[ARC] Allow forming 'id*' in an unevaluated context. Fixes rdar://10148540.

llvm-svn: 140212

clang/lib/Sema/SemaType.cpp

@@ -1038,6 +1038,11 @@ static QualType inferARCLifetimeForPointee(Sema &S, QualType type,
   } else if (type->isObjCARCImplicitlyUnretainedType()) {
     implicitLifetime = Qualifiers::OCL_ExplicitNone;
 
+  // If we are in an unevaluated context, like sizeof, assume ExplicitNone and
+  // don't give error.
+  } else if (S.ExprEvalContexts.back().Context == Sema::Unevaluated) {
+    implicitLifetime = Qualifiers::OCL_ExplicitNone;
+
   // If that failed, give an error and recover using __autoreleasing.
   } else {
     // These types can show up in private ivars in system headers, so

clang/test/SemaObjC/arc.m

@@ -646,6 +646,8 @@ void test37(Test37 *c) {
   for (id y in c) { // expected-error {{collection expression type 'Test37' is a forward declaration}}
     (void) y;
   }
+
+  (void)sizeof(id*); // no error.
 }
 
 // rdar://problem/9887979