[Mesa-dev] [PATCH v2] glsl: parser changes for GL_ARB_explicit_uniform_location

[Tapani Pälli]

On 06/12/2014 09:44 AM, Petri Latvala wrote:
> On 06/05/2014 08:08 AM, Tapani Pälli wrote:
>> Patch adds a preprocessor define for the extension and stores explicit
>> location data for uniforms during AST->HIR conversion. It also sets
>> layout token to be available when having the extension in place.
>>
>> v2: change parser check to require GLSL 330 or enabling
>>      GL_ARB_explicit_attrib_location (Ian)
>>
>> Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
>> ---
>>   src/glsl/ast_to_hir.cpp       | 36 ++++++++++++++++++++++++++++++++++++
>>   src/glsl/glcpp/glcpp-parse.y  |  3 +++
>>   src/glsl/glsl_lexer.ll        |  1 +
>>   src/glsl/glsl_parser_extras.h | 15 +++++++++++++++
>>   4 files changed, 55 insertions(+)
>>
>> diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
>> index d1c77f1..04452b8 100644
>> --- a/src/glsl/ast_to_hir.cpp
>> +++ b/src/glsl/ast_to_hir.cpp
>> @@ -2182,6 +2182,42 @@ validate_explicit_location(const struct ast_type_qualifier *qual,
>>   {
>>      bool fail = false;
>>   
>> +   /* Checks for GL_ARB_explicit_uniform_location. */
>> +   if (qual->flags.q.uniform) {
>> +      if (!state->check_explicit_uniform_location_allowed(loc, var))
>> +         return;
>> +
>> +      const struct gl_context *const ctx = state->ctx;
>> +      unsigned max_loc = qual->location + var->type->component_slots() - 1;
> var->type->uniform_locations() ?

yes indeed, will fix

>
>> +
>> +      /* ARB_explicit_uniform_location specification states:
>> +       *
>> +       *     "The explicitly defined locations and the generated locations
>> +       *     must be in the range of 0 to MAX_UNIFORM_LOCATIONS minus one."
>> +       *
>> +       *     "Valid locations for default-block uniform variable locations
>> +       *     are in the range of 0 to the implementation-defined maximum
>> +       *     number of uniform locations."
>> +       */
>> +      if (qual->location < 0) {
>> +         _mesa_glsl_error(loc, state,
>> +                          "explicit location < 0 for uniform %s", var->name);
>> +         return;
>> +      }
>> +
>> +      if (max_loc >= ctx->Const.MaxUserAssignableUniformLocations) {
>> +         _mesa_glsl_error(loc, state, "location qualifier for uniform %s "
>> +                          ">= MAX_UNIFORM_LOCATIONS (%u)",
>> +                          var->name,
>> +                          ctx->Const.MaxUserAssignableUniformLocations);
>> +         return;
>> +      }
> This error message might be too confusing.
>
> If MAX_UNIFORM_LOCATIONS were 6:
>
> uniform layout(location=3) float x[10];
>
> Error: Location qualifier for uniform x >= MAX_UNIFORM_LOCATIONS(6)
>
> "But 3 is not >= 6!" says the confused developer.
>
> Maybe "location qualifier or automatically assigned location" or something?
>

Nice catch and proposal, will change this.

>> +
>> +      var->data.explicit_location = true;
>> +      var->data.location = qual->location;
>> +      return;
>> +   }
>> +
>>      /* Between GL_ARB_explicit_attrib_location an
>>       * GL_ARB_separate_shader_objects, the inputs and outputs of any shader
>>       * stage can be assigned explicit locations.  The checking here associates
>> diff --git a/src/glsl/glcpp/glcpp-parse.y b/src/glsl/glcpp/glcpp-parse.y
>> index 9887583..dacb954 100644
>> --- a/src/glsl/glcpp/glcpp-parse.y
>> +++ b/src/glsl/glcpp/glcpp-parse.y
>> @@ -2089,6 +2089,9 @@ _glcpp_parser_handle_version_declaration(glcpp_parser_t *parser, intmax_t versio
>>   	      if (extensions->ARB_explicit_attrib_location)
>>   	         add_builtin_define(parser, "GL_ARB_explicit_attrib_location", 1);
>>   
>> +	      if (extensions->ARB_explicit_uniform_location)
>> +	         add_builtin_define(parser, "GL_ARB_explicit_uniform_location", 1);
>> +
>>   	      if (extensions->ARB_shader_texture_lod)
>>   	         add_builtin_define(parser, "GL_ARB_shader_texture_lod", 1);
>>   
>> diff --git a/src/glsl/glsl_lexer.ll b/src/glsl/glsl_lexer.ll
>> index 6c3f9b6..db7b1d1 100644
>> --- a/src/glsl/glsl_lexer.ll
>> +++ b/src/glsl/glsl_lexer.ll
>> @@ -396,6 +396,7 @@ layout		{
>>   		      || yyextra->AMD_conservative_depth_enable
>>   		      || yyextra->ARB_conservative_depth_enable
>>   		      || yyextra->ARB_explicit_attrib_location_enable
>> +		      || yyextra->ARB_explicit_uniform_location_enable
>>                         || yyextra->has_separate_shader_objects()
>>   		      || yyextra->ARB_uniform_buffer_object_enable
>>   		      || yyextra->ARB_fragment_coord_conventions_enable
>> diff --git a/src/glsl/glsl_parser_extras.h b/src/glsl/glsl_parser_extras.h
>> index e26460e..b73f816 100644
>> --- a/src/glsl/glsl_parser_extras.h
>> +++ b/src/glsl/glsl_parser_extras.h
>> @@ -151,6 +151,21 @@ struct _mesa_glsl_parse_state {
>>         return true;
>>      }
>>   
>> +   bool check_explicit_uniform_location_allowed(YYLTYPE *locp,
>> +                                                const ir_variable *var)
>> +   {
>> +      if (!this->has_explicit_attrib_location() ||
>> +          !this->ARB_explicit_uniform_location_enable) {
>> +         _mesa_glsl_error(locp, this,
>> +                          "uniform explicit location requires "
>> +                          "GL_ARB_explicit_uniform_location and either "
>> +                          "GL_ARB_explicit_attrib_location or GLSL 330.");
>> +         return false;
>> +      }
>> +
>> +      return true;
>> +   }
>> +
>>      bool has_explicit_attrib_location() const
>>      {
>>         return ARB_explicit_attrib_location_enable || is_version(330, 300);