[google gcc-4_7, integration] Build more of libstdc++ with frame pointers

[Paul Pluzhnikov]

On Wed, Feb 27, 2013 at 5:52 PM, Ian Lance Taylor <iant@google.com> wrote:

> I think that the libgcc unwinder only calls malloc if somebody calls
> __register_frame_info.

So I looked. Indeed it doesn't call malloc in our environment, but
does call dl_iterate_phdr, which is just as deadly.

To be fair, libunwind does that as well, and we have to provide a
workaround for that.

Still, out-of-the-box libgcc unwinder is not suitable for our unwind
requirements.

> I thought a more serious issue is that the libgcc unwinder has no way
> of dealing with a corrupt stack--it will simply crash.

That too ...

Thanks,
-- 
Paul Pluzhnikov