X-Git-Url: http://demsky.eecs.uci.edu/git/?a=blobdiff_plain;f=lib%2FCodeGen%2FTargetLoweringObjectFileImpl.cpp;h=e8ef63aa5a999746293f7dddd96e617afea75a70;hb=f3d745cdc916df5a5db78ac0a5c0efbd8925c097;hp=e41fbfc6d360e06fb4b242c59a0468ca1d3203d8;hpb=4fd5cd06c815724fa410c0bea276d919dea868c3;p=oota-llvm.git diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp index e41fbfc6d36..e8ef63aa5a9 100644 --- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp +++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -31,12 +31,14 @@ #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" #include "llvm/Support/raw_ostream.h" #include "llvm/Target/TargetLowering.h" #include "llvm/Target/TargetMachine.h" +#include "llvm/Target/TargetSubtargetInfo.h" using namespace llvm; using namespace dwarf; @@ -48,16 +50,12 @@ MCSymbol *TargetLoweringObjectFileELF::getCFIPersonalitySymbol( const GlobalValue *GV, Mangler &Mang, const TargetMachine &TM, MachineModuleInfo *MMI) const { unsigned Encoding = getPersonalityEncoding(); - switch (Encoding & 0x70) { - default: - report_fatal_error("We do not support this DWARF encoding yet!"); - case dwarf::DW_EH_PE_absptr: - return TM.getSymbol(GV, Mang); - case dwarf::DW_EH_PE_pcrel: { + if ((Encoding & 0x80) == dwarf::DW_EH_PE_indirect) return getContext().GetOrCreateSymbol(StringRef("DW.ref.") + TM.getSymbol(GV, Mang)->getName()); - } - } + if ((Encoding & 0x70) == dwarf::DW_EH_PE_absptr) + return TM.getSymbol(GV, Mang); + report_fatal_error("We do not support this DWARF encoding yet!"); } void TargetLoweringObjectFileELF::emitPersonalityValue(MCStreamer &Streamer, @@ -74,7 +72,6 @@ void TargetLoweringObjectFileELF::emitPersonalityValue(MCStreamer &Streamer, const MCSection *Sec = getContext().getELFSection(NameData, ELF::SHT_PROGBITS, Flags, - SectionKind::getDataRel(), 0, Label->getName()); unsigned Size = TM.getDataLayout()->getPointerSize(); Streamer.SwitchSection(Sec); @@ -100,7 +97,7 @@ const MCExpr *TargetLoweringObjectFileELF::getTTypeGlobalReference( // Add information about the stub reference to ELFMMI so that the stub // gets emitted by the asmprinter. MachineModuleInfoImpl::StubValueTy &StubSym = ELFMMI.getGVStubEntry(SSym); - if (StubSym.getPointer() == 0) { + if (!StubSym.getPointer()) { MCSymbol *Sym = TM.getSymbol(GV, Mang); StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage()); } @@ -168,9 +165,7 @@ static unsigned getELFSectionType(StringRef Name, SectionKind K) { return ELF::SHT_PROGBITS; } - -static unsigned -getELFSectionFlags(SectionKind K) { +static unsigned getELFSectionFlags(SectionKind K) { unsigned Flags = 0; if (!K.isMetadata()) @@ -185,9 +180,7 @@ getELFSectionFlags(SectionKind K) { if (K.isThreadLocal()) Flags |= ELF::SHF_TLS; - // K.isMergeableConst() is left out to honour PR4650 - if (K.isMergeableCString() || K.isMergeableConst4() || - K.isMergeableConst8() || K.isMergeableConst16()) + if (K.isMergeableCString() || K.isMergeableConst()) Flags |= ELF::SHF_MERGE; if (K.isMergeableCString()) @@ -196,6 +189,18 @@ getELFSectionFlags(SectionKind K) { return Flags; } +static const Comdat *getELFComdat(const GlobalValue *GV) { + const Comdat *C = GV->getComdat(); + if (!C) + return nullptr; + + if (C->getSelectionKind() != Comdat::Any) + report_fatal_error("ELF COMDATs only support SelectionKind::Any, '" + + C->getName() + "' cannot be lowered."); + + return C; +} + const MCSection *TargetLoweringObjectFileELF::getExplicitSectionGlobal( const GlobalValue *GV, SectionKind Kind, Mangler &Mang, const TargetMachine &TM) const { @@ -204,127 +209,145 @@ const MCSection *TargetLoweringObjectFileELF::getExplicitSectionGlobal( // Infer section flags from the section name if we can. Kind = getELFKindForNamedSection(SectionName, Kind); + StringRef Group = ""; + unsigned Flags = getELFSectionFlags(Kind); + if (const Comdat *C = getELFComdat(GV)) { + Group = C->getName(); + Flags |= ELF::SHF_GROUP; + } return getContext().getELFSection(SectionName, - getELFSectionType(SectionName, Kind), - getELFSectionFlags(Kind), Kind); + getELFSectionType(SectionName, Kind), Flags, + /*EntrySize=*/0, Group); } -/// getSectionPrefixForGlobal - Return the section prefix name used by options -/// FunctionsSections and DataSections. -static const char *getSectionPrefixForGlobal(SectionKind Kind) { - if (Kind.isText()) return ".text."; - if (Kind.isReadOnly()) return ".rodata."; - if (Kind.isBSS()) return ".bss."; - - if (Kind.isThreadData()) return ".tdata."; - if (Kind.isThreadBSS()) return ".tbss."; - - if (Kind.isDataNoRel()) return ".data."; - if (Kind.isDataRelLocal()) return ".data.rel.local."; - if (Kind.isDataRel()) return ".data.rel."; - if (Kind.isReadOnlyWithRelLocal()) return ".data.rel.ro.local."; - +/// Return the section prefix name used by options FunctionsSections and +/// DataSections. +static StringRef getSectionPrefixForGlobal(SectionKind Kind) { + if (Kind.isText()) + return ".text"; + if (Kind.isReadOnly()) + return ".rodata"; + if (Kind.isBSS()) + return ".bss"; + if (Kind.isThreadData()) + return ".tdata"; + if (Kind.isThreadBSS()) + return ".tbss"; + if (Kind.isDataNoRel()) + return ".data"; + if (Kind.isDataRelLocal()) + return ".data.rel.local"; + if (Kind.isDataRel()) + return ".data.rel"; + if (Kind.isReadOnlyWithRelLocal()) + return ".data.rel.ro.local"; assert(Kind.isReadOnlyWithRel() && "Unknown section kind"); - return ".data.rel.ro."; + return ".data.rel.ro"; } - -const MCSection *TargetLoweringObjectFileELF:: -SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, - Mangler &Mang, const TargetMachine &TM) const { - // If we have -ffunction-section or -fdata-section then we should emit the - // global value to a uniqued section specifically for it. - bool EmitUniquedSection; - if (Kind.isText()) - EmitUniquedSection = TM.getFunctionSections(); - else - EmitUniquedSection = TM.getDataSections(); - - // If this global is linkonce/weak and the target handles this by emitting it - // into a 'uniqued' section name, create and return the section now. - if ((GV->isWeakForLinker() || EmitUniquedSection) && - !Kind.isCommon()) { - const char *Prefix; - Prefix = getSectionPrefixForGlobal(Kind); - - SmallString<128> Name(Prefix, Prefix+strlen(Prefix)); - TM.getNameWithPrefix(Name, GV, Mang, true); - - StringRef Group = ""; - unsigned Flags = getELFSectionFlags(Kind); - if (GV->isWeakForLinker()) { - Group = Name.substr(strlen(Prefix)); - Flags |= ELF::SHF_GROUP; +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()) { + EntrySize = 2; + } else if (Kind.isMergeable4ByteCString()) { + EntrySize = 4; + } else { + EntrySize = 1; + assert(Kind.isMergeable1ByteCString() && "unknown string width"); + } + } else if (Kind.isMergeableConst()) { + if (Kind.isMergeableConst4()) { + EntrySize = 4; + } else if (Kind.isMergeableConst8()) { + EntrySize = 8; + } else { + assert(Kind.isMergeableConst16() && "unknown data width"); + EntrySize = 16; } - - return getContext().getELFSection(Name.str(), - getELFSectionType(Name.str(), Kind), - Flags, Kind, 0, Group); } - if (Kind.isText()) return TextSection; - - if (Kind.isMergeable1ByteCString() || - Kind.isMergeable2ByteCString() || - Kind.isMergeable4ByteCString()) { + StringRef Group = ""; + if (const Comdat *C = getELFComdat(GV)) { + Flags |= ELF::SHF_GROUP; + Group = C->getName(); + } + bool UniqueSectionNames = TM.getUniqueSectionNames(); + SmallString<128> Name; + if (Kind.isMergeableCString()) { // We also need alignment here. // FIXME: this is getting the alignment of the character, not the // alignment of the global! unsigned Align = - TM.getDataLayout()->getPreferredAlignment(cast(GV)); - - const char *SizeSpec = ".rodata.str1."; - if (Kind.isMergeable2ByteCString()) - SizeSpec = ".rodata.str2."; - else if (Kind.isMergeable4ByteCString()) - SizeSpec = ".rodata.str4."; - else - assert(Kind.isMergeable1ByteCString() && "unknown string width"); + TM.getDataLayout()->getPreferredAlignment(cast(GV)); - - std::string Name = SizeSpec + utostr(Align); - return getContext().getELFSection(Name, ELF::SHT_PROGBITS, - ELF::SHF_ALLOC | - ELF::SHF_MERGE | - ELF::SHF_STRINGS, - Kind); + std::string SizeSpec = ".rodata.str" + utostr(EntrySize) + "."; + Name = SizeSpec + utostr(Align); + } else if (Kind.isMergeableConst()) { + Name = ".rodata.cst"; + Name += utostr(EntrySize); + } else { + Name = getSectionPrefixForGlobal(Kind); } - if (Kind.isMergeableConst()) { - if (Kind.isMergeableConst4() && MergeableConst4Section) - return MergeableConst4Section; - if (Kind.isMergeableConst8() && MergeableConst8Section) - return MergeableConst8Section; - if (Kind.isMergeableConst16() && MergeableConst16Section) - return MergeableConst16Section; - return ReadOnlySection; // .const + if (EmitUniqueSection && UniqueSectionNames) { + Name.push_back('.'); + TM.getNameWithPrefix(Name, GV, Mang, true); } + 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 (Kind.isReadOnly()) return ReadOnlySection; + // 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(); - if (Kind.isThreadData()) return TLSDataSection; - if (Kind.isThreadBSS()) return TLSBSSSection; + return selectELFSectionForGlobal(getContext(), GV, Kind, Mang, TM, + EmitUniqueSection, Flags); +} - // Note: we claim that common symbols are put in BSSSection, but they are - // really emitted with the magic .comm directive, which creates a symbol table - // entry but not a section. - if (Kind.isBSS() || Kind.isCommon()) return BSSSection; +const MCSection *TargetLoweringObjectFileELF::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; - if (Kind.isDataNoRel()) return DataSection; - if (Kind.isDataRelLocal()) return DataRelLocalSection; - if (Kind.isDataRel()) return DataRelSection; - if (Kind.isReadOnlyWithRelLocal()) return DataRelROLocalSection; + return selectELFSectionForGlobal(getContext(), &F, SectionKind::getReadOnly(), + Mang, TM, EmitUniqueSection, ELF::SHF_ALLOC); +} - assert(Kind.isReadOnlyWithRel() && "Unknown section kind"); - return DataRelROSection; +bool TargetLoweringObjectFileELF::shouldPutJumpTableInFunctionSection( + bool UsesLabelDifference, const Function &F) const { + // We can always create relative relocations, so use another section + // that can be marked non-executable. + return false; } /// getSectionForConstant - Given a mergeable constant with the /// specified size and relocation information, return a section that it /// should be placed in. -const MCSection *TargetLoweringObjectFileELF:: -getSectionForConstant(SectionKind Kind) const { +const MCSection * +TargetLoweringObjectFileELF::getSectionForConstant(SectionKind Kind, + const Constant *C) const { if (Kind.isMergeableConst4() && MergeableConst4Section) return MergeableConst4Section; if (Kind.isMergeableConst8() && MergeableConst8Section) @@ -339,44 +362,58 @@ getSectionForConstant(SectionKind Kind) const { return DataRelROSection; } -const MCSection * -TargetLoweringObjectFileELF::getStaticCtorSection(unsigned Priority) const { - // The default scheme is .ctor / .dtor, so we have to invert the priority - // numbering. - if (Priority == 65535) - return StaticCtorSection; +static const MCSectionELF *getStaticStructorSection(MCContext &Ctx, + bool UseInitArray, + bool IsCtor, + unsigned Priority, + const MCSymbol *KeySym) { + std::string Name; + unsigned Type; + unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE; + StringRef COMDAT = KeySym ? KeySym->getName() : ""; + + if (KeySym) + Flags |= ELF::SHF_GROUP; if (UseInitArray) { - std::string Name = std::string(".init_array.") + utostr(Priority); - return getContext().getELFSection(Name, ELF::SHT_INIT_ARRAY, - ELF::SHF_ALLOC | ELF::SHF_WRITE, - SectionKind::getDataRel()); + if (IsCtor) { + Type = ELF::SHT_INIT_ARRAY; + Name = ".init_array"; + } else { + Type = ELF::SHT_FINI_ARRAY; + Name = ".fini_array"; + } + if (Priority != 65535) { + Name += '.'; + Name += utostr(Priority); + } } else { - std::string Name = std::string(".ctors.") + utostr(65535 - Priority); - return getContext().getELFSection(Name, ELF::SHT_PROGBITS, - ELF::SHF_ALLOC |ELF::SHF_WRITE, - SectionKind::getDataRel()); + // The default scheme is .ctor / .dtor, so we have to invert the priority + // numbering. + if (IsCtor) + Name = ".ctors"; + else + Name = ".dtors"; + if (Priority != 65535) { + Name += '.'; + Name += utostr(65535 - Priority); + } + Type = ELF::SHT_PROGBITS; } + + return Ctx.getELFSection(Name, Type, Flags, 0, COMDAT); } -const MCSection * -TargetLoweringObjectFileELF::getStaticDtorSection(unsigned Priority) const { - // The default scheme is .ctor / .dtor, so we have to invert the priority - // numbering. - if (Priority == 65535) - return StaticDtorSection; +const MCSection *TargetLoweringObjectFileELF::getStaticCtorSection( + unsigned Priority, const MCSymbol *KeySym) const { + return getStaticStructorSection(getContext(), UseInitArray, true, Priority, + KeySym); +} - if (UseInitArray) { - std::string Name = std::string(".fini_array.") + utostr(Priority); - return getContext().getELFSection(Name, ELF::SHT_FINI_ARRAY, - ELF::SHF_ALLOC | ELF::SHF_WRITE, - SectionKind::getDataRel()); - } else { - std::string Name = std::string(".dtors.") + utostr(65535 - Priority); - return getContext().getELFSection(Name, ELF::SHT_PROGBITS, - ELF::SHF_ALLOC |ELF::SHF_WRITE, - SectionKind::getDataRel()); - } +const MCSection *TargetLoweringObjectFileELF::getStaticDtorSection( + unsigned Priority, const MCSymbol *KeySym) const { + return getStaticStructorSection(getContext(), UseInitArray, false, Priority, + KeySym); } void @@ -385,22 +422,21 @@ TargetLoweringObjectFileELF::InitializeELF(bool UseInitArray_) { if (!UseInitArray) return; - StaticCtorSection = - getContext().getELFSection(".init_array", ELF::SHT_INIT_ARRAY, - ELF::SHF_WRITE | - ELF::SHF_ALLOC, - SectionKind::getDataRel()); - StaticDtorSection = - getContext().getELFSection(".fini_array", ELF::SHT_FINI_ARRAY, - ELF::SHF_WRITE | - ELF::SHF_ALLOC, - SectionKind::getDataRel()); + StaticCtorSection = getContext().getELFSection( + ".init_array", ELF::SHT_INIT_ARRAY, ELF::SHF_WRITE | ELF::SHF_ALLOC); + StaticDtorSection = getContext().getELFSection( + ".fini_array", ELF::SHT_FINI_ARRAY, ELF::SHF_WRITE | ELF::SHF_ALLOC); } //===----------------------------------------------------------------------===// // 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:: @@ -418,7 +454,7 @@ emitModuleFlags(MCStreamer &Streamer, Mangler &Mang, const TargetMachine &TM) const { unsigned VersionVal = 0; unsigned ImageInfoFlags = 0; - MDNode *LinkerOptions = 0; + MDNode *LinkerOptions = nullptr; StringRef SectionVal; for (ArrayRef::iterator @@ -430,14 +466,15 @@ emitModuleFlags(MCStreamer &Streamer, continue; StringRef Key = MFE.Key->getString(); - Value *Val = MFE.Val; + Metadata *Val = MFE.Val; if (Key == "Objective-C Image Info Version") { - VersionVal = cast(Val)->getZExtValue(); + VersionVal = mdconst::extract(Val)->getZExtValue(); } else if (Key == "Objective-C Garbage Collection" || Key == "Objective-C GC Only" || - Key == "Objective-C Is Simulated") { - ImageInfoFlags |= cast(Val)->getZExtValue(); + Key == "Objective-C Is Simulated" || + Key == "Objective-C Image Swift Version") { + ImageInfoFlags |= mdconst::extract(Val)->getZExtValue(); } else if (Key == "Objective-C Image Info Section") { SectionVal = cast(Val)->getString(); } else if (Key == "Linker Options") { @@ -487,6 +524,15 @@ emitModuleFlags(MCStreamer &Streamer, Streamer.AddBlankLine(); } +static void checkMachOComdat(const GlobalValue *GV) { + const Comdat *C = GV->getComdat(); + if (!C) + return; + + report_fatal_error("MachO doesn't support COMDATs, '" + C->getName() + + "' cannot be lowered."); +} + const MCSection *TargetLoweringObjectFileMachO::getExplicitSectionGlobal( const GlobalValue *GV, SectionKind Kind, Mangler &Mang, const TargetMachine &TM) const { @@ -494,6 +540,9 @@ const MCSection *TargetLoweringObjectFileMachO::getExplicitSectionGlobal( StringRef Segment, Section; unsigned TAA = 0, StubSize = 0; bool TAAParsed; + + checkMachOComdat(GV); + std::string ErrorCode = MCSectionMachO::ParseSectionSpecifier(GV->getSection(), Segment, Section, TAA, TAAParsed, StubSize); @@ -526,44 +575,10 @@ const MCSection *TargetLoweringObjectFileMachO::getExplicitSectionGlobal( return S; } -bool TargetLoweringObjectFileMachO::isSectionAtomizableBySymbols( - const MCSection &Section) const { - const MCSectionMachO &SMO = static_cast(Section); - - // Sections holding 1 byte strings are atomized based on the data - // they contain. - // Sections holding 2 byte strings require symbols in order to be - // atomized. - // There is no dedicated section for 4 byte strings. - if (SMO.getKind().isMergeable1ByteCString()) - return false; - - if (SMO.getSegmentName() == "__DATA" && - SMO.getSectionName() == "__cfstring") - return false; - - switch (SMO.getType()) { - default: - return true; - - // These sections are atomized at the element boundaries without using - // symbols. - case MachO::S_4BYTE_LITERALS: - case MachO::S_8BYTE_LITERALS: - case MachO::S_16BYTE_LITERALS: - case MachO::S_LITERAL_POINTERS: - case MachO::S_NON_LAZY_SYMBOL_POINTERS: - case MachO::S_LAZY_SYMBOL_POINTERS: - case MachO::S_MOD_INIT_FUNC_POINTERS: - case MachO::S_MOD_TERM_FUNC_POINTERS: - case MachO::S_INTERPOSING: - return false; - } -} - const MCSection *TargetLoweringObjectFileMachO:: SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler &Mang, const TargetMachine &TM) const { + checkMachOComdat(GV); // Handle thread local data. if (Kind.isThreadBSS()) return TLSBSSSection; @@ -592,7 +607,9 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, TM.getDataLayout()->getPreferredAlignment(cast(GV)) < 32) return UStringSection; - if (Kind.isMergeableConst()) { + // With MachO only variables whose corresponding symbol starts with 'l' or + // 'L' can be merged, so we only try merging GVs with private linkage. + if (GV->hasPrivateLinkage() && Kind.isMergeableConst()) { if (Kind.isMergeableConst4()) return FourByteConstantSection; if (Kind.isMergeableConst8()) @@ -626,7 +643,8 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, } const MCSection * -TargetLoweringObjectFileMachO::getSectionForConstant(SectionKind Kind) const { +TargetLoweringObjectFileMachO::getSectionForConstant(SectionKind Kind, + const Constant *C) const { // If this constant requires a relocation, we have to put it in the data // segment, not in the text segment. if (Kind.isDataRel() || Kind.isReadOnlyWithRel()) @@ -659,7 +677,7 @@ const MCExpr *TargetLoweringObjectFileMachO::getTTypeGlobalReference( MachineModuleInfoImpl::StubValueTy &StubSym = GV->hasHiddenVisibility() ? MachOMMI.getHiddenGVStubEntry(SSym) : MachOMMI.getGVStubEntry(SSym); - if (StubSym.getPointer() == 0) { + if (!StubSym.getPointer()) { MCSymbol *Sym = TM.getSymbol(GV, Mang); StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage()); } @@ -685,7 +703,7 @@ MCSymbol *TargetLoweringObjectFileMachO::getCFIPersonalitySymbol( // Add information about the stub reference to MachOMMI so that the stub // gets emitted by the asmprinter. MachineModuleInfoImpl::StubValueTy &StubSym = MachOMMI.getGVStubEntry(SSym); - if (StubSym.getPointer() == 0) { + if (!StubSym.getPointer()) { MCSymbol *Sym = TM.getSymbol(GV, Mang); StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage()); } @@ -693,6 +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(); + 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(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 //===----------------------------------------------------------------------===// @@ -709,7 +787,7 @@ getCOFFSectionFlags(SectionKind K) { COFF::IMAGE_SCN_MEM_EXECUTE | COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_CNT_CODE; - else if (K.isBSS ()) + else if (K.isBSS()) Flags |= COFF::IMAGE_SCN_CNT_UNINITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | @@ -719,7 +797,7 @@ getCOFFSectionFlags(SectionKind K) { COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ | COFF::IMAGE_SCN_MEM_WRITE; - else if (K.isReadOnly()) + else if (K.isReadOnly() || K.isReadOnlyWithRel()) Flags |= COFF::IMAGE_SCN_CNT_INITIALIZED_DATA | COFF::IMAGE_SCN_MEM_READ; @@ -732,6 +810,50 @@ getCOFFSectionFlags(SectionKind K) { return Flags; } +static const GlobalValue *getComdatGVForCOFF(const GlobalValue *GV) { + const Comdat *C = GV->getComdat(); + assert(C && "expected GV to have a Comdat!"); + + StringRef ComdatGVName = C->getName(); + const GlobalValue *ComdatGV = GV->getParent()->getNamedValue(ComdatGVName); + if (!ComdatGV) + report_fatal_error("Associative COMDAT symbol '" + ComdatGVName + + "' does not exist."); + + if (ComdatGV->getComdat() != C) + report_fatal_error("Associative COMDAT symbol '" + ComdatGVName + + "' is not a key for its COMDAT."); + + return ComdatGV; +} + +static int getSelectionForCOFF(const GlobalValue *GV) { + if (const Comdat *C = GV->getComdat()) { + const GlobalValue *ComdatKey = getComdatGVForCOFF(GV); + if (const auto *GA = dyn_cast(ComdatKey)) + ComdatKey = GA->getBaseObject(); + if (ComdatKey == GV) { + switch (C->getSelectionKind()) { + case Comdat::Any: + return COFF::IMAGE_COMDAT_SELECT_ANY; + case Comdat::ExactMatch: + return COFF::IMAGE_COMDAT_SELECT_EXACT_MATCH; + case Comdat::Largest: + return COFF::IMAGE_COMDAT_SELECT_LARGEST; + case Comdat::NoDuplicates: + return COFF::IMAGE_COMDAT_SELECT_NODUPLICATES; + case Comdat::SameSize: + return COFF::IMAGE_COMDAT_SELECT_SAME_SIZE; + } + } else { + return COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE; + } + } else if (GV->isWeakForLinker()) { + return COFF::IMAGE_COMDAT_SELECT_ANY; + } + return 0; +} + const MCSection *TargetLoweringObjectFileCOFF::getExplicitSectionGlobal( const GlobalValue *GV, SectionKind Kind, Mangler &Mang, const TargetMachine &TM) const { @@ -739,11 +861,21 @@ const MCSection *TargetLoweringObjectFileCOFF::getExplicitSectionGlobal( unsigned Characteristics = getCOFFSectionFlags(Kind); StringRef Name = GV->getSection(); StringRef COMDATSymName = ""; - if (GV->isWeakForLinker()) { - Selection = COFF::IMAGE_COMDAT_SELECT_ANY; - Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT; - MCSymbol *Sym = TM.getSymbol(GV, Mang); - COMDATSymName = Sym->getName(); + if (GV->hasComdat()) { + Selection = getSelectionForCOFF(GV); + const GlobalValue *ComdatGV; + if (Selection == COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE) + ComdatGV = getComdatGVForCOFF(GV); + else + ComdatGV = GV; + + if (!ComdatGV->hasPrivateLinkage()) { + MCSymbol *Sym = TM.getSymbol(ComdatGV, Mang); + COMDATSymName = Sym->getName(); + Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT; + } else { + Selection = 0; + } } return getContext().getCOFFSection(Name, Characteristics, @@ -755,13 +887,13 @@ const MCSection *TargetLoweringObjectFileCOFF::getExplicitSectionGlobal( static const char *getCOFFSectionNameForUniqueGlobal(SectionKind Kind) { if (Kind.isText()) return ".text"; - if (Kind.isBSS ()) + if (Kind.isBSS()) return ".bss"; if (Kind.isThreadLocal()) return ".tls$"; - if (Kind.isWriteable()) - return ".data"; - return ".rdata"; + if (Kind.isReadOnly() || Kind.isReadOnlyWithRel()) + return ".rdata"; + return ".data"; } @@ -776,21 +908,26 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, else EmitUniquedSection = TM.getDataSections(); - // If this global is linkonce/weak and the target handles this by emitting it - // into a 'uniqued' section name, create and return the section now. - // Section names depend on the name of the symbol which is not feasible if the - // symbol has private linkage. - if ((GV->isWeakForLinker() || EmitUniquedSection) && - !GV->hasPrivateLinkage()) { + if ((EmitUniquedSection && !Kind.isCommon()) || GV->hasComdat()) { const char *Name = getCOFFSectionNameForUniqueGlobal(Kind); unsigned Characteristics = getCOFFSectionFlags(Kind); Characteristics |= COFF::IMAGE_SCN_LNK_COMDAT; - MCSymbol *Sym = TM.getSymbol(GV, Mang); - return getContext().getCOFFSection( - Name, Characteristics, Kind, Sym->getName(), - GV->isWeakForLinker() ? COFF::IMAGE_COMDAT_SELECT_ANY - : COFF::IMAGE_COMDAT_SELECT_NODUPLICATES); + int Selection = getSelectionForCOFF(GV); + if (!Selection) + Selection = COFF::IMAGE_COMDAT_SELECT_NODUPLICATES; + const GlobalValue *ComdatGV; + if (GV->hasComdat()) + ComdatGV = getComdatGVForCOFF(GV); + else + ComdatGV = GV; + + if (!ComdatGV->hasPrivateLinkage()) { + MCSymbol *Sym = TM.getSymbol(ComdatGV, Mang); + StringRef COMDATSymName = Sym->getName(); + return getContext().getCOFFSection(Name, Characteristics, Kind, + COMDATSymName, Selection); + } } if (Kind.isText()) @@ -799,10 +936,13 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, if (Kind.isThreadLocal()) return TLSDataSection; - if (Kind.isReadOnly()) + if (Kind.isReadOnly() || Kind.isReadOnlyWithRel()) return ReadOnlySection; - if (Kind.isBSS()) + // Note: we claim that common symbols are put in BSSSection, but they are + // really emitted with the magic .comm directive, which creates a symbol table + // entry but not a section. + if (Kind.isBSS() || Kind.isCommon()) return BSSSection; return DataSection; @@ -820,14 +960,14 @@ void TargetLoweringObjectFileCOFF:: emitModuleFlags(MCStreamer &Streamer, ArrayRef ModuleFlags, Mangler &Mang, const TargetMachine &TM) const { - MDNode *LinkerOptions = 0; + MDNode *LinkerOptions = nullptr; // Look for the "Linker Options" flag, since it's the only one we support. for (ArrayRef::iterator i = ModuleFlags.begin(), e = ModuleFlags.end(); i != e; ++i) { const Module::ModuleFlagEntry &MFE = *i; StringRef Key = MFE.Key->getString(); - Value *Val = MFE.Val; + Metadata *Val = MFE.Val; if (Key == "Linker Options") { LinkerOptions = cast(Val); break; @@ -844,21 +984,22 @@ emitModuleFlags(MCStreamer &Streamer, MDNode *MDOptions = cast(LinkerOptions->getOperand(i)); for (unsigned ii = 0, ie = MDOptions->getNumOperands(); ii != ie; ++ii) { MDString *MDOption = cast(MDOptions->getOperand(ii)); - StringRef Op = MDOption->getString(); // Lead with a space for consistency with our dllexport implementation. - std::string Escaped(" "); - if (Op.find(" ") != StringRef::npos) { - // The PE-COFF spec says args with spaces must be quoted. It doesn't say - // how to escape quotes, but it probably uses this algorithm: - // http://msdn.microsoft.com/en-us/library/17w5ykft(v=vs.85).aspx - // FIXME: Reuse escaping code from Support/Windows/Program.inc - Escaped.push_back('\"'); - Escaped.append(Op); - Escaped.push_back('\"'); - } else { - Escaped.append(Op); - } - Streamer.EmitBytes(Escaped); + std::string Directive(" "); + Directive.append(MDOption->getString()); + Streamer.EmitBytes(Directive); } } } + +const MCSection *TargetLoweringObjectFileCOFF::getStaticCtorSection( + unsigned Priority, const MCSymbol *KeySym) const { + return getContext().getAssociativeCOFFSection( + cast(StaticCtorSection), KeySym); +} + +const MCSection *TargetLoweringObjectFileCOFF::getStaticDtorSection( + unsigned Priority, const MCSymbol *KeySym) const { + return getContext().getAssociativeCOFFSection( + cast(StaticDtorSection), KeySym); +}