[Piglit] [PATCH 1/6] shader_runner: Check feature support before querying GL_MAX_*.

[Matt Turner]

On Wed, Nov 11, 2015 at 4:47 PM, Kenneth Graunke <kenneth at whitecape.org> wrote:
> On Tuesday, November 10, 2015 10:46:18 PM Matt Turner wrote:
>> Otherwise, these will generate an error (to be noticed sometime later
>> when glGetError() is called), often resulting in a test failure.
>> ---
>>  tests/shaders/shader_runner.c | 18 ++++++++++++------
>>  1 file changed, 12 insertions(+), 6 deletions(-)
>>
>> diff --git a/tests/shaders/shader_runner.c b/tests/shaders/shader_runner.c
>> index 32ac7bd..4597b46 100644
>> --- a/tests/shaders/shader_runner.c
>> +++ b/tests/shaders/shader_runner.c
>> @@ -3111,12 +3111,18 @@ piglit_init(int argc, char **argv)
>>       if (piglit_get_gl_version() >= 32)
>>               glGetIntegerv(GL_MAX_VERTEX_OUTPUT_COMPONENTS,
>>                             &gl_max_vertex_output_components);
>> -     glGetIntegerv(GL_MAX_FRAGMENT_UNIFORM_COMPONENTS,
>> -                   &gl_max_fragment_uniform_components);
>> -     glGetIntegerv(GL_MAX_VERTEX_UNIFORM_COMPONENTS,
>> -                   &gl_max_vertex_uniform_components);
>> -     glGetIntegerv(GL_MAX_VARYING_COMPONENTS,
>> -                   &gl_max_varying_components);
>> +     if (piglit_get_gl_version() >= 20 ||
>> +         piglit_is_extension_supported("GL_ARB_fragment_shader"))
>> +             glGetIntegerv(GL_MAX_FRAGMENT_UNIFORM_COMPONENTS,
>> +                           &gl_max_fragment_uniform_components);
>> +     if (piglit_get_gl_version() >= 20 ||
>> +         piglit_is_extension_supported("GL_ARB_vertex_shader"))
>> +             glGetIntegerv(GL_MAX_VERTEX_UNIFORM_COMPONENTS,
>> +                           &gl_max_vertex_uniform_components);
>
> Above this, we call piglit_require_GLSL()...it seems like that
> ought to be causing us to skip in this case.  Maybe we don't
> return early enough?

We talked about this on IRC, but for the mailing list:

The problem is that piglit_require_GLSL() says "all okay" if you have
GL 2.0 or (GL_ARB_shader_objects and GL_ARB_shading_language_100), and
R200 exposes both of those extensions, even though it doesn't expose
the actual extensions you need for shading... ARB_fragment_shader or
ARB_vertex_shader.

And moreover, since we support fragment program and vertex program
shader_tests, we don't actually want to be requiring GLSL anyway.

I'll work on sorting that out, but I think t his patch is good as is
(with the GL_ARB_geometry_shader4 change).