if (trap_list[sig].cmd == 0) {
        switch (sig) {
          case SIGINT:
            rb_thread_interrupt();
            break;
#ifdef SIGHUP
          case SIGHUP:
#endif
#ifdef SIGQUIT
          case SIGQUIT:
#endif
#ifdef SIGTERM
          case SIGTERM:
#endif
#ifdef SIGALRM
          case SIGALRM:
#endif
#ifdef SIGUSR1
          case SIGUSR1:
#endif
#ifdef SIGUSR2
          case SIGUSR2:
#endif
            rb_thread_signal_raise(sig);
            break;
        }
    }
    else if (trap_list[sig].cmd == Qundef) {
        rb_thread_signal_exit();
    }
    else {
        rb_thread_trap_eval(trap_list[sig].cmd, sig, trap_list[sig].safe);
    }