/* HANDLE SIGNALS -- must be used on top level as function definition */
#define HANDLE(sig, flags, handlr)					\
  static void __sighandler_##sig(int, siginfo_t *, void *);		\
  static void __sigwrapper_##sig(int s, siginfo_t *i, void *c) {	\
    int old_errno = errno;						\
    __sighandler_##sig(s, i, c);					\
    errno = old_errno;							\
  }									\
  static void __attribute__((constructor)) __siginit_##sig() {		\
    struct sigaction act = { .sa_flags = flags };			\
    if (handlr) act.sa_handler = handlr;				\
    else act.sa_sigaction = __sigwrapper_##sig;				\
    MUSTP(QF, sigemptyset, &act.sa_mask);				\
    MUSTP(QF, sigaction, sig, &act, NULL);				\
  }									\
  static void __sighandler_##sig(int __attribute__((unused)) signal,	\
				 siginfo_t __attribute__((unused)) * info, \
				 void __attribute__((unused)) * ctx)