[ASTImporter] Error handling fix in ImportDefinition_New.

[balazske]

Summary

ASTImporter::ImportDefinition_New contained a call to Import
that should be Import_New now. This is fixed now.

[balazske]

• Removed unneeded and wrong type cast.

[balazske]

Rebase to current master.

[balazske]

ping

[balazske]

The error handling is already done in other way, but the current code does crash if called with non-DeclContext From argument. This may be possible from LLDB so it is better to have this change.

[balazske]

This change is obsolete in the current code. Casting related changes do not look important (and should be a new patch anyway).

lib/AST/ASTImporter.cpp

ASTImporter::Import(const CXXBaseSpecifier *BaseSpec) {
   CXXBaseSpecifier *Imported = new (ToContext) CXXBaseSpecifier(
       *ToSourceRange, BaseSpec->isVirtual(), BaseSpec->isBaseOfClass(),
       BaseSpec->getAccessSpecifierAsWritten(), *ToTSI, *ToEllipsisLoc);
   ImportedCXXBaseSpecifiers[BaseSpec] = Imported;
   return Imported;
 }
 
 Error ASTImporter::ImportDefinition(Decl *From) {
-  ExpectedDecl ToOrErr = Import(From);
-  if (!ToOrErr)
-    return ToOrErr.takeError();
-  Decl *To = *ToOrErr;
+  Decl *To;
+  if (Error Err = importInto(To, From))
+    return Err;
 
-  auto *FromDC = cast<DeclContext>(From);
   ASTNodeImporter Importer(*this);
 
   if (auto *ToRecord = dyn_cast<RecordDecl>(To)) {
     if (!ToRecord->getDefinition()) {
       return Importer.ImportDefinition(
-          cast<RecordDecl>(FromDC), ToRecord,
+          cast<RecordDecl>(From), ToRecord,
           ASTNodeImporter::IDK_Everything);
     }
   }
 
   if (auto *ToEnum = dyn_cast<EnumDecl>(To)) {
     if (!ToEnum->getDefinition()) {
       return Importer.ImportDefinition(
-          cast<EnumDecl>(FromDC), ToEnum, ASTNodeImporter::IDK_Everything);
+          cast<EnumDecl>(From), ToEnum, ASTNodeImporter::IDK_Everything);
     }
   }
 
   if (auto *ToIFace = dyn_cast<ObjCInterfaceDecl>(To)) {
     if (!ToIFace->getDefinition()) {
       return Importer.ImportDefinition(
-          cast<ObjCInterfaceDecl>(FromDC), ToIFace,
+          cast<ObjCInterfaceDecl>(From), ToIFace,
           ASTNodeImporter::IDK_Everything);
     }
   }
 
   if (auto *ToProto = dyn_cast<ObjCProtocolDecl>(To)) {
     if (!ToProto->getDefinition()) {
       return Importer.ImportDefinition(
-          cast<ObjCProtocolDecl>(FromDC), ToProto,
+          cast<ObjCProtocolDecl>(From), ToProto,
           ASTNodeImporter::IDK_Everything);
     }
   }
 
+  if (auto *FromDC = dyn_cast<DeclContext>(From))
     return Importer.ImportDeclContext(FromDC, true);
+
+  return Error::success();
 }
 
 Expected<DeclarationName> ASTImporter::Import(DeclarationName FromName) {
   if (!FromName)
     return DeclarationName{};
 
   switch (FromName.getNameKind()) {
   case DeclarationName::Identifier: