g++ Bug? use of alloca in a function prevents exception handler walkback on ppc linux

[Geoff Keating]

> From: Franz Sirl <Franz.Sirl-kernel@lauterbach.com>
> Date: Thu, 14 Dec 2000 23:31:09 +0100

> > It's a libgcc bug.
> 
> But hard to fix?

It needs some rewriting, but then lots of testing.  Not very hard, but
not easy either.

> Your patch is against the current mainline, but mainline compiles a correctly 
> throwing binary with Kevin's testcase. Do you have another testcase or is the 
> current mainline already fixed and your patch superflous now? If it is fixed, 
> it must have happened recently, since the 20001106 compiler still produced a 
> failing binary.

It worries me that this stopped failing.  It probably indicates we
lost an optimisation.  I don't believe the underlying bug was fixed.

> Anyway, Kevin is working with gcc-2.95.3 so I'll look into backporting your 
> fix, cause I don't have time to do gcc-2.97 RPM's before xmas.

Sure.  As a workaround, this is suitable for 2.95.3.

-- 
- Geoffrey Keating <geoffk@geoffk.org>