13 static void check_signum(int sig)  in check_signum()  argument
15 	if (sig < 1 || sig >= SIGCHAIN_MAX_SIGNALS)  in check_signum()
16 		die("BUG: signal out of range: %d", sig);  in check_signum()
19 static int sigchain_push(int sig, sigchain_fun f)  in sigchain_push()  argument
21 	struct sigchain_signal *s = signals + sig;  in sigchain_push()
22 	check_signum(sig);  in sigchain_push()
25 	s->old[s->n] = signal(sig, f);  in sigchain_push()
32 int sigchain_pop(int sig)  in sigchain_pop()  argument
34 	struct sigchain_signal *s = signals + sig;  in sigchain_pop()
35 	check_signum(sig);  in sigchain_pop()
39 	if (signal(sig, s->old[s->n - 1]) == SIG_ERR)  in sigchain_pop()