#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"
using namespace llvm;
using namespace dwarf;
// ELF
//===----------------------------------------------------------------------===//
-MCSymbol *
-TargetLoweringObjectFileELF::getCFIPersonalitySymbol(const GlobalValue *GV,
- Mangler &Mang,
- MachineModuleInfo *MMI) const {
+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 getSymbol(GV, Mang);
- case dwarf::DW_EH_PE_pcrel: {
+ if ((Encoding & 0x80) == dwarf::DW_EH_PE_indirect)
return getContext().GetOrCreateSymbol(StringRef("DW.ref.") +
- getSymbol(GV, Mang)->getName());
- }
- }
+ 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,
const MCExpr *TargetLoweringObjectFileELF::getTTypeGlobalReference(
const GlobalValue *GV, unsigned Encoding, Mangler &Mang,
- MachineModuleInfo *MMI, MCStreamer &Streamer) const {
+ const TargetMachine &TM, MachineModuleInfo *MMI,
+ MCStreamer &Streamer) const {
if (Encoding & dwarf::DW_EH_PE_indirect) {
MachineModuleInfoELF &ELFMMI = MMI->getObjFileInfo<MachineModuleInfoELF>();
- MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, ".DW.stub", Mang);
+ MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, ".DW.stub", Mang, TM);
// 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) {
- MCSymbol *Sym = getSymbol(GV, Mang);
+ if (!StubSym.getPointer()) {
+ MCSymbol *Sym = TM.getSymbol(GV, Mang);
StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
}
Encoding & ~dwarf::DW_EH_PE_indirect, Streamer);
}
- return TargetLoweringObjectFile::getTTypeGlobalReference(GV, Encoding, Mang,
- MMI, Streamer);
+ return TargetLoweringObjectFile::
+ getTTypeGlobalReference(GV, Encoding, Mang, TM, MMI, Streamer);
}
static SectionKind
return Flags;
}
+static const Comdat *getELFComdat(const GlobalValue *GV) {
+ const Comdat *C = GV->getComdat();
+ if (!C)
+ return nullptr;
-const MCSection *TargetLoweringObjectFileELF::
-getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
- Mangler &Mang, const TargetMachine &TM) const {
+ 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 {
StringRef SectionName = GV->getSection();
// 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
/// FunctionsSections and DataSections.
-static const char *getSectionPrefixForGlobal(SectionKind Kind) {
+static StringRef getSectionPrefixForGlobal(SectionKind Kind) {
if (Kind.isText()) return ".text.";
if (Kind.isReadOnly()) return ".rodata.";
if (Kind.isBSS()) return ".bss.";
return ".data.rel.ro.";
}
-
const MCSection *TargetLoweringObjectFileELF::
SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler &Mang, const TargetMachine &TM) const {
// 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()) {
- const char *Prefix;
- Prefix = getSectionPrefixForGlobal(Kind);
+ StringRef Prefix = getSectionPrefixForGlobal(Kind);
+
+ SmallString<128> Name(Prefix);
+ TM.getNameWithPrefix(Name, GV, Mang, true);
- SmallString<128> Name(Prefix, Prefix+strlen(Prefix));
- MCSymbol *Sym = getSymbol(GV, Mang);
- Name.append(Sym->getName().begin(), Sym->getName().end());
StringRef Group = "";
unsigned Flags = getELFSectionFlags(Kind);
- if (GV->isWeakForLinker()) {
- Group = Sym->getName();
+ if (GV->isWeakForLinker() || GV->hasComdat()) {
+ if (const Comdat *C = getELFComdat(GV))
+ Group = C->getName();
+ else
+ Group = Name.substr(Prefix.size());
Flags |= ELF::SHF_GROUP;
}
return DataRelROSection;
}
-const MCSection *
-TargetLoweringObjectFileELF::getStaticCtorSection(unsigned Priority) const {
+const MCSection *TargetLoweringObjectFileELF::getStaticCtorSection(
+ unsigned Priority, const MCSymbol *KeySym) const {
// The default scheme is .ctor / .dtor, so we have to invert the priority
// numbering.
if (Priority == 65535)
}
}
-const MCSection *
-TargetLoweringObjectFileELF::getStaticDtorSection(unsigned Priority) const {
+const MCSection *TargetLoweringObjectFileELF::getStaticDtorSection(
+ unsigned Priority, const MCSymbol *KeySym) const {
// The default scheme is .ctor / .dtor, so we have to invert the priority
// numbering.
if (Priority == 65535)
Mangler &Mang, const TargetMachine &TM) const {
unsigned VersionVal = 0;
unsigned ImageInfoFlags = 0;
- MDNode *LinkerOptions = 0;
+ MDNode *LinkerOptions = nullptr;
StringRef SectionVal;
for (ArrayRef<Module::ModuleFlagEntry>::iterator
Streamer.AddBlankLine();
}
-const MCSection *TargetLoweringObjectFileMachO::
-getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
- Mangler &Mang, const TargetMachine &TM) const {
+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 {
// Parse the section specifier and create it if valid.
StringRef Segment, Section;
unsigned TAA = 0, StubSize = 0;
bool TAAParsed;
+
+ checkMachOComdat(GV);
+
std::string ErrorCode =
MCSectionMachO::ParseSectionSpecifier(GV->getSection(), Segment, Section,
TAA, TAAParsed, StubSize);
return S;
}
+bool TargetLoweringObjectFileMachO::isSectionAtomizableBySymbols(
+ const MCSection &Section) const {
+ const MCSectionMachO &SMO = static_cast<const MCSectionMachO&>(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;
return FourByteConstantSection;
if (Kind.isMergeableConst8())
return EightByteConstantSection;
- if (Kind.isMergeableConst16() && SixteenByteConstantSection)
+ if (Kind.isMergeableConst16())
return SixteenByteConstantSection;
}
return FourByteConstantSection;
if (Kind.isMergeableConst8())
return EightByteConstantSection;
- if (Kind.isMergeableConst16() && SixteenByteConstantSection)
+ if (Kind.isMergeableConst16())
return SixteenByteConstantSection;
return ReadOnlySection; // .const
}
-/// shouldEmitUsedDirectiveFor - This hook allows targets to selectively decide
-/// not to emit the UsedDirective for some symbols in llvm.used.
-// FIXME: REMOVE this (rdar://7071300)
-bool TargetLoweringObjectFileMachO::
-shouldEmitUsedDirectiveFor(const GlobalValue *GV, Mangler &Mang) const {
- /// On Darwin, internally linked data beginning with "L" or "l" does not have
- /// the directive emitted (this occurs in ObjC metadata).
- if (!GV) return false;
-
- // Check whether the mangled name has the "Private" or "LinkerPrivate" prefix.
- if (GV->hasLocalLinkage() && !isa<Function>(GV)) {
- // FIXME: ObjC metadata is currently emitted as internal symbols that have
- // \1L and \0l prefixes on them. Fix them to be Private/LinkerPrivate and
- // this horrible hack can go away.
- MCSymbol *Sym = getSymbol(GV, Mang);
- if (Sym->getName()[0] == 'L' || Sym->getName()[0] == 'l')
- return false;
- }
-
- return true;
-}
-
const MCExpr *TargetLoweringObjectFileMachO::getTTypeGlobalReference(
const GlobalValue *GV, unsigned Encoding, Mangler &Mang,
- MachineModuleInfo *MMI, MCStreamer &Streamer) const {
+ const TargetMachine &TM, MachineModuleInfo *MMI,
+ MCStreamer &Streamer) const {
// The mach-o version of this method defaults to returning a stub reference.
if (Encoding & DW_EH_PE_indirect) {
MachineModuleInfoMachO &MachOMMI =
MMI->getObjFileInfo<MachineModuleInfoMachO>();
- MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr", Mang);
+ MCSymbol *SSym =
+ getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr", Mang, TM);
// Add information about the stub reference to MachOMMI so that the stub
// gets emitted by the asmprinter.
MachineModuleInfoImpl::StubValueTy &StubSym =
GV->hasHiddenVisibility() ? MachOMMI.getHiddenGVStubEntry(SSym) :
MachOMMI.getGVStubEntry(SSym);
- if (StubSym.getPointer() == 0) {
- MCSymbol *Sym = getSymbol(GV, Mang);
+ if (!StubSym.getPointer()) {
+ MCSymbol *Sym = TM.getSymbol(GV, Mang);
StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
}
Encoding & ~dwarf::DW_EH_PE_indirect, Streamer);
}
- return TargetLoweringObjectFile::
- getTTypeGlobalReference(GV, Encoding, Mang, MMI, Streamer);
+ return TargetLoweringObjectFile::getTTypeGlobalReference(GV, Encoding, Mang,
+ TM, MMI, Streamer);
}
-MCSymbol *TargetLoweringObjectFileMachO::
-getCFIPersonalitySymbol(const GlobalValue *GV, Mangler &Mang,
- MachineModuleInfo *MMI) const {
+MCSymbol *TargetLoweringObjectFileMachO::getCFIPersonalitySymbol(
+ const GlobalValue *GV, Mangler &Mang, const TargetMachine &TM,
+ MachineModuleInfo *MMI) const {
// The mach-o version of this method defaults to returning a stub reference.
MachineModuleInfoMachO &MachOMMI =
MMI->getObjFileInfo<MachineModuleInfoMachO>();
- MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr", Mang);
+ MCSymbol *SSym = getSymbolWithGlobalValueBase(GV, "$non_lazy_ptr", Mang, TM);
// 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) {
- MCSymbol *Sym = getSymbol(GV, Mang);
+ if (!StubSym.getPointer()) {
+ MCSymbol *Sym = TM.getSymbol(GV, Mang);
StubSym = MachineModuleInfoImpl::StubValueTy(Sym, !GV->hasLocalLinkage());
}
return Flags;
}
-const MCSection *TargetLoweringObjectFileCOFF::
-getExplicitSectionGlobal(const GlobalValue *GV, SectionKind Kind,
- Mangler &Mang, const TargetMachine &TM) const {
+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 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 {
int Selection = 0;
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 = 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,
static const char *getCOFFSectionNameForUniqueGlobal(SectionKind Kind) {
if (Kind.isText())
return ".text";
- if (Kind.isBSS ())
+ if (Kind.isBSS())
return ".bss";
if (Kind.isThreadLocal())
return ".tls$";
const MCSection *TargetLoweringObjectFileCOFF::
SelectSectionForGlobal(const GlobalValue *GV, SectionKind Kind,
Mangler &Mang, const TargetMachine &TM) const {
+ // If we have -ffunction-sections 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()) {
+ // Section names depend on the name of the symbol which is not feasible if the
+ // symbol has private linkage.
+ 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 = getSymbol(GV, Mang);
- return getContext().getCOFFSection(Name, Characteristics,
- Kind, Sym->getName(),
- COFF::IMAGE_COMDAT_SELECT_ANY);
+ 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())
if (Kind.isReadOnly())
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;
emitModuleFlags(MCStreamer &Streamer,
ArrayRef<Module::ModuleFlagEntry> 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<Module::ModuleFlagEntry>::iterator
}
}
}
+
+static const MCSection *getAssociativeCOFFSection(MCContext &Ctx,
+ const MCSection *Sec,
+ const MCSymbol *KeySym) {
+ // Return the normal section if we don't have to be associative.
+ if (!KeySym)
+ return Sec;
+
+ // Make an associative section with the same name and kind as the normal
+ // section.
+ const MCSectionCOFF *SecCOFF = cast<MCSectionCOFF>(Sec);
+ unsigned Characteristics =
+ SecCOFF->getCharacteristics() | COFF::IMAGE_SCN_LNK_COMDAT;
+ return Ctx.getCOFFSection(SecCOFF->getSectionName(), Characteristics,
+ SecCOFF->getKind(), KeySym->getName(),
+ COFF::IMAGE_COMDAT_SELECT_ASSOCIATIVE);
+}
+
+const MCSection *TargetLoweringObjectFileCOFF::getStaticCtorSection(
+ unsigned Priority, const MCSymbol *KeySym) const {
+ return getAssociativeCOFFSection(getContext(), StaticCtorSection, KeySym);
+}
+
+const MCSection *TargetLoweringObjectFileCOFF::getStaticDtorSection(
+ unsigned Priority, const MCSymbol *KeySym) const {
+ return getAssociativeCOFFSection(getContext(), StaticDtorSection, KeySym);
+}
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