1 static int ok(int *a, int *b)
   2 {
   3         return a - b;
   4 }
   5 
   6 struct s {
   7         int a, b, c;
   8 };
   9 
  10 static int ko(struct s *a, struct s *b)
  11 {
  12         return a - b;
  13 }
  14 
  15 /*
  16  * check-name: ptr-sub-blows
  17  * check-command: sparse -Wptr-subtraction-blows $file
  18  *
  19  * check-error-start
  20 ptr-sub-blows.c:12:18: warning: potentially expensive pointer subtraction
  21 ptr-sub-blows.c:12:18:     'struct s' has a non-power-of-2 size: 12
  22  * check-error-end
  23  */