//
//===----------------------------------------------------------------------===//
-#include "llvm/ADT/OwningPtr.h"
-#include "llvm/ADT/SmallPtrSet.h"
+#include "ELFObjectWriter.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringMap.h"
#include "llvm/ADT/Twine.h"
-#include "llvm/MC/MCAssembler.h"
#include "llvm/MC/MCAsmLayout.h"
#include "llvm/MC/MCContext.h"
-#include "llvm/MC/MCELFSymbolFlags.h"
#include "llvm/MC/MCExpr.h"
-#include "llvm/MC/MCELFObjectWriter.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 "llvm/ADT/StringSwitch.h"
+#include "llvm/Support/CommandLine.h"
+#include "llvm/ADT/Statistic.h"
#include "../Target/X86/X86FixupKinds.h"
#include "../Target/ARM/ARMFixupKinds.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;
-}
+#undef DEBUG_TYPE
+#define DEBUG_TYPE "reloc-info"
-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));
-}
+bool ELFObjectWriter::isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
+ const MCFixupKindInfo &FKI =
+ Asm.getBackend().getFixupKindInfo((MCFixupKind) Kind);
-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;
+ return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel;
}
-
-static bool RelocNeedsGOT(MCSymbolRefExpr::VariantKind Variant) {
+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:
}
}
-static bool isFixupKindPCRel(const MCAssembler &Asm, unsigned Kind) {
- const MCFixupKindInfo &FKI =
- Asm.getBackend().getFixupKindInfo((MCFixupKind) Kind);
-
- return FKI.Flags & MCFixupKindInfo::FKF_IsPCRel;
-}
-
-namespace {
- class ELFObjectWriter : public MCObjectWriter {
- protected:
- /*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 (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;
-
- ELFRelocationEntry()
- : r_offset(0), Index(0), Type(0), Symbol(0), r_addend(0) {}
-
- ELFRelocationEntry(uint64_t RelocOffset, int Idx,
- unsigned RelType, const MCSymbol *Sym,
- uint64_t Addend)
- : r_offset(RelocOffset), Index(Idx), Type(RelType),
- Symbol(Sym), r_addend(Addend) {}
-
- // Support lexicographic sorting.
- bool operator<(const ELFRelocationEntry &RE) const {
- return RE.r_offset < r_offset;
- }
- };
-
- /// The target specific ELF writer instance.
- llvm::OwningPtr<MCELFObjectTargetWriter> TargetObjectWriter;
-
- SmallPtrSet<const MCSymbol *, 16> UsedInReloc;
- SmallPtrSet<const MCSymbol *, 16> WeakrefUsedInReloc;
- DenseMap<const MCSymbol *, const MCSymbol *> Renames;
-
- llvm::DenseMap<const MCSectionData*,
- std::vector<ELFRelocationEntry> > Relocations;
- DenseMap<const MCSection*, uint64_t> SectionStringTableIndex;
-
- /// @}
- /// @name Symbol Table Data
- /// @{
-
- SmallString<256> StringTable;
- std::vector<ELFSymbolData> LocalSymbolData;
- std::vector<ELFSymbolData> ExternalSymbolData;
- std::vector<ELFSymbolData> 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;
-
- bool is64Bit() const { return TargetObjectWriter->is64Bit(); }
- bool hasRelocationAddend() const {
- return TargetObjectWriter->hasRelocationAddend();
- }
-
- 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);
- }
-
- virtual void WriteHeader(uint64_t SectionDataSize, unsigned NumberOfSections);
-
- virtual void WriteSymbolEntry(MCDataFragment *SymtabF, MCDataFragment *ShndxF,
- uint64_t name, uint8_t info,
- uint64_t value, uint64_t size,
- uint8_t other, uint32_t shndx,
- bool Reserved);
-
- virtual void WriteSymbol(MCDataFragment *SymtabF, MCDataFragment *ShndxF,
- ELFSymbolData &MSD,
- const MCAsmLayout &Layout);
-
- typedef DenseMap<const MCSectionELF*, uint32_t> SectionIndexMapTy;
- virtual 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);
-
- virtual 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;
-
- /// ComputeSymbolTable - Compute the symbol table data
- ///
- /// \param StringTable [out] - The string table data.
- /// \param StringIndexMap [out] - Map from symbol names to offsets in the
- /// string table.
- virtual void ComputeSymbolTable(MCAssembler &Asm,
- const SectionIndexMapTy &SectionIndexMap,
- RevGroupMapTy RevGroupMap);
-
- virtual void ComputeIndexMap(MCAssembler &Asm,
- SectionIndexMapTy &SectionIndexMap);
-
- virtual void WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout,
- const MCSectionData &SD);
-
- virtual void WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout) {
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- WriteRelocation(Asm, Layout, *it);
- }
- }
-
- virtual void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout,
- const SectionIndexMapTy &SectionIndexMap);
-
- virtual void CreateGroupSections(MCAssembler &Asm, MCAsmLayout &Layout,
- GroupMapTy &GroupMap, RevGroupMapTy &RevGroupMap);
-
- virtual void ExecutePostLayoutBinding(MCAssembler &Asm,
- const MCAsmLayout &Layout);
-
- virtual void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags,
- uint64_t Address, uint64_t Offset,
- uint64_t Size, uint32_t Link, uint32_t Info,
- uint64_t Alignment, uint64_t EntrySize);
-
- virtual void WriteRelocationsFragment(const MCAssembler &Asm,
- MCDataFragment *F,
- const MCSectionData *SD);
-
- virtual bool IsFixupFullyResolved(const MCAssembler &Asm,
- const MCValue Target,
- bool IsPCRel,
- const MCFragment *DF) const;
-
- virtual void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
- virtual void WriteSection(MCAssembler &Asm,
- const SectionIndexMapTy &SectionIndexMap,
- uint32_t GroupSymbolIndex,
- uint64_t Offset, uint64_t Size, uint64_t Alignment,
- const MCSectionELF &Section);
-
- protected:
- virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
- bool IsPCRel, bool IsRelocWithSymbol,
- int64_t Addend) = 0;
- };
-
- //===- X86ELFObjectWriter -------------------------------------------===//
-
- class X86ELFObjectWriter : public ELFObjectWriter {
- public:
- X86ELFObjectWriter(MCELFObjectTargetWriter *MOTW,
- raw_ostream &_OS,
- bool IsLittleEndian);
-
- virtual ~X86ELFObjectWriter();
- protected:
- virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
- bool IsPCRel, bool IsRelocWithSymbol,
- int64_t Addend);
- };
-
-
- //===- ARMELFObjectWriter -------------------------------------------===//
-
- class ARMELFObjectWriter : public ELFObjectWriter {
- public:
- ARMELFObjectWriter(MCELFObjectTargetWriter *MOTW,
- raw_ostream &_OS,
- bool IsLittleEndian);
-
- virtual ~ARMELFObjectWriter();
- protected:
- virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
- bool IsPCRel, bool IsRelocWithSymbol,
- int64_t Addend);
- };
-
- //===- MBlazeELFObjectWriter -------------------------------------------===//
-
- class MBlazeELFObjectWriter : public ELFObjectWriter {
- public:
- MBlazeELFObjectWriter(MCELFObjectTargetWriter *MOTW,
- raw_ostream &_OS,
- bool IsLittleEndian);
-
- virtual ~MBlazeELFObjectWriter();
- protected:
- virtual unsigned GetRelocType(const MCValue &Target, const MCFixup &Fixup,
- bool IsPCRel, bool IsRelocWithSymbol,
- int64_t Addend);
- };
-}
-
ELFObjectWriter::~ELFObjectWriter()
{}
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
+ WriteEFlags();
// e_ehsize = ELF header size
Write16(is64Bit() ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr));
}
}
-static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) {
+uint64_t ELFObjectWriter::SymbolValue(MCSymbolData &Data,
+ const MCAsmLayout &Layout) {
if (Data.isCommon() && Data.isExternal())
return Data.getCommonAlignment();
const MCSymbol &Symbol = Data.getSymbol();
+
+ if (Symbol.isAbsolute() && Symbol.isVariable()) {
+ if (const MCExpr *Value = Symbol.getVariableValue()) {
+ int64_t IntValue;
+ if (Value->EvaluateAsAbsolute(IntValue, Layout))
+ 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;
}
// Aliases defined with .symvar copy the binding from the symbol they alias.
// This is the first place we are able to copy this information.
it->setExternal(SD.isExternal());
- SetBinding(*it, GetBinding(SD));
+ MCELF::SetBinding(*it, MCELF::GetBinding(SD));
StringRef Rest = AliasName.substr(Pos);
if (!Symbol.isUndefined() && !Rest.startswith("@@@"))
bool IsReserved = Data.isCommon() || Data.getSymbol().isAbsolute() ||
Data.getSymbol().isVariable();
- uint8_t Binding = GetBinding(OrigData);
- uint8_t Visibility = GetVisibility(OrigData);
- uint8_t Type = GetType(Data);
+ uint8_t Binding = MCELF::GetBinding(OrigData);
+ uint8_t Visibility = MCELF::GetVisibility(OrigData);
+ uint8_t Type = MCELF::GetType(Data);
uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift);
uint8_t Other = Visibility;
uint64_t Value = SymbolValue(Data, Layout);
uint64_t Size = 0;
- const MCExpr *ESize;
assert(!(Data.isCommon() && !Data.isExternal()));
- ESize = Data.getSize();
- if (Data.getSize()) {
- MCValue Res;
- if (ESize->getKind() == MCExpr::Binary) {
- const MCBinaryExpr *BE = static_cast<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
(Data.getFlags() & ELF_STB_Weak)) &&
"External symbol requires STB_GLOBAL or STB_WEAK flag");
WriteSymbol(SymtabF, ShndxF, MSD, Layout);
- if (GetBinding(Data) == ELF::STB_LOCAL)
+ if (MCELF::GetBinding(Data) == ELF::STB_LOCAL)
LastLocalSymbolIndex++;
}
ELFSymbolData &MSD = UndefinedSymbolData[i];
MCSymbolData &Data = *MSD.SymbolData;
WriteSymbol(SymtabF, ShndxF, MSD, Layout);
- if (GetBinding(Data) == ELF::STB_LOCAL)
+ if (MCELF::GetBinding(Data) == ELF::STB_LOCAL)
LastLocalSymbolIndex++;
}
}
const MCSymbol *ELFObjectWriter::SymbolToReloc(const MCAssembler &Asm,
const MCValue &Target,
- const MCFragment &F) const {
+ const MCFragment &F,
+ const MCFixup &Fixup,
+ bool IsPCRel) const {
const MCSymbol &Symbol = Target.getSymA()->getSymbol();
const MCSymbol &ASymbol = Symbol.AliasedSymbol();
const MCSymbol *Renamed = Renames.lookup(&Symbol);
const SectionKind secKind = Section.getKind();
if (secKind.isBSS())
- return NULL;
+ return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel);
if (secKind.isThreadLocal()) {
if (Renamed)
return &Symbol;
}
- if (Section.getFlags() & MCSectionELF::SHF_MERGE) {
+ if (Section.getFlags() & ELF::SHF_MERGE) {
if (Target.getConstant() == 0)
- return NULL;
+ return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel);
if (Renamed)
return Renamed;
return &Symbol;
}
- return NULL;
+ return ExplicitRelSym(Asm, Target, F, Fixup, IsPCRel);
+
}
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();
FixedValue = Value;
unsigned Type = GetRelocType(Target, Fixup, IsPCRel,
(RelocSymbol != 0), Addend);
-
+
uint64_t RelocOffset = Layout.getFragmentOffset(Fragment) +
Fixup.getOffset();
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;
return true;
const MCSymbol &A = Symbol.AliasedSymbol();
- if (!A.isVariable() && A.isUndefined() && !Data.isCommon())
+ if (Symbol.isVariable() && !A.isVariable() && A.isUndefined())
+ return false;
+
+ bool IsGlobal = MCELF::GetBinding(Data) == ELF::STB_GLOBAL;
+ if (!Symbol.isVariable() && Symbol.isUndefined() && !IsGlobal)
return false;
if (!Asm.isSymbolLinkerVisible(Symbol) && !Symbol.isUndefined())
return true;
}
-static bool isLocal(const MCSymbolData &Data, bool isSignature,
- bool isUsedInReloc) {
+bool ELFObjectWriter::isLocal(const MCSymbolData &Data, bool isSignature,
+ bool isUsedInReloc) {
if (Data.isExternal())
return false;
}
void ELFObjectWriter::ComputeIndexMap(MCAssembler &Asm,
- SectionIndexMapTy &SectionIndexMap) {
+ SectionIndexMapTy &SectionIndexMap,
+ const RelMapTy &RelMap) {
unsigned Index = 1;
for (MCAssembler::iterator it = Asm.begin(),
ie = Asm.end(); it != ie; ++it) {
ie = Asm.end(); it != ie; ++it) {
const MCSectionELF &Section =
static_cast<const MCSectionELF &>(it->getSection());
- if (Section.getType() == ELF::SHT_GROUP)
+ if (Section.getType() == ELF::SHT_GROUP ||
+ Section.getType() == ELF::SHT_REL ||
+ Section.getType() == ELF::SHT_RELA)
continue;
SectionIndexMap[&Section] = Index++;
+ const MCSectionELF *RelSection = RelMap.lookup(&Section);
+ if (RelSection)
+ SectionIndexMap[RelSection] = Index++;
}
}
void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm,
const SectionIndexMapTy &SectionIndexMap,
- RevGroupMapTy RevGroupMap) {
+ RevGroupMapTy RevGroupMap,
+ unsigned NumRegularSections) {
// FIXME: Is this the correct place to do this?
+ // FIXME: Why is an undefined reference to _GLOBAL_OFFSET_TABLE_ needed?
if (NeedsGOT) {
llvm::StringRef Name = "_GLOBAL_OFFSET_TABLE_";
MCSymbol *Sym = Asm.getContext().GetOrCreateSymbol(Name);
MCSymbolData &Data = Asm.getOrCreateSymbolData(*Sym);
Data.setExternal(true);
- SetBinding(Data, ELF::STB_GLOBAL);
+ MCELF::SetBinding(Data, ELF::STB_GLOBAL);
}
- // Build section lookup table.
- int NumRegularSections = Asm.size();
-
// Index 0 is always the empty string.
StringMap<uint64_t> 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) {
// Undefined symbols are global, but this is the first place we
// are able to set it.
bool Local = isLocal(*it, isSignature, Used);
- if (!Local && GetBinding(*it) == ELF::STB_LOCAL) {
+ if (!Local && MCELF::GetBinding(*it) == ELF::STB_LOCAL) {
MCSymbolData &SD = Asm.getSymbolData(RefSymbol);
- SetBinding(*it, ELF::STB_GLOBAL);
- SetBinding(SD, ELF::STB_GLOBAL);
+ MCELF::SetBinding(*it, ELF::STB_GLOBAL);
+ MCELF::SetBinding(SD, ELF::STB_GLOBAL);
}
if (RefSymbol.isUndefined() && !Used && WeakrefUsed)
- SetBinding(*it, ELF::STB_WEAK);
+ MCELF::SetBinding(*it, ELF::STB_WEAK);
if (it->isCommon()) {
assert(!Local);
UndefinedSymbolData[i].SymbolData->setIndex(Index++);
}
-void ELFObjectWriter::WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout,
- const MCSectionData &SD) {
- if (!Relocations[&SD].empty()) {
+void ELFObjectWriter::CreateRelocationSections(MCAssembler &Asm,
+ MCAsmLayout &Layout,
+ RelMapTy &RelMap) {
+ for (MCAssembler::const_iterator it = Asm.begin(),
+ ie = Asm.end(); it != ie; ++it) {
+ const MCSectionData &SD = *it;
+ if (Relocations[&SD].empty())
+ continue;
+
MCContext &Ctx = Asm.getContext();
- const MCSectionELF *RelaSection;
const MCSectionELF &Section =
static_cast<const MCSectionELF&>(SD.getSection());
else
EntrySize = is64Bit() ? sizeof(ELF::Elf64_Rel) : sizeof(ELF::Elf32_Rel);
- RelaSection = Ctx.getELFSection(RelaSectionName, hasRelocationAddend() ?
- ELF::SHT_RELA : ELF::SHT_REL, 0,
- SectionKind::getReadOnly(),
- EntrySize, "");
+ const MCSectionELF *RelaSection =
+ Ctx.getELFSection(RelaSectionName, hasRelocationAddend() ?
+ ELF::SHT_RELA : ELF::SHT_REL, 0,
+ SectionKind::getReadOnly(),
+ EntrySize, "");
+ RelMap[&Section] = RelaSection;
+ Asm.getOrCreateSectionData(*RelaSection);
+ }
+}
+
+void ELFObjectWriter::WriteRelocations(MCAssembler &Asm, MCAsmLayout &Layout,
+ const RelMapTy &RelMap) {
+ for (MCAssembler::const_iterator it = Asm.begin(),
+ ie = Asm.end(); it != ie; ++it) {
+ const MCSectionData &SD = *it;
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(SD.getSection());
+ const MCSectionELF *RelaSection = RelMap.lookup(&Section);
+ if (!RelaSection)
+ continue;
MCSectionData &RelaSD = Asm.getOrCreateSectionData(*RelaSection);
RelaSD.setAlignment(is64Bit() ? 8 : 4);
MCDataFragment *F = new MCDataFragment(&RelaSD);
-
- WriteRelocationsFragment(Asm, F, &SD);
+ WriteRelocationsFragment(Asm, F, &*it);
}
}
}
}
+static int compareBySuffix(const void *a, const void *b) {
+ const MCSectionELF *secA = *static_cast<const MCSectionELF* const *>(a);
+ const MCSectionELF *secB = *static_cast<const MCSectionELF* const *>(b);
+ const StringRef &NameA = secA->getSectionName();
+ const StringRef &NameB = secB->getSectionName();
+ const unsigned sizeA = NameA.size();
+ const unsigned sizeB = NameB.size();
+ const unsigned len = std::min(sizeA, sizeB);
+ for (unsigned int i = 0; i < len; ++i) {
+ char ca = NameA[sizeA - i - 1];
+ char cb = NameB[sizeB - i - 1];
+ if (ca != cb)
+ return cb - ca;
+ }
+
+ return sizeB - sizeA;
+}
+
void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm,
MCAsmLayout &Layout,
- const SectionIndexMapTy &SectionIndexMap) {
+ SectionIndexMapTy &SectionIndexMap,
+ const RelMapTy &RelMap) {
MCContext &Ctx = Asm.getContext();
MCDataFragment *F;
SectionKind::getReadOnly());
MCSectionData &ShstrtabSD = Asm.getOrCreateSectionData(*ShstrtabSection);
ShstrtabSD.setAlignment(1);
- ShstrtabIndex = Asm.size();
const MCSectionELF *SymtabSection =
Ctx.getELFSection(".symtab", ELF::SHT_SYMTAB, 0,
EntrySize, "");
MCSectionData &SymtabSD = Asm.getOrCreateSectionData(*SymtabSection);
SymtabSD.setAlignment(is64Bit() ? 8 : 4);
- SymbolTableIndex = Asm.size();
MCSectionData *SymtabShndxSD = NULL;
SymtabShndxSD->setAlignment(4);
}
- const MCSection *StrtabSection;
+ const MCSectionELF *StrtabSection;
StrtabSection = Ctx.getELFSection(".strtab", ELF::SHT_STRTAB, 0,
SectionKind::getReadOnly());
MCSectionData &StrtabSD = Asm.getOrCreateSectionData(*StrtabSection);
StrtabSD.setAlignment(1);
- StringTableIndex = Asm.size();
- WriteRelocations(Asm, Layout);
+ ComputeIndexMap(Asm, SectionIndexMap, RelMap);
+
+ ShstrtabIndex = SectionIndexMap.lookup(ShstrtabSection);
+ SymbolTableIndex = SectionIndexMap.lookup(SymtabSection);
+ StringTableIndex = SectionIndexMap.lookup(StrtabSection);
// Symbol table
F = new MCDataFragment(&SymtabSD);
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
uint64_t Index = 1;
F->getContents() += '\x00';
- StringMap<uint64_t> SecStringMap;
- 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 (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;
}
}
-bool ELFObjectWriter::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);
- }
-
- const MCSection *SectionA = 0;
- const MCSymbol *SymbolA = 0;
- if (const MCSymbolRefExpr *A = Target.getSymA()) {
- SymbolA = &A->getSymbol();
- SectionA = &SymbolA->AliasedSymbol().getSection();
- }
-
- const MCSection *SectionB = 0;
- const MCSymbol *SymbolB = 0;
- if (const MCSymbolRefExpr *B = Target.getSymB()) {
- SymbolB = &B->getSymbol();
- SectionB = &SymbolB->AliasedSymbol().getSection();
+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);
}
- if (!BaseSection)
- return SectionA == SectionB;
-
- if (SymbolB)
- return false;
-
- // Absolute address but PCrel instruction, so we need a relocation.
- if (!SymbolA)
- return false;
-
- // FIXME: This is in here just to match gnu as output. If the two ends
- // are in the same section, there is nothing that the linker can do to
- // break it.
- const MCSymbolData &DataA = Asm.getSymbolData(*SymbolA);
- if (DataA.isExternal())
- return false;
-
- return BaseSection == SectionA;
-}
-
-void ELFObjectWriter::CreateGroupSections(MCAssembler &Asm,
- MCAsmLayout &Layout,
- GroupMapTy &GroupMap,
- RevGroupMapTy &RevGroupMap) {
// Build the groups
for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end();
it != ie; ++it) {
const MCSectionELF &Section =
static_cast<const MCSectionELF&>(it->getSection());
- if (!(Section.getFlags() & MCSectionELF::SHF_GROUP))
+ if (!(Section.getFlags() & ELF::SHF_GROUP))
continue;
const MCSymbol *SignatureSymbol = Section.getGroup();
Asm.getOrCreateSymbolData(*SignatureSymbol);
const MCSectionELF *&Group = RevGroupMap[SignatureSymbol];
if (!Group) {
- Group = Asm.getContext().CreateELFGroupSection();
+ Group = Ctx.CreateELFGroupSection();
MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
Data.setAlignment(4);
MCDataFragment *F = new MCDataFragment(&Data);
GroupMap[Group] = SignatureSymbol;
}
+ ComputeIndexMap(Asm, SectionIndexMap, RelMap);
+
// Add sections to the groups
- unsigned Index = 1;
- unsigned NumGroups = RevGroupMap.size();
for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end();
- it != ie; ++it, ++Index) {
+ it != ie; ++it) {
const MCSectionELF &Section =
static_cast<const MCSectionELF&>(it->getSection());
- if (!(Section.getFlags() & MCSectionELF::SHF_GROUP))
+ if (!(Section.getFlags() & ELF::SHF_GROUP))
continue;
const MCSectionELF *Group = RevGroupMap[Section.getGroup()];
MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
// FIXME: we could use the previous fragment
MCDataFragment *F = new MCDataFragment(&Data);
- String32(*F, NumGroups + Index);
+ unsigned Index = SectionIndexMap.lookup(&Section);
+ String32(*F, Index);
}
}
case ELF::SHT_PROGBITS:
case ELF::SHT_STRTAB:
case ELF::SHT_NOBITS:
+ case ELF::SHT_NOTE:
case ELF::SHT_NULL:
case ELF::SHT_ARM_ATTRIBUTES:
+ case ELF::SHT_INIT_ARRAY:
+ case ELF::SHT_FINI_ARRAY:
+ case ELF::SHT_PREINIT_ARRAY:
+ case ELF::SHT_X86_64_UNWIND:
// Nothing to do.
break;
Alignment, Section.getEntrySize());
}
-static bool IsELFMetaDataSection(const MCSectionData &SD) {
+bool ELFObjectWriter::IsELFMetaDataSection(const MCSectionData &SD) {
return SD.getOrdinal() == ~UINT32_C(0) &&
!SD.getSection().isVirtualSection();
}
-static uint64_t DataSectionSize(const MCSectionData &SD) {
+uint64_t ELFObjectWriter::DataSectionSize(const MCSectionData &SD) {
uint64_t Ret = 0;
for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e;
++i) {
return Ret;
}
-static uint64_t GetSectionFileSize(const MCAsmLayout &Layout,
- const MCSectionData &SD) {
+uint64_t ELFObjectWriter::GetSectionFileSize(const MCAsmLayout &Layout,
+ const MCSectionData &SD) {
if (IsELFMetaDataSection(SD))
return DataSectionSize(SD);
return Layout.getSectionFileSize(&SD);
}
-static uint64_t GetSectionAddressSize(const MCAsmLayout &Layout,
- const MCSectionData &SD) {
+uint64_t ELFObjectWriter::GetSectionAddressSize(const MCAsmLayout &Layout,
+ const MCSectionData &SD) {
if (IsELFMetaDataSection(SD))
return DataSectionSize(SD);
return Layout.getSectionAddressSize(&SD);
}
-static void WriteDataSectionData(ELFObjectWriter *W, const MCSectionData &SD) {
- for (MCSectionData::const_iterator i = SD.begin(), e = SD.end(); i != e;
- ++i) {
- const MCFragment &F = *i;
- assert(F.getKind() == MCFragment::FT_Data);
- W->WriteBytes(cast<MCDataFragment>(F).getContents().str());
+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());
+ WriteZeros(Padding);
+ FileOff += Padding;
+
+ FileOff += GetSectionFileSize(Layout, SD);
+
+ 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().str());
+ }
+ } else {
+ Asm.WriteSectionData(&SD, Layout);
+ }
+}
+
+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);
+
+ 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;
+ }
+
+ // 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));
+
+ uint64_t Size = GetSectionAddressSize(Layout, SD);
+
+ WriteSection(Asm, SectionIndexMap, GroupSymbolIndex,
+ SectionOffsetMap.lookup(&Section), Size,
+ SD.getAlignment(), Section);
+ }
+}
+
+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);
+ }
+
+ 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);
+ }
+
+ 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_REL ||
+ Section.getType() == ELF::SHT_RELA)
+ Sections.push_back(&Section);
}
}
const MCAsmLayout &Layout) {
GroupMapTy GroupMap;
RevGroupMapTy RevGroupMap;
- CreateGroupSections(Asm, const_cast<MCAsmLayout&>(Layout), GroupMap,
- RevGroupMap);
-
SectionIndexMapTy SectionIndexMap;
- ComputeIndexMap(Asm, SectionIndexMap);
+ 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, SectionIndexMap, RevGroupMap);
+ ComputeSymbolTable(Asm, SectionIndexMap, RevGroupMap, NumRegularSections);
+
+
+ WriteRelocations(Asm, const_cast<MCAsmLayout&>(Layout), RelMap);
CreateMetadataSections(const_cast<MCAssembler&>(Asm),
const_cast<MCAsmLayout&>(Layout),
- SectionIndexMap);
+ SectionIndexMap,
+ RelMap);
- // Update to include the metadata sections.
- ComputeIndexMap(Asm, SectionIndexMap);
-
- // 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;
std::vector<const MCSectionELF*> Sections;
- Sections.resize(NumSections);
-
- 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] = p.first;
- }
-
- for (unsigned i = 1; i < NumSections; ++i) {
+ 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);
}
FileOff = RoundUpToAlignment(FileOff, NaturalAlignment);
- // Write out the ELF header ...
- WriteHeader(FileOff - HeaderSize, NumSections);
-
- FileOff = HeaderSize;
+ const unsigned SectionHeaderOffset = FileOff - HeaderSize;
- // ... then all of the sections ...
- DenseMap<const MCSection*, uint64_t> SectionOffsetMap;
+ uint64_t SectionHeaderEntrySize = is64Bit() ?
+ sizeof(ELF::Elf64_Shdr) : sizeof(ELF::Elf32_Shdr);
+ FileOff += (NumSections + 1) * SectionHeaderEntrySize;
- for (unsigned i = 1; i < NumSections; ++i) {
+ for (unsigned i = NumRegularSections + 1; i < NumSections; ++i) {
const MCSectionELF &Section = *Sections[i];
const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
- uint64_t Padding = OffsetToAlignment(FileOff, SD.getAlignment());
- WriteZeros(Padding);
- FileOff += Padding;
+ 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);
-
- if (IsELFMetaDataSection(SD))
- WriteDataSectionData(this, SD);
- else
- Asm.WriteSectionData(&SD, Layout);
}
+ // Write out the ELF header ...
+ WriteHeader(SectionHeaderOffset, NumSections + 1);
+
+ // ... then the regular sections ...
+ // + because of .shstrtab
+ for (unsigned i = 0; i < NumRegularSections + 1; ++i)
+ WriteDataSectionData(Asm, Layout, *Sections[i]);
+
+ FileOff = OS.tell();
uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment);
WriteZeros(Padding);
- FileOff += Padding;
- // ... and then the section header table.
- // Should we align the section header table?
- //
- // Null section first.
- uint64_t FirstSectionSize =
- NumSections >= ELF::SHN_LORESERVE ? NumSections : 0;
- uint32_t FirstSectionLink =
- ShstrtabIndex >= ELF::SHN_LORESERVE ? ShstrtabIndex : 0;
- WriteSecHdrEntry(0, 0, 0, 0, 0, FirstSectionSize, FirstSectionLink, 0, 0, 0);
+ // ... then the section header table ...
+ WriteSectionHeader(Asm, GroupMap, Layout, SectionIndexMap,
+ SectionOffsetMap);
- for (unsigned i = 1; i < NumSections; ++i) {
- const MCSectionELF &Section = *Sections[i];
- const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
- uint32_t GroupSymbolIndex;
- if (Section.getType() != ELF::SHT_GROUP)
- GroupSymbolIndex = 0;
- else
- GroupSymbolIndex = getSymbolIndexInSymbolTable(Asm, GroupMap[&Section]);
+ FileOff = OS.tell();
- uint64_t Size = GetSectionAddressSize(Layout, SD);
+ // ... and then the remainting sections ...
+ for (unsigned i = NumRegularSections + 1; i < NumSections; ++i)
+ WriteDataSectionData(Asm, Layout, *Sections[i]);
+}
- WriteSection(Asm, SectionIndexMap, GroupSymbolIndex,
- SectionOffsetMap[&Section], Size,
- SD.getAlignment(), Section);
- }
+bool
+ELFObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(const MCAssembler &Asm,
+ const MCSymbolData &DataA,
+ const MCFragment &FB,
+ bool InSet,
+ bool IsPCRel) const {
+ if (DataA.getFlags() & ELF_STB_Weak)
+ return false;
+ return MCObjectWriter::IsSymbolRefDifferenceFullyResolvedImpl(
+ Asm, DataA, FB,InSet, IsPCRel);
}
MCObjectWriter *llvm::createELFObjectWriter(MCELFObjectTargetWriter *MOTW,
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 an approximation of what ARM/gcc does.
+
+STATISTIC(PCRelCount, "Total number of PIC Relocations");
+STATISTIC(NonPCRelCount, "Total number of non-PIC relocations");
+
+const MCSymbol *ARMELFObjectWriter::ExplicitRelSym(const MCAssembler &Asm,
+ const MCValue &Target,
+ const MCFragment &F,
+ const MCFixup &Fixup,
+ bool IsPCRel) const {
+ const MCSymbol &Symbol = Target.getSymA()->getSymbol();
+ bool EmitThisSym = false;
+
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(Symbol.getSection());
+ bool InNormalSection = true;
+ unsigned RelocType = 0;
+ RelocType = GetRelocTypeInner(Target, Fixup, IsPCRel);
+
+ DEBUG(
+ const MCSymbolRefExpr::VariantKind Kind = Target.getSymA()->getKind();
+ MCSymbolRefExpr::VariantKind Kind2;
+ Kind2 = Target.getSymB() ? Target.getSymB()->getKind() :
+ MCSymbolRefExpr::VK_None;
+ dbgs() << "considering symbol "
+ << Section.getSectionName() << "/"
+ << Symbol.getName() << "/"
+ << " Rel:" << (unsigned)RelocType
+ << " Kind: " << (int)Kind << "/" << (int)Kind2
+ << " Tmp:"
+ << Symbol.isAbsolute() << "/" << Symbol.isDefined() << "/"
+ << Symbol.isVariable() << "/" << Symbol.isTemporary()
+ << " Counts:" << PCRelCount << "/" << NonPCRelCount << "\n");
+
+ if (IsPCRel) { ++PCRelCount;
+ switch (RelocType) {
+ default:
+ // Most relocation types are emitted as explicit symbols
+ InNormalSection =
+ StringSwitch<bool>(Section.getSectionName())
+ .Case(".data.rel.ro.local", false)
+ .Case(".data.rel", false)
+ .Case(".bss", false)
+ .Default(true);
+ EmitThisSym = true;
+ break;
+ case ELF::R_ARM_ABS32:
+ // But things get strange with R_ARM_ABS32
+ // In this case, most things that go in .rodata show up
+ // as section relative relocations
+ InNormalSection =
+ StringSwitch<bool>(Section.getSectionName())
+ .Case(".data.rel.ro.local", false)
+ .Case(".data.rel", false)
+ .Case(".rodata", false)
+ .Case(".bss", false)
+ .Default(true);
+ EmitThisSym = false;
+ break;
+ }
+ } else {
+ NonPCRelCount++;
+ InNormalSection =
+ StringSwitch<bool>(Section.getSectionName())
+ .Case(".data.rel.ro.local", false)
+ .Case(".rodata", false)
+ .Case(".data.rel", false)
+ .Case(".bss", false)
+ .Default(true);
+
+ switch (RelocType) {
+ default: EmitThisSym = true; break;
+ case ELF::R_ARM_ABS32: EmitThisSym = false; break;
+ }
+ }
+
+ if (EmitThisSym)
+ return &Symbol;
+ if (! Symbol.isTemporary() && InNormalSection) {
+ return &Symbol;
+ }
+ return NULL;
+}
+
+// Need to examine the Fixup when determining whether to
+// emit the relocation as an explicit symbol or as a section relative
+// offset
unsigned ARMELFObjectWriter::GetRelocType(const MCValue &Target,
const MCFixup &Fixup,
bool IsPCRel,
MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
+ unsigned Type = GetRelocTypeInner(Target, Fixup, IsPCRel);
+
+ if (RelocNeedsGOT(Modifier))
+ NeedsGOT = true;
+
+ return Type;
+}
+
+unsigned ARMELFObjectWriter::GetRelocTypeInner(const MCValue &Target,
+ const MCFixup &Fixup,
+ bool IsPCRel) const {
+ MCSymbolRefExpr::VariantKind Modifier = Target.isAbsolute() ?
+ MCSymbolRefExpr::VK_None : Target.getSymA()->getKind();
+
unsigned Type = 0;
if (IsPCRel) {
switch ((unsigned)Fixup.getKind()) {
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier");
case MCSymbolRefExpr::VK_None:
- Type = ELF::R_ARM_BASE_PREL; break;
+ Type = ELF::R_ARM_REL32;
+ break;
case MCSymbolRefExpr::VK_ARM_TLSGD:
- assert(0 && "unimplemented"); break;
+ assert(0 && "unimplemented");
+ break;
case MCSymbolRefExpr::VK_ARM_GOTTPOFF:
Type = ELF::R_ARM_TLS_IE32;
- } break;
- case ARM::fixup_arm_branch:
+ break;
+ }
+ break;
+ case ARM::fixup_arm_uncondbranch:
switch (Modifier) {
case MCSymbolRefExpr::VK_ARM_PLT:
- Type = ELF::R_ARM_PLT32; break;
+ Type = ELF::R_ARM_PLT32;
+ break;
default:
- Type = ELF::R_ARM_CALL; break;
- } break;
+ 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;
+ case ARM::fixup_arm_thumb_bl:
+ case ARM::fixup_arm_thumb_blx:
+ switch (Modifier) {
+ case MCSymbolRefExpr::VK_ARM_PLT:
+ Type = ELF::R_ARM_THM_CALL;
+ break;
+ default:
+ Type = ELF::R_ARM_NONE;
+ break;
+ }
+ break;
}
} else {
switch ((unsigned)Fixup.getKind()) {
switch (Modifier) {
default: llvm_unreachable("Unsupported Modifier"); break;
case MCSymbolRefExpr::VK_ARM_GOT:
- Type = ELF::R_ARM_GOT_BREL; break;
+ Type = ELF::R_ARM_GOT_BREL;
+ break;
case MCSymbolRefExpr::VK_ARM_TLSGD:
- Type = ELF::R_ARM_TLS_GD32; break;
+ Type = ELF::R_ARM_TLS_GD32;
+ break;
case MCSymbolRefExpr::VK_ARM_TPOFF:
- Type = ELF::R_ARM_TLS_LE32; break;
+ Type = ELF::R_ARM_TLS_LE32;
+ break;
case MCSymbolRefExpr::VK_ARM_GOTTPOFF:
- Type = ELF::R_ARM_TLS_IE32; break;
+ Type = ELF::R_ARM_TLS_IE32;
+ break;
case MCSymbolRefExpr::VK_None:
- Type = ELF::R_ARM_ABS32; break;
+ Type = ELF::R_ARM_ABS32;
+ break;
case MCSymbolRefExpr::VK_ARM_GOTOFF:
- Type = ELF::R_ARM_GOTOFF32; break;
- } break;
+ 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_cb:
case ARM::fixup_arm_thumb_cp:
case ARM::fixup_arm_thumb_br:
- assert(0 && "Unimplemented"); break;
- case ARM::fixup_arm_branch:
- // FIXME: Differentiate between R_ARM_CALL and
- // R_ARM_JUMP24 (latter used for conditional jumps)
- Type = ELF::R_ARM_CALL; break;
- case ARM::fixup_arm_movt_hi16:
- Type = ELF::R_ARM_MOVT_ABS; break;
+ 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;
+ 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;
}
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;
+ switch ((unsigned)Fixup.getKind()) {
+ default: llvm_unreachable("invalid fixup kind!");
+
+ case FK_Data_8: Type = ELF::R_X86_64_PC64; break;
+ case FK_Data_4: Type = ELF::R_X86_64_PC32; break;
+ case FK_Data_2: Type = ELF::R_X86_64_PC16; break;
+
+ case FK_PCRel_8:
+ assert(Modifier == MCSymbolRefExpr::VK_None);
+ Type = ELF::R_X86_64_PC64;
break;
- case MCSymbolRefExpr::VK_GOTPCREL:
- Type = ELF::R_X86_64_GOTPCREL;
+ case X86::reloc_signed_4byte:
+ case X86::reloc_riprel_4byte_movq_load:
+ 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_GOTTPOFF:
- Type = ELF::R_X86_64_GOTTPOFF;
+ case MCSymbolRefExpr::VK_TLSGD:
+ Type = ELF::R_X86_64_TLSGD;
+ break;
+ case MCSymbolRefExpr::VK_TLSLD:
+ Type = ELF::R_X86_64_TLSLD;
+ break;
+ }
break;
- case MCSymbolRefExpr::VK_TLSGD:
- Type = ELF::R_X86_64_TLSGD;
+ case FK_PCRel_2:
+ assert(Modifier == MCSymbolRefExpr::VK_None);
+ Type = ELF::R_X86_64_PC16;
break;
- case MCSymbolRefExpr::VK_TLSLD:
- Type = ELF::R_X86_64_TLSLD;
+ case FK_PCRel_1:
+ assert(Modifier == MCSymbolRefExpr::VK_None);
+ Type = ELF::R_X86_64_PC8;
break;
}
} else {
default: llvm_unreachable("invalid fixup kind!");
case FK_Data_8: Type = ELF::R_X86_64_64; break;
case X86::reloc_signed_4byte:
- case FK_PCRel_4:
assert(isInt<32>(Target.getConstant()));
switch (Modifier) {
default:
case MCSymbolRefExpr::VK_DTPOFF:
Type = ELF::R_386_TLS_LDO_32;
break;
+ case MCSymbolRefExpr::VK_GOTTPOFF:
+ Type = ELF::R_386_TLS_IE_32;
+ break;
}
break;
case FK_Data_2: Type = ELF::R_386_16; break;