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diff --git a/docs/ReleaseNotes.rst b/docs/ReleaseNotes.rst index 01a984148b7e..dcd6ac0602d3 100644 --- a/docs/ReleaseNotes.rst +++ b/docs/ReleaseNotes.rst @@ -1,23 +1,22 @@ ======================= -lld 5.0.0 Release Notes +LLD 6.0.0 Release Notes ======================= .. contents:: :local: +.. warning:: + These are in-progress notes for the upcoming LLVM 6.0.0 release. + Release notes for previous releases can be found on + `the Download Page <http://releases.llvm.org/download.html>`_. + Introduction ============ -lld is a linker from the LLVM project. It supports ELF (Unix), COFF (Windows) -and Mach-O (macOS), and it is generally faster than the GNU bfd or gold linkers -or the MSVC linker. - -lld is designed to be a drop-in replacement for the system linkers, so that -users don't need to change their build systems other than swapping the linker -command. - -All lld releases may be downloaded from the `LLVM releases web site -<http://llvm.org/releases/>`_. +This document contains the release notes for the LLD linker, release 6.0.0. +Here we describe the status of LLD, including major improvements +from the previous release. All LLD releases may be downloaded +from the `LLVM releases web site <http://llvm.org/releases/>`_. Non-comprehensive list of changes in this release ================================================= @@ -25,148 +24,14 @@ Non-comprehensive list of changes in this release ELF Improvements ---------------- -* First and foremost, a lot of compatibility issues and bugs have been fixed. - Linker script support has significantly improved. As a result, we believe you - are very likely to be able to link your programs with lld without experiencing - any problem now. - -* Error message format has changed in order to improve readability. - Traditionally, linker's error messages are concise and arguably too terse. - This is an example of lld 4.0.0's error message (they are actually in one line):: - - /ssd/clang/bin/ld.lld: error: /ssd/llvm-project/lld/ELF/Writer.cpp:207: - undefined symbol 'lld::elf::EhFrameSection::addSection()' - - It is not easy to read because too much information is packed into a single line - and the embedded text, particularly a symbol name, is sometimes too long. - In lld 5.0.0, we use more vertical space to print out error messages in a more - structured manner like this:: - - bin/ld.lld: error: undefined symbol: lld::elf::EhFrameSection::addSection() - >>> Referenced by Writer.cpp:207 (/ssd/llvm-project/lld/ELF/Writer.cpp:207) - >>> Writer.cpp.o in archive lib/liblldELF.a - - As a bonus, the new error message contains source code location of the error - if it is available from debug info. - -* ``./configure`` scripts generated by GNU autoconf determines whether a linker - supports modern GNU-compatible features or not by searching for "GNU" in the - ``--help`` message. To be compatible with the scripts, we decided to add a - string "(compatible with GNU linkers)" to our ``--help`` message. This is a - hack, but just like the web browser's User-Agent string (which everyone still - claim they are "Mozilla/5.0"), we had no choice other than doing this to claim - that we accept GNU-compatible options. +* Item 1. -* The ``-Map`` option is added. The option is to make the linker to print out how - input files are mapped to the output file. Here is an example:: +COFF Improvements +----------------- - Address Size Align Out In Symbol - 00000000016d84d8 00000000008f8f50 8 .eh_frame - 00000000016d84d8 00000000008f8f50 8 <internal>:(.eh_frame) - 0000000001fd2000 00000000034b3bd0 16 .text - 0000000001fd2000 000000000000002a 1 /usr/lib/x86_64-linux-gnu/crt1.o:(.text) - 0000000001fd2000 0000000000000000 0 _start - 0000000001fd202a 0000000000000000 1 /usr/lib/x86_64-linux-gnu/crti.o:(.text) - 0000000001fd2030 00000000000000bd 16 /usr/lib/gcc/x86_64-linux-gnu/4.8/crtbegin.o:(.text) - 0000000001fd2030 0000000000000000 0 deregister_tm_clones - 0000000001fd2060 0000000000000000 0 register_tm_clones - - This format is not the same as GNU linkers as our linker internal data - structure is different from them but contains the same amount of information - and should be more readable than their outputs. - - As with other lld features, the ``-Map`` option is designed with speed in mind. - The option would generate a hundred megabyte text file if you link a large - program with it. lld can usually do that in a few seconds, and it is generally - a few times faster than the GNU gold's ``-Map`` option. - -* lld's ``--gdb-index`` option used to be slow, but we sped it up so that it is - at least as fast as the GNU gold. - -* Some nonstandard relocations, such as R_X86_64_8 or R_X86_64_16, are supported. - They are not used for 32/64-bit applications, but some 16-bit bootloaders need - them. - -* Paddings in executable text sections are now filled with trap instructions - (such as INT3) instead of being left as null bytes. This change improves - disassembler outputs because it now prints out trap instructions instead of - trying to decode 0x00 as an instruction. It also makes debugging of some type - of program easier because when the control reaches a padding, the program - immediately raises an error. - -* The following options are added: ``-M``, ``-Map``, - ``-compress-debug-sections``, ``-emit-relocs``, - ``-error-unresolved-symbols``, ``-exclude-libs``, ``-filter``, - ``-no-dynamic-linker``, ``-no-export-dynamic``, ``-no-fatal-warnings``, - ``-print-map``, ``-warn-unresolved-symbols``, ``-z nocopyreloc``, - ``-z notext``, ``-z rodynamic`` - - -Contributors to lld 5.0 -======================= +* Item 1. -We had 63 individuals contribute to lld 5.0. Thank you so much! +MachO Improvements +------------------ -- Adrian McCarthy -- Alberto Magni -- Alexander Richardson -- Andre Vieira -- Andrew Ng -- Anton Korobeynikov -- Bob Haarman -- David Blaikie -- Davide Italiano -- David L. Jones -- Dmitry Mikulin -- Ed Maste -- Ed Schouten -- Eric Beckmann -- Eric Fiselier -- Eugene Leviant -- Evgeniy Stepanov -- Galina Kistanova -- George Rimar -- Hans Wennborg -- Igor Kudrin -- Ismail Donmez -- Jake Ehrlich -- James Henderson -- Joel Jones -- Jon Chesterfield -- Kamil Rytarowski -- Kevin Enderby -- Konstantin Zhuravlyov -- Kyungwoo Lee -- Leslie Zhai -- Mark Kettenis -- Martell Malone -- Martin Storsjo -- Meador Inge -- Mehdi Amini -- Michal Gorny -- NAKAMURA Takumi -- Paul Robinson -- Pavel Labath -- Petar Jovanovic -- Peter Collingbourne -- Peter Smith -- Petr Hosek -- Rafael Espindola -- Reid Kleckner -- Richard Smith -- Robert Clarke -- Rui Ueyama -- Saleem Abdulrasool -- Sam Clegg -- Sean Eveson -- Sean Silva -- Shankar Easwaran -- Shoaib Meenai -- Simon Atanasyan -- Simon Dardis -- Simon Tatham -- Sylvestre Ledru -- Tom Stellard -- Vitaly Buka -- Yuka Takahashi -- Zachary Turner +* Item 1. |