From mboxrd@z Thu Jan  1 00:00:00 1970
From: Eric Le Bihan <eric.le.bihan.dev@free.fr>
Date: Wed, 30 Apr 2014 10:30:20 +0200
Subject: [Buildroot] [autobuild.buildroot.net] Build results for
 2014-04-25
In-Reply-To: <20140426235953.GA15466@ned>
References: <20140426063011.24622100FA4@stock.ovh.net>
 <20140426235953.GA15466@ned>
Message-ID: <20140430083018.GA27960@pc-eric>
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To: buildroot@busybox.net

On Sun, Apr 27, 2014 at 01:59:55AM +0200, Eric Le Bihan wrote:
> Hi!
> On Sat, Apr 26, 2014 at 08:30:11AM +0200, Thomas Petazzoni wrote:
> >     x86_64 |                  cairo-1.12.10 | NOK | http://autobuild.buildroot.net/results/d8c703043220ec95be9c793712570843ca7c0a16/
>
> This is not a cairo issue, but a mesa3d one: in the defconfig file, mesa3d is
> configured with Gallium3D drivers and GLES support only. In this case, the
> Makefile of the package adds --disable-shared-glapi to the configure options,
> but anyway, the configure script will also sets it by itself, as support for
> DRI is disabled.
>
> The build fails because libGLESv2.so has undefined references to
> _glapi_get_dispatch() which is defined... in libglapi.so! See
> http://www.mesa3d.org/dispatch.html to learn about this function.
>
> Looking at src/mapi/es2api/Makefile.am, we can see that, when
> --disable-shared-glapi is passed, the libglapi is not added as dependency:
>
>   if HAVE_SHARED_GLAPI
>   libGLESv2_la_LIBADD += ../shared-glapi/libglapi.la
>   endif
>
> But unfortunately, this is not correctly handled in src/mapi/entry.c, which
> is used to build libGLESv{1,2}.so and libglapi.so. In this file, we have:
>
>   /* in bridge mode, mapi is a user of glapi */
>   #ifdef MAPI_MODE_BRIDGE
>   #define ENTRY_CURRENT_TABLE_GET "_glapi_get_dispatch"
>   #else
>   #define ENTRY_CURRENT_TABLE_GET U_STRINGIFY(u_current_get_internal)
>   #endif
>
> When comparing src/mapi/glapi/Makefile.am and src/map/es2api/Makefile.am, we
> can see that, when passing --disable-shared-glapi, MAPI_MODE_BRIDGE is handled
> differently. For libGLESv2.so, entry.c will be compiled with
> -DMAPI_MODE_BRIDGE, hence the reference to _glapi_get_dispatch().
>
> I tried to build libGLESv2.so without -DMAPI_MODE_BRIDGE, but I ended up with
> new header issues...
>
> So it looks that building GLES with Gallium3D only is currently broken. I'll
> query upstream about this: finding the right configure options for building
> only specific parts of Mesa3D is not straight forward.

This problem has been discussed on the mesa-dev mailing list:
http://lists.freedesktop.org/archives/mesa-dev/2014-April/058610.html.

Recent changes in the upcoming version 10.0.6 now make --enabled-shared-glapi
mandatory if one or more GL* API is selected (which is the case in the
autobuild defconfig, with GLESv1/v2). Besides, building shared glapi is not
restricted to use DRI drivers anymore.

I backported:

- 0432aa064bf5d4d0ad8fc3c4d648b8feb238ddfa
- 1bb23abe0659559ec95d6d20cdcfc67b48619286
- 1a568e0f2b65e4e1e1d19a6dece3a792a33da825

to 10.0.4, and this error is fixed. I'll cook up a patch.

Best regards,
ELB