[patch] Use dlsym instead of glXGetProcAddress in xdriinfo

[Felix Kühling]

Am Dienstag, den 22.11.2005, 08:36 -0700 schrieb Brian Paul:
> Michel Dänzer wrote:
> > On Mon, 2005-11-21 at 18:08 -0500, Felix Kühling wrote: 
> > 
> >>The attached patches (monolithic and modular) should fix dynamic linking
> >>problems with xdriinfo, that NVidia users were complaining about. 
> 
> (referrring to previous message) Why not just use glXGetProcAddressARB 
> instead?

This problem was originally discussed in February on a private email
thread between Eric Anholt, Mikhail Teterin and myself. Eric reported
that using glXGetProcAddressARB segfaulted on his AMD64 system (weird, I
always thought the ARB function was just an alias). At that point the
thread ended and was forgotten about by everybody. Now it's getting
pretty late to get this fixed in the upcoming Xorg releases.

The dlopen hack is obviously not portable so it's no better than the
current solution. And given that Xorg 6.9 includes Mesa 6.4 and Xorg 7
requires Mesa 6.4 for DRI support, why should we worry about other GLX
implementations? Any build or run time errors could arguably be treated
as system configuration errors on the user's side.

I could be convinced to use glXGetProcAddressARB. But I'd like to get
more information about the AMD64 segfaults Eric reported first. If it
doesn't fix the problem but just changes the failure mode, then there is
no point in making this change so close to a release.

Regards,
  Felix

> 
> 
> > Does their driver support the DRI configuration infrastructure?
> > 
> > 
> >>Their libGL doesn't define glXGetProcAddress but only glXGetProcAddressARB.
> >>The cleanest solution that works with any libGL is to use dlopen and
> >>dlsym instead. This has the nice side effect that it removes all
> >>build-time dependencies on libGL and GLX headers.
> > 
> > 
> > Couldn't there be an implementation of the DRI configuration
> > infrastructure where glXGetProcAddress(ARB) works but dlopen/dlsym
> > doesn't though?
> 
> Possibly.
> 
> -Brian
> _______________________________________________
> xorg mailing list
> xorg at lists.freedesktop.org
> http://lists.freedesktop.org/mailman/listinfo/xorg
> 
> 
-- 
| Felix Kühling <fxkuehl at gmx.de>                     http://fxk.de.vu |
| PGP Fingerprint: 6A3C 9566 5B30 DDED 73C3  B152 151C 5CC1 D888 E595 |