1  /* { dg-do compile } */
       2  /* { dg-options "-O2 -Wall" } */
       3  
       4  struct g { long a; };
       5  unsigned long f(struct g *a) { return *(unsigned long *)&a->a; }
       6  
       7  struct A
       8  {
       9    void *a;
      10  };
      11  
      12  int g(const struct A *x, long *y)
      13  {
      14    typedef long __attribute__ ((may_alias)) long_a;
      15    *y = *(const long_a *) (&x->a);
      16    return 1;
      17  }
      18  
      19  void *a;
      20  
      21  int
      22  f0 (long *y)
      23  {
      24    *y = *(const long *) &a; /* { dg-warning "will break" } */
      25    return 1;
      26  }
      27  
      28  int
      29  f1 (long *y)
      30  {
      31    typedef long __attribute__ ((may_alias)) long_a;
      32    *y = *(const long_a *) &a;
      33    return 1;
      34  }
      35  
      36  int
      37  f2 (long *y)
      38  {
      39    *y = *(const long *) &a; /* { dg-warning "will break" } */
      40    return 1;
      41  }