[PATCH] os: use libunwind to generate backtraces

[Peter Hutterer]

On Sat, Feb 23, 2013 at 10:17:20PM +0100, Marcin Slusarz wrote:
> On Fri, Feb 22, 2013 at 09:02:39AM +1000, Peter Hutterer wrote:
> > On Thu, Feb 21, 2013 at 08:00:07AM +0100, Marcin Ślusarz wrote:
> > > 21 lut 2013 00:37, "Peter Hutterer" <peter.hutterer at who-t.net> napisał(a):
> > > > thanks for the changes but after applying this patch locally I do wonder:
> > > > how did you test this? i'm getting undefined references to the various
> > > > libunwind calls (_Ux86_64_getcontext, _Ux86_64_strerror,etc) for Xvfb,
> > > Xdmx, Xnext
> > > > and all the tests). This needs some more polishing.
> > > 
> > > Try to do make clean before building.
> > > For some reason libos.la is not updated automatically.
> > 
> > I did to a make distclean and it still won't work. did a fresh clone, and
> > I'm still getting 
> > 
> >   CCLD     Xvfb
> >   ../../os/os.O: In function `xorg_backtrace':
> >   /home/whot/xorg/xserver/os/backtrace.c:56: undefined reference to
> >   `_Ux86_64_getcontext'
> >   /home/whot/xorg/xserver/os/backtrace.c:58: undefined reference to
> >   `_Ux86_64_strerror'
> >   /home/whot/xorg/xserver/os/backtrace.c:63: undefined reference to
> >   `_ULx86_64_init_local'
> >   /home/whot/xorg/xserver/os/backtrace.c:65: undefined reference to
> >   `_Ux86_64_strerror'
> >   /home/whot/xorg/xserver/os/backtrace.c:72: undefined reference to
> >   `_ULx86_64_step'
> >   /home/whot/xorg/xserver/os/backtrace.c:74: undefined reference to
> >   `_ULx86_64_get_proc_info'
> >   /home/whot/xorg/xserver/os/backtrace.c:76: undefined reference to
> >   `_Ux86_64_strerror'
> >   /home/whot/xorg/xserver/os/backtrace.c:81: undefined reference to
> >   `_ULx86_64_get_proc_name'
> >   /home/whot/xorg/xserver/os/backtrace.c:84: undefined reference to
> >   `_Ux86_64_strerror'
> >   /home/whot/xorg/xserver/os/backtrace.c:100: undefined reference to
> >   `_ULx86_64_step'
> >   /home/whot/xorg/xserver/os/backtrace.c:102: undefined reference to
> >   `_Ux86_64_strerror'
> 
> It builds fine on Gentoo (~amd64) and Fedora 18, although Fedora 18 ships too
> old version of libunwind (no pkgconfig support), so I had to build it manually.
> 
> What do I need to do to reproduce it? :)

good question. I tried a scratch-build to make sure and that one failed as
well. So something isn't quite right, but I don't yet know what.

http://koji.fedoraproject.org/koji/taskinfo?taskID=5051896

Cheers,
   Peter

> > if you look at the hw/xfree86/Makefile.am, libos.la is uses twice, once from
> > XSERVER_LIBS, once at the end again. This isn't the case for the other
> > DDX's, I suspect this may be the reason.
> 
> I don't see why order (or number) of .la files would matter...
> 
> Marcin