Re: RedHat patch not found in mainline gcc

[Stefan Ring <stefanrin at gmail dot com>]

> I don't remember it well, but from re-reading the gcc-patches threads around
> that time like:
> http://gcc.gnu.org/ml/gcc-patches/2009-06/msg00368.html

That thread is from 2009.

> it seems that the actually committed fix for the bug that the
> gcc41-unwind-restore-state.patch was meant to fix was
> http://gcc.gnu.org/ml/gcc-patches/2006-01/msg00617.html committed as
> http://gcc.gnu.org/r118068

And this one from 2006. Are you sure they are related?

> If you are talking about devtoolset, that compiler doesn't come with it's
> own libgcc_s.so.1, uses the system one, just its own libgcc_eh.a, so e.g. if
> you'd use the default -shared-libgcc (for g++), then it should make no
> difference at all, because you'd be using the same system unwinder all the
> time.

I don't quite understand. If -shared-libgcc is default, I certainly
have not touched it. And since patching the system unwinder in
/lib64/libgcc_s-4.1.2-20080825.so.1 is what affects the crashing
behavior, it seems to be using the system unwinder already.

To me, it looks like the newer gcc from devtoolset generates unwind
instruction that the old unwinder does not understand (or doesn't
interpret correctly), whereas with gcc41-unwind-restore-state.patch
applied, it does.