X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FELFObjectWriter.cpp;h=b8b3188ce4808da643272f6d83400f7a958e97d0;hb=b21d9aebba7e45ddcbce61dd501000049cefb335;hp=9b344f7728988ebd20697686f2eccbcd65313334;hpb=f3eb3bba1614a7935b44fc963a805088d71267f3;p=oota-llvm.git diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp index 9b344f77289..b8b3188ce48 100644 --- a/lib/MC/ELFObjectWriter.cpp +++ b/lib/MC/ELFObjectWriter.cpp @@ -11,102 +11,62 @@ // //===----------------------------------------------------------------------===// +#include "MCELF.h" #include "llvm/ADT/OwningPtr.h" #include "llvm/ADT/SmallPtrSet.h" +#include "llvm/ADT/SmallString.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/StringMap.h" -#include "llvm/ADT/Twine.h" -#include "llvm/MC/MCAssembler.h" +#include "llvm/MC/MCAsmBackend.h" #include "llvm/MC/MCAsmLayout.h" +#include "llvm/MC/MCAssembler.h" #include "llvm/MC/MCContext.h" +#include "llvm/MC/MCELFObjectWriter.h" #include "llvm/MC/MCELFSymbolFlags.h" #include "llvm/MC/MCExpr.h" -#include "llvm/MC/MCELFObjectWriter.h" +#include "llvm/MC/MCFixupKindInfo.h" #include "llvm/MC/MCObjectWriter.h" #include "llvm/MC/MCSectionELF.h" -#include "llvm/MC/MCSymbol.h" #include "llvm/MC/MCValue.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/ELF.h" -#include "llvm/Target/TargetAsmBackend.h" - -#include "../Target/X86/X86FixupKinds.h" -#include "../Target/ARM/ARMFixupKinds.h" #include using namespace llvm; -static unsigned GetType(const MCSymbolData &SD) { - uint32_t Type = (SD.getFlags() & (0xf << ELF_STT_Shift)) >> ELF_STT_Shift; - assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT || - Type == ELF::STT_FUNC || Type == ELF::STT_SECTION || - Type == ELF::STT_FILE || Type == ELF::STT_COMMON || - Type == ELF::STT_TLS); - return Type; -} - -static unsigned GetBinding(const MCSymbolData &SD) { - uint32_t Binding = (SD.getFlags() & (0xf << ELF_STB_Shift)) >> ELF_STB_Shift; - assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL || - Binding == ELF::STB_WEAK); - return Binding; -} - -static void SetBinding(MCSymbolData &SD, unsigned Binding) { - assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL || - Binding == ELF::STB_WEAK); - uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STB_Shift); - SD.setFlags(OtherFlags | (Binding << ELF_STB_Shift)); -} - -static unsigned GetVisibility(MCSymbolData &SD) { - unsigned Visibility = - (SD.getFlags() & (0xf << ELF_STV_Shift)) >> ELF_STV_Shift; - assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL || - Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED); - return Visibility; -} - - -static bool RelocNeedsGOT(MCSymbolRefExpr::VariantKind Variant) { - switch (Variant) { - default: - return false; - case MCSymbolRefExpr::VK_GOT: - case MCSymbolRefExpr::VK_PLT: - case MCSymbolRefExpr::VK_GOTPCREL: - case MCSymbolRefExpr::VK_TPOFF: - case MCSymbolRefExpr::VK_TLSGD: - case MCSymbolRefExpr::VK_GOTTPOFF: - case MCSymbolRefExpr::VK_INDNTPOFF: - case MCSymbolRefExpr::VK_NTPOFF: - case MCSymbolRefExpr::VK_GOTNTPOFF: - case MCSymbolRefExpr::VK_TLSLDM: - case MCSymbolRefExpr::VK_DTPOFF: - case MCSymbolRefExpr::VK_TLSLD: - return true; - } -} - -static bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) { - const MCFixupKindInfo &FKI = - Asm.getBackend().getFixupKindInfo((MCFixupKind) Kind); - - return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel; -} +#undef DEBUG_TYPE +#define DEBUG_TYPE "reloc-info" namespace { - class ELFObjectWriter : public MCObjectWriter { +class ELFObjectWriter : public MCObjectWriter { protected: + + static bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind); + static bool RelocNeedsGOT(MCSymbolRefExpr::VariantKind Variant); + static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout); + static bool isInSymtab(const MCAssembler &Asm, const MCSymbolData &Data, + bool Used, bool Renamed); + static bool isLocal(const MCSymbolData &Data, bool isSignature, + bool isUsedInReloc); + static bool IsELFMetaDataSection(const MCSectionData &SD); + static uint64_t DataSectionSize(const MCSectionData &SD); + static uint64_t GetSectionFileSize(const MCAsmLayout &Layout, + const MCSectionData &SD); + static uint64_t GetSectionAddressSize(const MCAsmLayout &Layout, + const MCSectionData &SD); + + void WriteDataSectionData(MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCSectionELF &Section); + /*static bool isFixupKindX86RIPRel(unsigned Kind) { return Kind == X86::reloc_riprel_4byte || Kind == X86::reloc_riprel_4byte_movq_load; }*/ - - /// ELFSymbolData - Helper struct for containing some precomputed information - /// on symbols. + /// ELFSymbolData - Helper struct for containing some precomputed + /// information on symbols. struct ELFSymbolData { MCSymbolData *SymbolData; uint64_t StringIndex; @@ -114,41 +74,15 @@ namespace { // Support lexicographic sorting. bool operator<(const ELFSymbolData &RHS) const { - if (GetType(*SymbolData) == ELF::STT_FILE) + if (MCELF::GetType(*SymbolData) == ELF::STT_FILE) return true; - if (GetType(*RHS.SymbolData) == ELF::STT_FILE) + if (MCELF::GetType(*RHS.SymbolData) == ELF::STT_FILE) return false; return SymbolData->getSymbol().getName() < RHS.SymbolData->getSymbol().getName(); } }; - /// @name Relocation Data - /// @{ - - struct ELFRelocationEntry { - // Make these big enough for both 32-bit and 64-bit - uint64_t r_offset; - int Index; - unsigned Type; - const MCSymbol *Symbol; - uint64_t r_addend; - - ELFRelocationEntry() - : r_offset(0), Index(0), Type(0), Symbol(0), r_addend(0) {} - - ELFRelocationEntry(uint64_t RelocOffset, int Idx, - unsigned RelType, const MCSymbol *Sym, - uint64_t Addend) - : r_offset(RelocOffset), Index(Idx), Type(RelType), - Symbol(Sym), r_addend(Addend) {} - - // Support lexicographic sorting. - bool operator<(const ELFRelocationEntry &RE) const { - return RE.r_offset < r_offset; - } - }; - /// The target specific ELF writer instance. llvm::OwningPtr TargetObjectWriter; @@ -187,12 +121,33 @@ namespace { const MCSymbol *SymbolToReloc(const MCAssembler &Asm, const MCValue &Target, - const MCFragment &F) const; + const MCFragment &F, + const MCFixup &Fixup, + bool IsPCRel) const; + + // TargetObjectWriter wrappers. + const MCSymbol *ExplicitRelSym(const MCAssembler &Asm, + const MCValue &Target, + const MCFragment &F, + const MCFixup &Fixup, + bool IsPCRel) const { + return TargetObjectWriter->ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); + } bool is64Bit() const { return TargetObjectWriter->is64Bit(); } bool hasRelocationAddend() const { return TargetObjectWriter->hasRelocationAddend(); } + unsigned getEFlags() const { + return TargetObjectWriter->getEFlags(); + } + unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, + bool IsPCRel, bool IsRelocWithSymbol, + int64_t Addend) const { + return TargetObjectWriter->GetRelocType(Target, Fixup, IsPCRel, + IsRelocWithSymbol, Addend); + } + public: ELFObjectWriter(MCELFObjectTargetWriter *MOTW, @@ -274,75 +229,97 @@ namespace { F.getContents() += StringRef(buf, 8); } - virtual void WriteHeader(uint64_t SectionDataSize, unsigned NumberOfSections); + void WriteHeader(uint64_t SectionDataSize, + unsigned NumberOfSections); - virtual void WriteSymbolEntry(MCDataFragment *SymtabF, MCDataFragment *ShndxF, + void WriteSymbolEntry(MCDataFragment *SymtabF, + MCDataFragment *ShndxF, uint64_t name, uint8_t info, uint64_t value, uint64_t size, uint8_t other, uint32_t shndx, bool Reserved); - virtual void WriteSymbol(MCDataFragment *SymtabF, MCDataFragment *ShndxF, + void WriteSymbol(MCDataFragment *SymtabF, MCDataFragment *ShndxF, ELFSymbolData &MSD, const MCAsmLayout &Layout); typedef DenseMap SectionIndexMapTy; - virtual void WriteSymbolTable(MCDataFragment *SymtabF, MCDataFragment *ShndxF, + void WriteSymbolTable(MCDataFragment *SymtabF, + MCDataFragment *ShndxF, const MCAssembler &Asm, const MCAsmLayout &Layout, const SectionIndexMapTy &SectionIndexMap); - virtual void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout, - const MCFragment *Fragment, const MCFixup &Fixup, + virtual void RecordRelocation(const MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCFragment *Fragment, + const MCFixup &Fixup, MCValue Target, uint64_t &FixedValue); - virtual uint64_t getSymbolIndexInSymbolTable(const MCAssembler &Asm, + uint64_t getSymbolIndexInSymbolTable(const MCAssembler &Asm, const MCSymbol *S); // Map from a group section to the signature symbol typedef DenseMap GroupMapTy; // Map from a signature symbol to the group section typedef DenseMap RevGroupMapTy; + // Map from a section to the section with the relocations + typedef DenseMap RelMapTy; + // Map from a section to its offset + typedef DenseMap SectionOffsetMapTy; /// ComputeSymbolTable - Compute the symbol table data /// - /// \param StringTable [out] - The string table data. - /// \param StringIndexMap [out] - Map from symbol names to offsets in the - /// string table. - virtual void ComputeSymbolTable(MCAssembler &Asm, + /// \param Asm - The assembler. + /// \param SectionIndexMap - Maps a section to its index. + /// \param RevGroupMap - Maps a signature symbol to the group section. + /// \param NumRegularSections - Number of non-relocation sections. + void ComputeSymbolTable(MCAssembler &Asm, const SectionIndexMapTy &SectionIndexMap, - RevGroupMapTy RevGroupMap); + RevGroupMapTy RevGroupMap, + unsigned NumRegularSections); - virtual void ComputeIndexMap(MCAssembler &Asm, - SectionIndexMapTy &SectionIndexMap); + void ComputeIndexMap(MCAssembler &Asm, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap); - virtual void WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout, - const MCSectionData &SD); + void CreateRelocationSections(MCAssembler &Asm, MCAsmLayout &Layout, + RelMapTy &RelMap); - virtual void WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout) { - for (MCAssembler::const_iterator it = Asm.begin(), - ie = Asm.end(); it != ie; ++it) { - WriteRelocation(Asm, Layout, *it); - } - } + void WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout, + const RelMapTy &RelMap); - virtual void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout, - const SectionIndexMapTy &SectionIndexMap); + void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap); - virtual void CreateGroupSections(MCAssembler &Asm, MCAsmLayout &Layout, - GroupMapTy &GroupMap, RevGroupMapTy &RevGroupMap); + // Create the sections that show up in the symbol table. Currently + // those are the .note.GNU-stack section and the group sections. + void CreateIndexedSections(MCAssembler &Asm, MCAsmLayout &Layout, + GroupMapTy &GroupMap, + RevGroupMapTy &RevGroupMap, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap); virtual void ExecutePostLayoutBinding(MCAssembler &Asm, const MCAsmLayout &Layout); - virtual void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags, + void WriteSectionHeader(MCAssembler &Asm, const GroupMapTy &GroupMap, + const MCAsmLayout &Layout, + const SectionIndexMapTy &SectionIndexMap, + const SectionOffsetMapTy &SectionOffsetMap); + + void ComputeSectionOrder(MCAssembler &Asm, + std::vector &Sections); + + 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); - virtual void WriteRelocationsFragment(const MCAssembler &Asm, - MCDataFragment *F, - const MCSectionData *SD); + void WriteRelocationsFragment(const MCAssembler &Asm, + MCDataFragment *F, + const MCSectionData *SD); virtual bool IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, @@ -352,63 +329,40 @@ namespace { bool IsPCRel) const; virtual void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout); - virtual void WriteSection(MCAssembler &Asm, + void WriteSection(MCAssembler &Asm, const SectionIndexMapTy &SectionIndexMap, uint32_t GroupSymbolIndex, uint64_t Offset, uint64_t Size, uint64_t Alignment, const MCSectionELF &Section); - - protected: - virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, - bool IsPCRel, bool IsRelocWithSymbol, - int64_t Addend) = 0; - }; - - //===- X86ELFObjectWriter -------------------------------------------===// - - class X86ELFObjectWriter : public ELFObjectWriter { - public: - X86ELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian); - - virtual ~X86ELFObjectWriter(); - protected: - virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, - bool IsPCRel, bool IsRelocWithSymbol, - int64_t Addend); - }; - - - //===- ARMELFObjectWriter -------------------------------------------===// - - class ARMELFObjectWriter : public ELFObjectWriter { - public: - ARMELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian); - - virtual ~ARMELFObjectWriter(); - protected: - virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, - bool IsPCRel, bool IsRelocWithSymbol, - int64_t Addend); }; +} - //===- MBlazeELFObjectWriter -------------------------------------------===// +bool ELFObjectWriter::isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) { + const MCFixupKindInfo &FKI = + Asm.getBackend().getFixupKindInfo((MCFixupKind) Kind); - class MBlazeELFObjectWriter : public ELFObjectWriter { - public: - MBlazeELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian); + return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel; +} - virtual ~MBlazeELFObjectWriter(); - protected: - virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup, - bool IsPCRel, bool IsRelocWithSymbol, - int64_t Addend); - }; +bool ELFObjectWriter::RelocNeedsGOT(MCSymbolRefExpr::VariantKind Variant) { + switch (Variant) { + default: + return false; + case MCSymbolRefExpr::VK_GOT: + case MCSymbolRefExpr::VK_PLT: + case MCSymbolRefExpr::VK_GOTPCREL: + case MCSymbolRefExpr::VK_GOTOFF: + case MCSymbolRefExpr::VK_TPOFF: + case MCSymbolRefExpr::VK_TLSGD: + case MCSymbolRefExpr::VK_GOTTPOFF: + case MCSymbolRefExpr::VK_INDNTPOFF: + case MCSymbolRefExpr::VK_NTPOFF: + case MCSymbolRefExpr::VK_GOTNTPOFF: + case MCSymbolRefExpr::VK_TLSLDM: + case MCSymbolRefExpr::VK_DTPOFF: + case MCSymbolRefExpr::VK_TLSLD: + return true; + } } ELFObjectWriter::~ELFObjectWriter() @@ -437,11 +391,7 @@ void ELFObjectWriter::WriteHeader(uint64_t SectionDataSize, Write8(ELF::EV_CURRENT); // e_ident[EI_VERSION] // e_ident[EI_OSABI] - switch (TargetObjectWriter->getOSType()) { - case Triple::FreeBSD: Write8(ELF::ELFOSABI_FREEBSD); break; - case Triple::Linux: Write8(ELF::ELFOSABI_LINUX); break; - default: Write8(ELF::ELFOSABI_NONE); break; - } + Write8(TargetObjectWriter->getOSABI()); Write8(0); // e_ident[EI_ABIVERSION] WriteZeros(ELF::EI_NIDENT - ELF::EI_PAD); @@ -456,8 +406,8 @@ void ELFObjectWriter::WriteHeader(uint64_t SectionDataSize, WriteWord(SectionDataSize + (is64Bit() ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr))); // e_shoff = sec hdr table off in bytes - // FIXME: Make this configurable. - Write32(0); // e_flags = whatever the target wants + // e_flags = whatever the target wants + Write32(getEFlags()); // e_ehsize = ELF header size Write16(is64Bit() ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr)); @@ -470,12 +420,12 @@ void ELFObjectWriter::WriteHeader(uint64_t SectionDataSize, // e_shnum = # of section header ents if (NumberOfSections >= ELF::SHN_LORESERVE) - Write16(0); + Write16(ELF::SHN_UNDEF); else Write16(NumberOfSections); // e_shstrndx = Section # of '.shstrtab' - if (NumberOfSections >= ELF::SHN_LORESERVE) + if (ShstrtabIndex >= ELF::SHN_LORESERVE) Write16(ELF::SHN_XINDEX); else Write16(ShstrtabIndex); @@ -515,7 +465,8 @@ void ELFObjectWriter::WriteSymbolEntry(MCDataFragment *SymtabF, } } -static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) { +uint64_t ELFObjectWriter::SymbolValue(MCSymbolData &Data, + const MCAsmLayout &Layout) { if (Data.isCommon() && Data.isExternal()) return Data.getCommonAlignment(); @@ -525,15 +476,20 @@ static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) { if (const MCExpr *Value = Symbol.getVariableValue()) { int64_t IntValue; if (Value->EvaluateAsAbsolute(IntValue, Layout)) - return (uint64_t)IntValue; + return (uint64_t)IntValue; } } if (!Symbol.isInSection()) return 0; - if (Data.getFragment()) - return Layout.getSymbolOffset(&Data); + + if (Data.getFragment()) { + if (Data.getFlags() & ELF_Other_ThumbFunc) + return Layout.getSymbolOffset(&Data)+1; + else + return Layout.getSymbolOffset(&Data); + } return 0; } @@ -561,7 +517,7 @@ void ELFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm, // Aliases defined with .symvar copy the binding from the symbol they alias. // This is the first place we are able to copy this information. it->setExternal(SD.isExternal()); - SetBinding(*it, GetBinding(SD)); + MCELF::SetBinding(*it, MCELF::GetBinding(SD)); StringRef Rest = AliasName.substr(Pos); if (!Symbol.isUndefined() && !Rest.startswith("@@@")) @@ -587,9 +543,9 @@ void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF, bool IsReserved = Data.isCommon() || Data.getSymbol().isAbsolute() || Data.getSymbol().isVariable(); - uint8_t Binding = GetBinding(OrigData); - uint8_t Visibility = GetVisibility(OrigData); - uint8_t Type = GetType(Data); + uint8_t Binding = MCELF::GetBinding(OrigData); + uint8_t Visibility = MCELF::GetVisibility(OrigData); + uint8_t Type = MCELF::GetType(Data); uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift); uint8_t Other = Visibility; @@ -616,7 +572,7 @@ void ELFObjectWriter::WriteSymbolTable(MCDataFragment *SymtabF, MCDataFragment *ShndxF, const MCAssembler &Asm, const MCAsmLayout &Layout, - const SectionIndexMapTy &SectionIndexMap) { + const SectionIndexMapTy &SectionIndexMap) { // The string table must be emitted first because we need the index // into the string table for all the symbol names. assert(StringTable.size() && "Missing string table"); @@ -641,10 +597,12 @@ void ELFObjectWriter::WriteSymbolTable(MCDataFragment *SymtabF, if (Section.getType() == ELF::SHT_RELA || Section.getType() == ELF::SHT_REL || Section.getType() == ELF::SHT_STRTAB || - Section.getType() == ELF::SHT_SYMTAB) + Section.getType() == ELF::SHT_SYMTAB || + Section.getType() == ELF::SHT_SYMTAB_SHNDX) continue; WriteSymbolEntry(SymtabF, ShndxF, 0, ELF::STT_SECTION, 0, 0, - ELF::STV_DEFAULT, SectionIndexMap.lookup(&Section), false); + ELF::STV_DEFAULT, SectionIndexMap.lookup(&Section), + false); LastLocalSymbolIndex++; } @@ -655,7 +613,7 @@ void ELFObjectWriter::WriteSymbolTable(MCDataFragment *SymtabF, (Data.getFlags() & ELF_STB_Weak)) && "External symbol requires STB_GLOBAL or STB_WEAK flag"); WriteSymbol(SymtabF, ShndxF, MSD, Layout); - if (GetBinding(Data) == ELF::STB_LOCAL) + if (MCELF::GetBinding(Data) == ELF::STB_LOCAL) LastLocalSymbolIndex++; } @@ -663,14 +621,16 @@ void ELFObjectWriter::WriteSymbolTable(MCDataFragment *SymtabF, ELFSymbolData &MSD = UndefinedSymbolData[i]; MCSymbolData &Data = *MSD.SymbolData; WriteSymbol(SymtabF, ShndxF, MSD, Layout); - if (GetBinding(Data) == ELF::STB_LOCAL) + if (MCELF::GetBinding(Data) == ELF::STB_LOCAL) LastLocalSymbolIndex++; } } const MCSymbol *ELFObjectWriter::SymbolToReloc(const MCAssembler &Asm, const MCValue &Target, - const MCFragment &F) const { + const MCFragment &F, + const MCFixup &Fixup, + bool IsPCRel) const { const MCSymbol &Symbol = Target.getSymA()->getSymbol(); const MCSymbol &ASymbol = Symbol.AliasedSymbol(); const MCSymbol *Renamed = Renames.lookup(&Symbol); @@ -693,7 +653,7 @@ const MCSymbol *ELFObjectWriter::SymbolToReloc(const MCAssembler &Asm, const SectionKind secKind = Section.getKind(); if (secKind.isBSS()) - return NULL; + return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); if (secKind.isThreadLocal()) { if (Renamed) @@ -714,15 +674,16 @@ const MCSymbol *ELFObjectWriter::SymbolToReloc(const MCAssembler &Asm, return &Symbol; } - if (Section.getFlags() & MCSectionELF::SHF_MERGE) { + if (Section.getFlags() & ELF::SHF_MERGE) { if (Target.getConstant() == 0) - return NULL; + return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); if (Renamed) return Renamed; return &Symbol; } - return NULL; + return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); + } @@ -741,7 +702,7 @@ void ELFObjectWriter::RecordRelocation(const MCAssembler &Asm, if (!Target.isAbsolute()) { const MCSymbol &Symbol = Target.getSymA()->getSymbol(); const MCSymbol &ASymbol = Symbol.AliasedSymbol(); - RelocSymbol = SymbolToReloc(Asm, Target, *Fragment); + RelocSymbol = SymbolToReloc(Asm, Target, *Fragment, Fixup, IsPCRel); if (const MCSymbolRefExpr *RefB = Target.getSymB()) { const MCSymbol &SymbolB = RefB->getSymbol(); @@ -751,7 +712,7 @@ void ELFObjectWriter::RecordRelocation(const MCAssembler &Asm, // Offset of the symbol in the section int64_t a = Layout.getSymbolOffset(&SDB); - // Ofeset of the relocation in the section + // Offset of the relocation in the section int64_t b = Layout.getFragmentOffset(Fragment) + Fixup.getOffset(); Value += b - a; } @@ -772,21 +733,33 @@ void ELFObjectWriter::RecordRelocation(const MCAssembler &Asm, Index = -1; } Addend = Value; - // Compensate for the addend on i386. - if (is64Bit()) + if (hasRelocationAddend()) Value = 0; } FixedValue = Value; unsigned Type = GetRelocType(Target, Fixup, IsPCRel, (RelocSymbol != 0), Addend); - + MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ? + MCSymbolRefExpr::VK_None : Target.getSymA()->getKind(); + if (RelocNeedsGOT(Modifier)) + NeedsGOT = true; + uint64_t RelocOffset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset(); + // FIXME: no tests cover this. Is adjustFixupOffset dead code? + TargetObjectWriter->adjustFixupOffset(Fixup, RelocOffset); + if (!hasRelocationAddend()) Addend = 0; - ELFRelocationEntry ERE(RelocOffset, Index, Type, RelocSymbol, Addend); + + if (is64Bit()) + assert(isInt<64>(Addend)); + else + assert(isInt<32>(Addend)); + + ELFRelocationEntry ERE(RelocOffset, Index, Type, RelocSymbol, Addend, Fixup); Relocations[Fragment->getParent()].push_back(ERE); } @@ -798,8 +771,9 @@ ELFObjectWriter::getSymbolIndexInSymbolTable(const MCAssembler &Asm, return SD.getIndex(); } -static bool isInSymtab(const MCAssembler &Asm, const MCSymbolData &Data, - bool Used, bool Renamed) { +bool ELFObjectWriter::isInSymtab(const MCAssembler &Asm, + const MCSymbolData &Data, + bool Used, bool Renamed) { if (Data.getFlags() & ELF_Other_Weakref) return false; @@ -815,7 +789,11 @@ static bool isInSymtab(const MCAssembler &Asm, const MCSymbolData &Data, return true; const MCSymbol &A = Symbol.AliasedSymbol(); - if (!A.isVariable() && A.isUndefined() && !Data.isCommon()) + if (Symbol.isVariable() && !A.isVariable() && A.isUndefined()) + return false; + + bool IsGlobal = MCELF::GetBinding(Data) == ELF::STB_GLOBAL; + if (!Symbol.isVariable() && Symbol.isUndefined() && !IsGlobal) return false; if (!Asm.isSymbolLinkerVisible(Symbol) && !Symbol.isUndefined()) @@ -827,8 +805,8 @@ static bool isInSymtab(const MCAssembler &Asm, const MCSymbolData &Data, return true; } -static bool isLocal(const MCSymbolData &Data, bool isSignature, - bool isUsedInReloc) { +bool ELFObjectWriter::isLocal(const MCSymbolData &Data, bool isSignature, + bool isUsedInReloc) { if (Data.isExternal()) return false; @@ -846,7 +824,8 @@ static bool isLocal(const MCSymbolData &Data, bool isSignature, } void ELFObjectWriter::ComputeIndexMap(MCAssembler &Asm, - SectionIndexMapTy &SectionIndexMap) { + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap) { unsigned Index = 1; for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { @@ -861,31 +840,38 @@ void ELFObjectWriter::ComputeIndexMap(MCAssembler &Asm, ie = Asm.end(); it != ie; ++it) { const MCSectionELF &Section = static_cast(it->getSection()); - if (Section.getType() == ELF::SHT_GROUP) + if (Section.getType() == ELF::SHT_GROUP || + Section.getType() == ELF::SHT_REL || + Section.getType() == ELF::SHT_RELA) continue; SectionIndexMap[&Section] = Index++; + const MCSectionELF *RelSection = RelMap.lookup(&Section); + if (RelSection) + SectionIndexMap[RelSection] = Index++; } } void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm, const SectionIndexMapTy &SectionIndexMap, - RevGroupMapTy RevGroupMap) { + RevGroupMapTy RevGroupMap, + unsigned NumRegularSections) { // FIXME: Is this the correct place to do this? + // FIXME: Why is an undefined reference to _GLOBAL_OFFSET_TABLE_ needed? if (NeedsGOT) { llvm::StringRef Name = "_GLOBAL_OFFSET_TABLE_"; MCSymbol *Sym = Asm.getContext().GetOrCreateSymbol(Name); MCSymbolData &Data = Asm.getOrCreateSymbolData(*Sym); Data.setExternal(true); - SetBinding(Data, ELF::STB_GLOBAL); + MCELF::SetBinding(Data, ELF::STB_GLOBAL); } - // Build section lookup table. - int NumRegularSections = Asm.size(); - // Index 0 is always the empty string. StringMap StringIndexMap; StringTable += '\x00'; + // FIXME: We could optimize suffixes in strtab in the same way we + // optimize them in shstrtab. + // Add the data for the symbols. for (MCAssembler::symbol_iterator it = Asm.symbol_begin(), ie = Asm.symbol_end(); it != ie; ++it) { @@ -907,14 +893,14 @@ void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm, // Undefined symbols are global, but this is the first place we // are able to set it. bool Local = isLocal(*it, isSignature, Used); - if (!Local && GetBinding(*it) == ELF::STB_LOCAL) { + if (!Local && MCELF::GetBinding(*it) == ELF::STB_LOCAL) { MCSymbolData &SD = Asm.getSymbolData(RefSymbol); - SetBinding(*it, ELF::STB_GLOBAL); - SetBinding(SD, ELF::STB_GLOBAL); + MCELF::SetBinding(*it, ELF::STB_GLOBAL); + MCELF::SetBinding(SD, ELF::STB_GLOBAL); } if (RefSymbol.isUndefined() && !Used && WeakrefUsed) - SetBinding(*it, ELF::STB_WEAK); + MCELF::SetBinding(*it, ELF::STB_WEAK); if (it->isCommon()) { assert(!Local); @@ -980,13 +966,21 @@ void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm, ExternalSymbolData[i].SymbolData->setIndex(Index++); for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i) UndefinedSymbolData[i].SymbolData->setIndex(Index++); + + if (NumRegularSections > ELF::SHN_LORESERVE) + NeedsSymtabShndx = true; } -void ELFObjectWriter::WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout, - const MCSectionData &SD) { - if (!Relocations[&SD].empty()) { +void ELFObjectWriter::CreateRelocationSections(MCAssembler &Asm, + MCAsmLayout &Layout, + RelMapTy &RelMap) { + for (MCAssembler::const_iterator it = Asm.begin(), + ie = Asm.end(); it != ie; ++it) { + const MCSectionData &SD = *it; + if (Relocations[&SD].empty()) + continue; + MCContext &Ctx = Asm.getContext(); - const MCSectionELF *RelaSection; const MCSectionELF &Section = static_cast(SD.getSection()); @@ -1000,17 +994,32 @@ void ELFObjectWriter::WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout, else EntrySize = is64Bit() ? sizeof(ELF::Elf64_Rel) : sizeof(ELF::Elf32_Rel); - RelaSection = Ctx.getELFSection(RelaSectionName, hasRelocationAddend() ? - ELF::SHT_RELA : ELF::SHT_REL, 0, - SectionKind::getReadOnly(), - EntrySize, ""); + const MCSectionELF *RelaSection = + Ctx.getELFSection(RelaSectionName, hasRelocationAddend() ? + ELF::SHT_RELA : ELF::SHT_REL, 0, + SectionKind::getReadOnly(), + EntrySize, ""); + RelMap[&Section] = RelaSection; + Asm.getOrCreateSectionData(*RelaSection); + } +} + +void ELFObjectWriter::WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout, + const RelMapTy &RelMap) { + for (MCAssembler::const_iterator it = Asm.begin(), + ie = Asm.end(); it != ie; ++it) { + const MCSectionData &SD = *it; + const MCSectionELF &Section = + static_cast(SD.getSection()); + const MCSectionELF *RelaSection = RelMap.lookup(&Section); + if (!RelaSection) + continue; MCSectionData &RelaSD = Asm.getOrCreateSectionData(*RelaSection); RelaSD.setAlignment(is64Bit() ? 8 : 4); MCDataFragment *F = new MCDataFragment(&RelaSD); - - WriteRelocationsFragment(Asm, F, &SD); + WriteRelocationsFragment(Asm, F, &*it); } } @@ -1036,8 +1045,10 @@ void ELFObjectWriter::WriteRelocationsFragment(const MCAssembler &Asm, MCDataFragment *F, const MCSectionData *SD) { std::vector &Relocs = Relocations[SD]; - // sort by the r_offset just like gnu as does - array_pod_sort(Relocs.begin(), Relocs.end()); + + // Sort the relocation entries. Most targets just sort by r_offset, but some + // (e.g., MIPS) have additional constraints. + TargetObjectWriter->sortRelocs(Asm, Relocs); for (unsigned i = 0, e = Relocs.size(); i != e; ++i) { ELFRelocationEntry entry = Relocs[e - i - 1]; @@ -1050,11 +1061,19 @@ void ELFObjectWriter::WriteRelocationsFragment(const MCAssembler &Asm, entry.Index += LocalSymbolData.size(); if (is64Bit()) { String64(*F, entry.r_offset); + if (TargetObjectWriter->isN64()) { + String32(*F, entry.Index); - struct ELF::Elf64_Rela ERE64; - ERE64.setSymbolAndType(entry.Index, entry.Type); - String64(*F, ERE64.r_info); - + String8(*F, TargetObjectWriter->getRSsym(entry.Type)); + String8(*F, TargetObjectWriter->getRType3(entry.Type)); + String8(*F, TargetObjectWriter->getRType2(entry.Type)); + String8(*F, TargetObjectWriter->getRType(entry.Type)); + } + else { + struct ELF::Elf64_Rela ERE64; + ERE64.setSymbolAndType(entry.Index, entry.Type); + String64(*F, ERE64.r_info); + } if (hasRelocationAddend()) String64(*F, entry.r_addend); } else { @@ -1070,9 +1089,28 @@ void ELFObjectWriter::WriteRelocationsFragment(const MCAssembler &Asm, } } +static int compareBySuffix(const void *a, const void *b) { + const MCSectionELF *secA = *static_cast(a); + const MCSectionELF *secB = *static_cast(b); + const StringRef &NameA = secA->getSectionName(); + const StringRef &NameB = secB->getSectionName(); + const unsigned sizeA = NameA.size(); + const unsigned sizeB = NameB.size(); + const unsigned len = std::min(sizeA, sizeB); + for (unsigned int i = 0; i < len; ++i) { + char ca = NameA[sizeA - i - 1]; + char cb = NameB[sizeB - i - 1]; + if (ca != cb) + return cb - ca; + } + + return sizeB - sizeA; +} + void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout, - const SectionIndexMapTy &SectionIndexMap) { + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap) { MCContext &Ctx = Asm.getContext(); MCDataFragment *F; @@ -1084,7 +1122,6 @@ void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm, SectionKind::getReadOnly()); MCSectionData &ShstrtabSD = Asm.getOrCreateSectionData(*ShstrtabSection); ShstrtabSD.setAlignment(1); - ShstrtabIndex = Asm.size(); const MCSectionELF *SymtabSection = Ctx.getELFSection(".symtab", ELF::SHT_SYMTAB, 0, @@ -1092,7 +1129,6 @@ void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm, EntrySize, ""); MCSectionData &SymtabSD = Asm.getOrCreateSectionData(*SymtabSection); SymtabSD.setAlignment(is64Bit() ? 8 : 4); - SymbolTableIndex = Asm.size(); MCSectionData *SymtabShndxSD = NULL; @@ -1104,14 +1140,17 @@ void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm, SymtabShndxSD->setAlignment(4); } - const MCSection *StrtabSection; + const MCSectionELF *StrtabSection; StrtabSection = Ctx.getELFSection(".strtab", ELF::SHT_STRTAB, 0, SectionKind::getReadOnly()); MCSectionData &StrtabSD = Asm.getOrCreateSectionData(*StrtabSection); StrtabSD.setAlignment(1); - StringTableIndex = Asm.size(); - WriteRelocations(Asm, Layout); + ComputeIndexMap(Asm, SectionIndexMap, RelMap); + + ShstrtabIndex = SectionIndexMap.lookup(ShstrtabSection); + SymbolTableIndex = SectionIndexMap.lookup(SymtabSection); + StringTableIndex = SectionIndexMap.lookup(StrtabSection); // Symbol table F = new MCDataFragment(&SymtabSD); @@ -1126,6 +1165,15 @@ void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm, F = new MCDataFragment(&ShstrtabSD); + std::vector Sections; + for (MCAssembler::const_iterator it = Asm.begin(), + ie = Asm.end(); it != ie; ++it) { + const MCSectionELF &Section = + static_cast(it->getSection()); + Sections.push_back(&Section); + } + array_pod_sort(Sections.begin(), Sections.end(), compareBySuffix); + // Section header string table. // // The first entry of a string table holds a null character so skip @@ -1133,22 +1181,20 @@ void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm, uint64_t Index = 1; F->getContents() += '\x00'; - StringMap SecStringMap; - for (MCAssembler::const_iterator it = Asm.begin(), - ie = Asm.end(); it != ie; ++it) { - const MCSectionELF &Section = - static_cast(it->getSection()); - // FIXME: We could merge suffixes like in .text and .rela.text. + for (unsigned int I = 0, E = Sections.size(); I != E; ++I) { + const MCSectionELF &Section = *Sections[I]; StringRef Name = Section.getSectionName(); - if (SecStringMap.count(Name)) { - SectionStringTableIndex[&Section] = SecStringMap[Name]; - continue; + if (I != 0) { + StringRef PreviousName = Sections[I - 1]->getSectionName(); + if (PreviousName.endswith(Name)) { + SectionStringTableIndex[&Section] = Index - Name.size() - 1; + continue; + } } // Remember the index into the string table so we can write it // into the sh_name field of the section header table. SectionStringTableIndex[&Section] = Index; - SecStringMap[Name] = Index; Index += Name.size() + 1; F->getContents() += Name; @@ -1156,41 +1202,34 @@ void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm, } } -bool -ELFObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, - const MCSymbolData &DataA, - const MCFragment &FB, - bool InSet, - bool IsPCRel) const { - // FIXME: This is in here just to match gnu as output. If the two ends - // are in the same section, there is nothing that the linker can do to - // break it. - if (DataA.isExternal()) - return false; - - const MCSection &SecA = DataA.getSymbol().AliasedSymbol().getSection(); - const MCSection &SecB = FB.getParent()->getSection(); - // On ELF A - B is absolute if A and B are in the same section. - return &SecA == &SecB; -} +void ELFObjectWriter::CreateIndexedSections(MCAssembler &Asm, + MCAsmLayout &Layout, + GroupMapTy &GroupMap, + RevGroupMapTy &RevGroupMap, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap) { + // Create the .note.GNU-stack section if needed. + MCContext &Ctx = Asm.getContext(); + if (Asm.getNoExecStack()) { + const MCSectionELF *GnuStackSection = + Ctx.getELFSection(".note.GNU-stack", ELF::SHT_PROGBITS, 0, + SectionKind::getReadOnly()); + Asm.getOrCreateSectionData(*GnuStackSection); + } -void ELFObjectWriter::CreateGroupSections(MCAssembler &Asm, - MCAsmLayout &Layout, - GroupMapTy &GroupMap, - RevGroupMapTy &RevGroupMap) { // Build the groups for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { const MCSectionELF &Section = static_cast(it->getSection()); - if (!(Section.getFlags() & MCSectionELF::SHF_GROUP)) + if (!(Section.getFlags() & ELF::SHF_GROUP)) continue; const MCSymbol *SignatureSymbol = Section.getGroup(); Asm.getOrCreateSymbolData(*SignatureSymbol); const MCSectionELF *&Group = RevGroupMap[SignatureSymbol]; if (!Group) { - Group = Asm.getContext().CreateELFGroupSection(); + Group = Ctx.CreateELFGroupSection(); MCSectionData &Data = Asm.getOrCreateSectionData(*Group); Data.setAlignment(4); MCDataFragment *F = new MCDataFragment(&Data); @@ -1199,20 +1238,21 @@ void ELFObjectWriter::CreateGroupSections(MCAssembler &Asm, GroupMap[Group] = SignatureSymbol; } + ComputeIndexMap(Asm, SectionIndexMap, RelMap); + // Add sections to the groups - unsigned Index = 1; - unsigned NumGroups = RevGroupMap.size(); for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end(); - it != ie; ++it, ++Index) { + it != ie; ++it) { const MCSectionELF &Section = static_cast(it->getSection()); - if (!(Section.getFlags() & MCSectionELF::SHF_GROUP)) + if (!(Section.getFlags() & ELF::SHF_GROUP)) continue; const MCSectionELF *Group = RevGroupMap[Section.getGroup()]; MCSectionData &Data = Asm.getOrCreateSectionData(*Group); // FIXME: we could use the previous fragment MCDataFragment *F = new MCDataFragment(&Data); - String32(*F, NumGroups + Index); + unsigned Index = SectionIndexMap.lookup(&Section); + String32(*F, Index); } } @@ -1271,14 +1311,14 @@ void ELFObjectWriter::WriteSection(MCAssembler &Asm, case ELF::SHT_INIT_ARRAY: case ELF::SHT_FINI_ARRAY: case ELF::SHT_PREINIT_ARRAY: + case ELF::SHT_X86_64_UNWIND: // Nothing to do. break; - case ELF::SHT_GROUP: { + case ELF::SHT_GROUP: sh_link = SymbolTableIndex; sh_info = GroupSymbolIndex; break; - } default: assert(0 && "FIXME: sh_type value not supported!"); @@ -1290,12 +1330,12 @@ void ELFObjectWriter::WriteSection(MCAssembler &Asm, Alignment, Section.getEntrySize()); } -static bool IsELFMetaDataSection(const MCSectionData &SD) { +bool ELFObjectWriter::IsELFMetaDataSection(const MCSectionData &SD) { return SD.getOrdinal() == ~UINT32_C(0) && !SD.getSection().isVirtualSection(); } -static uint64_t DataSectionSize(const MCSectionData &SD) { +uint64_t ELFObjectWriter::DataSectionSize(const MCSectionData &SD) { uint64_t Ret = 0; for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e; ++i) { @@ -1306,112 +1346,56 @@ static uint64_t DataSectionSize(const MCSectionData &SD) { return Ret; } -static uint64_t GetSectionFileSize(const MCAsmLayout &Layout, - const MCSectionData &SD) { +uint64_t ELFObjectWriter::GetSectionFileSize(const MCAsmLayout &Layout, + const MCSectionData &SD) { if (IsELFMetaDataSection(SD)) return DataSectionSize(SD); return Layout.getSectionFileSize(&SD); } -static uint64_t GetSectionAddressSize(const MCAsmLayout &Layout, - const MCSectionData &SD) { +uint64_t ELFObjectWriter::GetSectionAddressSize(const MCAsmLayout &Layout, + const MCSectionData &SD) { if (IsELFMetaDataSection(SD)) return DataSectionSize(SD); return Layout.getSectionAddressSize(&SD); } -static void WriteDataSectionData(ELFObjectWriter *W, const MCSectionData &SD) { - for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e; - ++i) { - const MCFragment &F = *i; - assert(F.getKind() == MCFragment::FT_Data); - W->WriteBytes(cast(F).getContents().str()); - } -} - -void ELFObjectWriter::WriteObject(MCAssembler &Asm, - const MCAsmLayout &Layout) { - GroupMapTy GroupMap; - RevGroupMapTy RevGroupMap; - CreateGroupSections(Asm, const_cast(Layout), GroupMap, - RevGroupMap); - - SectionIndexMapTy SectionIndexMap; +void ELFObjectWriter::WriteDataSectionData(MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCSectionELF &Section) { + const MCSectionData &SD = Asm.getOrCreateSectionData(Section); - ComputeIndexMap(Asm, SectionIndexMap); - - // Compute symbol table information. - ComputeSymbolTable(Asm, SectionIndexMap, RevGroupMap); - - CreateMetadataSections(const_cast(Asm), - const_cast(Layout), - SectionIndexMap); + uint64_t Padding = OffsetToAlignment(OS.tell(), SD.getAlignment()); + WriteZeros(Padding); - // Update to include the metadata sections. - ComputeIndexMap(Asm, SectionIndexMap); + if (IsELFMetaDataSection(SD)) { + for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e; + ++i) { + const MCFragment &F = *i; + assert(F.getKind() == MCFragment::FT_Data); + WriteBytes(cast(F).getContents().str()); + } + } else { + Asm.writeSectionData(&SD, Layout); + } +} - // Add 1 for the null section. - unsigned NumSections = Asm.size() + 1; - uint64_t NaturalAlignment = is64Bit() ? 8 : 4; - uint64_t HeaderSize = is64Bit() ? sizeof(ELF::Elf64_Ehdr) : - sizeof(ELF::Elf32_Ehdr); - uint64_t FileOff = HeaderSize; +void ELFObjectWriter::WriteSectionHeader(MCAssembler &Asm, + const GroupMapTy &GroupMap, + const MCAsmLayout &Layout, + const SectionIndexMapTy &SectionIndexMap, + const SectionOffsetMapTy &SectionOffsetMap) { + const unsigned NumSections = Asm.size() + 1; std::vector Sections; - Sections.resize(NumSections); + Sections.resize(NumSections - 1); for (SectionIndexMapTy::const_iterator i= SectionIndexMap.begin(), e = SectionIndexMap.end(); i != e; ++i) { const std::pair &p = *i; - Sections[p.second] = p.first; + Sections[p.second - 1] = p.first; } - for (unsigned i = 1; i < NumSections; ++i) { - const MCSectionELF &Section = *Sections[i]; - const MCSectionData &SD = Asm.getOrCreateSectionData(Section); - - FileOff = RoundUpToAlignment(FileOff, SD.getAlignment()); - - // Get the size of the section in the output file (including padding). - FileOff += GetSectionFileSize(Layout, SD); - } - - FileOff = RoundUpToAlignment(FileOff, NaturalAlignment); - - // Write out the ELF header ... - WriteHeader(FileOff - HeaderSize, NumSections); - - FileOff = HeaderSize; - - // ... then all of the sections ... - DenseMap SectionOffsetMap; - - for (unsigned i = 1; i < NumSections; ++i) { - const MCSectionELF &Section = *Sections[i]; - const MCSectionData &SD = Asm.getOrCreateSectionData(Section); - - uint64_t Padding = OffsetToAlignment(FileOff, SD.getAlignment()); - WriteZeros(Padding); - FileOff += Padding; - - // Remember the offset into the file for this section. - SectionOffsetMap[&Section] = FileOff; - - FileOff += GetSectionFileSize(Layout, SD); - - if (IsELFMetaDataSection(SD)) - WriteDataSectionData(this, SD); - else - Asm.WriteSectionData(&SD, Layout); - } - - uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment); - WriteZeros(Padding); - FileOff += Padding; - - // ... and then the section header table. - // Should we align the section header table? - // // Null section first. uint64_t FirstSectionSize = NumSections >= ELF::SHN_LORESERVE ? NumSections : 0; @@ -1419,376 +1403,161 @@ void ELFObjectWriter::WriteObject(MCAssembler &Asm, ShstrtabIndex >= ELF::SHN_LORESERVE ? ShstrtabIndex : 0; WriteSecHdrEntry(0, 0, 0, 0, 0, FirstSectionSize, FirstSectionLink, 0, 0, 0); - for (unsigned i = 1; i < NumSections; ++i) { + for (unsigned i = 0; i < NumSections - 1; ++i) { const MCSectionELF &Section = *Sections[i]; const MCSectionData &SD = Asm.getOrCreateSectionData(Section); uint32_t GroupSymbolIndex; if (Section.getType() != ELF::SHT_GROUP) GroupSymbolIndex = 0; else - GroupSymbolIndex = getSymbolIndexInSymbolTable(Asm, GroupMap[&Section]); + GroupSymbolIndex = getSymbolIndexInSymbolTable(Asm, + GroupMap.lookup(&Section)); uint64_t Size = GetSectionAddressSize(Layout, SD); WriteSection(Asm, SectionIndexMap, GroupSymbolIndex, - SectionOffsetMap[&Section], Size, + SectionOffsetMap.lookup(&Section), Size, SD.getAlignment(), Section); } } -MCObjectWriter *llvm::createELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &OS, - bool IsLittleEndian) { - switch (MOTW->getEMachine()) { - case ELF::EM_386: - case ELF::EM_X86_64: - return new X86ELFObjectWriter(MOTW, OS, IsLittleEndian); break; - case ELF::EM_ARM: - return new ARMELFObjectWriter(MOTW, OS, IsLittleEndian); break; - case ELF::EM_MBLAZE: - return new MBlazeELFObjectWriter(MOTW, OS, IsLittleEndian); break; - default: llvm_unreachable("Unsupported architecture"); break; +void ELFObjectWriter::ComputeSectionOrder(MCAssembler &Asm, + std::vector &Sections) { + for (MCAssembler::iterator it = Asm.begin(), + ie = Asm.end(); it != ie; ++it) { + const MCSectionELF &Section = + static_cast(it->getSection()); + if (Section.getType() == ELF::SHT_GROUP) + Sections.push_back(&Section); + } + + for (MCAssembler::iterator it = Asm.begin(), + ie = Asm.end(); it != ie; ++it) { + const MCSectionELF &Section = + static_cast(it->getSection()); + if (Section.getType() != ELF::SHT_GROUP && + Section.getType() != ELF::SHT_REL && + Section.getType() != ELF::SHT_RELA) + Sections.push_back(&Section); + } + + for (MCAssembler::iterator it = Asm.begin(), + ie = Asm.end(); it != ie; ++it) { + const MCSectionELF &Section = + static_cast(it->getSection()); + if (Section.getType() == ELF::SHT_REL || + Section.getType() == ELF::SHT_RELA) + Sections.push_back(&Section); } } +void ELFObjectWriter::WriteObject(MCAssembler &Asm, + const MCAsmLayout &Layout) { + GroupMapTy GroupMap; + RevGroupMapTy RevGroupMap; + SectionIndexMapTy SectionIndexMap; -/// START OF SUBCLASSES for ELFObjectWriter -//===- ARMELFObjectWriter -------------------------------------------===// + unsigned NumUserSections = Asm.size(); -ARMELFObjectWriter::ARMELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian) - : ELFObjectWriter(MOTW, _OS, IsLittleEndian) -{} + DenseMap RelMap; + CreateRelocationSections(Asm, const_cast(Layout), RelMap); -ARMELFObjectWriter::~ARMELFObjectWriter() -{} + const unsigned NumUserAndRelocSections = Asm.size(); + CreateIndexedSections(Asm, const_cast(Layout), GroupMap, + RevGroupMap, SectionIndexMap, RelMap); + const unsigned AllSections = Asm.size(); + const unsigned NumIndexedSections = AllSections - NumUserAndRelocSections; -unsigned ARMELFObjectWriter::GetRelocType(const MCValue &Target, - const MCFixup &Fixup, - bool IsPCRel, - bool IsRelocWithSymbol, - int64_t Addend) { - MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ? - MCSymbolRefExpr::VK_None : Target.getSymA()->getKind(); + unsigned NumRegularSections = NumUserSections + NumIndexedSections; - unsigned Type = 0; - if (IsPCRel) { - switch ((unsigned)Fixup.getKind()) { - default: assert(0 && "Unimplemented"); - case FK_Data_4: - switch (Modifier) { - default: llvm_unreachable("Unsupported Modifier"); - case MCSymbolRefExpr::VK_None: - Type = ELF::R_ARM_BASE_PREL; - break; - case MCSymbolRefExpr::VK_ARM_TLSGD: - assert(0 && "unimplemented"); - break; - case MCSymbolRefExpr::VK_ARM_GOTTPOFF: - Type = ELF::R_ARM_TLS_IE32; - break; - } - break; - case ARM::fixup_arm_branch: - switch (Modifier) { - case MCSymbolRefExpr::VK_ARM_PLT: - Type = ELF::R_ARM_PLT32; - break; - default: - Type = ELF::R_ARM_CALL; - break; - } - break; - case ARM::fixup_arm_movt_hi16: - case ARM::fixup_arm_movt_hi16_pcrel: - Type = ELF::R_ARM_MOVT_PREL; - break; - case ARM::fixup_arm_movw_lo16: - case ARM::fixup_arm_movw_lo16_pcrel: - Type = ELF::R_ARM_MOVW_PREL_NC; - break; - case ARM::fixup_t2_movt_hi16: - case ARM::fixup_t2_movt_hi16_pcrel: - Type = ELF::R_ARM_THM_MOVT_PREL; - break; - case ARM::fixup_t2_movw_lo16: - case ARM::fixup_t2_movw_lo16_pcrel: - Type = ELF::R_ARM_THM_MOVW_PREL_NC; - break; - } - } else { - switch ((unsigned)Fixup.getKind()) { - default: llvm_unreachable("invalid fixup kind!"); - case FK_Data_4: - switch (Modifier) { - default: llvm_unreachable("Unsupported Modifier"); break; - case MCSymbolRefExpr::VK_ARM_GOT: - Type = ELF::R_ARM_GOT_BREL; - break; - case MCSymbolRefExpr::VK_ARM_TLSGD: - Type = ELF::R_ARM_TLS_GD32; - break; - case MCSymbolRefExpr::VK_ARM_TPOFF: - Type = ELF::R_ARM_TLS_LE32; - break; - case MCSymbolRefExpr::VK_ARM_GOTTPOFF: - Type = ELF::R_ARM_TLS_IE32; - break; - case MCSymbolRefExpr::VK_None: - Type = ELF::R_ARM_ABS32; - break; - case MCSymbolRefExpr::VK_ARM_GOTOFF: - Type = ELF::R_ARM_GOTOFF32; - break; - } - break; - case ARM::fixup_arm_ldst_pcrel_12: - case ARM::fixup_arm_pcrel_10: - case ARM::fixup_arm_adr_pcrel_12: - case ARM::fixup_arm_thumb_bl: - case ARM::fixup_arm_thumb_cb: - case ARM::fixup_arm_thumb_cp: - case ARM::fixup_arm_thumb_br: - assert(0 && "Unimplemented"); - break; - case ARM::fixup_arm_branch: - // FIXME: Differentiate between R_ARM_CALL and - // R_ARM_JUMP24 (latter used for conditional jumps) - Type = ELF::R_ARM_CALL; - break; - case ARM::fixup_arm_movt_hi16: - Type = ELF::R_ARM_MOVT_ABS; - break; - case ARM::fixup_arm_movw_lo16: - Type = ELF::R_ARM_MOVW_ABS_NC; - break; - case ARM::fixup_t2_movt_hi16: - Type = ELF::R_ARM_THM_MOVT_ABS; - break; - case ARM::fixup_t2_movw_lo16: - Type = ELF::R_ARM_THM_MOVW_ABS_NC; - break; - } - } + // Compute symbol table information. + ComputeSymbolTable(Asm, SectionIndexMap, RevGroupMap, NumRegularSections); - if (RelocNeedsGOT(Modifier)) - NeedsGOT = true; - - return Type; -} -//===- MBlazeELFObjectWriter -------------------------------------------===// + WriteRelocations(Asm, const_cast(Layout), RelMap); -MBlazeELFObjectWriter::MBlazeELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian) - : ELFObjectWriter(MOTW, _OS, IsLittleEndian) { -} + CreateMetadataSections(const_cast(Asm), + const_cast(Layout), + SectionIndexMap, + RelMap); -MBlazeELFObjectWriter::~MBlazeELFObjectWriter() { -} + uint64_t NaturalAlignment = is64Bit() ? 8 : 4; + uint64_t HeaderSize = is64Bit() ? sizeof(ELF::Elf64_Ehdr) : + sizeof(ELF::Elf32_Ehdr); + uint64_t FileOff = HeaderSize; -unsigned MBlazeELFObjectWriter::GetRelocType(const MCValue &Target, - const MCFixup &Fixup, - bool IsPCRel, - bool IsRelocWithSymbol, - int64_t Addend) { - // determine the type of the relocation - unsigned Type; - if (IsPCRel) { - switch ((unsigned)Fixup.getKind()) { - default: - llvm_unreachable("Unimplemented"); - case FK_PCRel_4: - Type = ELF::R_MICROBLAZE_64_PCREL; - break; - case FK_PCRel_2: - Type = ELF::R_MICROBLAZE_32_PCREL; - break; - } - } else { - switch ((unsigned)Fixup.getKind()) { - default: llvm_unreachable("invalid fixup kind!"); - case FK_Data_4: - Type = ((IsRelocWithSymbol || Addend !=0) - ? ELF::R_MICROBLAZE_32 - : ELF::R_MICROBLAZE_64); - break; - case FK_Data_2: - Type = ELF::R_MICROBLAZE_32; - break; - } + std::vector Sections; + ComputeSectionOrder(Asm, Sections); + unsigned NumSections = Sections.size(); + SectionOffsetMapTy SectionOffsetMap; + for (unsigned i = 0; i < NumRegularSections + 1; ++i) { + const MCSectionELF &Section = *Sections[i]; + const MCSectionData &SD = Asm.getOrCreateSectionData(Section); + + FileOff = RoundUpToAlignment(FileOff, SD.getAlignment()); + + // Remember the offset into the file for this section. + SectionOffsetMap[&Section] = FileOff; + + // Get the size of the section in the output file (including padding). + FileOff += GetSectionFileSize(Layout, SD); } - return Type; -} -//===- X86ELFObjectWriter -------------------------------------------===// + FileOff = RoundUpToAlignment(FileOff, NaturalAlignment); + const unsigned SectionHeaderOffset = FileOff - HeaderSize; -X86ELFObjectWriter::X86ELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian) - : ELFObjectWriter(MOTW, _OS, IsLittleEndian) -{} + uint64_t SectionHeaderEntrySize = is64Bit() ? + sizeof(ELF::Elf64_Shdr) : sizeof(ELF::Elf32_Shdr); + FileOff += (NumSections + 1) * SectionHeaderEntrySize; -X86ELFObjectWriter::~X86ELFObjectWriter() -{} + for (unsigned i = NumRegularSections + 1; i < NumSections; ++i) { + const MCSectionELF &Section = *Sections[i]; + const MCSectionData &SD = Asm.getOrCreateSectionData(Section); -unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target, - const MCFixup &Fixup, - bool IsPCRel, - bool IsRelocWithSymbol, - int64_t Addend) { - // determine the type of the relocation + FileOff = RoundUpToAlignment(FileOff, SD.getAlignment()); - MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ? - MCSymbolRefExpr::VK_None : Target.getSymA()->getKind(); - unsigned Type; - if (is64Bit()) { - if (IsPCRel) { - switch ((unsigned)Fixup.getKind()) { - default: llvm_unreachable("invalid fixup kind!"); - case FK_PCRel_8: - assert(Modifier == MCSymbolRefExpr::VK_None); - Type = ELF::R_X86_64_PC64; - break; - case X86::reloc_signed_4byte: - case X86::reloc_riprel_4byte_movq_load: - case FK_Data_4: // FIXME? - case X86::reloc_riprel_4byte: - case FK_PCRel_4: - switch (Modifier) { - default: - llvm_unreachable("Unimplemented"); - case MCSymbolRefExpr::VK_None: - Type = ELF::R_X86_64_PC32; - break; - case MCSymbolRefExpr::VK_PLT: - Type = ELF::R_X86_64_PLT32; - break; - case MCSymbolRefExpr::VK_GOTPCREL: - Type = ELF::R_X86_64_GOTPCREL; - break; - case MCSymbolRefExpr::VK_GOTTPOFF: - Type = ELF::R_X86_64_GOTTPOFF; - break; - case MCSymbolRefExpr::VK_TLSGD: - Type = ELF::R_X86_64_TLSGD; - break; - case MCSymbolRefExpr::VK_TLSLD: - Type = ELF::R_X86_64_TLSLD; - break; - } - break; - case FK_PCRel_2: - assert(Modifier == MCSymbolRefExpr::VK_None); - Type = ELF::R_X86_64_PC16; - break; - } - } else { - switch ((unsigned)Fixup.getKind()) { - default: llvm_unreachable("invalid fixup kind!"); - case FK_Data_8: Type = ELF::R_X86_64_64; break; - case X86::reloc_signed_4byte: - assert(isInt<32>(Target.getConstant())); - switch (Modifier) { - default: - llvm_unreachable("Unimplemented"); - case MCSymbolRefExpr::VK_None: - Type = ELF::R_X86_64_32S; - break; - case MCSymbolRefExpr::VK_GOT: - Type = ELF::R_X86_64_GOT32; - break; - case MCSymbolRefExpr::VK_GOTPCREL: - Type = ELF::R_X86_64_GOTPCREL; - break; - case MCSymbolRefExpr::VK_TPOFF: - Type = ELF::R_X86_64_TPOFF32; - break; - case MCSymbolRefExpr::VK_DTPOFF: - Type = ELF::R_X86_64_DTPOFF32; - break; - } - break; - case FK_Data_4: - Type = ELF::R_X86_64_32; - break; - case FK_Data_2: Type = ELF::R_X86_64_16; break; - case FK_PCRel_1: - case FK_Data_1: Type = ELF::R_X86_64_8; break; - } - } - } else { - if (IsPCRel) { - switch (Modifier) { - default: - llvm_unreachable("Unimplemented"); - case MCSymbolRefExpr::VK_None: - Type = ELF::R_386_PC32; - break; - case MCSymbolRefExpr::VK_PLT: - Type = ELF::R_386_PLT32; - break; - } - } else { - switch ((unsigned)Fixup.getKind()) { - default: llvm_unreachable("invalid fixup kind!"); - - case X86::reloc_global_offset_table: - Type = ELF::R_386_GOTPC; - break; - - // FIXME: Should we avoid selecting reloc_signed_4byte in 32 bit mode - // instead? - case X86::reloc_signed_4byte: - case FK_PCRel_4: - case FK_Data_4: - switch (Modifier) { - default: - llvm_unreachable("Unimplemented"); - case MCSymbolRefExpr::VK_None: - Type = ELF::R_386_32; - break; - case MCSymbolRefExpr::VK_GOT: - Type = ELF::R_386_GOT32; - break; - case MCSymbolRefExpr::VK_GOTOFF: - Type = ELF::R_386_GOTOFF; - break; - case MCSymbolRefExpr::VK_TLSGD: - Type = ELF::R_386_TLS_GD; - break; - case MCSymbolRefExpr::VK_TPOFF: - Type = ELF::R_386_TLS_LE_32; - break; - case MCSymbolRefExpr::VK_INDNTPOFF: - Type = ELF::R_386_TLS_IE; - break; - case MCSymbolRefExpr::VK_NTPOFF: - Type = ELF::R_386_TLS_LE; - break; - case MCSymbolRefExpr::VK_GOTNTPOFF: - Type = ELF::R_386_TLS_GOTIE; - break; - case MCSymbolRefExpr::VK_TLSLDM: - Type = ELF::R_386_TLS_LDM; - break; - case MCSymbolRefExpr::VK_DTPOFF: - Type = ELF::R_386_TLS_LDO_32; - break; - } - break; - case FK_Data_2: Type = ELF::R_386_16; break; - case FK_PCRel_1: - case FK_Data_1: Type = ELF::R_386_8; break; - } - } + // Remember the offset into the file for this section. + SectionOffsetMap[&Section] = FileOff; + + // Get the size of the section in the output file (including padding). + FileOff += GetSectionFileSize(Layout, SD); } - if (RelocNeedsGOT(Modifier)) - NeedsGOT = true; + // Write out the ELF header ... + WriteHeader(SectionHeaderOffset, NumSections + 1); + + // ... then the regular sections ... + // + because of .shstrtab + for (unsigned i = 0; i < NumRegularSections + 1; ++i) + WriteDataSectionData(Asm, Layout, *Sections[i]); + + uint64_t Padding = OffsetToAlignment(OS.tell(), NaturalAlignment); + WriteZeros(Padding); - return Type; + // ... then the section header table ... + WriteSectionHeader(Asm, GroupMap, Layout, SectionIndexMap, + SectionOffsetMap); + + // ... and then the remaining sections ... + for (unsigned i = NumRegularSections + 1; i < NumSections; ++i) + WriteDataSectionData(Asm, Layout, *Sections[i]); +} + +bool +ELFObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, + const MCSymbolData &DataA, + const MCFragment &FB, + bool InSet, + bool IsPCRel) const { + if (DataA.getFlags() & ELF_STB_Weak) + return false; + return MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl( + Asm, DataA, FB,InSet, IsPCRel); +} + +MCObjectWriter *llvm::createELFObjectWriter(MCELFObjectTargetWriter *MOTW, + raw_ostream &OS, + bool IsLittleEndian) { + return new ELFObjectWriter(MOTW, OS, IsLittleEndian); }