diff options
Diffstat (limited to 'lib/CodeGen/TargetLoweringObjectFileImpl.cpp')
| -rw-r--r-- | lib/CodeGen/TargetLoweringObjectFileImpl.cpp | 133 |
1 files changed, 115 insertions, 18 deletions
diff --git a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp index 9cef50e375..42a0e9290b 100644 --- a/lib/CodeGen/TargetLoweringObjectFileImpl.cpp +++ b/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -192,6 +192,18 @@ 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 { @@ -200,9 +212,15 @@ 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, + Kind, /*EntrySize=*/0, Group); } /// getSectionPrefixForGlobal - Return the section prefix name used by options @@ -224,7 +242,6 @@ static StringRef getSectionPrefixForGlobal(SectionKind Kind) { return ".data.rel.ro."; } - const MCSection *TargetLoweringObjectFileELF:: SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, Mangler &Mang, const TargetMachine &TM) const { @@ -238,7 +255,7 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, // 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) && + if ((GV->isWeakForLinker() || EmitUniquedSection || GV->hasComdat()) && !Kind.isCommon()) { StringRef Prefix = getSectionPrefixForGlobal(Kind); @@ -247,8 +264,11 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, StringRef Group = ""; unsigned Flags = getELFSectionFlags(Kind); - if (GV->isWeakForLinker()) { - Group = Name.substr(Prefix.size()); + if (GV->isWeakForLinker() || GV->hasComdat()) { + if (const Comdat *C = getELFComdat(GV)) + Group = C->getName(); + else + Group = Name.substr(Prefix.size()); Flags |= ELF::SHF_GROUP; } @@ -482,6 +502,15 @@ 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 { @@ -489,6 +518,9 @@ 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); @@ -559,6 +591,7 @@ bool TargetLoweringObjectFileMachO::isSectionAtomizableBySymbols( 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; @@ -727,6 +760,50 @@ getCOFFSectionFlags(SectionKind K) { return Flags; } +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 it's 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<GlobalAlias>(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 { @@ -734,11 +811,21 @@ 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->isWeakForLinker() || GV->hasComdat()) && !Kind.isCommon()) { + 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, @@ -775,17 +862,27 @@ SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind, // 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() && !Kind.isCommon()) { + if ((GV->isWeakForLinker() || EmitUniquedSection || GV->hasComdat()) && + !Kind.isCommon()) { 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()) |