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

[Emil Velikov]

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 ?

Thanks
Emil