Re: [ia64] Regression: Re: [rfc] Fix Obj-C method calls on 64-bit PowerPC

["Ulrich Weigand" <uweigand at de dot ibm dot com>]

Joel Brobecker wrote:
> > ia64 is now broken, also on the 7.0 branch due to the check-in:
> >  http://sourceware.org/ml/gdb-cvs/2009-09/msg00210.html
> 
> Darn function descriptors on ia64, and darn objc support that
> overmatches. One of the assumptions I was making when considering
> this patch for 7.0 was the fact that it would only affect ObjC.
> But I should have known better after all the discussions I had
> with Matt Rice. My suggestion is to revert it from 7.0, and maybe
> consider it for 7.0.1 if we manage to fix all unexpected side-effects
> by then.

Argh.  I (perhaps naively) assumed that the "decode_objc" routine
would only trigger for ObjC source files ...  Of course this turns
out not to be true, and it is in fact invoked for *any* symbol
lookup first, just to find out that the symbol is not ObjC.

In this case, I agree that this change is much too risky for 7.0
at this stage (even assuming Jan would manage to find and fix all
ia64 regressions).  In any case, ObjC has always been broken on
ppc64 so my patch isn't even a regression fix as such (reverting
it will get us back to testsuite runs taking 20 mins longer than
they should, but I guess I can live with that).

I'm going to revert my ObjC patch from the branch as soon as
testing completes.  However, I'll leave it in mainline for now,
to expose it to further testing and see what comes up.

If there is a follow-on release on the 7.0 branch (but I do not
consider the ppc64 ObjC issue by itself sufficient cause to
trigger such a release -- only if we decide to do it anyway),
and the patch has been on mainline for a while with the
resulting issues fixed, we can revisit the decision to put
it on the branch.

Bye,
Ulrich

-- 
  Dr. Ulrich Weigand
  GNU Toolchain for Linux on System z and Cell BE
  Ulrich.Weigand@de.ibm.com