sm_signal_noop
extern SIGFUNC_DECL sm_signal_noop __P((int));
FIX_SYSV_SIGNAL(sig, sm_signal_noop);
(old) = sm_signal((sig), sm_signal_noop); \
(void) sm_signal(SIGALRM, sm_signal_noop);
(void) sm_signal(SIGUSR1, sm_signal_noop);