X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FMC%2FELFObjectWriter.cpp;h=d249c92dad594557f4605331eba89ace27c9cdaa;hb=138abae2a2149b2bda3c5e28d3c4db97e3c82663;hp=9f9681ae3efc3a646fc2fcbcaf05689bc47291c6;hpb=3729d0052bda365d04fee900c6f3d09460f1e108;p=oota-llvm.git diff --git a/lib/MC/ELFObjectWriter.cpp b/lib/MC/ELFObjectWriter.cpp index 9f9681ae3ef..d249c92dad5 100644 --- a/lib/MC/ELFObjectWriter.cpp +++ b/lib/MC/ELFObjectWriter.cpp @@ -58,6 +58,14 @@ static void SetBinding(MCSymbolData &SD, unsigned Binding) { 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: @@ -427,11 +435,30 @@ static uint64_t SymbolValue(MCSymbolData &Data, const MCAsmLayout &Layout) { return 0; } +static const MCSymbol &AliasedSymbol(const MCSymbol &Symbol) { + const MCSymbol *S = &Symbol; + while (S->isVariable()) { + const MCExpr *Value = S->getVariableValue(); + assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented"); + const MCSymbolRefExpr *Ref = static_cast(Value); + S = &Ref->getSymbol(); + } + return *S; +} + 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); + MCSymbolData &OrigData = *MSD.SymbolData; + MCSymbolData &Data = + Layout.getAssembler().getSymbolData(AliasedSymbol(OrigData.getSymbol())); + + uint8_t Binding = GetBinding(OrigData); + uint8_t Visibility = GetVisibility(OrigData); + uint8_t Type = 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; @@ -512,8 +539,9 @@ void ELFObjectWriterImpl::WriteSymbolTable(MCDataFragment *F, 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"); + assert(((Data.getFlags() & ELF_STB_Global) || + (Data.getFlags() & ELF_STB_Weak)) && + "External symbol requires STB_GLOBAL or STB_WEAK flag"); WriteSymbol(F, MSD, Layout); if (GetBinding(Data) == ELF::STB_LOCAL) LastLocalSymbolIndex++; @@ -538,18 +566,18 @@ static bool ShouldRelocOnSymbol(const MCSymbolData &SD, const MCSectionELF &Section = static_cast(Symbol.getSection()); - if (Section.getFlags() & MCSectionELF::SHF_MERGE) - return Target.getConstant() != 0; - if (SD.isExternal()) return true; - const llvm::MCSymbolRefExpr& Ref = *Target.getSymA(); + if (Section.getFlags() & MCSectionELF::SHF_MERGE) + return Target.getConstant() != 0; + + MCSymbolRefExpr::VariantKind Kind = Target.getSymA()->getKind(); const MCSectionELF &Sec2 = static_cast(F.getParent()->getSection()); - if (Ref.getKind() == MCSymbolRefExpr::VK_PLT && - &Sec2 != &Section) + if (&Sec2 != &Section && + (Kind == MCSymbolRefExpr::VK_PLT || Kind == MCSymbolRefExpr::VK_GOTPCREL)) return true; return false; @@ -569,7 +597,7 @@ void ELFObjectWriterImpl::RecordRelocation(const MCAssembler &Asm, bool IsPCRel = isFixupKindX86PCRel(Fixup.getKind()); if (!Target.isAbsolute()) { - Symbol = &Target.getSymA()->getSymbol(); + Symbol = &AliasedSymbol(Target.getSymA()->getSymbol()); MCSymbolData &SD = Asm.getSymbolData(*Symbol); MCFragment *F = SD.getFragment(); @@ -648,6 +676,9 @@ void ELFObjectWriterImpl::RecordRelocation(const MCAssembler &Asm, case MCSymbolRefExpr::VK_GOT: Type = ELF::R_X86_64_GOT32; break; + case llvm::MCSymbolRefExpr::VK_GOTPCREL: + Type = ELF::R_X86_64_GOTPCREL; + break; default: llvm_unreachable("Unimplemented"); } @@ -755,7 +786,7 @@ void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) { StringMap 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(); @@ -763,87 +794,53 @@ void ELFObjectWriterImpl::ComputeSymbolTable(MCAssembler &Asm) { if (!isInSymtab(Asm, *it, UsedInReloc.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; - - if (Symbol.isAbsolute()) { - MSD.SectionIndex = ELF::SHN_ABS; - LocalSymbolData.push_back(MSD); - } else { - const MCSymbol *SymbolP = &Symbol; - if (Symbol.isVariable()) { - const MCExpr *Value = Symbol.getVariableValue(); - assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented"); - const MCSymbolRefExpr *Ref = static_cast(Value); - SymbolP = &Ref->getSymbol(); - } - MSD.SectionIndex = SectionIndexMap.lookup(&SymbolP->getSection()); - assert(MSD.SectionIndex && "Invalid section index!"); - LocalSymbolData.push_back(MSD); - } - } + bool Local = isLocal(*it); - // 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; - - uint64_t &Entry = StringIndexMap[Symbol.getName()]; - if (!Entry) { - Entry = StringTable.size(); - StringTable += Symbol.getName(); - StringTable += '\x00'; - } - - ELFSymbolData MSD; - MSD.SymbolData = it; - MSD.StringIndex = Entry; - - // FIXME: There is duplicated code with the local case. + bool Add = false; if (it->isCommon()) { + assert(!Local); MSD.SectionIndex = ELF::SHN_COMMON; - ExternalSymbolData.push_back(MSD); + Add = true; + } else if (Symbol.isAbsolute()) { + MSD.SectionIndex = ELF::SHN_ABS; + Add = true; } else if (Symbol.isVariable()) { - const MCExpr *Value = Symbol.getVariableValue(); - assert (Value->getKind() == MCExpr::SymbolRef && "Unimplemented"); - const MCSymbolRefExpr *Ref = static_cast(Value); - const MCSymbol &RefSymbol = Ref->getSymbol(); + const MCSymbol &RefSymbol = AliasedSymbol(Symbol); if (RefSymbol.isDefined()) { MSD.SectionIndex = SectionIndexMap.lookup(&RefSymbol.getSection()); assert(MSD.SectionIndex && "Invalid section index!"); - ExternalSymbolData.push_back(MSD); + Add = true; } } else if (Symbol.isUndefined()) { + assert(!Local); 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); - UndefinedSymbolData.push_back(MSD); - } else if (Symbol.isAbsolute()) { - MSD.SectionIndex = ELF::SHN_ABS; - ExternalSymbolData.push_back(MSD); + Add = true; } else { MSD.SectionIndex = SectionIndexMap.lookup(&Symbol.getSection()); assert(MSD.SectionIndex && "Invalid section index!"); - ExternalSymbolData.push_back(MSD); + Add = true; + } + + if (Add) { + uint64_t &Entry = StringIndexMap[Symbol.getName()]; + if (!Entry) { + Entry = StringTable.size(); + StringTable += Symbol.getName(); + StringTable += '\x00'; + } + MSD.StringIndex = Entry; + if (MSD.SectionIndex == ELF::SHN_UNDEF) + UndefinedSymbolData.push_back(MSD); + else if (Local) + LocalSymbolData.push_back(MSD); + else + ExternalSymbolData.push_back(MSD); } } @@ -1102,7 +1099,7 @@ void ELFObjectWriterImpl::WriteObject(MCAssembler &Asm, // ... then all of the sections ... DenseMap SectionOffsetMap; - DenseMap SectionIndexMap; + DenseMap SectionIndexMap; unsigned Index = 1; for (MCAssembler::const_iterator it = Asm.begin(),