diff options
| author | dim <dim@FreeBSD.org> | 2016-12-26 20:36:37 +0000 |
|---|---|---|
| committer | dim <dim@FreeBSD.org> | 2016-12-26 20:36:37 +0000 |
| commit | 06210ae42d418d50d8d9365d5c9419308ae9e7ee (patch) | |
| tree | ab60b4cdd6e430dda1f292a46a77ddb744723f31 /contrib/llvm/lib/MC/ELFObjectWriter.cpp | |
| parent | 2dd166267f53df1c3748b4325d294b9b839de74b (diff) | |
| download | FreeBSD-src-06210ae42d418d50d8d9365d5c9419308ae9e7ee.zip FreeBSD-src-06210ae42d418d50d8d9365d5c9419308ae9e7ee.tar.gz | |
MFC r309124:
Upgrade our copies of clang, llvm, lldb, compiler-rt and libc++ to 3.9.0
release, and add lld 3.9.0. Also completely revamp the build system for
clang, llvm, lldb and their related tools.
Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.
Release notes for llvm, clang and lld are available here:
<http://llvm.org/releases/3.9.0/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/clang/docs/ReleaseNotes.html>
<http://llvm.org/releases/3.9.0/tools/lld/docs/ReleaseNotes.html>
Thanks to Ed Maste, Bryan Drewery, Andrew Turner, Antoine Brodin and Jan
Beich for their help.
Relnotes: yes
MFC r309147:
Pull in r282174 from upstream llvm trunk (by Krzysztof Parzyszek):
[PPC] Set SP after loading data from stack frame, if no red zone is
present
Follow-up to r280705: Make sure that the SP is only restored after
all data is loaded from the stack frame, if there is no red zone.
This completes the fix for
https://llvm.org/bugs/show_bug.cgi?id=26519.
Differential Revision: https://reviews.llvm.org/D24466
Reported by: Mark Millard
PR: 214433
MFC r309149:
Pull in r283060 from upstream llvm trunk (by Hal Finkel):
[PowerPC] Refactor soft-float support, and enable PPC64 soft float
This change enables soft-float for PowerPC64, and also makes
soft-float disable all vector instruction sets for both 32-bit and
64-bit modes. This latter part is necessary because the PPC backend
canonicalizes many Altivec vector types to floating-point types, and
so soft-float breaks scalarization support for many operations. Both
for embedded targets and for operating-system kernels desiring
soft-float support, it seems reasonable that disabling hardware
floating-point also disables vector instructions (embedded targets
without hardware floating point support are unlikely to have Altivec,
etc. and operating system kernels desiring not to use floating-point
registers to lower syscall cost are unlikely to want to use vector
registers either). If someone needs this to work, we'll need to
change the fact that we promote many Altivec operations to act on
v4f32. To make it possible to disable Altivec when soft-float is
enabled, hardware floating-point support needs to be expressed as a
positive feature, like the others, and not a negative feature,
because target features cannot have dependencies on the disabling of
some other feature. So +soft-float has now become -hard-float.
Fixes PR26970.
Pull in r283061 from upstream clang trunk (by Hal Finkel):
[PowerPC] Enable soft-float for PPC64, and +soft-float -> -hard-float
Enable soft-float support on PPC64, as the backend now supports it.
Also, the backend now uses -hard-float instead of +soft-float, so set
the target features accordingly.
Fixes PR26970.
Reported by: Mark Millard
PR: 214433
MFC r309212:
Add a few missed clang 3.9.0 files to OptionalObsoleteFiles.
MFC r309262:
Fix packaging for clang, lldb and lld 3.9.0
During the upgrade of clang/llvm etc to 3.9.0 in r309124, the PACKAGE
directive in the usr.bin/clang/*.mk files got dropped accidentally.
Restore it, with a few minor changes and additions:
* Correct license in clang.ucl to NCSA
* Add PACKAGE=clang for clang and most of the "ll" tools
* Put lldb in its own package
* Put lld in its own package
Reviewed by: gjb, jmallett
Differential Revision: https://reviews.freebsd.org/D8666
MFC r309656:
During the bootstrap phase, when building the minimal llvm library on
PowerPC, add lib/Support/Atomic.cpp. This is needed because upstream
llvm revision r271821 disabled the use of std::call_once, which causes
some fallback functions from Atomic.cpp to be used instead.
Reported by: Mark Millard
PR: 214902
MFC r309835:
Tentatively apply https://reviews.llvm.org/D18730 to work around gcc PR
70528 (bogus error: constructor required before non-static data member).
This should fix buildworld with the external gcc package.
Reported by: https://jenkins.freebsd.org/job/FreeBSD_HEAD_amd64_gcc/
MFC r310194:
Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
3.9.1 release.
Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.
Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/3.9.1/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/3.9.1/tools/lld/docs/ReleaseNotes.html>
Relnotes: yes
Diffstat (limited to 'contrib/llvm/lib/MC/ELFObjectWriter.cpp')
| -rw-r--r-- | contrib/llvm/lib/MC/ELFObjectWriter.cpp | 395 |
1 files changed, 214 insertions, 181 deletions
diff --git a/contrib/llvm/lib/MC/ELFObjectWriter.cpp b/contrib/llvm/lib/MC/ELFObjectWriter.cpp index e6552be..dc21b48 100644 --- a/contrib/llvm/lib/MC/ELFObjectWriter.cpp +++ b/contrib/llvm/lib/MC/ELFObjectWriter.cpp @@ -35,13 +35,13 @@ #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/StringSaver.h" #include <vector> + using namespace llvm; #undef DEBUG_TYPE #define DEBUG_TYPE "reloc-info" namespace { - typedef DenseMap<const MCSectionELF *, uint32_t> SectionIndexMapTy; class ELFObjectWriter; @@ -70,169 +70,171 @@ public: }; class ELFObjectWriter : public MCObjectWriter { - static bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind); - static uint64_t SymbolValue(const MCSymbol &Sym, const MCAsmLayout &Layout); - static bool isInSymtab(const MCAsmLayout &Layout, const MCSymbolELF &Symbol, - bool Used, bool Renamed); - - /// Helper struct for containing some precomputed information on symbols. - struct ELFSymbolData { - const MCSymbolELF *Symbol; - uint32_t SectionIndex; - StringRef Name; - - // Support lexicographic sorting. - bool operator<(const ELFSymbolData &RHS) const { - unsigned LHSType = Symbol->getType(); - unsigned RHSType = RHS.Symbol->getType(); - if (LHSType == ELF::STT_SECTION && RHSType != ELF::STT_SECTION) - return false; - if (LHSType != ELF::STT_SECTION && RHSType == ELF::STT_SECTION) - return true; - if (LHSType == ELF::STT_SECTION && RHSType == ELF::STT_SECTION) - return SectionIndex < RHS.SectionIndex; - return Name < RHS.Name; - } - }; + static uint64_t SymbolValue(const MCSymbol &Sym, const MCAsmLayout &Layout); + static bool isInSymtab(const MCAsmLayout &Layout, const MCSymbolELF &Symbol, + bool Used, bool Renamed); + + /// Helper struct for containing some precomputed information on symbols. + struct ELFSymbolData { + const MCSymbolELF *Symbol; + uint32_t SectionIndex; + StringRef Name; + + // Support lexicographic sorting. + bool operator<(const ELFSymbolData &RHS) const { + unsigned LHSType = Symbol->getType(); + unsigned RHSType = RHS.Symbol->getType(); + if (LHSType == ELF::STT_SECTION && RHSType != ELF::STT_SECTION) + return false; + if (LHSType != ELF::STT_SECTION && RHSType == ELF::STT_SECTION) + return true; + if (LHSType == ELF::STT_SECTION && RHSType == ELF::STT_SECTION) + return SectionIndex < RHS.SectionIndex; + return Name < RHS.Name; + } + }; - /// The target specific ELF writer instance. - std::unique_ptr<MCELFObjectTargetWriter> TargetObjectWriter; + /// The target specific ELF writer instance. + std::unique_ptr<MCELFObjectTargetWriter> TargetObjectWriter; - DenseMap<const MCSymbolELF *, const MCSymbolELF *> Renames; + DenseMap<const MCSymbolELF *, const MCSymbolELF *> Renames; - llvm::DenseMap<const MCSectionELF *, std::vector<ELFRelocationEntry>> - Relocations; + llvm::DenseMap<const MCSectionELF *, std::vector<ELFRelocationEntry>> + Relocations; - /// @} - /// @name Symbol Table Data - /// @{ + /// @} + /// @name Symbol Table Data + /// @{ - BumpPtrAllocator Alloc; - StringSaver VersionSymSaver{Alloc}; - StringTableBuilder StrTabBuilder{StringTableBuilder::ELF}; + BumpPtrAllocator Alloc; + StringSaver VersionSymSaver{Alloc}; + StringTableBuilder StrTabBuilder{StringTableBuilder::ELF}; - /// @} + /// @} - // This holds the symbol table index of the last local symbol. - unsigned LastLocalSymbolIndex; - // This holds the .strtab section index. - unsigned StringTableIndex; - // This holds the .symtab section index. - unsigned SymbolTableIndex; + // This holds the symbol table index of the last local symbol. + unsigned LastLocalSymbolIndex; + // This holds the .strtab section index. + unsigned StringTableIndex; + // This holds the .symtab section index. + unsigned SymbolTableIndex; - // Sections in the order they are to be output in the section table. - std::vector<const MCSectionELF *> SectionTable; - unsigned addToSectionTable(const MCSectionELF *Sec); + // Sections in the order they are to be output in the section table. + std::vector<const MCSectionELF *> SectionTable; + unsigned addToSectionTable(const MCSectionELF *Sec); - // TargetObjectWriter wrappers. - bool is64Bit() const { return TargetObjectWriter->is64Bit(); } - bool hasRelocationAddend() const { - return TargetObjectWriter->hasRelocationAddend(); - } - unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, - bool IsPCRel) const { - return TargetObjectWriter->GetRelocType(Target, Fixup, IsPCRel); - } + // TargetObjectWriter wrappers. + bool is64Bit() const { return TargetObjectWriter->is64Bit(); } + bool hasRelocationAddend() const { + return TargetObjectWriter->hasRelocationAddend(); + } + unsigned getRelocType(MCContext &Ctx, const MCValue &Target, + const MCFixup &Fixup, bool IsPCRel) const { + return TargetObjectWriter->getRelocType(Ctx, Target, Fixup, IsPCRel); + } - void align(unsigned Alignment); + void align(unsigned Alignment); - public: - ELFObjectWriter(MCELFObjectTargetWriter *MOTW, raw_pwrite_stream &OS, - bool IsLittleEndian) - : MCObjectWriter(OS, IsLittleEndian), TargetObjectWriter(MOTW) {} + bool maybeWriteCompression(uint64_t Size, + SmallVectorImpl<char> &CompressedContents, + bool ZLibStyle, unsigned Alignment); - void reset() override { - Renames.clear(); - Relocations.clear(); - StrTabBuilder.clear(); - SectionTable.clear(); - MCObjectWriter::reset(); - } +public: + ELFObjectWriter(MCELFObjectTargetWriter *MOTW, raw_pwrite_stream &OS, + bool IsLittleEndian) + : MCObjectWriter(OS, IsLittleEndian), TargetObjectWriter(MOTW) {} + + void reset() override { + Renames.clear(); + Relocations.clear(); + StrTabBuilder.clear(); + SectionTable.clear(); + MCObjectWriter::reset(); + } - ~ELFObjectWriter() override; + ~ELFObjectWriter() override; - void WriteWord(uint64_t W) { - if (is64Bit()) - write64(W); - else - write32(W); - } + void WriteWord(uint64_t W) { + if (is64Bit()) + write64(W); + else + write32(W); + } - template <typename T> void write(T Val) { - if (IsLittleEndian) - support::endian::Writer<support::little>(getStream()).write(Val); - else - support::endian::Writer<support::big>(getStream()).write(Val); - } + template <typename T> void write(T Val) { + if (IsLittleEndian) + support::endian::Writer<support::little>(getStream()).write(Val); + else + support::endian::Writer<support::big>(getStream()).write(Val); + } - void writeHeader(const MCAssembler &Asm); + void writeHeader(const MCAssembler &Asm); - void writeSymbol(SymbolTableWriter &Writer, uint32_t StringIndex, - ELFSymbolData &MSD, const MCAsmLayout &Layout); + void writeSymbol(SymbolTableWriter &Writer, uint32_t StringIndex, + ELFSymbolData &MSD, const MCAsmLayout &Layout); - // Start and end offset of each section - typedef std::map<const MCSectionELF *, std::pair<uint64_t, uint64_t>> - SectionOffsetsTy; + // Start and end offset of each section + typedef std::map<const MCSectionELF *, std::pair<uint64_t, uint64_t>> + SectionOffsetsTy; - bool shouldRelocateWithSymbol(const MCAssembler &Asm, - const MCSymbolRefExpr *RefA, - const MCSymbol *Sym, uint64_t C, - unsigned Type) const; + bool shouldRelocateWithSymbol(const MCAssembler &Asm, + const MCSymbolRefExpr *RefA, + const MCSymbol *Sym, uint64_t C, + unsigned Type) const; - void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout, - const MCFragment *Fragment, const MCFixup &Fixup, - MCValue Target, bool &IsPCRel, - uint64_t &FixedValue) override; + void recordRelocation(MCAssembler &Asm, const MCAsmLayout &Layout, + const MCFragment *Fragment, const MCFixup &Fixup, + MCValue Target, bool &IsPCRel, + uint64_t &FixedValue) override; - // Map from a signature symbol to the group section index - typedef DenseMap<const MCSymbol *, unsigned> RevGroupMapTy; + // Map from a signature symbol to the group section index + typedef DenseMap<const MCSymbol *, unsigned> RevGroupMapTy; - /// Compute the symbol table data - /// - /// \param Asm - The assembler. - /// \param SectionIndexMap - Maps a section to its index. - /// \param RevGroupMap - Maps a signature symbol to the group section. - void computeSymbolTable(MCAssembler &Asm, const MCAsmLayout &Layout, - const SectionIndexMapTy &SectionIndexMap, - const RevGroupMapTy &RevGroupMap, - SectionOffsetsTy &SectionOffsets); + /// Compute the symbol table data + /// + /// \param Asm - The assembler. + /// \param SectionIndexMap - Maps a section to its index. + /// \param RevGroupMap - Maps a signature symbol to the group section. + void computeSymbolTable(MCAssembler &Asm, const MCAsmLayout &Layout, + const SectionIndexMapTy &SectionIndexMap, + const RevGroupMapTy &RevGroupMap, + SectionOffsetsTy &SectionOffsets); - MCSectionELF *createRelocationSection(MCContext &Ctx, - const MCSectionELF &Sec); + MCSectionELF *createRelocationSection(MCContext &Ctx, + const MCSectionELF &Sec); - const MCSectionELF *createStringTable(MCContext &Ctx); + const MCSectionELF *createStringTable(MCContext &Ctx); - void executePostLayoutBinding(MCAssembler &Asm, - const MCAsmLayout &Layout) override; + void executePostLayoutBinding(MCAssembler &Asm, + const MCAsmLayout &Layout) override; - void writeSectionHeader(const MCAsmLayout &Layout, - const SectionIndexMapTy &SectionIndexMap, - const SectionOffsetsTy &SectionOffsets); + void writeSectionHeader(const MCAsmLayout &Layout, + const SectionIndexMapTy &SectionIndexMap, + const SectionOffsetsTy &SectionOffsets); - void writeSectionData(const MCAssembler &Asm, MCSection &Sec, - const MCAsmLayout &Layout); + void writeSectionData(const MCAssembler &Asm, MCSection &Sec, + const MCAsmLayout &Layout); - void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags, - uint64_t Address, uint64_t Offset, uint64_t Size, - uint32_t Link, uint32_t Info, uint64_t Alignment, - uint64_t EntrySize); + void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags, + uint64_t Address, uint64_t Offset, uint64_t Size, + uint32_t Link, uint32_t Info, uint64_t Alignment, + uint64_t EntrySize); - void writeRelocations(const MCAssembler &Asm, const MCSectionELF &Sec); + void writeRelocations(const MCAssembler &Asm, const MCSectionELF &Sec); - bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, - const MCSymbol &SymA, - const MCFragment &FB, - bool InSet, - bool IsPCRel) const override; + bool isSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, + const MCSymbol &SymA, + const MCFragment &FB, bool InSet, + bool IsPCRel) const override; - bool isWeak(const MCSymbol &Sym) const override; + bool isWeak(const MCSymbol &Sym) const override; - void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override; - void writeSection(const SectionIndexMapTy &SectionIndexMap, - uint32_t GroupSymbolIndex, uint64_t Offset, uint64_t Size, - const MCSectionELF &Section); - }; -} + void writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) override; + void writeSection(const SectionIndexMapTy &SectionIndexMap, + uint32_t GroupSymbolIndex, uint64_t Offset, uint64_t Size, + const MCSectionELF &Section); +}; +} // end anonymous namespace void ELFObjectWriter::align(unsigned Alignment) { uint64_t Padding = OffsetToAlignment(getStream().tell(), Alignment); @@ -295,13 +297,6 @@ void SymbolTableWriter::writeSymbol(uint32_t name, uint8_t info, uint64_t value, ++NumWritten; } -bool ELFObjectWriter::isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) { - const MCFixupKindInfo &FKI = - Asm.getBackend().getFixupKindInfo((MCFixupKind) Kind); - - return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel; -} - ELFObjectWriter::~ELFObjectWriter() {} @@ -375,9 +370,24 @@ uint64_t ELFObjectWriter::SymbolValue(const MCSymbol &Sym, void ELFObjectWriter::executePostLayoutBinding(MCAssembler &Asm, const MCAsmLayout &Layout) { + // Section symbols are used as definitions for undefined symbols with matching + // names. If there are multiple sections with the same name, the first one is + // used. + for (const MCSection &Sec : Asm) { + const MCSymbol *Begin = Sec.getBeginSymbol(); + if (!Begin) + continue; + + const MCSymbol *Alias = Asm.getContext().lookupSymbol(Begin->getName()); + if (!Alias || !Alias->isUndefined()) + continue; + + Renames.insert( + std::make_pair(cast<MCSymbolELF>(Alias), cast<MCSymbolELF>(Begin))); + } + // The presence of symbol versions causes undefined symbols and // versions declared with @@@ to be renamed. - for (const MCSymbol &A : Asm.symbols()) { const auto &Alias = cast<MCSymbolELF>(A); // Not an alias. @@ -522,7 +532,6 @@ bool ELFObjectWriter::shouldRelocateWithSymbol(const MCAssembler &Asm, case MCSymbolRefExpr::VK_GOT: case MCSymbolRefExpr::VK_PLT: case MCSymbolRefExpr::VK_GOTPCREL: - case MCSymbolRefExpr::VK_Mips_GOT: case MCSymbolRefExpr::VK_PPC_GOT_LO: case MCSymbolRefExpr::VK_PPC_GOT_HI: case MCSymbolRefExpr::VK_PPC_GOT_HA: @@ -618,6 +627,7 @@ void ELFObjectWriter::recordRelocation(MCAssembler &Asm, const MCSectionELF &FixupSection = cast<MCSectionELF>(*Fragment->getParent()); uint64_t C = Target.getConstant(); uint64_t FixupOffset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset(); + MCContext &Ctx = Asm.getContext(); if (const MCSymbolRefExpr *RefB = Target.getSymB()) { assert(RefB->getKind() == MCSymbolRefExpr::VK_None && @@ -631,7 +641,7 @@ void ELFObjectWriter::recordRelocation(MCAssembler &Asm, // or (A + C - R). If B = R + K and the relocation is not pcrel, we can // replace B to implement it: (A - R - K + C) if (IsPCRel) { - Asm.getContext().reportError( + Ctx.reportError( Fixup.getLoc(), "No relocation available to represent this relative expression"); return; @@ -640,24 +650,17 @@ void ELFObjectWriter::recordRelocation(MCAssembler &Asm, const auto &SymB = cast<MCSymbolELF>(RefB->getSymbol()); if (SymB.isUndefined()) { - Asm.getContext().reportError( - Fixup.getLoc(), - Twine("symbol '") + SymB.getName() + - "' can not be undefined in a subtraction expression"); + Ctx.reportError(Fixup.getLoc(), + Twine("symbol '") + SymB.getName() + + "' can not be undefined in a subtraction expression"); return; } assert(!SymB.isAbsolute() && "Should have been folded"); const MCSection &SecB = SymB.getSection(); if (&SecB != &FixupSection) { - Asm.getContext().reportError( - Fixup.getLoc(), "Cannot represent a difference across sections"); - return; - } - - if (::isWeak(SymB)) { - Asm.getContext().reportError( - Fixup.getLoc(), "Cannot represent a subtraction with a weak symbol"); + Ctx.reportError(Fixup.getLoc(), + "Cannot represent a difference across sections"); return; } @@ -682,7 +685,8 @@ void ELFObjectWriter::recordRelocation(MCAssembler &Asm, } } - unsigned Type = GetRelocType(Target, Fixup, IsPCRel); + unsigned Type = getRelocType(Ctx, Target, Fixup, IsPCRel); + uint64_t OriginalC = C; bool RelocateWithSymbol = shouldRelocateWithSymbol(Asm, RefA, SymA, C, Type); if (!RelocateWithSymbol && SymA && !SymA->isUndefined()) C += Layout.getSymbolOffset(*SymA); @@ -703,23 +707,25 @@ void ELFObjectWriter::recordRelocation(MCAssembler &Asm, ELFSec ? cast<MCSymbolELF>(ELFSec->getBeginSymbol()) : nullptr; if (SectionSymbol) SectionSymbol->setUsedInReloc(); - ELFRelocationEntry Rec(FixupOffset, SectionSymbol, Type, Addend); + ELFRelocationEntry Rec(FixupOffset, SectionSymbol, Type, Addend, SymA, + OriginalC); Relocations[&FixupSection].push_back(Rec); return; } + const auto *RenamedSymA = SymA; if (SymA) { if (const MCSymbolELF *R = Renames.lookup(SymA)) - SymA = R; + RenamedSymA = R; if (ViaWeakRef) - SymA->setIsWeakrefUsedInReloc(); + RenamedSymA->setIsWeakrefUsedInReloc(); else - SymA->setUsedInReloc(); + RenamedSymA->setUsedInReloc(); } - ELFRelocationEntry Rec(FixupOffset, SymA, Type, Addend); + ELFRelocationEntry Rec(FixupOffset, RenamedSymA, Type, Addend, SymA, + OriginalC); Relocations[&FixupSection].push_back(Rec); - return; } bool ELFObjectWriter::isInSymtab(const MCAsmLayout &Layout, @@ -969,23 +975,38 @@ ELFObjectWriter::createRelocationSection(MCContext &Ctx, return RelaSection; } -// Include the debug info compression header: -// "ZLIB" followed by 8 bytes representing the uncompressed size of the section, -// useful for consumers to preallocate a buffer to decompress into. -static bool -prependCompressionHeader(uint64_t Size, - SmallVectorImpl<char> &CompressedContents) { +// Include the debug info compression header. +bool ELFObjectWriter::maybeWriteCompression( + uint64_t Size, SmallVectorImpl<char> &CompressedContents, bool ZLibStyle, + unsigned Alignment) { + if (ZLibStyle) { + uint64_t HdrSize = + is64Bit() ? sizeof(ELF::Elf32_Chdr) : sizeof(ELF::Elf64_Chdr); + if (Size <= HdrSize + CompressedContents.size()) + return false; + // Platform specific header is followed by compressed data. + if (is64Bit()) { + // Write Elf64_Chdr header. + write(static_cast<ELF::Elf64_Word>(ELF::ELFCOMPRESS_ZLIB)); + write(static_cast<ELF::Elf64_Word>(0)); // ch_reserved field. + write(static_cast<ELF::Elf64_Xword>(Size)); + write(static_cast<ELF::Elf64_Xword>(Alignment)); + } else { + // Write Elf32_Chdr header otherwise. + write(static_cast<ELF::Elf32_Word>(ELF::ELFCOMPRESS_ZLIB)); + write(static_cast<ELF::Elf32_Word>(Size)); + write(static_cast<ELF::Elf32_Word>(Alignment)); + } + return true; + } + + // "ZLIB" followed by 8 bytes representing the uncompressed size of the section, + // useful for consumers to preallocate a buffer to decompress into. const StringRef Magic = "ZLIB"; if (Size <= Magic.size() + sizeof(Size) + CompressedContents.size()) return false; - if (sys::IsLittleEndianHost) - sys::swapByteOrder(Size); - CompressedContents.insert(CompressedContents.begin(), - Magic.size() + sizeof(Size), 0); - std::copy(Magic.begin(), Magic.end(), CompressedContents.begin()); - std::copy(reinterpret_cast<char *>(&Size), - reinterpret_cast<char *>(&Size + 1), - CompressedContents.begin() + Magic.size()); + write(ArrayRef<char>(Magic.begin(), Magic.size())); + writeBE64(Size); return true; } @@ -997,8 +1018,11 @@ void ELFObjectWriter::writeSectionData(const MCAssembler &Asm, MCSection &Sec, // Compressing debug_frame requires handling alignment fragments which is // more work (possibly generalizing MCAssembler.cpp:writeFragment to allow // for writing to arbitrary buffers) for little benefit. - if (!Asm.getContext().getAsmInfo()->compressDebugSections() || - !SectionName.startswith(".debug_") || SectionName == ".debug_frame") { + bool CompressionEnabled = + Asm.getContext().getAsmInfo()->compressDebugSections() != + DebugCompressionType::DCT_None; + if (!CompressionEnabled || !SectionName.startswith(".debug_") || + SectionName == ".debug_frame") { Asm.writeSectionData(&Section, Layout); return; } @@ -1019,12 +1043,21 @@ void ELFObjectWriter::writeSectionData(const MCAssembler &Asm, MCSection &Sec, return; } - if (!prependCompressionHeader(UncompressedData.size(), CompressedContents)) { + bool ZlibStyle = Asm.getContext().getAsmInfo()->compressDebugSections() == + DebugCompressionType::DCT_Zlib; + if (!maybeWriteCompression(UncompressedData.size(), CompressedContents, + ZlibStyle, Sec.getAlignment())) { getStream() << UncompressedData; return; } - Asm.getContext().renameELFSection(&Section, - (".z" + SectionName.drop_front(1)).str()); + + if (ZlibStyle) + // Set the compressed flag. That is zlib style. + Section.setFlags(Section.getFlags() | ELF::SHF_COMPRESSED); + else + // Add "z" prefix to section name. This is zlib-gnu style. + Asm.getContext().renameELFSection(&Section, + (".z" + SectionName.drop_front(1)).str()); getStream() << CompressedContents; } @@ -1279,7 +1312,7 @@ void ELFObjectWriter::writeObject(MCAssembler &Asm, uint64_t NaturalAlignment = is64Bit() ? 8 : 4; align(NaturalAlignment); - const unsigned SectionHeaderOffset = getStream().tell(); + const uint64_t SectionHeaderOffset = getStream().tell(); // ... then the section header table ... writeSectionHeader(Layout, SectionIndexMap, SectionOffsets); |
