[lld] r235357 - [GNU/ELF] Add support for -X/--discard-locals.
Davide Italiano
davide at freebsd.org
Fri Apr 24 08:40:56 PDT 2015
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
>
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