Re: [PATCH] C undefined behavior fix

Tom Rini
2002-01-03T00:32:37Z

On Thu, Jan 03, 2002 at 01:19:05AM +0100, jtv wrote:
> On Wed, Jan 02, 2002 at 04:34:52PM -0700, Tom Rini wrote:
> > On Thu, Jan 03, 2002 at 01:28:42AM +0200, Momchil Velikov wrote:
> > >
> > > GCC thinks exactly what the function does.
> >
> > And then optimizes it to something that fails to work in this particular
> > case.
>
> Which it may do with another function *or expression* as well, because
> the real bug has already happened before the function call comes into
> the issue.

What's the bug? The 'funny' arithmetic?

> As far as I'm concerned the options are: fix RELOC;

How?

> obviate RELOC; use
> an appropriate gcc option if available (-fPIC might be it, -ffreestanding
> certainly isn't--see above);

Maybe for 2.5. Too invasive for 2.4.x (initially at least).

> *extend* (not fix, extend) gcc; or work
> around all individual cases. In rough descending order of preference.

Er, say what?

--
Tom Rini (TR1265)