#define DIFF_OPT_TST(opts, flag) ((opts)->flags & DIFF_OPT_##flag)
#define DIFF_OPT_SET(opts, flag) ((opts)->flags |= DIFF_OPT_##flag)
#define DIFF_OPT_CLR(opts, flag) ((opts)->flags &= ~DIFF_OPT_##flag)
#define DIFF_OPT_TST(opts, flag) ((opts)->flags & DIFF_OPT_##flag)
#define DIFF_OPT_SET(opts, flag) ((opts)->flags |= DIFF_OPT_##flag)
#define DIFF_OPT_CLR(opts, flag) ((opts)->flags &= ~DIFF_OPT_##flag)