static int ok(int *a, int *b) { return a - b; } struct s { int a, b, c; }; static int ko(struct s *a, struct s *b) { return a - b; } /* * check-name: ptr-sub-blows * check-command: sparse -Wptr-subtraction-blows $file * * check-error-start ptr-sub-blows.c:12:18: warning: potentially expensive pointer subtraction ptr-sub-blows.c:12:18: 'struct s' has a non-power-of-2 size: 12 * check-error-end */