diff options
Diffstat (limited to 'lib/MC/ELFObjectWriter.cpp')
| -rw-r--r-- | lib/MC/ELFObjectWriter.cpp | 67 |
1 files changed, 44 insertions, 23 deletions
diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp index 6a2a6e53da..b9d2acea46 100644 --- a/lib/MC/ELFObjectWriter.cpp +++ b/lib/MC/ELFObjectWriter.cpp @@ -12,6 +12,7 @@ //===----------------------------------------------------------------------===// #include "llvm/MC/ELFObjectWriter.h" +#include "llvm/ADT/SmallPtrSet.h" #include "llvm/ADT/STLExtras.h" #include "llvm/ADT/StringMap.h" #include "llvm/ADT/Twine.h" @@ -102,7 +103,9 @@ namespace { struct ELFRelocationEntry { // Make these big enough for both 32-bit and 64-bit uint64_t r_offset; - uint64_t r_info; + int Index; + unsigned Type; + const MCSymbol *Symbol; uint64_t r_addend; // Support lexicographic sorting. @@ -111,6 +114,8 @@ namespace { } }; + SmallPtrSet<const MCSymbol *, 16> UsedInReloc; + llvm::DenseMap<const MCSectionData*, std::vector<ELFRelocationEntry> > Relocations; DenseMap<const MCSection*, uint64_t> SectionStringTableIndex; @@ -126,6 +131,8 @@ namespace { /// @} + int NumRegularSections; + ELFObjectWriter *Writer; raw_ostream &OS; @@ -262,8 +269,6 @@ namespace { void CreateMetadataSections(MCAssembler &Asm, MCAsmLayout &Layout); void ExecutePostLayoutBinding(MCAssembler &Asm) { - // Compute symbol table information. - ComputeSymbolTable(Asm); } void WriteSecHdrEntry(uint32_t Name, uint32_t Type, uint64_t Flags, @@ -279,7 +284,7 @@ namespace { bool IsPCRel, const MCFragment *DF) const; - void WriteObject(const MCAssembler &Asm, const MCAsmLayout &Layout); + void WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout); }; } @@ -526,12 +531,13 @@ void ELFObjectWriterImpl::RecordRelocation(const MCAssembler &Asm, MCValue Target, uint64_t &FixedValue) { int64_t Addend = 0; - unsigned Index = 0; + int Index = 0; int64_t Value = Target.getConstant(); + const MCSymbol *Symbol = 0; bool IsPCRel = isFixupKindX86PCRel(Fixup.getKind()); if (!Target.isAbsolute()) { - const MCSymbol *Symbol = &Target.getSymA()->getSymbol(); + Symbol = &Target.getSymA()->getSymbol(); MCSymbolData &SD = Asm.getSymbolData(*Symbol); MCFragment *F = SD.getFragment(); @@ -560,13 +566,15 @@ void ELFObjectWriterImpl::RecordRelocation(const MCAssembler &Asm, bool RelocOnSymbol = ShouldRelocOnSymbol(SD, Target); if (!RelocOnSymbol) { - Index = F->getParent()->getOrdinal() + LocalSymbolData.size() + 1; + Index = F->getParent()->getOrdinal(); MCSectionData *FSD = F->getParent(); // Offset of the symbol in the section Value += Layout.getSymbolAddress(&SD) - Layout.getSectionAddress(FSD); - } else - Index = getSymbolIndexInSymbolTable(Asm, Symbol); + } else { + UsedInReloc.insert(Symbol); + Index = -1; + } Addend = Value; // Compensate for the addend on i386. if (Is64Bit) @@ -641,15 +649,9 @@ void ELFObjectWriterImpl::RecordRelocation(const MCAssembler &Asm, ELFRelocationEntry ERE; - 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.Index = Index; + ERE.Type = Type; + ERE.Symbol = Symbol; ERE.r_offset = Layout.getFragmentOffset(Fragment) + Fixup.getOffset(); @@ -671,11 +673,12 @@ ELFObjectWriterImpl::getSymbolIndexInSymbolTable(const MCAssembler &Asm, return SD.getIndex() + /* empty symbol */ 1; // External or undefined symbol. - return SD.getIndex() + Asm.size() + /* empty symbol */ 1; + return SD.getIndex() + NumRegularSections + /* empty symbol */ 1; } void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) { // Build section lookup table. + NumRegularSections = Asm.size(); DenseMap<const MCSection*, uint8_t> SectionIndexMap; unsigned Index = 1; for (MCAssembler::iterator it = Asm.begin(), @@ -698,6 +701,9 @@ void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) { if (it->isExternal() || Symbol.isUndefined()) continue; + if (Symbol.isTemporary() && !UsedInReloc.count(&Symbol)) + continue; + uint64_t &Entry = StringIndexMap[Symbol.getName()]; if (!Entry) { Entry = StringTable.size(); @@ -734,6 +740,10 @@ void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) { if (Symbol.isVariable()) continue; + if (Symbol.isUndefined() && !UsedInReloc.count(&Symbol) + && Symbol.isTemporary()) + continue; + uint64_t &Entry = StringIndexMap[Symbol.getName()]; if (!Entry) { Entry = StringTable.size(); @@ -843,13 +853,19 @@ void ELFObjectWriterImpl::WriteRelocationsFragment(const MCAssembler &Asm, for (unsigned i = 0, e = Relocs.size(); i != e; ++i) { ELFRelocationEntry entry = Relocs[e - i - 1]; + if (entry.Index < 0) + entry.Index = getSymbolIndexInSymbolTable(Asm, entry.Symbol); + else + entry.Index += LocalSymbolData.size() + 1; if (Is64Bit) { char buf[8]; String64(buf, entry.r_offset); F->getContents() += StringRef(buf, 8); - String64(buf, entry.r_info); + struct ELF::Elf64_Rela ERE64; + ERE64.setSymbolAndType(entry.Index, entry.Type); + String64(buf, ERE64.r_info); F->getContents() += StringRef(buf, 8); if (HasRelocationAddend) { @@ -862,7 +878,9 @@ void ELFObjectWriterImpl::WriteRelocationsFragment(const MCAssembler &Asm, String32(buf, entry.r_offset); F->getContents() += StringRef(buf, 4); - String32(buf, entry.r_info); + struct ELF::Elf32_Rela ERE32; + ERE32.setSymbolAndType(entry.Index, entry.Type); + String32(buf, ERE32.r_info); F->getContents() += StringRef(buf, 4); if (HasRelocationAddend) { @@ -976,8 +994,11 @@ bool ELFObjectWriterImpl::IsFixupFullyResolved(const MCAssembler &Asm, return !SectionB && BaseSection == SectionA; } -void ELFObjectWriterImpl::WriteObject(const MCAssembler &Asm, +void ELFObjectWriterImpl::WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) { + // Compute symbol table information. + ComputeSymbolTable(Asm); + CreateMetadataSections(const_cast<MCAssembler&>(Asm), const_cast<MCAsmLayout&>(Layout)); @@ -1142,7 +1163,7 @@ bool ELFObjectWriter::IsFixupFullyResolved(const MCAssembler &Asm, IsPCRel, DF); } -void ELFObjectWriter::WriteObject(const MCAssembler &Asm, +void ELFObjectWriter::WriteObject(MCAssembler &Asm, const MCAsmLayout &Layout) { ((ELFObjectWriterImpl*) Impl)->WriteObject(Asm, Layout); } |