1  /* PR c/25801 */
       2  /* { dg-do compile } */
       3  /* { dg-options "-std=c99" } */
       4  
       5  int (*a)[];
       6  struct S *s;
       7  union U *u;
       8  enum E *e;
       9  
      10  void
      11  f (void)
      12  {
      13    a++; /* { dg-error "increment of pointer to an incomplete type" } */
      14    ++a; /* { dg-error "increment of pointer to an incomplete type" } */
      15    a--; /* { dg-error "decrement of pointer to an incomplete type" } */
      16    --a; /* { dg-error "decrement of pointer to an incomplete type" } */
      17    a += 1; /* { dg-error "invalid use of array with unspecified bounds" } */
      18    a -= 1; /* { dg-error "invalid use of array with unspecified bounds" } */
      19    a - a; /* { dg-error "arithmetic on pointer to an incomplete type" } */
      20  
      21    s++; /* { dg-error "increment of pointer to an incomplete type" } */
      22    ++s; /* { dg-error "increment of pointer to an incomplete type" } */
      23    s--; /* { dg-error "decrement of pointer to an incomplete type" } */
      24    --s; /* { dg-error "decrement of pointer to an incomplete type" } */
      25    s += 1; /* { dg-error "invalid use of undefined type" } */
      26    s -= 1; /* { dg-error "invalid use of undefined type" } */
      27    s - s; /* { dg-error "arithmetic on pointer to an incomplete type" } */
      28  
      29    u++; /* { dg-error "increment of pointer to an incomplete type" } */
      30    ++u; /* { dg-error "increment of pointer to an incomplete type" } */
      31    u--; /* { dg-error "decrement of pointer to an incomplete type" } */
      32    --u; /* { dg-error "decrement of pointer to an incomplete type" } */
      33    u += 1; /* { dg-error "invalid use of undefined type" } */
      34    u -= 1; /* { dg-error "invalid use of undefined type" } */
      35    u - u; /* { dg-error "arithmetic on pointer to an incomplete type" } */
      36  
      37    e++; /* { dg-error "increment of pointer to an incomplete type" } */
      38    ++e; /* { dg-error "increment of pointer to an incomplete type" } */
      39    e--; /* { dg-error "decrement of pointer to an incomplete type" } */
      40    --e; /* { dg-error "decrement of pointer to an incomplete type" } */
      41    e += 1; /* { dg-error "invalid use of undefined type" } */
      42    e -= 1; /* { dg-error "invalid use of undefined type" } */
      43    e - e; /* { dg-error "arithmetic on pointer to an incomplete type" } */
      44  }