[Mesa-dev] [PATCH 4/9] prog; add weak _mesa_error_no_memory() symbol and add it to libglsl_util

[Brian Paul]

On 04/15/2015 11:56 AM, Emil Velikov wrote:
> On 15 April 2015 at 18:33, Matt Turner <mattst88 at gmail.com> wrote:
>> On Wed, Apr 15, 2015 at 7:08 AM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>>> Rather than forcing everyone to provide their own definition of the symbol
>>> provide a common weak one, which anyone can override if needed.
>>>
>>> This resolved the build of the standalone pipe-drivers, as it provides a
>>> default symbol which was missing previously.
>>>
>>> Cc: Rob Clark <robclark at freedesktop.org>
>>> Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
>>> ---
>>>   src/Makefile.am                        |  3 ++-
>>>   src/glsl/SConscript                    |  2 ++
>>>   src/mesa/Android.libmesa_glsl_utils.mk |  6 ++++--
>>>   src/mesa/program/weak_errors.c         | 30 ++++++++++++++++++++++++++++++
>>
>> Is program/ really the right place for this? (maybe main/ instead?)
> Hmm main/ might be better indeed. If there are any recommendations
> about the name I'll gladly take it :)
>
> Jose/Brian
>
>  From a quick look I cannot find a suitable alternative for
> __attribute__((weak)) for MSVC. Would you know any of the top of your
> head or should I just wrap the attribute in ifndef _MSC_VER and leave
> the rest ? If I drop the weak_errors.c hunk from the SCons here, and
> replace tests/common.c with it things should just work.

I'd have to do some digging to answer the MSVC question.

I guess I'm not totally clear on the background of what's going on here, 
but let me make a suggestion.

The comment in src/gallium/state_trackers/xa/xa_tracker.c says that it's 
called by NIR, but I can't find any calls to _mesa_error_no_memory() in 
src/glsl/nir/.  I guess the actual calls are in the src/glsl/ code, right?

I ran into a similar thing in the glapi code where I wanted to call some 
core Mesa function, but didn't want a dependency of that nature.

The solution was to use a callback function.

So, could we add a function to the glsl/nir code which registers an 
out-of-memory callback function?  The glsl/nir code could have a default 
fprintf(stderr) fallback.  But Mesa would register a callback that 
actually calls  _mesa_error() to record the error.

That seems cleaner than using a compiler/linker work-around.

-Brian