diff options
Diffstat (limited to 'lib/CodeGen/TargetLoweringObjectFileImpl.cpp')
| -rw-r--r-- | lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 155 |
1 files changed, 135 insertions, 20 deletions
diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp index c1b34f7..bcf2aa7 100644 --- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp +++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -31,6 +31,7 @@ #include "llvm/MC/MCSectionMachO.h" #include "llvm/MC/MCStreamer.h" #include "llvm/MC/MCSymbol.h" +#include "llvm/MC/MCValue.h" #include "llvm/Support/Dwarf.h" #include "llvm/Support/ELF.h" #include "llvm/Support/ErrorHandling.h" @@ -244,22 +245,9 @@ static StringRef getSectionPrefixForGlobal(SectionKind Kind) { return ".data.rel.ro"; } -const MCSection *TargetLoweringObjectFileELF:: -SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, - Mangler &Mang, const TargetMachine &TM) const { - unsigned Flags = getELFSectionFlags(Kind); - - // If we have -ffunction-section or -fdata-section then we should emit the - // global value to a uniqued section specifically for it. - bool EmitUniqueSection = false; - if (!(Flags & ELF::SHF_MERGE) && !Kind.isCommon()) { - if (Kind.isText()) - EmitUniqueSection = TM.getFunctionSections(); - else - EmitUniqueSection = TM.getDataSections(); - } - EmitUniqueSection |= GV->hasComdat(); - +static const MCSectionELF *selectELFSectionForGlobal( + MCContext &Ctx, const GlobalValue *GV, SectionKind Kind, Mangler &Mang, + const TargetMachine &TM, bool EmitUniqueSection, unsigned Flags) { unsigned EntrySize = 0; if (Kind.isMergeableCString()) { if (Kind.isMergeable2ByteCString()) { @@ -309,9 +297,29 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, Name.push_back('.'); TM.getNameWithPrefix(Name, GV, Mang, true); } - return getContext().getELFSection(Name, getELFSectionType(Name, Kind), Flags, - EntrySize, Group, - EmitUniqueSection && !UniqueSectionNames); + return Ctx.getELFSection(Name, getELFSectionType(Name, Kind), Flags, + EntrySize, Group, + EmitUniqueSection && !UniqueSectionNames); +} + +const MCSection *TargetLoweringObjectFileELF::SelectSectionForGlobal( + const GlobalValue *GV, SectionKind Kind, Mangler &Mang, + const TargetMachine &TM) const { + unsigned Flags = getELFSectionFlags(Kind); + + // If we have -ffunction-section or -fdata-section then we should emit the + // global value to a uniqued section specifically for it. + bool EmitUniqueSection = false; + if (!(Flags & ELF::SHF_MERGE) && !Kind.isCommon()) { + if (Kind.isText()) + EmitUniqueSection = TM.getFunctionSections(); + else + EmitUniqueSection = TM.getDataSections(); + } + EmitUniqueSection |= GV->hasComdat(); + + return selectELFSectionForGlobal(getContext(), GV, Kind, Mang, TM, + EmitUniqueSection, Flags); } const MCSection *TargetLoweringObjectFileELF::getSectionForJumpTable( @@ -323,7 +331,8 @@ const MCSection *TargetLoweringObjectFileELF::getSectionForJumpTable( if (!EmitUniqueSection) return ReadOnlySection; - return SelectSectionForGlobal(&F, SectionKind::getReadOnly(), Mang, TM); + return selectELFSectionForGlobal(getContext(), &F, SectionKind::getReadOnly(), + Mang, TM, EmitUniqueSection, ELF::SHF_ALLOC); } bool TargetLoweringObjectFileELF::shouldPutJumpTableInFunctionSection( @@ -423,6 +432,11 @@ TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) { // MachO //===----------------------------------------------------------------------===// +TargetLoweringObjectFileMachO::TargetLoweringObjectFileMachO() + : TargetLoweringObjectFile() { + SupportIndirectSymViaGOTPCRel = true; +} + /// getDepLibFromLinkerOpt - Extract the dependent library name from a linker /// option string. Returns StringRef() if the option does not specify a library. StringRef TargetLoweringObjectFileMachO:: @@ -697,6 +711,66 @@ MCSymbol *TargetLoweringObjectFileMachO::getCFIPersonalitySymbol( return SSym; } +const MCExpr *TargetLoweringObjectFileMachO::getIndirectSymViaGOTPCRel( + const MCSymbol *Sym, const MCValue &MV, int64_t Offset, + MachineModuleInfo *MMI, MCStreamer &Streamer) const { + // Although MachO 32-bit targets do not explictly have a GOTPCREL relocation + // as 64-bit do, we replace the GOT equivalent by accessing the final symbol + // through a non_lazy_ptr stub instead. One advantage is that it allows the + // computation of deltas to final external symbols. Example: + // + // _extgotequiv: + // .long _extfoo + // + // _delta: + // .long _extgotequiv-_delta + // + // is transformed to: + // + // _delta: + // .long L_extfoo$non_lazy_ptr-(_delta+0) + // + // .section __IMPORT,__pointers,non_lazy_symbol_pointers + // L_extfoo$non_lazy_ptr: + // .indirect_symbol _extfoo + // .long 0 + // + MachineModuleInfoMachO &MachOMMI = + MMI->getObjFileInfo<MachineModuleInfoMachO>(); + MCContext &Ctx = getContext(); + + // The offset must consider the original displacement from the base symbol + // since 32-bit targets don't have a GOTPCREL to fold the PC displacement. + Offset = -MV.getConstant(); + const MCSymbol *BaseSym = &MV.getSymB()->getSymbol(); + + // Access the final symbol via sym$non_lazy_ptr and generate the appropriated + // non_lazy_ptr stubs. + SmallString<128> Name; + StringRef Suffix = "$non_lazy_ptr"; + Name += DL->getPrivateGlobalPrefix(); + Name += Sym->getName(); + Name += Suffix; + MCSymbol *Stub = Ctx.GetOrCreateSymbol(Name); + + MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(Stub); + if (!StubSym.getPointer()) + StubSym = MachineModuleInfoImpl:: + StubValueTy(const_cast<MCSymbol *>(Sym), true /* access indirectly */); + + const MCExpr *BSymExpr = + MCSymbolRefExpr::Create(BaseSym, MCSymbolRefExpr::VK_None, Ctx); + const MCExpr *LHS = + MCSymbolRefExpr::Create(Stub, MCSymbolRefExpr::VK_None, Ctx); + + if (!Offset) + return MCBinaryExpr::CreateSub(LHS, BSymExpr, Ctx); + + const MCExpr *RHS = + MCBinaryExpr::CreateAdd(BSymExpr, MCConstantExpr::Create(Offset, Ctx), Ctx); + return MCBinaryExpr::CreateSub(LHS, RHS, Ctx); +} + //===----------------------------------------------------------------------===// // COFF //===----------------------------------------------------------------------===// @@ -853,6 +927,11 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, StringRef COMDATSymName = Sym->getName(); return getContext().getCOFFSection(Name, Characteristics, Kind, COMDATSymName, Selection); + } else { + SmallString<256> TmpData; + getNameWithPrefix(TmpData, GV, /*CannotUsePrivateLabel=*/true, Mang, TM); + return getContext().getCOFFSection(Name, Characteristics, Kind, TmpData, + Selection); } } @@ -874,6 +953,42 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, return DataSection; } +void TargetLoweringObjectFileCOFF::getNameWithPrefix( + SmallVectorImpl<char> &OutName, const GlobalValue *GV, + bool CannotUsePrivateLabel, Mangler &Mang, const TargetMachine &TM) const { + if (GV->hasPrivateLinkage() && + ((isa<Function>(GV) && TM.getFunctionSections()) || + (isa<GlobalVariable>(GV) && TM.getDataSections()))) + CannotUsePrivateLabel = true; + + Mang.getNameWithPrefix(OutName, GV, CannotUsePrivateLabel); +} + +const MCSection *TargetLoweringObjectFileCOFF::getSectionForJumpTable( + const Function &F, Mangler &Mang, const TargetMachine &TM) const { + // If the function can be removed, produce a unique section so that + // the table doesn't prevent the removal. + const Comdat *C = F.getComdat(); + bool EmitUniqueSection = TM.getFunctionSections() || C; + if (!EmitUniqueSection) + return ReadOnlySection; + + // FIXME: we should produce a symbol for F instead. + if (F.hasPrivateLinkage()) + return ReadOnlySection; + + MCSymbol *Sym = TM.getSymbol(&F, Mang); + StringRef COMDATSymName = Sym->getName(); + + SectionKind Kind = SectionKind::getReadOnly(); + const char *Name = getCOFFSectionNameForUniqueGlobal(Kind); + unsigned Characteristics = getCOFFSectionFlags(Kind); + Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT; + + return getContext().getCOFFSection(Name, Characteristics, Kind, COMDATSymName, + COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE); +} + StringRef TargetLoweringObjectFileCOFF:: getDepLibFromLinkerOpt(StringRef LinkerOption) const { const char *LibCmd = "/DEFAULTLIB:"; |