llvmbot wrote:
<!--LLVM PR SUMMARY COMMENT--> @llvm/pr-subscribers-llvm-ir Author: Peter Collingbourne (pcc) <details> <summary>Changes</summary> This new metadata type may be used to set sh_type and sh_entsize on a global's section. TODO: - Add tests. --- Full diff: https://github.com/llvm/llvm-project/pull/149260.diff 2 Files Affected: - (modified) llvm/include/llvm/IR/FixedMetadataKinds.def (+1) - (modified) llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp (+37-23) ``````````diff diff --git a/llvm/include/llvm/IR/FixedMetadataKinds.def b/llvm/include/llvm/IR/FixedMetadataKinds.def index df572e8791e13..16fd9f4996176 100644 --- a/llvm/include/llvm/IR/FixedMetadataKinds.def +++ b/llvm/include/llvm/IR/FixedMetadataKinds.def @@ -53,3 +53,4 @@ LLVM_FIXED_MD_KIND(MD_DIAssignID, "DIAssignID", 38) LLVM_FIXED_MD_KIND(MD_coro_outside_frame, "coro.outside.frame", 39) LLVM_FIXED_MD_KIND(MD_mmra, "mmra", 40) LLVM_FIXED_MD_KIND(MD_noalias_addrspace, "noalias.addrspace", 41) +LLVM_FIXED_MD_KIND(MD_elf_section_properties, "elf_section_properties", 42) diff --git a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp index 5454cd475f5ed..2c523b58d0de4 100644 --- a/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp +++ b/llvm/lib/CodeGen/TargetLoweringObjectFileImpl.cpp @@ -653,10 +653,11 @@ static StringRef getSectionPrefixForGlobal(SectionKind Kind, bool IsLarge) { static SmallString<128> getELFSectionNameForGlobal(const GlobalObject *GO, SectionKind Kind, Mangler &Mang, const TargetMachine &TM, - unsigned EntrySize, bool UniqueSectionName, + bool UniqueSectionName, const MachineJumpTableEntry *JTE) { SmallString<128> Name = getSectionPrefixForGlobal(Kind, TM.isLargeGlobalValue(GO)); + unsigned EntrySize = getEntrySizeForKind(Kind); if (Kind.isMergeableCString()) { // We also need alignment here. // FIXME: this is getting the alignment of the character, not the @@ -790,8 +791,8 @@ calcUniqueIDUpdateFlagsAndSize(const GlobalObject *GO, StringRef SectionName, // implicitly for this symbol e.g. .rodata.str1.1, then we don't need // to unique the section as the entry size for this symbol will be // compatible with implicitly created sections. - SmallString<128> ImplicitSectionNameStem = getELFSectionNameForGlobal( - GO, Kind, Mang, TM, EntrySize, false, /*MJTE=*/nullptr); + SmallString<128> ImplicitSectionNameStem = + getELFSectionNameForGlobal(GO, Kind, Mang, TM, false, /*MJTE=*/nullptr); if (SymbolMergeable && Ctx.isELFImplicitMergeableSectionNamePrefix(SectionName) && SectionName.starts_with(ImplicitSectionNameStem)) @@ -802,8 +803,9 @@ calcUniqueIDUpdateFlagsAndSize(const GlobalObject *GO, StringRef SectionName, return NextUniqueID++; } -static std::tuple<StringRef, bool, unsigned> -getGlobalObjectInfo(const GlobalObject *GO, const TargetMachine &TM) { +static std::tuple<StringRef, bool, unsigned, unsigned, unsigned> +getGlobalObjectInfo(const GlobalObject *GO, const TargetMachine &TM, + StringRef SectionName, SectionKind Kind) { StringRef Group = ""; bool IsComdat = false; unsigned Flags = 0; @@ -814,7 +816,23 @@ getGlobalObjectInfo(const GlobalObject *GO, const TargetMachine &TM) { } if (TM.isLargeGlobalValue(GO)) Flags |= ELF::SHF_X86_64_LARGE; - return {Group, IsComdat, Flags}; + + unsigned Type, EntrySize; + if (MDNode *MD = GO->getMetadata(LLVMContext::MD_elf_section_properties)) { + Type = cast<ConstantAsMetadata>(MD->getOperand(0)) + ->getValue() + ->getUniqueInteger() + .getZExtValue(); + EntrySize = cast<ConstantAsMetadata>(MD->getOperand(1)) + ->getValue() + ->getUniqueInteger() + .getZExtValue(); + } else { + Type = getELFSectionType(SectionName, Kind); + EntrySize = getEntrySizeForKind(Kind); + } + + return {Group, IsComdat, Flags, Type, EntrySize}; } static StringRef handlePragmaClangSection(const GlobalObject *GO, @@ -850,18 +868,18 @@ static MCSection *selectExplicitSectionGlobal(const GlobalObject *GO, Kind = getELFKindForNamedSection(SectionName, Kind); unsigned Flags = getELFSectionFlags(Kind, TM.getTargetTriple()); - auto [Group, IsComdat, ExtraFlags] = getGlobalObjectInfo(GO, TM); + auto [Group, IsComdat, ExtraFlags, Type, EntrySize] = + getGlobalObjectInfo(GO, TM, SectionName, Kind); Flags |= ExtraFlags; - unsigned EntrySize = getEntrySizeForKind(Kind); const unsigned UniqueID = calcUniqueIDUpdateFlagsAndSize( GO, SectionName, Kind, TM, Ctx, Mang, Flags, EntrySize, NextUniqueID, Retain, ForceUnique); const MCSymbolELF *LinkedToSym = getLinkedToSymbol(GO, TM); - MCSectionELF *Section = Ctx.getELFSection( - SectionName, getELFSectionType(SectionName, Kind), Flags, EntrySize, - Group, IsComdat, UniqueID, LinkedToSym); + MCSectionELF *Section = + Ctx.getELFSection(SectionName, Type, 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 && @@ -899,13 +917,6 @@ static MCSectionELF *selectELFSectionForGlobal( const TargetMachine &TM, bool EmitUniqueSection, unsigned Flags, unsigned *NextUniqueID, const MCSymbolELF *AssociatedSymbol, const MachineJumpTableEntry *MJTE = nullptr) { - - auto [Group, IsComdat, ExtraFlags] = getGlobalObjectInfo(GO, TM); - Flags |= ExtraFlags; - - // Get the section entry size based on the kind. - unsigned EntrySize = getEntrySizeForKind(Kind); - bool UniqueSectionName = false; unsigned UniqueID = MCSection::NonUniqueID; if (EmitUniqueSection) { @@ -916,15 +927,18 @@ static MCSectionELF *selectELFSectionForGlobal( (*NextUniqueID)++; } } - SmallString<128> Name = getELFSectionNameForGlobal( - GO, Kind, Mang, TM, EntrySize, UniqueSectionName, MJTE); + SmallString<128> Name = + getELFSectionNameForGlobal(GO, Kind, Mang, TM, UniqueSectionName, MJTE); + + auto [Group, IsComdat, ExtraFlags, Type, EntrySize] = + getGlobalObjectInfo(GO, TM, Name, Kind); + Flags |= ExtraFlags; // Use 0 as the unique ID for execute-only text. if (Kind.isExecuteOnly()) UniqueID = 0; - return Ctx.getELFSection(Name, getELFSectionType(Name, Kind), Flags, - EntrySize, Group, IsComdat, UniqueID, - AssociatedSymbol); + return Ctx.getELFSection(Name, Type, Flags, EntrySize, Group, IsComdat, + UniqueID, AssociatedSymbol); } static MCSection *selectELFSectionForGlobal( `````````` </details> https://github.com/llvm/llvm-project/pull/149260 _______________________________________________ llvm-branch-commits mailing list llvm-branch-commits@lists.llvm.org https://lists.llvm.org/cgi-bin/mailman/listinfo/llvm-branch-commits
