X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FELFObjectWriter.cpp;h=7203b9a4bfab0f195c1d5cb7dfe859af7a2732cc;hb=fef904d0e824a2c587f8c1063b6c4fbf47fec898;hp=9f9681ae3efc3a646fc2fcbcaf05689bc47291c6;hpb=3729d0052bda365d04fee900c6f3d09460f1e108;p=oota-llvm.git diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp index 9f9681ae3ef..7203b9a4bfa 100644 --- a/lib/MC/ELFObjectWriter.cpp +++ b/lib/MC/ELFObjectWriter.cpp @@ -11,87 +11,62 @@ // //===----------------------------------------------------------------------===// -#include "llvm/MC/ELFObjectWriter.h" +#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/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 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 bool isFixupKindX86PCRel(unsigned Kind) { - switch (Kind) { - default: - return false; - case X86::reloc_pcrel_1byte: - case X86::reloc_pcrel_4byte: - case X86::reloc_riprel_4byte: - case X86::reloc_riprel_4byte_movq_load: - return true; - } -} - -static bool RelocNeedsGOT(unsigned Type) { - switch (Type) { - default: - return false; - case ELF::R_X86_64_GOT32: - case ELF::R_X86_64_PLT32: - case ELF::R_X86_64_GOTPCREL: - return true; - } -} +#undef DEBUG_TYPE +#define DEBUG_TYPE "reloc-info" namespace { +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); - class ELFObjectWriterImpl { /*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; @@ -99,33 +74,21 @@ 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; - - // Support lexicographic sorting. - bool operator<(const ELFRelocationEntry &RE) const { - return RE.r_offset < r_offset; - } - }; + /// The target specific ELF writer instance. + llvm::OwningPtr TargetObjectWriter; SmallPtrSet UsedInReloc; + SmallPtrSet WeakrefUsedInReloc; + DenseMap Renames; llvm::DenseMap > Relocations; @@ -142,53 +105,65 @@ namespace { /// @} - int NumRegularSections; - bool NeedsGOT; - ELFObjectWriter *Writer; - - raw_ostream &OS; - - unsigned Is64Bit : 1; - - bool HasRelocationAddend; - - Triple::OSType OSType; + bool NeedsSymtabShndx; // 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; unsigned ShstrtabIndex; + + const MCSymbol *SymbolToReloc(const MCAssembler &Asm, + const MCValue &Target, + 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: - ELFObjectWriterImpl(ELFObjectWriter *_Writer, bool _Is64Bit, - bool _HasRelAddend, Triple::OSType _OSType) - : NeedsGOT(false), Writer(_Writer), OS(Writer->getStream()), - Is64Bit(_Is64Bit), HasRelocationAddend(_HasRelAddend), - OSType(_OSType) { + ELFObjectWriter(MCELFObjectTargetWriter *MOTW, + raw_ostream &_OS, bool IsLittleEndian) + : MCObjectWriter(_OS, IsLittleEndian), + TargetObjectWriter(MOTW), + NeedsGOT(false), NeedsSymtabShndx(false){ } - void Write8(uint8_t Value) { Writer->Write8(Value); } - void Write16(uint16_t Value) { Writer->Write16(Value); } - void Write32(uint32_t Value) { Writer->Write32(Value); } - //void Write64(uint64_t Value) { Writer->Write64(Value); } - void WriteZeros(unsigned N) { Writer->WriteZeros(N); } - //void WriteBytes(StringRef Str, unsigned ZeroFillSize = 0) { - // Writer->WriteBytes(Str, ZeroFillSize); - //} + virtual ~ELFObjectWriter(); void WriteWord(uint64_t W) { - if (Is64Bit) - Writer->Write64(W); + if (is64Bit()) + Write64(W); else - Writer->Write32(W); - } - - void String8(char *buf, uint8_t Value) { - buf[0] = Value; + Write32(W); } void StringLE16(char *buf, uint16_t Value) { @@ -221,90 +196,180 @@ namespace { StringBE32(buf + 4, uint32_t(Value >> 0)); } - void String16(char *buf, uint16_t Value) { - if (Writer->isLittleEndian()) + void String8(MCDataFragment &F, uint8_t Value) { + char buf[1]; + buf[0] = Value; + F.getContents() += StringRef(buf, 1); + } + + void String16(MCDataFragment &F, uint16_t Value) { + char buf[2]; + if (isLittleEndian()) StringLE16(buf, Value); else StringBE16(buf, Value); + F.getContents() += StringRef(buf, 2); } - void String32(char *buf, uint32_t Value) { - if (Writer->isLittleEndian()) + void String32(MCDataFragment &F, uint32_t Value) { + char buf[4]; + if (isLittleEndian()) StringLE32(buf, Value); else StringBE32(buf, Value); + F.getContents() += StringRef(buf, 4); } - void String64(char *buf, uint64_t Value) { - if (Writer->isLittleEndian()) + void String64(MCDataFragment &F, uint64_t Value) { + char buf[8]; + if (isLittleEndian()) StringLE64(buf, Value); else StringBE64(buf, Value); + F.getContents() += StringRef(buf, 8); } - void WriteHeader(uint64_t SectionDataSize, unsigned NumberOfSections); + void WriteHeader(uint64_t SectionDataSize, + unsigned NumberOfSections); - void WriteSymbolEntry(MCDataFragment *F, uint64_t name, uint8_t info, + void WriteSymbolEntry(MCDataFragment *SymtabF, + MCDataFragment *ShndxF, + uint64_t name, uint8_t info, uint64_t value, uint64_t size, - uint8_t other, uint16_t shndx); + uint8_t other, uint32_t shndx, + bool Reserved); - void WriteSymbol(MCDataFragment *F, ELFSymbolData &MSD, + void WriteSymbol(MCDataFragment *SymtabF, MCDataFragment *ShndxF, + ELFSymbolData &MSD, const MCAsmLayout &Layout); - void WriteSymbolTable(MCDataFragment *F, const MCAssembler &Asm, + typedef DenseMap SectionIndexMapTy; + void WriteSymbolTable(MCDataFragment *SymtabF, + MCDataFragment *ShndxF, + const MCAssembler &Asm, const MCAsmLayout &Layout, - unsigned NumRegularSections); + const SectionIndexMapTy &SectionIndexMap); - void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout, - const MCFragment *Fragment, const MCFixup &Fixup, - MCValue Target, uint64_t &FixedValue); + virtual void RecordRelocation(const MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCFragment *Fragment, + const MCFixup &Fixup, + MCValue Target, uint64_t &FixedValue); 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. - void ComputeSymbolTable(MCAssembler &Asm); + void ComputeSymbolTable(MCAssembler &Asm, + const SectionIndexMapTy &SectionIndexMap, + RevGroupMapTy RevGroupMap, + unsigned NumRegularSections); - void WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout, - const MCSectionData &SD); + void ComputeIndexMap(MCAssembler &Asm, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap); - void WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout) { - for (MCAssembler::const_iterator it = Asm.begin(), - ie = Asm.end(); it != ie; ++it) { - WriteRelocation(Asm, Layout, *it); - } - } + void CreateRelocationSections(MCAssembler &Asm, MCAsmLayout &Layout, + RelMapTy &RelMap); - void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout); + void WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout, + const RelMapTy &RelMap); - void ExecutePostLayoutBinding(MCAssembler &Asm) { - } + void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap); + + // 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); + + 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); - void WriteRelocationsFragment(const MCAssembler &Asm, MCDataFragment *F, + void WriteRelocationsFragment(const MCAssembler &Asm, + MCDataFragment *F, const MCSectionData *SD); - bool IsFixupFullyResolved(const MCAssembler &Asm, - const MCValue Target, - bool IsPCRel, - const MCFragment *DF) const; - - void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout); + virtual bool + IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, + const MCSymbolData &DataA, + const MCFragment &FB, + bool InSet, + bool IsPCRel) const; + + virtual void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout); + void WriteSection(MCAssembler &Asm, + const SectionIndexMapTy &SectionIndexMap, + uint32_t GroupSymbolIndex, + uint64_t Offset, uint64_t Size, uint64_t Alignment, + const MCSectionELF &Section); }; +} + +bool ELFObjectWriter::isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) { + const MCFixupKindInfo &FKI = + Asm.getBackend().getFixupKindInfo((MCFixupKind) Kind); + return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel; } +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() +{} + // Emit the ELF header. -void ELFObjectWriterImpl::WriteHeader(uint64_t SectionDataSize, - unsigned NumberOfSections) { +void ELFObjectWriter::WriteHeader(uint64_t SectionDataSize, + unsigned NumberOfSections) { // ELF Header // ---------- // @@ -318,166 +383,195 @@ void ELFObjectWriterImpl::WriteHeader(uint64_t SectionDataSize, Write8('L'); // e_ident[EI_MAG2] Write8('F'); // e_ident[EI_MAG3] - Write8(Is64Bit ? ELF::ELFCLASS64 : ELF::ELFCLASS32); // e_ident[EI_CLASS] + Write8(is64Bit() ? ELF::ELFCLASS64 : ELF::ELFCLASS32); // e_ident[EI_CLASS] // e_ident[EI_DATA] - Write8(Writer->isLittleEndian() ? ELF::ELFDATA2LSB : ELF::ELFDATA2MSB); + Write8(isLittleEndian() ? ELF::ELFDATA2LSB : ELF::ELFDATA2MSB); Write8(ELF::EV_CURRENT); // e_ident[EI_VERSION] // e_ident[EI_OSABI] - switch (OSType) { - 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); Write16(ELF::ET_REL); // e_type - // FIXME: Make this configurable - Write16(Is64Bit ? ELF::EM_X86_64 : ELF::EM_386); // e_machine = target + Write16(TargetObjectWriter->getEMachine()); // e_machine = target Write32(ELF::EV_CURRENT); // e_version WriteWord(0); // e_entry, no entry point in .o file WriteWord(0); // e_phoff, no program header for .o - WriteWord(SectionDataSize + (Is64Bit ? sizeof(ELF::Elf64_Ehdr) : + 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)); + Write16(is64Bit() ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr)); Write16(0); // e_phentsize = prog header entry size Write16(0); // e_phnum = # prog header entries = 0 // e_shentsize = Section header entry size - Write16(Is64Bit ? sizeof(ELF::Elf64_Shdr) : sizeof(ELF::Elf32_Shdr)); + Write16(is64Bit() ? sizeof(ELF::Elf64_Shdr) : sizeof(ELF::Elf32_Shdr)); // e_shnum = # of section header ents - Write16(NumberOfSections); + if (NumberOfSections >= ELF::SHN_LORESERVE) + Write16(ELF::SHN_UNDEF); + else + Write16(NumberOfSections); // e_shstrndx = Section # of '.shstrtab' - Write16(ShstrtabIndex); + if (ShstrtabIndex >= ELF::SHN_LORESERVE) + Write16(ELF::SHN_XINDEX); + else + Write16(ShstrtabIndex); } -void ELFObjectWriterImpl::WriteSymbolEntry(MCDataFragment *F, uint64_t name, - uint8_t info, uint64_t value, - uint64_t size, uint8_t other, - uint16_t shndx) { - if (Is64Bit) { - char buf[8]; +void ELFObjectWriter::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) { + if (ShndxF) { + if (shndx >= ELF::SHN_LORESERVE && !Reserved) + String32(*ShndxF, shndx); + else + String32(*ShndxF, 0); + } - String32(buf, name); - F->getContents() += StringRef(buf, 4); // st_name + uint16_t Index = (shndx >= ELF::SHN_LORESERVE && !Reserved) ? + uint16_t(ELF::SHN_XINDEX) : shndx; - String8(buf, info); - F->getContents() += StringRef(buf, 1); // st_info + if (is64Bit()) { + String32(*SymtabF, name); // st_name + String8(*SymtabF, info); // st_info + String8(*SymtabF, other); // st_other + String16(*SymtabF, Index); // st_shndx + String64(*SymtabF, value); // st_value + String64(*SymtabF, size); // st_size + } else { + String32(*SymtabF, name); // st_name + String32(*SymtabF, value); // st_value + String32(*SymtabF, size); // st_size + String8(*SymtabF, info); // st_info + String8(*SymtabF, other); // st_other + String16(*SymtabF, Index); // st_shndx + } +} - String8(buf, other); - F->getContents() += StringRef(buf, 1); // st_other +uint64_t ELFObjectWriter::SymbolValue(MCSymbolData &Data, + const MCAsmLayout &Layout) { + if (Data.isCommon() && Data.isExternal()) + return Data.getCommonAlignment(); - String16(buf, shndx); - F->getContents() += StringRef(buf, 2); // st_shndx + const MCSymbol &Symbol = Data.getSymbol(); - String64(buf, value); - F->getContents() += StringRef(buf, 8); // st_value + if (Symbol.isAbsolute() && Symbol.isVariable()) { + if (const MCExpr *Value = Symbol.getVariableValue()) { + int64_t IntValue; + if (Value->EvaluateAsAbsolute(IntValue, Layout)) + return (uint64_t)IntValue; + } + } - String64(buf, size); - F->getContents() += StringRef(buf, 8); // st_size - } else { - char buf[4]; + if (!Symbol.isInSection()) + return 0; - String32(buf, name); - F->getContents() += StringRef(buf, 4); // st_name - String32(buf, value); - F->getContents() += StringRef(buf, 4); // st_value + if (Data.getFragment()) { + if (Data.getFlags() & ELF_Other_ThumbFunc) + return Layout.getSymbolOffset(&Data)+1; + else + return Layout.getSymbolOffset(&Data); + } + + return 0; +} - String32(buf, size); - F->getContents() += StringRef(buf, 4); // st_size +void ELFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm, + const MCAsmLayout &Layout) { + // The presence of symbol versions causes undefined symbols and + // versions declared with @@@ to be renamed. - String8(buf, info); - F->getContents() += StringRef(buf, 1); // st_info + for (MCAssembler::symbol_iterator it = Asm.symbol_begin(), + ie = Asm.symbol_end(); it != ie; ++it) { + const MCSymbol &Alias = it->getSymbol(); + const MCSymbol &Symbol = Alias.AliasedSymbol(); + MCSymbolData &SD = Asm.getSymbolData(Symbol); + + // Not an alias. + if (&Symbol == &Alias) + continue; + + StringRef AliasName = Alias.getName(); + size_t Pos = AliasName.find('@'); + if (Pos == StringRef::npos) + continue; - String8(buf, other); - F->getContents() += StringRef(buf, 1); // st_other + // 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()); + MCELF::SetBinding(*it, MCELF::GetBinding(SD)); - String16(buf, shndx); - F->getContents() += StringRef(buf, 2); // st_shndx + StringRef Rest = AliasName.substr(Pos); + if (!Symbol.isUndefined() && !Rest.startswith("@@@")) + continue; + + // FIXME: produce a better error message. + if (Symbol.isUndefined() && Rest.startswith("@@") && + !Rest.startswith("@@@")) + report_fatal_error("A @@ version cannot be undefined"); + + Renames.insert(std::make_pair(&Symbol, &Alias)); } } -static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) { - if (Data.isCommon() && Data.isExternal()) - return Data.getCommonAlignment(); +void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF, + MCDataFragment *ShndxF, + ELFSymbolData &MSD, + const MCAsmLayout &Layout) { + MCSymbolData &OrigData = *MSD.SymbolData; + MCSymbolData &Data = + Layout.getAssembler().getSymbolData(OrigData.getSymbol().AliasedSymbol()); - const MCSymbol &Symbol = Data.getSymbol(); - if (!Symbol.isInSection()) - return 0; + bool IsReserved = Data.isCommon() || Data.getSymbol().isAbsolute() || + Data.getSymbol().isVariable(); - if (!Data.isCommon() && !(Data.getFlags() & ELF_STB_Weak)) - if (MCFragment *FF = Data.getFragment()) - return Layout.getSymbolAddress(&Data) - - Layout.getSectionAddress(FF->getParent()); + uint8_t Binding = MCELF::GetBinding(OrigData); + uint8_t Visibility = MCELF::GetVisibility(OrigData); + uint8_t Type = MCELF::GetType(Data); - return 0; -} + uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift); + uint8_t Other = Visibility; -void ELFObjectWriterImpl::WriteSymbol(MCDataFragment *F, ELFSymbolData &MSD, - const MCAsmLayout &Layout) { - MCSymbolData &Data = *MSD.SymbolData; - uint8_t Info = (Data.getFlags() & 0xff); - uint8_t Other = ((Data.getFlags() & 0xf00) >> ELF_STV_Shift); uint64_t Value = SymbolValue(Data, Layout); uint64_t Size = 0; - const MCExpr *ESize; assert(!(Data.isCommon() && !Data.isExternal())); - ESize = Data.getSize(); - if (Data.getSize()) { - MCValue Res; - if (ESize->getKind() == MCExpr::Binary) { - const MCBinaryExpr *BE = static_cast(ESize); - - if (BE->EvaluateAsRelocatable(Res, &Layout)) { - uint64_t AddressA = 0; - uint64_t AddressB = 0; - const MCSymbol &SymA = Res.getSymA()->getSymbol(); - const MCSymbol &SymB = Res.getSymB()->getSymbol(); - - if (SymA.isDefined()) { - MCSymbolData &A = Layout.getAssembler().getSymbolData(SymA); - AddressA = Layout.getSymbolAddress(&A); - } - - if (SymB.isDefined()) { - MCSymbolData &B = Layout.getAssembler().getSymbolData(SymB); - AddressB = Layout.getSymbolAddress(&B); - } - - Size = AddressA - AddressB; - } - } else if (ESize->getKind() == MCExpr::Constant) { - Size = static_cast(ESize)->getValue(); - } else { - assert(0 && "Unsupported size expression"); - } + const MCExpr *ESize = Data.getSize(); + if (ESize) { + int64_t Res; + if (!ESize->EvaluateAsAbsolute(Res, Layout)) + report_fatal_error("Size expression must be absolute."); + Size = Res; } // Write out the symbol table entry - WriteSymbolEntry(F, MSD.StringIndex, Info, Value, - Size, Other, MSD.SectionIndex); + WriteSymbolEntry(SymtabF, ShndxF, MSD.StringIndex, Info, Value, + Size, Other, MSD.SectionIndex, IsReserved); } -void ELFObjectWriterImpl::WriteSymbolTable(MCDataFragment *F, - const MCAssembler &Asm, - const MCAsmLayout &Layout, - unsigned NumRegularSections) { +void ELFObjectWriter::WriteSymbolTable(MCDataFragment *SymtabF, + MCDataFragment *ShndxF, + const MCAssembler &Asm, + const MCAsmLayout &Layout, + 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"); @@ -485,366 +579,374 @@ void ELFObjectWriterImpl::WriteSymbolTable(MCDataFragment *F, // FIXME: Make sure the start of the symbol table is aligned. // The first entry is the undefined symbol entry. - unsigned EntrySize = Is64Bit ? ELF::SYMENTRY_SIZE64 : ELF::SYMENTRY_SIZE32; - F->getContents().append(EntrySize, '\x00'); + WriteSymbolEntry(SymtabF, ShndxF, 0, 0, 0, 0, 0, 0, false); // Write the symbol table entries. LastLocalSymbolIndex = LocalSymbolData.size() + 1; for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i) { ELFSymbolData &MSD = LocalSymbolData[i]; - WriteSymbol(F, MSD, Layout); + WriteSymbol(SymtabF, ShndxF, MSD, Layout); } // Write out a symbol table entry for each regular section. - unsigned Index = 1; - for (MCAssembler::const_iterator it = Asm.begin(); - Index <= NumRegularSections; ++it, ++Index) { + for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e; + ++i) { const MCSectionELF &Section = - static_cast(it->getSection()); - // Leave out relocations so we don't have indexes within - // the relocations messed up - if (Section.getType() == ELF::SHT_RELA || Section.getType() == ELF::SHT_REL) + static_cast(i->getSection()); + 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_SHNDX) continue; - WriteSymbolEntry(F, 0, ELF::STT_SECTION, 0, 0, ELF::STV_DEFAULT, Index); + WriteSymbolEntry(SymtabF, ShndxF, 0, ELF::STT_SECTION, 0, 0, + ELF::STV_DEFAULT, SectionIndexMap.lookup(&Section), + false); LastLocalSymbolIndex++; } for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i) { ELFSymbolData &MSD = ExternalSymbolData[i]; MCSymbolData &Data = *MSD.SymbolData; - assert((Data.getFlags() & ELF_STB_Global) && - "External symbol requires STB_GLOBAL flag"); - WriteSymbol(F, MSD, Layout); - if (GetBinding(Data) == ELF::STB_LOCAL) + assert(((Data.getFlags() & ELF_STB_Global) || + (Data.getFlags() & ELF_STB_Weak)) && + "External symbol requires STB_GLOBAL or STB_WEAK flag"); + WriteSymbol(SymtabF, ShndxF, MSD, Layout); + if (MCELF::GetBinding(Data) == ELF::STB_LOCAL) LastLocalSymbolIndex++; } for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i) { ELFSymbolData &MSD = UndefinedSymbolData[i]; MCSymbolData &Data = *MSD.SymbolData; - WriteSymbol(F, MSD, Layout); - if (GetBinding(Data) == ELF::STB_LOCAL) + WriteSymbol(SymtabF, ShndxF, MSD, Layout); + if (MCELF::GetBinding(Data) == ELF::STB_LOCAL) LastLocalSymbolIndex++; } } -static bool ShouldRelocOnSymbol(const MCSymbolData &SD, - const MCValue &Target, - const MCFragment &F) { - const MCSymbol &Symbol = SD.getSymbol(); - if (Symbol.isUndefined()) - return true; +const MCSymbol *ELFObjectWriter::SymbolToReloc(const MCAssembler &Asm, + const MCValue &Target, + 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); + const MCSymbolData &SD = Asm.getSymbolData(Symbol); + + if (ASymbol.isUndefined()) { + if (Renamed) + return Renamed; + return &ASymbol; + } + + if (SD.isExternal()) { + if (Renamed) + return Renamed; + return &Symbol; + } const MCSectionELF &Section = - static_cast(Symbol.getSection()); + static_cast(ASymbol.getSection()); + const SectionKind secKind = Section.getKind(); - if (Section.getFlags() & MCSectionELF::SHF_MERGE) - return Target.getConstant() != 0; + if (secKind.isBSS()) + return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); - if (SD.isExternal()) - return true; + if (secKind.isThreadLocal()) { + if (Renamed) + return Renamed; + return &Symbol; + } - const llvm::MCSymbolRefExpr& Ref = *Target.getSymA(); + MCSymbolRefExpr::VariantKind Kind = Target.getSymA()->getKind(); const MCSectionELF &Sec2 = static_cast(F.getParent()->getSection()); - if (Ref.getKind() == MCSymbolRefExpr::VK_PLT && - &Sec2 != &Section) - return true; + if (&Sec2 != &Section && + (Kind == MCSymbolRefExpr::VK_PLT || + Kind == MCSymbolRefExpr::VK_GOTPCREL || + Kind == MCSymbolRefExpr::VK_GOTOFF)) { + if (Renamed) + return Renamed; + return &Symbol; + } + + if (Section.getFlags() & ELF::SHF_MERGE) { + if (Target.getConstant() == 0) + return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); + if (Renamed) + return Renamed; + return &Symbol; + } + + return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); - return false; } -// FIXME: this is currently X86/X86_64 only -void ELFObjectWriterImpl::RecordRelocation(const MCAssembler &Asm, - const MCAsmLayout &Layout, - const MCFragment *Fragment, - const MCFixup &Fixup, - MCValue Target, - uint64_t &FixedValue) { + +void ELFObjectWriter::RecordRelocation(const MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCFragment *Fragment, + const MCFixup &Fixup, + MCValue Target, + uint64_t &FixedValue) { int64_t Addend = 0; int Index = 0; int64_t Value = Target.getConstant(); - const MCSymbol *Symbol = 0; + const MCSymbol *RelocSymbol = NULL; - bool IsPCRel = isFixupKindX86PCRel(Fixup.getKind()); + bool IsPCRel = isFixupKindPCRel(Asm, Fixup.getKind()); if (!Target.isAbsolute()) { - Symbol = &Target.getSymA()->getSymbol(); - MCSymbolData &SD = Asm.getSymbolData(*Symbol); - MCFragment *F = SD.getFragment(); + const MCSymbol &Symbol = Target.getSymA()->getSymbol(); + const MCSymbol &ASymbol = Symbol.AliasedSymbol(); + RelocSymbol = SymbolToReloc(Asm, Target, *Fragment, Fixup, IsPCRel); if (const MCSymbolRefExpr *RefB = Target.getSymB()) { const MCSymbol &SymbolB = RefB->getSymbol(); MCSymbolData &SDB = Asm.getSymbolData(SymbolB); IsPCRel = true; - MCSectionData *Sec = Fragment->getParent(); // Offset of the symbol in the section - int64_t a = Layout.getSymbolAddress(&SDB) - Layout.getSectionAddress(Sec); + 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; } - // Check that this case has already been fully resolved before we get - // here. - if (Symbol->isDefined() && !SD.isExternal() && - IsPCRel && - &Fragment->getParent()->getSection() == &Symbol->getSection()) { - llvm_unreachable("We don't need a relocation in this case."); - return; - } + if (!RelocSymbol) { + MCSymbolData &SD = Asm.getSymbolData(ASymbol); + MCFragment *F = SD.getFragment(); - bool RelocOnSymbol = ShouldRelocOnSymbol(SD, Target, *Fragment); - if (!RelocOnSymbol) { - Index = F->getParent()->getOrdinal(); + Index = F->getParent()->getOrdinal() + 1; - MCSectionData *FSD = F->getParent(); // Offset of the symbol in the section - Value += Layout.getSymbolAddress(&SD) - Layout.getSectionAddress(FSD); + Value += Layout.getSymbolOffset(&SD); } else { - UsedInReloc.insert(Symbol); + if (Asm.getSymbolData(Symbol).getFlags() & ELF_Other_Weakref) + WeakrefUsedInReloc.insert(RelocSymbol); + else + UsedInReloc.insert(RelocSymbol); Index = -1; } Addend = Value; // Compensate for the addend on i386. - if (Is64Bit) + if (is64Bit()) Value = 0; } FixedValue = Value; - - // determine the type of the relocation - - MCSymbolRefExpr::VariantKind Modifier = Target.getSymA()->getKind(); - unsigned Type; - if (Is64Bit) { - if (IsPCRel) { - switch (Modifier) { - case MCSymbolRefExpr::VK_None: - Type = ELF::R_X86_64_PC32; - break; - case MCSymbolRefExpr::VK_PLT: - Type = ELF::R_X86_64_PLT32; - break; - case llvm::MCSymbolRefExpr::VK_GOTPCREL: - Type = ELF::R_X86_64_GOTPCREL; - break; - default: - llvm_unreachable("Unimplemented"); - } - } 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: - case X86::reloc_pcrel_4byte: - assert(isInt<32>(Target.getConstant())); - switch (Modifier) { - case MCSymbolRefExpr::VK_None: - Type = ELF::R_X86_64_32S; - break; - case MCSymbolRefExpr::VK_GOT: - Type = ELF::R_X86_64_GOT32; - break; - default: - llvm_unreachable("Unimplemented"); - } - break; - case FK_Data_4: - Type = ELF::R_X86_64_32; - break; - case FK_Data_2: Type = ELF::R_X86_64_16; break; - case X86::reloc_pcrel_1byte: - case FK_Data_1: Type = ELF::R_X86_64_8; break; - } - } - } else { - if (IsPCRel) { - Type = ELF::R_386_PC32; - } else { - switch ((unsigned)Fixup.getKind()) { - default: llvm_unreachable("invalid fixup kind!"); - - // FIXME: Should we avoid selecting reloc_signed_4byte in 32 bit mode - // instead? - case X86::reloc_signed_4byte: - case X86::reloc_pcrel_4byte: - case FK_Data_4: Type = ELF::R_386_32; break; - case FK_Data_2: Type = ELF::R_386_16; break; - case X86::reloc_pcrel_1byte: - case FK_Data_1: Type = ELF::R_386_8; break; - } - } - } - - if (RelocNeedsGOT(Type)) + 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; - ELFRelocationEntry ERE; + uint64_t RelocOffset = Layout.getFragmentOffset(Fragment) + + Fixup.getOffset(); - ERE.Index = Index; - ERE.Type = Type; - ERE.Symbol = Symbol; + // FIXME: no tests cover this. Is adjustFixupOffset dead code? + TargetObjectWriter->adjustFixupOffset(Fixup, RelocOffset); - ERE.r_offset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset(); + if (!hasRelocationAddend()) + Addend = 0; - if (HasRelocationAddend) - ERE.r_addend = Addend; + if (is64Bit()) + assert(isInt<64>(Addend)); else - ERE.r_addend = 0; // Silence compiler warning. + assert(isInt<32>(Addend)); + ELFRelocationEntry ERE(RelocOffset, Index, Type, RelocSymbol, Addend, Fixup); Relocations[Fragment->getParent()].push_back(ERE); } + uint64_t -ELFObjectWriterImpl::getSymbolIndexInSymbolTable(const MCAssembler &Asm, - const MCSymbol *S) { +ELFObjectWriter::getSymbolIndexInSymbolTable(const MCAssembler &Asm, + const MCSymbol *S) { MCSymbolData &SD = Asm.getSymbolData(*S); + return SD.getIndex(); +} - // Local symbol. - if (!SD.isExternal() && !S->isUndefined()) - return SD.getIndex() + /* empty symbol */ 1; +bool ELFObjectWriter::isInSymtab(const MCAssembler &Asm, + const MCSymbolData &Data, + bool Used, bool Renamed) { + if (Data.getFlags() & ELF_Other_Weakref) + return false; - // External or undefined symbol. - return SD.getIndex() + NumRegularSections + /* empty symbol */ 1; -} + if (Used) + return true; + + if (Renamed) + return false; -static bool isInSymtab(const MCAssembler &Asm, const MCSymbolData &Data, - bool Used) { const MCSymbol &Symbol = Data.getSymbol(); + + if (Symbol.getName() == "_GLOBAL_OFFSET_TABLE_") + return true; + + const MCSymbol &A = Symbol.AliasedSymbol(); + 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()) return false; - if (!Used && Symbol.isTemporary()) + if (Symbol.isTemporary()) return false; return true; } -static bool isLocal(const MCSymbolData &Data) { +bool ELFObjectWriter::isLocal(const MCSymbolData &Data, bool isSignature, + bool isUsedInReloc) { if (Data.isExternal()) return false; const MCSymbol &Symbol = Data.getSymbol(); - if (Symbol.isUndefined() && !Symbol.isVariable()) + const MCSymbol &RefSymbol = Symbol.AliasedSymbol(); + + if (RefSymbol.isUndefined() && !RefSymbol.isVariable()) { + if (isSignature && !isUsedInReloc) + return true; + return false; + } return true; } -void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) { +void ELFObjectWriter::ComputeIndexMap(MCAssembler &Asm, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap) { + unsigned Index = 1; + 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) + continue; + SectionIndexMap[&Section] = Index++; + } + + 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) + 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, + 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); + MCELF::SetBinding(Data, ELF::STB_GLOBAL); } - // Build section lookup table. - NumRegularSections = Asm.size(); - DenseMap SectionIndexMap; - unsigned Index = 1; - for (MCAssembler::iterator it = Asm.begin(), - ie = Asm.end(); it != ie; ++it, ++Index) - SectionIndexMap[&it->getSection()] = Index; - // Index 0 is always the empty string. StringMap StringIndexMap; StringTable += '\x00'; - // Add the data for local symbols. + // 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) { const MCSymbol &Symbol = it->getSymbol(); - if (!isInSymtab(Asm, *it, UsedInReloc.count(&Symbol))) - continue; + bool Used = UsedInReloc.count(&Symbol); + bool WeakrefUsed = WeakrefUsedInReloc.count(&Symbol); + bool isSignature = RevGroupMap.count(&Symbol); - if (!isLocal(*it)) + if (!isInSymtab(Asm, *it, + Used || WeakrefUsed || isSignature, + Renames.count(&Symbol))) continue; - uint64_t &Entry = StringIndexMap[Symbol.getName()]; - if (!Entry) { - Entry = StringTable.size(); - StringTable += Symbol.getName(); - StringTable += '\x00'; - } - ELFSymbolData MSD; MSD.SymbolData = it; - MSD.StringIndex = Entry; + const MCSymbol &RefSymbol = Symbol.AliasedSymbol(); + + // Undefined symbols are global, but this is the first place we + // are able to set it. + bool Local = isLocal(*it, isSignature, Used); + if (!Local && MCELF::GetBinding(*it) == ELF::STB_LOCAL) { + MCSymbolData &SD = Asm.getSymbolData(RefSymbol); + MCELF::SetBinding(*it, ELF::STB_GLOBAL); + MCELF::SetBinding(SD, ELF::STB_GLOBAL); + } - if (Symbol.isAbsolute()) { + if (RefSymbol.isUndefined() && !Used && WeakrefUsed) + MCELF::SetBinding(*it, ELF::STB_WEAK); + + if (it->isCommon()) { + assert(!Local); + MSD.SectionIndex = ELF::SHN_COMMON; + } else if (Symbol.isAbsolute() || RefSymbol.isVariable()) { MSD.SectionIndex = ELF::SHN_ABS; - LocalSymbolData.push_back(MSD); + } else if (RefSymbol.isUndefined()) { + if (isSignature && !Used) + MSD.SectionIndex = SectionIndexMap.lookup(RevGroupMap[&Symbol]); + else + MSD.SectionIndex = ELF::SHN_UNDEF; } else { - const MCSymbol *SymbolP = &Symbol; - if (Symbol.isVariable()) { - const MCExpr *Value = Symbol.getVariableValue(); - assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented"); - const MCSymbolRefExpr *Ref = static_cast(Value); - SymbolP = &Ref->getSymbol(); - } - MSD.SectionIndex = SectionIndexMap.lookup(&SymbolP->getSection()); + const MCSectionELF &Section = + static_cast(RefSymbol.getSection()); + MSD.SectionIndex = SectionIndexMap.lookup(&Section); + if (MSD.SectionIndex >= ELF::SHN_LORESERVE) + NeedsSymtabShndx = true; assert(MSD.SectionIndex && "Invalid section index!"); - LocalSymbolData.push_back(MSD); } - } - - // Now add non-local symbols. - for (MCAssembler::symbol_iterator it = Asm.symbol_begin(), - ie = Asm.symbol_end(); it != ie; ++it) { - const MCSymbol &Symbol = it->getSymbol(); - - if (!isInSymtab(Asm, *it, UsedInReloc.count(&Symbol))) - continue; - if (isLocal(*it)) - continue; + // The @@@ in symbol version is replaced with @ in undefined symbols and + // @@ in defined ones. + StringRef Name = Symbol.getName(); + SmallString<32> Buf; + + size_t Pos = Name.find("@@@"); + if (Pos != StringRef::npos) { + Buf += Name.substr(0, Pos); + unsigned Skip = MSD.SectionIndex == ELF::SHN_UNDEF ? 2 : 1; + Buf += Name.substr(Pos + Skip); + Name = Buf; + } - uint64_t &Entry = StringIndexMap[Symbol.getName()]; + uint64_t &Entry = StringIndexMap[Name]; if (!Entry) { Entry = StringTable.size(); - StringTable += Symbol.getName(); + StringTable += Name; StringTable += '\x00'; } - - ELFSymbolData MSD; - MSD.SymbolData = it; MSD.StringIndex = Entry; - - // FIXME: There is duplicated code with the local case. - if (it->isCommon()) { - MSD.SectionIndex = ELF::SHN_COMMON; - ExternalSymbolData.push_back(MSD); - } else if (Symbol.isVariable()) { - const MCExpr *Value = Symbol.getVariableValue(); - assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented"); - const MCSymbolRefExpr *Ref = static_cast(Value); - const MCSymbol &RefSymbol = Ref->getSymbol(); - if (RefSymbol.isDefined()) { - MSD.SectionIndex = SectionIndexMap.lookup(&RefSymbol.getSection()); - assert(MSD.SectionIndex && "Invalid section index!"); - ExternalSymbolData.push_back(MSD); - } - } else if (Symbol.isUndefined()) { - MSD.SectionIndex = ELF::SHN_UNDEF; - // FIXME: Undefined symbols are global, but this is the first place we - // are able to set it. - if (GetBinding(*it) == ELF::STB_LOCAL) - SetBinding(*it, ELF::STB_GLOBAL); + if (MSD.SectionIndex == ELF::SHN_UNDEF) UndefinedSymbolData.push_back(MSD); - } else if (Symbol.isAbsolute()) { - MSD.SectionIndex = ELF::SHN_ABS; - ExternalSymbolData.push_back(MSD); - } else { - MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection()); - assert(MSD.SectionIndex && "Invalid section index!"); + else if (Local) + LocalSymbolData.push_back(MSD); + else ExternalSymbolData.push_back(MSD); - } } // Symbols are required to be in lexicographic order. @@ -854,55 +956,79 @@ void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) { // Set the symbol indices. Local symbols must come before all other // symbols with non-local bindings. - Index = 0; + unsigned Index = 1; for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i) LocalSymbolData[i].SymbolData->setIndex(Index++); + + Index += NumRegularSections; + for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i) 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 ELFObjectWriterImpl::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 MCSection *RelaSection; const MCSectionELF &Section = static_cast(SD.getSection()); const StringRef SectionName = Section.getSectionName(); - std::string RelaSectionName = HasRelocationAddend ? ".rela" : ".rel"; + std::string RelaSectionName = hasRelocationAddend() ? ".rela" : ".rel"; RelaSectionName += SectionName; unsigned EntrySize; - if (HasRelocationAddend) - EntrySize = Is64Bit ? sizeof(ELF::Elf64_Rela) : sizeof(ELF::Elf32_Rela); + if (hasRelocationAddend()) + EntrySize = is64Bit() ? sizeof(ELF::Elf64_Rela) : sizeof(ELF::Elf32_Rela); else - EntrySize = Is64Bit ? sizeof(ELF::Elf64_Rel) : sizeof(ELF::Elf32_Rel); + EntrySize = is64Bit() ? sizeof(ELF::Elf64_Rel) : sizeof(ELF::Elf32_Rel); + + const MCSectionELF *RelaSection = + Ctx.getELFSection(RelaSectionName, hasRelocationAddend() ? + ELF::SHT_RELA : ELF::SHT_REL, 0, + SectionKind::getReadOnly(), + EntrySize, ""); + RelMap[&Section] = RelaSection; + Asm.getOrCreateSectionData(*RelaSection); + } +} - RelaSection = Ctx.getELFSection(RelaSectionName, HasRelocationAddend ? - ELF::SHT_RELA : ELF::SHT_REL, 0, - SectionKind::getReadOnly(), - false, EntrySize); +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); + RelaSD.setAlignment(is64Bit() ? 8 : 4); MCDataFragment *F = new MCDataFragment(&RelaSD); - - WriteRelocationsFragment(Asm, F, &SD); - - Asm.AddSectionToTheEnd(*Writer, RelaSD, Layout); + WriteRelocationsFragment(Asm, F, &*it); } } -void ELFObjectWriterImpl::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 ELFObjectWriter::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) { Write32(Name); // sh_name: index into string table Write32(Type); // sh_type WriteWord(Flags); // sh_flags @@ -915,98 +1041,139 @@ void ELFObjectWriterImpl::WriteSecHdrEntry(uint32_t Name, uint32_t Type, WriteWord(EntrySize); // sh_entsize } -void ELFObjectWriterImpl::WriteRelocationsFragment(const MCAssembler &Asm, - MCDataFragment *F, - const MCSectionData *SD) { +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]; - if (entry.Index < 0) + if (!entry.Index) + ; + else if (entry.Index < 0) entry.Index = getSymbolIndexInSymbolTable(Asm, entry.Symbol); else - entry.Index += LocalSymbolData.size() + 1; - if (Is64Bit) { - char buf[8]; - - String64(buf, entry.r_offset); - F->getContents() += StringRef(buf, 8); - - struct ELF::Elf64_Rela ERE64; - ERE64.setSymbolAndType(entry.Index, entry.Type); - String64(buf, ERE64.r_info); - F->getContents() += StringRef(buf, 8); - - if (HasRelocationAddend) { - String64(buf, entry.r_addend); - F->getContents() += StringRef(buf, 8); + entry.Index += LocalSymbolData.size(); + if (is64Bit()) { + String64(*F, entry.r_offset); + if (TargetObjectWriter->isN64()) { + String32(*F, entry.Index); + + 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 { - char buf[4]; - - String32(buf, entry.r_offset); - F->getContents() += StringRef(buf, 4); + String32(*F, entry.r_offset); struct ELF::Elf32_Rela ERE32; ERE32.setSymbolAndType(entry.Index, entry.Type); - String32(buf, ERE32.r_info); - F->getContents() += StringRef(buf, 4); + String32(*F, ERE32.r_info); - if (HasRelocationAddend) { - String32(buf, entry.r_addend); - F->getContents() += StringRef(buf, 4); - } + if (hasRelocationAddend()) + String32(*F, entry.r_addend); } } } -void ELFObjectWriterImpl::CreateMetadataSections(MCAssembler &Asm, - MCAsmLayout &Layout) { +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, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap) { MCContext &Ctx = Asm.getContext(); MCDataFragment *F; - const MCSection *SymtabSection; - unsigned EntrySize = Is64Bit ? ELF::SYMENTRY_SIZE64 : ELF::SYMENTRY_SIZE32; - - unsigned NumRegularSections = Asm.size(); + unsigned EntrySize = is64Bit() ? ELF::SYMENTRY_SIZE64 : ELF::SYMENTRY_SIZE32; // We construct .shstrtab, .symtab and .strtab in this order to match gnu as. - const MCSection *ShstrtabSection; - ShstrtabSection = Ctx.getELFSection(".shstrtab", ELF::SHT_STRTAB, 0, - SectionKind::getReadOnly(), false); + const MCSectionELF *ShstrtabSection = + Ctx.getELFSection(".shstrtab", ELF::SHT_STRTAB, 0, + SectionKind::getReadOnly()); MCSectionData &ShstrtabSD = Asm.getOrCreateSectionData(*ShstrtabSection); ShstrtabSD.setAlignment(1); - ShstrtabIndex = Asm.size(); - SymtabSection = Ctx.getELFSection(".symtab", ELF::SHT_SYMTAB, 0, - SectionKind::getReadOnly(), - false, EntrySize); + const MCSectionELF *SymtabSection = + Ctx.getELFSection(".symtab", ELF::SHT_SYMTAB, 0, + SectionKind::getReadOnly(), + EntrySize, ""); MCSectionData &SymtabSD = Asm.getOrCreateSectionData(*SymtabSection); - SymtabSD.setAlignment(Is64Bit ? 8 : 4); + SymtabSD.setAlignment(is64Bit() ? 8 : 4); + + MCSectionData *SymtabShndxSD = NULL; + + if (NeedsSymtabShndx) { + const MCSectionELF *SymtabShndxSection = + Ctx.getELFSection(".symtab_shndx", ELF::SHT_SYMTAB_SHNDX, 0, + SectionKind::getReadOnly(), 4, ""); + SymtabShndxSD = &Asm.getOrCreateSectionData(*SymtabShndxSection); + SymtabShndxSD->setAlignment(4); + } - const MCSection *StrtabSection; + const MCSectionELF *StrtabSection; StrtabSection = Ctx.getELFSection(".strtab", ELF::SHT_STRTAB, 0, - SectionKind::getReadOnly(), false); + 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); - WriteSymbolTable(F, Asm, Layout, NumRegularSections); - Asm.AddSectionToTheEnd(*Writer, SymtabSD, Layout); + MCDataFragment *ShndxF = NULL; + if (NeedsSymtabShndx) { + ShndxF = new MCDataFragment(SymtabShndxSD); + } + WriteSymbolTable(F, ShndxF, Asm, Layout, SectionIndexMap); F = new MCDataFragment(&StrtabSD); F->getContents().append(StringTable.begin(), StringTable.end()); - Asm.AddSectionToTheEnd(*Writer, StrtabSD, Layout); 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 @@ -1014,228 +1181,383 @@ void ELFObjectWriterImpl::CreateMetadataSections(MCAssembler &Asm, uint64_t Index = 1; F->getContents() += '\x00'; - 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 (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[&it->getSection()] = Index; + SectionStringTableIndex[&Section] = Index; - Index += Section.getSectionName().size() + 1; - F->getContents() += Section.getSectionName(); + Index += Name.size() + 1; + F->getContents() += Name; F->getContents() += '\x00'; } - - Asm.AddSectionToTheEnd(*Writer, ShstrtabSD, Layout); } -bool ELFObjectWriterImpl::IsFixupFullyResolved(const MCAssembler &Asm, - const MCValue Target, - bool IsPCRel, - const MCFragment *DF) const { - // If this is a PCrel relocation, find the section this fixup value is - // relative to. - const MCSection *BaseSection = 0; - if (IsPCRel) { - BaseSection = &DF->getParent()->getSection(); - assert(BaseSection); +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); } - const MCSection *SectionA = 0; - const MCSymbol *SymbolA = 0; - if (const MCSymbolRefExpr *A = Target.getSymA()) { - SymbolA = &A->getSymbol(); - SectionA = &SymbolA->getSection(); + // 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() & ELF::SHF_GROUP)) + continue; + + const MCSymbol *SignatureSymbol = Section.getGroup(); + Asm.getOrCreateSymbolData(*SignatureSymbol); + const MCSectionELF *&Group = RevGroupMap[SignatureSymbol]; + if (!Group) { + Group = Ctx.CreateELFGroupSection(); + MCSectionData &Data = Asm.getOrCreateSectionData(*Group); + Data.setAlignment(4); + MCDataFragment *F = new MCDataFragment(&Data); + String32(*F, ELF::GRP_COMDAT); + } + GroupMap[Group] = SignatureSymbol; } - const MCSection *SectionB = 0; - if (const MCSymbolRefExpr *B = Target.getSymB()) { - SectionB = &B->getSymbol().getSection(); + ComputeIndexMap(Asm, SectionIndexMap, RelMap); + + // Add sections to 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() & 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); + unsigned Index = SectionIndexMap.lookup(&Section); + String32(*F, Index); } +} - if (!BaseSection) - return SectionA == SectionB; +void ELFObjectWriter::WriteSection(MCAssembler &Asm, + const SectionIndexMapTy &SectionIndexMap, + uint32_t GroupSymbolIndex, + uint64_t Offset, uint64_t Size, + uint64_t Alignment, + const MCSectionELF &Section) { + uint64_t sh_link = 0; + uint64_t sh_info = 0; + + switch(Section.getType()) { + case ELF::SHT_DYNAMIC: + sh_link = SectionStringTableIndex[&Section]; + sh_info = 0; + break; + + case ELF::SHT_REL: + case ELF::SHT_RELA: { + const MCSectionELF *SymtabSection; + const MCSectionELF *InfoSection; + SymtabSection = Asm.getContext().getELFSection(".symtab", ELF::SHT_SYMTAB, + 0, + SectionKind::getReadOnly()); + sh_link = SectionIndexMap.lookup(SymtabSection); + assert(sh_link && ".symtab not found"); + + // Remove ".rel" and ".rela" prefixes. + unsigned SecNameLen = (Section.getType() == ELF::SHT_REL) ? 4 : 5; + StringRef SectionName = Section.getSectionName().substr(SecNameLen); + + InfoSection = Asm.getContext().getELFSection(SectionName, + ELF::SHT_PROGBITS, 0, + SectionKind::getReadOnly()); + sh_info = SectionIndexMap.lookup(InfoSection); + break; + } - const MCSymbolData &DataA = Asm.getSymbolData(*SymbolA); - if (DataA.isExternal()) - return false; + case ELF::SHT_SYMTAB: + case ELF::SHT_DYNSYM: + sh_link = StringTableIndex; + sh_info = LastLocalSymbolIndex; + break; + + case ELF::SHT_SYMTAB_SHNDX: + sh_link = SymbolTableIndex; + break; + + case ELF::SHT_PROGBITS: + case ELF::SHT_STRTAB: + case ELF::SHT_NOBITS: + case ELF::SHT_NOTE: + case ELF::SHT_NULL: + case ELF::SHT_ARM_ATTRIBUTES: + 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: + sh_link = SymbolTableIndex; + sh_info = GroupSymbolIndex; + break; + + default: + assert(0 && "FIXME: sh_type value not supported!"); + break; + } - return !SectionB && BaseSection == SectionA; + WriteSecHdrEntry(SectionStringTableIndex[&Section], Section.getType(), + Section.getFlags(), 0, Offset, Size, sh_link, sh_info, + Alignment, Section.getEntrySize()); } -void ELFObjectWriterImpl::WriteObject(MCAssembler &Asm, - const MCAsmLayout &Layout) { - // Compute symbol table information. - ComputeSymbolTable(Asm); +bool ELFObjectWriter::IsELFMetaDataSection(const MCSectionData &SD) { + return SD.getOrdinal() == ~UINT32_C(0) && + !SD.getSection().isVirtualSection(); +} - CreateMetadataSections(const_cast(Asm), - const_cast(Layout)); +uint64_t ELFObjectWriter::DataSectionSize(const MCSectionData &SD) { + uint64_t Ret = 0; + for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e; + ++i) { + const MCFragment &F = *i; + assert(F.getKind() == MCFragment::FT_Data); + Ret += cast(F).getContents().size(); + } + return Ret; +} - // 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; +uint64_t ELFObjectWriter::GetSectionFileSize(const MCAsmLayout &Layout, + const MCSectionData &SD) { + if (IsELFMetaDataSection(SD)) + return DataSectionSize(SD); + return Layout.getSectionFileSize(&SD); +} - for (MCAssembler::const_iterator it = Asm.begin(), - ie = Asm.end(); it != ie; ++it) { - const MCSectionData &SD = *it; +uint64_t ELFObjectWriter::GetSectionAddressSize(const MCAsmLayout &Layout, + const MCSectionData &SD) { + if (IsELFMetaDataSection(SD)) + return DataSectionSize(SD); + return Layout.getSectionAddressSize(&SD); +} - FileOff = RoundUpToAlignment(FileOff, SD.getAlignment()); +void ELFObjectWriter::WriteDataSectionData(MCAssembler &Asm, + const MCAsmLayout &Layout, + const MCSectionELF &Section) { + const MCSectionData &SD = Asm.getOrCreateSectionData(Section); - // Get the size of the section in the output file (including padding). - uint64_t Size = Layout.getSectionFileSize(&SD); + uint64_t Padding = OffsetToAlignment(OS.tell(), SD.getAlignment()); + WriteZeros(Padding); - FileOff += Size; + 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); } +} - FileOff = RoundUpToAlignment(FileOff, NaturalAlignment); +void ELFObjectWriter::WriteSectionHeader(MCAssembler &Asm, + const GroupMapTy &GroupMap, + const MCAsmLayout &Layout, + const SectionIndexMapTy &SectionIndexMap, + const SectionOffsetMapTy &SectionOffsetMap) { + const unsigned NumSections = Asm.size() + 1; - // Write out the ELF header ... - WriteHeader(FileOff - HeaderSize, NumSections); + std::vector Sections; + Sections.resize(NumSections - 1); - FileOff = HeaderSize; + for (SectionIndexMapTy::const_iterator i= + SectionIndexMap.begin(), e = SectionIndexMap.end(); i != e; ++i) { + const std::pair &p = *i; + Sections[p.second - 1] = p.first; + } - // ... then all of the sections ... - DenseMap SectionOffsetMap; + // Null section first. + uint64_t FirstSectionSize = + NumSections >= ELF::SHN_LORESERVE ? NumSections : 0; + uint32_t FirstSectionLink = + ShstrtabIndex >= ELF::SHN_LORESERVE ? ShstrtabIndex : 0; + WriteSecHdrEntry(0, 0, 0, 0, 0, FirstSectionSize, FirstSectionLink, 0, 0, 0); + + 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.lookup(&Section)); - DenseMap SectionIndexMap; + uint64_t Size = GetSectionAddressSize(Layout, SD); - unsigned Index = 1; - for (MCAssembler::const_iterator it = Asm.begin(), + WriteSection(Asm, SectionIndexMap, GroupSymbolIndex, + SectionOffsetMap.lookup(&Section), Size, + SD.getAlignment(), Section); + } +} + +void ELFObjectWriter::ComputeSectionOrder(MCAssembler &Asm, + std::vector &Sections) { + for (MCAssembler::iterator it = Asm.begin(), ie = Asm.end(); it != ie; ++it) { - const MCSectionData &SD = *it; + const MCSectionELF &Section = + static_cast(it->getSection()); + if (Section.getType() == ELF::SHT_GROUP) + Sections.push_back(&Section); + } - uint64_t Padding = OffsetToAlignment(FileOff, SD.getAlignment()); - WriteZeros(Padding); - FileOff += Padding; + 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); + } - // Remember the offset into the file for this section. - SectionOffsetMap[&it->getSection()] = FileOff; - SectionIndexMap[&it->getSection()] = Index++; + 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; + + unsigned NumUserSections = Asm.size(); + + DenseMap RelMap; + CreateRelocationSections(Asm, const_cast(Layout), RelMap); + + 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 NumRegularSections = NumUserSections + NumIndexedSections; + + // Compute symbol table information. + ComputeSymbolTable(Asm, SectionIndexMap, RevGroupMap, NumRegularSections); + + + WriteRelocations(Asm, const_cast(Layout), RelMap); + + CreateMetadataSections(const_cast(Asm), + const_cast(Layout), + SectionIndexMap, + RelMap); + + uint64_t NaturalAlignment = is64Bit() ? 8 : 4; + uint64_t HeaderSize = is64Bit() ? sizeof(ELF::Elf64_Ehdr) : + sizeof(ELF::Elf32_Ehdr); + uint64_t FileOff = HeaderSize; + + 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()); - FileOff += Layout.getSectionFileSize(&SD); + // Remember the offset into the file for this section. + SectionOffsetMap[&Section] = FileOff; - Asm.WriteSectionData(it, Layout, Writer); + // Get the size of the section in the output file (including padding). + FileOff += GetSectionFileSize(Layout, SD); } - uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment); - WriteZeros(Padding); - FileOff += Padding; + FileOff = RoundUpToAlignment(FileOff, NaturalAlignment); - // ... and then the section header table. - // Should we align the section header table? - // - // Null section first. - WriteSecHdrEntry(0, 0, 0, 0, 0, 0, 0, 0, 0, 0); + const unsigned SectionHeaderOffset = FileOff - HeaderSize; - for (MCAssembler::const_iterator it = Asm.begin(), - ie = Asm.end(); it != ie; ++it) { - const MCSectionData &SD = *it; - const MCSectionELF &Section = - static_cast(SD.getSection()); + uint64_t SectionHeaderEntrySize = is64Bit() ? + sizeof(ELF::Elf64_Shdr) : sizeof(ELF::Elf32_Shdr); + FileOff += (NumSections + 1) * SectionHeaderEntrySize; - uint64_t sh_link = 0; - uint64_t sh_info = 0; - - switch(Section.getType()) { - case ELF::SHT_DYNAMIC: - sh_link = SectionStringTableIndex[&it->getSection()]; - sh_info = 0; - break; - - case ELF::SHT_REL: - case ELF::SHT_RELA: { - const MCSection *SymtabSection; - const MCSection *InfoSection; - - SymtabSection = Asm.getContext().getELFSection(".symtab", ELF::SHT_SYMTAB, 0, - SectionKind::getReadOnly(), - false); - sh_link = SectionIndexMap[SymtabSection]; - - // Remove ".rel" and ".rela" prefixes. - unsigned SecNameLen = (Section.getType() == ELF::SHT_REL) ? 4 : 5; - StringRef SectionName = Section.getSectionName().substr(SecNameLen); - - InfoSection = Asm.getContext().getELFSection(SectionName, - ELF::SHT_PROGBITS, 0, - SectionKind::getReadOnly(), - false); - sh_info = SectionIndexMap[InfoSection]; - break; - } + for (unsigned i = NumRegularSections + 1; i < NumSections; ++i) { + const MCSectionELF &Section = *Sections[i]; + const MCSectionData &SD = Asm.getOrCreateSectionData(Section); - case ELF::SHT_SYMTAB: - case ELF::SHT_DYNSYM: - sh_link = StringTableIndex; - sh_info = LastLocalSymbolIndex; - break; - - case ELF::SHT_PROGBITS: - case ELF::SHT_STRTAB: - case ELF::SHT_NOBITS: - case ELF::SHT_NULL: - // Nothing to do. - break; - - case ELF::SHT_HASH: - case ELF::SHT_GROUP: - case ELF::SHT_SYMTAB_SHNDX: - default: - assert(0 && "FIXME: sh_type value not supported!"); - break; - } + FileOff = RoundUpToAlignment(FileOff, SD.getAlignment()); - WriteSecHdrEntry(SectionStringTableIndex[&it->getSection()], - Section.getType(), Section.getFlags(), - 0, - SectionOffsetMap.lookup(&SD.getSection()), - Layout.getSectionSize(&SD), sh_link, - sh_info, SD.getAlignment(), - Section.getEntrySize()); + // 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); } -} -ELFObjectWriter::ELFObjectWriter(raw_ostream &OS, - bool Is64Bit, - Triple::OSType OSType, - bool IsLittleEndian, - bool HasRelocationAddend) - : MCObjectWriter(OS, IsLittleEndian) -{ - Impl = new ELFObjectWriterImpl(this, Is64Bit, HasRelocationAddend, OSType); -} + // Write out the ELF header ... + WriteHeader(SectionHeaderOffset, NumSections + 1); -ELFObjectWriter::~ELFObjectWriter() { - delete (ELFObjectWriterImpl*) Impl; -} + // ... then the regular sections ... + // + because of .shstrtab + for (unsigned i = 0; i < NumRegularSections + 1; ++i) + WriteDataSectionData(Asm, Layout, *Sections[i]); -void ELFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm) { - ((ELFObjectWriterImpl*) Impl)->ExecutePostLayoutBinding(Asm); -} + uint64_t Padding = OffsetToAlignment(OS.tell(), NaturalAlignment); + WriteZeros(Padding); -void ELFObjectWriter::RecordRelocation(const MCAssembler &Asm, - const MCAsmLayout &Layout, - const MCFragment *Fragment, - const MCFixup &Fixup, MCValue Target, - uint64_t &FixedValue) { - ((ELFObjectWriterImpl*) Impl)->RecordRelocation(Asm, Layout, Fragment, Fixup, - Target, FixedValue); + // ... 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::IsFixupFullyResolved(const MCAssembler &Asm, - const MCValue Target, - bool IsPCRel, - const MCFragment *DF) const { - return ((ELFObjectWriterImpl*) Impl)->IsFixupFullyResolved(Asm, Target, - IsPCRel, DF); +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); } -void ELFObjectWriter::WriteObject(MCAssembler &Asm, - const MCAsmLayout &Layout) { - ((ELFObjectWriterImpl*) Impl)->WriteObject(Asm, Layout); +MCObjectWriter *llvm::createELFObjectWriter(MCELFObjectTargetWriter *MOTW, + raw_ostream &OS, + bool IsLittleEndian) { + return new ELFObjectWriter(MOTW, OS, IsLittleEndian); }