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Diffstat (limited to 'lib/libdtrace/common/dt_lex.l')
| -rw-r--r-- | lib/libdtrace/common/dt_lex.l | 860 |
1 files changed, 860 insertions, 0 deletions
diff --git a/lib/libdtrace/common/dt_lex.l b/lib/libdtrace/common/dt_lex.l new file mode 100644 index 000000000000..48975274dede --- /dev/null +++ b/lib/libdtrace/common/dt_lex.l @@ -0,0 +1,860 @@ +%{ +/* + * CDDL HEADER START + * + * The contents of this file are subject to the terms of the + * Common Development and Distribution License (the "License"). + * You may not use this file except in compliance with the License. + * + * You can obtain a copy of the license at usr/src/OPENSOLARIS.LICENSE + * or http://www.opensolaris.org/os/licensing. + * See the License for the specific language governing permissions + * and limitations under the License. + * + * When distributing Covered Code, include this CDDL HEADER in each + * file and include the License file at usr/src/OPENSOLARIS.LICENSE. + * If applicable, add the following below this CDDL HEADER, with the + * fields enclosed by brackets "[]" replaced with your own identifying + * information: Portions Copyright [yyyy] [name of copyright owner] + * + * CDDL HEADER END + * + * Copyright 2007 Sun Microsystems, Inc. All rights reserved. + * Use is subject to license terms. + */ + +#pragma ident "%Z%%M% %I% %E% SMI" + +#include <string.h> +#include <stdlib.h> +#include <stdio.h> +#include <assert.h> +#include <ctype.h> +#include <errno.h> + +#include <dt_impl.h> +#include <dt_grammar.h> +#include <dt_parser.h> +#include <dt_string.h> + +/* + * We need to undefine lex's input and unput macros so that references to these + * call the functions provided at the end of this source file. + */ +#if defined(sun) +#undef input +#undef unput +#else +/* + * Define YY_INPUT for flex since input() can't be re-defined. + */ +#define YY_INPUT(buf,result,max_size) \ + if (yypcb->pcb_fileptr != NULL) { \ + if (((result = fread(buf, 1, max_size, yypcb->pcb_fileptr)) == 0) \ + && ferror(yypcb->pcb_fileptr)) \ + longjmp(yypcb->pcb_jmpbuf, EDT_FIO); \ + } else { \ + int n; \ + for (n = 0; n < max_size && \ + yypcb->pcb_strptr < yypcb->pcb_string + yypcb->pcb_strlen; n++) \ + buf[n] = *yypcb->pcb_strptr++; \ + result = n; \ + } +#endif + +static int id_or_type(const char *); +#if defined(sun) +static int input(void); +static void unput(int); +#endif + +/* + * We first define a set of labeled states for use in the D lexer and then a + * set of regular expressions to simplify things below. The lexer states are: + * + * S0 - D program clause and expression lexing + * S1 - D comments (i.e. skip everything until end of comment) + * S2 - D program outer scope (probe specifiers and declarations) + * S3 - D control line parsing (i.e. after ^# is seen but before \n) + * S4 - D control line scan (locate control directives only and invoke S3) + */ +%} + +%e 1500 /* maximum nodes */ +%p 3700 /* maximum positions */ +%n 600 /* maximum states */ + +%s S0 S1 S2 S3 S4 + +RGX_AGG "@"[a-zA-Z_][0-9a-zA-Z_]* +RGX_PSPEC [-$:a-zA-Z_.?*\\\[\]!][-$:0-9a-zA-Z_.`?*\\\[\]!]* +RGX_IDENT [a-zA-Z_`][0-9a-zA-Z_`]* +RGX_INT ([0-9]+|0[xX][0-9A-Fa-f]+)[uU]?[lL]?[lL]? +RGX_FP ([0-9]+("."?)[0-9]*|"."[0-9]+)((e|E)("+"|-)?[0-9]+)?[fFlL]? +RGX_WS [\f\n\r\t\v ] +RGX_STR ([^"\\\n]|\\[^"\n]|\\\")* +RGX_CHR ([^'\\\n]|\\[^'\n]|\\')* +RGX_INTERP ^[\f\t\v ]*#!.* +RGX_CTL ^[\f\t\v ]*# + +%% + +%{ + +/* + * We insert a special prologue into yylex() itself: if the pcb contains a + * context token, we return that prior to running the normal lexer. This + * allows libdtrace to force yacc into one of our three parsing contexts: D + * expression (DT_CTX_DEXPR), D program (DT_CTX_DPROG) or D type (DT_CTX_DTYPE). + * Once the token is returned, we clear it so this only happens once. + */ +if (yypcb->pcb_token != 0) { + int tok = yypcb->pcb_token; + yypcb->pcb_token = 0; + return (tok); +} + +%} + +<S0>auto return (DT_KEY_AUTO); +<S0>break return (DT_KEY_BREAK); +<S0>case return (DT_KEY_CASE); +<S0>char return (DT_KEY_CHAR); +<S0>const return (DT_KEY_CONST); +<S0>continue return (DT_KEY_CONTINUE); +<S0>counter return (DT_KEY_COUNTER); +<S0>default return (DT_KEY_DEFAULT); +<S0>do return (DT_KEY_DO); +<S0>double return (DT_KEY_DOUBLE); +<S0>else return (DT_KEY_ELSE); +<S0>enum return (DT_KEY_ENUM); +<S0>extern return (DT_KEY_EXTERN); +<S0>float return (DT_KEY_FLOAT); +<S0>for return (DT_KEY_FOR); +<S0>goto return (DT_KEY_GOTO); +<S0>if return (DT_KEY_IF); +<S0>import return (DT_KEY_IMPORT); +<S0>inline return (DT_KEY_INLINE); +<S0>int return (DT_KEY_INT); +<S0>long return (DT_KEY_LONG); +<S0>offsetof return (DT_TOK_OFFSETOF); +<S0>probe return (DT_KEY_PROBE); +<S0>provider return (DT_KEY_PROVIDER); +<S0>register return (DT_KEY_REGISTER); +<S0>restrict return (DT_KEY_RESTRICT); +<S0>return return (DT_KEY_RETURN); +<S0>self return (DT_KEY_SELF); +<S0>short return (DT_KEY_SHORT); +<S0>signed return (DT_KEY_SIGNED); +<S0>sizeof return (DT_TOK_SIZEOF); +<S0>static return (DT_KEY_STATIC); +<S0>string return (DT_KEY_STRING); +<S0>stringof return (DT_TOK_STRINGOF); +<S0>struct return (DT_KEY_STRUCT); +<S0>switch return (DT_KEY_SWITCH); +<S0>this return (DT_KEY_THIS); +<S0>translator return (DT_KEY_XLATOR); +<S0>typedef return (DT_KEY_TYPEDEF); +<S0>union return (DT_KEY_UNION); +<S0>unsigned return (DT_KEY_UNSIGNED); +<S0>void return (DT_KEY_VOID); +<S0>volatile return (DT_KEY_VOLATILE); +<S0>while return (DT_KEY_WHILE); +<S0>xlate return (DT_TOK_XLATE); + +<S2>auto { yybegin(YYS_EXPR); return (DT_KEY_AUTO); } +<S2>char { yybegin(YYS_EXPR); return (DT_KEY_CHAR); } +<S2>const { yybegin(YYS_EXPR); return (DT_KEY_CONST); } +<S2>counter { yybegin(YYS_DEFINE); return (DT_KEY_COUNTER); } +<S2>double { yybegin(YYS_EXPR); return (DT_KEY_DOUBLE); } +<S2>enum { yybegin(YYS_EXPR); return (DT_KEY_ENUM); } +<S2>extern { yybegin(YYS_EXPR); return (DT_KEY_EXTERN); } +<S2>float { yybegin(YYS_EXPR); return (DT_KEY_FLOAT); } +<S2>import { yybegin(YYS_EXPR); return (DT_KEY_IMPORT); } +<S2>inline { yybegin(YYS_DEFINE); return (DT_KEY_INLINE); } +<S2>int { yybegin(YYS_EXPR); return (DT_KEY_INT); } +<S2>long { yybegin(YYS_EXPR); return (DT_KEY_LONG); } +<S2>provider { yybegin(YYS_DEFINE); return (DT_KEY_PROVIDER); } +<S2>register { yybegin(YYS_EXPR); return (DT_KEY_REGISTER); } +<S2>restrict { yybegin(YYS_EXPR); return (DT_KEY_RESTRICT); } +<S2>self { yybegin(YYS_EXPR); return (DT_KEY_SELF); } +<S2>short { yybegin(YYS_EXPR); return (DT_KEY_SHORT); } +<S2>signed { yybegin(YYS_EXPR); return (DT_KEY_SIGNED); } +<S2>static { yybegin(YYS_EXPR); return (DT_KEY_STATIC); } +<S2>string { yybegin(YYS_EXPR); return (DT_KEY_STRING); } +<S2>struct { yybegin(YYS_EXPR); return (DT_KEY_STRUCT); } +<S2>this { yybegin(YYS_EXPR); return (DT_KEY_THIS); } +<S2>translator { yybegin(YYS_DEFINE); return (DT_KEY_XLATOR); } +<S2>typedef { yybegin(YYS_EXPR); return (DT_KEY_TYPEDEF); } +<S2>union { yybegin(YYS_EXPR); return (DT_KEY_UNION); } +<S2>unsigned { yybegin(YYS_EXPR); return (DT_KEY_UNSIGNED); } +<S2>void { yybegin(YYS_EXPR); return (DT_KEY_VOID); } +<S2>volatile { yybegin(YYS_EXPR); return (DT_KEY_VOLATILE); } + +<S0>"$$"[0-9]+ { + int i = atoi(yytext + 2); + char *v = ""; + + /* + * A macro argument reference substitutes the text of + * an argument in place of the current token. When we + * see $$<d> we fetch the saved string from pcb_sargv + * (or use the default argument if the option has been + * set and the argument hasn't been specified) and + * return a token corresponding to this string. + */ + if (i < 0 || (i >= yypcb->pcb_sargc && + !(yypcb->pcb_cflags & DTRACE_C_DEFARG))) { + xyerror(D_MACRO_UNDEF, "macro argument %s is " + "not defined\n", yytext); + } + + if (i < yypcb->pcb_sargc) { + v = yypcb->pcb_sargv[i]; /* get val from pcb */ + yypcb->pcb_sflagv[i] |= DT_IDFLG_REF; + } + + if ((yylval.l_str = strdup(v)) == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + + (void) stresc2chr(yylval.l_str); + return (DT_TOK_STRING); + } + +<S0>"$"[0-9]+ { + int i = atoi(yytext + 1); + char *p, *v = "0"; + + /* + * A macro argument reference substitutes the text of + * one identifier or integer pattern for another. When + * we see $<d> we fetch the saved string from pcb_sargv + * (or use the default argument if the option has been + * set and the argument hasn't been specified) and + * return a token corresponding to this string. + */ + if (i < 0 || (i >= yypcb->pcb_sargc && + !(yypcb->pcb_cflags & DTRACE_C_DEFARG))) { + xyerror(D_MACRO_UNDEF, "macro argument %s is " + "not defined\n", yytext); + } + + if (i < yypcb->pcb_sargc) { + v = yypcb->pcb_sargv[i]; /* get val from pcb */ + yypcb->pcb_sflagv[i] |= DT_IDFLG_REF; + } + + /* + * If the macro text is not a valid integer or ident, + * then we treat it as a string. The string may be + * optionally enclosed in quotes, which we strip. + */ + if (strbadidnum(v)) { + size_t len = strlen(v); + + if (len != 1 && *v == '"' && v[len - 1] == '"') + yylval.l_str = strndup(v + 1, len - 2); + else + yylval.l_str = strndup(v, len); + + if (yylval.l_str == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + + (void) stresc2chr(yylval.l_str); + return (DT_TOK_STRING); + } + + /* + * If the macro text is not a string an begins with a + * digit or a +/- sign, process it as an integer token. + */ + if (isdigit(v[0]) || v[0] == '-' || v[0] == '+') { + if (isdigit(v[0])) + yyintprefix = 0; + else + yyintprefix = *v++; + + errno = 0; + yylval.l_int = strtoull(v, &p, 0); + (void) strncpy(yyintsuffix, p, + sizeof (yyintsuffix)); + yyintdecimal = *v != '0'; + + if (errno == ERANGE) { + xyerror(D_MACRO_OFLOW, "macro argument" + " %s constant %s results in integer" + " overflow\n", yytext, v); + } + + return (DT_TOK_INT); + } + + return (id_or_type(v)); + } + +<S0>"$$"{RGX_IDENT} { + dt_ident_t *idp = dt_idhash_lookup( + yypcb->pcb_hdl->dt_macros, yytext + 2); + + char s[16]; /* enough for UINT_MAX + \0 */ + + if (idp == NULL) { + xyerror(D_MACRO_UNDEF, "macro variable %s " + "is not defined\n", yytext); + } + + /* + * For the moment, all current macro variables are of + * type id_t (refer to dtrace_update() for details). + */ + (void) snprintf(s, sizeof (s), "%u", idp->di_id); + if ((yylval.l_str = strdup(s)) == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + + return (DT_TOK_STRING); + } + +<S0>"$"{RGX_IDENT} { + dt_ident_t *idp = dt_idhash_lookup( + yypcb->pcb_hdl->dt_macros, yytext + 1); + + if (idp == NULL) { + xyerror(D_MACRO_UNDEF, "macro variable %s " + "is not defined\n", yytext); + } + + /* + * For the moment, all current macro variables are of + * type id_t (refer to dtrace_update() for details). + */ + yylval.l_int = (intmax_t)(int)idp->di_id; + yyintprefix = 0; + yyintsuffix[0] = '\0'; + yyintdecimal = 1; + + return (DT_TOK_INT); + } + +<S0>{RGX_IDENT} { + return (id_or_type(yytext)); + } + +<S0>{RGX_AGG} { + if ((yylval.l_str = strdup(yytext)) == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + return (DT_TOK_AGG); + } + +<S0>"@" { + if ((yylval.l_str = strdup("@_")) == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + return (DT_TOK_AGG); + } + +<S0>{RGX_INT} | +<S2>{RGX_INT} | +<S3>{RGX_INT} { + char *p; + + errno = 0; + yylval.l_int = strtoull(yytext, &p, 0); + yyintprefix = 0; + (void) strncpy(yyintsuffix, p, sizeof (yyintsuffix)); + yyintdecimal = yytext[0] != '0'; + + if (errno == ERANGE) { + xyerror(D_INT_OFLOW, "constant %s results in " + "integer overflow\n", yytext); + } + + if (*p != '\0' && strchr("uUlL", *p) == NULL) { + xyerror(D_INT_DIGIT, "constant %s contains " + "invalid digit %c\n", yytext, *p); + } + + if ((YYSTATE) != S3) + return (DT_TOK_INT); + + yypragma = dt_node_link(yypragma, + dt_node_int(yylval.l_int)); + } + +<S0>{RGX_FP} yyerror("floating-point constants are not permitted\n"); + +<S0>\"{RGX_STR}$ | +<S3>\"{RGX_STR}$ xyerror(D_STR_NL, "newline encountered in string literal"); + +<S0>\"{RGX_STR}\" | +<S3>\"{RGX_STR}\" { + /* + * Quoted string -- convert C escape sequences and + * return the string as a token. + */ + yylval.l_str = strndup(yytext + 1, yyleng - 2); + + if (yylval.l_str == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + + (void) stresc2chr(yylval.l_str); + if ((YYSTATE) != S3) + return (DT_TOK_STRING); + + yypragma = dt_node_link(yypragma, + dt_node_string(yylval.l_str)); + } + +<S0>'{RGX_CHR}$ xyerror(D_CHR_NL, "newline encountered in character constant"); + +<S0>'{RGX_CHR}' { + char *s, *p, *q; + size_t nbytes; + + /* + * Character constant -- convert C escape sequences and + * return the character as an integer immediate value. + */ + if (yyleng == 2) + xyerror(D_CHR_NULL, "empty character constant"); + + s = yytext + 1; + yytext[yyleng - 1] = '\0'; + nbytes = stresc2chr(s); + yylval.l_int = 0; + yyintprefix = 0; + yyintsuffix[0] = '\0'; + yyintdecimal = 1; + + if (nbytes > sizeof (yylval.l_int)) { + xyerror(D_CHR_OFLOW, "character constant is " + "too long"); + } +#if BYTE_ORDER == _LITTLE_ENDIAN + p = ((char *)&yylval.l_int) + nbytes - 1; + for (q = s; nbytes != 0; nbytes--) + *p-- = *q++; +#else + bcopy(s, ((char *)&yylval.l_int) + + sizeof (yylval.l_int) - nbytes, nbytes); +#endif + return (DT_TOK_INT); + } + +<S0>"/*" | +<S2>"/*" { + yypcb->pcb_cstate = (YYSTATE); + BEGIN(S1); + } + +<S0>{RGX_INTERP} | +<S2>{RGX_INTERP} ; /* discard any #! lines */ + +<S0>{RGX_CTL} | +<S2>{RGX_CTL} | +<S4>{RGX_CTL} { + assert(yypragma == NULL); + yypcb->pcb_cstate = (YYSTATE); + BEGIN(S3); + } + +<S4>. ; /* discard */ +<S4>"\n" ; /* discard */ + +<S0>"/" { + int c, tok; + + /* + * The use of "/" as the predicate delimiter and as the + * integer division symbol requires special lookahead + * to avoid a shift/reduce conflict in the D grammar. + * We look ahead to the next non-whitespace character. + * If we encounter EOF, ";", "{", or "/", then this "/" + * closes the predicate and we return DT_TOK_EPRED. + * If we encounter anything else, it's DT_TOK_DIV. + */ + while ((c = input()) != 0) { + if (strchr("\f\n\r\t\v ", c) == NULL) + break; + } + + if (c == 0 || c == ';' || c == '{' || c == '/') { + if (yypcb->pcb_parens != 0) { + yyerror("closing ) expected in " + "predicate before /\n"); + } + if (yypcb->pcb_brackets != 0) { + yyerror("closing ] expected in " + "predicate before /\n"); + } + tok = DT_TOK_EPRED; + } else + tok = DT_TOK_DIV; + + unput(c); + return (tok); + } + +<S0>"(" { + yypcb->pcb_parens++; + return (DT_TOK_LPAR); + } + +<S0>")" { + if (--yypcb->pcb_parens < 0) + yyerror("extra ) in input stream\n"); + return (DT_TOK_RPAR); + } + +<S0>"[" { + yypcb->pcb_brackets++; + return (DT_TOK_LBRAC); + } + +<S0>"]" { + if (--yypcb->pcb_brackets < 0) + yyerror("extra ] in input stream\n"); + return (DT_TOK_RBRAC); + } + +<S0>"{" | +<S2>"{" { + yypcb->pcb_braces++; + return ('{'); + } + +<S0>"}" { + if (--yypcb->pcb_braces < 0) + yyerror("extra } in input stream\n"); + return ('}'); + } + +<S0>"|" return (DT_TOK_BOR); +<S0>"^" return (DT_TOK_XOR); +<S0>"&" return (DT_TOK_BAND); +<S0>"&&" return (DT_TOK_LAND); +<S0>"^^" return (DT_TOK_LXOR); +<S0>"||" return (DT_TOK_LOR); +<S0>"==" return (DT_TOK_EQU); +<S0>"!=" return (DT_TOK_NEQ); +<S0>"<" return (DT_TOK_LT); +<S0>"<=" return (DT_TOK_LE); +<S0>">" return (DT_TOK_GT); +<S0>">=" return (DT_TOK_GE); +<S0>"<<" return (DT_TOK_LSH); +<S0>">>" return (DT_TOK_RSH); +<S0>"+" return (DT_TOK_ADD); +<S0>"-" return (DT_TOK_SUB); +<S0>"*" return (DT_TOK_MUL); +<S0>"%" return (DT_TOK_MOD); +<S0>"~" return (DT_TOK_BNEG); +<S0>"!" return (DT_TOK_LNEG); +<S0>"?" return (DT_TOK_QUESTION); +<S0>":" return (DT_TOK_COLON); +<S0>"." return (DT_TOK_DOT); +<S0>"->" return (DT_TOK_PTR); +<S0>"=" return (DT_TOK_ASGN); +<S0>"+=" return (DT_TOK_ADD_EQ); +<S0>"-=" return (DT_TOK_SUB_EQ); +<S0>"*=" return (DT_TOK_MUL_EQ); +<S0>"/=" return (DT_TOK_DIV_EQ); +<S0>"%=" return (DT_TOK_MOD_EQ); +<S0>"&=" return (DT_TOK_AND_EQ); +<S0>"^=" return (DT_TOK_XOR_EQ); +<S0>"|=" return (DT_TOK_OR_EQ); +<S0>"<<=" return (DT_TOK_LSH_EQ); +<S0>">>=" return (DT_TOK_RSH_EQ); +<S0>"++" return (DT_TOK_ADDADD); +<S0>"--" return (DT_TOK_SUBSUB); +<S0>"..." return (DT_TOK_ELLIPSIS); +<S0>"," return (DT_TOK_COMMA); +<S0>";" return (';'); +<S0>{RGX_WS} ; /* discard */ +<S0>"\\"\n ; /* discard */ +<S0>. yyerror("syntax error near \"%c\"\n", yytext[0]); + +<S1>"/*" yyerror("/* encountered inside a comment\n"); +<S1>"*/" BEGIN(yypcb->pcb_cstate); +<S1>.|\n ; /* discard */ + +<S2>{RGX_PSPEC} { + /* + * S2 has an ambiguity because RGX_PSPEC includes '*' + * as a glob character and '*' also can be DT_TOK_STAR. + * Since lex always matches the longest token, this + * rule can be matched by an input string like "int*", + * which could begin a global variable declaration such + * as "int*x;" or could begin a RGX_PSPEC with globbing + * such as "int* { trace(timestamp); }". If C_PSPEC is + * not set, we must resolve the ambiguity in favor of + * the type and perform lexer pushback if the fragment + * before '*' or entire fragment matches a type name. + * If C_PSPEC is set, we always return a PSPEC token. + * If C_PSPEC is off, the user can avoid ambiguity by + * including a ':' delimiter in the specifier, which + * they should be doing anyway to specify the provider. + */ + if (!(yypcb->pcb_cflags & DTRACE_C_PSPEC) && + strchr(yytext, ':') == NULL) { + + char *p = strchr(yytext, '*'); + char *q = yytext + yyleng - 1; + + if (p != NULL && p > yytext) + *p = '\0'; /* prune yytext */ + + if (dt_type_lookup(yytext, NULL) == 0) { + yylval.l_str = strdup(yytext); + + if (yylval.l_str == NULL) { + longjmp(yypcb->pcb_jmpbuf, + EDT_NOMEM); + } + + if (p != NULL && p > yytext) { + for (*p = '*'; q >= p; q--) + unput(*q); + } + + yybegin(YYS_EXPR); + return (DT_TOK_TNAME); + } + + if (p != NULL && p > yytext) + *p = '*'; /* restore yytext */ + } + + if ((yylval.l_str = strdup(yytext)) == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + + return (DT_TOK_PSPEC); + } + +<S2>"/" return (DT_TOK_DIV); +<S2>"," return (DT_TOK_COMMA); + +<S2>{RGX_WS} ; /* discard */ +<S2>. yyerror("syntax error near \"%c\"\n", yytext[0]); + +<S3>\n { + dt_pragma(yypragma); + yypragma = NULL; + BEGIN(yypcb->pcb_cstate); + } + +<S3>[\f\t\v ]+ ; /* discard */ + +<S3>[^\f\n\t\v "]+ { + dt_node_t *dnp; + + if ((yylval.l_str = strdup(yytext)) == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + + /* + * We want to call dt_node_ident() here, but we can't + * because it will expand inlined identifiers, which we + * don't want to do from #pragma context in order to + * support pragmas that apply to the ident itself. We + * call dt_node_string() and then reset dn_op instead. + */ + dnp = dt_node_string(yylval.l_str); + dnp->dn_kind = DT_NODE_IDENT; + dnp->dn_op = DT_TOK_IDENT; + yypragma = dt_node_link(yypragma, dnp); + } + +<S3>. yyerror("syntax error near \"%c\"\n", yytext[0]); + +%% + +/* + * yybegin provides a wrapper for use from C code around the lex BEGIN() macro. + * We use two main states for lexing because probe descriptions use a syntax + * that is incompatible with the normal D tokens (e.g. names can contain "-"). + * yybegin also handles the job of switching between two lists of dt_nodes + * as we allocate persistent definitions, like inlines, and transient nodes + * that will be freed once we are done parsing the current program file. + */ +void +yybegin(yystate_t state) +{ +#ifdef YYDEBUG + yydebug = _dtrace_debug; +#endif + if (yypcb->pcb_yystate == state) + return; /* nothing to do if we're in the state already */ + + if (yypcb->pcb_yystate == YYS_DEFINE) { + yypcb->pcb_list = yypcb->pcb_hold; + yypcb->pcb_hold = NULL; + } + + switch (state) { + case YYS_CLAUSE: + BEGIN(S2); + break; + case YYS_DEFINE: + assert(yypcb->pcb_hold == NULL); + yypcb->pcb_hold = yypcb->pcb_list; + yypcb->pcb_list = NULL; + /*FALLTHRU*/ + case YYS_EXPR: + BEGIN(S0); + break; + case YYS_DONE: + break; + case YYS_CONTROL: + BEGIN(S4); + break; + default: + xyerror(D_UNKNOWN, "internal error -- bad yystate %d\n", state); + } + + yypcb->pcb_yystate = state; +} + +void +yyinit(dt_pcb_t *pcb) +{ + yypcb = pcb; + yylineno = 1; + yypragma = NULL; +#if defined(sun) + yysptr = yysbuf; +#endif +} + +/* + * Given a lexeme 's' (typically yytext), set yylval and return an appropriate + * token to the parser indicating either an identifier or a typedef name. + * User-defined global variables always take precedence over types, but we do + * use some heuristics because D programs can look at an ever-changing set of + * kernel types and also can implicitly instantiate variables by assignment, + * unlike in C. The code here is ordered carefully as lookups are not cheap. + */ +static int +id_or_type(const char *s) +{ + dtrace_hdl_t *dtp = yypcb->pcb_hdl; + dt_decl_t *ddp = yypcb->pcb_dstack.ds_decl; + int c0, c1, ttok = DT_TOK_TNAME; + dt_ident_t *idp; + + if ((s = yylval.l_str = strdup(s)) == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + + /* + * If the lexeme is a global variable or likely identifier or *not* a + * type_name, then it is an identifier token. + */ + if (dt_idstack_lookup(&yypcb->pcb_globals, s) != NULL || + dt_idhash_lookup(yypcb->pcb_idents, s) != NULL || + dt_type_lookup(s, NULL) != 0) + return (DT_TOK_IDENT); + + /* + * If we're in the midst of parsing a declaration and a type_specifier + * has already been shifted, then return DT_TOK_IDENT instead of TNAME. + * This semantic is necessary to permit valid ISO C code such as: + * + * typedef int foo; + * struct s { foo foo; }; + * + * without causing shift/reduce conflicts in the direct_declarator part + * of the grammar. The result is that we must check for conflicting + * redeclarations of the same identifier as part of dt_node_decl(). + */ + if (ddp != NULL && ddp->dd_name != NULL) + return (DT_TOK_IDENT); + + /* + * If the lexeme is a type name and we are not in a program clause, + * then always interpret it as a type and return DT_TOK_TNAME. + */ + if ((YYSTATE) != S0) + return (DT_TOK_TNAME); + + /* + * If the lexeme matches a type name but is in a program clause, then + * it could be a type or it could be an undefined variable. Peek at + * the next token to decide. If we see ++, --, [, or =, we know there + * might be an assignment that is trying to create a global variable, + * so we optimistically return DT_TOK_IDENT. There is no harm in being + * wrong: a type_name followed by ++, --, [, or = is a syntax error. + */ + while ((c0 = input()) != 0) { + if (strchr("\f\n\r\t\v ", c0) == NULL) + break; + } + + switch (c0) { + case '+': + case '-': + if ((c1 = input()) == c0) + ttok = DT_TOK_IDENT; + unput(c1); + break; + + case '=': + if ((c1 = input()) != c0) + ttok = DT_TOK_IDENT; + unput(c1); + break; + case '[': + ttok = DT_TOK_IDENT; + break; + } + + if (ttok == DT_TOK_IDENT) { + idp = dt_idhash_insert(yypcb->pcb_idents, s, DT_IDENT_SCALAR, 0, + 0, _dtrace_defattr, 0, &dt_idops_thaw, NULL, dtp->dt_gen); + + if (idp == NULL) + longjmp(yypcb->pcb_jmpbuf, EDT_NOMEM); + } + + unput(c0); + return (ttok); +} + +#if defined(sun) +static int +input(void) +{ + int c; + + if (yysptr > yysbuf) + c = *--yysptr; + else if (yypcb->pcb_fileptr != NULL) + c = fgetc(yypcb->pcb_fileptr); + else if (yypcb->pcb_strptr < yypcb->pcb_string + yypcb->pcb_strlen) + c = *yypcb->pcb_strptr++; + else + c = EOF; + + if (c == '\n') + yylineno++; + + if (c != EOF) + return (c); + + if ((YYSTATE) == S1) + yyerror("end-of-file encountered before matching */\n"); + + if ((YYSTATE) == S3) + yyerror("end-of-file encountered before end of control line\n"); + + if (yypcb->pcb_fileptr != NULL && ferror(yypcb->pcb_fileptr)) + longjmp(yypcb->pcb_jmpbuf, EDT_FIO); + + return (0); /* EOF */ +} + +static void +unput(int c) +{ + if (c == '\n') + yylineno--; + + *yysptr++ = c; + yytchar = c; +} +#endif |