[DebugInfo] generate btf_tag annotations for DIDerived types

Generate btf_tag annotations for DIDrived types. More specifically, clang frontend generates the btf_tag annotations for record fields. The annotations are represented as an DINodeArray in DebugInfo. The following example illustrate how annotations are encoded in IR: distinct !DIDerivedType(tag: DW_TAG_member, ..., annotations: !10) !10 = !{!11, !12} !11 = !{!"btf_tag", !"a"} !12 = !{!"btf_tag", !"b"} Differential Revision: https://reviews.llvm.org/D106616
llvm · Aug 20, 2021 · 430e223 · 430e223
1 parent 5425106
commit 430e223
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diff --git a/llvm/include/llvm/IR/DIBuilder.h b/llvm/include/llvm/IR/DIBuilder.h
@@ -279,12 +279,13 @@ namespace llvm {
     /// \param OffsetInBits Member offset.
     /// \param Flags        Flags to encode member attribute, e.g. private
     /// \param Ty           Parent type.
+    /// \param Annotations  Member annotations.
     DIDerivedType *createMemberType(DIScope *Scope, StringRef Name,
                                     DIFile *File, unsigned LineNo,
-                                    uint64_t SizeInBits,
-                                    uint32_t AlignInBits,
+                                    uint64_t SizeInBits, uint32_t AlignInBits,
                                     uint64_t OffsetInBits,
-                                    DINode::DIFlags Flags, DIType *Ty);
+                                    DINode::DIFlags Flags, DIType *Ty,
+                                    DINodeArray Annotations = nullptr);
 
     /// Create debugging information entry for a variant.  A variant
     /// normally should be a member of a variant part.
@@ -317,10 +318,14 @@ namespace llvm {
     /// \param StorageOffsetInBits Member storage offset.
     /// \param Flags               Flags to encode member attribute.
     /// \param Ty                  Parent type.
-    DIDerivedType *createBitFieldMemberType(
-        DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNo,
-        uint64_t SizeInBits, uint64_t OffsetInBits,
-        uint64_t StorageOffsetInBits, DINode::DIFlags Flags, DIType *Ty);
+    /// \param Annotations         Member annotations.
+    DIDerivedType *createBitFieldMemberType(DIScope *Scope, StringRef Name,
+                                            DIFile *File, unsigned LineNo,
+                                            uint64_t SizeInBits,
+                                            uint64_t OffsetInBits,
+                                            uint64_t StorageOffsetInBits,
+                                            DINode::DIFlags Flags, DIType *Ty,
+                                            DINodeArray Annotations = nullptr);
 
     /// Create debugging information entry for a
     /// C++ static data member.

diff --git a/llvm/include/llvm/IR/DebugInfoMetadata.h b/llvm/include/llvm/IR/DebugInfoMetadata.h
@@ -936,25 +936,26 @@ class DIDerivedType : public DIType {
           unsigned Line, DIScope *Scope, DIType *BaseType, uint64_t SizeInBits,
           uint32_t AlignInBits, uint64_t OffsetInBits,
           Optional<unsigned> DWARFAddressSpace, DIFlags Flags,
-          Metadata *ExtraData, StorageType Storage, bool ShouldCreate = true) {
+          Metadata *ExtraData, DINodeArray Annotations, StorageType Storage,
+          bool ShouldCreate = true) {
     return getImpl(Context, Tag, getCanonicalMDString(Context, Name), File,
                    Line, Scope, BaseType, SizeInBits, AlignInBits, OffsetInBits,
-                   DWARFAddressSpace, Flags, ExtraData, Storage, ShouldCreate);
-  }
-  static DIDerivedType *getImpl(LLVMContext &Context, unsigned Tag,
-                                MDString *Name, Metadata *File, unsigned Line,
-                                Metadata *Scope, Metadata *BaseType,
-                                uint64_t SizeInBits, uint32_t AlignInBits,
-                                uint64_t OffsetInBits,
-                                Optional<unsigned> DWARFAddressSpace,
-                                DIFlags Flags, Metadata *ExtraData,
-                                StorageType Storage, bool ShouldCreate = true);
+                   DWARFAddressSpace, Flags, ExtraData, Annotations.get(),
+                   Storage, ShouldCreate);
+  }
+  static DIDerivedType *
+  getImpl(LLVMContext &Context, unsigned Tag, MDString *Name, Metadata *File,
+          unsigned Line, Metadata *Scope, Metadata *BaseType,
+          uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
+          Optional<unsigned> DWARFAddressSpace, DIFlags Flags,
+          Metadata *ExtraData, Metadata *Annotations, StorageType Storage,
+          bool ShouldCreate = true);
 
   TempDIDerivedType cloneImpl() const {
-    return getTemporary(getContext(), getTag(), getName(), getFile(), getLine(),
-                        getScope(), getBaseType(), getSizeInBits(),
-                        getAlignInBits(), getOffsetInBits(),
-                        getDWARFAddressSpace(), getFlags(), getExtraData());
+    return getTemporary(
+        getContext(), getTag(), getName(), getFile(), getLine(), getScope(),
+        getBaseType(), getSizeInBits(), getAlignInBits(), getOffsetInBits(),
+        getDWARFAddressSpace(), getFlags(), getExtraData(), getAnnotations());
   }
 
 public:
@@ -964,19 +965,21 @@ class DIDerivedType : public DIType {
                      uint64_t SizeInBits, uint32_t AlignInBits,
                      uint64_t OffsetInBits,
                      Optional<unsigned> DWARFAddressSpace, DIFlags Flags,
-                     Metadata *ExtraData = nullptr),
+                     Metadata *ExtraData = nullptr,
+                     Metadata *Annotations = nullptr),
                     (Tag, Name, File, Line, Scope, BaseType, SizeInBits,
                      AlignInBits, OffsetInBits, DWARFAddressSpace, Flags,
-                     ExtraData))
+                     ExtraData, Annotations))
   DEFINE_MDNODE_GET(DIDerivedType,
                     (unsigned Tag, StringRef Name, DIFile *File, unsigned Line,
                      DIScope *Scope, DIType *BaseType, uint64_t SizeInBits,
                      uint32_t AlignInBits, uint64_t OffsetInBits,
                      Optional<unsigned> DWARFAddressSpace, DIFlags Flags,
-                     Metadata *ExtraData = nullptr),
+                     Metadata *ExtraData = nullptr,
+                     DINodeArray Annotations = nullptr),
                     (Tag, Name, File, Line, Scope, BaseType, SizeInBits,
                      AlignInBits, OffsetInBits, DWARFAddressSpace, Flags,
-                     ExtraData))
+                     ExtraData, Annotations))
 
   TempDIDerivedType clone() const { return cloneImpl(); }
 
@@ -999,6 +1002,12 @@ class DIDerivedType : public DIType {
   Metadata *getExtraData() const { return getRawExtraData(); }
   Metadata *getRawExtraData() const { return getOperand(4); }
 
+  /// Get annotations associated with this derived type.
+  DINodeArray getAnnotations() const {
+    return cast_or_null<MDTuple>(getRawAnnotations());
+  }
+  Metadata *getRawAnnotations() const { return getOperand(5); }
+
   /// Get casted version of extra data.
   /// @{
   DIType *getClassType() const {

diff --git a/llvm/lib/AsmParser/LLParser.cpp b/llvm/lib/AsmParser/LLParser.cpp
@@ -4554,7 +4554,8 @@ bool LLParser::parseDIDerivedType(MDNode *&Result, bool IsDistinct) {
   OPTIONAL(offset, MDUnsignedField, (0, UINT64_MAX));                          \
   OPTIONAL(flags, DIFlagField, );                                              \
   OPTIONAL(extraData, MDField, );                                              \
-  OPTIONAL(dwarfAddressSpace, MDUnsignedField, (UINT32_MAX, UINT32_MAX));
+  OPTIONAL(dwarfAddressSpace, MDUnsignedField, (UINT32_MAX, UINT32_MAX));      \
+  OPTIONAL(annotations, MDField, );
   PARSE_MD_FIELDS();
 #undef VISIT_MD_FIELDS
 
@@ -4566,7 +4567,7 @@ bool LLParser::parseDIDerivedType(MDNode *&Result, bool IsDistinct) {
                            (Context, tag.Val, name.Val, file.Val, line.Val,
                             scope.Val, baseType.Val, size.Val, align.Val,
                             offset.Val, DWARFAddressSpace, flags.Val,
-                            extraData.Val));
+                            extraData.Val, annotations.Val));
   return false;
 }
 

diff --git a/llvm/lib/Bitcode/Reader/MetadataLoader.cpp b/llvm/lib/Bitcode/Reader/MetadataLoader.cpp
@@ -1437,7 +1437,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     break;
   }
   case bitc::METADATA_DERIVED_TYPE: {
-    if (Record.size() < 12 || Record.size() > 13)
+    if (Record.size() < 12 || Record.size() > 14)
       return error("Invalid record");
 
     // DWARF address space is encoded as N->getDWARFAddressSpace() + 1. 0 means
@@ -1446,6 +1446,10 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
     if (Record.size() > 12 && Record[12])
       DWARFAddressSpace = Record[12] - 1;
 
+    Metadata *Annotations = nullptr;
+    if (Record.size() > 13 && Record[13])
+      Annotations = getMDOrNull(Record[13]);
+
     IsDistinct = Record[0];
     DINode::DIFlags Flags = static_cast<DINode::DIFlags>(Record[10]);
     MetadataList.assignValue(
@@ -1455,7 +1459,7 @@ Error MetadataLoader::MetadataLoaderImpl::parseOneMetadata(
                          getDITypeRefOrNull(Record[5]),
                          getDITypeRefOrNull(Record[6]), Record[7], Record[8],
                          Record[9], DWARFAddressSpace, Flags,
-                         getDITypeRefOrNull(Record[11]))),
+                         getDITypeRefOrNull(Record[11]), Annotations)),
         NextMetadataNo);
     NextMetadataNo++;
     break;

diff --git a/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp b/llvm/lib/Bitcode/Writer/BitcodeWriter.cpp
@@ -1687,6 +1687,8 @@ void ModuleBitcodeWriter::writeDIDerivedType(const DIDerivedType *N,
   else
     Record.push_back(0);
 
+  Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
+
   Stream.EmitRecord(bitc::METADATA_DERIVED_TYPE, Record, Abbrev);
   Record.clear();
 }

diff --git a/llvm/lib/IR/AsmWriter.cpp b/llvm/lib/IR/AsmWriter.cpp
@@ -2039,6 +2039,7 @@ static void writeDIDerivedType(raw_ostream &Out, const DIDerivedType *N,
   if (const auto &DWARFAddressSpace = N->getDWARFAddressSpace())
     Printer.printInt("dwarfAddressSpace", *DWARFAddressSpace,
                      /* ShouldSkipZero */ false);
+  Printer.printMetadata("annotations", N->getRawAnnotations());
   Out << ")";
 }
 

diff --git a/llvm/lib/IR/DIBuilder.cpp b/llvm/lib/IR/DIBuilder.cpp
@@ -345,15 +345,14 @@ DIDerivedType *DIBuilder::createInheritance(DIType *Ty, DIType *BaseTy,
                             Flags, ExtraData);
 }
 
-DIDerivedType *DIBuilder::createMemberType(DIScope *Scope, StringRef Name,
-                                           DIFile *File, unsigned LineNumber,
-                                           uint64_t SizeInBits,
-                                           uint32_t AlignInBits,
-                                           uint64_t OffsetInBits,
-                                           DINode::DIFlags Flags, DIType *Ty) {
+DIDerivedType *DIBuilder::createMemberType(
+    DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
+    uint64_t SizeInBits, uint32_t AlignInBits, uint64_t OffsetInBits,
+    DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
   return DIDerivedType::get(VMContext, dwarf::DW_TAG_member, Name, File,
                             LineNumber, getNonCompileUnitScope(Scope), Ty,
-                            SizeInBits, AlignInBits, OffsetInBits, None, Flags);
+                            SizeInBits, AlignInBits, OffsetInBits, None, Flags,
+                            nullptr, Annotations);
 }
 
 static ConstantAsMetadata *getConstantOrNull(Constant *C) {
@@ -375,14 +374,15 @@ DIDerivedType *DIBuilder::createVariantMemberType(
 DIDerivedType *DIBuilder::createBitFieldMemberType(
     DIScope *Scope, StringRef Name, DIFile *File, unsigned LineNumber,
     uint64_t SizeInBits, uint64_t OffsetInBits, uint64_t StorageOffsetInBits,
-    DINode::DIFlags Flags, DIType *Ty) {
+    DINode::DIFlags Flags, DIType *Ty, DINodeArray Annotations) {
   Flags |= DINode::FlagBitField;
   return DIDerivedType::get(
       VMContext, dwarf::DW_TAG_member, Name, File, LineNumber,
       getNonCompileUnitScope(Scope), Ty, SizeInBits, /* AlignInBits */ 0,
       OffsetInBits, None, Flags,
       ConstantAsMetadata::get(ConstantInt::get(IntegerType::get(VMContext, 64),
-                                               StorageOffsetInBits)));
+                                               StorageOffsetInBits)),
+      Annotations);
 }
 
 DIDerivedType *

diff --git a/llvm/lib/IR/DebugInfoMetadata.cpp b/llvm/lib/IR/DebugInfoMetadata.cpp
@@ -582,13 +582,13 @@ DIDerivedType *DIDerivedType::getImpl(
     unsigned Line, Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
     uint32_t AlignInBits, uint64_t OffsetInBits,
     Optional<unsigned> DWARFAddressSpace, DIFlags Flags, Metadata *ExtraData,
-    StorageType Storage, bool ShouldCreate) {
+    Metadata *Annotations, StorageType Storage, bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
   DEFINE_GETIMPL_LOOKUP(DIDerivedType,
                         (Tag, Name, File, Line, Scope, BaseType, SizeInBits,
                          AlignInBits, OffsetInBits, DWARFAddressSpace, Flags,
-                         ExtraData));
-  Metadata *Ops[] = {File, Scope, Name, BaseType, ExtraData};
+                         ExtraData, Annotations));
+  Metadata *Ops[] = {File, Scope, Name, BaseType, ExtraData, Annotations};
   DEFINE_GETIMPL_STORE(
       DIDerivedType, (Tag, Line, SizeInBits, AlignInBits, OffsetInBits,
                       DWARFAddressSpace, Flags), Ops);

diff --git a/llvm/lib/IR/LLVMContextImpl.h b/llvm/lib/IR/LLVMContextImpl.h
@@ -471,23 +471,24 @@ template <> struct MDNodeKeyImpl<DIDerivedType> {
   Optional<unsigned> DWARFAddressSpace;
   unsigned Flags;
   Metadata *ExtraData;
+  Metadata *Annotations;
 
   MDNodeKeyImpl(unsigned Tag, MDString *Name, Metadata *File, unsigned Line,
                 Metadata *Scope, Metadata *BaseType, uint64_t SizeInBits,
                 uint32_t AlignInBits, uint64_t OffsetInBits,
                 Optional<unsigned> DWARFAddressSpace, unsigned Flags,
-                Metadata *ExtraData)
+                Metadata *ExtraData, Metadata *Annotations)
       : Tag(Tag), Name(Name), File(File), Line(Line), Scope(Scope),
         BaseType(BaseType), SizeInBits(SizeInBits), OffsetInBits(OffsetInBits),
         AlignInBits(AlignInBits), DWARFAddressSpace(DWARFAddressSpace),
-        Flags(Flags), ExtraData(ExtraData) {}
+        Flags(Flags), ExtraData(ExtraData), Annotations(Annotations) {}
   MDNodeKeyImpl(const DIDerivedType *N)
       : Tag(N->getTag()), Name(N->getRawName()), File(N->getRawFile()),
         Line(N->getLine()), Scope(N->getRawScope()),
         BaseType(N->getRawBaseType()), SizeInBits(N->getSizeInBits()),
         OffsetInBits(N->getOffsetInBits()), AlignInBits(N->getAlignInBits()),
         DWARFAddressSpace(N->getDWARFAddressSpace()), Flags(N->getFlags()),
-        ExtraData(N->getRawExtraData()) {}
+        ExtraData(N->getRawExtraData()), Annotations(N->getRawAnnotations()) {}
 
   bool isKeyOf(const DIDerivedType *RHS) const {
     return Tag == RHS->getTag() && Name == RHS->getRawName() &&
@@ -497,8 +498,8 @@ template <> struct MDNodeKeyImpl<DIDerivedType> {
            AlignInBits == RHS->getAlignInBits() &&
            OffsetInBits == RHS->getOffsetInBits() &&
            DWARFAddressSpace == RHS->getDWARFAddressSpace() &&
-           Flags == RHS->getFlags() &&
-           ExtraData == RHS->getRawExtraData();
+           Flags == RHS->getFlags() && ExtraData == RHS->getRawExtraData() &&
+           Annotations == RHS->getRawAnnotations();
   }
 
   unsigned getHashValue() const {

diff --git a/llvm/test/Bitcode/attr-btf_tag-field.ll b/llvm/test/Bitcode/attr-btf_tag-field.ll
@@ -0,0 +1,91 @@
+; REQUIRES: x86-registered-target
+; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+
+%struct.t1 = type { i32 }
+%struct.t2 = type { i8, [3 x i8] }
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local i32 @foo(%struct.t1* %arg) #0 !dbg !9 {
+entry:
+  %arg.addr = alloca %struct.t1*, align 8
+  store %struct.t1* %arg, %struct.t1** %arg.addr, align 8
+  call void @llvm.dbg.declare(metadata %struct.t1** %arg.addr, metadata !20, metadata !DIExpression()), !dbg !21
+  %0 = load %struct.t1*, %struct.t1** %arg.addr, align 8, !dbg !22
+  %a = getelementptr inbounds %struct.t1, %struct.t1* %0, i32 0, i32 0, !dbg !23
+  %1 = load i32, i32* %a, align 4, !dbg !23
+  ret i32 %1, !dbg !24
+}
+
+; Function Attrs: nofree nosync nounwind readnone speculatable willreturn
+declare void @llvm.dbg.declare(metadata, metadata, metadata) #1
+
+; Function Attrs: noinline nounwind optnone uwtable
+define dso_local i32 @foo2(%struct.t2* %arg) #0 !dbg !25 {
+entry:
+  %arg.addr = alloca %struct.t2*, align 8
+  store %struct.t2* %arg, %struct.t2** %arg.addr, align 8
+  call void @llvm.dbg.declare(metadata %struct.t2** %arg.addr, metadata !32, metadata !DIExpression()), !dbg !33
+  %0 = load %struct.t2*, %struct.t2** %arg.addr, align 8, !dbg !34
+  %1 = bitcast %struct.t2* %0 to i8*, !dbg !35
+  %bf.load = load i8, i8* %1, align 4, !dbg !35
+  %bf.shl = shl i8 %bf.load, 7, !dbg !35
+  %bf.ashr = ashr i8 %bf.shl, 7, !dbg !35
+  %bf.cast = sext i8 %bf.ashr to i32, !dbg !35
+  ret i32 %bf.cast, !dbg !36
+}
+
+attributes #0 = { noinline nounwind optnone uwtable "frame-pointer"="all" "min-legal-vector-width"="0" "no-trapping-math"="true" "stack-protector-buffer-size"="8" "target-cpu"="x86-64" "target-features"="+cx8,+fxsr,+mmx,+sse,+sse2,+x87" "tune-cpu"="generic" }
+attributes #1 = { nofree nosync nounwind readnone speculatable willreturn }
+
+!llvm.dbg.cu = !{!0}
+!llvm.module.flags = !{!3, !4, !5, !6, !7}
+!llvm.ident = !{!8}
+
+!0 = distinct !DICompileUnit(language: DW_LANG_C99, file: !1, producer: "clang version 14.0.0 (https://github.com/llvm/llvm-project.git 4cbaee98885ead226304e8836090069db6596965)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !2, splitDebugInlining: false, nameTableKind: None)
+!1 = !DIFile(filename: "attr-btf_tag-field.c", directory: "/home/yhs/work/tests/llvm/btf_tag")
+!2 = !{}
+!3 = !{i32 7, !"Dwarf Version", i32 4}
+!4 = !{i32 2, !"Debug Info Version", i32 3}
+!5 = !{i32 1, !"wchar_size", i32 4}
+!6 = !{i32 7, !"uwtable", i32 1}
+!7 = !{i32 7, !"frame-pointer", i32 2}
+!8 = !{!"clang version 14.0.0 (https://github.com/llvm/llvm-project.git 4cbaee98885ead226304e8836090069db6596965)"}
+!9 = distinct !DISubprogram(name: "foo", scope: !1, file: !1, line: 11, type: !10, scopeLine: 11, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!10 = !DISubroutineType(types: !11)
+!11 = !{!12, !13}
+!12 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!13 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !14, size: 64)
+!14 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t1", file: !1, line: 7, size: 32, elements: !15)
+!15 = !{!16}
+!16 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !14, file: !1, line: 8, baseType: !12, size: 32, annotations: !17)
+!17 = !{!18, !19}
+!18 = !{!"btf_tag", !"tag1"}
+!19 = !{!"btf_tag", !"tag2"}
+
+; CHECK:        !DIDerivedType(tag: DW_TAG_member, name: "a"
+; CHECK-SAME:   annotations: ![[ANNOT:[0-9]+]]
+; CHECK:        ![[ANNOT]] = !{![[TAG1:[0-9]+]], ![[TAG2:[0-9]+]]}
+; CHECK:        ![[TAG1]] = !{!"btf_tag", !"tag1"}
+; CHECK:        ![[TAG2]] = !{!"btf_tag", !"tag2"}
+
+!20 = !DILocalVariable(name: "arg", arg: 1, scope: !9, file: !1, line: 11, type: !13)
+!21 = !DILocation(line: 11, column: 20, scope: !9)
+!22 = !DILocation(line: 12, column: 10, scope: !9)
+!23 = !DILocation(line: 12, column: 15, scope: !9)
+!24 = !DILocation(line: 12, column: 3, scope: !9)
+!25 = distinct !DISubprogram(name: "foo2", scope: !1, file: !1, line: 19, type: !26, scopeLine: 19, flags: DIFlagPrototyped, spFlags: DISPFlagDefinition, unit: !0, retainedNodes: !2)
+!26 = !DISubroutineType(types: !27)
+!27 = !{!12, !28}
+!28 = !DIDerivedType(tag: DW_TAG_pointer_type, baseType: !29, size: 64)
+!29 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t2", file: !1, line: 15, size: 32, elements: !30)
+!30 = !{!31}
+!31 = !DIDerivedType(tag: DW_TAG_member, name: "b", scope: !29, file: !1, line: 16, baseType: !12, size: 1, flags: DIFlagBitField, extraData: i64 0, annotations: !17)
+
+; CHECK:        !DIDerivedType(tag: DW_TAG_member, name: "b"
+; CHECK-SAME:   annotations: ![[ANNOT]]
+
+!32 = !DILocalVariable(name: "arg", arg: 1, scope: !25, file: !1, line: 19, type: !28)
+!33 = !DILocation(line: 19, column: 21, scope: !25)
+!34 = !DILocation(line: 20, column: 10, scope: !25)
+!35 = !DILocation(line: 20, column: 15, scope: !25)
+!36 = !DILocation(line: 20, column: 3, scope: !25)