llvm-gcc-4.2/gcc/testsuite/objc.dg/comp-types-11.m

/* { dg-do compile } */
#include <objc/Object.h>

@interface Derived: Object
@end

extern Object* foo(void);
static Derived *test(void)
{
   Derived *m = foo();   /* { dg-warning "initialization from distinct Objective\\-C type" } */

   return m;
}