[NFC] Let mangler accept GlobalDecl

[yaxunl]

Summary

This change is separated from https://reviews.llvm.org/D68578

[rjmccall]

clang/lib/CodeGen/CodeGenModule.cpp

1028

What would be necessary in order for this to turn into just mangleName(GD, Out)? I suspect there are a lot of subtle assumptions between the different mangling methods today that could probably be broken down a bit and we'd end up with something much cleaner.

[yaxunl]

clang/lib/CodeGen/CodeGenModule.cpp

1028

It seems to be just API changes. I will try changing them.

[yaxunl]

clang/lib/CodeGen/CodeGenModule.cpp

1028

I got one issue. When I tried to create GlobalDecl(CD, Ctor_DefaultClosure) I got assertion

include/llvm/ADT/PointerIntPair.h:186: static intptr_t llvm::PointerIntPairInfo<const clang::Decl *, 2, llvm::PointerLikeTypeTraits<const clang::Decl *> >::updateInt(intptr_t, intptr_t) [PointerT = const clang::Decl *, IntBits = 2, PtrTraits = llvm::PointerLikeTypeTraits<const clang::Decl *>]: Assertion `(IntWord & ~IntMask) == 0 && "Integer too large for field"' failed.
CXXConstructor=v:7:25 (default constructor) (converting constructor)

This is because Ctor_DefaultClosure has value 4, which exceeds the value that can be put into PointerIntPairInfo

[yaxunl]

Remove mangleCXXCtor/Dtor.

[rjmccall]

clang/lib/AST/Expr.cpp

693 ↗

(On Diff #248873)

This will need an extension for your case, right? Maybe there should be comments in GlobalDecl pointing out all the places where we need to go from an arbitrary Decl* to a GlobalDecl so that someone adding a new kind of discriminated declaration will know to update them all.

clang/lib/AST/ItaniumMangle.cpp

1568

cast? But I'm not sure this is true, local entities can be in non-function declarations: blocks, ObjC methods, and captured statements. You can just cast<Decl>(DC).

clang/lib/CodeGen/CodeGenModule.cpp

1028

It looks like Decl is declared with alignment 8, so yeah, it's safe to make that a 3-bit field.

[yaxunl]

revised by John's comments.

[rjmccall]

clang/lib/AST/ItaniumMangle.cpp

1568

I guess we just never enter this for local names within ObjC methods or blocks?

[yaxunl]

clang/lib/AST/Expr.cpp

693 ↗

(On Diff #248873)

Added extension for kernel reference here and other places in the other patch. Also added comments to GlobalDecl.

clang/lib/AST/ItaniumMangle.cpp

1568

Original code is cast<FunctionDecl>(DC) since ObjCMethodDecl and BlockDecl are handled separately. Since we dot have GlobalDecl ctor for Decl*, I will cast to FunctionDecl.

1568

Yes.

clang/include/clang/AST/GlobalDecl.h

 
 public:
   GlobalDecl() = default;
   GlobalDecl(const VarDecl *D) { Init(D);}
   GlobalDecl(const FunctionDecl *D, unsigned MVIndex = 0)
       : MultiVersionIndex(MVIndex) {
     Init(D);
   }
+  GlobalDecl(const NamedDecl *D) { Init(D); }
   GlobalDecl(const BlockDecl *D) { Init(D); }
   GlobalDecl(const CapturedDecl *D) { Init(D); }
   GlobalDecl(const ObjCMethodDecl *D) { Init(D); }
   GlobalDecl(const OMPDeclareReductionDecl *D) { Init(D); }
   GlobalDecl(const OMPDeclareMapperDecl *D) { Init(D); }
   GlobalDecl(const CXXConstructorDecl *D, CXXCtorType Type) : Value(D, Type) {}
   GlobalDecl(const CXXDestructorDecl *D, CXXDtorType Type) : Value(D, Type) {}
   GlobalDecl(const VarDecl *D, DynamicInitKind StubKind)
public:
 
   friend bool operator==(const GlobalDecl &LHS, const GlobalDecl &RHS) {
     return LHS.Value == RHS.Value &&
            LHS.MultiVersionIndex == RHS.MultiVersionIndex;
   }
 
   void *getAsOpaquePtr() const { return Value.getOpaqueValue(); }
 
+  explicit operator bool() const { return getAsOpaquePtr(); }
+
   static GlobalDecl getFromOpaquePtr(void *P) {
     GlobalDecl GD;
     GD.Value.setFromOpaqueValue(P);
     return GD;
   }
 
   GlobalDecl getWithDecl(const Decl *D) {
     GlobalDecl Result(*this);

clang/include/clang/AST/Mangle.h

 //===--- Mangle.h - Mangle C++ Names ----------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 //
 // Defines the C++ name mangling interface.
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_AST_MANGLE_H
 #define LLVM_CLANG_AST_MANGLE_H
 
 #include "clang/AST/Decl.h"
+#include "clang/AST/GlobalDecl.h"
 #include "clang/AST/Type.h"
 #include "clang/Basic/ABI.h"
 #include "llvm/ADT/DenseMap.h"
 #include "llvm/Support/Casting.h"
 
 namespace llvm {
   class raw_ostream;
 }
public:
   /// @name Mangler Entry Points
   /// @{
 
   bool shouldMangleDeclName(const NamedDecl *D);
   virtual bool shouldMangleCXXName(const NamedDecl *D) = 0;
   virtual bool shouldMangleStringLiteral(const StringLiteral *SL) = 0;
 
   // FIXME: consider replacing raw_ostream & with something like SmallString &.
-  void mangleName(const NamedDecl *D, raw_ostream &);
-  virtual void mangleCXXName(const NamedDecl *D, raw_ostream &) = 0;
+  void mangleName(GlobalDecl GD, raw_ostream &);
+  virtual void mangleCXXName(GlobalDecl GD, raw_ostream &) = 0;
   virtual void mangleThunk(const CXXMethodDecl *MD,
                           const ThunkInfo &Thunk,
                           raw_ostream &) = 0;
   virtual void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
                                   const ThisAdjustment &ThisAdjustment,
                                   raw_ostream &) = 0;
   virtual void mangleReferenceTemporary(const VarDecl *D,
                                         unsigned ManglingNumber,

clang/lib/AST/ItaniumMangle.cpp

public:
 
   /// @name Mangler Entry Points
   /// @{
 
   bool shouldMangleCXXName(const NamedDecl *D) override;
   bool shouldMangleStringLiteral(const StringLiteral *) override {
     return false;
   }
-  void mangleCXXName(const NamedDecl *D, raw_ostream &) override;
+  void mangleCXXName(GlobalDecl GD, raw_ostream &) override;
   void mangleThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk,
                    raw_ostream &) override;
   void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
                           const ThisAdjustment &ThisAdjustment,
                           raw_ostream &) override;
   void mangleReferenceTemporary(const VarDecl *D, unsigned ManglingNumber,
                                 raw_ostream &) override;
   void mangleCXXVTable(const CXXRecordDecl *RD, raw_ostream &) override;
CXXNameMangler(CXXNameMangler &Outer, llvm::raw_null_ostream &Out_)
         SeqID(Outer.SeqID), FunctionTypeDepth(Outer.FunctionTypeDepth),
         AbiTagsRoot(AbiTags), Substitutions(Outer.Substitutions) {}
 
   raw_ostream &getStream() { return Out; }
 
   void disableDerivedAbiTags() { DisableDerivedAbiTags = true; }
   static bool shouldHaveAbiTags(ItaniumMangleContextImpl &C, const VarDecl *VD);
 
-  void mangle(const NamedDecl *D);
+  void mangle(GlobalDecl GD);
   void mangleCallOffset(int64_t NonVirtual, int64_t Virtual);
   void mangleNumber(const llvm::APSInt &I);
   void mangleNumber(int64_t Number);
   void mangleFloat(const llvm::APFloat &F);
-  void mangleFunctionEncoding(const FunctionDecl *FD);
+  void mangleFunctionEncoding(GlobalDecl GD);
   void mangleSeqID(unsigned SeqID);
-  void mangleName(const NamedDecl *ND);
+  void mangleName(GlobalDecl GD);
   void mangleType(QualType T);
   void mangleNameOrStandardSubstitution(const NamedDecl *ND);
   void mangleLambdaSig(const CXXRecordDecl *Lambda);
 
 private:
 
   bool mangleSubstitution(const NamedDecl *ND);
   bool mangleSubstitution(QualType T);
private:
   void mangleUnresolvedName(NestedNameSpecifier *qualifier,
                             DeclarationName name,
                             const TemplateArgumentLoc *TemplateArgs,
                             unsigned NumTemplateArgs,
                             unsigned KnownArity = UnknownArity);
 
   void mangleFunctionEncodingBareType(const FunctionDecl *FD);
 
-  void mangleNameWithAbiTags(const NamedDecl *ND,
+  void mangleNameWithAbiTags(GlobalDecl GD,
                              const AbiTagList *AdditionalAbiTags);
   void mangleModuleName(const Module *M);
   void mangleModuleNamePrefix(StringRef Name);
   void mangleTemplateName(const TemplateDecl *TD,
                           const TemplateArgument *TemplateArgs,
                           unsigned NumTemplateArgs);
-  void mangleUnqualifiedName(const NamedDecl *ND,
+  void mangleUnqualifiedName(GlobalDecl GD,
                              const AbiTagList *AdditionalAbiTags) {
-    mangleUnqualifiedName(ND, ND->getDeclName(), UnknownArity,
+    mangleUnqualifiedName(GD, cast<NamedDecl>(GD.getDecl())->getDeclName(), UnknownArity,
                           AdditionalAbiTags);
   }
-  void mangleUnqualifiedName(const NamedDecl *ND, DeclarationName Name,
+  void mangleUnqualifiedName(GlobalDecl GD, DeclarationName Name,
                              unsigned KnownArity,
                              const AbiTagList *AdditionalAbiTags);
-  void mangleUnscopedName(const NamedDecl *ND,
+  void mangleUnscopedName(GlobalDecl GD,
                           const AbiTagList *AdditionalAbiTags);
-  void mangleUnscopedTemplateName(const TemplateDecl *ND,
+  void mangleUnscopedTemplateName(GlobalDecl GD,
                                   const AbiTagList *AdditionalAbiTags);
   void mangleUnscopedTemplateName(TemplateName,
                                   const AbiTagList *AdditionalAbiTags);
   void mangleSourceName(const IdentifierInfo *II);
   void mangleRegCallName(const IdentifierInfo *II);
+  void mangleDeviceStubName(const IdentifierInfo *II);
   void mangleSourceNameWithAbiTags(
       const NamedDecl *ND, const AbiTagList *AdditionalAbiTags = nullptr);
-  void mangleLocalName(const Decl *D,
+  void mangleLocalName(GlobalDecl GD,
                        const AbiTagList *AdditionalAbiTags);
   void mangleBlockForPrefix(const BlockDecl *Block);
   void mangleUnqualifiedBlock(const BlockDecl *Block);
   void mangleTemplateParamDecl(const NamedDecl *Decl);
   void mangleLambda(const CXXRecordDecl *Lambda);
-  void mangleNestedName(const NamedDecl *ND, const DeclContext *DC,
+  void mangleNestedName(GlobalDecl GD, const DeclContext *DC,
                         const AbiTagList *AdditionalAbiTags,
                         bool NoFunction=false);
   void mangleNestedName(const TemplateDecl *TD,
                         const TemplateArgument *TemplateArgs,
                         unsigned NumTemplateArgs);
   void manglePrefix(NestedNameSpecifier *qualifier);
   void manglePrefix(const DeclContext *DC, bool NoFunction=false);
   void manglePrefix(QualType type);
-  void mangleTemplatePrefix(const TemplateDecl *ND, bool NoFunction=false);
+  void mangleTemplatePrefix(GlobalDecl GD, bool NoFunction=false);
   void mangleTemplatePrefix(TemplateName Template);
   bool mangleUnresolvedTypeOrSimpleId(QualType DestroyedType,
                                       StringRef Prefix = "");
   void mangleOperatorName(DeclarationName Name, unsigned Arity);
   void mangleOperatorName(OverloadedOperatorKind OO, unsigned Arity);
   void mangleVendorQualifier(StringRef qualifier);
   void mangleQualifiers(Qualifiers Quals, const DependentAddressSpaceType *DAST = nullptr);
   void mangleRefQualifier(RefQualifierKind RefQualifier);

 }
 
 void CXXNameMangler::mangleSourceNameWithAbiTags(
     const NamedDecl *ND, const AbiTagList *AdditionalAbiTags) {
   mangleSourceName(ND->getIdentifier());
   writeAbiTags(ND, AdditionalAbiTags);
 }
 
-void CXXNameMangler::mangle(const NamedDecl *D) {
+void CXXNameMangler::mangle(GlobalDecl GD) {
   // <mangled-name> ::= _Z <encoding>
   //            ::= <data name>
   //            ::= <special-name>
   Out << "_Z";
-  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(D))
-    mangleFunctionEncoding(FD);
-  else if (const VarDecl *VD = dyn_cast<VarDecl>(D))
+  if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(GD.getDecl()))
+    mangleFunctionEncoding(GD);
+  else if (const VarDecl *VD = dyn_cast<VarDecl>(GD.getDecl()))
     mangleName(VD);
-  else if (const IndirectFieldDecl *IFD = dyn_cast<IndirectFieldDecl>(D))
+  else if (const IndirectFieldDecl *IFD =
+               dyn_cast<IndirectFieldDecl>(GD.getDecl()))
     mangleName(IFD->getAnonField());
   else
-    mangleName(cast<FieldDecl>(D));
+    mangleName(cast<FieldDecl>(GD.getDecl()));
 }
 
-void CXXNameMangler::mangleFunctionEncoding(const FunctionDecl *FD) {
+void CXXNameMangler::mangleFunctionEncoding(GlobalDecl GD) {
+  const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
   // <encoding> ::= <function name> <bare-function-type>
 
   // Don't mangle in the type if this isn't a decl we should typically mangle.
   if (!Context.shouldMangleDeclName(FD)) {
-    mangleName(FD);
+    mangleName(GD);
     return;
   }
 
   AbiTagList ReturnTypeAbiTags = makeFunctionReturnTypeTags(FD);
   if (ReturnTypeAbiTags.empty()) {
     // There are no tags for return type, the simplest case.
-    mangleName(FD);
+    mangleName(GD);
     mangleFunctionEncodingBareType(FD);
     return;
   }
 
   // Mangle function name and encoding to temporary buffer.
   // We have to output name and encoding to the same mangler to get the same
   // substitution as it will be in final mangling.
   SmallString<256> FunctionEncodingBuf;

 // namespace.
 static bool isStdNamespace(const DeclContext *DC) {
   if (!DC->isNamespace())
     return false;
 
   return isStd(cast<NamespaceDecl>(DC));
 }
 
-static const TemplateDecl *
-isTemplate(const NamedDecl *ND, const TemplateArgumentList *&TemplateArgs) {
+static const GlobalDecl
+isTemplate(GlobalDecl GD, const TemplateArgumentList *&TemplateArgs) {
+  const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
   // Check if we have a function template.
   if (const FunctionDecl *FD = dyn_cast<FunctionDecl>(ND)) {
     if (const TemplateDecl *TD = FD->getPrimaryTemplate()) {
       TemplateArgs = FD->getTemplateSpecializationArgs();
-      return TD;
+      return GD.getWithDecl(TD);
     }
   }
 
   // Check if we have a class template.
   if (const ClassTemplateSpecializationDecl *Spec =
         dyn_cast<ClassTemplateSpecializationDecl>(ND)) {
     TemplateArgs = &Spec->getTemplateArgs();
-    return Spec->getSpecializedTemplate();
+    return GD.getWithDecl(Spec->getSpecializedTemplate());
   }
 
   // Check if we have a variable template.
   if (const VarTemplateSpecializationDecl *Spec =
           dyn_cast<VarTemplateSpecializationDecl>(ND)) {
     TemplateArgs = &Spec->getTemplateArgs();
-    return Spec->getSpecializedTemplate();
+    return GD.getWithDecl(Spec->getSpecializedTemplate());
   }
 
-  return nullptr;
+  return GlobalDecl();
 }
 
-void CXXNameMangler::mangleName(const NamedDecl *ND) {
+void CXXNameMangler::mangleName(GlobalDecl GD) {
+  const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
   if (const VarDecl *VD = dyn_cast<VarDecl>(ND)) {
     // Variables should have implicit tags from its type.
     AbiTagList VariableTypeAbiTags = makeVariableTypeTags(VD);
     if (VariableTypeAbiTags.empty()) {
       // Simple case no variable type tags.
       mangleNameWithAbiTags(VD, nullptr);
       return;
     }
AdditionalAbiTags.erase(
         std::set_difference(VariableTypeAbiTags.begin(),
                             VariableTypeAbiTags.end(), UsedAbiTags.begin(),
                             UsedAbiTags.end(), AdditionalAbiTags.begin()),
         AdditionalAbiTags.end());
 
     // Output name with implicit tags.
     mangleNameWithAbiTags(VD, &AdditionalAbiTags);
   } else {
-    mangleNameWithAbiTags(ND, nullptr);
+    mangleNameWithAbiTags(GD, nullptr);
   }
 }
 
-void CXXNameMangler::mangleNameWithAbiTags(const NamedDecl *ND,
+void CXXNameMangler::mangleNameWithAbiTags(GlobalDecl GD,
                                            const AbiTagList *AdditionalAbiTags) {
+  const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
   //  <name> ::= [<module-name>] <nested-name>
   //         ::= [<module-name>] <unscoped-name>
   //         ::= [<module-name>] <unscoped-template-name> <template-args>
   //         ::= <local-name>
   //
   const DeclContext *DC = getEffectiveDeclContext(ND);
 
   // If this is an extern variable declared locally, the relevant DeclContext
   // is that of the containing namespace, or the translation unit.
   // FIXME: This is a hack; extern variables declared locally should have
   // a proper semantic declaration context!
   if (isLocalContainerContext(DC) && ND->hasLinkage() && !isLambda(ND))
     while (!DC->isNamespace() && !DC->isTranslationUnit())
       DC = getEffectiveParentContext(DC);
   else if (GetLocalClassDecl(ND)) {
-    mangleLocalName(ND, AdditionalAbiTags);
+    mangleLocalName(GD, AdditionalAbiTags);
     return;
   }
 
   DC = IgnoreLinkageSpecDecls(DC);
 
   if (isLocalContainerContext(DC)) {
-    mangleLocalName(ND, AdditionalAbiTags);
+    mangleLocalName(GD, AdditionalAbiTags);
     return;
   }
 
   // Do not mangle the owning module for an external linkage declaration.
   // This enables backwards-compatibility with non-modular code, and is
   // a valid choice since conflicts are not permitted by C++ Modules TS
   // [basic.def.odr]/6.2.
   if (!ND->hasExternalFormalLinkage())
     if (Module *M = ND->getOwningModuleForLinkage())
       mangleModuleName(M);
 
   if (DC->isTranslationUnit() || isStdNamespace(DC)) {
     // Check if we have a template.
     const TemplateArgumentList *TemplateArgs = nullptr;
-    if (const TemplateDecl *TD = isTemplate(ND, TemplateArgs)) {
+    if (GlobalDecl TD = isTemplate(GD, TemplateArgs)) {
       mangleUnscopedTemplateName(TD, AdditionalAbiTags);
       mangleTemplateArgs(*TemplateArgs);
       return;
     }
 
-    mangleUnscopedName(ND, AdditionalAbiTags);
+    mangleUnscopedName(GD, AdditionalAbiTags);
     return;
   }
 
-  mangleNestedName(ND, DC, AdditionalAbiTags);
+  mangleNestedName(GD, DC, AdditionalAbiTags);
 }
 
 void CXXNameMangler::mangleModuleName(const Module *M) {
   // Implement the C++ Modules TS name mangling proposal; see
   //     https://gcc.gnu.org/wiki/cxx-modules?action=AttachFile
   //
   //   <module-name> ::= W <unscoped-name>+ E
   //                 ::= W <module-subst> <unscoped-name>* E
void CXXNameMangler::mangleTemplateName(const TemplateDecl *TD,
   if (DC->isTranslationUnit() || isStdNamespace(DC)) {
     mangleUnscopedTemplateName(TD, nullptr);
     mangleTemplateArgs(TemplateArgs, NumTemplateArgs);
   } else {
     mangleNestedName(TD, TemplateArgs, NumTemplateArgs);
   }
 }
 
-void CXXNameMangler::mangleUnscopedName(const NamedDecl *ND,
+void CXXNameMangler::mangleUnscopedName(GlobalDecl GD,
                                         const AbiTagList *AdditionalAbiTags) {
+  const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
   //  <unscoped-name> ::= <unqualified-name>
   //                  ::= St <unqualified-name>   # ::std::
 
   if (isStdNamespace(IgnoreLinkageSpecDecls(getEffectiveDeclContext(ND))))
     Out << "St";
 
-  mangleUnqualifiedName(ND, AdditionalAbiTags);
+  mangleUnqualifiedName(GD, AdditionalAbiTags);
 }
 
 void CXXNameMangler::mangleUnscopedTemplateName(
-    const TemplateDecl *ND, const AbiTagList *AdditionalAbiTags) {
+    GlobalDecl GD, const AbiTagList *AdditionalAbiTags) {
+  const TemplateDecl *ND = cast<TemplateDecl>(GD.getDecl());
   //     <unscoped-template-name> ::= <unscoped-name>
   //                              ::= <substitution>
   if (mangleSubstitution(ND))
     return;
 
   // <template-template-param> ::= <template-param>
   if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(ND)) {
     assert(!AdditionalAbiTags &&
            "template template param cannot have abi tags");
     mangleTemplateParameter(TTP->getDepth(), TTP->getIndex());
   } else if (isa<BuiltinTemplateDecl>(ND) || isa<ConceptDecl>(ND)) {
-    mangleUnscopedName(ND, AdditionalAbiTags);
+    mangleUnscopedName(GD, AdditionalAbiTags);
   } else {
-    mangleUnscopedName(ND->getTemplatedDecl(), AdditionalAbiTags);
+    mangleUnscopedName(GD.getWithDecl(ND->getTemplatedDecl()), AdditionalAbiTags);
   }
 
   addSubstitution(ND);
 }
 
 void CXXNameMangler::mangleUnscopedTemplateName(
     TemplateName Template, const AbiTagList *AdditionalAbiTags) {
   //     <unscoped-template-name> ::= <unscoped-name>
void CXXNameMangler::mangleUnresolvedName(
   }
 
   // The <simple-id> and on <operator-name> productions end in an optional
   // <template-args>.
   if (TemplateArgs)
     mangleTemplateArgs(TemplateArgs, NumTemplateArgs);
 }
 
-void CXXNameMangler::mangleUnqualifiedName(const NamedDecl *ND,
+void CXXNameMangler::mangleUnqualifiedName(GlobalDecl GD,
                                            DeclarationName Name,
                                            unsigned KnownArity,
                                            const AbiTagList *AdditionalAbiTags) {
+  const NamedDecl *ND = cast_or_null<NamedDecl>(GD.getDecl());
   unsigned Arity = KnownArity;
   //  <unqualified-name> ::= <operator-name>
   //                     ::= <ctor-dtor-name>
   //                     ::= <source-name>
   switch (Name.getNameKind()) {
   case DeclarationName::Identifier: {
     const IdentifierInfo *II = Name.getAsIdentifierInfo();
 

 
 void CXXNameMangler::mangleSourceName(const IdentifierInfo *II) {
   // <source-name> ::= <positive length number> <identifier>
   // <number> ::= [n] <non-negative decimal integer>
   // <identifier> ::= <unqualified source code identifier>
   Out << II->getLength() << II->getName();
 }
 
-void CXXNameMangler::mangleNestedName(const NamedDecl *ND,
+void CXXNameMangler::mangleNestedName(GlobalDecl GD,
                                       const DeclContext *DC,
                                       const AbiTagList *AdditionalAbiTags,
                                       bool NoFunction) {
+  const NamedDecl *ND = cast<NamedDecl>(GD.getDecl());
   // <nested-name>
   //   ::= N [<CV-qualifiers>] [<ref-qualifier>] <prefix> <unqualified-name> E
   //   ::= N [<CV-qualifiers>] [<ref-qualifier>] <template-prefix>
   //       <template-args> E
 
   Out << 'N';
   if (const CXXMethodDecl *Method = dyn_cast<CXXMethodDecl>(ND)) {
     Qualifiers MethodQuals = Method->getMethodQualifiers();
     // We do not consider restrict a distinguishing attribute for overloading
     // purposes so we must not mangle it.
     MethodQuals.removeRestrict();
     mangleQualifiers(MethodQuals);
     mangleRefQualifier(Method->getRefQualifier());
   }
 
   // Check if we have a template.
   const TemplateArgumentList *TemplateArgs = nullptr;
-  if (const TemplateDecl *TD = isTemplate(ND, TemplateArgs)) {
+  if (GlobalDecl TD = isTemplate(GD, TemplateArgs)) {
     mangleTemplatePrefix(TD, NoFunction);
     mangleTemplateArgs(*TemplateArgs);
   }
   else {
     manglePrefix(DC, NoFunction);
-    mangleUnqualifiedName(ND, AdditionalAbiTags);
+    mangleUnqualifiedName(GD, AdditionalAbiTags);
   }
 
   Out << 'E';
 }
 void CXXNameMangler::mangleNestedName(const TemplateDecl *TD,
                                       const TemplateArgument *TemplateArgs,
                                       unsigned NumTemplateArgs) {
   // <nested-name> ::= N [<CV-qualifiers>] <template-prefix> <template-args> E
 
   Out << 'N';
 
   mangleTemplatePrefix(TD);
   mangleTemplateArgs(TemplateArgs, NumTemplateArgs);
 
   Out << 'E';
 }
 
-void CXXNameMangler::mangleLocalName(const Decl *D,
+static GlobalDecl getParentOfLocalEntity(const DeclContext *DC) {
+  GlobalDecl GD;
+  // The Itanium spec says:
+  // For entities in constructors and destructors, the mangling of the
+  // complete object constructor or destructor is used as the base function
+  // name, i.e. the C1 or D1 version.
+  if (auto *CD = dyn_cast<CXXConstructorDecl>(DC))
+    GD = GlobalDecl(CD, Ctor_Complete);
+  else if (auto *DD = dyn_cast<CXXDestructorDecl>(DC))
+    GD = GlobalDecl(DD, Dtor_Complete);
+  else
+    GD = GlobalDecl(dyn_cast<FunctionDecl>(DC));
+  return GD;
+}
+
+void CXXNameMangler::mangleLocalName(GlobalDecl GD,
                                      const AbiTagList *AdditionalAbiTags) {
+  const Decl *D = GD.getDecl();
   // <local-name> := Z <function encoding> E <entity name> [<discriminator>]
   //              := Z <function encoding> E s [<discriminator>]
   // <local-name> := Z <function encoding> E d [ <parameter number> ]
   //                 _ <entity name>
   // <discriminator> := _ <non-negative number>
   assert(isa<NamedDecl>(D) || isa<BlockDecl>(D));
   const RecordDecl *RD = GetLocalClassDecl(D);
   const DeclContext *DC = getEffectiveDeclContext(RD ? RD : D);
 
   Out << 'Z';
 
   {
     AbiTagState LocalAbiTags(AbiTags);
 
     if (const ObjCMethodDecl *MD = dyn_cast<ObjCMethodDecl>(DC))
       mangleObjCMethodName(MD);
     else if (const BlockDecl *BD = dyn_cast<BlockDecl>(DC))
       mangleBlockForPrefix(BD);
     else
-      mangleFunctionEncoding(cast<FunctionDecl>(DC));
+      mangleFunctionEncoding(getParentOfLocalEntity(DC));
 
     // Implicit ABI tags (from namespace) are not available in the following
     // entity; reset to actually emitted tags, which are available.
     LocalAbiTags.setUsedAbiTags(LocalAbiTags.getEmittedAbiTags());
   }
 
   Out << 'E';
 
if (RD) {
     if (D == RD)  {
       mangleUnqualifiedName(RD, AdditionalAbiTags);
     } else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
       manglePrefix(getEffectiveDeclContext(BD), true /*NoFunction*/);
       assert(!AdditionalAbiTags && "Block cannot have additional abi tags");
       mangleUnqualifiedBlock(BD);
     } else {
       const NamedDecl *ND = cast<NamedDecl>(D);
-      mangleNestedName(ND, getEffectiveDeclContext(ND), AdditionalAbiTags,
+      mangleNestedName(GD, getEffectiveDeclContext(ND), AdditionalAbiTags,
                        true /*NoFunction*/);
     }
   } else if (const BlockDecl *BD = dyn_cast<BlockDecl>(D)) {
     // Mangle a block in a default parameter; see above explanation for
     // lambdas.
     if (const ParmVarDecl *Parm
             = dyn_cast_or_null<ParmVarDecl>(BD->getBlockManglingContextDecl())) {
       if (const FunctionDecl *Func
             = dyn_cast<FunctionDecl>(Parm->getDeclContext())) {
         Out << 'd';
         unsigned Num = Func->getNumParams() - Parm->getFunctionScopeIndex();
         if (Num > 1)
           mangleNumber(Num - 2);
         Out << '_';
       }
     }
 
     assert(!AdditionalAbiTags && "Block cannot have additional abi tags");
     mangleUnqualifiedBlock(BD);
   } else {
-    mangleUnqualifiedName(cast<NamedDecl>(D), AdditionalAbiTags);
+    mangleUnqualifiedName(GD, AdditionalAbiTags);
   }
 
   if (const NamedDecl *ND = dyn_cast<NamedDecl>(RD ? RD : D)) {
     unsigned disc;
     if (Context.getNextDiscriminator(ND, disc)) {
       if (disc < 10)
         Out << '_' << disc;
       else
void CXXNameMangler::manglePrefix(const DeclContext *DC, bool NoFunction) {
   assert(!isLocalContainerContext(DC));
 
   const NamedDecl *ND = cast<NamedDecl>(DC);
   if (mangleSubstitution(ND))
     return;
 
   // Check if we have a template.
   const TemplateArgumentList *TemplateArgs = nullptr;
-  if (const TemplateDecl *TD = isTemplate(ND, TemplateArgs)) {
+  if (GlobalDecl TD = isTemplate(ND, TemplateArgs)) {
     mangleTemplatePrefix(TD);
     mangleTemplateArgs(*TemplateArgs);
   } else {
     manglePrefix(getEffectiveDeclContext(ND), NoFunction);
     mangleUnqualifiedName(ND, nullptr);
   }
 
   addSubstitution(ND);
 }
 
 void CXXNameMangler::mangleTemplatePrefix(TemplateName Template) {
   // <template-prefix> ::= <prefix> <template unqualified-name>
   //                   ::= <template-param>
   //                   ::= <substitution>
   if (TemplateDecl *TD = Template.getAsTemplateDecl())
     return mangleTemplatePrefix(TD);
 
   if (QualifiedTemplateName *Qualified = Template.getAsQualifiedTemplateName())
     manglePrefix(Qualified->getQualifier());
 
   if (OverloadedTemplateStorage *Overloaded
                                       = Template.getAsOverloadedTemplate()) {
-    mangleUnqualifiedName(nullptr, (*Overloaded->begin())->getDeclName(),
+    mangleUnqualifiedName(GlobalDecl(), (*Overloaded->begin())->getDeclName(),
                           UnknownArity, nullptr);
     return;
   }
 
   DependentTemplateName *Dependent = Template.getAsDependentTemplateName();
   assert(Dependent && "Unknown template name kind?");
   if (NestedNameSpecifier *Qualifier = Dependent->getQualifier())
     manglePrefix(Qualifier);
   mangleUnscopedTemplateName(Template, /* AdditionalAbiTags */ nullptr);
 }
 
-void CXXNameMangler::mangleTemplatePrefix(const TemplateDecl *ND,
+void CXXNameMangler::mangleTemplatePrefix(GlobalDecl GD,
                                           bool NoFunction) {
+  const TemplateDecl *ND = cast<TemplateDecl>(GD.getDecl());
   // <template-prefix> ::= <prefix> <template unqualified-name>
   //                   ::= <template-param>
   //                   ::= <substitution>
   // <template-template-param> ::= <template-param>
   //                               <substitution>
 
   if (mangleSubstitution(ND))
     return;
 
   // <template-template-param> ::= <template-param>
   if (const auto *TTP = dyn_cast<TemplateTemplateParmDecl>(ND)) {
     mangleTemplateParameter(TTP->getDepth(), TTP->getIndex());
   } else {
     manglePrefix(getEffectiveDeclContext(ND), NoFunction);
     if (isa<BuiltinTemplateDecl>(ND) || isa<ConceptDecl>(ND))
-      mangleUnqualifiedName(ND, nullptr);
+      mangleUnqualifiedName(GD, nullptr);
     else
-      mangleUnqualifiedName(ND->getTemplatedDecl(), nullptr);
+      mangleUnqualifiedName(GD.getWithDecl(ND->getTemplatedDecl()), nullptr);
   }
 
   addSubstitution(ND);
 }
 
 /// Mangles a template name under the production <type>.  Required for
 /// template template arguments.
 ///   <type> ::= <class-enum-type>

 /// Mangles the name of the declaration D and emits that name to the given
 /// output stream.
 ///
 /// If the declaration D requires a mangled name, this routine will emit that
 /// mangled name to \p os and return true. Otherwise, \p os will be unchanged
 /// and this routine will return false. In this case, the caller should just
 /// emit the identifier of the declaration (\c D->getIdentifier()) as its
 /// name.
-void ItaniumMangleContextImpl::mangleCXXName(const NamedDecl *D,
+void ItaniumMangleContextImpl::mangleCXXName(GlobalDecl GD,
                                              raw_ostream &Out) {
+  const NamedDecl *D = cast<NamedDecl>(GD.getDecl());
   assert((isa<FunctionDecl>(D) || isa<VarDecl>(D)) &&
           "Invalid mangleName() call, argument is not a variable or function!");
-  assert(!isa<CXXConstructorDecl>(D) && !isa<CXXDestructorDecl>(D) &&
-         "Invalid mangleName() call on 'structor decl!");
 
   PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
                                  getASTContext().getSourceManager(),
                                  "Mangling declaration");
 
   CXXNameMangler Mangler(*this, Out, D);
-  Mangler.mangle(D);
+  Mangler.mangle(GD);
 }
 
 void ItaniumMangleContextImpl::mangleCXXCtor(const CXXConstructorDecl *D,
                                              CXXCtorType Type,
                                              raw_ostream &Out) {
   CXXNameMangler Mangler(*this, Out, D, Type);
-  Mangler.mangle(D);
+  Mangler.mangle(GlobalDecl(D, Type));
 }
 
 void ItaniumMangleContextImpl::mangleCXXDtor(const CXXDestructorDecl *D,
                                              CXXDtorType Type,
                                              raw_ostream &Out) {
   CXXNameMangler Mangler(*this, Out, D, Type);
-  Mangler.mangle(D);
+  Mangler.mangle(GlobalDecl(D, Type));
 }
 
 void ItaniumMangleContextImpl::mangleCXXCtorComdat(const CXXConstructorDecl *D,
                                                    raw_ostream &Out) {
   CXXNameMangler Mangler(*this, Out, D, Ctor_Comdat);
-  Mangler.mangle(D);
+  Mangler.mangle(GlobalDecl(D, Ctor_Comdat));
 }
 
 void ItaniumMangleContextImpl::mangleCXXDtorComdat(const CXXDestructorDecl *D,
                                                    raw_ostream &Out) {
   CXXNameMangler Mangler(*this, Out, D, Dtor_Comdat);
-  Mangler.mangle(D);
+  Mangler.mangle(GlobalDecl(D, Dtor_Comdat));
 }
 
 void ItaniumMangleContextImpl::mangleThunk(const CXXMethodDecl *MD,
                                            const ThunkInfo &Thunk,
                                            raw_ostream &Out) {
   //  <special-name> ::= T <call-offset> <base encoding>
   //                      # base is the nominal target function of thunk
   //  <special-name> ::= Tc <call-offset> <call-offset> <base encoding>
void ItaniumMangleContextImpl::mangleCXXDtorThunk(
   //                      # base is the nominal target function of thunk
   CXXNameMangler Mangler(*this, Out, DD, Type);
   Mangler.getStream() << "_ZT";
 
   // Mangle the 'this' pointer adjustment.
   Mangler.mangleCallOffset(ThisAdjustment.NonVirtual,
                            ThisAdjustment.Virtual.Itanium.VCallOffsetOffset);
 
-  Mangler.mangleFunctionEncoding(DD);
+  Mangler.mangleFunctionEncoding(GlobalDecl(DD, Type));
 }
 
 /// Returns the mangled name for a guard variable for the passed in VarDecl.
 void ItaniumMangleContextImpl::mangleStaticGuardVariable(const VarDecl *D,
                                                          raw_ostream &Out) {
   //  <special-name> ::= GV <object name>       # Guard variable for one-time
   //                                            # initialization
   CXXNameMangler Mangler(*this, Out);

clang/lib/AST/Mangle.cpp

bool MangleContext::shouldMangleDeclName(const NamedDecl *D) {
   // Any decl can be declared with __asm("foo") on it, and this takes precedence
   // over all other naming in the .o file.
   if (D->hasAttr<AsmLabelAttr>())
     return true;
 
   return shouldMangleCXXName(D);
 }
 
-void MangleContext::mangleName(const NamedDecl *D, raw_ostream &Out) {
+void MangleContext::mangleName(GlobalDecl GD, raw_ostream &Out) {
+  const NamedDecl *D = cast<NamedDecl>(GD.getDecl());
   // Any decl can be declared with __asm("foo") on it, and this takes precedence
   // over all other naming in the .o file.
   if (const AsmLabelAttr *ALA = D->getAttr<AsmLabelAttr>()) {
     // If we have an asm name, then we use it as the mangling.
 
     // If the label isn't literal, or if this is an alias for an LLVM intrinsic,
     // do not add a "\01" prefix.
     if (!ALA->getIsLiteralLabel() || ALA->getLabel().startswith("llvm.")) {
void MangleContext::mangleName(GlobalDecl GD, raw_ostream &Out) {
   const ASTContext &ASTContext = getASTContext();
   CCMangling CC = getCallingConvMangling(ASTContext, D);
   bool MCXX = shouldMangleCXXName(D);
   const TargetInfo &TI = Context.getTargetInfo();
   if (CC == CCM_Other || (MCXX && TI.getCXXABI() == TargetCXXABI::Microsoft)) {
     if (const ObjCMethodDecl *OMD = dyn_cast<ObjCMethodDecl>(D))
       mangleObjCMethodName(OMD, Out);
     else
-      mangleCXXName(D, Out);
+      mangleCXXName(GD, Out);
     return;
   }
 
   Out << '\01';
   if (CC == CCM_Std)
     Out << '_';
   else if (CC == CCM_Fast)
     Out << '@';

clang/lib/AST/MicrosoftMangle.cpp

class MicrosoftMangleContextImpl : public MicrosoftMangleContext {
   llvm::DenseMap<const NamedDecl *, unsigned> SEHFilterIds;
   llvm::DenseMap<const NamedDecl *, unsigned> SEHFinallyIds;
   SmallString<16> AnonymousNamespaceHash;
 
 public:
   MicrosoftMangleContextImpl(ASTContext &Context, DiagnosticsEngine &Diags);
   bool shouldMangleCXXName(const NamedDecl *D) override;
   bool shouldMangleStringLiteral(const StringLiteral *SL) override;
-  void mangleCXXName(const NamedDecl *D, raw_ostream &Out) override;
+  void mangleCXXName(GlobalDecl GD, raw_ostream &Out) override;
   void mangleVirtualMemPtrThunk(const CXXMethodDecl *MD,
                                 const MethodVFTableLocation &ML,
                                 raw_ostream &Out) override;
   void mangleThunk(const CXXMethodDecl *MD, const ThunkInfo &Thunk,
                    raw_ostream &) override;
   void mangleCXXDtorThunk(const CXXDestructorDecl *DD, CXXDtorType Type,
                           const ThisAdjustment &ThisAdjustment,
                           raw_ostream &) override;
void MicrosoftCXXNameMangler::mangleType(const PipeType *T, Qualifiers,
                                          SourceRange Range) {
   DiagnosticsEngine &Diags = Context.getDiags();
   unsigned DiagID = Diags.getCustomDiagID(DiagnosticsEngine::Error,
     "cannot mangle this OpenCL pipe type yet");
   Diags.Report(Range.getBegin(), DiagID)
     << Range;
 }
 
-void MicrosoftMangleContextImpl::mangleCXXName(const NamedDecl *D,
+void MicrosoftMangleContextImpl::mangleCXXName(GlobalDecl GD,
                                                raw_ostream &Out) {
+  const NamedDecl *D = cast<NamedDecl>(GD.getDecl());
   assert((isa<FunctionDecl>(D) || isa<VarDecl>(D)) &&
          "Invalid mangleName() call, argument is not a variable or function!");
   assert(!isa<CXXConstructorDecl>(D) && !isa<CXXDestructorDecl>(D) &&
          "Invalid mangleName() call on 'structor decl!");
 
   PrettyStackTraceDecl CrashInfo(D, SourceLocation(),
                                  getASTContext().getSourceManager(),
                                  "Mangling declaration");

clang/lib/CodeGen/CGExpr.cpp

LValue LV = VD->getType()->isReferenceType() ?
       CGF.EmitLoadOfReferenceLValue(Addr, VD->getType(),
                                     AlignmentSource::Decl) :
       CGF.MakeAddrLValue(Addr, T, AlignmentSource::Decl);
   setObjCGCLValueClass(CGF.getContext(), E, LV);
   return LV;
 }
 
 static llvm::Constant *EmitFunctionDeclPointer(CodeGenModule &CGM,
-                                               const FunctionDecl *FD) {
+                                               GlobalDecl GD) {
+  const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
   if (FD->hasAttr<WeakRefAttr>()) {
     ConstantAddress aliasee = CGM.GetWeakRefReference(FD);
     return aliasee.getPointer();
   }
 
-  llvm::Constant *V = CGM.GetAddrOfFunction(FD);
+  llvm::Constant *V = CGM.GetAddrOfFunction(GD);
   if (!FD->hasPrototype()) {
     if (const FunctionProtoType *Proto =
             FD->getType()->getAs<FunctionProtoType>()) {
       // Ugly case: for a K&R-style definition, the type of the definition
       // isn't the same as the type of a use.  Correct for this with a
       // bitcast.
       QualType NoProtoType =
           CGM.getContext().getFunctionNoProtoType(Proto->getReturnType());
       NoProtoType = CGM.getContext().getPointerType(NoProtoType);
       V = llvm::ConstantExpr::getBitCast(V,
                                       CGM.getTypes().ConvertType(NoProtoType));
     }
   }
   return V;
 }
 
-static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF,
-                                     const Expr *E, const FunctionDecl *FD) {
-  llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, FD);
+static LValue EmitFunctionDeclLValue(CodeGenFunction &CGF, const Expr *E,
+                                     GlobalDecl GD) {
+  const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
+  llvm::Value *V = EmitFunctionDeclPointer(CGF.CGM, GD);
   CharUnits Alignment = CGF.getContext().getDeclAlign(FD);
   return CGF.MakeAddrLValue(V, E->getType(), Alignment,
                             AlignmentSource::Decl);
 }
 
 static LValue EmitCapturedFieldLValue(CodeGenFunction &CGF, const FieldDecl *FD,
                                       llvm::Value *ThisValue) {
   QualType TagType = CGF.getContext().getTagDeclType(FD->getParent());

 
 /// Emit a CallExpr without considering whether it might be a subclass.
 RValue CodeGenFunction::EmitSimpleCallExpr(const CallExpr *E,
                                            ReturnValueSlot ReturnValue) {
   CGCallee Callee = EmitCallee(E->getCallee());
   return EmitCall(E->getCallee()->getType(), Callee, E, ReturnValue);
 }
 
-static CGCallee EmitDirectCallee(CodeGenFunction &CGF, const FunctionDecl *FD) {
+static CGCallee EmitDirectCallee(CodeGenFunction &CGF, GlobalDecl GD) {
+  const FunctionDecl *FD = cast<FunctionDecl>(GD.getDecl());
 
   if (auto builtinID = FD->getBuiltinID()) {
     // Replaceable builtin provide their own implementation of a builtin. Unless
     // we are in the builtin implementation itself, don't call the actual
     // builtin. If we are in the builtin implementation, avoid trivial infinite
     // recursion.
     if (!FD->isInlineBuiltinDeclaration() ||
         CGF.CurFn->getName() == FD->getName())
       return CGCallee::forBuiltin(builtinID, FD);
   }
 
-  llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, FD);
-  return CGCallee::forDirect(calleePtr, GlobalDecl(FD));
+  llvm::Constant *calleePtr = EmitFunctionDeclPointer(CGF.CGM, GD);
+  return CGCallee::forDirect(calleePtr, GD);
 }
 
 CGCallee CodeGenFunction::EmitCallee(const Expr *E) {
   E = E->IgnoreParens();
 
   // Look through function-to-pointer decay.
   if (auto ICE = dyn_cast<ImplicitCastExpr>(E)) {
     if (ICE->getCastKind() == CK_FunctionToPointerDecay ||

clang/lib/CodeGen/CodeGenModule.cpp

 
 static std::string getMangledNameImpl(const CodeGenModule &CGM, GlobalDecl GD,
                                       const NamedDecl *ND,
                                       bool OmitMultiVersionMangling = false) {
   SmallString<256> Buffer;
   llvm::raw_svector_ostream Out(Buffer);
   MangleContext &MC = CGM.getCXXABI().getMangleContext();
   if (MC.shouldMangleDeclName(ND)) {
-    llvm::raw_svector_ostream Out(Buffer);
     if (const auto *D = dyn_cast<CXXConstructorDecl>(ND))
       MC.mangleCXXCtor(D, GD.getCtorType(), Out);
     else if (const auto *D = dyn_cast<CXXDestructorDecl>(ND))
       MC.mangleCXXDtor(D, GD.getDtorType(), Out);
     else
-      MC.mangleName(ND, Out);
+      MC.mangleName(GD, Out);
   } else {
     IdentifierInfo *II = ND->getIdentifier();
     assert(II && "Attempt to mangle unnamed decl.");
     const auto *FD = dyn_cast<FunctionDecl>(ND);
 
     if (FD &&
         FD->getType()->castAs<FunctionType>()->getCallConv() == CC_X86RegCall) {
-      llvm::raw_svector_ostream Out(Buffer);
       Out << "__regcall3__" << II->getName();
     } else {
       Out << II->getName();
     }
   }
 
   if (const auto *FD = dyn_cast<FunctionDecl>(ND))
     if (FD->isMultiVersion() && !OmitMultiVersionMangling) {
void CodeGenModule::EmitGlobalFunctionDefinition(GlobalDecl GD,
   // FIXME: this is redundant with part of setFunctionDefinitionAttributes
   setGVProperties(Fn, GD);
 
   MaybeHandleStaticInExternC(D, Fn);
 
 
   maybeSetTrivialComdat(*D, *Fn);
 
-  CodeGenFunction(*this).GenerateCode(D, Fn, FI);
+  CodeGenFunction(*this).GenerateCode(GD, Fn, FI);
 
   setNonAliasAttributes(GD, Fn);
   SetLLVMFunctionAttributesForDefinition(D, Fn);
 
   if (const ConstructorAttr *CA = D->getAttr<ConstructorAttr>())
     AddGlobalCtor(Fn, CA->getPriority());
   if (const DestructorAttr *DA = D->getAttr<DestructorAttr>())
     AddGlobalDtor(Fn, DA->getPriority());