value for the <em>step multiplier</em> of +the collector (see <a href="#2.5">§2.5</a>). +Returns the previous value for <em>step</em>. +</li> + +<li><b>"<code>isrunning</code>": </b> +returns a boolean that tells whether the collector is running +(i.e., not stopped). +</li> + +</ul> + + + +<p> +<hr><h3><a name="pdf-dofile"><code>dofile ([filename])</code></a></h3> +Opens the named file and executes its contents as a Lua chunk. +When called without arguments, +<code>dofile</code> executes the contents of the standard input (<code>stdin</code>). +Returns all values returned by the chunk. +In case of errors, <code>dofile</code> propagates the error +to its caller (that is, <code>dofile</code> does not run in protected mode). + + + + +<p> +<hr><h3><a name="pdf-error"><code>error (message [, level])</code></a></h3> +Terminates the last protected function called +and returns <code>message</code> as the error object. +Function <code>error</code> never returns. + + +<p> +Usually, <code>error</code> adds some information about the error position +at the beginning of the message, if the message is a string. +The <code>level</code> argument specifies how to get the error position. +With level 1 (the default), the error position is where the +<code>error</code> function was called. +Level 2 points the error to where the function +that called <code>error</code> was called; and so on. +Passing a level 0 avoids the addition of error position information +to the message. + + + + +<p> +<hr><h3><a name="pdf-_G"><code>_G</code></a></h3> +A global variable (not a function) that +holds the global environment (see <a href="#2.2">§2.2</a>). +Lua itself does not use this variable; +changing its value does not affect any environment, +nor vice versa. + + + + +<p> +<hr><h3><a name="pdf-getmetatable"><code>getmetatable (object)</code></a></h3> + + +<p> +If <code>object</code> does not have a metatable, returns <b>nil</b>. +Otherwise, +if the object's metatable has a <code>"__metatable"</code> field, +returns the associated value. +Otherwise, returns the metatable of the given object. + + + + +<p> +<hr><h3><a name="pdf-ipairs"><code>ipairs (t)</code></a></h3> + + +<p> +Returns three values (an iterator function, the table <code>t</code>, and 0) +so that the construction + +<pre> + for i,v in ipairs(t) do <em>body</em> end +</pre><p> +will iterate over the key–value pairs +(<code>1,t[1]</code>), (<code>2,t[2]</code>), ..., +up to the first nil value. + + + + +<p> +<hr><h3><a name="pdf-load"><code>load (chunk [, chunkname [, mode [, env]]])</code></a></h3> + + +<p> +Loads a chunk. + + +<p> +If <code>chunk</code> is a string, the chunk is this string. +If <code>chunk</code> is a function, +<code>load</code> calls it repeatedly to get the chunk pieces. +Each call to <code>chunk</code> must return a string that concatenates +with previous results. +A return of an empty string, <b>nil</b>, or no value signals the end of the chunk. + + +<p> +If there are no syntactic errors, +returns the compiled chunk as a function; +otherwise, returns <b>nil</b> plus the error message. + + +<p> +If the resulting function has upvalues, +the first upvalue is set to the value of <code>env</code>, +if that parameter is given, +or to the value of the global environment. +Other upvalues are initialized with <b>nil</b>. +(When you load a main chunk, +the resulting function will always have exactly one upvalue, +the <code>_ENV</code> variable (see <a href="#2.2">§2.2</a>). +However, +when you load a binary chunk created from a function (see <a href="#pdf-string.dump"><code>string.dump</code></a>), +the resulting function can have an arbitrary number of upvalues.) +All upvalues are fresh, that is, +they are not shared with any other function. + + +<p> +<code>chunkname</code> is used as the name of the chunk for error messages +and debug information (see <a href="#4.9">§4.9</a>). +When absent, +it defaults to <code>chunk</code>, if <code>chunk</code> is a string, +or to "<code>=(load)</code>" otherwise. + + +<p> +The string <code>mode</code> controls whether the chunk can be text or binary +(that is, a precompiled chunk). +It may be the string "<code>b</code>" (only binary chunks), +"<code>t</code>" (only text chunks), +or "<code>bt</code>" (both binary and text). +The default is "<code>bt</code>". + + +<p> +Lua does not check the consistency of binary chunks. +Maliciously crafted binary chunks can crash +the interpreter. + + + + +<p> +<hr><h3><a name="pdf-loadfile"><code>loadfile ([filename [, mode [, env]]])</code></a></h3> + + +<p> +Similar to <a href="#pdf-load"><code>load</code></a>, +but gets the chunk from file <code>filename</code> +or from the standard input, +if no file name is given. + + + + +<p> +<hr><h3><a name="pdf-next"><code>next (table [, index])</code></a></h3> + + +<p> +Allows a program to traverse all fields of a table. +Its first argument is a table and its second argument +is an index in this table. +<code>next</code> returns the next index of the table +and its associated value. +When called with <b>nil</b> as its second argument, +<code>next</code> returns an initial index +and its associated value. +When called with the last index, +or with <b>nil</b> in an empty table, +<code>next</code> returns <b>nil</b>. +If the second argument is absent, then it is interpreted as <b>nil</b>. +In particular, +you can use <code>next(t)</code> to check whether a table is empty. + + +<p> +The order in which the indices are enumerated is not specified, +<em>even for numeric indices</em>. +(To traverse a table in numeric order, +use a numerical <b>for</b>.) + + +<p> +The behavior of <code>next</code> is undefined if, +during the traversal, +you assign any value to a non-existent field in the table. +You may however modify existing fields. +In particular, you may clear existing fields. + + + + +<p> +<hr><h3><a name="pdf-pairs"><code>pairs (t)</code></a></h3> + + +<p> +If <code>t</code> has a metamethod <code>__pairs</code>, +calls it with <code>t</code> as argument and returns the first three +results from the call. + + +<p> +Otherwise, +returns three values: the <a href="#pdf-next"><code>next</code></a> function, the table <code>t</code>, and <b>nil</b>, +so that the construction + +<pre> + for k,v in pairs(t) do <em>body</em> end +</pre><p> +will iterate over all key–value pairs of table <code>t</code>. + + +<p> +See function <a href="#pdf-next"><code>next</code></a> for the caveats of modifying +the table during its traversal. + + + + +<p> +<hr><h3><a name="pdf-pcall"><code>pcall (f [, arg1, ···])</code></a></h3> + + +<p> +Calls function <code>f</code> with +the given arguments in <em>protected mode</em>. +This means that any error inside <code>f</code> is not propagated; +instead, <code>pcall</code> catches the error +and returns a status code. +Its first result is the status code (a boolean), +which is true if the call succeeds without errors. +In such case, <code>pcall</code> also returns all results from the call, +after this first result. +In case of any error, <code>pcall</code> returns <b>false</b> plus the error message. + + + + +<p> +<hr><h3><a name="pdf-print"><code>print (···)</code></a></h3> +Receives any number of arguments +and prints their values to <code>stdout</code>, +using the <a href="#pdf-tostring"><code>tostring</code></a> function to convert each argument to a string. +<code>print</code> is not intended for formatted output, +but only as a quick way to show a value, +for instance for debugging. +For complete control over the output, +use <a href="#pdf-string.format"><code>string.format</code></a> and <a href="#pdf-io.write"><code>io.write</code></a>. + + + + +<p> +<hr><h3><a name="pdf-rawequal"><code>rawequal (v1, v2)</code></a></h3> +Checks whether <code>v1</code> is equal to <code>v2</code>, +without invoking any metamethod. +Returns a boolean. + + + + +<p> +<hr><h3><a name="pdf-rawget"><code>rawget (table, index)</code></a></h3> +Gets the real value of <code>table[index]</code>, +without invoking any metamethod. +<code>table</code> must be a table; +<code>index</code> may be any value. + + + + +<p> +<hr><h3><a name="pdf-rawlen"><code>rawlen (v)</code></a></h3> +Returns the length of the object <code>v</code>, +which must be a table or a string, +without invoking any metamethod. +Returns an integer. + + + + +<p> +<hr><h3><a name="pdf-rawset"><code>rawset (table, index, value)</code></a></h3> +Sets the real value of <code>table[index]</code> to <code>value</code>, +without invoking any metamethod. +<code>table</code> must be a table, +<code>index</code> any value different from <b>nil</b> and NaN, +and <code>value</code> any Lua value. + + +<p> +This function returns <code>table</code>. + + + + +<p> +<hr><h3><a name="pdf-select"><code>select (index, ···)</code></a></h3> + + +<p> +If <code>index</code> is a number, +returns all arguments after argument number <code>index</code>; +a negative number indexes from the end (-1 is the last argument). +Otherwise, <code>index</code> must be the string <code>"#"</code>, +and <code>select</code> returns the total number of extra arguments it received. + + + + +<p> +<hr><h3><a name="pdf-setmetatable"><code>setmetatable (table, metatable)</code></a></h3> + + +<p> +Sets the metatable for the given table. +(You cannot change the metatable of other types from Lua, only from C.) +If <code>metatable</code> is <b>nil</b>, +removes the metatable of the given table. +If the original metatable has a <code>"__metatable"</code> field, +raises an error. + + +<p> +This function returns <code>table</code>. + + + + +<p> +<hr><h3><a name="pdf-tonumber"><code>tonumber (e [, base])</code></a></h3> + + +<p> +When called with no <code>base</code>, +<code>tonumber</code> tries to convert its argument to a number. +If the argument is already a number or +a string convertible to a number, +then <code>tonumber</code> returns this number; +otherwise, it returns <b>nil</b>. + + +<p> +The conversion of strings can result in integers or floats, +according to the lexical conventions of Lua (see <a href="#3.1">§3.1</a>). +(The string may have leading and trailing spaces and a sign.) + + +<p> +When called with <code>base</code>, +then <code>e</code> must be a string to be interpreted as +an integer numeral in that base. +The base may be any integer between 2 and 36, inclusive. +In bases above 10, the letter '<code>A</code>' (in either upper or lower case) +represents 10, '<code>B</code>' represents 11, and so forth, +with '<code>Z</code>' representing 35. +If the string <code>e</code> is not a valid numeral in the given base, +the function returns <b>nil</b>. + + + + +<p> +<hr><h3><a name="pdf-tostring"><code>tostring (v)</code></a></h3> +Receives a value of any type and +converts it to a string in a human-readable format. +Floats always produce strings with some +floating-point indication (either a decimal dot or an exponent). +(For complete control of how numbers are converted, +use <a href="#pdf-string.format"><code>string.format</code></a>.) + + +<p> +If the metatable of <code>v</code> has a <code>"__tostring"</code> field, +then <code>tostring</code> calls the corresponding value +with <code>v</code> as argument, +and uses the result of the call as its result. + + + + +<p> +<hr><h3><a name="pdf-type"><code>type (v)</code></a></h3> +Returns the type of its only argument, coded as a string. +The possible results of this function are +"<code>nil</code>" (a string, not the value <b>nil</b>), +"<code>number</code>", +"<code>string</code>", +"<code>boolean</code>", +"<code>table</code>", +"<code>function</code>", +"<code>thread</code>", +and "<code>userdata</code>". + + + + +<p> +<hr><h3><a name="pdf-_VERSION"><code>_VERSION</code></a></h3> +A global variable (not a function) that +holds a string containing the current interpreter version. +The current value of this variable is "<code>Lua 5.3</code>". + + + + +<p> +<hr><h3><a name="pdf-xpcall"><code>xpcall (f, msgh [, arg1, ···])</code></a></h3> + + +<p> +This function is similar to <a href="#pdf-pcall"><code>pcall</code></a>, +except that it sets a new message handler <code>msgh</code>. + + + + + + + +<h2>6.2 – <a name="6.2">Coroutine Manipulation</a></h2> + +<p> +The operations related to coroutines comprise a sub-library of +the basic library and come inside the table <a name="pdf-coroutine"><code>coroutine</code></a>. +See <a href="#2.6">§2.6</a> for a general description of coroutines. + + +<p> +<hr><h3><a name="pdf-coroutine.create"><code>coroutine.create (f)</code></a></h3> + + +<p> +Creates a new coroutine, with body <code>f</code>. +<code>f</code> must be a Lua function. +Returns this new coroutine, +an object with type <code>"thread"</code>. + + + + +<p> +<hr><h3><a name="pdf-coroutine.isyieldable"><code>coroutine.isyieldable ()</code></a></h3> + + +<p> +Returns true when the running coroutine can yield. + + +<p> +A running coroutine is yieldable if it is not the main thread and +it is not inside a non-yieldable C function. + + + + +<p> +<hr><h3><a name="pdf-coroutine.resume"><code>coroutine.resume (co [, val1, ···])</code></a></h3> + + +<p> +Starts or continues the execution of coroutine <code>co</code>. +The first time you resume a coroutine, +it starts running its body. +The values <code>val1</code>, ... are passed +as the arguments to the body function. +If the coroutine has yielded, +<code>resume</code> restarts it; +the values <code>val1</code>, ... are passed +as the results from the yield. + + +<p> +If the coroutine runs without any errors, +<code>resume</code> returns <b>true</b> plus any values passed to <code>yield</code> +(when the coroutine yields) or any values returned by the body function +(when the coroutine terminates). +If there is any error, +<code>resume</code> returns <b>false</b> plus the error message. + + + + +<p> +<hr><h3><a name="pdf-coroutine.running"><code>coroutine.running ()</code></a></h3> + + +<p> +Returns the running coroutine plus a boolean, +true when the running coroutine is the main one. + + + + +<p> +<hr><h3><a name="pdf-coroutine.status"><code>coroutine.status (co)</code></a></h3> + + +<p> +Returns the status of coroutine <code>co</code>, as a string: +<code>"running"</code>, +if the coroutine is running (that is, it called <code>status</code>); +<code>"suspended"</code>, if the coroutine is suspended in a call to <code>yield</code>, +or if it has not started running yet; +<code>"normal"</code> if the coroutine is active but not running +(that is, it has resumed another coroutine); +and <code>"dead"</code> if the coroutine has finished its body function, +or if it has stopped with an error. + + + + +<p> +<hr><h3><a name="pdf-coroutine.wrap"><code>coroutine.wrap (f)</code></a></h3> + + +<p> +Creates a new coroutine, with body <code>f</code>. +<code>f</code> must be a Lua function. +Returns a function that resumes the coroutine each time it is called. +Any arguments passed to the function behave as the +extra arguments to <code>resume</code>. +Returns the same values returned by <code>resume</code>, +except the first boolean. +In case of error, propagates the error. + + + + +<p> +<hr><h3><a name="pdf-coroutine.yield"><code>coroutine.yield (···)</code></a></h3> + + +<p> +Suspends the execution of the calling coroutine. +Any arguments to <code>yield</code> are passed as extra results to <code>resume</code>. + + + + + + + +<h2>6.3 – <a name="6.3">Modules</a></h2> + +<p> +The package library provides basic +facilities for loading modules in Lua. +It exports one function directly in the global environment: +<a href="#pdf-require"><code>require</code></a>. +Everything else is exported in a table <a name="pdf-package"><code>package</code></a>. + + +<p> +<hr><h3><a name="pdf-require"><code>require (modname)</code></a></h3> + + +<p> +Loads the given module. +The function starts by looking into the <a href="#pdf-package.loaded"><code>package.loaded</code></a> table +to determine whether <code>modname</code> is already loaded. +If it is, then <code>require</code> returns the value stored +at <code>package.loaded[modname]</code>. +Otherwise, it tries to find a <em>loader</em> for the module. + + +<p> +To find a loader, +<code>require</code> is guided by the <a href="#pdf-package.searchers"><code>package.searchers</code></a> sequence. +By changing this sequence, +we can change how <code>require</code> looks for a module. +The following explanation is based on the default configuration +for <a href="#pdf-package.searchers"><code>package.searchers</code></a>. + + +<p> +First <code>require</code> queries <code>package.preload[modname]</code>. +If it has a value, +this value (which must be a function) is the loader. +Otherwise <code>require</code> searches for a Lua loader using the +path stored in <a href="#pdf-package.path"><code>package.path</code></a>. +If that also fails, it searches for a C loader using the +path stored in <a href="#pdf-package.cpath"><code>package.cpath</code></a>. +If that also fails, +it tries an <em>all-in-one</em> loader (see <a href="#pdf-package.searchers"><code>package.searchers</code></a>). + + +<p> +Once a loader is found, +<code>require</code> calls the loader with two arguments: +<code>modname</code> and an extra value dependent on how it got the loader. +(If the loader came from a file, +this extra value is the file name.) +If the loader returns any non-nil value, +<code>require</code> assigns the returned value to <code>package.loaded[modname]</code>. +If the loader does not return a non-nil value and +has not assigned any value to <code>package.loaded[modname]</code>, +then <code>require</code> assigns <b>true</b> to this entry. +In any case, <code>require</code> returns the +final value of <code>package.loaded[modname]</code>. + + +<p> +If there is any error loading or running the module, +or if it cannot find any loader for the module, +then <code>require</code> raises an error. + + + + +<p> +<hr><h3><a name="pdf-package.config"><code>package.config</code></a></h3> + + +<p> +A string describing some compile-time configurations for packages. +This string is a sequence of lines: + +<ul> + +<li>The first line is the directory separator string. +Default is '<code>\</code>' for Windows and '<code>/</code>' for all other systems.</li> + +<li>The second line is the character that separates templates in a path. +Default is '<code>;</code>'.</li> + +<li>The third line is the string that marks the +substitution points in a template. +Default is '<code>?</code>'.</li> + +<li>The fourth line is a string that, in a path in Windows, +is replaced by the executable's directory. +Default is '<code>!</code>'.</li> + +<li>The fifth line is a mark to ignore all text after it +when building the <code>luaopen_</code> function name. +Default is '<code>-</code>'.</li> + +</ul> + + + +<p> +<hr><h3><a name="pdf-package.cpath"><code>package.cpath</code></a></h3> + + +<p> +The path used by <a href="#pdf-require"><code>require</code></a> to search for a C loader. + + +<p> +Lua initializes the C path <a href="#pdf-package.cpath"><code>package.cpath</code></a> in the same way +it initializes the Lua path <a href="#pdf-package.path"><code>package.path</code></a>, +using the environment variable <a name="pdf-LUA_CPATH_5_3"><code>LUA_CPATH_5_3</code></a> +or the environment variable <a name="pdf-LUA_CPATH"><code>LUA_CPATH</code></a> +or a default path defined in <code>luaconf.h</code>. + + + + +<p> +<hr><h3><a name="pdf-package.loaded"><code>package.loaded</code></a></h3> + + +<p> +A table used by <a href="#pdf-require"><code>require</code></a> to control which +modules are already loaded. +When you require a module <code>modname</code> and +<code>package.loaded[modname]</code> is not false, +<a href="#pdf-require"><code>require</code></a> simply returns the value stored there. + + +<p> +This variable is only a reference to the real table; +assignments to this variable do not change the +table used by <a href="#pdf-require"><code>require</code></a>. + + + + +<p> +<hr><h3><a name="pdf-package.loadlib"><code>package.loadlib (libname, funcname)</code></a></h3> + + +<p> +Dynamically links the host program with the C library <code>libname</code>. + + +<p> +If <code>funcname</code> is "<code>*</code>", +then it only links with the library, +making the symbols exported by the library +available to other dynamically linked libraries. +Otherwise, +it looks for a function <code>funcname</code> inside the library +and returns this function as a C function. +So, <code>funcname</code> must follow the <a href="#lua_CFunction"><code>lua_CFunction</code></a> prototype +(see <a href="#lua_CFunction"><code>lua_CFunction</code></a>). + + +<p> +This is a low-level function. +It completely bypasses the package and module system. +Unlike <a href="#pdf-require"><code>require</code></a>, +it does not perform any path searching and +does not automatically adds extensions. +<code>libname</code> must be the complete file name of the C library, +including if necessary a path and an extension. +<code>funcname</code> must be the exact name exported by the C library +(which may depend on the C compiler and linker used). + + +<p> +This function is not supported by Standard C. +As such, it is only available on some platforms +(Windows, Linux, Mac OS X, Solaris, BSD, +plus other Unix systems that support the <code>dlfcn</code> standard). + + + + +<p> +<hr><h3><a name="pdf-package.path"><code>package.path</code></a></h3> + + +<p> +The path used by <a href="#pdf-require"><code>require</code></a> to search for a Lua loader. + + +<p> +At start-up, Lua initializes this variable with +the value of the environment variable <a name="pdf-LUA_PATH_5_3"><code>LUA_PATH_5_3</code></a> or +the environment variable <a name="pdf-LUA_PATH"><code>LUA_PATH</code></a> or +with a default path defined in <code>luaconf.h</code>, +if those environment variables are not defined. +Any "<code>;;</code>" in the value of the environment variable +is replaced by the default path. + + + + +<p> +<hr><h3><a name="pdf-package.preload"><code>package.preload</code></a></h3> + + +<p> +A table to store loaders for specific modules +(see <a href="#pdf-require"><code>require</code></a>). + + +<p> +This variable is only a reference to the real table; +assignments to this variable do not change the +table used by <a href="#pdf-require"><code>require</code></a>. + + + + +<p> +<hr><h3><a name="pdf-package.searchers"><code>package.searchers</code></a></h3> + + +<p> +A table used by <a href="#pdf-require"><code>require</code></a> to control how to load modules. + + +<p> +Each entry in this table is a <em>searcher function</em>. +When looking for a module, +<a href="#pdf-require"><code>require</code></a> calls each of these searchers in ascending order, +with the module name (the argument given to <a href="#pdf-require"><code>require</code></a>) as its +sole parameter. +The function can return another function (the module <em>loader</em>) +plus an extra value that will be passed to that loader, +or a string explaining why it did not find that module +(or <b>nil</b> if it has nothing to say). + + +<p> +Lua initializes this table with four searcher functions. + + +<p> +The first searcher simply looks for a loader in the +<a href="#pdf-package.preload"><code>package.preload</code></a> table. + + +<p> +The second searcher looks for a loader as a Lua library, +using the path stored at <a href="#pdf-package.path"><code>package.path</code></a>. +The search is done as described in function <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>. + + +<p> +The third searcher looks for a loader as a C library, +using the path given by the variable <a href="#pdf-package.cpath"><code>package.cpath</code></a>. +Again, +the search is done as described in function <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>. +For instance, +if the C path is the string + +<pre> + "./?.so;./?.dll;/usr/local/?/init.so" +</pre><p> +the searcher for module <code>foo</code> +will try to open the files <code>./foo.so</code>, <code>./foo.dll</code>, +and <code>/usr/local/foo/init.so</code>, in that order. +Once it finds a C library, +this searcher first uses a dynamic link facility to link the +application with the library. +Then it tries to find a C function inside the library to +be used as the loader. +The name of this C function is the string "<code>luaopen_</code>" +concatenated with a copy of the module name where each dot +is replaced by an underscore. +Moreover, if the module name has a hyphen, +its suffix after (and including) the first hyphen is removed. +For instance, if the module name is <code>a.b.c-v2.1</code>, +the function name will be <code>luaopen_a_b_c</code>. + + +<p> +The fourth searcher tries an <em>all-in-one loader</em>. +It searches the C path for a library for +the root name of the given module. +For instance, when requiring <code>a.b.c</code>, +it will search for a C library for <code>a</code>. +If found, it looks into it for an open function for +the submodule; +in our example, that would be <code>luaopen_a_b_c</code>. +With this facility, a package can pack several C submodules +into one single library, +with each submodule keeping its original open function. + + +<p> +All searchers except the first one (preload) return as the extra value +the file name where the module was found, +as returned by <a href="#pdf-package.searchpath"><code>package.searchpath</code></a>. +The first searcher returns no extra value. + + + + +<p> +<hr><h3><a name="pdf-package.searchpath"><code>package.searchpath (name, path [, sep [, rep]])</code></a></h3> + + +<p> +Searches for the given <code>name</code> in the given <code>path</code>. + + +<p> +A path is a string containing a sequence of +<em>templates</em> separated by semicolons. +For each template, +the function replaces each interrogation mark (if any) +in the template with a copy of <code>name</code> +wherein all occurrences of <code>sep</code> +(a dot, by default) +were replaced by <code>rep</code> +(the system's directory separator, by default), +and then tries to open the resulting file name. + + +<p> +For instance, if the path is the string + +<pre> + "./?.lua;./?.lc;/usr/local/?/init.lua" +</pre><p> +the search for the name <code>foo.a</code> +will try to open the files +<code>./foo/a.lua</code>, <code>./foo/a.lc</code>, and +<code>/usr/local/foo/a/init.lua</code>, in that order. + + +<p> +Returns the resulting name of the first file that it can +open in read mode (after closing the file), +or <b>nil</b> plus an error message if none succeeds. +(This error message lists all file names it tried to open.) + + + + + + + +<h2>6.4 – <a name="6.4">String Manipulation</a></h2> + +<p> +This library provides generic functions for string manipulation, +such as finding and extracting substrings, and pattern matching. +When indexing a string in Lua, the first character is at position 1 +(not at 0, as in C). +Indices are allowed to be negative and are interpreted as indexing backwards, +from the end of the string. +Thus, the last character is at position -1, and so on. + + +<p> +The string library provides all its functions inside the table +<a name="pdf-string"><code>string</code></a>. +It also sets a metatable for strings +where the <code>__index</code> field points to the <code>string</code> table. +Therefore, you can use the string functions in object-oriented style. +For instance, <code>string.byte(s,i)</code> +can be written as <code>s:byte(i)</code>. + + +<p> +The string library assumes one-byte character encodings. + + +<p> +<hr><h3><a name="pdf-string.byte"><code>string.byte (s [, i [, j]])</code></a></h3> +Returns the internal numerical codes of the characters <code>s[i]</code>, +<code>s[i+1]</code>, ..., <code>s[j]</code>. +The default value for <code>i</code> is 1; +the default value for <code>j</code> is <code>i</code>. +These indices are corrected +following the same rules of function <a href="#pdf-string.sub"><code>string.sub</code></a>. + + +<p> +Numerical codes are not necessarily portable across platforms. + + + + +<p> +<hr><h3><a name="pdf-string.char"><code>string.char (···)</code></a></h3> +Receives zero or more integers. +Returns a string with length equal to the number of arguments, +in which each character has the internal numerical code equal +to its corresponding argument. + + +<p> +Numerical codes are not necessarily portable across platforms. + + + + +<p> +<hr><h3><a name="pdf-string.dump"><code>string.dump (function [, strip])</code></a></h3> + + +<p> +Returns a string containing a binary representation +(a <em>binary chunk</em>) +of the given function, +so that a later <a href="#pdf-load"><code>load</code></a> on this string returns +a copy of the function (but with new upvalues). +If <code>strip</code> is a true value, +the binary representation is created without debug information +about the function +(local variable names, lines, etc.). + + +<p> +Functions with upvalues have only their number of upvalues saved. +When (re)loaded, +those upvalues receive fresh instances containing <b>nil</b>. +(You can use the debug library to serialize +and reload the upvalues of a function +in a way adequate to your needs.) + + + + +<p> +<hr><h3><a name="pdf-string.find"><code>string.find (s, pattern [, init [, plain]])</code></a></h3> + + +<p> +Looks for the first match of +<code>pattern</code> (see <a href="#6.4.1">§6.4.1</a>) in the string <code>s</code>. +If it finds a match, then <code>find</code> returns the indices of <code>s</code> +where this occurrence starts and ends; +otherwise, it returns <b>nil</b>. +A third, optional numerical argument <code>init</code> specifies +where to start the search; +its default value is 1 and can be negative. +A value of <b>true</b> as a fourth, optional argument <code>plain</code> +turns off the pattern matching facilities, +so the function does a plain "find substring" operation, +with no characters in <code>pattern</code> being considered magic. +Note that if <code>plain</code> is given, then <code>init</code> must be given as well. + + +<p> +If the pattern has captures, +then in a successful match +the captured values are also returned, +after the two indices. + + + + +<p> +<hr><h3><a name="pdf-string.format"><code>string.format (formatstring, ···)</code></a></h3> + + +<p> +Returns a formatted version of its variable number of arguments +following the description given in its first argument (which must be a string). +The format string follows the same rules as the ISO C function <code>sprintf</code>. +The only differences are that the options/modifiers +<code>*</code>, <code>h</code>, <code>L</code>, <code>l</code>, <code>n</code>, +and <code>p</code> are not supported +and that there is an extra option, <code>q</code>. +The <code>q</code> option formats a string between double quotes, +using escape sequences when necessary to ensure that +it can safely be read back by the Lua interpreter. +For instance, the call + +<pre> + string.format('%q', 'a string with "quotes" and \n new line') +</pre><p> +may produce the string: + +<pre> + "a string with \"quotes\" and \ + new line" +</pre> + +<p> +Options +<code>A</code> and <code>a</code> (when available), +<code>E</code>, <code>e</code>, <code>f</code>, +<code>G</code>, and <code>g</code> all expect a number as argument. +Options <code>c</code>, <code>d</code>, +<code>i</code>, <code>o</code>, <code>u</code>, <code>X</code>, and <code>x</code> +expect an integer. +Option <code>q</code> expects a string; +option <code>s</code> expects a string without embedded zeros. +If the argument to option <code>s</code> is not a string, +it is converted to one following the same rules of <a href="#pdf-tostring"><code>tostring</code></a>. + + + + +<p> +<hr><h3><a name="pdf-string.gmatch"><code>string.gmatch (s, pattern)</code></a></h3> +Returns an iterator function that, +each time it is called, +returns the next captures from <code>pattern</code> (see <a href="#6.4.1">§6.4.1</a>) +over the string <code>s</code>. +If <code>pattern</code> specifies no captures, +then the whole match is produced in each call. + + +<p> +As an example, the following loop +will iterate over all the words from string <code>s</code>, +printing one per line: + +<pre> + s = "hello world from Lua" + for w in string.gmatch(s, "%a+") do + print(w) + end +</pre><p> +The next example collects all pairs <code>key=value</code> from the +given string into a table: + +<pre> + t = {} + s = "from=world, to=Lua" + for k, v in string.gmatch(s, "(%w+)=(%w+)") do + t[k] = v + end +</pre> + +<p> +For this function, a caret '<code>^</code>' at the start of a pattern does not +work as an anchor, as this would prevent the iteration. + + + + +<p> +<hr><h3><a name="pdf-string.gsub"><code>string.gsub (s, pattern, repl [, n])</code></a></h3> +Returns a copy of <code>s</code> +in which all (or the first <code>n</code>, if given) +occurrences of the <code>pattern</code> (see <a href="#6.4.1">§6.4.1</a>) have been +replaced by a replacement string specified by <code>repl</code>, +which can be a string, a table, or a function. +<code>gsub</code> also returns, as its second value, +the total number of matches that occurred. +The name <code>gsub</code> comes from <em>Global SUBstitution</em>. + + +<p> +If <code>repl</code> is a string, then its value is used for replacement. +The character <code>%</code> works as an escape character: +any sequence in <code>repl</code> of the form <code>%<em>d</em></code>, +with <em>d</em> between 1 and 9, +stands for the value of the <em>d</em>-th captured substring. +The sequence <code>%0</code> stands for the whole match. +The sequence <code>%%</code> stands for a single <code>%</code>. + + +<p> +If <code>repl</code> is a table, then the table is queried for every match, +using the first capture as the key. + + +<p> +If <code>repl</code> is a function, then this function is called every time a +match occurs, with all captured substrings passed as arguments, +in order. + + +<p> +In any case, +if the pattern specifies no captures, +then it behaves as if the whole pattern was inside a capture. + + +<p> +If the value returned by the table query or by the function call +is a string or a number, +then it is used as the replacement string; +otherwise, if it is <b>false</b> or <b>nil</b>, +then there is no replacement +(that is, the original match is kept in the string). + + +<p> +Here are some examples: + +<pre> + x = string.gsub("hello world", "(%w+)", "%1 %1") + --> x="hello hello world world" + + x = string.gsub("hello world", "%w+", "%0 %0", 1) + --> x="hello hello world" + + x = string.gsub("hello world from Lua", "(%w+)%s*(%w+)", "%2 %1") + --> x="world hello Lua from" + + x = string.gsub("home = $HOME, user = $USER", "%$(%w+)", os.getenv) + --> x="home = /home/roberto, user = roberto" + + x = string.gsub("4+5 = $return 4+5$", "%$(.-)%$", function (s) + return load(s)() + end) + --> x="4+5 = 9" + + local t = {name="lua", version="5.3"} + x = string.gsub("$name-$version.tar.gz", "%$(%w+)", t) + --> x="lua-5.3.tar.gz" +</pre> + + + +<p> +<hr><h3><a name="pdf-string.len"><code>string.len (s)</code></a></h3> +Receives a string and returns its length. +The empty string <code>""</code> has length 0. +Embedded zeros are counted, +so <code>"a\000bc\000"</code> has length 5. + + + + +<p> +<hr><h3><a name="pdf-string.lower"><code>string.lower (s)</code></a></h3> +Receives a string and returns a copy of this string with all +uppercase letters changed to lowercase. +All other characters are left unchanged. +The definition of what an uppercase letter is depends on the current locale. + + + + +<p> +<hr><h3><a name="pdf-string.match"><code>string.match (s, pattern [, init])</code></a></h3> +Looks for the first <em>match</em> of +<code>pattern</code> (see <a href="#6.4.1">§6.4.1</a>) in the string <code>s</code>. +If it finds one, then <code>match</code> returns +the captures from the pattern; +otherwise it returns <b>nil</b>. +If <code>pattern</code> specifies no captures, +then the whole match is returned. +A third, optional numerical argument <code>init</code> specifies +where to start the search; +its default value is 1 and can be negative. + + + + +<p> +<hr><h3><a name="pdf-string.pack"><code>string.pack (fmt, v1, v2, ···)</code></a></h3> + + +<p> +Returns a binary string containing the values <code>v1</code>, <code>v2</code>, etc. +packed (that is, serialized in binary form) +according to the format string <code>fmt</code> (see <a href="#6.4.2">§6.4.2</a>). + + + + +<p> +<hr><h3><a name="pdf-string.packsize"><code>string.packsize (fmt)</code></a></h3> + + +<p> +Returns the size of a string resulting from <a href="#pdf-string.pack"><code>string.pack</code></a> +with the given format. +The format string cannot have the variable-length options +'<code>s</code>' or '<code>z</code>' (see <a href="#6.4.2">§6.4.2</a>). + + + + +<p> +<hr><h3><a name="pdf-string.rep"><code>string.rep (s, n [, sep])</code></a></h3> +Returns a string that is the concatenation of <code>n</code> copies of +the string <code>s</code> separated by the string <code>sep</code>. +The default value for <code>sep</code> is the empty string +(that is, no separator). +Returns the empty string if <code>n</code> is not positive. + + + + +<p> +<hr><h3><a name="pdf-string.reverse"><code>string.reverse (s)</code></a></h3> +Returns a string that is the string <code>s</code> reversed. + + + + +<p> +<hr><h3><a name="pdf-string.sub"><code>string.sub (s, i [, j])</code></a></h3> +Returns the substring of <code>s</code> that +starts at <code>i</code> and continues until <code>j</code>; +<code>i</code> and <code>j</code> can be negative. +If <code>j</code> is absent, then it is assumed to be equal to -1 +(which is the same as the string length). +In particular, +the call <code>string.sub(s,1,j)</code> returns a prefix of <code>s</code> +with length <code>j</code>, +and <code>string.sub(s, -i)</code> returns a suffix of <code>s</code> +with length <code>i</code>. + + +<p> +If, after the translation of negative indices, +<code>i</code> is less than 1, +it is corrected to 1. +If <code>j</code> is greater than the string length, +it is corrected to that length. +If, after these corrections, +<code>i</code> is greater than <code>j</code>, +the function returns the empty string. + + + + +<p> +<hr><h3><a name="pdf-string.unpack"><code>string.unpack (fmt, s [, pos])</code></a></h3> + + +<p> +Returns the values packed in string <code>s</code> (see <a href="#pdf-string.pack"><code>string.pack</code></a>) +according to the format string <code>fmt</code> (see <a href="#6.4.2">§6.4.2</a>). +An optional <code>pos</code> marks where +to start reading in <code>s</code> (default is 1). +After the read values, +this function also returns the index of the first unread byte in <code>s</code>. + + + + +<p> +<hr><h3><a name="pdf-string.upper"><code>string.upper (s)</code></a></h3> +Receives a string and returns a copy of this string with all +lowercase letters changed to uppercase. +All other characters are left unchanged. +The definition of what a lowercase letter is depends on the current locale. + + + + + +<h3>6.4.1 – <a name="6.4.1">Patterns</a></h3> + +<p> +Patterns in Lua are described by regular strings, +which are interpreted as patterns by the pattern-matching functions +<a href="#pdf-string.find"><code>string.find</code></a>, +<a href="#pdf-string.gmatch"><code>string.gmatch</code></a>, +<a href="#pdf-string.gsub"><code>string.gsub</code></a>, +and <a href="#pdf-string.match"><code>string.match</code></a>. +This section describes the syntax and the meaning +(that is, what they match) of these strings. + + + +<h4>Character Class:</h4><p> +A <em>character class</em> is used to represent a set of characters. +The following combinations are allowed in describing a character class: + +<ul> + +<li><b><em>x</em>: </b> +(where <em>x</em> is not one of the <em>magic characters</em> +<code>^$()%.[]*+-?</code>) +represents the character <em>x</em> itself. +</li> + +<li><b><code>.</code>: </b> (a dot) represents all characters.</li> + +<li><b><code>%a</code>: </b> represents all letters.</li> + +<li><b><code>%c</code>: </b> represents all control characters.</li> + +<li><b><code>%d</code>: </b> represents all digits.</li> + +<li><b><code>%g</code>: </b> represents all printable characters except space.</li> + +<li><b><code>%l</code>: </b> represents all lowercase letters.</li> + +<li><b><code>%p</code>: </b> represents all punctuation characters.</li> + +<li><b><code>%s</code>: </b> represents all space characters.</li> + +<li><b><code>%u</code>: </b> represents all uppercase letters.</li> + +<li><b><code>%w</code>: </b> represents all alphanumeric characters.</li> + +<li><b><code>%x</code>: </b> represents all hexadecimal digits.</li> + +<li><b><code>%<em>x</em></code>: </b> (where <em>x</em> is any non-alphanumeric character) +represents the character <em>x</em>. +This is the standard way to escape the magic characters. +Any non-alphanumeric character +(including all punctuations, even the non-magical) +can be preceded by a '<code>%</code>' +when used to represent itself in a pattern. +</li> + +<li><b><code>[<em>set</em>]</code>: </b> +represents the class which is the union of all +characters in <em>set</em>. +A range of characters can be specified by +separating the end characters of the range, +in ascending order, with a '<code>-</code>'. +All classes <code>%</code><em>x</em> described above can also be used as +components in <em>set</em>. +All other characters in <em>set</em> represent themselves. +For example, <code>[%w_]</code> (or <code>[_%w]</code>) +represents all alphanumeric characters plus the underscore, +<code>[0-7]</code> represents the octal digits, +and <code>[0-7%l%-]</code> represents the octal digits plus +the lowercase letters plus the '<code>-</code>' character. + + +<p> +The interaction between ranges and classes is not defined. +Therefore, patterns like <code>[%a-z]</code> or <code>[a-%%]</code> +have no meaning. +</li> + +<li><b><code>[^<em>set</em>]</code>: </b> +represents the complement of <em>set</em>, +where <em>set</em> is interpreted as above. +</li> + +</ul><p> +For all classes represented by single letters (<code>%a</code>, <code>%c</code>, etc.), +the corresponding uppercase letter represents the complement of the class. +For instance, <code>%S</code> represents all non-space characters. + + +<p> +The definitions of letter, space, and other character groups +depend on the current locale. +In particular, the class <code>[a-z]</code> may not be equivalent to <code>%l</code>. + + + + + +<h4>Pattern Item:</h4><p> +A <em>pattern item</em> can be + +<ul> + +<li> +a single character class, +which matches any single character in the class; +</li> + +<li> +a single character class followed by '<code>*</code>', +which matches zero or more repetitions of characters in the class. +These repetition items will always match the longest possible sequence; +</li> + +<li> +a single character class followed by '<code>+</code>', +which matches one or more repetitions of characters in the class. +These repetition items will always match the longest possible sequence; +</li> + +<li> +a single character class followed by '<code>-</code>', +which also matches zero or more repetitions of characters in the class. +Unlike '<code>*</code>', +these repetition items will always match the shortest possible sequence; +</li> + +<li> +a single character class followed by '<code>?</code>', +which matches zero or one occurrence of a character in the class. +It always matches one occurrence if possible; +</li> + +<li> +<code>%<em>n</em></code>, for <em>n</em> between 1 and 9; +such item matches a substring equal to the <em>n</em>-th captured string +(see below); +</li> + +<li> +<code>%b<em>xy</em></code>, where <em>x</em> and <em>y</em> are two distinct characters; +such item matches strings that start with <em>x</em>, end with <em>y</em>, +and where the <em>x</em> and <em>y</em> are <em>balanced</em>. +This means that, if one reads the string from left to right, +counting <em>+1</em> for an <em>x</em> and <em>-1</em> for a <em>y</em>, +the ending <em>y</em> is the first <em>y</em> where the count reaches 0. +For instance, the item <code>%b()</code> matches expressions with +balanced parentheses. +</li> + +<li> +<code>%f[<em>set</em>]</code>, a <em>frontier pattern</em>; +such item matches an empty string at any position such that +the next character belongs to <em>set</em> +and the previous character does not belong to <em>set</em>. +The set <em>set</em> is interpreted as previously described. +The beginning and the end of the subject are handled as if +they were the character '<code>\0</code>'. +</li> + +</ul> + + + + +<h4>Pattern:</h4><p> +A <em>pattern</em> is a sequence of pattern items. +A caret '<code>^</code>' at the beginning of a pattern anchors the match at the +beginning of the subject string. +A '<code>$</code>' at the end of a pattern anchors the match at the +end of the subject string. +At other positions, +'<code>^</code>' and '<code>$</code>' have no special meaning and represent themselves. + + + + + +<h4>Captures:</h4><p> +A pattern can contain sub-patterns enclosed in parentheses; +they describe <em>captures</em>. +When a match succeeds, the substrings of the subject string +that match captures are stored (<em>captured</em>) for future use. +Captures are numbered according to their left parentheses. +For instance, in the pattern <code>"(a*(.)%w(%s*))"</code>, +the part of the string matching <code>"a*(.)%w(%s*)"</code> is +stored as the first capture (and therefore has number 1); +the character matching "<code>.</code>" is captured with number 2, +and the part matching "<code>%s*</code>" has number 3. + + +<p> +As a special case, the empty capture <code>()</code> captures +the current string position (a number). +For instance, if we apply the pattern <code>"()aa()"</code> on the +string <code>"flaaap"</code>, there will be two captures: 3 and 5. + + + + + + + +<h3>6.4.2 – <a name="6.4.2">Format Strings for Pack and Unpack</a></h3> + +<p> +The first argument to <a href="#pdf-string.pack"><code>string.pack</code></a>, +<a href="#pdf-string.packsize"><code>string.packsize</code></a>, and <a href="#pdf-string.unpack"><code>string.unpack</code></a> +is a format string, +which describes the layout of the structure being created or read. + + +<p> +A format string is a sequence of conversion options. +The conversion options are as follows: + +<ul> +<li><b><code><</code>: </b>sets little endian</li> +<li><b><code>></code>: </b>sets big endian</li> +<li><b><code>=</code>: </b>sets native endian</li> +<li><b><code>![<em>n</em>]</code>: </b>sets maximum alignment to <code>n</code> +(default is native alignment)</li> +<li><b><code>b</code>: </b>a signed byte (<code>char</code>)</li> +<li><b><code>B</code>: </b>an unsigned byte (<code>char</code>)</li> +<li><b><code>h</code>: </b>a signed <code>short</code> (native size)</li> +<li><b><code>H</code>: </b>an unsigned <code>short</code> (native size)</li> +<li><b><code>l</code>: </b>a signed <code>long</code> (native size)</li> +<li><b><code>L</code>: </b>an unsigned <code>long</code> (native size)</li> +<li><b><code>j</code>: </b>a <code>lua_Integer</code></li> +<li><b><code>J</code>: </b>a <code>lua_Unsigned</code></li> +<li><b><code>T</code>: </b>a <code>size_t</code> (native size)</li> +<li><b><code>i[<em>n</em>]</code>: </b>a signed <code>int</code> with <code>n</code> bytes +(default is native size)</li> +<li><b><code>I[<em>n</em>]</code>: </b>an unsigned <code>int</code> with <code>n</code> bytes +(default is native size)</li> +<li><b><code>f</code>: </b>a <code>float</code> (native size)</li> +<li><b><code>d</code>: </b>a <code>double</code> (native size)</li> +<li><b><code>n</code>: </b>a <code>lua_Number</code></li> +<li><b><code>c<em>n</em></code>: </b>a fixed-sized string with <code>n</code> bytes</li> +<li><b><code>z</code>: </b>a zero-terminated string</li> +<li><b><code>s[<em>n</em>]</code>: </b>a string preceded by its length +coded as an unsigned integer with <code>n</code> bytes +(default is a <code>size_t</code>)</li> +<li><b><code>x</code>: </b>one byte of padding</li> +<li><b><code>X<em>op</em></code>: </b>an empty item that aligns +according to option <code>op</code> +(which is otherwise ignored)</li> +<li><b>'<code> </code>': </b>(empty space) ignored</li> +</ul><p> +(A "<code>[<em>n</em>]</code>" means an optional integral numeral.) +Except for padding, spaces, and configurations +(options "<code>xX <=>!</code>"), +each option corresponds to an argument (in <a href="#pdf-string.pack"><code>string.pack</code></a>) +or a result (in <a href="#pdf-string.unpack"><code>string.unpack</code></a>). + + +<p> +For options "<code>!<em>n</em></code>", "<code>s<em>n</em></code>", "<code>i<em>n</em></code>", and "<code>I<em>n</em></code>", +<code>n</code> can be any integer between 1 and 16. +All integral options check overflows; +<a href="#pdf-string.pack"><code>string.pack</code></a> checks whether the given value fits in the given size; +<a href="#pdf-string.unpack"><code>string.unpack</code></a> checks whether the read value fits in a Lua integer. + + +<p> +Any format string starts as if prefixed by "<code>!1=</code>", +that is, +with maximum alignment of 1 (no alignment) +and native endianness. + + +<p> +Alignment works as follows: +For each option, +the format gets extra padding until the data starts +at an offset that is a multiple of the minimum between the +option size and the maximum alignment; +this minimum must be a power of 2. +Options "<code>c</code>" and "<code>z</code>" are not aligned; +option "<code>s</code>" follows the alignment of its starting integer. + + +<p> +All padding is filled with zeros by <a href="#pdf-string.pack"><code>string.pack</code></a> +(and ignored by <a href="#pdf-string.unpack"><code>string.unpack</code></a>). + + + + + + + +<h2>6.5 – <a name="6.5">UTF-8 Support</a></h2> + +<p> +This library provides basic support for UTF-8 encoding. +It provides all its functions inside the table <a name="pdf-utf8"><code>utf8</code></a>. +This library does not provide any support for Unicode other +than the handling of the encoding. +Any operation that needs the meaning of a character, +such as character classification, is outside its scope. + + +<p> +Unless stated otherwise, +all functions that expect a byte position as a parameter +assume that the given position is either the start of a byte sequence +or one plus the length of the subject string. +As in the string library, +negative indices count from the end of the string. + + +<p> +<hr><h3><a name="pdf-utf8.char"><code>utf8.char (···)</code></a></h3> +Receives zero or more integers, +converts each one to its corresponding UTF-8 byte sequence +and returns a string with the concatenation of all these sequences. + + + + +<p> +<hr><h3><a name="pdf-utf8.charpattern"><code>utf8.charpattern</code></a></h3> +The pattern (a string, not a function) "<code>[\0-\x7F\xC2-\xF4][\x80-\xBF]*</code>" +(see <a href="#6.4.1">§6.4.1</a>), +which matches exactly one UTF-8 byte sequence, +assuming that the subject is a valid UTF-8 string. + + + + +<p> +<hr><h3><a name="pdf-utf8.codes"><code>utf8.codes (s)</code></a></h3> + + +<p> +Returns values so that the construction + +<pre> + for p, c in utf8.codes(s) do <em>body</em> end +</pre><p> +will iterate over all characters in string <code>s</code>, +with <code>p</code> being the position (in bytes) and <code>c</code> the code point +of each character. +It raises an error if it meets any invalid byte sequence. + + + + +<p> +<hr><h3><a name="pdf-utf8.codepoint"><code>utf8.codepoint (s [, i [, j]])</code></a></h3> +Returns the codepoints (as integers) from all characters in <code>s</code> +that start between byte position <code>i</code> and <code>j</code> (both included). +The default for <code>i</code> is 1 and for <code>j</code> is <code>i</code>. +It raises an error if it meets any invalid byte sequence. + + + + +<p> +<hr><h3><a name="pdf-utf8.len"><code>utf8.len (s [, i [, j]])</code></a></h3> +Returns the number of UTF-8 characters in string <code>s</code> +that start between positions <code>i</code> and <code>j</code> (both inclusive). +The default for <code>i</code> is 1 and for <code>j</code> is -1. +If it finds any invalid byte sequence, +returns a false value plus the position of the first invalid byte. + + + + +<p> +<hr><h3><a name="pdf-utf8.offset"><code>utf8.offset (s, n [, i])</code></a></h3> +Returns the position (in bytes) where the encoding of the +<code>n</code>-th character of <code>s</code> +(counting from position <code>i</code>) starts. +A negative <code>n</code> gets characters before position <code>i</code>. +The default for <code>i</code> is 1 when <code>n</code> is non-negative +and <code>#s + 1</code> otherwise, +so that <code>utf8.offset(s, -n)</code> gets the offset of the +<code>n</code>-th character from the end of the string. +If the specified character is neither in the subject +nor right after its end, +the function returns <b>nil</b>. + + +<p> +As a special case, +when <code>n</code> is 0 the function returns the start of the encoding +of the character that contains the <code>i</code>-th byte of <code>s</code>. + + +<p> +This function assumes that <code>s</code> is a valid UTF-8 string. + + + + + + + +<h2>6.6 – <a name="6.6">Table Manipulation</a></h2> + +<p> +This library provides generic functions for table manipulation. +It provides all its functions inside the table <a name="pdf-table"><code>table</code></a>. + + +<p> +Remember that, whenever an operation needs the length of a table, +the table must be a proper sequence +or have a <code>__len</code> metamethod (see <a href="#3.4.7">§3.4.7</a>). +All functions ignore non-numeric keys +in the tables given as arguments. + + +<p> +<hr><h3><a name="pdf-table.concat"><code>table.concat (list [, sep [, i [, j]]])</code></a></h3> + + +<p> +Given a list where all elements are strings or numbers, +returns the string <code>list[i]..sep..list[i+1] ··· sep..list[j]</code>. +The default value for <code>sep</code> is the empty string, +the default for <code>i</code> is 1, +and the default for <code>j</code> is <code>#list</code>. +If <code>i</code> is greater than <code>j</code>, returns the empty string. + + + + +<p> +<hr><h3><a name="pdf-table.insert"><code>table.insert (list, [pos,] value)</code></a></h3> + + +<p> +Inserts element <code>value</code> at position <code>pos</code> in <code>list</code>, +shifting up the elements +<code>list[pos], list[pos+1], ···, list[#list]</code>. +The default value for <code>pos</code> is <code>#list+1</code>, +so that a call <code>table.insert(t,x)</code> inserts <code>x</code> at the end +of list <code>t</code>. + + + + +<p> +<hr><h3><a name="pdf-table.move"><code>table.move (a1, f, e, t [,a2])</code></a></h3> + + +<p> +Moves elements from table <code>a1</code> to table <code>a2</code>. +This function performs the equivalent to the following +multiple assignment: +<code>a2[t],··· = a1[f],···,a1[e]</code>. +The default for <code>a2</code> is <code>a1</code>. +The destination range can overlap with the source range. +Index <code>f</code> must be positive. + + + + +<p> +<hr><h3><a name="pdf-table.pack"><code>table.pack (···)</code></a></h3> + + +<p> +Returns a new table with all parameters stored into keys 1, 2, etc. +and with a field "<code>n</code>" with the total number of parameters. +Note that the resulting table may not be a sequence. + + + + +<p> +<hr><h3><a name="pdf-table.remove"><code>table.remove (list [, pos])</code></a></h3> + + +<p> +Removes from <code>list</code> the element at position <code>pos</code>, +returning the value of the removed element. +When <code>pos</code> is an integer between 1 and <code>#list</code>, +it shifts down the elements +<code>list[pos+1], list[pos+2], ···, list[#list]</code> +and erases element <code>list[#list]</code>; +The index <code>pos</code> can also be 0 when <code>#list</code> is 0, +or <code>#list + 1</code>; +in those cases, the function erases the element <code>list[pos]</code>. + + +<p> +The default value for <code>pos</code> is <code>#list</code>, +so that a call <code>table.remove(l)</code> removes the last element +of list <code>l</code>. + + + + +<p> +<hr><h3><a name="pdf-table.sort"><code>table.sort (list [, comp])</code></a></h3> + + +<p> +Sorts list elements in a given order, <em>in-place</em>, +from <code>list[1]</code> to <code>list[#list]</code>. +If <code>comp</code> is given, +then it must be a function that receives two list elements +and returns true when the first element must come +before the second in the final order +(so that <code>not comp(list[i+1],list[i])</code> will be true after the sort). +If <code>comp</code> is not given, +then the standard Lua operator <code><</code> is used instead. + + +<p> +The sort algorithm is not stable; +that is, elements considered equal by the given order +may have their relative positions changed by the sort. + + + + +<p> +<hr><h3><a name="pdf-table.unpack"><code>table.unpack (list [, i [, j]])</code></a></h3> + + +<p> +Returns the elements from the given list. +This function is equivalent to + +<pre> + return list[i], list[i+1], ···, list[j] +</pre><p> +By default, <code>i</code> is 1 and <code>j</code> is <code>#list</code>. + + + + + + + +<h2>6.7 – <a name="6.7">Mathematical Functions</a></h2> + +<p> +This library provides basic mathematical functions. +It provides all its functions and constants inside the table <a name="pdf-math"><code>math</code></a>. +Functions with the annotation "<code>integer/float</code>" give +integer results for integer arguments +and float results for float (or mixed) arguments. +Rounding functions +(<a href="#pdf-math.ceil"><code>math.ceil</code></a>, <a href="#pdf-math.floor"><code>math.floor</code></a>, and <a href="#pdf-math.modf"><code>math.modf</code></a>) +return an integer when the result fits in the range of an integer, +or a float otherwise. + + +<p> +<hr><h3><a name="pdf-math.abs"><code>math.abs (x)</code></a></h3> + + +<p> +Returns the absolute value of <code>x</code>. (integer/float) + + + + +<p> +<hr><h3><a name="pdf-math.acos"><code>math.acos (x)</code></a></h3> + + +<p> +Returns the arc cosine of <code>x</code> (in radians). + + + + +<p> +<hr><h3><a name="pdf-math.asin"><code>math.asin (x)</code></a></h3> + + +<p> +Returns the arc sine of <code>x</code> (in radians). + + + + +<p> +<hr><h3><a name="pdf-math.atan"><code>math.atan (y [, x])</code></a></h3> + + +<p> + +Returns the arc tangent of <code>y/x</code> (in radians), +but uses the signs of both parameters to find the +quadrant of the result. +(It also handles correctly the case of <code>x</code> being zero.) + + +<p> +The default value for <code>x</code> is 1, +so that the call <code>math.atan(y)</code> +returns the arc tangent of <code>y</code>. + + + + +<p> +<hr><h3><a name="pdf-math.ceil"><code>math.ceil (x)</code></a></h3> + + +<p> +Returns the smallest integral value larger than or equal to <code>x</code>. + + + + +<p> +<hr><h3><a name="pdf-math.cos"><code>math.cos (x)</code></a></h3> + + +<p> +Returns the cosine of <code>x</code> (assumed to be in radians). + + + + +<p> +<hr><h3><a name="pdf-math.deg"><code>math.deg (x)</code></a></h3> + + +<p> +Converts the angle <code>x</code> from radians to degrees. + + + + +<p> +<hr><h3><a name="pdf-math.exp"><code>math.exp (x)</code></a></h3> + + +<p> +Returns the value <em>e<sup>x</sup></em> +(where <code>e</code> is the base of natural logarithms). + + + + +<p> +<hr><h3><a name="pdf-math.floor"><code>math.floor (x)</code></a></h3> + + +<p> +Returns the largest integral value smaller than or equal to <code>x</code>. + + + + +<p> +<hr><h3><a name="pdf-math.fmod"><code>math.fmod (x, y)</code></a></h3> + + +<p> +Returns the remainder of the division of <code>x</code> by <code>y</code> +that rounds the quotient towards zero. (integer/float) + + + + +<p> +<hr><h3><a name="pdf-math.huge"><code>math.huge</code></a></h3> + + +<p> +The float value <code>HUGE_VAL</code>, +a value larger than any other numerical value. + + + + +<p> +<hr><h3><a name="pdf-math.log"><code>math.log (x [, base])</code></a></h3> + + +<p> +Returns the logarithm of <code>x</code> in the given base. +The default for <code>base</code> is <em>e</em> +(so that the function returns the natural logarithm of <code>x</code>). + + + + +<p> +<hr><h3><a name="pdf-math.max"><code>math.max (x, ···)</code></a></h3> + + +<p> +Returns the argument with the maximum value, +according to the Lua operator <code><</code>. (integer/float) + + + + +<p> +<hr><h3><a name="pdf-math.maxinteger"><code>math.maxinteger</code></a></h3> +An integer with the maximum value for an integer. + + + + +<p> +<hr><h3><a name="pdf-math.min"><code>math.min (x, ···)</code></a></h3> + + +<p> +Returns the argument with the minimum value, +according to the Lua operator <code><</code>. (integer/float) + + + + +<p> +<hr><h3><a name="pdf-math.mininteger"><code>math.mininteger</code></a></h3> +An integer with the minimum value for an integer. + + + + +<p> +<hr><h3><a name="pdf-math.modf"><code>math.modf (x)</code></a></h3> + + +<p> +Returns the integral part of <code>x</code> and the fractional part of <code>x</code>. +Its second result is always a float. + + + + +<p> +<hr><h3><a name="pdf-math.pi"><code>math.pi</code></a></h3> + + +<p> +The value of <em>π</em>. + + + + +<p> +<hr><h3><a name="pdf-math.rad"><code>math.rad (x)</code></a></h3> + + +<p> +Converts the angle <code>x</code> from degrees to radians. + + + + +<p> +<hr><h3><a name="pdf-math.random"><code>math.random ([m [, n]])</code></a></h3> + + +<p> +When called without arguments, +returns a pseudo-random float with uniform distribution +in the range <em>[0,1)</em>. +When called with two integers <code>m</code> and <code>n</code>, +<code>math.random</code> returns a pseudo-random integer +with uniform distribution in the range <em>[m, n]</em>. +(The value <em>m-n</em> cannot be negative and must fit in a Lua integer.) +The call <code>math.random(n)</code> is equivalent to <code>math.random(1,n)</code>. + + +<p> +This function is an interface to the underling +pseudo-random generator function provided by C. +No guarantees can be given for its statistical properties. + + + + +<p> +<hr><h3><a name="pdf-math.randomseed"><code>math.randomseed (x)</code></a></h3> + + +<p> +Sets <code>x</code> as the "seed" +for the pseudo-random generator: +equal seeds produce equal sequences of numbers. + + + + +<p> +<hr><h3><a name="pdf-math.sin"><code>math.sin (x)</code></a></h3> + + +<p> +Returns the sine of <code>x</code> (assumed to be in radians). + + + + +<p> +<hr><h3><a name="pdf-math.sqrt"><code>math.sqrt (x)</code></a></h3> + + +<p> +Returns the square root of <code>x</code>. +(You can also use the expression <code>x^0.5</code> to compute this value.) + + + + +<p> +<hr><h3><a name="pdf-math.tan"><code>math.tan (x)</code></a></h3> + + +<p> +Returns the tangent of <code>x</code> (assumed to be in radians). + + + + +<p> +<hr><h3><a name="pdf-math.tointeger"><code>math.tointeger (x)</code></a></h3> + + +<p> +If the value <code>x</code> is convertible to an integer, +returns that integer. +Otherwise, returns <b>nil</b>. + + + + +<p> +<hr><h3><a name="pdf-math.type"><code>math.type (x)</code></a></h3> + + +<p> +Returns "<code>integer</code>" if <code>x</code> is an integer, +"<code>float</code>" if it is a float, +or <b>nil</b> if <code>x</code> is not a number. + + + + +<p> +<hr><h3><a name="pdf-math.ult"><code>math.ult (m, n)</code></a></h3> + + +<p> +Returns a boolean, +true if integer <code>m</code> is below integer <code>n</code> when +they are compared as unsigned integers. + + + + + + + +<h2>6.8 – <a name="6.8">Input and Output Facilities</a></h2> + +<p> +The I/O library provides two different styles for file manipulation. +The first one uses implicit file handles; +that is, there are operations to set a default input file and a +default output file, +and all input/output operations are over these default files. +The second style uses explicit file handles. + + +<p> +When using implicit file handles, +all operations are supplied by table <a name="pdf-io"><code>io</code></a>. +When using explicit file handles, +the operation <a href="#pdf-io.open"><code>io.open</code></a> returns a file handle +and then all operations are supplied as methods of the file handle. + + +<p> +The table <code>io</code> also provides +three predefined file handles with their usual meanings from C: +<a name="pdf-io.stdin"><code>io.stdin</code></a>, <a name="pdf-io.stdout"><code>io.stdout</code></a>, and <a name="pdf-io.stderr"><code>io.stderr</code></a>. +The I/O library never closes these files. + + +<p> +Unless otherwise stated, +all I/O functions return <b>nil</b> on failure +(plus an error message as a second result and +a system-dependent error code as a third result) +and some value different from <b>nil</b> on success. +On non-POSIX systems, +the computation of the error message and error code +in case of errors +may be not thread safe, +because they rely on the global C variable <code>errno</code>. + + +<p> +<hr><h3><a name="pdf-io.close"><code>io.close ([file])</code></a></h3> + + +<p> +Equivalent to <code>file:close()</code>. +Without a <code>file</code>, closes the default output file. + + + + +<p> +<hr><h3><a name="pdf-io.flush"><code>io.flush ()</code></a></h3> + + +<p> +Equivalent to <code>io.output():flush()</code>. + + + + +<p> +<hr><h3><a name="pdf-io.input"><code>io.input ([file])</code></a></h3> + + +<p> +When called with a file name, it opens the named file (in text mode), +and sets its handle as the default input file. +When called with a file handle, +it simply sets this file handle as the default input file. +When called without parameters, +it returns the current default input file. + + +<p> +In case of errors this function raises the error, +instead of returning an error code. + + + + +<p> +<hr><h3><a name="pdf-io.lines"><code>io.lines ([filename ···])</code></a></h3> + + +<p> +Opens the given file name in read mode +and returns an iterator function that +works like <code>file:lines(···)</code> over the opened file. +When the iterator function detects the end of file, +it returns no values (to finish the loop) and automatically closes the file. + + +<p> +The call <code>io.lines()</code> (with no file name) is equivalent +to <code>io.input():lines("*l")</code>; +that is, it iterates over the lines of the default input file. +In this case it does not close the file when the loop ends. + + +<p> +In case of errors this function raises the error, +instead of returning an error code. + + + + +<p> +<hr><h3><a name="pdf-io.open"><code>io.open (filename [, mode])</code></a></h3> + + +<p> +This function opens a file, +in the mode specified in the string <code>mode</code>. +It returns a new file handle, +or, in case of errors, <b>nil</b> plus an error message. + + +<p> +The <code>mode</code> string can be any of the following: + +<ul> +<li><b>"<code>r</code>": </b> read mode (the default);</li> +<li><b>"<code>w</code>": </b> write mode;</li> +<li><b>"<code>a</code>": </b> append mode;</li> +<li><b>"<code>r+</code>": </b> update mode, all previous data is preserved;</li> +<li><b>"<code>w+</code>": </b> update mode, all previous data is erased;</li> +<li><b>"<code>a+</code>": </b> append update mode, previous data is preserved, + writing is only allowed at the end of file.</li> +</ul><p> +The <code>mode</code> string can also have a '<code>b</code>' at the end, +which is needed in some systems to open the file in binary mode. + + + + +<p> +<hr><h3><a name="pdf-io.output"><code>io.output ([file])</code></a></h3> + + +<p> +Similar to <a href="#pdf-io.input"><code>io.input</code></a>, but operates over the default output file. + + + + +<p> +<hr><h3><a name="pdf-io.popen"><code>io.popen (prog [, mode])</code></a></h3> + + +<p> +This function is system dependent and is not available +on all platforms. + + +<p> +Starts program <code>prog</code> in a separated process and returns +a file handle that you can use to read data from this program +(if <code>mode</code> is <code>"r"</code>, the default) +or to write data to this program +(if <code>mode</code> is <code>"w"</code>). + + + + +<p> +<hr><h3><a name="pdf-io.read"><code>io.read (···)</code></a></h3> + + +<p> +Equivalent to <code>io.input():read(···)</code>. + + + + +<p> +<hr><h3><a name="pdf-io.tmpfile"><code>io.tmpfile ()</code></a></h3> + + +<p> +Returns a handle for a temporary file. +This file is opened in update mode +and it is automatically removed when the program ends. + + + + +<p> +<hr><h3><a name="pdf-io.type"><code>io.type (obj)</code></a></h3> + + +<p> +Checks whether <code>obj</code> is a valid file handle. +Returns the string <code>"file"</code> if <code>obj</code> is an open file handle, +<code>"closed file"</code> if <code>obj</code> is a closed file handle, +or <b>nil</b> if <code>obj</code> is not a file handle. + + + + +<p> +<hr><h3><a name="pdf-io.write"><code>io.write (···)</code></a></h3> + + +<p> +Equivalent to <code>io.output():write(···)</code>. + + + + +<p> +<hr><h3><a name="pdf-file:close"><code>file:close ()</code></a></h3> + + +<p> +Closes <code>file</code>. +Note that files are automatically closed when +their handles are garbage collected, +but that takes an unpredictable amount of time to happen. + + +<p> +When closing a file handle created with <a href="#pdf-io.popen"><code>io.popen</code></a>, +<a href="#pdf-file:close"><code>file:close</code></a> returns the same values +returned by <a href="#pdf-os.execute"><code>os.execute</code></a>. + + + + +<p> +<hr><h3><a name="pdf-file:flush"><code>file:flush ()</code></a></h3> + + +<p> +Saves any written data to <code>file</code>. + + + + +<p> +<hr><h3><a name="pdf-file:lines"><code>file:lines (···)</code></a></h3> + + +<p> +Returns an iterator function that, +each time it is called, +reads the file according to the given formats. +When no format is given, +uses "<code>l</code>" as a default. +As an example, the construction + +<pre> + for c in file:lines(1) do <em>body</em> end +</pre><p> +will iterate over all characters of the file, +starting at the current position. +Unlike <a href="#pdf-io.lines"><code>io.lines</code></a>, this function does not close the file +when the loop ends. + + +<p> +In case of errors this function raises the error, +instead of returning an error code. + + + + +<p> +<hr><h3><a name="pdf-file:read"><code>file:read (···)</code></a></h3> + + +<p> +Reads the file <code>file</code>, +according to the given formats, which specify what to read. +For each format, +the function returns a string or a number with the characters read, +or <b>nil</b> if it cannot read data with the specified format. +(In this latter case, +the function does not read subsequent formats.) +When called without formats, +it uses a default format that reads the next line +(see below). + + +<p> +The available formats are + +<ul> + +<li><b>"<code>n</code>": </b> +reads a numeral and returns it as a float or an integer, +following the lexical conventions of Lua. +(The numeral may have leading spaces and a sign.) +This format always reads the longest input sequence that +is a valid prefix for a number; +if that prefix does not form a valid number +(e.g., an empty string, "<code>0x</code>", or "<code>3.4e-</code>"), +it is discarded and the function returns <b>nil</b>. +</li> + +<li><b>"<code>i</code>": </b> +reads an integral number and returns it as an integer. +</li> + +<li><b>"<code>a</code>": </b> +reads the whole file, starting at the current position. +On end of file, it returns the empty string. +</li> + +<li><b>"<code>l</code>": </b> +reads the next line skipping the end of line, +returning <b>nil</b> on end of file. +This is the default format. +</li> + +<li><b>"<code>L</code>": </b> +reads the next line keeping the end-of-line character (if present), +returning <b>nil</b> on end of file. +</li> + +<li><b><em>number</em>: </b> +reads a string with up to this number of bytes, +returning <b>nil</b> on end of file. +If <code>number</code> is zero, +it reads nothing and returns an empty string, +or <b>nil</b> on end of file. +</li> + +</ul><p> +The formats "<code>l</code>" and "<code>L</code>" should be used only for text files. + + + + +<p> +<hr><h3><a name="pdf-file:seek"><code>file:seek ([whence [, offset]])</code></a></h3> + + +<p> +Sets and gets the file position, +measured from the beginning of the file, +to the position given by <code>offset</code> plus a base +specified by the string <code>whence</code>, as follows: + +<ul> +<li><b>"<code>set</code>": </b> base is position 0 (beginning of the file);</li> +<li><b>"<code>cur</code>": </b> base is current position;</li> +<li><b>"<code>end</code>": </b> base is end of file;</li> +</ul><p> +In case of success, <code>seek</code> returns the final file position, +measured in bytes from the beginning of the file. +If <code>seek</code> fails, it returns <b>nil</b>, +plus a string describing the error. + + +<p> +The default value for <code>whence</code> is <code>"cur"</code>, +and for <code>offset</code> is 0. +Therefore, the call <code>file:seek()</code> returns the current +file position, without changing it; +the call <code>file:seek("set")</code> sets the position to the +beginning of the file (and returns 0); +and the call <code>file:seek("end")</code> sets the position to the +end of the file, and returns its size. + + + + +<p> +<hr><h3><a name="pdf-file:setvbuf"><code>file:setvbuf (mode [, size])</code></a></h3> + + +<p> +Sets the buffering mode for an output file. +There are three available modes: + +<ul> + +<li><b>"<code>no</code>": </b> +no buffering; the result of any output operation appears immediately. +</li> + +<li><b>"<code>full</code>": </b> +full buffering; output operation is performed only +when the buffer is full or when +you explicitly <code>flush</code> the file (see <a href="#pdf-io.flush"><code>io.flush</code></a>). +</li> + +<li><b>"<code>line</code>": </b> +line buffering; output is buffered until a newline is output +or there is any input from some special files +(such as a terminal device). +</li> + +</ul><p> +For the last two cases, <code>size</code> +specifies the size of the buffer, in bytes. +The default is an appropriate size. + + + + +<p> +<hr><h3><a name="pdf-file:write"><code>file:write (···)</code></a></h3> + + +<p> +Writes the value of each of its arguments to <code>file</code>. +The arguments must be strings or numbers. + + +<p> +In case of success, this function returns <code>file</code>. +Otherwise it returns <b>nil</b> plus a string describing the error. + + + + + + + +<h2>6.9 – <a name="6.9">Operating System Facilities</a></h2> + +<p> +This library is implemented through table <a name="pdf-os"><code>os</code></a>. + + +<p> +<hr><h3><a name="pdf-os.clock"><code>os.clock ()</code></a></h3> + + +<p> +Returns an approximation of the amount in seconds of CPU time +used by the program. + + + + +<p> +<hr><h3><a name="pdf-os.date"><code>os.date ([format [, time]])</code></a></h3> + + +<p> +Returns a string or a table containing date and time, +formatted according to the given string <code>format</code>. + + +<p> +If the <code>time</code> argument is present, +this is the time to be formatted +(see the <a href="#pdf-os.time"><code>os.time</code></a> function for a description of this value). +Otherwise, <code>date</code> formats the current time. + + +<p> +If <code>format</code> starts with '<code>!</code>', +then the date is formatted in Coordinated Universal Time. +After this optional character, +if <code>format</code> is the string "<code>*t</code>", +then <code>date</code> returns a table with the following fields: +<code>year</code> (four digits), <code>month</code> (1–12), <code>day</code> (1–31), +<code>hour</code> (0–23), <code>min</code> (0–59), <code>sec</code> (0–61), +<code>wday</code> (weekday, Sunday is 1), +<code>yday</code> (day of the year), +and <code>isdst</code> (daylight saving flag, a boolean). +This last field may be absent +if the information is not available. + + +<p> +If <code>format</code> is not "<code>*t</code>", +then <code>date</code> returns the date as a string, +formatted according to the same rules as the ISO C function <code>strftime</code>. + + +<p> +When called without arguments, +<code>date</code> returns a reasonable date and time representation that depends on +the host system and on the current locale +(that is, <code>os.date()</code> is equivalent to <code>os.date("%c")</code>). + + +<p> +On non-POSIX systems, +this function may be not thread safe +because of its reliance on C function <code>gmtime</code> and C function <code>localtime</code>. + + + + +<p> +<hr><h3><a name="pdf-os.difftime"><code>os.difftime (t2, t1)</code></a></h3> + + +<p> +Returns the difference, in seconds, +from time <code>t1</code> to time <code>t2</code> +(where the times are values returned by <a href="#pdf-os.time"><code>os.time</code></a>). +In POSIX, Windows, and some other systems, +this value is exactly <code>t2</code><em>-</em><code>t1</code>. + + + + +<p> +<hr><h3><a name="pdf-os.execute"><code>os.execute ([command])</code></a></h3> + + +<p> +This function is equivalent to the ISO C function <code>system</code>. +It passes <code>command</code> to be executed by an operating system shell. +Its first result is <b>true</b> +if the command terminated successfully, +or <b>nil</b> otherwise. +After this first result +the function returns a string plus a number, +as follows: + +<ul> + +<li><b>"<code>exit</code>": </b> +the command terminated normally; +the following number is the exit status of the command. +</li> + +<li><b>"<code>signal</code>": </b> +the command was terminated by a signal; +the following number is the signal that terminated the command. +</li> + +</ul> + +<p> +When called without a <code>command</code>, +<code>os.execute</code> returns a boolean that is true if a shell is available. + + + + +<p> +<hr><h3><a name="pdf-os.exit"><code>os.exit ([code [, close]])</code></a></h3> + + +<p> +Calls the ISO C function <code>exit</code> to terminate the host program. +If <code>code</code> is <b>true</b>, +the returned status is <code>EXIT_SUCCESS</code>; +if <code>code</code> is <b>false</b>, +the returned status is <code>EXIT_FAILURE</code>; +if <code>code</code> is a number, +the returned status is this number. +The default value for <code>code</code> is <b>true</b>. + + +<p> +If the optional second argument <code>close</code> is true, +closes the Lua state before exiting. + + + + +<p> +<hr><h3><a name="pdf-os.getenv"><code>os.getenv (varname)</code></a></h3> + + +<p> +Returns the value of the process environment variable <code>varname</code>, +or <b>nil</b> if the variable is not defined. + + + + +<p> +<hr><h3><a name="pdf-os.remove"><code>os.remove (filename)</code></a></h3> + + +<p> +Deletes the file (or empty directory, on POSIX systems) +with the given name. +If this function fails, it returns <b>nil</b>, +plus a string describing the error and the error code. + + + + +<p> +<hr><h3><a name="pdf-os.rename"><code>os.rename (oldname, newname)</code></a></h3> + + +<p> +Renames file or directory named <code>oldname</code> to <code>newname</code>. +If this function fails, it returns <b>nil</b>, +plus a string describing the error and the error code. + + + + +<p> +<hr><h3><a name="pdf-os.setlocale"><code>os.setlocale (locale [, category])</code></a></h3> + + +<p> +Sets the current locale of the program. +<code>locale</code> is a system-dependent string specifying a locale; +<code>category</code> is an optional string describing which category to change: +<code>"all"</code>, <code>"collate"</code>, <code>"ctype"</code>, +<code>"monetary"</code>, <code>"numeric"</code>, or <code>"time"</code>; +the default category is <code>"all"</code>. +The function returns the name of the new locale, +or <b>nil</b> if the request cannot be honored. + + +<p> +If <code>locale</code> is the empty string, +the current locale is set to an implementation-defined native locale. +If <code>locale</code> is the string "<code>C</code>", +the current locale is set to the standard C locale. + + +<p> +When called with <b>nil</b> as the first argument, +this function only returns the name of the current locale +for the given category. + + +<p> +This function may be not thread safe +because of its reliance on C function <code>setlocale</code>. + + + + +<p> +<hr><h3><a name="pdf-os.time"><code>os.time ([table])</code></a></h3> + + +<p> +Returns the current time when called without arguments, +or a time representing the date and time specified by the given table. +This table must have fields <code>year</code>, <code>month</code>, and <code>day</code>, +and may have fields +<code>hour</code> (default is 12), +<code>min</code> (default is 0), +<code>sec</code> (default is 0), +and <code>isdst</code> (default is <b>nil</b>). +For a description of these fields, see the <a href="#pdf-os.date"><code>os.date</code></a> function. + + +<p> +The returned value is a number, whose meaning depends on your system. +In POSIX, Windows, and some other systems, +this number counts the number +of seconds since some given start time (the "epoch"). +In other systems, the meaning is not specified, +and the number returned by <code>time</code> can be used only as an argument to +<a href="#pdf-os.date"><code>os.date</code></a> and <a href="#pdf-os.difftime"><code>os.difftime</code></a>. + + + + +<p> +<hr><h3><a name="pdf-os.tmpname"><code>os.tmpname ()</code></a></h3> + + +<p> +Returns a string with a file name that can +be used for a temporary file. +The file must be explicitly opened before its use +and explicitly removed when no longer needed. + + +<p> +On POSIX systems, +this function also creates a file with that name, +to avoid security risks. +(Someone else might create the file with wrong permissions +in the time between getting the name and creating the file.) +You still have to open the file to use it +and to remove it (even if you do not use it). + + +<p> +When possible, +you may prefer to use <a href="#pdf-io.tmpfile"><code>io.tmpfile</code></a>, +which automatically removes the file when the program ends. + + + + + + + +<h2>6.10 – <a name="6.10">The Debug Library</a></h2> + +<p> +This library provides +the functionality of the debug interface (<a href="#4.9">§4.9</a>) to Lua programs. +You should exert care when using this library. +Several of its functions +violate basic assumptions about Lua code +(e.g., that variables local to a function +cannot be accessed from outside; +that userdata metatables cannot be changed by Lua code; +that Lua programs do not crash) +and therefore can compromise otherwise secure code. +Moreover, some functions in this library may be slow. + + +<p> +All functions in this library are provided +inside the <a name="pdf-debug"><code>debug</code></a> table. +All functions that operate over a thread +have an optional first argument which is the +thread to operate over. +The default is always the current thread. + + +<p> +<hr><h3><a name="pdf-debug.debug"><code>debug.debug ()</code></a></h3> + + +<p> +Enters an interactive mode with the user, +running each string that the user enters. +Using simple commands and other debug facilities, +the user can inspect global and local variables, +change their values, evaluate expressions, and so on. +A line containing only the word <code>cont</code> finishes this function, +so that the caller continues its execution. + + +<p> +Note that commands for <code>debug.debug</code> are not lexically nested +within any function and so have no direct access to local variables. + + + + +<p> +<hr><h3><a name="pdf-debug.gethook"><code>debug.gethook ([thread])</code></a></h3> + + +<p> +Returns the current hook settings of the thread, as three values: +the current hook function, the current hook mask, +and the current hook count +(as set by the <a href="#pdf-debug.sethook"><code>debug.sethook</code></a> function). + + + + +<p> +<hr><h3><a name="pdf-debug.getinfo"><code>debug.getinfo ([thread,] f [, what])</code></a></h3> + + +<p> +Returns a table with information about a function. +You can give the function directly +or you can give a number as the value of <code>f</code>, +which means the function running at level <code>f</code> of the call stack +of the given thread: +level 0 is the current function (<code>getinfo</code> itself); +level 1 is the function that called <code>getinfo</code> +(except for tail calls, which do not count on the stack); +and so on. +If <code>f</code> is a number larger than the number of active functions, +then <code>getinfo</code> returns <b>nil</b>. + + +<p> +The returned table can contain all the fields returned by <a href="#lua_getinfo"><code>lua_getinfo</code></a>, +with the string <code>what</code> describing which fields to fill in. +The default for <code>what</code> is to get all information available, +except the table of valid lines. +If present, +the option '<code>f</code>' +adds a field named <code>func</code> with the function itself. +If present, +the option '<code>L</code>' +adds a field named <code>activelines</code> with the table of +valid lines. + + +<p> +For instance, the expression <code>debug.getinfo(1,"n").name</code> returns +a table with a name for the current function, +if a reasonable name can be found, +and the expression <code>debug.getinfo(print)</code> +returns a table with all available information +about the <a href="#pdf-print"><code>print</code></a> function. + + + + +<p> +<hr><h3><a name="pdf-debug.getlocal"><code>debug.getlocal ([thread,] f, local)</code></a></h3> + + +<p> +This function returns the name and the value of the local variable +with index <code>local</code> of the function at level <code>f</code> of the stack. +This function accesses not only explicit local variables, +but also parameters, temporaries, etc. + + +<p> +The first parameter or local variable has index 1, and so on, +following the order that they are declared in the code, +counting only the variables that are active +in the current scope of the function. +Negative indices refer to vararg parameters; +-1 is the first vararg parameter. +The function returns <b>nil</b> if there is no variable with the given index, +and raises an error when called with a level out of range. +(You can call <a href="#pdf-debug.getinfo"><code>debug.getinfo</code></a> to check whether the level is valid.) + + +<p> +Variable names starting with '<code>(</code>' (open parenthesis) +represent variables with no known names +(internal variables such as loop control variables, +and variables from chunks saved without debug information). + + +<p> +The parameter <code>f</code> may also be a function. +In that case, <code>getlocal</code> returns only the name of function parameters. + + + + +<p> +<hr><h3><a name="pdf-debug.getmetatable"><code>debug.getmetatable (value)</code></a></h3> + + +<p> +Returns the metatable of the given <code>value</code> +or <b>nil</b> if it does not have a metatable. + + + + +<p> +<hr><h3><a name="pdf-debug.getregistry"><code>debug.getregistry ()</code></a></h3> + + +<p> +Returns the registry table (see <a href="#4.5">§4.5</a>). + + + + +<p> +<hr><h3><a name="pdf-debug.getupvalue"><code>debug.getupvalue (f, up)</code></a></h3> + + +<p> +This function returns the name and the value of the upvalue +with index <code>up</code> of the function <code>f</code>. +The function returns <b>nil</b> if there is no upvalue with the given index. + + +<p> +Variable names starting with '<code>(</code>' (open parenthesis) +represent variables with no known names +(variables from chunks saved without debug information). + + + + +<p> +<hr><h3><a name="pdf-debug.getuservalue"><code>debug.getuservalue (u)</code></a></h3> + + +<p> +Returns the Lua value associated to <code>u</code>. +If <code>u</code> is not a userdata, +returns <b>nil</b>. + + + + +<p> +<hr><h3><a name="pdf-debug.sethook"><code>debug.sethook ([thread,] hook, mask [, count])</code></a></h3> + + +<p> +Sets the given function as a hook. +The string <code>mask</code> and the number <code>count</code> describe +when the hook will be called. +The string mask may have any combination of the following characters, +with the given meaning: + +<ul> +<li><b>'<code>c</code>': </b> the hook is called every time Lua calls a function;</li> +<li><b>'<code>r</code>': </b> the hook is called every time Lua returns from a function;</li> +<li><b>'<code>l</code>': </b> the hook is called every time Lua enters a new line of code.</li> +</ul><p> +Moreover, +with a <code>count</code> different from zero, +the hook is called also after every <code>count</code> instructions. + + +<p> +When called without arguments, +<a href="#pdf-debug.sethook"><code>debug.sethook</code></a> turns off the hook. + + +<p> +When the hook is called, its first parameter is a string +describing the event that has triggered its call: +<code>"call"</code> (or <code>"tail call"</code>), +<code>"return"</code>, +<code>"line"</code>, and <code>"count"</code>. +For line events, +the hook also gets the new line number as its second parameter. +Inside a hook, +you can call <code>getinfo</code> with level 2 to get more information about +the running function +(level 0 is the <code>getinfo</code> function, +and level 1 is the hook function). + + + + +<p> +<hr><h3><a name="pdf-debug.setlocal"><code>debug.setlocal ([thread,] level, local, value)</code></a></h3> + + +<p> +This function assigns the value <code>value</code> to the local variable +with index <code>local</code> of the function at level <code>level</code> of the stack. +The function returns <b>nil</b> if there is no local +variable with the given index, +and raises an error when called with a <code>level</code> out of range. +(You can call <code>getinfo</code> to check whether the level is valid.) +Otherwise, it returns the name of the local variable. + + +<p> +See <a href="#pdf-debug.getlocal"><code>debug.getlocal</code></a> for more information about +variable indices and names. + + + + +<p> +<hr><h3><a name="pdf-debug.setmetatable"><code>debug.setmetatable (value, table)</code></a></h3> + + +<p> +Sets the metatable for the given <code>value</code> to the given <code>table</code> +(which can be <b>nil</b>). +Returns <code>value</code>. + + + + +<p> +<hr><h3><a name="pdf-debug.setupvalue"><code>debug.setupvalue (f, up, value)</code></a></h3> + + +<p> +This function assigns the value <code>value</code> to the upvalue +with index <code>up</code> of the function <code>f</code>. +The function returns <b>nil</b> if there is no upvalue +with the given index. +Otherwise, it returns the name of the upvalue. + + + + +<p> +<hr><h3><a name="pdf-debug.setuservalue"><code>debug.setuservalue (udata, value)</code></a></h3> + + +<p> +Sets the given <code>value</code> as +the Lua value associated to the given <code>udata</code>. +<code>udata</code> must be a full userdata. + + +<p> +Returns <code>udata</code>. + + + + +<p> +<hr><h3><a name="pdf-debug.traceback"><code>debug.traceback ([thread,] [message [, level]])</code></a></h3> + + +<p> +If <code>message</code> is present but is neither a string nor <b>nil</b>, +this function returns <code>message</code> without further processing. +Otherwise, +it returns a string with a traceback of the call stack. +The optional <code>message</code> string is appended +at the beginning of the traceback. +An optional <code>level</code> number tells at which level +to start the traceback +(default is 1, the function calling <code>traceback</code>). + + + + +<p> +<hr><h3><a name="pdf-debug.upvalueid"><code>debug.upvalueid (f, n)</code></a></h3> + + +<p> +Returns a unique identifier (as a light userdata) +for the upvalue numbered <code>n</code> +from the given function. + + +<p> +These unique identifiers allow a program to check whether different +closures share upvalues. +Lua closures that share an upvalue +(that is, that access a same external local variable) +will return identical ids for those upvalue indices. + + + + +<p> +<hr><h3><a name="pdf-debug.upvaluejoin"><code>debug.upvaluejoin (f1, n1, f2, n2)</code></a></h3> + + +<p> +Make the <code>n1</code>-th upvalue of the Lua closure <code>f1</code> +refer to the <code>n2</code>-th upvalue of the Lua closure <code>f2</code>. + + + + + + + +<h1>7 – <a name="7">Lua Standalone</a></h1> + +<p> +Although Lua has been designed as an extension language, +to be embedded in a host C program, +it is also frequently used as a standalone language. +An interpreter for Lua as a standalone language, +called simply <code>lua</code>, +is provided with the standard distribution. +The standalone interpreter includes +all standard libraries, including the debug library. +Its usage is: + +<pre> + lua [options] [script [args]] +</pre><p> +The options are: + +<ul> +<li><b><code>-e <em>stat</em></code>: </b> executes string <em>stat</em>;</li> +<li><b><code>-l <em>mod</em></code>: </b> "requires" <em>mod</em>;</li> +<li><b><code>-i</code>: </b> enters interactive mode after running <em>script</em>;</li> +<li><b><code>-v</code>: </b> prints version information;</li> +<li><b><code>-E</code>: </b> ignores environment variables;</li> +<li><b><code>--</code>: </b> stops handling options;</li> +<li><b><code>-</code>: </b> executes <code>stdin</code> as a file and stops handling options.</li> +</ul><p> +After handling its options, <code>lua</code> runs the given <em>script</em>. +When called without arguments, +<code>lua</code> behaves as <code>lua -v -i</code> +when the standard input (<code>stdin</code>) is a terminal, +and as <code>lua -</code> otherwise. + + +<p> +When called without option <code>-E</code>, +the interpreter checks for an environment variable <a name="pdf-LUA_INIT_5_3"><code>LUA_INIT_5_3</code></a> +(or <a name="pdf-LUA_INIT"><code>LUA_INIT</code></a> if the versioned name is not defined) +before running any argument. +If the variable content has the format <code>@<em>filename</em></code>, +then <code>lua</code> executes the file. +Otherwise, <code>lua</code> executes the string itself. + + +<p> +When called with option <code>-E</code>, +besides ignoring <code>LUA_INIT</code>, +Lua also ignores +the values of <code>LUA_PATH</code> and <code>LUA_CPATH</code>, +setting the values of +<a href="#pdf-package.path"><code>package.path</code></a> and <a href="#pdf-package.cpath"><code>package.cpath</code></a> +with the default paths defined in <code>luaconf.h</code>. + + +<p> +All options are handled in order, except <code>-i</code> and <code>-E</code>. +For instance, an invocation like + +<pre> + $ lua -e'a=1' -e 'print(a)' script.lua +</pre><p> +will first set <code>a</code> to 1, then print the value of <code>a</code>, +and finally run the file <code>script.lua</code> with no arguments. +(Here <code>$</code> is the shell prompt. Your prompt may be different.) + + +<p> +Before running any code, +<code>lua</code> collects all command-line arguments +in a global table called <code>arg</code>. +The script name goes to index 0, +the first argument after the script name goes to index 1, +and so on. +Any arguments before the script name +(that is, the interpreter name plus its options) +go to negative indices. +For instance, in the call + +<pre> + $ lua -la b.lua t1 t2 +</pre><p> +the table is like this: + +<pre> + arg = { [-2] = "lua", [-1] = "-la", + [0] = "b.lua", + [1] = "t1", [2] = "t2" } +</pre><p> +If there is no script in the call, +the interpreter name goes to index 0, +followed by the other arguments. +For instance, the call + +<pre> + $ lua -e "print(arg[1])" +</pre><p> +will print "<code>-e</code>". +If there is a script, +the script is called with parameters +<code>arg[1]</code>, ···, <code>arg[#arg]</code>. +(Like all chunks in Lua, +the script is compiled as a vararg function.) + + +<p> +In interactive mode, +Lua repeatedly prompts and waits for a line. +After reading a line, +Lua first try to interpret the line as an expression. +If it succeeds, it prints its value. +Otherwise, it interprets the line as a statement. +If you write an incomplete statement, +the interpreter waits for its completion +by issuing a different prompt. + + +<p> +In case of unprotected errors in the script, +the interpreter reports the error to the standard error stream. +If the error object is not a string but +has a metamethod <code>__tostring</code>, +the interpreter calls this metamethod to produce the final message. +Otherwise, the interpreter converts the error object to a string +and adds a stack traceback to it. + + +<p> +When finishing normally, +the interpreter closes its main Lua state +(see <a href="#lua_close"><code>lua_close</code></a>). +The script can avoid this step by +calling <a href="#pdf-os.exit"><code>os.exit</code></a> to terminate. + + +<p> +To allow the use of Lua as a +script interpreter in Unix systems, +the standalone interpreter skips +the first line of a chunk if it starts with <code>#</code>. +Therefore, Lua scripts can be made into executable programs +by using <code>chmod +x</code> and the <code>#!</code> form, +as in + +<pre> + #!/usr/local/bin/lua +</pre><p> +(Of course, +the location of the Lua interpreter may be different in your machine. +If <code>lua</code> is in your <code>PATH</code>, +then + +<pre> + #!/usr/bin/env lua +</pre><p> +is a more portable solution.) + + + +<h1>8 – <a name="8">Incompatibilities with the Previous Version</a></h1> + +<p> +Here we list the incompatibilities that you may find when moving a program +from Lua 5.2 to Lua 5.3. +You can avoid some incompatibilities by compiling Lua with +appropriate options (see file <code>luaconf.h</code>). +However, +all these compatibility options will be removed in the future. + + +<p> +Lua versions can always change the C API in ways that +do not imply source-code changes in a program, +such as the numeric values for constants +or the implementation of functions as macros. +Therefore, +you should not assume that binaries are compatible between +different Lua versions. +Always recompile clients of the Lua API when +using a new version. + + +<p> +Similarly, Lua versions can always change the internal representation +of precompiled chunks; +precompiled chunks are not compatible between different Lua versions. + + +<p> +The standard paths in the official distribution may +change between versions. + + + +<h2>8.1 – <a name="8.1">Changes in the Language</a></h2> +<ul> + +<li> +The main difference between Lua 5.2 and Lua 5.3 is the +introduction of an integer subtype for numbers. +Although this change should not affect "normal" computations, +some computations +(mainly those that involve some kind of overflow) +can give different results. + + +<p> +You can fix these differences by forcing a number to be a float +(in Lua 5.2 all numbers were float), +in particular writing constants with an ending <code>.0</code> +or using <code>x = x + 0.0</code> to convert a variable. +(This recommendation is only for a quick fix +for an occasional incompatibility; +it is not a general guideline for good programming. +For good programming, +use floats where you need floats +and integers where you need integers.) +</li> + +<li> +The conversion of a float to a string now adds a <code>.0</code> suffix +to the result if it looks like an integer. +(For instance, the float 2.0 will be printed as <code>2.0</code>, +not as <code>2</code>.) +You should always use an explicit format +when you need a specific format for numbers. + + +<p> +(Formally this is not an incompatibility, +because Lua does not specify how numbers are formatted as strings, +but some programs assumed a specific format.) +</li> + +<li> +The generational mode for the garbage collector was removed. +(It was an experimental feature in Lua 5.2.) +</li> + +</ul> + + + + +<h2>8.2 – <a name="8.2">Changes in the Libraries</a></h2> +<ul> + +<li> +The <code>bit32</code> library has been deprecated. +It is easy to require a compatible external library or, +better yet, to replace its functions with appropriate bitwise operations. +(Keep in mind that <code>bit32</code> operates on 32-bit integers, +while the bitwise operators in standard Lua operate on 64-bit integers.) +</li> + +<li> +The Table library now respects metamethods +for setting and getting elements. +</li> + +<li> +The <a href="#pdf-ipairs"><code>ipairs</code></a> iterator now respects metamethods and +its <code>__ipairs</code> metamethod has been deprecated. +</li> + +<li> +Option names in <a href="#pdf-io.read"><code>io.read</code></a> do not have a starting '<code>*</code>' anymore. +For compatibility, Lua will continue to ignore this character. +</li> + +<li> +The following functions were deprecated in the mathematical library: +<code>atan2</code>, <code>cosh</code>, <code>sinh</code>, <code>tanh</code>, <code>pow</code>, +<code>frexp</code>, and <code>ldexp</code>. +You can replace <code>math.pow(x,y)</code> with <code>x^y</code>; +you can replace <code>math.atan2</code> with <code>math.atan</code>, +which now accepts one or two parameters; +you can replace <code>math.ldexp(x,exp)</code> with <code>x * 2.0^exp</code>. +For the other operations, +you can either use an external library or +implement them in Lua. +</li> + +<li> +The searcher for C loaders used by <a href="#pdf-require"><code>require</code></a> +changed the way it handles versioned names. +Now, the version should come after the module name +(as is usual in most other tools). +For compatibility, that searcher still tries the old format +if it cannot find an open function according to the new style. +(Lua 5.2 already worked that way, +but it did not document the change.) +</li> + +</ul> + + + + +<h2>8.3 – <a name="8.3">Changes in the API</a></h2> + + +<ul> + +<li> +Continuation functions now receive as parameters what they needed +to get through <code>lua_getctx</code>, +so <code>lua_getctx</code> has been removed. +Adapt your code accordingly. +</li> + +<li> +Function <a href="#lua_dump"><code>lua_dump</code></a> has an extra parameter, <code>strip</code>. +Use 0 as the value of this parameter to get the old behavior. +</li> + +<li> +Functions to inject/project unsigned integers +(<code>lua_pushunsigned</code>, <code>lua_tounsigned</code>, <code>lua_tounsignedx</code>, +<code>luaL_checkunsigned</code>, <code>luaL_optunsigned</code>) +were deprecated. +Use their signed equivalents with a type cast. +</li> + +<li> +Macros to project non-default integer types +(<code>luaL_checkint</code>, <code>luaL_optint</code>, <code>luaL_checklong</code>, <code>luaL_optlong</code>) +were deprecated. +Use their equivalent over <a href="#lua_Integer"><code>lua_Integer</code></a> with a type cast +(or, when possible, use <a href="#lua_Integer"><code>lua_Integer</code></a> in your code). +</li> + +</ul> + + + + +<h1>9 – <a name="9">The Complete Syntax of Lua</a></h1> + +<p> +Here is the complete syntax of Lua in extended BNF. +As usual in extended BNF, +{A} means 0 or more As, +and [A] means an optional A. +(For operator precedences, see <a href="#3.4.8">§3.4.8</a>; +for a description of the terminals +Name, Numeral, +and LiteralString, see <a href="#3.1">§3.1</a>.) + + + + +<pre> + + chunk ::= block + + block ::= {stat} [retstat] + + stat ::= ‘<b>;</b>’ | + varlist ‘<b>=</b>’ explist | + functioncall | + label | + <b>break</b> | + <b>goto</b> Name | + <b>do</b> block <b>end</b> | + <b>while</b> exp <b>do</b> block <b>end</b> | + <b>repeat</b> block <b>until</b> exp | + <b>if</b> exp <b>then</b> block {<b>elseif</b> exp <b>then</b> block} [<b>else</b> block] <b>end</b> | + <b>for</b> Name ‘<b>=</b>’ exp ‘<b>,</b>’ exp [‘<b>,</b>’ exp] <b>do</b> block <b>end</b> | + <b>for</b> namelist <b>in</b> explist <b>do</b> block <b>end</b> | + <b>function</b> funcname funcbody | + <b>local</b> <b>function</b> Name funcbody | + <b>local</b> namelist [‘<b>=</b>’ explist] + + retstat ::= <b>return</b> [explist] [‘<b>;</b>’] + + label ::= ‘<b>::</b>’ Name ‘<b>::</b>’ + + funcname ::= Name {‘<b>.</b>’ Name} [‘<b>:</b>’ Name] + + varlist ::= var {‘<b>,</b>’ var} + + var ::= Name | prefixexp ‘<b>[</b>’ exp ‘<b>]</b>’ | prefixexp ‘<b>.</b>’ Name + + namelist ::= Name {‘<b>,</b>’ Name} + + explist ::= exp {‘<b>,</b>’ exp} + + exp ::= <b>nil</b> | <b>false</b> | <b>true</b> | Numeral | LiteralString | ‘<b>...</b>’ | functiondef | + prefixexp | tableconstructor | exp binop exp | unop exp + + prefixexp ::= var | functioncall | ‘<b>(</b>’ exp ‘<b>)</b>’ + + functioncall ::= prefixexp args | prefixexp ‘<b>:</b>’ Name args + + args ::= ‘<b>(</b>’ [explist] ‘<b>)</b>’ | tableconstructor | LiteralString + + functiondef ::= <b>function</b> funcbody + + funcbody ::= ‘<b>(</b>’ [parlist] ‘<b>)</b>’ block <b>end</b> + + parlist ::= namelist [‘<b>,</b>’ ‘<b>...</b>’] | ‘<b>...</b>’ + + tableconstructor ::= ‘<b>{</b>’ [fieldlist] ‘<b>}</b>’ + + fieldlist ::= field {fieldsep field} [fieldsep] + + field ::= ‘<b>[</b>’ exp ‘<b>]</b>’ ‘<b>=</b>’ exp | Name ‘<b>=</b>’ exp | exp + + fieldsep ::= ‘<b>,</b>’ | ‘<b>;</b>’ + + binop ::= ‘<b>+</b>’ | ‘<b>-</b>’ | ‘<b>*</b>’ | ‘<b>/</b>’ | ‘<b>//</b>’ | ‘<b>^</b>’ | ‘<b>%</b>’ | + ‘<b>&</b>’ | ‘<b>~</b>’ | ‘<b>|</b>’ | ‘<b>>></b>’ | ‘<b><<</b>’ | ‘<b>..</b>’ | + ‘<b><</b>’ | ‘<b><=</b>’ | ‘<b>></b>’ | ‘<b>>=</b>’ | ‘<b>==</b>’ | ‘<b>~=</b>’ | + <b>and</b> | <b>or</b> + + unop ::= ‘<b>-</b>’ | <b>not</b> | ‘<b>#</b>’ | ‘<b>~</b>’ + +</pre> + +<p> + + + + + + + + +<HR> +<SMALL CLASS="footer"> +Last update: +Tue Jan 6 10:10:50 BRST 2015 +</SMALL> +<!-- +Last change: revised for Lua 5.3.0 (final) +--> + +</body></html> + diff --git a/doc/osi-certified-72x60.png b/doc/osi-certified-72x60.png Binary files differnew file mode 100644 index 000000000000..07df5f6ee7a7 --- /dev/null +++ b/doc/osi-certified-72x60.png diff --git a/doc/readme.html b/doc/readme.html new file mode 100644 index 000000000000..016575570133 --- /dev/null +++ b/doc/readme.html @@ -0,0 +1,371 @@ +<!DOCTYPE HTML PUBLIC "-//W3C//DTD HTML 4.01 Transitional//EN"> +<HTML> +<HEAD> +<TITLE>Lua 5.3 readme</TITLE> +<LINK REL="stylesheet" TYPE="text/css" HREF="lua.css"> +<META HTTP-EQUIV="content-type" CONTENT="text/html; charset=iso-8859-1"> +<STYLE TYPE="text/css"> +blockquote, .display { + border: solid #a0a0a0 2px ; + padding: 1em ; + margin: 0px ; + border-radius: 8px ; +} + +.display { + word-spacing: 0.25em ; +} + +dl.display dd { + padding-bottom: 0.2em ; +} + +tt, kbd, code { + font-size: 12pt ; +} +</STYLE> +</HEAD> + +<BODY> + +<HR> +<H1> +<A HREF="http://www.lua.org/"><IMG SRC="logo.gif" ALT="Lua" BORDER=0></A> +Welcome to Lua 5.3.0 +</H1> + +<P> +<A HREF="#about">about</A> +· +<A HREF="#install">installation</A> +· +<A HREF="#changes">changes</A> +· +<A HREF="#license">license</A> +· +<A HREF="contents.html">reference manual</A> + +<H2><A NAME="about">About Lua</A></H2> + +<P> +Lua is a powerful, fast, lightweight, embeddable scripting language +developed by a +<A HREF="http://www.lua.org/authors.html">team</A> +at +<A HREF="http://www.puc-rio.br/">PUC-Rio</A>, +the Pontifical Catholic University of Rio de Janeiro in Brazil. +Lua is +<A HREF="#license">free software</A> +used in many products and projects around the world. + +<P> +Lua's +<A HREF="http://www.lua.org/">official web site</A> +provides complete information +about Lua, +including +an +<A HREF="http://www.lua.org/about.html">executive summary</A> +and +updated +<A HREF="http://www.lua.org/docs.html">documentation</A>, +especially the +<A HREF="http://www.lua.org/manual/5.3/">reference manual</A>, +which may differ slightly from the +<A HREF="contents.html">local copy</A> +distributed in this package. + +<H2><A NAME="install">Installing Lua</A></H2> + +<P> +Lua is distributed in +<A HREF="http://www.lua.org/ftp/">source</A> +form. +You need to build it before using it. +Building Lua should be straightforward +because +Lua is implemented in pure ANSI C and compiles unmodified in all known +platforms that have an ANSI C compiler. +Lua also compiles unmodified as C++. +The instructions given below for building Lua are for Unix-like platforms. +See also +<A HREF="#other">instructions for other systems</A> +and +<A HREF="#customization">customization options</A>. + +<P> +If you don't have the time or the inclination to compile Lua yourself, +get a binary from +<A HREF="http://lua-users.org/wiki/LuaBinaries">LuaBinaries</A>. +Try also +<A HREF="http://luadist.org/">LuaDist</A>, +a multi-platform distribution of Lua that includes batteries. + +<H3>Building Lua</H3> + +<P> +In most Unix-like platforms, simply do "<KBD>make</KBD>" with a suitable target. +Here are the details. + +<OL> +<LI> +Open a terminal window and move to +the top-level directory, which is named <TT>lua-5.3.0</TT>. +The <TT>Makefile</TT> there controls both the build process and the installation process. +<P> +<LI> + Do "<KBD>make</KBD>" and see if your platform is listed. + The platforms currently supported are: +<P> +<P CLASS="display"> + aix bsd c89 freebsd generic linux macosx mingw posix solaris +</P> +<P> + If your platform is listed, just do "<KBD>make xxx</KBD>", where xxx + is your platform name. +<P> + If your platform is not listed, try the closest one or posix, generic, + c89, in this order. +<P> +<LI> +The compilation takes only a few moments +and produces three files in the <TT>src</TT> directory: +lua (the interpreter), +luac (the compiler), +and liblua.a (the library). +<P> +<LI> + To check that Lua has been built correctly, do "<KBD>make test</KBD>" + after building Lua. This will run the interpreter and print its version. +</OL> +<P> +If you're running Linux and get compilation errors, +make sure you have installed the <TT>readline</TT> development package. +If you get link errors after that, +then try "<KBD>make linux MYLIBS=-ltermcap</KBD>". + +<H3>Installing Lua</H3> +<P> + Once you have built Lua, you may want to install it in an official + place in your system. In this case, do "<KBD>make install</KBD>". The official + place and the way to install files are defined in the <TT>Makefile</TT>. You'll + probably need the right permissions to install files. + +<P> + To build and install Lua in one step, do "<KBD>make xxx install</KBD>", + where xxx is your platform name. + +<P> + To install Lua locally, do "<KBD>make local</KBD>". + This will create a directory <TT>install</TT> with subdirectories + <TT>bin</TT>, <TT>include</TT>, <TT>lib</TT>, <TT>man</TT>, <TT>share</TT>, + and install Lua as listed below. + + To install Lua locally, but in some other directory, do + "<KBD>make install INSTALL_TOP=xxx</KBD>", where xxx is your chosen directory. + The installation starts in the <TT>src</TT> and <TT>doc</TT> directories, + so take care if <TT>INSTALL_TOP</TT> is not an absolute path. + +<DL CLASS="display"> +<DT> + bin: +<DD> + lua luac +<DT> + include: +<DD> + lauxlib.h lua.h lua.hpp luaconf.h lualib.h +<DT> + lib: +<DD> + liblua.a +<DT> + man/man1: +<DD> + lua.1 luac.1 +</DL> + +<P> + These are the only directories you need for development. + If you only want to run Lua programs, + you only need the files in <TT>bin</TT> and <TT>man</TT>. + The files in <TT>include</TT> and <TT>lib</TT> are needed for + embedding Lua in C or C++ programs. + +<H3><A NAME="customization">Customization</A></H3> +<P> + Three kinds of things can be customized by editing a file: +<UL> + <LI> Where and how to install Lua — edit <TT>Makefile</TT>. + <LI> How to build Lua — edit <TT>src/Makefile</TT>. + <LI> Lua features — edit <TT>src/luaconf.h</TT>. +</UL> + +<P> + You don't actually need to edit the Makefiles because you may set the + relevant variables in the command line when invoking make. + Nevertheless, it's probably best to edit and save the Makefiles to + record the changes you've made. + +<P> + On the other hand, if you need to customize some Lua features, you'll need + to edit <TT>src/luaconf.h</TT> before building and installing Lua. + The edited file will be the one installed, and + it will be used by any Lua clients that you build, to ensure consistency. + Further customization is available to experts by editing the Lua sources. + +<H3><A NAME="other">Building Lua on other systems</A></H3> + +<P> + If you're not using the usual Unix tools, then the instructions for + building Lua depend on the compiler you use. You'll need to create + projects (or whatever your compiler uses) for building the library, + the interpreter, and the compiler, as follows: + +<DL CLASS="display"> +<DT> +library: +<DD> +lapi.c lcode.c lctype.c ldebug.c ldo.c ldump.c lfunc.c lgc.c llex.c +lmem.c lobject.c lopcodes.c lparser.c lstate.c lstring.c ltable.c +ltm.c lundump.c lvm.c lzio.c +lauxlib.c lbaselib.c lbitlib.c lcorolib.c ldblib.c liolib.c +lmathlib.c loslib.c lstrlib.c ltablib.c lutf8lib.c loadlib.c linit.c +<DT> +interpreter: +<DD> + library, lua.c +<DT> +compiler: +<DD> + library, luac.c +</DL> + +<P> + To use Lua as a library in your own programs you'll need to know how to + create and use libraries with your compiler. Moreover, to dynamically load + C libraries for Lua you'll need to know how to create dynamic libraries + and you'll need to make sure that the Lua API functions are accessible to + those dynamic libraries — but <EM>don't</EM> link the Lua library + into each dynamic library. For Unix, we recommend that the Lua library + be linked statically into the host program and its symbols exported for + dynamic linking; <TT>src/Makefile</TT> does this for the Lua interpreter. + For Windows, we recommend that the Lua library be a DLL. + In all cases, the compiler luac should be linked statically. + +<P> + As mentioned above, you may edit <TT>src/luaconf.h</TT> to customize + some features before building Lua. + +<H2><A NAME="changes">Changes since Lua 5.2</A></H2> + +<P> +Here are the main changes introduced in Lua 5.3. +The +<A HREF="contents.html">reference manual</A> +lists the +<A HREF="manual.html#8">incompatibilities</A> that had to be introduced. + +<H3>Main changes</H3> +<UL> +<LI> integers (64-bit by default) +<LI> official support for 32-bit numbers +<LI> bitwise operators +<LI> basic utf-8 support +<LI> functions for packing and unpacking values + +</UL> + +Here are the other changes introduced in Lua 5.3: +<H3>Language</H3> +<UL> +<LI> userdata can have any Lua value as uservalue +<LI> integer division +<LI> more flexible rules for some metamethods +</UL> + +<H3>Libraries</H3> +<UL> +<LI> <CODE>ipairs</CODE> and the table library respect metamethods +<LI> strip option in <CODE>string.dump</CODE> +<LI> table library respects metamethods +<LI> new function <CODE>table.move</CODE> +<LI> new function <CODE>string.pack</CODE> +<LI> new function <CODE>string.unpack</CODE> +<LI> new function <CODE>string.packsize</CODE> +</UL> + +<H3>C API</H3> +<UL> +<LI> simpler API for continuation functions in C +<LI> <CODE>lua_gettable</CODE> and similar functions return type of resulted value +<LI> strip option in <CODE>lua_dump</CODE> +<LI> new function: <CODE>lua_geti</CODE> +<LI> new function: <CODE>lua_seti</CODE> +<LI> new function: <CODE>lua_isyieldable</CODE> +<LI> new function: <CODE>lua_numbertointeger</CODE> +<LI> new function: <CODE>lua_rotate</CODE> +<LI> new function: <CODE>lua_stringtonumber</CODE> +</UL> + +<H3>Lua standalone interpreter</H3> +<UL> +<LI> can be used as calculator; no need to prefix with '=' +<LI> <CODE>arg</CODE> table available to all code +</UL> + +<H2><A NAME="license">License</A></H2> +<A HREF="http://www.opensource.org/docs/definition.php"> +<IMG SRC="osi-certified-72x60.png" ALIGN="right" BORDER="0" ALT="[osi certified]" STYLE="padding-left: 30px ;"> +</A> + +<P> +Lua is free software distributed under the terms of the +<A HREF="http://www.opensource.org/licenses/mit-license.html">MIT license</A> +reproduced below; +it may be used for any purpose, including commercial purposes, +at absolutely no cost without having to ask us. + +The only requirement is that if you do use Lua, +then you should give us credit by including the appropriate copyright notice somewhere in your product or its documentation. + +For details, see +<A HREF="http://www.lua.org/license.html">this</A>. + +<BLOCKQUOTE STYLE="padding-bottom: 0em"> +Copyright © 1994–2015 Lua.org, PUC-Rio. + +<P> +Permission is hereby granted, free of charge, to any person obtaining a copy +of this software and associated documentation files (the "Software"), to deal +in the Software without restriction, including without limitation the rights +to use, copy, modify, merge, publish, distribute, sublicense, and/or sell +copies of the Software, and to permit persons to whom the Software is +furnished to do so, subject to the following conditions: + +<P> +The above copyright notice and this permission notice shall be included in +all copies or substantial portions of the Software. + +<P> +THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR +IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, +FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE +AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER +LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, +OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN +THE SOFTWARE. +</BLOCKQUOTE> +<P> + +<HR> +<SMALL CLASS="footer"> +Last update: +Fri Dec 12 09:58:42 BRST 2014 +</SMALL> +<!-- +Last change: updated for Lua 5.3.0 (final) +--> + +</BODY> +</HTML> diff --git a/src/Makefile b/src/Makefile new file mode 100644 index 000000000000..2e7a4120cef2 --- /dev/null +++ b/src/Makefile @@ -0,0 +1,197 @@ +# Makefile for building Lua +# See ../doc/readme.html for installation and customization instructions. + +# == CHANGE THE SETTINGS BELOW TO SUIT YOUR ENVIRONMENT ======================= + +# Your platform. See PLATS for possible values. +PLAT= none + +CC= gcc -std=gnu99 +CFLAGS= -O2 -Wall -Wextra -DLUA_COMPAT_5_2 $(SYSCFLAGS) $(MYCFLAGS) +LDFLAGS= $(SYSLDFLAGS) $(MYLDFLAGS) +LIBS= -lm $(SYSLIBS) $(MYLIBS) + +AR= ar rcu +RANLIB= ranlib +RM= rm -f + +SYSCFLAGS= +SYSLDFLAGS= +SYSLIBS= + +MYCFLAGS= +MYLDFLAGS= +MYLIBS= +MYOBJS= + +# == END OF USER SETTINGS -- NO NEED TO CHANGE ANYTHING BELOW THIS LINE ======= + +PLATS= aix bsd c89 freebsd generic linux macosx mingw posix solaris + +LUA_A= liblua.a +CORE_O= lapi.o lcode.o lctype.o ldebug.o ldo.o ldump.o lfunc.o lgc.o llex.o \ + lmem.o lobject.o lopcodes.o lparser.o lstate.o lstring.o ltable.o \ + ltm.o lundump.o lvm.o lzio.o +LIB_O= lauxlib.o lbaselib.o lbitlib.o lcorolib.o ldblib.o liolib.o \ + lmathlib.o loslib.o lstrlib.o ltablib.o lutf8lib.o loadlib.o linit.o +BASE_O= $(CORE_O) $(LIB_O) $(MYOBJS) + +LUA_T= lua +LUA_O= lua.o + +LUAC_T= luac +LUAC_O= luac.o + +ALL_O= $(BASE_O) $(LUA_O) $(LUAC_O) +ALL_T= $(LUA_A) $(LUA_T) $(LUAC_T) +ALL_A= $(LUA_A) + +# Targets start here. +default: $(PLAT) + +all: $(ALL_T) + +o: $(ALL_O) + +a: $(ALL_A) + +$(LUA_A): $(BASE_O) + $(AR) $@ $(BASE_O) + $(RANLIB) $@ + +$(LUA_T): $(LUA_O) $(LUA_A) + $(CC) -o $@ $(LDFLAGS) $(LUA_O) $(LUA_A) $(LIBS) + +$(LUAC_T): $(LUAC_O) $(LUA_A) + $(CC) -o $@ $(LDFLAGS) $(LUAC_O) $(LUA_A) $(LIBS) + +clean: + $(RM) $(ALL_T) $(ALL_O) + +depend: + @$(CC) $(CFLAGS) -MM l*.c + +echo: + @echo "PLAT= $(PLAT)" + @echo "CC= $(CC)" + @echo "CFLAGS= $(CFLAGS)" + @echo "LDFLAGS= $(SYSLDFLAGS)" + @echo "LIBS= $(LIBS)" + @echo "AR= $(AR)" + @echo "RANLIB= $(RANLIB)" + @echo "RM= $(RM)" + +# Convenience targets for popular platforms +ALL= all + +none: + @echo "Please do 'make PLATFORM' where PLATFORM is one of these:" + @echo " $(PLATS)" + +aix: + $(MAKE) $(ALL) CC="xlc" CFLAGS="-O2 -DLUA_USE_POSIX -DLUA_USE_DLOPEN" SYSLIBS="-ldl" SYSLDFLAGS="-brtl -bexpall" + +bsd: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX -DLUA_USE_DLOPEN" SYSLIBS="-Wl,-E" + +c89: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_C89" CC="gcc -std=c89" + @echo '' + @echo '*** C89 does not guarantee 64-bit integers for Lua.' + @echo '' + + +freebsd: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX" SYSLIBS="-Wl,-E -lreadline" + +generic: $(ALL) + +linux: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_LINUX" SYSLIBS="-Wl,-E -ldl -lreadline" + +macosx: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_MACOSX" SYSLIBS="-lreadline" CC=cc + +mingw: + $(MAKE) "LUA_A=lua53.dll" "LUA_T=lua.exe" \ + "AR=$(CC) -shared -o" "RANLIB=strip --strip-unneeded" \ + "SYSCFLAGS=-DLUA_BUILD_AS_DLL" "SYSLIBS=" "SYSLDFLAGS=-s" lua.exe + $(MAKE) "LUAC_T=luac.exe" luac.exe + +posix: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX" + +solaris: + $(MAKE) $(ALL) SYSCFLAGS="-DLUA_USE_POSIX -DLUA_USE_DLOPEN -D_REENTRANT" SYSLIBS="-ldl" + +# list targets that do not create files (but not all makes understand .PHONY) +.PHONY: all $(PLATS) default o a clean depend echo none + +# DO NOT DELETE + +lapi.o: lapi.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \ + lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h lstring.h \ + ltable.h lundump.h lvm.h +lauxlib.o: lauxlib.c lprefix.h lua.h luaconf.h lauxlib.h +lbaselib.o: lbaselib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lbitlib.o: lbitlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lcode.o: lcode.c lprefix.h lua.h luaconf.h lcode.h llex.h lobject.h \ + llimits.h lzio.h lmem.h lopcodes.h lparser.h ldebug.h lstate.h ltm.h \ + ldo.h lgc.h lstring.h ltable.h lvm.h +lcorolib.o: lcorolib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lctype.o: lctype.c lprefix.h lctype.h lua.h luaconf.h llimits.h +ldblib.o: ldblib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +ldebug.o: ldebug.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \ + lobject.h ltm.h lzio.h lmem.h lcode.h llex.h lopcodes.h lparser.h \ + ldebug.h ldo.h lfunc.h lstring.h lgc.h ltable.h lvm.h +ldo.o: ldo.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \ + lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h lopcodes.h \ + lparser.h lstring.h ltable.h lundump.h lvm.h +ldump.o: ldump.c lprefix.h lua.h luaconf.h lobject.h llimits.h lstate.h \ + ltm.h lzio.h lmem.h lundump.h +lfunc.o: lfunc.c lprefix.h lua.h luaconf.h lfunc.h lobject.h llimits.h \ + lgc.h lstate.h ltm.h lzio.h lmem.h +lgc.o: lgc.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lgc.h lstring.h ltable.h +linit.o: linit.c lprefix.h lua.h luaconf.h lualib.h lauxlib.h +liolib.o: liolib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +llex.o: llex.c lprefix.h lua.h luaconf.h lctype.h llimits.h ldo.h \ + lobject.h lstate.h ltm.h lzio.h lmem.h lgc.h llex.h lparser.h lstring.h \ + ltable.h +lmathlib.o: lmathlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lmem.o: lmem.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lgc.h +loadlib.o: loadlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lobject.o: lobject.c lprefix.h lua.h luaconf.h lctype.h llimits.h \ + ldebug.h lstate.h lobject.h ltm.h lzio.h lmem.h ldo.h lstring.h lgc.h \ + lvm.h +lopcodes.o: lopcodes.c lprefix.h lopcodes.h llimits.h lua.h luaconf.h +loslib.o: loslib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lparser.o: lparser.c lprefix.h lua.h luaconf.h lcode.h llex.h lobject.h \ + llimits.h lzio.h lmem.h lopcodes.h lparser.h ldebug.h lstate.h ltm.h \ + ldo.h lfunc.h lstring.h lgc.h ltable.h +lstate.o: lstate.c lprefix.h lua.h luaconf.h lapi.h llimits.h lstate.h \ + lobject.h ltm.h lzio.h lmem.h ldebug.h ldo.h lfunc.h lgc.h llex.h \ + lstring.h ltable.h +lstring.o: lstring.c lprefix.h lua.h luaconf.h ldebug.h lstate.h \ + lobject.h llimits.h ltm.h lzio.h lmem.h ldo.h lstring.h lgc.h +lstrlib.o: lstrlib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +ltable.o: ltable.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lgc.h lstring.h ltable.h lvm.h +ltablib.o: ltablib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +ltm.o: ltm.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lstring.h lgc.h ltable.h lvm.h +lua.o: lua.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +luac.o: luac.c lprefix.h lua.h luaconf.h lauxlib.h lobject.h llimits.h \ + lstate.h ltm.h lzio.h lmem.h lundump.h ldebug.h lopcodes.h +lundump.o: lundump.c lprefix.h lua.h luaconf.h ldebug.h lstate.h \ + lobject.h llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lstring.h lgc.h \ + lundump.h +lutf8lib.o: lutf8lib.c lprefix.h lua.h luaconf.h lauxlib.h lualib.h +lvm.o: lvm.c lprefix.h lua.h luaconf.h ldebug.h lstate.h lobject.h \ + llimits.h ltm.h lzio.h lmem.h ldo.h lfunc.h lgc.h lopcodes.h lstring.h \ + ltable.h lvm.h +lzio.o: lzio.c lprefix.h lua.h luaconf.h llimits.h lmem.h lstate.h \ + lobject.h ltm.h lzio.h + +# (end of Makefile) diff --git a/src/lapi.c b/src/lapi.c new file mode 100644 index 000000000000..fbfafa304ff8 --- /dev/null +++ b/src/lapi.c @@ -0,0 +1,1270 @@ +/* +** $Id: lapi.c,v 2.244 2014/12/26 14:43:45 roberto Exp $ +** Lua API +** See Copyright Notice in lua.h +*/ + +#define lapi_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stdarg.h> +#include <string.h> + +#include "lua.h" + +#include "lapi.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lundump.h" +#include "lvm.h" + + + +const char lua_ident[] = + "$LuaVersion: " LUA_COPYRIGHT " $" + "$LuaAuthors: " LUA_AUTHORS " $"; + + +/* value at a non-valid index */ +#define NONVALIDVALUE cast(TValue *, luaO_nilobject) + +/* corresponding test */ +#define isvalid(o) ((o) != luaO_nilobject) + +/* test for pseudo index */ +#define ispseudo(i) ((i) <= LUA_REGISTRYINDEX) + +/* test for upvalue */ +#define isupvalue(i) ((i) < LUA_REGISTRYINDEX) + +/* test for valid but not pseudo index */ +#define isstackindex(i, o) (isvalid(o) && !ispseudo(i)) + +#define api_checkvalidindex(o) api_check(isvalid(o), "invalid index") + +#define api_checkstackindex(i, o) \ + api_check(isstackindex(i, o), "index not in the stack") + + +static TValue *index2addr (lua_State *L, int idx) { + CallInfo *ci = L->ci; + if (idx > 0) { + TValue *o = ci->func + idx; + api_check(idx <= ci->top - (ci->func + 1), "unacceptable index"); + if (o >= L->top) return NONVALIDVALUE; + else return o; + } + else if (!ispseudo(idx)) { /* negative index */ + api_check(idx != 0 && -idx <= L->top - (ci->func + 1), "invalid index"); + return L->top + idx; + } + else if (idx == LUA_REGISTRYINDEX) + return &G(L)->l_registry; + else { /* upvalues */ + idx = LUA_REGISTRYINDEX - idx; + api_check(idx <= MAXUPVAL + 1, "upvalue index too large"); + if (ttislcf(ci->func)) /* light C function? */ + return NONVALIDVALUE; /* it has no upvalues */ + else { + CClosure *func = clCvalue(ci->func); + return (idx <= func->nupvalues) ? &func->upvalue[idx-1] : NONVALIDVALUE; + } + } +} + + +/* +** to be called by 'lua_checkstack' in protected mode, to grow stack +** capturing memory errors +*/ +static void growstack (lua_State *L, void *ud) { + int size = *(int *)ud; + luaD_growstack(L, size); +} + + +LUA_API int lua_checkstack (lua_State *L, int n) { + int res; + CallInfo *ci = L->ci; + lua_lock(L); + api_check(n >= 0, "negative 'n'"); + if (L->stack_last - L->top > n) /* stack large enough? */ + res = 1; /* yes; check is OK */ + else { /* no; need to grow stack */ + int inuse = cast_int(L->top - L->stack) + EXTRA_STACK; + if (inuse > LUAI_MAXSTACK - n) /* can grow without overflow? */ + res = 0; /* no */ + else /* try to grow stack */ + res = (luaD_rawrunprotected(L, &growstack, &n) == LUA_OK); + } + if (res && ci->top < L->top + n) + ci->top = L->top + n; /* adjust frame top */ + lua_unlock(L); + return res; +} + + +LUA_API void lua_xmove (lua_State *from, lua_State *to, int n) { + int i; + if (from == to) return; + lua_lock(to); + api_checknelems(from, n); + api_check(G(from) == G(to), "moving among independent states"); + api_check(to->ci->top - to->top >= n, "not enough elements to move"); + from->top -= n; + for (i = 0; i < n; i++) { + setobj2s(to, to->top++, from->top + i); + } + lua_unlock(to); +} + + +LUA_API lua_CFunction lua_atpanic (lua_State *L, lua_CFunction panicf) { + lua_CFunction old; + lua_lock(L); + old = G(L)->panic; + G(L)->panic = panicf; + lua_unlock(L); + return old; +} + + +LUA_API const lua_Number *lua_version (lua_State *L) { + static const lua_Number version = LUA_VERSION_NUM; + if (L == NULL) return &version; + else return G(L)->version; +} + + + +/* +** basic stack manipulation +*/ + + +/* +** convert an acceptable stack index into an absolute index +*/ +LUA_API int lua_absindex (lua_State *L, int idx) { + return (idx > 0 || ispseudo(idx)) + ? idx + : cast_int(L->top - L->ci->func + idx); +} + + +LUA_API int lua_gettop (lua_State *L) { + return cast_int(L->top - (L->ci->func + 1)); +} + + +LUA_API void lua_settop (lua_State *L, int idx) { + StkId func = L->ci->func; + lua_lock(L); + if (idx >= 0) { + api_check(idx <= L->stack_last - (func + 1), "new top too large"); + while (L->top < (func + 1) + idx) + setnilvalue(L->top++); + L->top = (func + 1) + idx; + } + else { + api_check(-(idx+1) <= (L->top - (func + 1)), "invalid new top"); + L->top += idx+1; /* 'subtract' index (index is negative) */ + } + lua_unlock(L); +} + + +/* +** Reverse the stack segment from 'from' to 'to' +** (auxiliary to 'lua_rotate') +*/ +static void reverse (lua_State *L, StkId from, StkId to) { + for (; from < to; from++, to--) { + TValue temp; + setobj(L, &temp, from); + setobjs2s(L, from, to); + setobj2s(L, to, &temp); + } +} + + +/* +** Let x = AB, where A is a prefix of length 'n'. Then, +** rotate x n == BA. But BA == (A^r . B^r)^r. +*/ +LUA_API void lua_rotate (lua_State *L, int idx, int n) { + StkId p, t, m; + lua_lock(L); + t = L->top - 1; /* end of stack segment being rotated */ + p = index2addr(L, idx); /* start of segment */ + api_checkstackindex(idx, p); + api_check((n >= 0 ? n : -n) <= (t - p + 1), "invalid 'n'"); + m = (n >= 0 ? t - n : p - n - 1); /* end of prefix */ + reverse(L, p, m); /* reverse the prefix with length 'n' */ + reverse(L, m + 1, t); /* reverse the suffix */ + reverse(L, p, t); /* reverse the entire segment */ + lua_unlock(L); +} + + +LUA_API void lua_copy (lua_State *L, int fromidx, int toidx) { + TValue *fr, *to; + lua_lock(L); + fr = index2addr(L, fromidx); + to = index2addr(L, toidx); + api_checkvalidindex(to); + setobj(L, to, fr); + if (isupvalue(toidx)) /* function upvalue? */ + luaC_barrier(L, clCvalue(L->ci->func), fr); + /* LUA_REGISTRYINDEX does not need gc barrier + (collector revisits it before finishing collection) */ + lua_unlock(L); +} + + +LUA_API void lua_pushvalue (lua_State *L, int idx) { + lua_lock(L); + setobj2s(L, L->top, index2addr(L, idx)); + api_incr_top(L); + lua_unlock(L); +} + + + +/* +** access functions (stack -> C) +*/ + + +LUA_API int lua_type (lua_State *L, int idx) { + StkId o = index2addr(L, idx); + return (isvalid(o) ? ttnov(o) : LUA_TNONE); +} + + +LUA_API const char *lua_typename (lua_State *L, int t) { + UNUSED(L); + api_check(LUA_TNONE <= t && t < LUA_NUMTAGS, "invalid tag"); + return ttypename(t); +} + + +LUA_API int lua_iscfunction (lua_State *L, int idx) { + StkId o = index2addr(L, idx); + return (ttislcf(o) || (ttisCclosure(o))); +} + + +LUA_API int lua_isinteger (lua_State *L, int idx) { + StkId o = index2addr(L, idx); + return ttisinteger(o); +} + + +LUA_API int lua_isnumber (lua_State *L, int idx) { + lua_Number n; + const TValue *o = index2addr(L, idx); + return tonumber(o, &n); +} + + +LUA_API int lua_isstring (lua_State *L, int idx) { + const TValue *o = index2addr(L, idx); + return (ttisstring(o) || cvt2str(o)); +} + + +LUA_API int lua_isuserdata (lua_State *L, int idx) { + const TValue *o = index2addr(L, idx); + return (ttisfulluserdata(o) || ttislightuserdata(o)); +} + + +LUA_API int lua_rawequal (lua_State *L, int index1, int index2) { + StkId o1 = index2addr(L, index1); + StkId o2 = index2addr(L, index2); + return (isvalid(o1) && isvalid(o2)) ? luaV_rawequalobj(o1, o2) : 0; +} + + +LUA_API void lua_arith (lua_State *L, int op) { + lua_lock(L); + if (op != LUA_OPUNM && op != LUA_OPBNOT) + api_checknelems(L, 2); /* all other operations expect two operands */ + else { /* for unary operations, add fake 2nd operand */ + api_checknelems(L, 1); + setobjs2s(L, L->top, L->top - 1); + L->top++; + } + /* first operand at top - 2, second at top - 1; result go to top - 2 */ + luaO_arith(L, op, L->top - 2, L->top - 1, L->top - 2); + L->top--; /* remove second operand */ + lua_unlock(L); +} + + +LUA_API int lua_compare (lua_State *L, int index1, int index2, int op) { + StkId o1, o2; + int i = 0; + lua_lock(L); /* may call tag method */ + o1 = index2addr(L, index1); + o2 = index2addr(L, index2); + if (isvalid(o1) && isvalid(o2)) { + switch (op) { + case LUA_OPEQ: i = luaV_equalobj(L, o1, o2); break; + case LUA_OPLT: i = luaV_lessthan(L, o1, o2); break; + case LUA_OPLE: i = luaV_lessequal(L, o1, o2); break; + default: api_check(0, "invalid option"); + } + } + lua_unlock(L); + return i; +} + + +LUA_API size_t lua_stringtonumber (lua_State *L, const char *s) { + size_t sz = luaO_str2num(s, L->top); + if (sz != 0) + api_incr_top(L); + return sz; +} + + +LUA_API lua_Number lua_tonumberx (lua_State *L, int idx, int *pisnum) { + lua_Number n; + const TValue *o = index2addr(L, idx); + int isnum = tonumber(o, &n); + if (!isnum) + n = 0; /* call to 'tonumber' may change 'n' even if it fails */ + if (pisnum) *pisnum = isnum; + return n; +} + + +LUA_API lua_Integer lua_tointegerx (lua_State *L, int idx, int *pisnum) { + lua_Integer res; + const TValue *o = index2addr(L, idx); + int isnum = tointeger(o, &res); + if (!isnum) + res = 0; /* call to 'tointeger' may change 'n' even if it fails */ + if (pisnum) *pisnum = isnum; + return res; +} + + +LUA_API int lua_toboolean (lua_State *L, int idx) { + const TValue *o = index2addr(L, idx); + return !l_isfalse(o); +} + + +LUA_API const char *lua_tolstring (lua_State *L, int idx, size_t *len) { + StkId o = index2addr(L, idx); + if (!ttisstring(o)) { + if (!cvt2str(o)) { /* not convertible? */ + if (len != NULL) *len = 0; + return NULL; + } + lua_lock(L); /* 'luaO_tostring' may create a new string */ + luaC_checkGC(L); + o = index2addr(L, idx); /* previous call may reallocate the stack */ + luaO_tostring(L, o); + lua_unlock(L); + } + if (len != NULL) *len = tsvalue(o)->len; + return svalue(o); +} + + +LUA_API size_t lua_rawlen (lua_State *L, int idx) { + StkId o = index2addr(L, idx); + switch (ttnov(o)) { + case LUA_TSTRING: return tsvalue(o)->len; + case LUA_TUSERDATA: return uvalue(o)->len; + case LUA_TTABLE: return luaH_getn(hvalue(o)); + default: return 0; + } +} + + +LUA_API lua_CFunction lua_tocfunction (lua_State *L, int idx) { + StkId o = index2addr(L, idx); + if (ttislcf(o)) return fvalue(o); + else if (ttisCclosure(o)) + return clCvalue(o)->f; + else return NULL; /* not a C function */ +} + + +LUA_API void *lua_touserdata (lua_State *L, int idx) { + StkId o = index2addr(L, idx); + switch (ttnov(o)) { + case LUA_TUSERDATA: return getudatamem(uvalue(o)); + case LUA_TLIGHTUSERDATA: return pvalue(o); + default: return NULL; + } +} + + +LUA_API lua_State *lua_tothread (lua_State *L, int idx) { + StkId o = index2addr(L, idx); + return (!ttisthread(o)) ? NULL : thvalue(o); +} + + +LUA_API const void *lua_topointer (lua_State *L, int idx) { + StkId o = index2addr(L, idx); + switch (ttype(o)) { + case LUA_TTABLE: return hvalue(o); + case LUA_TLCL: return clLvalue(o); + case LUA_TCCL: return clCvalue(o); + case LUA_TLCF: return cast(void *, cast(size_t, fvalue(o))); + case LUA_TTHREAD: return thvalue(o); + case LUA_TUSERDATA: + case LUA_TLIGHTUSERDATA: + return lua_touserdata(L, idx); + default: return NULL; + } +} + + + +/* +** push functions (C -> stack) +*/ + + +LUA_API void lua_pushnil (lua_State *L) { + lua_lock(L); + setnilvalue(L->top); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API void lua_pushnumber (lua_State *L, lua_Number n) { + lua_lock(L); + setfltvalue(L->top, n); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API void lua_pushinteger (lua_State *L, lua_Integer n) { + lua_lock(L); + setivalue(L->top, n); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API const char *lua_pushlstring (lua_State *L, const char *s, size_t len) { + TString *ts; + lua_lock(L); + luaC_checkGC(L); + ts = luaS_newlstr(L, s, len); + setsvalue2s(L, L->top, ts); + api_incr_top(L); + lua_unlock(L); + return getstr(ts); +} + + +LUA_API const char *lua_pushstring (lua_State *L, const char *s) { + if (s == NULL) { + lua_pushnil(L); + return NULL; + } + else { + TString *ts; + lua_lock(L); + luaC_checkGC(L); + ts = luaS_new(L, s); + setsvalue2s(L, L->top, ts); + api_incr_top(L); + lua_unlock(L); + return getstr(ts); + } +} + + +LUA_API const char *lua_pushvfstring (lua_State *L, const char *fmt, + va_list argp) { + const char *ret; + lua_lock(L); + luaC_checkGC(L); + ret = luaO_pushvfstring(L, fmt, argp); + lua_unlock(L); + return ret; +} + + +LUA_API const char *lua_pushfstring (lua_State *L, const char *fmt, ...) { + const char *ret; + va_list argp; + lua_lock(L); + luaC_checkGC(L); + va_start(argp, fmt); + ret = luaO_pushvfstring(L, fmt, argp); + va_end(argp); + lua_unlock(L); + return ret; +} + + +LUA_API void lua_pushcclosure (lua_State *L, lua_CFunction fn, int n) { + lua_lock(L); + if (n == 0) { + setfvalue(L->top, fn); + } + else { + CClosure *cl; + api_checknelems(L, n); + api_check(n <= MAXUPVAL, "upvalue index too large"); + luaC_checkGC(L); + cl = luaF_newCclosure(L, n); + cl->f = fn; + L->top -= n; + while (n--) { + setobj2n(L, &cl->upvalue[n], L->top + n); + /* does not need barrier because closure is white */ + } + setclCvalue(L, L->top, cl); + } + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API void lua_pushboolean (lua_State *L, int b) { + lua_lock(L); + setbvalue(L->top, (b != 0)); /* ensure that true is 1 */ + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API void lua_pushlightuserdata (lua_State *L, void *p) { + lua_lock(L); + setpvalue(L->top, p); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API int lua_pushthread (lua_State *L) { + lua_lock(L); + setthvalue(L, L->top, L); + api_incr_top(L); + lua_unlock(L); + return (G(L)->mainthread == L); +} + + + +/* +** get functions (Lua -> stack) +*/ + + +LUA_API int lua_getglobal (lua_State *L, const char *name) { + Table *reg = hvalue(&G(L)->l_registry); + const TValue *gt; /* global table */ + lua_lock(L); + gt = luaH_getint(reg, LUA_RIDX_GLOBALS); + setsvalue2s(L, L->top++, luaS_new(L, name)); + luaV_gettable(L, gt, L->top - 1, L->top - 1); + lua_unlock(L); + return ttnov(L->top - 1); +} + + +LUA_API int lua_gettable (lua_State *L, int idx) { + StkId t; + lua_lock(L); + t = index2addr(L, idx); + luaV_gettable(L, t, L->top - 1, L->top - 1); + lua_unlock(L); + return ttnov(L->top - 1); +} + + +LUA_API int lua_getfield (lua_State *L, int idx, const char *k) { + StkId t; + lua_lock(L); + t = index2addr(L, idx); + setsvalue2s(L, L->top, luaS_new(L, k)); + api_incr_top(L); + luaV_gettable(L, t, L->top - 1, L->top - 1); + lua_unlock(L); + return ttnov(L->top - 1); +} + + +LUA_API int lua_geti (lua_State *L, int idx, lua_Integer n) { + StkId t; + lua_lock(L); + t = index2addr(L, idx); + setivalue(L->top, n); + api_incr_top(L); + luaV_gettable(L, t, L->top - 1, L->top - 1); + lua_unlock(L); + return ttnov(L->top - 1); +} + + +LUA_API int lua_rawget (lua_State *L, int idx) { + StkId t; + lua_lock(L); + t = index2addr(L, idx); + api_check(ttistable(t), "table expected"); + setobj2s(L, L->top - 1, luaH_get(hvalue(t), L->top - 1)); + lua_unlock(L); + return ttnov(L->top - 1); +} + + +LUA_API int lua_rawgeti (lua_State *L, int idx, lua_Integer n) { + StkId t; + lua_lock(L); + t = index2addr(L, idx); + api_check(ttistable(t), "table expected"); + setobj2s(L, L->top, luaH_getint(hvalue(t), n)); + api_incr_top(L); + lua_unlock(L); + return ttnov(L->top - 1); +} + + +LUA_API int lua_rawgetp (lua_State *L, int idx, const void *p) { + StkId t; + TValue k; + lua_lock(L); + t = index2addr(L, idx); + api_check(ttistable(t), "table expected"); + setpvalue(&k, cast(void *, p)); + setobj2s(L, L->top, luaH_get(hvalue(t), &k)); + api_incr_top(L); + lua_unlock(L); + return ttnov(L->top - 1); +} + + +LUA_API void lua_createtable (lua_State *L, int narray, int nrec) { + Table *t; + lua_lock(L); + luaC_checkGC(L); + t = luaH_new(L); + sethvalue(L, L->top, t); + api_incr_top(L); + if (narray > 0 || nrec > 0) + luaH_resize(L, t, narray, nrec); + lua_unlock(L); +} + + +LUA_API int lua_getmetatable (lua_State *L, int objindex) { + const TValue *obj; + Table *mt; + int res = 0; + lua_lock(L); + obj = index2addr(L, objindex); + switch (ttnov(obj)) { + case LUA_TTABLE: + mt = hvalue(obj)->metatable; + break; + case LUA_TUSERDATA: + mt = uvalue(obj)->metatable; + break; + default: + mt = G(L)->mt[ttnov(obj)]; + break; + } + if (mt != NULL) { + sethvalue(L, L->top, mt); + api_incr_top(L); + res = 1; + } + lua_unlock(L); + return res; +} + + +LUA_API int lua_getuservalue (lua_State *L, int idx) { + StkId o; + lua_lock(L); + o = index2addr(L, idx); + api_check(ttisfulluserdata(o), "full userdata expected"); + getuservalue(L, uvalue(o), L->top); + api_incr_top(L); + lua_unlock(L); + return ttnov(L->top - 1); +} + + +/* +** set functions (stack -> Lua) +*/ + + +LUA_API void lua_setglobal (lua_State *L, const char *name) { + Table *reg = hvalue(&G(L)->l_registry); + const TValue *gt; /* global table */ + lua_lock(L); + api_checknelems(L, 1); + gt = luaH_getint(reg, LUA_RIDX_GLOBALS); + setsvalue2s(L, L->top++, luaS_new(L, name)); + luaV_settable(L, gt, L->top - 1, L->top - 2); + L->top -= 2; /* pop value and key */ + lua_unlock(L); +} + + +LUA_API void lua_settable (lua_State *L, int idx) { + StkId t; + lua_lock(L); + api_checknelems(L, 2); + t = index2addr(L, idx); + luaV_settable(L, t, L->top - 2, L->top - 1); + L->top -= 2; /* pop index and value */ + lua_unlock(L); +} + + +LUA_API void lua_setfield (lua_State *L, int idx, const char *k) { + StkId t; + lua_lock(L); + api_checknelems(L, 1); + t = index2addr(L, idx); + setsvalue2s(L, L->top++, luaS_new(L, k)); + luaV_settable(L, t, L->top - 1, L->top - 2); + L->top -= 2; /* pop value and key */ + lua_unlock(L); +} + + +LUA_API void lua_seti (lua_State *L, int idx, lua_Integer n) { + StkId t; + lua_lock(L); + api_checknelems(L, 1); + t = index2addr(L, idx); + setivalue(L->top++, n); + luaV_settable(L, t, L->top - 1, L->top - 2); + L->top -= 2; /* pop value and key */ + lua_unlock(L); +} + + +LUA_API void lua_rawset (lua_State *L, int idx) { + StkId o; + Table *t; + lua_lock(L); + api_checknelems(L, 2); + o = index2addr(L, idx); + api_check(ttistable(o), "table expected"); + t = hvalue(o); + setobj2t(L, luaH_set(L, t, L->top-2), L->top-1); + invalidateTMcache(t); + luaC_barrierback(L, t, L->top-1); + L->top -= 2; + lua_unlock(L); +} + + +LUA_API void lua_rawseti (lua_State *L, int idx, lua_Integer n) { + StkId o; + Table *t; + lua_lock(L); + api_checknelems(L, 1); + o = index2addr(L, idx); + api_check(ttistable(o), "table expected"); + t = hvalue(o); + luaH_setint(L, t, n, L->top - 1); + luaC_barrierback(L, t, L->top-1); + L->top--; + lua_unlock(L); +} + + +LUA_API void lua_rawsetp (lua_State *L, int idx, const void *p) { + StkId o; + Table *t; + TValue k; + lua_lock(L); + api_checknelems(L, 1); + o = index2addr(L, idx); + api_check(ttistable(o), "table expected"); + t = hvalue(o); + setpvalue(&k, cast(void *, p)); + setobj2t(L, luaH_set(L, t, &k), L->top - 1); + luaC_barrierback(L, t, L->top - 1); + L->top--; + lua_unlock(L); +} + + +LUA_API int lua_setmetatable (lua_State *L, int objindex) { + TValue *obj; + Table *mt; + lua_lock(L); + api_checknelems(L, 1); + obj = index2addr(L, objindex); + if (ttisnil(L->top - 1)) + mt = NULL; + else { + api_check(ttistable(L->top - 1), "table expected"); + mt = hvalue(L->top - 1); + } + switch (ttnov(obj)) { + case LUA_TTABLE: { + hvalue(obj)->metatable = mt; + if (mt) { + luaC_objbarrier(L, gcvalue(obj), mt); + luaC_checkfinalizer(L, gcvalue(obj), mt); + } + break; + } + case LUA_TUSERDATA: { + uvalue(obj)->metatable = mt; + if (mt) { + luaC_objbarrier(L, uvalue(obj), mt); + luaC_checkfinalizer(L, gcvalue(obj), mt); + } + break; + } + default: { + G(L)->mt[ttnov(obj)] = mt; + break; + } + } + L->top--; + lua_unlock(L); + return 1; +} + + +LUA_API void lua_setuservalue (lua_State *L, int idx) { + StkId o; + lua_lock(L); + api_checknelems(L, 1); + o = index2addr(L, idx); + api_check(ttisfulluserdata(o), "full userdata expected"); + setuservalue(L, uvalue(o), L->top - 1); + luaC_barrier(L, gcvalue(o), L->top - 1); + L->top--; + lua_unlock(L); +} + + +/* +** 'load' and 'call' functions (run Lua code) +*/ + + +#define checkresults(L,na,nr) \ + api_check((nr) == LUA_MULTRET || (L->ci->top - L->top >= (nr) - (na)), \ + "results from function overflow current stack size") + + +LUA_API void lua_callk (lua_State *L, int nargs, int nresults, + lua_KContext ctx, lua_KFunction k) { + StkId func; + lua_lock(L); + api_check(k == NULL || !isLua(L->ci), + "cannot use continuations inside hooks"); + api_checknelems(L, nargs+1); + api_check(L->status == LUA_OK, "cannot do calls on non-normal thread"); + checkresults(L, nargs, nresults); + func = L->top - (nargs+1); + if (k != NULL && L->nny == 0) { /* need to prepare continuation? */ + L->ci->u.c.k = k; /* save continuation */ + L->ci->u.c.ctx = ctx; /* save context */ + luaD_call(L, func, nresults, 1); /* do the call */ + } + else /* no continuation or no yieldable */ + luaD_call(L, func, nresults, 0); /* just do the call */ + adjustresults(L, nresults); + lua_unlock(L); +} + + + +/* +** Execute a protected call. +*/ +struct CallS { /* data to 'f_call' */ + StkId func; + int nresults; +}; + + +static void f_call (lua_State *L, void *ud) { + struct CallS *c = cast(struct CallS *, ud); + luaD_call(L, c->func, c->nresults, 0); +} + + + +LUA_API int lua_pcallk (lua_State *L, int nargs, int nresults, int errfunc, + lua_KContext ctx, lua_KFunction k) { + struct CallS c; + int status; + ptrdiff_t func; + lua_lock(L); + api_check(k == NULL || !isLua(L->ci), + "cannot use continuations inside hooks"); + api_checknelems(L, nargs+1); + api_check(L->status == LUA_OK, "cannot do calls on non-normal thread"); + checkresults(L, nargs, nresults); + if (errfunc == 0) + func = 0; + else { + StkId o = index2addr(L, errfunc); + api_checkstackindex(errfunc, o); + func = savestack(L, o); + } + c.func = L->top - (nargs+1); /* function to be called */ + if (k == NULL || L->nny > 0) { /* no continuation or no yieldable? */ + c.nresults = nresults; /* do a 'conventional' protected call */ + status = luaD_pcall(L, f_call, &c, savestack(L, c.func), func); + } + else { /* prepare continuation (call is already protected by 'resume') */ + CallInfo *ci = L->ci; + ci->u.c.k = k; /* save continuation */ + ci->u.c.ctx = ctx; /* save context */ + /* save information for error recovery */ + ci->extra = savestack(L, c.func); + ci->u.c.old_errfunc = L->errfunc; + L->errfunc = func; + setoah(ci->callstatus, L->allowhook); /* save value of 'allowhook' */ + ci->callstatus |= CIST_YPCALL; /* function can do error recovery */ + luaD_call(L, c.func, nresults, 1); /* do the call */ + ci->callstatus &= ~CIST_YPCALL; + L->errfunc = ci->u.c.old_errfunc; + status = LUA_OK; /* if it is here, there were no errors */ + } + adjustresults(L, nresults); + lua_unlock(L); + return status; +} + + +LUA_API int lua_load (lua_State *L, lua_Reader reader, void *data, + const char *chunkname, const char *mode) { + ZIO z; + int status; + lua_lock(L); + if (!chunkname) chunkname = "?"; + luaZ_init(L, &z, reader, data); + status = luaD_protectedparser(L, &z, chunkname, mode); + if (status == LUA_OK) { /* no errors? */ + LClosure *f = clLvalue(L->top - 1); /* get newly created function */ + if (f->nupvalues >= 1) { /* does it have an upvalue? */ + /* get global table from registry */ + Table *reg = hvalue(&G(L)->l_registry); + const TValue *gt = luaH_getint(reg, LUA_RIDX_GLOBALS); + /* set global table as 1st upvalue of 'f' (may be LUA_ENV) */ + setobj(L, f->upvals[0]->v, gt); + luaC_upvalbarrier(L, f->upvals[0]); + } + } + lua_unlock(L); + return status; +} + + +LUA_API int lua_dump (lua_State *L, lua_Writer writer, void *data, int strip) { + int status; + TValue *o; + lua_lock(L); + api_checknelems(L, 1); + o = L->top - 1; + if (isLfunction(o)) + status = luaU_dump(L, getproto(o), writer, data, strip); + else + status = 1; + lua_unlock(L); + return status; +} + + +LUA_API int lua_status (lua_State *L) { + return L->status; +} + + +/* +** Garbage-collection function +*/ + +LUA_API int lua_gc (lua_State *L, int what, int data) { + int res = 0; + global_State *g; + lua_lock(L); + g = G(L); + switch (what) { + case LUA_GCSTOP: { + g->gcrunning = 0; + break; + } + case LUA_GCRESTART: { + luaE_setdebt(g, 0); + g->gcrunning = 1; + break; + } + case LUA_GCCOLLECT: { + luaC_fullgc(L, 0); + break; + } + case LUA_GCCOUNT: { + /* GC values are expressed in Kbytes: #bytes/2^10 */ + res = cast_int(gettotalbytes(g) >> 10); + break; + } + case LUA_GCCOUNTB: { + res = cast_int(gettotalbytes(g) & 0x3ff); + break; + } + case LUA_GCSTEP: { + l_mem debt = 1; /* =1 to signal that it did an actual step */ + int oldrunning = g->gcrunning; + g->gcrunning = 1; /* allow GC to run */ + if (data == 0) { + luaE_setdebt(g, -GCSTEPSIZE); /* to do a "small" step */ + luaC_step(L); + } + else { /* add 'data' to total debt */ + debt = cast(l_mem, data) * 1024 + g->GCdebt; + luaE_setdebt(g, debt); + luaC_checkGC(L); + } + g->gcrunning = oldrunning; /* restore previous state */ + if (debt > 0 && g->gcstate == GCSpause) /* end of cycle? */ + res = 1; /* signal it */ + break; + } + case LUA_GCSETPAUSE: { + res = g->gcpause; + g->gcpause = data; + break; + } + case LUA_GCSETSTEPMUL: { + res = g->gcstepmul; + if (data < 40) data = 40; /* avoid ridiculous low values (and 0) */ + g->gcstepmul = data; + break; + } + case LUA_GCISRUNNING: { + res = g->gcrunning; + break; + } + default: res = -1; /* invalid option */ + } + lua_unlock(L); + return res; +} + + + +/* +** miscellaneous functions +*/ + + +LUA_API int lua_error (lua_State *L) { + lua_lock(L); + api_checknelems(L, 1); + luaG_errormsg(L); + /* code unreachable; will unlock when control actually leaves the kernel */ + return 0; /* to avoid warnings */ +} + + +LUA_API int lua_next (lua_State *L, int idx) { + StkId t; + int more; + lua_lock(L); + t = index2addr(L, idx); + api_check(ttistable(t), "table expected"); + more = luaH_next(L, hvalue(t), L->top - 1); + if (more) { + api_incr_top(L); + } + else /* no more elements */ + L->top -= 1; /* remove key */ + lua_unlock(L); + return more; +} + + +LUA_API void lua_concat (lua_State *L, int n) { + lua_lock(L); + api_checknelems(L, n); + if (n >= 2) { + luaC_checkGC(L); + luaV_concat(L, n); + } + else if (n == 0) { /* push empty string */ + setsvalue2s(L, L->top, luaS_newlstr(L, "", 0)); + api_incr_top(L); + } + /* else n == 1; nothing to do */ + lua_unlock(L); +} + + +LUA_API void lua_len (lua_State *L, int idx) { + StkId t; + lua_lock(L); + t = index2addr(L, idx); + luaV_objlen(L, L->top, t); + api_incr_top(L); + lua_unlock(L); +} + + +LUA_API lua_Alloc lua_getallocf (lua_State *L, void **ud) { + lua_Alloc f; + lua_lock(L); + if (ud) *ud = G(L)->ud; + f = G(L)->frealloc; + lua_unlock(L); + return f; +} + + +LUA_API void lua_setallocf (lua_State *L, lua_Alloc f, void *ud) { + lua_lock(L); + G(L)->ud = ud; + G(L)->frealloc = f; + lua_unlock(L); +} + + +LUA_API void *lua_newuserdata (lua_State *L, size_t size) { + Udata *u; + lua_lock(L); + luaC_checkGC(L); + u = luaS_newudata(L, size); + setuvalue(L, L->top, u); + api_incr_top(L); + lua_unlock(L); + return getudatamem(u); +} + + + +static const char *aux_upvalue (StkId fi, int n, TValue **val, + CClosure **owner, UpVal **uv) { + switch (ttype(fi)) { + case LUA_TCCL: { /* C closure */ + CClosure *f = clCvalue(fi); + if (!(1 <= n && n <= f->nupvalues)) return NULL; + *val = &f->upvalue[n-1]; + if (owner) *owner = f; + return ""; + } + case LUA_TLCL: { /* Lua closure */ + LClosure *f = clLvalue(fi); + TString *name; + Proto *p = f->p; + if (!(1 <= n && n <= p->sizeupvalues)) return NULL; + *val = f->upvals[n-1]->v; + if (uv) *uv = f->upvals[n - 1]; + name = p->upvalues[n-1].name; + return (name == NULL) ? "(*no name)" : getstr(name); + } + default: return NULL; /* not a closure */ + } +} + + +LUA_API const char *lua_getupvalue (lua_State *L, int funcindex, int n) { + const char *name; + TValue *val = NULL; /* to avoid warnings */ + lua_lock(L); + name = aux_upvalue(index2addr(L, funcindex), n, &val, NULL, NULL); + if (name) { + setobj2s(L, L->top, val); + api_incr_top(L); + } + lua_unlock(L); + return name; +} + + +LUA_API const char *lua_setupvalue (lua_State *L, int funcindex, int n) { + const char *name; + TValue *val = NULL; /* to avoid warnings */ + CClosure *owner = NULL; + UpVal *uv = NULL; + StkId fi; + lua_lock(L); + fi = index2addr(L, funcindex); + api_checknelems(L, 1); + name = aux_upvalue(fi, n, &val, &owner, &uv); + if (name) { + L->top--; + setobj(L, val, L->top); + if (owner) { luaC_barrier(L, owner, L->top); } + else if (uv) { luaC_upvalbarrier(L, uv); } + } + lua_unlock(L); + return name; +} + + +static UpVal **getupvalref (lua_State *L, int fidx, int n, LClosure **pf) { + LClosure *f; + StkId fi = index2addr(L, fidx); + api_check(ttisLclosure(fi), "Lua function expected"); + f = clLvalue(fi); + api_check((1 <= n && n <= f->p->sizeupvalues), "invalid upvalue index"); + if (pf) *pf = f; + return &f->upvals[n - 1]; /* get its upvalue pointer */ +} + + +LUA_API void *lua_upvalueid (lua_State *L, int fidx, int n) { + StkId fi = index2addr(L, fidx); + switch (ttype(fi)) { + case LUA_TLCL: { /* lua closure */ + return *getupvalref(L, fidx, n, NULL); + } + case LUA_TCCL: { /* C closure */ + CClosure *f = clCvalue(fi); + api_check(1 <= n && n <= f->nupvalues, "invalid upvalue index"); + return &f->upvalue[n - 1]; + } + default: { + api_check(0, "closure expected"); + return NULL; + } + } +} + + +LUA_API void lua_upvaluejoin (lua_State *L, int fidx1, int n1, + int fidx2, int n2) { + LClosure *f1; + UpVal **up1 = getupvalref(L, fidx1, n1, &f1); + UpVal **up2 = getupvalref(L, fidx2, n2, NULL); + luaC_upvdeccount(L, *up1); + *up1 = *up2; + (*up1)->refcount++; + if (upisopen(*up1)) (*up1)->u.open.touched = 1; + luaC_upvalbarrier(L, *up1); +} + + diff --git a/src/lapi.h b/src/lapi.h new file mode 100644 index 000000000000..092f5e974cb1 --- /dev/null +++ b/src/lapi.h @@ -0,0 +1,24 @@ +/* +** $Id: lapi.h,v 2.8 2014/07/15 21:26:50 roberto Exp $ +** Auxiliary functions from Lua API +** See Copyright Notice in lua.h +*/ + +#ifndef lapi_h +#define lapi_h + + +#include "llimits.h" +#include "lstate.h" + +#define api_incr_top(L) {L->top++; api_check(L->top <= L->ci->top, \ + "stack overflow");} + +#define adjustresults(L,nres) \ + { if ((nres) == LUA_MULTRET && L->ci->top < L->top) L->ci->top = L->top; } + +#define api_checknelems(L,n) api_check((n) < (L->top - L->ci->func), \ + "not enough elements in the stack") + + +#endif diff --git a/src/lauxlib.c b/src/lauxlib.c new file mode 100644 index 000000000000..1c41d6a8eaf4 --- /dev/null +++ b/src/lauxlib.c @@ -0,0 +1,972 @@ +/* +** $Id: lauxlib.c,v 1.279 2014/12/14 18:32:26 roberto Exp $ +** Auxiliary functions for building Lua libraries +** See Copyright Notice in lua.h +*/ + +#define lauxlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <errno.h> +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + + +/* This file uses only the official API of Lua. +** Any function declared here could be written as an application function. +*/ + +#include "lua.h" + +#include "lauxlib.h" + + +/* +** {====================================================== +** Traceback +** ======================================================= +*/ + + +#define LEVELS1 12 /* size of the first part of the stack */ +#define LEVELS2 10 /* size of the second part of the stack */ + + + +/* +** search for 'objidx' in table at index -1. +** return 1 + string at top if find a good name. +*/ +static int findfield (lua_State *L, int objidx, int level) { + if (level == 0 || !lua_istable(L, -1)) + return 0; /* not found */ + lua_pushnil(L); /* start 'next' loop */ + while (lua_next(L, -2)) { /* for each pair in table */ + if (lua_type(L, -2) == LUA_TSTRING) { /* ignore non-string keys */ + if (lua_rawequal(L, objidx, -1)) { /* found object? */ + lua_pop(L, 1); /* remove value (but keep name) */ + return 1; + } + else if (findfield(L, objidx, level - 1)) { /* try recursively */ + lua_remove(L, -2); /* remove table (but keep name) */ + lua_pushliteral(L, "."); + lua_insert(L, -2); /* place '.' between the two names */ + lua_concat(L, 3); + return 1; + } + } + lua_pop(L, 1); /* remove value */ + } + return 0; /* not found */ +} + + +/* +** Search for a name for a function in all loaded modules +** (registry._LOADED). +*/ +static int pushglobalfuncname (lua_State *L, lua_Debug *ar) { + int top = lua_gettop(L); + lua_getinfo(L, "f", ar); /* push function */ + lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED"); + if (findfield(L, top + 1, 2)) { + const char *name = lua_tostring(L, -1); + if (strncmp(name, "_G.", 3) == 0) { /* name start with '_G.'? */ + lua_pushstring(L, name + 3); /* push name without prefix */ + lua_remove(L, -2); /* remove original name */ + } + lua_copy(L, -1, top + 1); /* move name to proper place */ + lua_pop(L, 2); /* remove pushed values */ + return 1; + } + else { + lua_settop(L, top); /* remove function and global table */ + return 0; + } +} + + +static void pushfuncname (lua_State *L, lua_Debug *ar) { + if (pushglobalfuncname(L, ar)) { /* try first a global name */ + lua_pushfstring(L, "function '%s'", lua_tostring(L, -1)); + lua_remove(L, -2); /* remove name */ + } + else if (*ar->namewhat != '\0') /* is there a name from code? */ + lua_pushfstring(L, "%s '%s'", ar->namewhat, ar->name); /* use it */ + else if (*ar->what == 'm') /* main? */ + lua_pushliteral(L, "main chunk"); + else if (*ar->what != 'C') /* for Lua functions, use <file:line> */ + lua_pushfstring(L, "function <%s:%d>", ar->short_src, ar->linedefined); + else /* nothing left... */ + lua_pushliteral(L, "?"); +} + + +static int countlevels (lua_State *L) { + lua_Debug ar; + int li = 1, le = 1; + /* find an upper bound */ + while (lua_getstack(L, le, &ar)) { li = le; le *= 2; } + /* do a binary search */ + while (li < le) { + int m = (li + le)/2; + if (lua_getstack(L, m, &ar)) li = m + 1; + else le = m; + } + return le - 1; +} + + +LUALIB_API void luaL_traceback (lua_State *L, lua_State *L1, + const char *msg, int level) { + lua_Debug ar; + int top = lua_gettop(L); + int numlevels = countlevels(L1); + int mark = (numlevels > LEVELS1 + LEVELS2) ? LEVELS1 : 0; + if (msg) lua_pushfstring(L, "%s\n", msg); + lua_pushliteral(L, "stack traceback:"); + while (lua_getstack(L1, level++, &ar)) { + if (level == mark) { /* too many levels? */ + lua_pushliteral(L, "\n\t..."); /* add a '...' */ + level = numlevels - LEVELS2; /* and skip to last ones */ + } + else { + lua_getinfo(L1, "Slnt", &ar); + lua_pushfstring(L, "\n\t%s:", ar.short_src); + if (ar.currentline > 0) + lua_pushfstring(L, "%d:", ar.currentline); + lua_pushliteral(L, " in "); + pushfuncname(L, &ar); + if (ar.istailcall) + lua_pushliteral(L, "\n\t(...tail calls...)"); + lua_concat(L, lua_gettop(L) - top); + } + } + lua_concat(L, lua_gettop(L) - top); +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Error-report functions +** ======================================================= +*/ + +LUALIB_API int luaL_argerror (lua_State *L, int arg, const char *extramsg) { + lua_Debug ar; + if (!lua_getstack(L, 0, &ar)) /* no stack frame? */ + return luaL_error(L, "bad argument #%d (%s)", arg, extramsg); + lua_getinfo(L, "n", &ar); + if (strcmp(ar.namewhat, "method") == 0) { + arg--; /* do not count 'self' */ + if (arg == 0) /* error is in the self argument itself? */ + return luaL_error(L, "calling '%s' on bad self (%s)", + ar.name, extramsg); + } + if (ar.name == NULL) + ar.name = (pushglobalfuncname(L, &ar)) ? lua_tostring(L, -1) : "?"; + return luaL_error(L, "bad argument #%d to '%s' (%s)", + arg, ar.name, extramsg); +} + + +static int typeerror (lua_State *L, int arg, const char *tname) { + const char *msg; + const char *typearg; /* name for the type of the actual argument */ + if (luaL_getmetafield(L, arg, "__name") == LUA_TSTRING) + typearg = lua_tostring(L, -1); /* use the given type name */ + else if (lua_type(L, arg) == LUA_TLIGHTUSERDATA) + typearg = "light userdata"; /* special name for messages */ + else + typearg = luaL_typename(L, arg); /* standard name */ + msg = lua_pushfstring(L, "%s expected, got %s", tname, typearg); + return luaL_argerror(L, arg, msg); +} + + +static void tag_error (lua_State *L, int arg, int tag) { + typeerror(L, arg, lua_typename(L, tag)); +} + + +LUALIB_API void luaL_where (lua_State *L, int level) { + lua_Debug ar; + if (lua_getstack(L, level, &ar)) { /* check function at level */ + lua_getinfo(L, "Sl", &ar); /* get info about it */ + if (ar.currentline > 0) { /* is there info? */ + lua_pushfstring(L, "%s:%d: ", ar.short_src, ar.currentline); + return; + } + } + lua_pushliteral(L, ""); /* else, no information available... */ +} + + +LUALIB_API int luaL_error (lua_State *L, const char *fmt, ...) { + va_list argp; + va_start(argp, fmt); + luaL_where(L, 1); + lua_pushvfstring(L, fmt, argp); + va_end(argp); + lua_concat(L, 2); + return lua_error(L); +} + + +LUALIB_API int luaL_fileresult (lua_State *L, int stat, const char *fname) { + int en = errno; /* calls to Lua API may change this value */ + if (stat) { + lua_pushboolean(L, 1); + return 1; + } + else { + lua_pushnil(L); + if (fname) + lua_pushfstring(L, "%s: %s", fname, strerror(en)); + else + lua_pushstring(L, strerror(en)); + lua_pushinteger(L, en); + return 3; + } +} + + +#if !defined(l_inspectstat) /* { */ + +#if defined(LUA_USE_POSIX) + +#include <sys/wait.h> + +/* +** use appropriate macros to interpret 'pclose' return status +*/ +#define l_inspectstat(stat,what) \ + if (WIFEXITED(stat)) { stat = WEXITSTATUS(stat); } \ + else if (WIFSIGNALED(stat)) { stat = WTERMSIG(stat); what = "signal"; } + +#else + +#define l_inspectstat(stat,what) /* no op */ + +#endif + +#endif /* } */ + + +LUALIB_API int luaL_execresult (lua_State *L, int stat) { + const char *what = "exit"; /* type of termination */ + if (stat == -1) /* error? */ + return luaL_fileresult(L, 0, NULL); + else { + l_inspectstat(stat, what); /* interpret result */ + if (*what == 'e' && stat == 0) /* successful termination? */ + lua_pushboolean(L, 1); + else + lua_pushnil(L); + lua_pushstring(L, what); + lua_pushinteger(L, stat); + return 3; /* return true/nil,what,code */ + } +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Userdata's metatable manipulation +** ======================================================= +*/ + +LUALIB_API int luaL_newmetatable (lua_State *L, const char *tname) { + if (luaL_getmetatable(L, tname)) /* name already in use? */ + return 0; /* leave previous value on top, but return 0 */ + lua_pop(L, 1); + lua_newtable(L); /* create metatable */ + lua_pushstring(L, tname); + lua_setfield(L, -2, "__name"); /* metatable.__name = tname */ + lua_pushvalue(L, -1); + lua_setfield(L, LUA_REGISTRYINDEX, tname); /* registry.name = metatable */ + return 1; +} + + +LUALIB_API void luaL_setmetatable (lua_State *L, const char *tname) { + luaL_getmetatable(L, tname); + lua_setmetatable(L, -2); +} + + +LUALIB_API void *luaL_testudata (lua_State *L, int ud, const char *tname) { + void *p = lua_touserdata(L, ud); + if (p != NULL) { /* value is a userdata? */ + if (lua_getmetatable(L, ud)) { /* does it have a metatable? */ + luaL_getmetatable(L, tname); /* get correct metatable */ + if (!lua_rawequal(L, -1, -2)) /* not the same? */ + p = NULL; /* value is a userdata with wrong metatable */ + lua_pop(L, 2); /* remove both metatables */ + return p; + } + } + return NULL; /* value is not a userdata with a metatable */ +} + + +LUALIB_API void *luaL_checkudata (lua_State *L, int ud, const char *tname) { + void *p = luaL_testudata(L, ud, tname); + if (p == NULL) typeerror(L, ud, tname); + return p; +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Argument check functions +** ======================================================= +*/ + +LUALIB_API int luaL_checkoption (lua_State *L, int arg, const char *def, + const char *const lst[]) { + const char *name = (def) ? luaL_optstring(L, arg, def) : + luaL_checkstring(L, arg); + int i; + for (i=0; lst[i]; i++) + if (strcmp(lst[i], name) == 0) + return i; + return luaL_argerror(L, arg, + lua_pushfstring(L, "invalid option '%s'", name)); +} + + +LUALIB_API void luaL_checkstack (lua_State *L, int space, const char *msg) { + /* keep some extra space to run error routines, if needed */ + const int extra = LUA_MINSTACK; + if (!lua_checkstack(L, space + extra)) { + if (msg) + luaL_error(L, "stack overflow (%s)", msg); + else + luaL_error(L, "stack overflow"); + } +} + + +LUALIB_API void luaL_checktype (lua_State *L, int arg, int t) { + if (lua_type(L, arg) != t) + tag_error(L, arg, t); +} + + +LUALIB_API void luaL_checkany (lua_State *L, int arg) { + if (lua_type(L, arg) == LUA_TNONE) + luaL_argerror(L, arg, "value expected"); +} + + +LUALIB_API const char *luaL_checklstring (lua_State *L, int arg, size_t *len) { + const char *s = lua_tolstring(L, arg, len); + if (!s) tag_error(L, arg, LUA_TSTRING); + return s; +} + + +LUALIB_API const char *luaL_optlstring (lua_State *L, int arg, + const char *def, size_t *len) { + if (lua_isnoneornil(L, arg)) { + if (len) + *len = (def ? strlen(def) : 0); + return def; + } + else return luaL_checklstring(L, arg, len); +} + + +LUALIB_API lua_Number luaL_checknumber (lua_State *L, int arg) { + int isnum; + lua_Number d = lua_tonumberx(L, arg, &isnum); + if (!isnum) + tag_error(L, arg, LUA_TNUMBER); + return d; +} + + +LUALIB_API lua_Number luaL_optnumber (lua_State *L, int arg, lua_Number def) { + return luaL_opt(L, luaL_checknumber, arg, def); +} + + +static void interror (lua_State *L, int arg) { + if (lua_isnumber(L, arg)) + luaL_argerror(L, arg, "number has no integer representation"); + else + tag_error(L, arg, LUA_TNUMBER); +} + + +LUALIB_API lua_Integer luaL_checkinteger (lua_State *L, int arg) { + int isnum; + lua_Integer d = lua_tointegerx(L, arg, &isnum); + if (!isnum) { + interror(L, arg); + } + return d; +} + + +LUALIB_API lua_Integer luaL_optinteger (lua_State *L, int arg, + lua_Integer def) { + return luaL_opt(L, luaL_checkinteger, arg, def); +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Generic Buffer manipulation +** ======================================================= +*/ + +/* +** check whether buffer is using a userdata on the stack as a temporary +** buffer +*/ +#define buffonstack(B) ((B)->b != (B)->initb) + + +/* +** returns a pointer to a free area with at least 'sz' bytes +*/ +LUALIB_API char *luaL_prepbuffsize (luaL_Buffer *B, size_t sz) { + lua_State *L = B->L; + if (B->size - B->n < sz) { /* not enough space? */ + char *newbuff; + size_t newsize = B->size * 2; /* double buffer size */ + if (newsize - B->n < sz) /* not big enough? */ + newsize = B->n + sz; + if (newsize < B->n || newsize - B->n < sz) + luaL_error(L, "buffer too large"); + /* create larger buffer */ + newbuff = (char *)lua_newuserdata(L, newsize * sizeof(char)); + /* move content to new buffer */ + memcpy(newbuff, B->b, B->n * sizeof(char)); + if (buffonstack(B)) + lua_remove(L, -2); /* remove old buffer */ + B->b = newbuff; + B->size = newsize; + } + return &B->b[B->n]; +} + + +LUALIB_API void luaL_addlstring (luaL_Buffer *B, const char *s, size_t l) { + char *b = luaL_prepbuffsize(B, l); + memcpy(b, s, l * sizeof(char)); + luaL_addsize(B, l); +} + + +LUALIB_API void luaL_addstring (luaL_Buffer *B, const char *s) { + luaL_addlstring(B, s, strlen(s)); +} + + +LUALIB_API void luaL_pushresult (luaL_Buffer *B) { + lua_State *L = B->L; + lua_pushlstring(L, B->b, B->n); + if (buffonstack(B)) + lua_remove(L, -2); /* remove old buffer */ +} + + +LUALIB_API void luaL_pushresultsize (luaL_Buffer *B, size_t sz) { + luaL_addsize(B, sz); + luaL_pushresult(B); +} + + +LUALIB_API void luaL_addvalue (luaL_Buffer *B) { + lua_State *L = B->L; + size_t l; + const char *s = lua_tolstring(L, -1, &l); + if (buffonstack(B)) + lua_insert(L, -2); /* put value below buffer */ + luaL_addlstring(B, s, l); + lua_remove(L, (buffonstack(B)) ? -2 : -1); /* remove value */ +} + + +LUALIB_API void luaL_buffinit (lua_State *L, luaL_Buffer *B) { + B->L = L; + B->b = B->initb; + B->n = 0; + B->size = LUAL_BUFFERSIZE; +} + + +LUALIB_API char *luaL_buffinitsize (lua_State *L, luaL_Buffer *B, size_t sz) { + luaL_buffinit(L, B); + return luaL_prepbuffsize(B, sz); +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Reference system +** ======================================================= +*/ + +/* index of free-list header */ +#define freelist 0 + + +LUALIB_API int luaL_ref (lua_State *L, int t) { + int ref; + if (lua_isnil(L, -1)) { + lua_pop(L, 1); /* remove from stack */ + return LUA_REFNIL; /* 'nil' has a unique fixed reference */ + } + t = lua_absindex(L, t); + lua_rawgeti(L, t, freelist); /* get first free element */ + ref = (int)lua_tointeger(L, -1); /* ref = t[freelist] */ + lua_pop(L, 1); /* remove it from stack */ + if (ref != 0) { /* any free element? */ + lua_rawgeti(L, t, ref); /* remove it from list */ + lua_rawseti(L, t, freelist); /* (t[freelist] = t[ref]) */ + } + else /* no free elements */ + ref = (int)lua_rawlen(L, t) + 1; /* get a new reference */ + lua_rawseti(L, t, ref); + return ref; +} + + +LUALIB_API void luaL_unref (lua_State *L, int t, int ref) { + if (ref >= 0) { + t = lua_absindex(L, t); + lua_rawgeti(L, t, freelist); + lua_rawseti(L, t, ref); /* t[ref] = t[freelist] */ + lua_pushinteger(L, ref); + lua_rawseti(L, t, freelist); /* t[freelist] = ref */ + } +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Load functions +** ======================================================= +*/ + +typedef struct LoadF { + int n; /* number of pre-read characters */ + FILE *f; /* file being read */ + char buff[BUFSIZ]; /* area for reading file */ +} LoadF; + + +static const char *getF (lua_State *L, void *ud, size_t *size) { + LoadF *lf = (LoadF *)ud; + (void)L; /* not used */ + if (lf->n > 0) { /* are there pre-read characters to be read? */ + *size = lf->n; /* return them (chars already in buffer) */ + lf->n = 0; /* no more pre-read characters */ + } + else { /* read a block from file */ + /* 'fread' can return > 0 *and* set the EOF flag. If next call to + 'getF' called 'fread', it might still wait for user input. + The next check avoids this problem. */ + if (feof(lf->f)) return NULL; + *size = fread(lf->buff, 1, sizeof(lf->buff), lf->f); /* read block */ + } + return lf->buff; +} + + +static int errfile (lua_State *L, const char *what, int fnameindex) { + const char *serr = strerror(errno); + const char *filename = lua_tostring(L, fnameindex) + 1; + lua_pushfstring(L, "cannot %s %s: %s", what, filename, serr); + lua_remove(L, fnameindex); + return LUA_ERRFILE; +} + + +static int skipBOM (LoadF *lf) { + const char *p = "\xEF\xBB\xBF"; /* Utf8 BOM mark */ + int c; + lf->n = 0; + do { + c = getc(lf->f); + if (c == EOF || c != *(const unsigned char *)p++) return c; + lf->buff[lf->n++] = c; /* to be read by the parser */ + } while (*p != '\0'); + lf->n = 0; /* prefix matched; discard it */ + return getc(lf->f); /* return next character */ +} + + +/* +** reads the first character of file 'f' and skips an optional BOM mark +** in its beginning plus its first line if it starts with '#'. Returns +** true if it skipped the first line. In any case, '*cp' has the +** first "valid" character of the file (after the optional BOM and +** a first-line comment). +*/ +static int skipcomment (LoadF *lf, int *cp) { + int c = *cp = skipBOM(lf); + if (c == '#') { /* first line is a comment (Unix exec. file)? */ + do { /* skip first line */ + c = getc(lf->f); + } while (c != EOF && c != '\n') ; + *cp = getc(lf->f); /* skip end-of-line, if present */ + return 1; /* there was a comment */ + } + else return 0; /* no comment */ +} + + +LUALIB_API int luaL_loadfilex (lua_State *L, const char *filename, + const char *mode) { + LoadF lf; + int status, readstatus; + int c; + int fnameindex = lua_gettop(L) + 1; /* index of filename on the stack */ + if (filename == NULL) { + lua_pushliteral(L, "=stdin"); + lf.f = stdin; + } + else { + lua_pushfstring(L, "@%s", filename); + lf.f = fopen(filename, "r"); + if (lf.f == NULL) return errfile(L, "open", fnameindex); + } + if (skipcomment(&lf, &c)) /* read initial portion */ + lf.buff[lf.n++] = '\n'; /* add line to correct line numbers */ + if (c == LUA_SIGNATURE[0] && filename) { /* binary file? */ + lf.f = freopen(filename, "rb", lf.f); /* reopen in binary mode */ + if (lf.f == NULL) return errfile(L, "reopen", fnameindex); + skipcomment(&lf, &c); /* re-read initial portion */ + } + if (c != EOF) + lf.buff[lf.n++] = c; /* 'c' is the first character of the stream */ + status = lua_load(L, getF, &lf, lua_tostring(L, -1), mode); + readstatus = ferror(lf.f); + if (filename) fclose(lf.f); /* close file (even in case of errors) */ + if (readstatus) { + lua_settop(L, fnameindex); /* ignore results from 'lua_load' */ + return errfile(L, "read", fnameindex); + } + lua_remove(L, fnameindex); + return status; +} + + +typedef struct LoadS { + const char *s; + size_t size; +} LoadS; + + +static const char *getS (lua_State *L, void *ud, size_t *size) { + LoadS *ls = (LoadS *)ud; + (void)L; /* not used */ + if (ls->size == 0) return NULL; + *size = ls->size; + ls->size = 0; + return ls->s; +} + + +LUALIB_API int luaL_loadbufferx (lua_State *L, const char *buff, size_t size, + const char *name, const char *mode) { + LoadS ls; + ls.s = buff; + ls.size = size; + return lua_load(L, getS, &ls, name, mode); +} + + +LUALIB_API int luaL_loadstring (lua_State *L, const char *s) { + return luaL_loadbuffer(L, s, strlen(s), s); +} + +/* }====================================================== */ + + + +LUALIB_API int luaL_getmetafield (lua_State *L, int obj, const char *event) { + if (!lua_getmetatable(L, obj)) /* no metatable? */ + return LUA_TNIL; + else { + int tt; + lua_pushstring(L, event); + tt = lua_rawget(L, -2); + if (tt == LUA_TNIL) /* is metafield nil? */ + lua_pop(L, 2); /* remove metatable and metafield */ + else + lua_remove(L, -2); /* remove only metatable */ + return tt; /* return metafield type */ + } +} + + +LUALIB_API int luaL_callmeta (lua_State *L, int obj, const char *event) { + obj = lua_absindex(L, obj); + if (luaL_getmetafield(L, obj, event) == LUA_TNIL) /* no metafield? */ + return 0; + lua_pushvalue(L, obj); + lua_call(L, 1, 1); + return 1; +} + + +LUALIB_API lua_Integer luaL_len (lua_State *L, int idx) { + lua_Integer l; + int isnum; + lua_len(L, idx); + l = lua_tointegerx(L, -1, &isnum); + if (!isnum) + luaL_error(L, "object length is not an integer"); + lua_pop(L, 1); /* remove object */ + return l; +} + + +LUALIB_API const char *luaL_tolstring (lua_State *L, int idx, size_t *len) { + if (!luaL_callmeta(L, idx, "__tostring")) { /* no metafield? */ + switch (lua_type(L, idx)) { + case LUA_TNUMBER: { + if (lua_isinteger(L, idx)) + lua_pushfstring(L, "%I", lua_tointeger(L, idx)); + else + lua_pushfstring(L, "%f", lua_tonumber(L, idx)); + break; + } + case LUA_TSTRING: + lua_pushvalue(L, idx); + break; + case LUA_TBOOLEAN: + lua_pushstring(L, (lua_toboolean(L, idx) ? "true" : "false")); + break; + case LUA_TNIL: + lua_pushliteral(L, "nil"); + break; + default: + lua_pushfstring(L, "%s: %p", luaL_typename(L, idx), + lua_topointer(L, idx)); + break; + } + } + return lua_tolstring(L, -1, len); +} + + +/* +** {====================================================== +** Compatibility with 5.1 module functions +** ======================================================= +*/ +#if defined(LUA_COMPAT_MODULE) + +static const char *luaL_findtable (lua_State *L, int idx, + const char *fname, int szhint) { + const char *e; + if (idx) lua_pushvalue(L, idx); + do { + e = strchr(fname, '.'); + if (e == NULL) e = fname + strlen(fname); + lua_pushlstring(L, fname, e - fname); + if (lua_rawget(L, -2) == LUA_TNIL) { /* no such field? */ + lua_pop(L, 1); /* remove this nil */ + lua_createtable(L, 0, (*e == '.' ? 1 : szhint)); /* new table for field */ + lua_pushlstring(L, fname, e - fname); + lua_pushvalue(L, -2); + lua_settable(L, -4); /* set new table into field */ + } + else if (!lua_istable(L, -1)) { /* field has a non-table value? */ + lua_pop(L, 2); /* remove table and value */ + return fname; /* return problematic part of the name */ + } + lua_remove(L, -2); /* remove previous table */ + fname = e + 1; + } while (*e == '.'); + return NULL; +} + + +/* +** Count number of elements in a luaL_Reg list. +*/ +static int libsize (const luaL_Reg *l) { + int size = 0; + for (; l && l->name; l++) size++; + return size; +} + + +/* +** Find or create a module table with a given name. The function +** first looks at the _LOADED table and, if that fails, try a +** global variable with that name. In any case, leaves on the stack +** the module table. +*/ +LUALIB_API void luaL_pushmodule (lua_State *L, const char *modname, + int sizehint) { + luaL_findtable(L, LUA_REGISTRYINDEX, "_LOADED", 1); /* get _LOADED table */ + if (lua_getfield(L, -1, modname) != LUA_TTABLE) { /* no _LOADED[modname]? */ + lua_pop(L, 1); /* remove previous result */ + /* try global variable (and create one if it does not exist) */ + lua_pushglobaltable(L); + if (luaL_findtable(L, 0, modname, sizehint) != NULL) + luaL_error(L, "name conflict for module '%s'", modname); + lua_pushvalue(L, -1); + lua_setfield(L, -3, modname); /* _LOADED[modname] = new table */ + } + lua_remove(L, -2); /* remove _LOADED table */ +} + + +LUALIB_API void luaL_openlib (lua_State *L, const char *libname, + const luaL_Reg *l, int nup) { + luaL_checkversion(L); + if (libname) { + luaL_pushmodule(L, libname, libsize(l)); /* get/create library table */ + lua_insert(L, -(nup + 1)); /* move library table to below upvalues */ + } + if (l) + luaL_setfuncs(L, l, nup); + else + lua_pop(L, nup); /* remove upvalues */ +} + +#endif +/* }====================================================== */ + +/* +** set functions from list 'l' into table at top - 'nup'; each +** function gets the 'nup' elements at the top as upvalues. +** Returns with only the table at the stack. +*/ +LUALIB_API void luaL_setfuncs (lua_State *L, const luaL_Reg *l, int nup) { + luaL_checkstack(L, nup, "too many upvalues"); + for (; l->name != NULL; l++) { /* fill the table with given functions */ + int i; + for (i = 0; i < nup; i++) /* copy upvalues to the top */ + lua_pushvalue(L, -nup); + lua_pushcclosure(L, l->func, nup); /* closure with those upvalues */ + lua_setfield(L, -(nup + 2), l->name); + } + lua_pop(L, nup); /* remove upvalues */ +} + + +/* +** ensure that stack[idx][fname] has a table and push that table +** into the stack +*/ +LUALIB_API int luaL_getsubtable (lua_State *L, int idx, const char *fname) { + if (lua_getfield(L, idx, fname) == LUA_TTABLE) + return 1; /* table already there */ + else { + lua_pop(L, 1); /* remove previous result */ + idx = lua_absindex(L, idx); + lua_newtable(L); + lua_pushvalue(L, -1); /* copy to be left at top */ + lua_setfield(L, idx, fname); /* assign new table to field */ + return 0; /* false, because did not find table there */ + } +} + + +/* +** Stripped-down 'require': After checking "loaded" table, calls 'openf' +** to open a module, registers the result in 'package.loaded' table and, +** if 'glb' is true, also registers the result in the global table. +** Leaves resulting module on the top. +*/ +LUALIB_API void luaL_requiref (lua_State *L, const char *modname, + lua_CFunction openf, int glb) { + luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED"); + lua_getfield(L, -1, modname); /* _LOADED[modname] */ + if (!lua_toboolean(L, -1)) { /* package not already loaded? */ + lua_pop(L, 1); /* remove field */ + lua_pushcfunction(L, openf); + lua_pushstring(L, modname); /* argument to open function */ + lua_call(L, 1, 1); /* call 'openf' to open module */ + lua_pushvalue(L, -1); /* make copy of module (call result) */ + lua_setfield(L, -3, modname); /* _LOADED[modname] = module */ + } + lua_remove(L, -2); /* remove _LOADED table */ + if (glb) { + lua_pushvalue(L, -1); /* copy of module */ + lua_setglobal(L, modname); /* _G[modname] = module */ + } +} + + +LUALIB_API const char *luaL_gsub (lua_State *L, const char *s, const char *p, + const char *r) { + const char *wild; + size_t l = strlen(p); + luaL_Buffer b; + luaL_buffinit(L, &b); + while ((wild = strstr(s, p)) != NULL) { + luaL_addlstring(&b, s, wild - s); /* push prefix */ + luaL_addstring(&b, r); /* push replacement in place of pattern */ + s = wild + l; /* continue after 'p' */ + } + luaL_addstring(&b, s); /* push last suffix */ + luaL_pushresult(&b); + return lua_tostring(L, -1); +} + + +static void *l_alloc (void *ud, void *ptr, size_t osize, size_t nsize) { + (void)ud; (void)osize; /* not used */ + if (nsize == 0) { + free(ptr); + return NULL; + } + else + return realloc(ptr, nsize); +} + + +static int panic (lua_State *L) { + lua_writestringerror("PANIC: unprotected error in call to Lua API (%s)\n", + lua_tostring(L, -1)); + return 0; /* return to Lua to abort */ +} + + +LUALIB_API lua_State *luaL_newstate (void) { + lua_State *L = lua_newstate(l_alloc, NULL); + if (L) lua_atpanic(L, &panic); + return L; +} + + +LUALIB_API void luaL_checkversion_ (lua_State *L, lua_Number ver, size_t sz) { + const lua_Number *v = lua_version(L); + if (sz != LUAL_NUMSIZES) /* check numeric types */ + luaL_error(L, "core and library have incompatible numeric types"); + if (v != lua_version(NULL)) + luaL_error(L, "multiple Lua VMs detected"); + else if (*v != ver) + luaL_error(L, "version mismatch: app. needs %f, Lua core provides %f", + ver, *v); +} + diff --git a/src/lauxlib.h b/src/lauxlib.h new file mode 100644 index 000000000000..0bac2467ec61 --- /dev/null +++ b/src/lauxlib.h @@ -0,0 +1,256 @@ +/* +** $Id: lauxlib.h,v 1.128 2014/10/29 16:11:17 roberto Exp $ +** Auxiliary functions for building Lua libraries +** See Copyright Notice in lua.h +*/ + + +#ifndef lauxlib_h +#define lauxlib_h + + +#include <stddef.h> +#include <stdio.h> + +#include "lua.h" + + + +/* extra error code for 'luaL_load' */ +#define LUA_ERRFILE (LUA_ERRERR+1) + + +typedef struct luaL_Reg { + const char *name; + lua_CFunction func; +} luaL_Reg; + + +#define LUAL_NUMSIZES (sizeof(lua_Integer)*16 + sizeof(lua_Number)) + +LUALIB_API void (luaL_checkversion_) (lua_State *L, lua_Number ver, size_t sz); +#define luaL_checkversion(L) \ + luaL_checkversion_(L, LUA_VERSION_NUM, LUAL_NUMSIZES) + +LUALIB_API int (luaL_getmetafield) (lua_State *L, int obj, const char *e); +LUALIB_API int (luaL_callmeta) (lua_State *L, int obj, const char *e); +LUALIB_API const char *(luaL_tolstring) (lua_State *L, int idx, size_t *len); +LUALIB_API int (luaL_argerror) (lua_State *L, int arg, const char *extramsg); +LUALIB_API const char *(luaL_checklstring) (lua_State *L, int arg, + size_t *l); +LUALIB_API const char *(luaL_optlstring) (lua_State *L, int arg, + const char *def, size_t *l); +LUALIB_API lua_Number (luaL_checknumber) (lua_State *L, int arg); +LUALIB_API lua_Number (luaL_optnumber) (lua_State *L, int arg, lua_Number def); + +LUALIB_API lua_Integer (luaL_checkinteger) (lua_State *L, int arg); +LUALIB_API lua_Integer (luaL_optinteger) (lua_State *L, int arg, + lua_Integer def); + +LUALIB_API void (luaL_checkstack) (lua_State *L, int sz, const char *msg); +LUALIB_API void (luaL_checktype) (lua_State *L, int arg, int t); +LUALIB_API void (luaL_checkany) (lua_State *L, int arg); + +LUALIB_API int (luaL_newmetatable) (lua_State *L, const char *tname); +LUALIB_API void (luaL_setmetatable) (lua_State *L, const char *tname); +LUALIB_API void *(luaL_testudata) (lua_State *L, int ud, const char *tname); +LUALIB_API void *(luaL_checkudata) (lua_State *L, int ud, const char *tname); + +LUALIB_API void (luaL_where) (lua_State *L, int lvl); +LUALIB_API int (luaL_error) (lua_State *L, const char *fmt, ...); + +LUALIB_API int (luaL_checkoption) (lua_State *L, int arg, const char *def, + const char *const lst[]); + +LUALIB_API int (luaL_fileresult) (lua_State *L, int stat, const char *fname); +LUALIB_API int (luaL_execresult) (lua_State *L, int stat); + +/* pre-defined references */ +#define LUA_NOREF (-2) +#define LUA_REFNIL (-1) + +LUALIB_API int (luaL_ref) (lua_State *L, int t); +LUALIB_API void (luaL_unref) (lua_State *L, int t, int ref); + +LUALIB_API int (luaL_loadfilex) (lua_State *L, const char *filename, + const char *mode); + +#define luaL_loadfile(L,f) luaL_loadfilex(L,f,NULL) + +LUALIB_API int (luaL_loadbufferx) (lua_State *L, const char *buff, size_t sz, + const char *name, const char *mode); +LUALIB_API int (luaL_loadstring) (lua_State *L, const char *s); + +LUALIB_API lua_State *(luaL_newstate) (void); + +LUALIB_API lua_Integer (luaL_len) (lua_State *L, int idx); + +LUALIB_API const char *(luaL_gsub) (lua_State *L, const char *s, const char *p, + const char *r); + +LUALIB_API void (luaL_setfuncs) (lua_State *L, const luaL_Reg *l, int nup); + +LUALIB_API int (luaL_getsubtable) (lua_State *L, int idx, const char *fname); + +LUALIB_API void (luaL_traceback) (lua_State *L, lua_State *L1, + const char *msg, int level); + +LUALIB_API void (luaL_requiref) (lua_State *L, const char *modname, + lua_CFunction openf, int glb); + +/* +** =============================================================== +** some useful macros +** =============================================================== +*/ + + +#define luaL_newlibtable(L,l) \ + lua_createtable(L, 0, sizeof(l)/sizeof((l)[0]) - 1) + +#define luaL_newlib(L,l) \ + (luaL_checkversion(L), luaL_newlibtable(L,l), luaL_setfuncs(L,l,0)) + +#define luaL_argcheck(L, cond,arg,extramsg) \ + ((void)((cond) || luaL_argerror(L, (arg), (extramsg)))) +#define luaL_checkstring(L,n) (luaL_checklstring(L, (n), NULL)) +#define luaL_optstring(L,n,d) (luaL_optlstring(L, (n), (d), NULL)) + +#define luaL_typename(L,i) lua_typename(L, lua_type(L,(i))) + +#define luaL_dofile(L, fn) \ + (luaL_loadfile(L, fn) || lua_pcall(L, 0, LUA_MULTRET, 0)) + +#define luaL_dostring(L, s) \ + (luaL_loadstring(L, s) || lua_pcall(L, 0, LUA_MULTRET, 0)) + +#define luaL_getmetatable(L,n) (lua_getfield(L, LUA_REGISTRYINDEX, (n))) + +#define luaL_opt(L,f,n,d) (lua_isnoneornil(L,(n)) ? (d) : f(L,(n))) + +#define luaL_loadbuffer(L,s,sz,n) luaL_loadbufferx(L,s,sz,n,NULL) + + +/* +** {====================================================== +** Generic Buffer manipulation +** ======================================================= +*/ + +typedef struct luaL_Buffer { + char *b; /* buffer address */ + size_t size; /* buffer size */ + size_t n; /* number of characters in buffer */ + lua_State *L; + char initb[LUAL_BUFFERSIZE]; /* initial buffer */ +} luaL_Buffer; + + +#define luaL_addchar(B,c) \ + ((void)((B)->n < (B)->size || luaL_prepbuffsize((B), 1)), \ + ((B)->b[(B)->n++] = (c))) + +#define luaL_addsize(B,s) ((B)->n += (s)) + +LUALIB_API void (luaL_buffinit) (lua_State *L, luaL_Buffer *B); +LUALIB_API char *(luaL_prepbuffsize) (luaL_Buffer *B, size_t sz); +LUALIB_API void (luaL_addlstring) (luaL_Buffer *B, const char *s, size_t l); +LUALIB_API void (luaL_addstring) (luaL_Buffer *B, const char *s); +LUALIB_API void (luaL_addvalue) (luaL_Buffer *B); +LUALIB_API void (luaL_pushresult) (luaL_Buffer *B); +LUALIB_API void (luaL_pushresultsize) (luaL_Buffer *B, size_t sz); +LUALIB_API char *(luaL_buffinitsize) (lua_State *L, luaL_Buffer *B, size_t sz); + +#define luaL_prepbuffer(B) luaL_prepbuffsize(B, LUAL_BUFFERSIZE) + +/* }====================================================== */ + + + +/* +** {====================================================== +** File handles for IO library +** ======================================================= +*/ + +/* +** A file handle is a userdata with metatable 'LUA_FILEHANDLE' and +** initial structure 'luaL_Stream' (it may contain other fields +** after that initial structure). +*/ + +#define LUA_FILEHANDLE "FILE*" + + +typedef struct luaL_Stream { + FILE *f; /* stream (NULL for incompletely created streams) */ + lua_CFunction closef; /* to close stream (NULL for closed streams) */ +} luaL_Stream; + +/* }====================================================== */ + + + +/* compatibility with old module system */ +#if defined(LUA_COMPAT_MODULE) + +LUALIB_API void (luaL_pushmodule) (lua_State *L, const char *modname, + int sizehint); +LUALIB_API void (luaL_openlib) (lua_State *L, const char *libname, + const luaL_Reg *l, int nup); + +#define luaL_register(L,n,l) (luaL_openlib(L,(n),(l),0)) + +#endif + + +/* +** {================================================================== +** "Abstraction Layer" for basic report of messages and errors +** =================================================================== +*/ + +/* print a string */ +#if !defined(lua_writestring) +#define lua_writestring(s,l) fwrite((s), sizeof(char), (l), stdout) +#endif + +/* print a newline and flush the output */ +#if !defined(lua_writeline) +#define lua_writeline() (lua_writestring("\n", 1), fflush(stdout)) +#endif + +/* print an error message */ +#if !defined(lua_writestringerror) +#define lua_writestringerror(s,p) \ + (fprintf(stderr, (s), (p)), fflush(stderr)) +#endif + +/* }================================================================== */ + + +/* +** {============================================================ +** Compatibility with deprecated conversions +** ============================================================= +*/ +#if defined(LUA_COMPAT_APIINTCASTS) + +#define luaL_checkunsigned(L,a) ((lua_Unsigned)luaL_checkinteger(L,a)) +#define luaL_optunsigned(L,a,d) \ + ((lua_Unsigned)luaL_optinteger(L,a,(lua_Integer)(d))) + +#define luaL_checkint(L,n) ((int)luaL_checkinteger(L, (n))) +#define luaL_optint(L,n,d) ((int)luaL_optinteger(L, (n), (d))) + +#define luaL_checklong(L,n) ((long)luaL_checkinteger(L, (n))) +#define luaL_optlong(L,n,d) ((long)luaL_optinteger(L, (n), (d))) + +#endif +/* }============================================================ */ + + + +#endif + + diff --git a/src/lbaselib.c b/src/lbaselib.c new file mode 100644 index 000000000000..a2403952f028 --- /dev/null +++ b/src/lbaselib.c @@ -0,0 +1,520 @@ +/* +** $Id: lbaselib.c,v 1.309 2014/12/10 12:26:42 roberto Exp $ +** Basic library +** See Copyright Notice in lua.h +*/ + +#define lbaselib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <ctype.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +static int luaB_print (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + int i; + lua_getglobal(L, "tostring"); + for (i=1; i<=n; i++) { + const char *s; + size_t l; + lua_pushvalue(L, -1); /* function to be called */ + lua_pushvalue(L, i); /* value to print */ + lua_call(L, 1, 1); + s = lua_tolstring(L, -1, &l); /* get result */ + if (s == NULL) + return luaL_error(L, "'tostring' must return a string to 'print'"); + if (i>1) lua_writestring("\t", 1); + lua_writestring(s, l); + lua_pop(L, 1); /* pop result */ + } + lua_writeline(); + return 0; +} + + +#define SPACECHARS " \f\n\r\t\v" + +static const char *b_str2int (const char *s, int base, lua_Integer *pn) { + lua_Unsigned n = 0; + int neg = 0; + s += strspn(s, SPACECHARS); /* skip initial spaces */ + if (*s == '-') { s++; neg = 1; } /* handle signal */ + else if (*s == '+') s++; + if (!isalnum((unsigned char)*s)) /* no digit? */ + return NULL; + do { + int digit = (isdigit((unsigned char)*s)) ? *s - '0' + : toupper((unsigned char)*s) - 'A' + 10; + if (digit >= base) return NULL; /* invalid numeral */ + n = n * base + digit; + s++; + } while (isalnum((unsigned char)*s)); + s += strspn(s, SPACECHARS); /* skip trailing spaces */ + *pn = (lua_Integer)((neg) ? (0u - n) : n); + return s; +} + + +static int luaB_tonumber (lua_State *L) { + if (lua_isnoneornil(L, 2)) { /* standard conversion? */ + luaL_checkany(L, 1); + if (lua_type(L, 1) == LUA_TNUMBER) { /* already a number? */ + lua_settop(L, 1); /* yes; return it */ + return 1; + } + else { + size_t l; + const char *s = lua_tolstring(L, 1, &l); + if (s != NULL && lua_stringtonumber(L, s) == l + 1) + return 1; /* successful conversion to number */ + /* else not a number */ + } + } + else { + size_t l; + const char *s; + lua_Integer n = 0; /* to avoid warnings */ + lua_Integer base = luaL_checkinteger(L, 2); + luaL_checktype(L, 1, LUA_TSTRING); /* before 'luaL_checklstring'! */ + s = luaL_checklstring(L, 1, &l); + luaL_argcheck(L, 2 <= base && base <= 36, 2, "base out of range"); + if (b_str2int(s, (int)base, &n) == s + l) { + lua_pushinteger(L, n); + return 1; + } /* else not a number */ + } /* else not a number */ + lua_pushnil(L); /* not a number */ + return 1; +} + + +static int luaB_error (lua_State *L) { + int level = (int)luaL_optinteger(L, 2, 1); + lua_settop(L, 1); + if (lua_isstring(L, 1) && level > 0) { /* add extra information? */ + luaL_where(L, level); + lua_pushvalue(L, 1); + lua_concat(L, 2); + } + return lua_error(L); +} + + +static int luaB_getmetatable (lua_State *L) { + luaL_checkany(L, 1); + if (!lua_getmetatable(L, 1)) { + lua_pushnil(L); + return 1; /* no metatable */ + } + luaL_getmetafield(L, 1, "__metatable"); + return 1; /* returns either __metatable field (if present) or metatable */ +} + + +static int luaB_setmetatable (lua_State *L) { + int t = lua_type(L, 2); + luaL_checktype(L, 1, LUA_TTABLE); + luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2, + "nil or table expected"); + if (luaL_getmetafield(L, 1, "__metatable") != LUA_TNIL) + return luaL_error(L, "cannot change a protected metatable"); + lua_settop(L, 2); + lua_setmetatable(L, 1); + return 1; +} + + +static int luaB_rawequal (lua_State *L) { + luaL_checkany(L, 1); + luaL_checkany(L, 2); + lua_pushboolean(L, lua_rawequal(L, 1, 2)); + return 1; +} + + +static int luaB_rawlen (lua_State *L) { + int t = lua_type(L, 1); + luaL_argcheck(L, t == LUA_TTABLE || t == LUA_TSTRING, 1, + "table or string expected"); + lua_pushinteger(L, lua_rawlen(L, 1)); + return 1; +} + + +static int luaB_rawget (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); + luaL_checkany(L, 2); + lua_settop(L, 2); + lua_rawget(L, 1); + return 1; +} + +static int luaB_rawset (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); + luaL_checkany(L, 2); + luaL_checkany(L, 3); + lua_settop(L, 3); + lua_rawset(L, 1); + return 1; +} + + +static int luaB_collectgarbage (lua_State *L) { + static const char *const opts[] = {"stop", "restart", "collect", + "count", "step", "setpause", "setstepmul", + "isrunning", NULL}; + static const int optsnum[] = {LUA_GCSTOP, LUA_GCRESTART, LUA_GCCOLLECT, + LUA_GCCOUNT, LUA_GCSTEP, LUA_GCSETPAUSE, LUA_GCSETSTEPMUL, + LUA_GCISRUNNING}; + int o = optsnum[luaL_checkoption(L, 1, "collect", opts)]; + int ex = (int)luaL_optinteger(L, 2, 0); + int res = lua_gc(L, o, ex); + switch (o) { + case LUA_GCCOUNT: { + int b = lua_gc(L, LUA_GCCOUNTB, 0); + lua_pushnumber(L, (lua_Number)res + ((lua_Number)b/1024)); + return 1; + } + case LUA_GCSTEP: case LUA_GCISRUNNING: { + lua_pushboolean(L, res); + return 1; + } + default: { + lua_pushinteger(L, res); + return 1; + } + } +} + + +/* +** This function has all type names as upvalues, to maximize performance. +*/ +static int luaB_type (lua_State *L) { + luaL_checkany(L, 1); + lua_pushvalue(L, lua_upvalueindex(lua_type(L, 1) + 1)); + return 1; +} + + +static int pairsmeta (lua_State *L, const char *method, int iszero, + lua_CFunction iter) { + if (luaL_getmetafield(L, 1, method) == LUA_TNIL) { /* no metamethod? */ + luaL_checktype(L, 1, LUA_TTABLE); /* argument must be a table */ + lua_pushcfunction(L, iter); /* will return generator, */ + lua_pushvalue(L, 1); /* state, */ + if (iszero) lua_pushinteger(L, 0); /* and initial value */ + else lua_pushnil(L); + } + else { + lua_pushvalue(L, 1); /* argument 'self' to metamethod */ + lua_call(L, 1, 3); /* get 3 values from metamethod */ + } + return 3; +} + + +static int luaB_next (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); + lua_settop(L, 2); /* create a 2nd argument if there isn't one */ + if (lua_next(L, 1)) + return 2; + else { + lua_pushnil(L); + return 1; + } +} + + +static int luaB_pairs (lua_State *L) { + return pairsmeta(L, "__pairs", 0, luaB_next); +} + + +/* +** Traversal function for 'ipairs' for raw tables +*/ +static int ipairsaux_raw (lua_State *L) { + lua_Integer i = luaL_checkinteger(L, 2) + 1; + luaL_checktype(L, 1, LUA_TTABLE); + lua_pushinteger(L, i); + return (lua_rawgeti(L, 1, i) == LUA_TNIL) ? 1 : 2; +} + + +/* +** Traversal function for 'ipairs' for tables with metamethods +*/ +static int ipairsaux (lua_State *L) { + lua_Integer i = luaL_checkinteger(L, 2) + 1; + lua_pushinteger(L, i); + return (lua_geti(L, 1, i) == LUA_TNIL) ? 1 : 2; +} + + +/* +** This function will use either 'ipairsaux' or 'ipairsaux_raw' to +** traverse a table, depending on whether the table has metamethods +** that can affect the traversal. +*/ +static int luaB_ipairs (lua_State *L) { + lua_CFunction iter = (luaL_getmetafield(L, 1, "__index") != LUA_TNIL) + ? ipairsaux : ipairsaux_raw; +#if defined(LUA_COMPAT_IPAIRS) + return pairsmeta(L, "__ipairs", 1, iter); +#else + luaL_checkany(L, 1); + lua_pushcfunction(L, iter); /* iteration function */ + lua_pushvalue(L, 1); /* state */ + lua_pushinteger(L, 0); /* initial value */ + return 3; +#endif +} + + +static int load_aux (lua_State *L, int status, int envidx) { + if (status == LUA_OK) { + if (envidx != 0) { /* 'env' parameter? */ + lua_pushvalue(L, envidx); /* environment for loaded function */ + if (!lua_setupvalue(L, -2, 1)) /* set it as 1st upvalue */ + lua_pop(L, 1); /* remove 'env' if not used by previous call */ + } + return 1; + } + else { /* error (message is on top of the stack) */ + lua_pushnil(L); + lua_insert(L, -2); /* put before error message */ + return 2; /* return nil plus error message */ + } +} + + +static int luaB_loadfile (lua_State *L) { + const char *fname = luaL_optstring(L, 1, NULL); + const char *mode = luaL_optstring(L, 2, NULL); + int env = (!lua_isnone(L, 3) ? 3 : 0); /* 'env' index or 0 if no 'env' */ + int status = luaL_loadfilex(L, fname, mode); + return load_aux(L, status, env); +} + + +/* +** {====================================================== +** Generic Read function +** ======================================================= +*/ + + +/* +** reserved slot, above all arguments, to hold a copy of the returned +** string to avoid it being collected while parsed. 'load' has four +** optional arguments (chunk, source name, mode, and environment). +*/ +#define RESERVEDSLOT 5 + + +/* +** Reader for generic 'load' function: 'lua_load' uses the +** stack for internal stuff, so the reader cannot change the +** stack top. Instead, it keeps its resulting string in a +** reserved slot inside the stack. +*/ +static const char *generic_reader (lua_State *L, void *ud, size_t *size) { + (void)(ud); /* not used */ + luaL_checkstack(L, 2, "too many nested functions"); + lua_pushvalue(L, 1); /* get function */ + lua_call(L, 0, 1); /* call it */ + if (lua_isnil(L, -1)) { + lua_pop(L, 1); /* pop result */ + *size = 0; + return NULL; + } + else if (!lua_isstring(L, -1)) + luaL_error(L, "reader function must return a string"); + lua_replace(L, RESERVEDSLOT); /* save string in reserved slot */ + return lua_tolstring(L, RESERVEDSLOT, size); +} + + +static int luaB_load (lua_State *L) { + int status; + size_t l; + const char *s = lua_tolstring(L, 1, &l); + const char *mode = luaL_optstring(L, 3, "bt"); + int env = (!lua_isnone(L, 4) ? 4 : 0); /* 'env' index or 0 if no 'env' */ + if (s != NULL) { /* loading a string? */ + const char *chunkname = luaL_optstring(L, 2, s); + status = luaL_loadbufferx(L, s, l, chunkname, mode); + } + else { /* loading from a reader function */ + const char *chunkname = luaL_optstring(L, 2, "=(load)"); + luaL_checktype(L, 1, LUA_TFUNCTION); + lua_settop(L, RESERVEDSLOT); /* create reserved slot */ + status = lua_load(L, generic_reader, NULL, chunkname, mode); + } + return load_aux(L, status, env); +} + +/* }====================================================== */ + + +static int dofilecont (lua_State *L, int d1, lua_KContext d2) { + (void)d1; (void)d2; /* only to match 'lua_Kfunction' prototype */ + return lua_gettop(L) - 1; +} + + +static int luaB_dofile (lua_State *L) { + const char *fname = luaL_optstring(L, 1, NULL); + lua_settop(L, 1); + if (luaL_loadfile(L, fname) != LUA_OK) + return lua_error(L); + lua_callk(L, 0, LUA_MULTRET, 0, dofilecont); + return dofilecont(L, 0, 0); +} + + +static int luaB_assert (lua_State *L) { + if (lua_toboolean(L, 1)) /* condition is true? */ + return lua_gettop(L); /* return all arguments */ + else { /* error */ + luaL_checkany(L, 1); /* there must be a condition */ + lua_remove(L, 1); /* remove it */ + lua_pushliteral(L, "assertion failed!"); /* default message */ + lua_settop(L, 1); /* leave only message (default if no other one) */ + return luaB_error(L); /* call 'error' */ + } +} + + +static int luaB_select (lua_State *L) { + int n = lua_gettop(L); + if (lua_type(L, 1) == LUA_TSTRING && *lua_tostring(L, 1) == '#') { + lua_pushinteger(L, n-1); + return 1; + } + else { + lua_Integer i = luaL_checkinteger(L, 1); + if (i < 0) i = n + i; + else if (i > n) i = n; + luaL_argcheck(L, 1 <= i, 1, "index out of range"); + return n - (int)i; + } +} + + +/* +** Continuation function for 'pcall' and 'xpcall'. Both functions +** already pushed a 'true' before doing the call, so in case of success +** 'finishpcall' only has to return everything in the stack minus +** 'extra' values (where 'extra' is exactly the number of items to be +** ignored). +*/ +static int finishpcall (lua_State *L, int status, lua_KContext extra) { + if (status != LUA_OK && status != LUA_YIELD) { /* error? */ + lua_pushboolean(L, 0); /* first result (false) */ + lua_pushvalue(L, -2); /* error message */ + return 2; /* return false, msg */ + } + else + return lua_gettop(L) - (int)extra; /* return all results */ +} + + +static int luaB_pcall (lua_State *L) { + int status; + luaL_checkany(L, 1); + lua_pushboolean(L, 1); /* first result if no errors */ + lua_insert(L, 1); /* put it in place */ + status = lua_pcallk(L, lua_gettop(L) - 2, LUA_MULTRET, 0, 0, finishpcall); + return finishpcall(L, status, 0); +} + + +/* +** Do a protected call with error handling. After 'lua_rotate', the +** stack will have <f, err, true, f, [args...]>; so, the function passes +** 2 to 'finishpcall' to skip the 2 first values when returning results. +*/ +static int luaB_xpcall (lua_State *L) { + int status; + int n = lua_gettop(L); + luaL_checktype(L, 2, LUA_TFUNCTION); /* check error function */ + lua_pushboolean(L, 1); /* first result */ + lua_pushvalue(L, 1); /* function */ + lua_rotate(L, 3, 2); /* move them below function's arguments */ + status = lua_pcallk(L, n - 2, LUA_MULTRET, 2, 2, finishpcall); + return finishpcall(L, status, 2); +} + + +static int luaB_tostring (lua_State *L) { + luaL_checkany(L, 1); + luaL_tolstring(L, 1, NULL); + return 1; +} + + +static const luaL_Reg base_funcs[] = { + {"assert", luaB_assert}, + {"collectgarbage", luaB_collectgarbage}, + {"dofile", luaB_dofile}, + {"error", luaB_error}, + {"getmetatable", luaB_getmetatable}, + {"ipairs", luaB_ipairs}, + {"loadfile", luaB_loadfile}, + {"load", luaB_load}, +#if defined(LUA_COMPAT_LOADSTRING) + {"loadstring", luaB_load}, +#endif + {"next", luaB_next}, + {"pairs", luaB_pairs}, + {"pcall", luaB_pcall}, + {"print", luaB_print}, + {"rawequal", luaB_rawequal}, + {"rawlen", luaB_rawlen}, + {"rawget", luaB_rawget}, + {"rawset", luaB_rawset}, + {"select", luaB_select}, + {"setmetatable", luaB_setmetatable}, + {"tonumber", luaB_tonumber}, + {"tostring", luaB_tostring}, + {"xpcall", luaB_xpcall}, + /* placeholders */ + {"type", NULL}, + {"_G", NULL}, + {"_VERSION", NULL}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_base (lua_State *L) { + int i; + /* open lib into global table */ + lua_pushglobaltable(L); + luaL_setfuncs(L, base_funcs, 0); + /* set global _G */ + lua_pushvalue(L, -1); + lua_setfield(L, -2, "_G"); + /* set global _VERSION */ + lua_pushliteral(L, LUA_VERSION); + lua_setfield(L, -2, "_VERSION"); + /* set function 'type' with proper upvalues */ + for (i = 0; i < LUA_NUMTAGS; i++) /* push all type names as upvalues */ + lua_pushstring(L, lua_typename(L, i)); + lua_pushcclosure(L, luaB_type, LUA_NUMTAGS); + lua_setfield(L, -2, "type"); + return 1; +} + diff --git a/src/lbitlib.c b/src/lbitlib.c new file mode 100644 index 000000000000..15d5f0cdfc40 --- /dev/null +++ b/src/lbitlib.c @@ -0,0 +1,230 @@ +/* +** $Id: lbitlib.c,v 1.28 2014/11/02 19:19:04 roberto Exp $ +** Standard library for bitwise operations +** See Copyright Notice in lua.h +*/ + +#define lbitlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#if defined(LUA_COMPAT_BITLIB) /* { */ + + +/* number of bits to consider in a number */ +#if !defined(LUA_NBITS) +#define LUA_NBITS 32 +#endif + + +/* +** a lua_Unsigned with its first LUA_NBITS bits equal to 1. (Shift must +** be made in two parts to avoid problems when LUA_NBITS is equal to the +** number of bits in a lua_Unsigned.) +*/ +#define ALLONES (~(((~(lua_Unsigned)0) << (LUA_NBITS - 1)) << 1)) + + +/* macro to trim extra bits */ +#define trim(x) ((x) & ALLONES) + + +/* builds a number with 'n' ones (1 <= n <= LUA_NBITS) */ +#define mask(n) (~((ALLONES << 1) << ((n) - 1))) + + + +static lua_Unsigned andaux (lua_State *L) { + int i, n = lua_gettop(L); + lua_Unsigned r = ~(lua_Unsigned)0; + for (i = 1; i <= n; i++) + r &= luaL_checkunsigned(L, i); + return trim(r); +} + + +static int b_and (lua_State *L) { + lua_Unsigned r = andaux(L); + lua_pushunsigned(L, r); + return 1; +} + + +static int b_test (lua_State *L) { + lua_Unsigned r = andaux(L); + lua_pushboolean(L, r != 0); + return 1; +} + + +static int b_or (lua_State *L) { + int i, n = lua_gettop(L); + lua_Unsigned r = 0; + for (i = 1; i <= n; i++) + r |= luaL_checkunsigned(L, i); + lua_pushunsigned(L, trim(r)); + return 1; +} + + +static int b_xor (lua_State *L) { + int i, n = lua_gettop(L); + lua_Unsigned r = 0; + for (i = 1; i <= n; i++) + r ^= luaL_checkunsigned(L, i); + lua_pushunsigned(L, trim(r)); + return 1; +} + + +static int b_not (lua_State *L) { + lua_Unsigned r = ~luaL_checkunsigned(L, 1); + lua_pushunsigned(L, trim(r)); + return 1; +} + + +static int b_shift (lua_State *L, lua_Unsigned r, lua_Integer i) { + if (i < 0) { /* shift right? */ + i = -i; + r = trim(r); + if (i >= LUA_NBITS) r = 0; + else r >>= i; + } + else { /* shift left */ + if (i >= LUA_NBITS) r = 0; + else r <<= i; + r = trim(r); + } + lua_pushunsigned(L, r); + return 1; +} + + +static int b_lshift (lua_State *L) { + return b_shift(L, luaL_checkunsigned(L, 1), luaL_checkinteger(L, 2)); +} + + +static int b_rshift (lua_State *L) { + return b_shift(L, luaL_checkunsigned(L, 1), -luaL_checkinteger(L, 2)); +} + + +static int b_arshift (lua_State *L) { + lua_Unsigned r = luaL_checkunsigned(L, 1); + lua_Integer i = luaL_checkinteger(L, 2); + if (i < 0 || !(r & ((lua_Unsigned)1 << (LUA_NBITS - 1)))) + return b_shift(L, r, -i); + else { /* arithmetic shift for 'negative' number */ + if (i >= LUA_NBITS) r = ALLONES; + else + r = trim((r >> i) | ~(trim(~(lua_Unsigned)0) >> i)); /* add signal bit */ + lua_pushunsigned(L, r); + return 1; + } +} + + +static int b_rot (lua_State *L, lua_Integer d) { + lua_Unsigned r = luaL_checkunsigned(L, 1); + int i = d & (LUA_NBITS - 1); /* i = d % NBITS */ + r = trim(r); + if (i != 0) /* avoid undefined shift of LUA_NBITS when i == 0 */ + r = (r << i) | (r >> (LUA_NBITS - i)); + lua_pushunsigned(L, trim(r)); + return 1; +} + + +static int b_lrot (lua_State *L) { + return b_rot(L, luaL_checkinteger(L, 2)); +} + + +static int b_rrot (lua_State *L) { + return b_rot(L, -luaL_checkinteger(L, 2)); +} + + +/* +** get field and width arguments for field-manipulation functions, +** checking whether they are valid. +** ('luaL_error' called without 'return' to avoid later warnings about +** 'width' being used uninitialized.) +*/ +static int fieldargs (lua_State *L, int farg, int *width) { + lua_Integer f = luaL_checkinteger(L, farg); + lua_Integer w = luaL_optinteger(L, farg + 1, 1); + luaL_argcheck(L, 0 <= f, farg, "field cannot be negative"); + luaL_argcheck(L, 0 < w, farg + 1, "width must be positive"); + if (f + w > LUA_NBITS) + luaL_error(L, "trying to access non-existent bits"); + *width = (int)w; + return (int)f; +} + + +static int b_extract (lua_State *L) { + int w; + lua_Unsigned r = trim(luaL_checkunsigned(L, 1)); + int f = fieldargs(L, 2, &w); + r = (r >> f) & mask(w); + lua_pushunsigned(L, r); + return 1; +} + + +static int b_replace (lua_State *L) { + int w; + lua_Unsigned r = trim(luaL_checkunsigned(L, 1)); + lua_Unsigned v = luaL_checkunsigned(L, 2); + int f = fieldargs(L, 3, &w); + int m = mask(w); + v &= m; /* erase bits outside given width */ + r = (r & ~(m << f)) | (v << f); + lua_pushunsigned(L, r); + return 1; +} + + +static const luaL_Reg bitlib[] = { + {"arshift", b_arshift}, + {"band", b_and}, + {"bnot", b_not}, + {"bor", b_or}, + {"bxor", b_xor}, + {"btest", b_test}, + {"extract", b_extract}, + {"lrotate", b_lrot}, + {"lshift", b_lshift}, + {"replace", b_replace}, + {"rrotate", b_rrot}, + {"rshift", b_rshift}, + {NULL, NULL} +}; + + + +LUAMOD_API int luaopen_bit32 (lua_State *L) { + luaL_newlib(L, bitlib); + return 1; +} + + +#else /* }{ */ + + +LUAMOD_API int luaopen_bit32 (lua_State *L) { + return luaL_error(L, "library 'bit32' has been deprecated"); +} + +#endif /* } */ diff --git a/src/lcode.c b/src/lcode.c new file mode 100644 index 000000000000..5e34624bf462 --- /dev/null +++ b/src/lcode.c @@ -0,0 +1,954 @@ +/* +** $Id: lcode.c,v 2.99 2014/12/29 16:49:25 roberto Exp $ +** Code generator for Lua +** See Copyright Notice in lua.h +*/ + +#define lcode_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <math.h> +#include <stdlib.h> + +#include "lua.h" + +#include "lcode.h" +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "llex.h" +#include "lmem.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" +#include "lstring.h" +#include "ltable.h" +#include "lvm.h" + + +/* Maximum number of registers in a Lua function */ +#define MAXREGS 250 + + +#define hasjumps(e) ((e)->t != (e)->f) + + +static int tonumeral(expdesc *e, TValue *v) { + if (e->t != NO_JUMP || e->f != NO_JUMP) + return 0; /* not a numeral */ + switch (e->k) { + case VKINT: + if (v) setivalue(v, e->u.ival); + return 1; + case VKFLT: + if (v) setfltvalue(v, e->u.nval); + return 1; + default: return 0; + } +} + + +void luaK_nil (FuncState *fs, int from, int n) { + Instruction *previous; + int l = from + n - 1; /* last register to set nil */ + if (fs->pc > fs->lasttarget) { /* no jumps to current position? */ + previous = &fs->f->code[fs->pc-1]; + if (GET_OPCODE(*previous) == OP_LOADNIL) { + int pfrom = GETARG_A(*previous); + int pl = pfrom + GETARG_B(*previous); + if ((pfrom <= from && from <= pl + 1) || + (from <= pfrom && pfrom <= l + 1)) { /* can connect both? */ + if (pfrom < from) from = pfrom; /* from = min(from, pfrom) */ + if (pl > l) l = pl; /* l = max(l, pl) */ + SETARG_A(*previous, from); + SETARG_B(*previous, l - from); + return; + } + } /* else go through */ + } + luaK_codeABC(fs, OP_LOADNIL, from, n - 1, 0); /* else no optimization */ +} + + +int luaK_jump (FuncState *fs) { + int jpc = fs->jpc; /* save list of jumps to here */ + int j; + fs->jpc = NO_JUMP; + j = luaK_codeAsBx(fs, OP_JMP, 0, NO_JUMP); + luaK_concat(fs, &j, jpc); /* keep them on hold */ + return j; +} + + +void luaK_ret (FuncState *fs, int first, int nret) { + luaK_codeABC(fs, OP_RETURN, first, nret+1, 0); +} + + +static int condjump (FuncState *fs, OpCode op, int A, int B, int C) { + luaK_codeABC(fs, op, A, B, C); + return luaK_jump(fs); +} + + +static void fixjump (FuncState *fs, int pc, int dest) { + Instruction *jmp = &fs->f->code[pc]; + int offset = dest-(pc+1); + lua_assert(dest != NO_JUMP); + if (abs(offset) > MAXARG_sBx) + luaX_syntaxerror(fs->ls, "control structure too long"); + SETARG_sBx(*jmp, offset); +} + + +/* +** returns current 'pc' and marks it as a jump target (to avoid wrong +** optimizations with consecutive instructions not in the same basic block). +*/ +int luaK_getlabel (FuncState *fs) { + fs->lasttarget = fs->pc; + return fs->pc; +} + + +static int getjump (FuncState *fs, int pc) { + int offset = GETARG_sBx(fs->f->code[pc]); + if (offset == NO_JUMP) /* point to itself represents end of list */ + return NO_JUMP; /* end of list */ + else + return (pc+1)+offset; /* turn offset into absolute position */ +} + + +static Instruction *getjumpcontrol (FuncState *fs, int pc) { + Instruction *pi = &fs->f->code[pc]; + if (pc >= 1 && testTMode(GET_OPCODE(*(pi-1)))) + return pi-1; + else + return pi; +} + + +/* +** check whether list has any jump that do not produce a value +** (or produce an inverted value) +*/ +static int need_value (FuncState *fs, int list) { + for (; list != NO_JUMP; list = getjump(fs, list)) { + Instruction i = *getjumpcontrol(fs, list); + if (GET_OPCODE(i) != OP_TESTSET) return 1; + } + return 0; /* not found */ +} + + +static int patchtestreg (FuncState *fs, int node, int reg) { + Instruction *i = getjumpcontrol(fs, node); + if (GET_OPCODE(*i) != OP_TESTSET) + return 0; /* cannot patch other instructions */ + if (reg != NO_REG && reg != GETARG_B(*i)) + SETARG_A(*i, reg); + else /* no register to put value or register already has the value */ + *i = CREATE_ABC(OP_TEST, GETARG_B(*i), 0, GETARG_C(*i)); + + return 1; +} + + +static void removevalues (FuncState *fs, int list) { + for (; list != NO_JUMP; list = getjump(fs, list)) + patchtestreg(fs, list, NO_REG); +} + + +static void patchlistaux (FuncState *fs, int list, int vtarget, int reg, + int dtarget) { + while (list != NO_JUMP) { + int next = getjump(fs, list); + if (patchtestreg(fs, list, reg)) + fixjump(fs, list, vtarget); + else + fixjump(fs, list, dtarget); /* jump to default target */ + list = next; + } +} + + +static void dischargejpc (FuncState *fs) { + patchlistaux(fs, fs->jpc, fs->pc, NO_REG, fs->pc); + fs->jpc = NO_JUMP; +} + + +void luaK_patchlist (FuncState *fs, int list, int target) { + if (target == fs->pc) + luaK_patchtohere(fs, list); + else { + lua_assert(target < fs->pc); + patchlistaux(fs, list, target, NO_REG, target); + } +} + + +void luaK_patchclose (FuncState *fs, int list, int level) { + level++; /* argument is +1 to reserve 0 as non-op */ + while (list != NO_JUMP) { + int next = getjump(fs, list); + lua_assert(GET_OPCODE(fs->f->code[list]) == OP_JMP && + (GETARG_A(fs->f->code[list]) == 0 || + GETARG_A(fs->f->code[list]) >= level)); + SETARG_A(fs->f->code[list], level); + list = next; + } +} + + +void luaK_patchtohere (FuncState *fs, int list) { + luaK_getlabel(fs); + luaK_concat(fs, &fs->jpc, list); +} + + +void luaK_concat (FuncState *fs, int *l1, int l2) { + if (l2 == NO_JUMP) return; + else if (*l1 == NO_JUMP) + *l1 = l2; + else { + int list = *l1; + int next; + while ((next = getjump(fs, list)) != NO_JUMP) /* find last element */ + list = next; + fixjump(fs, list, l2); + } +} + + +static int luaK_code (FuncState *fs, Instruction i) { + Proto *f = fs->f; + dischargejpc(fs); /* 'pc' will change */ + /* put new instruction in code array */ + luaM_growvector(fs->ls->L, f->code, fs->pc, f->sizecode, Instruction, + MAX_INT, "opcodes"); + f->code[fs->pc] = i; + /* save corresponding line information */ + luaM_growvector(fs->ls->L, f->lineinfo, fs->pc, f->sizelineinfo, int, + MAX_INT, "opcodes"); + f->lineinfo[fs->pc] = fs->ls->lastline; + return fs->pc++; +} + + +int luaK_codeABC (FuncState *fs, OpCode o, int a, int b, int c) { + lua_assert(getOpMode(o) == iABC); + lua_assert(getBMode(o) != OpArgN || b == 0); + lua_assert(getCMode(o) != OpArgN || c == 0); + lua_assert(a <= MAXARG_A && b <= MAXARG_B && c <= MAXARG_C); + return luaK_code(fs, CREATE_ABC(o, a, b, c)); +} + + +int luaK_codeABx (FuncState *fs, OpCode o, int a, unsigned int bc) { + lua_assert(getOpMode(o) == iABx || getOpMode(o) == iAsBx); + lua_assert(getCMode(o) == OpArgN); + lua_assert(a <= MAXARG_A && bc <= MAXARG_Bx); + return luaK_code(fs, CREATE_ABx(o, a, bc)); +} + + +static int codeextraarg (FuncState *fs, int a) { + lua_assert(a <= MAXARG_Ax); + return luaK_code(fs, CREATE_Ax(OP_EXTRAARG, a)); +} + + +int luaK_codek (FuncState *fs, int reg, int k) { + if (k <= MAXARG_Bx) + return luaK_codeABx(fs, OP_LOADK, reg, k); + else { + int p = luaK_codeABx(fs, OP_LOADKX, reg, 0); + codeextraarg(fs, k); + return p; + } +} + + +void luaK_checkstack (FuncState *fs, int n) { + int newstack = fs->freereg + n; + if (newstack > fs->f->maxstacksize) { + if (newstack >= MAXREGS) + luaX_syntaxerror(fs->ls, "function or expression too complex"); + fs->f->maxstacksize = cast_byte(newstack); + } +} + + +void luaK_reserveregs (FuncState *fs, int n) { + luaK_checkstack(fs, n); + fs->freereg += n; +} + + +static void freereg (FuncState *fs, int reg) { + if (!ISK(reg) && reg >= fs->nactvar) { + fs->freereg--; + lua_assert(reg == fs->freereg); + } +} + + +static void freeexp (FuncState *fs, expdesc *e) { + if (e->k == VNONRELOC) + freereg(fs, e->u.info); +} + + +/* +** Use scanner's table to cache position of constants in constant list +** and try to reuse constants +*/ +static int addk (FuncState *fs, TValue *key, TValue *v) { + lua_State *L = fs->ls->L; + Proto *f = fs->f; + TValue *idx = luaH_set(L, fs->ls->h, key); /* index scanner table */ + int k, oldsize; + if (ttisinteger(idx)) { /* is there an index there? */ + k = cast_int(ivalue(idx)); + /* correct value? (warning: must distinguish floats from integers!) */ + if (k < fs->nk && ttype(&f->k[k]) == ttype(v) && + luaV_rawequalobj(&f->k[k], v)) + return k; /* reuse index */ + } + /* constant not found; create a new entry */ + oldsize = f->sizek; + k = fs->nk; + /* numerical value does not need GC barrier; + table has no metatable, so it does not need to invalidate cache */ + setivalue(idx, k); + luaM_growvector(L, f->k, k, f->sizek, TValue, MAXARG_Ax, "constants"); + while (oldsize < f->sizek) setnilvalue(&f->k[oldsize++]); + setobj(L, &f->k[k], v); + fs->nk++; + luaC_barrier(L, f, v); + return k; +} + + +int luaK_stringK (FuncState *fs, TString *s) { + TValue o; + setsvalue(fs->ls->L, &o, s); + return addk(fs, &o, &o); +} + + +/* +** Integers use userdata as keys to avoid collision with floats with same +** value; conversion to 'void*' used only for hashing, no "precision" +** problems +*/ +int luaK_intK (FuncState *fs, lua_Integer n) { + TValue k, o; + setpvalue(&k, cast(void*, cast(size_t, n))); + setivalue(&o, n); + return addk(fs, &k, &o); +} + + +static int luaK_numberK (FuncState *fs, lua_Number r) { + TValue o; + setfltvalue(&o, r); + return addk(fs, &o, &o); +} + + +static int boolK (FuncState *fs, int b) { + TValue o; + setbvalue(&o, b); + return addk(fs, &o, &o); +} + + +static int nilK (FuncState *fs) { + TValue k, v; + setnilvalue(&v); + /* cannot use nil as key; instead use table itself to represent nil */ + sethvalue(fs->ls->L, &k, fs->ls->h); + return addk(fs, &k, &v); +} + + +void luaK_setreturns (FuncState *fs, expdesc *e, int nresults) { + if (e->k == VCALL) { /* expression is an open function call? */ + SETARG_C(getcode(fs, e), nresults+1); + } + else if (e->k == VVARARG) { + SETARG_B(getcode(fs, e), nresults+1); + SETARG_A(getcode(fs, e), fs->freereg); + luaK_reserveregs(fs, 1); + } +} + + +void luaK_setoneret (FuncState *fs, expdesc *e) { + if (e->k == VCALL) { /* expression is an open function call? */ + e->k = VNONRELOC; + e->u.info = GETARG_A(getcode(fs, e)); + } + else if (e->k == VVARARG) { + SETARG_B(getcode(fs, e), 2); + e->k = VRELOCABLE; /* can relocate its simple result */ + } +} + + +void luaK_dischargevars (FuncState *fs, expdesc *e) { + switch (e->k) { + case VLOCAL: { + e->k = VNONRELOC; + break; + } + case VUPVAL: { + e->u.info = luaK_codeABC(fs, OP_GETUPVAL, 0, e->u.info, 0); + e->k = VRELOCABLE; + break; + } + case VINDEXED: { + OpCode op = OP_GETTABUP; /* assume 't' is in an upvalue */ + freereg(fs, e->u.ind.idx); + if (e->u.ind.vt == VLOCAL) { /* 't' is in a register? */ + freereg(fs, e->u.ind.t); + op = OP_GETTABLE; + } + e->u.info = luaK_codeABC(fs, op, 0, e->u.ind.t, e->u.ind.idx); + e->k = VRELOCABLE; + break; + } + case VVARARG: + case VCALL: { + luaK_setoneret(fs, e); + break; + } + default: break; /* there is one value available (somewhere) */ + } +} + + +static int code_label (FuncState *fs, int A, int b, int jump) { + luaK_getlabel(fs); /* those instructions may be jump targets */ + return luaK_codeABC(fs, OP_LOADBOOL, A, b, jump); +} + + +static void discharge2reg (FuncState *fs, expdesc *e, int reg) { + luaK_dischargevars(fs, e); + switch (e->k) { + case VNIL: { + luaK_nil(fs, reg, 1); + break; + } + case VFALSE: case VTRUE: { + luaK_codeABC(fs, OP_LOADBOOL, reg, e->k == VTRUE, 0); + break; + } + case VK: { + luaK_codek(fs, reg, e->u.info); + break; + } + case VKFLT: { + luaK_codek(fs, reg, luaK_numberK(fs, e->u.nval)); + break; + } + case VKINT: { + luaK_codek(fs, reg, luaK_intK(fs, e->u.ival)); + break; + } + case VRELOCABLE: { + Instruction *pc = &getcode(fs, e); + SETARG_A(*pc, reg); + break; + } + case VNONRELOC: { + if (reg != e->u.info) + luaK_codeABC(fs, OP_MOVE, reg, e->u.info, 0); + break; + } + default: { + lua_assert(e->k == VVOID || e->k == VJMP); + return; /* nothing to do... */ + } + } + e->u.info = reg; + e->k = VNONRELOC; +} + + +static void discharge2anyreg (FuncState *fs, expdesc *e) { + if (e->k != VNONRELOC) { + luaK_reserveregs(fs, 1); + discharge2reg(fs, e, fs->freereg-1); + } +} + + +static void exp2reg (FuncState *fs, expdesc *e, int reg) { + discharge2reg(fs, e, reg); + if (e->k == VJMP) + luaK_concat(fs, &e->t, e->u.info); /* put this jump in 't' list */ + if (hasjumps(e)) { + int final; /* position after whole expression */ + int p_f = NO_JUMP; /* position of an eventual LOAD false */ + int p_t = NO_JUMP; /* position of an eventual LOAD true */ + if (need_value(fs, e->t) || need_value(fs, e->f)) { + int fj = (e->k == VJMP) ? NO_JUMP : luaK_jump(fs); + p_f = code_label(fs, reg, 0, 1); + p_t = code_label(fs, reg, 1, 0); + luaK_patchtohere(fs, fj); + } + final = luaK_getlabel(fs); + patchlistaux(fs, e->f, final, reg, p_f); + patchlistaux(fs, e->t, final, reg, p_t); + } + e->f = e->t = NO_JUMP; + e->u.info = reg; + e->k = VNONRELOC; +} + + +void luaK_exp2nextreg (FuncState *fs, expdesc *e) { + luaK_dischargevars(fs, e); + freeexp(fs, e); + luaK_reserveregs(fs, 1); + exp2reg(fs, e, fs->freereg - 1); +} + + +int luaK_exp2anyreg (FuncState *fs, expdesc *e) { + luaK_dischargevars(fs, e); + if (e->k == VNONRELOC) { + if (!hasjumps(e)) return e->u.info; /* exp is already in a register */ + if (e->u.info >= fs->nactvar) { /* reg. is not a local? */ + exp2reg(fs, e, e->u.info); /* put value on it */ + return e->u.info; + } + } + luaK_exp2nextreg(fs, e); /* default */ + return e->u.info; +} + + +void luaK_exp2anyregup (FuncState *fs, expdesc *e) { + if (e->k != VUPVAL || hasjumps(e)) + luaK_exp2anyreg(fs, e); +} + + +void luaK_exp2val (FuncState *fs, expdesc *e) { + if (hasjumps(e)) + luaK_exp2anyreg(fs, e); + else + luaK_dischargevars(fs, e); +} + + +int luaK_exp2RK (FuncState *fs, expdesc *e) { + luaK_exp2val(fs, e); + switch (e->k) { + case VTRUE: + case VFALSE: + case VNIL: { + if (fs->nk <= MAXINDEXRK) { /* constant fits in RK operand? */ + e->u.info = (e->k == VNIL) ? nilK(fs) : boolK(fs, (e->k == VTRUE)); + e->k = VK; + return RKASK(e->u.info); + } + else break; + } + case VKINT: { + e->u.info = luaK_intK(fs, e->u.ival); + e->k = VK; + goto vk; + } + case VKFLT: { + e->u.info = luaK_numberK(fs, e->u.nval); + e->k = VK; + /* go through */ + } + case VK: { + vk: + if (e->u.info <= MAXINDEXRK) /* constant fits in 'argC'? */ + return RKASK(e->u.info); + else break; + } + default: break; + } + /* not a constant in the right range: put it in a register */ + return luaK_exp2anyreg(fs, e); +} + + +void luaK_storevar (FuncState *fs, expdesc *var, expdesc *ex) { + switch (var->k) { + case VLOCAL: { + freeexp(fs, ex); + exp2reg(fs, ex, var->u.info); + return; + } + case VUPVAL: { + int e = luaK_exp2anyreg(fs, ex); + luaK_codeABC(fs, OP_SETUPVAL, e, var->u.info, 0); + break; + } + case VINDEXED: { + OpCode op = (var->u.ind.vt == VLOCAL) ? OP_SETTABLE : OP_SETTABUP; + int e = luaK_exp2RK(fs, ex); + luaK_codeABC(fs, op, var->u.ind.t, var->u.ind.idx, e); + break; + } + default: { + lua_assert(0); /* invalid var kind to store */ + break; + } + } + freeexp(fs, ex); +} + + +void luaK_self (FuncState *fs, expdesc *e, expdesc *key) { + int ereg; + luaK_exp2anyreg(fs, e); + ereg = e->u.info; /* register where 'e' was placed */ + freeexp(fs, e); + e->u.info = fs->freereg; /* base register for op_self */ + e->k = VNONRELOC; + luaK_reserveregs(fs, 2); /* function and 'self' produced by op_self */ + luaK_codeABC(fs, OP_SELF, e->u.info, ereg, luaK_exp2RK(fs, key)); + freeexp(fs, key); +} + + +static void invertjump (FuncState *fs, expdesc *e) { + Instruction *pc = getjumpcontrol(fs, e->u.info); + lua_assert(testTMode(GET_OPCODE(*pc)) && GET_OPCODE(*pc) != OP_TESTSET && + GET_OPCODE(*pc) != OP_TEST); + SETARG_A(*pc, !(GETARG_A(*pc))); +} + + +static int jumponcond (FuncState *fs, expdesc *e, int cond) { + if (e->k == VRELOCABLE) { + Instruction ie = getcode(fs, e); + if (GET_OPCODE(ie) == OP_NOT) { + fs->pc--; /* remove previous OP_NOT */ + return condjump(fs, OP_TEST, GETARG_B(ie), 0, !cond); + } + /* else go through */ + } + discharge2anyreg(fs, e); + freeexp(fs, e); + return condjump(fs, OP_TESTSET, NO_REG, e->u.info, cond); +} + + +void luaK_goiftrue (FuncState *fs, expdesc *e) { + int pc; /* pc of last jump */ + luaK_dischargevars(fs, e); + switch (e->k) { + case VJMP: { + invertjump(fs, e); + pc = e->u.info; + break; + } + case VK: case VKFLT: case VKINT: case VTRUE: { + pc = NO_JUMP; /* always true; do nothing */ + break; + } + default: { + pc = jumponcond(fs, e, 0); + break; + } + } + luaK_concat(fs, &e->f, pc); /* insert last jump in 'f' list */ + luaK_patchtohere(fs, e->t); + e->t = NO_JUMP; +} + + +void luaK_goiffalse (FuncState *fs, expdesc *e) { + int pc; /* pc of last jump */ + luaK_dischargevars(fs, e); + switch (e->k) { + case VJMP: { + pc = e->u.info; + break; + } + case VNIL: case VFALSE: { + pc = NO_JUMP; /* always false; do nothing */ + break; + } + default: { + pc = jumponcond(fs, e, 1); + break; + } + } + luaK_concat(fs, &e->t, pc); /* insert last jump in 't' list */ + luaK_patchtohere(fs, e->f); + e->f = NO_JUMP; +} + + +static void codenot (FuncState *fs, expdesc *e) { + luaK_dischargevars(fs, e); + switch (e->k) { + case VNIL: case VFALSE: { + e->k = VTRUE; + break; + } + case VK: case VKFLT: case VKINT: case VTRUE: { + e->k = VFALSE; + break; + } + case VJMP: { + invertjump(fs, e); + break; + } + case VRELOCABLE: + case VNONRELOC: { + discharge2anyreg(fs, e); + freeexp(fs, e); + e->u.info = luaK_codeABC(fs, OP_NOT, 0, e->u.info, 0); + e->k = VRELOCABLE; + break; + } + default: { + lua_assert(0); /* cannot happen */ + break; + } + } + /* interchange true and false lists */ + { int temp = e->f; e->f = e->t; e->t = temp; } + removevalues(fs, e->f); + removevalues(fs, e->t); +} + + +void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k) { + lua_assert(!hasjumps(t)); + t->u.ind.t = t->u.info; + t->u.ind.idx = luaK_exp2RK(fs, k); + t->u.ind.vt = (t->k == VUPVAL) ? VUPVAL + : check_exp(vkisinreg(t->k), VLOCAL); + t->k = VINDEXED; +} + + +/* +** return false if folding can raise an error +*/ +static int validop (int op, TValue *v1, TValue *v2) { + switch (op) { + case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR: + case LUA_OPSHL: case LUA_OPSHR: case LUA_OPBNOT: { /* conversion errors */ + lua_Integer i; + return (tointeger(v1, &i) && tointeger(v2, &i)); + } + case LUA_OPDIV: case LUA_OPIDIV: case LUA_OPMOD: /* division by 0 */ + return (nvalue(v2) != 0); + default: return 1; /* everything else is valid */ + } +} + + +/* +** Try to "constant-fold" an operation; return 1 iff successful +*/ +static int constfolding (FuncState *fs, int op, expdesc *e1, expdesc *e2) { + TValue v1, v2, res; + if (!tonumeral(e1, &v1) || !tonumeral(e2, &v2) || !validop(op, &v1, &v2)) + return 0; /* non-numeric operands or not safe to fold */ + luaO_arith(fs->ls->L, op, &v1, &v2, &res); /* does operation */ + if (ttisinteger(&res)) { + e1->k = VKINT; + e1->u.ival = ivalue(&res); + } + else { /* folds neither NaN nor 0.0 (to avoid collapsing with -0.0) */ + lua_Number n = fltvalue(&res); + if (luai_numisnan(n) || n == 0) + return 0; + e1->k = VKFLT; + e1->u.nval = n; + } + return 1; +} + + +/* +** Code for binary and unary expressions that "produce values" +** (arithmetic operations, bitwise operations, concat, length). First +** try to do constant folding (only for numeric [arithmetic and +** bitwise] operations, which is what 'lua_arith' accepts). +** Expression to produce final result will be encoded in 'e1'. +*/ +static void codeexpval (FuncState *fs, OpCode op, + expdesc *e1, expdesc *e2, int line) { + lua_assert(op >= OP_ADD); + if (op <= OP_BNOT && constfolding(fs, op - OP_ADD + LUA_OPADD, e1, e2)) + return; /* result has been folded */ + else { + int o1, o2; + /* move operands to registers (if needed) */ + if (op == OP_UNM || op == OP_BNOT || op == OP_LEN) { /* unary op? */ + o2 = 0; /* no second expression */ + o1 = luaK_exp2anyreg(fs, e1); /* cannot operate on constants */ + } + else { /* regular case (binary operators) */ + o2 = luaK_exp2RK(fs, e2); /* both operands are "RK" */ + o1 = luaK_exp2RK(fs, e1); + } + if (o1 > o2) { /* free registers in proper order */ + freeexp(fs, e1); + freeexp(fs, e2); + } + else { + freeexp(fs, e2); + freeexp(fs, e1); + } + e1->u.info = luaK_codeABC(fs, op, 0, o1, o2); /* generate opcode */ + e1->k = VRELOCABLE; /* all those operations are relocable */ + luaK_fixline(fs, line); + } +} + + +static void codecomp (FuncState *fs, OpCode op, int cond, expdesc *e1, + expdesc *e2) { + int o1 = luaK_exp2RK(fs, e1); + int o2 = luaK_exp2RK(fs, e2); + freeexp(fs, e2); + freeexp(fs, e1); + if (cond == 0 && op != OP_EQ) { + int temp; /* exchange args to replace by '<' or '<=' */ + temp = o1; o1 = o2; o2 = temp; /* o1 <==> o2 */ + cond = 1; + } + e1->u.info = condjump(fs, op, cond, o1, o2); + e1->k = VJMP; +} + + +void luaK_prefix (FuncState *fs, UnOpr op, expdesc *e, int line) { + expdesc e2; + e2.t = e2.f = NO_JUMP; e2.k = VKINT; e2.u.ival = 0; + switch (op) { + case OPR_MINUS: case OPR_BNOT: case OPR_LEN: { + codeexpval(fs, cast(OpCode, (op - OPR_MINUS) + OP_UNM), e, &e2, line); + break; + } + case OPR_NOT: codenot(fs, e); break; + default: lua_assert(0); + } +} + + +void luaK_infix (FuncState *fs, BinOpr op, expdesc *v) { + switch (op) { + case OPR_AND: { + luaK_goiftrue(fs, v); + break; + } + case OPR_OR: { + luaK_goiffalse(fs, v); + break; + } + case OPR_CONCAT: { + luaK_exp2nextreg(fs, v); /* operand must be on the 'stack' */ + break; + } + case OPR_ADD: case OPR_SUB: + case OPR_MUL: case OPR_DIV: case OPR_IDIV: + case OPR_MOD: case OPR_POW: + case OPR_BAND: case OPR_BOR: case OPR_BXOR: + case OPR_SHL: case OPR_SHR: { + if (!tonumeral(v, NULL)) luaK_exp2RK(fs, v); + break; + } + default: { + luaK_exp2RK(fs, v); + break; + } + } +} + + +void luaK_posfix (FuncState *fs, BinOpr op, + expdesc *e1, expdesc *e2, int line) { + switch (op) { + case OPR_AND: { + lua_assert(e1->t == NO_JUMP); /* list must be closed */ + luaK_dischargevars(fs, e2); + luaK_concat(fs, &e2->f, e1->f); + *e1 = *e2; + break; + } + case OPR_OR: { + lua_assert(e1->f == NO_JUMP); /* list must be closed */ + luaK_dischargevars(fs, e2); + luaK_concat(fs, &e2->t, e1->t); + *e1 = *e2; + break; + } + case OPR_CONCAT: { + luaK_exp2val(fs, e2); + if (e2->k == VRELOCABLE && GET_OPCODE(getcode(fs, e2)) == OP_CONCAT) { + lua_assert(e1->u.info == GETARG_B(getcode(fs, e2))-1); + freeexp(fs, e1); + SETARG_B(getcode(fs, e2), e1->u.info); + e1->k = VRELOCABLE; e1->u.info = e2->u.info; + } + else { + luaK_exp2nextreg(fs, e2); /* operand must be on the 'stack' */ + codeexpval(fs, OP_CONCAT, e1, e2, line); + } + break; + } + case OPR_ADD: case OPR_SUB: case OPR_MUL: case OPR_DIV: + case OPR_IDIV: case OPR_MOD: case OPR_POW: + case OPR_BAND: case OPR_BOR: case OPR_BXOR: + case OPR_SHL: case OPR_SHR: { + codeexpval(fs, cast(OpCode, (op - OPR_ADD) + OP_ADD), e1, e2, line); + break; + } + case OPR_EQ: case OPR_LT: case OPR_LE: { + codecomp(fs, cast(OpCode, op - OPR_EQ + OP_EQ), 1, e1, e2); + break; + } + case OPR_NE: case OPR_GT: case OPR_GE: { + codecomp(fs, cast(OpCode, op - OPR_NE + OP_EQ), 0, e1, e2); + break; + } + default: lua_assert(0); + } +} + + +void luaK_fixline (FuncState *fs, int line) { + fs->f->lineinfo[fs->pc - 1] = line; +} + + +void luaK_setlist (FuncState *fs, int base, int nelems, int tostore) { + int c = (nelems - 1)/LFIELDS_PER_FLUSH + 1; + int b = (tostore == LUA_MULTRET) ? 0 : tostore; + lua_assert(tostore != 0); + if (c <= MAXARG_C) + luaK_codeABC(fs, OP_SETLIST, base, b, c); + else if (c <= MAXARG_Ax) { + luaK_codeABC(fs, OP_SETLIST, base, b, 0); + codeextraarg(fs, c); + } + else + luaX_syntaxerror(fs->ls, "constructor too long"); + fs->freereg = base + 1; /* free registers with list values */ +} + diff --git a/src/lcode.h b/src/lcode.h new file mode 100644 index 000000000000..43ab86db77b0 --- /dev/null +++ b/src/lcode.h @@ -0,0 +1,87 @@ +/* +** $Id: lcode.h,v 1.63 2013/12/30 20:47:58 roberto Exp $ +** Code generator for Lua +** See Copyright Notice in lua.h +*/ + +#ifndef lcode_h +#define lcode_h + +#include "llex.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" + + +/* +** Marks the end of a patch list. It is an invalid value both as an absolute +** address, and as a list link (would link an element to itself). +*/ +#define NO_JUMP (-1) + + +/* +** grep "ORDER OPR" if you change these enums (ORDER OP) +*/ +typedef enum BinOpr { + OPR_ADD, OPR_SUB, OPR_MUL, OPR_MOD, OPR_POW, + OPR_DIV, + OPR_IDIV, + OPR_BAND, OPR_BOR, OPR_BXOR, + OPR_SHL, OPR_SHR, + OPR_CONCAT, + OPR_EQ, OPR_LT, OPR_LE, + OPR_NE, OPR_GT, OPR_GE, + OPR_AND, OPR_OR, + OPR_NOBINOPR +} BinOpr; + + +typedef enum UnOpr { OPR_MINUS, OPR_BNOT, OPR_NOT, OPR_LEN, OPR_NOUNOPR } UnOpr; + + +#define getcode(fs,e) ((fs)->f->code[(e)->u.info]) + +#define luaK_codeAsBx(fs,o,A,sBx) luaK_codeABx(fs,o,A,(sBx)+MAXARG_sBx) + +#define luaK_setmultret(fs,e) luaK_setreturns(fs, e, LUA_MULTRET) + +#define luaK_jumpto(fs,t) luaK_patchlist(fs, luaK_jump(fs), t) + +LUAI_FUNC int luaK_codeABx (FuncState *fs, OpCode o, int A, unsigned int Bx); +LUAI_FUNC int luaK_codeABC (FuncState *fs, OpCode o, int A, int B, int C); +LUAI_FUNC int luaK_codek (FuncState *fs, int reg, int k); +LUAI_FUNC void luaK_fixline (FuncState *fs, int line); +LUAI_FUNC void luaK_nil (FuncState *fs, int from, int n); +LUAI_FUNC void luaK_reserveregs (FuncState *fs, int n); +LUAI_FUNC void luaK_checkstack (FuncState *fs, int n); +LUAI_FUNC int luaK_stringK (FuncState *fs, TString *s); +LUAI_FUNC int luaK_intK (FuncState *fs, lua_Integer n); +LUAI_FUNC void luaK_dischargevars (FuncState *fs, expdesc *e); +LUAI_FUNC int luaK_exp2anyreg (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_exp2anyregup (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_exp2nextreg (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_exp2val (FuncState *fs, expdesc *e); +LUAI_FUNC int luaK_exp2RK (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_self (FuncState *fs, expdesc *e, expdesc *key); +LUAI_FUNC void luaK_indexed (FuncState *fs, expdesc *t, expdesc *k); +LUAI_FUNC void luaK_goiftrue (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_goiffalse (FuncState *fs, expdesc *e); +LUAI_FUNC void luaK_storevar (FuncState *fs, expdesc *var, expdesc *e); +LUAI_FUNC void luaK_setreturns (FuncState *fs, expdesc *e, int nresults); +LUAI_FUNC void luaK_setoneret (FuncState *fs, expdesc *e); +LUAI_FUNC int luaK_jump (FuncState *fs); +LUAI_FUNC void luaK_ret (FuncState *fs, int first, int nret); +LUAI_FUNC void luaK_patchlist (FuncState *fs, int list, int target); +LUAI_FUNC void luaK_patchtohere (FuncState *fs, int list); +LUAI_FUNC void luaK_patchclose (FuncState *fs, int list, int level); +LUAI_FUNC void luaK_concat (FuncState *fs, int *l1, int l2); +LUAI_FUNC int luaK_getlabel (FuncState *fs); +LUAI_FUNC void luaK_prefix (FuncState *fs, UnOpr op, expdesc *v, int line); +LUAI_FUNC void luaK_infix (FuncState *fs, BinOpr op, expdesc *v); +LUAI_FUNC void luaK_posfix (FuncState *fs, BinOpr op, expdesc *v1, + expdesc *v2, int line); +LUAI_FUNC void luaK_setlist (FuncState *fs, int base, int nelems, int tostore); + + +#endif diff --git a/src/lcorolib.c b/src/lcorolib.c new file mode 100644 index 000000000000..0c0b7fa6b31c --- /dev/null +++ b/src/lcorolib.c @@ -0,0 +1,168 @@ +/* +** $Id: lcorolib.c,v 1.9 2014/11/02 19:19:04 roberto Exp $ +** Coroutine Library +** See Copyright Notice in lua.h +*/ + +#define lcorolib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <stdlib.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +static lua_State *getco (lua_State *L) { + lua_State *co = lua_tothread(L, 1); + luaL_argcheck(L, co, 1, "thread expected"); + return co; +} + + +static int auxresume (lua_State *L, lua_State *co, int narg) { + int status; + if (!lua_checkstack(co, narg)) { + lua_pushliteral(L, "too many arguments to resume"); + return -1; /* error flag */ + } + if (lua_status(co) == LUA_OK && lua_gettop(co) == 0) { + lua_pushliteral(L, "cannot resume dead coroutine"); + return -1; /* error flag */ + } + lua_xmove(L, co, narg); + status = lua_resume(co, L, narg); + if (status == LUA_OK || status == LUA_YIELD) { + int nres = lua_gettop(co); + if (!lua_checkstack(L, nres + 1)) { + lua_pop(co, nres); /* remove results anyway */ + lua_pushliteral(L, "too many results to resume"); + return -1; /* error flag */ + } + lua_xmove(co, L, nres); /* move yielded values */ + return nres; + } + else { + lua_xmove(co, L, 1); /* move error message */ + return -1; /* error flag */ + } +} + + +static int luaB_coresume (lua_State *L) { + lua_State *co = getco(L); + int r; + r = auxresume(L, co, lua_gettop(L) - 1); + if (r < 0) { + lua_pushboolean(L, 0); + lua_insert(L, -2); + return 2; /* return false + error message */ + } + else { + lua_pushboolean(L, 1); + lua_insert(L, -(r + 1)); + return r + 1; /* return true + 'resume' returns */ + } +} + + +static int luaB_auxwrap (lua_State *L) { + lua_State *co = lua_tothread(L, lua_upvalueindex(1)); + int r = auxresume(L, co, lua_gettop(L)); + if (r < 0) { + if (lua_isstring(L, -1)) { /* error object is a string? */ + luaL_where(L, 1); /* add extra info */ + lua_insert(L, -2); + lua_concat(L, 2); + } + return lua_error(L); /* propagate error */ + } + return r; +} + + +static int luaB_cocreate (lua_State *L) { + lua_State *NL; + luaL_checktype(L, 1, LUA_TFUNCTION); + NL = lua_newthread(L); + lua_pushvalue(L, 1); /* move function to top */ + lua_xmove(L, NL, 1); /* move function from L to NL */ + return 1; +} + + +static int luaB_cowrap (lua_State *L) { + luaB_cocreate(L); + lua_pushcclosure(L, luaB_auxwrap, 1); + return 1; +} + + +static int luaB_yield (lua_State *L) { + return lua_yield(L, lua_gettop(L)); +} + + +static int luaB_costatus (lua_State *L) { + lua_State *co = getco(L); + if (L == co) lua_pushliteral(L, "running"); + else { + switch (lua_status(co)) { + case LUA_YIELD: + lua_pushliteral(L, "suspended"); + break; + case LUA_OK: { + lua_Debug ar; + if (lua_getstack(co, 0, &ar) > 0) /* does it have frames? */ + lua_pushliteral(L, "normal"); /* it is running */ + else if (lua_gettop(co) == 0) + lua_pushliteral(L, "dead"); + else + lua_pushliteral(L, "suspended"); /* initial state */ + break; + } + default: /* some error occurred */ + lua_pushliteral(L, "dead"); + break; + } + } + return 1; +} + + +static int luaB_yieldable (lua_State *L) { + lua_pushboolean(L, lua_isyieldable(L)); + return 1; +} + + +static int luaB_corunning (lua_State *L) { + int ismain = lua_pushthread(L); + lua_pushboolean(L, ismain); + return 2; +} + + +static const luaL_Reg co_funcs[] = { + {"create", luaB_cocreate}, + {"resume", luaB_coresume}, + {"running", luaB_corunning}, + {"status", luaB_costatus}, + {"wrap", luaB_cowrap}, + {"yield", luaB_yield}, + {"isyieldable", luaB_yieldable}, + {NULL, NULL} +}; + + + +LUAMOD_API int luaopen_coroutine (lua_State *L) { + luaL_newlib(L, co_funcs); + return 1; +} + diff --git a/src/lctype.c b/src/lctype.c new file mode 100644 index 000000000000..ae9367e691bd --- /dev/null +++ b/src/lctype.c @@ -0,0 +1,55 @@ +/* +** $Id: lctype.c,v 1.12 2014/11/02 19:19:04 roberto Exp $ +** 'ctype' functions for Lua +** See Copyright Notice in lua.h +*/ + +#define lctype_c +#define LUA_CORE + +#include "lprefix.h" + + +#include "lctype.h" + +#if !LUA_USE_CTYPE /* { */ + +#include <limits.h> + +LUAI_DDEF const lu_byte luai_ctype_[UCHAR_MAX + 2] = { + 0x00, /* EOZ */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 0. */ + 0x00, 0x08, 0x08, 0x08, 0x08, 0x08, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 1. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x0c, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, /* 2. */ + 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, + 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, 0x16, /* 3. */ + 0x16, 0x16, 0x04, 0x04, 0x04, 0x04, 0x04, 0x04, + 0x04, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x05, /* 4. */ + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, /* 5. */ + 0x05, 0x05, 0x05, 0x04, 0x04, 0x04, 0x04, 0x05, + 0x04, 0x15, 0x15, 0x15, 0x15, 0x15, 0x15, 0x05, /* 6. */ + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, + 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, 0x05, /* 7. */ + 0x05, 0x05, 0x05, 0x04, 0x04, 0x04, 0x04, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 8. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* 9. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* a. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* b. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* c. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* d. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* e. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, /* f. */ + 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, 0x00, +}; + +#endif /* } */ diff --git a/src/lctype.h b/src/lctype.h new file mode 100644 index 000000000000..99c7d122376a --- /dev/null +++ b/src/lctype.h @@ -0,0 +1,95 @@ +/* +** $Id: lctype.h,v 1.12 2011/07/15 12:50:29 roberto Exp $ +** 'ctype' functions for Lua +** See Copyright Notice in lua.h +*/ + +#ifndef lctype_h +#define lctype_h + +#include "lua.h" + + +/* +** WARNING: the functions defined here do not necessarily correspond +** to the similar functions in the standard C ctype.h. They are +** optimized for the specific needs of Lua +*/ + +#if !defined(LUA_USE_CTYPE) + +#if 'A' == 65 && '0' == 48 +/* ASCII case: can use its own tables; faster and fixed */ +#define LUA_USE_CTYPE 0 +#else +/* must use standard C ctype */ +#define LUA_USE_CTYPE 1 +#endif + +#endif + + +#if !LUA_USE_CTYPE /* { */ + +#include <limits.h> + +#include "llimits.h" + + +#define ALPHABIT 0 +#define DIGITBIT 1 +#define PRINTBIT 2 +#define SPACEBIT 3 +#define XDIGITBIT 4 + + +#define MASK(B) (1 << (B)) + + +/* +** add 1 to char to allow index -1 (EOZ) +*/ +#define testprop(c,p) (luai_ctype_[(c)+1] & (p)) + +/* +** 'lalpha' (Lua alphabetic) and 'lalnum' (Lua alphanumeric) both include '_' +*/ +#define lislalpha(c) testprop(c, MASK(ALPHABIT)) +#define lislalnum(c) testprop(c, (MASK(ALPHABIT) | MASK(DIGITBIT))) +#define lisdigit(c) testprop(c, MASK(DIGITBIT)) +#define lisspace(c) testprop(c, MASK(SPACEBIT)) +#define lisprint(c) testprop(c, MASK(PRINTBIT)) +#define lisxdigit(c) testprop(c, MASK(XDIGITBIT)) + +/* +** this 'ltolower' only works for alphabetic characters +*/ +#define ltolower(c) ((c) | ('A' ^ 'a')) + + +/* two more entries for 0 and -1 (EOZ) */ +LUAI_DDEC const lu_byte luai_ctype_[UCHAR_MAX + 2]; + + +#else /* }{ */ + +/* +** use standard C ctypes +*/ + +#include <ctype.h> + + +#define lislalpha(c) (isalpha(c) || (c) == '_') +#define lislalnum(c) (isalnum(c) || (c) == '_') +#define lisdigit(c) (isdigit(c)) +#define lisspace(c) (isspace(c)) +#define lisprint(c) (isprint(c)) +#define lisxdigit(c) (isxdigit(c)) + +#define ltolower(c) (tolower(c)) + +#endif /* } */ + +#endif + diff --git a/src/ldblib.c b/src/ldblib.c new file mode 100644 index 000000000000..24a11b53ee32 --- /dev/null +++ b/src/ldblib.c @@ -0,0 +1,437 @@ +/* +** $Id: ldblib.c,v 1.148 2015/01/02 12:52:22 roberto Exp $ +** Interface from Lua to its debug API +** See Copyright Notice in lua.h +*/ + +#define ldblib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** The hook table at registry[&HOOKKEY] maps threads to their current +** hook function. (We only need the unique address of 'HOOKKEY'.) +*/ +static const int HOOKKEY = 0; + + +static int db_getregistry (lua_State *L) { + lua_pushvalue(L, LUA_REGISTRYINDEX); + return 1; +} + + +static int db_getmetatable (lua_State *L) { + luaL_checkany(L, 1); + if (!lua_getmetatable(L, 1)) { + lua_pushnil(L); /* no metatable */ + } + return 1; +} + + +static int db_setmetatable (lua_State *L) { + int t = lua_type(L, 2); + luaL_argcheck(L, t == LUA_TNIL || t == LUA_TTABLE, 2, + "nil or table expected"); + lua_settop(L, 2); + lua_setmetatable(L, 1); + return 1; /* return 1st argument */ +} + + +static int db_getuservalue (lua_State *L) { + if (lua_type(L, 1) != LUA_TUSERDATA) + lua_pushnil(L); + else + lua_getuservalue(L, 1); + return 1; +} + + +static int db_setuservalue (lua_State *L) { + luaL_checktype(L, 1, LUA_TUSERDATA); + luaL_checkany(L, 2); + lua_settop(L, 2); + lua_setuservalue(L, 1); + return 1; +} + + +/* +** Auxiliary function used by several library functions: check for +** an optional thread as function's first argument and set 'arg' with +** 1 if this argument is present (so that functions can skip it to +** access their other arguments) +*/ +static lua_State *getthread (lua_State *L, int *arg) { + if (lua_isthread(L, 1)) { + *arg = 1; + return lua_tothread(L, 1); + } + else { + *arg = 0; + return L; /* function will operate over current thread */ + } +} + + +/* +** Variations of 'lua_settable', used by 'db_getinfo' to put results +** from 'lua_getinfo' into result table. Key is always a string; +** value can be a string, an int, or a boolean. +*/ +static void settabss (lua_State *L, const char *k, const char *v) { + lua_pushstring(L, v); + lua_setfield(L, -2, k); +} + +static void settabsi (lua_State *L, const char *k, int v) { + lua_pushinteger(L, v); + lua_setfield(L, -2, k); +} + +static void settabsb (lua_State *L, const char *k, int v) { + lua_pushboolean(L, v); + lua_setfield(L, -2, k); +} + + +/* +** In function 'db_getinfo', the call to 'lua_getinfo' may push +** results on the stack; later it creates the result table to put +** these objects. Function 'treatstackoption' puts the result from +** 'lua_getinfo' on top of the result table so that it can call +** 'lua_setfield'. +*/ +static void treatstackoption (lua_State *L, lua_State *L1, const char *fname) { + if (L == L1) + lua_rotate(L, -2, 1); /* exchange object and table */ + else + lua_xmove(L1, L, 1); /* move object to the "main" stack */ + lua_setfield(L, -2, fname); /* put object into table */ +} + + +/* +** Calls 'lua_getinfo' and collects all results in a new table. +*/ +static int db_getinfo (lua_State *L) { + lua_Debug ar; + int arg; + lua_State *L1 = getthread(L, &arg); + const char *options = luaL_optstring(L, arg+2, "flnStu"); + if (lua_isfunction(L, arg + 1)) { /* info about a function? */ + options = lua_pushfstring(L, ">%s", options); /* add '>' to 'options' */ + lua_pushvalue(L, arg + 1); /* move function to 'L1' stack */ + lua_xmove(L, L1, 1); + } + else { /* stack level */ + if (!lua_getstack(L1, (int)luaL_checkinteger(L, arg + 1), &ar)) { + lua_pushnil(L); /* level out of range */ + return 1; + } + } + if (!lua_getinfo(L1, options, &ar)) + return luaL_argerror(L, arg+2, "invalid option"); + lua_newtable(L); /* table to collect results */ + if (strchr(options, 'S')) { + settabss(L, "source", ar.source); + settabss(L, "short_src", ar.short_src); + settabsi(L, "linedefined", ar.linedefined); + settabsi(L, "lastlinedefined", ar.lastlinedefined); + settabss(L, "what", ar.what); + } + if (strchr(options, 'l')) + settabsi(L, "currentline", ar.currentline); + if (strchr(options, 'u')) { + settabsi(L, "nups", ar.nups); + settabsi(L, "nparams", ar.nparams); + settabsb(L, "isvararg", ar.isvararg); + } + if (strchr(options, 'n')) { + settabss(L, "name", ar.name); + settabss(L, "namewhat", ar.namewhat); + } + if (strchr(options, 't')) + settabsb(L, "istailcall", ar.istailcall); + if (strchr(options, 'L')) + treatstackoption(L, L1, "activelines"); + if (strchr(options, 'f')) + treatstackoption(L, L1, "func"); + return 1; /* return table */ +} + + +static int db_getlocal (lua_State *L) { + int arg; + lua_State *L1 = getthread(L, &arg); + lua_Debug ar; + const char *name; + int nvar = (int)luaL_checkinteger(L, arg + 2); /* local-variable index */ + if (lua_isfunction(L, arg + 1)) { /* function argument? */ + lua_pushvalue(L, arg + 1); /* push function */ + lua_pushstring(L, lua_getlocal(L, NULL, nvar)); /* push local name */ + return 1; /* return only name (there is no value) */ + } + else { /* stack-level argument */ + int level = (int)luaL_checkinteger(L, arg + 1); + if (!lua_getstack(L1, level, &ar)) /* out of range? */ + return luaL_argerror(L, arg+1, "level out of range"); + name = lua_getlocal(L1, &ar, nvar); + if (name) { + lua_xmove(L1, L, 1); /* move local value */ + lua_pushstring(L, name); /* push name */ + lua_rotate(L, -2, 1); /* re-order */ + return 2; + } + else { + lua_pushnil(L); /* no name (nor value) */ + return 1; + } + } +} + + +static int db_setlocal (lua_State *L) { + int arg; + const char *name; + lua_State *L1 = getthread(L, &arg); + lua_Debug ar; + int level = (int)luaL_checkinteger(L, arg + 1); + int nvar = (int)luaL_checkinteger(L, arg + 2); + if (!lua_getstack(L1, level, &ar)) /* out of range? */ + return luaL_argerror(L, arg+1, "level out of range"); + luaL_checkany(L, arg+3); + lua_settop(L, arg+3); + lua_xmove(L, L1, 1); + name = lua_setlocal(L1, &ar, nvar); + if (name == NULL) + lua_pop(L1, 1); /* pop value (if not popped by 'lua_setlocal') */ + lua_pushstring(L, name); + return 1; +} + + +/* +** get (if 'get' is true) or set an upvalue from a closure +*/ +static int auxupvalue (lua_State *L, int get) { + const char *name; + int n = (int)luaL_checkinteger(L, 2); /* upvalue index */ + luaL_checktype(L, 1, LUA_TFUNCTION); /* closure */ + name = get ? lua_getupvalue(L, 1, n) : lua_setupvalue(L, 1, n); + if (name == NULL) return 0; + lua_pushstring(L, name); + lua_insert(L, -(get+1)); /* no-op if get is false */ + return get + 1; +} + + +static int db_getupvalue (lua_State *L) { + return auxupvalue(L, 1); +} + + +static int db_setupvalue (lua_State *L) { + luaL_checkany(L, 3); + return auxupvalue(L, 0); +} + + +/* +** Check whether a given upvalue from a given closure exists and +** returns its index +*/ +static int checkupval (lua_State *L, int argf, int argnup) { + int nup = (int)luaL_checkinteger(L, argnup); /* upvalue index */ + luaL_checktype(L, argf, LUA_TFUNCTION); /* closure */ + luaL_argcheck(L, (lua_getupvalue(L, argf, nup) != NULL), argnup, + "invalid upvalue index"); + return nup; +} + + +static int db_upvalueid (lua_State *L) { + int n = checkupval(L, 1, 2); + lua_pushlightuserdata(L, lua_upvalueid(L, 1, n)); + return 1; +} + + +static int db_upvaluejoin (lua_State *L) { + int n1 = checkupval(L, 1, 2); + int n2 = checkupval(L, 3, 4); + luaL_argcheck(L, !lua_iscfunction(L, 1), 1, "Lua function expected"); + luaL_argcheck(L, !lua_iscfunction(L, 3), 3, "Lua function expected"); + lua_upvaluejoin(L, 1, n1, 3, n2); + return 0; +} + + +/* +** Call hook function registered at hook table for the current +** thread (if there is one) +*/ +static void hookf (lua_State *L, lua_Debug *ar) { + static const char *const hooknames[] = + {"call", "return", "line", "count", "tail call"}; + lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY); + lua_pushthread(L); + if (lua_rawget(L, -2) == LUA_TFUNCTION) { /* is there a hook function? */ + lua_pushstring(L, hooknames[(int)ar->event]); /* push event name */ + if (ar->currentline >= 0) + lua_pushinteger(L, ar->currentline); /* push current line */ + else lua_pushnil(L); + lua_assert(lua_getinfo(L, "lS", ar)); + lua_call(L, 2, 0); /* call hook function */ + } +} + + +/* +** Convert a string mask (for 'sethook') into a bit mask +*/ +static int makemask (const char *smask, int count) { + int mask = 0; + if (strchr(smask, 'c')) mask |= LUA_MASKCALL; + if (strchr(smask, 'r')) mask |= LUA_MASKRET; + if (strchr(smask, 'l')) mask |= LUA_MASKLINE; + if (count > 0) mask |= LUA_MASKCOUNT; + return mask; +} + + +/* +** Convert a bit mask (for 'gethook') into a string mask +*/ +static char *unmakemask (int mask, char *smask) { + int i = 0; + if (mask & LUA_MASKCALL) smask[i++] = 'c'; + if (mask & LUA_MASKRET) smask[i++] = 'r'; + if (mask & LUA_MASKLINE) smask[i++] = 'l'; + smask[i] = '\0'; + return smask; +} + + +static int db_sethook (lua_State *L) { + int arg, mask, count; + lua_Hook func; + lua_State *L1 = getthread(L, &arg); + if (lua_isnoneornil(L, arg+1)) { /* no hook? */ + lua_settop(L, arg+1); + func = NULL; mask = 0; count = 0; /* turn off hooks */ + } + else { + const char *smask = luaL_checkstring(L, arg+2); + luaL_checktype(L, arg+1, LUA_TFUNCTION); + count = (int)luaL_optinteger(L, arg + 3, 0); + func = hookf; mask = makemask(smask, count); + } + if (lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY) == LUA_TNIL) { + lua_createtable(L, 0, 2); /* create a hook table */ + lua_pushvalue(L, -1); + lua_rawsetp(L, LUA_REGISTRYINDEX, &HOOKKEY); /* set it in position */ + lua_pushstring(L, "k"); + lua_setfield(L, -2, "__mode"); /** hooktable.__mode = "k" */ + lua_pushvalue(L, -1); + lua_setmetatable(L, -2); /* setmetatable(hooktable) = hooktable */ + } + lua_pushthread(L1); lua_xmove(L1, L, 1); /* key (thread) */ + lua_pushvalue(L, arg + 1); /* value (hook function) */ + lua_rawset(L, -3); /* hooktable[L1] = new Lua hook */ + lua_sethook(L1, func, mask, count); + return 0; +} + + +static int db_gethook (lua_State *L) { + int arg; + lua_State *L1 = getthread(L, &arg); + char buff[5]; + int mask = lua_gethookmask(L1); + lua_Hook hook = lua_gethook(L1); + if (hook == NULL) /* no hook? */ + lua_pushnil(L); + else if (hook != hookf) /* external hook? */ + lua_pushliteral(L, "external hook"); + else { /* hook table must exist */ + lua_rawgetp(L, LUA_REGISTRYINDEX, &HOOKKEY); + lua_pushthread(L1); lua_xmove(L1, L, 1); + lua_rawget(L, -2); /* 1st result = hooktable[L1] */ + lua_remove(L, -2); /* remove hook table */ + } + lua_pushstring(L, unmakemask(mask, buff)); /* 2nd result = mask */ + lua_pushinteger(L, lua_gethookcount(L1)); /* 3rd result = count */ + return 3; +} + + +static int db_debug (lua_State *L) { + for (;;) { + char buffer[250]; + lua_writestringerror("%s", "lua_debug> "); + if (fgets(buffer, sizeof(buffer), stdin) == 0 || + strcmp(buffer, "cont\n") == 0) + return 0; + if (luaL_loadbuffer(L, buffer, strlen(buffer), "=(debug command)") || + lua_pcall(L, 0, 0, 0)) + lua_writestringerror("%s\n", lua_tostring(L, -1)); + lua_settop(L, 0); /* remove eventual returns */ + } +} + + +static int db_traceback (lua_State *L) { + int arg; + lua_State *L1 = getthread(L, &arg); + const char *msg = lua_tostring(L, arg + 1); + if (msg == NULL && !lua_isnoneornil(L, arg + 1)) /* non-string 'msg'? */ + lua_pushvalue(L, arg + 1); /* return it untouched */ + else { + int level = (int)luaL_optinteger(L, arg + 2, (L == L1) ? 1 : 0); + luaL_traceback(L, L1, msg, level); + } + return 1; +} + + +static const luaL_Reg dblib[] = { + {"debug", db_debug}, + {"getuservalue", db_getuservalue}, + {"gethook", db_gethook}, + {"getinfo", db_getinfo}, + {"getlocal", db_getlocal}, + {"getregistry", db_getregistry}, + {"getmetatable", db_getmetatable}, + {"getupvalue", db_getupvalue}, + {"upvaluejoin", db_upvaluejoin}, + {"upvalueid", db_upvalueid}, + {"setuservalue", db_setuservalue}, + {"sethook", db_sethook}, + {"setlocal", db_setlocal}, + {"setmetatable", db_setmetatable}, + {"setupvalue", db_setupvalue}, + {"traceback", db_traceback}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_debug (lua_State *L) { + luaL_newlib(L, dblib); + return 1; +} + diff --git a/src/ldebug.c b/src/ldebug.c new file mode 100644 index 000000000000..6986bf0f6098 --- /dev/null +++ b/src/ldebug.c @@ -0,0 +1,643 @@ +/* +** $Id: ldebug.c,v 2.110 2015/01/02 12:52:22 roberto Exp $ +** Debug Interface +** See Copyright Notice in lua.h +*/ + +#define ldebug_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stdarg.h> +#include <stddef.h> +#include <string.h> + +#include "lua.h" + +#include "lapi.h" +#include "lcode.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lvm.h" + + + +#define noLuaClosure(f) ((f) == NULL || (f)->c.tt == LUA_TCCL) + + +static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name); + + +static int currentpc (CallInfo *ci) { + lua_assert(isLua(ci)); + return pcRel(ci->u.l.savedpc, ci_func(ci)->p); +} + + +static int currentline (CallInfo *ci) { + return getfuncline(ci_func(ci)->p, currentpc(ci)); +} + + +/* +** this function can be called asynchronous (e.g. during a signal) +*/ +LUA_API void lua_sethook (lua_State *L, lua_Hook func, int mask, int count) { + if (func == NULL || mask == 0) { /* turn off hooks? */ + mask = 0; + func = NULL; + } + if (isLua(L->ci)) + L->oldpc = L->ci->u.l.savedpc; + L->hook = func; + L->basehookcount = count; + resethookcount(L); + L->hookmask = cast_byte(mask); +} + + +LUA_API lua_Hook lua_gethook (lua_State *L) { + return L->hook; +} + + +LUA_API int lua_gethookmask (lua_State *L) { + return L->hookmask; +} + + +LUA_API int lua_gethookcount (lua_State *L) { + return L->basehookcount; +} + + +LUA_API int lua_getstack (lua_State *L, int level, lua_Debug *ar) { + int status; + CallInfo *ci; + if (level < 0) return 0; /* invalid (negative) level */ + lua_lock(L); + for (ci = L->ci; level > 0 && ci != &L->base_ci; ci = ci->previous) + level--; + if (level == 0 && ci != &L->base_ci) { /* level found? */ + status = 1; + ar->i_ci = ci; + } + else status = 0; /* no such level */ + lua_unlock(L); + return status; +} + + +static const char *upvalname (Proto *p, int uv) { + TString *s = check_exp(uv < p->sizeupvalues, p->upvalues[uv].name); + if (s == NULL) return "?"; + else return getstr(s); +} + + +static const char *findvararg (CallInfo *ci, int n, StkId *pos) { + int nparams = clLvalue(ci->func)->p->numparams; + if (n >= ci->u.l.base - ci->func - nparams) + return NULL; /* no such vararg */ + else { + *pos = ci->func + nparams + n; + return "(*vararg)"; /* generic name for any vararg */ + } +} + + +static const char *findlocal (lua_State *L, CallInfo *ci, int n, + StkId *pos) { + const char *name = NULL; + StkId base; + if (isLua(ci)) { + if (n < 0) /* access to vararg values? */ + return findvararg(ci, -n, pos); + else { + base = ci->u.l.base; + name = luaF_getlocalname(ci_func(ci)->p, n, currentpc(ci)); + } + } + else + base = ci->func + 1; + if (name == NULL) { /* no 'standard' name? */ + StkId limit = (ci == L->ci) ? L->top : ci->next->func; + if (limit - base >= n && n > 0) /* is 'n' inside 'ci' stack? */ + name = "(*temporary)"; /* generic name for any valid slot */ + else + return NULL; /* no name */ + } + *pos = base + (n - 1); + return name; +} + + +LUA_API const char *lua_getlocal (lua_State *L, const lua_Debug *ar, int n) { + const char *name; + lua_lock(L); + if (ar == NULL) { /* information about non-active function? */ + if (!isLfunction(L->top - 1)) /* not a Lua function? */ + name = NULL; + else /* consider live variables at function start (parameters) */ + name = luaF_getlocalname(clLvalue(L->top - 1)->p, n, 0); + } + else { /* active function; get information through 'ar' */ + StkId pos = 0; /* to avoid warnings */ + name = findlocal(L, ar->i_ci, n, &pos); + if (name) { + setobj2s(L, L->top, pos); + api_incr_top(L); + } + } + lua_unlock(L); + return name; +} + + +LUA_API const char *lua_setlocal (lua_State *L, const lua_Debug *ar, int n) { + StkId pos = 0; /* to avoid warnings */ + const char *name = findlocal(L, ar->i_ci, n, &pos); + lua_lock(L); + if (name) { + setobjs2s(L, pos, L->top - 1); + L->top--; /* pop value */ + } + lua_unlock(L); + return name; +} + + +static void funcinfo (lua_Debug *ar, Closure *cl) { + if (noLuaClosure(cl)) { + ar->source = "=[C]"; + ar->linedefined = -1; + ar->lastlinedefined = -1; + ar->what = "C"; + } + else { + Proto *p = cl->l.p; + ar->source = p->source ? getstr(p->source) : "=?"; + ar->linedefined = p->linedefined; + ar->lastlinedefined = p->lastlinedefined; + ar->what = (ar->linedefined == 0) ? "main" : "Lua"; + } + luaO_chunkid(ar->short_src, ar->source, LUA_IDSIZE); +} + + +static void collectvalidlines (lua_State *L, Closure *f) { + if (noLuaClosure(f)) { + setnilvalue(L->top); + api_incr_top(L); + } + else { + int i; + TValue v; + int *lineinfo = f->l.p->lineinfo; + Table *t = luaH_new(L); /* new table to store active lines */ + sethvalue(L, L->top, t); /* push it on stack */ + api_incr_top(L); + setbvalue(&v, 1); /* boolean 'true' to be the value of all indices */ + for (i = 0; i < f->l.p->sizelineinfo; i++) /* for all lines with code */ + luaH_setint(L, t, lineinfo[i], &v); /* table[line] = true */ + } +} + + +static int auxgetinfo (lua_State *L, const char *what, lua_Debug *ar, + Closure *f, CallInfo *ci) { + int status = 1; + for (; *what; what++) { + switch (*what) { + case 'S': { + funcinfo(ar, f); + break; + } + case 'l': { + ar->currentline = (ci && isLua(ci)) ? currentline(ci) : -1; + break; + } + case 'u': { + ar->nups = (f == NULL) ? 0 : f->c.nupvalues; + if (noLuaClosure(f)) { + ar->isvararg = 1; + ar->nparams = 0; + } + else { + ar->isvararg = f->l.p->is_vararg; + ar->nparams = f->l.p->numparams; + } + break; + } + case 't': { + ar->istailcall = (ci) ? ci->callstatus & CIST_TAIL : 0; + break; + } + case 'n': { + /* calling function is a known Lua function? */ + if (ci && !(ci->callstatus & CIST_TAIL) && isLua(ci->previous)) + ar->namewhat = getfuncname(L, ci->previous, &ar->name); + else + ar->namewhat = NULL; + if (ar->namewhat == NULL) { + ar->namewhat = ""; /* not found */ + ar->name = NULL; + } + break; + } + case 'L': + case 'f': /* handled by lua_getinfo */ + break; + default: status = 0; /* invalid option */ + } + } + return status; +} + + +LUA_API int lua_getinfo (lua_State *L, const char *what, lua_Debug *ar) { + int status; + Closure *cl; + CallInfo *ci; + StkId func; + lua_lock(L); + if (*what == '>') { + ci = NULL; + func = L->top - 1; + api_check(ttisfunction(func), "function expected"); + what++; /* skip the '>' */ + L->top--; /* pop function */ + } + else { + ci = ar->i_ci; + func = ci->func; + lua_assert(ttisfunction(ci->func)); + } + cl = ttisclosure(func) ? clvalue(func) : NULL; + status = auxgetinfo(L, what, ar, cl, ci); + if (strchr(what, 'f')) { + setobjs2s(L, L->top, func); + api_incr_top(L); + } + if (strchr(what, 'L')) + collectvalidlines(L, cl); + lua_unlock(L); + return status; +} + + +/* +** {====================================================== +** Symbolic Execution +** ======================================================= +*/ + +static const char *getobjname (Proto *p, int lastpc, int reg, + const char **name); + + +/* +** find a "name" for the RK value 'c' +*/ +static void kname (Proto *p, int pc, int c, const char **name) { + if (ISK(c)) { /* is 'c' a constant? */ + TValue *kvalue = &p->k[INDEXK(c)]; + if (ttisstring(kvalue)) { /* literal constant? */ + *name = svalue(kvalue); /* it is its own name */ + return; + } + /* else no reasonable name found */ + } + else { /* 'c' is a register */ + const char *what = getobjname(p, pc, c, name); /* search for 'c' */ + if (what && *what == 'c') { /* found a constant name? */ + return; /* 'name' already filled */ + } + /* else no reasonable name found */ + } + *name = "?"; /* no reasonable name found */ +} + + +static int filterpc (int pc, int jmptarget) { + if (pc < jmptarget) /* is code conditional (inside a jump)? */ + return -1; /* cannot know who sets that register */ + else return pc; /* current position sets that register */ +} + + +/* +** try to find last instruction before 'lastpc' that modified register 'reg' +*/ +static int findsetreg (Proto *p, int lastpc, int reg) { + int pc; + int setreg = -1; /* keep last instruction that changed 'reg' */ + int jmptarget = 0; /* any code before this address is conditional */ + for (pc = 0; pc < lastpc; pc++) { + Instruction i = p->code[pc]; + OpCode op = GET_OPCODE(i); + int a = GETARG_A(i); + switch (op) { + case OP_LOADNIL: { + int b = GETARG_B(i); + if (a <= reg && reg <= a + b) /* set registers from 'a' to 'a+b' */ + setreg = filterpc(pc, jmptarget); + break; + } + case OP_TFORCALL: { + if (reg >= a + 2) /* affect all regs above its base */ + setreg = filterpc(pc, jmptarget); + break; + } + case OP_CALL: + case OP_TAILCALL: { + if (reg >= a) /* affect all registers above base */ + setreg = filterpc(pc, jmptarget); + break; + } + case OP_JMP: { + int b = GETARG_sBx(i); + int dest = pc + 1 + b; + /* jump is forward and do not skip 'lastpc'? */ + if (pc < dest && dest <= lastpc) { + if (dest > jmptarget) + jmptarget = dest; /* update 'jmptarget' */ + } + break; + } + default: + if (testAMode(op) && reg == a) /* any instruction that set A */ + setreg = filterpc(pc, jmptarget); + break; + } + } + return setreg; +} + + +static const char *getobjname (Proto *p, int lastpc, int reg, + const char **name) { + int pc; + *name = luaF_getlocalname(p, reg + 1, lastpc); + if (*name) /* is a local? */ + return "local"; + /* else try symbolic execution */ + pc = findsetreg(p, lastpc, reg); + if (pc != -1) { /* could find instruction? */ + Instruction i = p->code[pc]; + OpCode op = GET_OPCODE(i); + switch (op) { + case OP_MOVE: { + int b = GETARG_B(i); /* move from 'b' to 'a' */ + if (b < GETARG_A(i)) + return getobjname(p, pc, b, name); /* get name for 'b' */ + break; + } + case OP_GETTABUP: + case OP_GETTABLE: { + int k = GETARG_C(i); /* key index */ + int t = GETARG_B(i); /* table index */ + const char *vn = (op == OP_GETTABLE) /* name of indexed variable */ + ? luaF_getlocalname(p, t + 1, pc) + : upvalname(p, t); + kname(p, pc, k, name); + return (vn && strcmp(vn, LUA_ENV) == 0) ? "global" : "field"; + } + case OP_GETUPVAL: { + *name = upvalname(p, GETARG_B(i)); + return "upvalue"; + } + case OP_LOADK: + case OP_LOADKX: { + int b = (op == OP_LOADK) ? GETARG_Bx(i) + : GETARG_Ax(p->code[pc + 1]); + if (ttisstring(&p->k[b])) { + *name = svalue(&p->k[b]); + return "constant"; + } + break; + } + case OP_SELF: { + int k = GETARG_C(i); /* key index */ + kname(p, pc, k, name); + return "method"; + } + default: break; /* go through to return NULL */ + } + } + return NULL; /* could not find reasonable name */ +} + + +static const char *getfuncname (lua_State *L, CallInfo *ci, const char **name) { + TMS tm = (TMS)0; /* to avoid warnings */ + Proto *p = ci_func(ci)->p; /* calling function */ + int pc = currentpc(ci); /* calling instruction index */ + Instruction i = p->code[pc]; /* calling instruction */ + if (ci->callstatus & CIST_HOOKED) { /* was it called inside a hook? */ + *name = "?"; + return "hook"; + } + switch (GET_OPCODE(i)) { + case OP_CALL: + case OP_TAILCALL: /* get function name */ + return getobjname(p, pc, GETARG_A(i), name); + case OP_TFORCALL: { /* for iterator */ + *name = "for iterator"; + return "for iterator"; + } + /* all other instructions can call only through metamethods */ + case OP_SELF: case OP_GETTABUP: case OP_GETTABLE: + tm = TM_INDEX; + break; + case OP_SETTABUP: case OP_SETTABLE: + tm = TM_NEWINDEX; + break; + case OP_ADD: case OP_SUB: case OP_MUL: case OP_MOD: + case OP_POW: case OP_DIV: case OP_IDIV: case OP_BAND: + case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: { + int offset = cast_int(GET_OPCODE(i)) - cast_int(OP_ADD); /* ORDER OP */ + tm = cast(TMS, offset + cast_int(TM_ADD)); /* ORDER TM */ + break; + } + case OP_UNM: tm = TM_UNM; break; + case OP_BNOT: tm = TM_BNOT; break; + case OP_LEN: tm = TM_LEN; break; + case OP_CONCAT: tm = TM_CONCAT; break; + case OP_EQ: tm = TM_EQ; break; + case OP_LT: tm = TM_LT; break; + case OP_LE: tm = TM_LE; break; + default: lua_assert(0); /* other instructions cannot call a function */ + } + *name = getstr(G(L)->tmname[tm]); + return "metamethod"; +} + +/* }====================================================== */ + + + +/* +** The subtraction of two potentially unrelated pointers is +** not ISO C, but it should not crash a program; the subsequent +** checks are ISO C and ensure a correct result. +*/ +static int isinstack (CallInfo *ci, const TValue *o) { + ptrdiff_t i = o - ci->u.l.base; + return (0 <= i && i < (ci->top - ci->u.l.base) && ci->u.l.base + i == o); +} + + +/* +** Checks whether value 'o' came from an upvalue. (That can only happen +** with instructions OP_GETTABUP/OP_SETTABUP, which operate directly on +** upvalues.) +*/ +static const char *getupvalname (CallInfo *ci, const TValue *o, + const char **name) { + LClosure *c = ci_func(ci); + int i; + for (i = 0; i < c->nupvalues; i++) { + if (c->upvals[i]->v == o) { + *name = upvalname(c->p, i); + return "upvalue"; + } + } + return NULL; +} + + +static const char *varinfo (lua_State *L, const TValue *o) { + const char *name = NULL; /* to avoid warnings */ + CallInfo *ci = L->ci; + const char *kind = NULL; + if (isLua(ci)) { + kind = getupvalname(ci, o, &name); /* check whether 'o' is an upvalue */ + if (!kind && isinstack(ci, o)) /* no? try a register */ + kind = getobjname(ci_func(ci)->p, currentpc(ci), + cast_int(o - ci->u.l.base), &name); + } + return (kind) ? luaO_pushfstring(L, " (%s '%s')", kind, name) : ""; +} + + +l_noret luaG_typeerror (lua_State *L, const TValue *o, const char *op) { + const char *t = objtypename(o); + luaG_runerror(L, "attempt to %s a %s value%s", op, t, varinfo(L, o)); +} + + +l_noret luaG_concaterror (lua_State *L, const TValue *p1, const TValue *p2) { + if (ttisstring(p1) || cvt2str(p1)) p1 = p2; + luaG_typeerror(L, p1, "concatenate"); +} + + +l_noret luaG_opinterror (lua_State *L, const TValue *p1, + const TValue *p2, const char *msg) { + lua_Number temp; + if (!tonumber(p1, &temp)) /* first operand is wrong? */ + p2 = p1; /* now second is wrong */ + luaG_typeerror(L, p2, msg); +} + + +/* +** Error when both values are convertible to numbers, but not to integers +*/ +l_noret luaG_tointerror (lua_State *L, const TValue *p1, const TValue *p2) { + lua_Integer temp; + if (!tointeger(p1, &temp)) + p2 = p1; + luaG_runerror(L, "number%s has no integer representation", varinfo(L, p2)); +} + + +l_noret luaG_ordererror (lua_State *L, const TValue *p1, const TValue *p2) { + const char *t1 = objtypename(p1); + const char *t2 = objtypename(p2); + if (t1 == t2) + luaG_runerror(L, "attempt to compare two %s values", t1); + else + luaG_runerror(L, "attempt to compare %s with %s", t1, t2); +} + + +static void addinfo (lua_State *L, const char *msg) { + CallInfo *ci = L->ci; + if (isLua(ci)) { /* is Lua code? */ + char buff[LUA_IDSIZE]; /* add file:line information */ + int line = currentline(ci); + TString *src = ci_func(ci)->p->source; + if (src) + luaO_chunkid(buff, getstr(src), LUA_IDSIZE); + else { /* no source available; use "?" instead */ + buff[0] = '?'; buff[1] = '\0'; + } + luaO_pushfstring(L, "%s:%d: %s", buff, line, msg); + } +} + + +l_noret luaG_errormsg (lua_State *L) { + if (L->errfunc != 0) { /* is there an error handling function? */ + StkId errfunc = restorestack(L, L->errfunc); + setobjs2s(L, L->top, L->top - 1); /* move argument */ + setobjs2s(L, L->top - 1, errfunc); /* push function */ + L->top++; /* assume EXTRA_STACK */ + luaD_call(L, L->top - 2, 1, 0); /* call it */ + } + luaD_throw(L, LUA_ERRRUN); +} + + +l_noret luaG_runerror (lua_State *L, const char *fmt, ...) { + va_list argp; + va_start(argp, fmt); + addinfo(L, luaO_pushvfstring(L, fmt, argp)); + va_end(argp); + luaG_errormsg(L); +} + + +void luaG_traceexec (lua_State *L) { + CallInfo *ci = L->ci; + lu_byte mask = L->hookmask; + int counthook = ((mask & LUA_MASKCOUNT) && L->hookcount == 0); + if (counthook) + resethookcount(L); /* reset count */ + if (ci->callstatus & CIST_HOOKYIELD) { /* called hook last time? */ + ci->callstatus &= ~CIST_HOOKYIELD; /* erase mark */ + return; /* do not call hook again (VM yielded, so it did not move) */ + } + if (counthook) + luaD_hook(L, LUA_HOOKCOUNT, -1); /* call count hook */ + if (mask & LUA_MASKLINE) { + Proto *p = ci_func(ci)->p; + int npc = pcRel(ci->u.l.savedpc, p); + int newline = getfuncline(p, npc); + if (npc == 0 || /* call linehook when enter a new function, */ + ci->u.l.savedpc <= L->oldpc || /* when jump back (loop), or when */ + newline != getfuncline(p, pcRel(L->oldpc, p))) /* enter a new line */ + luaD_hook(L, LUA_HOOKLINE, newline); /* call line hook */ + } + L->oldpc = ci->u.l.savedpc; + if (L->status == LUA_YIELD) { /* did hook yield? */ + if (counthook) + L->hookcount = 1; /* undo decrement to zero */ + ci->u.l.savedpc--; /* undo increment (resume will increment it again) */ + ci->callstatus |= CIST_HOOKYIELD; /* mark that it yielded */ + ci->func = L->top - 1; /* protect stack below results */ + luaD_throw(L, LUA_YIELD); + } +} + diff --git a/src/ldebug.h b/src/ldebug.h new file mode 100644 index 000000000000..0d8966ca9a61 --- /dev/null +++ b/src/ldebug.h @@ -0,0 +1,40 @@ +/* +** $Id: ldebug.h,v 2.12 2014/11/10 14:46:05 roberto Exp $ +** Auxiliary functions from Debug Interface module +** See Copyright Notice in lua.h +*/ + +#ifndef ldebug_h +#define ldebug_h + + +#include "lstate.h" + + +#define pcRel(pc, p) (cast(int, (pc) - (p)->code) - 1) + +#define getfuncline(f,pc) (((f)->lineinfo) ? (f)->lineinfo[pc] : -1) + +#define resethookcount(L) (L->hookcount = L->basehookcount) + +/* Active Lua function (given call info) */ +#define ci_func(ci) (clLvalue((ci)->func)) + + +LUAI_FUNC l_noret luaG_typeerror (lua_State *L, const TValue *o, + const char *opname); +LUAI_FUNC l_noret luaG_concaterror (lua_State *L, const TValue *p1, + const TValue *p2); +LUAI_FUNC l_noret luaG_opinterror (lua_State *L, const TValue *p1, + const TValue *p2, + const char *msg); +LUAI_FUNC l_noret luaG_tointerror (lua_State *L, const TValue *p1, + const TValue *p2); +LUAI_FUNC l_noret luaG_ordererror (lua_State *L, const TValue *p1, + const TValue *p2); +LUAI_FUNC l_noret luaG_runerror (lua_State *L, const char *fmt, ...); +LUAI_FUNC l_noret luaG_errormsg (lua_State *L); +LUAI_FUNC void luaG_traceexec (lua_State *L); + + +#endif diff --git a/src/ldo.c b/src/ldo.c new file mode 100644 index 000000000000..6159e51da2d4 --- /dev/null +++ b/src/ldo.c @@ -0,0 +1,717 @@ +/* +** $Id: ldo.c,v 2.135 2014/11/11 17:13:39 roberto Exp $ +** Stack and Call structure of Lua +** See Copyright Notice in lua.h +*/ + +#define ldo_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <setjmp.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lapi.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lundump.h" +#include "lvm.h" +#include "lzio.h" + + + +#define errorstatus(s) ((s) > LUA_YIELD) + + +/* +** {====================================================== +** Error-recovery functions +** ======================================================= +*/ + +/* +** LUAI_THROW/LUAI_TRY define how Lua does exception handling. By +** default, Lua handles errors with exceptions when compiling as +** C++ code, with _longjmp/_setjmp when asked to use them, and with +** longjmp/setjmp otherwise. +*/ +#if !defined(LUAI_THROW) /* { */ + +#if defined(__cplusplus) && !defined(LUA_USE_LONGJMP) /* { */ + +/* C++ exceptions */ +#define LUAI_THROW(L,c) throw(c) +#define LUAI_TRY(L,c,a) \ + try { a } catch(...) { if ((c)->status == 0) (c)->status = -1; } +#define luai_jmpbuf int /* dummy variable */ + +#elif defined(LUA_USE_POSIX) /* }{ */ + +/* in POSIX, try _longjmp/_setjmp (more efficient) */ +#define LUAI_THROW(L,c) _longjmp((c)->b, 1) +#define LUAI_TRY(L,c,a) if (_setjmp((c)->b) == 0) { a } +#define luai_jmpbuf jmp_buf + +#else /* }{ */ + +/* ISO C handling with long jumps */ +#define LUAI_THROW(L,c) longjmp((c)->b, 1) +#define LUAI_TRY(L,c,a) if (setjmp((c)->b) == 0) { a } +#define luai_jmpbuf jmp_buf + +#endif /* } */ + +#endif /* } */ + + + +/* chain list of long jump buffers */ +struct lua_longjmp { + struct lua_longjmp *previous; + luai_jmpbuf b; + volatile int status; /* error code */ +}; + + +static void seterrorobj (lua_State *L, int errcode, StkId oldtop) { + switch (errcode) { + case LUA_ERRMEM: { /* memory error? */ + setsvalue2s(L, oldtop, G(L)->memerrmsg); /* reuse preregistered msg. */ + break; + } + case LUA_ERRERR: { + setsvalue2s(L, oldtop, luaS_newliteral(L, "error in error handling")); + break; + } + default: { + setobjs2s(L, oldtop, L->top - 1); /* error message on current top */ + break; + } + } + L->top = oldtop + 1; +} + + +l_noret luaD_throw (lua_State *L, int errcode) { + if (L->errorJmp) { /* thread has an error handler? */ + L->errorJmp->status = errcode; /* set status */ + LUAI_THROW(L, L->errorJmp); /* jump to it */ + } + else { /* thread has no error handler */ + global_State *g = G(L); + L->status = cast_byte(errcode); /* mark it as dead */ + if (g->mainthread->errorJmp) { /* main thread has a handler? */ + setobjs2s(L, g->mainthread->top++, L->top - 1); /* copy error obj. */ + luaD_throw(g->mainthread, errcode); /* re-throw in main thread */ + } + else { /* no handler at all; abort */ + if (g->panic) { /* panic function? */ + seterrorobj(L, errcode, L->top); /* assume EXTRA_STACK */ + if (L->ci->top < L->top) + L->ci->top = L->top; /* pushing msg. can break this invariant */ + lua_unlock(L); + g->panic(L); /* call panic function (last chance to jump out) */ + } + abort(); + } + } +} + + +int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud) { + unsigned short oldnCcalls = L->nCcalls; + struct lua_longjmp lj; + lj.status = LUA_OK; + lj.previous = L->errorJmp; /* chain new error handler */ + L->errorJmp = &lj; + LUAI_TRY(L, &lj, + (*f)(L, ud); + ); + L->errorJmp = lj.previous; /* restore old error handler */ + L->nCcalls = oldnCcalls; + return lj.status; +} + +/* }====================================================== */ + + +static void correctstack (lua_State *L, TValue *oldstack) { + CallInfo *ci; + UpVal *up; + L->top = (L->top - oldstack) + L->stack; + for (up = L->openupval; up != NULL; up = up->u.open.next) + up->v = (up->v - oldstack) + L->stack; + for (ci = L->ci; ci != NULL; ci = ci->previous) { + ci->top = (ci->top - oldstack) + L->stack; + ci->func = (ci->func - oldstack) + L->stack; + if (isLua(ci)) + ci->u.l.base = (ci->u.l.base - oldstack) + L->stack; + } +} + + +/* some space for error handling */ +#define ERRORSTACKSIZE (LUAI_MAXSTACK + 200) + + +void luaD_reallocstack (lua_State *L, int newsize) { + TValue *oldstack = L->stack; + int lim = L->stacksize; + lua_assert(newsize <= LUAI_MAXSTACK || newsize == ERRORSTACKSIZE); + lua_assert(L->stack_last - L->stack == L->stacksize - EXTRA_STACK); + luaM_reallocvector(L, L->stack, L->stacksize, newsize, TValue); + for (; lim < newsize; lim++) + setnilvalue(L->stack + lim); /* erase new segment */ + L->stacksize = newsize; + L->stack_last = L->stack + newsize - EXTRA_STACK; + correctstack(L, oldstack); +} + + +void luaD_growstack (lua_State *L, int n) { + int size = L->stacksize; + if (size > LUAI_MAXSTACK) /* error after extra size? */ + luaD_throw(L, LUA_ERRERR); + else { + int needed = cast_int(L->top - L->stack) + n + EXTRA_STACK; + int newsize = 2 * size; + if (newsize > LUAI_MAXSTACK) newsize = LUAI_MAXSTACK; + if (newsize < needed) newsize = needed; + if (newsize > LUAI_MAXSTACK) { /* stack overflow? */ + luaD_reallocstack(L, ERRORSTACKSIZE); + luaG_runerror(L, "stack overflow"); + } + else + luaD_reallocstack(L, newsize); + } +} + + +static int stackinuse (lua_State *L) { + CallInfo *ci; + StkId lim = L->top; + for (ci = L->ci; ci != NULL; ci = ci->previous) { + lua_assert(ci->top <= L->stack_last); + if (lim < ci->top) lim = ci->top; + } + return cast_int(lim - L->stack) + 1; /* part of stack in use */ +} + + +void luaD_shrinkstack (lua_State *L) { + int inuse = stackinuse(L); + int goodsize = inuse + (inuse / 8) + 2*EXTRA_STACK; + if (goodsize > LUAI_MAXSTACK) goodsize = LUAI_MAXSTACK; + if (L->stacksize > LUAI_MAXSTACK) /* was handling stack overflow? */ + luaE_freeCI(L); /* free all CIs (list grew because of an error) */ + else + luaE_shrinkCI(L); /* shrink list */ + if (inuse > LUAI_MAXSTACK || /* still handling stack overflow? */ + goodsize >= L->stacksize) /* would grow instead of shrink? */ + condmovestack(L); /* don't change stack (change only for debugging) */ + else + luaD_reallocstack(L, goodsize); /* shrink it */ +} + + +void luaD_hook (lua_State *L, int event, int line) { + lua_Hook hook = L->hook; + if (hook && L->allowhook) { + CallInfo *ci = L->ci; + ptrdiff_t top = savestack(L, L->top); + ptrdiff_t ci_top = savestack(L, ci->top); + lua_Debug ar; + ar.event = event; + ar.currentline = line; + ar.i_ci = ci; + luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ + ci->top = L->top + LUA_MINSTACK; + lua_assert(ci->top <= L->stack_last); + L->allowhook = 0; /* cannot call hooks inside a hook */ + ci->callstatus |= CIST_HOOKED; + lua_unlock(L); + (*hook)(L, &ar); + lua_lock(L); + lua_assert(!L->allowhook); + L->allowhook = 1; + ci->top = restorestack(L, ci_top); + L->top = restorestack(L, top); + ci->callstatus &= ~CIST_HOOKED; + } +} + + +static void callhook (lua_State *L, CallInfo *ci) { + int hook = LUA_HOOKCALL; + ci->u.l.savedpc++; /* hooks assume 'pc' is already incremented */ + if (isLua(ci->previous) && + GET_OPCODE(*(ci->previous->u.l.savedpc - 1)) == OP_TAILCALL) { + ci->callstatus |= CIST_TAIL; + hook = LUA_HOOKTAILCALL; + } + luaD_hook(L, hook, -1); + ci->u.l.savedpc--; /* correct 'pc' */ +} + + +static StkId adjust_varargs (lua_State *L, Proto *p, int actual) { + int i; + int nfixargs = p->numparams; + StkId base, fixed; + lua_assert(actual >= nfixargs); + /* move fixed parameters to final position */ + luaD_checkstack(L, p->maxstacksize); /* check again for new 'base' */ + fixed = L->top - actual; /* first fixed argument */ + base = L->top; /* final position of first argument */ + for (i=0; i<nfixargs; i++) { + setobjs2s(L, L->top++, fixed + i); + setnilvalue(fixed + i); + } + return base; +} + + +/* +** Check whether __call metafield of 'func' is a function. If so, put +** it in stack below original 'func' so that 'luaD_precall' can call +** it. Raise an error if __call metafield is not a function. +*/ +static void tryfuncTM (lua_State *L, StkId func) { + const TValue *tm = luaT_gettmbyobj(L, func, TM_CALL); + StkId p; + if (!ttisfunction(tm)) + luaG_typeerror(L, func, "call"); + /* Open a hole inside the stack at 'func' */ + for (p = L->top; p > func; p--) + setobjs2s(L, p, p-1); + L->top++; /* slot ensured by caller */ + setobj2s(L, func, tm); /* tag method is the new function to be called */ +} + + + +#define next_ci(L) (L->ci = (L->ci->next ? L->ci->next : luaE_extendCI(L))) + + +/* +** returns true if function has been executed (C function) +*/ +int luaD_precall (lua_State *L, StkId func, int nresults) { + lua_CFunction f; + CallInfo *ci; + int n; /* number of arguments (Lua) or returns (C) */ + ptrdiff_t funcr = savestack(L, func); + switch (ttype(func)) { + case LUA_TLCF: /* light C function */ + f = fvalue(func); + goto Cfunc; + case LUA_TCCL: { /* C closure */ + f = clCvalue(func)->f; + Cfunc: + luaD_checkstack(L, LUA_MINSTACK); /* ensure minimum stack size */ + ci = next_ci(L); /* now 'enter' new function */ + ci->nresults = nresults; + ci->func = restorestack(L, funcr); + ci->top = L->top + LUA_MINSTACK; + lua_assert(ci->top <= L->stack_last); + ci->callstatus = 0; + luaC_checkGC(L); /* stack grow uses memory */ + if (L->hookmask & LUA_MASKCALL) + luaD_hook(L, LUA_HOOKCALL, -1); + lua_unlock(L); + n = (*f)(L); /* do the actual call */ + lua_lock(L); + api_checknelems(L, n); + luaD_poscall(L, L->top - n); + return 1; + } + case LUA_TLCL: { /* Lua function: prepare its call */ + StkId base; + Proto *p = clLvalue(func)->p; + n = cast_int(L->top - func) - 1; /* number of real arguments */ + luaD_checkstack(L, p->maxstacksize); + for (; n < p->numparams; n++) + setnilvalue(L->top++); /* complete missing arguments */ + if (!p->is_vararg) { + func = restorestack(L, funcr); + base = func + 1; + } + else { + base = adjust_varargs(L, p, n); + func = restorestack(L, funcr); /* previous call can change stack */ + } + ci = next_ci(L); /* now 'enter' new function */ + ci->nresults = nresults; + ci->func = func; + ci->u.l.base = base; + ci->top = base + p->maxstacksize; + lua_assert(ci->top <= L->stack_last); + ci->u.l.savedpc = p->code; /* starting point */ + ci->callstatus = CIST_LUA; + L->top = ci->top; + luaC_checkGC(L); /* stack grow uses memory */ + if (L->hookmask & LUA_MASKCALL) + callhook(L, ci); + return 0; + } + default: { /* not a function */ + luaD_checkstack(L, 1); /* ensure space for metamethod */ + func = restorestack(L, funcr); /* previous call may change stack */ + tryfuncTM(L, func); /* try to get '__call' metamethod */ + return luaD_precall(L, func, nresults); /* now it must be a function */ + } + } +} + + +int luaD_poscall (lua_State *L, StkId firstResult) { + StkId res; + int wanted, i; + CallInfo *ci = L->ci; + if (L->hookmask & (LUA_MASKRET | LUA_MASKLINE)) { + if (L->hookmask & LUA_MASKRET) { + ptrdiff_t fr = savestack(L, firstResult); /* hook may change stack */ + luaD_hook(L, LUA_HOOKRET, -1); + firstResult = restorestack(L, fr); + } + L->oldpc = ci->previous->u.l.savedpc; /* 'oldpc' for caller function */ + } + res = ci->func; /* res == final position of 1st result */ + wanted = ci->nresults; + L->ci = ci = ci->previous; /* back to caller */ + /* move results to correct place */ + for (i = wanted; i != 0 && firstResult < L->top; i--) + setobjs2s(L, res++, firstResult++); + while (i-- > 0) + setnilvalue(res++); + L->top = res; + return (wanted - LUA_MULTRET); /* 0 iff wanted == LUA_MULTRET */ +} + + +/* +** Call a function (C or Lua). The function to be called is at *func. +** The arguments are on the stack, right after the function. +** When returns, all the results are on the stack, starting at the original +** function position. +*/ +void luaD_call (lua_State *L, StkId func, int nResults, int allowyield) { + if (++L->nCcalls >= LUAI_MAXCCALLS) { + if (L->nCcalls == LUAI_MAXCCALLS) + luaG_runerror(L, "C stack overflow"); + else if (L->nCcalls >= (LUAI_MAXCCALLS + (LUAI_MAXCCALLS>>3))) + luaD_throw(L, LUA_ERRERR); /* error while handing stack error */ + } + if (!allowyield) L->nny++; + if (!luaD_precall(L, func, nResults)) /* is a Lua function? */ + luaV_execute(L); /* call it */ + if (!allowyield) L->nny--; + L->nCcalls--; +} + + +/* +** Completes the execution of an interrupted C function, calling its +** continuation function. +*/ +static void finishCcall (lua_State *L, int status) { + CallInfo *ci = L->ci; + int n; + /* must have a continuation and must be able to call it */ + lua_assert(ci->u.c.k != NULL && L->nny == 0); + /* error status can only happen in a protected call */ + lua_assert((ci->callstatus & CIST_YPCALL) || status == LUA_YIELD); + if (ci->callstatus & CIST_YPCALL) { /* was inside a pcall? */ + ci->callstatus &= ~CIST_YPCALL; /* finish 'lua_pcall' */ + L->errfunc = ci->u.c.old_errfunc; + } + /* finish 'lua_callk'/'lua_pcall'; CIST_YPCALL and 'errfunc' already + handled */ + adjustresults(L, ci->nresults); + /* call continuation function */ + lua_unlock(L); + n = (*ci->u.c.k)(L, status, ci->u.c.ctx); + lua_lock(L); + api_checknelems(L, n); + /* finish 'luaD_precall' */ + luaD_poscall(L, L->top - n); +} + + +/* +** Executes "full continuation" (everything in the stack) of a +** previously interrupted coroutine until the stack is empty (or another +** interruption long-jumps out of the loop). If the coroutine is +** recovering from an error, 'ud' points to the error status, which must +** be passed to the first continuation function (otherwise the default +** status is LUA_YIELD). +*/ +static void unroll (lua_State *L, void *ud) { + if (ud != NULL) /* error status? */ + finishCcall(L, *(int *)ud); /* finish 'lua_pcallk' callee */ + while (L->ci != &L->base_ci) { /* something in the stack */ + if (!isLua(L->ci)) /* C function? */ + finishCcall(L, LUA_YIELD); /* complete its execution */ + else { /* Lua function */ + luaV_finishOp(L); /* finish interrupted instruction */ + luaV_execute(L); /* execute down to higher C 'boundary' */ + } + } +} + + +/* +** Try to find a suspended protected call (a "recover point") for the +** given thread. +*/ +static CallInfo *findpcall (lua_State *L) { + CallInfo *ci; + for (ci = L->ci; ci != NULL; ci = ci->previous) { /* search for a pcall */ + if (ci->callstatus & CIST_YPCALL) + return ci; + } + return NULL; /* no pending pcall */ +} + + +/* +** Recovers from an error in a coroutine. Finds a recover point (if +** there is one) and completes the execution of the interrupted +** 'luaD_pcall'. If there is no recover point, returns zero. +*/ +static int recover (lua_State *L, int status) { + StkId oldtop; + CallInfo *ci = findpcall(L); + if (ci == NULL) return 0; /* no recovery point */ + /* "finish" luaD_pcall */ + oldtop = restorestack(L, ci->extra); + luaF_close(L, oldtop); + seterrorobj(L, status, oldtop); + L->ci = ci; + L->allowhook = getoah(ci->callstatus); /* restore original 'allowhook' */ + L->nny = 0; /* should be zero to be yieldable */ + luaD_shrinkstack(L); + L->errfunc = ci->u.c.old_errfunc; + return 1; /* continue running the coroutine */ +} + + +/* +** signal an error in the call to 'resume', not in the execution of the +** coroutine itself. (Such errors should not be handled by any coroutine +** error handler and should not kill the coroutine.) +*/ +static l_noret resume_error (lua_State *L, const char *msg, StkId firstArg) { + L->top = firstArg; /* remove args from the stack */ + setsvalue2s(L, L->top, luaS_new(L, msg)); /* push error message */ + api_incr_top(L); + luaD_throw(L, -1); /* jump back to 'lua_resume' */ +} + + +/* +** Do the work for 'lua_resume' in protected mode. Most of the work +** depends on the status of the coroutine: initial state, suspended +** inside a hook, or regularly suspended (optionally with a continuation +** function), plus erroneous cases: non-suspended coroutine or dead +** coroutine. +*/ +static void resume (lua_State *L, void *ud) { + int nCcalls = L->nCcalls; + StkId firstArg = cast(StkId, ud); + CallInfo *ci = L->ci; + if (nCcalls >= LUAI_MAXCCALLS) + resume_error(L, "C stack overflow", firstArg); + if (L->status == LUA_OK) { /* may be starting a coroutine */ + if (ci != &L->base_ci) /* not in base level? */ + resume_error(L, "cannot resume non-suspended coroutine", firstArg); + /* coroutine is in base level; start running it */ + if (!luaD_precall(L, firstArg - 1, LUA_MULTRET)) /* Lua function? */ + luaV_execute(L); /* call it */ + } + else if (L->status != LUA_YIELD) + resume_error(L, "cannot resume dead coroutine", firstArg); + else { /* resuming from previous yield */ + L->status = LUA_OK; /* mark that it is running (again) */ + ci->func = restorestack(L, ci->extra); + if (isLua(ci)) /* yielded inside a hook? */ + luaV_execute(L); /* just continue running Lua code */ + else { /* 'common' yield */ + if (ci->u.c.k != NULL) { /* does it have a continuation function? */ + int n; + lua_unlock(L); + n = (*ci->u.c.k)(L, LUA_YIELD, ci->u.c.ctx); /* call continuation */ + lua_lock(L); + api_checknelems(L, n); + firstArg = L->top - n; /* yield results come from continuation */ + } + luaD_poscall(L, firstArg); /* finish 'luaD_precall' */ + } + unroll(L, NULL); /* run continuation */ + } + lua_assert(nCcalls == L->nCcalls); +} + + +LUA_API int lua_resume (lua_State *L, lua_State *from, int nargs) { + int status; + int oldnny = L->nny; /* save "number of non-yieldable" calls */ + lua_lock(L); + luai_userstateresume(L, nargs); + L->nCcalls = (from) ? from->nCcalls + 1 : 1; + L->nny = 0; /* allow yields */ + api_checknelems(L, (L->status == LUA_OK) ? nargs + 1 : nargs); + status = luaD_rawrunprotected(L, resume, L->top - nargs); + if (status == -1) /* error calling 'lua_resume'? */ + status = LUA_ERRRUN; + else { /* continue running after recoverable errors */ + while (errorstatus(status) && recover(L, status)) { + /* unroll continuation */ + status = luaD_rawrunprotected(L, unroll, &status); + } + if (errorstatus(status)) { /* unrecoverable error? */ + L->status = cast_byte(status); /* mark thread as 'dead' */ + seterrorobj(L, status, L->top); /* push error message */ + L->ci->top = L->top; + } + else lua_assert(status == L->status); /* normal end or yield */ + } + L->nny = oldnny; /* restore 'nny' */ + L->nCcalls--; + lua_assert(L->nCcalls == ((from) ? from->nCcalls : 0)); + lua_unlock(L); + return status; +} + + +LUA_API int lua_isyieldable (lua_State *L) { + return (L->nny == 0); +} + + +LUA_API int lua_yieldk (lua_State *L, int nresults, lua_KContext ctx, + lua_KFunction k) { + CallInfo *ci = L->ci; + luai_userstateyield(L, nresults); + lua_lock(L); + api_checknelems(L, nresults); + if (L->nny > 0) { + if (L != G(L)->mainthread) + luaG_runerror(L, "attempt to yield across a C-call boundary"); + else + luaG_runerror(L, "attempt to yield from outside a coroutine"); + } + L->status = LUA_YIELD; + ci->extra = savestack(L, ci->func); /* save current 'func' */ + if (isLua(ci)) { /* inside a hook? */ + api_check(k == NULL, "hooks cannot continue after yielding"); + } + else { + if ((ci->u.c.k = k) != NULL) /* is there a continuation? */ + ci->u.c.ctx = ctx; /* save context */ + ci->func = L->top - nresults - 1; /* protect stack below results */ + luaD_throw(L, LUA_YIELD); + } + lua_assert(ci->callstatus & CIST_HOOKED); /* must be inside a hook */ + lua_unlock(L); + return 0; /* return to 'luaD_hook' */ +} + + +int luaD_pcall (lua_State *L, Pfunc func, void *u, + ptrdiff_t old_top, ptrdiff_t ef) { + int status; + CallInfo *old_ci = L->ci; + lu_byte old_allowhooks = L->allowhook; + unsigned short old_nny = L->nny; + ptrdiff_t old_errfunc = L->errfunc; + L->errfunc = ef; + status = luaD_rawrunprotected(L, func, u); + if (status != LUA_OK) { /* an error occurred? */ + StkId oldtop = restorestack(L, old_top); + luaF_close(L, oldtop); /* close possible pending closures */ + seterrorobj(L, status, oldtop); + L->ci = old_ci; + L->allowhook = old_allowhooks; + L->nny = old_nny; + luaD_shrinkstack(L); + } + L->errfunc = old_errfunc; + return status; +} + + + +/* +** Execute a protected parser. +*/ +struct SParser { /* data to 'f_parser' */ + ZIO *z; + Mbuffer buff; /* dynamic structure used by the scanner */ + Dyndata dyd; /* dynamic structures used by the parser */ + const char *mode; + const char *name; +}; + + +static void checkmode (lua_State *L, const char *mode, const char *x) { + if (mode && strchr(mode, x[0]) == NULL) { + luaO_pushfstring(L, + "attempt to load a %s chunk (mode is '%s')", x, mode); + luaD_throw(L, LUA_ERRSYNTAX); + } +} + + +static void f_parser (lua_State *L, void *ud) { + LClosure *cl; + struct SParser *p = cast(struct SParser *, ud); + int c = zgetc(p->z); /* read first character */ + if (c == LUA_SIGNATURE[0]) { + checkmode(L, p->mode, "binary"); + cl = luaU_undump(L, p->z, &p->buff, p->name); + } + else { + checkmode(L, p->mode, "text"); + cl = luaY_parser(L, p->z, &p->buff, &p->dyd, p->name, c); + } + lua_assert(cl->nupvalues == cl->p->sizeupvalues); + luaF_initupvals(L, cl); +} + + +int luaD_protectedparser (lua_State *L, ZIO *z, const char *name, + const char *mode) { + struct SParser p; + int status; + L->nny++; /* cannot yield during parsing */ + p.z = z; p.name = name; p.mode = mode; + p.dyd.actvar.arr = NULL; p.dyd.actvar.size = 0; + p.dyd.gt.arr = NULL; p.dyd.gt.size = 0; + p.dyd.label.arr = NULL; p.dyd.label.size = 0; + luaZ_initbuffer(L, &p.buff); + status = luaD_pcall(L, f_parser, &p, savestack(L, L->top), L->errfunc); + luaZ_freebuffer(L, &p.buff); + luaM_freearray(L, p.dyd.actvar.arr, p.dyd.actvar.size); + luaM_freearray(L, p.dyd.gt.arr, p.dyd.gt.size); + luaM_freearray(L, p.dyd.label.arr, p.dyd.label.size); + L->nny--; + return status; +} + + diff --git a/src/ldo.h b/src/ldo.h new file mode 100644 index 000000000000..05745c8ad8d5 --- /dev/null +++ b/src/ldo.h @@ -0,0 +1,46 @@ +/* +** $Id: ldo.h,v 2.21 2014/10/25 11:50:46 roberto Exp $ +** Stack and Call structure of Lua +** See Copyright Notice in lua.h +*/ + +#ifndef ldo_h +#define ldo_h + + +#include "lobject.h" +#include "lstate.h" +#include "lzio.h" + + +#define luaD_checkstack(L,n) if (L->stack_last - L->top <= (n)) \ + luaD_growstack(L, n); else condmovestack(L); + + +#define incr_top(L) {L->top++; luaD_checkstack(L,0);} + +#define savestack(L,p) ((char *)(p) - (char *)L->stack) +#define restorestack(L,n) ((TValue *)((char *)L->stack + (n))) + + +/* type of protected functions, to be ran by 'runprotected' */ +typedef void (*Pfunc) (lua_State *L, void *ud); + +LUAI_FUNC int luaD_protectedparser (lua_State *L, ZIO *z, const char *name, + const char *mode); +LUAI_FUNC void luaD_hook (lua_State *L, int event, int line); +LUAI_FUNC int luaD_precall (lua_State *L, StkId func, int nresults); +LUAI_FUNC void luaD_call (lua_State *L, StkId func, int nResults, + int allowyield); +LUAI_FUNC int luaD_pcall (lua_State *L, Pfunc func, void *u, + ptrdiff_t oldtop, ptrdiff_t ef); +LUAI_FUNC int luaD_poscall (lua_State *L, StkId firstResult); +LUAI_FUNC void luaD_reallocstack (lua_State *L, int newsize); +LUAI_FUNC void luaD_growstack (lua_State *L, int n); +LUAI_FUNC void luaD_shrinkstack (lua_State *L); + +LUAI_FUNC l_noret luaD_throw (lua_State *L, int errcode); +LUAI_FUNC int luaD_rawrunprotected (lua_State *L, Pfunc f, void *ud); + +#endif + diff --git a/src/ldump.c b/src/ldump.c new file mode 100644 index 000000000000..b6c7114f5d9f --- /dev/null +++ b/src/ldump.c @@ -0,0 +1,214 @@ +/* +** $Id: ldump.c,v 2.34 2014/11/02 19:19:04 roberto Exp $ +** save precompiled Lua chunks +** See Copyright Notice in lua.h +*/ + +#define ldump_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stddef.h> + +#include "lua.h" + +#include "lobject.h" +#include "lstate.h" +#include "lundump.h" + + +typedef struct { + lua_State *L; + lua_Writer writer; + void *data; + int strip; + int status; +} DumpState; + + +/* +** All high-level dumps go through DumpVector; you can change it to +** change the endianness of the result +*/ +#define DumpVector(v,n,D) DumpBlock(v,(n)*sizeof((v)[0]),D) + +#define DumpLiteral(s,D) DumpBlock(s, sizeof(s) - sizeof(char), D) + + +static void DumpBlock (const void *b, size_t size, DumpState *D) { + if (D->status == 0) { + lua_unlock(D->L); + D->status = (*D->writer)(D->L, b, size, D->data); + lua_lock(D->L); + } +} + + +#define DumpVar(x,D) DumpVector(&x,1,D) + + +static void DumpByte (int y, DumpState *D) { + lu_byte x = (lu_byte)y; + DumpVar(x, D); +} + + +static void DumpInt (int x, DumpState *D) { + DumpVar(x, D); +} + + +static void DumpNumber (lua_Number x, DumpState *D) { + DumpVar(x, D); +} + + +static void DumpInteger (lua_Integer x, DumpState *D) { + DumpVar(x, D); +} + + +static void DumpString (const TString *s, DumpState *D) { + if (s == NULL) + DumpByte(0, D); + else { + size_t size = s->len + 1; /* include trailing '\0' */ + if (size < 0xFF) + DumpByte(cast_int(size), D); + else { + DumpByte(0xFF, D); + DumpVar(size, D); + } + DumpVector(getstr(s), size - 1, D); /* no need to save '\0' */ + } +} + + +static void DumpCode (const Proto *f, DumpState *D) { + DumpInt(f->sizecode, D); + DumpVector(f->code, f->sizecode, D); +} + + +static void DumpFunction(const Proto *f, TString *psource, DumpState *D); + +static void DumpConstants (const Proto *f, DumpState *D) { + int i; + int n = f->sizek; + DumpInt(n, D); + for (i = 0; i < n; i++) { + const TValue *o = &f->k[i]; + DumpByte(ttype(o), D); + switch (ttype(o)) { + case LUA_TNIL: + break; + case LUA_TBOOLEAN: + DumpByte(bvalue(o), D); + break; + case LUA_TNUMFLT: + DumpNumber(fltvalue(o), D); + break; + case LUA_TNUMINT: + DumpInteger(ivalue(o), D); + break; + case LUA_TSHRSTR: + case LUA_TLNGSTR: + DumpString(tsvalue(o), D); + break; + default: + lua_assert(0); + } + } +} + + +static void DumpProtos (const Proto *f, DumpState *D) { + int i; + int n = f->sizep; + DumpInt(n, D); + for (i = 0; i < n; i++) + DumpFunction(f->p[i], f->source, D); +} + + +static void DumpUpvalues (const Proto *f, DumpState *D) { + int i, n = f->sizeupvalues; + DumpInt(n, D); + for (i = 0; i < n; i++) { + DumpByte(f->upvalues[i].instack, D); + DumpByte(f->upvalues[i].idx, D); + } +} + + +static void DumpDebug (const Proto *f, DumpState *D) { + int i, n; + n = (D->strip) ? 0 : f->sizelineinfo; + DumpInt(n, D); + DumpVector(f->lineinfo, n, D); + n = (D->strip) ? 0 : f->sizelocvars; + DumpInt(n, D); + for (i = 0; i < n; i++) { + DumpString(f->locvars[i].varname, D); + DumpInt(f->locvars[i].startpc, D); + DumpInt(f->locvars[i].endpc, D); + } + n = (D->strip) ? 0 : f->sizeupvalues; + DumpInt(n, D); + for (i = 0; i < n; i++) + DumpString(f->upvalues[i].name, D); +} + + +static void DumpFunction (const Proto *f, TString *psource, DumpState *D) { + if (D->strip || f->source == psource) + DumpString(NULL, D); /* no debug info or same source as its parent */ + else + DumpString(f->source, D); + DumpInt(f->linedefined, D); + DumpInt(f->lastlinedefined, D); + DumpByte(f->numparams, D); + DumpByte(f->is_vararg, D); + DumpByte(f->maxstacksize, D); + DumpCode(f, D); + DumpConstants(f, D); + DumpUpvalues(f, D); + DumpProtos(f, D); + DumpDebug(f, D); +} + + +static void DumpHeader (DumpState *D) { + DumpLiteral(LUA_SIGNATURE, D); + DumpByte(LUAC_VERSION, D); + DumpByte(LUAC_FORMAT, D); + DumpLiteral(LUAC_DATA, D); + DumpByte(sizeof(int), D); + DumpByte(sizeof(size_t), D); + DumpByte(sizeof(Instruction), D); + DumpByte(sizeof(lua_Integer), D); + DumpByte(sizeof(lua_Number), D); + DumpInteger(LUAC_INT, D); + DumpNumber(LUAC_NUM, D); +} + + +/* +** dump Lua function as precompiled chunk +*/ +int luaU_dump(lua_State *L, const Proto *f, lua_Writer w, void *data, + int strip) { + DumpState D; + D.L = L; + D.writer = w; + D.data = data; + D.strip = strip; + D.status = 0; + DumpHeader(&D); + DumpByte(f->sizeupvalues, &D); + DumpFunction(f, NULL, &D); + return D.status; +} + diff --git a/src/lfunc.c b/src/lfunc.c new file mode 100644 index 000000000000..67967dab3fc8 --- /dev/null +++ b/src/lfunc.c @@ -0,0 +1,151 @@ +/* +** $Id: lfunc.c,v 2.45 2014/11/02 19:19:04 roberto Exp $ +** Auxiliary functions to manipulate prototypes and closures +** See Copyright Notice in lua.h +*/ + +#define lfunc_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stddef.h> + +#include "lua.h" + +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" + + + +CClosure *luaF_newCclosure (lua_State *L, int n) { + GCObject *o = luaC_newobj(L, LUA_TCCL, sizeCclosure(n)); + CClosure *c = gco2ccl(o); + c->nupvalues = cast_byte(n); + return c; +} + + +LClosure *luaF_newLclosure (lua_State *L, int n) { + GCObject *o = luaC_newobj(L, LUA_TLCL, sizeLclosure(n)); + LClosure *c = gco2lcl(o); + c->p = NULL; + c->nupvalues = cast_byte(n); + while (n--) c->upvals[n] = NULL; + return c; +} + +/* +** fill a closure with new closed upvalues +*/ +void luaF_initupvals (lua_State *L, LClosure *cl) { + int i; + for (i = 0; i < cl->nupvalues; i++) { + UpVal *uv = luaM_new(L, UpVal); + uv->refcount = 1; + uv->v = &uv->u.value; /* make it closed */ + setnilvalue(uv->v); + cl->upvals[i] = uv; + } +} + + +UpVal *luaF_findupval (lua_State *L, StkId level) { + UpVal **pp = &L->openupval; + UpVal *p; + UpVal *uv; + lua_assert(isintwups(L) || L->openupval == NULL); + while (*pp != NULL && (p = *pp)->v >= level) { + lua_assert(upisopen(p)); + if (p->v == level) /* found a corresponding upvalue? */ + return p; /* return it */ + pp = &p->u.open.next; + } + /* not found: create a new upvalue */ + uv = luaM_new(L, UpVal); + uv->refcount = 0; + uv->u.open.next = *pp; /* link it to list of open upvalues */ + uv->u.open.touched = 1; + *pp = uv; + uv->v = level; /* current value lives in the stack */ + if (!isintwups(L)) { /* thread not in list of threads with upvalues? */ + L->twups = G(L)->twups; /* link it to the list */ + G(L)->twups = L; + } + return uv; +} + + +void luaF_close (lua_State *L, StkId level) { + UpVal *uv; + while (L->openupval != NULL && (uv = L->openupval)->v >= level) { + lua_assert(upisopen(uv)); + L->openupval = uv->u.open.next; /* remove from 'open' list */ + if (uv->refcount == 0) /* no references? */ + luaM_free(L, uv); /* free upvalue */ + else { + setobj(L, &uv->u.value, uv->v); /* move value to upvalue slot */ + uv->v = &uv->u.value; /* now current value lives here */ + luaC_upvalbarrier(L, uv); + } + } +} + + +Proto *luaF_newproto (lua_State *L) { + GCObject *o = luaC_newobj(L, LUA_TPROTO, sizeof(Proto)); + Proto *f = gco2p(o); + f->k = NULL; + f->sizek = 0; + f->p = NULL; + f->sizep = 0; + f->code = NULL; + f->cache = NULL; + f->sizecode = 0; + f->lineinfo = NULL; + f->sizelineinfo = 0; + f->upvalues = NULL; + f->sizeupvalues = 0; + f->numparams = 0; + f->is_vararg = 0; + f->maxstacksize = 0; + f->locvars = NULL; + f->sizelocvars = 0; + f->linedefined = 0; + f->lastlinedefined = 0; + f->source = NULL; + return f; +} + + +void luaF_freeproto (lua_State *L, Proto *f) { + luaM_freearray(L, f->code, f->sizecode); + luaM_freearray(L, f->p, f->sizep); + luaM_freearray(L, f->k, f->sizek); + luaM_freearray(L, f->lineinfo, f->sizelineinfo); + luaM_freearray(L, f->locvars, f->sizelocvars); + luaM_freearray(L, f->upvalues, f->sizeupvalues); + luaM_free(L, f); +} + + +/* +** Look for n-th local variable at line 'line' in function 'func'. +** Returns NULL if not found. +*/ +const char *luaF_getlocalname (const Proto *f, int local_number, int pc) { + int i; + for (i = 0; i<f->sizelocvars && f->locvars[i].startpc <= pc; i++) { + if (pc < f->locvars[i].endpc) { /* is variable active? */ + local_number--; + if (local_number == 0) + return getstr(f->locvars[i].varname); + } + } + return NULL; /* not found */ +} + diff --git a/src/lfunc.h b/src/lfunc.h new file mode 100644 index 000000000000..256d3cf90bd2 --- /dev/null +++ b/src/lfunc.h @@ -0,0 +1,54 @@ +/* +** $Id: lfunc.h,v 2.14 2014/06/19 18:27:20 roberto Exp $ +** Auxiliary functions to manipulate prototypes and closures +** See Copyright Notice in lua.h +*/ + +#ifndef lfunc_h +#define lfunc_h + + +#include "lobject.h" + + +#define sizeCclosure(n) (cast(int, sizeof(CClosure)) + \ + cast(int, sizeof(TValue)*((n)-1))) + +#define sizeLclosure(n) (cast(int, sizeof(LClosure)) + \ + cast(int, sizeof(TValue *)*((n)-1))) + + +/* test whether thread is in 'twups' list */ +#define isintwups(L) (L->twups != L) + + +/* +** Upvalues for Lua closures +*/ +struct UpVal { + TValue *v; /* points to stack or to its own value */ + lu_mem refcount; /* reference counter */ + union { + struct { /* (when open) */ + UpVal *next; /* linked list */ + int touched; /* mark to avoid cycles with dead threads */ + } open; + TValue value; /* the value (when closed) */ + } u; +}; + +#define upisopen(up) ((up)->v != &(up)->u.value) + + +LUAI_FUNC Proto *luaF_newproto (lua_State *L); +LUAI_FUNC CClosure *luaF_newCclosure (lua_State *L, int nelems); +LUAI_FUNC LClosure *luaF_newLclosure (lua_State *L, int nelems); +LUAI_FUNC void luaF_initupvals (lua_State *L, LClosure *cl); +LUAI_FUNC UpVal *luaF_findupval (lua_State *L, StkId level); +LUAI_FUNC void luaF_close (lua_State *L, StkId level); +LUAI_FUNC void luaF_freeproto (lua_State *L, Proto *f); +LUAI_FUNC const char *luaF_getlocalname (const Proto *func, int local_number, + int pc); + + +#endif diff --git a/src/lgc.c b/src/lgc.c new file mode 100644 index 000000000000..8b95fb67da03 --- /dev/null +++ b/src/lgc.c @@ -0,0 +1,1159 @@ +/* +** $Id: lgc.c,v 2.201 2014/12/20 13:58:15 roberto Exp $ +** Garbage Collector +** See Copyright Notice in lua.h +*/ + +#define lgc_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <string.h> + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" + + +/* +** internal state for collector while inside the atomic phase. The +** collector should never be in this state while running regular code. +*/ +#define GCSinsideatomic (GCSpause + 1) + +/* +** cost of sweeping one element (the size of a small object divided +** by some adjust for the sweep speed) +*/ +#define GCSWEEPCOST ((sizeof(TString) + 4) / 4) + +/* maximum number of elements to sweep in each single step */ +#define GCSWEEPMAX (cast_int((GCSTEPSIZE / GCSWEEPCOST) / 4)) + +/* cost of calling one finalizer */ +#define GCFINALIZECOST GCSWEEPCOST + + +/* +** macro to adjust 'stepmul': 'stepmul' is actually used like +** 'stepmul / STEPMULADJ' (value chosen by tests) +*/ +#define STEPMULADJ 200 + + +/* +** macro to adjust 'pause': 'pause' is actually used like +** 'pause / PAUSEADJ' (value chosen by tests) +*/ +#define PAUSEADJ 100 + + +/* +** 'makewhite' erases all color bits then sets only the current white +** bit +*/ +#define maskcolors (~(bitmask(BLACKBIT) | WHITEBITS)) +#define makewhite(g,x) \ + (x->marked = cast_byte((x->marked & maskcolors) | luaC_white(g))) + +#define white2gray(x) resetbits(x->marked, WHITEBITS) +#define black2gray(x) resetbit(x->marked, BLACKBIT) + + +#define valiswhite(x) (iscollectable(x) && iswhite(gcvalue(x))) + +#define checkdeadkey(n) lua_assert(!ttisdeadkey(gkey(n)) || ttisnil(gval(n))) + + +#define checkconsistency(obj) \ + lua_longassert(!iscollectable(obj) || righttt(obj)) + + +#define markvalue(g,o) { checkconsistency(o); \ + if (valiswhite(o)) reallymarkobject(g,gcvalue(o)); } + +#define markobject(g,t) \ + { if ((t) && iswhite(t)) reallymarkobject(g, obj2gco(t)); } + +static void reallymarkobject (global_State *g, GCObject *o); + + +/* +** {====================================================== +** Generic functions +** ======================================================= +*/ + + +/* +** one after last element in a hash array +*/ +#define gnodelast(h) gnode(h, cast(size_t, sizenode(h))) + + +/* +** link collectable object 'o' into list pointed by 'p' +*/ +#define linkgclist(o,p) ((o)->gclist = (p), (p) = obj2gco(o)) + + +/* +** if key is not marked, mark its entry as dead (therefore removing it +** from the table) +*/ +static void removeentry (Node *n) { + lua_assert(ttisnil(gval(n))); + if (valiswhite(gkey(n))) + setdeadvalue(wgkey(n)); /* unused and unmarked key; remove it */ +} + + +/* +** tells whether a key or value can be cleared from a weak +** table. Non-collectable objects are never removed from weak +** tables. Strings behave as 'values', so are never removed too. for +** other objects: if really collected, cannot keep them; for objects +** being finalized, keep them in keys, but not in values +*/ +static int iscleared (global_State *g, const TValue *o) { + if (!iscollectable(o)) return 0; + else if (ttisstring(o)) { + markobject(g, tsvalue(o)); /* strings are 'values', so are never weak */ + return 0; + } + else return iswhite(gcvalue(o)); +} + + +/* +** barrier that moves collector forward, that is, mark the white object +** being pointed by a black object. (If in sweep phase, clear the black +** object to white [sweep it] to avoid other barrier calls for this +** same object.) +*/ +void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v) { + global_State *g = G(L); + lua_assert(isblack(o) && iswhite(v) && !isdead(g, v) && !isdead(g, o)); + if (keepinvariant(g)) /* must keep invariant? */ + reallymarkobject(g, v); /* restore invariant */ + else { /* sweep phase */ + lua_assert(issweepphase(g)); + makewhite(g, o); /* mark main obj. as white to avoid other barriers */ + } +} + + +/* +** barrier that moves collector backward, that is, mark the black object +** pointing to a white object as gray again. +*/ +void luaC_barrierback_ (lua_State *L, Table *t) { + global_State *g = G(L); + lua_assert(isblack(t) && !isdead(g, t)); + black2gray(t); /* make table gray (again) */ + linkgclist(t, g->grayagain); +} + + +/* +** barrier for assignments to closed upvalues. Because upvalues are +** shared among closures, it is impossible to know the color of all +** closures pointing to it. So, we assume that the object being assigned +** must be marked. +*/ +void luaC_upvalbarrier_ (lua_State *L, UpVal *uv) { + global_State *g = G(L); + GCObject *o = gcvalue(uv->v); + lua_assert(!upisopen(uv)); /* ensured by macro luaC_upvalbarrier */ + if (keepinvariant(g)) + markobject(g, o); +} + + +void luaC_fix (lua_State *L, GCObject *o) { + global_State *g = G(L); + lua_assert(g->allgc == o); /* object must be 1st in 'allgc' list! */ + white2gray(o); /* they will be gray forever */ + g->allgc = o->next; /* remove object from 'allgc' list */ + o->next = g->fixedgc; /* link it to 'fixedgc' list */ + g->fixedgc = o; +} + + +/* +** create a new collectable object (with given type and size) and link +** it to 'allgc' list. +*/ +GCObject *luaC_newobj (lua_State *L, int tt, size_t sz) { + global_State *g = G(L); + GCObject *o = cast(GCObject *, luaM_newobject(L, novariant(tt), sz)); + o->marked = luaC_white(g); + o->tt = tt; + o->next = g->allgc; + g->allgc = o; + return o; +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** Mark functions +** ======================================================= +*/ + + +/* +** mark an object. Userdata, strings, and closed upvalues are visited +** and turned black here. Other objects are marked gray and added +** to appropriate list to be visited (and turned black) later. (Open +** upvalues are already linked in 'headuv' list.) +*/ +static void reallymarkobject (global_State *g, GCObject *o) { + reentry: + white2gray(o); + switch (o->tt) { + case LUA_TSHRSTR: + case LUA_TLNGSTR: { + gray2black(o); + g->GCmemtrav += sizestring(gco2ts(o)); + break; + } + case LUA_TUSERDATA: { + TValue uvalue; + markobject(g, gco2u(o)->metatable); /* mark its metatable */ + gray2black(o); + g->GCmemtrav += sizeudata(gco2u(o)); + getuservalue(g->mainthread, gco2u(o), &uvalue); + if (valiswhite(&uvalue)) { /* markvalue(g, &uvalue); */ + o = gcvalue(&uvalue); + goto reentry; + } + break; + } + case LUA_TLCL: { + linkgclist(gco2lcl(o), g->gray); + break; + } + case LUA_TCCL: { + linkgclist(gco2ccl(o), g->gray); + break; + } + case LUA_TTABLE: { + linkgclist(gco2t(o), g->gray); + break; + } + case LUA_TTHREAD: { + linkgclist(gco2th(o), g->gray); + break; + } + case LUA_TPROTO: { + linkgclist(gco2p(o), g->gray); + break; + } + default: lua_assert(0); break; + } +} + + +/* +** mark metamethods for basic types +*/ +static void markmt (global_State *g) { + int i; + for (i=0; i < LUA_NUMTAGS; i++) + markobject(g, g->mt[i]); +} + + +/* +** mark all objects in list of being-finalized +*/ +static void markbeingfnz (global_State *g) { + GCObject *o; + for (o = g->tobefnz; o != NULL; o = o->next) + markobject(g, o); +} + + +/* +** Mark all values stored in marked open upvalues from non-marked threads. +** (Values from marked threads were already marked when traversing the +** thread.) Remove from the list threads that no longer have upvalues and +** not-marked threads. +*/ +static void remarkupvals (global_State *g) { + lua_State *thread; + lua_State **p = &g->twups; + while ((thread = *p) != NULL) { + lua_assert(!isblack(thread)); /* threads are never black */ + if (isgray(thread) && thread->openupval != NULL) + p = &thread->twups; /* keep marked thread with upvalues in the list */ + else { /* thread is not marked or without upvalues */ + UpVal *uv; + *p = thread->twups; /* remove thread from the list */ + thread->twups = thread; /* mark that it is out of list */ + for (uv = thread->openupval; uv != NULL; uv = uv->u.open.next) { + if (uv->u.open.touched) { + markvalue(g, uv->v); /* remark upvalue's value */ + uv->u.open.touched = 0; + } + } + } + } +} + + +/* +** mark root set and reset all gray lists, to start a new collection +*/ +static void restartcollection (global_State *g) { + g->gray = g->grayagain = NULL; + g->weak = g->allweak = g->ephemeron = NULL; + markobject(g, g->mainthread); + markvalue(g, &g->l_registry); + markmt(g); + markbeingfnz(g); /* mark any finalizing object left from previous cycle */ +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Traverse functions +** ======================================================= +*/ + +/* +** Traverse a table with weak values and link it to proper list. During +** propagate phase, keep it in 'grayagain' list, to be revisited in the +** atomic phase. In the atomic phase, if table has any white value, +** put it in 'weak' list, to be cleared. +*/ +static void traverseweakvalue (global_State *g, Table *h) { + Node *n, *limit = gnodelast(h); + /* if there is array part, assume it may have white values (it is not + worth traversing it now just to check) */ + int hasclears = (h->sizearray > 0); + for (n = gnode(h, 0); n < limit; n++) { /* traverse hash part */ + checkdeadkey(n); + if (ttisnil(gval(n))) /* entry is empty? */ + removeentry(n); /* remove it */ + else { + lua_assert(!ttisnil(gkey(n))); + markvalue(g, gkey(n)); /* mark key */ + if (!hasclears && iscleared(g, gval(n))) /* is there a white value? */ + hasclears = 1; /* table will have to be cleared */ + } + } + if (g->gcstate == GCSpropagate) + linkgclist(h, g->grayagain); /* must retraverse it in atomic phase */ + else if (hasclears) + linkgclist(h, g->weak); /* has to be cleared later */ +} + + +/* +** Traverse an ephemeron table and link it to proper list. Returns true +** iff any object was marked during this traversal (which implies that +** convergence has to continue). During propagation phase, keep table +** in 'grayagain' list, to be visited again in the atomic phase. In +** the atomic phase, if table has any white->white entry, it has to +** be revisited during ephemeron convergence (as that key may turn +** black). Otherwise, if it has any white key, table has to be cleared +** (in the atomic phase). +*/ +static int traverseephemeron (global_State *g, Table *h) { + int marked = 0; /* true if an object is marked in this traversal */ + int hasclears = 0; /* true if table has white keys */ + int hasww = 0; /* true if table has entry "white-key -> white-value" */ + Node *n, *limit = gnodelast(h); + unsigned int i; + /* traverse array part */ + for (i = 0; i < h->sizearray; i++) { + if (valiswhite(&h->array[i])) { + marked = 1; + reallymarkobject(g, gcvalue(&h->array[i])); + } + } + /* traverse hash part */ + for (n = gnode(h, 0); n < limit; n++) { + checkdeadkey(n); + if (ttisnil(gval(n))) /* entry is empty? */ + removeentry(n); /* remove it */ + else if (iscleared(g, gkey(n))) { /* key is not marked (yet)? */ + hasclears = 1; /* table must be cleared */ + if (valiswhite(gval(n))) /* value not marked yet? */ + hasww = 1; /* white-white entry */ + } + else if (valiswhite(gval(n))) { /* value not marked yet? */ + marked = 1; + reallymarkobject(g, gcvalue(gval(n))); /* mark it now */ + } + } + /* link table into proper list */ + if (g->gcstate == GCSpropagate) + linkgclist(h, g->grayagain); /* must retraverse it in atomic phase */ + else if (hasww) /* table has white->white entries? */ + linkgclist(h, g->ephemeron); /* have to propagate again */ + else if (hasclears) /* table has white keys? */ + linkgclist(h, g->allweak); /* may have to clean white keys */ + return marked; +} + + +static void traversestrongtable (global_State *g, Table *h) { + Node *n, *limit = gnodelast(h); + unsigned int i; + for (i = 0; i < h->sizearray; i++) /* traverse array part */ + markvalue(g, &h->array[i]); + for (n = gnode(h, 0); n < limit; n++) { /* traverse hash part */ + checkdeadkey(n); + if (ttisnil(gval(n))) /* entry is empty? */ + removeentry(n); /* remove it */ + else { + lua_assert(!ttisnil(gkey(n))); + markvalue(g, gkey(n)); /* mark key */ + markvalue(g, gval(n)); /* mark value */ + } + } +} + + +static lu_mem traversetable (global_State *g, Table *h) { + const char *weakkey, *weakvalue; + const TValue *mode = gfasttm(g, h->metatable, TM_MODE); + markobject(g, h->metatable); + if (mode && ttisstring(mode) && /* is there a weak mode? */ + ((weakkey = strchr(svalue(mode), 'k')), + (weakvalue = strchr(svalue(mode), 'v')), + (weakkey || weakvalue))) { /* is really weak? */ + black2gray(h); /* keep table gray */ + if (!weakkey) /* strong keys? */ + traverseweakvalue(g, h); + else if (!weakvalue) /* strong values? */ + traverseephemeron(g, h); + else /* all weak */ + linkgclist(h, g->allweak); /* nothing to traverse now */ + } + else /* not weak */ + traversestrongtable(g, h); + return sizeof(Table) + sizeof(TValue) * h->sizearray + + sizeof(Node) * cast(size_t, sizenode(h)); +} + + +static int traverseproto (global_State *g, Proto *f) { + int i; + if (f->cache && iswhite(f->cache)) + f->cache = NULL; /* allow cache to be collected */ + markobject(g, f->source); + for (i = 0; i < f->sizek; i++) /* mark literals */ + markvalue(g, &f->k[i]); + for (i = 0; i < f->sizeupvalues; i++) /* mark upvalue names */ + markobject(g, f->upvalues[i].name); + for (i = 0; i < f->sizep; i++) /* mark nested protos */ + markobject(g, f->p[i]); + for (i = 0; i < f->sizelocvars; i++) /* mark local-variable names */ + markobject(g, f->locvars[i].varname); + return sizeof(Proto) + sizeof(Instruction) * f->sizecode + + sizeof(Proto *) * f->sizep + + sizeof(TValue) * f->sizek + + sizeof(int) * f->sizelineinfo + + sizeof(LocVar) * f->sizelocvars + + sizeof(Upvaldesc) * f->sizeupvalues; +} + + +static lu_mem traverseCclosure (global_State *g, CClosure *cl) { + int i; + for (i = 0; i < cl->nupvalues; i++) /* mark its upvalues */ + markvalue(g, &cl->upvalue[i]); + return sizeCclosure(cl->nupvalues); +} + +/* +** open upvalues point to values in a thread, so those values should +** be marked when the thread is traversed except in the atomic phase +** (because then the value cannot be changed by the thread and the +** thread may not be traversed again) +*/ +static lu_mem traverseLclosure (global_State *g, LClosure *cl) { + int i; + markobject(g, cl->p); /* mark its prototype */ + for (i = 0; i < cl->nupvalues; i++) { /* mark its upvalues */ + UpVal *uv = cl->upvals[i]; + if (uv != NULL) { + if (upisopen(uv) && g->gcstate != GCSinsideatomic) + uv->u.open.touched = 1; /* can be marked in 'remarkupvals' */ + else + markvalue(g, uv->v); + } + } + return sizeLclosure(cl->nupvalues); +} + + +static lu_mem traversethread (global_State *g, lua_State *th) { + StkId o = th->stack; + if (o == NULL) + return 1; /* stack not completely built yet */ + lua_assert(g->gcstate == GCSinsideatomic || + th->openupval == NULL || isintwups(th)); + for (; o < th->top; o++) /* mark live elements in the stack */ + markvalue(g, o); + if (g->gcstate == GCSinsideatomic) { /* final traversal? */ + StkId lim = th->stack + th->stacksize; /* real end of stack */ + for (; o < lim; o++) /* clear not-marked stack slice */ + setnilvalue(o); + /* 'remarkupvals' may have removed thread from 'twups' list */ + if (!isintwups(th) && th->openupval != NULL) { + th->twups = g->twups; /* link it back to the list */ + g->twups = th; + } + } + else if (g->gckind != KGC_EMERGENCY) + luaD_shrinkstack(th); /* do not change stack in emergency cycle */ + return (sizeof(lua_State) + sizeof(TValue) * th->stacksize); +} + + +/* +** traverse one gray object, turning it to black (except for threads, +** which are always gray). +*/ +static void propagatemark (global_State *g) { + lu_mem size; + GCObject *o = g->gray; + lua_assert(isgray(o)); + gray2black(o); + switch (o->tt) { + case LUA_TTABLE: { + Table *h = gco2t(o); + g->gray = h->gclist; /* remove from 'gray' list */ + size = traversetable(g, h); + break; + } + case LUA_TLCL: { + LClosure *cl = gco2lcl(o); + g->gray = cl->gclist; /* remove from 'gray' list */ + size = traverseLclosure(g, cl); + break; + } + case LUA_TCCL: { + CClosure *cl = gco2ccl(o); + g->gray = cl->gclist; /* remove from 'gray' list */ + size = traverseCclosure(g, cl); + break; + } + case LUA_TTHREAD: { + lua_State *th = gco2th(o); + g->gray = th->gclist; /* remove from 'gray' list */ + linkgclist(th, g->grayagain); /* insert into 'grayagain' list */ + black2gray(o); + size = traversethread(g, th); + break; + } + case LUA_TPROTO: { + Proto *p = gco2p(o); + g->gray = p->gclist; /* remove from 'gray' list */ + size = traverseproto(g, p); + break; + } + default: lua_assert(0); return; + } + g->GCmemtrav += size; +} + + +static void propagateall (global_State *g) { + while (g->gray) propagatemark(g); +} + + +static void convergeephemerons (global_State *g) { + int changed; + do { + GCObject *w; + GCObject *next = g->ephemeron; /* get ephemeron list */ + g->ephemeron = NULL; /* tables may return to this list when traversed */ + changed = 0; + while ((w = next) != NULL) { + next = gco2t(w)->gclist; + if (traverseephemeron(g, gco2t(w))) { /* traverse marked some value? */ + propagateall(g); /* propagate changes */ + changed = 1; /* will have to revisit all ephemeron tables */ + } + } + } while (changed); +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Sweep Functions +** ======================================================= +*/ + + +/* +** clear entries with unmarked keys from all weaktables in list 'l' up +** to element 'f' +*/ +static void clearkeys (global_State *g, GCObject *l, GCObject *f) { + for (; l != f; l = gco2t(l)->gclist) { + Table *h = gco2t(l); + Node *n, *limit = gnodelast(h); + for (n = gnode(h, 0); n < limit; n++) { + if (!ttisnil(gval(n)) && (iscleared(g, gkey(n)))) { + setnilvalue(gval(n)); /* remove value ... */ + removeentry(n); /* and remove entry from table */ + } + } + } +} + + +/* +** clear entries with unmarked values from all weaktables in list 'l' up +** to element 'f' +*/ +static void clearvalues (global_State *g, GCObject *l, GCObject *f) { + for (; l != f; l = gco2t(l)->gclist) { + Table *h = gco2t(l); + Node *n, *limit = gnodelast(h); + unsigned int i; + for (i = 0; i < h->sizearray; i++) { + TValue *o = &h->array[i]; + if (iscleared(g, o)) /* value was collected? */ + setnilvalue(o); /* remove value */ + } + for (n = gnode(h, 0); n < limit; n++) { + if (!ttisnil(gval(n)) && iscleared(g, gval(n))) { + setnilvalue(gval(n)); /* remove value ... */ + removeentry(n); /* and remove entry from table */ + } + } + } +} + + +void luaC_upvdeccount (lua_State *L, UpVal *uv) { + lua_assert(uv->refcount > 0); + uv->refcount--; + if (uv->refcount == 0 && !upisopen(uv)) + luaM_free(L, uv); +} + + +static void freeLclosure (lua_State *L, LClosure *cl) { + int i; + for (i = 0; i < cl->nupvalues; i++) { + UpVal *uv = cl->upvals[i]; + if (uv) + luaC_upvdeccount(L, uv); + } + luaM_freemem(L, cl, sizeLclosure(cl->nupvalues)); +} + + +static void freeobj (lua_State *L, GCObject *o) { + switch (o->tt) { + case LUA_TPROTO: luaF_freeproto(L, gco2p(o)); break; + case LUA_TLCL: { + freeLclosure(L, gco2lcl(o)); + break; + } + case LUA_TCCL: { + luaM_freemem(L, o, sizeCclosure(gco2ccl(o)->nupvalues)); + break; + } + case LUA_TTABLE: luaH_free(L, gco2t(o)); break; + case LUA_TTHREAD: luaE_freethread(L, gco2th(o)); break; + case LUA_TUSERDATA: luaM_freemem(L, o, sizeudata(gco2u(o))); break; + case LUA_TSHRSTR: + luaS_remove(L, gco2ts(o)); /* remove it from hash table */ + /* go through */ + case LUA_TLNGSTR: { + luaM_freemem(L, o, sizestring(gco2ts(o))); + break; + } + default: lua_assert(0); + } +} + + +#define sweepwholelist(L,p) sweeplist(L,p,MAX_LUMEM) +static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count); + + +/* +** sweep at most 'count' elements from a list of GCObjects erasing dead +** objects, where a dead object is one marked with the old (non current) +** white; change all non-dead objects back to white, preparing for next +** collection cycle. Return where to continue the traversal or NULL if +** list is finished. +*/ +static GCObject **sweeplist (lua_State *L, GCObject **p, lu_mem count) { + global_State *g = G(L); + int ow = otherwhite(g); + int white = luaC_white(g); /* current white */ + while (*p != NULL && count-- > 0) { + GCObject *curr = *p; + int marked = curr->marked; + if (isdeadm(ow, marked)) { /* is 'curr' dead? */ + *p = curr->next; /* remove 'curr' from list */ + freeobj(L, curr); /* erase 'curr' */ + } + else { /* change mark to 'white' */ + curr->marked = cast_byte((marked & maskcolors) | white); + p = &curr->next; /* go to next element */ + } + } + return (*p == NULL) ? NULL : p; +} + + +/* +** sweep a list until a live object (or end of list) +*/ +static GCObject **sweeptolive (lua_State *L, GCObject **p, int *n) { + GCObject **old = p; + int i = 0; + do { + i++; + p = sweeplist(L, p, 1); + } while (p == old); + if (n) *n += i; + return p; +} + +/* }====================================================== */ + + +/* +** {====================================================== +** Finalization +** ======================================================= +*/ + +/* +** If possible, free concatenation buffer and shrink string table +*/ +static void checkSizes (lua_State *L, global_State *g) { + if (g->gckind != KGC_EMERGENCY) { + l_mem olddebt = g->GCdebt; + luaZ_freebuffer(L, &g->buff); /* free concatenation buffer */ + if (g->strt.nuse < g->strt.size / 4) /* string table too big? */ + luaS_resize(L, g->strt.size / 2); /* shrink it a little */ + g->GCestimate += g->GCdebt - olddebt; /* update estimate */ + } +} + + +static GCObject *udata2finalize (global_State *g) { + GCObject *o = g->tobefnz; /* get first element */ + lua_assert(tofinalize(o)); + g->tobefnz = o->next; /* remove it from 'tobefnz' list */ + o->next = g->allgc; /* return it to 'allgc' list */ + g->allgc = o; + resetbit(o->marked, FINALIZEDBIT); /* object is "normal" again */ + if (issweepphase(g)) + makewhite(g, o); /* "sweep" object */ + return o; +} + + +static void dothecall (lua_State *L, void *ud) { + UNUSED(ud); + luaD_call(L, L->top - 2, 0, 0); +} + + +static void GCTM (lua_State *L, int propagateerrors) { + global_State *g = G(L); + const TValue *tm; + TValue v; + setgcovalue(L, &v, udata2finalize(g)); + tm = luaT_gettmbyobj(L, &v, TM_GC); + if (tm != NULL && ttisfunction(tm)) { /* is there a finalizer? */ + int status; + lu_byte oldah = L->allowhook; + int running = g->gcrunning; + L->allowhook = 0; /* stop debug hooks during GC metamethod */ + g->gcrunning = 0; /* avoid GC steps */ + setobj2s(L, L->top, tm); /* push finalizer... */ + setobj2s(L, L->top + 1, &v); /* ... and its argument */ + L->top += 2; /* and (next line) call the finalizer */ + status = luaD_pcall(L, dothecall, NULL, savestack(L, L->top - 2), 0); + L->allowhook = oldah; /* restore hooks */ + g->gcrunning = running; /* restore state */ + if (status != LUA_OK && propagateerrors) { /* error while running __gc? */ + if (status == LUA_ERRRUN) { /* is there an error object? */ + const char *msg = (ttisstring(L->top - 1)) + ? svalue(L->top - 1) + : "no message"; + luaO_pushfstring(L, "error in __gc metamethod (%s)", msg); + status = LUA_ERRGCMM; /* error in __gc metamethod */ + } + luaD_throw(L, status); /* re-throw error */ + } + } +} + + +/* +** call a few (up to 'g->gcfinnum') finalizers +*/ +static int runafewfinalizers (lua_State *L) { + global_State *g = G(L); + unsigned int i; + lua_assert(!g->tobefnz || g->gcfinnum > 0); + for (i = 0; g->tobefnz && i < g->gcfinnum; i++) + GCTM(L, 1); /* call one finalizer */ + g->gcfinnum = (!g->tobefnz) ? 0 /* nothing more to finalize? */ + : g->gcfinnum * 2; /* else call a few more next time */ + return i; +} + + +/* +** call all pending finalizers +*/ +static void callallpendingfinalizers (lua_State *L, int propagateerrors) { + global_State *g = G(L); + while (g->tobefnz) + GCTM(L, propagateerrors); +} + + +/* +** find last 'next' field in list 'p' list (to add elements in its end) +*/ +static GCObject **findlast (GCObject **p) { + while (*p != NULL) + p = &(*p)->next; + return p; +} + + +/* +** move all unreachable objects (or 'all' objects) that need +** finalization from list 'finobj' to list 'tobefnz' (to be finalized) +*/ +static void separatetobefnz (global_State *g, int all) { + GCObject *curr; + GCObject **p = &g->finobj; + GCObject **lastnext = findlast(&g->tobefnz); + while ((curr = *p) != NULL) { /* traverse all finalizable objects */ + lua_assert(tofinalize(curr)); + if (!(iswhite(curr) || all)) /* not being collected? */ + p = &curr->next; /* don't bother with it */ + else { + *p = curr->next; /* remove 'curr' from 'finobj' list */ + curr->next = *lastnext; /* link at the end of 'tobefnz' list */ + *lastnext = curr; + lastnext = &curr->next; + } + } +} + + +/* +** if object 'o' has a finalizer, remove it from 'allgc' list (must +** search the list to find it) and link it in 'finobj' list. +*/ +void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt) { + global_State *g = G(L); + if (tofinalize(o) || /* obj. is already marked... */ + gfasttm(g, mt, TM_GC) == NULL) /* or has no finalizer? */ + return; /* nothing to be done */ + else { /* move 'o' to 'finobj' list */ + GCObject **p; + if (issweepphase(g)) { + makewhite(g, o); /* "sweep" object 'o' */ + if (g->sweepgc == &o->next) /* should not remove 'sweepgc' object */ + g->sweepgc = sweeptolive(L, g->sweepgc, NULL); /* change 'sweepgc' */ + } + /* search for pointer pointing to 'o' */ + for (p = &g->allgc; *p != o; p = &(*p)->next) { /* empty */ } + *p = o->next; /* remove 'o' from 'allgc' list */ + o->next = g->finobj; /* link it in 'finobj' list */ + g->finobj = o; + l_setbit(o->marked, FINALIZEDBIT); /* mark it as such */ + } +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** GC control +** ======================================================= +*/ + + +/* +** Set a reasonable "time" to wait before starting a new GC cycle; cycle +** will start when memory use hits threshold. (Division by 'estimate' +** should be OK: it cannot be zero (because Lua cannot even start with +** less than PAUSEADJ bytes). +*/ +static void setpause (global_State *g) { + l_mem threshold, debt; + l_mem estimate = g->GCestimate / PAUSEADJ; /* adjust 'estimate' */ + lua_assert(estimate > 0); + threshold = (g->gcpause < MAX_LMEM / estimate) /* overflow? */ + ? estimate * g->gcpause /* no overflow */ + : MAX_LMEM; /* overflow; truncate to maximum */ + debt = gettotalbytes(g) - threshold; + luaE_setdebt(g, debt); +} + + +/* +** Enter first sweep phase. +** The call to 'sweeptolive' makes pointer point to an object inside +** the list (instead of to the header), so that the real sweep do not +** need to skip objects created between "now" and the start of the real +** sweep. +** Returns how many objects it swept. +*/ +static int entersweep (lua_State *L) { + global_State *g = G(L); + int n = 0; + g->gcstate = GCSswpallgc; + lua_assert(g->sweepgc == NULL); + g->sweepgc = sweeptolive(L, &g->allgc, &n); + return n; +} + + +void luaC_freeallobjects (lua_State *L) { + global_State *g = G(L); + separatetobefnz(g, 1); /* separate all objects with finalizers */ + lua_assert(g->finobj == NULL); + callallpendingfinalizers(L, 0); + lua_assert(g->tobefnz == NULL); + g->currentwhite = WHITEBITS; /* this "white" makes all objects look dead */ + g->gckind = KGC_NORMAL; + sweepwholelist(L, &g->finobj); + sweepwholelist(L, &g->allgc); + sweepwholelist(L, &g->fixedgc); /* collect fixed objects */ + lua_assert(g->strt.nuse == 0); +} + + +static l_mem atomic (lua_State *L) { + global_State *g = G(L); + l_mem work; + GCObject *origweak, *origall; + GCObject *grayagain = g->grayagain; /* save original list */ + lua_assert(g->ephemeron == NULL && g->weak == NULL); + lua_assert(!iswhite(g->mainthread)); + g->gcstate = GCSinsideatomic; + g->GCmemtrav = 0; /* start counting work */ + markobject(g, L); /* mark running thread */ + /* registry and global metatables may be changed by API */ + markvalue(g, &g->l_registry); + markmt(g); /* mark global metatables */ + /* remark occasional upvalues of (maybe) dead threads */ + remarkupvals(g); + propagateall(g); /* propagate changes */ + work = g->GCmemtrav; /* stop counting (do not recount 'grayagain') */ + g->gray = grayagain; + propagateall(g); /* traverse 'grayagain' list */ + g->GCmemtrav = 0; /* restart counting */ + convergeephemerons(g); + /* at this point, all strongly accessible objects are marked. */ + /* Clear values from weak tables, before checking finalizers */ + clearvalues(g, g->weak, NULL); + clearvalues(g, g->allweak, NULL); + origweak = g->weak; origall = g->allweak; + work += g->GCmemtrav; /* stop counting (objects being finalized) */ + separatetobefnz(g, 0); /* separate objects to be finalized */ + g->gcfinnum = 1; /* there may be objects to be finalized */ + markbeingfnz(g); /* mark objects that will be finalized */ + propagateall(g); /* remark, to propagate 'resurrection' */ + g->GCmemtrav = 0; /* restart counting */ + convergeephemerons(g); + /* at this point, all resurrected objects are marked. */ + /* remove dead objects from weak tables */ + clearkeys(g, g->ephemeron, NULL); /* clear keys from all ephemeron tables */ + clearkeys(g, g->allweak, NULL); /* clear keys from all 'allweak' tables */ + /* clear values from resurrected weak tables */ + clearvalues(g, g->weak, origweak); + clearvalues(g, g->allweak, origall); + g->currentwhite = cast_byte(otherwhite(g)); /* flip current white */ + work += g->GCmemtrav; /* complete counting */ + return work; /* estimate of memory marked by 'atomic' */ +} + + +static lu_mem sweepstep (lua_State *L, global_State *g, + int nextstate, GCObject **nextlist) { + if (g->sweepgc) { + l_mem olddebt = g->GCdebt; + g->sweepgc = sweeplist(L, g->sweepgc, GCSWEEPMAX); + g->GCestimate += g->GCdebt - olddebt; /* update estimate */ + if (g->sweepgc) /* is there still something to sweep? */ + return (GCSWEEPMAX * GCSWEEPCOST); + } + /* else enter next state */ + g->gcstate = nextstate; + g->sweepgc = nextlist; + return 0; +} + + +static lu_mem singlestep (lua_State *L) { + global_State *g = G(L); + switch (g->gcstate) { + case GCSpause: { + g->GCmemtrav = g->strt.size * sizeof(GCObject*); + restartcollection(g); + g->gcstate = GCSpropagate; + return g->GCmemtrav; + } + case GCSpropagate: { + g->GCmemtrav = 0; + lua_assert(g->gray); + propagatemark(g); + if (g->gray == NULL) /* no more gray objects? */ + g->gcstate = GCSatomic; /* finish propagate phase */ + return g->GCmemtrav; /* memory traversed in this step */ + } + case GCSatomic: { + lu_mem work; + int sw; + propagateall(g); /* make sure gray list is empty */ + work = atomic(L); /* work is what was traversed by 'atomic' */ + sw = entersweep(L); + g->GCestimate = gettotalbytes(g); /* first estimate */; + return work + sw * GCSWEEPCOST; + } + case GCSswpallgc: { /* sweep "regular" objects */ + return sweepstep(L, g, GCSswpfinobj, &g->finobj); + } + case GCSswpfinobj: { /* sweep objects with finalizers */ + return sweepstep(L, g, GCSswptobefnz, &g->tobefnz); + } + case GCSswptobefnz: { /* sweep objects to be finalized */ + return sweepstep(L, g, GCSswpend, NULL); + } + case GCSswpend: { /* finish sweeps */ + makewhite(g, g->mainthread); /* sweep main thread */ + checkSizes(L, g); + g->gcstate = GCScallfin; + return 0; + } + case GCScallfin: { /* call remaining finalizers */ + if (g->tobefnz && g->gckind != KGC_EMERGENCY) { + int n = runafewfinalizers(L); + return (n * GCFINALIZECOST); + } + else { /* emergency mode or no more finalizers */ + g->gcstate = GCSpause; /* finish collection */ + return 0; + } + } + default: lua_assert(0); return 0; + } +} + + +/* +** advances the garbage collector until it reaches a state allowed +** by 'statemask' +*/ +void luaC_runtilstate (lua_State *L, int statesmask) { + global_State *g = G(L); + while (!testbit(statesmask, g->gcstate)) + singlestep(L); +} + + +/* +** get GC debt and convert it from Kb to 'work units' (avoid zero debt +** and overflows) +*/ +static l_mem getdebt (global_State *g) { + l_mem debt = g->GCdebt; + int stepmul = g->gcstepmul; + debt = (debt / STEPMULADJ) + 1; + debt = (debt < MAX_LMEM / stepmul) ? debt * stepmul : MAX_LMEM; + return debt; +} + +/* +** performs a basic GC step when collector is running +*/ +void luaC_step (lua_State *L) { + global_State *g = G(L); + l_mem debt = getdebt(g); /* GC deficit (be paid now) */ + if (!g->gcrunning) { /* not running? */ + luaE_setdebt(g, -GCSTEPSIZE * 10); /* avoid being called too often */ + return; + } + do { /* repeat until pause or enough "credit" (negative debt) */ + lu_mem work = singlestep(L); /* perform one single step */ + debt -= work; + } while (debt > -GCSTEPSIZE && g->gcstate != GCSpause); + if (g->gcstate == GCSpause) + setpause(g); /* pause until next cycle */ + else { + debt = (debt / g->gcstepmul) * STEPMULADJ; /* convert 'work units' to Kb */ + luaE_setdebt(g, debt); + runafewfinalizers(L); + } +} + + +/* +** Performs a full GC cycle; if 'isemergency', set a flag to avoid +** some operations which could change the interpreter state in some +** unexpected ways (running finalizers and shrinking some structures). +** Before running the collection, check 'keepinvariant'; if it is true, +** there may be some objects marked as black, so the collector has +** to sweep all objects to turn them back to white (as white has not +** changed, nothing will be collected). +*/ +void luaC_fullgc (lua_State *L, int isemergency) { + global_State *g = G(L); + lua_assert(g->gckind == KGC_NORMAL); + if (isemergency) g->gckind = KGC_EMERGENCY; /* set flag */ + if (keepinvariant(g)) { /* black objects? */ + entersweep(L); /* sweep everything to turn them back to white */ + } + /* finish any pending sweep phase to start a new cycle */ + luaC_runtilstate(L, bitmask(GCSpause)); + luaC_runtilstate(L, ~bitmask(GCSpause)); /* start new collection */ + luaC_runtilstate(L, bitmask(GCScallfin)); /* run up to finalizers */ + /* estimate must be correct after a full GC cycle */ + lua_assert(g->GCestimate == gettotalbytes(g)); + luaC_runtilstate(L, bitmask(GCSpause)); /* finish collection */ + g->gckind = KGC_NORMAL; + setpause(g); +} + +/* }====================================================== */ + + diff --git a/src/lgc.h b/src/lgc.h new file mode 100644 index 000000000000..0eedf84204a3 --- /dev/null +++ b/src/lgc.h @@ -0,0 +1,138 @@ +/* +** $Id: lgc.h,v 2.86 2014/10/25 11:50:46 roberto Exp $ +** Garbage Collector +** See Copyright Notice in lua.h +*/ + +#ifndef lgc_h +#define lgc_h + + +#include "lobject.h" +#include "lstate.h" + +/* +** Collectable objects may have one of three colors: white, which +** means the object is not marked; gray, which means the +** object is marked, but its references may be not marked; and +** black, which means that the object and all its references are marked. +** The main invariant of the garbage collector, while marking objects, +** is that a black object can never point to a white one. Moreover, +** any gray object must be in a "gray list" (gray, grayagain, weak, +** allweak, ephemeron) so that it can be visited again before finishing +** the collection cycle. These lists have no meaning when the invariant +** is not being enforced (e.g., sweep phase). +*/ + + + +/* how much to allocate before next GC step */ +#if !defined(GCSTEPSIZE) +/* ~100 small strings */ +#define GCSTEPSIZE (cast_int(100 * sizeof(TString))) +#endif + + +/* +** Possible states of the Garbage Collector +*/ +#define GCSpropagate 0 +#define GCSatomic 1 +#define GCSswpallgc 2 +#define GCSswpfinobj 3 +#define GCSswptobefnz 4 +#define GCSswpend 5 +#define GCScallfin 6 +#define GCSpause 7 + + +#define issweepphase(g) \ + (GCSswpallgc <= (g)->gcstate && (g)->gcstate <= GCSswpend) + + +/* +** macro to tell when main invariant (white objects cannot point to black +** ones) must be kept. During a collection, the sweep +** phase may break the invariant, as objects turned white may point to +** still-black objects. The invariant is restored when sweep ends and +** all objects are white again. +*/ + +#define keepinvariant(g) ((g)->gcstate <= GCSatomic) + + +/* +** some useful bit tricks +*/ +#define resetbits(x,m) ((x) &= cast(lu_byte, ~(m))) +#define setbits(x,m) ((x) |= (m)) +#define testbits(x,m) ((x) & (m)) +#define bitmask(b) (1<<(b)) +#define bit2mask(b1,b2) (bitmask(b1) | bitmask(b2)) +#define l_setbit(x,b) setbits(x, bitmask(b)) +#define resetbit(x,b) resetbits(x, bitmask(b)) +#define testbit(x,b) testbits(x, bitmask(b)) + + +/* Layout for bit use in 'marked' field: */ +#define WHITE0BIT 0 /* object is white (type 0) */ +#define WHITE1BIT 1 /* object is white (type 1) */ +#define BLACKBIT 2 /* object is black */ +#define FINALIZEDBIT 3 /* object has been marked for finalization */ +/* bit 7 is currently used by tests (luaL_checkmemory) */ + +#define WHITEBITS bit2mask(WHITE0BIT, WHITE1BIT) + + +#define iswhite(x) testbits((x)->marked, WHITEBITS) +#define isblack(x) testbit((x)->marked, BLACKBIT) +#define isgray(x) /* neither white nor black */ \ + (!testbits((x)->marked, WHITEBITS | bitmask(BLACKBIT))) + +#define tofinalize(x) testbit((x)->marked, FINALIZEDBIT) + +#define otherwhite(g) ((g)->currentwhite ^ WHITEBITS) +#define isdeadm(ow,m) (!(((m) ^ WHITEBITS) & (ow))) +#define isdead(g,v) isdeadm(otherwhite(g), (v)->marked) + +#define changewhite(x) ((x)->marked ^= WHITEBITS) +#define gray2black(x) l_setbit((x)->marked, BLACKBIT) + +#define luaC_white(g) cast(lu_byte, (g)->currentwhite & WHITEBITS) + + +#define luaC_condGC(L,c) \ + {if (G(L)->GCdebt > 0) {c;}; condchangemem(L);} +#define luaC_checkGC(L) luaC_condGC(L, luaC_step(L);) + + +#define luaC_barrier(L,p,v) { \ + if (iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) \ + luaC_barrier_(L,obj2gco(p),gcvalue(v)); } + +#define luaC_barrierback(L,p,v) { \ + if (iscollectable(v) && isblack(p) && iswhite(gcvalue(v))) \ + luaC_barrierback_(L,p); } + +#define luaC_objbarrier(L,p,o) { \ + if (isblack(p) && iswhite(o)) \ + luaC_barrier_(L,obj2gco(p),obj2gco(o)); } + +#define luaC_upvalbarrier(L,uv) \ + { if (iscollectable((uv)->v) && !upisopen(uv)) \ + luaC_upvalbarrier_(L,uv); } + +LUAI_FUNC void luaC_fix (lua_State *L, GCObject *o); +LUAI_FUNC void luaC_freeallobjects (lua_State *L); +LUAI_FUNC void luaC_step (lua_State *L); +LUAI_FUNC void luaC_runtilstate (lua_State *L, int statesmask); +LUAI_FUNC void luaC_fullgc (lua_State *L, int isemergency); +LUAI_FUNC GCObject *luaC_newobj (lua_State *L, int tt, size_t sz); +LUAI_FUNC void luaC_barrier_ (lua_State *L, GCObject *o, GCObject *v); +LUAI_FUNC void luaC_barrierback_ (lua_State *L, Table *o); +LUAI_FUNC void luaC_upvalbarrier_ (lua_State *L, UpVal *uv); +LUAI_FUNC void luaC_checkfinalizer (lua_State *L, GCObject *o, Table *mt); +LUAI_FUNC void luaC_upvdeccount (lua_State *L, UpVal *uv); + + +#endif diff --git a/src/linit.c b/src/linit.c new file mode 100644 index 000000000000..8ce94ccb3554 --- /dev/null +++ b/src/linit.c @@ -0,0 +1,68 @@ +/* +** $Id: linit.c,v 1.38 2015/01/05 13:48:33 roberto Exp $ +** Initialization of libraries for lua.c and other clients +** See Copyright Notice in lua.h +*/ + + +#define linit_c +#define LUA_LIB + +/* +** If you embed Lua in your program and need to open the standard +** libraries, call luaL_openlibs in your program. If you need a +** different set of libraries, copy this file to your project and edit +** it to suit your needs. +** +** You can also *preload* libraries, so that a later 'require' can +** open the library, which is already linked to the application. +** For that, do the following code: +** +** luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD"); +** lua_pushcfunction(L, luaopen_modname); +** lua_setfield(L, -2, modname); +** lua_pop(L, 1); // remove _PRELOAD table +*/ + +#include "lprefix.h" + + +#include <stddef.h> + +#include "lua.h" + +#include "lualib.h" +#include "lauxlib.h" + + +/* +** these libs are loaded by lua.c and are readily available to any Lua +** program +*/ +static const luaL_Reg loadedlibs[] = { + {"_G", luaopen_base}, + {LUA_LOADLIBNAME, luaopen_package}, + {LUA_COLIBNAME, luaopen_coroutine}, + {LUA_TABLIBNAME, luaopen_table}, + {LUA_IOLIBNAME, luaopen_io}, + {LUA_OSLIBNAME, luaopen_os}, + {LUA_STRLIBNAME, luaopen_string}, + {LUA_MATHLIBNAME, luaopen_math}, + {LUA_UTF8LIBNAME, luaopen_utf8}, + {LUA_DBLIBNAME, luaopen_debug}, +#if defined(LUA_COMPAT_BITLIB) + {LUA_BITLIBNAME, luaopen_bit32}, +#endif + {NULL, NULL} +}; + + +LUALIB_API void luaL_openlibs (lua_State *L) { + const luaL_Reg *lib; + /* "require" functions from 'loadedlibs' and set results to global table */ + for (lib = loadedlibs; lib->func; lib++) { + luaL_requiref(L, lib->name, lib->func, 1); + lua_pop(L, 1); /* remove lib */ + } +} + diff --git a/src/liolib.c b/src/liolib.c new file mode 100644 index 000000000000..4dea39684a3b --- /dev/null +++ b/src/liolib.c @@ -0,0 +1,757 @@ +/* +** $Id: liolib.c,v 2.142 2015/01/02 12:50:28 roberto Exp $ +** Standard I/O (and system) library +** See Copyright Notice in lua.h +*/ + +#define liolib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <ctype.h> +#include <errno.h> +#include <locale.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#if !defined(l_checkmode) + +/* +** Check whether 'mode' matches '[rwa]%+?b?'. +** Change this macro to accept other modes for 'fopen' besides +** the standard ones. +*/ +#define l_checkmode(mode) \ + (*mode != '\0' && strchr("rwa", *(mode++)) != NULL && \ + (*mode != '+' || ++mode) && /* skip if char is '+' */ \ + (*mode != 'b' || ++mode) && /* skip if char is 'b' */ \ + (*mode == '\0')) + +#endif + +/* +** {====================================================== +** l_popen spawns a new process connected to the current +** one through the file streams. +** ======================================================= +*/ + +#if !defined(l_popen) /* { */ + +#if defined(LUA_USE_POSIX) /* { */ + +#define l_popen(L,c,m) (fflush(NULL), popen(c,m)) +#define l_pclose(L,file) (pclose(file)) + +#elif defined(LUA_USE_WINDOWS) /* }{ */ + +#define l_popen(L,c,m) (_popen(c,m)) +#define l_pclose(L,file) (_pclose(file)) + +#else /* }{ */ + +/* ISO C definitions */ +#define l_popen(L,c,m) \ + ((void)((void)c, m), \ + luaL_error(L, "'popen' not supported"), \ + (FILE*)0) +#define l_pclose(L,file) ((void)L, (void)file, -1) + +#endif /* } */ + +#endif /* } */ + +/* }====================================================== */ + + +#if !defined(l_getc) /* { */ + +#if defined(LUA_USE_POSIX) +#define l_getc(f) getc_unlocked(f) +#define l_lockfile(f) flockfile(f) +#define l_unlockfile(f) funlockfile(f) +#else +#define l_getc(f) getc(f) +#define l_lockfile(f) ((void)0) +#define l_unlockfile(f) ((void)0) +#endif + +#endif /* } */ + + +/* +** {====================================================== +** l_fseek: configuration for longer offsets +** ======================================================= +*/ + +#if !defined(l_fseek) /* { */ + +#if defined(LUA_USE_POSIX) /* { */ + +#include <sys/types.h> + +#define l_fseek(f,o,w) fseeko(f,o,w) +#define l_ftell(f) ftello(f) +#define l_seeknum off_t + +#elif defined(LUA_USE_WINDOWS) && !defined(_CRTIMP_TYPEINFO) \ + && defined(_MSC_VER) && (_MSC_VER >= 1400) /* }{ */ + +/* Windows (but not DDK) and Visual C++ 2005 or higher */ +#define l_fseek(f,o,w) _fseeki64(f,o,w) +#define l_ftell(f) _ftelli64(f) +#define l_seeknum __int64 + +#else /* }{ */ + +/* ISO C definitions */ +#define l_fseek(f,o,w) fseek(f,o,w) +#define l_ftell(f) ftell(f) +#define l_seeknum long + +#endif /* } */ + +#endif /* } */ + +/* }====================================================== */ + + +#define IO_PREFIX "_IO_" +#define IOPREF_LEN (sizeof(IO_PREFIX)/sizeof(char) - 1) +#define IO_INPUT (IO_PREFIX "input") +#define IO_OUTPUT (IO_PREFIX "output") + + +typedef luaL_Stream LStream; + + +#define tolstream(L) ((LStream *)luaL_checkudata(L, 1, LUA_FILEHANDLE)) + +#define isclosed(p) ((p)->closef == NULL) + + +static int io_type (lua_State *L) { + LStream *p; + luaL_checkany(L, 1); + p = (LStream *)luaL_testudata(L, 1, LUA_FILEHANDLE); + if (p == NULL) + lua_pushnil(L); /* not a file */ + else if (isclosed(p)) + lua_pushliteral(L, "closed file"); + else + lua_pushliteral(L, "file"); + return 1; +} + + +static int f_tostring (lua_State *L) { + LStream *p = tolstream(L); + if (isclosed(p)) + lua_pushliteral(L, "file (closed)"); + else + lua_pushfstring(L, "file (%p)", p->f); + return 1; +} + + +static FILE *tofile (lua_State *L) { + LStream *p = tolstream(L); + if (isclosed(p)) + luaL_error(L, "attempt to use a closed file"); + lua_assert(p->f); + return p->f; +} + + +/* +** When creating file handles, always creates a 'closed' file handle +** before opening the actual file; so, if there is a memory error, the +** file is not left opened. +*/ +static LStream *newprefile (lua_State *L) { + LStream *p = (LStream *)lua_newuserdata(L, sizeof(LStream)); + p->closef = NULL; /* mark file handle as 'closed' */ + luaL_setmetatable(L, LUA_FILEHANDLE); + return p; +} + + +/* +** Calls the 'close' function from a file handle. The 'volatile' avoids +** a bug in some versions of the Clang compiler (e.g., clang 3.0 for +** 32 bits). +*/ +static int aux_close (lua_State *L) { + LStream *p = tolstream(L); + volatile lua_CFunction cf = p->closef; + p->closef = NULL; /* mark stream as closed */ + return (*cf)(L); /* close it */ +} + + +static int io_close (lua_State *L) { + if (lua_isnone(L, 1)) /* no argument? */ + lua_getfield(L, LUA_REGISTRYINDEX, IO_OUTPUT); /* use standard output */ + tofile(L); /* make sure argument is an open stream */ + return aux_close(L); +} + + +static int f_gc (lua_State *L) { + LStream *p = tolstream(L); + if (!isclosed(p) && p->f != NULL) + aux_close(L); /* ignore closed and incompletely open files */ + return 0; +} + + +/* +** function to close regular files +*/ +static int io_fclose (lua_State *L) { + LStream *p = tolstream(L); + int res = fclose(p->f); + return luaL_fileresult(L, (res == 0), NULL); +} + + +static LStream *newfile (lua_State *L) { + LStream *p = newprefile(L); + p->f = NULL; + p->closef = &io_fclose; + return p; +} + + +static void opencheck (lua_State *L, const char *fname, const char *mode) { + LStream *p = newfile(L); + p->f = fopen(fname, mode); + if (p->f == NULL) + luaL_error(L, "cannot open file '%s' (%s)", fname, strerror(errno)); +} + + +static int io_open (lua_State *L) { + const char *filename = luaL_checkstring(L, 1); + const char *mode = luaL_optstring(L, 2, "r"); + LStream *p = newfile(L); + const char *md = mode; /* to traverse/check mode */ + luaL_argcheck(L, l_checkmode(md), 2, "invalid mode"); + p->f = fopen(filename, mode); + return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; +} + + +/* +** function to close 'popen' files +*/ +static int io_pclose (lua_State *L) { + LStream *p = tolstream(L); + return luaL_execresult(L, l_pclose(L, p->f)); +} + + +static int io_popen (lua_State *L) { + const char *filename = luaL_checkstring(L, 1); + const char *mode = luaL_optstring(L, 2, "r"); + LStream *p = newprefile(L); + p->f = l_popen(L, filename, mode); + p->closef = &io_pclose; + return (p->f == NULL) ? luaL_fileresult(L, 0, filename) : 1; +} + + +static int io_tmpfile (lua_State *L) { + LStream *p = newfile(L); + p->f = tmpfile(); + return (p->f == NULL) ? luaL_fileresult(L, 0, NULL) : 1; +} + + +static FILE *getiofile (lua_State *L, const char *findex) { + LStream *p; + lua_getfield(L, LUA_REGISTRYINDEX, findex); + p = (LStream *)lua_touserdata(L, -1); + if (isclosed(p)) + luaL_error(L, "standard %s file is closed", findex + IOPREF_LEN); + return p->f; +} + + +static int g_iofile (lua_State *L, const char *f, const char *mode) { + if (!lua_isnoneornil(L, 1)) { + const char *filename = lua_tostring(L, 1); + if (filename) + opencheck(L, filename, mode); + else { + tofile(L); /* check that it's a valid file handle */ + lua_pushvalue(L, 1); + } + lua_setfield(L, LUA_REGISTRYINDEX, f); + } + /* return current value */ + lua_getfield(L, LUA_REGISTRYINDEX, f); + return 1; +} + + +static int io_input (lua_State *L) { + return g_iofile(L, IO_INPUT, "r"); +} + + +static int io_output (lua_State *L) { + return g_iofile(L, IO_OUTPUT, "w"); +} + + +static int io_readline (lua_State *L); + + +static void aux_lines (lua_State *L, int toclose) { + int n = lua_gettop(L) - 1; /* number of arguments to read */ + lua_pushinteger(L, n); /* number of arguments to read */ + lua_pushboolean(L, toclose); /* close/not close file when finished */ + lua_rotate(L, 2, 2); /* move 'n' and 'toclose' to their positions */ + lua_pushcclosure(L, io_readline, 3 + n); +} + + +static int f_lines (lua_State *L) { + tofile(L); /* check that it's a valid file handle */ + aux_lines(L, 0); + return 1; +} + + +static int io_lines (lua_State *L) { + int toclose; + if (lua_isnone(L, 1)) lua_pushnil(L); /* at least one argument */ + if (lua_isnil(L, 1)) { /* no file name? */ + lua_getfield(L, LUA_REGISTRYINDEX, IO_INPUT); /* get default input */ + lua_replace(L, 1); /* put it at index 1 */ + tofile(L); /* check that it's a valid file handle */ + toclose = 0; /* do not close it after iteration */ + } + else { /* open a new file */ + const char *filename = luaL_checkstring(L, 1); + opencheck(L, filename, "r"); + lua_replace(L, 1); /* put file at index 1 */ + toclose = 1; /* close it after iteration */ + } + aux_lines(L, toclose); + return 1; +} + + +/* +** {====================================================== +** READ +** ======================================================= +*/ + + +/* maximum length of a numeral */ +#define MAXRN 200 + +/* auxiliary structure used by 'read_number' */ +typedef struct { + FILE *f; /* file being read */ + int c; /* current character (look ahead) */ + int n; /* number of elements in buffer 'buff' */ + char buff[MAXRN + 1]; /* +1 for ending '\0' */ +} RN; + + +/* +** Add current char to buffer (if not out of space) and read next one +*/ +static int nextc (RN *rn) { + if (rn->n >= MAXRN) { /* buffer overflow? */ + rn->buff[0] = '\0'; /* invalidate result */ + return 0; /* fail */ + } + else { + rn->buff[rn->n++] = rn->c; /* save current char */ + rn->c = l_getc(rn->f); /* read next one */ + return 1; + } +} + + +/* +** Accept current char if it is in 'set' (of size 1 or 2) +*/ +static int test2 (RN *rn, const char *set) { + if (rn->c == set[0] || (rn->c == set[1] && rn->c != '\0')) + return nextc(rn); + else return 0; +} + + +/* +** Read a sequence of (hex)digits +*/ +static int readdigits (RN *rn, int hex) { + int count = 0; + while ((hex ? isxdigit(rn->c) : isdigit(rn->c)) && nextc(rn)) + count++; + return count; +} + + +/* access to locale "radix character" (decimal point) */ +#if !defined(l_getlocaledecpoint) +#define l_getlocaledecpoint() (localeconv()->decimal_point[0]) +#endif + + +/* +** Read a number: first reads a valid prefix of a numeral into a buffer. +** Then it calls 'lua_stringtonumber' to check whether the format is +** correct and to convert it to a Lua number +*/ +static int read_number (lua_State *L, FILE *f) { + RN rn; + int count = 0; + int hex = 0; + char decp[2] = "."; + rn.f = f; rn.n = 0; + decp[0] = l_getlocaledecpoint(); /* get decimal point from locale */ + l_lockfile(rn.f); + do { rn.c = l_getc(rn.f); } while (isspace(rn.c)); /* skip spaces */ + test2(&rn, "-+"); /* optional signal */ + if (test2(&rn, "0")) { + if (test2(&rn, "xX")) hex = 1; /* numeral is hexadecimal */ + else count = 1; /* count initial '0' as a valid digit */ + } + count += readdigits(&rn, hex); /* integral part */ + if (test2(&rn, decp)) /* decimal point? */ + count += readdigits(&rn, hex); /* fractional part */ + if (count > 0 && test2(&rn, (hex ? "pP" : "eE"))) { /* exponent mark? */ + test2(&rn, "-+"); /* exponent signal */ + readdigits(&rn, 0); /* exponent digits */ + } + ungetc(rn.c, rn.f); /* unread look-ahead char */ + l_unlockfile(rn.f); + rn.buff[rn.n] = '\0'; /* finish string */ + if (lua_stringtonumber(L, rn.buff)) /* is this a valid number? */ + return 1; /* ok */ + else { /* invalid format */ + lua_pushnil(L); /* "result" to be removed */ + return 0; /* read fails */ + } +} + + +static int test_eof (lua_State *L, FILE *f) { + int c = getc(f); + ungetc(c, f); /* no-op when c == EOF */ + lua_pushlstring(L, NULL, 0); + return (c != EOF); +} + + +static int read_line (lua_State *L, FILE *f, int chop) { + luaL_Buffer b; + int c = '\0'; + luaL_buffinit(L, &b); + while (c != EOF && c != '\n') { /* repeat until end of line */ + char *buff = luaL_prepbuffer(&b); /* pre-allocate buffer */ + int i = 0; + l_lockfile(f); /* no memory errors can happen inside the lock */ + while (i < LUAL_BUFFERSIZE && (c = l_getc(f)) != EOF && c != '\n') + buff[i++] = c; + l_unlockfile(f); + luaL_addsize(&b, i); + } + if (!chop && c == '\n') /* want a newline and have one? */ + luaL_addchar(&b, c); /* add ending newline to result */ + luaL_pushresult(&b); /* close buffer */ + /* return ok if read something (either a newline or something else) */ + return (c == '\n' || lua_rawlen(L, -1) > 0); +} + + +static void read_all (lua_State *L, FILE *f) { + size_t nr; + luaL_Buffer b; + luaL_buffinit(L, &b); + do { /* read file in chunks of LUAL_BUFFERSIZE bytes */ + char *p = luaL_prepbuffsize(&b, LUAL_BUFFERSIZE); + nr = fread(p, sizeof(char), LUAL_BUFFERSIZE, f); + luaL_addsize(&b, nr); + } while (nr == LUAL_BUFFERSIZE); + luaL_pushresult(&b); /* close buffer */ +} + + +static int read_chars (lua_State *L, FILE *f, size_t n) { + size_t nr; /* number of chars actually read */ + char *p; + luaL_Buffer b; + luaL_buffinit(L, &b); + p = luaL_prepbuffsize(&b, n); /* prepare buffer to read whole block */ + nr = fread(p, sizeof(char), n, f); /* try to read 'n' chars */ + luaL_addsize(&b, nr); + luaL_pushresult(&b); /* close buffer */ + return (nr > 0); /* true iff read something */ +} + + +static int g_read (lua_State *L, FILE *f, int first) { + int nargs = lua_gettop(L) - 1; + int success; + int n; + clearerr(f); + if (nargs == 0) { /* no arguments? */ + success = read_line(L, f, 1); + n = first+1; /* to return 1 result */ + } + else { /* ensure stack space for all results and for auxlib's buffer */ + luaL_checkstack(L, nargs+LUA_MINSTACK, "too many arguments"); + success = 1; + for (n = first; nargs-- && success; n++) { + if (lua_type(L, n) == LUA_TNUMBER) { + size_t l = (size_t)luaL_checkinteger(L, n); + success = (l == 0) ? test_eof(L, f) : read_chars(L, f, l); + } + else { + const char *p = luaL_checkstring(L, n); + if (*p == '*') p++; /* skip optional '*' (for compatibility) */ + switch (*p) { + case 'n': /* number */ + success = read_number(L, f); + break; + case 'l': /* line */ + success = read_line(L, f, 1); + break; + case 'L': /* line with end-of-line */ + success = read_line(L, f, 0); + break; + case 'a': /* file */ + read_all(L, f); /* read entire file */ + success = 1; /* always success */ + break; + default: + return luaL_argerror(L, n, "invalid format"); + } + } + } + } + if (ferror(f)) + return luaL_fileresult(L, 0, NULL); + if (!success) { + lua_pop(L, 1); /* remove last result */ + lua_pushnil(L); /* push nil instead */ + } + return n - first; +} + + +static int io_read (lua_State *L) { + return g_read(L, getiofile(L, IO_INPUT), 1); +} + + +static int f_read (lua_State *L) { + return g_read(L, tofile(L), 2); +} + + +static int io_readline (lua_State *L) { + LStream *p = (LStream *)lua_touserdata(L, lua_upvalueindex(1)); + int i; + int n = (int)lua_tointeger(L, lua_upvalueindex(2)); + if (isclosed(p)) /* file is already closed? */ + return luaL_error(L, "file is already closed"); + lua_settop(L , 1); + luaL_checkstack(L, n, "too many arguments"); + for (i = 1; i <= n; i++) /* push arguments to 'g_read' */ + lua_pushvalue(L, lua_upvalueindex(3 + i)); + n = g_read(L, p->f, 2); /* 'n' is number of results */ + lua_assert(n > 0); /* should return at least a nil */ + if (lua_toboolean(L, -n)) /* read at least one value? */ + return n; /* return them */ + else { /* first result is nil: EOF or error */ + if (n > 1) { /* is there error information? */ + /* 2nd result is error message */ + return luaL_error(L, "%s", lua_tostring(L, -n + 1)); + } + if (lua_toboolean(L, lua_upvalueindex(3))) { /* generator created file? */ + lua_settop(L, 0); + lua_pushvalue(L, lua_upvalueindex(1)); + aux_close(L); /* close it */ + } + return 0; + } +} + +/* }====================================================== */ + + +static int g_write (lua_State *L, FILE *f, int arg) { + int nargs = lua_gettop(L) - arg; + int status = 1; + for (; nargs--; arg++) { + if (lua_type(L, arg) == LUA_TNUMBER) { + /* optimization: could be done exactly as for strings */ + int len = lua_isinteger(L, arg) + ? fprintf(f, LUA_INTEGER_FMT, lua_tointeger(L, arg)) + : fprintf(f, LUA_NUMBER_FMT, lua_tonumber(L, arg)); + status = status && (len > 0); + } + else { + size_t l; + const char *s = luaL_checklstring(L, arg, &l); + status = status && (fwrite(s, sizeof(char), l, f) == l); + } + } + if (status) return 1; /* file handle already on stack top */ + else return luaL_fileresult(L, status, NULL); +} + + +static int io_write (lua_State *L) { + return g_write(L, getiofile(L, IO_OUTPUT), 1); +} + + +static int f_write (lua_State *L) { + FILE *f = tofile(L); + lua_pushvalue(L, 1); /* push file at the stack top (to be returned) */ + return g_write(L, f, 2); +} + + +static int f_seek (lua_State *L) { + static const int mode[] = {SEEK_SET, SEEK_CUR, SEEK_END}; + static const char *const modenames[] = {"set", "cur", "end", NULL}; + FILE *f = tofile(L); + int op = luaL_checkoption(L, 2, "cur", modenames); + lua_Integer p3 = luaL_optinteger(L, 3, 0); + l_seeknum offset = (l_seeknum)p3; + luaL_argcheck(L, (lua_Integer)offset == p3, 3, + "not an integer in proper range"); + op = l_fseek(f, offset, mode[op]); + if (op) + return luaL_fileresult(L, 0, NULL); /* error */ + else { + lua_pushinteger(L, (lua_Integer)l_ftell(f)); + return 1; + } +} + + +static int f_setvbuf (lua_State *L) { + static const int mode[] = {_IONBF, _IOFBF, _IOLBF}; + static const char *const modenames[] = {"no", "full", "line", NULL}; + FILE *f = tofile(L); + int op = luaL_checkoption(L, 2, NULL, modenames); + lua_Integer sz = luaL_optinteger(L, 3, LUAL_BUFFERSIZE); + int res = setvbuf(f, NULL, mode[op], (size_t)sz); + return luaL_fileresult(L, res == 0, NULL); +} + + + +static int io_flush (lua_State *L) { + return luaL_fileresult(L, fflush(getiofile(L, IO_OUTPUT)) == 0, NULL); +} + + +static int f_flush (lua_State *L) { + return luaL_fileresult(L, fflush(tofile(L)) == 0, NULL); +} + + +/* +** functions for 'io' library +*/ +static const luaL_Reg iolib[] = { + {"close", io_close}, + {"flush", io_flush}, + {"input", io_input}, + {"lines", io_lines}, + {"open", io_open}, + {"output", io_output}, + {"popen", io_popen}, + {"read", io_read}, + {"tmpfile", io_tmpfile}, + {"type", io_type}, + {"write", io_write}, + {NULL, NULL} +}; + + +/* +** methods for file handles +*/ +static const luaL_Reg flib[] = { + {"close", io_close}, + {"flush", f_flush}, + {"lines", f_lines}, + {"read", f_read}, + {"seek", f_seek}, + {"setvbuf", f_setvbuf}, + {"write", f_write}, + {"__gc", f_gc}, + {"__tostring", f_tostring}, + {NULL, NULL} +}; + + +static void createmeta (lua_State *L) { + luaL_newmetatable(L, LUA_FILEHANDLE); /* create metatable for file handles */ + lua_pushvalue(L, -1); /* push metatable */ + lua_setfield(L, -2, "__index"); /* metatable.__index = metatable */ + luaL_setfuncs(L, flib, 0); /* add file methods to new metatable */ + lua_pop(L, 1); /* pop new metatable */ +} + + +/* +** function to (not) close the standard files stdin, stdout, and stderr +*/ +static int io_noclose (lua_State *L) { + LStream *p = tolstream(L); + p->closef = &io_noclose; /* keep file opened */ + lua_pushnil(L); + lua_pushliteral(L, "cannot close standard file"); + return 2; +} + + +static void createstdfile (lua_State *L, FILE *f, const char *k, + const char *fname) { + LStream *p = newprefile(L); + p->f = f; + p->closef = &io_noclose; + if (k != NULL) { + lua_pushvalue(L, -1); + lua_setfield(L, LUA_REGISTRYINDEX, k); /* add file to registry */ + } + lua_setfield(L, -2, fname); /* add file to module */ +} + + +LUAMOD_API int luaopen_io (lua_State *L) { + luaL_newlib(L, iolib); /* new module */ + createmeta(L); + /* create (and set) default files */ + createstdfile(L, stdin, IO_INPUT, "stdin"); + createstdfile(L, stdout, IO_OUTPUT, "stdout"); + createstdfile(L, stderr, NULL, "stderr"); + return 1; +} + diff --git a/src/llex.c b/src/llex.c new file mode 100644 index 000000000000..6e4a457ad635 --- /dev/null +++ b/src/llex.c @@ -0,0 +1,602 @@ +/* +** $Id: llex.c,v 2.89 2014/11/14 16:06:09 roberto Exp $ +** Lexical Analyzer +** See Copyright Notice in lua.h +*/ + +#define llex_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <locale.h> +#include <string.h> + +#include "lua.h" + +#include "lctype.h" +#include "ldo.h" +#include "lgc.h" +#include "llex.h" +#include "lobject.h" +#include "lparser.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "lzio.h" + + + +#define next(ls) (ls->current = zgetc(ls->z)) + + + +#define currIsNewline(ls) (ls->current == '\n' || ls->current == '\r') + + +/* ORDER RESERVED */ +static const char *const luaX_tokens [] = { + "and", "break", "do", "else", "elseif", + "end", "false", "for", "function", "goto", "if", + "in", "local", "nil", "not", "or", "repeat", + "return", "then", "true", "until", "while", + "//", "..", "...", "==", ">=", "<=", "~=", + "<<", ">>", "::", "<eof>", + "<number>", "<integer>", "<name>", "<string>" +}; + + +#define save_and_next(ls) (save(ls, ls->current), next(ls)) + + +static l_noret lexerror (LexState *ls, const char *msg, int token); + + +static void save (LexState *ls, int c) { + Mbuffer *b = ls->buff; + if (luaZ_bufflen(b) + 1 > luaZ_sizebuffer(b)) { + size_t newsize; + if (luaZ_sizebuffer(b) >= MAX_SIZE/2) + lexerror(ls, "lexical element too long", 0); + newsize = luaZ_sizebuffer(b) * 2; + luaZ_resizebuffer(ls->L, b, newsize); + } + b->buffer[luaZ_bufflen(b)++] = cast(char, c); +} + + +void luaX_init (lua_State *L) { + int i; + TString *e = luaS_new(L, LUA_ENV); /* create env name */ + luaC_fix(L, obj2gco(e)); /* never collect this name */ + for (i=0; i<NUM_RESERVED; i++) { + TString *ts = luaS_new(L, luaX_tokens[i]); + luaC_fix(L, obj2gco(ts)); /* reserved words are never collected */ + ts->extra = cast_byte(i+1); /* reserved word */ + } +} + + +const char *luaX_token2str (LexState *ls, int token) { + if (token < FIRST_RESERVED) { /* single-byte symbols? */ + lua_assert(token == cast_uchar(token)); + return luaO_pushfstring(ls->L, "'%c'", token); + } + else { + const char *s = luaX_tokens[token - FIRST_RESERVED]; + if (token < TK_EOS) /* fixed format (symbols and reserved words)? */ + return luaO_pushfstring(ls->L, "'%s'", s); + else /* names, strings, and numerals */ + return s; + } +} + + +static const char *txtToken (LexState *ls, int token) { + switch (token) { + case TK_NAME: case TK_STRING: + case TK_FLT: case TK_INT: + save(ls, '\0'); + return luaO_pushfstring(ls->L, "'%s'", luaZ_buffer(ls->buff)); + default: + return luaX_token2str(ls, token); + } +} + + +static l_noret lexerror (LexState *ls, const char *msg, int token) { + char buff[LUA_IDSIZE]; + luaO_chunkid(buff, getstr(ls->source), LUA_IDSIZE); + msg = luaO_pushfstring(ls->L, "%s:%d: %s", buff, ls->linenumber, msg); + if (token) + luaO_pushfstring(ls->L, "%s near %s", msg, txtToken(ls, token)); + luaD_throw(ls->L, LUA_ERRSYNTAX); +} + + +l_noret luaX_syntaxerror (LexState *ls, const char *msg) { + lexerror(ls, msg, ls->t.token); +} + + +/* +** creates a new string and anchors it in scanner's table so that +** it will not be collected until the end of the compilation +** (by that time it should be anchored somewhere) +*/ +TString *luaX_newstring (LexState *ls, const char *str, size_t l) { + lua_State *L = ls->L; + TValue *o; /* entry for 'str' */ + TString *ts = luaS_newlstr(L, str, l); /* create new string */ + setsvalue2s(L, L->top++, ts); /* temporarily anchor it in stack */ + o = luaH_set(L, ls->h, L->top - 1); + if (ttisnil(o)) { /* not in use yet? */ + /* boolean value does not need GC barrier; + table has no metatable, so it does not need to invalidate cache */ + setbvalue(o, 1); /* t[string] = true */ + luaC_checkGC(L); + } + else { /* string already present */ + ts = tsvalue(keyfromval(o)); /* re-use value previously stored */ + } + L->top--; /* remove string from stack */ + return ts; +} + + +/* +** increment line number and skips newline sequence (any of +** \n, \r, \n\r, or \r\n) +*/ +static void inclinenumber (LexState *ls) { + int old = ls->current; + lua_assert(currIsNewline(ls)); + next(ls); /* skip '\n' or '\r' */ + if (currIsNewline(ls) && ls->current != old) + next(ls); /* skip '\n\r' or '\r\n' */ + if (++ls->linenumber >= MAX_INT) + lexerror(ls, "chunk has too many lines", 0); +} + + +void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, TString *source, + int firstchar) { + ls->t.token = 0; + ls->decpoint = '.'; + ls->L = L; + ls->current = firstchar; + ls->lookahead.token = TK_EOS; /* no look-ahead token */ + ls->z = z; + ls->fs = NULL; + ls->linenumber = 1; + ls->lastline = 1; + ls->source = source; + ls->envn = luaS_new(L, LUA_ENV); /* get env name */ + luaZ_resizebuffer(ls->L, ls->buff, LUA_MINBUFFER); /* initialize buffer */ +} + + + +/* +** ======================================================= +** LEXICAL ANALYZER +** ======================================================= +*/ + + +static int check_next1 (LexState *ls, int c) { + if (ls->current == c) { + next(ls); + return 1; + } + else return 0; +} + + +/* +** Check whether current char is in set 'set' (with two chars) and +** saves it +*/ +static int check_next2 (LexState *ls, const char *set) { + lua_assert(set[2] == '\0'); + if (ls->current == set[0] || ls->current == set[1]) { + save_and_next(ls); + return 1; + } + else return 0; +} + + +/* +** change all characters 'from' in buffer to 'to' +*/ +static void buffreplace (LexState *ls, char from, char to) { + if (from != to) { + size_t n = luaZ_bufflen(ls->buff); + char *p = luaZ_buffer(ls->buff); + while (n--) + if (p[n] == from) p[n] = to; + } +} + + +#if !defined(l_getlocaledecpoint) +#define l_getlocaledecpoint() (localeconv()->decimal_point[0]) +#endif + + +#define buff2num(b,o) (luaO_str2num(luaZ_buffer(b), o) != 0) + +/* +** in case of format error, try to change decimal point separator to +** the one defined in the current locale and check again +*/ +static void trydecpoint (LexState *ls, TValue *o) { + char old = ls->decpoint; + ls->decpoint = l_getlocaledecpoint(); + buffreplace(ls, old, ls->decpoint); /* try new decimal separator */ + if (!buff2num(ls->buff, o)) { + /* format error with correct decimal point: no more options */ + buffreplace(ls, ls->decpoint, '.'); /* undo change (for error message) */ + lexerror(ls, "malformed number", TK_FLT); + } +} + + +/* LUA_NUMBER */ +/* +** this function is quite liberal in what it accepts, as 'luaO_str2num' +** will reject ill-formed numerals. +*/ +static int read_numeral (LexState *ls, SemInfo *seminfo) { + TValue obj; + const char *expo = "Ee"; + int first = ls->current; + lua_assert(lisdigit(ls->current)); + save_and_next(ls); + if (first == '0' && check_next2(ls, "xX")) /* hexadecimal? */ + expo = "Pp"; + for (;;) { + if (check_next2(ls, expo)) /* exponent part? */ + check_next2(ls, "-+"); /* optional exponent sign */ + if (lisxdigit(ls->current)) + save_and_next(ls); + else if (ls->current == '.') + save_and_next(ls); + else break; + } + save(ls, '\0'); + buffreplace(ls, '.', ls->decpoint); /* follow locale for decimal point */ + if (!buff2num(ls->buff, &obj)) /* format error? */ + trydecpoint(ls, &obj); /* try to update decimal point separator */ + if (ttisinteger(&obj)) { + seminfo->i = ivalue(&obj); + return TK_INT; + } + else { + lua_assert(ttisfloat(&obj)); + seminfo->r = fltvalue(&obj); + return TK_FLT; + } +} + + +/* +** skip a sequence '[=*[' or ']=*]' and return its number of '='s or +** -1 if sequence is malformed +*/ +static int skip_sep (LexState *ls) { + int count = 0; + int s = ls->current; + lua_assert(s == '[' || s == ']'); + save_and_next(ls); + while (ls->current == '=') { + save_and_next(ls); + count++; + } + return (ls->current == s) ? count : (-count) - 1; +} + + +static void read_long_string (LexState *ls, SemInfo *seminfo, int sep) { + int line = ls->linenumber; /* initial line (for error message) */ + save_and_next(ls); /* skip 2nd '[' */ + if (currIsNewline(ls)) /* string starts with a newline? */ + inclinenumber(ls); /* skip it */ + for (;;) { + switch (ls->current) { + case EOZ: { /* error */ + const char *what = (seminfo ? "string" : "comment"); + const char *msg = luaO_pushfstring(ls->L, + "unfinished long %s (starting at line %d)", what, line); + lexerror(ls, msg, TK_EOS); + break; /* to avoid warnings */ + } + case ']': { + if (skip_sep(ls) == sep) { + save_and_next(ls); /* skip 2nd ']' */ + goto endloop; + } + break; + } + case '\n': case '\r': { + save(ls, '\n'); + inclinenumber(ls); + if (!seminfo) luaZ_resetbuffer(ls->buff); /* avoid wasting space */ + break; + } + default: { + if (seminfo) save_and_next(ls); + else next(ls); + } + } + } endloop: + if (seminfo) + seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + (2 + sep), + luaZ_bufflen(ls->buff) - 2*(2 + sep)); +} + + +static void esccheck (LexState *ls, int c, const char *msg) { + if (!c) { + if (ls->current != EOZ) + save_and_next(ls); /* add current to buffer for error message */ + lexerror(ls, msg, TK_STRING); + } +} + + +static int gethexa (LexState *ls) { + save_and_next(ls); + esccheck (ls, lisxdigit(ls->current), "hexadecimal digit expected"); + return luaO_hexavalue(ls->current); +} + + +static int readhexaesc (LexState *ls) { + int r = gethexa(ls); + r = (r << 4) + gethexa(ls); + luaZ_buffremove(ls->buff, 2); /* remove saved chars from buffer */ + return r; +} + + +static unsigned long readutf8esc (LexState *ls) { + unsigned long r; + int i = 4; /* chars to be removed: '\', 'u', '{', and first digit */ + save_and_next(ls); /* skip 'u' */ + esccheck(ls, ls->current == '{', "missing '{'"); + r = gethexa(ls); /* must have at least one digit */ + while ((save_and_next(ls), lisxdigit(ls->current))) { + i++; + r = (r << 4) + luaO_hexavalue(ls->current); + esccheck(ls, r <= 0x10FFFF, "UTF-8 value too large"); + } + esccheck(ls, ls->current == '}', "missing '}'"); + next(ls); /* skip '}' */ + luaZ_buffremove(ls->buff, i); /* remove saved chars from buffer */ + return r; +} + + +static void utf8esc (LexState *ls) { + char buff[UTF8BUFFSZ]; + int n = luaO_utf8esc(buff, readutf8esc(ls)); + for (; n > 0; n--) /* add 'buff' to string */ + save(ls, buff[UTF8BUFFSZ - n]); +} + + +static int readdecesc (LexState *ls) { + int i; + int r = 0; /* result accumulator */ + for (i = 0; i < 3 && lisdigit(ls->current); i++) { /* read up to 3 digits */ + r = 10*r + ls->current - '0'; + save_and_next(ls); + } + esccheck(ls, r <= UCHAR_MAX, "decimal escape too large"); + luaZ_buffremove(ls->buff, i); /* remove read digits from buffer */ + return r; +} + + +static void read_string (LexState *ls, int del, SemInfo *seminfo) { + save_and_next(ls); /* keep delimiter (for error messages) */ + while (ls->current != del) { + switch (ls->current) { + case EOZ: + lexerror(ls, "unfinished string", TK_EOS); + break; /* to avoid warnings */ + case '\n': + case '\r': + lexerror(ls, "unfinished string", TK_STRING); + break; /* to avoid warnings */ + case '\\': { /* escape sequences */ + int c; /* final character to be saved */ + save_and_next(ls); /* keep '\\' for error messages */ + switch (ls->current) { + case 'a': c = '\a'; goto read_save; + case 'b': c = '\b'; goto read_save; + case 'f': c = '\f'; goto read_save; + case 'n': c = '\n'; goto read_save; + case 'r': c = '\r'; goto read_save; + case 't': c = '\t'; goto read_save; + case 'v': c = '\v'; goto read_save; + case 'x': c = readhexaesc(ls); goto read_save; + case 'u': utf8esc(ls); goto no_save; + case '\n': case '\r': + inclinenumber(ls); c = '\n'; goto only_save; + case '\\': case '\"': case '\'': + c = ls->current; goto read_save; + case EOZ: goto no_save; /* will raise an error next loop */ + case 'z': { /* zap following span of spaces */ + luaZ_buffremove(ls->buff, 1); /* remove '\\' */ + next(ls); /* skip the 'z' */ + while (lisspace(ls->current)) { + if (currIsNewline(ls)) inclinenumber(ls); + else next(ls); + } + goto no_save; + } + default: { + esccheck(ls, lisdigit(ls->current), "invalid escape sequence"); + c = readdecesc(ls); /* digital escape '\ddd' */ + goto only_save; + } + } + read_save: + next(ls); + /* go through */ + only_save: + luaZ_buffremove(ls->buff, 1); /* remove '\\' */ + save(ls, c); + /* go through */ + no_save: break; + } + default: + save_and_next(ls); + } + } + save_and_next(ls); /* skip delimiter */ + seminfo->ts = luaX_newstring(ls, luaZ_buffer(ls->buff) + 1, + luaZ_bufflen(ls->buff) - 2); +} + + +static int llex (LexState *ls, SemInfo *seminfo) { + luaZ_resetbuffer(ls->buff); + for (;;) { + switch (ls->current) { + case '\n': case '\r': { /* line breaks */ + inclinenumber(ls); + break; + } + case ' ': case '\f': case '\t': case '\v': { /* spaces */ + next(ls); + break; + } + case '-': { /* '-' or '--' (comment) */ + next(ls); + if (ls->current != '-') return '-'; + /* else is a comment */ + next(ls); + if (ls->current == '[') { /* long comment? */ + int sep = skip_sep(ls); + luaZ_resetbuffer(ls->buff); /* 'skip_sep' may dirty the buffer */ + if (sep >= 0) { + read_long_string(ls, NULL, sep); /* skip long comment */ + luaZ_resetbuffer(ls->buff); /* previous call may dirty the buff. */ + break; + } + } + /* else short comment */ + while (!currIsNewline(ls) && ls->current != EOZ) + next(ls); /* skip until end of line (or end of file) */ + break; + } + case '[': { /* long string or simply '[' */ + int sep = skip_sep(ls); + if (sep >= 0) { + read_long_string(ls, seminfo, sep); + return TK_STRING; + } + else if (sep == -1) return '['; + else lexerror(ls, "invalid long string delimiter", TK_STRING); + } + case '=': { + next(ls); + if (check_next1(ls, '=')) return TK_EQ; + else return '='; + } + case '<': { + next(ls); + if (check_next1(ls, '=')) return TK_LE; + else if (check_next1(ls, '<')) return TK_SHL; + else return '<'; + } + case '>': { + next(ls); + if (check_next1(ls, '=')) return TK_GE; + else if (check_next1(ls, '>')) return TK_SHR; + else return '>'; + } + case '/': { + next(ls); + if (check_next1(ls, '/')) return TK_IDIV; + else return '/'; + } + case '~': { + next(ls); + if (check_next1(ls, '=')) return TK_NE; + else return '~'; + } + case ':': { + next(ls); + if (check_next1(ls, ':')) return TK_DBCOLON; + else return ':'; + } + case '"': case '\'': { /* short literal strings */ + read_string(ls, ls->current, seminfo); + return TK_STRING; + } + case '.': { /* '.', '..', '...', or number */ + save_and_next(ls); + if (check_next1(ls, '.')) { + if (check_next1(ls, '.')) + return TK_DOTS; /* '...' */ + else return TK_CONCAT; /* '..' */ + } + else if (!lisdigit(ls->current)) return '.'; + else return read_numeral(ls, seminfo); + } + case '0': case '1': case '2': case '3': case '4': + case '5': case '6': case '7': case '8': case '9': { + return read_numeral(ls, seminfo); + } + case EOZ: { + return TK_EOS; + } + default: { + if (lislalpha(ls->current)) { /* identifier or reserved word? */ + TString *ts; + do { + save_and_next(ls); + } while (lislalnum(ls->current)); + ts = luaX_newstring(ls, luaZ_buffer(ls->buff), + luaZ_bufflen(ls->buff)); + seminfo->ts = ts; + if (isreserved(ts)) /* reserved word? */ + return ts->extra - 1 + FIRST_RESERVED; + else { + return TK_NAME; + } + } + else { /* single-char tokens (+ - / ...) */ + int c = ls->current; + next(ls); + return c; + } + } + } + } +} + + +void luaX_next (LexState *ls) { + ls->lastline = ls->linenumber; + if (ls->lookahead.token != TK_EOS) { /* is there a look-ahead token? */ + ls->t = ls->lookahead; /* use this one */ + ls->lookahead.token = TK_EOS; /* and discharge it */ + } + else + ls->t.token = llex(ls, &ls->t.seminfo); /* read next token */ +} + + +int luaX_lookahead (LexState *ls) { + lua_assert(ls->lookahead.token == TK_EOS); + ls->lookahead.token = llex(ls, &ls->lookahead.seminfo); + return ls->lookahead.token; +} + diff --git a/src/llex.h b/src/llex.h new file mode 100644 index 000000000000..afb40b56228f --- /dev/null +++ b/src/llex.h @@ -0,0 +1,86 @@ +/* +** $Id: llex.h,v 1.78 2014/10/29 15:38:24 roberto Exp $ +** Lexical Analyzer +** See Copyright Notice in lua.h +*/ + +#ifndef llex_h +#define llex_h + +#include "lobject.h" +#include "lzio.h" + + +#define FIRST_RESERVED 257 + + +#if !defined(LUA_ENV) +#define LUA_ENV "_ENV" +#endif + + +/* +* WARNING: if you change the order of this enumeration, +* grep "ORDER RESERVED" +*/ +enum RESERVED { + /* terminal symbols denoted by reserved words */ + TK_AND = FIRST_RESERVED, TK_BREAK, + TK_DO, TK_ELSE, TK_ELSEIF, TK_END, TK_FALSE, TK_FOR, TK_FUNCTION, + TK_GOTO, TK_IF, TK_IN, TK_LOCAL, TK_NIL, TK_NOT, TK_OR, TK_REPEAT, + TK_RETURN, TK_THEN, TK_TRUE, TK_UNTIL, TK_WHILE, + /* other terminal symbols */ + TK_IDIV, TK_CONCAT, TK_DOTS, TK_EQ, TK_GE, TK_LE, TK_NE, + TK_SHL, TK_SHR, + TK_DBCOLON, TK_EOS, + TK_FLT, TK_INT, TK_NAME, TK_STRING +}; + +/* number of reserved words */ +#define NUM_RESERVED (cast(int, TK_WHILE-FIRST_RESERVED+1)) + + +typedef union { + lua_Number r; + lua_Integer i; + TString *ts; +} SemInfo; /* semantics information */ + + +typedef struct Token { + int token; + SemInfo seminfo; +} Token; + + +/* state of the lexer plus state of the parser when shared by all + functions */ +typedef struct LexState { + int current; /* current character (charint) */ + int linenumber; /* input line counter */ + int lastline; /* line of last token 'consumed' */ + Token t; /* current token */ + Token lookahead; /* look ahead token */ + struct FuncState *fs; /* current function (parser) */ + struct lua_State *L; + ZIO *z; /* input stream */ + Mbuffer *buff; /* buffer for tokens */ + Table *h; /* to avoid collection/reuse strings */ + struct Dyndata *dyd; /* dynamic structures used by the parser */ + TString *source; /* current source name */ + TString *envn; /* environment variable name */ + char decpoint; /* locale decimal point */ +} LexState; + + +LUAI_FUNC void luaX_init (lua_State *L); +LUAI_FUNC void luaX_setinput (lua_State *L, LexState *ls, ZIO *z, + TString *source, int firstchar); +LUAI_FUNC TString *luaX_newstring (LexState *ls, const char *str, size_t l); +LUAI_FUNC void luaX_next (LexState *ls); +LUAI_FUNC int luaX_lookahead (LexState *ls); +LUAI_FUNC l_noret luaX_syntaxerror (LexState *ls, const char *s); +LUAI_FUNC const char *luaX_token2str (LexState *ls, int token); + + +#endif diff --git a/src/llimits.h b/src/llimits.h new file mode 100644 index 000000000000..8f71a6ffb951 --- /dev/null +++ b/src/llimits.h @@ -0,0 +1,242 @@ +/* +** $Id: llimits.h,v 1.125 2014/12/19 13:30:23 roberto Exp $ +** Limits, basic types, and some other 'installation-dependent' definitions +** See Copyright Notice in lua.h +*/ + +#ifndef llimits_h +#define llimits_h + + +#include <limits.h> +#include <stddef.h> + + +#include "lua.h" + +/* +** 'lu_mem' and 'l_mem' are unsigned/signed integers big enough to count +** the total memory used by Lua (in bytes). Usually, 'size_t' and +** 'ptrdiff_t' should work, but we use 'long' for 16-bit machines. +*/ +#if defined(LUAI_MEM) /* { external definitions? */ +typedef LUAI_UMEM lu_mem; +typedef LUAI_MEM l_mem; +#elif LUAI_BITSINT >= 32 /* }{ */ +typedef size_t lu_mem; +typedef ptrdiff_t l_mem; +#else /* 16-bit ints */ /* }{ */ +typedef unsigned long lu_mem; +typedef long l_mem; +#endif /* } */ + + +/* chars used as small naturals (so that 'char' is reserved for characters) */ +typedef unsigned char lu_byte; + + +/* maximum value for size_t */ +#define MAX_SIZET ((size_t)(~(size_t)0)) + +/* maximum size visible for Lua (must be representable in a lua_Integer */ +#define MAX_SIZE (sizeof(size_t) < sizeof(lua_Integer) ? MAX_SIZET \ + : (size_t)(LUA_MAXINTEGER)) + + +#define MAX_LUMEM ((lu_mem)(~(lu_mem)0)) + +#define MAX_LMEM ((l_mem)(MAX_LUMEM >> 1)) + + +#define MAX_INT INT_MAX /* maximum value of an int */ + + +/* +** conversion of pointer to integer: +** this is for hashing only; there is no problem if the integer +** cannot hold the whole pointer value +*/ +#define point2int(p) ((unsigned int)((size_t)(p) & UINT_MAX)) + + + +/* type to ensure maximum alignment */ +#if defined(LUAI_USER_ALIGNMENT_T) +typedef LUAI_USER_ALIGNMENT_T L_Umaxalign; +#else +typedef union { double u; void *s; lua_Integer i; long l; } L_Umaxalign; +#endif + + + +/* types of 'usual argument conversions' for lua_Number and lua_Integer */ +typedef LUAI_UACNUMBER l_uacNumber; +typedef LUAI_UACINT l_uacInt; + + +/* internal assertions for in-house debugging */ +#if defined(lua_assert) +#define check_exp(c,e) (lua_assert(c), (e)) +/* to avoid problems with conditions too long */ +#define lua_longassert(c) { if (!(c)) lua_assert(0); } +#else +#define lua_assert(c) ((void)0) +#define check_exp(c,e) (e) +#define lua_longassert(c) ((void)0) +#endif + +/* +** assertion for checking API calls +*/ +#if defined(LUA_USE_APICHECK) +#include <assert.h> +#define luai_apicheck(e) assert(e) +#else +#define luai_apicheck(e) lua_assert(e) +#endif + + +#define api_check(e,msg) luai_apicheck((e) && msg) + + +#if !defined(UNUSED) +#define UNUSED(x) ((void)(x)) /* to avoid warnings */ +#endif + + +#define cast(t, exp) ((t)(exp)) + +#define cast_void(i) cast(void, (i)) +#define cast_byte(i) cast(lu_byte, (i)) +#define cast_num(i) cast(lua_Number, (i)) +#define cast_int(i) cast(int, (i)) +#define cast_uchar(i) cast(unsigned char, (i)) + + +/* cast a signed lua_Integer to lua_Unsigned */ +#if !defined(l_castS2U) +#define l_castS2U(i) ((lua_Unsigned)(i)) +#endif + +/* +** cast a lua_Unsigned to a signed lua_Integer; this cast is +** not strict ISO C, but two-complement architectures should +** work fine. +*/ +#if !defined(l_castU2S) +#define l_castU2S(i) ((lua_Integer)(i)) +#endif + + +/* +** non-return type +*/ +#if defined(__GNUC__) +#define l_noret void __attribute__((noreturn)) +#elif defined(_MSC_VER) && _MSC_VER >= 1200 +#define l_noret void __declspec(noreturn) +#else +#define l_noret void +#endif + + + +/* +** maximum depth for nested C calls and syntactical nested non-terminals +** in a program. (Value must fit in an unsigned short int.) +*/ +#if !defined(LUAI_MAXCCALLS) +#define LUAI_MAXCCALLS 200 +#endif + +/* +** maximum number of upvalues in a closure (both C and Lua). (Value +** must fit in an unsigned char.) +*/ +#define MAXUPVAL UCHAR_MAX + + +/* +** type for virtual-machine instructions; +** must be an unsigned with (at least) 4 bytes (see details in lopcodes.h) +*/ +#if LUAI_BITSINT >= 32 +typedef unsigned int Instruction; +#else +typedef unsigned long Instruction; +#endif + + + + +/* minimum size for the string table (must be power of 2) */ +#if !defined(MINSTRTABSIZE) +#define MINSTRTABSIZE 64 /* minimum size for "predefined" strings */ +#endif + + +/* minimum size for string buffer */ +#if !defined(LUA_MINBUFFER) +#define LUA_MINBUFFER 32 +#endif + + +#if !defined(lua_lock) +#define lua_lock(L) ((void) 0) +#define lua_unlock(L) ((void) 0) +#endif + +#if !defined(luai_threadyield) +#define luai_threadyield(L) {lua_unlock(L); lua_lock(L);} +#endif + + +/* +** these macros allow user-specific actions on threads when you defined +** LUAI_EXTRASPACE and need to do something extra when a thread is +** created/deleted/resumed/yielded. +*/ +#if !defined(luai_userstateopen) +#define luai_userstateopen(L) ((void)L) +#endif + +#if !defined(luai_userstateclose) +#define luai_userstateclose(L) ((void)L) +#endif + +#if !defined(luai_userstatethread) +#define luai_userstatethread(L,L1) ((void)L) +#endif + +#if !defined(luai_userstatefree) +#define luai_userstatefree(L,L1) ((void)L) +#endif + +#if !defined(luai_userstateresume) +#define luai_userstateresume(L,n) ((void)L) +#endif + +#if !defined(luai_userstateyield) +#define luai_userstateyield(L,n) ((void)L) +#endif + + + +/* +** macro to control inclusion of some hard tests on stack reallocation +*/ +#if !defined(HARDSTACKTESTS) +#define condmovestack(L) ((void)0) +#else +/* realloc stack keeping its size */ +#define condmovestack(L) luaD_reallocstack((L), (L)->stacksize) +#endif + +#if !defined(HARDMEMTESTS) +#define condchangemem(L) condmovestack(L) +#else +#define condchangemem(L) \ + ((void)(!(G(L)->gcrunning) || (luaC_fullgc(L, 0), 1))) +#endif + +#endif diff --git a/src/lmathlib.c b/src/lmathlib.c new file mode 100644 index 000000000000..002c508bc465 --- /dev/null +++ b/src/lmathlib.c @@ -0,0 +1,404 @@ +/* +** $Id: lmathlib.c,v 1.114 2014/12/27 20:32:26 roberto Exp $ +** Standard mathematical library +** See Copyright Notice in lua.h +*/ + +#define lmathlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <stdlib.h> +#include <math.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#undef PI +#define PI (l_mathop(3.141592653589793238462643383279502884)) + + +#if !defined(l_rand) /* { */ +#if defined(LUA_USE_POSIX) +#define l_rand() random() +#define l_srand(x) srandom(x) +#define L_RANDMAX 2147483647 /* (2^31 - 1), following POSIX */ +#else +#define l_rand() rand() +#define l_srand(x) srand(x) +#define L_RANDMAX RAND_MAX +#endif +#endif /* } */ + + +static int math_abs (lua_State *L) { + if (lua_isinteger(L, 1)) { + lua_Integer n = lua_tointeger(L, 1); + if (n < 0) n = (lua_Integer)(0u - n); + lua_pushinteger(L, n); + } + else + lua_pushnumber(L, l_mathop(fabs)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_sin (lua_State *L) { + lua_pushnumber(L, l_mathop(sin)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_cos (lua_State *L) { + lua_pushnumber(L, l_mathop(cos)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_tan (lua_State *L) { + lua_pushnumber(L, l_mathop(tan)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_asin (lua_State *L) { + lua_pushnumber(L, l_mathop(asin)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_acos (lua_State *L) { + lua_pushnumber(L, l_mathop(acos)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_atan (lua_State *L) { + lua_Number y = luaL_checknumber(L, 1); + lua_Number x = luaL_optnumber(L, 2, 1); + lua_pushnumber(L, l_mathop(atan2)(y, x)); + return 1; +} + + +static int math_toint (lua_State *L) { + int valid; + lua_Integer n = lua_tointegerx(L, 1, &valid); + if (valid) + lua_pushinteger(L, n); + else { + luaL_checkany(L, 1); + lua_pushnil(L); /* value is not convertible to integer */ + } + return 1; +} + + +static void pushnumint (lua_State *L, lua_Number d) { + lua_Integer n; + if (lua_numbertointeger(d, &n)) /* does 'd' fit in an integer? */ + lua_pushinteger(L, n); /* result is integer */ + else + lua_pushnumber(L, d); /* result is float */ +} + + +static int math_floor (lua_State *L) { + if (lua_isinteger(L, 1)) + lua_settop(L, 1); /* integer is its own floor */ + else { + lua_Number d = l_mathop(floor)(luaL_checknumber(L, 1)); + pushnumint(L, d); + } + return 1; +} + + +static int math_ceil (lua_State *L) { + if (lua_isinteger(L, 1)) + lua_settop(L, 1); /* integer is its own ceil */ + else { + lua_Number d = l_mathop(ceil)(luaL_checknumber(L, 1)); + pushnumint(L, d); + } + return 1; +} + + +static int math_fmod (lua_State *L) { + if (lua_isinteger(L, 1) && lua_isinteger(L, 2)) { + lua_Integer d = lua_tointeger(L, 2); + if ((lua_Unsigned)d + 1u <= 1u) { /* special cases: -1 or 0 */ + luaL_argcheck(L, d != 0, 2, "zero"); + lua_pushinteger(L, 0); /* avoid overflow with 0x80000... / -1 */ + } + else + lua_pushinteger(L, lua_tointeger(L, 1) % d); + } + else + lua_pushnumber(L, l_mathop(fmod)(luaL_checknumber(L, 1), + luaL_checknumber(L, 2))); + return 1; +} + + +/* +** next function does not use 'modf', avoiding problems with 'double*' +** (which is not compatible with 'float*') when lua_Number is not +** 'double'. +*/ +static int math_modf (lua_State *L) { + if (lua_isinteger(L ,1)) { + lua_settop(L, 1); /* number is its own integer part */ + lua_pushnumber(L, 0); /* no fractional part */ + } + else { + lua_Number n = luaL_checknumber(L, 1); + /* integer part (rounds toward zero) */ + lua_Number ip = (n < 0) ? l_mathop(ceil)(n) : l_mathop(floor)(n); + pushnumint(L, ip); + /* fractional part (test needed for inf/-inf) */ + lua_pushnumber(L, (n == ip) ? l_mathop(0.0) : (n - ip)); + } + return 2; +} + + +static int math_sqrt (lua_State *L) { + lua_pushnumber(L, l_mathop(sqrt)(luaL_checknumber(L, 1))); + return 1; +} + + +static int math_ult (lua_State *L) { + lua_Integer a = luaL_checkinteger(L, 1); + lua_Integer b = luaL_checkinteger(L, 2); + lua_pushboolean(L, (lua_Unsigned)a < (lua_Unsigned)b); + return 1; +} + +static int math_log (lua_State *L) { + lua_Number x = luaL_checknumber(L, 1); + lua_Number res; + if (lua_isnoneornil(L, 2)) + res = l_mathop(log)(x); + else { + lua_Number base = luaL_checknumber(L, 2); + if (base == 10.0) res = l_mathop(log10)(x); + else res = l_mathop(log)(x)/l_mathop(log)(base); + } + lua_pushnumber(L, res); + return 1; +} + +static int math_exp (lua_State *L) { + lua_pushnumber(L, l_mathop(exp)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_deg (lua_State *L) { + lua_pushnumber(L, luaL_checknumber(L, 1) * (l_mathop(180.0) / PI)); + return 1; +} + +static int math_rad (lua_State *L) { + lua_pushnumber(L, luaL_checknumber(L, 1) * (PI / l_mathop(180.0))); + return 1; +} + + +static int math_min (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + int imin = 1; /* index of current minimum value */ + int i; + luaL_argcheck(L, n >= 1, 1, "value expected"); + for (i = 2; i <= n; i++) { + if (lua_compare(L, i, imin, LUA_OPLT)) + imin = i; + } + lua_pushvalue(L, imin); + return 1; +} + + +static int math_max (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + int imax = 1; /* index of current maximum value */ + int i; + luaL_argcheck(L, n >= 1, 1, "value expected"); + for (i = 2; i <= n; i++) { + if (lua_compare(L, imax, i, LUA_OPLT)) + imax = i; + } + lua_pushvalue(L, imax); + return 1; +} + +/* +** This function uses 'double' (instead of 'lua_Number') to ensure that +** all bits from 'l_rand' can be represented, and that 'RANDMAX + 1.0' +** will keep full precision (ensuring that 'r' is always less than 1.0.) +*/ +static int math_random (lua_State *L) { + lua_Integer low, up; + double r = (double)l_rand() * (1.0 / ((double)L_RANDMAX + 1.0)); + switch (lua_gettop(L)) { /* check number of arguments */ + case 0: { /* no arguments */ + lua_pushnumber(L, (lua_Number)r); /* Number between 0 and 1 */ + return 1; + } + case 1: { /* only upper limit */ + low = 1; + up = luaL_checkinteger(L, 1); + break; + } + case 2: { /* lower and upper limits */ + low = luaL_checkinteger(L, 1); + up = luaL_checkinteger(L, 2); + break; + } + default: return luaL_error(L, "wrong number of arguments"); + } + /* random integer in the interval [low, up] */ + luaL_argcheck(L, low <= up, 1, "interval is empty"); + luaL_argcheck(L, low >= 0 || up <= LUA_MAXINTEGER + low, 1, + "interval too large"); + r *= (double)(up - low) + 1.0; + lua_pushinteger(L, (lua_Integer)r + low); + return 1; +} + + +static int math_randomseed (lua_State *L) { + l_srand((unsigned int)(lua_Integer)luaL_checknumber(L, 1)); + (void)rand(); /* discard first value to avoid undesirable correlations */ + return 0; +} + + +static int math_type (lua_State *L) { + if (lua_type(L, 1) == LUA_TNUMBER) { + if (lua_isinteger(L, 1)) + lua_pushliteral(L, "integer"); + else + lua_pushliteral(L, "float"); + } + else { + luaL_checkany(L, 1); + lua_pushnil(L); + } + return 1; +} + + +/* +** {================================================================== +** Deprecated functions (for compatibility only) +** =================================================================== +*/ +#if defined(LUA_COMPAT_MATHLIB) + +static int math_cosh (lua_State *L) { + lua_pushnumber(L, l_mathop(cosh)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_sinh (lua_State *L) { + lua_pushnumber(L, l_mathop(sinh)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_tanh (lua_State *L) { + lua_pushnumber(L, l_mathop(tanh)(luaL_checknumber(L, 1))); + return 1; +} + +static int math_pow (lua_State *L) { + lua_Number x = luaL_checknumber(L, 1); + lua_Number y = luaL_checknumber(L, 2); + lua_pushnumber(L, l_mathop(pow)(x, y)); + return 1; +} + +static int math_frexp (lua_State *L) { + int e; + lua_pushnumber(L, l_mathop(frexp)(luaL_checknumber(L, 1), &e)); + lua_pushinteger(L, e); + return 2; +} + +static int math_ldexp (lua_State *L) { + lua_Number x = luaL_checknumber(L, 1); + int ep = (int)luaL_checkinteger(L, 2); + lua_pushnumber(L, l_mathop(ldexp)(x, ep)); + return 1; +} + +static int math_log10 (lua_State *L) { + lua_pushnumber(L, l_mathop(log10)(luaL_checknumber(L, 1))); + return 1; +} + +#endif +/* }================================================================== */ + + + +static const luaL_Reg mathlib[] = { + {"abs", math_abs}, + {"acos", math_acos}, + {"asin", math_asin}, + {"atan", math_atan}, + {"ceil", math_ceil}, + {"cos", math_cos}, + {"deg", math_deg}, + {"exp", math_exp}, + {"tointeger", math_toint}, + {"floor", math_floor}, + {"fmod", math_fmod}, + {"ult", math_ult}, + {"log", math_log}, + {"max", math_max}, + {"min", math_min}, + {"modf", math_modf}, + {"rad", math_rad}, + {"random", math_random}, + {"randomseed", math_randomseed}, + {"sin", math_sin}, + {"sqrt", math_sqrt}, + {"tan", math_tan}, + {"type", math_type}, +#if defined(LUA_COMPAT_MATHLIB) + {"atan2", math_atan}, + {"cosh", math_cosh}, + {"sinh", math_sinh}, + {"tanh", math_tanh}, + {"pow", math_pow}, + {"frexp", math_frexp}, + {"ldexp", math_ldexp}, + {"log10", math_log10}, +#endif + /* placeholders */ + {"pi", NULL}, + {"huge", NULL}, + {"maxinteger", NULL}, + {"mininteger", NULL}, + {NULL, NULL} +}; + + +/* +** Open math library +*/ +LUAMOD_API int luaopen_math (lua_State *L) { + luaL_newlib(L, mathlib); + lua_pushnumber(L, PI); + lua_setfield(L, -2, "pi"); + lua_pushnumber(L, (lua_Number)HUGE_VAL); + lua_setfield(L, -2, "huge"); + lua_pushinteger(L, LUA_MAXINTEGER); + lua_setfield(L, -2, "maxinteger"); + lua_pushinteger(L, LUA_MININTEGER); + lua_setfield(L, -2, "mininteger"); + return 1; +} + diff --git a/src/lmem.c b/src/lmem.c new file mode 100644 index 000000000000..4feaf036c726 --- /dev/null +++ b/src/lmem.c @@ -0,0 +1,99 @@ +/* +** $Id: lmem.c,v 1.89 2014/11/02 19:33:33 roberto Exp $ +** Interface to Memory Manager +** See Copyright Notice in lua.h +*/ + +#define lmem_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stddef.h> + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" + + + +/* +** About the realloc function: +** void * frealloc (void *ud, void *ptr, size_t osize, size_t nsize); +** ('osize' is the old size, 'nsize' is the new size) +** +** * frealloc(ud, NULL, x, s) creates a new block of size 's' (no +** matter 'x'). +** +** * frealloc(ud, p, x, 0) frees the block 'p' +** (in this specific case, frealloc must return NULL); +** particularly, frealloc(ud, NULL, 0, 0) does nothing +** (which is equivalent to free(NULL) in ISO C) +** +** frealloc returns NULL if it cannot create or reallocate the area +** (any reallocation to an equal or smaller size cannot fail!) +*/ + + + +#define MINSIZEARRAY 4 + + +void *luaM_growaux_ (lua_State *L, void *block, int *size, size_t size_elems, + int limit, const char *what) { + void *newblock; + int newsize; + if (*size >= limit/2) { /* cannot double it? */ + if (*size >= limit) /* cannot grow even a little? */ + luaG_runerror(L, "too many %s (limit is %d)", what, limit); + newsize = limit; /* still have at least one free place */ + } + else { + newsize = (*size)*2; + if (newsize < MINSIZEARRAY) + newsize = MINSIZEARRAY; /* minimum size */ + } + newblock = luaM_reallocv(L, block, *size, newsize, size_elems); + *size = newsize; /* update only when everything else is OK */ + return newblock; +} + + +l_noret luaM_toobig (lua_State *L) { + luaG_runerror(L, "memory allocation error: block too big"); +} + + + +/* +** generic allocation routine. +*/ +void *luaM_realloc_ (lua_State *L, void *block, size_t osize, size_t nsize) { + void *newblock; + global_State *g = G(L); + size_t realosize = (block) ? osize : 0; + lua_assert((realosize == 0) == (block == NULL)); +#if defined(HARDMEMTESTS) + if (nsize > realosize && g->gcrunning) + luaC_fullgc(L, 1); /* force a GC whenever possible */ +#endif + newblock = (*g->frealloc)(g->ud, block, osize, nsize); + if (newblock == NULL && nsize > 0) { + api_check( nsize > realosize, + "realloc cannot fail when shrinking a block"); + luaC_fullgc(L, 1); /* try to free some memory... */ + newblock = (*g->frealloc)(g->ud, block, osize, nsize); /* try again */ + if (newblock == NULL) + luaD_throw(L, LUA_ERRMEM); + } + lua_assert((nsize == 0) == (newblock == NULL)); + g->GCdebt = (g->GCdebt + nsize) - realosize; + return newblock; +} + diff --git a/src/lmem.h b/src/lmem.h new file mode 100644 index 000000000000..30f484895e7e --- /dev/null +++ b/src/lmem.h @@ -0,0 +1,69 @@ +/* +** $Id: lmem.h,v 1.43 2014/12/19 17:26:14 roberto Exp $ +** Interface to Memory Manager +** See Copyright Notice in lua.h +*/ + +#ifndef lmem_h +#define lmem_h + + +#include <stddef.h> + +#include "llimits.h" +#include "lua.h" + + +/* +** This macro reallocs a vector 'b' from 'on' to 'n' elements, where +** each element has size 'e'. In case of arithmetic overflow of the +** product 'n'*'e', it raises an error (calling 'luaM_toobig'). Because +** 'e' is always constant, it avoids the runtime division MAX_SIZET/(e). +** +** (The macro is somewhat complex to avoid warnings: The 'sizeof' +** comparison avoids a runtime comparison when overflow cannot occur. +** The compiler should be able to optimize the real test by itself, but +** when it does it, it may give a warning about "comparison is always +** false due to limited range of data type"; the +1 tricks the compiler, +** avoiding this warning but also this optimization.) +*/ +#define luaM_reallocv(L,b,on,n,e) \ + (((sizeof(n) >= sizeof(size_t) && cast(size_t, (n)) + 1 > MAX_SIZET/(e)) \ + ? luaM_toobig(L) : cast_void(0)) , \ + luaM_realloc_(L, (b), (on)*(e), (n)*(e))) + +/* +** Arrays of chars do not need any test +*/ +#define luaM_reallocvchar(L,b,on,n) \ + cast(char *, luaM_realloc_(L, (b), (on)*sizeof(char), (n)*sizeof(char))) + +#define luaM_freemem(L, b, s) luaM_realloc_(L, (b), (s), 0) +#define luaM_free(L, b) luaM_realloc_(L, (b), sizeof(*(b)), 0) +#define luaM_freearray(L, b, n) luaM_realloc_(L, (b), (n)*sizeof(*(b)), 0) + +#define luaM_malloc(L,s) luaM_realloc_(L, NULL, 0, (s)) +#define luaM_new(L,t) cast(t *, luaM_malloc(L, sizeof(t))) +#define luaM_newvector(L,n,t) \ + cast(t *, luaM_reallocv(L, NULL, 0, n, sizeof(t))) + +#define luaM_newobject(L,tag,s) luaM_realloc_(L, NULL, tag, (s)) + +#define luaM_growvector(L,v,nelems,size,t,limit,e) \ + if ((nelems)+1 > (size)) \ + ((v)=cast(t *, luaM_growaux_(L,v,&(size),sizeof(t),limit,e))) + +#define luaM_reallocvector(L, v,oldn,n,t) \ + ((v)=cast(t *, luaM_reallocv(L, v, oldn, n, sizeof(t)))) + +LUAI_FUNC l_noret luaM_toobig (lua_State *L); + +/* not to be called directly */ +LUAI_FUNC void *luaM_realloc_ (lua_State *L, void *block, size_t oldsize, + size_t size); +LUAI_FUNC void *luaM_growaux_ (lua_State *L, void *block, int *size, + size_t size_elem, int limit, + const char *what); + +#endif + diff --git a/src/loadlib.c b/src/loadlib.c new file mode 100644 index 000000000000..7f8d99029866 --- /dev/null +++ b/src/loadlib.c @@ -0,0 +1,786 @@ +/* +** $Id: loadlib.c,v 1.124 2015/01/05 13:51:39 roberto Exp $ +** Dynamic library loader for Lua +** See Copyright Notice in lua.h +** +** This module contains an implementation of loadlib for Unix systems +** that have dlfcn, an implementation for Windows, and a stub for other +** systems. +*/ + +#define loadlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** LUA_PATH_VAR and LUA_CPATH_VAR are the names of the environment +** variables that Lua check to set its paths. +*/ +#if !defined(LUA_PATH_VAR) +#define LUA_PATH_VAR "LUA_PATH" +#endif + +#if !defined(LUA_CPATH_VAR) +#define LUA_CPATH_VAR "LUA_CPATH" +#endif + +#define LUA_PATHSUFFIX "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR + +#define LUA_PATHVARVERSION LUA_PATH_VAR LUA_PATHSUFFIX +#define LUA_CPATHVARVERSION LUA_CPATH_VAR LUA_PATHSUFFIX + +/* +** LUA_PATH_SEP is the character that separates templates in a path. +** LUA_PATH_MARK is the string that marks the substitution points in a +** template. +** LUA_EXEC_DIR in a Windows path is replaced by the executable's +** directory. +** LUA_IGMARK is a mark to ignore all before it when building the +** luaopen_ function name. +*/ +#if !defined (LUA_PATH_SEP) +#define LUA_PATH_SEP ";" +#endif +#if !defined (LUA_PATH_MARK) +#define LUA_PATH_MARK "?" +#endif +#if !defined (LUA_EXEC_DIR) +#define LUA_EXEC_DIR "!" +#endif +#if !defined (LUA_IGMARK) +#define LUA_IGMARK "-" +#endif + + +/* +** LUA_CSUBSEP is the character that replaces dots in submodule names +** when searching for a C loader. +** LUA_LSUBSEP is the character that replaces dots in submodule names +** when searching for a Lua loader. +*/ +#if !defined(LUA_CSUBSEP) +#define LUA_CSUBSEP LUA_DIRSEP +#endif + +#if !defined(LUA_LSUBSEP) +#define LUA_LSUBSEP LUA_DIRSEP +#endif + + +/* prefix for open functions in C libraries */ +#define LUA_POF "luaopen_" + +/* separator for open functions in C libraries */ +#define LUA_OFSEP "_" + + +/* +** unique key for table in the registry that keeps handles +** for all loaded C libraries +*/ +static const int CLIBS = 0; + +#define LIB_FAIL "open" + +#define setprogdir(L) ((void)0) + + +/* +** system-dependent functions +*/ + +/* +** unload library 'lib' +*/ +static void lsys_unloadlib (void *lib); + +/* +** load C library in file 'path'. If 'seeglb', load with all names in +** the library global. +** Returns the library; in case of error, returns NULL plus an +** error string in the stack. +*/ +static void *lsys_load (lua_State *L, const char *path, int seeglb); + +/* +** Try to find a function named 'sym' in library 'lib'. +** Returns the function; in case of error, returns NULL plus an +** error string in the stack. +*/ +static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym); + + + + +#if defined(LUA_USE_DLOPEN) /* { */ +/* +** {======================================================================== +** This is an implementation of loadlib based on the dlfcn interface. +** The dlfcn interface is available in Linux, SunOS, Solaris, IRIX, FreeBSD, +** NetBSD, AIX 4.2, HPUX 11, and probably most other Unix flavors, at least +** as an emulation layer on top of native functions. +** ========================================================================= +*/ + +#include <dlfcn.h> + +/* +** Macro to covert pointer to void* to pointer to function. This cast +** is undefined according to ISO C, but POSIX assumes that it must work. +** (The '__extension__' in gnu compilers is only to avoid warnings.) +*/ +#if defined(__GNUC__) +#define cast_func(p) (__extension__ (lua_CFunction)(p)) +#else +#define cast_func(p) ((lua_CFunction)(p)) +#endif + + +static void lsys_unloadlib (void *lib) { + dlclose(lib); +} + + +static void *lsys_load (lua_State *L, const char *path, int seeglb) { + void *lib = dlopen(path, RTLD_NOW | (seeglb ? RTLD_GLOBAL : RTLD_LOCAL)); + if (lib == NULL) lua_pushstring(L, dlerror()); + return lib; +} + + +static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { + lua_CFunction f = cast_func(dlsym(lib, sym)); + if (f == NULL) lua_pushstring(L, dlerror()); + return f; +} + +/* }====================================================== */ + + + +#elif defined(LUA_DL_DLL) /* }{ */ +/* +** {====================================================================== +** This is an implementation of loadlib for Windows using native functions. +** ======================================================================= +*/ + +#include <windows.h> + +#undef setprogdir + +/* +** optional flags for LoadLibraryEx +*/ +#if !defined(LUA_LLE_FLAGS) +#define LUA_LLE_FLAGS 0 +#endif + + +static void setprogdir (lua_State *L) { + char buff[MAX_PATH + 1]; + char *lb; + DWORD nsize = sizeof(buff)/sizeof(char); + DWORD n = GetModuleFileNameA(NULL, buff, nsize); + if (n == 0 || n == nsize || (lb = strrchr(buff, '\\')) == NULL) + luaL_error(L, "unable to get ModuleFileName"); + else { + *lb = '\0'; + luaL_gsub(L, lua_tostring(L, -1), LUA_EXEC_DIR, buff); + lua_remove(L, -2); /* remove original string */ + } +} + + +static void pusherror (lua_State *L) { + int error = GetLastError(); + char buffer[128]; + if (FormatMessageA(FORMAT_MESSAGE_IGNORE_INSERTS | FORMAT_MESSAGE_FROM_SYSTEM, + NULL, error, 0, buffer, sizeof(buffer)/sizeof(char), NULL)) + lua_pushstring(L, buffer); + else + lua_pushfstring(L, "system error %d\n", error); +} + +static void lsys_unloadlib (void *lib) { + FreeLibrary((HMODULE)lib); +} + + +static void *lsys_load (lua_State *L, const char *path, int seeglb) { + HMODULE lib = LoadLibraryExA(path, NULL, LUA_LLE_FLAGS); + (void)(seeglb); /* not used: symbols are 'global' by default */ + if (lib == NULL) pusherror(L); + return lib; +} + + +static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { + lua_CFunction f = (lua_CFunction)GetProcAddress((HMODULE)lib, sym); + if (f == NULL) pusherror(L); + return f; +} + +/* }====================================================== */ + + +#else /* }{ */ +/* +** {====================================================== +** Fallback for other systems +** ======================================================= +*/ + +#undef LIB_FAIL +#define LIB_FAIL "absent" + + +#define DLMSG "dynamic libraries not enabled; check your Lua installation" + + +static void lsys_unloadlib (void *lib) { + (void)(lib); /* not used */ +} + + +static void *lsys_load (lua_State *L, const char *path, int seeglb) { + (void)(path); (void)(seeglb); /* not used */ + lua_pushliteral(L, DLMSG); + return NULL; +} + + +static lua_CFunction lsys_sym (lua_State *L, void *lib, const char *sym) { + (void)(lib); (void)(sym); /* not used */ + lua_pushliteral(L, DLMSG); + return NULL; +} + +/* }====================================================== */ +#endif /* } */ + + +/* +** return registry.CLIBS[path] +*/ +static void *checkclib (lua_State *L, const char *path) { + void *plib; + lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS); + lua_getfield(L, -1, path); + plib = lua_touserdata(L, -1); /* plib = CLIBS[path] */ + lua_pop(L, 2); /* pop CLIBS table and 'plib' */ + return plib; +} + + +/* +** registry.CLIBS[path] = plib -- for queries +** registry.CLIBS[#CLIBS + 1] = plib -- also keep a list of all libraries +*/ +static void addtoclib (lua_State *L, const char *path, void *plib) { + lua_rawgetp(L, LUA_REGISTRYINDEX, &CLIBS); + lua_pushlightuserdata(L, plib); + lua_pushvalue(L, -1); + lua_setfield(L, -3, path); /* CLIBS[path] = plib */ + lua_rawseti(L, -2, luaL_len(L, -2) + 1); /* CLIBS[#CLIBS + 1] = plib */ + lua_pop(L, 1); /* pop CLIBS table */ +} + + +/* +** __gc tag method for CLIBS table: calls 'lsys_unloadlib' for all lib +** handles in list CLIBS +*/ +static int gctm (lua_State *L) { + lua_Integer n = luaL_len(L, 1); + for (; n >= 1; n--) { /* for each handle, in reverse order */ + lua_rawgeti(L, 1, n); /* get handle CLIBS[n] */ + lsys_unloadlib(lua_touserdata(L, -1)); + lua_pop(L, 1); /* pop handle */ + } + return 0; +} + + + +/* error codes for 'lookforfunc' */ +#define ERRLIB 1 +#define ERRFUNC 2 + +/* +** Look for a C function named 'sym' in a dynamically loaded library +** 'path'. +** First, check whether the library is already loaded; if not, try +** to load it. +** Then, if 'sym' is '*', return true (as library has been loaded). +** Otherwise, look for symbol 'sym' in the library and push a +** C function with that symbol. +** Return 0 and 'true' or a function in the stack; in case of +** errors, return an error code and an error message in the stack. +*/ +static int lookforfunc (lua_State *L, const char *path, const char *sym) { + void *reg = checkclib(L, path); /* check loaded C libraries */ + if (reg == NULL) { /* must load library? */ + reg = lsys_load(L, path, *sym == '*'); /* global symbols if 'sym'=='*' */ + if (reg == NULL) return ERRLIB; /* unable to load library */ + addtoclib(L, path, reg); + } + if (*sym == '*') { /* loading only library (no function)? */ + lua_pushboolean(L, 1); /* return 'true' */ + return 0; /* no errors */ + } + else { + lua_CFunction f = lsys_sym(L, reg, sym); + if (f == NULL) + return ERRFUNC; /* unable to find function */ + lua_pushcfunction(L, f); /* else create new function */ + return 0; /* no errors */ + } +} + + +static int ll_loadlib (lua_State *L) { + const char *path = luaL_checkstring(L, 1); + const char *init = luaL_checkstring(L, 2); + int stat = lookforfunc(L, path, init); + if (stat == 0) /* no errors? */ + return 1; /* return the loaded function */ + else { /* error; error message is on stack top */ + lua_pushnil(L); + lua_insert(L, -2); + lua_pushstring(L, (stat == ERRLIB) ? LIB_FAIL : "init"); + return 3; /* return nil, error message, and where */ + } +} + + + +/* +** {====================================================== +** 'require' function +** ======================================================= +*/ + + +static int readable (const char *filename) { + FILE *f = fopen(filename, "r"); /* try to open file */ + if (f == NULL) return 0; /* open failed */ + fclose(f); + return 1; +} + + +static const char *pushnexttemplate (lua_State *L, const char *path) { + const char *l; + while (*path == *LUA_PATH_SEP) path++; /* skip separators */ + if (*path == '\0') return NULL; /* no more templates */ + l = strchr(path, *LUA_PATH_SEP); /* find next separator */ + if (l == NULL) l = path + strlen(path); + lua_pushlstring(L, path, l - path); /* template */ + return l; +} + + +static const char *searchpath (lua_State *L, const char *name, + const char *path, + const char *sep, + const char *dirsep) { + luaL_Buffer msg; /* to build error message */ + luaL_buffinit(L, &msg); + if (*sep != '\0') /* non-empty separator? */ + name = luaL_gsub(L, name, sep, dirsep); /* replace it by 'dirsep' */ + while ((path = pushnexttemplate(L, path)) != NULL) { + const char *filename = luaL_gsub(L, lua_tostring(L, -1), + LUA_PATH_MARK, name); + lua_remove(L, -2); /* remove path template */ + if (readable(filename)) /* does file exist and is readable? */ + return filename; /* return that file name */ + lua_pushfstring(L, "\n\tno file '%s'", filename); + lua_remove(L, -2); /* remove file name */ + luaL_addvalue(&msg); /* concatenate error msg. entry */ + } + luaL_pushresult(&msg); /* create error message */ + return NULL; /* not found */ +} + + +static int ll_searchpath (lua_State *L) { + const char *f = searchpath(L, luaL_checkstring(L, 1), + luaL_checkstring(L, 2), + luaL_optstring(L, 3, "."), + luaL_optstring(L, 4, LUA_DIRSEP)); + if (f != NULL) return 1; + else { /* error message is on top of the stack */ + lua_pushnil(L); + lua_insert(L, -2); + return 2; /* return nil + error message */ + } +} + + +static const char *findfile (lua_State *L, const char *name, + const char *pname, + const char *dirsep) { + const char *path; + lua_getfield(L, lua_upvalueindex(1), pname); + path = lua_tostring(L, -1); + if (path == NULL) + luaL_error(L, "'package.%s' must be a string", pname); + return searchpath(L, name, path, ".", dirsep); +} + + +static int checkload (lua_State *L, int stat, const char *filename) { + if (stat) { /* module loaded successfully? */ + lua_pushstring(L, filename); /* will be 2nd argument to module */ + return 2; /* return open function and file name */ + } + else + return luaL_error(L, "error loading module '%s' from file '%s':\n\t%s", + lua_tostring(L, 1), filename, lua_tostring(L, -1)); +} + + +static int searcher_Lua (lua_State *L) { + const char *filename; + const char *name = luaL_checkstring(L, 1); + filename = findfile(L, name, "path", LUA_LSUBSEP); + if (filename == NULL) return 1; /* module not found in this path */ + return checkload(L, (luaL_loadfile(L, filename) == LUA_OK), filename); +} + + +/* +** Try to find a load function for module 'modname' at file 'filename'. +** First, change '.' to '_' in 'modname'; then, if 'modname' has +** the form X-Y (that is, it has an "ignore mark"), build a function +** name "luaopen_X" and look for it. (For compatibility, if that +** fails, it also tries "luaopen_Y".) If there is no ignore mark, +** look for a function named "luaopen_modname". +*/ +static int loadfunc (lua_State *L, const char *filename, const char *modname) { + const char *openfunc; + const char *mark; + modname = luaL_gsub(L, modname, ".", LUA_OFSEP); + mark = strchr(modname, *LUA_IGMARK); + if (mark) { + int stat; + openfunc = lua_pushlstring(L, modname, mark - modname); + openfunc = lua_pushfstring(L, LUA_POF"%s", openfunc); + stat = lookforfunc(L, filename, openfunc); + if (stat != ERRFUNC) return stat; + modname = mark + 1; /* else go ahead and try old-style name */ + } + openfunc = lua_pushfstring(L, LUA_POF"%s", modname); + return lookforfunc(L, filename, openfunc); +} + + +static int searcher_C (lua_State *L) { + const char *name = luaL_checkstring(L, 1); + const char *filename = findfile(L, name, "cpath", LUA_CSUBSEP); + if (filename == NULL) return 1; /* module not found in this path */ + return checkload(L, (loadfunc(L, filename, name) == 0), filename); +} + + +static int searcher_Croot (lua_State *L) { + const char *filename; + const char *name = luaL_checkstring(L, 1); + const char *p = strchr(name, '.'); + int stat; + if (p == NULL) return 0; /* is root */ + lua_pushlstring(L, name, p - name); + filename = findfile(L, lua_tostring(L, -1), "cpath", LUA_CSUBSEP); + if (filename == NULL) return 1; /* root not found */ + if ((stat = loadfunc(L, filename, name)) != 0) { + if (stat != ERRFUNC) + return checkload(L, 0, filename); /* real error */ + else { /* open function not found */ + lua_pushfstring(L, "\n\tno module '%s' in file '%s'", name, filename); + return 1; + } + } + lua_pushstring(L, filename); /* will be 2nd argument to module */ + return 2; +} + + +static int searcher_preload (lua_State *L) { + const char *name = luaL_checkstring(L, 1); + lua_getfield(L, LUA_REGISTRYINDEX, "_PRELOAD"); + if (lua_getfield(L, -1, name) == LUA_TNIL) /* not found? */ + lua_pushfstring(L, "\n\tno field package.preload['%s']", name); + return 1; +} + + +static void findloader (lua_State *L, const char *name) { + int i; + luaL_Buffer msg; /* to build error message */ + luaL_buffinit(L, &msg); + /* push 'package.searchers' to index 3 in the stack */ + if (lua_getfield(L, lua_upvalueindex(1), "searchers") != LUA_TTABLE) + luaL_error(L, "'package.searchers' must be a table"); + /* iterate over available searchers to find a loader */ + for (i = 1; ; i++) { + if (lua_rawgeti(L, 3, i) == LUA_TNIL) { /* no more searchers? */ + lua_pop(L, 1); /* remove nil */ + luaL_pushresult(&msg); /* create error message */ + luaL_error(L, "module '%s' not found:%s", name, lua_tostring(L, -1)); + } + lua_pushstring(L, name); + lua_call(L, 1, 2); /* call it */ + if (lua_isfunction(L, -2)) /* did it find a loader? */ + return; /* module loader found */ + else if (lua_isstring(L, -2)) { /* searcher returned error message? */ + lua_pop(L, 1); /* remove extra return */ + luaL_addvalue(&msg); /* concatenate error message */ + } + else + lua_pop(L, 2); /* remove both returns */ + } +} + + +static int ll_require (lua_State *L) { + const char *name = luaL_checkstring(L, 1); + lua_settop(L, 1); /* _LOADED table will be at index 2 */ + lua_getfield(L, LUA_REGISTRYINDEX, "_LOADED"); + lua_getfield(L, 2, name); /* _LOADED[name] */ + if (lua_toboolean(L, -1)) /* is it there? */ + return 1; /* package is already loaded */ + /* else must load package */ + lua_pop(L, 1); /* remove 'getfield' result */ + findloader(L, name); + lua_pushstring(L, name); /* pass name as argument to module loader */ + lua_insert(L, -2); /* name is 1st argument (before search data) */ + lua_call(L, 2, 1); /* run loader to load module */ + if (!lua_isnil(L, -1)) /* non-nil return? */ + lua_setfield(L, 2, name); /* _LOADED[name] = returned value */ + if (lua_getfield(L, 2, name) == LUA_TNIL) { /* module set no value? */ + lua_pushboolean(L, 1); /* use true as result */ + lua_pushvalue(L, -1); /* extra copy to be returned */ + lua_setfield(L, 2, name); /* _LOADED[name] = true */ + } + return 1; +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** 'module' function +** ======================================================= +*/ +#if defined(LUA_COMPAT_MODULE) + +/* +** changes the environment variable of calling function +*/ +static void set_env (lua_State *L) { + lua_Debug ar; + if (lua_getstack(L, 1, &ar) == 0 || + lua_getinfo(L, "f", &ar) == 0 || /* get calling function */ + lua_iscfunction(L, -1)) + luaL_error(L, "'module' not called from a Lua function"); + lua_pushvalue(L, -2); /* copy new environment table to top */ + lua_setupvalue(L, -2, 1); + lua_pop(L, 1); /* remove function */ +} + + +static void dooptions (lua_State *L, int n) { + int i; + for (i = 2; i <= n; i++) { + if (lua_isfunction(L, i)) { /* avoid 'calling' extra info. */ + lua_pushvalue(L, i); /* get option (a function) */ + lua_pushvalue(L, -2); /* module */ + lua_call(L, 1, 0); + } + } +} + + +static void modinit (lua_State *L, const char *modname) { + const char *dot; + lua_pushvalue(L, -1); + lua_setfield(L, -2, "_M"); /* module._M = module */ + lua_pushstring(L, modname); + lua_setfield(L, -2, "_NAME"); + dot = strrchr(modname, '.'); /* look for last dot in module name */ + if (dot == NULL) dot = modname; + else dot++; + /* set _PACKAGE as package name (full module name minus last part) */ + lua_pushlstring(L, modname, dot - modname); + lua_setfield(L, -2, "_PACKAGE"); +} + + +static int ll_module (lua_State *L) { + const char *modname = luaL_checkstring(L, 1); + int lastarg = lua_gettop(L); /* last parameter */ + luaL_pushmodule(L, modname, 1); /* get/create module table */ + /* check whether table already has a _NAME field */ + if (lua_getfield(L, -1, "_NAME") != LUA_TNIL) + lua_pop(L, 1); /* table is an initialized module */ + else { /* no; initialize it */ + lua_pop(L, 1); + modinit(L, modname); + } + lua_pushvalue(L, -1); + set_env(L); + dooptions(L, lastarg); + return 1; +} + + +static int ll_seeall (lua_State *L) { + luaL_checktype(L, 1, LUA_TTABLE); + if (!lua_getmetatable(L, 1)) { + lua_createtable(L, 0, 1); /* create new metatable */ + lua_pushvalue(L, -1); + lua_setmetatable(L, 1); + } + lua_pushglobaltable(L); + lua_setfield(L, -2, "__index"); /* mt.__index = _G */ + return 0; +} + +#endif +/* }====================================================== */ + + + +/* auxiliary mark (for internal use) */ +#define AUXMARK "\1" + + +/* +** return registry.LUA_NOENV as a boolean +*/ +static int noenv (lua_State *L) { + int b; + lua_getfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); + b = lua_toboolean(L, -1); + lua_pop(L, 1); /* remove value */ + return b; +} + + +static void setpath (lua_State *L, const char *fieldname, const char *envname1, + const char *envname2, const char *def) { + const char *path = getenv(envname1); + if (path == NULL) /* no environment variable? */ + path = getenv(envname2); /* try alternative name */ + if (path == NULL || noenv(L)) /* no environment variable? */ + lua_pushstring(L, def); /* use default */ + else { + /* replace ";;" by ";AUXMARK;" and then AUXMARK by default path */ + path = luaL_gsub(L, path, LUA_PATH_SEP LUA_PATH_SEP, + LUA_PATH_SEP AUXMARK LUA_PATH_SEP); + luaL_gsub(L, path, AUXMARK, def); + lua_remove(L, -2); + } + setprogdir(L); + lua_setfield(L, -2, fieldname); +} + + +static const luaL_Reg pk_funcs[] = { + {"loadlib", ll_loadlib}, + {"searchpath", ll_searchpath}, +#if defined(LUA_COMPAT_MODULE) + {"seeall", ll_seeall}, +#endif + /* placeholders */ + {"preload", NULL}, + {"cpath", NULL}, + {"path", NULL}, + {"searchers", NULL}, + {"loaded", NULL}, + {NULL, NULL} +}; + + +static const luaL_Reg ll_funcs[] = { +#if defined(LUA_COMPAT_MODULE) + {"module", ll_module}, +#endif + {"require", ll_require}, + {NULL, NULL} +}; + + +static void createsearcherstable (lua_State *L) { + static const lua_CFunction searchers[] = + {searcher_preload, searcher_Lua, searcher_C, searcher_Croot, NULL}; + int i; + /* create 'searchers' table */ + lua_createtable(L, sizeof(searchers)/sizeof(searchers[0]) - 1, 0); + /* fill it with pre-defined searchers */ + for (i=0; searchers[i] != NULL; i++) { + lua_pushvalue(L, -2); /* set 'package' as upvalue for all searchers */ + lua_pushcclosure(L, searchers[i], 1); + lua_rawseti(L, -2, i+1); + } +#if defined(LUA_COMPAT_LOADERS) + lua_pushvalue(L, -1); /* make a copy of 'searchers' table */ + lua_setfield(L, -3, "loaders"); /* put it in field 'loaders' */ +#endif + lua_setfield(L, -2, "searchers"); /* put it in field 'searchers' */ +} + + +/* +** create table CLIBS to keep track of loaded C libraries, +** setting a finalizer to close all libraries when closing state. +*/ +static void createclibstable (lua_State *L) { + lua_newtable(L); /* create CLIBS table */ + lua_createtable(L, 0, 1); /* create metatable for CLIBS */ + lua_pushcfunction(L, gctm); + lua_setfield(L, -2, "__gc"); /* set finalizer for CLIBS table */ + lua_setmetatable(L, -2); + lua_rawsetp(L, LUA_REGISTRYINDEX, &CLIBS); /* set CLIBS table in registry */ +} + + +LUAMOD_API int luaopen_package (lua_State *L) { + createclibstable(L); + luaL_newlib(L, pk_funcs); /* create 'package' table */ + createsearcherstable(L); + /* set field 'path' */ + setpath(L, "path", LUA_PATHVARVERSION, LUA_PATH_VAR, LUA_PATH_DEFAULT); + /* set field 'cpath' */ + setpath(L, "cpath", LUA_CPATHVARVERSION, LUA_CPATH_VAR, LUA_CPATH_DEFAULT); + /* store config information */ + lua_pushliteral(L, LUA_DIRSEP "\n" LUA_PATH_SEP "\n" LUA_PATH_MARK "\n" + LUA_EXEC_DIR "\n" LUA_IGMARK "\n"); + lua_setfield(L, -2, "config"); + /* set field 'loaded' */ + luaL_getsubtable(L, LUA_REGISTRYINDEX, "_LOADED"); + lua_setfield(L, -2, "loaded"); + /* set field 'preload' */ + luaL_getsubtable(L, LUA_REGISTRYINDEX, "_PRELOAD"); + lua_setfield(L, -2, "preload"); + lua_pushglobaltable(L); + lua_pushvalue(L, -2); /* set 'package' as upvalue for next lib */ + luaL_setfuncs(L, ll_funcs, 1); /* open lib into global table */ + lua_pop(L, 1); /* pop global table */ + return 1; /* return 'package' table */ +} + diff --git a/src/lobject.c b/src/lobject.c new file mode 100644 index 000000000000..6a24aff95d9a --- /dev/null +++ b/src/lobject.c @@ -0,0 +1,470 @@ +/* +** $Id: lobject.c,v 2.101 2014/12/26 14:43:45 roberto Exp $ +** Some generic functions over Lua objects +** See Copyright Notice in lua.h +*/ + +#define lobject_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stdarg.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lctype.h" +#include "ldebug.h" +#include "ldo.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "lvm.h" + + + +LUAI_DDEF const TValue luaO_nilobject_ = {NILCONSTANT}; + + +/* +** converts an integer to a "floating point byte", represented as +** (eeeeexxx), where the real value is (1xxx) * 2^(eeeee - 1) if +** eeeee != 0 and (xxx) otherwise. +*/ +int luaO_int2fb (unsigned int x) { + int e = 0; /* exponent */ + if (x < 8) return x; + while (x >= 0x10) { + x = (x+1) >> 1; + e++; + } + return ((e+1) << 3) | (cast_int(x) - 8); +} + + +/* converts back */ +int luaO_fb2int (int x) { + int e = (x >> 3) & 0x1f; + if (e == 0) return x; + else return ((x & 7) + 8) << (e - 1); +} + + +int luaO_ceillog2 (unsigned int x) { + static const lu_byte log_2[256] = { + 0,1,2,2,3,3,3,3,4,4,4,4,4,4,4,4,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5,5, + 6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6,6, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7,7, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8, + 8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8,8 + }; + int l = 0; + x--; + while (x >= 256) { l += 8; x >>= 8; } + return l + log_2[x]; +} + + +static lua_Integer intarith (lua_State *L, int op, lua_Integer v1, + lua_Integer v2) { + switch (op) { + case LUA_OPADD: return intop(+, v1, v2); + case LUA_OPSUB:return intop(-, v1, v2); + case LUA_OPMUL:return intop(*, v1, v2); + case LUA_OPMOD: return luaV_mod(L, v1, v2); + case LUA_OPIDIV: return luaV_div(L, v1, v2); + case LUA_OPBAND: return intop(&, v1, v2); + case LUA_OPBOR: return intop(|, v1, v2); + case LUA_OPBXOR: return intop(^, v1, v2); + case LUA_OPSHL: return luaV_shiftl(v1, v2); + case LUA_OPSHR: return luaV_shiftl(v1, -v2); + case LUA_OPUNM: return intop(-, 0, v1); + case LUA_OPBNOT: return intop(^, ~l_castS2U(0), v1); + default: lua_assert(0); return 0; + } +} + + +static lua_Number numarith (lua_State *L, int op, lua_Number v1, + lua_Number v2) { + switch (op) { + case LUA_OPADD: return luai_numadd(L, v1, v2); + case LUA_OPSUB: return luai_numsub(L, v1, v2); + case LUA_OPMUL: return luai_nummul(L, v1, v2); + case LUA_OPDIV: return luai_numdiv(L, v1, v2); + case LUA_OPPOW: return luai_numpow(L, v1, v2); + case LUA_OPIDIV: return luai_numidiv(L, v1, v2); + case LUA_OPUNM: return luai_numunm(L, v1); + case LUA_OPMOD: { + lua_Number m; + luai_nummod(L, v1, v2, m); + return m; + } + default: lua_assert(0); return 0; + } +} + + +void luaO_arith (lua_State *L, int op, const TValue *p1, const TValue *p2, + TValue *res) { + switch (op) { + case LUA_OPBAND: case LUA_OPBOR: case LUA_OPBXOR: + case LUA_OPSHL: case LUA_OPSHR: + case LUA_OPBNOT: { /* operate only on integers */ + lua_Integer i1; lua_Integer i2; + if (tointeger(p1, &i1) && tointeger(p2, &i2)) { + setivalue(res, intarith(L, op, i1, i2)); + return; + } + else break; /* go to the end */ + } + case LUA_OPDIV: case LUA_OPPOW: { /* operate only on floats */ + lua_Number n1; lua_Number n2; + if (tonumber(p1, &n1) && tonumber(p2, &n2)) { + setfltvalue(res, numarith(L, op, n1, n2)); + return; + } + else break; /* go to the end */ + } + default: { /* other operations */ + lua_Number n1; lua_Number n2; + if (ttisinteger(p1) && ttisinteger(p2)) { + setivalue(res, intarith(L, op, ivalue(p1), ivalue(p2))); + return; + } + else if (tonumber(p1, &n1) && tonumber(p2, &n2)) { + setfltvalue(res, numarith(L, op, n1, n2)); + return; + } + else break; /* go to the end */ + } + } + /* could not perform raw operation; try metamethod */ + lua_assert(L != NULL); /* should not fail when folding (compile time) */ + luaT_trybinTM(L, p1, p2, res, cast(TMS, op - LUA_OPADD + TM_ADD)); +} + + +int luaO_hexavalue (int c) { + if (lisdigit(c)) return c - '0'; + else return ltolower(c) - 'a' + 10; +} + + +static int isneg (const char **s) { + if (**s == '-') { (*s)++; return 1; } + else if (**s == '+') (*s)++; + return 0; +} + + + +/* +** {================================================================== +** Lua's implementation for 'lua_strx2number' +** =================================================================== +*/ +#if !defined(lua_strx2number) + +#include <math.h> + +/* maximum number of significant digits to read (to avoid overflows + even with single floats) */ +#define MAXSIGDIG 30 + +/* +** convert an hexadecimal numeric string to a number, following +** C99 specification for 'strtod' +*/ +static lua_Number lua_strx2number (const char *s, char **endptr) { + lua_Number r = 0.0; /* result (accumulator) */ + int sigdig = 0; /* number of significant digits */ + int nosigdig = 0; /* number of non-significant digits */ + int e = 0; /* exponent correction */ + int neg; /* 1 if number is negative */ + int dot = 0; /* true after seen a dot */ + *endptr = cast(char *, s); /* nothing is valid yet */ + while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */ + neg = isneg(&s); /* check signal */ + if (!(*s == '0' && (*(s + 1) == 'x' || *(s + 1) == 'X'))) /* check '0x' */ + return 0.0; /* invalid format (no '0x') */ + for (s += 2; ; s++) { /* skip '0x' and read numeral */ + if (*s == '.') { + if (dot) break; /* second dot? stop loop */ + else dot = 1; + } + else if (lisxdigit(cast_uchar(*s))) { + if (sigdig == 0 && *s == '0') /* non-significant digit (zero)? */ + nosigdig++; + else if (++sigdig <= MAXSIGDIG) /* can read it without overflow? */ + r = (r * cast_num(16.0)) + luaO_hexavalue(*s); + else e++; /* too many digits; ignore, but still count for exponent */ + if (dot) e--; /* decimal digit? correct exponent */ + } + else break; /* neither a dot nor a digit */ + } + if (nosigdig + sigdig == 0) /* no digits? */ + return 0.0; /* invalid format */ + *endptr = cast(char *, s); /* valid up to here */ + e *= 4; /* each digit multiplies/divides value by 2^4 */ + if (*s == 'p' || *s == 'P') { /* exponent part? */ + int exp1 = 0; /* exponent value */ + int neg1; /* exponent signal */ + s++; /* skip 'p' */ + neg1 = isneg(&s); /* signal */ + if (!lisdigit(cast_uchar(*s))) + return 0.0; /* invalid; must have at least one digit */ + while (lisdigit(cast_uchar(*s))) /* read exponent */ + exp1 = exp1 * 10 + *(s++) - '0'; + if (neg1) exp1 = -exp1; + e += exp1; + *endptr = cast(char *, s); /* valid up to here */ + } + if (neg) r = -r; + return l_mathop(ldexp)(r, e); +} + +#endif +/* }====================================================== */ + + +static const char *l_str2d (const char *s, lua_Number *result) { + char *endptr; + if (strpbrk(s, "nN")) /* reject 'inf' and 'nan' */ + return NULL; + else if (strpbrk(s, "xX")) /* hex? */ + *result = lua_strx2number(s, &endptr); + else + *result = lua_str2number(s, &endptr); + if (endptr == s) return 0; /* nothing recognized */ + while (lisspace(cast_uchar(*endptr))) endptr++; + return (*endptr == '\0' ? endptr : NULL); /* OK if no trailing characters */ +} + + +static const char *l_str2int (const char *s, lua_Integer *result) { + lua_Unsigned a = 0; + int empty = 1; + int neg; + while (lisspace(cast_uchar(*s))) s++; /* skip initial spaces */ + neg = isneg(&s); + if (s[0] == '0' && + (s[1] == 'x' || s[1] == 'X')) { /* hex? */ + s += 2; /* skip '0x' */ + for (; lisxdigit(cast_uchar(*s)); s++) { + a = a * 16 + luaO_hexavalue(*s); + empty = 0; + } + } + else { /* decimal */ + for (; lisdigit(cast_uchar(*s)); s++) { + a = a * 10 + *s - '0'; + empty = 0; + } + } + while (lisspace(cast_uchar(*s))) s++; /* skip trailing spaces */ + if (empty || *s != '\0') return NULL; /* something wrong in the numeral */ + else { + *result = l_castU2S((neg) ? 0u - a : a); + return s; + } +} + + +size_t luaO_str2num (const char *s, TValue *o) { + lua_Integer i; lua_Number n; + const char *e; + if ((e = l_str2int(s, &i)) != NULL) { /* try as an integer */ + setivalue(o, i); + } + else if ((e = l_str2d(s, &n)) != NULL) { /* else try as a float */ + setfltvalue(o, n); + } + else + return 0; /* conversion failed */ + return (e - s + 1); /* success; return string size */ +} + + +int luaO_utf8esc (char *buff, unsigned long x) { + int n = 1; /* number of bytes put in buffer (backwards) */ + lua_assert(x <= 0x10FFFF); + if (x < 0x80) /* ascii? */ + buff[UTF8BUFFSZ - 1] = cast(char, x); + else { /* need continuation bytes */ + unsigned int mfb = 0x3f; /* maximum that fits in first byte */ + do { /* add continuation bytes */ + buff[UTF8BUFFSZ - (n++)] = cast(char, 0x80 | (x & 0x3f)); + x >>= 6; /* remove added bits */ + mfb >>= 1; /* now there is one less bit available in first byte */ + } while (x > mfb); /* still needs continuation byte? */ + buff[UTF8BUFFSZ - n] = cast(char, (~mfb << 1) | x); /* add first byte */ + } + return n; +} + + +/* maximum length of the conversion of a number to a string */ +#define MAXNUMBER2STR 50 + + +/* +** Convert a number object to a string +*/ +void luaO_tostring (lua_State *L, StkId obj) { + char buff[MAXNUMBER2STR]; + size_t len; + lua_assert(ttisnumber(obj)); + if (ttisinteger(obj)) + len = lua_integer2str(buff, ivalue(obj)); + else { + len = lua_number2str(buff, fltvalue(obj)); +#if !defined(LUA_COMPAT_FLOATSTRING) + if (buff[strspn(buff, "-0123456789")] == '\0') { /* looks like an int? */ + buff[len++] = '.'; + buff[len++] = '0'; /* adds '.0' to result */ + } +#endif + } + setsvalue2s(L, obj, luaS_newlstr(L, buff, len)); +} + + +static void pushstr (lua_State *L, const char *str, size_t l) { + setsvalue2s(L, L->top++, luaS_newlstr(L, str, l)); +} + + +/* this function handles only '%d', '%c', '%f', '%p', and '%s' + conventional formats, plus Lua-specific '%I' and '%U' */ +const char *luaO_pushvfstring (lua_State *L, const char *fmt, va_list argp) { + int n = 0; + for (;;) { + const char *e = strchr(fmt, '%'); + if (e == NULL) break; + luaD_checkstack(L, 2); /* fmt + item */ + pushstr(L, fmt, e - fmt); + switch (*(e+1)) { + case 's': { + const char *s = va_arg(argp, char *); + if (s == NULL) s = "(null)"; + pushstr(L, s, strlen(s)); + break; + } + case 'c': { + char buff = cast(char, va_arg(argp, int)); + if (lisprint(cast_uchar(buff))) + pushstr(L, &buff, 1); + else /* non-printable character; print its code */ + luaO_pushfstring(L, "<\\%d>", cast_uchar(buff)); + break; + } + case 'd': { + setivalue(L->top++, va_arg(argp, int)); + luaO_tostring(L, L->top - 1); + break; + } + case 'I': { + setivalue(L->top++, cast(lua_Integer, va_arg(argp, l_uacInt))); + luaO_tostring(L, L->top - 1); + break; + } + case 'f': { + setfltvalue(L->top++, cast_num(va_arg(argp, l_uacNumber))); + luaO_tostring(L, L->top - 1); + break; + } + case 'p': { + char buff[4*sizeof(void *) + 8]; /* should be enough space for a '%p' */ + int l = sprintf(buff, "%p", va_arg(argp, void *)); + pushstr(L, buff, l); + break; + } + case 'U': { + char buff[UTF8BUFFSZ]; + int l = luaO_utf8esc(buff, cast(long, va_arg(argp, long))); + pushstr(L, buff + UTF8BUFFSZ - l, l); + break; + } + case '%': { + pushstr(L, "%", 1); + break; + } + default: { + luaG_runerror(L, "invalid option '%%%c' to 'lua_pushfstring'", + *(e + 1)); + } + } + n += 2; + fmt = e+2; + } + luaD_checkstack(L, 1); + pushstr(L, fmt, strlen(fmt)); + if (n > 0) luaV_concat(L, n + 1); + return svalue(L->top - 1); +} + + +const char *luaO_pushfstring (lua_State *L, const char *fmt, ...) { + const char *msg; + va_list argp; + va_start(argp, fmt); + msg = luaO_pushvfstring(L, fmt, argp); + va_end(argp); + return msg; +} + + +/* number of chars of a literal string without the ending \0 */ +#define LL(x) (sizeof(x)/sizeof(char) - 1) + +#define RETS "..." +#define PRE "[string \"" +#define POS "\"]" + +#define addstr(a,b,l) ( memcpy(a,b,(l) * sizeof(char)), a += (l) ) + +void luaO_chunkid (char *out, const char *source, size_t bufflen) { + size_t l = strlen(source); + if (*source == '=') { /* 'literal' source */ + if (l <= bufflen) /* small enough? */ + memcpy(out, source + 1, l * sizeof(char)); + else { /* truncate it */ + addstr(out, source + 1, bufflen - 1); + *out = '\0'; + } + } + else if (*source == '@') { /* file name */ + if (l <= bufflen) /* small enough? */ + memcpy(out, source + 1, l * sizeof(char)); + else { /* add '...' before rest of name */ + addstr(out, RETS, LL(RETS)); + bufflen -= LL(RETS); + memcpy(out, source + 1 + l - bufflen, bufflen * sizeof(char)); + } + } + else { /* string; format as [string "source"] */ + const char *nl = strchr(source, '\n'); /* find first new line (if any) */ + addstr(out, PRE, LL(PRE)); /* add prefix */ + bufflen -= LL(PRE RETS POS) + 1; /* save space for prefix+suffix+'\0' */ + if (l < bufflen && nl == NULL) { /* small one-line source? */ + addstr(out, source, l); /* keep it */ + } + else { + if (nl != NULL) l = nl - source; /* stop at first newline */ + if (l > bufflen) l = bufflen; + addstr(out, source, l); + addstr(out, RETS, LL(RETS)); + } + memcpy(out, POS, (LL(POS) + 1) * sizeof(char)); + } +} + diff --git a/src/lobject.h b/src/lobject.h new file mode 100644 index 000000000000..d7d0ebf31b05 --- /dev/null +++ b/src/lobject.h @@ -0,0 +1,540 @@ +/* +** $Id: lobject.h,v 2.106 2015/01/05 13:52:37 roberto Exp $ +** Type definitions for Lua objects +** See Copyright Notice in lua.h +*/ + + +#ifndef lobject_h +#define lobject_h + + +#include <stdarg.h> + + +#include "llimits.h" +#include "lua.h" + + +/* +** Extra tags for non-values +*/ +#define LUA_TPROTO LUA_NUMTAGS +#define LUA_TDEADKEY (LUA_NUMTAGS+1) + +/* +** number of all possible tags (including LUA_TNONE but excluding DEADKEY) +*/ +#define LUA_TOTALTAGS (LUA_TPROTO + 2) + + +/* +** tags for Tagged Values have the following use of bits: +** bits 0-3: actual tag (a LUA_T* value) +** bits 4-5: variant bits +** bit 6: whether value is collectable +*/ + +#define VARBITS (3 << 4) + + +/* +** LUA_TFUNCTION variants: +** 0 - Lua function +** 1 - light C function +** 2 - regular C function (closure) +*/ + +/* Variant tags for functions */ +#define LUA_TLCL (LUA_TFUNCTION | (0 << 4)) /* Lua closure */ +#define LUA_TLCF (LUA_TFUNCTION | (1 << 4)) /* light C function */ +#define LUA_TCCL (LUA_TFUNCTION | (2 << 4)) /* C closure */ + + +/* Variant tags for strings */ +#define LUA_TSHRSTR (LUA_TSTRING | (0 << 4)) /* short strings */ +#define LUA_TLNGSTR (LUA_TSTRING | (1 << 4)) /* long strings */ + + +/* Variant tags for numbers */ +#define LUA_TNUMFLT (LUA_TNUMBER | (0 << 4)) /* float numbers */ +#define LUA_TNUMINT (LUA_TNUMBER | (1 << 4)) /* integer numbers */ + + +/* Bit mark for collectable types */ +#define BIT_ISCOLLECTABLE (1 << 6) + +/* mark a tag as collectable */ +#define ctb(t) ((t) | BIT_ISCOLLECTABLE) + + +/* +** Common type for all collectable objects +*/ +typedef struct GCObject GCObject; + + +/* +** Common Header for all collectable objects (in macro form, to be +** included in other objects) +*/ +#define CommonHeader GCObject *next; lu_byte tt; lu_byte marked + + +/* +** Common type has only the common header +*/ +struct GCObject { + CommonHeader; +}; + + + +/* +** Union of all Lua values +*/ +typedef union Value Value; + + + + +/* +** Tagged Values. This is the basic representation of values in Lua, +** an actual value plus a tag with its type. +*/ + +#define TValuefields Value value_; int tt_ + +typedef struct lua_TValue TValue; + + +/* macro defining a nil value */ +#define NILCONSTANT {NULL}, LUA_TNIL + + +#define val_(o) ((o)->value_) + + +/* raw type tag of a TValue */ +#define rttype(o) ((o)->tt_) + +/* tag with no variants (bits 0-3) */ +#define novariant(x) ((x) & 0x0F) + +/* type tag of a TValue (bits 0-3 for tags + variant bits 4-5) */ +#define ttype(o) (rttype(o) & 0x3F) + +/* type tag of a TValue with no variants (bits 0-3) */ +#define ttnov(o) (novariant(rttype(o))) + + +/* Macros to test type */ +#define checktag(o,t) (rttype(o) == (t)) +#define checktype(o,t) (ttnov(o) == (t)) +#define ttisnumber(o) checktype((o), LUA_TNUMBER) +#define ttisfloat(o) checktag((o), LUA_TNUMFLT) +#define ttisinteger(o) checktag((o), LUA_TNUMINT) +#define ttisnil(o) checktag((o), LUA_TNIL) +#define ttisboolean(o) checktag((o), LUA_TBOOLEAN) +#define ttislightuserdata(o) checktag((o), LUA_TLIGHTUSERDATA) +#define ttisstring(o) checktype((o), LUA_TSTRING) +#define ttisshrstring(o) checktag((o), ctb(LUA_TSHRSTR)) +#define ttislngstring(o) checktag((o), ctb(LUA_TLNGSTR)) +#define ttistable(o) checktag((o), ctb(LUA_TTABLE)) +#define ttisfunction(o) checktype(o, LUA_TFUNCTION) +#define ttisclosure(o) ((rttype(o) & 0x1F) == LUA_TFUNCTION) +#define ttisCclosure(o) checktag((o), ctb(LUA_TCCL)) +#define ttisLclosure(o) checktag((o), ctb(LUA_TLCL)) +#define ttislcf(o) checktag((o), LUA_TLCF) +#define ttisfulluserdata(o) checktag((o), ctb(LUA_TUSERDATA)) +#define ttisthread(o) checktag((o), ctb(LUA_TTHREAD)) +#define ttisdeadkey(o) checktag((o), LUA_TDEADKEY) + + +/* Macros to access values */ +#define ivalue(o) check_exp(ttisinteger(o), val_(o).i) +#define fltvalue(o) check_exp(ttisfloat(o), val_(o).n) +#define nvalue(o) check_exp(ttisnumber(o), \ + (ttisinteger(o) ? cast_num(ivalue(o)) : fltvalue(o))) +#define gcvalue(o) check_exp(iscollectable(o), val_(o).gc) +#define pvalue(o) check_exp(ttislightuserdata(o), val_(o).p) +#define tsvalue(o) check_exp(ttisstring(o), gco2ts(val_(o).gc)) +#define uvalue(o) check_exp(ttisfulluserdata(o), gco2u(val_(o).gc)) +#define clvalue(o) check_exp(ttisclosure(o), gco2cl(val_(o).gc)) +#define clLvalue(o) check_exp(ttisLclosure(o), gco2lcl(val_(o).gc)) +#define clCvalue(o) check_exp(ttisCclosure(o), gco2ccl(val_(o).gc)) +#define fvalue(o) check_exp(ttislcf(o), val_(o).f) +#define hvalue(o) check_exp(ttistable(o), gco2t(val_(o).gc)) +#define bvalue(o) check_exp(ttisboolean(o), val_(o).b) +#define thvalue(o) check_exp(ttisthread(o), gco2th(val_(o).gc)) +/* a dead value may get the 'gc' field, but cannot access its contents */ +#define deadvalue(o) check_exp(ttisdeadkey(o), cast(void *, val_(o).gc)) + +#define l_isfalse(o) (ttisnil(o) || (ttisboolean(o) && bvalue(o) == 0)) + + +#define iscollectable(o) (rttype(o) & BIT_ISCOLLECTABLE) + + +/* Macros for internal tests */ +#define righttt(obj) (ttype(obj) == gcvalue(obj)->tt) + +#define checkliveness(g,obj) \ + lua_longassert(!iscollectable(obj) || \ + (righttt(obj) && !isdead(g,gcvalue(obj)))) + + +/* Macros to set values */ +#define settt_(o,t) ((o)->tt_=(t)) + +#define setfltvalue(obj,x) \ + { TValue *io=(obj); val_(io).n=(x); settt_(io, LUA_TNUMFLT); } + +#define setivalue(obj,x) \ + { TValue *io=(obj); val_(io).i=(x); settt_(io, LUA_TNUMINT); } + +#define setnilvalue(obj) settt_(obj, LUA_TNIL) + +#define setfvalue(obj,x) \ + { TValue *io=(obj); val_(io).f=(x); settt_(io, LUA_TLCF); } + +#define setpvalue(obj,x) \ + { TValue *io=(obj); val_(io).p=(x); settt_(io, LUA_TLIGHTUSERDATA); } + +#define setbvalue(obj,x) \ + { TValue *io=(obj); val_(io).b=(x); settt_(io, LUA_TBOOLEAN); } + +#define setgcovalue(L,obj,x) \ + { TValue *io = (obj); GCObject *i_g=(x); \ + val_(io).gc = i_g; settt_(io, ctb(i_g->tt)); } + +#define setsvalue(L,obj,x) \ + { TValue *io = (obj); TString *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(x_->tt)); \ + checkliveness(G(L),io); } + +#define setuvalue(L,obj,x) \ + { TValue *io = (obj); Udata *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TUSERDATA)); \ + checkliveness(G(L),io); } + +#define setthvalue(L,obj,x) \ + { TValue *io = (obj); lua_State *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTHREAD)); \ + checkliveness(G(L),io); } + +#define setclLvalue(L,obj,x) \ + { TValue *io = (obj); LClosure *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TLCL)); \ + checkliveness(G(L),io); } + +#define setclCvalue(L,obj,x) \ + { TValue *io = (obj); CClosure *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TCCL)); \ + checkliveness(G(L),io); } + +#define sethvalue(L,obj,x) \ + { TValue *io = (obj); Table *x_ = (x); \ + val_(io).gc = obj2gco(x_); settt_(io, ctb(LUA_TTABLE)); \ + checkliveness(G(L),io); } + +#define setdeadvalue(obj) settt_(obj, LUA_TDEADKEY) + + + +#define setobj(L,obj1,obj2) \ + { TValue *io1=(obj1); *io1 = *(obj2); \ + (void)L; checkliveness(G(L),io1); } + + +/* +** different types of assignments, according to destination +*/ + +/* from stack to (same) stack */ +#define setobjs2s setobj +/* to stack (not from same stack) */ +#define setobj2s setobj +#define setsvalue2s setsvalue +#define sethvalue2s sethvalue +#define setptvalue2s setptvalue +/* from table to same table */ +#define setobjt2t setobj +/* to table */ +#define setobj2t setobj +/* to new object */ +#define setobj2n setobj +#define setsvalue2n setsvalue + + + + +/* +** {====================================================== +** types and prototypes +** ======================================================= +*/ + + +union Value { + GCObject *gc; /* collectable objects */ + void *p; /* light userdata */ + int b; /* booleans */ + lua_CFunction f; /* light C functions */ + lua_Integer i; /* integer numbers */ + lua_Number n; /* float numbers */ +}; + + +struct lua_TValue { + TValuefields; +}; + + +typedef TValue *StkId; /* index to stack elements */ + + + + +/* +** Header for string value; string bytes follow the end of this structure +** (aligned according to 'UTString'; see next). +*/ +typedef struct TString { + CommonHeader; + lu_byte extra; /* reserved words for short strings; "has hash" for longs */ + unsigned int hash; + size_t len; /* number of characters in string */ + struct TString *hnext; /* linked list for hash table */ +} TString; + + +/* +** Ensures that address after this type is always fully aligned. +*/ +typedef union UTString { + L_Umaxalign dummy; /* ensures maximum alignment for strings */ + TString tsv; +} UTString; + + +/* +** Get the actual string (array of bytes) from a 'TString'. +** (Access to 'extra' ensures that value is really a 'TString'.) +*/ +#define getaddrstr(ts) (cast(char *, (ts)) + sizeof(UTString)) +#define getstr(ts) \ + check_exp(sizeof((ts)->extra), cast(const char*, getaddrstr(ts))) + +/* get the actual string (array of bytes) from a Lua value */ +#define svalue(o) getstr(tsvalue(o)) + + +/* +** Header for userdata; memory area follows the end of this structure +** (aligned according to 'UUdata'; see next). +*/ +typedef struct Udata { + CommonHeader; + lu_byte ttuv_; /* user value's tag */ + struct Table *metatable; + size_t len; /* number of bytes */ + union Value user_; /* user value */ +} Udata; + + +/* +** Ensures that address after this type is always fully aligned. +*/ +typedef union UUdata { + L_Umaxalign dummy; /* ensures maximum alignment for 'local' udata */ + Udata uv; +} UUdata; + + +/* +** Get the address of memory block inside 'Udata'. +** (Access to 'ttuv_' ensures that value is really a 'Udata'.) +*/ +#define getudatamem(u) \ + check_exp(sizeof((u)->ttuv_), (cast(char*, (u)) + sizeof(UUdata))) + +#define setuservalue(L,u,o) \ + { const TValue *io=(o); Udata *iu = (u); \ + iu->user_ = io->value_; iu->ttuv_ = io->tt_; \ + checkliveness(G(L),io); } + + +#define getuservalue(L,u,o) \ + { TValue *io=(o); const Udata *iu = (u); \ + io->value_ = iu->user_; io->tt_ = iu->ttuv_; \ + checkliveness(G(L),io); } + + +/* +** Description of an upvalue for function prototypes +*/ +typedef struct Upvaldesc { + TString *name; /* upvalue name (for debug information) */ + lu_byte instack; /* whether it is in stack */ + lu_byte idx; /* index of upvalue (in stack or in outer function's list) */ +} Upvaldesc; + + +/* +** Description of a local variable for function prototypes +** (used for debug information) +*/ +typedef struct LocVar { + TString *varname; + int startpc; /* first point where variable is active */ + int endpc; /* first point where variable is dead */ +} LocVar; + + +/* +** Function Prototypes +*/ +typedef struct Proto { + CommonHeader; + lu_byte numparams; /* number of fixed parameters */ + lu_byte is_vararg; + lu_byte maxstacksize; /* maximum stack used by this function */ + int sizeupvalues; /* size of 'upvalues' */ + int sizek; /* size of 'k' */ + int sizecode; + int sizelineinfo; + int sizep; /* size of 'p' */ + int sizelocvars; + int linedefined; + int lastlinedefined; + TValue *k; /* constants used by the function */ + Instruction *code; + struct Proto **p; /* functions defined inside the function */ + int *lineinfo; /* map from opcodes to source lines (debug information) */ + LocVar *locvars; /* information about local variables (debug information) */ + Upvaldesc *upvalues; /* upvalue information */ + struct LClosure *cache; /* last created closure with this prototype */ + TString *source; /* used for debug information */ + GCObject *gclist; +} Proto; + + + +/* +** Lua Upvalues +*/ +typedef struct UpVal UpVal; + + +/* +** Closures +*/ + +#define ClosureHeader \ + CommonHeader; lu_byte nupvalues; GCObject *gclist + +typedef struct CClosure { + ClosureHeader; + lua_CFunction f; + TValue upvalue[1]; /* list of upvalues */ +} CClosure; + + +typedef struct LClosure { + ClosureHeader; + struct Proto *p; + UpVal *upvals[1]; /* list of upvalues */ +} LClosure; + + +typedef union Closure { + CClosure c; + LClosure l; +} Closure; + + +#define isLfunction(o) ttisLclosure(o) + +#define getproto(o) (clLvalue(o)->p) + + +/* +** Tables +*/ + +typedef union TKey { + struct { + TValuefields; + int next; /* for chaining (offset for next node) */ + } nk; + TValue tvk; +} TKey; + + +/* copy a value into a key without messing up field 'next' */ +#define setnodekey(L,key,obj) \ + { TKey *k_=(key); const TValue *io_=(obj); \ + k_->nk.value_ = io_->value_; k_->nk.tt_ = io_->tt_; \ + (void)L; checkliveness(G(L),io_); } + + +typedef struct Node { + TValue i_val; + TKey i_key; +} Node; + + +typedef struct Table { + CommonHeader; + lu_byte flags; /* 1<<p means tagmethod(p) is not present */ + lu_byte lsizenode; /* log2 of size of 'node' array */ + unsigned int sizearray; /* size of 'array' array */ + TValue *array; /* array part */ + Node *node; + Node *lastfree; /* any free position is before this position */ + struct Table *metatable; + GCObject *gclist; +} Table; + + + +/* +** 'module' operation for hashing (size is always a power of 2) +*/ +#define lmod(s,size) \ + (check_exp((size&(size-1))==0, (cast(int, (s) & ((size)-1))))) + + +#define twoto(x) (1<<(x)) +#define sizenode(t) (twoto((t)->lsizenode)) + + +/* +** (address of) a fixed nil value +*/ +#define luaO_nilobject (&luaO_nilobject_) + + +LUAI_DDEC const TValue luaO_nilobject_; + +/* size of buffer for 'luaO_utf8esc' function */ +#define UTF8BUFFSZ 8 + +LUAI_FUNC int luaO_int2fb (unsigned int x); +LUAI_FUNC int luaO_fb2int (int x); +LUAI_FUNC int luaO_utf8esc (char *buff, unsigned long x); +LUAI_FUNC int luaO_ceillog2 (unsigned int x); +LUAI_FUNC void luaO_arith (lua_State *L, int op, const TValue *p1, + const TValue *p2, TValue *res); +LUAI_FUNC size_t luaO_str2num (const char *s, TValue *o); +LUAI_FUNC int luaO_hexavalue (int c); +LUAI_FUNC void luaO_tostring (lua_State *L, StkId obj); +LUAI_FUNC const char *luaO_pushvfstring (lua_State *L, const char *fmt, + va_list argp); +LUAI_FUNC const char *luaO_pushfstring (lua_State *L, const char *fmt, ...); +LUAI_FUNC void luaO_chunkid (char *out, const char *source, size_t len); + + +#endif + diff --git a/src/lopcodes.c b/src/lopcodes.c new file mode 100644 index 000000000000..a1cbef857372 --- /dev/null +++ b/src/lopcodes.c @@ -0,0 +1,124 @@ +/* +** $Id: lopcodes.c,v 1.55 2015/01/05 13:48:33 roberto Exp $ +** Opcodes for Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#define lopcodes_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stddef.h> + +#include "lopcodes.h" + + +/* ORDER OP */ + +LUAI_DDEF const char *const luaP_opnames[NUM_OPCODES+1] = { + "MOVE", + "LOADK", + "LOADKX", + "LOADBOOL", + "LOADNIL", + "GETUPVAL", + "GETTABUP", + "GETTABLE", + "SETTABUP", + "SETUPVAL", + "SETTABLE", + "NEWTABLE", + "SELF", + "ADD", + "SUB", + "MUL", + "MOD", + "POW", + "DIV", + "IDIV", + "BAND", + "BOR", + "BXOR", + "SHL", + "SHR", + "UNM", + "BNOT", + "NOT", + "LEN", + "CONCAT", + "JMP", + "EQ", + "LT", + "LE", + "TEST", + "TESTSET", + "CALL", + "TAILCALL", + "RETURN", + "FORLOOP", + "FORPREP", + "TFORCALL", + "TFORLOOP", + "SETLIST", + "CLOSURE", + "VARARG", + "EXTRAARG", + NULL +}; + + +#define opmode(t,a,b,c,m) (((t)<<7) | ((a)<<6) | ((b)<<4) | ((c)<<2) | (m)) + +LUAI_DDEF const lu_byte luaP_opmodes[NUM_OPCODES] = { +/* T A B C mode opcode */ + opmode(0, 1, OpArgR, OpArgN, iABC) /* OP_MOVE */ + ,opmode(0, 1, OpArgK, OpArgN, iABx) /* OP_LOADK */ + ,opmode(0, 1, OpArgN, OpArgN, iABx) /* OP_LOADKX */ + ,opmode(0, 1, OpArgU, OpArgU, iABC) /* OP_LOADBOOL */ + ,opmode(0, 1, OpArgU, OpArgN, iABC) /* OP_LOADNIL */ + ,opmode(0, 1, OpArgU, OpArgN, iABC) /* OP_GETUPVAL */ + ,opmode(0, 1, OpArgU, OpArgK, iABC) /* OP_GETTABUP */ + ,opmode(0, 1, OpArgR, OpArgK, iABC) /* OP_GETTABLE */ + ,opmode(0, 0, OpArgK, OpArgK, iABC) /* OP_SETTABUP */ + ,opmode(0, 0, OpArgU, OpArgN, iABC) /* OP_SETUPVAL */ + ,opmode(0, 0, OpArgK, OpArgK, iABC) /* OP_SETTABLE */ + ,opmode(0, 1, OpArgU, OpArgU, iABC) /* OP_NEWTABLE */ + ,opmode(0, 1, OpArgR, OpArgK, iABC) /* OP_SELF */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_ADD */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_SUB */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_MUL */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_MOD */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_POW */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_DIV */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_IDIV */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_BAND */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_BOR */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_BXOR */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_SHL */ + ,opmode(0, 1, OpArgK, OpArgK, iABC) /* OP_SHR */ + ,opmode(0, 1, OpArgR, OpArgN, iABC) /* OP_UNM */ + ,opmode(0, 1, OpArgR, OpArgN, iABC) /* OP_BNOT */ + ,opmode(0, 1, OpArgR, OpArgN, iABC) /* OP_NOT */ + ,opmode(0, 1, OpArgR, OpArgN, iABC) /* OP_LEN */ + ,opmode(0, 1, OpArgR, OpArgR, iABC) /* OP_CONCAT */ + ,opmode(0, 0, OpArgR, OpArgN, iAsBx) /* OP_JMP */ + ,opmode(1, 0, OpArgK, OpArgK, iABC) /* OP_EQ */ + ,opmode(1, 0, OpArgK, OpArgK, iABC) /* OP_LT */ + ,opmode(1, 0, OpArgK, OpArgK, iABC) /* OP_LE */ + ,opmode(1, 0, OpArgN, OpArgU, iABC) /* OP_TEST */ + ,opmode(1, 1, OpArgR, OpArgU, iABC) /* OP_TESTSET */ + ,opmode(0, 1, OpArgU, OpArgU, iABC) /* OP_CALL */ + ,opmode(0, 1, OpArgU, OpArgU, iABC) /* OP_TAILCALL */ + ,opmode(0, 0, OpArgU, OpArgN, iABC) /* OP_RETURN */ + ,opmode(0, 1, OpArgR, OpArgN, iAsBx) /* OP_FORLOOP */ + ,opmode(0, 1, OpArgR, OpArgN, iAsBx) /* OP_FORPREP */ + ,opmode(0, 0, OpArgN, OpArgU, iABC) /* OP_TFORCALL */ + ,opmode(0, 1, OpArgR, OpArgN, iAsBx) /* OP_TFORLOOP */ + ,opmode(0, 0, OpArgU, OpArgU, iABC) /* OP_SETLIST */ + ,opmode(0, 1, OpArgU, OpArgN, iABx) /* OP_CLOSURE */ + ,opmode(0, 1, OpArgU, OpArgN, iABC) /* OP_VARARG */ + ,opmode(0, 0, OpArgU, OpArgU, iAx) /* OP_EXTRAARG */ +}; + diff --git a/src/lopcodes.h b/src/lopcodes.h new file mode 100644 index 000000000000..864b8e4bb5d4 --- /dev/null +++ b/src/lopcodes.h @@ -0,0 +1,295 @@ +/* +** $Id: lopcodes.h,v 1.148 2014/10/25 11:50:46 roberto Exp $ +** Opcodes for Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#ifndef lopcodes_h +#define lopcodes_h + +#include "llimits.h" + + +/*=========================================================================== + We assume that instructions are unsigned numbers. + All instructions have an opcode in the first 6 bits. + Instructions can have the following fields: + 'A' : 8 bits + 'B' : 9 bits + 'C' : 9 bits + 'Ax' : 26 bits ('A', 'B', and 'C' together) + 'Bx' : 18 bits ('B' and 'C' together) + 'sBx' : signed Bx + + A signed argument is represented in excess K; that is, the number + value is the unsigned value minus K. K is exactly the maximum value + for that argument (so that -max is represented by 0, and +max is + represented by 2*max), which is half the maximum for the corresponding + unsigned argument. +===========================================================================*/ + + +enum OpMode {iABC, iABx, iAsBx, iAx}; /* basic instruction format */ + + +/* +** size and position of opcode arguments. +*/ +#define SIZE_C 9 +#define SIZE_B 9 +#define SIZE_Bx (SIZE_C + SIZE_B) +#define SIZE_A 8 +#define SIZE_Ax (SIZE_C + SIZE_B + SIZE_A) + +#define SIZE_OP 6 + +#define POS_OP 0 +#define POS_A (POS_OP + SIZE_OP) +#define POS_C (POS_A + SIZE_A) +#define POS_B (POS_C + SIZE_C) +#define POS_Bx POS_C +#define POS_Ax POS_A + + +/* +** limits for opcode arguments. +** we use (signed) int to manipulate most arguments, +** so they must fit in LUAI_BITSINT-1 bits (-1 for sign) +*/ +#if SIZE_Bx < LUAI_BITSINT-1 +#define MAXARG_Bx ((1<<SIZE_Bx)-1) +#define MAXARG_sBx (MAXARG_Bx>>1) /* 'sBx' is signed */ +#else +#define MAXARG_Bx MAX_INT +#define MAXARG_sBx MAX_INT +#endif + +#if SIZE_Ax < LUAI_BITSINT-1 +#define MAXARG_Ax ((1<<SIZE_Ax)-1) +#else +#define MAXARG_Ax MAX_INT +#endif + + +#define MAXARG_A ((1<<SIZE_A)-1) +#define MAXARG_B ((1<<SIZE_B)-1) +#define MAXARG_C ((1<<SIZE_C)-1) + + +/* creates a mask with 'n' 1 bits at position 'p' */ +#define MASK1(n,p) ((~((~(Instruction)0)<<(n)))<<(p)) + +/* creates a mask with 'n' 0 bits at position 'p' */ +#define MASK0(n,p) (~MASK1(n,p)) + +/* +** the following macros help to manipulate instructions +*/ + +#define GET_OPCODE(i) (cast(OpCode, ((i)>>POS_OP) & MASK1(SIZE_OP,0))) +#define SET_OPCODE(i,o) ((i) = (((i)&MASK0(SIZE_OP,POS_OP)) | \ + ((cast(Instruction, o)<<POS_OP)&MASK1(SIZE_OP,POS_OP)))) + +#define getarg(i,pos,size) (cast(int, ((i)>>pos) & MASK1(size,0))) +#define setarg(i,v,pos,size) ((i) = (((i)&MASK0(size,pos)) | \ + ((cast(Instruction, v)<<pos)&MASK1(size,pos)))) + +#define GETARG_A(i) getarg(i, POS_A, SIZE_A) +#define SETARG_A(i,v) setarg(i, v, POS_A, SIZE_A) + +#define GETARG_B(i) getarg(i, POS_B, SIZE_B) +#define SETARG_B(i,v) setarg(i, v, POS_B, SIZE_B) + +#define GETARG_C(i) getarg(i, POS_C, SIZE_C) +#define SETARG_C(i,v) setarg(i, v, POS_C, SIZE_C) + +#define GETARG_Bx(i) getarg(i, POS_Bx, SIZE_Bx) +#define SETARG_Bx(i,v) setarg(i, v, POS_Bx, SIZE_Bx) + +#define GETARG_Ax(i) getarg(i, POS_Ax, SIZE_Ax) +#define SETARG_Ax(i,v) setarg(i, v, POS_Ax, SIZE_Ax) + +#define GETARG_sBx(i) (GETARG_Bx(i)-MAXARG_sBx) +#define SETARG_sBx(i,b) SETARG_Bx((i),cast(unsigned int, (b)+MAXARG_sBx)) + + +#define CREATE_ABC(o,a,b,c) ((cast(Instruction, o)<<POS_OP) \ + | (cast(Instruction, a)<<POS_A) \ + | (cast(Instruction, b)<<POS_B) \ + | (cast(Instruction, c)<<POS_C)) + +#define CREATE_ABx(o,a,bc) ((cast(Instruction, o)<<POS_OP) \ + | (cast(Instruction, a)<<POS_A) \ + | (cast(Instruction, bc)<<POS_Bx)) + +#define CREATE_Ax(o,a) ((cast(Instruction, o)<<POS_OP) \ + | (cast(Instruction, a)<<POS_Ax)) + + +/* +** Macros to operate RK indices +*/ + +/* this bit 1 means constant (0 means register) */ +#define BITRK (1 << (SIZE_B - 1)) + +/* test whether value is a constant */ +#define ISK(x) ((x) & BITRK) + +/* gets the index of the constant */ +#define INDEXK(r) ((int)(r) & ~BITRK) + +#define MAXINDEXRK (BITRK - 1) + +/* code a constant index as a RK value */ +#define RKASK(x) ((x) | BITRK) + + +/* +** invalid register that fits in 8 bits +*/ +#define NO_REG MAXARG_A + + +/* +** R(x) - register +** Kst(x) - constant (in constant table) +** RK(x) == if ISK(x) then Kst(INDEXK(x)) else R(x) +*/ + + +/* +** grep "ORDER OP" if you change these enums +*/ + +typedef enum { +/*---------------------------------------------------------------------- +name args description +------------------------------------------------------------------------*/ +OP_MOVE,/* A B R(A) := R(B) */ +OP_LOADK,/* A Bx R(A) := Kst(Bx) */ +OP_LOADKX,/* A R(A) := Kst(extra arg) */ +OP_LOADBOOL,/* A B C R(A) := (Bool)B; if (C) pc++ */ +OP_LOADNIL,/* A B R(A), R(A+1), ..., R(A+B) := nil */ +OP_GETUPVAL,/* A B R(A) := UpValue[B] */ + +OP_GETTABUP,/* A B C R(A) := UpValue[B][RK(C)] */ +OP_GETTABLE,/* A B C R(A) := R(B)[RK(C)] */ + +OP_SETTABUP,/* A B C UpValue[A][RK(B)] := RK(C) */ +OP_SETUPVAL,/* A B UpValue[B] := R(A) */ +OP_SETTABLE,/* A B C R(A)[RK(B)] := RK(C) */ + +OP_NEWTABLE,/* A B C R(A) := {} (size = B,C) */ + +OP_SELF,/* A B C R(A+1) := R(B); R(A) := R(B)[RK(C)] */ + +OP_ADD,/* A B C R(A) := RK(B) + RK(C) */ +OP_SUB,/* A B C R(A) := RK(B) - RK(C) */ +OP_MUL,/* A B C R(A) := RK(B) * RK(C) */ +OP_MOD,/* A B C R(A) := RK(B) % RK(C) */ +OP_POW,/* A B C R(A) := RK(B) ^ RK(C) */ +OP_DIV,/* A B C R(A) := RK(B) / RK(C) */ +OP_IDIV,/* A B C R(A) := RK(B) // RK(C) */ +OP_BAND,/* A B C R(A) := RK(B) & RK(C) */ +OP_BOR,/* A B C R(A) := RK(B) | RK(C) */ +OP_BXOR,/* A B C R(A) := RK(B) ~ RK(C) */ +OP_SHL,/* A B C R(A) := RK(B) << RK(C) */ +OP_SHR,/* A B C R(A) := RK(B) >> RK(C) */ +OP_UNM,/* A B R(A) := -R(B) */ +OP_BNOT,/* A B R(A) := ~R(B) */ +OP_NOT,/* A B R(A) := not R(B) */ +OP_LEN,/* A B R(A) := length of R(B) */ + +OP_CONCAT,/* A B C R(A) := R(B).. ... ..R(C) */ + +OP_JMP,/* A sBx pc+=sBx; if (A) close all upvalues >= R(A - 1) */ +OP_EQ,/* A B C if ((RK(B) == RK(C)) ~= A) then pc++ */ +OP_LT,/* A B C if ((RK(B) < RK(C)) ~= A) then pc++ */ +OP_LE,/* A B C if ((RK(B) <= RK(C)) ~= A) then pc++ */ + +OP_TEST,/* A C if not (R(A) <=> C) then pc++ */ +OP_TESTSET,/* A B C if (R(B) <=> C) then R(A) := R(B) else pc++ */ + +OP_CALL,/* A B C R(A), ... ,R(A+C-2) := R(A)(R(A+1), ... ,R(A+B-1)) */ +OP_TAILCALL,/* A B C return R(A)(R(A+1), ... ,R(A+B-1)) */ +OP_RETURN,/* A B return R(A), ... ,R(A+B-2) (see note) */ + +OP_FORLOOP,/* A sBx R(A)+=R(A+2); + if R(A) <?= R(A+1) then { pc+=sBx; R(A+3)=R(A) }*/ +OP_FORPREP,/* A sBx R(A)-=R(A+2); pc+=sBx */ + +OP_TFORCALL,/* A C R(A+3), ... ,R(A+2+C) := R(A)(R(A+1), R(A+2)); */ +OP_TFORLOOP,/* A sBx if R(A+1) ~= nil then { R(A)=R(A+1); pc += sBx }*/ + +OP_SETLIST,/* A B C R(A)[(C-1)*FPF+i] := R(A+i), 1 <= i <= B */ + +OP_CLOSURE,/* A Bx R(A) := closure(KPROTO[Bx]) */ + +OP_VARARG,/* A B R(A), R(A+1), ..., R(A+B-2) = vararg */ + +OP_EXTRAARG/* Ax extra (larger) argument for previous opcode */ +} OpCode; + + +#define NUM_OPCODES (cast(int, OP_EXTRAARG) + 1) + + + +/*=========================================================================== + Notes: + (*) In OP_CALL, if (B == 0) then B = top. If (C == 0), then 'top' is + set to last_result+1, so next open instruction (OP_CALL, OP_RETURN, + OP_SETLIST) may use 'top'. + + (*) In OP_VARARG, if (B == 0) then use actual number of varargs and + set top (like in OP_CALL with C == 0). + + (*) In OP_RETURN, if (B == 0) then return up to 'top'. + + (*) In OP_SETLIST, if (B == 0) then B = 'top'; if (C == 0) then next + 'instruction' is EXTRAARG(real C). + + (*) In OP_LOADKX, the next 'instruction' is always EXTRAARG. + + (*) For comparisons, A specifies what condition the test should accept + (true or false). + + (*) All 'skips' (pc++) assume that next instruction is a jump. + +===========================================================================*/ + + +/* +** masks for instruction properties. The format is: +** bits 0-1: op mode +** bits 2-3: C arg mode +** bits 4-5: B arg mode +** bit 6: instruction set register A +** bit 7: operator is a test (next instruction must be a jump) +*/ + +enum OpArgMask { + OpArgN, /* argument is not used */ + OpArgU, /* argument is used */ + OpArgR, /* argument is a register or a jump offset */ + OpArgK /* argument is a constant or register/constant */ +}; + +LUAI_DDEC const lu_byte luaP_opmodes[NUM_OPCODES]; + +#define getOpMode(m) (cast(enum OpMode, luaP_opmodes[m] & 3)) +#define getBMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 4) & 3)) +#define getCMode(m) (cast(enum OpArgMask, (luaP_opmodes[m] >> 2) & 3)) +#define testAMode(m) (luaP_opmodes[m] & (1 << 6)) +#define testTMode(m) (luaP_opmodes[m] & (1 << 7)) + + +LUAI_DDEC const char *const luaP_opnames[NUM_OPCODES+1]; /* opcode names */ + + +/* number of list items to accumulate before a SETLIST instruction */ +#define LFIELDS_PER_FLUSH 50 + + +#endif diff --git a/src/loslib.c b/src/loslib.c new file mode 100644 index 000000000000..20359b24747c --- /dev/null +++ b/src/loslib.c @@ -0,0 +1,356 @@ +/* +** $Id: loslib.c,v 1.54 2014/12/26 14:46:07 roberto Exp $ +** Standard Operating System library +** See Copyright Notice in lua.h +*/ + +#define loslib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <errno.h> +#include <locale.h> +#include <stdlib.h> +#include <string.h> +#include <time.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#if !defined(LUA_STRFTIMEOPTIONS) /* { */ +/* +** list of valid conversion specifiers for the 'strftime' function +*/ + +#if defined(LUA_USE_C89) +#define LUA_STRFTIMEOPTIONS { "aAbBcdHIjmMpSUwWxXyYz%", "" } +#else /* C99 specification */ +#define LUA_STRFTIMEOPTIONS \ + { "aAbBcCdDeFgGhHIjmMnprRStTuUVwWxXyYzZ%", "", \ + "E", "cCxXyY", \ + "O", "deHImMSuUVwWy" } +#endif + +#endif /* } */ + + + +#if !defined(l_time_t) /* { */ +/* +** type to represent time_t in Lua +*/ +#define l_timet lua_Integer +#define l_pushtime(L,t) lua_pushinteger(L,(lua_Integer)(t)) +#define l_checktime(L,a) ((time_t)luaL_checkinteger(L,a)) + +#endif /* } */ + + + +#if !defined(lua_tmpnam) /* { */ +/* +** By default, Lua uses tmpnam except when POSIX is available, where it +** uses mkstemp. +*/ + +#if defined(LUA_USE_POSIX) /* { */ + +#include <unistd.h> + +#define LUA_TMPNAMBUFSIZE 32 + +#if !defined(LUA_TMPNAMTEMPLATE) +#define LUA_TMPNAMTEMPLATE "/tmp/lua_XXXXXX" +#endif + +#define lua_tmpnam(b,e) { \ + strcpy(b, LUA_TMPNAMTEMPLATE); \ + e = mkstemp(b); \ + if (e != -1) close(e); \ + e = (e == -1); } + +#else /* }{ */ + +/* ISO C definitions */ +#define LUA_TMPNAMBUFSIZE L_tmpnam +#define lua_tmpnam(b,e) { e = (tmpnam(b) == NULL); } + +#endif /* } */ + +#endif /* } */ + + + +#if !defined(l_gmtime) /* { */ +/* +** By default, Lua uses gmtime/localtime, except when POSIX is available, +** where it uses gmtime_r/localtime_r +*/ + +#if defined(LUA_USE_POSIX) /* { */ + +#define l_gmtime(t,r) gmtime_r(t,r) +#define l_localtime(t,r) localtime_r(t,r) + +#else /* }{ */ + +/* ISO C definitions */ +#define l_gmtime(t,r) ((void)(r)->tm_sec, gmtime(t)) +#define l_localtime(t,r) ((void)(r)->tm_sec, localtime(t)) + +#endif /* } */ + +#endif /* } */ + + + +static int os_execute (lua_State *L) { + const char *cmd = luaL_optstring(L, 1, NULL); + int stat = system(cmd); + if (cmd != NULL) + return luaL_execresult(L, stat); + else { + lua_pushboolean(L, stat); /* true if there is a shell */ + return 1; + } +} + + +static int os_remove (lua_State *L) { + const char *filename = luaL_checkstring(L, 1); + return luaL_fileresult(L, remove(filename) == 0, filename); +} + + +static int os_rename (lua_State *L) { + const char *fromname = luaL_checkstring(L, 1); + const char *toname = luaL_checkstring(L, 2); + return luaL_fileresult(L, rename(fromname, toname) == 0, NULL); +} + + +static int os_tmpname (lua_State *L) { + char buff[LUA_TMPNAMBUFSIZE]; + int err; + lua_tmpnam(buff, err); + if (err) + return luaL_error(L, "unable to generate a unique filename"); + lua_pushstring(L, buff); + return 1; +} + + +static int os_getenv (lua_State *L) { + lua_pushstring(L, getenv(luaL_checkstring(L, 1))); /* if NULL push nil */ + return 1; +} + + +static int os_clock (lua_State *L) { + lua_pushnumber(L, ((lua_Number)clock())/(lua_Number)CLOCKS_PER_SEC); + return 1; +} + + +/* +** {====================================================== +** Time/Date operations +** { year=%Y, month=%m, day=%d, hour=%H, min=%M, sec=%S, +** wday=%w+1, yday=%j, isdst=? } +** ======================================================= +*/ + +static void setfield (lua_State *L, const char *key, int value) { + lua_pushinteger(L, value); + lua_setfield(L, -2, key); +} + +static void setboolfield (lua_State *L, const char *key, int value) { + if (value < 0) /* undefined? */ + return; /* does not set field */ + lua_pushboolean(L, value); + lua_setfield(L, -2, key); +} + +static int getboolfield (lua_State *L, const char *key) { + int res; + res = (lua_getfield(L, -1, key) == LUA_TNIL) ? -1 : lua_toboolean(L, -1); + lua_pop(L, 1); + return res; +} + + +static int getfield (lua_State *L, const char *key, int d) { + int res, isnum; + lua_getfield(L, -1, key); + res = (int)lua_tointegerx(L, -1, &isnum); + if (!isnum) { + if (d < 0) + return luaL_error(L, "field '%s' missing in date table", key); + res = d; + } + lua_pop(L, 1); + return res; +} + + +static const char *checkoption (lua_State *L, const char *conv, char *buff) { + static const char *const options[] = LUA_STRFTIMEOPTIONS; + unsigned int i; + for (i = 0; i < sizeof(options)/sizeof(options[0]); i += 2) { + if (*conv != '\0' && strchr(options[i], *conv) != NULL) { + buff[1] = *conv; + if (*options[i + 1] == '\0') { /* one-char conversion specifier? */ + buff[2] = '\0'; /* end buffer */ + return conv + 1; + } + else if (*(conv + 1) != '\0' && + strchr(options[i + 1], *(conv + 1)) != NULL) { + buff[2] = *(conv + 1); /* valid two-char conversion specifier */ + buff[3] = '\0'; /* end buffer */ + return conv + 2; + } + } + } + luaL_argerror(L, 1, + lua_pushfstring(L, "invalid conversion specifier '%%%s'", conv)); + return conv; /* to avoid warnings */ +} + + +static int os_date (lua_State *L) { + const char *s = luaL_optstring(L, 1, "%c"); + time_t t = luaL_opt(L, l_checktime, 2, time(NULL)); + struct tm tmr, *stm; + if (*s == '!') { /* UTC? */ + stm = l_gmtime(&t, &tmr); + s++; /* skip '!' */ + } + else + stm = l_localtime(&t, &tmr); + if (stm == NULL) /* invalid date? */ + lua_pushnil(L); + else if (strcmp(s, "*t") == 0) { + lua_createtable(L, 0, 9); /* 9 = number of fields */ + setfield(L, "sec", stm->tm_sec); + setfield(L, "min", stm->tm_min); + setfield(L, "hour", stm->tm_hour); + setfield(L, "day", stm->tm_mday); + setfield(L, "month", stm->tm_mon+1); + setfield(L, "year", stm->tm_year+1900); + setfield(L, "wday", stm->tm_wday+1); + setfield(L, "yday", stm->tm_yday+1); + setboolfield(L, "isdst", stm->tm_isdst); + } + else { + char cc[4]; + luaL_Buffer b; + cc[0] = '%'; + luaL_buffinit(L, &b); + while (*s) { + if (*s != '%') /* no conversion specifier? */ + luaL_addchar(&b, *s++); + else { + size_t reslen; + char buff[200]; /* should be big enough for any conversion result */ + s = checkoption(L, s + 1, cc); + reslen = strftime(buff, sizeof(buff), cc, stm); + luaL_addlstring(&b, buff, reslen); + } + } + luaL_pushresult(&b); + } + return 1; +} + + +static int os_time (lua_State *L) { + time_t t; + if (lua_isnoneornil(L, 1)) /* called without args? */ + t = time(NULL); /* get current time */ + else { + struct tm ts; + luaL_checktype(L, 1, LUA_TTABLE); + lua_settop(L, 1); /* make sure table is at the top */ + ts.tm_sec = getfield(L, "sec", 0); + ts.tm_min = getfield(L, "min", 0); + ts.tm_hour = getfield(L, "hour", 12); + ts.tm_mday = getfield(L, "day", -1); + ts.tm_mon = getfield(L, "month", -1) - 1; + ts.tm_year = getfield(L, "year", -1) - 1900; + ts.tm_isdst = getboolfield(L, "isdst"); + t = mktime(&ts); + } + if (t != (time_t)(l_timet)t) + luaL_error(L, "time result cannot be represented in this Lua instalation"); + else if (t == (time_t)(-1)) + lua_pushnil(L); + else + l_pushtime(L, t); + return 1; +} + + +static int os_difftime (lua_State *L) { + double res = difftime((l_checktime(L, 1)), (l_checktime(L, 2))); + lua_pushnumber(L, (lua_Number)res); + return 1; +} + +/* }====================================================== */ + + +static int os_setlocale (lua_State *L) { + static const int cat[] = {LC_ALL, LC_COLLATE, LC_CTYPE, LC_MONETARY, + LC_NUMERIC, LC_TIME}; + static const char *const catnames[] = {"all", "collate", "ctype", "monetary", + "numeric", "time", NULL}; + const char *l = luaL_optstring(L, 1, NULL); + int op = luaL_checkoption(L, 2, "all", catnames); + lua_pushstring(L, setlocale(cat[op], l)); + return 1; +} + + +static int os_exit (lua_State *L) { + int status; + if (lua_isboolean(L, 1)) + status = (lua_toboolean(L, 1) ? EXIT_SUCCESS : EXIT_FAILURE); + else + status = (int)luaL_optinteger(L, 1, EXIT_SUCCESS); + if (lua_toboolean(L, 2)) + lua_close(L); + if (L) exit(status); /* 'if' to avoid warnings for unreachable 'return' */ + return 0; +} + + +static const luaL_Reg syslib[] = { + {"clock", os_clock}, + {"date", os_date}, + {"difftime", os_difftime}, + {"execute", os_execute}, + {"exit", os_exit}, + {"getenv", os_getenv}, + {"remove", os_remove}, + {"rename", os_rename}, + {"setlocale", os_setlocale}, + {"time", os_time}, + {"tmpname", os_tmpname}, + {NULL, NULL} +}; + +/* }====================================================== */ + + + +LUAMOD_API int luaopen_os (lua_State *L) { + luaL_newlib(L, syslib); + return 1; +} + diff --git a/src/lparser.c b/src/lparser.c new file mode 100644 index 000000000000..9a54dfc98d70 --- /dev/null +++ b/src/lparser.c @@ -0,0 +1,1647 @@ +/* +** $Id: lparser.c,v 2.147 2014/12/27 20:31:43 roberto Exp $ +** Lua Parser +** See Copyright Notice in lua.h +*/ + +#define lparser_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <string.h> + +#include "lua.h" + +#include "lcode.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "llex.h" +#include "lmem.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lparser.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" + + + +/* maximum number of local variables per function (must be smaller + than 250, due to the bytecode format) */ +#define MAXVARS 200 + + +#define hasmultret(k) ((k) == VCALL || (k) == VVARARG) + + +/* because all strings are unified by the scanner, the parser + can use pointer equality for string equality */ +#define eqstr(a,b) ((a) == (b)) + + +/* +** nodes for block list (list of active blocks) +*/ +typedef struct BlockCnt { + struct BlockCnt *previous; /* chain */ + int firstlabel; /* index of first label in this block */ + int firstgoto; /* index of first pending goto in this block */ + lu_byte nactvar; /* # active locals outside the block */ + lu_byte upval; /* true if some variable in the block is an upvalue */ + lu_byte isloop; /* true if 'block' is a loop */ +} BlockCnt; + + + +/* +** prototypes for recursive non-terminal functions +*/ +static void statement (LexState *ls); +static void expr (LexState *ls, expdesc *v); + + +/* semantic error */ +static l_noret semerror (LexState *ls, const char *msg) { + ls->t.token = 0; /* remove "near <token>" from final message */ + luaX_syntaxerror(ls, msg); +} + + +static l_noret error_expected (LexState *ls, int token) { + luaX_syntaxerror(ls, + luaO_pushfstring(ls->L, "%s expected", luaX_token2str(ls, token))); +} + + +static l_noret errorlimit (FuncState *fs, int limit, const char *what) { + lua_State *L = fs->ls->L; + const char *msg; + int line = fs->f->linedefined; + const char *where = (line == 0) + ? "main function" + : luaO_pushfstring(L, "function at line %d", line); + msg = luaO_pushfstring(L, "too many %s (limit is %d) in %s", + what, limit, where); + luaX_syntaxerror(fs->ls, msg); +} + + +static void checklimit (FuncState *fs, int v, int l, const char *what) { + if (v > l) errorlimit(fs, l, what); +} + + +static int testnext (LexState *ls, int c) { + if (ls->t.token == c) { + luaX_next(ls); + return 1; + } + else return 0; +} + + +static void check (LexState *ls, int c) { + if (ls->t.token != c) + error_expected(ls, c); +} + + +static void checknext (LexState *ls, int c) { + check(ls, c); + luaX_next(ls); +} + + +#define check_condition(ls,c,msg) { if (!(c)) luaX_syntaxerror(ls, msg); } + + + +static void check_match (LexState *ls, int what, int who, int where) { + if (!testnext(ls, what)) { + if (where == ls->linenumber) + error_expected(ls, what); + else { + luaX_syntaxerror(ls, luaO_pushfstring(ls->L, + "%s expected (to close %s at line %d)", + luaX_token2str(ls, what), luaX_token2str(ls, who), where)); + } + } +} + + +static TString *str_checkname (LexState *ls) { + TString *ts; + check(ls, TK_NAME); + ts = ls->t.seminfo.ts; + luaX_next(ls); + return ts; +} + + +static void init_exp (expdesc *e, expkind k, int i) { + e->f = e->t = NO_JUMP; + e->k = k; + e->u.info = i; +} + + +static void codestring (LexState *ls, expdesc *e, TString *s) { + init_exp(e, VK, luaK_stringK(ls->fs, s)); +} + + +static void checkname (LexState *ls, expdesc *e) { + codestring(ls, e, str_checkname(ls)); +} + + +static int registerlocalvar (LexState *ls, TString *varname) { + FuncState *fs = ls->fs; + Proto *f = fs->f; + int oldsize = f->sizelocvars; + luaM_growvector(ls->L, f->locvars, fs->nlocvars, f->sizelocvars, + LocVar, SHRT_MAX, "local variables"); + while (oldsize < f->sizelocvars) f->locvars[oldsize++].varname = NULL; + f->locvars[fs->nlocvars].varname = varname; + luaC_objbarrier(ls->L, f, varname); + return fs->nlocvars++; +} + + +static void new_localvar (LexState *ls, TString *name) { + FuncState *fs = ls->fs; + Dyndata *dyd = ls->dyd; + int reg = registerlocalvar(ls, name); + checklimit(fs, dyd->actvar.n + 1 - fs->firstlocal, + MAXVARS, "local variables"); + luaM_growvector(ls->L, dyd->actvar.arr, dyd->actvar.n + 1, + dyd->actvar.size, Vardesc, MAX_INT, "local variables"); + dyd->actvar.arr[dyd->actvar.n++].idx = cast(short, reg); +} + + +static void new_localvarliteral_ (LexState *ls, const char *name, size_t sz) { + new_localvar(ls, luaX_newstring(ls, name, sz)); +} + +#define new_localvarliteral(ls,v) \ + new_localvarliteral_(ls, "" v, (sizeof(v)/sizeof(char))-1) + + +static LocVar *getlocvar (FuncState *fs, int i) { + int idx = fs->ls->dyd->actvar.arr[fs->firstlocal + i].idx; + lua_assert(idx < fs->nlocvars); + return &fs->f->locvars[idx]; +} + + +static void adjustlocalvars (LexState *ls, int nvars) { + FuncState *fs = ls->fs; + fs->nactvar = cast_byte(fs->nactvar + nvars); + for (; nvars; nvars--) { + getlocvar(fs, fs->nactvar - nvars)->startpc = fs->pc; + } +} + + +static void removevars (FuncState *fs, int tolevel) { + fs->ls->dyd->actvar.n -= (fs->nactvar - tolevel); + while (fs->nactvar > tolevel) + getlocvar(fs, --fs->nactvar)->endpc = fs->pc; +} + + +static int searchupvalue (FuncState *fs, TString *name) { + int i; + Upvaldesc *up = fs->f->upvalues; + for (i = 0; i < fs->nups; i++) { + if (eqstr(up[i].name, name)) return i; + } + return -1; /* not found */ +} + + +static int newupvalue (FuncState *fs, TString *name, expdesc *v) { + Proto *f = fs->f; + int oldsize = f->sizeupvalues; + checklimit(fs, fs->nups + 1, MAXUPVAL, "upvalues"); + luaM_growvector(fs->ls->L, f->upvalues, fs->nups, f->sizeupvalues, + Upvaldesc, MAXUPVAL, "upvalues"); + while (oldsize < f->sizeupvalues) f->upvalues[oldsize++].name = NULL; + f->upvalues[fs->nups].instack = (v->k == VLOCAL); + f->upvalues[fs->nups].idx = cast_byte(v->u.info); + f->upvalues[fs->nups].name = name; + luaC_objbarrier(fs->ls->L, f, name); + return fs->nups++; +} + + +static int searchvar (FuncState *fs, TString *n) { + int i; + for (i = cast_int(fs->nactvar) - 1; i >= 0; i--) { + if (eqstr(n, getlocvar(fs, i)->varname)) + return i; + } + return -1; /* not found */ +} + + +/* + Mark block where variable at given level was defined + (to emit close instructions later). +*/ +static void markupval (FuncState *fs, int level) { + BlockCnt *bl = fs->bl; + while (bl->nactvar > level) bl = bl->previous; + bl->upval = 1; +} + + +/* + Find variable with given name 'n'. If it is an upvalue, add this + upvalue into all intermediate functions. +*/ +static int singlevaraux (FuncState *fs, TString *n, expdesc *var, int base) { + if (fs == NULL) /* no more levels? */ + return VVOID; /* default is global */ + else { + int v = searchvar(fs, n); /* look up locals at current level */ + if (v >= 0) { /* found? */ + init_exp(var, VLOCAL, v); /* variable is local */ + if (!base) + markupval(fs, v); /* local will be used as an upval */ + return VLOCAL; + } + else { /* not found as local at current level; try upvalues */ + int idx = searchupvalue(fs, n); /* try existing upvalues */ + if (idx < 0) { /* not found? */ + if (singlevaraux(fs->prev, n, var, 0) == VVOID) /* try upper levels */ + return VVOID; /* not found; is a global */ + /* else was LOCAL or UPVAL */ + idx = newupvalue(fs, n, var); /* will be a new upvalue */ + } + init_exp(var, VUPVAL, idx); + return VUPVAL; + } + } +} + + +static void singlevar (LexState *ls, expdesc *var) { + TString *varname = str_checkname(ls); + FuncState *fs = ls->fs; + if (singlevaraux(fs, varname, var, 1) == VVOID) { /* global name? */ + expdesc key; + singlevaraux(fs, ls->envn, var, 1); /* get environment variable */ + lua_assert(var->k == VLOCAL || var->k == VUPVAL); + codestring(ls, &key, varname); /* key is variable name */ + luaK_indexed(fs, var, &key); /* env[varname] */ + } +} + + +static void adjust_assign (LexState *ls, int nvars, int nexps, expdesc *e) { + FuncState *fs = ls->fs; + int extra = nvars - nexps; + if (hasmultret(e->k)) { + extra++; /* includes call itself */ + if (extra < 0) extra = 0; + luaK_setreturns(fs, e, extra); /* last exp. provides the difference */ + if (extra > 1) luaK_reserveregs(fs, extra-1); + } + else { + if (e->k != VVOID) luaK_exp2nextreg(fs, e); /* close last expression */ + if (extra > 0) { + int reg = fs->freereg; + luaK_reserveregs(fs, extra); + luaK_nil(fs, reg, extra); + } + } +} + + +static void enterlevel (LexState *ls) { + lua_State *L = ls->L; + ++L->nCcalls; + checklimit(ls->fs, L->nCcalls, LUAI_MAXCCALLS, "C levels"); +} + + +#define leavelevel(ls) ((ls)->L->nCcalls--) + + +static void closegoto (LexState *ls, int g, Labeldesc *label) { + int i; + FuncState *fs = ls->fs; + Labellist *gl = &ls->dyd->gt; + Labeldesc *gt = &gl->arr[g]; + lua_assert(eqstr(gt->name, label->name)); + if (gt->nactvar < label->nactvar) { + TString *vname = getlocvar(fs, gt->nactvar)->varname; + const char *msg = luaO_pushfstring(ls->L, + "<goto %s> at line %d jumps into the scope of local '%s'", + getstr(gt->name), gt->line, getstr(vname)); + semerror(ls, msg); + } + luaK_patchlist(fs, gt->pc, label->pc); + /* remove goto from pending list */ + for (i = g; i < gl->n - 1; i++) + gl->arr[i] = gl->arr[i + 1]; + gl->n--; +} + + +/* +** try to close a goto with existing labels; this solves backward jumps +*/ +static int findlabel (LexState *ls, int g) { + int i; + BlockCnt *bl = ls->fs->bl; + Dyndata *dyd = ls->dyd; + Labeldesc *gt = &dyd->gt.arr[g]; + /* check labels in current block for a match */ + for (i = bl->firstlabel; i < dyd->label.n; i++) { + Labeldesc *lb = &dyd->label.arr[i]; + if (eqstr(lb->name, gt->name)) { /* correct label? */ + if (gt->nactvar > lb->nactvar && + (bl->upval || dyd->label.n > bl->firstlabel)) + luaK_patchclose(ls->fs, gt->pc, lb->nactvar); + closegoto(ls, g, lb); /* close it */ + return 1; + } + } + return 0; /* label not found; cannot close goto */ +} + + +static int newlabelentry (LexState *ls, Labellist *l, TString *name, + int line, int pc) { + int n = l->n; + luaM_growvector(ls->L, l->arr, n, l->size, + Labeldesc, SHRT_MAX, "labels/gotos"); + l->arr[n].name = name; + l->arr[n].line = line; + l->arr[n].nactvar = ls->fs->nactvar; + l->arr[n].pc = pc; + l->n = n + 1; + return n; +} + + +/* +** check whether new label 'lb' matches any pending gotos in current +** block; solves forward jumps +*/ +static void findgotos (LexState *ls, Labeldesc *lb) { + Labellist *gl = &ls->dyd->gt; + int i = ls->fs->bl->firstgoto; + while (i < gl->n) { + if (eqstr(gl->arr[i].name, lb->name)) + closegoto(ls, i, lb); + else + i++; + } +} + + +/* +** export pending gotos to outer level, to check them against +** outer labels; if the block being exited has upvalues, and +** the goto exits the scope of any variable (which can be the +** upvalue), close those variables being exited. +*/ +static void movegotosout (FuncState *fs, BlockCnt *bl) { + int i = bl->firstgoto; + Labellist *gl = &fs->ls->dyd->gt; + /* correct pending gotos to current block and try to close it + with visible labels */ + while (i < gl->n) { + Labeldesc *gt = &gl->arr[i]; + if (gt->nactvar > bl->nactvar) { + if (bl->upval) + luaK_patchclose(fs, gt->pc, bl->nactvar); + gt->nactvar = bl->nactvar; + } + if (!findlabel(fs->ls, i)) + i++; /* move to next one */ + } +} + + +static void enterblock (FuncState *fs, BlockCnt *bl, lu_byte isloop) { + bl->isloop = isloop; + bl->nactvar = fs->nactvar; + bl->firstlabel = fs->ls->dyd->label.n; + bl->firstgoto = fs->ls->dyd->gt.n; + bl->upval = 0; + bl->previous = fs->bl; + fs->bl = bl; + lua_assert(fs->freereg == fs->nactvar); +} + + +/* +** create a label named 'break' to resolve break statements +*/ +static void breaklabel (LexState *ls) { + TString *n = luaS_new(ls->L, "break"); + int l = newlabelentry(ls, &ls->dyd->label, n, 0, ls->fs->pc); + findgotos(ls, &ls->dyd->label.arr[l]); +} + +/* +** generates an error for an undefined 'goto'; choose appropriate +** message when label name is a reserved word (which can only be 'break') +*/ +static l_noret undefgoto (LexState *ls, Labeldesc *gt) { + const char *msg = isreserved(gt->name) + ? "<%s> at line %d not inside a loop" + : "no visible label '%s' for <goto> at line %d"; + msg = luaO_pushfstring(ls->L, msg, getstr(gt->name), gt->line); + semerror(ls, msg); +} + + +static void leaveblock (FuncState *fs) { + BlockCnt *bl = fs->bl; + LexState *ls = fs->ls; + if (bl->previous && bl->upval) { + /* create a 'jump to here' to close upvalues */ + int j = luaK_jump(fs); + luaK_patchclose(fs, j, bl->nactvar); + luaK_patchtohere(fs, j); + } + if (bl->isloop) + breaklabel(ls); /* close pending breaks */ + fs->bl = bl->previous; + removevars(fs, bl->nactvar); + lua_assert(bl->nactvar == fs->nactvar); + fs->freereg = fs->nactvar; /* free registers */ + ls->dyd->label.n = bl->firstlabel; /* remove local labels */ + if (bl->previous) /* inner block? */ + movegotosout(fs, bl); /* update pending gotos to outer block */ + else if (bl->firstgoto < ls->dyd->gt.n) /* pending gotos in outer block? */ + undefgoto(ls, &ls->dyd->gt.arr[bl->firstgoto]); /* error */ +} + + +/* +** adds a new prototype into list of prototypes +*/ +static Proto *addprototype (LexState *ls) { + Proto *clp; + lua_State *L = ls->L; + FuncState *fs = ls->fs; + Proto *f = fs->f; /* prototype of current function */ + if (fs->np >= f->sizep) { + int oldsize = f->sizep; + luaM_growvector(L, f->p, fs->np, f->sizep, Proto *, MAXARG_Bx, "functions"); + while (oldsize < f->sizep) f->p[oldsize++] = NULL; + } + f->p[fs->np++] = clp = luaF_newproto(L); + luaC_objbarrier(L, f, clp); + return clp; +} + + +/* +** codes instruction to create new closure in parent function. +** The OP_CLOSURE instruction must use the last available register, +** so that, if it invokes the GC, the GC knows which registers +** are in use at that time. +*/ +static void codeclosure (LexState *ls, expdesc *v) { + FuncState *fs = ls->fs->prev; + init_exp(v, VRELOCABLE, luaK_codeABx(fs, OP_CLOSURE, 0, fs->np - 1)); + luaK_exp2nextreg(fs, v); /* fix it at the last register */ +} + + +static void open_func (LexState *ls, FuncState *fs, BlockCnt *bl) { + Proto *f; + fs->prev = ls->fs; /* linked list of funcstates */ + fs->ls = ls; + ls->fs = fs; + fs->pc = 0; + fs->lasttarget = 0; + fs->jpc = NO_JUMP; + fs->freereg = 0; + fs->nk = 0; + fs->np = 0; + fs->nups = 0; + fs->nlocvars = 0; + fs->nactvar = 0; + fs->firstlocal = ls->dyd->actvar.n; + fs->bl = NULL; + f = fs->f; + f->source = ls->source; + f->maxstacksize = 2; /* registers 0/1 are always valid */ + enterblock(fs, bl, 0); +} + + +static void close_func (LexState *ls) { + lua_State *L = ls->L; + FuncState *fs = ls->fs; + Proto *f = fs->f; + luaK_ret(fs, 0, 0); /* final return */ + leaveblock(fs); + luaM_reallocvector(L, f->code, f->sizecode, fs->pc, Instruction); + f->sizecode = fs->pc; + luaM_reallocvector(L, f->lineinfo, f->sizelineinfo, fs->pc, int); + f->sizelineinfo = fs->pc; + luaM_reallocvector(L, f->k, f->sizek, fs->nk, TValue); + f->sizek = fs->nk; + luaM_reallocvector(L, f->p, f->sizep, fs->np, Proto *); + f->sizep = fs->np; + luaM_reallocvector(L, f->locvars, f->sizelocvars, fs->nlocvars, LocVar); + f->sizelocvars = fs->nlocvars; + luaM_reallocvector(L, f->upvalues, f->sizeupvalues, fs->nups, Upvaldesc); + f->sizeupvalues = fs->nups; + lua_assert(fs->bl == NULL); + ls->fs = fs->prev; + luaC_checkGC(L); +} + + + +/*============================================================*/ +/* GRAMMAR RULES */ +/*============================================================*/ + + +/* +** check whether current token is in the follow set of a block. +** 'until' closes syntactical blocks, but do not close scope, +** so it is handled in separate. +*/ +static int block_follow (LexState *ls, int withuntil) { + switch (ls->t.token) { + case TK_ELSE: case TK_ELSEIF: + case TK_END: case TK_EOS: + return 1; + case TK_UNTIL: return withuntil; + default: return 0; + } +} + + +static void statlist (LexState *ls) { + /* statlist -> { stat [';'] } */ + while (!block_follow(ls, 1)) { + if (ls->t.token == TK_RETURN) { + statement(ls); + return; /* 'return' must be last statement */ + } + statement(ls); + } +} + + +static void fieldsel (LexState *ls, expdesc *v) { + /* fieldsel -> ['.' | ':'] NAME */ + FuncState *fs = ls->fs; + expdesc key; + luaK_exp2anyregup(fs, v); + luaX_next(ls); /* skip the dot or colon */ + checkname(ls, &key); + luaK_indexed(fs, v, &key); +} + + +static void yindex (LexState *ls, expdesc *v) { + /* index -> '[' expr ']' */ + luaX_next(ls); /* skip the '[' */ + expr(ls, v); + luaK_exp2val(ls->fs, v); + checknext(ls, ']'); +} + + +/* +** {====================================================================== +** Rules for Constructors +** ======================================================================= +*/ + + +struct ConsControl { + expdesc v; /* last list item read */ + expdesc *t; /* table descriptor */ + int nh; /* total number of 'record' elements */ + int na; /* total number of array elements */ + int tostore; /* number of array elements pending to be stored */ +}; + + +static void recfield (LexState *ls, struct ConsControl *cc) { + /* recfield -> (NAME | '['exp1']') = exp1 */ + FuncState *fs = ls->fs; + int reg = ls->fs->freereg; + expdesc key, val; + int rkkey; + if (ls->t.token == TK_NAME) { + checklimit(fs, cc->nh, MAX_INT, "items in a constructor"); + checkname(ls, &key); + } + else /* ls->t.token == '[' */ + yindex(ls, &key); + cc->nh++; + checknext(ls, '='); + rkkey = luaK_exp2RK(fs, &key); + expr(ls, &val); + luaK_codeABC(fs, OP_SETTABLE, cc->t->u.info, rkkey, luaK_exp2RK(fs, &val)); + fs->freereg = reg; /* free registers */ +} + + +static void closelistfield (FuncState *fs, struct ConsControl *cc) { + if (cc->v.k == VVOID) return; /* there is no list item */ + luaK_exp2nextreg(fs, &cc->v); + cc->v.k = VVOID; + if (cc->tostore == LFIELDS_PER_FLUSH) { + luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); /* flush */ + cc->tostore = 0; /* no more items pending */ + } +} + + +static void lastlistfield (FuncState *fs, struct ConsControl *cc) { + if (cc->tostore == 0) return; + if (hasmultret(cc->v.k)) { + luaK_setmultret(fs, &cc->v); + luaK_setlist(fs, cc->t->u.info, cc->na, LUA_MULTRET); + cc->na--; /* do not count last expression (unknown number of elements) */ + } + else { + if (cc->v.k != VVOID) + luaK_exp2nextreg(fs, &cc->v); + luaK_setlist(fs, cc->t->u.info, cc->na, cc->tostore); + } +} + + +static void listfield (LexState *ls, struct ConsControl *cc) { + /* listfield -> exp */ + expr(ls, &cc->v); + checklimit(ls->fs, cc->na, MAX_INT, "items in a constructor"); + cc->na++; + cc->tostore++; +} + + +static void field (LexState *ls, struct ConsControl *cc) { + /* field -> listfield | recfield */ + switch(ls->t.token) { + case TK_NAME: { /* may be 'listfield' or 'recfield' */ + if (luaX_lookahead(ls) != '=') /* expression? */ + listfield(ls, cc); + else + recfield(ls, cc); + break; + } + case '[': { + recfield(ls, cc); + break; + } + default: { + listfield(ls, cc); + break; + } + } +} + + +static void constructor (LexState *ls, expdesc *t) { + /* constructor -> '{' [ field { sep field } [sep] ] '}' + sep -> ',' | ';' */ + FuncState *fs = ls->fs; + int line = ls->linenumber; + int pc = luaK_codeABC(fs, OP_NEWTABLE, 0, 0, 0); + struct ConsControl cc; + cc.na = cc.nh = cc.tostore = 0; + cc.t = t; + init_exp(t, VRELOCABLE, pc); + init_exp(&cc.v, VVOID, 0); /* no value (yet) */ + luaK_exp2nextreg(ls->fs, t); /* fix it at stack top */ + checknext(ls, '{'); + do { + lua_assert(cc.v.k == VVOID || cc.tostore > 0); + if (ls->t.token == '}') break; + closelistfield(fs, &cc); + field(ls, &cc); + } while (testnext(ls, ',') || testnext(ls, ';')); + check_match(ls, '}', '{', line); + lastlistfield(fs, &cc); + SETARG_B(fs->f->code[pc], luaO_int2fb(cc.na)); /* set initial array size */ + SETARG_C(fs->f->code[pc], luaO_int2fb(cc.nh)); /* set initial table size */ +} + +/* }====================================================================== */ + + + +static void parlist (LexState *ls) { + /* parlist -> [ param { ',' param } ] */ + FuncState *fs = ls->fs; + Proto *f = fs->f; + int nparams = 0; + f->is_vararg = 0; + if (ls->t.token != ')') { /* is 'parlist' not empty? */ + do { + switch (ls->t.token) { + case TK_NAME: { /* param -> NAME */ + new_localvar(ls, str_checkname(ls)); + nparams++; + break; + } + case TK_DOTS: { /* param -> '...' */ + luaX_next(ls); + f->is_vararg = 1; + break; + } + default: luaX_syntaxerror(ls, "<name> or '...' expected"); + } + } while (!f->is_vararg && testnext(ls, ',')); + } + adjustlocalvars(ls, nparams); + f->numparams = cast_byte(fs->nactvar); + luaK_reserveregs(fs, fs->nactvar); /* reserve register for parameters */ +} + + +static void body (LexState *ls, expdesc *e, int ismethod, int line) { + /* body -> '(' parlist ')' block END */ + FuncState new_fs; + BlockCnt bl; + new_fs.f = addprototype(ls); + new_fs.f->linedefined = line; + open_func(ls, &new_fs, &bl); + checknext(ls, '('); + if (ismethod) { + new_localvarliteral(ls, "self"); /* create 'self' parameter */ + adjustlocalvars(ls, 1); + } + parlist(ls); + checknext(ls, ')'); + statlist(ls); + new_fs.f->lastlinedefined = ls->linenumber; + check_match(ls, TK_END, TK_FUNCTION, line); + codeclosure(ls, e); + close_func(ls); +} + + +static int explist (LexState *ls, expdesc *v) { + /* explist -> expr { ',' expr } */ + int n = 1; /* at least one expression */ + expr(ls, v); + while (testnext(ls, ',')) { + luaK_exp2nextreg(ls->fs, v); + expr(ls, v); + n++; + } + return n; +} + + +static void funcargs (LexState *ls, expdesc *f, int line) { + FuncState *fs = ls->fs; + expdesc args; + int base, nparams; + switch (ls->t.token) { + case '(': { /* funcargs -> '(' [ explist ] ')' */ + luaX_next(ls); + if (ls->t.token == ')') /* arg list is empty? */ + args.k = VVOID; + else { + explist(ls, &args); + luaK_setmultret(fs, &args); + } + check_match(ls, ')', '(', line); + break; + } + case '{': { /* funcargs -> constructor */ + constructor(ls, &args); + break; + } + case TK_STRING: { /* funcargs -> STRING */ + codestring(ls, &args, ls->t.seminfo.ts); + luaX_next(ls); /* must use 'seminfo' before 'next' */ + break; + } + default: { + luaX_syntaxerror(ls, "function arguments expected"); + } + } + lua_assert(f->k == VNONRELOC); + base = f->u.info; /* base register for call */ + if (hasmultret(args.k)) + nparams = LUA_MULTRET; /* open call */ + else { + if (args.k != VVOID) + luaK_exp2nextreg(fs, &args); /* close last argument */ + nparams = fs->freereg - (base+1); + } + init_exp(f, VCALL, luaK_codeABC(fs, OP_CALL, base, nparams+1, 2)); + luaK_fixline(fs, line); + fs->freereg = base+1; /* call remove function and arguments and leaves + (unless changed) one result */ +} + + + + +/* +** {====================================================================== +** Expression parsing +** ======================================================================= +*/ + + +static void primaryexp (LexState *ls, expdesc *v) { + /* primaryexp -> NAME | '(' expr ')' */ + switch (ls->t.token) { + case '(': { + int line = ls->linenumber; + luaX_next(ls); + expr(ls, v); + check_match(ls, ')', '(', line); + luaK_dischargevars(ls->fs, v); + return; + } + case TK_NAME: { + singlevar(ls, v); + return; + } + default: { + luaX_syntaxerror(ls, "unexpected symbol"); + } + } +} + + +static void suffixedexp (LexState *ls, expdesc *v) { + /* suffixedexp -> + primaryexp { '.' NAME | '[' exp ']' | ':' NAME funcargs | funcargs } */ + FuncState *fs = ls->fs; + int line = ls->linenumber; + primaryexp(ls, v); + for (;;) { + switch (ls->t.token) { + case '.': { /* fieldsel */ + fieldsel(ls, v); + break; + } + case '[': { /* '[' exp1 ']' */ + expdesc key; + luaK_exp2anyregup(fs, v); + yindex(ls, &key); + luaK_indexed(fs, v, &key); + break; + } + case ':': { /* ':' NAME funcargs */ + expdesc key; + luaX_next(ls); + checkname(ls, &key); + luaK_self(fs, v, &key); + funcargs(ls, v, line); + break; + } + case '(': case TK_STRING: case '{': { /* funcargs */ + luaK_exp2nextreg(fs, v); + funcargs(ls, v, line); + break; + } + default: return; + } + } +} + + +static void simpleexp (LexState *ls, expdesc *v) { + /* simpleexp -> FLT | INT | STRING | NIL | TRUE | FALSE | ... | + constructor | FUNCTION body | suffixedexp */ + switch (ls->t.token) { + case TK_FLT: { + init_exp(v, VKFLT, 0); + v->u.nval = ls->t.seminfo.r; + break; + } + case TK_INT: { + init_exp(v, VKINT, 0); + v->u.ival = ls->t.seminfo.i; + break; + } + case TK_STRING: { + codestring(ls, v, ls->t.seminfo.ts); + break; + } + case TK_NIL: { + init_exp(v, VNIL, 0); + break; + } + case TK_TRUE: { + init_exp(v, VTRUE, 0); + break; + } + case TK_FALSE: { + init_exp(v, VFALSE, 0); + break; + } + case TK_DOTS: { /* vararg */ + FuncState *fs = ls->fs; + check_condition(ls, fs->f->is_vararg, + "cannot use '...' outside a vararg function"); + init_exp(v, VVARARG, luaK_codeABC(fs, OP_VARARG, 0, 1, 0)); + break; + } + case '{': { /* constructor */ + constructor(ls, v); + return; + } + case TK_FUNCTION: { + luaX_next(ls); + body(ls, v, 0, ls->linenumber); + return; + } + default: { + suffixedexp(ls, v); + return; + } + } + luaX_next(ls); +} + + +static UnOpr getunopr (int op) { + switch (op) { + case TK_NOT: return OPR_NOT; + case '-': return OPR_MINUS; + case '~': return OPR_BNOT; + case '#': return OPR_LEN; + default: return OPR_NOUNOPR; + } +} + + +static BinOpr getbinopr (int op) { + switch (op) { + case '+': return OPR_ADD; + case '-': return OPR_SUB; + case '*': return OPR_MUL; + case '%': return OPR_MOD; + case '^': return OPR_POW; + case '/': return OPR_DIV; + case TK_IDIV: return OPR_IDIV; + case '&': return OPR_BAND; + case '|': return OPR_BOR; + case '~': return OPR_BXOR; + case TK_SHL: return OPR_SHL; + case TK_SHR: return OPR_SHR; + case TK_CONCAT: return OPR_CONCAT; + case TK_NE: return OPR_NE; + case TK_EQ: return OPR_EQ; + case '<': return OPR_LT; + case TK_LE: return OPR_LE; + case '>': return OPR_GT; + case TK_GE: return OPR_GE; + case TK_AND: return OPR_AND; + case TK_OR: return OPR_OR; + default: return OPR_NOBINOPR; + } +} + + +static const struct { + lu_byte left; /* left priority for each binary operator */ + lu_byte right; /* right priority */ +} priority[] = { /* ORDER OPR */ + {10, 10}, {10, 10}, /* '+' '-' */ + {11, 11}, {11, 11}, /* '*' '%' */ + {14, 13}, /* '^' (right associative) */ + {11, 11}, {11, 11}, /* '/' '//' */ + {6, 6}, {4, 4}, {5, 5}, /* '&' '|' '~' */ + {7, 7}, {7, 7}, /* '<<' '>>' */ + {9, 8}, /* '..' (right associative) */ + {3, 3}, {3, 3}, {3, 3}, /* ==, <, <= */ + {3, 3}, {3, 3}, {3, 3}, /* ~=, >, >= */ + {2, 2}, {1, 1} /* and, or */ +}; + +#define UNARY_PRIORITY 12 /* priority for unary operators */ + + +/* +** subexpr -> (simpleexp | unop subexpr) { binop subexpr } +** where 'binop' is any binary operator with a priority higher than 'limit' +*/ +static BinOpr subexpr (LexState *ls, expdesc *v, int limit) { + BinOpr op; + UnOpr uop; + enterlevel(ls); + uop = getunopr(ls->t.token); + if (uop != OPR_NOUNOPR) { + int line = ls->linenumber; + luaX_next(ls); + subexpr(ls, v, UNARY_PRIORITY); + luaK_prefix(ls->fs, uop, v, line); + } + else simpleexp(ls, v); + /* expand while operators have priorities higher than 'limit' */ + op = getbinopr(ls->t.token); + while (op != OPR_NOBINOPR && priority[op].left > limit) { + expdesc v2; + BinOpr nextop; + int line = ls->linenumber; + luaX_next(ls); + luaK_infix(ls->fs, op, v); + /* read sub-expression with higher priority */ + nextop = subexpr(ls, &v2, priority[op].right); + luaK_posfix(ls->fs, op, v, &v2, line); + op = nextop; + } + leavelevel(ls); + return op; /* return first untreated operator */ +} + + +static void expr (LexState *ls, expdesc *v) { + subexpr(ls, v, 0); +} + +/* }==================================================================== */ + + + +/* +** {====================================================================== +** Rules for Statements +** ======================================================================= +*/ + + +static void block (LexState *ls) { + /* block -> statlist */ + FuncState *fs = ls->fs; + BlockCnt bl; + enterblock(fs, &bl, 0); + statlist(ls); + leaveblock(fs); +} + + +/* +** structure to chain all variables in the left-hand side of an +** assignment +*/ +struct LHS_assign { + struct LHS_assign *prev; + expdesc v; /* variable (global, local, upvalue, or indexed) */ +}; + + +/* +** check whether, in an assignment to an upvalue/local variable, the +** upvalue/local variable is begin used in a previous assignment to a +** table. If so, save original upvalue/local value in a safe place and +** use this safe copy in the previous assignment. +*/ +static void check_conflict (LexState *ls, struct LHS_assign *lh, expdesc *v) { + FuncState *fs = ls->fs; + int extra = fs->freereg; /* eventual position to save local variable */ + int conflict = 0; + for (; lh; lh = lh->prev) { /* check all previous assignments */ + if (lh->v.k == VINDEXED) { /* assigning to a table? */ + /* table is the upvalue/local being assigned now? */ + if (lh->v.u.ind.vt == v->k && lh->v.u.ind.t == v->u.info) { + conflict = 1; + lh->v.u.ind.vt = VLOCAL; + lh->v.u.ind.t = extra; /* previous assignment will use safe copy */ + } + /* index is the local being assigned? (index cannot be upvalue) */ + if (v->k == VLOCAL && lh->v.u.ind.idx == v->u.info) { + conflict = 1; + lh->v.u.ind.idx = extra; /* previous assignment will use safe copy */ + } + } + } + if (conflict) { + /* copy upvalue/local value to a temporary (in position 'extra') */ + OpCode op = (v->k == VLOCAL) ? OP_MOVE : OP_GETUPVAL; + luaK_codeABC(fs, op, extra, v->u.info, 0); + luaK_reserveregs(fs, 1); + } +} + + +static void assignment (LexState *ls, struct LHS_assign *lh, int nvars) { + expdesc e; + check_condition(ls, vkisvar(lh->v.k), "syntax error"); + if (testnext(ls, ',')) { /* assignment -> ',' suffixedexp assignment */ + struct LHS_assign nv; + nv.prev = lh; + suffixedexp(ls, &nv.v); + if (nv.v.k != VINDEXED) + check_conflict(ls, lh, &nv.v); + checklimit(ls->fs, nvars + ls->L->nCcalls, LUAI_MAXCCALLS, + "C levels"); + assignment(ls, &nv, nvars+1); + } + else { /* assignment -> '=' explist */ + int nexps; + checknext(ls, '='); + nexps = explist(ls, &e); + if (nexps != nvars) { + adjust_assign(ls, nvars, nexps, &e); + if (nexps > nvars) + ls->fs->freereg -= nexps - nvars; /* remove extra values */ + } + else { + luaK_setoneret(ls->fs, &e); /* close last expression */ + luaK_storevar(ls->fs, &lh->v, &e); + return; /* avoid default */ + } + } + init_exp(&e, VNONRELOC, ls->fs->freereg-1); /* default assignment */ + luaK_storevar(ls->fs, &lh->v, &e); +} + + +static int cond (LexState *ls) { + /* cond -> exp */ + expdesc v; + expr(ls, &v); /* read condition */ + if (v.k == VNIL) v.k = VFALSE; /* 'falses' are all equal here */ + luaK_goiftrue(ls->fs, &v); + return v.f; +} + + +static void gotostat (LexState *ls, int pc) { + int line = ls->linenumber; + TString *label; + int g; + if (testnext(ls, TK_GOTO)) + label = str_checkname(ls); + else { + luaX_next(ls); /* skip break */ + label = luaS_new(ls->L, "break"); + } + g = newlabelentry(ls, &ls->dyd->gt, label, line, pc); + findlabel(ls, g); /* close it if label already defined */ +} + + +/* check for repeated labels on the same block */ +static void checkrepeated (FuncState *fs, Labellist *ll, TString *label) { + int i; + for (i = fs->bl->firstlabel; i < ll->n; i++) { + if (eqstr(label, ll->arr[i].name)) { + const char *msg = luaO_pushfstring(fs->ls->L, + "label '%s' already defined on line %d", + getstr(label), ll->arr[i].line); + semerror(fs->ls, msg); + } + } +} + + +/* skip no-op statements */ +static void skipnoopstat (LexState *ls) { + while (ls->t.token == ';' || ls->t.token == TK_DBCOLON) + statement(ls); +} + + +static void labelstat (LexState *ls, TString *label, int line) { + /* label -> '::' NAME '::' */ + FuncState *fs = ls->fs; + Labellist *ll = &ls->dyd->label; + int l; /* index of new label being created */ + checkrepeated(fs, ll, label); /* check for repeated labels */ + checknext(ls, TK_DBCOLON); /* skip double colon */ + /* create new entry for this label */ + l = newlabelentry(ls, ll, label, line, fs->pc); + skipnoopstat(ls); /* skip other no-op statements */ + if (block_follow(ls, 0)) { /* label is last no-op statement in the block? */ + /* assume that locals are already out of scope */ + ll->arr[l].nactvar = fs->bl->nactvar; + } + findgotos(ls, &ll->arr[l]); +} + + +static void whilestat (LexState *ls, int line) { + /* whilestat -> WHILE cond DO block END */ + FuncState *fs = ls->fs; + int whileinit; + int condexit; + BlockCnt bl; + luaX_next(ls); /* skip WHILE */ + whileinit = luaK_getlabel(fs); + condexit = cond(ls); + enterblock(fs, &bl, 1); + checknext(ls, TK_DO); + block(ls); + luaK_jumpto(fs, whileinit); + check_match(ls, TK_END, TK_WHILE, line); + leaveblock(fs); + luaK_patchtohere(fs, condexit); /* false conditions finish the loop */ +} + + +static void repeatstat (LexState *ls, int line) { + /* repeatstat -> REPEAT block UNTIL cond */ + int condexit; + FuncState *fs = ls->fs; + int repeat_init = luaK_getlabel(fs); + BlockCnt bl1, bl2; + enterblock(fs, &bl1, 1); /* loop block */ + enterblock(fs, &bl2, 0); /* scope block */ + luaX_next(ls); /* skip REPEAT */ + statlist(ls); + check_match(ls, TK_UNTIL, TK_REPEAT, line); + condexit = cond(ls); /* read condition (inside scope block) */ + if (bl2.upval) /* upvalues? */ + luaK_patchclose(fs, condexit, bl2.nactvar); + leaveblock(fs); /* finish scope */ + luaK_patchlist(fs, condexit, repeat_init); /* close the loop */ + leaveblock(fs); /* finish loop */ +} + + +static int exp1 (LexState *ls) { + expdesc e; + int reg; + expr(ls, &e); + luaK_exp2nextreg(ls->fs, &e); + lua_assert(e.k == VNONRELOC); + reg = e.u.info; + return reg; +} + + +static void forbody (LexState *ls, int base, int line, int nvars, int isnum) { + /* forbody -> DO block */ + BlockCnt bl; + FuncState *fs = ls->fs; + int prep, endfor; + adjustlocalvars(ls, 3); /* control variables */ + checknext(ls, TK_DO); + prep = isnum ? luaK_codeAsBx(fs, OP_FORPREP, base, NO_JUMP) : luaK_jump(fs); + enterblock(fs, &bl, 0); /* scope for declared variables */ + adjustlocalvars(ls, nvars); + luaK_reserveregs(fs, nvars); + block(ls); + leaveblock(fs); /* end of scope for declared variables */ + luaK_patchtohere(fs, prep); + if (isnum) /* numeric for? */ + endfor = luaK_codeAsBx(fs, OP_FORLOOP, base, NO_JUMP); + else { /* generic for */ + luaK_codeABC(fs, OP_TFORCALL, base, 0, nvars); + luaK_fixline(fs, line); + endfor = luaK_codeAsBx(fs, OP_TFORLOOP, base + 2, NO_JUMP); + } + luaK_patchlist(fs, endfor, prep + 1); + luaK_fixline(fs, line); +} + + +static void fornum (LexState *ls, TString *varname, int line) { + /* fornum -> NAME = exp1,exp1[,exp1] forbody */ + FuncState *fs = ls->fs; + int base = fs->freereg; + new_localvarliteral(ls, "(for index)"); + new_localvarliteral(ls, "(for limit)"); + new_localvarliteral(ls, "(for step)"); + new_localvar(ls, varname); + checknext(ls, '='); + exp1(ls); /* initial value */ + checknext(ls, ','); + exp1(ls); /* limit */ + if (testnext(ls, ',')) + exp1(ls); /* optional step */ + else { /* default step = 1 */ + luaK_codek(fs, fs->freereg, luaK_intK(fs, 1)); + luaK_reserveregs(fs, 1); + } + forbody(ls, base, line, 1, 1); +} + + +static void forlist (LexState *ls, TString *indexname) { + /* forlist -> NAME {,NAME} IN explist forbody */ + FuncState *fs = ls->fs; + expdesc e; + int nvars = 4; /* gen, state, control, plus at least one declared var */ + int line; + int base = fs->freereg; + /* create control variables */ + new_localvarliteral(ls, "(for generator)"); + new_localvarliteral(ls, "(for state)"); + new_localvarliteral(ls, "(for control)"); + /* create declared variables */ + new_localvar(ls, indexname); + while (testnext(ls, ',')) { + new_localvar(ls, str_checkname(ls)); + nvars++; + } + checknext(ls, TK_IN); + line = ls->linenumber; + adjust_assign(ls, 3, explist(ls, &e), &e); + luaK_checkstack(fs, 3); /* extra space to call generator */ + forbody(ls, base, line, nvars - 3, 0); +} + + +static void forstat (LexState *ls, int line) { + /* forstat -> FOR (fornum | forlist) END */ + FuncState *fs = ls->fs; + TString *varname; + BlockCnt bl; + enterblock(fs, &bl, 1); /* scope for loop and control variables */ + luaX_next(ls); /* skip 'for' */ + varname = str_checkname(ls); /* first variable name */ + switch (ls->t.token) { + case '=': fornum(ls, varname, line); break; + case ',': case TK_IN: forlist(ls, varname); break; + default: luaX_syntaxerror(ls, "'=' or 'in' expected"); + } + check_match(ls, TK_END, TK_FOR, line); + leaveblock(fs); /* loop scope ('break' jumps to this point) */ +} + + +static void test_then_block (LexState *ls, int *escapelist) { + /* test_then_block -> [IF | ELSEIF] cond THEN block */ + BlockCnt bl; + FuncState *fs = ls->fs; + expdesc v; + int jf; /* instruction to skip 'then' code (if condition is false) */ + luaX_next(ls); /* skip IF or ELSEIF */ + expr(ls, &v); /* read condition */ + checknext(ls, TK_THEN); + if (ls->t.token == TK_GOTO || ls->t.token == TK_BREAK) { + luaK_goiffalse(ls->fs, &v); /* will jump to label if condition is true */ + enterblock(fs, &bl, 0); /* must enter block before 'goto' */ + gotostat(ls, v.t); /* handle goto/break */ + skipnoopstat(ls); /* skip other no-op statements */ + if (block_follow(ls, 0)) { /* 'goto' is the entire block? */ + leaveblock(fs); + return; /* and that is it */ + } + else /* must skip over 'then' part if condition is false */ + jf = luaK_jump(fs); + } + else { /* regular case (not goto/break) */ + luaK_goiftrue(ls->fs, &v); /* skip over block if condition is false */ + enterblock(fs, &bl, 0); + jf = v.f; + } + statlist(ls); /* 'then' part */ + leaveblock(fs); + if (ls->t.token == TK_ELSE || + ls->t.token == TK_ELSEIF) /* followed by 'else'/'elseif'? */ + luaK_concat(fs, escapelist, luaK_jump(fs)); /* must jump over it */ + luaK_patchtohere(fs, jf); +} + + +static void ifstat (LexState *ls, int line) { + /* ifstat -> IF cond THEN block {ELSEIF cond THEN block} [ELSE block] END */ + FuncState *fs = ls->fs; + int escapelist = NO_JUMP; /* exit list for finished parts */ + test_then_block(ls, &escapelist); /* IF cond THEN block */ + while (ls->t.token == TK_ELSEIF) + test_then_block(ls, &escapelist); /* ELSEIF cond THEN block */ + if (testnext(ls, TK_ELSE)) + block(ls); /* 'else' part */ + check_match(ls, TK_END, TK_IF, line); + luaK_patchtohere(fs, escapelist); /* patch escape list to 'if' end */ +} + + +static void localfunc (LexState *ls) { + expdesc b; + FuncState *fs = ls->fs; + new_localvar(ls, str_checkname(ls)); /* new local variable */ + adjustlocalvars(ls, 1); /* enter its scope */ + body(ls, &b, 0, ls->linenumber); /* function created in next register */ + /* debug information will only see the variable after this point! */ + getlocvar(fs, b.u.info)->startpc = fs->pc; +} + + +static void localstat (LexState *ls) { + /* stat -> LOCAL NAME {',' NAME} ['=' explist] */ + int nvars = 0; + int nexps; + expdesc e; + do { + new_localvar(ls, str_checkname(ls)); + nvars++; + } while (testnext(ls, ',')); + if (testnext(ls, '=')) + nexps = explist(ls, &e); + else { + e.k = VVOID; + nexps = 0; + } + adjust_assign(ls, nvars, nexps, &e); + adjustlocalvars(ls, nvars); +} + + +static int funcname (LexState *ls, expdesc *v) { + /* funcname -> NAME {fieldsel} [':' NAME] */ + int ismethod = 0; + singlevar(ls, v); + while (ls->t.token == '.') + fieldsel(ls, v); + if (ls->t.token == ':') { + ismethod = 1; + fieldsel(ls, v); + } + return ismethod; +} + + +static void funcstat (LexState *ls, int line) { + /* funcstat -> FUNCTION funcname body */ + int ismethod; + expdesc v, b; + luaX_next(ls); /* skip FUNCTION */ + ismethod = funcname(ls, &v); + body(ls, &b, ismethod, line); + luaK_storevar(ls->fs, &v, &b); + luaK_fixline(ls->fs, line); /* definition "happens" in the first line */ +} + + +static void exprstat (LexState *ls) { + /* stat -> func | assignment */ + FuncState *fs = ls->fs; + struct LHS_assign v; + suffixedexp(ls, &v.v); + if (ls->t.token == '=' || ls->t.token == ',') { /* stat -> assignment ? */ + v.prev = NULL; + assignment(ls, &v, 1); + } + else { /* stat -> func */ + check_condition(ls, v.v.k == VCALL, "syntax error"); + SETARG_C(getcode(fs, &v.v), 1); /* call statement uses no results */ + } +} + + +static void retstat (LexState *ls) { + /* stat -> RETURN [explist] [';'] */ + FuncState *fs = ls->fs; + expdesc e; + int first, nret; /* registers with returned values */ + if (block_follow(ls, 1) || ls->t.token == ';') + first = nret = 0; /* return no values */ + else { + nret = explist(ls, &e); /* optional return values */ + if (hasmultret(e.k)) { + luaK_setmultret(fs, &e); + if (e.k == VCALL && nret == 1) { /* tail call? */ + SET_OPCODE(getcode(fs,&e), OP_TAILCALL); + lua_assert(GETARG_A(getcode(fs,&e)) == fs->nactvar); + } + first = fs->nactvar; + nret = LUA_MULTRET; /* return all values */ + } + else { + if (nret == 1) /* only one single value? */ + first = luaK_exp2anyreg(fs, &e); + else { + luaK_exp2nextreg(fs, &e); /* values must go to the stack */ + first = fs->nactvar; /* return all active values */ + lua_assert(nret == fs->freereg - first); + } + } + } + luaK_ret(fs, first, nret); + testnext(ls, ';'); /* skip optional semicolon */ +} + + +static void statement (LexState *ls) { + int line = ls->linenumber; /* may be needed for error messages */ + enterlevel(ls); + switch (ls->t.token) { + case ';': { /* stat -> ';' (empty statement) */ + luaX_next(ls); /* skip ';' */ + break; + } + case TK_IF: { /* stat -> ifstat */ + ifstat(ls, line); + break; + } + case TK_WHILE: { /* stat -> whilestat */ + whilestat(ls, line); + break; + } + case TK_DO: { /* stat -> DO block END */ + luaX_next(ls); /* skip DO */ + block(ls); + check_match(ls, TK_END, TK_DO, line); + break; + } + case TK_FOR: { /* stat -> forstat */ + forstat(ls, line); + break; + } + case TK_REPEAT: { /* stat -> repeatstat */ + repeatstat(ls, line); + break; + } + case TK_FUNCTION: { /* stat -> funcstat */ + funcstat(ls, line); + break; + } + case TK_LOCAL: { /* stat -> localstat */ + luaX_next(ls); /* skip LOCAL */ + if (testnext(ls, TK_FUNCTION)) /* local function? */ + localfunc(ls); + else + localstat(ls); + break; + } + case TK_DBCOLON: { /* stat -> label */ + luaX_next(ls); /* skip double colon */ + labelstat(ls, str_checkname(ls), line); + break; + } + case TK_RETURN: { /* stat -> retstat */ + luaX_next(ls); /* skip RETURN */ + retstat(ls); + break; + } + case TK_BREAK: /* stat -> breakstat */ + case TK_GOTO: { /* stat -> 'goto' NAME */ + gotostat(ls, luaK_jump(ls->fs)); + break; + } + default: { /* stat -> func | assignment */ + exprstat(ls); + break; + } + } + lua_assert(ls->fs->f->maxstacksize >= ls->fs->freereg && + ls->fs->freereg >= ls->fs->nactvar); + ls->fs->freereg = ls->fs->nactvar; /* free registers */ + leavelevel(ls); +} + +/* }====================================================================== */ + + +/* +** compiles the main function, which is a regular vararg function with an +** upvalue named LUA_ENV +*/ +static void mainfunc (LexState *ls, FuncState *fs) { + BlockCnt bl; + expdesc v; + open_func(ls, fs, &bl); + fs->f->is_vararg = 1; /* main function is always vararg */ + init_exp(&v, VLOCAL, 0); /* create and... */ + newupvalue(fs, ls->envn, &v); /* ...set environment upvalue */ + luaX_next(ls); /* read first token */ + statlist(ls); /* parse main body */ + check(ls, TK_EOS); + close_func(ls); +} + + +LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, + Dyndata *dyd, const char *name, int firstchar) { + LexState lexstate; + FuncState funcstate; + LClosure *cl = luaF_newLclosure(L, 1); /* create main closure */ + setclLvalue(L, L->top, cl); /* anchor it (to avoid being collected) */ + incr_top(L); + lexstate.h = luaH_new(L); /* create table for scanner */ + sethvalue(L, L->top, lexstate.h); /* anchor it */ + incr_top(L); + funcstate.f = cl->p = luaF_newproto(L); + funcstate.f->source = luaS_new(L, name); /* create and anchor TString */ + lua_assert(iswhite(funcstate.f)); /* do not need barrier here */ + lexstate.buff = buff; + lexstate.dyd = dyd; + dyd->actvar.n = dyd->gt.n = dyd->label.n = 0; + luaX_setinput(L, &lexstate, z, funcstate.f->source, firstchar); + mainfunc(&lexstate, &funcstate); + lua_assert(!funcstate.prev && funcstate.nups == 1 && !lexstate.fs); + /* all scopes should be correctly finished */ + lua_assert(dyd->actvar.n == 0 && dyd->gt.n == 0 && dyd->label.n == 0); + L->top--; /* remove scanner's table */ + return cl; /* closure is on the stack, too */ +} + diff --git a/src/lparser.h b/src/lparser.h new file mode 100644 index 000000000000..62c50cac7cc8 --- /dev/null +++ b/src/lparser.h @@ -0,0 +1,120 @@ +/* +** $Id: lparser.h,v 1.74 2014/10/25 11:50:46 roberto Exp $ +** Lua Parser +** See Copyright Notice in lua.h +*/ + +#ifndef lparser_h +#define lparser_h + +#include "llimits.h" +#include "lobject.h" +#include "lzio.h" + + +/* +** Expression descriptor +*/ + +typedef enum { + VVOID, /* no value */ + VNIL, + VTRUE, + VFALSE, + VK, /* info = index of constant in 'k' */ + VKFLT, /* nval = numerical float value */ + VKINT, /* nval = numerical integer value */ + VNONRELOC, /* info = result register */ + VLOCAL, /* info = local register */ + VUPVAL, /* info = index of upvalue in 'upvalues' */ + VINDEXED, /* t = table register/upvalue; idx = index R/K */ + VJMP, /* info = instruction pc */ + VRELOCABLE, /* info = instruction pc */ + VCALL, /* info = instruction pc */ + VVARARG /* info = instruction pc */ +} expkind; + + +#define vkisvar(k) (VLOCAL <= (k) && (k) <= VINDEXED) +#define vkisinreg(k) ((k) == VNONRELOC || (k) == VLOCAL) + +typedef struct expdesc { + expkind k; + union { + struct { /* for indexed variables (VINDEXED) */ + short idx; /* index (R/K) */ + lu_byte t; /* table (register or upvalue) */ + lu_byte vt; /* whether 't' is register (VLOCAL) or upvalue (VUPVAL) */ + } ind; + int info; /* for generic use */ + lua_Number nval; /* for VKFLT */ + lua_Integer ival; /* for VKINT */ + } u; + int t; /* patch list of 'exit when true' */ + int f; /* patch list of 'exit when false' */ +} expdesc; + + +/* description of active local variable */ +typedef struct Vardesc { + short idx; /* variable index in stack */ +} Vardesc; + + +/* description of pending goto statements and label statements */ +typedef struct Labeldesc { + TString *name; /* label identifier */ + int pc; /* position in code */ + int line; /* line where it appeared */ + lu_byte nactvar; /* local level where it appears in current block */ +} Labeldesc; + + +/* list of labels or gotos */ +typedef struct Labellist { + Labeldesc *arr; /* array */ + int n; /* number of entries in use */ + int size; /* array size */ +} Labellist; + + +/* dynamic structures used by the parser */ +typedef struct Dyndata { + struct { /* list of active local variables */ + Vardesc *arr; + int n; + int size; + } actvar; + Labellist gt; /* list of pending gotos */ + Labellist label; /* list of active labels */ +} Dyndata; + + +/* control of blocks */ +struct BlockCnt; /* defined in lparser.c */ + + +/* state needed to generate code for a given function */ +typedef struct FuncState { + Proto *f; /* current function header */ + struct FuncState *prev; /* enclosing function */ + struct LexState *ls; /* lexical state */ + struct BlockCnt *bl; /* chain of current blocks */ + int pc; /* next position to code (equivalent to 'ncode') */ + int lasttarget; /* 'label' of last 'jump label' */ + int jpc; /* list of pending jumps to 'pc' */ + int nk; /* number of elements in 'k' */ + int np; /* number of elements in 'p' */ + int firstlocal; /* index of first local var (in Dyndata array) */ + short nlocvars; /* number of elements in 'f->locvars' */ + lu_byte nactvar; /* number of active local variables */ + lu_byte nups; /* number of upvalues */ + lu_byte freereg; /* first free register */ +} FuncState; + + +LUAI_FUNC LClosure *luaY_parser (lua_State *L, ZIO *z, Mbuffer *buff, + Dyndata *dyd, const char *name, int firstchar); + + +#endif diff --git a/src/lprefix.h b/src/lprefix.h new file mode 100644 index 000000000000..02daa837f552 --- /dev/null +++ b/src/lprefix.h @@ -0,0 +1,45 @@ +/* +** $Id: lprefix.h,v 1.2 2014/12/29 16:54:13 roberto Exp $ +** Definitions for Lua code that must come before any other header file +** See Copyright Notice in lua.h +*/ + +#ifndef lprefix_h +#define lprefix_h + + +/* +** Allows POSIX/XSI stuff +*/ +#if !defined(LUA_USE_C89) /* { */ + +#if !defined(_XOPEN_SOURCE) +#define _XOPEN_SOURCE 600 +#elif _XOPEN_SOURCE == 0 +#undef _XOPEN_SOURCE /* use -D_XOPEN_SOURCE=0 to undefine it */ +#endif + +/* +** Allows manipulation of large files in gcc and some other compilers +*/ +#if !defined(LUA_32BITS) && !defined(_FILE_OFFSET_BITS) +#define _LARGEFILE_SOURCE 1 +#define _FILE_OFFSET_BITS 64 +#endif + +#endif /* } */ + + +/* +** Windows stuff +*/ +#if defined(_WIN32) /* { */ + +#if !defined(_CRT_SECURE_NO_WARNINGS) +#define _CRT_SECURE_NO_WARNINGS /* avoid warnings about ISO C functions */ +#endif + +#endif /* } */ + +#endif + diff --git a/src/lstate.c b/src/lstate.c new file mode 100644 index 000000000000..ff6b02d36ae0 --- /dev/null +++ b/src/lstate.c @@ -0,0 +1,346 @@ +/* +** $Id: lstate.c,v 2.127 2014/11/02 19:33:33 roberto Exp $ +** Global State +** See Copyright Notice in lua.h +*/ + +#define lstate_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <stddef.h> +#include <string.h> + +#include "lua.h" + +#include "lapi.h" +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "llex.h" +#include "lmem.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" + + +#if !defined(LUAI_GCPAUSE) +#define LUAI_GCPAUSE 200 /* 200% */ +#endif + +#if !defined(LUAI_GCMUL) +#define LUAI_GCMUL 200 /* GC runs 'twice the speed' of memory allocation */ +#endif + + +#define MEMERRMSG "not enough memory" + + +/* +** a macro to help the creation of a unique random seed when a state is +** created; the seed is used to randomize hashes. +*/ +#if !defined(luai_makeseed) +#include <time.h> +#define luai_makeseed() cast(unsigned int, time(NULL)) +#endif + + + +/* +** thread state + extra space +*/ +typedef struct LX { + lu_byte extra_[LUA_EXTRASPACE]; + lua_State l; +} LX; + + +/* +** Main thread combines a thread state and the global state +*/ +typedef struct LG { + LX l; + global_State g; +} LG; + + + +#define fromstate(L) (cast(LX *, cast(lu_byte *, (L)) - offsetof(LX, l))) + + +/* +** Compute an initial seed as random as possible. Rely on Address Space +** Layout Randomization (if present) to increase randomness.. +*/ +#define addbuff(b,p,e) \ + { size_t t = cast(size_t, e); \ + memcpy(buff + p, &t, sizeof(t)); p += sizeof(t); } + +static unsigned int makeseed (lua_State *L) { + char buff[4 * sizeof(size_t)]; + unsigned int h = luai_makeseed(); + int p = 0; + addbuff(buff, p, L); /* heap variable */ + addbuff(buff, p, &h); /* local variable */ + addbuff(buff, p, luaO_nilobject); /* global variable */ + addbuff(buff, p, &lua_newstate); /* public function */ + lua_assert(p == sizeof(buff)); + return luaS_hash(buff, p, h); +} + + +/* +** set GCdebt to a new value keeping the value (totalbytes + GCdebt) +** invariant +*/ +void luaE_setdebt (global_State *g, l_mem debt) { + g->totalbytes -= (debt - g->GCdebt); + g->GCdebt = debt; +} + + +CallInfo *luaE_extendCI (lua_State *L) { + CallInfo *ci = luaM_new(L, CallInfo); + lua_assert(L->ci->next == NULL); + L->ci->next = ci; + ci->previous = L->ci; + ci->next = NULL; + return ci; +} + + +/* +** free all CallInfo structures not in use by a thread +*/ +void luaE_freeCI (lua_State *L) { + CallInfo *ci = L->ci; + CallInfo *next = ci->next; + ci->next = NULL; + while ((ci = next) != NULL) { + next = ci->next; + luaM_free(L, ci); + } +} + + +/* +** free half of the CallInfo structures not in use by a thread +*/ +void luaE_shrinkCI (lua_State *L) { + CallInfo *ci = L->ci; + while (ci->next != NULL) { /* while there is 'next' */ + CallInfo *next2 = ci->next->next; /* next's next */ + if (next2 == NULL) break; + luaM_free(L, ci->next); /* remove next */ + ci->next = next2; /* remove 'next' from the list */ + next2->previous = ci; + ci = next2; + } +} + + +static void stack_init (lua_State *L1, lua_State *L) { + int i; CallInfo *ci; + /* initialize stack array */ + L1->stack = luaM_newvector(L, BASIC_STACK_SIZE, TValue); + L1->stacksize = BASIC_STACK_SIZE; + for (i = 0; i < BASIC_STACK_SIZE; i++) + setnilvalue(L1->stack + i); /* erase new stack */ + L1->top = L1->stack; + L1->stack_last = L1->stack + L1->stacksize - EXTRA_STACK; + /* initialize first ci */ + ci = &L1->base_ci; + ci->next = ci->previous = NULL; + ci->callstatus = 0; + ci->func = L1->top; + setnilvalue(L1->top++); /* 'function' entry for this 'ci' */ + ci->top = L1->top + LUA_MINSTACK; + L1->ci = ci; +} + + +static void freestack (lua_State *L) { + if (L->stack == NULL) + return; /* stack not completely built yet */ + L->ci = &L->base_ci; /* free the entire 'ci' list */ + luaE_freeCI(L); + luaM_freearray(L, L->stack, L->stacksize); /* free stack array */ +} + + +/* +** Create registry table and its predefined values +*/ +static void init_registry (lua_State *L, global_State *g) { + TValue temp; + /* create registry */ + Table *registry = luaH_new(L); + sethvalue(L, &g->l_registry, registry); + luaH_resize(L, registry, LUA_RIDX_LAST, 0); + /* registry[LUA_RIDX_MAINTHREAD] = L */ + setthvalue(L, &temp, L); /* temp = L */ + luaH_setint(L, registry, LUA_RIDX_MAINTHREAD, &temp); + /* registry[LUA_RIDX_GLOBALS] = table of globals */ + sethvalue(L, &temp, luaH_new(L)); /* temp = new table (global table) */ + luaH_setint(L, registry, LUA_RIDX_GLOBALS, &temp); +} + + +/* +** open parts of the state that may cause memory-allocation errors. +** ('g->version' != NULL flags that the state was completely build) +*/ +static void f_luaopen (lua_State *L, void *ud) { + global_State *g = G(L); + UNUSED(ud); + stack_init(L, L); /* init stack */ + init_registry(L, g); + luaS_resize(L, MINSTRTABSIZE); /* initial size of string table */ + luaT_init(L); + luaX_init(L); + /* pre-create memory-error message */ + g->memerrmsg = luaS_newliteral(L, MEMERRMSG); + luaC_fix(L, obj2gco(g->memerrmsg)); /* it should never be collected */ + g->gcrunning = 1; /* allow gc */ + g->version = lua_version(NULL); + luai_userstateopen(L); +} + + +/* +** preinitialize a thread with consistent values without allocating +** any memory (to avoid errors) +*/ +static void preinit_thread (lua_State *L, global_State *g) { + G(L) = g; + L->stack = NULL; + L->ci = NULL; + L->stacksize = 0; + L->twups = L; /* thread has no upvalues */ + L->errorJmp = NULL; + L->nCcalls = 0; + L->hook = NULL; + L->hookmask = 0; + L->basehookcount = 0; + L->allowhook = 1; + resethookcount(L); + L->openupval = NULL; + L->nny = 1; + L->status = LUA_OK; + L->errfunc = 0; +} + + +static void close_state (lua_State *L) { + global_State *g = G(L); + luaF_close(L, L->stack); /* close all upvalues for this thread */ + luaC_freeallobjects(L); /* collect all objects */ + if (g->version) /* closing a fully built state? */ + luai_userstateclose(L); + luaM_freearray(L, G(L)->strt.hash, G(L)->strt.size); + luaZ_freebuffer(L, &g->buff); + freestack(L); + lua_assert(gettotalbytes(g) == sizeof(LG)); + (*g->frealloc)(g->ud, fromstate(L), sizeof(LG), 0); /* free main block */ +} + + +LUA_API lua_State *lua_newthread (lua_State *L) { + global_State *g = G(L); + lua_State *L1; + lua_lock(L); + luaC_checkGC(L); + /* create new thread */ + L1 = &cast(LX *, luaM_newobject(L, LUA_TTHREAD, sizeof(LX)))->l; + L1->marked = luaC_white(g); + L1->tt = LUA_TTHREAD; + /* link it on list 'allgc' */ + L1->next = g->allgc; + g->allgc = obj2gco(L1); + /* anchor it on L stack */ + setthvalue(L, L->top, L1); + api_incr_top(L); + preinit_thread(L1, g); + L1->hookmask = L->hookmask; + L1->basehookcount = L->basehookcount; + L1->hook = L->hook; + resethookcount(L1); + /* initialize L1 extra space */ + memcpy(lua_getextraspace(L1), lua_getextraspace(g->mainthread), + LUA_EXTRASPACE); + luai_userstatethread(L, L1); + stack_init(L1, L); /* init stack */ + lua_unlock(L); + return L1; +} + + +void luaE_freethread (lua_State *L, lua_State *L1) { + LX *l = fromstate(L1); + luaF_close(L1, L1->stack); /* close all upvalues for this thread */ + lua_assert(L1->openupval == NULL); + luai_userstatefree(L, L1); + freestack(L1); + luaM_free(L, l); +} + + +LUA_API lua_State *lua_newstate (lua_Alloc f, void *ud) { + int i; + lua_State *L; + global_State *g; + LG *l = cast(LG *, (*f)(ud, NULL, LUA_TTHREAD, sizeof(LG))); + if (l == NULL) return NULL; + L = &l->l.l; + g = &l->g; + L->next = NULL; + L->tt = LUA_TTHREAD; + g->currentwhite = bitmask(WHITE0BIT); + L->marked = luaC_white(g); + preinit_thread(L, g); + g->frealloc = f; + g->ud = ud; + g->mainthread = L; + g->seed = makeseed(L); + g->gcrunning = 0; /* no GC while building state */ + g->GCestimate = 0; + g->strt.size = g->strt.nuse = 0; + g->strt.hash = NULL; + setnilvalue(&g->l_registry); + luaZ_initbuffer(L, &g->buff); + g->panic = NULL; + g->version = NULL; + g->gcstate = GCSpause; + g->gckind = KGC_NORMAL; + g->allgc = g->finobj = g->tobefnz = g->fixedgc = NULL; + g->sweepgc = NULL; + g->gray = g->grayagain = NULL; + g->weak = g->ephemeron = g->allweak = NULL; + g->twups = NULL; + g->totalbytes = sizeof(LG); + g->GCdebt = 0; + g->gcfinnum = 0; + g->gcpause = LUAI_GCPAUSE; + g->gcstepmul = LUAI_GCMUL; + for (i=0; i < LUA_NUMTAGS; i++) g->mt[i] = NULL; + if (luaD_rawrunprotected(L, f_luaopen, NULL) != LUA_OK) { + /* memory allocation error: free partial state */ + close_state(L); + L = NULL; + } + return L; +} + + +LUA_API void lua_close (lua_State *L) { + L = G(L)->mainthread; /* only the main thread can be closed */ + lua_lock(L); + close_state(L); +} + + diff --git a/src/lstate.h b/src/lstate.h new file mode 100644 index 000000000000..81e12c40db0a --- /dev/null +++ b/src/lstate.h @@ -0,0 +1,223 @@ +/* +** $Id: lstate.h,v 2.119 2014/10/30 18:53:28 roberto Exp $ +** Global State +** See Copyright Notice in lua.h +*/ + +#ifndef lstate_h +#define lstate_h + +#include "lua.h" + +#include "lobject.h" +#include "ltm.h" +#include "lzio.h" + + +/* + +** Some notes about garbage-collected objects: All objects in Lua must +** be kept somehow accessible until being freed, so all objects always +** belong to one (and only one) of these lists, using field 'next' of +** the 'CommonHeader' for the link: +** +** 'allgc': all objects not marked for finalization; +** 'finobj': all objects marked for finalization; +** 'tobefnz': all objects ready to be finalized; +** 'fixedgc': all objects that are not to be collected (currently +** only small strings, such as reserved words). + +*/ + + +struct lua_longjmp; /* defined in ldo.c */ + + + +/* extra stack space to handle TM calls and some other extras */ +#define EXTRA_STACK 5 + + +#define BASIC_STACK_SIZE (2*LUA_MINSTACK) + + +/* kinds of Garbage Collection */ +#define KGC_NORMAL 0 +#define KGC_EMERGENCY 1 /* gc was forced by an allocation failure */ + + +typedef struct stringtable { + TString **hash; + int nuse; /* number of elements */ + int size; +} stringtable; + + +/* +** Information about a call. +** When a thread yields, 'func' is adjusted to pretend that the +** top function has only the yielded values in its stack; in that +** case, the actual 'func' value is saved in field 'extra'. +** When a function calls another with a continuation, 'extra' keeps +** the function index so that, in case of errors, the continuation +** function can be called with the correct top. +*/ +typedef struct CallInfo { + StkId func; /* function index in the stack */ + StkId top; /* top for this function */ + struct CallInfo *previous, *next; /* dynamic call link */ + union { + struct { /* only for Lua functions */ + StkId base; /* base for this function */ + const Instruction *savedpc; + } l; + struct { /* only for C functions */ + lua_KFunction k; /* continuation in case of yields */ + ptrdiff_t old_errfunc; + lua_KContext ctx; /* context info. in case of yields */ + } c; + } u; + ptrdiff_t extra; + short nresults; /* expected number of results from this function */ + lu_byte callstatus; +} CallInfo; + + +/* +** Bits in CallInfo status +*/ +#define CIST_OAH (1<<0) /* original value of 'allowhook' */ +#define CIST_LUA (1<<1) /* call is running a Lua function */ +#define CIST_HOOKED (1<<2) /* call is running a debug hook */ +#define CIST_REENTRY (1<<3) /* call is running on same invocation of + luaV_execute of previous call */ +#define CIST_YPCALL (1<<4) /* call is a yieldable protected call */ +#define CIST_TAIL (1<<5) /* call was tail called */ +#define CIST_HOOKYIELD (1<<6) /* last hook called yielded */ + +#define isLua(ci) ((ci)->callstatus & CIST_LUA) + +/* assume that CIST_OAH has offset 0 and that 'v' is strictly 0/1 */ +#define setoah(st,v) ((st) = ((st) & ~CIST_OAH) | (v)) +#define getoah(st) ((st) & CIST_OAH) + + +/* +** 'global state', shared by all threads of this state +*/ +typedef struct global_State { + lua_Alloc frealloc; /* function to reallocate memory */ + void *ud; /* auxiliary data to 'frealloc' */ + lu_mem totalbytes; /* number of bytes currently allocated - GCdebt */ + l_mem GCdebt; /* bytes allocated not yet compensated by the collector */ + lu_mem GCmemtrav; /* memory traversed by the GC */ + lu_mem GCestimate; /* an estimate of the non-garbage memory in use */ + stringtable strt; /* hash table for strings */ + TValue l_registry; + unsigned int seed; /* randomized seed for hashes */ + lu_byte currentwhite; + lu_byte gcstate; /* state of garbage collector */ + lu_byte gckind; /* kind of GC running */ + lu_byte gcrunning; /* true if GC is running */ + GCObject *allgc; /* list of all collectable objects */ + GCObject **sweepgc; /* current position of sweep in list */ + GCObject *finobj; /* list of collectable objects with finalizers */ + GCObject *gray; /* list of gray objects */ + GCObject *grayagain; /* list of objects to be traversed atomically */ + GCObject *weak; /* list of tables with weak values */ + GCObject *ephemeron; /* list of ephemeron tables (weak keys) */ + GCObject *allweak; /* list of all-weak tables */ + GCObject *tobefnz; /* list of userdata to be GC */ + GCObject *fixedgc; /* list of objects not to be collected */ + struct lua_State *twups; /* list of threads with open upvalues */ + Mbuffer buff; /* temporary buffer for string concatenation */ + unsigned int gcfinnum; /* number of finalizers to call in each GC step */ + int gcpause; /* size of pause between successive GCs */ + int gcstepmul; /* GC 'granularity' */ + lua_CFunction panic; /* to be called in unprotected errors */ + struct lua_State *mainthread; + const lua_Number *version; /* pointer to version number */ + TString *memerrmsg; /* memory-error message */ + TString *tmname[TM_N]; /* array with tag-method names */ + struct Table *mt[LUA_NUMTAGS]; /* metatables for basic types */ +} global_State; + + +/* +** 'per thread' state +*/ +struct lua_State { + CommonHeader; + lu_byte status; + StkId top; /* first free slot in the stack */ + global_State *l_G; + CallInfo *ci; /* call info for current function */ + const Instruction *oldpc; /* last pc traced */ + StkId stack_last; /* last free slot in the stack */ + StkId stack; /* stack base */ + UpVal *openupval; /* list of open upvalues in this stack */ + GCObject *gclist; + struct lua_State *twups; /* list of threads with open upvalues */ + struct lua_longjmp *errorJmp; /* current error recover point */ + CallInfo base_ci; /* CallInfo for first level (C calling Lua) */ + lua_Hook hook; + ptrdiff_t errfunc; /* current error handling function (stack index) */ + int stacksize; + int basehookcount; + int hookcount; + unsigned short nny; /* number of non-yieldable calls in stack */ + unsigned short nCcalls; /* number of nested C calls */ + lu_byte hookmask; + lu_byte allowhook; +}; + + +#define G(L) (L->l_G) + + +/* +** Union of all collectable objects (only for conversions) +*/ +union GCUnion { + GCObject gc; /* common header */ + struct TString ts; + struct Udata u; + union Closure cl; + struct Table h; + struct Proto p; + struct lua_State th; /* thread */ +}; + + +#define cast_u(o) cast(union GCUnion *, (o)) + +/* macros to convert a GCObject into a specific value */ +#define gco2ts(o) \ + check_exp(novariant((o)->tt) == LUA_TSTRING, &((cast_u(o))->ts)) +#define gco2u(o) check_exp((o)->tt == LUA_TUSERDATA, &((cast_u(o))->u)) +#define gco2lcl(o) check_exp((o)->tt == LUA_TLCL, &((cast_u(o))->cl.l)) +#define gco2ccl(o) check_exp((o)->tt == LUA_TCCL, &((cast_u(o))->cl.c)) +#define gco2cl(o) \ + check_exp(novariant((o)->tt) == LUA_TFUNCTION, &((cast_u(o))->cl)) +#define gco2t(o) check_exp((o)->tt == LUA_TTABLE, &((cast_u(o))->h)) +#define gco2p(o) check_exp((o)->tt == LUA_TPROTO, &((cast_u(o))->p)) +#define gco2th(o) check_exp((o)->tt == LUA_TTHREAD, &((cast_u(o))->th)) + + +/* macro to convert a Lua object into a GCObject */ +#define obj2gco(v) \ + check_exp(novariant((v)->tt) < LUA_TDEADKEY, (&(cast_u(v)->gc))) + + +/* actual number of total bytes allocated */ +#define gettotalbytes(g) ((g)->totalbytes + (g)->GCdebt) + +LUAI_FUNC void luaE_setdebt (global_State *g, l_mem debt); +LUAI_FUNC void luaE_freethread (lua_State *L, lua_State *L1); +LUAI_FUNC CallInfo *luaE_extendCI (lua_State *L); +LUAI_FUNC void luaE_freeCI (lua_State *L); +LUAI_FUNC void luaE_shrinkCI (lua_State *L); + + +#endif + diff --git a/src/lstring.c b/src/lstring.c new file mode 100644 index 000000000000..2947113c3c9d --- /dev/null +++ b/src/lstring.c @@ -0,0 +1,182 @@ +/* +** $Id: lstring.c,v 2.45 2014/11/02 19:19:04 roberto Exp $ +** String table (keeps all strings handled by Lua) +** See Copyright Notice in lua.h +*/ + +#define lstring_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <string.h> + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" + + + +/* +** Lua will use at most ~(2^LUAI_HASHLIMIT) bytes from a string to +** compute its hash +*/ +#if !defined(LUAI_HASHLIMIT) +#define LUAI_HASHLIMIT 5 +#endif + + +/* +** equality for long strings +*/ +int luaS_eqlngstr (TString *a, TString *b) { + size_t len = a->len; + lua_assert(a->tt == LUA_TLNGSTR && b->tt == LUA_TLNGSTR); + return (a == b) || /* same instance or... */ + ((len == b->len) && /* equal length and ... */ + (memcmp(getstr(a), getstr(b), len) == 0)); /* equal contents */ +} + + +unsigned int luaS_hash (const char *str, size_t l, unsigned int seed) { + unsigned int h = seed ^ cast(unsigned int, l); + size_t l1; + size_t step = (l >> LUAI_HASHLIMIT) + 1; + for (l1 = l; l1 >= step; l1 -= step) + h = h ^ ((h<<5) + (h>>2) + cast_byte(str[l1 - 1])); + return h; +} + + +/* +** resizes the string table +*/ +void luaS_resize (lua_State *L, int newsize) { + int i; + stringtable *tb = &G(L)->strt; + if (newsize > tb->size) { /* grow table if needed */ + luaM_reallocvector(L, tb->hash, tb->size, newsize, TString *); + for (i = tb->size; i < newsize; i++) + tb->hash[i] = NULL; + } + for (i = 0; i < tb->size; i++) { /* rehash */ + TString *p = tb->hash[i]; + tb->hash[i] = NULL; + while (p) { /* for each node in the list */ + TString *hnext = p->hnext; /* save next */ + unsigned int h = lmod(p->hash, newsize); /* new position */ + p->hnext = tb->hash[h]; /* chain it */ + tb->hash[h] = p; + p = hnext; + } + } + if (newsize < tb->size) { /* shrink table if needed */ + /* vanishing slice should be empty */ + lua_assert(tb->hash[newsize] == NULL && tb->hash[tb->size - 1] == NULL); + luaM_reallocvector(L, tb->hash, tb->size, newsize, TString *); + } + tb->size = newsize; +} + + + +/* +** creates a new string object +*/ +static TString *createstrobj (lua_State *L, const char *str, size_t l, + int tag, unsigned int h) { + TString *ts; + GCObject *o; + size_t totalsize; /* total size of TString object */ + totalsize = sizelstring(l); + o = luaC_newobj(L, tag, totalsize); + ts = gco2ts(o); + ts->len = l; + ts->hash = h; + ts->extra = 0; + memcpy(getaddrstr(ts), str, l * sizeof(char)); + getaddrstr(ts)[l] = '\0'; /* ending 0 */ + return ts; +} + + +void luaS_remove (lua_State *L, TString *ts) { + stringtable *tb = &G(L)->strt; + TString **p = &tb->hash[lmod(ts->hash, tb->size)]; + while (*p != ts) /* find previous element */ + p = &(*p)->hnext; + *p = (*p)->hnext; /* remove element from its list */ + tb->nuse--; +} + + +/* +** checks whether short string exists and reuses it or creates a new one +*/ +static TString *internshrstr (lua_State *L, const char *str, size_t l) { + TString *ts; + global_State *g = G(L); + unsigned int h = luaS_hash(str, l, g->seed); + TString **list = &g->strt.hash[lmod(h, g->strt.size)]; + for (ts = *list; ts != NULL; ts = ts->hnext) { + if (l == ts->len && + (memcmp(str, getstr(ts), l * sizeof(char)) == 0)) { + /* found! */ + if (isdead(g, ts)) /* dead (but not collected yet)? */ + changewhite(ts); /* resurrect it */ + return ts; + } + } + if (g->strt.nuse >= g->strt.size && g->strt.size <= MAX_INT/2) { + luaS_resize(L, g->strt.size * 2); + list = &g->strt.hash[lmod(h, g->strt.size)]; /* recompute with new size */ + } + ts = createstrobj(L, str, l, LUA_TSHRSTR, h); + ts->hnext = *list; + *list = ts; + g->strt.nuse++; + return ts; +} + + +/* +** new string (with explicit length) +*/ +TString *luaS_newlstr (lua_State *L, const char *str, size_t l) { + if (l <= LUAI_MAXSHORTLEN) /* short string? */ + return internshrstr(L, str, l); + else { + if (l + 1 > (MAX_SIZE - sizeof(TString))/sizeof(char)) + luaM_toobig(L); + return createstrobj(L, str, l, LUA_TLNGSTR, G(L)->seed); + } +} + + +/* +** new zero-terminated string +*/ +TString *luaS_new (lua_State *L, const char *str) { + return luaS_newlstr(L, str, strlen(str)); +} + + +Udata *luaS_newudata (lua_State *L, size_t s) { + Udata *u; + GCObject *o; + if (s > MAX_SIZE - sizeof(Udata)) + luaM_toobig(L); + o = luaC_newobj(L, LUA_TUSERDATA, sizeludata(s)); + u = gco2u(o); + u->len = s; + u->metatable = NULL; + setuservalue(L, u, luaO_nilobject); + return u; +} + diff --git a/src/lstring.h b/src/lstring.h new file mode 100644 index 000000000000..d3f04caf7289 --- /dev/null +++ b/src/lstring.h @@ -0,0 +1,46 @@ +/* +** $Id: lstring.h,v 1.56 2014/07/18 14:46:47 roberto Exp $ +** String table (keep all strings handled by Lua) +** See Copyright Notice in lua.h +*/ + +#ifndef lstring_h +#define lstring_h + +#include "lgc.h" +#include "lobject.h" +#include "lstate.h" + + +#define sizelstring(l) (sizeof(union UTString) + ((l) + 1) * sizeof(char)) +#define sizestring(s) sizelstring((s)->len) + +#define sizeludata(l) (sizeof(union UUdata) + (l)) +#define sizeudata(u) sizeludata((u)->len) + +#define luaS_newliteral(L, s) (luaS_newlstr(L, "" s, \ + (sizeof(s)/sizeof(char))-1)) + + +/* +** test whether a string is a reserved word +*/ +#define isreserved(s) ((s)->tt == LUA_TSHRSTR && (s)->extra > 0) + + +/* +** equality for short strings, which are always internalized +*/ +#define eqshrstr(a,b) check_exp((a)->tt == LUA_TSHRSTR, (a) == (b)) + + +LUAI_FUNC unsigned int luaS_hash (const char *str, size_t l, unsigned int seed); +LUAI_FUNC int luaS_eqlngstr (TString *a, TString *b); +LUAI_FUNC void luaS_resize (lua_State *L, int newsize); +LUAI_FUNC void luaS_remove (lua_State *L, TString *ts); +LUAI_FUNC Udata *luaS_newudata (lua_State *L, size_t s); +LUAI_FUNC TString *luaS_newlstr (lua_State *L, const char *str, size_t l); +LUAI_FUNC TString *luaS_new (lua_State *L, const char *str); + + +#endif diff --git a/src/lstrlib.c b/src/lstrlib.c new file mode 100644 index 000000000000..a650b768d574 --- /dev/null +++ b/src/lstrlib.c @@ -0,0 +1,1430 @@ +/* +** $Id: lstrlib.c,v 1.221 2014/12/11 14:03:07 roberto Exp $ +** Standard library for string operations and pattern-matching +** See Copyright Notice in lua.h +*/ + +#define lstrlib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <ctype.h> +#include <limits.h> +#include <stddef.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +/* +** maximum number of captures that a pattern can do during +** pattern-matching. This limit is arbitrary. +*/ +#if !defined(LUA_MAXCAPTURES) +#define LUA_MAXCAPTURES 32 +#endif + + +/* macro to 'unsign' a character */ +#define uchar(c) ((unsigned char)(c)) + + +/* +** Some sizes are better limited to fit in 'int', but must also fit in +** 'size_t'. (We assume that 'lua_Integer' cannot be smaller than 'int'.) +*/ +#define MAXSIZE \ + (sizeof(size_t) < sizeof(int) ? (~(size_t)0) : (size_t)(INT_MAX)) + + + + +static int str_len (lua_State *L) { + size_t l; + luaL_checklstring(L, 1, &l); + lua_pushinteger(L, (lua_Integer)l); + return 1; +} + + +/* translate a relative string position: negative means back from end */ +static lua_Integer posrelat (lua_Integer pos, size_t len) { + if (pos >= 0) return pos; + else if (0u - (size_t)pos > len) return 0; + else return (lua_Integer)len + pos + 1; +} + + +static int str_sub (lua_State *L) { + size_t l; + const char *s = luaL_checklstring(L, 1, &l); + lua_Integer start = posrelat(luaL_checkinteger(L, 2), l); + lua_Integer end = posrelat(luaL_optinteger(L, 3, -1), l); + if (start < 1) start = 1; + if (end > (lua_Integer)l) end = l; + if (start <= end) + lua_pushlstring(L, s + start - 1, (size_t)(end - start + 1)); + else lua_pushliteral(L, ""); + return 1; +} + + +static int str_reverse (lua_State *L) { + size_t l, i; + luaL_Buffer b; + const char *s = luaL_checklstring(L, 1, &l); + char *p = luaL_buffinitsize(L, &b, l); + for (i = 0; i < l; i++) + p[i] = s[l - i - 1]; + luaL_pushresultsize(&b, l); + return 1; +} + + +static int str_lower (lua_State *L) { + size_t l; + size_t i; + luaL_Buffer b; + const char *s = luaL_checklstring(L, 1, &l); + char *p = luaL_buffinitsize(L, &b, l); + for (i=0; i<l; i++) + p[i] = tolower(uchar(s[i])); + luaL_pushresultsize(&b, l); + return 1; +} + + +static int str_upper (lua_State *L) { + size_t l; + size_t i; + luaL_Buffer b; + const char *s = luaL_checklstring(L, 1, &l); + char *p = luaL_buffinitsize(L, &b, l); + for (i=0; i<l; i++) + p[i] = toupper(uchar(s[i])); + luaL_pushresultsize(&b, l); + return 1; +} + + +static int str_rep (lua_State *L) { + size_t l, lsep; + const char *s = luaL_checklstring(L, 1, &l); + lua_Integer n = luaL_checkinteger(L, 2); + const char *sep = luaL_optlstring(L, 3, "", &lsep); + if (n <= 0) lua_pushliteral(L, ""); + else if (l + lsep < l || l + lsep > MAXSIZE / n) /* may overflow? */ + return luaL_error(L, "resulting string too large"); + else { + size_t totallen = (size_t)n * l + (size_t)(n - 1) * lsep; + luaL_Buffer b; + char *p = luaL_buffinitsize(L, &b, totallen); + while (n-- > 1) { /* first n-1 copies (followed by separator) */ + memcpy(p, s, l * sizeof(char)); p += l; + if (lsep > 0) { /* empty 'memcpy' is not that cheap */ + memcpy(p, sep, lsep * sizeof(char)); + p += lsep; + } + } + memcpy(p, s, l * sizeof(char)); /* last copy (not followed by separator) */ + luaL_pushresultsize(&b, totallen); + } + return 1; +} + + +static int str_byte (lua_State *L) { + size_t l; + const char *s = luaL_checklstring(L, 1, &l); + lua_Integer posi = posrelat(luaL_optinteger(L, 2, 1), l); + lua_Integer pose = posrelat(luaL_optinteger(L, 3, posi), l); + int n, i; + if (posi < 1) posi = 1; + if (pose > (lua_Integer)l) pose = l; + if (posi > pose) return 0; /* empty interval; return no values */ + n = (int)(pose - posi + 1); + if (posi + n <= pose) /* arithmetic overflow? */ + return luaL_error(L, "string slice too long"); + luaL_checkstack(L, n, "string slice too long"); + for (i=0; i<n; i++) + lua_pushinteger(L, uchar(s[posi+i-1])); + return n; +} + + +static int str_char (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + int i; + luaL_Buffer b; + char *p = luaL_buffinitsize(L, &b, n); + for (i=1; i<=n; i++) { + lua_Integer c = luaL_checkinteger(L, i); + luaL_argcheck(L, uchar(c) == c, i, "value out of range"); + p[i - 1] = uchar(c); + } + luaL_pushresultsize(&b, n); + return 1; +} + + +static int writer (lua_State *L, const void *b, size_t size, void *B) { + (void)L; + luaL_addlstring((luaL_Buffer *) B, (const char *)b, size); + return 0; +} + + +static int str_dump (lua_State *L) { + luaL_Buffer b; + int strip = lua_toboolean(L, 2); + luaL_checktype(L, 1, LUA_TFUNCTION); + lua_settop(L, 1); + luaL_buffinit(L,&b); + if (lua_dump(L, writer, &b, strip) != 0) + return luaL_error(L, "unable to dump given function"); + luaL_pushresult(&b); + return 1; +} + + + +/* +** {====================================================== +** PATTERN MATCHING +** ======================================================= +*/ + + +#define CAP_UNFINISHED (-1) +#define CAP_POSITION (-2) + + +typedef struct MatchState { + int matchdepth; /* control for recursive depth (to avoid C stack overflow) */ + const char *src_init; /* init of source string */ + const char *src_end; /* end ('\0') of source string */ + const char *p_end; /* end ('\0') of pattern */ + lua_State *L; + int level; /* total number of captures (finished or unfinished) */ + struct { + const char *init; + ptrdiff_t len; + } capture[LUA_MAXCAPTURES]; +} MatchState; + + +/* recursive function */ +static const char *match (MatchState *ms, const char *s, const char *p); + + +/* maximum recursion depth for 'match' */ +#if !defined(MAXCCALLS) +#define MAXCCALLS 200 +#endif + + +#define L_ESC '%' +#define SPECIALS "^$*+?.([%-" + + +static int check_capture (MatchState *ms, int l) { + l -= '1'; + if (l < 0 || l >= ms->level || ms->capture[l].len == CAP_UNFINISHED) + return luaL_error(ms->L, "invalid capture index %%%d", l + 1); + return l; +} + + +static int capture_to_close (MatchState *ms) { + int level = ms->level; + for (level--; level>=0; level--) + if (ms->capture[level].len == CAP_UNFINISHED) return level; + return luaL_error(ms->L, "invalid pattern capture"); +} + + +static const char *classend (MatchState *ms, const char *p) { + switch (*p++) { + case L_ESC: { + if (p == ms->p_end) + luaL_error(ms->L, "malformed pattern (ends with '%%')"); + return p+1; + } + case '[': { + if (*p == '^') p++; + do { /* look for a ']' */ + if (p == ms->p_end) + luaL_error(ms->L, "malformed pattern (missing ']')"); + if (*(p++) == L_ESC && p < ms->p_end) + p++; /* skip escapes (e.g. '%]') */ + } while (*p != ']'); + return p+1; + } + default: { + return p; + } + } +} + + +static int match_class (int c, int cl) { + int res; + switch (tolower(cl)) { + case 'a' : res = isalpha(c); break; + case 'c' : res = iscntrl(c); break; + case 'd' : res = isdigit(c); break; + case 'g' : res = isgraph(c); break; + case 'l' : res = islower(c); break; + case 'p' : res = ispunct(c); break; + case 's' : res = isspace(c); break; + case 'u' : res = isupper(c); break; + case 'w' : res = isalnum(c); break; + case 'x' : res = isxdigit(c); break; + case 'z' : res = (c == 0); break; /* deprecated option */ + default: return (cl == c); + } + return (islower(cl) ? res : !res); +} + + +static int matchbracketclass (int c, const char *p, const char *ec) { + int sig = 1; + if (*(p+1) == '^') { + sig = 0; + p++; /* skip the '^' */ + } + while (++p < ec) { + if (*p == L_ESC) { + p++; + if (match_class(c, uchar(*p))) + return sig; + } + else if ((*(p+1) == '-') && (p+2 < ec)) { + p+=2; + if (uchar(*(p-2)) <= c && c <= uchar(*p)) + return sig; + } + else if (uchar(*p) == c) return sig; + } + return !sig; +} + + +static int singlematch (MatchState *ms, const char *s, const char *p, + const char *ep) { + if (s >= ms->src_end) + return 0; + else { + int c = uchar(*s); + switch (*p) { + case '.': return 1; /* matches any char */ + case L_ESC: return match_class(c, uchar(*(p+1))); + case '[': return matchbracketclass(c, p, ep-1); + default: return (uchar(*p) == c); + } + } +} + + +static const char *matchbalance (MatchState *ms, const char *s, + const char *p) { + if (p >= ms->p_end - 1) + luaL_error(ms->L, "malformed pattern (missing arguments to '%%b')"); + if (*s != *p) return NULL; + else { + int b = *p; + int e = *(p+1); + int cont = 1; + while (++s < ms->src_end) { + if (*s == e) { + if (--cont == 0) return s+1; + } + else if (*s == b) cont++; + } + } + return NULL; /* string ends out of balance */ +} + + +static const char *max_expand (MatchState *ms, const char *s, + const char *p, const char *ep) { + ptrdiff_t i = 0; /* counts maximum expand for item */ + while (singlematch(ms, s + i, p, ep)) + i++; + /* keeps trying to match with the maximum repetitions */ + while (i>=0) { + const char *res = match(ms, (s+i), ep+1); + if (res) return res; + i--; /* else didn't match; reduce 1 repetition to try again */ + } + return NULL; +} + + +static const char *min_expand (MatchState *ms, const char *s, + const char *p, const char *ep) { + for (;;) { + const char *res = match(ms, s, ep+1); + if (res != NULL) + return res; + else if (singlematch(ms, s, p, ep)) + s++; /* try with one more repetition */ + else return NULL; + } +} + + +static const char *start_capture (MatchState *ms, const char *s, + const char *p, int what) { + const char *res; + int level = ms->level; + if (level >= LUA_MAXCAPTURES) luaL_error(ms->L, "too many captures"); + ms->capture[level].init = s; + ms->capture[level].len = what; + ms->level = level+1; + if ((res=match(ms, s, p)) == NULL) /* match failed? */ + ms->level--; /* undo capture */ + return res; +} + + +static const char *end_capture (MatchState *ms, const char *s, + const char *p) { + int l = capture_to_close(ms); + const char *res; + ms->capture[l].len = s - ms->capture[l].init; /* close capture */ + if ((res = match(ms, s, p)) == NULL) /* match failed? */ + ms->capture[l].len = CAP_UNFINISHED; /* undo capture */ + return res; +} + + +static const char *match_capture (MatchState *ms, const char *s, int l) { + size_t len; + l = check_capture(ms, l); + len = ms->capture[l].len; + if ((size_t)(ms->src_end-s) >= len && + memcmp(ms->capture[l].init, s, len) == 0) + return s+len; + else return NULL; +} + + +static const char *match (MatchState *ms, const char *s, const char *p) { + if (ms->matchdepth-- == 0) + luaL_error(ms->L, "pattern too complex"); + init: /* using goto's to optimize tail recursion */ + if (p != ms->p_end) { /* end of pattern? */ + switch (*p) { + case '(': { /* start capture */ + if (*(p + 1) == ')') /* position capture? */ + s = start_capture(ms, s, p + 2, CAP_POSITION); + else + s = start_capture(ms, s, p + 1, CAP_UNFINISHED); + break; + } + case ')': { /* end capture */ + s = end_capture(ms, s, p + 1); + break; + } + case '$': { + if ((p + 1) != ms->p_end) /* is the '$' the last char in pattern? */ + goto dflt; /* no; go to default */ + s = (s == ms->src_end) ? s : NULL; /* check end of string */ + break; + } + case L_ESC: { /* escaped sequences not in the format class[*+?-]? */ + switch (*(p + 1)) { + case 'b': { /* balanced string? */ + s = matchbalance(ms, s, p + 2); + if (s != NULL) { + p += 4; goto init; /* return match(ms, s, p + 4); */ + } /* else fail (s == NULL) */ + break; + } + case 'f': { /* frontier? */ + const char *ep; char previous; + p += 2; + if (*p != '[') + luaL_error(ms->L, "missing '[' after '%%f' in pattern"); + ep = classend(ms, p); /* points to what is next */ + previous = (s == ms->src_init) ? '\0' : *(s - 1); + if (!matchbracketclass(uchar(previous), p, ep - 1) && + matchbracketclass(uchar(*s), p, ep - 1)) { + p = ep; goto init; /* return match(ms, s, ep); */ + } + s = NULL; /* match failed */ + break; + } + case '0': case '1': case '2': case '3': + case '4': case '5': case '6': case '7': + case '8': case '9': { /* capture results (%0-%9)? */ + s = match_capture(ms, s, uchar(*(p + 1))); + if (s != NULL) { + p += 2; goto init; /* return match(ms, s, p + 2) */ + } + break; + } + default: goto dflt; + } + break; + } + default: dflt: { /* pattern class plus optional suffix */ + const char *ep = classend(ms, p); /* points to optional suffix */ + /* does not match at least once? */ + if (!singlematch(ms, s, p, ep)) { + if (*ep == '*' || *ep == '?' || *ep == '-') { /* accept empty? */ + p = ep + 1; goto init; /* return match(ms, s, ep + 1); */ + } + else /* '+' or no suffix */ + s = NULL; /* fail */ + } + else { /* matched once */ + switch (*ep) { /* handle optional suffix */ + case '?': { /* optional */ + const char *res; + if ((res = match(ms, s + 1, ep + 1)) != NULL) + s = res; + else { + p = ep + 1; goto init; /* else return match(ms, s, ep + 1); */ + } + break; + } + case '+': /* 1 or more repetitions */ + s++; /* 1 match already done */ + /* go through */ + case '*': /* 0 or more repetitions */ + s = max_expand(ms, s, p, ep); + break; + case '-': /* 0 or more repetitions (minimum) */ + s = min_expand(ms, s, p, ep); + break; + default: /* no suffix */ + s++; p = ep; goto init; /* return match(ms, s + 1, ep); */ + } + } + break; + } + } + } + ms->matchdepth++; + return s; +} + + + +static const char *lmemfind (const char *s1, size_t l1, + const char *s2, size_t l2) { + if (l2 == 0) return s1; /* empty strings are everywhere */ + else if (l2 > l1) return NULL; /* avoids a negative 'l1' */ + else { + const char *init; /* to search for a '*s2' inside 's1' */ + l2--; /* 1st char will be checked by 'memchr' */ + l1 = l1-l2; /* 's2' cannot be found after that */ + while (l1 > 0 && (init = (const char *)memchr(s1, *s2, l1)) != NULL) { + init++; /* 1st char is already checked */ + if (memcmp(init, s2+1, l2) == 0) + return init-1; + else { /* correct 'l1' and 's1' to try again */ + l1 -= init-s1; + s1 = init; + } + } + return NULL; /* not found */ + } +} + + +static void push_onecapture (MatchState *ms, int i, const char *s, + const char *e) { + if (i >= ms->level) { + if (i == 0) /* ms->level == 0, too */ + lua_pushlstring(ms->L, s, e - s); /* add whole match */ + else + luaL_error(ms->L, "invalid capture index %%%d", i + 1); + } + else { + ptrdiff_t l = ms->capture[i].len; + if (l == CAP_UNFINISHED) luaL_error(ms->L, "unfinished capture"); + if (l == CAP_POSITION) + lua_pushinteger(ms->L, ms->capture[i].init - ms->src_init + 1); + else + lua_pushlstring(ms->L, ms->capture[i].init, l); + } +} + + +static int push_captures (MatchState *ms, const char *s, const char *e) { + int i; + int nlevels = (ms->level == 0 && s) ? 1 : ms->level; + luaL_checkstack(ms->L, nlevels, "too many captures"); + for (i = 0; i < nlevels; i++) + push_onecapture(ms, i, s, e); + return nlevels; /* number of strings pushed */ +} + + +/* check whether pattern has no special characters */ +static int nospecials (const char *p, size_t l) { + size_t upto = 0; + do { + if (strpbrk(p + upto, SPECIALS)) + return 0; /* pattern has a special character */ + upto += strlen(p + upto) + 1; /* may have more after \0 */ + } while (upto <= l); + return 1; /* no special chars found */ +} + + +static int str_find_aux (lua_State *L, int find) { + size_t ls, lp; + const char *s = luaL_checklstring(L, 1, &ls); + const char *p = luaL_checklstring(L, 2, &lp); + lua_Integer init = posrelat(luaL_optinteger(L, 3, 1), ls); + if (init < 1) init = 1; + else if (init > (lua_Integer)ls + 1) { /* start after string's end? */ + lua_pushnil(L); /* cannot find anything */ + return 1; + } + /* explicit request or no special characters? */ + if (find && (lua_toboolean(L, 4) || nospecials(p, lp))) { + /* do a plain search */ + const char *s2 = lmemfind(s + init - 1, ls - (size_t)init + 1, p, lp); + if (s2) { + lua_pushinteger(L, s2 - s + 1); + lua_pushinteger(L, s2 - s + lp); + return 2; + } + } + else { + MatchState ms; + const char *s1 = s + init - 1; + int anchor = (*p == '^'); + if (anchor) { + p++; lp--; /* skip anchor character */ + } + ms.L = L; + ms.matchdepth = MAXCCALLS; + ms.src_init = s; + ms.src_end = s + ls; + ms.p_end = p + lp; + do { + const char *res; + ms.level = 0; + lua_assert(ms.matchdepth == MAXCCALLS); + if ((res=match(&ms, s1, p)) != NULL) { + if (find) { + lua_pushinteger(L, s1 - s + 1); /* start */ + lua_pushinteger(L, res - s); /* end */ + return push_captures(&ms, NULL, 0) + 2; + } + else + return push_captures(&ms, s1, res); + } + } while (s1++ < ms.src_end && !anchor); + } + lua_pushnil(L); /* not found */ + return 1; +} + + +static int str_find (lua_State *L) { + return str_find_aux(L, 1); +} + + +static int str_match (lua_State *L) { + return str_find_aux(L, 0); +} + + +static int gmatch_aux (lua_State *L) { + MatchState ms; + size_t ls, lp; + const char *s = lua_tolstring(L, lua_upvalueindex(1), &ls); + const char *p = lua_tolstring(L, lua_upvalueindex(2), &lp); + const char *src; + ms.L = L; + ms.matchdepth = MAXCCALLS; + ms.src_init = s; + ms.src_end = s+ls; + ms.p_end = p + lp; + for (src = s + (size_t)lua_tointeger(L, lua_upvalueindex(3)); + src <= ms.src_end; + src++) { + const char *e; + ms.level = 0; + lua_assert(ms.matchdepth == MAXCCALLS); + if ((e = match(&ms, src, p)) != NULL) { + lua_Integer newstart = e-s; + if (e == src) newstart++; /* empty match? go at least one position */ + lua_pushinteger(L, newstart); + lua_replace(L, lua_upvalueindex(3)); + return push_captures(&ms, src, e); + } + } + return 0; /* not found */ +} + + +static int gmatch (lua_State *L) { + luaL_checkstring(L, 1); + luaL_checkstring(L, 2); + lua_settop(L, 2); + lua_pushinteger(L, 0); + lua_pushcclosure(L, gmatch_aux, 3); + return 1; +} + + +static void add_s (MatchState *ms, luaL_Buffer *b, const char *s, + const char *e) { + size_t l, i; + lua_State *L = ms->L; + const char *news = lua_tolstring(L, 3, &l); + for (i = 0; i < l; i++) { + if (news[i] != L_ESC) + luaL_addchar(b, news[i]); + else { + i++; /* skip ESC */ + if (!isdigit(uchar(news[i]))) { + if (news[i] != L_ESC) + luaL_error(L, "invalid use of '%c' in replacement string", L_ESC); + luaL_addchar(b, news[i]); + } + else if (news[i] == '0') + luaL_addlstring(b, s, e - s); + else { + push_onecapture(ms, news[i] - '1', s, e); + luaL_tolstring(L, -1, NULL); /* if number, convert it to string */ + lua_remove(L, -2); /* remove original value */ + luaL_addvalue(b); /* add capture to accumulated result */ + } + } + } +} + + +static void add_value (MatchState *ms, luaL_Buffer *b, const char *s, + const char *e, int tr) { + lua_State *L = ms->L; + switch (tr) { + case LUA_TFUNCTION: { + int n; + lua_pushvalue(L, 3); + n = push_captures(ms, s, e); + lua_call(L, n, 1); + break; + } + case LUA_TTABLE: { + push_onecapture(ms, 0, s, e); + lua_gettable(L, 3); + break; + } + default: { /* LUA_TNUMBER or LUA_TSTRING */ + add_s(ms, b, s, e); + return; + } + } + if (!lua_toboolean(L, -1)) { /* nil or false? */ + lua_pop(L, 1); + lua_pushlstring(L, s, e - s); /* keep original text */ + } + else if (!lua_isstring(L, -1)) + luaL_error(L, "invalid replacement value (a %s)", luaL_typename(L, -1)); + luaL_addvalue(b); /* add result to accumulator */ +} + + +static int str_gsub (lua_State *L) { + size_t srcl, lp; + const char *src = luaL_checklstring(L, 1, &srcl); + const char *p = luaL_checklstring(L, 2, &lp); + int tr = lua_type(L, 3); + lua_Integer max_s = luaL_optinteger(L, 4, srcl + 1); + int anchor = (*p == '^'); + lua_Integer n = 0; + MatchState ms; + luaL_Buffer b; + luaL_argcheck(L, tr == LUA_TNUMBER || tr == LUA_TSTRING || + tr == LUA_TFUNCTION || tr == LUA_TTABLE, 3, + "string/function/table expected"); + luaL_buffinit(L, &b); + if (anchor) { + p++; lp--; /* skip anchor character */ + } + ms.L = L; + ms.matchdepth = MAXCCALLS; + ms.src_init = src; + ms.src_end = src+srcl; + ms.p_end = p + lp; + while (n < max_s) { + const char *e; + ms.level = 0; + lua_assert(ms.matchdepth == MAXCCALLS); + e = match(&ms, src, p); + if (e) { + n++; + add_value(&ms, &b, src, e, tr); + } + if (e && e>src) /* non empty match? */ + src = e; /* skip it */ + else if (src < ms.src_end) + luaL_addchar(&b, *src++); + else break; + if (anchor) break; + } + luaL_addlstring(&b, src, ms.src_end-src); + luaL_pushresult(&b); + lua_pushinteger(L, n); /* number of substitutions */ + return 2; +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** STRING FORMAT +** ======================================================= +*/ + +/* maximum size of each formatted item (> len(format('%99.99f', -1e308))) */ +#define MAX_ITEM 512 + +/* valid flags in a format specification */ +#define FLAGS "-+ #0" + +/* +** maximum size of each format specification (such as "%-099.99d") +** (+2 for length modifiers; +10 accounts for %99.99x plus margin of error) +*/ +#define MAX_FORMAT (sizeof(FLAGS) + 2 + 10) + + +static void addquoted (lua_State *L, luaL_Buffer *b, int arg) { + size_t l; + const char *s = luaL_checklstring(L, arg, &l); + luaL_addchar(b, '"'); + while (l--) { + if (*s == '"' || *s == '\\' || *s == '\n') { + luaL_addchar(b, '\\'); + luaL_addchar(b, *s); + } + else if (*s == '\0' || iscntrl(uchar(*s))) { + char buff[10]; + if (!isdigit(uchar(*(s+1)))) + sprintf(buff, "\\%d", (int)uchar(*s)); + else + sprintf(buff, "\\%03d", (int)uchar(*s)); + luaL_addstring(b, buff); + } + else + luaL_addchar(b, *s); + s++; + } + luaL_addchar(b, '"'); +} + +static const char *scanformat (lua_State *L, const char *strfrmt, char *form) { + const char *p = strfrmt; + while (*p != '\0' && strchr(FLAGS, *p) != NULL) p++; /* skip flags */ + if ((size_t)(p - strfrmt) >= sizeof(FLAGS)/sizeof(char)) + luaL_error(L, "invalid format (repeated flags)"); + if (isdigit(uchar(*p))) p++; /* skip width */ + if (isdigit(uchar(*p))) p++; /* (2 digits at most) */ + if (*p == '.') { + p++; + if (isdigit(uchar(*p))) p++; /* skip precision */ + if (isdigit(uchar(*p))) p++; /* (2 digits at most) */ + } + if (isdigit(uchar(*p))) + luaL_error(L, "invalid format (width or precision too long)"); + *(form++) = '%'; + memcpy(form, strfrmt, (p - strfrmt + 1) * sizeof(char)); + form += p - strfrmt + 1; + *form = '\0'; + return p; +} + + +/* +** add length modifier into formats +*/ +static void addlenmod (char *form, const char *lenmod) { + size_t l = strlen(form); + size_t lm = strlen(lenmod); + char spec = form[l - 1]; + strcpy(form + l - 1, lenmod); + form[l + lm - 1] = spec; + form[l + lm] = '\0'; +} + + +static int str_format (lua_State *L) { + int top = lua_gettop(L); + int arg = 1; + size_t sfl; + const char *strfrmt = luaL_checklstring(L, arg, &sfl); + const char *strfrmt_end = strfrmt+sfl; + luaL_Buffer b; + luaL_buffinit(L, &b); + while (strfrmt < strfrmt_end) { + if (*strfrmt != L_ESC) + luaL_addchar(&b, *strfrmt++); + else if (*++strfrmt == L_ESC) + luaL_addchar(&b, *strfrmt++); /* %% */ + else { /* format item */ + char form[MAX_FORMAT]; /* to store the format ('%...') */ + char *buff = luaL_prepbuffsize(&b, MAX_ITEM); /* to put formatted item */ + int nb = 0; /* number of bytes in added item */ + if (++arg > top) + luaL_argerror(L, arg, "no value"); + strfrmt = scanformat(L, strfrmt, form); + switch (*strfrmt++) { + case 'c': { + nb = sprintf(buff, form, (int)luaL_checkinteger(L, arg)); + break; + } + case 'd': case 'i': + case 'o': case 'u': case 'x': case 'X': { + lua_Integer n = luaL_checkinteger(L, arg); + addlenmod(form, LUA_INTEGER_FRMLEN); + nb = sprintf(buff, form, n); + break; + } +#if defined(LUA_USE_AFORMAT) + case 'a': case 'A': +#endif + case 'e': case 'E': case 'f': + case 'g': case 'G': { + addlenmod(form, LUA_NUMBER_FRMLEN); + nb = sprintf(buff, form, luaL_checknumber(L, arg)); + break; + } + case 'q': { + addquoted(L, &b, arg); + break; + } + case 's': { + size_t l; + const char *s = luaL_tolstring(L, arg, &l); + if (!strchr(form, '.') && l >= 100) { + /* no precision and string is too long to be formatted; + keep original string */ + luaL_addvalue(&b); + break; + } + else { + nb = sprintf(buff, form, s); + lua_pop(L, 1); /* remove result from 'luaL_tolstring' */ + break; + } + } + default: { /* also treat cases 'pnLlh' */ + return luaL_error(L, "invalid option '%%%c' to 'format'", + *(strfrmt - 1)); + } + } + luaL_addsize(&b, nb); + } + } + luaL_pushresult(&b); + return 1; +} + +/* }====================================================== */ + + +/* +** {====================================================== +** PACK/UNPACK +** ======================================================= +*/ + + +/* value used for padding */ +#if !defined(LUA_PACKPADBYTE) +#define LUA_PACKPADBYTE 0x00 +#endif + +/* maximum size for the binary representation of an integer */ +#define MAXINTSIZE 16 + +/* number of bits in a character */ +#define NB CHAR_BIT + +/* mask for one character (NB 1's) */ +#define MC ((1 << NB) - 1) + +/* size of a lua_Integer */ +#define SZINT ((int)sizeof(lua_Integer)) + + +/* dummy union to get native endianness */ +static const union { + int dummy; + char little; /* true iff machine is little endian */ +} nativeendian = {1}; + + +/* dummy structure to get native alignment requirements */ +struct cD { + char c; + union { double d; void *p; lua_Integer i; lua_Number n; } u; +}; + +#define MAXALIGN (offsetof(struct cD, u)) + + +/* +** Union for serializing floats +*/ +typedef union Ftypes { + float f; + double d; + lua_Number n; + char buff[5 * sizeof(lua_Number)]; /* enough for any float type */ +} Ftypes; + + +/* +** information to pack/unpack stuff +*/ +typedef struct Header { + lua_State *L; + int islittle; + int maxalign; +} Header; + + +/* +** options for pack/unpack +*/ +typedef enum KOption { + Kint, /* signed integers */ + Kuint, /* unsigned integers */ + Kfloat, /* floating-point numbers */ + Kchar, /* fixed-length strings */ + Kstring, /* strings with prefixed length */ + Kzstr, /* zero-terminated strings */ + Kpadding, /* padding */ + Kpaddalign, /* padding for alignment */ + Knop /* no-op (configuration or spaces) */ +} KOption; + + +/* +** Read an integer numeral from string 'fmt' or return 'df' if +** there is no numeral +*/ +static int digit (int c) { return '0' <= c && c <= '9'; } + +static int getnum (const char **fmt, int df) { + if (!digit(**fmt)) /* no number? */ + return df; /* return default value */ + else { + int a = 0; + do { + a = a*10 + (*((*fmt)++) - '0'); + } while (digit(**fmt) && a <= ((int)MAXSIZE - 9)/10); + return a; + } +} + + +/* +** Read an integer numeral and raises an error if it is larger +** than the maximum size for integers. +*/ +static int getnumlimit (Header *h, const char **fmt, int df) { + int sz = getnum(fmt, df); + if (sz > MAXINTSIZE || sz <= 0) + luaL_error(h->L, "integral size (%d) out of limits [1,%d]", + sz, MAXINTSIZE); + return sz; +} + + +/* +** Initialize Header +*/ +static void initheader (lua_State *L, Header *h) { + h->L = L; + h->islittle = nativeendian.little; + h->maxalign = 1; +} + + +/* +** Read and classify next option. 'size' is filled with option's size. +*/ +static KOption getoption (Header *h, const char **fmt, int *size) { + int opt = *((*fmt)++); + *size = 0; /* default */ + switch (opt) { + case 'b': *size = sizeof(char); return Kint; + case 'B': *size = sizeof(char); return Kuint; + case 'h': *size = sizeof(short); return Kint; + case 'H': *size = sizeof(short); return Kuint; + case 'l': *size = sizeof(long); return Kint; + case 'L': *size = sizeof(long); return Kuint; + case 'j': *size = sizeof(lua_Integer); return Kint; + case 'J': *size = sizeof(lua_Integer); return Kuint; + case 'T': *size = sizeof(size_t); return Kuint; + case 'f': *size = sizeof(float); return Kfloat; + case 'd': *size = sizeof(double); return Kfloat; + case 'n': *size = sizeof(lua_Number); return Kfloat; + case 'i': *size = getnumlimit(h, fmt, sizeof(int)); return Kint; + case 'I': *size = getnumlimit(h, fmt, sizeof(int)); return Kuint; + case 's': *size = getnumlimit(h, fmt, sizeof(size_t)); return Kstring; + case 'c': + *size = getnum(fmt, -1); + if (*size == -1) + luaL_error(h->L, "missing size for format option 'c'"); + return Kchar; + case 'z': return Kzstr; + case 'x': *size = 1; return Kpadding; + case 'X': return Kpaddalign; + case ' ': break; + case '<': h->islittle = 1; break; + case '>': h->islittle = 0; break; + case '=': h->islittle = nativeendian.little; break; + case '!': h->maxalign = getnumlimit(h, fmt, MAXALIGN); break; + default: luaL_error(h->L, "invalid format option '%c'", opt); + } + return Knop; +} + + +/* +** Read, classify, and fill other details about the next option. +** 'psize' is filled with option's size, 'notoalign' with its +** alignment requirements. +** Local variable 'size' gets the size to be aligned. (Kpadal option +** always gets its full alignment, other options are limited by +** the maximum alignment ('maxalign'). Kchar option needs no alignment +** despite its size. +*/ +static KOption getdetails (Header *h, size_t totalsize, + const char **fmt, int *psize, int *ntoalign) { + KOption opt = getoption(h, fmt, psize); + int align = *psize; /* usually, alignment follows size */ + if (opt == Kpaddalign) { /* 'X' gets alignment from following option */ + if (**fmt == '\0' || getoption(h, fmt, &align) == Kchar || align == 0) + luaL_argerror(h->L, 1, "invalid next option for option 'X'"); + } + if (align <= 1 || opt == Kchar) /* need no alignment? */ + *ntoalign = 0; + else { + if (align > h->maxalign) /* enforce maximum alignment */ + align = h->maxalign; + if ((align & (align - 1)) != 0) /* is 'align' not a power of 2? */ + luaL_argerror(h->L, 1, "format asks for alignment not power of 2"); + *ntoalign = (align - (int)(totalsize & (align - 1))) & (align - 1); + } + return opt; +} + + +/* +** Pack integer 'n' with 'size' bytes and 'islittle' endianness. +** The final 'if' handles the case when 'size' is larger than +** the size of a Lua integer, correcting the extra sign-extension +** bytes if necessary (by default they would be zeros). +*/ +static void packint (luaL_Buffer *b, lua_Unsigned n, + int islittle, int size, int neg) { + char *buff = luaL_prepbuffsize(b, size); + int i; + buff[islittle ? 0 : size - 1] = (char)(n & MC); /* first byte */ + for (i = 1; i < size; i++) { + n >>= NB; + buff[islittle ? i : size - 1 - i] = (char)(n & MC); + } + if (neg && size > SZINT) { /* negative number need sign extension? */ + for (i = SZINT; i < size; i++) /* correct extra bytes */ + buff[islittle ? i : size - 1 - i] = (char)MC; + } + luaL_addsize(b, size); /* add result to buffer */ +} + + +/* +** Copy 'size' bytes from 'src' to 'dest', correcting endianness if +** given 'islittle' is different from native endianness. +*/ +static void copywithendian (volatile char *dest, volatile const char *src, + int size, int islittle) { + if (islittle == nativeendian.little) { + while (size-- != 0) + *(dest++) = *(src++); + } + else { + dest += size - 1; + while (size-- != 0) + *(dest--) = *(src++); + } +} + + +static int str_pack (lua_State *L) { + luaL_Buffer b; + Header h; + const char *fmt = luaL_checkstring(L, 1); /* format string */ + int arg = 1; /* current argument to pack */ + size_t totalsize = 0; /* accumulate total size of result */ + initheader(L, &h); + lua_pushnil(L); /* mark to separate arguments from string buffer */ + luaL_buffinit(L, &b); + while (*fmt != '\0') { + int size, ntoalign; + KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign); + totalsize += ntoalign + size; + while (ntoalign-- > 0) + luaL_addchar(&b, LUA_PACKPADBYTE); /* fill alignment */ + arg++; + switch (opt) { + case Kint: { /* signed integers */ + lua_Integer n = luaL_checkinteger(L, arg); + if (size < SZINT) { /* need overflow check? */ + lua_Integer lim = (lua_Integer)1 << ((size * NB) - 1); + luaL_argcheck(L, -lim <= n && n < lim, arg, "integer overflow"); + } + packint(&b, (lua_Unsigned)n, h.islittle, size, (n < 0)); + break; + } + case Kuint: { /* unsigned integers */ + lua_Integer n = luaL_checkinteger(L, arg); + if (size < SZINT) /* need overflow check? */ + luaL_argcheck(L, (lua_Unsigned)n < ((lua_Unsigned)1 << (size * NB)), + arg, "unsigned overflow"); + packint(&b, (lua_Unsigned)n, h.islittle, size, 0); + break; + } + case Kfloat: { /* floating-point options */ + volatile Ftypes u; + char *buff = luaL_prepbuffsize(&b, size); + lua_Number n = luaL_checknumber(L, arg); /* get argument */ + if (size == sizeof(u.f)) u.f = (float)n; /* copy it into 'u' */ + else if (size == sizeof(u.d)) u.d = (double)n; + else u.n = n; + /* move 'u' to final result, correcting endianness if needed */ + copywithendian(buff, u.buff, size, h.islittle); + luaL_addsize(&b, size); + break; + } + case Kchar: { /* fixed-size string */ + size_t len; + const char *s = luaL_checklstring(L, arg, &len); + luaL_argcheck(L, len == (size_t)size, arg, "wrong length"); + luaL_addlstring(&b, s, size); + break; + } + case Kstring: { /* strings with length count */ + size_t len; + const char *s = luaL_checklstring(L, arg, &len); + luaL_argcheck(L, size >= (int)sizeof(size_t) || + len < ((size_t)1 << (size * NB)), + arg, "string length does not fit in given size"); + packint(&b, (lua_Unsigned)len, h.islittle, size, 0); /* pack length */ + luaL_addlstring(&b, s, len); + totalsize += len; + break; + } + case Kzstr: { /* zero-terminated string */ + size_t len; + const char *s = luaL_checklstring(L, arg, &len); + luaL_argcheck(L, strlen(s) == len, arg, "string contains zeros"); + luaL_addlstring(&b, s, len); + luaL_addchar(&b, '\0'); /* add zero at the end */ + totalsize += len + 1; + break; + } + case Kpadding: luaL_addchar(&b, LUA_PACKPADBYTE); /* go through */ + case Kpaddalign: case Knop: + arg--; /* undo increment */ + break; + } + } + luaL_pushresult(&b); + return 1; +} + + +static int str_packsize (lua_State *L) { + Header h; + const char *fmt = luaL_checkstring(L, 1); /* format string */ + size_t totalsize = 0; /* accumulate total size of result */ + initheader(L, &h); + while (*fmt != '\0') { + int size, ntoalign; + KOption opt = getdetails(&h, totalsize, &fmt, &size, &ntoalign); + size += ntoalign; /* total space used by option */ + luaL_argcheck(L, totalsize <= MAXSIZE - size, 1, + "format result too large"); + totalsize += size; + switch (opt) { + case Kstring: /* strings with length count */ + case Kzstr: /* zero-terminated string */ + luaL_argerror(L, 1, "variable-length format"); + break; + default: break; + } + } + lua_pushinteger(L, (lua_Integer)totalsize); + return 1; +} + + +/* +** Unpack an integer with 'size' bytes and 'islittle' endianness. +** If size is smaller than the size of a Lua integer and integer +** is signed, must do sign extension (propagating the sign to the +** higher bits); if size is larger than the size of a Lua integer, +** it must check the unread bytes to see whether they do not cause an +** overflow. +*/ +static lua_Integer unpackint (lua_State *L, const char *str, + int islittle, int size, int issigned) { + lua_Unsigned res = 0; + int i; + int limit = (size <= SZINT) ? size : SZINT; + for (i = limit - 1; i >= 0; i--) { + res <<= NB; + res |= (lua_Unsigned)(unsigned char)str[islittle ? i : size - 1 - i]; + } + if (size < SZINT) { /* real size smaller than lua_Integer? */ + if (issigned) { /* needs sign extension? */ + lua_Unsigned mask = (lua_Unsigned)1 << (size*NB - 1); + res = ((res ^ mask) - mask); /* do sign extension */ + } + } + else if (size > SZINT) { /* must check unread bytes */ + int mask = (!issigned || (lua_Integer)res >= 0) ? 0 : MC; + for (i = limit; i < size; i++) { + if ((unsigned char)str[islittle ? i : size - 1 - i] != mask) + luaL_error(L, "%d-byte integer does not fit into Lua Integer", size); + } + } + return (lua_Integer)res; +} + + +static int str_unpack (lua_State *L) { + Header h; + const char *fmt = luaL_checkstring(L, 1); + size_t ld; + const char *data = luaL_checklstring(L, 2, &ld); + size_t pos = (size_t)posrelat(luaL_optinteger(L, 3, 1), ld) - 1; + int n = 0; /* number of results */ + luaL_argcheck(L, pos <= ld, 3, "initial position out of string"); + initheader(L, &h); + while (*fmt != '\0') { + int size, ntoalign; + KOption opt = getdetails(&h, pos, &fmt, &size, &ntoalign); + if ((size_t)ntoalign + size > ~pos || pos + ntoalign + size > ld) + luaL_argerror(L, 2, "data string too short"); + pos += ntoalign; /* skip alignment */ + /* stack space for item + next position */ + luaL_checkstack(L, 2, "too many results"); + n++; + switch (opt) { + case Kint: + case Kuint: { + lua_Integer res = unpackint(L, data + pos, h.islittle, size, + (opt == Kint)); + lua_pushinteger(L, res); + break; + } + case Kfloat: { + volatile Ftypes u; + lua_Number num; + copywithendian(u.buff, data + pos, size, h.islittle); + if (size == sizeof(u.f)) num = (lua_Number)u.f; + else if (size == sizeof(u.d)) num = (lua_Number)u.d; + else num = u.n; + lua_pushnumber(L, num); + break; + } + case Kchar: { + lua_pushlstring(L, data + pos, size); + break; + } + case Kstring: { + size_t len = (size_t)unpackint(L, data + pos, h.islittle, size, 0); + luaL_argcheck(L, pos + len + size <= ld, 2, "data string too short"); + lua_pushlstring(L, data + pos + size, len); + pos += len; /* skip string */ + break; + } + case Kzstr: { + size_t len = (int)strlen(data + pos); + lua_pushlstring(L, data + pos, len); + pos += len + 1; /* skip string plus final '\0' */ + break; + } + case Kpaddalign: case Kpadding: case Knop: + n--; /* undo increment */ + break; + } + pos += size; + } + lua_pushinteger(L, pos + 1); /* next position */ + return n + 1; +} + +/* }====================================================== */ + + +static const luaL_Reg strlib[] = { + {"byte", str_byte}, + {"char", str_char}, + {"dump", str_dump}, + {"find", str_find}, + {"format", str_format}, + {"gmatch", gmatch}, + {"gsub", str_gsub}, + {"len", str_len}, + {"lower", str_lower}, + {"match", str_match}, + {"rep", str_rep}, + {"reverse", str_reverse}, + {"sub", str_sub}, + {"upper", str_upper}, + {"pack", str_pack}, + {"packsize", str_packsize}, + {"unpack", str_unpack}, + {NULL, NULL} +}; + + +static void createmetatable (lua_State *L) { + lua_createtable(L, 0, 1); /* table to be metatable for strings */ + lua_pushliteral(L, ""); /* dummy string */ + lua_pushvalue(L, -2); /* copy table */ + lua_setmetatable(L, -2); /* set table as metatable for strings */ + lua_pop(L, 1); /* pop dummy string */ + lua_pushvalue(L, -2); /* get string library */ + lua_setfield(L, -2, "__index"); /* metatable.__index = string */ + lua_pop(L, 1); /* pop metatable */ +} + + +/* +** Open string library +*/ +LUAMOD_API int luaopen_string (lua_State *L) { + luaL_newlib(L, strlib); + createmetatable(L); + return 1; +} + diff --git a/src/ltable.c b/src/ltable.c new file mode 100644 index 000000000000..38be00513dc8 --- /dev/null +++ b/src/ltable.c @@ -0,0 +1,650 @@ +/* +** $Id: ltable.c,v 2.100 2015/01/05 13:52:37 roberto Exp $ +** Lua tables (hash) +** See Copyright Notice in lua.h +*/ + +#define ltable_c +#define LUA_CORE + +#include "lprefix.h" + + +/* +** Implementation of tables (aka arrays, objects, or hash tables). +** Tables keep its elements in two parts: an array part and a hash part. +** Non-negative integer keys are all candidates to be kept in the array +** part. The actual size of the array is the largest 'n' such that at +** least half the slots between 0 and n are in use. +** Hash uses a mix of chained scatter table with Brent's variation. +** A main invariant of these tables is that, if an element is not +** in its main position (i.e. the 'original' position that its hash gives +** to it), then the colliding element is in its own main position. +** Hence even when the load factor reaches 100%, performance remains good. +*/ + +#include <float.h> +#include <math.h> +#include <string.h> +#include <limits.h> + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lgc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "lvm.h" + + +/* +** Maximum size of array part (MAXASIZE) is 2^MAXABITS. MAXABITS is +** the largest integer such that MAXASIZE fits in an unsigned int. +*/ +#define MAXABITS cast_int(sizeof(int) * CHAR_BIT - 1) +#define MAXASIZE (1u << MAXABITS) + +/* +** Maximum size of hash part is 2^MAXHBITS. MAXHBITS is the largest +** integer such that 2^MAXHBITS fits in a signed int. (Note that the +** maximum number of elements in a table, 2^MAXABITS + 2^MAXHBITS, still +** fits comfortably in an unsigned int.) +*/ +#define MAXHBITS (MAXABITS - 1) + + +#define hashpow2(t,n) (gnode(t, lmod((n), sizenode(t)))) + +#define hashstr(t,str) hashpow2(t, (str)->hash) +#define hashboolean(t,p) hashpow2(t, p) +#define hashint(t,i) hashpow2(t, i) + + +/* +** for some types, it is better to avoid modulus by power of 2, as +** they tend to have many 2 factors. +*/ +#define hashmod(t,n) (gnode(t, ((n) % ((sizenode(t)-1)|1)))) + + +#define hashpointer(t,p) hashmod(t, point2int(p)) + + +#define dummynode (&dummynode_) + +#define isdummy(n) ((n) == dummynode) + +static const Node dummynode_ = { + {NILCONSTANT}, /* value */ + {{NILCONSTANT, 0}} /* key */ +}; + + +/* +** Checks whether a float has a value representable as a lua_Integer +** (and does the conversion if so) +*/ +static int numisinteger (lua_Number x, lua_Integer *p) { + if ((x) == l_floor(x)) /* integral value? */ + return lua_numbertointeger(x, p); /* try as an integer */ + else return 0; +} + + +/* +** hash for floating-point numbers +*/ +static Node *hashfloat (const Table *t, lua_Number n) { + int i; + n = l_mathop(frexp)(n, &i) * cast_num(INT_MAX - DBL_MAX_EXP); + i += cast_int(n); + if (i < 0) { + if (cast(unsigned int, i) == 0u - i) /* use unsigned to avoid overflows */ + i = 0; /* handle INT_MIN */ + i = -i; /* must be a positive value */ + } + return hashmod(t, i); +} + + + +/* +** returns the 'main' position of an element in a table (that is, the index +** of its hash value) +*/ +static Node *mainposition (const Table *t, const TValue *key) { + switch (ttype(key)) { + case LUA_TNUMINT: + return hashint(t, ivalue(key)); + case LUA_TNUMFLT: + return hashfloat(t, fltvalue(key)); + case LUA_TSHRSTR: + return hashstr(t, tsvalue(key)); + case LUA_TLNGSTR: { + TString *s = tsvalue(key); + if (s->extra == 0) { /* no hash? */ + s->hash = luaS_hash(getstr(s), s->len, s->hash); + s->extra = 1; /* now it has its hash */ + } + return hashstr(t, tsvalue(key)); + } + case LUA_TBOOLEAN: + return hashboolean(t, bvalue(key)); + case LUA_TLIGHTUSERDATA: + return hashpointer(t, pvalue(key)); + case LUA_TLCF: + return hashpointer(t, fvalue(key)); + default: + return hashpointer(t, gcvalue(key)); + } +} + + +/* +** returns the index for 'key' if 'key' is an appropriate key to live in +** the array part of the table, 0 otherwise. +*/ +static unsigned int arrayindex (const TValue *key) { + if (ttisinteger(key)) { + lua_Integer k = ivalue(key); + if (0 < k && (lua_Unsigned)k <= MAXASIZE) + return cast(unsigned int, k); /* 'key' is an appropriate array index */ + } + return 0; /* 'key' did not match some condition */ +} + + +/* +** returns the index of a 'key' for table traversals. First goes all +** elements in the array part, then elements in the hash part. The +** beginning of a traversal is signaled by 0. +*/ +static unsigned int findindex (lua_State *L, Table *t, StkId key) { + unsigned int i; + if (ttisnil(key)) return 0; /* first iteration */ + i = arrayindex(key); + if (i != 0 && i <= t->sizearray) /* is 'key' inside array part? */ + return i; /* yes; that's the index */ + else { + int nx; + Node *n = mainposition(t, key); + for (;;) { /* check whether 'key' is somewhere in the chain */ + /* key may be dead already, but it is ok to use it in 'next' */ + if (luaV_rawequalobj(gkey(n), key) || + (ttisdeadkey(gkey(n)) && iscollectable(key) && + deadvalue(gkey(n)) == gcvalue(key))) { + i = cast_int(n - gnode(t, 0)); /* key index in hash table */ + /* hash elements are numbered after array ones */ + return (i + 1) + t->sizearray; + } + nx = gnext(n); + if (nx == 0) + luaG_runerror(L, "invalid key to 'next'"); /* key not found */ + else n += nx; + } + } +} + + +int luaH_next (lua_State *L, Table *t, StkId key) { + unsigned int i = findindex(L, t, key); /* find original element */ + for (; i < t->sizearray; i++) { /* try first array part */ + if (!ttisnil(&t->array[i])) { /* a non-nil value? */ + setivalue(key, i + 1); + setobj2s(L, key+1, &t->array[i]); + return 1; + } + } + for (i -= t->sizearray; cast_int(i) < sizenode(t); i++) { /* hash part */ + if (!ttisnil(gval(gnode(t, i)))) { /* a non-nil value? */ + setobj2s(L, key, gkey(gnode(t, i))); + setobj2s(L, key+1, gval(gnode(t, i))); + return 1; + } + } + return 0; /* no more elements */ +} + + +/* +** {============================================================= +** Rehash +** ============================================================== +*/ + +/* +** Compute the optimal size for the array part of table 't'. 'nums' is a +** "count array" where 'nums[i]' is the number of integers in the table +** between 2^(i - 1) + 1 and 2^i. Put in '*narray' the optimal size, and +** return the number of elements that will go to that part. +*/ +static unsigned int computesizes (unsigned int nums[], unsigned int *narray) { + int i; + unsigned int twotoi; /* 2^i */ + unsigned int a = 0; /* number of elements smaller than 2^i */ + unsigned int na = 0; /* number of elements to go to array part */ + unsigned int n = 0; /* optimal size for array part */ + for (i = 0, twotoi = 1; twotoi/2 < *narray; i++, twotoi *= 2) { + if (nums[i] > 0) { + a += nums[i]; + if (a > twotoi/2) { /* more than half elements present? */ + n = twotoi; /* optimal size (till now) */ + na = a; /* all elements up to 'n' will go to array part */ + } + } + if (a == *narray) break; /* all elements already counted */ + } + *narray = n; + lua_assert(*narray/2 <= na && na <= *narray); + return na; +} + + +static int countint (const TValue *key, unsigned int *nums) { + unsigned int k = arrayindex(key); + if (k != 0) { /* is 'key' an appropriate array index? */ + nums[luaO_ceillog2(k)]++; /* count as such */ + return 1; + } + else + return 0; +} + + +static unsigned int numusearray (const Table *t, unsigned int *nums) { + int lg; + unsigned int ttlg; /* 2^lg */ + unsigned int ause = 0; /* summation of 'nums' */ + unsigned int i = 1; /* count to traverse all array keys */ + /* traverse each slice */ + for (lg = 0, ttlg = 1; lg <= MAXABITS; lg++, ttlg *= 2) { + unsigned int lc = 0; /* counter */ + unsigned int lim = ttlg; + if (lim > t->sizearray) { + lim = t->sizearray; /* adjust upper limit */ + if (i > lim) + break; /* no more elements to count */ + } + /* count elements in range (2^(lg - 1), 2^lg] */ + for (; i <= lim; i++) { + if (!ttisnil(&t->array[i-1])) + lc++; + } + nums[lg] += lc; + ause += lc; + } + return ause; +} + + +static int numusehash (const Table *t, unsigned int *nums, + unsigned int *pnasize) { + int totaluse = 0; /* total number of elements */ + int ause = 0; /* elements added to 'nums' (can go to array part) */ + int i = sizenode(t); + while (i--) { + Node *n = &t->node[i]; + if (!ttisnil(gval(n))) { + ause += countint(gkey(n), nums); + totaluse++; + } + } + *pnasize += ause; + return totaluse; +} + + +static void setarrayvector (lua_State *L, Table *t, unsigned int size) { + unsigned int i; + luaM_reallocvector(L, t->array, t->sizearray, size, TValue); + for (i=t->sizearray; i<size; i++) + setnilvalue(&t->array[i]); + t->sizearray = size; +} + + +static void setnodevector (lua_State *L, Table *t, unsigned int size) { + int lsize; + if (size == 0) { /* no elements to hash part? */ + t->node = cast(Node *, dummynode); /* use common 'dummynode' */ + lsize = 0; + } + else { + int i; + lsize = luaO_ceillog2(size); + if (lsize > MAXHBITS) + luaG_runerror(L, "table overflow"); + size = twoto(lsize); + t->node = luaM_newvector(L, size, Node); + for (i = 0; i < (int)size; i++) { + Node *n = gnode(t, i); + gnext(n) = 0; + setnilvalue(wgkey(n)); + setnilvalue(gval(n)); + } + } + t->lsizenode = cast_byte(lsize); + t->lastfree = gnode(t, size); /* all positions are free */ +} + + +void luaH_resize (lua_State *L, Table *t, unsigned int nasize, + unsigned int nhsize) { + unsigned int i; + int j; + unsigned int oldasize = t->sizearray; + int oldhsize = t->lsizenode; + Node *nold = t->node; /* save old hash ... */ + if (nasize > oldasize) /* array part must grow? */ + setarrayvector(L, t, nasize); + /* create new hash part with appropriate size */ + setnodevector(L, t, nhsize); + if (nasize < oldasize) { /* array part must shrink? */ + t->sizearray = nasize; + /* re-insert elements from vanishing slice */ + for (i=nasize; i<oldasize; i++) { + if (!ttisnil(&t->array[i])) + luaH_setint(L, t, i + 1, &t->array[i]); + } + /* shrink array */ + luaM_reallocvector(L, t->array, oldasize, nasize, TValue); + } + /* re-insert elements from hash part */ + for (j = twoto(oldhsize) - 1; j >= 0; j--) { + Node *old = nold + j; + if (!ttisnil(gval(old))) { + /* doesn't need barrier/invalidate cache, as entry was + already present in the table */ + setobjt2t(L, luaH_set(L, t, gkey(old)), gval(old)); + } + } + if (!isdummy(nold)) + luaM_freearray(L, nold, cast(size_t, twoto(oldhsize))); /* free old array */ +} + + +void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize) { + int nsize = isdummy(t->node) ? 0 : sizenode(t); + luaH_resize(L, t, nasize, nsize); +} + +/* +** nums[i] = number of keys 'k' where 2^(i - 1) < k <= 2^i +*/ +static void rehash (lua_State *L, Table *t, const TValue *ek) { + unsigned int nasize, na; + unsigned int nums[MAXABITS + 1]; + int i; + int totaluse; + for (i = 0; i <= MAXABITS; i++) nums[i] = 0; /* reset counts */ + nasize = numusearray(t, nums); /* count keys in array part */ + totaluse = nasize; /* all those keys are integer keys */ + totaluse += numusehash(t, nums, &nasize); /* count keys in hash part */ + /* count extra key */ + nasize += countint(ek, nums); + totaluse++; + /* compute new size for array part */ + na = computesizes(nums, &nasize); + /* resize the table to new computed sizes */ + luaH_resize(L, t, nasize, totaluse - na); +} + + + +/* +** }============================================================= +*/ + + +Table *luaH_new (lua_State *L) { + GCObject *o = luaC_newobj(L, LUA_TTABLE, sizeof(Table)); + Table *t = gco2t(o); + t->metatable = NULL; + t->flags = cast_byte(~0); + t->array = NULL; + t->sizearray = 0; + setnodevector(L, t, 0); + return t; +} + + +void luaH_free (lua_State *L, Table *t) { + if (!isdummy(t->node)) + luaM_freearray(L, t->node, cast(size_t, sizenode(t))); + luaM_freearray(L, t->array, t->sizearray); + luaM_free(L, t); +} + + +static Node *getfreepos (Table *t) { + while (t->lastfree > t->node) { + t->lastfree--; + if (ttisnil(gkey(t->lastfree))) + return t->lastfree; + } + return NULL; /* could not find a free place */ +} + + + +/* +** inserts a new key into a hash table; first, check whether key's main +** position is free. If not, check whether colliding node is in its main +** position or not: if it is not, move colliding node to an empty place and +** put new key in its main position; otherwise (colliding node is in its main +** position), new key goes to an empty position. +*/ +TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key) { + Node *mp; + TValue aux; + if (ttisnil(key)) luaG_runerror(L, "table index is nil"); + else if (ttisfloat(key)) { + lua_Number n = fltvalue(key); + lua_Integer k; + if (luai_numisnan(n)) + luaG_runerror(L, "table index is NaN"); + if (numisinteger(n, &k)) { /* index is int? */ + setivalue(&aux, k); + key = &aux; /* insert it as an integer */ + } + } + mp = mainposition(t, key); + if (!ttisnil(gval(mp)) || isdummy(mp)) { /* main position is taken? */ + Node *othern; + Node *f = getfreepos(t); /* get a free place */ + if (f == NULL) { /* cannot find a free place? */ + rehash(L, t, key); /* grow table */ + /* whatever called 'newkey' takes care of TM cache and GC barrier */ + return luaH_set(L, t, key); /* insert key into grown table */ + } + lua_assert(!isdummy(f)); + othern = mainposition(t, gkey(mp)); + if (othern != mp) { /* is colliding node out of its main position? */ + /* yes; move colliding node into free position */ + while (othern + gnext(othern) != mp) /* find previous */ + othern += gnext(othern); + gnext(othern) = cast_int(f - othern); /* rechain to point to 'f' */ + *f = *mp; /* copy colliding node into free pos. (mp->next also goes) */ + if (gnext(mp) != 0) { + gnext(f) += cast_int(mp - f); /* correct 'next' */ + gnext(mp) = 0; /* now 'mp' is free */ + } + setnilvalue(gval(mp)); + } + else { /* colliding node is in its own main position */ + /* new node will go into free position */ + if (gnext(mp) != 0) + gnext(f) = cast_int((mp + gnext(mp)) - f); /* chain new position */ + else lua_assert(gnext(f) == 0); + gnext(mp) = cast_int(f - mp); + mp = f; + } + } + setnodekey(L, &mp->i_key, key); + luaC_barrierback(L, t, key); + lua_assert(ttisnil(gval(mp))); + return gval(mp); +} + + +/* +** search function for integers +*/ +const TValue *luaH_getint (Table *t, lua_Integer key) { + /* (1 <= key && key <= t->sizearray) */ + if (l_castS2U(key - 1) < t->sizearray) + return &t->array[key - 1]; + else { + Node *n = hashint(t, key); + for (;;) { /* check whether 'key' is somewhere in the chain */ + if (ttisinteger(gkey(n)) && ivalue(gkey(n)) == key) + return gval(n); /* that's it */ + else { + int nx = gnext(n); + if (nx == 0) break; + n += nx; + } + }; + return luaO_nilobject; + } +} + + +/* +** search function for short strings +*/ +const TValue *luaH_getstr (Table *t, TString *key) { + Node *n = hashstr(t, key); + lua_assert(key->tt == LUA_TSHRSTR); + for (;;) { /* check whether 'key' is somewhere in the chain */ + const TValue *k = gkey(n); + if (ttisshrstring(k) && eqshrstr(tsvalue(k), key)) + return gval(n); /* that's it */ + else { + int nx = gnext(n); + if (nx == 0) break; + n += nx; + } + }; + return luaO_nilobject; +} + + +/* +** main search function +*/ +const TValue *luaH_get (Table *t, const TValue *key) { + switch (ttype(key)) { + case LUA_TSHRSTR: return luaH_getstr(t, tsvalue(key)); + case LUA_TNUMINT: return luaH_getint(t, ivalue(key)); + case LUA_TNIL: return luaO_nilobject; + case LUA_TNUMFLT: { + lua_Integer k; + if (numisinteger(fltvalue(key), &k)) /* index is int? */ + return luaH_getint(t, k); /* use specialized version */ + /* else go through */ + } + default: { + Node *n = mainposition(t, key); + for (;;) { /* check whether 'key' is somewhere in the chain */ + if (luaV_rawequalobj(gkey(n), key)) + return gval(n); /* that's it */ + else { + int nx = gnext(n); + if (nx == 0) break; + n += nx; + } + }; + return luaO_nilobject; + } + } +} + + +/* +** beware: when using this function you probably need to check a GC +** barrier and invalidate the TM cache. +*/ +TValue *luaH_set (lua_State *L, Table *t, const TValue *key) { + const TValue *p = luaH_get(t, key); + if (p != luaO_nilobject) + return cast(TValue *, p); + else return luaH_newkey(L, t, key); +} + + +void luaH_setint (lua_State *L, Table *t, lua_Integer key, TValue *value) { + const TValue *p = luaH_getint(t, key); + TValue *cell; + if (p != luaO_nilobject) + cell = cast(TValue *, p); + else { + TValue k; + setivalue(&k, key); + cell = luaH_newkey(L, t, &k); + } + setobj2t(L, cell, value); +} + + +static int unbound_search (Table *t, unsigned int j) { + unsigned int i = j; /* i is zero or a present index */ + j++; + /* find 'i' and 'j' such that i is present and j is not */ + while (!ttisnil(luaH_getint(t, j))) { + i = j; + if (j > cast(unsigned int, MAX_INT)/2) { /* overflow? */ + /* table was built with bad purposes: resort to linear search */ + i = 1; + while (!ttisnil(luaH_getint(t, i))) i++; + return i - 1; + } + j *= 2; + } + /* now do a binary search between them */ + while (j - i > 1) { + unsigned int m = (i+j)/2; + if (ttisnil(luaH_getint(t, m))) j = m; + else i = m; + } + return i; +} + + +/* +** Try to find a boundary in table 't'. A 'boundary' is an integer index +** such that t[i] is non-nil and t[i+1] is nil (and 0 if t[1] is nil). +*/ +int luaH_getn (Table *t) { + unsigned int j = t->sizearray; + if (j > 0 && ttisnil(&t->array[j - 1])) { + /* there is a boundary in the array part: (binary) search for it */ + unsigned int i = 0; + while (j - i > 1) { + unsigned int m = (i+j)/2; + if (ttisnil(&t->array[m - 1])) j = m; + else i = m; + } + return i; + } + /* else must find a boundary in hash part */ + else if (isdummy(t->node)) /* hash part is empty? */ + return j; /* that is easy... */ + else return unbound_search(t, j); +} + + + +#if defined(LUA_DEBUG) + +Node *luaH_mainposition (const Table *t, const TValue *key) { + return mainposition(t, key); +} + +int luaH_isdummy (Node *n) { return isdummy(n); } + +#endif diff --git a/src/ltable.h b/src/ltable.h new file mode 100644 index 000000000000..53d25511ad49 --- /dev/null +++ b/src/ltable.h @@ -0,0 +1,53 @@ +/* +** $Id: ltable.h,v 2.20 2014/09/04 18:15:29 roberto Exp $ +** Lua tables (hash) +** See Copyright Notice in lua.h +*/ + +#ifndef ltable_h +#define ltable_h + +#include "lobject.h" + + +#define gnode(t,i) (&(t)->node[i]) +#define gval(n) (&(n)->i_val) +#define gnext(n) ((n)->i_key.nk.next) + + +/* 'const' to avoid wrong writings that can mess up field 'next' */ +#define gkey(n) cast(const TValue*, (&(n)->i_key.tvk)) + +#define wgkey(n) (&(n)->i_key.nk) + +#define invalidateTMcache(t) ((t)->flags = 0) + + +/* returns the key, given the value of a table entry */ +#define keyfromval(v) \ + (gkey(cast(Node *, cast(char *, (v)) - offsetof(Node, i_val)))) + + +LUAI_FUNC const TValue *luaH_getint (Table *t, lua_Integer key); +LUAI_FUNC void luaH_setint (lua_State *L, Table *t, lua_Integer key, + TValue *value); +LUAI_FUNC const TValue *luaH_getstr (Table *t, TString *key); +LUAI_FUNC const TValue *luaH_get (Table *t, const TValue *key); +LUAI_FUNC TValue *luaH_newkey (lua_State *L, Table *t, const TValue *key); +LUAI_FUNC TValue *luaH_set (lua_State *L, Table *t, const TValue *key); +LUAI_FUNC Table *luaH_new (lua_State *L); +LUAI_FUNC void luaH_resize (lua_State *L, Table *t, unsigned int nasize, + unsigned int nhsize); +LUAI_FUNC void luaH_resizearray (lua_State *L, Table *t, unsigned int nasize); +LUAI_FUNC void luaH_free (lua_State *L, Table *t); +LUAI_FUNC int luaH_next (lua_State *L, Table *t, StkId key); +LUAI_FUNC int luaH_getn (Table *t); + + +#if defined(LUA_DEBUG) +LUAI_FUNC Node *luaH_mainposition (const Table *t, const TValue *key); +LUAI_FUNC int luaH_isdummy (Node *n); +#endif + + +#endif diff --git a/src/ltablib.c b/src/ltablib.c new file mode 100644 index 000000000000..8f78afb7f25e --- /dev/null +++ b/src/ltablib.c @@ -0,0 +1,357 @@ +/* +** $Id: ltablib.c,v 1.79 2014/11/02 19:19:04 roberto Exp $ +** Library for Table Manipulation +** See Copyright Notice in lua.h +*/ + +#define ltablib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <limits.h> +#include <stddef.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + + +/* +** Structure with table-access functions +*/ +typedef struct { + int (*geti) (lua_State *L, int idx, lua_Integer n); + void (*seti) (lua_State *L, int idx, lua_Integer n); +} TabA; + + +/* +** Check that 'arg' has a table and set access functions in 'ta' to raw +** or non-raw according to the presence of corresponding metamethods. +*/ +static void checktab (lua_State *L, int arg, TabA *ta) { + ta->geti = NULL; ta->seti = NULL; + if (lua_getmetatable(L, arg)) { + lua_pushliteral(L, "__index"); /* 'index' metamethod */ + if (lua_rawget(L, -2) != LUA_TNIL) + ta->geti = lua_geti; + lua_pushliteral(L, "__newindex"); /* 'newindex' metamethod */ + if (lua_rawget(L, -3) != LUA_TNIL) + ta->seti = lua_seti; + lua_pop(L, 3); /* pop metatable plus both metamethods */ + } + if (ta->geti == NULL || ta->seti == NULL) { + luaL_checktype(L, arg, LUA_TTABLE); /* must be table for raw methods */ + if (ta->geti == NULL) ta->geti = lua_rawgeti; + if (ta->seti == NULL) ta->seti = lua_rawseti; + } +} + + +#define aux_getn(L,n,ta) (checktab(L, n, ta), luaL_len(L, n)) + + +#if defined(LUA_COMPAT_MAXN) +static int maxn (lua_State *L) { + lua_Number max = 0; + luaL_checktype(L, 1, LUA_TTABLE); + lua_pushnil(L); /* first key */ + while (lua_next(L, 1)) { + lua_pop(L, 1); /* remove value */ + if (lua_type(L, -1) == LUA_TNUMBER) { + lua_Number v = lua_tonumber(L, -1); + if (v > max) max = v; + } + } + lua_pushnumber(L, max); + return 1; +} +#endif + + +static int tinsert (lua_State *L) { + TabA ta; + lua_Integer e = aux_getn(L, 1, &ta) + 1; /* first empty element */ + lua_Integer pos; /* where to insert new element */ + switch (lua_gettop(L)) { + case 2: { /* called with only 2 arguments */ + pos = e; /* insert new element at the end */ + break; + } + case 3: { + lua_Integer i; + pos = luaL_checkinteger(L, 2); /* 2nd argument is the position */ + luaL_argcheck(L, 1 <= pos && pos <= e, 2, "position out of bounds"); + for (i = e; i > pos; i--) { /* move up elements */ + (*ta.geti)(L, 1, i - 1); + (*ta.seti)(L, 1, i); /* t[i] = t[i - 1] */ + } + break; + } + default: { + return luaL_error(L, "wrong number of arguments to 'insert'"); + } + } + (*ta.seti)(L, 1, pos); /* t[pos] = v */ + return 0; +} + + +static int tremove (lua_State *L) { + TabA ta; + lua_Integer size = aux_getn(L, 1, &ta); + lua_Integer pos = luaL_optinteger(L, 2, size); + if (pos != size) /* validate 'pos' if given */ + luaL_argcheck(L, 1 <= pos && pos <= size + 1, 1, "position out of bounds"); + (*ta.geti)(L, 1, pos); /* result = t[pos] */ + for ( ; pos < size; pos++) { + (*ta.geti)(L, 1, pos + 1); + (*ta.seti)(L, 1, pos); /* t[pos] = t[pos + 1] */ + } + lua_pushnil(L); + (*ta.seti)(L, 1, pos); /* t[pos] = nil */ + return 1; +} + + +static int tmove (lua_State *L) { + TabA ta; + lua_Integer f = luaL_checkinteger(L, 2); + lua_Integer e = luaL_checkinteger(L, 3); + lua_Integer t = luaL_checkinteger(L, 4); + int tt = !lua_isnoneornil(L, 5) ? 5 : 1; /* destination table */ + /* the following restriction avoids several problems with overflows */ + luaL_argcheck(L, f > 0, 2, "initial position must be positive"); + if (e >= f) { /* otherwise, nothing to move */ + lua_Integer n, i; + ta.geti = (luaL_getmetafield(L, 1, "__index") == LUA_TNIL) + ? (luaL_checktype(L, 1, LUA_TTABLE), lua_rawgeti) + : lua_geti; + ta.seti = (luaL_getmetafield(L, tt, "__newindex") == LUA_TNIL) + ? (luaL_checktype(L, tt, LUA_TTABLE), lua_rawseti) + : lua_seti; + n = e - f + 1; /* number of elements to move */ + if (t > f) { + for (i = n - 1; i >= 0; i--) { + (*ta.geti)(L, 1, f + i); + (*ta.seti)(L, tt, t + i); + } + } + else { + for (i = 0; i < n; i++) { + (*ta.geti)(L, 1, f + i); + (*ta.seti)(L, tt, t + i); + } + } + } + lua_pushvalue(L, tt); /* return "to table" */ + return 1; +} + + +static void addfield (lua_State *L, luaL_Buffer *b, TabA *ta, lua_Integer i) { + (*ta->geti)(L, 1, i); + if (!lua_isstring(L, -1)) + luaL_error(L, "invalid value (%s) at index %d in table for 'concat'", + luaL_typename(L, -1), i); + luaL_addvalue(b); +} + + +static int tconcat (lua_State *L) { + TabA ta; + luaL_Buffer b; + size_t lsep; + lua_Integer i, last; + const char *sep = luaL_optlstring(L, 2, "", &lsep); + checktab(L, 1, &ta); + i = luaL_optinteger(L, 3, 1); + last = luaL_opt(L, luaL_checkinteger, 4, luaL_len(L, 1)); + luaL_buffinit(L, &b); + for (; i < last; i++) { + addfield(L, &b, &ta, i); + luaL_addlstring(&b, sep, lsep); + } + if (i == last) /* add last value (if interval was not empty) */ + addfield(L, &b, &ta, i); + luaL_pushresult(&b); + return 1; +} + + +/* +** {====================================================== +** Pack/unpack +** ======================================================= +*/ + +static int pack (lua_State *L) { + int i; + int n = lua_gettop(L); /* number of elements to pack */ + lua_createtable(L, n, 1); /* create result table */ + lua_insert(L, 1); /* put it at index 1 */ + for (i = n; i >= 1; i--) /* assign elements */ + lua_rawseti(L, 1, i); + lua_pushinteger(L, n); + lua_setfield(L, 1, "n"); /* t.n = number of elements */ + return 1; /* return table */ +} + + +static int unpack (lua_State *L) { + TabA ta; + lua_Integer i, e; + lua_Unsigned n; + checktab(L, 1, &ta); + i = luaL_optinteger(L, 2, 1); + e = luaL_opt(L, luaL_checkinteger, 3, luaL_len(L, 1)); + if (i > e) return 0; /* empty range */ + n = (lua_Unsigned)e - i; /* number of elements minus 1 (avoid overflows) */ + if (n >= (unsigned int)INT_MAX || !lua_checkstack(L, (int)(++n))) + return luaL_error(L, "too many results to unpack"); + do { /* must have at least one element */ + (*ta.geti)(L, 1, i); /* push arg[i..e] */ + } while (i++ < e); + + return (int)n; +} + +/* }====================================================== */ + + + +/* +** {====================================================== +** Quicksort +** (based on 'Algorithms in MODULA-3', Robert Sedgewick; +** Addison-Wesley, 1993.) +** ======================================================= +*/ + + +static void set2 (lua_State *L, TabA *ta, int i, int j) { + (*ta->seti)(L, 1, i); + (*ta->seti)(L, 1, j); +} + +static int sort_comp (lua_State *L, int a, int b) { + if (!lua_isnil(L, 2)) { /* function? */ + int res; + lua_pushvalue(L, 2); + lua_pushvalue(L, a-1); /* -1 to compensate function */ + lua_pushvalue(L, b-2); /* -2 to compensate function and 'a' */ + lua_call(L, 2, 1); + res = lua_toboolean(L, -1); + lua_pop(L, 1); + return res; + } + else /* a < b? */ + return lua_compare(L, a, b, LUA_OPLT); +} + +static void auxsort (lua_State *L, TabA *ta, int l, int u) { + while (l < u) { /* for tail recursion */ + int i, j; + /* sort elements a[l], a[(l+u)/2] and a[u] */ + (*ta->geti)(L, 1, l); + (*ta->geti)(L, 1, u); + if (sort_comp(L, -1, -2)) /* a[u] < a[l]? */ + set2(L, ta, l, u); /* swap a[l] - a[u] */ + else + lua_pop(L, 2); + if (u-l == 1) break; /* only 2 elements */ + i = (l+u)/2; + (*ta->geti)(L, 1, i); + (*ta->geti)(L, 1, l); + if (sort_comp(L, -2, -1)) /* a[i]<a[l]? */ + set2(L, ta, i, l); + else { + lua_pop(L, 1); /* remove a[l] */ + (*ta->geti)(L, 1, u); + if (sort_comp(L, -1, -2)) /* a[u]<a[i]? */ + set2(L, ta, i, u); + else + lua_pop(L, 2); + } + if (u-l == 2) break; /* only 3 elements */ + (*ta->geti)(L, 1, i); /* Pivot */ + lua_pushvalue(L, -1); + (*ta->geti)(L, 1, u-1); + set2(L, ta, i, u-1); + /* a[l] <= P == a[u-1] <= a[u], only need to sort from l+1 to u-2 */ + i = l; j = u-1; + for (;;) { /* invariant: a[l..i] <= P <= a[j..u] */ + /* repeat ++i until a[i] >= P */ + while ((*ta->geti)(L, 1, ++i), sort_comp(L, -1, -2)) { + if (i>=u) luaL_error(L, "invalid order function for sorting"); + lua_pop(L, 1); /* remove a[i] */ + } + /* repeat --j until a[j] <= P */ + while ((*ta->geti)(L, 1, --j), sort_comp(L, -3, -1)) { + if (j<=l) luaL_error(L, "invalid order function for sorting"); + lua_pop(L, 1); /* remove a[j] */ + } + if (j<i) { + lua_pop(L, 3); /* pop pivot, a[i], a[j] */ + break; + } + set2(L, ta, i, j); + } + (*ta->geti)(L, 1, u-1); + (*ta->geti)(L, 1, i); + set2(L, ta, u-1, i); /* swap pivot (a[u-1]) with a[i] */ + /* a[l..i-1] <= a[i] == P <= a[i+1..u] */ + /* adjust so that smaller half is in [j..i] and larger one in [l..u] */ + if (i-l < u-i) { + j=l; i=i-1; l=i+2; + } + else { + j=i+1; i=u; u=j-2; + } + auxsort(L, ta, j, i); /* call recursively the smaller one */ + } /* repeat the routine for the larger one */ +} + +static int sort (lua_State *L) { + TabA ta; + int n = (int)aux_getn(L, 1, &ta); + luaL_checkstack(L, 50, ""); /* assume array is smaller than 2^50 */ + if (!lua_isnoneornil(L, 2)) /* is there a 2nd argument? */ + luaL_checktype(L, 2, LUA_TFUNCTION); + lua_settop(L, 2); /* make sure there are two arguments */ + auxsort(L, &ta, 1, n); + return 0; +} + +/* }====================================================== */ + + +static const luaL_Reg tab_funcs[] = { + {"concat", tconcat}, +#if defined(LUA_COMPAT_MAXN) + {"maxn", maxn}, +#endif + {"insert", tinsert}, + {"pack", pack}, + {"unpack", unpack}, + {"remove", tremove}, + {"move", tmove}, + {"sort", sort}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_table (lua_State *L) { + luaL_newlib(L, tab_funcs); +#if defined(LUA_COMPAT_UNPACK) + /* _G.unpack = table.unpack */ + lua_getfield(L, -1, "unpack"); + lua_setglobal(L, "unpack"); +#endif + return 1; +} + diff --git a/src/ltm.c b/src/ltm.c new file mode 100644 index 000000000000..25b46b17f90d --- /dev/null +++ b/src/ltm.c @@ -0,0 +1,143 @@ +/* +** $Id: ltm.c,v 2.33 2014/11/21 12:15:57 roberto Exp $ +** Tag methods +** See Copyright Notice in lua.h +*/ + +#define ltm_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <string.h> + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lobject.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lvm.h" + + +static const char udatatypename[] = "userdata"; + +LUAI_DDEF const char *const luaT_typenames_[LUA_TOTALTAGS] = { + "no value", + "nil", "boolean", udatatypename, "number", + "string", "table", "function", udatatypename, "thread", + "proto" /* this last case is used for tests only */ +}; + + +void luaT_init (lua_State *L) { + static const char *const luaT_eventname[] = { /* ORDER TM */ + "__index", "__newindex", + "__gc", "__mode", "__len", "__eq", + "__add", "__sub", "__mul", "__mod", "__pow", + "__div", "__idiv", + "__band", "__bor", "__bxor", "__shl", "__shr", + "__unm", "__bnot", "__lt", "__le", + "__concat", "__call" + }; + int i; + for (i=0; i<TM_N; i++) { + G(L)->tmname[i] = luaS_new(L, luaT_eventname[i]); + luaC_fix(L, obj2gco(G(L)->tmname[i])); /* never collect these names */ + } +} + + +/* +** function to be used with macro "fasttm": optimized for absence of +** tag methods +*/ +const TValue *luaT_gettm (Table *events, TMS event, TString *ename) { + const TValue *tm = luaH_getstr(events, ename); + lua_assert(event <= TM_EQ); + if (ttisnil(tm)) { /* no tag method? */ + events->flags |= cast_byte(1u<<event); /* cache this fact */ + return NULL; + } + else return tm; +} + + +const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, TMS event) { + Table *mt; + switch (ttnov(o)) { + case LUA_TTABLE: + mt = hvalue(o)->metatable; + break; + case LUA_TUSERDATA: + mt = uvalue(o)->metatable; + break; + default: + mt = G(L)->mt[ttnov(o)]; + } + return (mt ? luaH_getstr(mt, G(L)->tmname[event]) : luaO_nilobject); +} + + +void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1, + const TValue *p2, TValue *p3, int hasres) { + ptrdiff_t result = savestack(L, p3); + setobj2s(L, L->top++, f); /* push function (assume EXTRA_STACK) */ + setobj2s(L, L->top++, p1); /* 1st argument */ + setobj2s(L, L->top++, p2); /* 2nd argument */ + if (!hasres) /* no result? 'p3' is third argument */ + setobj2s(L, L->top++, p3); /* 3rd argument */ + /* metamethod may yield only when called from Lua code */ + luaD_call(L, L->top - (4 - hasres), hasres, isLua(L->ci)); + if (hasres) { /* if has result, move it to its place */ + p3 = restorestack(L, result); + setobjs2s(L, p3, --L->top); + } +} + + +int luaT_callbinTM (lua_State *L, const TValue *p1, const TValue *p2, + StkId res, TMS event) { + const TValue *tm = luaT_gettmbyobj(L, p1, event); /* try first operand */ + if (ttisnil(tm)) + tm = luaT_gettmbyobj(L, p2, event); /* try second operand */ + if (ttisnil(tm)) return 0; + luaT_callTM(L, tm, p1, p2, res, 1); + return 1; +} + + +void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2, + StkId res, TMS event) { + if (!luaT_callbinTM(L, p1, p2, res, event)) { + switch (event) { + case TM_CONCAT: + luaG_concaterror(L, p1, p2); + case TM_BAND: case TM_BOR: case TM_BXOR: + case TM_SHL: case TM_SHR: case TM_BNOT: { + lua_Number dummy; + if (tonumber(p1, &dummy) && tonumber(p2, &dummy)) + luaG_tointerror(L, p1, p2); + else + luaG_opinterror(L, p1, p2, "perform bitwise operation on"); + /* else go through */ + } + default: + luaG_opinterror(L, p1, p2, "perform arithmetic on"); + } + } +} + + +int luaT_callorderTM (lua_State *L, const TValue *p1, const TValue *p2, + TMS event) { + if (!luaT_callbinTM(L, p1, p2, L->top, event)) + return -1; /* no metamethod */ + else + return !l_isfalse(L->top); +} + diff --git a/src/ltm.h b/src/ltm.h new file mode 100644 index 000000000000..180179ce038e --- /dev/null +++ b/src/ltm.h @@ -0,0 +1,75 @@ +/* +** $Id: ltm.h,v 2.21 2014/10/25 11:50:46 roberto Exp $ +** Tag methods +** See Copyright Notice in lua.h +*/ + +#ifndef ltm_h +#define ltm_h + + +#include "lobject.h" + + +/* +* WARNING: if you change the order of this enumeration, +* grep "ORDER TM" and "ORDER OP" +*/ +typedef enum { + TM_INDEX, + TM_NEWINDEX, + TM_GC, + TM_MODE, + TM_LEN, + TM_EQ, /* last tag method with fast access */ + TM_ADD, + TM_SUB, + TM_MUL, + TM_MOD, + TM_POW, + TM_DIV, + TM_IDIV, + TM_BAND, + TM_BOR, + TM_BXOR, + TM_SHL, + TM_SHR, + TM_UNM, + TM_BNOT, + TM_LT, + TM_LE, + TM_CONCAT, + TM_CALL, + TM_N /* number of elements in the enum */ +} TMS; + + + +#define gfasttm(g,et,e) ((et) == NULL ? NULL : \ + ((et)->flags & (1u<<(e))) ? NULL : luaT_gettm(et, e, (g)->tmname[e])) + +#define fasttm(l,et,e) gfasttm(G(l), et, e) + +#define ttypename(x) luaT_typenames_[(x) + 1] +#define objtypename(x) ttypename(ttnov(x)) + +LUAI_DDEC const char *const luaT_typenames_[LUA_TOTALTAGS]; + + +LUAI_FUNC const TValue *luaT_gettm (Table *events, TMS event, TString *ename); +LUAI_FUNC const TValue *luaT_gettmbyobj (lua_State *L, const TValue *o, + TMS event); +LUAI_FUNC void luaT_init (lua_State *L); + +LUAI_FUNC void luaT_callTM (lua_State *L, const TValue *f, const TValue *p1, + const TValue *p2, TValue *p3, int hasres); +LUAI_FUNC int luaT_callbinTM (lua_State *L, const TValue *p1, const TValue *p2, + StkId res, TMS event); +LUAI_FUNC void luaT_trybinTM (lua_State *L, const TValue *p1, const TValue *p2, + StkId res, TMS event); +LUAI_FUNC int luaT_callorderTM (lua_State *L, const TValue *p1, + const TValue *p2, TMS event); + + + +#endif diff --git a/src/lua.c b/src/lua.c new file mode 100644 index 000000000000..34a3900a7949 --- /dev/null +++ b/src/lua.c @@ -0,0 +1,611 @@ +/* +** $Id: lua.c,v 1.222 2014/11/11 19:41:27 roberto Exp $ +** Lua stand-alone interpreter +** See Copyright Notice in lua.h +*/ + +#define lua_c + +#include "lprefix.h" + + +#include <signal.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + + +#if !defined(LUA_PROMPT) +#define LUA_PROMPT "> " +#define LUA_PROMPT2 ">> " +#endif + +#if !defined(LUA_PROGNAME) +#define LUA_PROGNAME "lua" +#endif + +#if !defined(LUA_MAXINPUT) +#define LUA_MAXINPUT 512 +#endif + +#if !defined(LUA_INIT_VAR) +#define LUA_INIT_VAR "LUA_INIT" +#endif + +#define LUA_INITVARVERSION \ + LUA_INIT_VAR "_" LUA_VERSION_MAJOR "_" LUA_VERSION_MINOR + + +/* +** lua_stdin_is_tty detects whether the standard input is a 'tty' (that +** is, whether we're running lua interactively). +*/ +#if !defined(lua_stdin_is_tty) /* { */ + +#if defined(LUA_USE_POSIX) /* { */ + +#include <unistd.h> +#define lua_stdin_is_tty() isatty(0) + +#elif defined(LUA_USE_WINDOWS) /* }{ */ + +#include <io.h> +#define lua_stdin_is_tty() _isatty(_fileno(stdin)) + +#else /* }{ */ + +/* ISO C definition */ +#define lua_stdin_is_tty() 1 /* assume stdin is a tty */ + +#endif /* } */ + +#endif /* } */ + + +/* +** lua_readline defines how to show a prompt and then read a line from +** the standard input. +** lua_saveline defines how to "save" a read line in a "history". +** lua_freeline defines how to free a line read by lua_readline. +*/ +#if !defined(lua_readline) /* { */ + +#if defined(LUA_USE_READLINE) /* { */ + +#include <readline/readline.h> +#include <readline/history.h> +#define lua_readline(L,b,p) ((void)L, ((b)=readline(p)) != NULL) +#define lua_saveline(L,idx) \ + if (lua_rawlen(L,idx) > 0) /* non-empty line? */ \ + add_history(lua_tostring(L, idx)); /* add it to history */ +#define lua_freeline(L,b) ((void)L, free(b)) + +#else /* }{ */ + +#define lua_readline(L,b,p) \ + ((void)L, fputs(p, stdout), fflush(stdout), /* show prompt */ \ + fgets(b, LUA_MAXINPUT, stdin) != NULL) /* get line */ +#define lua_saveline(L,idx) { (void)L; (void)idx; } +#define lua_freeline(L,b) { (void)L; (void)b; } + +#endif /* } */ + +#endif /* } */ + + + + +static lua_State *globalL = NULL; + +static const char *progname = LUA_PROGNAME; + + +/* +** Hook set by signal function to stop the interpreter. +*/ +static void lstop (lua_State *L, lua_Debug *ar) { + (void)ar; /* unused arg. */ + lua_sethook(L, NULL, 0, 0); /* reset hook */ + luaL_error(L, "interrupted!"); +} + + +/* +** Function to be called at a C signal. Because a C signal cannot +** just change a Lua state (as there is no proper synchronization), +** this function only sets a hook that, when called, will stop the +** interpreter. +*/ +static void laction (int i) { + signal(i, SIG_DFL); /* if another SIGINT happens, terminate process */ + lua_sethook(globalL, lstop, LUA_MASKCALL | LUA_MASKRET | LUA_MASKCOUNT, 1); +} + + +static void print_usage (const char *badoption) { + lua_writestringerror("%s: ", progname); + if (badoption[1] == 'e' || badoption[1] == 'l') + lua_writestringerror("'%s' needs argument\n", badoption); + else + lua_writestringerror("unrecognized option '%s'\n", badoption); + lua_writestringerror( + "usage: %s [options] [script [args]]\n" + "Available options are:\n" + " -e stat execute string 'stat'\n" + " -i enter interactive mode after executing 'script'\n" + " -l name require library 'name'\n" + " -v show version information\n" + " -E ignore environment variables\n" + " -- stop handling options\n" + " - stop handling options and execute stdin\n" + , + progname); +} + + +/* +** Prints an error message, adding the program name in front of it +** (if present) +*/ +static void l_message (const char *pname, const char *msg) { + if (pname) lua_writestringerror("%s: ", pname); + lua_writestringerror("%s\n", msg); +} + + +/* +** Check whether 'status' is not OK and, if so, prints the error +** message on the top of the stack. It assumes that the error object +** is a string, as it was either generated by Lua or by 'msghandler'. +*/ +static int report (lua_State *L, int status) { + if (status != LUA_OK) { + const char *msg = lua_tostring(L, -1); + l_message(progname, msg); + lua_pop(L, 1); /* remove message */ + } + return status; +} + + +/* +** Message handler used to run all chunks +*/ +static int msghandler (lua_State *L) { + const char *msg = lua_tostring(L, 1); + if (msg == NULL) { /* is error object not a string? */ + if (luaL_callmeta(L, 1, "__tostring") && /* does it have a metamethod */ + lua_type(L, -1) == LUA_TSTRING) /* that produces a string? */ + return 1; /* that is the message */ + else + msg = lua_pushfstring(L, "(error object is a %s value)", + luaL_typename(L, 1)); + } + luaL_traceback(L, L, msg, 1); /* append a standard traceback */ + return 1; /* return the traceback */ +} + + +/* +** Interface to 'lua_pcall', which sets appropriate message function +** and C-signal handler. Used to run all chunks. +*/ +static int docall (lua_State *L, int narg, int nres) { + int status; + int base = lua_gettop(L) - narg; /* function index */ + lua_pushcfunction(L, msghandler); /* push message handler */ + lua_insert(L, base); /* put it under function and args */ + globalL = L; /* to be available to 'laction' */ + signal(SIGINT, laction); /* set C-signal handler */ + status = lua_pcall(L, narg, nres, base); + signal(SIGINT, SIG_DFL); /* reset C-signal handler */ + lua_remove(L, base); /* remove message handler from the stack */ + return status; +} + + +static void print_version (void) { + lua_writestring(LUA_COPYRIGHT, strlen(LUA_COPYRIGHT)); + lua_writeline(); +} + + +/* +** Create the 'arg' table, which stores all arguments from the +** command line ('argv'). It should be aligned so that, at index 0, +** it has 'argv[script]', which is the script name. The arguments +** to the script (everything after 'script') go to positive indices; +** other arguments (before the script name) go to negative indices. +** If there is no script name, assume interpreter's name as base. +*/ +static void createargtable (lua_State *L, char **argv, int argc, int script) { + int i, narg; + if (script == argc) script = 0; /* no script name? */ + narg = argc - (script + 1); /* number of positive indices */ + lua_createtable(L, narg, script + 1); + for (i = 0; i < argc; i++) { + lua_pushstring(L, argv[i]); + lua_rawseti(L, -2, i - script); + } + lua_setglobal(L, "arg"); +} + + +static int dochunk (lua_State *L, int status) { + if (status == LUA_OK) status = docall(L, 0, 0); + return report(L, status); +} + + +static int dofile (lua_State *L, const char *name) { + return dochunk(L, luaL_loadfile(L, name)); +} + + +static int dostring (lua_State *L, const char *s, const char *name) { + return dochunk(L, luaL_loadbuffer(L, s, strlen(s), name)); +} + + +/* +** Calls 'require(name)' and stores the result in a global variable +** with the given name. +*/ +static int dolibrary (lua_State *L, const char *name) { + int status; + lua_getglobal(L, "require"); + lua_pushstring(L, name); + status = docall(L, 1, 1); /* call 'require(name)' */ + if (status == LUA_OK) + lua_setglobal(L, name); /* global[name] = require return */ + return report(L, status); +} + + +/* +** Returns the string to be used as a prompt by the interpreter. +*/ +static const char *get_prompt (lua_State *L, int firstline) { + const char *p; + lua_getglobal(L, firstline ? "_PROMPT" : "_PROMPT2"); + p = lua_tostring(L, -1); + if (p == NULL) p = (firstline ? LUA_PROMPT : LUA_PROMPT2); + return p; +} + +/* mark in error messages for incomplete statements */ +#define EOFMARK "<eof>" +#define marklen (sizeof(EOFMARK)/sizeof(char) - 1) + + +/* +** Check whether 'status' signals a syntax error and the error +** message at the top of the stack ends with the above mark for +** incomplete statements. +*/ +static int incomplete (lua_State *L, int status) { + if (status == LUA_ERRSYNTAX) { + size_t lmsg; + const char *msg = lua_tolstring(L, -1, &lmsg); + if (lmsg >= marklen && strcmp(msg + lmsg - marklen, EOFMARK) == 0) { + lua_pop(L, 1); + return 1; + } + } + return 0; /* else... */ +} + + +/* +** Prompt the user, read a line, and push it into the Lua stack. +*/ +static int pushline (lua_State *L, int firstline) { + char buffer[LUA_MAXINPUT]; + char *b = buffer; + size_t l; + const char *prmt = get_prompt(L, firstline); + int readstatus = lua_readline(L, b, prmt); + if (readstatus == 0) + return 0; /* no input (prompt will be popped by caller) */ + lua_pop(L, 1); /* remove prompt */ + l = strlen(b); + if (l > 0 && b[l-1] == '\n') /* line ends with newline? */ + b[l-1] = '\0'; /* remove it */ + if (firstline && b[0] == '=') /* for compatibility with 5.2, ... */ + lua_pushfstring(L, "return %s", b + 1); /* change '=' to 'return' */ + else + lua_pushstring(L, b); + lua_freeline(L, b); + return 1; +} + + +/* +** Try to compile line on the stack as 'return <line>'; on return, stack +** has either compiled chunk or original line (if compilation failed). +*/ +static int addreturn (lua_State *L) { + int status; + size_t len; const char *line; + lua_pushliteral(L, "return "); + lua_pushvalue(L, -2); /* duplicate line */ + lua_concat(L, 2); /* new line is "return ..." */ + line = lua_tolstring(L, -1, &len); + if ((status = luaL_loadbuffer(L, line, len, "=stdin")) == LUA_OK) + lua_remove(L, -3); /* remove original line */ + else + lua_pop(L, 2); /* remove result from 'luaL_loadbuffer' and new line */ + return status; +} + + +/* +** Read multiple lines until a complete Lua statement +*/ +static int multiline (lua_State *L) { + for (;;) { /* repeat until gets a complete statement */ + size_t len; + const char *line = lua_tolstring(L, 1, &len); /* get what it has */ + int status = luaL_loadbuffer(L, line, len, "=stdin"); /* try it */ + if (!incomplete(L, status) || !pushline(L, 0)) + return status; /* cannot or should not try to add continuation line */ + lua_pushliteral(L, "\n"); /* add newline... */ + lua_insert(L, -2); /* ...between the two lines */ + lua_concat(L, 3); /* join them */ + } +} + + +/* +** Read a line and try to load (compile) it first as an expression (by +** adding "return " in front of it) and second as a statement. Return +** the final status of load/call with the resulting function (if any) +** in the top of the stack. +*/ +static int loadline (lua_State *L) { + int status; + lua_settop(L, 0); + if (!pushline(L, 1)) + return -1; /* no input */ + if ((status = addreturn(L)) != LUA_OK) /* 'return ...' did not work? */ + status = multiline(L); /* try as command, maybe with continuation lines */ + lua_saveline(L, 1); /* keep history */ + lua_remove(L, 1); /* remove line from the stack */ + lua_assert(lua_gettop(L) == 1); + return status; +} + + +/* +** Prints (calling the Lua 'print' function) any values on the stack +*/ +static void l_print (lua_State *L) { + int n = lua_gettop(L); + if (n > 0) { /* any result to be printed? */ + luaL_checkstack(L, LUA_MINSTACK, "too many results to print"); + lua_getglobal(L, "print"); + lua_insert(L, 1); + if (lua_pcall(L, n, 0, 0) != LUA_OK) + l_message(progname, lua_pushfstring(L, "error calling 'print' (%s)", + lua_tostring(L, -1))); + } +} + + +/* +** Do the REPL: repeatedly read (load) a line, evaluate (call) it, and +** print any results. +*/ +static void doREPL (lua_State *L) { + int status; + const char *oldprogname = progname; + progname = NULL; /* no 'progname' on errors in interactive mode */ + while ((status = loadline(L)) != -1) { + if (status == LUA_OK) + status = docall(L, 0, LUA_MULTRET); + if (status == LUA_OK) l_print(L); + else report(L, status); + } + lua_settop(L, 0); /* clear stack */ + lua_writeline(); + progname = oldprogname; +} + + +/* +** Push on the stack the contents of table 'arg' from 1 to #arg +*/ +static int pushargs (lua_State *L) { + int i, n; + if (lua_getglobal(L, "arg") != LUA_TTABLE) + luaL_error(L, "'arg' is not a table"); + n = (int)luaL_len(L, -1); + luaL_checkstack(L, n + 3, "too many arguments to script"); + for (i = 1; i <= n; i++) + lua_rawgeti(L, -i, i); + lua_remove(L, -i); /* remove table from the stack */ + return n; +} + + +static int handle_script (lua_State *L, char **argv) { + int status; + const char *fname = argv[0]; + if (strcmp(fname, "-") == 0 && strcmp(argv[-1], "--") != 0) + fname = NULL; /* stdin */ + status = luaL_loadfile(L, fname); + if (status == LUA_OK) { + int n = pushargs(L); /* push arguments to script */ + status = docall(L, n, LUA_MULTRET); + } + return report(L, status); +} + + + +/* bits of various argument indicators in 'args' */ +#define has_error 1 /* bad option */ +#define has_i 2 /* -i */ +#define has_v 4 /* -v */ +#define has_e 8 /* -e */ +#define has_E 16 /* -E */ + +/* +** Traverses all arguments from 'argv', returning a mask with those +** needed before running any Lua code (or an error code if it finds +** any invalid argument). 'first' returns the first not-handled argument +** (either the script name or a bad argument in case of error). +*/ +static int collectargs (char **argv, int *first) { + int args = 0; + int i; + for (i = 1; argv[i] != NULL; i++) { + *first = i; + if (argv[i][0] != '-') /* not an option? */ + return args; /* stop handling options */ + switch (argv[i][1]) { /* else check option */ + case '-': /* '--' */ + if (argv[i][2] != '\0') /* extra characters after '--'? */ + return has_error; /* invalid option */ + *first = i + 1; + return args; + case '\0': /* '-' */ + return args; /* script "name" is '-' */ + case 'E': + if (argv[i][2] != '\0') /* extra characters after 1st? */ + return has_error; /* invalid option */ + args |= has_E; + break; + case 'i': + args |= has_i; /* goes through (-i implies -v) */ + case 'v': + if (argv[i][2] != '\0') /* extra characters after 1st? */ + return has_error; /* invalid option */ + args |= has_v; + break; + case 'e': + args |= has_e; /* go through */ + case 'l': /* both options need an argument */ + if (argv[i][2] == '\0') { /* no concatenated argument? */ + i++; /* try next 'argv' */ + if (argv[i] == NULL || argv[i][0] == '-') + return has_error; /* no next argument or it is another option */ + } + break; + default: /* invalid option */ + return has_error; + } + } + *first = i; /* no script name */ + return args; +} + + +/* +** Processes options 'e' and 'l', which involve running Lua code. +** Returns 0 if some code raises an error. +*/ +static int runargs (lua_State *L, char **argv, int n) { + int i; + for (i = 1; i < n; i++) { + int status; + int option = argv[i][1]; + lua_assert(argv[i][0] == '-'); /* already checked */ + if (option == 'e' || option == 'l') { + const char *extra = argv[i] + 2; /* both options need an argument */ + if (*extra == '\0') extra = argv[++i]; + lua_assert(extra != NULL); + if (option == 'e') + status = dostring(L, extra, "=(command line)"); + else + status = dolibrary(L, extra); + if (status != LUA_OK) return 0; + } + } + return 1; +} + + +static int handle_luainit (lua_State *L) { + const char *name = "=" LUA_INITVARVERSION; + const char *init = getenv(name + 1); + if (init == NULL) { + name = "=" LUA_INIT_VAR; + init = getenv(name + 1); /* try alternative name */ + } + if (init == NULL) return LUA_OK; + else if (init[0] == '@') + return dofile(L, init+1); + else + return dostring(L, init, name); +} + + +/* +** Main body of stand-alone interpreter (to be called in protected mode). +** Reads the options and handles them all. +*/ +static int pmain (lua_State *L) { + int argc = (int)lua_tointeger(L, 1); + char **argv = (char **)lua_touserdata(L, 2); + int script; + int args = collectargs(argv, &script); + luaL_checkversion(L); /* check that interpreter has correct version */ + if (argv[0] && argv[0][0]) progname = argv[0]; + if (args == has_error) { /* bad arg? */ + print_usage(argv[script]); /* 'script' has index of bad arg. */ + return 0; + } + if (args & has_v) /* option '-v'? */ + print_version(); + if (args & has_E) { /* option '-E'? */ + lua_pushboolean(L, 1); /* signal for libraries to ignore env. vars. */ + lua_setfield(L, LUA_REGISTRYINDEX, "LUA_NOENV"); + } + luaL_openlibs(L); /* open standard libraries */ + createargtable(L, argv, argc, script); /* create table 'arg' */ + if (!(args & has_E)) { /* no option '-E'? */ + if (handle_luainit(L) != LUA_OK) /* run LUA_INIT */ + return 0; /* error running LUA_INIT */ + } + if (!runargs(L, argv, script)) /* execute arguments -e and -l */ + return 0; /* something failed */ + if (script < argc && /* execute main script (if there is one) */ + handle_script(L, argv + script) != LUA_OK) + return 0; + if (args & has_i) /* -i option? */ + doREPL(L); /* do read-eval-print loop */ + else if (script == argc && !(args & (has_e | has_v))) { /* no arguments? */ + if (lua_stdin_is_tty()) { /* running in interactive mode? */ + print_version(); + doREPL(L); /* do read-eval-print loop */ + } + else dofile(L, NULL); /* executes stdin as a file */ + } + lua_pushboolean(L, 1); /* signal no errors */ + return 1; +} + + +int main (int argc, char **argv) { + int status, result; + lua_State *L = luaL_newstate(); /* create state */ + if (L == NULL) { + l_message(argv[0], "cannot create state: not enough memory"); + return EXIT_FAILURE; + } + lua_pushcfunction(L, &pmain); /* to call 'pmain' in protected mode */ + lua_pushinteger(L, argc); /* 1st argument */ + lua_pushlightuserdata(L, argv); /* 2nd argument */ + status = lua_pcall(L, 2, 1, 0); /* do the call */ + result = lua_toboolean(L, -1); /* get result */ + report(L, status); + lua_close(L); + return (result && status == LUA_OK) ? EXIT_SUCCESS : EXIT_FAILURE; +} + diff --git a/src/lua.h b/src/lua.h new file mode 100644 index 000000000000..09a4ccaf89f2 --- /dev/null +++ b/src/lua.h @@ -0,0 +1,485 @@ +/* +** $Id: lua.h,v 1.325 2014/12/26 17:24:27 roberto Exp $ +** Lua - A Scripting Language +** Lua.org, PUC-Rio, Brazil (http://www.lua.org) +** See Copyright Notice at the end of this file +*/ + + +#ifndef lua_h +#define lua_h + +#include <stdarg.h> +#include <stddef.h> + + +#include "luaconf.h" + + +#define LUA_VERSION_MAJOR "5" +#define LUA_VERSION_MINOR "3" +#define LUA_VERSION_NUM 503 +#define LUA_VERSION_RELEASE "0" + +#define LUA_VERSION "Lua " LUA_VERSION_MAJOR "." LUA_VERSION_MINOR +#define LUA_RELEASE LUA_VERSION "." LUA_VERSION_RELEASE +#define LUA_COPYRIGHT LUA_RELEASE " Copyright (C) 1994-2015 Lua.org, PUC-Rio" +#define LUA_AUTHORS "R. Ierusalimschy, L. H. de Figueiredo, W. Celes" + + +/* mark for precompiled code ('<esc>Lua') */ +#define LUA_SIGNATURE "\x1bLua" + +/* option for multiple returns in 'lua_pcall' and 'lua_call' */ +#define LUA_MULTRET (-1) + + +/* +** pseudo-indices +*/ +#define LUA_REGISTRYINDEX LUAI_FIRSTPSEUDOIDX +#define lua_upvalueindex(i) (LUA_REGISTRYINDEX - (i)) + + +/* thread status */ +#define LUA_OK 0 +#define LUA_YIELD 1 +#define LUA_ERRRUN 2 +#define LUA_ERRSYNTAX 3 +#define LUA_ERRMEM 4 +#define LUA_ERRGCMM 5 +#define LUA_ERRERR 6 + + +typedef struct lua_State lua_State; + + +/* +** basic types +*/ +#define LUA_TNONE (-1) + +#define LUA_TNIL 0 +#define LUA_TBOOLEAN 1 +#define LUA_TLIGHTUSERDATA 2 +#define LUA_TNUMBER 3 +#define LUA_TSTRING 4 +#define LUA_TTABLE 5 +#define LUA_TFUNCTION 6 +#define LUA_TUSERDATA 7 +#define LUA_TTHREAD 8 + +#define LUA_NUMTAGS 9 + + + +/* minimum Lua stack available to a C function */ +#define LUA_MINSTACK 20 + + +/* predefined values in the registry */ +#define LUA_RIDX_MAINTHREAD 1 +#define LUA_RIDX_GLOBALS 2 +#define LUA_RIDX_LAST LUA_RIDX_GLOBALS + + +/* type of numbers in Lua */ +typedef LUA_NUMBER lua_Number; + + +/* type for integer functions */ +typedef LUA_INTEGER lua_Integer; + +/* unsigned integer type */ +typedef LUA_UNSIGNED lua_Unsigned; + +/* type for continuation-function contexts */ +typedef LUA_KCONTEXT lua_KContext; + + +/* +** Type for C functions registered with Lua +*/ +typedef int (*lua_CFunction) (lua_State *L); + +/* +** Type for continuation functions +*/ +typedef int (*lua_KFunction) (lua_State *L, int status, lua_KContext ctx); + + +/* +** Type for functions that read/write blocks when loading/dumping Lua chunks +*/ +typedef const char * (*lua_Reader) (lua_State *L, void *ud, size_t *sz); + +typedef int (*lua_Writer) (lua_State *L, const void *p, size_t sz, void *ud); + + +/* +** Type for memory-allocation functions +*/ +typedef void * (*lua_Alloc) (void *ud, void *ptr, size_t osize, size_t nsize); + + + +/* +** generic extra include file +*/ +#if defined(LUA_USER_H) +#include LUA_USER_H +#endif + + +/* +** RCS ident string +*/ +extern const char lua_ident[]; + + +/* +** state manipulation +*/ +LUA_API lua_State *(lua_newstate) (lua_Alloc f, void *ud); +LUA_API void (lua_close) (lua_State *L); +LUA_API lua_State *(lua_newthread) (lua_State *L); + +LUA_API lua_CFunction (lua_atpanic) (lua_State *L, lua_CFunction panicf); + + +LUA_API const lua_Number *(lua_version) (lua_State *L); + + +/* +** basic stack manipulation +*/ +LUA_API int (lua_absindex) (lua_State *L, int idx); +LUA_API int (lua_gettop) (lua_State *L); +LUA_API void (lua_settop) (lua_State *L, int idx); +LUA_API void (lua_pushvalue) (lua_State *L, int idx); +LUA_API void (lua_rotate) (lua_State *L, int idx, int n); +LUA_API void (lua_copy) (lua_State *L, int fromidx, int toidx); +LUA_API int (lua_checkstack) (lua_State *L, int n); + +LUA_API void (lua_xmove) (lua_State *from, lua_State *to, int n); + + +/* +** access functions (stack -> C) +*/ + +LUA_API int (lua_isnumber) (lua_State *L, int idx); +LUA_API int (lua_isstring) (lua_State *L, int idx); +LUA_API int (lua_iscfunction) (lua_State *L, int idx); +LUA_API int (lua_isinteger) (lua_State *L, int idx); +LUA_API int (lua_isuserdata) (lua_State *L, int idx); +LUA_API int (lua_type) (lua_State *L, int idx); +LUA_API const char *(lua_typename) (lua_State *L, int tp); + +LUA_API lua_Number (lua_tonumberx) (lua_State *L, int idx, int *isnum); +LUA_API lua_Integer (lua_tointegerx) (lua_State *L, int idx, int *isnum); +LUA_API int (lua_toboolean) (lua_State *L, int idx); +LUA_API const char *(lua_tolstring) (lua_State *L, int idx, size_t *len); +LUA_API size_t (lua_rawlen) (lua_State *L, int idx); +LUA_API lua_CFunction (lua_tocfunction) (lua_State *L, int idx); +LUA_API void *(lua_touserdata) (lua_State *L, int idx); +LUA_API lua_State *(lua_tothread) (lua_State *L, int idx); +LUA_API const void *(lua_topointer) (lua_State *L, int idx); + + +/* +** Comparison and arithmetic functions +*/ + +#define LUA_OPADD 0 /* ORDER TM, ORDER OP */ +#define LUA_OPSUB 1 +#define LUA_OPMUL 2 +#define LUA_OPMOD 3 +#define LUA_OPPOW 4 +#define LUA_OPDIV 5 +#define LUA_OPIDIV 6 +#define LUA_OPBAND 7 +#define LUA_OPBOR 8 +#define LUA_OPBXOR 9 +#define LUA_OPSHL 10 +#define LUA_OPSHR 11 +#define LUA_OPUNM 12 +#define LUA_OPBNOT 13 + +LUA_API void (lua_arith) (lua_State *L, int op); + +#define LUA_OPEQ 0 +#define LUA_OPLT 1 +#define LUA_OPLE 2 + +LUA_API int (lua_rawequal) (lua_State *L, int idx1, int idx2); +LUA_API int (lua_compare) (lua_State *L, int idx1, int idx2, int op); + + +/* +** push functions (C -> stack) +*/ +LUA_API void (lua_pushnil) (lua_State *L); +LUA_API void (lua_pushnumber) (lua_State *L, lua_Number n); +LUA_API void (lua_pushinteger) (lua_State *L, lua_Integer n); +LUA_API const char *(lua_pushlstring) (lua_State *L, const char *s, size_t len); +LUA_API const char *(lua_pushstring) (lua_State *L, const char *s); +LUA_API const char *(lua_pushvfstring) (lua_State *L, const char *fmt, + va_list argp); +LUA_API const char *(lua_pushfstring) (lua_State *L, const char *fmt, ...); +LUA_API void (lua_pushcclosure) (lua_State *L, lua_CFunction fn, int n); +LUA_API void (lua_pushboolean) (lua_State *L, int b); +LUA_API void (lua_pushlightuserdata) (lua_State *L, void *p); +LUA_API int (lua_pushthread) (lua_State *L); + + +/* +** get functions (Lua -> stack) +*/ +LUA_API int (lua_getglobal) (lua_State *L, const char *name); +LUA_API int (lua_gettable) (lua_State *L, int idx); +LUA_API int (lua_getfield) (lua_State *L, int idx, const char *k); +LUA_API int (lua_geti) (lua_State *L, int idx, lua_Integer n); +LUA_API int (lua_rawget) (lua_State *L, int idx); +LUA_API int (lua_rawgeti) (lua_State *L, int idx, lua_Integer n); +LUA_API int (lua_rawgetp) (lua_State *L, int idx, const void *p); + +LUA_API void (lua_createtable) (lua_State *L, int narr, int nrec); +LUA_API void *(lua_newuserdata) (lua_State *L, size_t sz); +LUA_API int (lua_getmetatable) (lua_State *L, int objindex); +LUA_API int (lua_getuservalue) (lua_State *L, int idx); + + +/* +** set functions (stack -> Lua) +*/ +LUA_API void (lua_setglobal) (lua_State *L, const char *name); +LUA_API void (lua_settable) (lua_State *L, int idx); +LUA_API void (lua_setfield) (lua_State *L, int idx, const char *k); +LUA_API void (lua_seti) (lua_State *L, int idx, lua_Integer n); +LUA_API void (lua_rawset) (lua_State *L, int idx); +LUA_API void (lua_rawseti) (lua_State *L, int idx, lua_Integer n); +LUA_API void (lua_rawsetp) (lua_State *L, int idx, const void *p); +LUA_API int (lua_setmetatable) (lua_State *L, int objindex); +LUA_API void (lua_setuservalue) (lua_State *L, int idx); + + +/* +** 'load' and 'call' functions (load and run Lua code) +*/ +LUA_API void (lua_callk) (lua_State *L, int nargs, int nresults, + lua_KContext ctx, lua_KFunction k); +#define lua_call(L,n,r) lua_callk(L, (n), (r), 0, NULL) + +LUA_API int (lua_pcallk) (lua_State *L, int nargs, int nresults, int errfunc, + lua_KContext ctx, lua_KFunction k); +#define lua_pcall(L,n,r,f) lua_pcallk(L, (n), (r), (f), 0, NULL) + +LUA_API int (lua_load) (lua_State *L, lua_Reader reader, void *dt, + const char *chunkname, const char *mode); + +LUA_API int (lua_dump) (lua_State *L, lua_Writer writer, void *data, int strip); + + +/* +** coroutine functions +*/ +LUA_API int (lua_yieldk) (lua_State *L, int nresults, lua_KContext ctx, + lua_KFunction k); +LUA_API int (lua_resume) (lua_State *L, lua_State *from, int narg); +LUA_API int (lua_status) (lua_State *L); +LUA_API int (lua_isyieldable) (lua_State *L); + +#define lua_yield(L,n) lua_yieldk(L, (n), 0, NULL) + + +/* +** garbage-collection function and options +*/ + +#define LUA_GCSTOP 0 +#define LUA_GCRESTART 1 +#define LUA_GCCOLLECT 2 +#define LUA_GCCOUNT 3 +#define LUA_GCCOUNTB 4 +#define LUA_GCSTEP 5 +#define LUA_GCSETPAUSE 6 +#define LUA_GCSETSTEPMUL 7 +#define LUA_GCISRUNNING 9 + +LUA_API int (lua_gc) (lua_State *L, int what, int data); + + +/* +** miscellaneous functions +*/ + +LUA_API int (lua_error) (lua_State *L); + +LUA_API int (lua_next) (lua_State *L, int idx); + +LUA_API void (lua_concat) (lua_State *L, int n); +LUA_API void (lua_len) (lua_State *L, int idx); + +LUA_API size_t (lua_stringtonumber) (lua_State *L, const char *s); + +LUA_API lua_Alloc (lua_getallocf) (lua_State *L, void **ud); +LUA_API void (lua_setallocf) (lua_State *L, lua_Alloc f, void *ud); + + + +/* +** {============================================================== +** some useful macros +** =============================================================== +*/ + +#define lua_getextraspace(L) ((void *)((char *)(L) - LUA_EXTRASPACE)) + +#define lua_tonumber(L,i) lua_tonumberx(L,(i),NULL) +#define lua_tointeger(L,i) lua_tointegerx(L,(i),NULL) + +#define lua_pop(L,n) lua_settop(L, -(n)-1) + +#define lua_newtable(L) lua_createtable(L, 0, 0) + +#define lua_register(L,n,f) (lua_pushcfunction(L, (f)), lua_setglobal(L, (n))) + +#define lua_pushcfunction(L,f) lua_pushcclosure(L, (f), 0) + +#define lua_isfunction(L,n) (lua_type(L, (n)) == LUA_TFUNCTION) +#define lua_istable(L,n) (lua_type(L, (n)) == LUA_TTABLE) +#define lua_islightuserdata(L,n) (lua_type(L, (n)) == LUA_TLIGHTUSERDATA) +#define lua_isnil(L,n) (lua_type(L, (n)) == LUA_TNIL) +#define lua_isboolean(L,n) (lua_type(L, (n)) == LUA_TBOOLEAN) +#define lua_isthread(L,n) (lua_type(L, (n)) == LUA_TTHREAD) +#define lua_isnone(L,n) (lua_type(L, (n)) == LUA_TNONE) +#define lua_isnoneornil(L, n) (lua_type(L, (n)) <= 0) + +#define lua_pushliteral(L, s) \ + lua_pushlstring(L, "" s, (sizeof(s)/sizeof(char))-1) + +#define lua_pushglobaltable(L) \ + lua_rawgeti(L, LUA_REGISTRYINDEX, LUA_RIDX_GLOBALS) + +#define lua_tostring(L,i) lua_tolstring(L, (i), NULL) + + +#define lua_insert(L,idx) lua_rotate(L, (idx), 1) + +#define lua_remove(L,idx) (lua_rotate(L, (idx), -1), lua_pop(L, 1)) + +#define lua_replace(L,idx) (lua_copy(L, -1, (idx)), lua_pop(L, 1)) + +/* }============================================================== */ + + +/* +** {============================================================== +** compatibility macros for unsigned conversions +** =============================================================== +*/ +#if defined(LUA_COMPAT_APIINTCASTS) + +#define lua_pushunsigned(L,n) lua_pushinteger(L, (lua_Integer)(n)) +#define lua_tounsignedx(L,i,is) ((lua_Unsigned)lua_tointegerx(L,i,is)) +#define lua_tounsigned(L,i) lua_tounsignedx(L,(i),NULL) + +#endif +/* }============================================================== */ + +/* +** {====================================================================== +** Debug API +** ======================================================================= +*/ + + +/* +** Event codes +*/ +#define LUA_HOOKCALL 0 +#define LUA_HOOKRET 1 +#define LUA_HOOKLINE 2 +#define LUA_HOOKCOUNT 3 +#define LUA_HOOKTAILCALL 4 + + +/* +** Event masks +*/ +#define LUA_MASKCALL (1 << LUA_HOOKCALL) +#define LUA_MASKRET (1 << LUA_HOOKRET) +#define LUA_MASKLINE (1 << LUA_HOOKLINE) +#define LUA_MASKCOUNT (1 << LUA_HOOKCOUNT) + +typedef struct lua_Debug lua_Debug; /* activation record */ + + +/* Functions to be called by the debugger in specific events */ +typedef void (*lua_Hook) (lua_State *L, lua_Debug *ar); + + +LUA_API int (lua_getstack) (lua_State *L, int level, lua_Debug *ar); +LUA_API int (lua_getinfo) (lua_State *L, const char *what, lua_Debug *ar); +LUA_API const char *(lua_getlocal) (lua_State *L, const lua_Debug *ar, int n); +LUA_API const char *(lua_setlocal) (lua_State *L, const lua_Debug *ar, int n); +LUA_API const char *(lua_getupvalue) (lua_State *L, int funcindex, int n); +LUA_API const char *(lua_setupvalue) (lua_State *L, int funcindex, int n); + +LUA_API void *(lua_upvalueid) (lua_State *L, int fidx, int n); +LUA_API void (lua_upvaluejoin) (lua_State *L, int fidx1, int n1, + int fidx2, int n2); + +LUA_API void (lua_sethook) (lua_State *L, lua_Hook func, int mask, int count); +LUA_API lua_Hook (lua_gethook) (lua_State *L); +LUA_API int (lua_gethookmask) (lua_State *L); +LUA_API int (lua_gethookcount) (lua_State *L); + + +struct lua_Debug { + int event; + const char *name; /* (n) */ + const char *namewhat; /* (n) 'global', 'local', 'field', 'method' */ + const char *what; /* (S) 'Lua', 'C', 'main', 'tail' */ + const char *source; /* (S) */ + int currentline; /* (l) */ + int linedefined; /* (S) */ + int lastlinedefined; /* (S) */ + unsigned char nups; /* (u) number of upvalues */ + unsigned char nparams;/* (u) number of parameters */ + char isvararg; /* (u) */ + char istailcall; /* (t) */ + char short_src[LUA_IDSIZE]; /* (S) */ + /* private part */ + struct CallInfo *i_ci; /* active function */ +}; + +/* }====================================================================== */ + + +/****************************************************************************** +* Copyright (C) 1994-2015 Lua.org, PUC-Rio. +* +* Permission is hereby granted, free of charge, to any person obtaining +* a copy of this software and associated documentation files (the +* "Software"), to deal in the Software without restriction, including +* without limitation the rights to use, copy, modify, merge, publish, +* distribute, sublicense, and/or sell copies of the Software, and to +* permit persons to whom the Software is furnished to do so, subject to +* the following conditions: +* +* The above copyright notice and this permission notice shall be +* included in all copies or substantial portions of the Software. +* +* THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, +* EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF +* MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. +* IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY +* CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF CONTRACT, +* TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION WITH THE +* SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. +******************************************************************************/ + + +#endif diff --git a/src/lua.hpp b/src/lua.hpp new file mode 100644 index 000000000000..ec417f59469c --- /dev/null +++ b/src/lua.hpp @@ -0,0 +1,9 @@ +// lua.hpp +// Lua header files for C++ +// <<extern "C">> not supplied automatically because Lua also compiles as C++ + +extern "C" { +#include "lua.h" +#include "lualib.h" +#include "lauxlib.h" +} diff --git a/src/luac.c b/src/luac.c new file mode 100644 index 000000000000..c565f46aa50a --- /dev/null +++ b/src/luac.c @@ -0,0 +1,449 @@ +/* +** $Id: luac.c,v 1.72 2015/01/06 03:09:13 lhf Exp $ +** Lua compiler (saves bytecodes to files; also lists bytecodes) +** See Copyright Notice in lua.h +*/ + +#define luac_c +#define LUA_CORE + +#include "lprefix.h" + +#include <ctype.h> +#include <errno.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" +#include "lauxlib.h" + +#include "lobject.h" +#include "lstate.h" +#include "lundump.h" + +static void PrintFunction(const Proto* f, int full); +#define luaU_print PrintFunction + +#define PROGNAME "luac" /* default program name */ +#define OUTPUT PROGNAME ".out" /* default output file */ + +static int listing=0; /* list bytecodes? */ +static int dumping=1; /* dump bytecodes? */ +static int stripping=0; /* strip debug information? */ +static char Output[]={ OUTPUT }; /* default output file name */ +static const char* output=Output; /* actual output file name */ +static const char* progname=PROGNAME; /* actual program name */ + +static void fatal(const char* message) +{ + fprintf(stderr,"%s: %s\n",progname,message); + exit(EXIT_FAILURE); +} + +static void cannot(const char* what) +{ + fprintf(stderr,"%s: cannot %s %s: %s\n",progname,what,output,strerror(errno)); + exit(EXIT_FAILURE); +} + +static void usage(const char* message) +{ + if (*message=='-') + fprintf(stderr,"%s: unrecognized option '%s'\n",progname,message); + else + fprintf(stderr,"%s: %s\n",progname,message); + fprintf(stderr, + "usage: %s [options] [filenames]\n" + "Available options are:\n" + " -l list (use -l -l for full listing)\n" + " -o name output to file 'name' (default is \"%s\")\n" + " -p parse only\n" + " -s strip debug information\n" + " -v show version information\n" + " -- stop handling options\n" + " - stop handling options and process stdin\n" + ,progname,Output); + exit(EXIT_FAILURE); +} + +#define IS(s) (strcmp(argv[i],s)==0) + +static int doargs(int argc, char* argv[]) +{ + int i; + int version=0; + if (argv[0]!=NULL && *argv[0]!=0) progname=argv[0]; + for (i=1; i<argc; i++) + { + if (*argv[i]!='-') /* end of options; keep it */ + break; + else if (IS("--")) /* end of options; skip it */ + { + ++i; + if (version) ++version; + break; + } + else if (IS("-")) /* end of options; use stdin */ + break; + else if (IS("-l")) /* list */ + ++listing; + else if (IS("-o")) /* output file */ + { + output=argv[++i]; + if (output==NULL || *output==0 || (*output=='-' && output[1]!=0)) + usage("'-o' needs argument"); + if (IS("-")) output=NULL; + } + else if (IS("-p")) /* parse only */ + dumping=0; + else if (IS("-s")) /* strip debug information */ + stripping=1; + else if (IS("-v")) /* show version */ + ++version; + else /* unknown option */ + usage(argv[i]); + } + if (i==argc && (listing || !dumping)) + { + dumping=0; + argv[--i]=Output; + } + if (version) + { + printf("%s\n",LUA_COPYRIGHT); + if (version==argc-1) exit(EXIT_SUCCESS); + } + return i; +} + +#define FUNCTION "(function()end)();" + +static const char* reader(lua_State *L, void *ud, size_t *size) +{ + UNUSED(L); + if ((*(int*)ud)--) + { + *size=sizeof(FUNCTION)-1; + return FUNCTION; + } + else + { + *size=0; + return NULL; + } +} + +#define toproto(L,i) getproto(L->top+(i)) + +static const Proto* combine(lua_State* L, int n) +{ + if (n==1) + return toproto(L,-1); + else + { + Proto* f; + int i=n; + if (lua_load(L,reader,&i,"=(" PROGNAME ")",NULL)!=LUA_OK) fatal(lua_tostring(L,-1)); + f=toproto(L,-1); + for (i=0; i<n; i++) + { + f->p[i]=toproto(L,i-n-1); + if (f->p[i]->sizeupvalues>0) f->p[i]->upvalues[0].instack=0; + } + f->sizelineinfo=0; + return f; + } +} + +static int writer(lua_State* L, const void* p, size_t size, void* u) +{ + UNUSED(L); + return (fwrite(p,size,1,(FILE*)u)!=1) && (size!=0); +} + +static int pmain(lua_State* L) +{ + int argc=(int)lua_tointeger(L,1); + char** argv=(char**)lua_touserdata(L,2); + const Proto* f; + int i; + if (!lua_checkstack(L,argc)) fatal("too many input files"); + for (i=0; i<argc; i++) + { + const char* filename=IS("-") ? NULL : argv[i]; + if (luaL_loadfile(L,filename)!=LUA_OK) fatal(lua_tostring(L,-1)); + } + f=combine(L,argc); + if (listing) luaU_print(f,listing>1); + if (dumping) + { + FILE* D= (output==NULL) ? stdout : fopen(output,"wb"); + if (D==NULL) cannot("open"); + lua_lock(L); + luaU_dump(L,f,writer,D,stripping); + lua_unlock(L); + if (ferror(D)) cannot("write"); + if (fclose(D)) cannot("close"); + } + return 0; +} + +int main(int argc, char* argv[]) +{ + lua_State* L; + int i=doargs(argc,argv); + argc-=i; argv+=i; + if (argc<=0) usage("no input files given"); + L=luaL_newstate(); + if (L==NULL) fatal("cannot create state: not enough memory"); + lua_pushcfunction(L,&pmain); + lua_pushinteger(L,argc); + lua_pushlightuserdata(L,argv); + if (lua_pcall(L,2,0,0)!=LUA_OK) fatal(lua_tostring(L,-1)); + lua_close(L); + return EXIT_SUCCESS; +} + +/* +** $Id: print.c,v 1.76 2015/01/05 16:12:50 lhf Exp $ +** print bytecodes +** See Copyright Notice in lua.h +*/ + +#include <ctype.h> +#include <stdio.h> + +#define luac_c +#define LUA_CORE + +#include "ldebug.h" +#include "lobject.h" +#include "lopcodes.h" + +#define VOID(p) ((const void*)(p)) + +static void PrintString(const TString* ts) +{ + const char* s=getstr(ts); + size_t i,n=ts->len; + printf("%c",'"'); + for (i=0; i<n; i++) + { + int c=(int)(unsigned char)s[i]; + switch (c) + { + case '"': printf("\\\""); break; + case '\\': printf("\\\\"); break; + case '\a': printf("\\a"); break; + case '\b': printf("\\b"); break; + case '\f': printf("\\f"); break; + case '\n': printf("\\n"); break; + case '\r': printf("\\r"); break; + case '\t': printf("\\t"); break; + case '\v': printf("\\v"); break; + default: if (isprint(c)) + printf("%c",c); + else + printf("\\%03d",c); + } + } + printf("%c",'"'); +} + +static void PrintConstant(const Proto* f, int i) +{ + const TValue* o=&f->k[i]; + switch (ttype(o)) + { + case LUA_TNIL: + printf("nil"); + break; + case LUA_TBOOLEAN: + printf(bvalue(o) ? "true" : "false"); + break; + case LUA_TNUMFLT: + { + char buff[100]; + sprintf(buff,LUA_NUMBER_FMT,fltvalue(o)); + printf("%s",buff); + if (buff[strspn(buff,"-0123456789")]=='\0') printf(".0"); + break; + } + case LUA_TNUMINT: + printf(LUA_INTEGER_FMT,ivalue(o)); + break; + case LUA_TSHRSTR: case LUA_TLNGSTR: + PrintString(tsvalue(o)); + break; + default: /* cannot happen */ + printf("? type=%d",ttype(o)); + break; + } +} + +#define UPVALNAME(x) ((f->upvalues[x].name) ? getstr(f->upvalues[x].name) : "-") +#define MYK(x) (-1-(x)) + +static void PrintCode(const Proto* f) +{ + const Instruction* code=f->code; + int pc,n=f->sizecode; + for (pc=0; pc<n; pc++) + { + Instruction i=code[pc]; + OpCode o=GET_OPCODE(i); + int a=GETARG_A(i); + int b=GETARG_B(i); + int c=GETARG_C(i); + int ax=GETARG_Ax(i); + int bx=GETARG_Bx(i); + int sbx=GETARG_sBx(i); + int line=getfuncline(f,pc); + printf("\t%d\t",pc+1); + if (line>0) printf("[%d]\t",line); else printf("[-]\t"); + printf("%-9s\t",luaP_opnames[o]); + switch (getOpMode(o)) + { + case iABC: + printf("%d",a); + if (getBMode(o)!=OpArgN) printf(" %d",ISK(b) ? (MYK(INDEXK(b))) : b); + if (getCMode(o)!=OpArgN) printf(" %d",ISK(c) ? (MYK(INDEXK(c))) : c); + break; + case iABx: + printf("%d",a); + if (getBMode(o)==OpArgK) printf(" %d",MYK(bx)); + if (getBMode(o)==OpArgU) printf(" %d",bx); + break; + case iAsBx: + printf("%d %d",a,sbx); + break; + case iAx: + printf("%d",MYK(ax)); + break; + } + switch (o) + { + case OP_LOADK: + printf("\t; "); PrintConstant(f,bx); + break; + case OP_GETUPVAL: + case OP_SETUPVAL: + printf("\t; %s",UPVALNAME(b)); + break; + case OP_GETTABUP: + printf("\t; %s",UPVALNAME(b)); + if (ISK(c)) { printf(" "); PrintConstant(f,INDEXK(c)); } + break; + case OP_SETTABUP: + printf("\t; %s",UPVALNAME(a)); + if (ISK(b)) { printf(" "); PrintConstant(f,INDEXK(b)); } + if (ISK(c)) { printf(" "); PrintConstant(f,INDEXK(c)); } + break; + case OP_GETTABLE: + case OP_SELF: + if (ISK(c)) { printf("\t; "); PrintConstant(f,INDEXK(c)); } + break; + case OP_SETTABLE: + case OP_ADD: + case OP_SUB: + case OP_MUL: + case OP_POW: + case OP_DIV: + case OP_IDIV: + case OP_BAND: + case OP_BOR: + case OP_BXOR: + case OP_SHL: + case OP_SHR: + case OP_EQ: + case OP_LT: + case OP_LE: + if (ISK(b) || ISK(c)) + { + printf("\t; "); + if (ISK(b)) PrintConstant(f,INDEXK(b)); else printf("-"); + printf(" "); + if (ISK(c)) PrintConstant(f,INDEXK(c)); else printf("-"); + } + break; + case OP_JMP: + case OP_FORLOOP: + case OP_FORPREP: + case OP_TFORLOOP: + printf("\t; to %d",sbx+pc+2); + break; + case OP_CLOSURE: + printf("\t; %p",VOID(f->p[bx])); + break; + case OP_SETLIST: + if (c==0) printf("\t; %d",(int)code[++pc]); else printf("\t; %d",c); + break; + case OP_EXTRAARG: + printf("\t; "); PrintConstant(f,ax); + break; + default: + break; + } + printf("\n"); + } +} + +#define SS(x) ((x==1)?"":"s") +#define S(x) (int)(x),SS(x) + +static void PrintHeader(const Proto* f) +{ + const char* s=f->source ? getstr(f->source) : "=?"; + if (*s=='@' || *s=='=') + s++; + else if (*s==LUA_SIGNATURE[0]) + s="(bstring)"; + else + s="(string)"; + printf("\n%s <%s:%d,%d> (%d instruction%s at %p)\n", + (f->linedefined==0)?"main":"function",s, + f->linedefined,f->lastlinedefined, + S(f->sizecode),VOID(f)); + printf("%d%s param%s, %d slot%s, %d upvalue%s, ", + (int)(f->numparams),f->is_vararg?"+":"",SS(f->numparams), + S(f->maxstacksize),S(f->sizeupvalues)); + printf("%d local%s, %d constant%s, %d function%s\n", + S(f->sizelocvars),S(f->sizek),S(f->sizep)); +} + +static void PrintDebug(const Proto* f) +{ + int i,n; + n=f->sizek; + printf("constants (%d) for %p:\n",n,VOID(f)); + for (i=0; i<n; i++) + { + printf("\t%d\t",i+1); + PrintConstant(f,i); + printf("\n"); + } + n=f->sizelocvars; + printf("locals (%d) for %p:\n",n,VOID(f)); + for (i=0; i<n; i++) + { + printf("\t%d\t%s\t%d\t%d\n", + i,getstr(f->locvars[i].varname),f->locvars[i].startpc+1,f->locvars[i].endpc+1); + } + n=f->sizeupvalues; + printf("upvalues (%d) for %p:\n",n,VOID(f)); + for (i=0; i<n; i++) + { + printf("\t%d\t%s\t%d\t%d\n", + i,UPVALNAME(i),f->upvalues[i].instack,f->upvalues[i].idx); + } +} + +static void PrintFunction(const Proto* f, int full) +{ + int i,n=f->sizep; + PrintHeader(f); + PrintCode(f); + if (full) PrintDebug(f); + for (i=0; i<n; i++) PrintFunction(f->p[i],full); +} diff --git a/src/luaconf.h b/src/luaconf.h new file mode 100644 index 000000000000..fd28d21aec96 --- /dev/null +++ b/src/luaconf.h @@ -0,0 +1,735 @@ +/* +** $Id: luaconf.h,v 1.238 2014/12/29 13:27:55 roberto Exp $ +** Configuration file for Lua +** See Copyright Notice in lua.h +*/ + + +#ifndef luaconf_h +#define luaconf_h + +#include <limits.h> +#include <stddef.h> + + +/* +** =================================================================== +** Search for "@@" to find all configurable definitions. +** =================================================================== +*/ + + +/* +** {==================================================================== +** System Configuration: macros to adapt (if needed) Lua to some +** particular platform, for instance compiling it with 32-bit numbers or +** restricting it to C89. +** ===================================================================== +*/ + +/* +@@ LUA_32BITS enables Lua with 32-bit integers and 32-bit floats. You +** can also define LUA_32BITS in the make file, but changing here you +** ensure that all software connected to Lua will be compiled with the +** same configuration. +*/ +/* #define LUA_32BITS */ + + +/* +@@ LUA_USE_C89 controls the use of non-ISO-C89 features. +** Define it if you want Lua to avoid the use of a few C99 features +** or Windows-specific features on Windows. +*/ +/* #define LUA_USE_C89 */ + + +/* +** By default, Lua on Windows use (some) specific Windows features +*/ +#if !defined(LUA_USE_C89) && defined(_WIN32) && !defined(_WIN32_WCE) +#define LUA_USE_WINDOWS /* enable goodies for regular Windows */ +#endif + + +#if defined(LUA_USE_WINDOWS) +#define LUA_DL_DLL /* enable support for DLL */ +#define LUA_USE_C89 /* broadly, Windows is C89 */ +#endif + + +#if defined(LUA_USE_LINUX) +#define LUA_USE_POSIX +#define LUA_USE_DLOPEN /* needs an extra library: -ldl */ +#define LUA_USE_READLINE /* needs some extra libraries */ +#endif + + +#if defined(LUA_USE_MACOSX) +#define LUA_USE_POSIX +#define LUA_USE_DLOPEN /* MacOS does not need -ldl */ +#define LUA_USE_READLINE /* needs an extra library: -lreadline */ +#endif + + +/* +@@ LUA_C89_NUMBERS ensures that Lua uses the largest types available for +** C89 ('long' and 'double'); Windows always has '__int64', so it does +** not need to use this case. +*/ +#if defined(LUA_USE_C89) && !defined(LUA_USE_WINDOWS) +#define LUA_C89_NUMBERS +#endif + + + +/* +@@ LUAI_BITSINT defines the (minimum) number of bits in an 'int'. +*/ +/* avoid undefined shifts */ +#if ((INT_MAX >> 15) >> 15) >= 1 +#define LUAI_BITSINT 32 +#else +/* 'int' always must have at least 16 bits */ +#define LUAI_BITSINT 16 +#endif + + +/* +@@ LUA_INT_INT / LUA_INT_LONG / LUA_INT_LONGLONG defines the type for +** Lua integers. +@@ LUA_REAL_FLOAT / LUA_REAL_DOUBLE / LUA_REAL_LONGDOUBLE defines +** the type for Lua floats. +** Lua should work fine with any mix of these options (if supported +** by your C compiler). The usual configurations are 64-bit integers +** and 'double' (the default), 32-bit integers and 'float' (for +** restricted platforms), and 'long'/'double' (for C compilers not +** compliant with C99, which may not have support for 'long long'). +*/ + +#if defined(LUA_32BITS) /* { */ +/* +** 32-bit integers and 'float' +*/ +#if LUAI_BITSINT >= 32 /* use 'int' if big enough */ +#define LUA_INT_INT +#else /* otherwise use 'long' */ +#define LUA_INT_LONG +#endif +#define LUA_REAL_FLOAT + +#elif defined(LUA_C89_NUMBERS) /* }{ */ +/* +** largest types available for C89 ('long' and 'double') +*/ +#define LUA_INT_LONG +#define LUA_REAL_DOUBLE + +#else /* }{ */ +/* +** default configuration for 64-bit Lua ('long long' and 'double') +*/ +#define LUA_INT_LONGLONG +#define LUA_REAL_DOUBLE + +#endif /* } */ + +/* }================================================================== */ + + + + +/* +** {================================================================== +** Configuration for Paths. +** =================================================================== +*/ + +/* +@@ LUA_PATH_DEFAULT is the default path that Lua uses to look for +** Lua libraries. +@@ LUA_CPATH_DEFAULT is the default path that Lua uses to look for +** C libraries. +** CHANGE them if your machine has a non-conventional directory +** hierarchy or if you want to install your libraries in +** non-conventional directories. +*/ +#define LUA_VDIR LUA_VERSION_MAJOR "." LUA_VERSION_MINOR +#if defined(_WIN32) /* { */ +/* +** In Windows, any exclamation mark ('!') in the path is replaced by the +** path of the directory of the executable file of the current process. +*/ +#define LUA_LDIR "!\\lua\\" +#define LUA_CDIR "!\\" +#define LUA_SHRDIR "!\\..\\share\\lua\\" LUA_VDIR "\\" +#define LUA_PATH_DEFAULT \ + LUA_LDIR"?.lua;" LUA_LDIR"?\\init.lua;" \ + LUA_CDIR"?.lua;" LUA_CDIR"?\\init.lua;" \ + LUA_SHRDIR"?.lua;" LUA_SHRDIR"?\\init.lua;" \ + ".\\?.lua;" ".\\?\\init.lua" +#define LUA_CPATH_DEFAULT \ + LUA_CDIR"?.dll;" \ + LUA_CDIR"..\\lib\\lua\\" LUA_VDIR "\\?.dll;" \ + LUA_CDIR"loadall.dll;" ".\\?.dll" + +#else /* }{ */ + +#define LUA_ROOT "/usr/local/" +#define LUA_LDIR LUA_ROOT "share/lua/" LUA_VDIR "/" +#define LUA_CDIR LUA_ROOT "lib/lua/" LUA_VDIR "/" +#define LUA_PATH_DEFAULT \ + LUA_LDIR"?.lua;" LUA_LDIR"?/init.lua;" \ + LUA_CDIR"?.lua;" LUA_CDIR"?/init.lua;" \ + "./?.lua;" "./?/init.lua" +#define LUA_CPATH_DEFAULT \ + LUA_CDIR"?.so;" LUA_CDIR"loadall.so;" "./?.so" +#endif /* } */ + + +/* +@@ LUA_DIRSEP is the directory separator (for submodules). +** CHANGE it if your machine does not use "/" as the directory separator +** and is not Windows. (On Windows Lua automatically uses "\".) +*/ +#if defined(_WIN32) +#define LUA_DIRSEP "\\" +#else +#define LUA_DIRSEP "/" +#endif + +/* }================================================================== */ + + +/* +** {================================================================== +** Marks for exported symbols in the C code +** =================================================================== +*/ + +/* +@@ LUA_API is a mark for all core API functions. +@@ LUALIB_API is a mark for all auxiliary library functions. +@@ LUAMOD_API is a mark for all standard library opening functions. +** CHANGE them if you need to define those functions in some special way. +** For instance, if you want to create one Windows DLL with the core and +** the libraries, you may want to use the following definition (define +** LUA_BUILD_AS_DLL to get it). +*/ +#if defined(LUA_BUILD_AS_DLL) /* { */ + +#if defined(LUA_CORE) || defined(LUA_LIB) /* { */ +#define LUA_API __declspec(dllexport) +#else /* }{ */ +#define LUA_API __declspec(dllimport) +#endif /* } */ + +#else /* }{ */ + +#define LUA_API extern + +#endif /* } */ + + +/* more often than not the libs go together with the core */ +#define LUALIB_API LUA_API +#define LUAMOD_API LUALIB_API + + +/* +@@ LUAI_FUNC is a mark for all extern functions that are not to be +** exported to outside modules. +@@ LUAI_DDEF and LUAI_DDEC are marks for all extern (const) variables +** that are not to be exported to outside modules (LUAI_DDEF for +** definitions and LUAI_DDEC for declarations). +** CHANGE them if you need to mark them in some special way. Elf/gcc +** (versions 3.2 and later) mark them as "hidden" to optimize access +** when Lua is compiled as a shared library. Not all elf targets support +** this attribute. Unfortunately, gcc does not offer a way to check +** whether the target offers that support, and those without support +** give a warning about it. To avoid these warnings, change to the +** default definition. +*/ +#if defined(__GNUC__) && ((__GNUC__*100 + __GNUC_MINOR__) >= 302) && \ + defined(__ELF__) /* { */ +#define LUAI_FUNC __attribute__((visibility("hidden"))) extern +#else /* }{ */ +#define LUAI_FUNC extern +#endif /* } */ + +#define LUAI_DDEC LUAI_FUNC +#define LUAI_DDEF /* empty */ + +/* }================================================================== */ + + +/* +** {================================================================== +** Compatibility with previous versions +** =================================================================== +*/ + +/* +@@ LUA_COMPAT_5_2 controls other macros for compatibility with Lua 5.2. +@@ LUA_COMPAT_5_1 controls other macros for compatibility with Lua 5.1. +** You can define it to get all options, or change specific options +** to fit your specific needs. +*/ +#if defined(LUA_COMPAT_5_2) /* { */ + +/* +@@ LUA_COMPAT_MATHLIB controls the presence of several deprecated +** functions in the mathematical library. +*/ +#define LUA_COMPAT_MATHLIB + +/* +@@ LUA_COMPAT_BITLIB controls the presence of library 'bit32'. +*/ +#define LUA_COMPAT_BITLIB + +/* +@@ LUA_COMPAT_IPAIRS controls the effectiveness of the __ipairs metamethod. +*/ +#define LUA_COMPAT_IPAIRS + +/* +@@ LUA_COMPAT_APIINTCASTS controls the presence of macros for +** manipulating other integer types (lua_pushunsigned, lua_tounsigned, +** luaL_checkint, luaL_checklong, etc.) +*/ +#define LUA_COMPAT_APIINTCASTS + + +/* +@@ LUA_COMPAT_FLOATSTRING makes Lua format integral floats without a +@@ a float mark ('.0'). +** This macro is not on by default even in compatibility mode, +** because this is not really an incompatibility. +*/ +/* #define LUA_COMPAT_FLOATSTRING */ + +#endif /* } */ + + +#if defined(LUA_COMPAT_5_1) /* { */ + +/* +@@ LUA_COMPAT_UNPACK controls the presence of global 'unpack'. +** You can replace it with 'table.unpack'. +*/ +#define LUA_COMPAT_UNPACK + +/* +@@ LUA_COMPAT_LOADERS controls the presence of table 'package.loaders'. +** You can replace it with 'package.searchers'. +*/ +#define LUA_COMPAT_LOADERS + +/* +@@ macro 'lua_cpcall' emulates deprecated function lua_cpcall. +** You can call your C function directly (with light C functions). +*/ +#define lua_cpcall(L,f,u) \ + (lua_pushcfunction(L, (f)), \ + lua_pushlightuserdata(L,(u)), \ + lua_pcall(L,1,0,0)) + + +/* +@@ LUA_COMPAT_LOG10 defines the function 'log10' in the math library. +** You can rewrite 'log10(x)' as 'log(x, 10)'. +*/ +#define LUA_COMPAT_LOG10 + +/* +@@ LUA_COMPAT_LOADSTRING defines the function 'loadstring' in the base +** library. You can rewrite 'loadstring(s)' as 'load(s)'. +*/ +#define LUA_COMPAT_LOADSTRING + +/* +@@ LUA_COMPAT_MAXN defines the function 'maxn' in the table library. +*/ +#define LUA_COMPAT_MAXN + +/* +@@ The following macros supply trivial compatibility for some +** changes in the API. The macros themselves document how to +** change your code to avoid using them. +*/ +#define lua_strlen(L,i) lua_rawlen(L, (i)) + +#define lua_objlen(L,i) lua_rawlen(L, (i)) + +#define lua_equal(L,idx1,idx2) lua_compare(L,(idx1),(idx2),LUA_OPEQ) +#define lua_lessthan(L,idx1,idx2) lua_compare(L,(idx1),(idx2),LUA_OPLT) + +/* +@@ LUA_COMPAT_MODULE controls compatibility with previous +** module functions 'module' (Lua) and 'luaL_register' (C). +*/ +#define LUA_COMPAT_MODULE + +#endif /* } */ + +/* }================================================================== */ + + + +/* +** {================================================================== +** Configuration for Numbers. +** Change these definitions if no predefined LUA_REAL_* / LUA_INT_* +** satisfy your needs. +** =================================================================== +*/ + +/* +@@ LUA_NUMBER is the floating-point type used by Lua. +** +@@ LUAI_UACNUMBER is the result of an 'usual argument conversion' +@@ over a floating number. +** +@@ LUA_NUMBER_FRMLEN is the length modifier for writing floats. +@@ LUA_NUMBER_FMT is the format for writing floats. +@@ lua_number2str converts a float to a string. +** +@@ l_mathop allows the addition of an 'l' or 'f' to all math operations. +** +@@ lua_str2number converts a decimal numeric string to a number. +*/ + +#if defined(LUA_REAL_FLOAT) /* { single float */ + +#define LUA_NUMBER float + +#define LUAI_UACNUMBER double + +#define LUA_NUMBER_FRMLEN "" +#define LUA_NUMBER_FMT "%.7g" + +#define l_mathop(op) op##f + +#define lua_str2number(s,p) strtof((s), (p)) + + +#elif defined(LUA_REAL_LONGDOUBLE) /* }{ long double */ + +#define LUA_NUMBER long double + +#define LUAI_UACNUMBER long double + +#define LUA_NUMBER_FRMLEN "L" +#define LUA_NUMBER_FMT "%.19Lg" + +#define l_mathop(op) op##l + +#define lua_str2number(s,p) strtold((s), (p)) + +#elif defined(LUA_REAL_DOUBLE) /* }{ double */ + +#define LUA_NUMBER double + +#define LUAI_UACNUMBER double + +#define LUA_NUMBER_FRMLEN "" +#define LUA_NUMBER_FMT "%.14g" + +#define l_mathop(op) op + +#define lua_str2number(s,p) strtod((s), (p)) + +#else /* }{ */ + +#error "numeric real type not defined" + +#endif /* } */ + + +#define l_floor(x) (l_mathop(floor)(x)) + +#define lua_number2str(s,n) sprintf((s), LUA_NUMBER_FMT, (n)) + + +/* +@@ lua_numbertointeger converts a float number to an integer, or +** returns 0 if float is not within the range of a lua_Integer. +** (The range comparisons are tricky because of rounding. The tests +** here assume a two-complement representation, where MININTEGER always +** has an exact representation as a float; MAXINTEGER may not have one, +** and therefore its conversion to float may have an ill-defined value.) +*/ +#define lua_numbertointeger(n,p) \ + ((n) >= (LUA_NUMBER)(LUA_MININTEGER) && \ + (n) < -(LUA_NUMBER)(LUA_MININTEGER) && \ + (*(p) = (LUA_INTEGER)(n), 1)) + + +/* +@@ The luai_num* macros define the primitive operations over numbers. +** They should work for any size of floating numbers. +*/ + +/* the following operations need the math library */ +#if defined(lobject_c) || defined(lvm_c) +#include <math.h> + +/* floor division (defined as 'floor(a/b)') */ +#define luai_numidiv(L,a,b) ((void)L, l_mathop(floor)(luai_numdiv(L,a,b))) + +/* +** module: defined as 'a - floor(a/b)*b'; the previous definition gives +** NaN when 'b' is huge, but the result should be 'a'. 'fmod' gives the +** result of 'a - trunc(a/b)*b', and therefore must be corrected when +** 'trunc(a/b) ~= floor(a/b)'. That happens when the division has a +** non-integer negative result, which is equivalent to the test below +*/ +#define luai_nummod(L,a,b,m) \ + { (m) = l_mathop(fmod)(a,b); if ((m)*(b) < 0) (m) += (b); } + +/* exponentiation */ +#define luai_numpow(L,a,b) ((void)L, l_mathop(pow)(a,b)) + +#endif + +/* these are quite standard operations */ +#if defined(LUA_CORE) +#define luai_numadd(L,a,b) ((a)+(b)) +#define luai_numsub(L,a,b) ((a)-(b)) +#define luai_nummul(L,a,b) ((a)*(b)) +#define luai_numdiv(L,a,b) ((a)/(b)) +#define luai_numunm(L,a) (-(a)) +#define luai_numeq(a,b) ((a)==(b)) +#define luai_numlt(a,b) ((a)<(b)) +#define luai_numle(a,b) ((a)<=(b)) +#define luai_numisnan(a) (!luai_numeq((a), (a))) +#endif + + +/* +@@ LUA_INTEGER is the integer type used by Lua. +** +@@ LUA_UNSIGNED is the unsigned version of LUA_INTEGER. +** +@@ LUAI_UACINT is the result of an 'usual argument conversion' +@@ over a lUA_INTEGER. +@@ LUA_INTEGER_FRMLEN is the length modifier for reading/writing integers. +@@ LUA_INTEGER_FMT is the format for writing integers. +@@ LUA_MAXINTEGER is the maximum value for a LUA_INTEGER. +@@ LUA_MININTEGER is the minimum value for a LUA_INTEGER. +@@ lua_integer2str converts an integer to a string. +*/ + + +/* The following definitions are good for most cases here */ + +#define LUA_INTEGER_FMT "%" LUA_INTEGER_FRMLEN "d" +#define lua_integer2str(s,n) sprintf((s), LUA_INTEGER_FMT, (n)) + +#define LUAI_UACINT LUA_INTEGER + +/* +** use LUAI_UACINT here to avoid problems with promotions (which +** can turn a comparison between unsigneds into a signed comparison) +*/ +#define LUA_UNSIGNED unsigned LUAI_UACINT + + +/* now the variable definitions */ + +#if defined(LUA_INT_INT) /* { int */ + +#define LUA_INTEGER int +#define LUA_INTEGER_FRMLEN "" + +#define LUA_MAXINTEGER INT_MAX +#define LUA_MININTEGER INT_MIN + +#elif defined(LUA_INT_LONG) /* }{ long */ + +#define LUA_INTEGER long +#define LUA_INTEGER_FRMLEN "l" + +#define LUA_MAXINTEGER LONG_MAX +#define LUA_MININTEGER LONG_MIN + +#elif defined(LUA_INT_LONGLONG) /* }{ long long */ + +#if defined(LLONG_MAX) /* { */ +/* use ISO C99 stuff */ + +#define LUA_INTEGER long long +#define LUA_INTEGER_FRMLEN "ll" + +#define LUA_MAXINTEGER LLONG_MAX +#define LUA_MININTEGER LLONG_MIN + +#elif defined(LUA_USE_WINDOWS) /* }{ */ +/* in Windows, can use specific Windows types */ + +#define LUA_INTEGER __int64 +#define LUA_INTEGER_FRMLEN "I64" + +#define LUA_MAXINTEGER _I64_MAX +#define LUA_MININTEGER _I64_MIN + +#else /* }{ */ + +#error "Compiler does not support 'long long'. Use option '-DLUA_32BITS' \ + or '-DLUA_C89_NUMBERS' (see file 'luaconf.h' for details)" + +#endif /* } */ + +#else /* }{ */ + +#error "numeric integer type not defined" + +#endif /* } */ + +/* }================================================================== */ + + +/* +** {================================================================== +** Dependencies with C99 +** =================================================================== +*/ + +/* +@@ lua_strx2number converts an hexadecimal numeric string to a number. +** In C99, 'strtod' does both conversions. Otherwise, you can +** leave 'lua_strx2number' undefined and Lua will provide its own +** implementation. +*/ +#if !defined(LUA_USE_C89) +#define lua_strx2number(s,p) lua_str2number(s,p) +#endif + + +/* +@@ LUA_USE_AFORMAT allows '%a'/'%A' specifiers in 'string.format' +** Enable it if the C function 'printf' supports these specifiers. +** (C99 demands it and Windows also supports it.) +*/ +#if !defined(LUA_USE_C89) || defined(LUA_USE_WINDOWS) +#define LUA_USE_AFORMAT +#endif + + +/* +** 'strtof' and 'opf' variants for math functions are not valid in +** C89. Otherwise, the macro 'HUGE_VALF' is a good proxy for testing the +** availability of these variants. ('math.h' is already included in +** all files that use these macros.) +*/ +#if defined(LUA_USE_C89) || (defined(HUGE_VAL) && !defined(HUGE_VALF)) +#undef l_mathop /* variants not available */ +#undef lua_str2number +#define l_mathop(op) (lua_Number)op /* no variant */ +#define lua_str2number(s,p) ((lua_Number)strtod((s), (p))) +#endif + + +/* +@@ LUA_KCONTEXT is the type of the context ('ctx') for continuation +** functions. It must be a numerical type; Lua will use 'intptr_t' if +** available, otherwise it will use 'ptrdiff_t' (the nearest thing to +** 'intptr_t' in C89) +*/ +#define LUA_KCONTEXT ptrdiff_t + +#if !defined(LUA_USE_C89) && defined(__STDC_VERSION__) && \ + __STDC_VERSION__ >= 199901L +#include <stdint.h> +#if defined (INTPTR_MAX) /* even in C99 this type is optional */ +#undef LUA_KCONTEXT +#define LUA_KCONTEXT intptr_t +#endif +#endif + +/* }================================================================== */ + + +/* +** {================================================================== +** Macros that affect the API and must be stable (that is, must be the +** same when you compile Lua and when you compile code that links to +** Lua). You probably do not want/need to change them. +** ===================================================================== +*/ + +/* +@@ LUAI_MAXSTACK limits the size of the Lua stack. +** CHANGE it if you need a different limit. This limit is arbitrary; +** its only purpose is to stop Lua from consuming unlimited stack +** space (and to reserve some numbers for pseudo-indices). +*/ +#if LUAI_BITSINT >= 32 +#define LUAI_MAXSTACK 1000000 +#else +#define LUAI_MAXSTACK 15000 +#endif + +/* reserve some space for error handling */ +#define LUAI_FIRSTPSEUDOIDX (-LUAI_MAXSTACK - 1000) + + +/* +@@ LUA_EXTRASPACE defines the size of a raw memory area associated with +** a Lua state with very fast access. +** CHANGE it if you need a different size. +*/ +#define LUA_EXTRASPACE (sizeof(void *)) + + +/* +@@ LUA_IDSIZE gives the maximum size for the description of the source +@@ of a function in debug information. +** CHANGE it if you want a different size. +*/ +#define LUA_IDSIZE 60 + + +/* +@@ LUAI_MAXSHORTLEN is the maximum length for short strings, that is, +** strings that are internalized. (Cannot be smaller than reserved words +** or tags for metamethods, as these strings must be internalized; +** #("function") = 8, #("__newindex") = 10.) +*/ +#define LUAI_MAXSHORTLEN 40 + + +/* +@@ LUAL_BUFFERSIZE is the buffer size used by the lauxlib buffer system. +** CHANGE it if it uses too much C-stack space. +*/ +#define LUAL_BUFFERSIZE ((int)(0x80 * sizeof(void*) * sizeof(lua_Integer))) + +/* }================================================================== */ + + +/* +@@ LUA_QL describes how error messages quote program elements. +** Lua does not use these macros anymore; they are here for +** compatibility only. +*/ +#define LUA_QL(x) "'" x "'" +#define LUA_QS LUA_QL("%s") + + + + +/* =================================================================== */ + +/* +** Local configuration. You can use this space to add your redefinitions +** without modifying the main part of the file. +*/ + + + + + +#endif + diff --git a/src/lualib.h b/src/lualib.h new file mode 100644 index 000000000000..5165c0fb3f0f --- /dev/null +++ b/src/lualib.h @@ -0,0 +1,58 @@ +/* +** $Id: lualib.h,v 1.44 2014/02/06 17:32:33 roberto Exp $ +** Lua standard libraries +** See Copyright Notice in lua.h +*/ + + +#ifndef lualib_h +#define lualib_h + +#include "lua.h" + + + +LUAMOD_API int (luaopen_base) (lua_State *L); + +#define LUA_COLIBNAME "coroutine" +LUAMOD_API int (luaopen_coroutine) (lua_State *L); + +#define LUA_TABLIBNAME "table" +LUAMOD_API int (luaopen_table) (lua_State *L); + +#define LUA_IOLIBNAME "io" +LUAMOD_API int (luaopen_io) (lua_State *L); + +#define LUA_OSLIBNAME "os" +LUAMOD_API int (luaopen_os) (lua_State *L); + +#define LUA_STRLIBNAME "string" +LUAMOD_API int (luaopen_string) (lua_State *L); + +#define LUA_UTF8LIBNAME "utf8" +LUAMOD_API int (luaopen_utf8) (lua_State *L); + +#define LUA_BITLIBNAME "bit32" +LUAMOD_API int (luaopen_bit32) (lua_State *L); + +#define LUA_MATHLIBNAME "math" +LUAMOD_API int (luaopen_math) (lua_State *L); + +#define LUA_DBLIBNAME "debug" +LUAMOD_API int (luaopen_debug) (lua_State *L); + +#define LUA_LOADLIBNAME "package" +LUAMOD_API int (luaopen_package) (lua_State *L); + + +/* open all previous libraries */ +LUALIB_API void (luaL_openlibs) (lua_State *L); + + + +#if !defined(lua_assert) +#define lua_assert(x) ((void)0) +#endif + + +#endif diff --git a/src/lundump.c b/src/lundump.c new file mode 100644 index 000000000000..510f32582748 --- /dev/null +++ b/src/lundump.c @@ -0,0 +1,277 @@ +/* +** $Id: lundump.c,v 2.41 2014/11/02 19:19:04 roberto Exp $ +** load precompiled Lua chunks +** See Copyright Notice in lua.h +*/ + +#define lundump_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <string.h> + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lmem.h" +#include "lobject.h" +#include "lstring.h" +#include "lundump.h" +#include "lzio.h" + + +#if !defined(luai_verifycode) +#define luai_verifycode(L,b,f) /* empty */ +#endif + + +typedef struct { + lua_State *L; + ZIO *Z; + Mbuffer *b; + const char *name; +} LoadState; + + +static l_noret error(LoadState *S, const char *why) { + luaO_pushfstring(S->L, "%s: %s precompiled chunk", S->name, why); + luaD_throw(S->L, LUA_ERRSYNTAX); +} + + +/* +** All high-level loads go through LoadVector; you can change it to +** adapt to the endianness of the input +*/ +#define LoadVector(S,b,n) LoadBlock(S,b,(n)*sizeof((b)[0])) + +static void LoadBlock (LoadState *S, void *b, size_t size) { + if (luaZ_read(S->Z, b, size) != 0) + error(S, "truncated"); +} + + +#define LoadVar(S,x) LoadVector(S,&x,1) + + +static lu_byte LoadByte (LoadState *S) { + lu_byte x; + LoadVar(S, x); + return x; +} + + +static int LoadInt (LoadState *S) { + int x; + LoadVar(S, x); + return x; +} + + +static lua_Number LoadNumber (LoadState *S) { + lua_Number x; + LoadVar(S, x); + return x; +} + + +static lua_Integer LoadInteger (LoadState *S) { + lua_Integer x; + LoadVar(S, x); + return x; +} + + +static TString *LoadString (LoadState *S) { + size_t size = LoadByte(S); + if (size == 0xFF) + LoadVar(S, size); + if (size == 0) + return NULL; + else { + char *s = luaZ_openspace(S->L, S->b, --size); + LoadVector(S, s, size); + return luaS_newlstr(S->L, s, size); + } +} + + +static void LoadCode (LoadState *S, Proto *f) { + int n = LoadInt(S); + f->code = luaM_newvector(S->L, n, Instruction); + f->sizecode = n; + LoadVector(S, f->code, n); +} + + +static void LoadFunction(LoadState *S, Proto *f, TString *psource); + + +static void LoadConstants (LoadState *S, Proto *f) { + int i; + int n = LoadInt(S); + f->k = luaM_newvector(S->L, n, TValue); + f->sizek = n; + for (i = 0; i < n; i++) + setnilvalue(&f->k[i]); + for (i = 0; i < n; i++) { + TValue *o = &f->k[i]; + int t = LoadByte(S); + switch (t) { + case LUA_TNIL: + setnilvalue(o); + break; + case LUA_TBOOLEAN: + setbvalue(o, LoadByte(S)); + break; + case LUA_TNUMFLT: + setfltvalue(o, LoadNumber(S)); + break; + case LUA_TNUMINT: + setivalue(o, LoadInteger(S)); + break; + case LUA_TSHRSTR: + case LUA_TLNGSTR: + setsvalue2n(S->L, o, LoadString(S)); + break; + default: + lua_assert(0); + } + } +} + + +static void LoadProtos (LoadState *S, Proto *f) { + int i; + int n = LoadInt(S); + f->p = luaM_newvector(S->L, n, Proto *); + f->sizep = n; + for (i = 0; i < n; i++) + f->p[i] = NULL; + for (i = 0; i < n; i++) { + f->p[i] = luaF_newproto(S->L); + LoadFunction(S, f->p[i], f->source); + } +} + + +static void LoadUpvalues (LoadState *S, Proto *f) { + int i, n; + n = LoadInt(S); + f->upvalues = luaM_newvector(S->L, n, Upvaldesc); + f->sizeupvalues = n; + for (i = 0; i < n; i++) + f->upvalues[i].name = NULL; + for (i = 0; i < n; i++) { + f->upvalues[i].instack = LoadByte(S); + f->upvalues[i].idx = LoadByte(S); + } +} + + +static void LoadDebug (LoadState *S, Proto *f) { + int i, n; + n = LoadInt(S); + f->lineinfo = luaM_newvector(S->L, n, int); + f->sizelineinfo = n; + LoadVector(S, f->lineinfo, n); + n = LoadInt(S); + f->locvars = luaM_newvector(S->L, n, LocVar); + f->sizelocvars = n; + for (i = 0; i < n; i++) + f->locvars[i].varname = NULL; + for (i = 0; i < n; i++) { + f->locvars[i].varname = LoadString(S); + f->locvars[i].startpc = LoadInt(S); + f->locvars[i].endpc = LoadInt(S); + } + n = LoadInt(S); + for (i = 0; i < n; i++) + f->upvalues[i].name = LoadString(S); +} + + +static void LoadFunction (LoadState *S, Proto *f, TString *psource) { + f->source = LoadString(S); + if (f->source == NULL) /* no source in dump? */ + f->source = psource; /* reuse parent's source */ + f->linedefined = LoadInt(S); + f->lastlinedefined = LoadInt(S); + f->numparams = LoadByte(S); + f->is_vararg = LoadByte(S); + f->maxstacksize = LoadByte(S); + LoadCode(S, f); + LoadConstants(S, f); + LoadUpvalues(S, f); + LoadProtos(S, f); + LoadDebug(S, f); +} + + +static void checkliteral (LoadState *S, const char *s, const char *msg) { + char buff[sizeof(LUA_SIGNATURE) + sizeof(LUAC_DATA)]; /* larger than both */ + size_t len = strlen(s); + LoadVector(S, buff, len); + if (memcmp(s, buff, len) != 0) + error(S, msg); +} + + +static void fchecksize (LoadState *S, size_t size, const char *tname) { + if (LoadByte(S) != size) + error(S, luaO_pushfstring(S->L, "%s size mismatch in", tname)); +} + + +#define checksize(S,t) fchecksize(S,sizeof(t),#t) + +static void checkHeader (LoadState *S) { + checkliteral(S, LUA_SIGNATURE + 1, "not a"); /* 1st char already checked */ + if (LoadByte(S) != LUAC_VERSION) + error(S, "version mismatch in"); + if (LoadByte(S) != LUAC_FORMAT) + error(S, "format mismatch in"); + checkliteral(S, LUAC_DATA, "corrupted"); + checksize(S, int); + checksize(S, size_t); + checksize(S, Instruction); + checksize(S, lua_Integer); + checksize(S, lua_Number); + if (LoadInteger(S) != LUAC_INT) + error(S, "endianness mismatch in"); + if (LoadNumber(S) != LUAC_NUM) + error(S, "float format mismatch in"); +} + + +/* +** load precompiled chunk +*/ +LClosure *luaU_undump(lua_State *L, ZIO *Z, Mbuffer *buff, + const char *name) { + LoadState S; + LClosure *cl; + if (*name == '@' || *name == '=') + S.name = name + 1; + else if (*name == LUA_SIGNATURE[0]) + S.name = "binary string"; + else + S.name = name; + S.L = L; + S.Z = Z; + S.b = buff; + checkHeader(&S); + cl = luaF_newLclosure(L, LoadByte(&S)); + setclLvalue(L, L->top, cl); + incr_top(L); + cl->p = luaF_newproto(L); + LoadFunction(&S, cl->p, NULL); + lua_assert(cl->nupvalues == cl->p->sizeupvalues); + luai_verifycode(L, buff, cl->p); + return cl; +} + diff --git a/src/lundump.h b/src/lundump.h new file mode 100644 index 000000000000..ef43d5126476 --- /dev/null +++ b/src/lundump.h @@ -0,0 +1,33 @@ +/* +** $Id: lundump.h,v 1.44 2014/06/19 18:27:20 roberto Exp $ +** load precompiled Lua chunks +** See Copyright Notice in lua.h +*/ + +#ifndef lundump_h +#define lundump_h + +#include "llimits.h" +#include "lobject.h" +#include "lzio.h" + + +/* data to catch conversion errors */ +#define LUAC_DATA "\x19\x93\r\n\x1a\n" + +#define LUAC_INT 0x5678 +#define LUAC_NUM cast_num(370.5) + +#define MYINT(s) (s[0]-'0') +#define LUAC_VERSION (MYINT(LUA_VERSION_MAJOR)*16+MYINT(LUA_VERSION_MINOR)) +#define LUAC_FORMAT 0 /* this is the official format */ + +/* load one chunk; from lundump.c */ +LUAI_FUNC LClosure* luaU_undump (lua_State* L, ZIO* Z, Mbuffer* buff, + const char* name); + +/* dump one chunk; from ldump.c */ +LUAI_FUNC int luaU_dump (lua_State* L, const Proto* f, lua_Writer w, + void* data, int strip); + +#endif diff --git a/src/lutf8lib.c b/src/lutf8lib.c new file mode 100644 index 000000000000..be4f087f7606 --- /dev/null +++ b/src/lutf8lib.c @@ -0,0 +1,255 @@ +/* +** $Id: lutf8lib.c,v 1.13 2014/11/02 19:19:04 roberto Exp $ +** Standard library for UTF-8 manipulation +** See Copyright Notice in lua.h +*/ + +#define lutf8lib_c +#define LUA_LIB + +#include "lprefix.h" + + +#include <assert.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "lauxlib.h" +#include "lualib.h" + +#define MAXUNICODE 0x10FFFF + +#define iscont(p) ((*(p) & 0xC0) == 0x80) + + +/* from strlib */ +/* translate a relative string position: negative means back from end */ +static lua_Integer u_posrelat (lua_Integer pos, size_t len) { + if (pos >= 0) return pos; + else if (0u - (size_t)pos > len) return 0; + else return (lua_Integer)len + pos + 1; +} + + +/* +** Decode one UTF-8 sequence, returning NULL if byte sequence is invalid. +*/ +static const char *utf8_decode (const char *o, int *val) { + static unsigned int limits[] = {0xFF, 0x7F, 0x7FF, 0xFFFF}; + const unsigned char *s = (const unsigned char *)o; + unsigned int c = s[0]; + unsigned int res = 0; /* final result */ + if (c < 0x80) /* ascii? */ + res = c; + else { + int count = 0; /* to count number of continuation bytes */ + while (c & 0x40) { /* still have continuation bytes? */ + int cc = s[++count]; /* read next byte */ + if ((cc & 0xC0) != 0x80) /* not a continuation byte? */ + return NULL; /* invalid byte sequence */ + res = (res << 6) | (cc & 0x3F); /* add lower 6 bits from cont. byte */ + c <<= 1; /* to test next bit */ + } + res |= ((c & 0x7F) << (count * 5)); /* add first byte */ + if (count > 3 || res > MAXUNICODE || res <= limits[count]) + return NULL; /* invalid byte sequence */ + s += count; /* skip continuation bytes read */ + } + if (val) *val = res; + return (const char *)s + 1; /* +1 to include first byte */ +} + + +/* +** utf8len(s [, i [, j]]) --> number of characters that start in the +** range [i,j], or nil + current position if 's' is not well formed in +** that interval +*/ +static int utflen (lua_State *L) { + int n = 0; + size_t len; + const char *s = luaL_checklstring(L, 1, &len); + lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len); + lua_Integer posj = u_posrelat(luaL_optinteger(L, 3, -1), len); + luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 2, + "initial position out of string"); + luaL_argcheck(L, --posj < (lua_Integer)len, 3, + "final position out of string"); + while (posi <= posj) { + const char *s1 = utf8_decode(s + posi, NULL); + if (s1 == NULL) { /* conversion error? */ + lua_pushnil(L); /* return nil ... */ + lua_pushinteger(L, posi + 1); /* ... and current position */ + return 2; + } + posi = s1 - s; + n++; + } + lua_pushinteger(L, n); + return 1; +} + + +/* +** codepoint(s, [i, [j]]) -> returns codepoints for all characters +** that start in the range [i,j] +*/ +static int codepoint (lua_State *L) { + size_t len; + const char *s = luaL_checklstring(L, 1, &len); + lua_Integer posi = u_posrelat(luaL_optinteger(L, 2, 1), len); + lua_Integer pose = u_posrelat(luaL_optinteger(L, 3, posi), len); + int n; + const char *se; + luaL_argcheck(L, posi >= 1, 2, "out of range"); + luaL_argcheck(L, pose <= (lua_Integer)len, 3, "out of range"); + if (posi > pose) return 0; /* empty interval; return no values */ + n = (int)(pose - posi + 1); + if (posi + n <= pose) /* (lua_Integer -> int) overflow? */ + return luaL_error(L, "string slice too long"); + luaL_checkstack(L, n, "string slice too long"); + n = 0; + se = s + pose; + for (s += posi - 1; s < se;) { + int code; + s = utf8_decode(s, &code); + if (s == NULL) + return luaL_error(L, "invalid UTF-8 code"); + lua_pushinteger(L, code); + n++; + } + return n; +} + + +static void pushutfchar (lua_State *L, int arg) { + lua_Integer code = luaL_checkinteger(L, arg); + luaL_argcheck(L, 0 <= code && code <= MAXUNICODE, arg, "value out of range"); + lua_pushfstring(L, "%U", (long)code); +} + + +/* +** utfchar(n1, n2, ...) -> char(n1)..char(n2)... +*/ +static int utfchar (lua_State *L) { + int n = lua_gettop(L); /* number of arguments */ + if (n == 1) /* optimize common case of single char */ + pushutfchar(L, 1); + else { + int i; + luaL_Buffer b; + luaL_buffinit(L, &b); + for (i = 1; i <= n; i++) { + pushutfchar(L, i); + luaL_addvalue(&b); + } + luaL_pushresult(&b); + } + return 1; +} + + +/* +** offset(s, n, [i]) -> index where n-th character counting from +** position 'i' starts; 0 means character at 'i'. +*/ +static int byteoffset (lua_State *L) { + size_t len; + const char *s = luaL_checklstring(L, 1, &len); + lua_Integer n = luaL_checkinteger(L, 2); + lua_Integer posi = (n >= 0) ? 1 : len + 1; + posi = u_posrelat(luaL_optinteger(L, 3, posi), len); + luaL_argcheck(L, 1 <= posi && --posi <= (lua_Integer)len, 3, + "position out of range"); + if (n == 0) { + /* find beginning of current byte sequence */ + while (posi > 0 && iscont(s + posi)) posi--; + } + else { + if (iscont(s + posi)) + luaL_error(L, "initial position is a continuation byte"); + if (n < 0) { + while (n < 0 && posi > 0) { /* move back */ + do { /* find beginning of previous character */ + posi--; + } while (posi > 0 && iscont(s + posi)); + n++; + } + } + else { + n--; /* do not move for 1st character */ + while (n > 0 && posi < (lua_Integer)len) { + do { /* find beginning of next character */ + posi++; + } while (iscont(s + posi)); /* (cannot pass final '\0') */ + n--; + } + } + } + if (n == 0) /* did it find given character? */ + lua_pushinteger(L, posi + 1); + else /* no such character */ + lua_pushnil(L); + return 1; +} + + +static int iter_aux (lua_State *L) { + size_t len; + const char *s = luaL_checklstring(L, 1, &len); + lua_Integer n = lua_tointeger(L, 2) - 1; + if (n < 0) /* first iteration? */ + n = 0; /* start from here */ + else if (n < (lua_Integer)len) { + n++; /* skip current byte */ + while (iscont(s + n)) n++; /* and its continuations */ + } + if (n >= (lua_Integer)len) + return 0; /* no more codepoints */ + else { + int code; + const char *next = utf8_decode(s + n, &code); + if (next == NULL || iscont(next)) + return luaL_error(L, "invalid UTF-8 code"); + lua_pushinteger(L, n + 1); + lua_pushinteger(L, code); + return 2; + } +} + + +static int iter_codes (lua_State *L) { + luaL_checkstring(L, 1); + lua_pushcfunction(L, iter_aux); + lua_pushvalue(L, 1); + lua_pushinteger(L, 0); + return 3; +} + + +/* pattern to match a single UTF-8 character */ +#define UTF8PATT "[\0-\x7F\xC2-\xF4][\x80-\xBF]*" + + +static struct luaL_Reg funcs[] = { + {"offset", byteoffset}, + {"codepoint", codepoint}, + {"char", utfchar}, + {"len", utflen}, + {"codes", iter_codes}, + /* placeholders */ + {"charpattern", NULL}, + {NULL, NULL} +}; + + +LUAMOD_API int luaopen_utf8 (lua_State *L) { + luaL_newlib(L, funcs); + lua_pushliteral(L, UTF8PATT); + lua_setfield(L, -2, "charpattern"); + return 1; +} + diff --git a/src/lvm.c b/src/lvm.c new file mode 100644 index 000000000000..2ac1b02df48f --- /dev/null +++ b/src/lvm.c @@ -0,0 +1,1182 @@ +/* +** $Id: lvm.c,v 2.232 2014/12/27 20:30:38 roberto Exp $ +** Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#define lvm_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <limits.h> +#include <stdio.h> +#include <stdlib.h> +#include <string.h> + +#include "lua.h" + +#include "ldebug.h" +#include "ldo.h" +#include "lfunc.h" +#include "lgc.h" +#include "lobject.h" +#include "lopcodes.h" +#include "lstate.h" +#include "lstring.h" +#include "ltable.h" +#include "ltm.h" +#include "lvm.h" + + +/* +** You can define LUA_FLOORN2I if you want to convert floats to integers +** by flooring them (instead of raising an error if they are not +** integral values) +*/ +#if !defined(LUA_FLOORN2I) +#define LUA_FLOORN2I 0 +#endif + + +/* limit for table tag-method chains (to avoid loops) */ +#define MAXTAGLOOP 2000 + + +/* +** Similar to 'tonumber', but does not attempt to convert strings and +** ensure correct precision (no extra bits). Used in comparisons. +*/ +static int tofloat (const TValue *obj, lua_Number *n) { + if (ttisfloat(obj)) *n = fltvalue(obj); + else if (ttisinteger(obj)) { + volatile lua_Number x = cast_num(ivalue(obj)); /* avoid extra precision */ + *n = x; + } + else { + *n = 0; /* to avoid warnings */ + return 0; + } + return 1; +} + + +/* +** Try to convert a value to a float. The float case is already handled +** by the macro 'tonumber'. +*/ +int luaV_tonumber_ (const TValue *obj, lua_Number *n) { + TValue v; + if (ttisinteger(obj)) { + *n = cast_num(ivalue(obj)); + return 1; + } + else if (cvt2num(obj) && /* string convertible to number? */ + luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) { + *n = nvalue(&v); /* convert result of 'luaO_str2num' to a float */ + return 1; + } + else + return 0; /* conversion failed */ +} + + +/* +** try to convert a value to an integer, rounding according to 'mode': +** mode == 0: accepts only integral values +** mode == 1: takes the floor of the number +** mode == 2: takes the ceil of the number +*/ +static int tointeger_aux (const TValue *obj, lua_Integer *p, int mode) { + TValue v; + again: + if (ttisfloat(obj)) { + lua_Number n = fltvalue(obj); + lua_Number f = l_floor(n); + if (n != f) { /* not an integral value? */ + if (mode == 0) return 0; /* fails if mode demands integral value */ + else if (mode > 1) /* needs ceil? */ + f += 1; /* convert floor to ceil (remember: n != f) */ + } + return lua_numbertointeger(f, p); + } + else if (ttisinteger(obj)) { + *p = ivalue(obj); + return 1; + } + else if (cvt2num(obj) && + luaO_str2num(svalue(obj), &v) == tsvalue(obj)->len + 1) { + obj = &v; + goto again; /* convert result from 'luaO_str2num' to an integer */ + } + return 0; /* conversion failed */ +} + + +/* +** try to convert a value to an integer +*/ +int luaV_tointeger_ (const TValue *obj, lua_Integer *p) { + return tointeger_aux(obj, p, LUA_FLOORN2I); +} + + +/* +** Try to convert a 'for' limit to an integer, preserving the +** semantics of the loop. +** (The following explanation assumes a non-negative step; it is valid +** for negative steps mutatis mutandis.) +** If the limit can be converted to an integer, rounding down, that is +** it. +** Otherwise, check whether the limit can be converted to a number. If +** the number is too large, it is OK to set the limit as LUA_MAXINTEGER, +** which means no limit. If the number is too negative, the loop +** should not run, because any initial integer value is larger than the +** limit. So, it sets the limit to LUA_MININTEGER. 'stopnow' corrects +** the extreme case when the initial value is LUA_MININTEGER, in which +** case the LUA_MININTEGER limit would still run the loop once. +*/ +static int forlimit (const TValue *obj, lua_Integer *p, lua_Integer step, + int *stopnow) { + *stopnow = 0; /* usually, let loops run */ + if (!tointeger_aux(obj, p, (step < 0 ? 2 : 1))) { /* not fit in integer? */ + lua_Number n; /* try to convert to float */ + if (!tonumber(obj, &n)) /* cannot convert to float? */ + return 0; /* not a number */ + if (n > 0) { /* if true, float is larger than max integer */ + *p = LUA_MAXINTEGER; + if (step < 0) *stopnow = 1; + } + else { /* float is smaller than min integer */ + *p = LUA_MININTEGER; + if (step >= 0) *stopnow = 1; + } + } + return 1; +} + + +/* +** Main function for table access (invoking metamethods if needed). +** Compute 'val = t[key]' +*/ +void luaV_gettable (lua_State *L, const TValue *t, TValue *key, StkId val) { + int loop; /* counter to avoid infinite loops */ + for (loop = 0; loop < MAXTAGLOOP; loop++) { + const TValue *tm; + if (ttistable(t)) { /* 't' is a table? */ + Table *h = hvalue(t); + const TValue *res = luaH_get(h, key); /* do a primitive get */ + if (!ttisnil(res) || /* result is not nil? */ + (tm = fasttm(L, h->metatable, TM_INDEX)) == NULL) { /* or no TM? */ + setobj2s(L, val, res); /* result is the raw get */ + return; + } + /* else will try metamethod */ + } + else if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_INDEX))) + luaG_typeerror(L, t, "index"); /* no metamethod */ + if (ttisfunction(tm)) { /* metamethod is a function */ + luaT_callTM(L, tm, t, key, val, 1); + return; + } + t = tm; /* else repeat access over 'tm' */ + } + luaG_runerror(L, "gettable chain too long; possible loop"); +} + + +/* +** Main function for table assignment (invoking metamethods if needed). +** Compute 't[key] = val' +*/ +void luaV_settable (lua_State *L, const TValue *t, TValue *key, StkId val) { + int loop; /* counter to avoid infinite loops */ + for (loop = 0; loop < MAXTAGLOOP; loop++) { + const TValue *tm; + if (ttistable(t)) { /* 't' is a table? */ + Table *h = hvalue(t); + TValue *oldval = cast(TValue *, luaH_get(h, key)); + /* if previous value is not nil, there must be a previous entry + in the table; a metamethod has no relevance */ + if (!ttisnil(oldval) || + /* previous value is nil; must check the metamethod */ + ((tm = fasttm(L, h->metatable, TM_NEWINDEX)) == NULL && + /* no metamethod; is there a previous entry in the table? */ + (oldval != luaO_nilobject || + /* no previous entry; must create one. (The next test is + always true; we only need the assignment.) */ + (oldval = luaH_newkey(L, h, key), 1)))) { + /* no metamethod and (now) there is an entry with given key */ + setobj2t(L, oldval, val); /* assign new value to that entry */ + invalidateTMcache(h); + luaC_barrierback(L, h, val); + return; + } + /* else will try the metamethod */ + } + else /* not a table; check metamethod */ + if (ttisnil(tm = luaT_gettmbyobj(L, t, TM_NEWINDEX))) + luaG_typeerror(L, t, "index"); + /* try the metamethod */ + if (ttisfunction(tm)) { + luaT_callTM(L, tm, t, key, val, 0); + return; + } + t = tm; /* else repeat assignment over 'tm' */ + } + luaG_runerror(L, "settable chain too long; possible loop"); +} + + +/* +** Compare two strings 'ls' x 'rs', returning an integer smaller-equal- +** -larger than zero if 'ls' is smaller-equal-larger than 'rs'. +** The code is a little tricky because it allows '\0' in the strings +** and it uses 'strcoll' (to respect locales) for each segments +** of the strings. +*/ +static int l_strcmp (const TString *ls, const TString *rs) { + const char *l = getstr(ls); + size_t ll = ls->len; + const char *r = getstr(rs); + size_t lr = rs->len; + for (;;) { /* for each segment */ + int temp = strcoll(l, r); + if (temp != 0) /* not equal? */ + return temp; /* done */ + else { /* strings are equal up to a '\0' */ + size_t len = strlen(l); /* index of first '\0' in both strings */ + if (len == lr) /* 'rs' is finished? */ + return (len == ll) ? 0 : 1; /* check 'ls' */ + else if (len == ll) /* 'ls' is finished? */ + return -1; /* 'ls' is smaller than 'rs' ('rs' is not finished) */ + /* both strings longer than 'len'; go on comparing after the '\0' */ + len++; + l += len; ll -= len; r += len; lr -= len; + } + } +} + + +/* +** Main operation less than; return 'l < r'. +*/ +int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r) { + int res; + lua_Number nl, nr; + if (ttisinteger(l) && ttisinteger(r)) /* both operands are integers? */ + return (ivalue(l) < ivalue(r)); + else if (tofloat(l, &nl) && tofloat(r, &nr)) /* both are numbers? */ + return luai_numlt(nl, nr); + else if (ttisstring(l) && ttisstring(r)) /* both are strings? */ + return l_strcmp(tsvalue(l), tsvalue(r)) < 0; + else if ((res = luaT_callorderTM(L, l, r, TM_LT)) < 0) /* no metamethod? */ + luaG_ordererror(L, l, r); /* error */ + return res; +} + + +/* +** Main operation less than or equal to; return 'l <= r'. +*/ +int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r) { + int res; + lua_Number nl, nr; + if (ttisinteger(l) && ttisinteger(r)) /* both operands are integers? */ + return (ivalue(l) <= ivalue(r)); + else if (tofloat(l, &nl) && tofloat(r, &nr)) /* both are numbers? */ + return luai_numle(nl, nr); + else if (ttisstring(l) && ttisstring(r)) /* both are strings? */ + return l_strcmp(tsvalue(l), tsvalue(r)) <= 0; + else if ((res = luaT_callorderTM(L, l, r, TM_LE)) >= 0) /* first try 'le' */ + return res; + else if ((res = luaT_callorderTM(L, r, l, TM_LT)) < 0) /* else try 'lt' */ + luaG_ordererror(L, l, r); + return !res; +} + + +/* +** Main operation for equality of Lua values; return 't1 == t2'. +** L == NULL means raw equality (no metamethods) +*/ +int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2) { + const TValue *tm; + if (ttype(t1) != ttype(t2)) { /* not the same variant? */ + if (ttnov(t1) != ttnov(t2) || ttnov(t1) != LUA_TNUMBER) + return 0; /* only numbers can be equal with different variants */ + else { /* two numbers with different variants */ + lua_Number n1, n2; /* compare them as floats */ + lua_assert(ttisnumber(t1) && ttisnumber(t2)); + cast_void(tofloat(t1, &n1)); cast_void(tofloat(t2, &n2)); + return luai_numeq(n1, n2); + } + } + /* values have same type and same variant */ + switch (ttype(t1)) { + case LUA_TNIL: return 1; + case LUA_TNUMINT: return (ivalue(t1) == ivalue(t2)); + case LUA_TNUMFLT: return luai_numeq(fltvalue(t1), fltvalue(t2)); + case LUA_TBOOLEAN: return bvalue(t1) == bvalue(t2); /* true must be 1 !! */ + case LUA_TLIGHTUSERDATA: return pvalue(t1) == pvalue(t2); + case LUA_TLCF: return fvalue(t1) == fvalue(t2); + case LUA_TSHRSTR: return eqshrstr(tsvalue(t1), tsvalue(t2)); + case LUA_TLNGSTR: return luaS_eqlngstr(tsvalue(t1), tsvalue(t2)); + case LUA_TUSERDATA: { + if (uvalue(t1) == uvalue(t2)) return 1; + else if (L == NULL) return 0; + tm = fasttm(L, uvalue(t1)->metatable, TM_EQ); + if (tm == NULL) + tm = fasttm(L, uvalue(t2)->metatable, TM_EQ); + break; /* will try TM */ + } + case LUA_TTABLE: { + if (hvalue(t1) == hvalue(t2)) return 1; + else if (L == NULL) return 0; + tm = fasttm(L, hvalue(t1)->metatable, TM_EQ); + if (tm == NULL) + tm = fasttm(L, hvalue(t2)->metatable, TM_EQ); + break; /* will try TM */ + } + default: + return gcvalue(t1) == gcvalue(t2); + } + if (tm == NULL) /* no TM? */ + return 0; /* objects are different */ + luaT_callTM(L, tm, t1, t2, L->top, 1); /* call TM */ + return !l_isfalse(L->top); +} + + +/* macro used by 'luaV_concat' to ensure that element at 'o' is a string */ +#define tostring(L,o) \ + (ttisstring(o) || (cvt2str(o) && (luaO_tostring(L, o), 1))) + +/* +** Main operation for concatenation: concat 'total' values in the stack, +** from 'L->top - total' up to 'L->top - 1'. +*/ +void luaV_concat (lua_State *L, int total) { + lua_assert(total >= 2); + do { + StkId top = L->top; + int n = 2; /* number of elements handled in this pass (at least 2) */ + if (!(ttisstring(top-2) || cvt2str(top-2)) || !tostring(L, top-1)) + luaT_trybinTM(L, top-2, top-1, top-2, TM_CONCAT); + else if (tsvalue(top-1)->len == 0) /* second operand is empty? */ + cast_void(tostring(L, top - 2)); /* result is first operand */ + else if (ttisstring(top-2) && tsvalue(top-2)->len == 0) { + setobjs2s(L, top - 2, top - 1); /* result is second op. */ + } + else { + /* at least two non-empty string values; get as many as possible */ + size_t tl = tsvalue(top-1)->len; + char *buffer; + int i; + /* collect total length */ + for (i = 1; i < total && tostring(L, top-i-1); i++) { + size_t l = tsvalue(top-i-1)->len; + if (l >= (MAX_SIZE/sizeof(char)) - tl) + luaG_runerror(L, "string length overflow"); + tl += l; + } + buffer = luaZ_openspace(L, &G(L)->buff, tl); + tl = 0; + n = i; + do { /* copy all strings to buffer */ + size_t l = tsvalue(top-i)->len; + memcpy(buffer+tl, svalue(top-i), l * sizeof(char)); + tl += l; + } while (--i > 0); + setsvalue2s(L, top-n, luaS_newlstr(L, buffer, tl)); /* create result */ + } + total -= n-1; /* got 'n' strings to create 1 new */ + L->top -= n-1; /* popped 'n' strings and pushed one */ + } while (total > 1); /* repeat until only 1 result left */ +} + + +/* +** Main operation 'ra' = #rb'. +*/ +void luaV_objlen (lua_State *L, StkId ra, const TValue *rb) { + const TValue *tm; + switch (ttnov(rb)) { + case LUA_TTABLE: { + Table *h = hvalue(rb); + tm = fasttm(L, h->metatable, TM_LEN); + if (tm) break; /* metamethod? break switch to call it */ + setivalue(ra, luaH_getn(h)); /* else primitive len */ + return; + } + case LUA_TSTRING: { + setivalue(ra, tsvalue(rb)->len); + return; + } + default: { /* try metamethod */ + tm = luaT_gettmbyobj(L, rb, TM_LEN); + if (ttisnil(tm)) /* no metamethod? */ + luaG_typeerror(L, rb, "get length of"); + break; + } + } + luaT_callTM(L, tm, rb, rb, ra, 1); +} + + +/* +** Integer division; return 'm // n', that is, floor(m/n). +** C division truncates its result (rounds towards zero). +** 'floor(q) == trunc(q)' when 'q >= 0' or when 'q' is integer, +** otherwise 'floor(q) == trunc(q) - 1'. +*/ +lua_Integer luaV_div (lua_State *L, lua_Integer m, lua_Integer n) { + if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */ + if (n == 0) + luaG_runerror(L, "attempt to divide by zero"); + return intop(-, 0, m); /* n==-1; avoid overflow with 0x80000...//-1 */ + } + else { + lua_Integer q = m / n; /* perform C division */ + if ((m ^ n) < 0 && m % n != 0) /* 'm/n' would be negative non-integer? */ + q -= 1; /* correct result for different rounding */ + return q; + } +} + + +/* +** Integer modulus; return 'm % n'. (Assume that C '%' with +** negative operands follows C99 behavior. See previous comment +** about luaV_div.) +*/ +lua_Integer luaV_mod (lua_State *L, lua_Integer m, lua_Integer n) { + if (l_castS2U(n) + 1u <= 1u) { /* special cases: -1 or 0 */ + if (n == 0) + luaG_runerror(L, "attempt to perform 'n%%0'"); + return 0; /* m % -1 == 0; avoid overflow with 0x80000...%-1 */ + } + else { + lua_Integer r = m % n; + if (r != 0 && (m ^ n) < 0) /* 'm/n' would be non-integer negative? */ + r += n; /* correct result for different rounding */ + return r; + } +} + + +/* number of bits in an integer */ +#define NBITS cast_int(sizeof(lua_Integer) * CHAR_BIT) + +/* +** Shift left operation. (Shift right just negates 'y'.) +*/ +lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y) { + if (y < 0) { /* shift right? */ + if (y <= -NBITS) return 0; + else return intop(>>, x, -y); + } + else { /* shift left */ + if (y >= NBITS) return 0; + else return intop(<<, x, y); + } +} + + +/* +** check whether cached closure in prototype 'p' may be reused, that is, +** whether there is a cached closure with the same upvalues needed by +** new closure to be created. +*/ +static LClosure *getcached (Proto *p, UpVal **encup, StkId base) { + LClosure *c = p->cache; + if (c != NULL) { /* is there a cached closure? */ + int nup = p->sizeupvalues; + Upvaldesc *uv = p->upvalues; + int i; + for (i = 0; i < nup; i++) { /* check whether it has right upvalues */ + TValue *v = uv[i].instack ? base + uv[i].idx : encup[uv[i].idx]->v; + if (c->upvals[i]->v != v) + return NULL; /* wrong upvalue; cannot reuse closure */ + } + } + return c; /* return cached closure (or NULL if no cached closure) */ +} + + +/* +** create a new Lua closure, push it in the stack, and initialize +** its upvalues. Note that the closure is not cached if prototype is +** already black (which means that 'cache' was already cleared by the +** GC). +*/ +static void pushclosure (lua_State *L, Proto *p, UpVal **encup, StkId base, + StkId ra) { + int nup = p->sizeupvalues; + Upvaldesc *uv = p->upvalues; + int i; + LClosure *ncl = luaF_newLclosure(L, nup); + ncl->p = p; + setclLvalue(L, ra, ncl); /* anchor new closure in stack */ + for (i = 0; i < nup; i++) { /* fill in its upvalues */ + if (uv[i].instack) /* upvalue refers to local variable? */ + ncl->upvals[i] = luaF_findupval(L, base + uv[i].idx); + else /* get upvalue from enclosing function */ + ncl->upvals[i] = encup[uv[i].idx]; + ncl->upvals[i]->refcount++; + /* new closure is white, so we do not need a barrier here */ + } + if (!isblack(p)) /* cache will not break GC invariant? */ + p->cache = ncl; /* save it on cache for reuse */ +} + + +/* +** finish execution of an opcode interrupted by an yield +*/ +void luaV_finishOp (lua_State *L) { + CallInfo *ci = L->ci; + StkId base = ci->u.l.base; + Instruction inst = *(ci->u.l.savedpc - 1); /* interrupted instruction */ + OpCode op = GET_OPCODE(inst); + switch (op) { /* finish its execution */ + case OP_ADD: case OP_SUB: case OP_MUL: case OP_DIV: case OP_IDIV: + case OP_BAND: case OP_BOR: case OP_BXOR: case OP_SHL: case OP_SHR: + case OP_MOD: case OP_POW: + case OP_UNM: case OP_BNOT: case OP_LEN: + case OP_GETTABUP: case OP_GETTABLE: case OP_SELF: { + setobjs2s(L, base + GETARG_A(inst), --L->top); + break; + } + case OP_LE: case OP_LT: case OP_EQ: { + int res = !l_isfalse(L->top - 1); + L->top--; + /* metamethod should not be called when operand is K */ + lua_assert(!ISK(GETARG_B(inst))); + if (op == OP_LE && /* "<=" using "<" instead? */ + ttisnil(luaT_gettmbyobj(L, base + GETARG_B(inst), TM_LE))) + res = !res; /* invert result */ + lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_JMP); + if (res != GETARG_A(inst)) /* condition failed? */ + ci->u.l.savedpc++; /* skip jump instruction */ + break; + } + case OP_CONCAT: { + StkId top = L->top - 1; /* top when 'luaT_trybinTM' was called */ + int b = GETARG_B(inst); /* first element to concatenate */ + int total = cast_int(top - 1 - (base + b)); /* yet to concatenate */ + setobj2s(L, top - 2, top); /* put TM result in proper position */ + if (total > 1) { /* are there elements to concat? */ + L->top = top - 1; /* top is one after last element (at top-2) */ + luaV_concat(L, total); /* concat them (may yield again) */ + } + /* move final result to final position */ + setobj2s(L, ci->u.l.base + GETARG_A(inst), L->top - 1); + L->top = ci->top; /* restore top */ + break; + } + case OP_TFORCALL: { + lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_TFORLOOP); + L->top = ci->top; /* correct top */ + break; + } + case OP_CALL: { + if (GETARG_C(inst) - 1 >= 0) /* nresults >= 0? */ + L->top = ci->top; /* adjust results */ + break; + } + case OP_TAILCALL: case OP_SETTABUP: case OP_SETTABLE: + break; + default: lua_assert(0); + } +} + + + + +/* +** {================================================================== +** Function 'luaV_execute': main interpreter loop +** =================================================================== +*/ + + +/* +** some macros for common tasks in 'luaV_execute' +*/ + +#if !defined luai_runtimecheck +#define luai_runtimecheck(L, c) /* void */ +#endif + + +#define RA(i) (base+GETARG_A(i)) +/* to be used after possible stack reallocation */ +#define RB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgR, base+GETARG_B(i)) +#define RC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgR, base+GETARG_C(i)) +#define RKB(i) check_exp(getBMode(GET_OPCODE(i)) == OpArgK, \ + ISK(GETARG_B(i)) ? k+INDEXK(GETARG_B(i)) : base+GETARG_B(i)) +#define RKC(i) check_exp(getCMode(GET_OPCODE(i)) == OpArgK, \ + ISK(GETARG_C(i)) ? k+INDEXK(GETARG_C(i)) : base+GETARG_C(i)) +#define KBx(i) \ + (k + (GETARG_Bx(i) != 0 ? GETARG_Bx(i) - 1 : GETARG_Ax(*ci->u.l.savedpc++))) + + +/* execute a jump instruction */ +#define dojump(ci,i,e) \ + { int a = GETARG_A(i); \ + if (a > 0) luaF_close(L, ci->u.l.base + a - 1); \ + ci->u.l.savedpc += GETARG_sBx(i) + e; } + +/* for test instructions, execute the jump instruction that follows it */ +#define donextjump(ci) { i = *ci->u.l.savedpc; dojump(ci, i, 1); } + + +#define Protect(x) { {x;}; base = ci->u.l.base; } + +#define checkGC(L,c) \ + Protect( luaC_condGC(L,{L->top = (c); /* limit of live values */ \ + luaC_step(L); \ + L->top = ci->top;}) /* restore top */ \ + luai_threadyield(L); ) + + +#define vmdispatch(o) switch(o) +#define vmcase(l) case l: +#define vmbreak break + +void luaV_execute (lua_State *L) { + CallInfo *ci = L->ci; + LClosure *cl; + TValue *k; + StkId base; + newframe: /* reentry point when frame changes (call/return) */ + lua_assert(ci == L->ci); + cl = clLvalue(ci->func); + k = cl->p->k; + base = ci->u.l.base; + /* main loop of interpreter */ + for (;;) { + Instruction i = *(ci->u.l.savedpc++); + StkId ra; + if ((L->hookmask & (LUA_MASKLINE | LUA_MASKCOUNT)) && + (--L->hookcount == 0 || L->hookmask & LUA_MASKLINE)) { + Protect(luaG_traceexec(L)); + } + /* WARNING: several calls may realloc the stack and invalidate 'ra' */ + ra = RA(i); + lua_assert(base == ci->u.l.base); + lua_assert(base <= L->top && L->top < L->stack + L->stacksize); + vmdispatch (GET_OPCODE(i)) { + vmcase(OP_MOVE) { + setobjs2s(L, ra, RB(i)); + vmbreak; + } + vmcase(OP_LOADK) { + TValue *rb = k + GETARG_Bx(i); + setobj2s(L, ra, rb); + vmbreak; + } + vmcase(OP_LOADKX) { + TValue *rb; + lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG); + rb = k + GETARG_Ax(*ci->u.l.savedpc++); + setobj2s(L, ra, rb); + vmbreak; + } + vmcase(OP_LOADBOOL) { + setbvalue(ra, GETARG_B(i)); + if (GETARG_C(i)) ci->u.l.savedpc++; /* skip next instruction (if C) */ + vmbreak; + } + vmcase(OP_LOADNIL) { + int b = GETARG_B(i); + do { + setnilvalue(ra++); + } while (b--); + vmbreak; + } + vmcase(OP_GETUPVAL) { + int b = GETARG_B(i); + setobj2s(L, ra, cl->upvals[b]->v); + vmbreak; + } + vmcase(OP_GETTABUP) { + int b = GETARG_B(i); + Protect(luaV_gettable(L, cl->upvals[b]->v, RKC(i), ra)); + vmbreak; + } + vmcase(OP_GETTABLE) { + Protect(luaV_gettable(L, RB(i), RKC(i), ra)); + vmbreak; + } + vmcase(OP_SETTABUP) { + int a = GETARG_A(i); + Protect(luaV_settable(L, cl->upvals[a]->v, RKB(i), RKC(i))); + vmbreak; + } + vmcase(OP_SETUPVAL) { + UpVal *uv = cl->upvals[GETARG_B(i)]; + setobj(L, uv->v, ra); + luaC_upvalbarrier(L, uv); + vmbreak; + } + vmcase(OP_SETTABLE) { + Protect(luaV_settable(L, ra, RKB(i), RKC(i))); + vmbreak; + } + vmcase(OP_NEWTABLE) { + int b = GETARG_B(i); + int c = GETARG_C(i); + Table *t = luaH_new(L); + sethvalue(L, ra, t); + if (b != 0 || c != 0) + luaH_resize(L, t, luaO_fb2int(b), luaO_fb2int(c)); + checkGC(L, ra + 1); + vmbreak; + } + vmcase(OP_SELF) { + StkId rb = RB(i); + setobjs2s(L, ra+1, rb); + Protect(luaV_gettable(L, rb, RKC(i), ra)); + vmbreak; + } + vmcase(OP_ADD) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Number nb; lua_Number nc; + if (ttisinteger(rb) && ttisinteger(rc)) { + lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); + setivalue(ra, intop(+, ib, ic)); + } + else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { + setfltvalue(ra, luai_numadd(L, nb, nc)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_ADD)); } + vmbreak; + } + vmcase(OP_SUB) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Number nb; lua_Number nc; + if (ttisinteger(rb) && ttisinteger(rc)) { + lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); + setivalue(ra, intop(-, ib, ic)); + } + else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { + setfltvalue(ra, luai_numsub(L, nb, nc)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SUB)); } + vmbreak; + } + vmcase(OP_MUL) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Number nb; lua_Number nc; + if (ttisinteger(rb) && ttisinteger(rc)) { + lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); + setivalue(ra, intop(*, ib, ic)); + } + else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { + setfltvalue(ra, luai_nummul(L, nb, nc)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MUL)); } + vmbreak; + } + vmcase(OP_DIV) { /* float division (always with floats) */ + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Number nb; lua_Number nc; + if (tonumber(rb, &nb) && tonumber(rc, &nc)) { + setfltvalue(ra, luai_numdiv(L, nb, nc)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_DIV)); } + vmbreak; + } + vmcase(OP_BAND) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Integer ib; lua_Integer ic; + if (tointeger(rb, &ib) && tointeger(rc, &ic)) { + setivalue(ra, intop(&, ib, ic)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BAND)); } + vmbreak; + } + vmcase(OP_BOR) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Integer ib; lua_Integer ic; + if (tointeger(rb, &ib) && tointeger(rc, &ic)) { + setivalue(ra, intop(|, ib, ic)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BOR)); } + vmbreak; + } + vmcase(OP_BXOR) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Integer ib; lua_Integer ic; + if (tointeger(rb, &ib) && tointeger(rc, &ic)) { + setivalue(ra, intop(^, ib, ic)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_BXOR)); } + vmbreak; + } + vmcase(OP_SHL) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Integer ib; lua_Integer ic; + if (tointeger(rb, &ib) && tointeger(rc, &ic)) { + setivalue(ra, luaV_shiftl(ib, ic)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHL)); } + vmbreak; + } + vmcase(OP_SHR) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Integer ib; lua_Integer ic; + if (tointeger(rb, &ib) && tointeger(rc, &ic)) { + setivalue(ra, luaV_shiftl(ib, -ic)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_SHR)); } + vmbreak; + } + vmcase(OP_MOD) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Number nb; lua_Number nc; + if (ttisinteger(rb) && ttisinteger(rc)) { + lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); + setivalue(ra, luaV_mod(L, ib, ic)); + } + else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { + lua_Number m; + luai_nummod(L, nb, nc, m); + setfltvalue(ra, m); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_MOD)); } + vmbreak; + } + vmcase(OP_IDIV) { /* floor division */ + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Number nb; lua_Number nc; + if (ttisinteger(rb) && ttisinteger(rc)) { + lua_Integer ib = ivalue(rb); lua_Integer ic = ivalue(rc); + setivalue(ra, luaV_div(L, ib, ic)); + } + else if (tonumber(rb, &nb) && tonumber(rc, &nc)) { + setfltvalue(ra, luai_numidiv(L, nb, nc)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_IDIV)); } + vmbreak; + } + vmcase(OP_POW) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + lua_Number nb; lua_Number nc; + if (tonumber(rb, &nb) && tonumber(rc, &nc)) { + setfltvalue(ra, luai_numpow(L, nb, nc)); + } + else { Protect(luaT_trybinTM(L, rb, rc, ra, TM_POW)); } + vmbreak; + } + vmcase(OP_UNM) { + TValue *rb = RB(i); + lua_Number nb; + if (ttisinteger(rb)) { + lua_Integer ib = ivalue(rb); + setivalue(ra, intop(-, 0, ib)); + } + else if (tonumber(rb, &nb)) { + setfltvalue(ra, luai_numunm(L, nb)); + } + else { + Protect(luaT_trybinTM(L, rb, rb, ra, TM_UNM)); + } + vmbreak; + } + vmcase(OP_BNOT) { + TValue *rb = RB(i); + lua_Integer ib; + if (tointeger(rb, &ib)) { + setivalue(ra, intop(^, ~l_castS2U(0), ib)); + } + else { + Protect(luaT_trybinTM(L, rb, rb, ra, TM_BNOT)); + } + vmbreak; + } + vmcase(OP_NOT) { + TValue *rb = RB(i); + int res = l_isfalse(rb); /* next assignment may change this value */ + setbvalue(ra, res); + vmbreak; + } + vmcase(OP_LEN) { + Protect(luaV_objlen(L, ra, RB(i))); + vmbreak; + } + vmcase(OP_CONCAT) { + int b = GETARG_B(i); + int c = GETARG_C(i); + StkId rb; + L->top = base + c + 1; /* mark the end of concat operands */ + Protect(luaV_concat(L, c - b + 1)); + ra = RA(i); /* 'luav_concat' may invoke TMs and move the stack */ + rb = b + base; + setobjs2s(L, ra, rb); + checkGC(L, (ra >= rb ? ra + 1 : rb)); + L->top = ci->top; /* restore top */ + vmbreak; + } + vmcase(OP_JMP) { + dojump(ci, i, 0); + vmbreak; + } + vmcase(OP_EQ) { + TValue *rb = RKB(i); + TValue *rc = RKC(i); + Protect( + if (cast_int(luaV_equalobj(L, rb, rc)) != GETARG_A(i)) + ci->u.l.savedpc++; + else + donextjump(ci); + ) + vmbreak; + } + vmcase(OP_LT) { + Protect( + if (luaV_lessthan(L, RKB(i), RKC(i)) != GETARG_A(i)) + ci->u.l.savedpc++; + else + donextjump(ci); + ) + vmbreak; + } + vmcase(OP_LE) { + Protect( + if (luaV_lessequal(L, RKB(i), RKC(i)) != GETARG_A(i)) + ci->u.l.savedpc++; + else + donextjump(ci); + ) + vmbreak; + } + vmcase(OP_TEST) { + if (GETARG_C(i) ? l_isfalse(ra) : !l_isfalse(ra)) + ci->u.l.savedpc++; + else + donextjump(ci); + vmbreak; + } + vmcase(OP_TESTSET) { + TValue *rb = RB(i); + if (GETARG_C(i) ? l_isfalse(rb) : !l_isfalse(rb)) + ci->u.l.savedpc++; + else { + setobjs2s(L, ra, rb); + donextjump(ci); + } + vmbreak; + } + vmcase(OP_CALL) { + int b = GETARG_B(i); + int nresults = GETARG_C(i) - 1; + if (b != 0) L->top = ra+b; /* else previous instruction set top */ + if (luaD_precall(L, ra, nresults)) { /* C function? */ + if (nresults >= 0) L->top = ci->top; /* adjust results */ + base = ci->u.l.base; + } + else { /* Lua function */ + ci = L->ci; + ci->callstatus |= CIST_REENTRY; + goto newframe; /* restart luaV_execute over new Lua function */ + } + vmbreak; + } + vmcase(OP_TAILCALL) { + int b = GETARG_B(i); + if (b != 0) L->top = ra+b; /* else previous instruction set top */ + lua_assert(GETARG_C(i) - 1 == LUA_MULTRET); + if (luaD_precall(L, ra, LUA_MULTRET)) /* C function? */ + base = ci->u.l.base; + else { + /* tail call: put called frame (n) in place of caller one (o) */ + CallInfo *nci = L->ci; /* called frame */ + CallInfo *oci = nci->previous; /* caller frame */ + StkId nfunc = nci->func; /* called function */ + StkId ofunc = oci->func; /* caller function */ + /* last stack slot filled by 'precall' */ + StkId lim = nci->u.l.base + getproto(nfunc)->numparams; + int aux; + /* close all upvalues from previous call */ + if (cl->p->sizep > 0) luaF_close(L, oci->u.l.base); + /* move new frame into old one */ + for (aux = 0; nfunc + aux < lim; aux++) + setobjs2s(L, ofunc + aux, nfunc + aux); + oci->u.l.base = ofunc + (nci->u.l.base - nfunc); /* correct base */ + oci->top = L->top = ofunc + (L->top - nfunc); /* correct top */ + oci->u.l.savedpc = nci->u.l.savedpc; + oci->callstatus |= CIST_TAIL; /* function was tail called */ + ci = L->ci = oci; /* remove new frame */ + lua_assert(L->top == oci->u.l.base + getproto(ofunc)->maxstacksize); + goto newframe; /* restart luaV_execute over new Lua function */ + } + vmbreak; + } + vmcase(OP_RETURN) { + int b = GETARG_B(i); + if (b != 0) L->top = ra+b-1; + if (cl->p->sizep > 0) luaF_close(L, base); + b = luaD_poscall(L, ra); + if (!(ci->callstatus & CIST_REENTRY)) /* 'ci' still the called one */ + return; /* external invocation: return */ + else { /* invocation via reentry: continue execution */ + ci = L->ci; + if (b) L->top = ci->top; + lua_assert(isLua(ci)); + lua_assert(GET_OPCODE(*((ci)->u.l.savedpc - 1)) == OP_CALL); + goto newframe; /* restart luaV_execute over new Lua function */ + } + } + vmcase(OP_FORLOOP) { + if (ttisinteger(ra)) { /* integer loop? */ + lua_Integer step = ivalue(ra + 2); + lua_Integer idx = ivalue(ra) + step; /* increment index */ + lua_Integer limit = ivalue(ra + 1); + if ((0 < step) ? (idx <= limit) : (limit <= idx)) { + ci->u.l.savedpc += GETARG_sBx(i); /* jump back */ + setivalue(ra, idx); /* update internal index... */ + setivalue(ra + 3, idx); /* ...and external index */ + } + } + else { /* floating loop */ + lua_Number step = fltvalue(ra + 2); + lua_Number idx = luai_numadd(L, fltvalue(ra), step); /* inc. index */ + lua_Number limit = fltvalue(ra + 1); + if (luai_numlt(0, step) ? luai_numle(idx, limit) + : luai_numle(limit, idx)) { + ci->u.l.savedpc += GETARG_sBx(i); /* jump back */ + setfltvalue(ra, idx); /* update internal index... */ + setfltvalue(ra + 3, idx); /* ...and external index */ + } + } + vmbreak; + } + vmcase(OP_FORPREP) { + TValue *init = ra; + TValue *plimit = ra + 1; + TValue *pstep = ra + 2; + lua_Integer ilimit; + int stopnow; + if (ttisinteger(init) && ttisinteger(pstep) && + forlimit(plimit, &ilimit, ivalue(pstep), &stopnow)) { + /* all values are integer */ + lua_Integer initv = (stopnow ? 0 : ivalue(init)); + setivalue(plimit, ilimit); + setivalue(init, initv - ivalue(pstep)); + } + else { /* try making all values floats */ + lua_Number ninit; lua_Number nlimit; lua_Number nstep; + if (!tonumber(plimit, &nlimit)) + luaG_runerror(L, "'for' limit must be a number"); + setfltvalue(plimit, nlimit); + if (!tonumber(pstep, &nstep)) + luaG_runerror(L, "'for' step must be a number"); + setfltvalue(pstep, nstep); + if (!tonumber(init, &ninit)) + luaG_runerror(L, "'for' initial value must be a number"); + setfltvalue(init, luai_numsub(L, ninit, nstep)); + } + ci->u.l.savedpc += GETARG_sBx(i); + vmbreak; + } + vmcase(OP_TFORCALL) { + StkId cb = ra + 3; /* call base */ + setobjs2s(L, cb+2, ra+2); + setobjs2s(L, cb+1, ra+1); + setobjs2s(L, cb, ra); + L->top = cb + 3; /* func. + 2 args (state and index) */ + Protect(luaD_call(L, cb, GETARG_C(i), 1)); + L->top = ci->top; + i = *(ci->u.l.savedpc++); /* go to next instruction */ + ra = RA(i); + lua_assert(GET_OPCODE(i) == OP_TFORLOOP); + goto l_tforloop; + } + vmcase(OP_TFORLOOP) { + l_tforloop: + if (!ttisnil(ra + 1)) { /* continue loop? */ + setobjs2s(L, ra, ra + 1); /* save control variable */ + ci->u.l.savedpc += GETARG_sBx(i); /* jump back */ + } + vmbreak; + } + vmcase(OP_SETLIST) { + int n = GETARG_B(i); + int c = GETARG_C(i); + unsigned int last; + Table *h; + if (n == 0) n = cast_int(L->top - ra) - 1; + if (c == 0) { + lua_assert(GET_OPCODE(*ci->u.l.savedpc) == OP_EXTRAARG); + c = GETARG_Ax(*ci->u.l.savedpc++); + } + luai_runtimecheck(L, ttistable(ra)); + h = hvalue(ra); + last = ((c-1)*LFIELDS_PER_FLUSH) + n; + if (last > h->sizearray) /* needs more space? */ + luaH_resizearray(L, h, last); /* pre-allocate it at once */ + for (; n > 0; n--) { + TValue *val = ra+n; + luaH_setint(L, h, last--, val); + luaC_barrierback(L, h, val); + } + L->top = ci->top; /* correct top (in case of previous open call) */ + vmbreak; + } + vmcase(OP_CLOSURE) { + Proto *p = cl->p->p[GETARG_Bx(i)]; + LClosure *ncl = getcached(p, cl->upvals, base); /* cached closure */ + if (ncl == NULL) /* no match? */ + pushclosure(L, p, cl->upvals, base, ra); /* create a new one */ + else + setclLvalue(L, ra, ncl); /* push cashed closure */ + checkGC(L, ra + 1); + vmbreak; + } + vmcase(OP_VARARG) { + int b = GETARG_B(i) - 1; + int j; + int n = cast_int(base - ci->func) - cl->p->numparams - 1; + if (b < 0) { /* B == 0? */ + b = n; /* get all var. arguments */ + Protect(luaD_checkstack(L, n)); + ra = RA(i); /* previous call may change the stack */ + L->top = ra + n; + } + for (j = 0; j < b; j++) { + if (j < n) { + setobjs2s(L, ra + j, base - n + j); + } + else { + setnilvalue(ra + j); + } + } + vmbreak; + } + vmcase(OP_EXTRAARG) { + lua_assert(0); + vmbreak; + } + } + } +} + +/* }================================================================== */ + diff --git a/src/lvm.h b/src/lvm.h new file mode 100644 index 000000000000..5c5e18c3ac7c --- /dev/null +++ b/src/lvm.h @@ -0,0 +1,58 @@ +/* +** $Id: lvm.h,v 2.34 2014/08/01 17:24:02 roberto Exp $ +** Lua virtual machine +** See Copyright Notice in lua.h +*/ + +#ifndef lvm_h +#define lvm_h + + +#include "ldo.h" +#include "lobject.h" +#include "ltm.h" + + +#if !defined(LUA_NOCVTN2S) +#define cvt2str(o) ttisnumber(o) +#else +#define cvt2str(o) 0 /* no conversion from numbers to strings */ +#endif + + +#if !defined(LUA_NOCVTS2N) +#define cvt2num(o) ttisstring(o) +#else +#define cvt2num(o) 0 /* no conversion from strings to numbers */ +#endif + + +#define tonumber(o,n) \ + (ttisfloat(o) ? (*(n) = fltvalue(o), 1) : luaV_tonumber_(o,n)) + +#define tointeger(o,i) \ + (ttisinteger(o) ? (*(i) = ivalue(o), 1) : luaV_tointeger_(o,i)) + +#define intop(op,v1,v2) l_castU2S(l_castS2U(v1) op l_castS2U(v2)) + +#define luaV_rawequalobj(t1,t2) luaV_equalobj(NULL,t1,t2) + + +LUAI_FUNC int luaV_equalobj (lua_State *L, const TValue *t1, const TValue *t2); +LUAI_FUNC int luaV_lessthan (lua_State *L, const TValue *l, const TValue *r); +LUAI_FUNC int luaV_lessequal (lua_State *L, const TValue *l, const TValue *r); +LUAI_FUNC int luaV_tonumber_ (const TValue *obj, lua_Number *n); +LUAI_FUNC int luaV_tointeger_ (const TValue *obj, lua_Integer *p); +LUAI_FUNC void luaV_gettable (lua_State *L, const TValue *t, TValue *key, + StkId val); +LUAI_FUNC void luaV_settable (lua_State *L, const TValue *t, TValue *key, + StkId val); +LUAI_FUNC void luaV_finishOp (lua_State *L); +LUAI_FUNC void luaV_execute (lua_State *L); +LUAI_FUNC void luaV_concat (lua_State *L, int total); +LUAI_FUNC lua_Integer luaV_div (lua_State *L, lua_Integer x, lua_Integer y); +LUAI_FUNC lua_Integer luaV_mod (lua_State *L, lua_Integer x, lua_Integer y); +LUAI_FUNC lua_Integer luaV_shiftl (lua_Integer x, lua_Integer y); +LUAI_FUNC void luaV_objlen (lua_State *L, StkId ra, const TValue *rb); + +#endif diff --git a/src/lzio.c b/src/lzio.c new file mode 100644 index 000000000000..46493920f414 --- /dev/null +++ b/src/lzio.c @@ -0,0 +1,78 @@ +/* +** $Id: lzio.c,v 1.36 2014/11/02 19:19:04 roberto Exp $ +** Buffered streams +** See Copyright Notice in lua.h +*/ + +#define lzio_c +#define LUA_CORE + +#include "lprefix.h" + + +#include <string.h> + +#include "lua.h" + +#include "llimits.h" +#include "lmem.h" +#include "lstate.h" +#include "lzio.h" + + +int luaZ_fill (ZIO *z) { + size_t size; + lua_State *L = z->L; + const char *buff; + lua_unlock(L); + buff = z->reader(L, z->data, &size); + lua_lock(L); + if (buff == NULL || size == 0) + return EOZ; + z->n = size - 1; /* discount char being returned */ + z->p = buff; + return cast_uchar(*(z->p++)); +} + + +void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, void *data) { + z->L = L; + z->reader = reader; + z->data = data; + z->n = 0; + z->p = NULL; +} + + +/* --------------------------------------------------------------- read --- */ +size_t luaZ_read (ZIO *z, void *b, size_t n) { + while (n) { + size_t m; + if (z->n == 0) { /* no bytes in buffer? */ + if (luaZ_fill(z) == EOZ) /* try to read more */ + return n; /* no more input; return number of missing bytes */ + else { + z->n++; /* luaZ_fill consumed first byte; put it back */ + z->p--; + } + } + m = (n <= z->n) ? n : z->n; /* min. between n and z->n */ + memcpy(b, z->p, m); + z->n -= m; + z->p += m; + b = (char *)b + m; + n -= m; + } + return 0; +} + +/* ------------------------------------------------------------------------ */ +char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n) { + if (n > buff->buffsize) { + if (n < LUA_MINBUFFER) n = LUA_MINBUFFER; + luaZ_resizebuffer(L, buff, n); + } + return buff->buffer; +} + + diff --git a/src/lzio.h b/src/lzio.h new file mode 100644 index 000000000000..b2e56bcd6e39 --- /dev/null +++ b/src/lzio.h @@ -0,0 +1,67 @@ +/* +** $Id: lzio.h,v 1.30 2014/12/19 17:26:14 roberto Exp $ +** Buffered streams +** See Copyright Notice in lua.h +*/ + + +#ifndef lzio_h +#define lzio_h + +#include "lua.h" + +#include "lmem.h" + + +#define EOZ (-1) /* end of stream */ + +typedef struct Zio ZIO; + +#define zgetc(z) (((z)->n--)>0 ? cast_uchar(*(z)->p++) : luaZ_fill(z)) + + +typedef struct Mbuffer { + char *buffer; + size_t n; + size_t buffsize; +} Mbuffer; + +#define luaZ_initbuffer(L, buff) ((buff)->buffer = NULL, (buff)->buffsize = 0) + +#define luaZ_buffer(buff) ((buff)->buffer) +#define luaZ_sizebuffer(buff) ((buff)->buffsize) +#define luaZ_bufflen(buff) ((buff)->n) + +#define luaZ_buffremove(buff,i) ((buff)->n -= (i)) +#define luaZ_resetbuffer(buff) ((buff)->n = 0) + + +#define luaZ_resizebuffer(L, buff, size) \ + ((buff)->buffer = luaM_reallocvchar(L, (buff)->buffer, \ + (buff)->buffsize, size), \ + (buff)->buffsize = size) + +#define luaZ_freebuffer(L, buff) luaZ_resizebuffer(L, buff, 0) + + +LUAI_FUNC char *luaZ_openspace (lua_State *L, Mbuffer *buff, size_t n); +LUAI_FUNC void luaZ_init (lua_State *L, ZIO *z, lua_Reader reader, + void *data); +LUAI_FUNC size_t luaZ_read (ZIO* z, void *b, size_t n); /* read next n bytes */ + + + +/* --------- Private Part ------------------ */ + +struct Zio { + size_t n; /* bytes still unread */ + const char *p; /* current position in buffer */ + lua_Reader reader; /* reader function */ + void *data; /* additional data */ + lua_State *L; /* Lua state (for reader) */ +}; + + +LUAI_FUNC int luaZ_fill (ZIO *z); + +#endif |
