Re: sigaction, SA_SIGINFO, and SIG_IGN

[Paul Eggert]

Bruno Haible <[EMAIL PROTECTED]> writes:

> This will not compile on Interix 3.5, whereas the current code does.

True; how about working around that problem by inserting the following
prelude into fatal-signal.c:

   typedef void (*sa_handler_t) (int);

   /* Return the handler of a signal, as a sa_handler_t value regardless
      of its true type.  The resulting function can be compared to
      special values like SIG_IGN but it is not portable to call it.  */
   static sa_handler_t
   get_handler (struct sigaction const *a)
   {
   #ifdef SA_SIGINFO
     /* POSIX says that special values like SIG_IGN can only occur
        when action.sa_flags does not contain SA_SIGINFO.  But in
        Linux 2.4, for example, sa_sigaction and sa_handler are
        aliases and a signal is ignored if sa_sigaction (after
        casting) equals SIG_IGN.  So use (and cast) sa_sigaction in
        that case.  */
     if (a->sa_flags & SA_SIGINFO)
       return (sa_handler_t) a->sa_sigaction;
   #endif
     return a->sa_handler;
   }

and then using the following code in init_fatal_signals?

  if (sigaction (fatal_signals[i], NULL, &action) == 0
      && get_handler (&action) == SIG_IGN)
    fatal_signals[i] = -1;