[Clang][AST][NFC] (RecordDecl -> CXXRecordDecl)::isInjectedClassName (#148195)

Move `RecordDecl::isInjectedClassName` to
`CXXRecordDecl::isInjectedClassName`. C language doesn't have the term
"injected class name".

Co-authored-by: Matheus Izvekov <mizvekov@gmail.com>

Author: zwuis

clang-tools-extra/clangd/CodeComplete.cpp

@@ -870,7 +870,7 @@ bool contextAllowsIndex(enum CodeCompletionContext::Kind K) {
 }
 
 static bool isInjectedClass(const NamedDecl &D) {
-  if (auto *R = dyn_cast_or_null<RecordDecl>(&D))
+  if (auto *R = dyn_cast_or_null<CXXRecordDecl>(&D))
     if (R->isInjectedClassName())
       return true;
   return false;

clang-tools-extra/clangd/Quality.cpp

@@ -258,7 +258,7 @@ static SymbolRelevanceSignals::AccessibleScope
 computeScope(const NamedDecl *D) {
   // Injected "Foo" within the class "Foo" has file scope, not class scope.
   const DeclContext *DC = D->getDeclContext();
-  if (auto *R = dyn_cast_or_null<RecordDecl>(D))
+  if (auto *R = dyn_cast_or_null<CXXRecordDecl>(D))
     if (R->isInjectedClassName())
       DC = DC->getParent();
   // Class constructor should have the same scope as the class.

clang-tools-extra/clangd/SemanticHighlighting.cpp

@@ -597,7 +597,7 @@ class HighlightingsBuilder {
 std::optional<HighlightingModifier> scopeModifier(const NamedDecl *D) {
   const DeclContext *DC = D->getDeclContext();
   // Injected "Foo" within the class "Foo" has file scope, not class scope.
-  if (auto *R = dyn_cast_or_null<RecordDecl>(D))
+  if (auto *R = dyn_cast_or_null<CXXRecordDecl>(D))
     if (R->isInjectedClassName())
       DC = DC->getParent();
   // Lambda captures are considered function scope, not class scope.

clang/include/clang/AST/Decl.h

@@ -4420,21 +4420,6 @@ class RecordDecl : public TagDecl {
 
   void reorderDecls(const SmallVectorImpl<Decl *> &Decls);
 
-  /// Determines whether this declaration represents the
-  /// injected class name.
-  ///
-  /// The injected class name in C++ is the name of the class that
-  /// appears inside the class itself. For example:
-  ///
-  /// \code
-  /// struct C {
-  ///   // C is implicitly declared here as a synonym for the class name.
-  /// };
-  ///
-  /// C::C c; // same as "C c;"
-  /// \endcode
-  bool isInjectedClassName() const;
-
   /// Determine whether this record is a class describing a lambda
   /// function object.
   bool isLambda() const;

clang/include/clang/AST/DeclCXX.h

@@ -546,8 +546,7 @@ class CXXRecordDecl : public RecordDecl {
   }
 
   CXXRecordDecl *getMostRecentNonInjectedDecl() {
-    CXXRecordDecl *Recent =
-        static_cast<CXXRecordDecl *>(this)->getMostRecentDecl();
+    CXXRecordDecl *Recent = getMostRecentDecl();
     while (Recent->isInjectedClassName()) {
       // FIXME: Does injected class name need to be in the redeclarations chain?
       assert(Recent->getPreviousDecl());
@@ -1889,6 +1888,21 @@ class CXXRecordDecl : public RecordDecl {
     DL.IsGenericLambda = IsGeneric;
   }
 
+  /// Determines whether this declaration represents the
+  /// injected class name.
+  ///
+  /// The injected class name in C++ is the name of the class that
+  /// appears inside the class itself. For example:
+  ///
+  /// \code
+  /// struct C {
+  ///   // C is implicitly declared here as a synonym for the class name.
+  /// };
+  ///
+  /// C::C c; // same as "C c;"
+  /// \endcode
+  bool isInjectedClassName() const;
+
   // Determine whether this type is an Interface Like type for
   // __interface inheritance purposes.
   bool isInterfaceLike() const;

clang/lib/AST/Decl.cpp

@@ -5136,11 +5136,6 @@ RecordDecl *RecordDecl::CreateDeserialized(const ASTContext &C,
   return R;
 }
 
-bool RecordDecl::isInjectedClassName() const {
-  return isImplicit() && getDeclName() && getDeclContext()->isRecord() &&
-    cast<RecordDecl>(getDeclContext())->getDeclName() == getDeclName();
-}
-
 bool RecordDecl::isLambda() const {
   if (auto RD = dyn_cast<CXXRecordDecl>(this))
     return RD->isLambda();

clang/lib/AST/DeclCXX.cpp

@@ -2149,6 +2149,16 @@ bool CXXRecordDecl::hasDeletedDestructor() const {
   return false;
 }
 
+bool CXXRecordDecl::isInjectedClassName() const {
+  if (!isImplicit() || !getDeclName())
+    return false;
+
+  if (const auto *RD = dyn_cast<CXXRecordDecl>(getDeclContext()))
+    return RD->getDeclName() == getDeclName();
+
+  return false;
+}
+
 static bool isDeclContextInNamespace(const DeclContext *DC) {
   while (!DC->isTranslationUnit()) {
     if (DC->isNamespace())

clang/lib/Sema/SemaAccess.cpp

@@ -1129,7 +1129,8 @@ static void diagnoseBadDirectAccess(Sema &S,
     else if (TypedefNameDecl *TND = dyn_cast<TypedefNameDecl>(D))
       PrevDecl = TND->getPreviousDecl();
     else if (TagDecl *TD = dyn_cast<TagDecl>(D)) {
-      if (isa<RecordDecl>(D) && cast<RecordDecl>(D)->isInjectedClassName())
+      if (auto *RD = dyn_cast<CXXRecordDecl>(D);
+          RD && RD->isInjectedClassName())
         break;
       PrevDecl = TD->getPreviousDecl();
     }

lldb/source/Plugins/ExpressionParser/Clang/ClangASTImporter.cpp

@@ -288,7 +288,7 @@ class CompleteTagDeclsScope : public ClangASTImporter::NewDeclListener {
     // Filter out decls that we can't complete later.
     if (!isa<TagDecl>(to) && !isa<ObjCInterfaceDecl>(to))
       return;
-    RecordDecl *from_record_decl = dyn_cast<RecordDecl>(from);
+    auto *from_record_decl = dyn_cast<CXXRecordDecl>(from);
     // We don't need to complete injected class name decls.
     if (from_record_decl && from_record_decl->isInjectedClassName())
       return;

lldb/source/Plugins/TypeSystem/Clang/TypeSystemClang.cpp

@@ -2420,9 +2420,12 @@ void TypeSystemClang::DumpDeclHiearchy(clang::Decl *decl) {
 
   clang::RecordDecl *record_decl = llvm::dyn_cast<clang::RecordDecl>(decl);
   if (record_decl) {
+    bool is_injected_class_name =
+        llvm::isa<clang::CXXRecordDecl>(record_decl) &&
+        llvm::cast<CXXRecordDecl>(record_decl)->isInjectedClassName();
     printf("%20s: %s%s\n", decl->getDeclKindName(),
            record_decl->getDeclName().getAsString().c_str(),
-           record_decl->isInjectedClassName() ? " (injected class name)" : "");
+           is_injected_class_name ? " (injected class name)" : "");
 
   } else {
     clang::NamedDecl *named_decl = llvm::dyn_cast<clang::NamedDecl>(decl);