//
//===----------------------------------------------------------------------===//
-#include "llvm/MC/ELFObjectWriter.h"
#include "llvm/ADT/SmallPtrSet.h"
#include "llvm/ADT/STLExtras.h"
#include "llvm/ADT/StringMap.h"
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:
}
}
-static bool RelocNeedsGOT(unsigned Type) {
- switch (Type) {
+static bool RelocNeedsGOT(MCSymbolRefExpr::VariantKind Variant) {
+ switch (Variant) {
default:
return false;
- case ELF::R_X86_64_GOT32:
- case ELF::R_X86_64_PLT32:
- case ELF::R_X86_64_GOTPCREL:
+ case MCSymbolRefExpr::VK_GOT:
+ case MCSymbolRefExpr::VK_PLT:
+ case MCSymbolRefExpr::VK_GOTPCREL:
+ case MCSymbolRefExpr::VK_TPOFF:
+ case MCSymbolRefExpr::VK_TLSGD:
+ case MCSymbolRefExpr::VK_GOTTPOFF:
+ case MCSymbolRefExpr::VK_INDNTPOFF:
+ case MCSymbolRefExpr::VK_NTPOFF:
+ case MCSymbolRefExpr::VK_GOTNTPOFF:
+ case MCSymbolRefExpr::VK_TLSLDM:
+ case MCSymbolRefExpr::VK_DTPOFF:
+ case MCSymbolRefExpr::VK_TLSLD:
return true;
}
}
namespace {
-
- class ELFObjectWriterImpl {
+ class ELFObjectWriter : public MCObjectWriter {
/*static bool isFixupKindX86RIPRel(unsigned Kind) {
return Kind == X86::reloc_riprel_4byte ||
Kind == X86::reloc_riprel_4byte_movq_load;
};
SmallPtrSet<const MCSymbol *, 16> UsedInReloc;
+ SmallPtrSet<const MCSymbol *, 16> WeakrefUsedInReloc;
+ DenseMap<const MCSymbol *, const MCSymbol *> Renames;
llvm::DenseMap<const MCSectionData*,
std::vector<ELFRelocationEntry> > Relocations;
/// @}
- int NumRegularSections;
-
bool NeedsGOT;
- ELFObjectWriter *Writer;
-
- raw_ostream &OS;
+ bool NeedsSymtabShndx;
unsigned Is64Bit : 1;
Triple::OSType OSType;
+ uint16_t EMachine;
+
// 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;
public:
- ELFObjectWriterImpl(ELFObjectWriter *_Writer, bool _Is64Bit,
- bool _HasRelAddend, Triple::OSType _OSType)
- : NeedsGOT(false), Writer(_Writer), OS(Writer->getStream()),
+ ELFObjectWriter(raw_ostream &_OS, bool _Is64Bit, bool IsLittleEndian,
+ uint16_t _EMachine, bool _HasRelAddend,
+ Triple::OSType _OSType)
+ : MCObjectWriter(_OS, IsLittleEndian),
+ NeedsGOT(false), NeedsSymtabShndx(false),
Is64Bit(_Is64Bit), HasRelocationAddend(_HasRelAddend),
- OSType(_OSType) {
+ OSType(_OSType), EMachine(_EMachine) {
}
-
- 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);
- //}
-
+
void WriteWord(uint64_t W) {
if (Is64Bit)
- Writer->Write64(W);
+ 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() += StringRef(buf, 1);
+ }
+
+ void String16(MCDataFragment &F, uint16_t Value) {
+ char buf[2];
+ if (isLittleEndian())
StringLE16(buf, Value);
else
StringBE16(buf, Value);
+ F.getContents() += StringRef(buf, 2);
}
- void String32(char *buf, uint32_t Value) {
- if (Writer->isLittleEndian())
+ void String32(MCDataFragment &F, uint32_t Value) {
+ char buf[4];
+ if (isLittleEndian())
StringLE32(buf, Value);
else
StringBE32(buf, Value);
+ F.getContents() += StringRef(buf, 4);
}
- void String64(char *buf, uint64_t Value) {
- if (Writer->isLittleEndian())
+ void String64(MCDataFragment &F, uint64_t Value) {
+ char buf[8];
+ if (isLittleEndian())
StringLE64(buf, Value);
else
StringBE64(buf, Value);
+ F.getContents() += StringRef(buf, 8);
}
void WriteHeader(uint64_t SectionDataSize, unsigned NumberOfSections);
- void 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,
/// \param StringTable [out] - The string table data.
/// \param StringIndexMap [out] - Map from symbol names to offsets in the
/// string table.
- void ComputeSymbolTable(MCAssembler &Asm);
+ void ComputeSymbolTable(MCAssembler &Asm,
+ const SectionIndexMapTy &SectionIndexMap);
+
+ void ComputeIndexMap(MCAssembler &Asm,
+ SectionIndexMapTy &SectionIndexMap);
void WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout,
const MCSectionData &SD);
}
}
- void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout);
+ void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout,
+ const SectionIndexMapTy &SectionIndexMap);
- void ExecutePostLayoutBinding(MCAssembler &Asm) {
- }
+ // Map from a group section to the signature symbol
+ typedef DenseMap<const MCSectionELF*, const MCSymbol*> GroupMapTy;
+ void CreateGroupSections(MCAssembler &Asm, MCAsmLayout &Layout,
+ GroupMapTy &GroupMap);
+
+ void ExecutePostLayoutBinding(MCAssembler &Asm);
void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags,
uint64_t Address, uint64_t Offset,
const MCFragment *DF) const;
void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout);
+ void WriteSection(MCAssembler &Asm,
+ const SectionIndexMapTy &SectionIndexMap,
+ uint32_t GroupSymbolIndex,
+ uint64_t Offset, uint64_t Size, uint64_t Alignment,
+ const MCSectionELF &Section);
};
}
// Emit the ELF header.
-void ELFObjectWriterImpl::WriteHeader(uint64_t SectionDataSize,
- unsigned NumberOfSections) {
+void ELFObjectWriter::WriteHeader(uint64_t SectionDataSize,
+ unsigned NumberOfSections) {
// ELF Header
// ----------
//
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]
Write16(ELF::ET_REL); // e_type
- // FIXME: Make this configurable
- Write16(Is64Bit ? ELF::EM_X86_64 : ELF::EM_386); // e_machine = target
+ Write16(EMachine); // e_machine = target
Write32(ELF::EV_CURRENT); // e_version
WriteWord(0); // e_entry, no entry point in .o file
Write16(Is64Bit ? sizeof(ELF::Elf64_Shdr) : sizeof(ELF::Elf32_Shdr));
// e_shnum = # of section header ents
- Write16(NumberOfSections);
+ if (NumberOfSections >= ELF::SHN_LORESERVE)
+ Write16(0);
+ else
+ Write16(NumberOfSections);
// e_shstrndx = Section # of '.shstrtab'
- Write16(ShstrtabIndex);
+ if (NumberOfSections >= 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) {
+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);
+ }
+
+ uint16_t Index = (shndx >= ELF::SHN_LORESERVE && !Reserved) ?
+ uint16_t(ELF::SHN_XINDEX) : shndx;
+
if (Is64Bit) {
- char buf[8];
+ String32(*SymtabF, name); // st_name
+ String8(*SymtabF, info); // st_info
+ String8(*SymtabF, other); // st_other
+ String16(*SymtabF, Index); // st_shndx
+ String64(*SymtabF, value); // st_value
+ String64(*SymtabF, size); // st_size
+ } else {
+ String32(*SymtabF, name); // st_name
+ String32(*SymtabF, value); // st_value
+ String32(*SymtabF, size); // st_size
+ String8(*SymtabF, info); // st_info
+ String8(*SymtabF, other); // st_other
+ String16(*SymtabF, Index); // st_shndx
+ }
+}
- String32(buf, name);
- F->getContents() += StringRef(buf, 4); // st_name
+static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) {
+ if (Data.isCommon() && Data.isExternal())
+ return Data.getCommonAlignment();
- String8(buf, info);
- F->getContents() += StringRef(buf, 1); // st_info
+ const MCSymbol &Symbol = Data.getSymbol();
+ if (!Symbol.isInSection())
+ return 0;
- String8(buf, other);
- F->getContents() += StringRef(buf, 1); // st_other
+ if (MCFragment *FF = Data.getFragment())
+ return Layout.getSymbolAddress(&Data) -
+ Layout.getSectionAddress(FF->getParent());
- String16(buf, shndx);
- F->getContents() += StringRef(buf, 2); // st_shndx
+ return 0;
+}
+
+static const MCSymbol &AliasedSymbol(const MCSymbol &Symbol) {
+ const MCSymbol *S = &Symbol;
+ while (S->isVariable()) {
+ const MCExpr *Value = S->getVariableValue();
+ MCExpr::ExprKind Kind = Value->getKind();
+ switch (Kind) {
+ case MCExpr::SymbolRef: {
+ const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value);
+ S = &Ref->getSymbol();
+ break;
+ }
+ case MCExpr::Target: {
+ const MCTargetExpr *TExp = static_cast<const MCTargetExpr*>(Value);
+ MCValue Res;
+ TExp->EvaluateAsRelocatableImpl(Res, NULL);
+ S = &Res.getSymA()->getSymbol();
+ break;
+ }
+ default:
+ return *S;
+ }
+ }
+ return *S;
+}
- String64(buf, value);
- F->getContents() += StringRef(buf, 8); // st_value
+void ELFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm) {
+ // The presence of symbol versions causes undefined symbols and
+ // versions declared with @@@ to be renamed.
- String64(buf, size);
- F->getContents() += StringRef(buf, 8); // st_size
- } else {
- char buf[4];
+ for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
+ ie = Asm.symbol_end(); it != ie; ++it) {
+ const MCSymbol &Alias = it->getSymbol();
+ const MCSymbol &Symbol = AliasedSymbol(Alias);
+ MCSymbolData &SD = Asm.getSymbolData(Symbol);
+
+ // Undefined symbols are global, but this is the first place we
+ // are able to set it.
+ if (Symbol.isUndefined() && !Symbol.isVariable()) {
+ if (GetBinding(SD) == ELF::STB_LOCAL) {
+ SetBinding(SD, ELF::STB_GLOBAL);
+ SetBinding(*it, ELF::STB_GLOBAL);
+ }
+ }
- String32(buf, name);
- F->getContents() += StringRef(buf, 4); // st_name
+ // Not an alias.
+ if (&Symbol == &Alias)
+ continue;
- String32(buf, value);
- F->getContents() += StringRef(buf, 4); // st_value
+ StringRef AliasName = Alias.getName();
+ size_t Pos = AliasName.find('@');
+ if (Pos == StringRef::npos)
+ continue;
- String32(buf, size);
- F->getContents() += StringRef(buf, 4); // st_size
+ // 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));
- String8(buf, info);
- F->getContents() += StringRef(buf, 1); // st_info
+ StringRef Rest = AliasName.substr(Pos);
+ if (!Symbol.isUndefined() && !Rest.startswith("@@@"))
+ continue;
- String8(buf, other);
- F->getContents() += StringRef(buf, 1); // st_other
+ // FIXME: produce a better error message.
+ if (Symbol.isUndefined() && Rest.startswith("@@") &&
+ !Rest.startswith("@@@"))
+ report_fatal_error("A @@ version cannot be undefined");
- String16(buf, shndx);
- F->getContents() += StringRef(buf, 2); // st_shndx
+ Renames.insert(std::make_pair(&Symbol, &Alias));
}
}
-static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) {
- if (Data.isCommon() && Data.isExternal())
- return Data.getCommonAlignment();
+void ELFObjectWriter::WriteSymbol(MCDataFragment *SymtabF,
+ MCDataFragment *ShndxF,
+ ELFSymbolData &MSD,
+ const MCAsmLayout &Layout) {
+ MCSymbolData &OrigData = *MSD.SymbolData;
+ MCSymbolData &Data =
+ Layout.getAssembler().getSymbolData(AliasedSymbol(OrigData.getSymbol()));
- const MCSymbol &Symbol = Data.getSymbol();
- if (!Symbol.isInSection())
- return 0;
+ bool IsReserved = Data.isCommon() || Data.getSymbol().isAbsolute() ||
+ Data.getSymbol().isVariable();
- if (!Data.isCommon() && !(Data.getFlags() & ELF_STB_Weak))
- if (MCFragment *FF = Data.getFragment())
- return Layout.getSymbolAddress(&Data) -
- Layout.getSectionAddress(FF->getParent());
+ uint8_t Binding = GetBinding(OrigData);
+ uint8_t Visibility = GetVisibility(OrigData);
+ uint8_t Type = GetType(Data);
- return 0;
-}
+ uint8_t Info = (Binding << ELF_STB_Shift) | (Type << ELF_STT_Shift);
+ uint8_t Other = Visibility;
-void ELFObjectWriterImpl::WriteSymbol(MCDataFragment *F, ELFSymbolData &MSD,
- const MCAsmLayout &Layout) {
- MCSymbolData &Data = *MSD.SymbolData;
- uint8_t Info = (Data.getFlags() & 0xff);
- uint8_t Other = ((Data.getFlags() & 0xf00) >> ELF_STV_Shift);
uint64_t Value = SymbolValue(Data, Layout);
uint64_t Size = 0;
const MCExpr *ESize;
const MCBinaryExpr *BE = static_cast<const MCBinaryExpr *>(ESize);
if (BE->EvaluateAsRelocatable(Res, &Layout)) {
- uint64_t AddressA = 0;
- uint64_t AddressB = 0;
- const MCSymbol &SymA = Res.getSymA()->getSymbol();
- const MCSymbol &SymB = Res.getSymB()->getSymbol();
-
- if (SymA.isDefined()) {
- MCSymbolData &A = Layout.getAssembler().getSymbolData(SymA);
- AddressA = Layout.getSymbolAddress(&A);
- }
-
- if (SymB.isDefined()) {
- MCSymbolData &B = Layout.getAssembler().getSymbolData(SymB);
- AddressB = Layout.getSymbolAddress(&B);
- }
-
- Size = AddressA - AddressB;
+ 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();
}
// 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);
// Write the symbol table entries.
LastLocalSymbolIndex = LocalSymbolData.size() + 1;
for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i) {
ELFSymbolData &MSD = LocalSymbolData[i];
- WriteSymbol(F, MSD, Layout);
+ WriteSymbol(SymtabF, ShndxF, MSD, Layout);
}
// Write out a symbol table entry for each regular section.
- unsigned Index = 1;
- for (MCAssembler::const_iterator it = Asm.begin();
- Index <= NumRegularSections; ++it, ++Index) {
+ for (MCAssembler::const_iterator i = Asm.begin(), e = Asm.end(); i != e;
+ ++i) {
const MCSectionELF &Section =
- static_cast<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)
continue;
- WriteSymbolEntry(F, 0, ELF::STT_SECTION, 0, 0, ELF::STV_DEFAULT, Index);
+ WriteSymbolEntry(SymtabF, ShndxF, 0, ELF::STT_SECTION, 0, 0,
+ ELF::STV_DEFAULT, SectionIndexMap.lookup(&Section), false);
LastLocalSymbolIndex++;
}
for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i) {
ELFSymbolData &MSD = ExternalSymbolData[i];
MCSymbolData &Data = *MSD.SymbolData;
- assert((Data.getFlags() & ELF_STB_Global) &&
- "External symbol requires STB_GLOBAL flag");
- WriteSymbol(F, MSD, Layout);
+ assert(((Data.getFlags() & ELF_STB_Global) ||
+ (Data.getFlags() & ELF_STB_Weak)) &&
+ "External symbol requires STB_GLOBAL or STB_WEAK flag");
+ WriteSymbol(SymtabF, ShndxF, MSD, Layout);
if (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);
+ WriteSymbol(SymtabF, ShndxF, MSD, Layout);
if (GetBinding(Data) == ELF::STB_LOCAL)
LastLocalSymbolIndex++;
}
const MCSectionELF &Section =
static_cast<const MCSectionELF&>(Symbol.getSection());
- if (Section.getFlags() & MCSectionELF::SHF_MERGE)
- return Target.getConstant() != 0;
-
if (SD.isExternal())
return true;
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_PLT ||
+ Kind == MCSymbolRefExpr::VK_GOTPCREL ||
+ Kind == MCSymbolRefExpr::VK_GOTOFF))
return true;
+ if (Section.getFlags() & MCSectionELF::SHF_MERGE)
+ return Target.getConstant() != 0;
+
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 &Symbol = Target.getSymA()->getSymbol();
+ const MCSymbol &ASymbol = AliasedSymbol(Symbol);
+ const MCSymbol *RenamedP = Renames.lookup(&Symbol);
+ if (!RenamedP)
+ RenamedP = &ASymbol;
+ const MCSymbol &Renamed = *RenamedP;
bool IsPCRel = isFixupKindX86PCRel(Fixup.getKind());
if (!Target.isAbsolute()) {
- Symbol = &Target.getSymA()->getSymbol();
- MCSymbolData &SD = Asm.getSymbolData(*Symbol);
+ MCSymbolData &SD = Asm.getSymbolData(Symbol);
MCFragment *F = SD.getFragment();
if (const MCSymbolRefExpr *RefB = Target.getSymB()) {
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();
// Offset of the symbol in the section
Value += Layout.getSymbolAddress(&SD) - Layout.getSectionAddress(FSD);
} else {
- UsedInReloc.insert(Symbol);
+ if (Asm.getSymbolData(Symbol).getFlags() & ELF_Other_Weakref)
+ WeakrefUsedInReloc.insert(&Renamed);
+ else
+ UsedInReloc.insert(&Renamed);
Index = -1;
}
Addend = Value;
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:
+ case MCSymbolRefExpr::VK_GOTPCREL:
Type = ELF::R_X86_64_GOTPCREL;
break;
- default:
- llvm_unreachable("Unimplemented");
+ case MCSymbolRefExpr::VK_GOTTPOFF:
+ Type = ELF::R_X86_64_GOTTPOFF;
+ break;
+ case MCSymbolRefExpr::VK_TLSGD:
+ Type = ELF::R_X86_64_TLSGD;
+ break;
+ case MCSymbolRefExpr::VK_TLSLD:
+ Type = ELF::R_X86_64_TLSLD;
+ break;
}
} else {
switch ((unsigned)Fixup.getKind()) {
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 llvm::MCSymbolRefExpr::VK_GOTPCREL:
+ case MCSymbolRefExpr::VK_GOTPCREL:
Type = ELF::R_X86_64_GOTPCREL;
break;
- default:
- llvm_unreachable("Unimplemented");
+ case MCSymbolRefExpr::VK_TPOFF:
+ Type = ELF::R_X86_64_TPOFF32;
+ break;
+ case MCSymbolRefExpr::VK_DTPOFF:
+ Type = ELF::R_X86_64_DTPOFF32;
+ break;
}
break;
case FK_Data_4:
}
} else {
if (IsPCRel) {
- Type = ELF::R_386_PC32;
+ 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: Type = ELF::R_386_32; break;
+ case FK_Data_4:
+ switch (Modifier) {
+ default:
+ llvm_unreachable("Unimplemented");
+ case MCSymbolRefExpr::VK_None:
+ Type = ELF::R_386_32;
+ break;
+ case MCSymbolRefExpr::VK_GOT:
+ Type = ELF::R_386_GOT32;
+ break;
+ case MCSymbolRefExpr::VK_GOTOFF:
+ Type = ELF::R_386_GOTOFF;
+ break;
+ case MCSymbolRefExpr::VK_TLSGD:
+ Type = ELF::R_386_TLS_GD;
+ break;
+ case MCSymbolRefExpr::VK_TPOFF:
+ Type = ELF::R_386_TLS_LE_32;
+ break;
+ case MCSymbolRefExpr::VK_INDNTPOFF:
+ Type = ELF::R_386_TLS_IE;
+ break;
+ case MCSymbolRefExpr::VK_NTPOFF:
+ Type = ELF::R_386_TLS_LE;
+ break;
+ case MCSymbolRefExpr::VK_GOTNTPOFF:
+ Type = ELF::R_386_TLS_GOTIE;
+ break;
+ case MCSymbolRefExpr::VK_TLSLDM:
+ Type = ELF::R_386_TLS_LDM;
+ break;
+ case MCSymbolRefExpr::VK_DTPOFF:
+ Type = ELF::R_386_TLS_LDO_32;
+ break;
+ }
+ break;
case FK_Data_2: Type = ELF::R_386_16; break;
case X86::reloc_pcrel_1byte:
case FK_Data_1: Type = ELF::R_386_8; break;
}
}
- if (RelocNeedsGOT(Type))
+ if (RelocNeedsGOT(Modifier))
NeedsGOT = true;
ELFRelocationEntry ERE;
ERE.Index = Index;
ERE.Type = Type;
- ERE.Symbol = Symbol;
+ ERE.Symbol = &Renamed;
ERE.r_offset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
}
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 Used, bool Renamed) {
+ if (Data.getFlags() & ELF_Other_Weakref)
+ return false;
+
+ if (Used)
+ return true;
+
+ if (Renamed)
+ return false;
+
const MCSymbol &Symbol = Data.getSymbol();
+
+ if (Symbol.getName() == "_GLOBAL_OFFSET_TABLE_")
+ return true;
+
+ const MCSymbol &A = AliasedSymbol(Symbol);
+ if (!A.isVariable() && A.isUndefined() && !Data.isCommon())
+ return false;
+
if (!Asm.isSymbolLinkerVisible(Symbol) && !Symbol.isUndefined())
return false;
- if (!Used && Symbol.isTemporary())
+ if (Symbol.isTemporary())
return false;
return true;
return true;
}
-void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) {
+void ELFObjectWriter::ComputeIndexMap(MCAssembler &Asm,
+ SectionIndexMapTy &SectionIndexMap) {
+ 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)
+ continue;
+ SectionIndexMap[&Section] = Index++;
+ }
+}
+
+void ELFObjectWriter::ComputeSymbolTable(MCAssembler &Asm,
+ const SectionIndexMapTy &SectionIndexMap) {
// FIXME: Is this the correct place to do this?
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);
}
// 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;
+ int NumRegularSections = Asm.size();
// Index 0 is always the empty string.
StringMap<uint64_t> StringIndexMap;
StringTable += '\x00';
- // Add the data for local symbols.
+ // 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);
+ if (!isInSymtab(Asm, *it, Used || WeakrefUsed,
+ Renames.count(&Symbol)))
continue;
- if (!isLocal(*it))
- continue;
-
- uint64_t &Entry = StringIndexMap[Symbol.getName()];
- if (!Entry) {
- Entry = StringTable.size();
- StringTable += Symbol.getName();
- StringTable += '\x00';
- }
-
ELFSymbolData MSD;
MSD.SymbolData = it;
- MSD.StringIndex = Entry;
+ bool Local = isLocal(*it);
+ const MCSymbol &RefSymbol = AliasedSymbol(Symbol);
- if (Symbol.isAbsolute()) {
+ if (RefSymbol.isUndefined() && !Used && WeakrefUsed)
+ SetBinding(*it, ELF::STB_WEAK);
+
+ if (it->isCommon()) {
+ assert(!Local);
+ MSD.SectionIndex = ELF::SHN_COMMON;
+ } else if (Symbol.isAbsolute() || RefSymbol.isVariable()) {
MSD.SectionIndex = ELF::SHN_ABS;
- LocalSymbolData.push_back(MSD);
+ } else if (RefSymbol.isUndefined()) {
+ MSD.SectionIndex = ELF::SHN_UNDEF;
} else {
- const MCSymbol *SymbolP = &Symbol;
- if (Symbol.isVariable()) {
- const MCExpr *Value = Symbol.getVariableValue();
- assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented");
- const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value);
- SymbolP = &Ref->getSymbol();
- }
- MSD.SectionIndex = SectionIndexMap.lookup(&SymbolP->getSection());
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(RefSymbol.getSection());
+ MSD.SectionIndex = SectionIndexMap.lookup(&Section);
+ if (MSD.SectionIndex >= ELF::SHN_LORESERVE)
+ NeedsSymtabShndx = true;
assert(MSD.SectionIndex && "Invalid section index!");
- LocalSymbolData.push_back(MSD);
}
- }
-
- // Now add non-local symbols.
- for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
- ie = Asm.symbol_end(); it != ie; ++it) {
- const MCSymbol &Symbol = it->getSymbol();
-
- if (!isInSymtab(Asm, *it, UsedInReloc.count(&Symbol)))
- continue;
- if (isLocal(*it))
- continue;
+ // The @@@ in symbol version is replaced with @ in undefined symbols and
+ // @@ in defined ones.
+ StringRef Name = Symbol.getName();
+ SmallString<32> Buf;
+
+ size_t Pos = Name.find("@@@");
+ if (Pos != StringRef::npos) {
+ Buf += Name.substr(0, Pos);
+ unsigned Skip = MSD.SectionIndex == ELF::SHN_UNDEF ? 2 : 1;
+ Buf += Name.substr(Pos + Skip);
+ Name = Buf;
+ }
- uint64_t &Entry = StringIndexMap[Symbol.getName()];
+ uint64_t &Entry = StringIndexMap[Name];
if (!Entry) {
Entry = StringTable.size();
- StringTable += Symbol.getName();
+ StringTable += Name;
StringTable += '\x00';
}
-
- ELFSymbolData MSD;
- MSD.SymbolData = it;
MSD.StringIndex = Entry;
-
- // FIXME: There is duplicated code with the local case.
- if (it->isCommon()) {
- MSD.SectionIndex = ELF::SHN_COMMON;
- ExternalSymbolData.push_back(MSD);
- } else if (Symbol.isVariable()) {
- const MCExpr *Value = Symbol.getVariableValue();
- assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented");
- const MCSymbolRefExpr *Ref = static_cast<const MCSymbolRefExpr*>(Value);
- const MCSymbol &RefSymbol = Ref->getSymbol();
- if (RefSymbol.isDefined()) {
- MSD.SectionIndex = SectionIndexMap.lookup(&RefSymbol.getSection());
- assert(MSD.SectionIndex && "Invalid section index!");
- ExternalSymbolData.push_back(MSD);
- }
- } else if (Symbol.isUndefined()) {
- MSD.SectionIndex = ELF::SHN_UNDEF;
- // FIXME: Undefined symbols are global, but this is the first place we
- // are able to set it.
- if (GetBinding(*it) == ELF::STB_LOCAL)
- SetBinding(*it, ELF::STB_GLOBAL);
+ if (MSD.SectionIndex == ELF::SHN_UNDEF)
UndefinedSymbolData.push_back(MSD);
- } else if (Symbol.isAbsolute()) {
- MSD.SectionIndex = ELF::SHN_ABS;
- ExternalSymbolData.push_back(MSD);
- } else {
- MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
- assert(MSD.SectionIndex && "Invalid section index!");
+ else if (Local)
+ LocalSymbolData.push_back(MSD);
+ else
ExternalSymbolData.push_back(MSD);
- }
}
// Symbols are required to be in lexicographic order.
// Set the symbol indices. Local symbols must come before all other
// symbols with non-local bindings.
- Index = 0;
+ unsigned Index = 1;
for (unsigned i = 0, e = LocalSymbolData.size(); i != e; ++i)
LocalSymbolData[i].SymbolData->setIndex(Index++);
+
+ Index += NumRegularSections;
+
for (unsigned i = 0, e = ExternalSymbolData.size(); i != e; ++i)
ExternalSymbolData[i].SymbolData->setIndex(Index++);
for (unsigned i = 0, e = UndefinedSymbolData.size(); i != e; ++i)
UndefinedSymbolData[i].SymbolData->setIndex(Index++);
}
-void ELFObjectWriterImpl::WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout,
- const MCSectionData &SD) {
+void ELFObjectWriter::WriteRelocation(MCAssembler &Asm, MCAsmLayout &Layout,
+ const MCSectionData &SD) {
if (!Relocations[&SD].empty()) {
MCContext &Ctx = Asm.getContext();
- const MCSection *RelaSection;
+ const MCSectionELF *RelaSection;
const MCSectionELF &Section =
static_cast<const MCSectionELF&>(SD.getSection());
RelaSection = Ctx.getELFSection(RelaSectionName, HasRelocationAddend ?
ELF::SHT_RELA : ELF::SHT_REL, 0,
SectionKind::getReadOnly(),
- false, EntrySize);
+ EntrySize, "");
MCSectionData &RelaSD = Asm.getOrCreateSectionData(*RelaSection);
RelaSD.setAlignment(Is64Bit ? 8 : 4);
WriteRelocationsFragment(Asm, F, &SD);
- Asm.AddSectionToTheEnd(*Writer, RelaSD, Layout);
+ Asm.AddSectionToTheEnd(*this, RelaSD, Layout);
}
}
-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());
else
entry.Index += LocalSymbolData.size() + 1;
if (Is64Bit) {
- char buf[8];
-
- String64(buf, entry.r_offset);
- F->getContents() += StringRef(buf, 8);
+ String64(*F, entry.r_offset);
struct ELF::Elf64_Rela ERE64;
ERE64.setSymbolAndType(entry.Index, entry.Type);
- String64(buf, ERE64.r_info);
- F->getContents() += StringRef(buf, 8);
+ String64(*F, ERE64.r_info);
- if (HasRelocationAddend) {
- String64(buf, entry.r_addend);
- F->getContents() += StringRef(buf, 8);
- }
+ 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) {
+void ELFObjectWriter::CreateMetadataSections(MCAssembler &Asm,
+ MCAsmLayout &Layout,
+ const SectionIndexMapTy &SectionIndexMap) {
MCContext &Ctx = Asm.getContext();
MCDataFragment *F;
- const MCSection *SymtabSection;
unsigned EntrySize = Is64Bit ? ELF::SYMENTRY_SIZE64 : ELF::SYMENTRY_SIZE32;
- unsigned NumRegularSections = Asm.size();
-
// 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);
+ SymbolTableIndex = Asm.size();
+
+ MCSectionData *SymtabShndxSD = NULL;
+
+ if (NeedsSymtabShndx) {
+ const MCSectionELF *SymtabShndxSection =
+ Ctx.getELFSection(".symtab_shndx", ELF::SHT_SYMTAB_SHNDX, 0,
+ SectionKind::getReadOnly(), 4, "");
+ SymtabShndxSD = &Asm.getOrCreateSectionData(*SymtabShndxSection);
+ SymtabShndxSD->setAlignment(4);
+ }
const MCSection *StrtabSection;
StrtabSection = Ctx.getELFSection(".strtab", ELF::SHT_STRTAB, 0,
- SectionKind::getReadOnly(), false);
+ SectionKind::getReadOnly());
MCSectionData &StrtabSD = Asm.getOrCreateSectionData(*StrtabSection);
StrtabSD.setAlignment(1);
StringTableIndex = Asm.size();
// 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);
+ Asm.AddSectionToTheEnd(*this, *SymtabShndxSD, Layout);
+ }
+ WriteSymbolTable(F, ShndxF, Asm, Layout, SectionIndexMap);
+ Asm.AddSectionToTheEnd(*this, SymtabSD, Layout);
F = new MCDataFragment(&StrtabSD);
F->getContents().append(StringTable.begin(), StringTable.end());
- Asm.AddSectionToTheEnd(*Writer, StrtabSD, Layout);
+ Asm.AddSectionToTheEnd(*this, StrtabSD, Layout);
F = new MCDataFragment(&ShstrtabSD);
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.
+ StringRef Name = Section.getSectionName();
+ if (SecStringMap.count(Name)) {
+ SectionStringTableIndex[&Section] = SecStringMap[Name];
+ 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;
+ SecStringMap[Name] = Index;
- Index += Section.getSectionName().size() + 1;
- F->getContents() += Section.getSectionName();
+ Index += Name.size() + 1;
+ F->getContents() += Name;
F->getContents() += '\x00';
}
- Asm.AddSectionToTheEnd(*Writer, ShstrtabSD, Layout);
+ Asm.AddSectionToTheEnd(*this, ShstrtabSD, Layout);
}
-bool ELFObjectWriterImpl::IsFixupFullyResolved(const MCAssembler &Asm,
- const MCValue Target,
- bool IsPCRel,
- const MCFragment *DF) const {
+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;
return !SectionB && BaseSection == SectionA;
}
-void ELFObjectWriterImpl::WriteObject(MCAssembler &Asm,
- const MCAsmLayout &Layout) {
+void ELFObjectWriter::CreateGroupSections(MCAssembler &Asm,
+ MCAsmLayout &Layout,
+ GroupMapTy &GroupMap) {
+ typedef DenseMap<const MCSymbol*, const MCSectionELF*> RevGroupMapTy;
+ // Build the groups
+ RevGroupMapTy 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))
+ continue;
+
+ const MCSymbol *SignatureSymbol = Section.getGroup();
+ Asm.getOrCreateSymbolData(*SignatureSymbol);
+ const MCSectionELF *&Group = Groups[SignatureSymbol];
+ if (!Group) {
+ Group = Asm.getContext().CreateELFGroupSection();
+ MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
+ Data.setAlignment(4);
+ MCDataFragment *F = new MCDataFragment(&Data);
+ String32(*F, ELF::GRP_COMDAT);
+ }
+ GroupMap[Group] = SignatureSymbol;
+ }
+
+ // Add sections to the groups
+ unsigned Index = 1;
+ unsigned NumGroups = Groups.size();
+ for (MCAssembler::const_iterator it = Asm.begin(), ie = Asm.end();
+ it != ie; ++it, ++Index) {
+ const MCSectionELF &Section =
+ static_cast<const MCSectionELF&>(it->getSection());
+ if (!(Section.getFlags() & MCSectionELF::SHF_GROUP))
+ continue;
+ const MCSectionELF *Group = Groups[Section.getGroup()];
+ MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
+ // FIXME: we could use the previous fragment
+ MCDataFragment *F = new MCDataFragment(&Data);
+ String32(*F, NumGroups + Index);
+ }
+
+ for (RevGroupMapTy::const_iterator i = Groups.begin(), e = Groups.end();
+ i != e; ++i) {
+ const MCSectionELF *Group = i->second;
+ MCSectionData &Data = Asm.getOrCreateSectionData(*Group);
+ Asm.AddSectionToTheEnd(*this, Data, Layout);
+ }
+}
+
+void ELFObjectWriter::WriteSection(MCAssembler &Asm,
+ const SectionIndexMapTy &SectionIndexMap,
+ uint32_t GroupSymbolIndex,
+ uint64_t Offset, uint64_t Size,
+ uint64_t Alignment,
+ const MCSectionELF &Section) {
+ uint64_t sh_link = 0;
+ uint64_t sh_info = 0;
+
+ switch(Section.getType()) {
+ case ELF::SHT_DYNAMIC:
+ sh_link = SectionStringTableIndex[&Section];
+ sh_info = 0;
+ break;
+
+ case ELF::SHT_REL:
+ case ELF::SHT_RELA: {
+ const MCSectionELF *SymtabSection;
+ const MCSectionELF *InfoSection;
+ SymtabSection = Asm.getContext().getELFSection(".symtab", ELF::SHT_SYMTAB,
+ 0,
+ SectionKind::getReadOnly());
+ sh_link = SectionIndexMap.lookup(SymtabSection);
+ assert(sh_link && ".symtab not found");
+
+ // Remove ".rel" and ".rela" prefixes.
+ unsigned SecNameLen = (Section.getType() == ELF::SHT_REL) ? 4 : 5;
+ StringRef SectionName = Section.getSectionName().substr(SecNameLen);
+
+ InfoSection = Asm.getContext().getELFSection(SectionName,
+ ELF::SHT_PROGBITS, 0,
+ SectionKind::getReadOnly());
+ sh_info = SectionIndexMap.lookup(InfoSection);
+ break;
+ }
+
+ 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_NULL:
+ case ELF::SHT_ARM_ATTRIBUTES:
+ // 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;
+ }
+
+ WriteSecHdrEntry(SectionStringTableIndex[&Section], Section.getType(),
+ Section.getFlags(), 0, Offset, Size, sh_link, sh_info,
+ Alignment, Section.getEntrySize());
+}
+
+void ELFObjectWriter::WriteObject(MCAssembler &Asm,
+ const MCAsmLayout &Layout) {
+ GroupMapTy GroupMap;
+ CreateGroupSections(Asm, const_cast<MCAsmLayout&>(Layout), GroupMap);
+
+ SectionIndexMapTy SectionIndexMap;
+
+ ComputeIndexMap(Asm, SectionIndexMap);
+
// Compute symbol table information.
- ComputeSymbolTable(Asm);
+ ComputeSymbolTable(Asm, SectionIndexMap);
CreateMetadataSections(const_cast<MCAssembler&>(Asm),
- const_cast<MCAsmLayout&>(Layout));
+ const_cast<MCAsmLayout&>(Layout),
+ SectionIndexMap);
+
+ // Update to include the metadata sections.
+ ComputeIndexMap(Asm, SectionIndexMap);
// Add 1 for the null section.
unsigned NumSections = Asm.size() + 1;
uint64_t HeaderSize = Is64Bit ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr);
uint64_t FileOff = HeaderSize;
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- const MCSectionData &SD = *it;
+ 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) {
+ const MCSectionELF &Section = *Sections[i];
+ const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
FileOff = RoundUpToAlignment(FileOff, SD.getAlignment());
// ... then all of the sections ...
DenseMap<const MCSection*, uint64_t> SectionOffsetMap;
- DenseMap<const MCSection*, uint8_t> SectionIndexMap;
-
- unsigned Index = 1;
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it) {
- const MCSectionData &SD = *it;
+ for (unsigned i = 1; i < NumSections; ++i) {
+ const MCSectionELF &Section = *Sections[i];
+ const MCSectionData &SD = Asm.getOrCreateSectionData(Section);
uint64_t Padding = OffsetToAlignment(FileOff, SD.getAlignment());
WriteZeros(Padding);
FileOff += Padding;
// Remember the offset into the file for this section.
- SectionOffsetMap[&it->getSection()] = FileOff;
- SectionIndexMap[&it->getSection()] = Index++;
+ SectionOffsetMap[&Section] = FileOff;
FileOff += Layout.getSectionFileSize(&SD);
- Asm.WriteSectionData(it, Layout, Writer);
+ Asm.WriteSectionData(&SD, Layout, this);
}
uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment);
// Should we align the section header table?
//
// Null section first.
- WriteSecHdrEntry(0, 0, 0, 0, 0, 0, 0, 0, 0, 0);
-
- 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 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;
- }
-
- case ELF::SHT_SYMTAB:
- case ELF::SHT_DYNSYM:
- sh_link = StringTableIndex;
- sh_info = LastLocalSymbolIndex;
- break;
-
- case ELF::SHT_PROGBITS:
- case ELF::SHT_STRTAB:
- case ELF::SHT_NOBITS:
- case ELF::SHT_NULL:
- // Nothing to do.
- break;
-
- case ELF::SHT_HASH:
- case ELF::SHT_GROUP:
- case ELF::SHT_SYMTAB_SHNDX:
- default:
- assert(0 && "FIXME: sh_type value not supported!");
- break;
- }
+ 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 = 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]);
- WriteSecHdrEntry(SectionStringTableIndex[&it->getSection()],
- Section.getType(), Section.getFlags(),
- 0,
- SectionOffsetMap.lookup(&SD.getSection()),
- Layout.getSectionSize(&SD), sh_link,
- sh_info, SD.getAlignment(),
- Section.getEntrySize());
+ WriteSection(Asm, SectionIndexMap, GroupSymbolIndex,
+ SectionOffsetMap[&Section], Layout.getSectionSize(&SD),
+ SD.getAlignment(), Section);
}
}
-ELFObjectWriter::ELFObjectWriter(raw_ostream &OS,
- bool Is64Bit,
- Triple::OSType OSType,
- bool IsLittleEndian,
- bool HasRelocationAddend)
- : MCObjectWriter(OS, IsLittleEndian)
-{
- Impl = new ELFObjectWriterImpl(this, Is64Bit, HasRelocationAddend, OSType);
-}
-
-ELFObjectWriter::~ELFObjectWriter() {
- delete (ELFObjectWriterImpl*) Impl;
-}
-
-void ELFObjectWriter::ExecutePostLayoutBinding(MCAssembler &Asm) {
- ((ELFObjectWriterImpl*) Impl)->ExecutePostLayoutBinding(Asm);
-}
-
-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);
-}
-
-bool ELFObjectWriter::IsFixupFullyResolved(const MCAssembler &Asm,
- const MCValue Target,
- bool IsPCRel,
- const MCFragment *DF) const {
- return ((ELFObjectWriterImpl*) Impl)->IsFixupFullyResolved(Asm, Target,
- IsPCRel, DF);
-}
-
-void ELFObjectWriter::WriteObject(MCAssembler &Asm,
- const MCAsmLayout &Layout) {
- ((ELFObjectWriterImpl*) Impl)->WriteObject(Asm, Layout);
+MCObjectWriter *llvm::createELFObjectWriter(raw_ostream &OS,
+ bool Is64Bit,
+ Triple::OSType OSType,
+ uint16_t EMachine,
+ bool IsLittleEndian,
+ bool HasRelocationAddend) {
+ return new ELFObjectWriter(OS, Is64Bit, IsLittleEndian, EMachine,
+ HasRelocationAddend, OSType);
}
projects / oota-llvm.git / blobdiff