[AST] Add a convenient getter from QualType to RecordDecl

Differential Revision: https://reviews.llvm.org/D49951

llvm-svn: 338187

clang/include/clang/AST/Type.h

@@ -2017,6 +2017,9 @@ public:
   /// type of a class template or class template partial specialization.
   CXXRecordDecl *getAsCXXRecordDecl() const;
 
+  /// Retrieves the RecordDecl this type refers to.
+  RecordDecl *getAsRecordDecl() const;
+
   /// Retrieves the TagDecl that this type refers to, either
   /// because the type is a TagType or because it is the injected-class-name
   /// type of a class template or class template partial specialization.

clang/lib/AST/Decl.cpp

@@ -3149,12 +3149,9 @@ SourceRange FunctionDecl::getExceptionSpecSourceRange() const {
 
 const Attr *FunctionDecl::getUnusedResultAttr() const {
   QualType RetType = getReturnType();
-  if (RetType->isRecordType()) {
-    if (const auto *Ret =
-            dyn_cast_or_null<RecordDecl>(RetType->getAsTagDecl())) {
-      if (const auto *R = Ret->getAttr<WarnUnusedResultAttr>())
-        return R;
-    }
+  if (const auto *Ret = RetType->getAsRecordDecl()) {
+    if (const auto *R = Ret->getAttr<WarnUnusedResultAttr>())
+      return R;
   } else if (const auto *ET = RetType->getAs<EnumType>()) {
     if (const EnumDecl *ED = ET->getDecl()) {
       if (const auto *R = ED->getAttr<WarnUnusedResultAttr>())

clang/lib/AST/Type.cpp

@@ -1628,6 +1628,10 @@ CXXRecordDecl *Type::getAsCXXRecordDecl() const {
   return dyn_cast_or_null<CXXRecordDecl>(getAsTagDecl());
 }
 
+RecordDecl *Type::getAsRecordDecl() const {
+  return dyn_cast_or_null<RecordDecl>(getAsTagDecl());
+}
+
 TagDecl *Type::getAsTagDecl() const {
   if (const auto *TT = getAs<TagType>())
     return TT->getDecl();

clang/lib/Analysis/BodyFarm.cpp

@@ -342,7 +342,7 @@ static Stmt *create_call_once(ASTContext &C, const FunctionDecl *D) {
   // Nullable pointer, non-null iff function is a CXXRecordDecl.
   CXXRecordDecl *CallbackRecordDecl = CallbackType->getAsCXXRecordDecl();
   QualType FlagType = Flag->getType().getNonReferenceType();
-  auto *FlagRecordDecl = dyn_cast_or_null<RecordDecl>(FlagType->getAsTagDecl());
+  auto *FlagRecordDecl = FlagType->getAsRecordDecl();
 
   if (!FlagRecordDecl) {
     LLVM_DEBUG(llvm::dbgs() << "Flag field is not a record: "

clang/lib/CodeGen/CGExprConstant.cpp

@@ -2064,8 +2064,7 @@ static llvm::Constant *EmitNullConstant(CodeGenModule &CGM,
     if (record->isUnion()) {
       if (Field->getIdentifier())
         break;
-      if (const auto *FieldRD =
-              dyn_cast_or_null<RecordDecl>(Field->getType()->getAsTagDecl()))
+      if (const auto *FieldRD = Field->getType()->getAsRecordDecl())
         if (FieldRD->findFirstNamedDataMember())
           break;
     }

clang/lib/CodeGen/CGRecordLayoutBuilder.cpp

@@ -313,9 +313,8 @@ void CGRecordLowering::lowerUnion() {
     if (!SeenNamedMember) {
       SeenNamedMember = Field->getIdentifier();
       if (!SeenNamedMember)
-        if (const auto *FieldRD =
-                dyn_cast_or_null<RecordDecl>(Field->getType()->getAsTagDecl()))
-        SeenNamedMember = FieldRD->findFirstNamedDataMember();
+        if (const auto *FieldRD = Field->getType()->getAsRecordDecl())
+          SeenNamedMember = FieldRD->findFirstNamedDataMember();
       if (SeenNamedMember && !isZeroInitializable(Field)) {
         IsZeroInitializable = IsZeroInitializableAsBase = false;
         StorageType = FieldType;