#include <vector>
using namespace llvm;
+static unsigned GetType(const MCSymbolData &SD) {
+ uint32_t Type = (SD.getFlags() & (0xf << ELF_STT_Shift)) >> ELF_STT_Shift;
+ assert(Type == ELF::STT_NOTYPE || Type == ELF::STT_OBJECT ||
+ Type == ELF::STT_FUNC || Type == ELF::STT_SECTION ||
+ Type == ELF::STT_FILE || Type == ELF::STT_COMMON ||
+ Type == ELF::STT_TLS);
+ return Type;
+}
+
+static unsigned GetBinding(const MCSymbolData &SD) {
+ uint32_t Binding = (SD.getFlags() & (0xf << ELF_STB_Shift)) >> ELF_STB_Shift;
+ assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
+ Binding == ELF::STB_WEAK);
+ return Binding;
+}
+
+static void SetBinding(MCSymbolData &SD, unsigned Binding) {
+ assert(Binding == ELF::STB_LOCAL || Binding == ELF::STB_GLOBAL ||
+ Binding == ELF::STB_WEAK);
+ uint32_t OtherFlags = SD.getFlags() & ~(0xf << ELF_STB_Shift);
+ SD.setFlags(OtherFlags | (Binding << ELF_STB_Shift));
+}
+
namespace {
class ELFObjectWriterImpl {
}
}
- static bool isFixupKindX86RIPRel(unsigned Kind) {
+ /*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
// Support lexicographic sorting.
bool operator<(const ELFSymbolData &RHS) const {
- const std::string &Name = SymbolData->getSymbol().getName();
- return Name < RHS.SymbolData->getSymbol().getName();
+ 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();
}
};
raw_ostream &OS;
- // This holds the current offset into the object file.
- size_t FileOff;
-
unsigned Is64Bit : 1;
bool HasRelocationAddend;
+ Triple::OSType OSType;
+
// This holds the symbol table index of the last local symbol.
unsigned LastLocalSymbolIndex;
// This holds the .strtab section index.
public:
ELFObjectWriterImpl(ELFObjectWriter *_Writer, bool _Is64Bit,
- bool _HasRelAddend)
- : Writer(_Writer), OS(Writer->getStream()), FileOff(0),
- Is64Bit(_Is64Bit), HasRelocationAddend(_HasRelAddend) {
+ bool _HasRelAddend, Triple::OSType _OSType)
+ : Writer(_Writer), OS(Writer->getStream()),
+ Is64Bit(_Is64Bit), HasRelocationAddend(_HasRelAddend),
+ OSType(_OSType) {
}
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 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 WriteBytes(StringRef Str, unsigned ZeroFillSize = 0) {
+ // Writer->WriteBytes(Str, ZeroFillSize);
+ //}
void WriteWord(uint64_t W) {
- if (Is64Bit) {
+ if (Is64Bit)
Writer->Write64(W);
- } else {
+ else
Writer->Write32(W);
- }
}
void String8(char *buf, uint8_t Value) {
}
void StringLE32(char *buf, uint32_t Value) {
- buf[0] = char(Value >> 0);
- buf[1] = char(Value >> 8);
- buf[2] = char(Value >> 16);
- buf[3] = char(Value >> 24);
+ StringLE16(buf, uint16_t(Value >> 0));
+ StringLE16(buf + 2, uint16_t(Value >> 16));
}
void StringLE64(char *buf, uint64_t Value) {
- buf[0] = char(Value >> 0);
- buf[1] = char(Value >> 8);
- buf[2] = char(Value >> 16);
- buf[3] = char(Value >> 24);
- buf[4] = char(Value >> 32);
- buf[5] = char(Value >> 40);
- buf[6] = char(Value >> 48);
- buf[7] = char(Value >> 56);
+ StringLE32(buf, uint32_t(Value >> 0));
+ StringLE32(buf + 4, uint32_t(Value >> 32));
}
void StringBE16(char *buf ,uint16_t Value) {
}
void StringBE32(char *buf, uint32_t Value) {
- buf[0] = char(Value >> 24);
- buf[1] = char(Value >> 16);
- buf[2] = char(Value >> 8);
- buf[3] = char(Value >> 0);
+ StringBE16(buf, uint16_t(Value >> 16));
+ StringBE16(buf + 2, uint16_t(Value >> 0));
}
void StringBE64(char *buf, uint64_t Value) {
- buf[0] = char(Value >> 56);
- buf[1] = char(Value >> 48);
- buf[2] = char(Value >> 40);
- buf[3] = char(Value >> 32);
- buf[4] = char(Value >> 24);
- buf[5] = char(Value >> 16);
- buf[6] = char(Value >> 8);
- buf[7] = char(Value >> 0);
+ StringBE32(buf, uint32_t(Value >> 32));
+ StringBE32(buf + 4, uint32_t(Value >> 0));
}
void String16(char *buf, uint16_t Value) {
const MCAsmLayout &Layout);
void WriteSymbolTable(MCDataFragment *F, const MCAssembler &Asm,
- const MCAsmLayout &Layout);
+ const MCAsmLayout &Layout,
+ unsigned NumRegularSections);
void RecordRelocation(const MCAssembler &Asm, const MCAsmLayout &Layout,
const MCFragment *Fragment, const MCFixup &Fixup,
MCValue Target, uint64_t &FixedValue);
- // XXX-PERF: this should be cached
- uint64_t getNumOfLocalSymbols(const MCAssembler &Asm) {
- std::vector<const MCSymbol*> Local;
-
- uint64_t Index = 0;
- for (MCAssembler::const_symbol_iterator it = Asm.symbol_begin(),
- ie = Asm.symbol_end(); it != ie; ++it) {
- const MCSymbol &Symbol = it->getSymbol();
-
- // Ignore non-linker visible symbols.
- if (!Asm.isSymbolLinkerVisible(Symbol))
- continue;
-
- if (it->isExternal() || Symbol.isUndefined())
- continue;
-
- Index++;
- }
-
- return Index;
- }
-
- uint64_t getSymbolIndexInSymbolTable(MCAssembler &Asm, const MCSymbol *S);
+ uint64_t getSymbolIndexInSymbolTable(const MCAssembler &Asm,
+ const MCSymbol *S);
/// ComputeSymbolTable - Compute the symbol table data
///
void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout);
- void ExecutePostLayoutBinding(MCAssembler &Asm) {}
+ void ExecutePostLayoutBinding(MCAssembler &Asm) {
+ // Compute symbol table information.
+ ComputeSymbolTable(Asm);
+ }
void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags,
uint64_t Address, uint64_t Offset,
void WriteRelocationsFragment(const MCAssembler &Asm, MCDataFragment *F,
const MCSectionData *SD);
+ bool IsFixupFullyResolved(const MCAssembler &Asm,
+ const MCValue Target,
+ bool IsPCRel,
+ const MCFragment *DF) const;
+
void WriteObject(const MCAssembler &Asm, const MCAsmLayout &Layout);
};
Write8(Writer->isLittleEndian() ? ELF::ELFDATA2LSB : ELF::ELFDATA2MSB);
Write8(ELF::EV_CURRENT); // e_ident[EI_VERSION]
- Write8(ELF::ELFOSABI_LINUX); // e_ident[EI_OSABI]
+ // e_ident[EI_OSABI]
+ switch (OSType) {
+ case Triple::FreeBSD: Write8(ELF::ELFOSABI_FREEBSD); break;
+ case Triple::Linux: Write8(ELF::ELFOSABI_LINUX); break;
+ default: Write8(ELF::ELFOSABI_NONE); break;
+ }
Write8(0); // e_ident[EI_ABIVERSION]
WriteZeros(ELF::EI_NIDENT - ELF::EI_PAD);
Write16(ELF::ET_REL); // e_type
// FIXME: Make this configurable
- Write16(ELF::EM_X86_64); // e_machine = target
+ Write16(Is64Bit ? ELF::EM_X86_64 : ELF::EM_386); // e_machine = target
Write32(ELF::EV_CURRENT); // e_version
WriteWord(0); // e_entry, no entry point in .o file
WriteWord(0); // e_phoff, no program header for .o
- WriteWord(SectionDataSize + 64); // e_shoff = sec hdr table off in bytes
+ 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
}
}
+static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) {
+ if (Data.isCommon() && Data.isExternal())
+ return Data.getCommonAlignment();
+
+ const MCSymbol &Symbol = Data.getSymbol();
+ if (!Symbol.isInSection())
+ return 0;
+
+ if (!Data.isCommon() && !(Data.getFlags() & ELF_STB_Weak))
+ if (MCFragment *FF = Data.getFragment())
+ return Layout.getSymbolAddress(&Data) -
+ Layout.getSectionAddress(FF->getParent());
+
+ return 0;
+}
+
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 = 0;
+ uint64_t Value = SymbolValue(Data, Layout);
uint64_t Size = 0;
const MCExpr *ESize;
- if (Data.isCommon() && Data.isExternal())
- Value = Data.getCommonAlignment();
+ assert(!(Data.isCommon() && !Data.isExternal()));
ESize = Data.getSize();
if (Data.getSize()) {
Layout.getAssembler().getSymbolData(Res.getSymB()->getSymbol());
Size = Layout.getSymbolAddress(&A) - Layout.getSymbolAddress(&B);
- Value = Layout.getSymbolAddress(&Data);
}
} else if (ESize->getKind() == MCExpr::Constant) {
Size = static_cast<const MCConstantExpr *>(ESize)->getValue();
void ELFObjectWriterImpl::WriteSymbolTable(MCDataFragment *F,
const MCAssembler &Asm,
- const MCAsmLayout &Layout) {
+ const MCAsmLayout &Layout,
+ unsigned NumRegularSections) {
// 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");
WriteSymbol(F, MSD, Layout);
}
- // Write out a symbol table entry for each section.
- // leaving out the just added .symtab which is at
- // the very end
+ // Write out a symbol table entry for each regular section.
unsigned Index = 1;
- for (MCAssembler::const_iterator it = Asm.begin(),
- ie = Asm.end(); it != ie; ++it, ++Index) {
+ for (MCAssembler::const_iterator it = Asm.begin();
+ Index <= NumRegularSections; ++it, ++Index) {
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)
- continue;
- if (Index == Asm.size())
+ if (Section.getType() == ELF::SHT_RELA || Section.getType() == ELF::SHT_REL)
continue;
WriteSymbolEntry(F, 0, ELF::STT_SECTION, 0, 0, ELF::STV_DEFAULT, Index);
LastLocalSymbolIndex++;
assert((Data.getFlags() & ELF_STB_Global) &&
"External symbol requires STB_GLOBAL flag");
WriteSymbol(F, MSD, Layout);
- if (Data.getFlags() & ELF_STB_Local)
+ 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;
- Data.setFlags(Data.getFlags() | ELF_STB_Global);
WriteSymbol(F, MSD, Layout);
- if (Data.getFlags() & ELF_STB_Local)
+ if (GetBinding(Data) == ELF::STB_LOCAL)
LastLocalSymbolIndex++;
}
}
-// FIXME: this is currently X86_64 only
+static const MCSymbolData *getAtom(const MCSymbolData &SD) {
+ if (!SD.getFragment())
+ return 0;
+
+ return SD.getFragment()->getAtom();
+}
+
+// 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) {
- unsigned IsPCRel = isFixupKindX86PCRel(Fixup.getKind());
- ELFRelocationEntry ERE;
- struct ELF::Elf64_Rela ERE64;
-
- uint64_t FixupOffset =
- Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
- int64_t Value;
int64_t Addend = 0;
unsigned Index = 0;
- unsigned Type;
-
- Value = Target.getConstant();
+ int64_t Value = Target.getConstant();
- if (Target.isAbsolute()) {
- Type = ELF::R_X86_64_NONE;
- Index = 0;
- } else {
+ bool IsPCRel = isFixupKindX86PCRel(Fixup.getKind());
+ if (!Target.isAbsolute()) {
const MCSymbol *Symbol = &Target.getSymA()->getSymbol();
MCSymbolData &SD = Asm.getSymbolData(*Symbol);
- const MCSymbolData *Base = Asm.getAtom(Layout, &SD);
+ const MCSymbolData *Base = getAtom(SD);
+ MCFragment *F = SD.getFragment();
+
+ // Avoid relocations for cases like jumps and calls in the same file.
+ if (Symbol->isDefined() && !SD.isExternal() &&
+ IsPCRel &&
+ &Fragment->getParent()->getSection() == &Symbol->getSection()) {
+ uint64_t FixupAddr = Layout.getFragmentAddress(Fragment) + Fixup.getOffset();
+ FixedValue = Layout.getSymbolAddress(&SD) + Target.getConstant() - FixupAddr;
+ return;
+ }
if (Base) {
- Index = getSymbolIndexInSymbolTable(const_cast<MCAssembler &>(Asm), &Base->getSymbol());
- if (Base != &SD)
- Value += Layout.getSymbolAddress(&SD) - Layout.getSymbolAddress(Base);
+ if (Base != &SD) {
+ Index = F->getParent()->getOrdinal() + LocalSymbolData.size() + 1;
+
+ MCSectionData *FSD = F->getParent();
+ // Offset of the symbol in the section
+ Value += Layout.getSymbolAddress(&SD) - Layout.getSectionAddress(FSD);
+ } else
+ Index = getSymbolIndexInSymbolTable(Asm, Symbol);
Addend = Value;
- Value = 0;
+ // Compensate for the addend on i386.
+ if (Is64Bit)
+ Value = 0;
} else {
- MCFragment *F = SD.getFragment();
if (F) {
// Index of the section in .symtab against this symbol
// is being relocated + 2 (empty section + abs. symbols).
- Index = SD.getFragment()->getParent()->getOrdinal() +
- getNumOfLocalSymbols(Asm) + 1;
+ Index = F->getParent()->getOrdinal() + LocalSymbolData.size() + 1;
MCSectionData *FSD = F->getParent();
// Offset of the symbol in the section
- Addend = Layout.getSymbolAddress(&SD) - Layout.getSectionAddress(FSD);
+ Value += Layout.getSymbolAddress(&SD) - Layout.getSectionAddress(FSD);
} else {
- FixedValue = Value;
- return;
+ Index = getSymbolIndexInSymbolTable(Asm, Symbol);
}
+ Addend = Value;
+ // Compensate for the addend on i386.
+ if (Is64Bit)
+ Value = 0;
}
}
+ FixedValue = Value;
+
// determine the type of the relocation
- if (IsPCRel) {
- Type = ELF::R_X86_64_PC32;
+ unsigned Type;
+ if (Is64Bit) {
+ if (IsPCRel) {
+ Type = ELF::R_X86_64_PC32;
+ } else {
+ switch ((unsigned)Fixup.getKind()) {
+ default: llvm_unreachable("invalid fixup kind!");
+ case FK_Data_8: Type = ELF::R_X86_64_64; break;
+ case X86::reloc_pcrel_4byte:
+ case FK_Data_4:
+ // check that the offset fits within a signed long
+ if (Target.getConstant() < 0) {
+ assert(isInt<32>(Target.getConstant()));
+ Type = ELF::R_X86_64_32S;
+ } else {
+ assert(isUInt<32>(Target.getConstant()));
+ Type = ELF::R_X86_64_32;
+ }
+ break;
+ case FK_Data_2: Type = ELF::R_X86_64_16; break;
+ case X86::reloc_pcrel_1byte:
+ case FK_Data_1: Type = ELF::R_X86_64_8; break;
+ }
+ }
} else {
- switch ((unsigned)Fixup.getKind()) {
- default: llvm_unreachable("invalid fixup kind!");
- case FK_Data_8: Type = ELF::R_X86_64_64; break;
- case X86::reloc_pcrel_4byte:
- case FK_Data_4:
- // check that the offset fits within a signed long
- if (isInt<32>(Target.getConstant()))
- Type = ELF::R_X86_64_32S;
- else
- Type = ELF::R_X86_64_32;
- break;
- case FK_Data_2: Type = ELF::R_X86_64_16; break;
- case X86::reloc_pcrel_1byte:
- case FK_Data_1:
- Type = ELF::R_X86_64_8;
- break;
+ if (IsPCRel) {
+ Type = ELF::R_386_PC32;
+ } else {
+ switch ((unsigned)Fixup.getKind()) {
+ default: llvm_unreachable("invalid fixup kind!");
+ case X86::reloc_pcrel_4byte:
+ case FK_Data_4: Type = ELF::R_386_32; break;
+ case FK_Data_2: Type = ELF::R_386_16; break;
+ case X86::reloc_pcrel_1byte:
+ case FK_Data_1: Type = ELF::R_386_8; break;
+ }
}
}
- FixedValue = Value;
+ ELFRelocationEntry ERE;
- ERE64.setSymbolAndType(Index, Type);
+ if (Is64Bit) {
+ struct ELF::Elf64_Rela ERE64;
+ ERE64.setSymbolAndType(Index, Type);
+ ERE.r_info = ERE64.r_info;
+ } else {
+ struct ELF::Elf32_Rela ERE32;
+ ERE32.setSymbolAndType(Index, Type);
+ ERE.r_info = ERE32.r_info;
+ }
+
+ ERE.r_offset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset();
- ERE.r_offset = FixupOffset;
- ERE.r_info = ERE64.r_info;
if (HasRelocationAddend)
ERE.r_addend = Addend;
+ else
+ ERE.r_addend = 0; // Silence compiler warning.
Relocations[Fragment->getParent()].push_back(ERE);
}
-// XXX-PERF: this should be cached
-uint64_t ELFObjectWriterImpl::getSymbolIndexInSymbolTable(MCAssembler &Asm,
- const MCSymbol *S) {
- std::vector<ELFSymbolData> Local;
- std::vector<ELFSymbolData> External;
- std::vector<ELFSymbolData> Undefined;
-
- for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
- ie = Asm.symbol_end(); it != ie; ++it) {
- const MCSymbol &Symbol = it->getSymbol();
-
- // Ignore non-linker visible symbols.
- if (!Asm.isSymbolLinkerVisible(Symbol))
- continue;
-
- if (it->isExternal() || Symbol.isUndefined())
- continue;
-
- ELFSymbolData MSD;
- MSD.SymbolData = it;
-
- Local.push_back(MSD);
- }
- for (MCAssembler::symbol_iterator it = Asm.symbol_begin(),
- ie = Asm.symbol_end(); it != ie; ++it) {
- const MCSymbol &Symbol = it->getSymbol();
-
- // Ignore non-linker visible symbols.
- if (!Asm.isSymbolLinkerVisible(Symbol))
- continue;
-
- if (!it->isExternal() && !Symbol.isUndefined())
- continue;
-
- ELFSymbolData MSD;
- MSD.SymbolData = it;
+uint64_t
+ELFObjectWriterImpl::getSymbolIndexInSymbolTable(const MCAssembler &Asm,
+ const MCSymbol *S) {
+ MCSymbolData &SD = Asm.getSymbolData(*S);
- if (Symbol.isUndefined())
- Undefined.push_back(MSD);
- else
- External.push_back(MSD);
- }
+ // Local symbol.
+ if (!SD.isExternal() && !S->isUndefined())
+ return SD.getIndex() + /* empty symbol */ 1;
- array_pod_sort(Local.begin(), Local.end());
- array_pod_sort(External.begin(), External.end());
- array_pod_sort(Undefined.begin(), Undefined.end());
-
- for (unsigned i = 0, e = Local.size(); i != e; ++i)
- if (&Local[i].SymbolData->getSymbol() == S)
- return i + /* empty symbol */ 1;
- for (unsigned i = 0, e = External.size(); i != e; ++i)
- if (&External[i].SymbolData->getSymbol() == S)
- return i + Local.size() + Asm.size() + /* empty symbol */ 1;
- for (unsigned i = 0, e = Undefined.size(); i != e; ++i)
- if (&Undefined[i].SymbolData->getSymbol() == S)
- return i + Local.size() + External.size() + Asm.size() + /* empty symbol */ 1;
-
- llvm_unreachable("Cannot find symbol which should exist!");
+ // External or undefined symbol.
+ return SD.getIndex() + Asm.size() + /* empty symbol */ 1;
}
void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) {
const MCSymbol &Symbol = it->getSymbol();
// Ignore non-linker visible symbols.
- if (!Asm.isSymbolLinkerVisible(Symbol))
+ if (!Asm.isSymbolLinkerVisible(Symbol) && !Symbol.isUndefined())
continue;
if (!it->isExternal() && !Symbol.isUndefined())
continue;
+ if (Symbol.isVariable())
+ continue;
+
uint64_t &Entry = StringIndexMap[Symbol.getName()];
if (!Entry) {
Entry = StringTable.size();
MSD.SymbolData = it;
MSD.StringIndex = Entry;
- if (Symbol.isUndefined()) {
+ if (it->isCommon()) {
+ MSD.SectionIndex = ELF::SHN_COMMON;
+ ExternalSymbolData.push_back(MSD);
+ } else if (Symbol.isUndefined()) {
MSD.SectionIndex = ELF::SHN_UNDEF;
- // XXX: for some reason we dont Emit* this
- it->setFlags(it->getFlags() | ELF_STB_Global);
+ // 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);
UndefinedSymbolData.push_back(MSD);
} else if (Symbol.isAbsolute()) {
MSD.SectionIndex = ELF::SHN_ABS;
ExternalSymbolData.push_back(MSD);
- } else if (it->isCommon()) {
- MSD.SectionIndex = ELF::SHN_COMMON;
- ExternalSymbolData.push_back(MSD);
} else {
MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection());
assert(MSD.SectionIndex && "Invalid section index!");
static_cast<const MCSectionELF&>(SD.getSection());
const StringRef SectionName = Section.getSectionName();
- std::string RelaSectionName = ".rela";
-
+ std::string RelaSectionName = HasRelocationAddend ? ".rela" : ".rel";
RelaSectionName += SectionName;
- unsigned EntrySize = Is64Bit ? ELF::SYMENTRY_SIZE64 : ELF::SYMENTRY_SIZE32;
- RelaSection = Ctx.getELFSection(RelaSectionName, ELF::SHT_RELA, 0,
+ unsigned EntrySize;
+ if (HasRelocationAddend)
+ EntrySize = Is64Bit ? sizeof(ELF::Elf64_Rela) : sizeof(ELF::Elf32_Rela);
+ 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(),
false, EntrySize);
MCSectionData &RelaSD = Asm.getOrCreateSectionData(*RelaSection);
- RelaSD.setAlignment(1);
+ RelaSD.setAlignment(Is64Bit ? 8 : 4);
MCDataFragment *F = new MCDataFragment(&RelaSD);
WriteRelocationsFragment(Asm, F, &SD);
- Asm.AddSectionToTheEnd(RelaSD, Layout);
+ Asm.AddSectionToTheEnd(*Writer, RelaSD, Layout);
}
}
for (unsigned i = 0, e = Relocs.size(); i != e; ++i) {
ELFRelocationEntry entry = Relocs[e - i - 1];
- unsigned WordSize = Is64Bit ? 8 : 4;
- F->getContents() += StringRef((const char *)&entry.r_offset, WordSize);
- F->getContents() += StringRef((const char *)&entry.r_info, WordSize);
+ if (Is64Bit) {
+ char buf[8];
- if (HasRelocationAddend)
- F->getContents() += StringRef((const char *)&entry.r_addend, WordSize);
+ String64(buf, entry.r_offset);
+ F->getContents() += StringRef(buf, 8);
+
+ String64(buf, entry.r_info);
+ F->getContents() += StringRef(buf, 8);
+
+ if (HasRelocationAddend) {
+ String64(buf, entry.r_addend);
+ F->getContents() += StringRef(buf, 8);
+ }
+ } else {
+ char buf[4];
+
+ String32(buf, entry.r_offset);
+ F->getContents() += StringRef(buf, 4);
+
+ String32(buf, entry.r_info);
+ F->getContents() += StringRef(buf, 4);
+
+ if (HasRelocationAddend) {
+ String32(buf, entry.r_addend);
+ F->getContents() += StringRef(buf, 4);
+ }
+ }
}
}
MCContext &Ctx = Asm.getContext();
MCDataFragment *F;
- WriteRelocations(Asm, Layout);
-
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);
+ MCSectionData &ShstrtabSD = Asm.getOrCreateSectionData(*ShstrtabSection);
+ ShstrtabSD.setAlignment(1);
+ ShstrtabIndex = Asm.size();
+
SymtabSection = Ctx.getELFSection(".symtab", ELF::SHT_SYMTAB, 0,
SectionKind::getReadOnly(),
false, EntrySize);
-
MCSectionData &SymtabSD = Asm.getOrCreateSectionData(*SymtabSection);
-
SymtabSD.setAlignment(Is64Bit ? 8 : 4);
- F = new MCDataFragment(&SymtabSD);
-
- // Symbol table
- WriteSymbolTable(F, Asm, Layout);
- Asm.AddSectionToTheEnd(SymtabSD, Layout);
-
const MCSection *StrtabSection;
StrtabSection = Ctx.getELFSection(".strtab", ELF::SHT_STRTAB, 0,
SectionKind::getReadOnly(), false);
-
MCSectionData &StrtabSD = Asm.getOrCreateSectionData(*StrtabSection);
StrtabSD.setAlignment(1);
-
- // FIXME: This isn't right. If the sections get rearranged this will
- // be wrong. We need a proper lookup.
StringTableIndex = Asm.size();
- F = new MCDataFragment(&StrtabSD);
- F->getContents().append(StringTable.begin(), StringTable.end());
- Asm.AddSectionToTheEnd(StrtabSD, Layout);
+ WriteRelocations(Asm, Layout);
- const MCSection *ShstrtabSection;
- ShstrtabSection = Ctx.getELFSection(".shstrtab", ELF::SHT_STRTAB, 0,
- SectionKind::getReadOnly(), false);
+ // Symbol table
+ F = new MCDataFragment(&SymtabSD);
+ WriteSymbolTable(F, Asm, Layout, NumRegularSections);
+ Asm.AddSectionToTheEnd(*Writer, SymtabSD, Layout);
- MCSectionData &ShstrtabSD = Asm.getOrCreateSectionData(*ShstrtabSection);
- ShstrtabSD.setAlignment(1);
+ F = new MCDataFragment(&StrtabSD);
+ F->getContents().append(StringTable.begin(), StringTable.end());
+ Asm.AddSectionToTheEnd(*Writer, StrtabSD, Layout);
F = new MCDataFragment(&ShstrtabSD);
- // FIXME: This isn't right. If the sections get rearranged this will
- // be wrong. We need a proper lookup.
- ShstrtabIndex = Asm.size();
-
// Section header string table.
//
// The first entry of a string table holds a null character so skip
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.
// Remember the index into the string table so we can write it
// into the sh_name field of the section header table.
F->getContents() += '\x00';
}
- Asm.AddSectionToTheEnd(ShstrtabSD, Layout);
+ Asm.AddSectionToTheEnd(*Writer, ShstrtabSD, Layout);
+}
+
+bool ELFObjectWriterImpl::IsFixupFullyResolved(const MCAssembler &Asm,
+ const MCValue Target,
+ bool IsPCRel,
+ const MCFragment *DF) const {
+ // If this is a PCrel relocation, find the section this fixup value is
+ // relative to.
+ const MCSection *BaseSection = 0;
+ if (IsPCRel) {
+ BaseSection = &DF->getParent()->getSection();
+ assert(BaseSection);
+ }
+
+ const MCSection *SectionA = 0;
+ const MCSymbol *SymbolA = 0;
+ if (const MCSymbolRefExpr *A = Target.getSymA()) {
+ SymbolA = &A->getSymbol();
+ SectionA = &SymbolA->getSection();
+ }
+
+ const MCSection *SectionB = 0;
+ if (const MCSymbolRefExpr *B = Target.getSymB()) {
+ SectionB = &B->getSymbol().getSection();
+ }
+
+ if (!BaseSection)
+ return SectionA == SectionB;
+
+ const MCSymbolData &DataA = Asm.getSymbolData(*SymbolA);
+ if (DataA.isExternal())
+ return false;
+
+ return !SectionB && BaseSection == SectionA;
}
void ELFObjectWriterImpl::WriteObject(const MCAssembler &Asm,
const MCAsmLayout &Layout) {
- // Compute symbol table information.
- ComputeSymbolTable(const_cast<MCAssembler&>(Asm));
-
CreateMetadataSections(const_cast<MCAssembler&>(Asm),
const_cast<MCAsmLayout&>(Layout));
// Add 1 for the null section.
unsigned NumSections = Asm.size() + 1;
-
- uint64_t SectionDataSize = 0;
+ uint64_t NaturalAlignment = Is64Bit ? 8 : 4;
+ 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;
+ FileOff = RoundUpToAlignment(FileOff, SD.getAlignment());
+
// Get the size of the section in the output file (including padding).
uint64_t Size = Layout.getSectionFileSize(&SD);
- SectionDataSize += Size;
+
+ FileOff += Size;
}
+ FileOff = RoundUpToAlignment(FileOff, NaturalAlignment);
+
// Write out the ELF header ...
- WriteHeader(SectionDataSize, NumSections);
- FileOff = Is64Bit ? sizeof(ELF::Elf64_Ehdr) : sizeof(ELF::Elf32_Ehdr);
+ WriteHeader(FileOff - HeaderSize, NumSections);
+
+ FileOff = HeaderSize;
// ... 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;
+
+ 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++;
- const MCSectionData &SD = *it;
FileOff += Layout.getSectionFileSize(&SD);
Asm.WriteSectionData(it, Layout, Writer);
}
+ uint64_t Padding = OffsetToAlignment(FileOff, NaturalAlignment);
+ WriteZeros(Padding);
+ FileOff += Padding;
+
// ... and then the section header table.
// Should we align the section header table?
//
case ELF::SHT_RELA: {
const MCSection *SymtabSection;
const MCSection *InfoSection;
- StringRef SectionName;
- const MCSectionData *SymtabSD;
- const MCSectionData *InfoSD;
SymtabSection = Asm.getContext().getELFSection(".symtab", ELF::SHT_SYMTAB, 0,
SectionKind::getReadOnly(),
false);
- SymtabSD = &Asm.getSectionData(*SymtabSection);
- // we have to count the empty section in too
- sh_link = SymtabSD->getLayoutOrder() + 1;
+ sh_link = SectionIndexMap[SymtabSection];
+
+ // Remove ".rel" and ".rela" prefixes.
+ unsigned SecNameLen = (Section.getType() == ELF::SHT_REL) ? 4 : 5;
+ StringRef SectionName = Section.getSectionName().substr(SecNameLen);
- SectionName = Section.getSectionName();
- SectionName = SectionName.slice(5, SectionName.size());
InfoSection = Asm.getContext().getELFSection(SectionName,
ELF::SHT_PROGBITS, 0,
SectionKind::getReadOnly(),
false);
- InfoSD = &Asm.getSectionData(*InfoSection);
- sh_info = InfoSD->getLayoutOrder() + 1;
+ sh_info = SectionIndexMap[InfoSection];
break;
}
case ELF::SHT_PROGBITS:
case ELF::SHT_STRTAB:
case ELF::SHT_NOBITS:
+ case ELF::SHT_NULL:
// Nothing to do.
break;
WriteSecHdrEntry(SectionStringTableIndex[&it->getSection()],
Section.getType(), Section.getFlags(),
- Layout.getSectionAddress(&SD),
+ 0,
SectionOffsetMap.lookup(&SD.getSection()),
Layout.getSectionSize(&SD), sh_link,
sh_info, SD.getAlignment(),
ELFObjectWriter::ELFObjectWriter(raw_ostream &OS,
bool Is64Bit,
+ Triple::OSType OSType,
bool IsLittleEndian,
bool HasRelocationAddend)
: MCObjectWriter(OS, IsLittleEndian)
{
- Impl = new ELFObjectWriterImpl(this, Is64Bit, HasRelocationAddend);
+ Impl = new ELFObjectWriterImpl(this, Is64Bit, HasRelocationAddend, OSType);
}
ELFObjectWriter::~ELFObjectWriter() {
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(const MCAssembler &Asm,
const MCAsmLayout &Layout) {
((ELFObjectWriterImpl*) Impl)->WriteObject(Asm, Layout);
projects / oota-llvm.git / blobdiff