signal.c:340
static void signal_exec _((int sig));
static void
signal_exec(sig)
    int sig;
{
    if (trap_list[sig] == 0) {
	switch (sig) {
	  case SIGINT:
	    rb_thread_interrupt();
	    break;
#ifdef SIGHUP
	  case SIGHUP:
#endif
#ifdef SIGQUIT
	  case SIGQUIT:
#endif
#ifdef SIGALRM
	  case SIGALRM:
#endif
#ifdef SIGUSR1
	  case SIGUSR1:
#endif
#ifdef SIGUSR2
	  case SIGUSR2:
#endif
	    rb_thread_signal_raise(signo2signm(sig));
	    break;
	}
    }
    else {
	rb_thread_trap_eval(trap_list[sig], sig);
    }
}
