[Clang][LLVM] generate btf_tag annotations for DIGlobalVariable

[yonghong-song]

Summary

Generate btf_tag annotations for DIGlobalVariable.
A field "annotations" is introduced to DIGlobalVariable, and
annotations are represented as an DINodeArray, similar to
DIComposite elements. The following example illustrates how
annotations are encoded in IR:

distinct !DIGlobalVariable(..., annotations: !10)
!10 = !{!11, !12}
!11 = !{!"btf_tag", !"a"}
!12 = !{!"btf_tag", !"b"}

[yonghong-song]

• add more cases in clang test attr-btf_tag-diglobalvariable.c

[yonghong-song]

• fix llvm/unittest failures.

[dblaikie]

Sounds good.

(any chance have you measured/could you measure how much larger the bitcode for, say, an LLVM self-host Debug build gets with all these btf patches? (even without targeting/using btf, this is adding an extra field to lots of the debug info metadata, and I'd like to know whether that makes an observable difference in file size))

clang/lib/CodeGen/CGDebugInfo.cpp

void CGDebugInfo::EmitGlobalVariable(llvm::GlobalVariable *Var,
   collectVarDeclProps(D, Unit, LineNo, T, DeclName, LinkageName,
                       TemplateParameters, DContext);
 
   // Attempt to store one global variable for the declaration - even if we
   // emit a lot of fields.
   llvm::DIGlobalVariableExpression *GVE = nullptr;
 
   // If this is an anonymous union then we'll want to emit a global
   // variable for each member of the anonymous union so that it's possible
   // to find the name of any field in the union.
   if (T->isUnionType() && DeclName.empty()) {
     const RecordDecl *RD = T->castAs<RecordType>()->getDecl();
     assert(RD->isAnonymousStructOrUnion() &&
            "unnamed non-anonymous struct or union?");
     GVE = CollectAnonRecordDecls(RD, Unit, LineNo, LinkageName, Var, DContext);
   } else {
     auto Align = getDeclAlignIfRequired(D, CGM.getContext());
 
     SmallVector<int64_t, 4> Expr;
     unsigned AddressSpace =
         CGM.getContext().getTargetAddressSpace(D->getType());
     if (CGM.getLangOpts().CUDA && CGM.getLangOpts().CUDAIsDevice) {
       if (D->hasAttr<CUDASharedAttr>())
         AddressSpace =
             CGM.getContext().getTargetAddressSpace(LangAS::cuda_shared);
       else if (D->hasAttr<CUDAConstantAttr>())
         AddressSpace =
             CGM.getContext().getTargetAddressSpace(LangAS::cuda_constant);
     }
     AppendAddressSpaceXDeref(AddressSpace, Expr);
 
+    llvm::DINodeArray Annotations = nullptr;
+    if (D->hasAttr<BTFTagAttr>())
+      Annotations = CollectBTFTagAnnotations(D);
+
     GVE = DBuilder.createGlobalVariableExpression(
         DContext, DeclName, LinkageName, Unit, LineNo, getOrCreateType(T, Unit),
         Var->hasLocalLinkage(), true,
         Expr.empty() ? nullptr : DBuilder.createExpression(Expr),
         getOrCreateStaticDataMemberDeclarationOrNull(D), TemplateParameters,
-        Align);
+        Align, Annotations);
     Var->addDebugInfo(GVE);
   }
   DeclCache[D->getCanonicalDecl()].reset(GVE);
 }
 
 void CGDebugInfo::EmitGlobalVariable(const ValueDecl *VD, const APValue &Init) {
   assert(CGM.getCodeGenOpts().hasReducedDebugInfo());
   if (VD->hasAttr<NoDebugAttr>())

clang/test/CodeGen/attr-btf_tag-diglobalvariable.c

+// REQUIRES: x86-registered-target
+// RUN: %clang -target x86_64 -g -S -emit-llvm -o - %s | FileCheck %s
+
+#define __tag1 __attribute__((btf_tag("tag1")))
+#define __tag2 __attribute__((btf_tag("tag2")))
+
+struct t1 {
+  int a;
+};
+struct t1 g1 __tag1 __tag2;
+
+extern struct t1 g2 __tag1 __tag2;
+struct t1 g2;
+
+// CHECK: distinct !DIGlobalVariable(name: "g1", scope: ![[#]], file: ![[#]], line: [[#]], type: ![[#]], isLocal: false, isDefinition: true, annotations: ![[ANNOT:[0-9]+]])
+// CHECK: distinct !DIGlobalVariable(name: "g2", scope: ![[#]], file: ![[#]], line: [[#]], type: ![[#]], isLocal: false, isDefinition: true, annotations: ![[ANNOT]])
+// CHECK: ![[ANNOT]] = !{![[TAG1:[0-9]+]], ![[TAG2:[0-9]+]]}
+// CHECK: ![[TAG1]] = !{!"btf_tag", !"tag1"}
+// CHECK: ![[TAG2]] = !{!"btf_tag", !"tag2"}
+
+extern struct t1 g3 __tag1;
+struct t1 g3 __tag2;
+
+// CHECK: distinct !DIGlobalVariable(name: "g3", scope: ![[#]], file: ![[#]], line: [[#]], type: ![[#]], isLocal: false, isDefinition: true, annotations: ![[ANNOT]])
+
+extern struct t1 g4;
+struct t1 g4 __tag1 __tag2;
+
+// CHECK: distinct !DIGlobalVariable(name: "g4", scope: ![[#]], file: ![[#]], line: [[#]], type: ![[#]], isLocal: false, isDefinition: true, annotations: ![[ANNOT]])

llvm/include/llvm/IR/DIBuilder.h

public:
     ///                    GlobalVariable.
     /// \param Decl        Reference to the corresponding declaration.
     /// \param AlignInBits Variable alignment(or 0 if no alignment attr was
     ///                    specified)
     DIGlobalVariableExpression *createGlobalVariableExpression(
         DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
         unsigned LineNo, DIType *Ty, bool IsLocalToUnit, bool isDefined = true,
         DIExpression *Expr = nullptr, MDNode *Decl = nullptr,
-        MDTuple *TemplateParams = nullptr, uint32_t AlignInBits = 0);
+        MDTuple *TemplateParams = nullptr, uint32_t AlignInBits = 0,
+        DINodeArray Annotations = nullptr);
 
     /// Identical to createGlobalVariable
     /// except that the resulting DbgNode is temporary and meant to be RAUWed.
     DIGlobalVariable *createTempGlobalVariableFwdDecl(
         DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *File,
         unsigned LineNo, DIType *Ty, bool IsLocalToUnit, MDNode *Decl = nullptr,
         MDTuple *TemplateParams= nullptr, uint32_t AlignInBits = 0);
 

llvm/include/llvm/IR/DebugInfoMetadata.h

 
 /// Global variables.
 ///
 /// TODO: Remove DisplayName.  It's always equal to Name.
 class DIGlobalVariable : public DIVariable {
   friend class LLVMContextImpl;
   friend class MDNode;
 
   bool IsLocalToUnit;
   bool IsDefinition;
 
   DIGlobalVariable(LLVMContext &C, StorageType Storage, unsigned Line,
                    bool IsLocalToUnit, bool IsDefinition, uint32_t AlignInBits,
                    ArrayRef<Metadata *> Ops)
       : DIVariable(C, DIGlobalVariableKind, Storage, Line, Ops, AlignInBits),
         IsLocalToUnit(IsLocalToUnit), IsDefinition(IsDefinition) {}
   ~DIGlobalVariable() = default;
 
   static DIGlobalVariable *
   getImpl(LLVMContext &Context, DIScope *Scope, StringRef Name,
           StringRef LinkageName, DIFile *File, unsigned Line, DIType *Type,
           bool IsLocalToUnit, bool IsDefinition,
           DIDerivedType *StaticDataMemberDeclaration, MDTuple *TemplateParams,
-          uint32_t AlignInBits, StorageType Storage, bool ShouldCreate = true) {
+          uint32_t AlignInBits, DINodeArray Annotations, StorageType Storage,
+          bool ShouldCreate = true) {
     return getImpl(Context, Scope, getCanonicalMDString(Context, Name),
                    getCanonicalMDString(Context, LinkageName), File, Line, Type,
                    IsLocalToUnit, IsDefinition, StaticDataMemberDeclaration,
-                   cast_or_null<Metadata>(TemplateParams), AlignInBits, Storage,
-                   ShouldCreate);
+                   cast_or_null<Metadata>(TemplateParams), AlignInBits,
+                   Annotations.get(), Storage, ShouldCreate);
   }
   static DIGlobalVariable *
   getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
           MDString *LinkageName, Metadata *File, unsigned Line, Metadata *Type,
           bool IsLocalToUnit, bool IsDefinition,
           Metadata *StaticDataMemberDeclaration, Metadata *TemplateParams,
-          uint32_t AlignInBits, StorageType Storage, bool ShouldCreate = true);
+          uint32_t AlignInBits, Metadata *Annotations, StorageType Storage,
+          bool ShouldCreate = true);
 
   TempDIGlobalVariable cloneImpl() const {
     return getTemporary(getContext(), getScope(), getName(), getLinkageName(),
                         getFile(), getLine(), getType(), isLocalToUnit(),
                         isDefinition(), getStaticDataMemberDeclaration(),
-                        getTemplateParams(), getAlignInBits());
+                        getTemplateParams(), getAlignInBits(),
+                        getAnnotations());
   }
 
 public:
   DEFINE_MDNODE_GET(DIGlobalVariable,
                     (DIScope * Scope, StringRef Name, StringRef LinkageName,
                      DIFile *File, unsigned Line, DIType *Type,
                      bool IsLocalToUnit, bool IsDefinition,
                      DIDerivedType *StaticDataMemberDeclaration,
-                     MDTuple *TemplateParams, uint32_t AlignInBits),
+                     MDTuple *TemplateParams, uint32_t AlignInBits,
+                     DINodeArray Annotations),
                     (Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit,
                      IsDefinition, StaticDataMemberDeclaration, TemplateParams,
-                     AlignInBits))
+                     AlignInBits, Annotations))
   DEFINE_MDNODE_GET(DIGlobalVariable,
                     (Metadata * Scope, MDString *Name, MDString *LinkageName,
                      Metadata *File, unsigned Line, Metadata *Type,
                      bool IsLocalToUnit, bool IsDefinition,
                      Metadata *StaticDataMemberDeclaration,
-                     Metadata *TemplateParams, uint32_t AlignInBits),
+                     Metadata *TemplateParams, uint32_t AlignInBits,
+                     Metadata *Annotations),
                     (Scope, Name, LinkageName, File, Line, Type, IsLocalToUnit,
                      IsDefinition, StaticDataMemberDeclaration, TemplateParams,
-                     AlignInBits))
+                     AlignInBits, Annotations))
 
   TempDIGlobalVariable clone() const { return cloneImpl(); }
 
   bool isLocalToUnit() const { return IsLocalToUnit; }
   bool isDefinition() const { return IsDefinition; }
   StringRef getDisplayName() const { return getStringOperand(4); }
   StringRef getLinkageName() const { return getStringOperand(5); }
   DIDerivedType *getStaticDataMemberDeclaration() const {
     return cast_or_null<DIDerivedType>(getRawStaticDataMemberDeclaration());
   }
+  DINodeArray getAnnotations() const {
+    return cast_or_null<MDTuple>(getRawAnnotations());
+  }
 
   MDString *getRawLinkageName() const { return getOperandAs<MDString>(5); }
   Metadata *getRawStaticDataMemberDeclaration() const { return getOperand(6); }
   Metadata *getRawTemplateParams() const { return getOperand(7); }
   MDTuple *getTemplateParams() const { return getOperandAs<MDTuple>(7); }
+  Metadata *getRawAnnotations() const { return getOperand(8); }
 
   static bool classof(const Metadata *MD) {
     return MD->getMetadataID() == DIGlobalVariableKind;
   }
 };
 
 class DICommonBlock : public DIScope {
   unsigned LineNo;

llvm/lib/AsmParser/LLParser.cpp

#define VISIT_MD_FIELDS(OPTIONAL, REQUIRED)                                    \
   OPTIONAL(linkageName, MDStringField, );                                      \
   OPTIONAL(file, MDField, );                                                   \
   OPTIONAL(line, LineField, );                                                 \
   OPTIONAL(type, MDField, );                                                   \
   OPTIONAL(isLocal, MDBoolField, );                                            \
   OPTIONAL(isDefinition, MDBoolField, (true));                                 \
   OPTIONAL(templateParams, MDField, );                                         \
   OPTIONAL(declaration, MDField, );                                            \
-  OPTIONAL(align, MDUnsignedField, (0, UINT32_MAX));
+  OPTIONAL(align, MDUnsignedField, (0, UINT32_MAX));                           \
+  OPTIONAL(annotations, MDField, );
   PARSE_MD_FIELDS();
 #undef VISIT_MD_FIELDS
 
   Result =
       GET_OR_DISTINCT(DIGlobalVariable,
                       (Context, scope.Val, name.Val, linkageName.Val, file.Val,
                        line.Val, type.Val, isLocal.Val, isDefinition.Val,
-                       declaration.Val, templateParams.Val, align.Val));
+                       declaration.Val, templateParams.Val, align.Val,
+                       annotations.Val));
   return false;
 }
 
 /// parseDILocalVariable:
 ///   ::= !DILocalVariable(arg: 7, scope: !0, name: "foo",
 ///                        file: !1, line: 7, type: !2, arg: 2, flags: 7,
 ///                        align: 8)
 ///   ::= !DILocalVariable(scope: !0, name: "foo",

llvm/lib/Bitcode/Reader/MetadataLoader.cpp

MetadataList.assignValue(
             (Context, Record[1], getMDString(Record[2]),
              getDITypeRefOrNull(Record[3]),
              (Record.size() == 6) ? getMDOrNull(Record[4]) : getMDOrNull(false),
              (Record.size() == 6) ? getMDOrNull(Record[5])
                                   : getMDOrNull(Record[4]))),
         NextMetadataNo);
     NextMetadataNo++;
     break;
   }
   case bitc::METADATA_GLOBAL_VAR: {
     if (Record.size() < 11 || Record.size() > 13)
       return error("Invalid record");
 
     IsDistinct = Record[0] & 1;
     unsigned Version = Record[0] >> 1;
 
     if (Version == 2) {
+      Metadata *Annotations = nullptr;
+      if (Record.size() > 12)
+        Annotations = getMDOrNull(Record[12]);
+
       MetadataList.assignValue(
           GET_OR_DISTINCT(
               DIGlobalVariable,
               (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
                getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
                getDITypeRefOrNull(Record[6]), Record[7], Record[8],
-               getMDOrNull(Record[9]), getMDOrNull(Record[10]), Record[11])),
+               getMDOrNull(Record[9]), getMDOrNull(Record[10]), Record[11],
+               Annotations)),
           NextMetadataNo);
 
       NextMetadataNo++;
     } else if (Version == 1) {
       // No upgrade necessary. A null field will be introduced to indicate
       // that no parameter information is available.
       MetadataList.assignValue(
           GET_OR_DISTINCT(DIGlobalVariable,
                           (Context, getMDOrNull(Record[1]),
                            getMDString(Record[2]), getMDString(Record[3]),
                            getMDOrNull(Record[4]), Record[5],
                            getDITypeRefOrNull(Record[6]), Record[7], Record[8],
-                           getMDOrNull(Record[10]), nullptr, Record[11])),
+                           getMDOrNull(Record[10]), nullptr, Record[11],
+                           nullptr)),
           NextMetadataNo);
 
       NextMetadataNo++;
     } else if (Version == 0) {
       // Upgrade old metadata, which stored a global variable reference or a
       // ConstantInt here.
       NeedUpgradeToDIGlobalVariableExpression = true;
       Metadata *Expr = getMDOrNull(Record[9]);
if (Version == 2) {
           Expr = nullptr;
         }
       }
       DIGlobalVariable *DGV = GET_OR_DISTINCT(
           DIGlobalVariable,
           (Context, getMDOrNull(Record[1]), getMDString(Record[2]),
            getMDString(Record[3]), getMDOrNull(Record[4]), Record[5],
            getDITypeRefOrNull(Record[6]), Record[7], Record[8],
-           getMDOrNull(Record[10]), nullptr, AlignInBits));
+           getMDOrNull(Record[10]), nullptr, AlignInBits, nullptr));
 
       DIGlobalVariableExpression *DGVE = nullptr;
       if (Attach || Expr)
         DGVE = DIGlobalVariableExpression::getDistinct(
             Context, DGV, Expr ? Expr : DIExpression::get(Context, {}));
       if (Attach)
         Attach->addDebugInfo(DGVE);
 

llvm/lib/Bitcode/Writer/BitcodeWriter.cpp

void ModuleBitcodeWriter::writeDIGlobalVariable(
   Record.push_back(VE.getMetadataOrNullID(N->getFile()));
   Record.push_back(N->getLine());
   Record.push_back(VE.getMetadataOrNullID(N->getType()));
   Record.push_back(N->isLocalToUnit());
   Record.push_back(N->isDefinition());
   Record.push_back(VE.getMetadataOrNullID(N->getStaticDataMemberDeclaration()));
   Record.push_back(VE.getMetadataOrNullID(N->getTemplateParams()));
   Record.push_back(N->getAlignInBits());
+  Record.push_back(VE.getMetadataOrNullID(N->getAnnotations().get()));
 
   Stream.EmitRecord(bitc::METADATA_GLOBAL_VAR, Record, Abbrev);
   Record.clear();
 }
 
 void ModuleBitcodeWriter::writeDILocalVariable(
     const DILocalVariable *N, SmallVectorImpl<uint64_t> &Record,
     unsigned Abbrev) {

llvm/lib/IR/AsmWriter.cpp

static void writeDIGlobalVariable(raw_ostream &Out, const DIGlobalVariable *N,
   Printer.printMetadata("file", N->getRawFile());
   Printer.printInt("line", N->getLine());
   Printer.printMetadata("type", N->getRawType());
   Printer.printBool("isLocal", N->isLocalToUnit());
   Printer.printBool("isDefinition", N->isDefinition());
   Printer.printMetadata("declaration", N->getRawStaticDataMemberDeclaration());
   Printer.printMetadata("templateParams", N->getRawTemplateParams());
   Printer.printInt("align", N->getAlignInBits());
+  Printer.printMetadata("annotations", N->getRawAnnotations());
   Out << ")";
 }
 
 static void writeDILocalVariable(raw_ostream &Out, const DILocalVariable *N,
                                  TypePrinting *TypePrinter,
                                  SlotTracker *Machine, const Module *Context) {
   Out << "!DILocalVariable(";
   MDFieldPrinter Printer(Out, TypePrinter, Machine, Context);

llvm/lib/IR/DIBuilder.cpp

if (auto *CT =
           dyn_cast_or_null<DICompositeType>(getNonCompileUnitScope(Context)))
     assert(CT->getIdentifier().empty() &&
            "Context of a global variable should not be a type with identifier");
 #endif
 }
 
 DIGlobalVariableExpression *DIBuilder::createGlobalVariableExpression(
     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit,
     bool isDefined, DIExpression *Expr,
-    MDNode *Decl, MDTuple *TemplateParams, uint32_t AlignInBits) {
+    MDNode *Decl, MDTuple *TemplateParams, uint32_t AlignInBits,
+    DINodeArray Annotations) {
   checkGlobalVariableScope(Context);
 
   auto *GV = DIGlobalVariable::getDistinct(
       VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
       LineNumber, Ty, IsLocalToUnit, isDefined, cast_or_null<DIDerivedType>(Decl),
-      TemplateParams, AlignInBits);
+      TemplateParams, AlignInBits, Annotations);
   if (!Expr)
     Expr = createExpression();
   auto *N = DIGlobalVariableExpression::get(VMContext, GV, Expr);
   AllGVs.push_back(N);
   return N;
 }
 
 DIGlobalVariable *DIBuilder::createTempGlobalVariableFwdDecl(
     DIScope *Context, StringRef Name, StringRef LinkageName, DIFile *F,
     unsigned LineNumber, DIType *Ty, bool IsLocalToUnit, MDNode *Decl,
     MDTuple *TemplateParams, uint32_t AlignInBits) {
   checkGlobalVariableScope(Context);
 
   return DIGlobalVariable::getTemporary(
              VMContext, cast_or_null<DIScope>(Context), Name, LinkageName, F,
              LineNumber, Ty, IsLocalToUnit, false,
-             cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits)
+             cast_or_null<DIDerivedType>(Decl), TemplateParams, AlignInBits,
+             nullptr)
       .release();
 }
 
 static DILocalVariable *createLocalVariable(
     LLVMContext &VMContext,
     DenseMap<MDNode *, SmallVector<TrackingMDNodeRef, 1>> &PreservedVariables,
     DIScope *Scope, StringRef Name, unsigned ArgNo, DIFile *File,
     unsigned LineNo, DIType *Ty, bool AlwaysPreserve, DINode::DIFlags Flags,

llvm/lib/IR/DebugInfoMetadata.cpp

DEFINE_GETIMPL_LOOKUP(DITemplateValueParameter,
                         (Tag, Name, Type, isDefault, Value));
   Metadata *Ops[] = {Name, Type, Value};
   DEFINE_GETIMPL_STORE(DITemplateValueParameter, (Tag, isDefault), Ops);
 }
 
 DIGlobalVariable *
 DIGlobalVariable::getImpl(LLVMContext &Context, Metadata *Scope, MDString *Name,
                           MDString *LinkageName, Metadata *File, unsigned Line,
                           Metadata *Type, bool IsLocalToUnit, bool IsDefinition,
                           Metadata *StaticDataMemberDeclaration,
                           Metadata *TemplateParams, uint32_t AlignInBits,
-                          StorageType Storage, bool ShouldCreate) {
+                          Metadata *Annotations, StorageType Storage,
+                          bool ShouldCreate) {
   assert(isCanonical(Name) && "Expected canonical MDString");
   assert(isCanonical(LinkageName) && "Expected canonical MDString");
   DEFINE_GETIMPL_LOOKUP(DIGlobalVariable, (Scope, Name, LinkageName, File, Line,
                                            Type, IsLocalToUnit, IsDefinition,
                                            StaticDataMemberDeclaration,
-                                           TemplateParams, AlignInBits));
+                                           TemplateParams, AlignInBits,
+                                           Annotations));
   Metadata *Ops[] = {Scope,
                      Name,
                      File,
                      Type,
                      Name,
                      LinkageName,
                      StaticDataMemberDeclaration,
-                     TemplateParams};
+                     TemplateParams,
+                     Annotations};
   DEFINE_GETIMPL_STORE(DIGlobalVariable,
                        (Line, IsLocalToUnit, IsDefinition, AlignInBits), Ops);
 }
 
 DILocalVariable *DILocalVariable::getImpl(LLVMContext &Context, Metadata *Scope,
                                           MDString *Name, Metadata *File,
                                           unsigned Line, Metadata *Type,
                                           unsigned Arg, DIFlags Flags,

llvm/lib/IR/LLVMContextImpl.h

template <> struct MDNodeKeyImpl<DIGlobalVariable> {
   Metadata *File;
   unsigned Line;
   Metadata *Type;
   bool IsLocalToUnit;
   bool IsDefinition;
   Metadata *StaticDataMemberDeclaration;
   Metadata *TemplateParams;
   uint32_t AlignInBits;
+  Metadata *Annotations;
 
   MDNodeKeyImpl(Metadata *Scope, MDString *Name, MDString *LinkageName,
                 Metadata *File, unsigned Line, Metadata *Type,
                 bool IsLocalToUnit, bool IsDefinition,
                 Metadata *StaticDataMemberDeclaration, Metadata *TemplateParams,
-                uint32_t AlignInBits)
+                uint32_t AlignInBits, Metadata *Annotations)
       : Scope(Scope), Name(Name), LinkageName(LinkageName), File(File),
         Line(Line), Type(Type), IsLocalToUnit(IsLocalToUnit),
         IsDefinition(IsDefinition),
         StaticDataMemberDeclaration(StaticDataMemberDeclaration),
-        TemplateParams(TemplateParams), AlignInBits(AlignInBits) {}
+        TemplateParams(TemplateParams), AlignInBits(AlignInBits),
+        Annotations(Annotations) {}
   MDNodeKeyImpl(const DIGlobalVariable *N)
       : Scope(N->getRawScope()), Name(N->getRawName()),
         LinkageName(N->getRawLinkageName()), File(N->getRawFile()),
         Line(N->getLine()), Type(N->getRawType()),
         IsLocalToUnit(N->isLocalToUnit()), IsDefinition(N->isDefinition()),
         StaticDataMemberDeclaration(N->getRawStaticDataMemberDeclaration()),
         TemplateParams(N->getRawTemplateParams()),
-        AlignInBits(N->getAlignInBits()) {}
+        AlignInBits(N->getAlignInBits()), Annotations(N->getRawAnnotations()) {}
 
   bool isKeyOf(const DIGlobalVariable *RHS) const {
     return Scope == RHS->getRawScope() && Name == RHS->getRawName() &&
            LinkageName == RHS->getRawLinkageName() &&
            File == RHS->getRawFile() && Line == RHS->getLine() &&
            Type == RHS->getRawType() && IsLocalToUnit == RHS->isLocalToUnit() &&
            IsDefinition == RHS->isDefinition() &&
            StaticDataMemberDeclaration ==
                RHS->getRawStaticDataMemberDeclaration() &&
            TemplateParams == RHS->getRawTemplateParams() &&
-           AlignInBits == RHS->getAlignInBits();
+           AlignInBits == RHS->getAlignInBits() &&
+           Annotations == RHS->getRawAnnotations();
   }
 
   unsigned getHashValue() const {
     // We do not use AlignInBits in hashing function here on purpose:
     // in most cases this param for local variable is zero (for function param
     // it is always zero). This leads to lots of hash collisions and errors on
     // cases with lots of similar variables.
     // clang/test/CodeGen/debug-info-257-args.c is an example of this problem,
     // generated IR is random for each run and test fails with Align included.
     // TODO: make hashing work fine with such situations
     return hash_combine(Scope, Name, LinkageName, File, Line, Type,
                         IsLocalToUnit, IsDefinition, /* AlignInBits, */
-                        StaticDataMemberDeclaration);
+                        StaticDataMemberDeclaration, Annotations);
   }
 };
 
 template <> struct MDNodeKeyImpl<DILocalVariable> {
   Metadata *Scope;
   MDString *Name;
   Metadata *File;
   unsigned Line;

llvm/test/Bitcode/attr-btf_tag-diglobalvariable.ll

+; REQUIRES: x86-registered-target
+; RUN: llvm-as < %s | llvm-dis | FileCheck %s
+
+%struct.t1 = type { i32 }
+
+@g1 = dso_local global %struct.t1 zeroinitializer, align 4, !dbg !0
+
+!llvm.dbg.cu = !{!2}
+!llvm.module.flags = !{!13, !14, !15, !16, !17}
+!llvm.ident = !{!18}
+
+!0 = !DIGlobalVariableExpression(var: !1, expr: !DIExpression())
+!1 = distinct !DIGlobalVariable(name: "g1", scope: !2, file: !3, line: 7, type: !6, isLocal: false, isDefinition: true, annotations: !10)
+!2 = distinct !DICompileUnit(language: DW_LANG_C99, file: !3, producer: "clang version 13.0.0 (https://github.com/llvm/llvm-project.git 47af5574a87dc298b5c6c36ff6a969c8c77c8499)", isOptimized: false, runtimeVersion: 0, emissionKind: FullDebug, enums: !4, globals: !5, splitDebugInlining: false, nameTableKind: None)
+!3 = !DIFile(filename: "t.c", directory: "/home/yhs/work/tests/llvm/btf_tag")
+!4 = !{}
+!5 = !{!0}
+!6 = distinct !DICompositeType(tag: DW_TAG_structure_type, name: "t1", file: !3, line: 4, size: 32, elements: !7)
+!7 = !{!8}
+!8 = !DIDerivedType(tag: DW_TAG_member, name: "a", scope: !6, file: !3, line: 5, baseType: !9, size: 32)
+!9 = !DIBasicType(name: "int", size: 32, encoding: DW_ATE_signed)
+!10 = !{!11, !12}
+!11 = !{!"btf_tag", !"tag1"}
+!12 = !{!"btf_tag", !"tag2"}
+
+; CHECK:        distinct !DIGlobalVariable(name: "g1"
+; CHECK-SAME:   annotations: ![[ANNOT:[0-9]+]]
+; CHECK:        ![[ANNOT]] = !{![[TAG1:[0-9]+]], ![[TAG2:[0-9]+]]}
+; CHECK:        ![[TAG1]] = !{!"btf_tag", !"tag1"}
+; CHECK:        ![[TAG2]] = !{!"btf_tag", !"tag2"}
+
+!13 = !{i32 7, !"Dwarf Version", i32 4}
+!14 = !{i32 2, !"Debug Info Version", i32 3}
+!15 = !{i32 1, !"wchar_size", i32 4}
+!16 = !{i32 7, !"uwtable", i32 1}
+!17 = !{i32 7, !"frame-pointer", i32 2}
+!18 = !{!"clang version 13.0.0 (https://github.com/llvm/llvm-project.git 47af5574a87dc298b5c6c36ff6a969c8c77c8499)"}