[Buildroot] [PATCH v1] libdrm: fix libatomic_ops linking

[Peter Seiderer <ps.report@gmx.net>]

Hello Thomas,

On Mon, 18 Dec 2017 14:07:02 +0100, Thomas Petazzoni <thomas.petazzoni@free-electrons.com> wrote:

> Hello,
> 
> On Sat, 16 Dec 2017 20:55:16 +0100, Peter Seiderer wrote:
> > Add explicit libatomic_ops linking, fixes etnavid tests linking
> > 
> > Fixes [1]:
> > 
> >     CCLD     etnaviv_cmd_stream_test
> >   ../../etnaviv/.libs/libdrm_etnaviv.so: undefined reference to `AO_store_full_emulation'
> >   ../../etnaviv/.libs/libdrm_etnaviv.so: undefined reference to `AO_fetch_compare_and_swap_emulation'
> >   collect2: error: ld returned 1 exit status
> > 
> > [1] http://autobuild.buildroot.net/results/92e074c49417261843eef95872ff935a56077c98
> > 
> > Signed-off-by: Peter Seiderer <ps.report@gmx.net>
> > ---
> >  package/libdrm/libdrm.mk | 1 +
> >  1 file changed, 1 insertion(+)
> > 
> > diff --git a/package/libdrm/libdrm.mk b/package/libdrm/libdrm.mk
> > index 3d7b67122b..ecc525ca1e 100644
> > --- a/package/libdrm/libdrm.mk
> > +++ b/package/libdrm/libdrm.mk
> > @@ -21,6 +21,7 @@ LIBDRM_CONF_ENV = ac_cv_prog_cc_c99='-std=gnu99'
> >  
> >  ifeq ($(BR2_PACKAGE_LIBATOMIC_OPS),y)
> >  LIBDRM_DEPENDENCIES += libatomic_ops
> > +LIBDRM_CONF_ENV += LIBS="-latomic_ops"
> >  ifeq ($(BR2_sparc_v8)$(BR2_sparc_leon3),y)
> >  LIBDRM_CONF_ENV += CFLAGS="$(TARGET_CFLAGS) -DAO_NO_SPARC_V9"
> >  endif  
> 
> I think this is not the correct fix, because you will link against
> atomic_ops as soon as libatomic_ops is available for the target, even
> when libdrm doesn't need it (like when it uses the atomic built-ins of
> the compiler).
> 
> I think the right approach is to fix libdrm instead to use pkg-config
> to detect libatomic_ops and link against it when needed. See the
> attached libdrm patch that does this (tested successfully with the
> breaking SPARC configuration).
> 
> You just need to modify libdrm.mk for autoreconf, which includes the
> need to add host-xutil_util-macros to the dependencies.
> 
> Could you have a look at this, and if it also works for you, submit it
> as a patch?

Works (and updated patch submitted)...

Regards,
Peter

> 
> Thanks a lot!
> 
> Thomas