src/signal/sigaddset.c

   1 #include <signal.h>
   2 #include <errno.h>
   3
   4 int sigaddset(sigset_t *set, int sig)
   5 {
   6         unsigned s = sig-1;
   7         if (s >= _NSIG-1 || sig-32U < 3) {
   8                 errno = EINVAL;
   9                 return -1;
  10         }
  11         set->__bits[s/8/sizeof *set->__bits] |= 1UL<<(s&8*sizeof *set->__bits-1);
  12         return 0;
  13 }