[lld] r235357 - [GNU/ELF] Add support for -X/--discard-locals.
Aaron Ballman
aaron at aaronballman.com
Fri Apr 24 09:14:48 PDT 2015
Thanks!
-Aaron
On Apr 24, 2015 11:40 AM, "Davide Italiano" <davide at freebsd.org> wrote:
> Sorry I missed this I'll take a look at it now.
> On Apr 24, 2015 7:40 AM, "Aaron Ballman" <aaron at aaronballman.com> wrote:
>
>> This commit is still causing failures on Windows. Can you please fix or
>> revert?
>>
>> Thanks!
>>
>> ~Aaron
>>
>> On Thu, Apr 23, 2015 at 11:11 AM, Aaron Ballman <aaron at aaronballman.com>
>> wrote:
>> > On Mon, Apr 20, 2015 at 6:52 PM, Davide Italiano <davide at freebsd.org>
>> wrote:
>> >> Author: davide
>> >> Date: Mon Apr 20 17:52:56 2015
>> >> New Revision: 235357
>> >>
>> >> URL: http://llvm.org/viewvc/llvm-project?rev=235357&view=rev
>> >> Log:
>> >> [GNU/ELF] Add support for -X/--discard-locals.
>> >>
>> >> There's (almost) never need to keep .L symbols around for production
>> >> builds. In fact, the FreeBSD kernel explicitly specify -X beacuse the
>> >> size impact (and the subsequent performance impact) might be
>> significant,
>> >> because we keep symbols in memory.
>> >> I was tempted to make this the default, but I haven't (yet).
>> >>
>> >> PR: 23232
>> >>
>> >> Added:
>> >> lld/trunk/test/elf/discard-locals.test
>> >> Modified:
>> >> lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h
>> >> lld/trunk/lib/Driver/GnuLdDriver.cpp
>> >> lld/trunk/lib/Driver/GnuLdOptions.td
>> >> lld/trunk/lib/ReaderWriter/ELF/SectionChunks.cpp
>> >>
>> >> Modified: lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h
>> >> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h?rev=235357&r1=235356&r2=235357&view=diff
>> >>
>> ==============================================================================
>> >> --- lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h (original)
>> >> +++ lld/trunk/include/lld/ReaderWriter/ELFLinkingContext.h Mon Apr 20
>> 17:52:56 2015
>> >> @@ -314,6 +314,10 @@ public:
>> >> bool discardLocals() const { return _discardLocals; }
>> >> void setDiscardLocals(bool d) { _discardLocals = d; }
>> >>
>> >> + /// \brief Discard temprorary local symbols.
>> >> + bool discardTempLocals() const { return _discardTempLocals; }
>> >> + void setDiscardTempLocals(bool d) { _discardTempLocals = d; }
>> >> +
>> >> /// \brief Strip symbols.
>> >> bool stripSymbols() const { return _stripSymbols; }
>> >> void setStripSymbols(bool strip) { _stripSymbols = strip; }
>> >> @@ -370,6 +374,7 @@ protected:
>> >> bool _noAllowDynamicLibraries = false;
>> >> bool _mergeRODataToTextSegment = true;
>> >> bool _demangle = true;
>> >> + bool _discardTempLocals = false;
>> >> bool _discardLocals = false;
>> >> bool _stripSymbols = false;
>> >> bool _alignSegments = true;
>> >>
>> >> Modified: lld/trunk/lib/Driver/GnuLdDriver.cpp
>> >> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Driver/GnuLdDriver.cpp?rev=235357&r1=235356&r2=235357&view=diff
>> >>
>> ==============================================================================
>> >> --- lld/trunk/lib/Driver/GnuLdDriver.cpp (original)
>> >> +++ lld/trunk/lib/Driver/GnuLdDriver.cpp Mon Apr 20 17:52:56 2015
>> >> @@ -478,6 +478,9 @@ bool GnuLdDriver::parse(int argc, const
>> >> if (parsedArgs->hasArg(OPT_discard_loc))
>> >> ctx->setDiscardLocals(true);
>> >>
>> >> + if (parsedArgs->hasArg(OPT_discard_temp_loc))
>> >> + ctx->setDiscardTempLocals(true);
>> >> +
>> >> if (parsedArgs->hasArg(OPT_strip_all))
>> >> ctx->setStripSymbols(true);
>> >>
>> >>
>> >> Modified: lld/trunk/lib/Driver/GnuLdOptions.td
>> >> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/lib/Driver/GnuLdOptions.td?rev=235357&r1=235356&r2=235357&view=diff
>> >>
>> ==============================================================================
>> >> --- lld/trunk/lib/Driver/GnuLdOptions.td (original)
>> >> +++ lld/trunk/lib/Driver/GnuLdOptions.td Mon Apr 20 17:52:56 2015
>> >> @@ -260,6 +260,11 @@ def discard_loc : Flag<["--"], "discard-
>> >> Group<grp_symbolopts>;
>> >> def alias_discard_loc: Flag<["-"], "x">,
>> >> Alias<discard_loc>;
>> >> +def discard_temp_loc : Flag<["--"], "discard-locals">,
>> >> + HelpText<"Discard temporary local symbols">,
>> >> + Group<grp_symbolopts>;
>> >> +def alias_discard_temp_loc : Flag<["-"], "X">,
>> >> + Alias<discard_temp_loc>;
>> >> def no_demangle : Flag<["--"], "no-demangle">,
>> >> HelpText<"Dont demangle C++ symbols">,
>> >> Group<grp_symbolopts>;
>> >>
>> >> Modified: lld/trunk/lib/ReaderWriter/ELF/SectionChunks.cpp
>> >> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/lib/ReaderWriter/ELF/SectionChunks.cpp?rev=235357&r1=235356&r2=235357&view=diff
>> >>
>> ==============================================================================
>> >> --- lld/trunk/lib/ReaderWriter/ELF/SectionChunks.cpp (original)
>> >> +++ lld/trunk/lib/ReaderWriter/ELF/SectionChunks.cpp Mon Apr 20
>> 17:52:56 2015
>> >> @@ -489,6 +489,11 @@ void SymbolTable<ELFT>::addSymbol(const
>> >> if (this->_ctx.discardLocals() && symbol.getBinding() ==
>> llvm::ELF::STB_LOCAL)
>> >> return;
>> >>
>> >> + // Temporary locals are all the symbols which name starts with .L.
>> >> + // This is defined by the ELF standard.
>> >> + if (this->_ctx.discardTempLocals() && atom->name().startswith(".L"))
>> >> + return;
>> >> +
>> >> _symbolTable.push_back(SymbolEntry(atom, symbol, atomLayout));
>> >> this->_fsize += sizeof(Elf_Sym);
>> >> if (this->_flags & SHF_ALLOC)
>> >>
>> >> Added: lld/trunk/test/elf/discard-locals.test
>> >> URL:
>> http://llvm.org/viewvc/llvm-project/lld/trunk/test/elf/discard-locals.test?rev=235357&view=auto
>> >>
>> ==============================================================================
>> >> --- lld/trunk/test/elf/discard-locals.test (added)
>> >> +++ lld/trunk/test/elf/discard-locals.test Mon Apr 20 17:52:56 2015
>> >> @@ -0,0 +1,66 @@
>> >> +# Test that -X/--discard-locals works.
>> >> +#
>> >> +#RUN: yaml2obj -format=elf %s -o=%t.o
>> >> +#RUN: lld -flavor gnu %t.o -shared -X -o %t1
>> >> +#RUN: llvm-objdump -t %t1 | FileCheck %s
>> >> +
>> >> +#CHECK-NOT: 0000000000400121 l .rodata 00000000 .Lsym8
>> >> +
>> >> +---
>> >> +FileHeader:
>> >> + Class: ELFCLASS64
>> >> + Data: ELFDATA2LSB
>> >> + OSABI: ELFOSABI_FREEBSD
>> >> + Type: ET_REL
>> >> + Machine: EM_X86_64
>> >> +Sections:
>> >> + - Name: .text
>> >> + Type: SHT_PROGBITS
>> >> + Flags: [ SHF_ALLOC, SHF_EXECINSTR ]
>> >> + AddressAlign: 0x0000000000000004
>> >> + Content: 00000000F20F100D00000000C3
>> >> + - Name: .data
>> >> + Type: SHT_PROGBITS
>> >> + Flags: [ SHF_WRITE, SHF_ALLOC ]
>> >> + AddressAlign: 0x0000000000000004
>> >> + Content: ''
>> >> + - Name: .bss
>> >> + Type: SHT_NOBITS
>> >> + Flags: [ SHF_WRITE, SHF_ALLOC ]
>> >> + AddressAlign: 0x0000000000000004
>> >> + Content: ''
>> >> + - Name: .rodata.str1.1
>> >> + Type: SHT_PROGBITS
>> >> + Flags: [ SHF_ALLOC, SHF_MERGE, SHF_STRINGS ]
>> >> + AddressAlign: 0x0000000000000001
>> >> + Content: ''
>> >> + - Name: .rela.text
>> >> + Type: SHT_RELA
>> >> + Link: .symtab
>> >> + AddressAlign: 0x0000000000000008
>> >> + Info: .text
>> >> + Relocations:
>> >> + - Offset: 0x0000000000000008
>> >> + Symbol: .Lsym8
>> >> + Type: R_X86_64_PC32
>> >> + Addend: -4
>> >> +Symbols:
>> >> + Local:
>> >> + - Name: .Lsym8
>> >> + Section: .rodata.str1.1
>> >> + - Name: test
>> >> + Section: .text
>> >> + Value: 0x000000000000000C
>> >> + - Name: .text
>> >> + Type: STT_SECTION
>> >> + Section: .text
>> >> + - Name: .data
>> >> + Type: STT_SECTION
>> >> + Section: .data
>> >> + - Name: .bss
>> >> + Type: STT_SECTION
>> >> + Section: .bss
>> >> + - Name: .rodata.str1.1
>> >> + Type: STT_SECTION
>> >> + Section: .rodata.str1.1
>> >> +...
>> >
>> > This test is failing for me on Windows, with:
>> >
>> >>lit E:\llvm\llvm\tools\lld\test\elf\discard-locals.test
>> > -- Testing: 1 tests, 1 threads --
>> > FAIL: lld :: elf/discard-locals.test (1 of 1)
>> > ******************** TEST 'lld :: elf/discard-locals.test' FAILED
>> > ********************
>> > Script:
>> > --
>> > yaml2obj -format=elf
>> > E:\llvm\llvm\tools\lld\test\elf\discard-locals.test
>> > -o=E:\llvm\2013\tools\lld\test\elf\Output\discard-locals.test.tmp.o
>> > lld -flavor gnu
>> > E:\llvm\2013\tools\lld\test\elf\Output\discard-locals.test.tmp.o
>> > -shared -X -o
>> E:\llvm\2013\tools\lld\test\elf\Output\discard-locals.test.tmp1
>> > llvm-objdump -t
>> > E:\llvm\2013\tools\lld\test\elf\Output\discard-locals.test.tmp1 |
>> > FileCheck E:\llvm\llvm\tools\lld\test\elf\discard-locals.test
>> > --
>> > Exit Code: 1
>> >
>> > Command Output (stdout):
>> > --
>> > Command 0: "yaml2obj" "-format=elf"
>> > "E:\llvm\llvm\tools\lld\test\elf\discard-locals.test"
>> > "-o=E:\llvm\2013\tools\lld\test\elf\Output\discard-locals.test.tmp.o"
>> > Command 0 Result: 0
>> > Command 0 Output:
>> >
>> >
>> > Command 0 Stderr:
>> >
>> >
>> > Command 1: "lld" "-flavor" "gnu"
>> > "E:\llvm\2013\tools\lld\test\elf\Output\discard-locals.test.tmp.o"
>> > "-shared" "-X" "-o"
>> > "E:\llvm\2013\tools\lld\test\elf\Output\discard-locals.test.tmp1"
>> > Command 1 Result: 1
>> > Command 1 Output:
>> >
>> >
>> > Command 1 Stderr:
>> > Cannot open
>> E:\llvm\2013\tools\lld\test\elf\Output\discard-locals.test.tmp.o:
>> > incompatible machine type
>> >
>> >
>> >
>> >
>> > --
>> >
>> > ********************
>> > Testing Time: 0.04s
>> > ********************
>> > Failing Tests (1):
>> > lld :: elf/discard-locals.test
>> >
>> > Unexpected Failures: 1
>> >
>> > ~Aaron
>> >
>> >>
>> >>
>> >> _______________________________________________
>> >> llvm-commits mailing list
>> >> llvm-commits at cs.uiuc.edu
>> >> http://lists.cs.uiuc.edu/mailman/listinfo/llvm-commits
>>
>
-------------- next part --------------
An HTML attachment was scrubbed...
URL: <http://lists.llvm.org/pipermail/llvm-commits/attachments/20150424/282ca422/attachment.html>
More information about the llvm-commits
mailing list