Re: [Patch] x % 0 hangs

[Mark Kettenis <kettenis@chello.nl>]

   From: Ian Lance Taylor <ian@wasabisystems.com>
   Date: 27 Jun 2004 11:06:19 -0400

   Andrew Cagney <cagney@gnu.org> writes:

   > > The only approach that's somewhat
   > > portable is longjmp-ing out of the signal handler, and even that seems
   > > to have its problems on some platforms.
   > 
   > I'm curious, which platforms?

Over the years I've seen quite a few bug-reports about this failing to
work, but I can't remember exectly which platforms were affected.  It
may be related to what I say in the next paragraph though.

Anyway, if/when we start longjmp-ing out of signal handlers we have to
realize the we must restore the proper signal mask (not all
sigjmp/longjmp implementations do that) and perhaps re-install the
SIGFPE signal handler.

   I would think that it would be safe enough to longjmp on SIGFPE into
   the gdb catch_errors stack.  You would obviously be in trouble if the
   SIGFPE came from any libc stdio routine, but I would expect that to be
   impossible with a working library.

The worst case is that we'll crash, which still is an improvement over
just hanging like we do now on some platforms :-).

Mark