X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FELFObjectWriter.cpp;h=b8b3188ce4808da643272f6d83400f7a958e97d0;hb=b21d9aebba7e45ddcbce61dd501000049cefb335;hp=e44d8c53447caef6a3f39ffd8cdbbe6411054fa5;hpb=7c18fa87a4d4ed8b0cfe1ec65597c748c6d91ca9;p=oota-llvm.git diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp index e44d8c53447..b8b3188ce48 100644 --- a/lib/MC/ELFObjectWriter.cpp +++ b/lib/MC/ELFObjectWriter.cpp @@ -11,27 +11,332 @@ // //===----------------------------------------------------------------------===// -#include "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/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/MCValue.h" #include "llvm/Support/Debug.h" #include "llvm/Support/ErrorHandling.h" #include "llvm/Support/ELF.h" -#include "llvm/Target/TargetAsmBackend.h" -#include "llvm/ADT/StringSwitch.h" - -#include "../Target/X86/X86FixupKinds.h" -#include "../Target/ARM/ARMFixupKinds.h" #include using namespace llvm; +#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); + + /*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. + struct ELFSymbolData { + MCSymbolData *SymbolData; + uint64_t StringIndex; + uint32_t SectionIndex; + + // Support lexicographic sorting. + bool operator<(const ELFSymbolData &RHS) const { + if (MCELF::GetType(*SymbolData) == ELF::STT_FILE) + return true; + if (MCELF::GetType(*RHS.SymbolData) == ELF::STT_FILE) + return false; + return SymbolData->getSymbol().getName() < + RHS.SymbolData->getSymbol().getName(); + } + }; + + /// The target specific ELF writer instance. + llvm::OwningPtr TargetObjectWriter; + + SmallPtrSet UsedInReloc; + SmallPtrSet WeakrefUsedInReloc; + DenseMap Renames; + + llvm::DenseMap > Relocations; + DenseMap SectionStringTableIndex; + + /// @} + /// @name Symbol Table Data + /// @{ + + SmallString<256> StringTable; + std::vector LocalSymbolData; + std::vector ExternalSymbolData; + std::vector UndefinedSymbolData; + + /// @} + + bool NeedsGOT; + + 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: + ELFObjectWriter(MCELFObjectTargetWriter *MOTW, + raw_ostream &_OS, bool IsLittleEndian) + : MCObjectWriter(_OS, IsLittleEndian), + TargetObjectWriter(MOTW), + NeedsGOT(false), NeedsSymtabShndx(false){ + } + + virtual ~ELFObjectWriter(); + + void WriteWord(uint64_t W) { + if (is64Bit()) + Write64(W); + else + Write32(W); + } + + void StringLE16(char *buf, uint16_t Value) { + buf[0] = char(Value >> 0); + buf[1] = char(Value >> 8); + } + + void StringLE32(char *buf, uint32_t Value) { + StringLE16(buf, uint16_t(Value >> 0)); + StringLE16(buf + 2, uint16_t(Value >> 16)); + } + + void StringLE64(char *buf, uint64_t Value) { + StringLE32(buf, uint32_t(Value >> 0)); + StringLE32(buf + 4, uint32_t(Value >> 32)); + } + + void StringBE16(char *buf ,uint16_t Value) { + buf[0] = char(Value >> 8); + buf[1] = char(Value >> 0); + } + + void StringBE32(char *buf, uint32_t Value) { + StringBE16(buf, uint16_t(Value >> 16)); + StringBE16(buf + 2, uint16_t(Value >> 0)); + } + + void StringBE64(char *buf, uint64_t Value) { + StringBE32(buf, uint32_t(Value >> 32)); + StringBE32(buf + 4, uint32_t(Value >> 0)); + } + + 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(MCDataFragment &F, uint32_t Value) { + char buf[4]; + if (isLittleEndian()) + StringLE32(buf, Value); + else + StringBE32(buf, Value); + F.getContents() += StringRef(buf, 4); + } + + 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 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); + + void WriteSymbol(MCDataFragment *SymtabF, MCDataFragment *ShndxF, + ELFSymbolData &MSD, + const MCAsmLayout &Layout); + + typedef DenseMap SectionIndexMapTy; + 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, + 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 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, + unsigned NumRegularSections); + + void ComputeIndexMap(MCAssembler &Asm, + SectionIndexMapTy &SectionIndexMap, + const RelMapTy &RelMap); + + void CreateRelocationSections(MCAssembler &Asm, MCAsmLayout &Layout, + RelMapTy &RelMap); + + void WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout, + const RelMapTy &RelMap); + + 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, + const MCSectionData *SD); + + 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); @@ -46,6 +351,7 @@ bool ELFObjectWriter::RelocNeedsGOT(MCSymbolRefExpr::VariantKind Variant) { 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: @@ -85,11 +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); @@ -105,7 +407,7 @@ void ELFObjectWriter::WriteHeader(uint64_t SectionDataSize, sizeof(ELF::Elf32_Ehdr))); // e_shoff = sec hdr table off in bytes // e_flags = whatever the target wants - WriteEFlags(); + Write32(getEFlags()); // e_ehsize = ELF header size Write16(is64Bit() ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr)); @@ -118,12 +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); @@ -174,15 +476,20 @@ uint64_t ELFObjectWriter::SymbolValue(MCSymbolData &Data, 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; } @@ -265,7 +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"); @@ -290,10 +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++; } @@ -319,7 +628,9 @@ void ELFObjectWriter::WriteSymbolTable(MCDataFragment *SymtabF, 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); @@ -342,7 +653,7 @@ const MCSymbol *ELFObjectWriter::SymbolToReloc(const MCAssembler &Asm, const SectionKind secKind = Section.getKind(); if (secKind.isBSS()) - return ExplicitRelSym(Asm, Target, F, true); + return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); if (secKind.isThreadLocal()) { if (Renamed) @@ -365,13 +676,14 @@ const MCSymbol *ELFObjectWriter::SymbolToReloc(const MCAssembler &Asm, 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 ExplicitRelSym(Asm, Target, F, false); + return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel); + } @@ -390,7 +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(); @@ -400,7 +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; } @@ -421,21 +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); } @@ -532,6 +856,7 @@ void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm, 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); @@ -544,6 +869,9 @@ void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm, 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) { @@ -638,6 +966,9 @@ 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::CreateRelocationSections(MCAssembler &Asm, @@ -714,8 +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]; @@ -728,11 +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 { @@ -748,6 +1089,24 @@ 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, SectionIndexMapTy &SectionIndexMap, @@ -806,6 +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 @@ -813,22 +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; @@ -949,11 +1315,10 @@ void ELFObjectWriter::WriteSection(MCAssembler &Asm, // 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!"); @@ -998,14 +1363,10 @@ uint64_t ELFObjectWriter::GetSectionAddressSize(const MCAsmLayout &Layout, void ELFObjectWriter::WriteDataSectionData(MCAssembler &Asm, const MCAsmLayout &Layout, const MCSectionELF &Section) { - uint64_t FileOff = OS.tell(); const MCSectionData &SD = Asm.getOrCreateSectionData(Section); - uint64_t Padding = OffsetToAlignment(FileOff, SD.getAlignment()); + uint64_t Padding = OffsetToAlignment(OS.tell(), SD.getAlignment()); WriteZeros(Padding); - FileOff += Padding; - - FileOff += GetSectionFileSize(Layout, SD); if (IsELFMetaDataSection(SD)) { for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e; @@ -1015,7 +1376,7 @@ void ELFObjectWriter::WriteDataSectionData(MCAssembler &Asm, WriteBytes(cast(F).getContents().str()); } } else { - Asm.WriteSectionData(&SD, Layout); + Asm.writeSectionData(&SD, Layout); } } @@ -1171,17 +1532,14 @@ void ELFObjectWriter::WriteObject(MCAssembler &Asm, for (unsigned i = 0; i < NumRegularSections + 1; ++i) WriteDataSectionData(Asm, Layout, *Sections[i]); - FileOff = OS.tell(); - uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment); + uint64_t Padding = OffsetToAlignment(OS.tell(), NaturalAlignment); WriteZeros(Padding); // ... then the section header table ... WriteSectionHeader(Asm, GroupMap, Layout, SectionIndexMap, SectionOffsetMap); - FileOff = OS.tell(); - - // ... and then the remainting sections ... + // ... and then the remaining sections ... for (unsigned i = NumRegularSections + 1; i < NumSections; ++i) WriteDataSectionData(Asm, Layout, *Sections[i]); } @@ -1201,397 +1559,5 @@ ELFObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm, 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; - } -} - - -/// START OF SUBCLASSES for ELFObjectWriter -//===- ARMELFObjectWriter -------------------------------------------===// - -ARMELFObjectWriter::ARMELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian) - : ELFObjectWriter(MOTW, _OS, IsLittleEndian) -{} - -ARMELFObjectWriter::~ARMELFObjectWriter() -{} - -// FIXME: get the real EABI Version from the Triple. -void ARMELFObjectWriter::WriteEFlags() { - Write32(ELF::EF_ARM_EABIMASK & DefaultEABIVersion); -} - -// In ARM, _MergedGlobals and other most symbols get emitted directly. -// I.e. not as an offset to a section symbol. -// This code is a first-cut approximation of what ARM/gcc does. - -const MCSymbol *ARMELFObjectWriter::ExplicitRelSym(const MCAssembler &Asm, - const MCValue &Target, - const MCFragment &F, - bool IsBSS) const { - const MCSymbol &Symbol = Target.getSymA()->getSymbol(); - bool EmitThisSym = false; - - if (IsBSS) { - EmitThisSym = StringSwitch(Symbol.getName()) - .Case("_MergedGlobals", true) - .Default(false); - } else { - EmitThisSym = StringSwitch(Symbol.getName()) - .Case("_MergedGlobals", true) - .StartsWith(".L.str", true) - .Default(false); - } - if (EmitThisSym) - return &Symbol; - if (! Symbol.isTemporary()) - return &Symbol; - return NULL; -} - -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 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_uncondbranch: - 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_condbranch: - Type = ELF::R_ARM_JUMP24; - 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_uncondbranch: - Type = ELF::R_ARM_CALL; - break; - case ARM::fixup_arm_condbranch: - Type = ELF::R_ARM_JUMP24; - 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; - } - } - - if (RelocNeedsGOT(Modifier)) - NeedsGOT = true; - - return Type; -} - -//===- MBlazeELFObjectWriter -------------------------------------------===// - -MBlazeELFObjectWriter::MBlazeELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian) - : ELFObjectWriter(MOTW, _OS, IsLittleEndian) { -} - -MBlazeELFObjectWriter::~MBlazeELFObjectWriter() { -} - -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; - } - } - return Type; -} - -//===- X86ELFObjectWriter -------------------------------------------===// - - -X86ELFObjectWriter::X86ELFObjectWriter(MCELFObjectTargetWriter *MOTW, - raw_ostream &_OS, - bool IsLittleEndian) - : ELFObjectWriter(MOTW, _OS, IsLittleEndian) -{} - -X86ELFObjectWriter::~X86ELFObjectWriter() -{} - -unsigned X86ELFObjectWriter::GetRelocType(const MCValue &Target, - const MCFixup &Fixup, - bool IsPCRel, - bool IsRelocWithSymbol, - int64_t Addend) { - // determine the type of the relocation - - 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; - case FK_PCRel_1: - assert(Modifier == MCSymbolRefExpr::VK_None); - Type = ELF::R_X86_64_PC8; - 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; - } - } - } - - if (RelocNeedsGOT(Modifier)) - NeedsGOT = true; - - return Type; + return new ELFObjectWriter(MOTW, OS, IsLittleEndian); }