glibc segfault on "special" long double values is _ok_!?

[James Youngman]

On 6/8/07, Jan-Benedict Glaw <jbglaw@lug-owl.de> wrote:
> On Fri, 2007-06-08 11:54:17 +0100, James Youngman <jay@gnu.org> wrote:
> > On 6/8/07, Jan-Benedict Glaw <jbglaw@lug-owl.de> wrote:
> > > hexdump (&my_long_double, sizeof my_long_double());
> > > kill (getpid (), SIGABRT);
> >
> > or just call abort() which is designed for the purpose.
> >
> > > That way, you get a nice core dump and can call GDB with it. With
> > > "clean" floats, just use GDB's "print" to print it (or even call
> > > printf() with it.)
> >
> > If printf fails on the offending bit pattern, presumably that is not
> > going to help.
>
> It does!  You've got the core file, so you have a second (and
> third...) try to examine the offending bit pattern with different
> methods.

You're certainly right.  The only problem is that this approach
doesn't scale particularly well, because although it is still
susceptible to automation, the automation itself is harder.

> Even for those cases: a loud crash is something that can be easily
> debugged.

My central point, which I'm sure you didn't miss, is that in some of
these cases, the invalid data is not the result of an application bug.

James.