From 2b9fc83db5c892044f86a160a66f9709b8e44ff6 Mon Sep 17 00:00:00 2001
From: Fariborz Jahanian <fjahanian@apple.com>
Date: Tue, 15 Dec 2009 21:34:52 +0000
Subject: [PATCH] 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            | 1 +
 clang/lib/Sema/SemaExpr.cpp             | 4 +++-
 clang/test/CodeGenObjC/id-isa-codegen.m | 9 +++++++++
 3 files changed, 13 insertions(+), 1 deletion(-)

diff --git a/clang/lib/CodeGen/CGExpr.cpp b/clang/lib/CodeGen/CGExpr.cpp
index 8e1413386af4..c5a89e032b29 100644
--- a/clang/lib/CodeGen/CGExpr.cpp
+++ b/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: {
diff --git a/clang/lib/Sema/SemaExpr.cpp b/clang/lib/Sema/SemaExpr.cpp
index cda27cf68716..65c95b36aa07 100644
--- a/clang/lib/Sema/SemaExpr.cpp
+++ b/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;
   }
diff --git a/clang/test/CodeGenObjC/id-isa-codegen.m b/clang/test/CodeGenObjC/id-isa-codegen.m
index dc0bac3000e7..89e992209071 100644
--- a/clang/test/CodeGenObjC/id-isa-codegen.m
+++ b/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;
+}