#define PL_signals              (vTHX->Isignals)

   if (PL_signals & PERL_SIGNALS_UNSAFE_FLAG) - failure here 
##</code><code>##

   /* Block most signals for calling thread, setting the old signal mask to
   + * oldmask, if it is not NULL */
   +STATIC int
   +S_block_most_signals(sigset_t *oldmask)
   +{
   +    sigset_t newmask;
   +
   +    sigfillset(&newmask);
   +    /* Don't block certain "important" signals (stolen from mg.c) */
   +#ifdef SIGILL
   +    sigdelset(&newmask, SIGILL);
   +#endif
   +#ifdef SIGBUS
   +    sigdelset(&newmask, SIGBUS);
   +#endif
   +#ifdef SIGSEGV
   +    sigdelset(&newmask, SIGSEGV);
   +#endif