[Mesa-dev] [PATCH 4/6] mesa: Use shared code for converting shader targets to short strings.

[Kenneth Graunke]

On 06/18/2013 12:12 PM, Eric Anholt wrote:
> Kenneth Graunke <kenneth at whitecape.org> writes:
>
>> On 06/17/2013 04:10 PM, Eric Anholt wrote:
>>> We were duplicating this code all over the place, and they all would need
>>> updating for the next set of shader targets.
>>> ---
>>>    src/glsl/glsl_parser_extras.cpp            | 35 ++++++++++++++++++++++++++++++
>>>    src/glsl/glsl_parser_extras.h              |  3 +++
>>>    src/glsl/link_varyings.cpp                 | 15 ++++++++-----
>>>    src/glsl/linker.cpp                        |  4 ++--
>>>    src/mesa/drivers/dri/i965/brw_shader.cpp   |  9 ++++----
>>>    src/mesa/main/shaderapi.c                  | 17 ++-------------
>>>    src/mesa/main/uniform_query.cpp            |  9 ++------
>>>    src/mesa/program/ir_to_mesa.cpp            |  5 +----
>>>    src/mesa/state_tracker/st_glsl_to_tgsi.cpp |  7 ++----
>>>    9 files changed, 61 insertions(+), 43 deletions(-)
>>>
>>> diff --git a/src/glsl/glsl_parser_extras.cpp b/src/glsl/glsl_parser_extras.cpp
>>> index 9862714..7b827ba 100644
>>> --- a/src/glsl/glsl_parser_extras.cpp
>>> +++ b/src/glsl/glsl_parser_extras.cpp
>>> @@ -302,6 +302,41 @@ _mesa_glsl_parse_state::process_version_directive(YYLTYPE *locp, int version,
>>>       }
>>>    }
>>>
>>> +extern "C" {
>>> +
>>> +/**
>>> + * The most common use of _mesa_glsl_shader_target_name(), which is
>>> + * shared with C code in Mesa core to translate a GLenum to a short
>>> + * shader stage name in debug printouts.
>>> + *
>>> + * It recognizes the PROGRAM variants of the names so it can be used
>>> + * with a struct gl_program->Target, not just a struct
>>> + * gl_shader->Type.
>>> + */
>>> +const char *
>>> +_mesa_glsl_shader_target_name(GLenum type)
>>> +{
>>> +   switch (type) {
>>> +   case GL_VERTEX_SHADER:
>>> +   case GL_VERTEX_PROGRAM_ARB:
>>> +      return "vertex";
>>> +   case GL_FRAGMENT_SHADER:
>>> +   case GL_FRAGMENT_PROGRAM_ARB:
>>> +      return "fragment";
>>> +   case GL_GEOMETRY_SHADER:
>>> +      return "geometry";
>>> +   default:
>>> +      assert(!"Should not get here.");
>>> +      return "unknown";
>>> +   }
>>> +}
>>> +
>>> +} /* extern "C" */
>>> +
>>> +/**
>>> + * Overloaded C++ variant usable within the compiler for translating
>>> + * our internal enum into short stage names.
>>> + */
>>>    const char *
>>>    _mesa_glsl_shader_target_name(enum _mesa_glsl_parser_targets target)
>>>    {
>>
>> I'm kind of wary of having an overloaded function where the
>> distinguisher is GLenum (int) vs. enum (basically int).  I think the C
>> vs. C++ enum rules save us here, but still not something I'm crazy about.
>>
>> Still, this is a really nice cleanup.  I'm glad to see this centralized,
>> as well as the vertex/fragment hardcoding going away.
>
> Yeah, I wasn't really happy with it either, but I was having a hell of a
> time coming up with names to distinguish the two that weren't
> ridiculously verbose.
>
> I'd much rather see us consistently use either the enum or the GLenum
> throughout mesa.  The GL_VERTEX_PROGRAM vs GL_VERTEX_SHADER is the
> worst, though.

Yeah, I agree - it's not obvious which are the MESA_SHADER_VERTEX enums 
and which are the GL_VERTEX_SHADER enums.  I do like how you handle both 
GL enums in this function.

I think this is sensible and we can tidy up the enums in the future.