Fixes a code gen bug related to accessing a now

non-existing 'isa' field of a non-existing struct type
all related to legacy type definition for 'id' which we have
dropped in clang in favor of a built-in type.
(fixes radar 7470820).

llvm-svn: 91455

clang/lib/CodeGen/CGExpr.cpp

@@ -1389,6 +1389,7 @@ LValue CodeGenFunction::EmitCastLValue(const CastExpr *E) {
   case CastExpr::CK_NoOp:
   case CastExpr::CK_ConstructorConversion:
   case CastExpr::CK_UserDefinedConversion:
+  case CastExpr::CK_AnyPointerToObjCPointerCast:
     return EmitLValue(E->getSubExpr());
   
   case CastExpr::CK_DerivedToBase: {

clang/lib/Sema/SemaExpr.cpp

@@ -3584,7 +3584,9 @@ static CastExpr::CastKind getScalarCastKind(ASTContext &Context,
 
   if (SrcTy->hasPointerRepresentation()) {
     if (DestTy->hasPointerRepresentation())
-      return CastExpr::CK_BitCast;
+      return DestTy->isObjCObjectPointerType() ? 
+                CastExpr::CK_AnyPointerToObjCPointerCast : 
+                CastExpr::CK_BitCast;
     if (DestTy->isIntegerType())
       return CastExpr::CK_PointerToIntegral;
   }

clang/test/CodeGenObjC/id-isa-codegen.m

@@ -25,3 +25,12 @@ typedef struct objc_object {
 }
 @end
 
+
+// rdar 7470820
+static Class MyClass;
+
+Class Test(const void *inObject1) {
+  if(((id)inObject1)->isa == MyClass)
+   return ((id)inObject1)->isa;
+  return (id)0;
+}