[Mesa-dev] [PATCH] meson: Add Haiku platform support v3

[Emil Velikov]

On 16 February 2018 at 22:12, Dylan Baker <dylan at pnwbakers.com> wrote:
> Quoting Emil Velikov (2018-02-16 13:55:06)
>> On 16 February 2018 at 19:28, Dylan Baker <dylan at pnwbakers.com> wrote:
>> > Quoting Alexander von Gluck IV (2018-02-16 11:08:33)
>> >> February 16, 2018 11:49 AM, "Emil Velikov" <emil.l.velikov at gmail.com> wrote:
>> >> > Hi Alexander,
>> >> >
>> >> > Did you drop the ball on the autotools patches? I could re-spin them
>> >> > but have no way to test.
>> >>
>> >> I've been focused on meson since it's the future.
>> >> Feel free to re-spin them if you have the bandwidth.
>> >>
>> >> > There's a couple of comments inline, but nothing major.
>> >> >
>> >> > On 16 February 2018 at 00:32, Alexander von Gluck IV
>> >> > <kallisti5 at unixzen.com> wrote:
>> >> >
>> >> >> --- a/meson.build
>> >> >> +++ b/meson.build
>> >> >>
>> >> >> gl_priv_libs = []
>> >> >> -if dep_thread.found()
>> >> >> +if dep_thread.found() and host_machine.system() != 'haiku'
>> >> >> gl_priv_libs += ['-lpthread', '-pthread']
>> >> >> endif
>> >> >
>> >> > There's a bug report/fix in Meson for this one right?
>> >> > Please mention the ticket number of Meson version where the fix
>> >> > landed. Thus way one can drop this when we bump the Meson requirement.
>> >>
>> >> I did a bump of Meson on my Haiku build system and still saw the same
>> >> incorrect searching for -lpthread issues.  I think there are places where
>> >> -lpthread -pthread were specified without looking at dep_thread.found()
>> >> though which could be at play.  (see below)
>> >
>> > dep_pthread.found() returns true on anything that has pthreads, so for us that
>> > means anything except windows (non-cygwin windows). I think this is the right
>> > way to handle this, haiku does have pthreads, they're just not a separate
>> > library. macOS has some weird pthreads stuff too, and this is how we handle
>> > macOS.
>> >
>> Could swear I read your reply somewhere which said that we can as
>> Meson to provide the correct flags - be that -lpthread or others.
>> Yet we're doing the completely opposite thing here.
>>
>> Did I misunderstand you or ?
>>
>> -Emil
>
> What I said was that adding `dependency('threads')` to a target, ala
> mylib = library(
>   'mylib',
>   'mylib.c',
>   dependencies : dependency('threads'),
> )
>
> Will always (as of 0.44 when I fixed Haiku) do the right thing.
>
> The problem is that haiku *does* have pthreads, it just doesn't have a pthreads
> library. So the dep returns found because there are pthreads, it just doesn't
> add any -l, -L, or -I arguments because none are necessary.
>
Right. Using -lpthread (notice the L) is kind of wrong and incomplete.
-pthread is sufficient and the "right thing to do". Modulo the odd
platform (msvc, maybe suncc and maybe haiku) that wants to use
something else ;-)

As you mentioned meson has dependency('threads') - which we can
transcribe and use in the pkg-config files, right?

-Emil