[PATCH 1/7] [clang] Improve nested name specifier AST representation

clang/docs/ReleaseNotes.rst

@@ -85,6 +85,7 @@ ABI Changes in This Version
 AST Dumping Potentially Breaking Changes
 ----------------------------------------
 
+- How nested name specifiers are dumped and printed changes, keeping track of clang AST changes.
 - Added support for dumping template arguments of structural value kinds.
 
 Clang Frontend Potentially Breaking Changes
@@ -95,6 +96,9 @@ Clang Frontend Potentially Breaking Changes
 
 Clang Python Bindings Potentially Breaking Changes
 --------------------------------------------------
+- TypeKind ``ELABORATED`` is not used anymore, per clang AST changes removing
+  ElaboratedTypes. The value becomes unused, and all the existing users should
+  expect the former underlying type to be reported instead.
 - ``Cursor.from_location`` now returns ``None`` instead of a null cursor.
   This eliminates the last known source of null cursors.
 - Almost all ``Cursor`` methods now assert that they are called on non-null cursors.
@@ -494,6 +498,7 @@ Improvements to Clang's diagnostics
   under the subgroup ``-Wunsafe-buffer-usage-in-libc-call``.
 - Diagnostics on chained comparisons (``a < b < c``) are now an error by default. This can be disabled with
   ``-Wno-error=parentheses``.
+- Fix duplicate diagnostics for incomplete type in nested name specifier. (#GH147000)
 - Similarly, fold expressions over a comparison operator are now an error by default.
 - Clang now better preserves the sugared types of pointers to member.
 - Clang now better preserves the presence of the template keyword with dependent
@@ -987,8 +992,11 @@ Bug Fixes to AST Handling
 - Fixed a malformed printout of ``CXXParenListInitExpr`` in certain contexts.
 - Fixed a malformed printout of certain calling convention function attributes. (#GH143160)
 - Fixed dependency calculation for TypedefTypes (#GH89774)
+- Fix incorrect name qualifiers applied to alias CTAD. (#GH136624)
 - The ODR checker now correctly hashes the names of conversion operators. (#GH143152)
 - Fixed the right parenthesis source location of ``CXXTemporaryObjectExpr``. (#GH143711)
+- Fixed ElaboratedTypes appearing within NestedNameSpecifier, which was not a
+  legal representation. This is fixed because ElaboratedTypes don't exist anymore. (#GH43179) (#GH68670) (#GH92757)
 - Fixed a crash when performing an ``IgnoreUnlessSpelledInSource`` traversal of ASTs containing ``catch(...)`` statements. (#GH146103)
 
 Miscellaneous Bug Fixes
@@ -1158,6 +1166,8 @@ AST Matchers
 - Ensure ``hasBitWidth`` doesn't crash on bit widths that are dependent on template
   parameters.
 - Ensure ``isDerivedFrom`` matches the correct base in case more than one alias exists.
+- Removed elaboratedType matchers, and related nested name specifier changes,
+  following the corresponding changes in the clang AST.
 - Extend ``templateArgumentCountIs`` to support function and variable template
   specialization.
 

clang/include/clang/AST/ASTNodeTraverser.h

@@ -510,7 +510,7 @@ class ASTNodeTraverser
   }
   void VisitMemberPointerTypeLoc(MemberPointerTypeLoc TL) {
     // FIXME: Provide NestedNamespecifierLoc visitor.
-    Visit(TL.getQualifierLoc().getTypeLoc());
+    Visit(TL.getQualifierLoc().castAsTypeLoc());
   }
   void VisitVariableArrayTypeLoc(VariableArrayTypeLoc TL) {
     Visit(TL.getSizeExpr());
@@ -772,17 +772,16 @@ class ASTNodeTraverser
   }
 
   void VisitUsingShadowDecl(const UsingShadowDecl *D) {
-    if (auto *TD = dyn_cast<TypeDecl>(D->getUnderlyingDecl()))
-      Visit(TD->getTypeForDecl());
+    Visit(D->getTargetDecl());
   }
 
   void VisitFriendDecl(const FriendDecl *D) {
     if (D->getFriendType()) {
       // Traverse any CXXRecordDecl owned by this type, since
       // it will not be in the parent context:
-      if (auto *ET = D->getFriendType()->getType()->getAs<ElaboratedType>())
-        if (auto *TD = ET->getOwnedTagDecl())
-          Visit(TD);
+      if (auto *TT = D->getFriendType()->getType()->getAs<TagType>())
+        if (TT->isTagOwned())
+          Visit(TT->getOriginalDecl());
     } else {
       Visit(D->getFriendDecl());
     }

clang/include/clang/AST/ASTTypeTraits.h

@@ -307,7 +307,7 @@ class DynTypedNode {
 
   /// For nodes which represent textual entities in the source code,
   /// return their SourceRange.  For all other nodes, return SourceRange().
-  SourceRange getSourceRange() const;
+  SourceRange getSourceRange(bool IncludeQualifier = false) const;
 
   /// @{
   /// Imposes an order on \c DynTypedNode.

clang/include/clang/AST/AbstractBasicReader.h

@@ -197,7 +197,7 @@ class DataStreamBasicReader : public BasicReaderBase<Impl> {
         unsigned int_ = asImpl().readUInt32();
         Decl *decl = asImpl().template readDeclAs<Decl>();
         if (auto *recordDecl = dyn_cast<CXXRecordDecl>(decl))
-          elemTy = getASTContext().getRecordType(recordDecl);
+          elemTy = getASTContext().getCanonicalTagType(recordDecl);
         else
           elemTy = cast<ValueDecl>(decl)->getType();
         path.push_back(

clang/include/clang/AST/AbstractBasicWriter.h

@@ -181,7 +181,7 @@ class DataStreamBasicWriter : public BasicWriterBase<Impl> {
         const Decl *baseOrMember = elem.getAsBaseOrMember().getPointer();
         if (const auto *recordDecl = dyn_cast<CXXRecordDecl>(baseOrMember)) {
           asImpl().writeDeclRef(recordDecl);
-          elemTy = ctx.getRecordType(recordDecl);
+          elemTy = ctx.getCanonicalTagType(recordDecl);
         } else {
           const auto *valueDecl = cast<ValueDecl>(baseOrMember);
           asImpl().writeDeclRef(valueDecl);

clang/include/clang/AST/CanonicalType.h

@@ -551,21 +551,18 @@ struct CanProxyAdaptor<UnaryTransformType>
 
 template<>
 struct CanProxyAdaptor<TagType> : public CanProxyBase<TagType> {
-  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(TagDecl *, getDecl)
-  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(bool, isBeingDefined)
+  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(TagDecl *, getOriginalDecl)
 };
 
 template<>
 struct CanProxyAdaptor<RecordType> : public CanProxyBase<RecordType> {
-  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(RecordDecl *, getDecl)
-  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(bool, isBeingDefined)
+  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(RecordDecl *, getOriginalDecl)
   LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(bool, hasConstFields)
 };
 
 template<>
 struct CanProxyAdaptor<EnumType> : public CanProxyBase<EnumType> {
-  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(EnumDecl *, getDecl)
-  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(bool, isBeingDefined)
+  LLVM_CLANG_CANPROXY_SIMPLE_ACCESSOR(EnumDecl *, getOriginalDecl)
 };
 
 template<>

clang/include/clang/AST/Decl.h

@@ -3528,8 +3528,14 @@ class TypeDecl : public NamedDecl {
   // check out ASTContext::getTypeDeclType or one of
   // ASTContext::getTypedefType, ASTContext::getRecordType, etc. if you
   // already know the specific kind of node this is.
-  const Type *getTypeForDecl() const { return TypeForDecl; }
-  void setTypeForDecl(const Type *TD) { TypeForDecl = TD; }
+  const Type *getTypeForDecl() const {
+    assert(!isa<TagDecl>(this));
+    return TypeForDecl;
+  }
+  void setTypeForDecl(const Type *TD) {
+    assert(!isa<TagDecl>(this));
+    TypeForDecl = TD;
+  }
 
   SourceLocation getBeginLoc() const LLVM_READONLY { return LocStart; }
   void setLocStart(SourceLocation L) { LocStart = L; }
@@ -3635,6 +3641,10 @@ class TypedefNameDecl : public TypeDecl, public Redeclarable<TypedefNameDecl> {
     return isTransparentTagSlow();
   }
 
+  // These types are created lazily, use the ASTContext methods to obtain them.
+  const Type *getTypeForDecl() const = delete;
+  void setTypeForDecl(const Type *TD) = delete;
+
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) {
@@ -3754,14 +3764,6 @@ class TagDecl : public TypeDecl,
   /// True if this decl is currently being defined.
   void setBeingDefined(bool V = true) { TagDeclBits.IsBeingDefined = V; }
 
-  /// Indicates whether it is possible for declarations of this kind
-  /// to have an out-of-date definition.
-  ///
-  /// This option is only enabled when modules are enabled.
-  void setMayHaveOutOfDateDef(bool V = true) {
-    TagDeclBits.MayHaveOutOfDateDef = V;
-  }
-
 public:
   friend class ASTDeclReader;
   friend class ASTDeclWriter;
@@ -3842,12 +3844,6 @@ class TagDecl : public TypeDecl,
     TagDeclBits.IsFreeStanding = isFreeStanding;
   }
 
-  /// Indicates whether it is possible for declarations of this kind
-  /// to have an out-of-date definition.
-  ///
-  /// This option is only enabled when modules are enabled.
-  bool mayHaveOutOfDateDef() const { return TagDeclBits.MayHaveOutOfDateDef; }
-
   /// Whether this declaration declares a type that is
   /// dependent, i.e., a type that somehow depends on template
   /// parameters.
@@ -3888,6 +3884,19 @@ class TagDecl : public TypeDecl,
   ///  the struct/union/class/enum.
   TagDecl *getDefinition() const;
 
+  TagDecl *getDefinitionOrSelf() const {
+    if (TagDecl *Def = getDefinition())
+      return Def;
+    return const_cast<TagDecl *>(this);
+  }
+
+  /// Determines whether this entity is in the process of being defined.
+  bool isEntityBeingDefined() const {
+    if (const TagDecl *Def = getDefinition())
+      return Def->isBeingDefined();
+    return false;
+  }
+
   StringRef getKindName() const {
     return TypeWithKeyword::getTagTypeKindName(getTagKind());
   }
@@ -3958,6 +3967,10 @@ class TagDecl : public TypeDecl,
     return getExtInfo()->TemplParamLists[i];
   }
 
+  // These types are created lazily, use the ASTContext methods to obtain them.
+  const Type *getTypeForDecl() const = delete;
+  void setTypeForDecl(const Type *TD) = delete;
+
   using TypeDecl::printName;
   void printName(raw_ostream &OS, const PrintingPolicy &Policy) const override;
 
@@ -4087,6 +4100,10 @@ class EnumDecl : public TagDecl {
     return cast_or_null<EnumDecl>(TagDecl::getDefinition());
   }
 
+  EnumDecl *getDefinitionOrSelf() const {
+    return cast_or_null<EnumDecl>(TagDecl::getDefinitionOrSelf());
+  }
+
   static EnumDecl *Create(ASTContext &C, DeclContext *DC,
                           SourceLocation StartLoc, SourceLocation IdLoc,
                           IdentifierInfo *Id, EnumDecl *PrevDecl,
@@ -4469,6 +4486,10 @@ class RecordDecl : public TagDecl {
     return cast_or_null<RecordDecl>(TagDecl::getDefinition());
   }
 
+  RecordDecl *getDefinitionOrSelf() const {
+    return cast_or_null<RecordDecl>(TagDecl::getDefinitionOrSelf());
+  }
+
   /// Returns whether this record is a union, or contains (at any nesting level)
   /// a union member. This is used by CMSE to warn about possible information
   /// leaks.
@@ -5299,6 +5320,8 @@ void Redeclarable<decl_type>::setPreviousDecl(decl_type *PrevDecl) {
 /// We use this function to break a cycle between the inline definitions in
 /// Type.h and Decl.h.
 inline bool IsEnumDeclComplete(EnumDecl *ED) {
+  if (const auto *Def = ED->getDefinition())
+    return Def->isComplete();
   return ED->isComplete();
 }
 

clang/include/clang/AST/DeclBase.h

@@ -410,9 +410,6 @@ class alignas(8) Decl {
 
   virtual ~Decl();
 
-  /// Update a potentially out-of-date declaration.
-  void updateOutOfDate(IdentifierInfo &II) const;
-
   Linkage getCachedLinkage() const {
     return static_cast<Linkage>(CacheValidAndLinkage);
   }
@@ -1564,13 +1561,6 @@ class DeclContext {
     LLVM_PREFERRED_TYPE(bool)
     uint64_t IsFreeStanding : 1;
 
-    /// Indicates whether it is possible for declarations of this kind
-    /// to have an out-of-date definition.
-    ///
-    /// This option is only enabled when modules are enabled.
-    LLVM_PREFERRED_TYPE(bool)
-    uint64_t MayHaveOutOfDateDef : 1;
-
     /// Has the full definition of this type been required by a use somewhere in
     /// the TU.
     LLVM_PREFERRED_TYPE(bool)

clang/include/clang/AST/DeclCXX.h

@@ -545,34 +545,25 @@ class CXXRecordDecl : public RecordDecl {
     return const_cast<CXXRecordDecl*>(this)->getMostRecentDecl();
   }
 
-  CXXRecordDecl *getMostRecentNonInjectedDecl() {
-    CXXRecordDecl *Recent = getMostRecentDecl();
-    while (Recent->isInjectedClassName()) {
-      // FIXME: Does injected class name need to be in the redeclarations chain?
-      assert(Recent->getPreviousDecl());
-      Recent = Recent->getPreviousDecl();
-    }
-    return Recent;
-  }
-
-  const CXXRecordDecl *getMostRecentNonInjectedDecl() const {
-    return const_cast<CXXRecordDecl*>(this)->getMostRecentNonInjectedDecl();
-  }
-
   CXXRecordDecl *getDefinition() const {
     // We only need an update if we don't already know which
     // declaration is the definition.
     auto *DD = DefinitionData ? DefinitionData : dataPtr();
     return DD ? DD->Definition : nullptr;
   }
 
+  CXXRecordDecl *getDefinitionOrSelf() const {
+    if (auto *Def = getDefinition())
+      return Def;
+    return const_cast<CXXRecordDecl *>(this);
+  }
+
   bool hasDefinition() const { return DefinitionData || dataPtr(); }
 
   static CXXRecordDecl *Create(const ASTContext &C, TagKind TK, DeclContext *DC,
                                SourceLocation StartLoc, SourceLocation IdLoc,
                                IdentifierInfo *Id,
-                               CXXRecordDecl *PrevDecl = nullptr,
-                               bool DelayTypeCreation = false);
+                               CXXRecordDecl *PrevDecl = nullptr);
   static CXXRecordDecl *CreateLambda(const ASTContext &C, DeclContext *DC,
                                      TypeSourceInfo *Info, SourceLocation Loc,
                                      unsigned DependencyKind, bool IsGeneric,
@@ -1903,6 +1894,20 @@ class CXXRecordDecl : public RecordDecl {
   /// \endcode
   bool isInjectedClassName() const;
 
+  /// Determines whether this declaration has is canonically of an injected
+  /// class type. These are non-instantiated class template patterns, which can
+  /// be used from within the class template itself. For example:
+  ///
+  /// \code
+  /// template<class T> struct C {
+  ///   C *t; // Here `C *` is a pointer to an injected class type.
+  /// };
+  /// \endcode
+  bool hasInjectedClassType() const;
+
+  CanQualType
+  getCanonicalTemplateSpecializationType(const ASTContext &Ctx) const;
+
   // Determine whether this type is an Interface Like type for
   // __interface inheritance purposes.
   bool isInterfaceLike() const;

clang/include/clang/AST/DeclObjC.h

@@ -643,6 +643,9 @@ class ObjCTypeParamDecl : public TypedefNameDecl {
   /// from the explicitly-specified bound.
   SourceLocation getColonLoc() const { return ColonLoc; }
 
+  using TypeDecl::getTypeForDecl;
+  using TypeDecl::setTypeForDecl;
+
   // Implement isa/cast/dyncast/etc.
   static bool classof(const Decl *D) { return classofKind(D->getKind()); }
   static bool classofKind(Kind K) { return K == ObjCTypeParam; }