[Mesa-dev] [PATCH] egl/dri2: add a libname to dlopen for OpenBSD

[Jonathan Gray]

On Mon, Oct 17, 2016 at 05:34:02PM +0100, Emil Velikov wrote:
> On 17 October 2016 at 16:39, Eric Engestrom <eric.engestrom at imgtec.com> wrote:
> > On Monday, 2016-10-17 22:53:20 +1100, Jonathan Gray wrote:
> >> On Mon, Oct 17, 2016 at 12:39:11PM +0100, Emil Velikov wrote:
> >> > On 17 October 2016 at 10:53, Eric Engestrom <eric.engestrom at imgtec.com> wrote:
> >> > > On Sunday, 2016-10-16 16:38:35 +1100, Jonathan Gray wrote:
> >> > >> On OpenBSD try to dlopen 'libglapi.so', ld.so will find
> >> > >> the highest major/minor version and open it in this case.
> >> > >>
> >> > >> Avoids '#error Unknown glapi provider for this platform' at build time.
> >> > >>
> >> > >> Signed-off-by: Jonathan Gray <jsg at jsg.id.au>
> >> > >
> >> > > LGTM, and I guess the other *BSD will want the same since 7a9c92d0 broke
> >> > > them too.
> >> > >
> >> > I'm not 100% sure about that. OpenBSD (unlike other BSD) did bump the
> >> > major when the ABI breaks due to 'internal' changes - think of
> >> > off_t/time_t on 32 vs 64bit systems and alike.
> >> >
> >> > Unlike Linux kernel/distros, BSDs tend to be more relaxed when in
> >> > comes to ABI, I believe. Don't quote me on that one ;-)
> >>
> >> OpenBSD tends to favour simplified interfaces over backwards compatiblity
> >> and is more like a research system in that respect.  As the kernel
> >> and userland are one source tree ioctl compat largely doesn't exist.
> >> System calls get deprecated and removed over the course of a few releases.
> >> So we didn't go through the pain of duplicated systems calls for off_t
> >> as mentioned, and don't go in for symbol versioning.  Just major.minor
> >> library versioning, which is roughly symbol removals, major crank,
> >> symbol additions minor crank.
> >>
> >> I believe FreeBSD tends to go in for backwards compatibility more
> >> but am not familiar with the details.  They also have a different ld.so.
> >>
> >> Perhaps an else case for 'libglapi.so.0' would be appropriate for all
> >> the other various unices instead of the #error ?
> >
> > Yeah actually, I'm thinking reverting this hunk of 7a9c92d0 might be a better,
> > to avoid the potentially huge list of every *BSD and other Unix:
> >
> Fwiw I've intentionally added the hunk since I was a bit lazy to check
> if the BSD(s?)/Solaris/others have bumped the major locally. Having a
> closer look that's not the case, so indeed we can add revert to
> libglapi.so.0 in the else statement.
> 
> Jonathan, how about we with the above instead ?

At the moment OpenBSD has libglapi.so.0.2 for Mesa 11.2.2.
New versions of Mesa add new shared_dispatch_stub_* symbols,
which the minor would crank for.

I'd prefer the diff I mailed for OpenBSD for if the major version
should crank for some reason.