-//===- lib/MC/ELFObjectWriter.cpp - ELF File Writer -------------------===//
+//===- lib/MC/ELFObjectWriter.cpp - ELF File Writer -----------------------===//
//
// The LLVM Compiler Infrastructure
//
//
//===----------------------------------------------------------------------===//
-#include "llvm/MC/ELFObjectWriter.h"
-#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/MC/MCELFObjectWriter.h"
#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/SmallPtrSet.h"
+#include "llvm/ADT/SmallString.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/MCELF.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 "llvm/Support/ErrorHandling.h"
#include <vector>
using namespace llvm;
-static unsigned GetType(const MCSymbolData &SD) {
- uint32_t Type = (SD.getFlags() & (0xf << ELF_STT_Shift)) >> ELF_STT_Shift;
- assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT ||
- Type == ELF::STT_FUNC || Type == ELF::STT_SECTION ||
- Type == ELF::STT_FILE || Type == ELF::STT_COMMON ||
- Type == ELF::STT_TLS);
- return Type;
-}
-
-static unsigned GetBinding(const MCSymbolData &SD) {
- uint32_t Binding = (SD.getFlags() & (0xf << ELF_STB_Shift)) >> ELF_STB_Shift;
- assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
- Binding == ELF::STB_WEAK);
- return Binding;
-}
-
-static void SetBinding(MCSymbolData &SD, unsigned Binding) {
- assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
- Binding == ELF::STB_WEAK);
- uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STB_Shift);
- SD.setFlags(OtherFlags | (Binding << ELF_STB_Shift));
-}
-
-static unsigned GetVisibility(MCSymbolData &SD) {
- unsigned Visibility =
- (SD.getFlags() & (0xf << ELF_STV_Shift)) >> ELF_STV_Shift;
- assert(Visibility == ELF::STV_DEFAULT || Visibility == ELF::STV_INTERNAL ||
- Visibility == ELF::STV_HIDDEN || Visibility == ELF::STV_PROTECTED);
- return Visibility;
-}
-
-static bool 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;
// Support lexicographic sorting.
bool operator<(const ELFSymbolData &RHS) const {
- if (GetType(*SymbolData) == ELF::STT_FILE)
- return true;
- if (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.
+ std::unique_ptr<MCELFObjectTargetWriter> TargetObjectWriter;
SmallPtrSet<const MCSymbol *, 16> UsedInReloc;
+ SmallPtrSet<const MCSymbol *, 16> WeakrefUsedInReloc;
DenseMap<const MCSymbol *, const MCSymbol *> Renames;
llvm::DenseMap<const MCSectionData*,
/// @{
SmallString<256> StringTable;
+ std::vector<uint64_t> FileSymbolData;
std::vector<ELFSymbolData> LocalSymbolData;
std::vector<ELFSymbolData> ExternalSymbolData;
std::vector<ELFSymbolData> UndefinedSymbolData;
/// @}
- int NumRegularSections;
-
bool NeedsGOT;
- ELFObjectWriter *Writer;
-
- raw_ostream &OS;
-
- unsigned Is64Bit : 1;
-
- bool HasRelocationAddend;
-
- Triple::OSType OSType;
-
- uint16_t EMachine;
+ 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);
+ }
+ const MCSymbol *undefinedExplicitRelSym(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const {
+ return TargetObjectWriter->undefinedExplicitRelSym(Target, Fixup,
+ IsPCRel);
+ }
+
+ bool is64Bit() const { return TargetObjectWriter->is64Bit(); }
+ bool hasRelocationAddend() const {
+ return TargetObjectWriter->hasRelocationAddend();
+ }
+ 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,
- uint16_t _EMachine, bool _HasRelAddend,
- Triple::OSType _OSType)
- : NeedsGOT(false), Writer(_Writer), OS(Writer->getStream()),
- Is64Bit(_Is64Bit), HasRelocationAddend(_HasRelAddend),
- OSType(_OSType), EMachine(_EMachine) {
+ 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) {
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().append(&buf[0], &buf[1]);
+ }
+
+ void String16(MCDataFragment &F, uint16_t Value) {
+ char buf[2];
+ if (isLittleEndian())
StringLE16(buf, Value);
else
StringBE16(buf, Value);
+ F.getContents().append(&buf[0], &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().append(&buf[0], &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().append(&buf[0], &buf[8]);
}
- void WriteHeader(uint64_t SectionDataSize, unsigned NumberOfSections);
+ void WriteHeader(const MCAssembler &Asm,
+ 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<const MCSectionELF*, uint32_t> 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);
+ MCValue Target, uint64_t &FixedValue) override;
uint64_t getSymbolIndexInSymbolTable(const MCAssembler &Asm,
const MCSymbol *S);
+ // Map from a group section to the signature symbol
+ typedef DenseMap<const MCSectionELF*, const MCSymbol*> GroupMapTy;
+ // Map from a signature symbol to the group section
+ typedef DenseMap<const MCSymbol*, const MCSectionELF*> RevGroupMapTy;
+ // Map from a section to the section with the relocations
+ typedef DenseMap<const MCSectionELF*, const MCSectionELF*> RelMapTy;
+ // Map from a section to its offset
+ typedef DenseMap<const MCSectionELF*, uint64_t> 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 WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout,
- const MCSectionData &SD);
-
- void WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout) {
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- WriteRelocation(Asm, Layout, *it);
- }
- }
-
- void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout);
-
- void ExecutePostLayoutBinding(MCAssembler &Asm);
+ /// \param Asm - The assembler.
+ /// \param SectionIndexMap - Maps a section to its index.
+ /// \param RevGroupMap - Maps a signature symbol to the group section.
+ /// \param NumRegularSections - Number of non-relocation sections.
+ void ComputeSymbolTable(MCAssembler &Asm,
+ const MCAsmLayout &Layout,
+ 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);
+
+ void ExecutePostLayoutBinding(MCAssembler &Asm,
+ const MCAsmLayout &Layout) override;
+
+ void WriteSectionHeader(MCAssembler &Asm, const GroupMapTy &GroupMap,
+ const MCAsmLayout &Layout,
+ const SectionIndexMapTy &SectionIndexMap,
+ const SectionOffsetMapTy &SectionOffsetMap);
+
+ void ComputeSectionOrder(MCAssembler &Asm,
+ std::vector<const MCSectionELF*> &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);
+ bool
+ IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+ const MCSymbolData &DataA,
+ const MCFragment &FB,
+ bool InSet,
+ bool IsPCRel) const override;
+
+ void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) override;
+ 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(const MCAssembler &Asm,
+ uint64_t SectionDataSize,
+ unsigned NumberOfSections) {
// ELF Header
// ----------
//
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
- Write16(EMachine); // 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(Asm.getELFHeaderEFlags());
// 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];
-
- String32(buf, name);
- F->getContents() += StringRef(buf, 4); // st_name
-
- String8(buf, info);
- F->getContents() += StringRef(buf, 1); // st_info
-
- String8(buf, other);
- F->getContents() += StringRef(buf, 1); // st_other
-
- String16(buf, shndx);
- F->getContents() += StringRef(buf, 2); // st_shndx
+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);
+ }
- String64(buf, value);
- F->getContents() += StringRef(buf, 8); // st_value
+ uint16_t Index = (shndx >= ELF::SHN_LORESERVE && !Reserved) ?
+ uint16_t(ELF::SHN_XINDEX) : shndx;
- String64(buf, size);
- F->getContents() += StringRef(buf, 8); // st_size
+ 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 {
- char buf[4];
-
- String32(buf, name);
- F->getContents() += StringRef(buf, 4); // st_name
-
- String32(buf, value);
- F->getContents() += StringRef(buf, 4); // st_value
-
- String32(buf, size);
- F->getContents() += StringRef(buf, 4); // st_size
-
- String8(buf, info);
- F->getContents() += StringRef(buf, 1); // st_info
-
- String8(buf, other);
- F->getContents() += StringRef(buf, 1); // st_other
-
- String16(buf, shndx);
- F->getContents() += StringRef(buf, 2); // st_shndx
+ 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
}
}
-static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) {
- if (Data.isCommon() && Data.isExternal())
- return Data.getCommonAlignment();
+uint64_t ELFObjectWriter::SymbolValue(MCSymbolData &OrigData,
+ const MCAsmLayout &Layout) {
+ MCSymbolData *Data = &OrigData;
+ if (Data->isCommon() && Data->isExternal())
+ return Data->getCommonAlignment();
+
+ const MCSymbol *Symbol = &Data->getSymbol();
+
+ uint64_t Res = 0;
+ if (Symbol->isVariable()) {
+ const MCExpr *Expr = Symbol->getVariableValue();
+ MCValue Value;
+ if (!Expr->EvaluateAsRelocatable(Value, &Layout))
+ return 0;
+ if (Value.getSymB())
+ return 0;
+ Res = Value.getConstant();
+
+ const MCSymbolRefExpr *A = Value.getSymA();
+ if (!A)
+ return Res;
+
+ Symbol = &A->getSymbol();
+ Data = &Layout.getAssembler().getSymbolData(*Symbol);
+ }
- const MCSymbol &Symbol = Data.getSymbol();
- if (!Symbol.isInSection())
+ if (!Symbol->isInSection())
return 0;
- if (!Data.isCommon() && !(Data.getFlags() & ELF_STB_Weak))
- if (MCFragment *FF = Data.getFragment())
- return Layout.getSymbolAddress(&Data) -
- Layout.getSectionAddress(FF->getParent());
+ if (!Data->getFragment())
+ return 0;
- return 0;
-}
+ Res += Layout.getSymbolOffset(Data);
+ if (Data->getFlags() & ELF_Other_ThumbFunc)
+ ++Res;
-static const MCSymbol &AliasedSymbol(const MCSymbol &Symbol) {
- const MCSymbol *S = &Symbol;
- while (S->isVariable()) {
- const MCExpr *Value = S->getVariableValue();
- if (Value->getKind() != MCExpr::SymbolRef)
- return *S;
- const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value);
- S = &Ref->getSymbol();
- }
- return *S;
+ return Res;
}
-void ELFObjectWriterImpl::ExecutePostLayoutBinding(MCAssembler &Asm) {
+void ELFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
// The presence of symbol versions causes undefined symbols and
// versions declared with @@@ to be renamed.
for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
ie = Asm.symbol_end(); it != ie; ++it) {
const MCSymbol &Alias = it->getSymbol();
- if (!Alias.isVariable())
+ const MCSymbol &Symbol = Alias.AliasedSymbol();
+ MCSymbolData &SD = Asm.getSymbolData(Symbol);
+
+ // Not an alias.
+ if (&Symbol == &Alias)
continue;
- const MCSymbol &Symbol = AliasedSymbol(Alias);
- const StringRef &AliasName = Alias.getName();
+
+ StringRef AliasName = Alias.getName();
size_t Pos = AliasName.find('@');
if (Pos == StringRef::npos)
continue;
- StringRef Rest(AliasName.begin() + Pos);
+ // 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));
+
+ StringRef Rest = AliasName.substr(Pos);
if (!Symbol.isUndefined() && !Rest.startswith("@@@"))
continue;
- std::pair<const MCSymbol *, const MCSymbol *> t(&Symbol, &Alias);
- Renames.insert(t);
+ // 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));
}
}
-void ELFObjectWriterImpl::WriteSymbol(MCDataFragment *F, ELFSymbolData &MSD,
- const MCAsmLayout &Layout) {
+static uint8_t mergeTypeForSet(uint8_t origType, uint8_t newType) {
+ uint8_t Type = newType;
+
+ // Propagation rules:
+ // IFUNC > FUNC > OBJECT > NOTYPE
+ // TLS_OBJECT > OBJECT > NOTYPE
+ //
+ // dont let the new type degrade the old type
+ switch (origType) {
+ default:
+ break;
+ case ELF::STT_GNU_IFUNC:
+ if (Type == ELF::STT_FUNC || Type == ELF::STT_OBJECT ||
+ Type == ELF::STT_NOTYPE || Type == ELF::STT_TLS)
+ Type = ELF::STT_GNU_IFUNC;
+ break;
+ case ELF::STT_FUNC:
+ if (Type == ELF::STT_OBJECT || Type == ELF::STT_NOTYPE ||
+ Type == ELF::STT_TLS)
+ Type = ELF::STT_FUNC;
+ break;
+ case ELF::STT_OBJECT:
+ if (Type == ELF::STT_NOTYPE)
+ Type = ELF::STT_OBJECT;
+ break;
+ case ELF::STT_TLS:
+ if (Type == ELF::STT_OBJECT || Type == ELF::STT_NOTYPE ||
+ Type == ELF::STT_GNU_IFUNC || Type == ELF::STT_FUNC)
+ Type = ELF::STT_TLS;
+ break;
+ }
+
+ return Type;
+}
+
+void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF,
+ MCDataFragment *ShndxF,
+ ELFSymbolData &MSD,
+ const MCAsmLayout &Layout) {
MCSymbolData &OrigData = *MSD.SymbolData;
MCSymbolData &Data =
- Layout.getAssembler().getSymbolData(AliasedSymbol(OrigData.getSymbol()));
+ Layout.getAssembler().getSymbolData(OrigData.getSymbol().AliasedSymbol());
- uint8_t Binding = GetBinding(OrigData);
- uint8_t Visibility = GetVisibility(OrigData);
- uint8_t Type = GetType(Data);
+ bool IsReserved = Data.isCommon() || Data.getSymbol().isAbsolute() ||
+ Data.getSymbol().isVariable();
+ // Binding and Type share the same byte as upper and lower nibbles
+ uint8_t Binding = MCELF::GetBinding(OrigData);
+ uint8_t Type = mergeTypeForSet(MCELF::GetType(OrigData), MCELF::GetType(Data));
uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift);
- uint8_t Other = Visibility;
- uint64_t Value = SymbolValue(Data, Layout);
+ // Other and Visibility share the same byte with Visibility using the lower
+ // 2 bits
+ uint8_t Visibility = MCELF::GetVisibility(OrigData);
+ uint8_t Other = MCELF::getOther(OrigData) << (ELF_STO_Shift - ELF_STV_Shift);
+ Other |= Visibility;
+
+ uint64_t Value = SymbolValue(OrigData, 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<const MCBinaryExpr *>(ESize);
-
- if (BE->EvaluateAsRelocatable(Res, &Layout)) {
- assert(!Res.getSymA() || !Res.getSymA()->getSymbol().isDefined());
- assert(!Res.getSymB() || !Res.getSymB()->getSymbol().isDefined());
- Size = Res.getConstant();
- }
- } else if (ESize->getKind() == MCExpr::Constant) {
- Size = static_cast<const MCConstantExpr *>(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");
// 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);
+
+ for (unsigned i = 0, e = FileSymbolData.size(); i != e; ++i) {
+ WriteSymbolEntry(SymtabF, ShndxF, FileSymbolData[i],
+ ELF::STT_FILE | ELF::STB_LOCAL, 0, 0,
+ ELF::STV_DEFAULT, ELF::SHN_ABS, true);
+ }
// Write the symbol table entries.
- LastLocalSymbolIndex = LocalSymbolData.size() + 1;
+ LastLocalSymbolIndex = FileSymbolData.size() + 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<const MCSectionELF&>(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<const MCSectionELF&>(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++;
}
assert(((Data.getFlags() & ELF_STB_Global) ||
(Data.getFlags() & ELF_STB_Weak)) &&
"External symbol requires STB_GLOBAL or STB_WEAK flag");
- WriteSymbol(F, MSD, Layout);
- if (GetBinding(Data) == ELF::STB_LOCAL)
+ 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 undefinedExplicitRelSym(Target, Fixup, IsPCRel);
+ }
+
+ if (SD.isExternal()) {
+ if (Renamed)
+ return Renamed;
+ return &Symbol;
+ }
const MCSectionELF &Section =
- static_cast<const MCSectionELF&>(Symbol.getSection());
+ static_cast<const MCSectionELF&>(ASymbol.getSection());
+ const SectionKind secKind = Section.getKind();
- if (SD.isExternal())
- return true;
+ if (secKind.isBSS())
+ return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel);
+
+ if (secKind.isThreadLocal()) {
+ if (Renamed)
+ return Renamed;
+ return &Symbol;
+ }
MCSymbolRefExpr::VariantKind Kind = Target.getSymA()->getKind();
const MCSectionELF &Sec2 =
static_cast<const MCSectionELF&>(F.getParent()->getSection());
- if (Section.getKind().isBSS())
- return false;
-
if (&Sec2 != &Section &&
(Kind == MCSymbolRefExpr::VK_PLT ||
Kind == MCSymbolRefExpr::VK_GOTPCREL ||
- Kind == MCSymbolRefExpr::VK_GOTOFF))
- return true;
+ Kind == MCSymbolRefExpr::VK_GOTOFF)) {
+ if (Renamed)
+ return Renamed;
+ return &Symbol;
+ }
- if (Section.getFlags() & MCSectionELF::SHF_MERGE)
- return Target.getConstant() != 0;
+ 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 = &AliasedSymbol(Target.getSymA()->getSymbol());
- const MCSymbol *Renamed = Renames.lookup(Symbol);
- if (Renamed)
- Symbol = Renamed;
- 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();
+
+ if (!SDB.getFragment())
+ Asm.getContext().FatalError(
+ Fixup.getLoc(),
+ Twine("symbol '") + SymbolB.getName() +
+ "' can not be undefined in a subtraction expression");
// 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;
- }
-
- bool RelocOnSymbol = ShouldRelocOnSymbol(SD, Target, *Fragment);
- if (!RelocOnSymbol) {
- Index = F->getParent()->getOrdinal();
+ if (!RelocSymbol) {
+ MCSymbolData &SD = Asm.getSymbolData(ASymbol);
+ MCFragment *F = SD.getFragment();
- MCSectionData *FSD = F->getParent();
- // Offset of the symbol in the section
- Value += Layout.getSymbolAddress(&SD) - Layout.getSectionAddress(FSD);
+ if (F) {
+ Index = F->getParent()->getOrdinal() + 1;
+ // Offset of the symbol in the section
+ Value += Layout.getSymbolOffset(&SD);
+ } else {
+ Index = 0;
+ }
} 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 (hasRelocationAddend())
Value = 0;
}
FixedValue = Value;
-
- // determine the type of the relocation
-
- MCSymbolRefExpr::VariantKind Modifier = Target.getSymA()->getKind();
- unsigned Type;
- if (Is64Bit) {
- if (IsPCRel) {
- 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 llvm::MCSymbolRefExpr::VK_GOTPCREL:
- Type = ELF::R_X86_64_GOTPCREL;
- 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:
- case X86::reloc_pcrel_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;
- }
- 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) {
- 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 X86::reloc_pcrel_4byte:
- 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;
- }
- 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;
-
- ERE.Index = Index;
- ERE.Type = Type;
- ERE.Symbol = Symbol;
+ uint64_t RelocOffset = Layout.getFragmentOffset(Fragment) +
+ Fixup.getOffset();
- 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);
-
- // Local symbol.
- if (!SD.isExternal() && !S->isUndefined())
- return SD.getIndex() + /* empty symbol */ 1;
-
- // External or undefined symbol.
- return SD.getIndex() + NumRegularSections + /* empty symbol */ 1;
+ return SD.getIndex();
}
-static bool isInSymtab(const MCAssembler &Asm, const MCSymbolData &Data,
- bool Used, bool Renamed) {
+bool ELFObjectWriter::isInSymtab(const MCAssembler &Asm,
+ const MCSymbolData &Data,
+ bool Used, bool Renamed) {
+ if (Data.getFlags() & ELF_Other_Weakref)
+ return false;
+
if (Used)
return true;
const MCSymbol &Symbol = Data.getSymbol();
- const MCSymbol &A = AliasedSymbol(Symbol);
- if (&A != &Symbol && A.isUndefined())
+ if (Symbol.getName() == "_GLOBAL_OFFSET_TABLE_")
+ return true;
+
+ const MCSymbol &A = Symbol.AliasedSymbol();
+ if (Symbol.isVariable() && !A.isVariable() && A.isUndefined())
return false;
- if (!Asm.isSymbolLinkerVisible(Symbol) && !Symbol.isUndefined())
+ bool IsGlobal = MCELF::GetBinding(Data) == ELF::STB_GLOBAL;
+ if (!Symbol.isVariable() && Symbol.isUndefined() && !IsGlobal)
return false;
if (Symbol.isTemporary())
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<const MCSectionELF &>(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<const MCSectionELF &>(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 MCAsmLayout &Layout,
+ 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_";
+ 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<const MCSection*, uint32_t> 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<uint64_t> StringIndexMap;
StringTable += '\x00';
+ // FIXME: We could optimize suffixes in strtab in the same way we
+ // optimize them in shstrtab.
+
+ for (MCAssembler::const_file_name_iterator it = Asm.file_names_begin(),
+ ie = Asm.file_names_end();
+ it != ie;
+ ++it) {
+ StringRef Name = *it;
+ uint64_t &Entry = StringIndexMap[Name];
+ if (!Entry) {
+ Entry = StringTable.size();
+ StringTable += Name;
+ StringTable += '\x00';
+ }
+ FileSymbolData.push_back(Entry);
+ }
+
// 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),
+ bool Used = UsedInReloc.count(&Symbol);
+ bool WeakrefUsed = WeakrefUsedInReloc.count(&Symbol);
+ bool isSignature = RevGroupMap.count(&Symbol);
+
+ if (!isInSymtab(Asm, *it,
+ Used || WeakrefUsed || isSignature,
Renames.count(&Symbol)))
continue;
ELFSymbolData MSD;
MSD.SymbolData = it;
- bool Local = isLocal(*it);
- const MCSymbol &RefSymbol = AliasedSymbol(Symbol);
+ const MCSymbol *BaseSymbol = Symbol.getBaseSymbol(Layout);
+
+ // 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) {
+ assert(BaseSymbol);
+ MCSymbolData &SD = Asm.getSymbolData(*BaseSymbol);
+ MCELF::SetBinding(*it, ELF::STB_GLOBAL);
+ MCELF::SetBinding(SD, ELF::STB_GLOBAL);
+ }
- if (it->isCommon()) {
+ if (!BaseSymbol) {
+ MSD.SectionIndex = ELF::SHN_ABS;
+ } else if (it->isCommon()) {
assert(!Local);
MSD.SectionIndex = ELF::SHN_COMMON;
- } else if (Symbol.isAbsolute()) {
- MSD.SectionIndex = ELF::SHN_ABS;
- } else if (RefSymbol.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);
- } else if (Symbol.isVariable()) {
- MSD.SectionIndex = SectionIndexMap.lookup(&RefSymbol.getSection());
- assert(MSD.SectionIndex && "Invalid section index!");
+ } else if (BaseSymbol->isUndefined()) {
+ if (isSignature && !Used)
+ MSD.SectionIndex = SectionIndexMap.lookup(RevGroupMap[&Symbol]);
+ else
+ MSD.SectionIndex = ELF::SHN_UNDEF;
+ if (!Used && WeakrefUsed)
+ MCELF::SetBinding(*it, ELF::STB_WEAK);
} else {
- MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(BaseSymbol->getSection());
+ MSD.SectionIndex = SectionIndexMap.lookup(&Section);
+ if (MSD.SectionIndex >= ELF::SHN_LORESERVE)
+ NeedsSymtabShndx = true;
assert(MSD.SectionIndex && "Invalid section index!");
}
// 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("@@@");
- std::string FinalName;
if (Pos != StringRef::npos) {
- StringRef Prefix(Name.begin(), Pos);
- unsigned n = MSD.SectionIndex == ELF::SHN_UNDEF ? 2 : 1;
- StringRef Suffix(Name.begin() + Pos + n);
- FinalName = Prefix.str() + Suffix.str();
- } else {
- FinalName = Name.str();
+ 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[FinalName];
+ uint64_t &Entry = StringIndexMap[Name];
if (!Entry) {
Entry = StringTable.size();
- StringTable += FinalName;
+ StringTable += Name;
StringTable += '\x00';
}
MSD.StringIndex = Entry;
// Set the symbol indices. Local symbols must come before all other
// symbols with non-local bindings.
- Index = 0;
+ unsigned Index = FileSymbolData.size() + 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 (Index >= 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<const MCSectionELF&>(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);
- RelaSection = Ctx.getELFSection(RelaSectionName, HasRelocationAddend ?
- ELF::SHT_RELA : ELF::SHT_REL, 0,
- SectionKind::getReadOnly(),
- false, EntrySize);
+ unsigned Flags = 0;
+ StringRef Group = "";
+ if (Section.getFlags() & ELF::SHF_GROUP) {
+ Flags = ELF::SHF_GROUP;
+ Group = Section.getGroup()->getName();
+ }
- MCSectionData &RelaSD = Asm.getOrCreateSectionData(*RelaSection);
- RelaSD.setAlignment(Is64Bit ? 8 : 4);
+ const MCSectionELF *RelaSection =
+ Ctx.getELFSection(RelaSectionName, hasRelocationAddend() ?
+ ELF::SHT_RELA : ELF::SHT_REL, Flags,
+ SectionKind::getReadOnly(),
+ EntrySize, Group);
+ RelMap[&Section] = RelaSection;
+ Asm.getOrCreateSectionData(*RelaSection);
+ }
+}
- MCDataFragment *F = new MCDataFragment(&RelaSD);
+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<const MCSectionELF&>(SD.getSection());
- WriteRelocationsFragment(Asm, F, &SD);
+ const MCSectionELF *RelaSection = RelMap.lookup(&Section);
+ if (!RelaSection)
+ continue;
+ MCSectionData &RelaSD = Asm.getOrCreateSectionData(*RelaSection);
+ RelaSD.setAlignment(is64Bit() ? 8 : 4);
- Asm.AddSectionToTheEnd(*Writer, RelaSD, Layout);
+ MCDataFragment *F = new MCDataFragment(&RelaSD);
+ 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
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<ELFRelocationEntry> &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 += FileSymbolData.size() + 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 MCSectionELF *const *a,
+ const MCSectionELF *const *b) {
+ const StringRef &NameA = (*a)->getSectionName();
+ const StringRef &NameB = (*b)->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;
- const MCSection *StrtabSection;
+ 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 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<const MCSectionELF*> Sections;
+ for (MCAssembler::const_iterator it = Asm.begin(),
+ ie = Asm.end(); it != ie; ++it) {
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(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
// section 0.
uint64_t Index = 1;
- F->getContents() += '\x00';
+ F->getContents().push_back('\x00');
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- const MCSectionELF &Section =
- static_cast<const MCSectionELF&>(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 += Name.size() + 1;
+ F->getContents().append(Name.begin(), Name.end());
+ F->getContents().push_back('\x00');
+ }
+}
- Index += Section.getSectionName().size() + 1;
- F->getContents() += Section.getSectionName();
- F->getContents() += '\x00';
+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);
}
- Asm.AddSectionToTheEnd(*Writer, ShstrtabSD, Layout);
+ // Build the groups
+ for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end();
+ it != ie; ++it) {
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(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;
+ }
+
+ 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<const MCSectionELF&>(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);
+ }
}
-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::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);
+ StringRef GroupName =
+ Section.getGroup() ? Section.getGroup()->getName() : "";
+
+ InfoSection = Asm.getContext().getELFSection(SectionName, ELF::SHT_PROGBITS,
+ 0, SectionKind::getReadOnly(),
+ 0, GroupName);
+ sh_info = SectionIndexMap.lookup(InfoSection);
+ break;
}
- const MCSection *SectionA = 0;
- const MCSymbol *SymbolA = 0;
- if (const MCSymbolRefExpr *A = Target.getSymA()) {
- SymbolA = &A->getSymbol();
- SectionA = &SymbolA->getSection();
+ 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:
+ case ELF::SHT_MIPS_REGINFO:
+ case ELF::SHT_MIPS_OPTIONS:
+ // 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;
}
- const MCSection *SectionB = 0;
- if (const MCSymbolRefExpr *B = Target.getSymB()) {
- SectionB = &B->getSymbol().getSection();
+ if (TargetObjectWriter->getEMachine() == ELF::EM_ARM &&
+ Section.getType() == ELF::SHT_ARM_EXIDX) {
+ StringRef SecName(Section.getSectionName());
+ if (SecName == ".ARM.exidx") {
+ sh_link = SectionIndexMap.lookup(
+ Asm.getContext().getELFSection(".text",
+ ELF::SHT_PROGBITS,
+ ELF::SHF_EXECINSTR | ELF::SHF_ALLOC,
+ SectionKind::getText()));
+ } else if (SecName.startswith(".ARM.exidx")) {
+ StringRef GroupName =
+ Section.getGroup() ? Section.getGroup()->getName() : "";
+ sh_link = SectionIndexMap.lookup(Asm.getContext().getELFSection(
+ SecName.substr(sizeof(".ARM.exidx") - 1), ELF::SHT_PROGBITS,
+ ELF::SHF_EXECINSTR | ELF::SHF_ALLOC, SectionKind::getText(), 0,
+ GroupName));
+ }
}
- if (!BaseSection)
- return SectionA == SectionB;
+ WriteSecHdrEntry(SectionStringTableIndex[&Section], Section.getType(),
+ Section.getFlags(), 0, Offset, Size, sh_link, sh_info,
+ Alignment, Section.getEntrySize());
+}
- const MCSymbolData &DataA = Asm.getSymbolData(*SymbolA);
- if (DataA.isExternal())
- return false;
+bool ELFObjectWriter::IsELFMetaDataSection(const MCSectionData &SD) {
+ return SD.getOrdinal() == ~UINT32_C(0) &&
+ !SD.getSection().isVirtualSection();
+}
- return !SectionB && BaseSection == SectionA;
+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<MCDataFragment>(F).getContents().size();
+ }
+ return Ret;
}
-void ELFObjectWriterImpl::WriteObject(MCAssembler &Asm,
- const MCAsmLayout &Layout) {
- // Compute symbol table information.
- ComputeSymbolTable(Asm);
+uint64_t ELFObjectWriter::GetSectionFileSize(const MCAsmLayout &Layout,
+ const MCSectionData &SD) {
+ if (IsELFMetaDataSection(SD))
+ return DataSectionSize(SD);
+ return Layout.getSectionFileSize(&SD);
+}
- CreateMetadataSections(const_cast<MCAssembler&>(Asm),
- const_cast<MCAsmLayout&>(Layout));
+uint64_t ELFObjectWriter::GetSectionAddressSize(const MCAsmLayout &Layout,
+ const MCSectionData &SD) {
+ if (IsELFMetaDataSection(SD))
+ return DataSectionSize(SD);
+ return Layout.getSectionAddressSize(&SD);
+}
- // Add 1 for the null section.
- unsigned NumSections = Asm.size() + 1;
- uint64_t NaturalAlignment = Is64Bit ? 8 : 4;
- uint64_t HeaderSize = Is64Bit ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr);
- uint64_t FileOff = HeaderSize;
+void ELFObjectWriter::WriteDataSectionData(MCAssembler &Asm,
+ const MCAsmLayout &Layout,
+ const MCSectionELF &Section) {
+ const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- const MCSectionData &SD = *it;
+ uint64_t Padding = OffsetToAlignment(OS.tell(), SD.getAlignment());
+ WriteZeros(Padding);
- FileOff = RoundUpToAlignment(FileOff, SD.getAlignment());
+ 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<MCDataFragment>(F).getContents());
+ }
+ } else {
+ Asm.writeSectionData(&SD, Layout);
+ }
+}
- // Get the size of the section in the output file (including padding).
- uint64_t Size = Layout.getSectionFileSize(&SD);
+void ELFObjectWriter::WriteSectionHeader(MCAssembler &Asm,
+ const GroupMapTy &GroupMap,
+ const MCAsmLayout &Layout,
+ const SectionIndexMapTy &SectionIndexMap,
+ const SectionOffsetMapTy &SectionOffsetMap) {
+ const unsigned NumSections = Asm.size() + 1;
+
+ std::vector<const MCSectionELF*> Sections;
+ Sections.resize(NumSections - 1);
- FileOff += Size;
+ for (SectionIndexMapTy::const_iterator i=
+ SectionIndexMap.begin(), e = SectionIndexMap.end(); i != e; ++i) {
+ const std::pair<const MCSectionELF*, uint32_t> &p = *i;
+ Sections[p.second - 1] = p.first;
}
- FileOff = RoundUpToAlignment(FileOff, NaturalAlignment);
+ // 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));
- // Write out the ELF header ...
- WriteHeader(FileOff - HeaderSize, NumSections);
+ uint64_t Size = GetSectionAddressSize(Layout, SD);
- FileOff = HeaderSize;
+ WriteSection(Asm, SectionIndexMap, GroupSymbolIndex,
+ SectionOffsetMap.lookup(&Section), Size,
+ SD.getAlignment(), Section);
+ }
+}
- // ... then all of the sections ...
- DenseMap<const MCSection*, uint64_t> SectionOffsetMap;
+void ELFObjectWriter::ComputeSectionOrder(MCAssembler &Asm,
+ std::vector<const MCSectionELF*> &Sections) {
+ for (MCAssembler::iterator it = Asm.begin(),
+ ie = Asm.end(); it != ie; ++it) {
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF &>(it->getSection());
+ if (Section.getType() == ELF::SHT_GROUP)
+ Sections.push_back(&Section);
+ }
- DenseMap<const MCSection*, uint32_t> SectionIndexMap;
+ for (MCAssembler::iterator it = Asm.begin(),
+ ie = Asm.end(); it != ie; ++it) {
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF &>(it->getSection());
+ if (Section.getType() != ELF::SHT_GROUP &&
+ Section.getType() != ELF::SHT_REL &&
+ Section.getType() != ELF::SHT_RELA)
+ Sections.push_back(&Section);
+ }
- unsigned Index = 1;
- for (MCAssembler::const_iterator it = Asm.begin(),
+ for (MCAssembler::iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
- const MCSectionData &SD = *it;
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF &>(it->getSection());
+ if (Section.getType() == ELF::SHT_REL ||
+ Section.getType() == ELF::SHT_RELA)
+ Sections.push_back(&Section);
+ }
+}
- uint64_t Padding = OffsetToAlignment(FileOff, SD.getAlignment());
- WriteZeros(Padding);
- FileOff += Padding;
+void ELFObjectWriter::WriteObject(MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
+ GroupMapTy GroupMap;
+ RevGroupMapTy RevGroupMap;
+ SectionIndexMapTy SectionIndexMap;
- // Remember the offset into the file for this section.
- SectionOffsetMap[&it->getSection()] = FileOff;
- SectionIndexMap[&it->getSection()] = Index++;
+ unsigned NumUserSections = Asm.size();
+
+ DenseMap<const MCSectionELF*, const MCSectionELF*> RelMap;
+ CreateRelocationSections(Asm, const_cast<MCAsmLayout&>(Layout), RelMap);
+
+ const unsigned NumUserAndRelocSections = Asm.size();
+ CreateIndexedSections(Asm, const_cast<MCAsmLayout&>(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, Layout, SectionIndexMap, RevGroupMap,
+ NumRegularSections);
- FileOff += Layout.getSectionFileSize(&SD);
+ WriteRelocations(Asm, const_cast<MCAsmLayout&>(Layout), RelMap);
- Asm.WriteSectionData(it, Layout, Writer);
+ CreateMetadataSections(const_cast<MCAssembler&>(Asm),
+ const_cast<MCAsmLayout&>(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<const MCSectionELF*> Sections;
+ ComputeSectionOrder(Asm, Sections);
+ unsigned NumSections = Sections.size();
+ SectionOffsetMapTy SectionOffsetMap;
+ for (unsigned i = 0; i < NumRegularSections + 1; ++i) {
+ const MCSectionELF &Section = *Sections[i];
+ const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
+
+ FileOff = RoundUpToAlignment(FileOff, SD.getAlignment());
+
+ // Remember the offset into the file for this section.
+ SectionOffsetMap[&Section] = FileOff;
+
+ // Get the size of the section in the output file (including padding).
+ FileOff += GetSectionFileSize(Layout, SD);
}
- 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<const MCSectionELF&>(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:
- case ELF::SHT_ARM_ATTRIBUTES:
- // Nothing to do.
- break;
-
- 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,
- uint16_t EMachine,
- bool IsLittleEndian,
- bool HasRelocationAddend)
- : MCObjectWriter(OS, IsLittleEndian)
-{
- Impl = new ELFObjectWriterImpl(this, Is64Bit, EMachine,
- HasRelocationAddend, OSType);
-}
+ // Write out the ELF header ...
+ WriteHeader(Asm, 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 || MCELF::GetType(DataA) == ELF::STT_GNU_IFUNC)
+ 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);
}
projects / oota-llvm.git / blobdiff