[llvm] 16af973 - [MC][ELF] Support for zero flag section groups
Petr Hosek via llvm-commits
llvm-commits at lists.llvm.org
Tue Feb 16 14:23:55 PST 2021
Author: Petr Hosek
Date: 2021-02-16T14:23:40-08:00
New Revision: 16af97393346ad636298605930a8b503a55eb40a
URL: https://github.com/llvm/llvm-project/commit/16af97393346ad636298605930a8b503a55eb40a
DIFF: https://github.com/llvm/llvm-project/commit/16af97393346ad636298605930a8b503a55eb40a.diff
LOG: [MC][ELF] Support for zero flag section groups
This change introduces support for zero flag ELF section groups to LLVM.
LLVM already supports COMDAT sections, which in ELF are a special type
of ELF section groups. These are generally useful to enable linker GC
where you want a group of sections to always travel together, that is to
be either retained or discarded as a whole, but without the COMDAT
semantics. Other ELF assemblers already support zero flag ELF section
groups and this change helps us reach feature parity.
Differential Revision: https://reviews.llvm.org/D95851
Added:
llvm/test/CodeGen/X86/elf-group.ll
Modified:
llvm/include/llvm/MC/MCContext.h
llvm/include/llvm/MC/MCSectionELF.h
llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
llvm/lib/MC/ELFObjectWriter.cpp
llvm/lib/MC/MCContext.cpp
llvm/lib/MC/MCELFStreamer.cpp
llvm/lib/MC/MCObjectFileInfo.cpp
llvm/lib/MC/MCParser/ELFAsmParser.cpp
llvm/lib/MC/MCSectionELF.cpp
llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
llvm/lib/Target/ARM/ARMTargetObjectFile.cpp
llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
llvm/lib/Target/Mips/MCTargetDesc/MipsOptionRecord.cpp
llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
llvm/lib/Target/XCore/XCoreTargetObjectFile.cpp
Removed:
################################################################################
diff --git a/llvm/include/llvm/MC/MCContext.h b/llvm/include/llvm/MC/MCContext.h
index 49ab0ce8d6fd..1eb31deca081 100644
--- a/llvm/include/llvm/MC/MCContext.h
+++ b/llvm/include/llvm/MC/MCContext.h
@@ -310,7 +310,7 @@ namespace llvm {
MCSectionELF *createELFSectionImpl(StringRef Section, unsigned Type,
unsigned Flags, SectionKind K,
unsigned EntrySize,
- const MCSymbolELF *Group,
+ const MCSymbolELF *Group, bool IsComdat,
unsigned UniqueID,
const MCSymbolELF *LinkedToSym);
@@ -482,24 +482,32 @@ namespace llvm {
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags) {
- return getELFSection(Section, Type, Flags, 0, "");
+ return getELFSection(Section, Type, Flags, 0, "", false);
+ }
+
+ MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
+ unsigned Flags, unsigned EntrySize) {
+ return getELFSection(Section, Type, Flags, EntrySize, "", false,
+ MCSection::NonUniqueID, nullptr);
}
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
- const Twine &Group) {
- return getELFSection(Section, Type, Flags, EntrySize, Group,
+ const Twine &Group, bool IsComdat) {
+ return getELFSection(Section, Type, Flags, EntrySize, Group, IsComdat,
MCSection::NonUniqueID, nullptr);
}
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
- const Twine &Group, unsigned UniqueID,
+ const Twine &Group, bool IsComdat,
+ unsigned UniqueID,
const MCSymbolELF *LinkedToSym);
MCSectionELF *getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
- const MCSymbolELF *Group, unsigned UniqueID,
+ const MCSymbolELF *Group, bool IsComdat,
+ unsigned UniqueID,
const MCSymbolELF *LinkedToSym);
/// Get a section with the provided group identifier. This section is
@@ -517,7 +525,8 @@ namespace llvm {
void renameELFSection(MCSectionELF *Section, StringRef Name);
- MCSectionELF *createELFGroupSection(const MCSymbolELF *Group);
+ MCSectionELF *createELFGroupSection(const MCSymbolELF *Group,
+ bool IsComdat);
void recordELFMergeableSectionInfo(StringRef SectionName, unsigned Flags,
unsigned UniqueID, unsigned EntrySize);
diff --git a/llvm/include/llvm/MC/MCSectionELF.h b/llvm/include/llvm/MC/MCSectionELF.h
index 4136ea79de41..8b17df25a158 100644
--- a/llvm/include/llvm/MC/MCSectionELF.h
+++ b/llvm/include/llvm/MC/MCSectionELF.h
@@ -13,6 +13,7 @@
#ifndef LLVM_MC_MCSECTIONELF_H
#define LLVM_MC_MCSECTIONELF_H
+#include "llvm/ADT/PointerIntPair.h"
#include "llvm/ADT/StringRef.h"
#include "llvm/MC/MCSection.h"
#include "llvm/MC/MCSymbolELF.h"
@@ -38,7 +39,9 @@ class MCSectionELF final : public MCSection {
/// fixed-sized entries 'EntrySize' will be 0.
unsigned EntrySize;
- const MCSymbolELF *Group;
+ /// The section group signature symbol (if not null) and a bool indicating
+ /// whether this is a GRP_COMDAT group.
+ const PointerIntPair<const MCSymbolELF *, 1, bool> Group;
/// Used by SHF_LINK_ORDER. If non-null, the sh_link field will be set to the
/// section header index of the section where LinkedToSym is defined.
@@ -49,13 +52,14 @@ class MCSectionELF final : public MCSection {
// The storage of Name is owned by MCContext's ELFUniquingMap.
MCSectionELF(StringRef Name, unsigned type, unsigned flags, SectionKind K,
- unsigned entrySize, const MCSymbolELF *group, unsigned UniqueID,
- MCSymbol *Begin, const MCSymbolELF *LinkedToSym)
+ unsigned entrySize, const MCSymbolELF *group, bool IsComdat,
+ unsigned UniqueID, MCSymbol *Begin,
+ const MCSymbolELF *LinkedToSym)
: MCSection(SV_ELF, Name, K, Begin), Type(type), Flags(flags),
- UniqueID(UniqueID), EntrySize(entrySize), Group(group),
+ UniqueID(UniqueID), EntrySize(entrySize), Group(group, IsComdat),
LinkedToSym(LinkedToSym) {
- if (Group)
- Group->setIsSignature();
+ if (Group.getPointer())
+ Group.getPointer()->setIsSignature();
}
// TODO Delete after we stop supporting generation of GNU-style .zdebug_*
@@ -71,7 +75,8 @@ class MCSectionELF final : public MCSection {
unsigned getFlags() const { return Flags; }
unsigned getEntrySize() const { return EntrySize; }
void setFlags(unsigned F) { Flags = F; }
- const MCSymbolELF *getGroup() const { return Group; }
+ const MCSymbolELF *getGroup() const { return Group.getPointer(); }
+ bool isComdat() const { return Group.getInt(); }
void PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
raw_ostream &OS,
diff --git a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
index 9123f207e836..764293e7f536 100644
--- a/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
+++ b/llvm/lib/CodeGen/AsmPrinter/AsmPrinter.cpp
@@ -1827,7 +1827,7 @@ bool AsmPrinter::doFinalization(Module &M) {
OutStreamer->SwitchSection(
OutContext.getELFSection(".llvm_sympart", ELF::SHT_LLVM_SYMPART, 0, 0,
- "", ++UniqueID, nullptr));
+ "", false, ++UniqueID, nullptr));
OutStreamer->emitBytes(GV.getPartition());
OutStreamer->emitZeros(1);
OutStreamer->emitValue(
@@ -3378,13 +3378,13 @@ void AsmPrinter::emitXRayTable() {
GroupName = F.getComdat()->getName();
}
InstMap = OutContext.getELFSection("xray_instr_map", ELF::SHT_PROGBITS,
- Flags, 0, GroupName,
+ Flags, 0, GroupName, F.hasComdat(),
MCSection::NonUniqueID, LinkedToSym);
if (!TM.Options.XRayOmitFunctionIndex)
FnSledIndex = OutContext.getELFSection(
"xray_fn_idx", ELF::SHT_PROGBITS, Flags | ELF::SHF_WRITE, 0,
- GroupName, MCSection::NonUniqueID, LinkedToSym);
+ GroupName, F.hasComdat(), MCSection::NonUniqueID, LinkedToSym);
} else if (MF->getSubtarget().getTargetTriple().isOSBinFormatMachO()) {
InstMap = OutContext.getMachOSection("__DATA", "xray_instr_map", 0,
SectionKind::getReadOnlyWithRel());
@@ -3480,7 +3480,7 @@ void AsmPrinter::emitPatchableFunctionEntries() {
}
OutStreamer->SwitchSection(OutContext.getELFSection(
"__patchable_function_entries", ELF::SHT_PROGBITS, Flags, 0, GroupName,
- MCSection::NonUniqueID, LinkedToSym));
+ F.hasComdat(), MCSection::NonUniqueID, LinkedToSym));
emitAlignment(Align(PointerSize));
OutStreamer->emitSymbolValue(CurrentPatchableFunctionEntrySym, PointerSize);
}
diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
index cccac072a9e6..eef05557a353 100644
--- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
+++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp
@@ -315,7 +315,7 @@ void TargetLoweringObjectFileELF::emitModuleMetadata(MCStreamer &Streamer,
if (NamedMDNode *DependentLibraries = M.getNamedMetadata("llvm.dependent-libraries")) {
auto *S = C.getELFSection(".deplibs", ELF::SHT_LLVM_DEPENDENT_LIBRARIES,
- ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
+ ELF::SHF_MERGE | ELF::SHF_STRINGS, 1);
Streamer.SwitchSection(S);
@@ -522,9 +522,11 @@ static const Comdat *getELFComdat(const GlobalValue *GV) {
if (!C)
return nullptr;
- if (C->getSelectionKind() != Comdat::Any)
- report_fatal_error("ELF COMDATs only support SelectionKind::Any, '" +
- C->getName() + "' cannot be lowered.");
+ if (C->getSelectionKind() != Comdat::Any &&
+ C->getSelectionKind() != Comdat::NoDuplicates)
+ report_fatal_error("ELF COMDATs only support SelectionKind::Any and "
+ "SelectionKind::NoDuplicates, '" + C->getName() +
+ "' cannot be lowered.");
return C;
}
@@ -669,9 +671,11 @@ MCSection *TargetLoweringObjectFileELF::getExplicitSectionGlobal(
Kind = getELFKindForNamedSection(SectionName, Kind);
StringRef Group = "";
+ bool IsComdat = false;
unsigned Flags = getELFSectionFlags(Kind);
if (const Comdat *C = getELFComdat(GO)) {
Group = C->getName();
+ IsComdat = C->getSelectionKind() == Comdat::Any;
Flags |= ELF::SHF_GROUP;
}
@@ -730,8 +734,8 @@ MCSection *TargetLoweringObjectFileELF::getExplicitSectionGlobal(
}
MCSectionELF *Section = getContext().getELFSection(
- SectionName, getELFSectionType(SectionName, Kind), Flags,
- EntrySize, Group, UniqueID, LinkedToSym);
+ SectionName, getELFSectionType(SectionName, Kind), Flags, EntrySize,
+ Group, IsComdat, UniqueID, LinkedToSym);
// Make sure that we did not get some other section with incompatible sh_link.
// This should not be possible due to UniqueID code above.
assert(Section->getLinkedToSymbol() == LinkedToSym &&
@@ -763,9 +767,11 @@ static MCSectionELF *selectELFSectionForGlobal(
unsigned *NextUniqueID, const MCSymbolELF *AssociatedSymbol) {
StringRef Group = "";
+ bool IsComdat = false;
if (const Comdat *C = getELFComdat(GO)) {
Flags |= ELF::SHF_GROUP;
Group = C->getName();
+ IsComdat = C->getSelectionKind() == Comdat::Any;
}
// Get the section entry size based on the kind.
@@ -788,7 +794,8 @@ static MCSectionELF *selectELFSectionForGlobal(
if (Kind.isExecuteOnly())
UniqueID = 0;
return Ctx.getELFSection(Name, getELFSectionType(Name, Kind), Flags,
- EntrySize, Group, UniqueID, AssociatedSymbol);
+ EntrySize, Group, IsComdat, UniqueID,
+ AssociatedSymbol);
}
MCSection *TargetLoweringObjectFileELF::SelectSectionForGlobal(
@@ -843,11 +850,13 @@ MCSection *TargetLoweringObjectFileELF::getSectionForLSDA(
const auto *LSDA = cast<MCSectionELF>(LSDASection);
unsigned Flags = LSDA->getFlags();
- StringRef Group;
const MCSymbolELF *LinkedToSym = nullptr;
- if (F.hasComdat()) {
- Group = F.getComdat()->getName();
+ StringRef Group;
+ bool IsComdat = false;
+ if (const Comdat *C = getELFComdat(&F)) {
Flags |= ELF::SHF_GROUP;
+ Group = C->getName();
+ IsComdat = C->getSelectionKind() == Comdat::Any;
}
// Use SHF_LINK_ORDER to facilitate --gc-sections if we can use GNU ld>=2.36
// or LLD, which support mixed SHF_LINK_ORDER & non-SHF_LINK_ORDER.
@@ -863,7 +872,8 @@ MCSection *TargetLoweringObjectFileELF::getSectionForLSDA(
return getContext().getELFSection(
(TM.getUniqueSectionNames() ? LSDA->getName() + "." + F.getName()
: LSDA->getName()),
- LSDA->getType(), Flags, 0, Group, MCSection::NonUniqueID, LinkedToSym);
+ LSDA->getType(), Flags, 0, Group, F.hasComdat(), MCSection::NonUniqueID,
+ LinkedToSym);
}
bool TargetLoweringObjectFileELF::shouldPutJumpTableInFunctionSection(
@@ -929,8 +939,8 @@ MCSection *TargetLoweringObjectFileELF::getSectionForMachineBasicBlock(
GroupName = F.getComdat()->getName().str();
}
return getContext().getELFSection(Name, ELF::SHT_PROGBITS, Flags,
- 0 /* Entry Size */, GroupName, UniqueID,
- nullptr);
+ 0 /* Entry Size */, GroupName,
+ F.hasComdat(), UniqueID, nullptr);
}
static MCSectionELF *getStaticStructorSection(MCContext &Ctx, bool UseInitArray,
@@ -939,7 +949,7 @@ static MCSectionELF *getStaticStructorSection(MCContext &Ctx, bool UseInitArray,
std::string Name;
unsigned Type;
unsigned Flags = ELF::SHF_ALLOC | ELF::SHF_WRITE;
- StringRef COMDAT = KeySym ? KeySym->getName() : "";
+ StringRef Comdat = KeySym ? KeySym->getName() : "";
if (KeySym)
Flags |= ELF::SHF_GROUP;
@@ -968,7 +978,7 @@ static MCSectionELF *getStaticStructorSection(MCContext &Ctx, bool UseInitArray,
Type = ELF::SHT_PROGBITS;
}
- return Ctx.getELFSection(Name, Type, Flags, 0, COMDAT);
+ return Ctx.getELFSection(Name, Type, Flags, 0, Comdat, /*IsComdat=*/true);
}
MCSection *TargetLoweringObjectFileELF::getStaticCtorSection(
@@ -1022,7 +1032,7 @@ MCSection *TargetLoweringObjectFileELF::getSectionForCommandLines() const {
// -frecord-gcc-switches which in turn attempts to mimic GCC's switch of the
// same name.
return getContext().getELFSection(".GCC.command.line", ELF::SHT_PROGBITS,
- ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
+ ELF::SHF_MERGE | ELF::SHF_STRINGS, 1);
}
void
diff --git a/llvm/lib/MC/ELFObjectWriter.cpp b/llvm/lib/MC/ELFObjectWriter.cpp
index 14556d3a7666..b99fce330c28 100644
--- a/llvm/lib/MC/ELFObjectWriter.cpp
+++ b/llvm/lib/MC/ELFObjectWriter.cpp
@@ -601,7 +601,7 @@ void ELFWriter::computeSymbolTable(
// Symbol table
unsigned EntrySize = is64Bit() ? ELF::SYMENTRY_SIZE64 : ELF::SYMENTRY_SIZE32;
MCSectionELF *SymtabSection =
- Ctx.getELFSection(".symtab", ELF::SHT_SYMTAB, 0, EntrySize, "");
+ Ctx.getELFSection(".symtab", ELF::SHT_SYMTAB, 0, EntrySize);
SymtabSection->setAlignment(is64Bit() ? Align(8) : Align(4));
SymbolTableIndex = addToSectionTable(SymtabSection);
@@ -702,7 +702,7 @@ void ELFWriter::computeSymbolTable(
if (HasLargeSectionIndex) {
MCSectionELF *SymtabShndxSection =
- Ctx.getELFSection(".symtab_shndx", ELF::SHT_SYMTAB_SHNDX, 0, 4, "");
+ Ctx.getELFSection(".symtab_shndx", ELF::SHT_SYMTAB_SHNDX, 0, 4);
SymtabShndxSectionIndex = addToSectionTable(SymtabShndxSection);
SymtabShndxSection->setAlignment(Align(4));
}
@@ -1098,7 +1098,8 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) {
if (SignatureSymbol) {
unsigned &GroupIdx = RevGroupMap[SignatureSymbol];
if (!GroupIdx) {
- MCSectionELF *Group = Ctx.createELFGroupSection(SignatureSymbol);
+ MCSectionELF *Group =
+ Ctx.createELFGroupSection(SignatureSymbol, Section.isComdat());
GroupIdx = addToSectionTable(Group);
Group->setAlignment(Align(4));
Groups.push_back(Group);
@@ -1123,7 +1124,7 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) {
if (!Asm.CGProfile.empty()) {
CGProfileSection = Ctx.getELFSection(".llvm.call-graph-profile",
ELF::SHT_LLVM_CALL_GRAPH_PROFILE,
- ELF::SHF_EXCLUDE, 16, "");
+ ELF::SHF_EXCLUDE, 16);
SectionIndexMap[CGProfileSection] = addToSectionTable(CGProfileSection);
}
@@ -1133,7 +1134,7 @@ uint64_t ELFWriter::writeObject(MCAssembler &Asm, const MCAsmLayout &Layout) {
const MCSymbol *SignatureSymbol = Group->getGroup();
assert(SignatureSymbol);
- write(uint32_t(ELF::GRP_COMDAT));
+ write(uint32_t(Group->isComdat() ? ELF::GRP_COMDAT : 0));
for (const MCSectionELF *Member : GroupMembers[SignatureSymbol]) {
uint32_t SecIndex = SectionIndexMap.lookup(Member);
write(SecIndex);
diff --git a/llvm/lib/MC/MCContext.cpp b/llvm/lib/MC/MCContext.cpp
index 9dab8a6c0910..bbff59065898 100644
--- a/llvm/lib/MC/MCContext.cpp
+++ b/llvm/lib/MC/MCContext.cpp
@@ -419,7 +419,7 @@ MCSectionELF *MCContext::createELFSectionImpl(StringRef Section, unsigned Type,
unsigned Flags, SectionKind K,
unsigned EntrySize,
const MCSymbolELF *Group,
- unsigned UniqueID,
+ bool Comdat, unsigned UniqueID,
const MCSymbolELF *LinkedToSym) {
MCSymbolELF *R;
MCSymbol *&Sym = Symbols[Section];
@@ -439,8 +439,9 @@ MCSectionELF *MCContext::createELFSectionImpl(StringRef Section, unsigned Type,
R->setBinding(ELF::STB_LOCAL);
R->setType(ELF::STT_SECTION);
- auto *Ret = new (ELFAllocator.Allocate()) MCSectionELF(
- Section, Type, Flags, K, EntrySize, Group, UniqueID, R, LinkedToSym);
+ auto *Ret = new (ELFAllocator.Allocate())
+ MCSectionELF(Section, Type, Flags, K, EntrySize, Group, Comdat, UniqueID,
+ R, LinkedToSym);
auto *F = new MCDataFragment();
Ret->getFragmentList().insert(Ret->begin(), F);
@@ -461,32 +462,34 @@ MCSectionELF *MCContext::createELFRelSection(const Twine &Name, unsigned Type,
return createELFSectionImpl(
I->getKey(), Type, Flags, SectionKind::getReadOnly(), EntrySize, Group,
- true, cast<MCSymbolELF>(RelInfoSection->getBeginSymbol()));
+ true, true, cast<MCSymbolELF>(RelInfoSection->getBeginSymbol()));
}
MCSectionELF *MCContext::getELFNamedSection(const Twine &Prefix,
const Twine &Suffix, unsigned Type,
unsigned Flags,
unsigned EntrySize) {
- return getELFSection(Prefix + "." + Suffix, Type, Flags, EntrySize, Suffix);
+ return getELFSection(Prefix + "." + Suffix, Type, Flags, EntrySize, Suffix,
+ /*IsComdat=*/true);
}
MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
- const Twine &Group, unsigned UniqueID,
+ const Twine &Group, bool IsComdat,
+ unsigned UniqueID,
const MCSymbolELF *LinkedToSym) {
MCSymbolELF *GroupSym = nullptr;
if (!Group.isTriviallyEmpty() && !Group.str().empty())
GroupSym = cast<MCSymbolELF>(getOrCreateSymbol(Group));
- return getELFSection(Section, Type, Flags, EntrySize, GroupSym, UniqueID,
- LinkedToSym);
+ return getELFSection(Section, Type, Flags, EntrySize, GroupSym, IsComdat,
+ UniqueID, LinkedToSym);
}
MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
unsigned Flags, unsigned EntrySize,
const MCSymbolELF *GroupSym,
- unsigned UniqueID,
+ bool IsComdat, unsigned UniqueID,
const MCSymbolELF *LinkedToSym) {
StringRef Group = "";
if (GroupSym)
@@ -513,7 +516,7 @@ MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
MCSectionELF *Result =
createELFSectionImpl(CachedName, Type, Flags, Kind, EntrySize, GroupSym,
- UniqueID, LinkedToSym);
+ IsComdat, UniqueID, LinkedToSym);
Entry.second = Result;
recordELFMergeableSectionInfo(Result->getName(), Result->getFlags(),
@@ -522,9 +525,10 @@ MCSectionELF *MCContext::getELFSection(const Twine &Section, unsigned Type,
return Result;
}
-MCSectionELF *MCContext::createELFGroupSection(const MCSymbolELF *Group) {
+MCSectionELF *MCContext::createELFGroupSection(const MCSymbolELF *Group,
+ bool IsComdat) {
return createELFSectionImpl(".group", ELF::SHT_GROUP, 0,
- SectionKind::getReadOnly(), 4, Group,
+ SectionKind::getReadOnly(), 4, Group, IsComdat,
MCSection::NonUniqueID, nullptr);
}
diff --git a/llvm/lib/MC/MCELFStreamer.cpp b/llvm/lib/MC/MCELFStreamer.cpp
index db45aef7d506..f51f0997a4b4 100644
--- a/llvm/lib/MC/MCELFStreamer.cpp
+++ b/llvm/lib/MC/MCELFStreamer.cpp
@@ -375,7 +375,7 @@ void MCELFStreamer::emitCGProfileEntry(const MCSymbolRefExpr *From,
void MCELFStreamer::emitIdent(StringRef IdentString) {
MCSection *Comment = getAssembler().getContext().getELFSection(
- ".comment", ELF::SHT_PROGBITS, ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
+ ".comment", ELF::SHT_PROGBITS, ELF::SHF_MERGE | ELF::SHF_STRINGS, 1);
PushSection();
SwitchSection(Comment);
if (!SeenIdent) {
diff --git a/llvm/lib/MC/MCObjectFileInfo.cpp b/llvm/lib/MC/MCObjectFileInfo.cpp
index 0a682fb95767..9690eafe3653 100644
--- a/llvm/lib/MC/MCObjectFileInfo.cpp
+++ b/llvm/lib/MC/MCObjectFileInfo.cpp
@@ -371,19 +371,19 @@ void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
MergeableConst4Section =
Ctx->getELFSection(".rodata.cst4", ELF::SHT_PROGBITS,
- ELF::SHF_ALLOC | ELF::SHF_MERGE, 4, "");
+ ELF::SHF_ALLOC | ELF::SHF_MERGE, 4);
MergeableConst8Section =
Ctx->getELFSection(".rodata.cst8", ELF::SHT_PROGBITS,
- ELF::SHF_ALLOC | ELF::SHF_MERGE, 8, "");
+ ELF::SHF_ALLOC | ELF::SHF_MERGE, 8);
MergeableConst16Section =
Ctx->getELFSection(".rodata.cst16", ELF::SHT_PROGBITS,
- ELF::SHF_ALLOC | ELF::SHF_MERGE, 16, "");
+ ELF::SHF_ALLOC | ELF::SHF_MERGE, 16);
MergeableConst32Section =
Ctx->getELFSection(".rodata.cst32", ELF::SHT_PROGBITS,
- ELF::SHF_ALLOC | ELF::SHF_MERGE, 32, "");
+ ELF::SHF_ALLOC | ELF::SHF_MERGE, 32);
// Exception Handling Sections.
@@ -412,7 +412,7 @@ void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
DwarfLineSection = Ctx->getELFSection(".debug_line", DebugSecType, 0);
DwarfLineStrSection =
Ctx->getELFSection(".debug_line_str", DebugSecType,
- ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
+ ELF::SHF_MERGE | ELF::SHF_STRINGS, 1);
DwarfFrameSection = Ctx->getELFSection(".debug_frame", DebugSecType, 0);
DwarfPubNamesSection =
Ctx->getELFSection(".debug_pubnames", DebugSecType, 0);
@@ -424,7 +424,7 @@ void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
Ctx->getELFSection(".debug_gnu_pubtypes", DebugSecType, 0);
DwarfStrSection =
Ctx->getELFSection(".debug_str", DebugSecType,
- ELF::SHF_MERGE | ELF::SHF_STRINGS, 1, "");
+ ELF::SHF_MERGE | ELF::SHF_STRINGS, 1);
DwarfLocSection = Ctx->getELFSection(".debug_loc", DebugSecType, 0);
DwarfARangesSection =
Ctx->getELFSection(".debug_aranges", DebugSecType, 0);
@@ -464,7 +464,7 @@ void MCObjectFileInfo::initELFMCObjectFileInfo(const Triple &T, bool Large) {
Ctx->getELFSection(".debug_abbrev.dwo", DebugSecType, ELF::SHF_EXCLUDE);
DwarfStrDWOSection = Ctx->getELFSection(
".debug_str.dwo", DebugSecType,
- ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1, "");
+ ELF::SHF_MERGE | ELF::SHF_STRINGS | ELF::SHF_EXCLUDE, 1);
DwarfLineDWOSection =
Ctx->getELFSection(".debug_line.dwo", DebugSecType, ELF::SHF_EXCLUDE);
DwarfLocDWOSection =
@@ -981,7 +981,7 @@ MCSection *MCObjectFileInfo::getDwarfComdatSection(const char *Name,
switch (TT.getObjectFormat()) {
case Triple::ELF:
return Ctx->getELFSection(Name, ELF::SHT_PROGBITS, ELF::SHF_GROUP, 0,
- utostr(Hash));
+ utostr(Hash), /*IsComdat=*/true);
case Triple::Wasm:
return Ctx->getWasmSection(Name, SectionKind::getMetadata(), utostr(Hash),
MCContext::GenericSectionID);
@@ -1011,7 +1011,7 @@ MCObjectFileInfo::getStackSizesSection(const MCSection &TextSec) const {
}
return Ctx->getELFSection(".stack_sizes", ELF::SHT_PROGBITS, Flags, 0,
- GroupName, ElfSec.getUniqueID(),
+ GroupName, true, ElfSec.getUniqueID(),
cast<MCSymbolELF>(TextSec.getBeginSymbol()));
}
@@ -1031,7 +1031,7 @@ MCObjectFileInfo::getBBAddrMapSection(const MCSection &TextSec) const {
// Use the text section's begin symbol and unique ID to create a separate
// .llvm_bb_addr_map section associated with every unique text section.
return Ctx->getELFSection(".llvm_bb_addr_map", ELF::SHT_LLVM_BB_ADDR_MAP,
- Flags, 0, GroupName, ElfSec.getUniqueID(),
+ Flags, 0, GroupName, true, ElfSec.getUniqueID(),
cast<MCSymbolELF>(TextSec.getBeginSymbol()));
}
@@ -1044,7 +1044,8 @@ MCObjectFileInfo::getPseudoProbeSection(const MCSection *TextSec) const {
auto *S = static_cast<MCSectionELF *>(PseudoProbeSection);
auto Flags = S->getFlags() | ELF::SHF_GROUP;
return Ctx->getELFSection(S->getName(), S->getType(), Flags,
- S->getEntrySize(), Group->getName());
+ S->getEntrySize(), Group->getName(),
+ /*IsComdat=*/true);
}
}
return PseudoProbeSection;
@@ -1067,7 +1068,8 @@ MCObjectFileInfo::getPseudoProbeDescSection(StringRef FuncName) const {
auto Flags = S->getFlags() | ELF::SHF_GROUP;
return Ctx->getELFSection(S->getName(), S->getType(), Flags,
S->getEntrySize(),
- S->getName() + "_" + FuncName);
+ S->getName() + "_" + FuncName,
+ /*IsComdat=*/true);
}
}
return PseudoProbeDescSection;
diff --git a/llvm/lib/MC/MCParser/ELFAsmParser.cpp b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
index 39ccaa45c9e1..7de19a067a61 100644
--- a/llvm/lib/MC/MCParser/ELFAsmParser.cpp
+++ b/llvm/lib/MC/MCParser/ELFAsmParser.cpp
@@ -157,7 +157,7 @@ class ELFAsmParser : public MCAsmParserExtension {
unsigned parseSunStyleSectionFlags();
bool maybeParseSectionType(StringRef &TypeName);
bool parseMergeSize(int64_t &Size);
- bool parseGroup(StringRef &GroupName);
+ bool parseGroup(StringRef &GroupName, bool &IsComdat);
bool parseLinkedToSym(MCSymbolELF *&LinkedToSym);
bool maybeParseUniqueID(int64_t &UniqueID);
};
@@ -424,7 +424,7 @@ bool ELFAsmParser::parseMergeSize(int64_t &Size) {
return false;
}
-bool ELFAsmParser::parseGroup(StringRef &GroupName) {
+bool ELFAsmParser::parseGroup(StringRef &GroupName, bool &IsComdat) {
MCAsmLexer &L = getLexer();
if (L.isNot(AsmToken::Comma))
return TokError("expected group name");
@@ -442,6 +442,9 @@ bool ELFAsmParser::parseGroup(StringRef &GroupName) {
return TokError("invalid linkage");
if (Linkage != "comdat")
return TokError("Linkage must be 'comdat'");
+ IsComdat = true;
+ } else {
+ IsComdat = false;
}
return false;
}
@@ -502,6 +505,7 @@ bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc) {
StringRef TypeName;
int64_t Size = 0;
StringRef GroupName;
+ bool IsComdat = false;
unsigned Flags = 0;
unsigned extraFlags = 0;
const MCExpr *Subsection = nullptr;
@@ -574,7 +578,7 @@ bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc) {
if (parseMergeSize(Size))
return true;
if (Group)
- if (parseGroup(GroupName))
+ if (parseGroup(GroupName, IsComdat))
return true;
if (Flags & ELF::SHF_LINK_ORDER)
if (parseLinkedToSym(LinkedToSym))
@@ -640,12 +644,14 @@ bool ELFAsmParser::ParseSectionArguments(bool IsPush, SMLoc loc) {
cast_or_null<MCSectionELF>(CurrentSection.first))
if (const MCSymbol *Group = Section->getGroup()) {
GroupName = Group->getName();
+ IsComdat = Section->isComdat();
Flags |= ELF::SHF_GROUP;
}
}
- MCSectionELF *Section = getContext().getELFSection(
- SectionName, Type, Flags, Size, GroupName, UniqueID, LinkedToSym);
+ MCSectionELF *Section =
+ getContext().getELFSection(SectionName, Type, Flags, Size, GroupName,
+ IsComdat, UniqueID, LinkedToSym);
getStreamer().SwitchSection(Section, Subsection);
// x86-64 psABI names SHT_X86_64_UNWIND as the canonical type for .eh_frame,
// but GNU as emits SHT_PROGBITS .eh_frame for .cfi_* directives. Don't error
diff --git a/llvm/lib/MC/MCSectionELF.cpp b/llvm/lib/MC/MCSectionELF.cpp
index 300f209d213d..d18876507cd7 100644
--- a/llvm/lib/MC/MCSectionELF.cpp
+++ b/llvm/lib/MC/MCSectionELF.cpp
@@ -171,8 +171,9 @@ void MCSectionELF::PrintSwitchToSection(const MCAsmInfo &MAI, const Triple &T,
if (Flags & ELF::SHF_GROUP) {
OS << ",";
- printName(OS, Group->getName());
- OS << ",comdat";
+ printName(OS, Group.getPointer()->getName());
+ if (isComdat())
+ OS << ",comdat";
}
if (Flags & ELF::SHF_LINK_ORDER) {
diff --git a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
index ecace64a6530..672efdfe0c80 100644
--- a/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
+++ b/llvm/lib/Target/AArch64/AArch64AsmPrinter.cpp
@@ -377,7 +377,7 @@ void AArch64AsmPrinter::EmitHwasanMemaccessSymbols(Module &M) {
OutStreamer->SwitchSection(OutContext.getELFSection(
".text.hot", ELF::SHT_PROGBITS,
ELF::SHF_EXECINSTR | ELF::SHF_ALLOC | ELF::SHF_GROUP, 0,
- Sym->getName()));
+ Sym->getName(), /*IsComdat=*/true));
OutStreamer->emitSymbolAttribute(Sym, MCSA_ELF_TypeFunction);
OutStreamer->emitSymbolAttribute(Sym, MCSA_Weak);
diff --git a/llvm/lib/Target/ARM/ARMTargetObjectFile.cpp b/llvm/lib/Target/ARM/ARMTargetObjectFile.cpp
index 3f0e3360632d..b03bff92f373 100644
--- a/llvm/lib/Target/ARM/ARMTargetObjectFile.cpp
+++ b/llvm/lib/Target/ARM/ARMTargetObjectFile.cpp
@@ -49,7 +49,8 @@ void ARMElfTargetObjectFile::Initialize(MCContext &Ctx,
// Since we cannot modify flags for an existing section, we create a new
// section with the right flags, and use 0 as the unique ID for
// execute-only text
- TextSection = Ctx.getELFSection(".text", Type, Flags, 0, "", 0U, nullptr);
+ TextSection =
+ Ctx.getELFSection(".text", Type, Flags, 0, "", false, 0U, nullptr);
}
}
diff --git a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
index 07ca5c29f0ec..2fc104b87221 100644
--- a/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
+++ b/llvm/lib/Target/ARM/MCTargetDesc/ARMELFStreamer.cpp
@@ -1203,7 +1203,8 @@ inline void ARMELFStreamer::SwitchToEHSection(StringRef Prefix,
if (Group)
Flags |= ELF::SHF_GROUP;
MCSectionELF *EHSection = getContext().getELFSection(
- EHSecName, Type, Flags, 0, Group, FnSection.getUniqueID(),
+ EHSecName, Type, Flags, 0, Group, /*IsComdat=*/true,
+ FnSection.getUniqueID(),
static_cast<const MCSymbolELF *>(FnSection.getBeginSymbol()));
assert(EHSection && "Failed to get the required EH section");
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsOptionRecord.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsOptionRecord.cpp
index a4a953bcd7c3..befa883d5877 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsOptionRecord.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsOptionRecord.cpp
@@ -35,7 +35,7 @@ void MipsRegInfoRecord::EmitMipsOptionRecord() {
// 1-byte long nor fixed length but it matches the value GAS emits.
MCSectionELF *Sec =
Context.getELFSection(".MIPS.options", ELF::SHT_MIPS_OPTIONS,
- ELF::SHF_ALLOC | ELF::SHF_MIPS_NOSTRIP, 1, "");
+ ELF::SHF_ALLOC | ELF::SHF_MIPS_NOSTRIP, 1);
MCA.registerSection(*Sec);
Sec->setAlignment(Align(8));
Streamer->SwitchSection(Sec);
@@ -53,7 +53,7 @@ void MipsRegInfoRecord::EmitMipsOptionRecord() {
Streamer->emitIntValue(ri_gp_value, 8);
} else {
MCSectionELF *Sec = Context.getELFSection(".reginfo", ELF::SHT_MIPS_REGINFO,
- ELF::SHF_ALLOC, 24, "");
+ ELF::SHF_ALLOC, 24);
MCA.registerSection(*Sec);
Sec->setAlignment(MTS->getABI().IsN32() ? Align(8) : Align(4));
Streamer->SwitchSection(Sec);
diff --git a/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp b/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
index 6ec8fe805968..232d0eb33164 100644
--- a/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
+++ b/llvm/lib/Target/Mips/MCTargetDesc/MipsTargetStreamer.cpp
@@ -1309,7 +1309,7 @@ void MipsTargetELFStreamer::emitMipsAbiFlags() {
MCContext &Context = MCA.getContext();
MCStreamer &OS = getStreamer();
MCSectionELF *Sec = Context.getELFSection(
- ".MIPS.abiflags", ELF::SHT_MIPS_ABIFLAGS, ELF::SHF_ALLOC, 24, "");
+ ".MIPS.abiflags", ELF::SHT_MIPS_ABIFLAGS, ELF::SHF_ALLOC, 24);
MCA.registerSection(*Sec);
Sec->setAlignment(Align(8));
OS.SwitchSection(Sec);
diff --git a/llvm/lib/Target/XCore/XCoreTargetObjectFile.cpp b/llvm/lib/Target/XCore/XCoreTargetObjectFile.cpp
index 9fec74a372fb..52a0a09d3ea5 100644
--- a/llvm/lib/Target/XCore/XCoreTargetObjectFile.cpp
+++ b/llvm/lib/Target/XCore/XCoreTargetObjectFile.cpp
@@ -46,13 +46,13 @@ void XCoreTargetObjectFile::Initialize(MCContext &Ctx, const TargetMachine &TM){
ELF::SHF_ALLOC | ELF::XCORE_SHF_CP_SECTION);
MergeableConst4Section = Ctx.getELFSection(
".cp.rodata.cst4", ELF::SHT_PROGBITS,
- ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 4, "");
+ ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 4);
MergeableConst8Section = Ctx.getELFSection(
".cp.rodata.cst8", ELF::SHT_PROGBITS,
- ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 8, "");
+ ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 8);
MergeableConst16Section = Ctx.getELFSection(
".cp.rodata.cst16", ELF::SHT_PROGBITS,
- ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 16, "");
+ ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::XCORE_SHF_CP_SECTION, 16);
CStringSection =
Ctx.getELFSection(".cp.rodata.string", ELF::SHT_PROGBITS,
ELF::SHF_ALLOC | ELF::SHF_MERGE | ELF::SHF_STRINGS |
diff --git a/llvm/test/CodeGen/X86/elf-group.ll b/llvm/test/CodeGen/X86/elf-group.ll
new file mode 100644
index 000000000000..79fa41e5ba8f
--- /dev/null
+++ b/llvm/test/CodeGen/X86/elf-group.ll
@@ -0,0 +1,19 @@
+; Checks that comdat with noduplicates kind is lowered to a zero-flag ELF
+; section group.
+; RUN: llc < %s -mtriple=x86_64-unknown-linux | FileCheck %s
+
+; CHECK: .section .text.f1,"axG", at progbits,f1{{$}}
+; CHECK: .section .text.f2,"axG", at progbits,f1{{$}}
+; CHECK: .section .bss.g1,"aGw", at nobits,f1{{$}}
+
+$f1 = comdat noduplicates
+
+define void @f1() comdat {
+ unreachable
+}
+
+define hidden void @f2() comdat($f1) {
+ unreachable
+}
+
+ at g1 = global i32 0, comdat($f1)
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