[Mesa-dev] [PATCH 08/10] glsl: parser changes for GL_ARB_explicit_uniform_location

[Ian Romanick]

On 04/09/2014 02:56 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.
> 
> Signed-off-by: Tapani Pälli <tapani.palli at intel.com>
> ---
>  src/glsl/ast_to_hir.cpp       | 37 +++++++++++++++++++++++++++++++++++++
>  src/glsl/glcpp/glcpp-parse.y  |  3 +++
>  src/glsl/glsl_lexer.ll        |  1 +
>  src/glsl/glsl_parser_extras.h | 14 ++++++++++++++
>  4 files changed, 55 insertions(+)
> 
> diff --git a/src/glsl/ast_to_hir.cpp b/src/glsl/ast_to_hir.cpp
> index 8d55ee3..7431ad7 100644
> --- a/src/glsl/ast_to_hir.cpp
> +++ b/src/glsl/ast_to_hir.cpp
> @@ -2170,6 +2170,43 @@ validate_explicit_location(const struct ast_type_qualifier *qual,
>  {
>     bool fail = false;
>  
> +   /* Checks for GL_ARB_explicit_uniform_location. */
> +   if (qual->flags.q.uniform) {
> +

Extra blank line.

> +      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;

I think that over counts for this purpose, and we can blame confusing
nomenclature.  component_slots for a mat4 is 4, so a mat4 uniform counts
4*4 against the GL_MAX_VERTEX_UNIFORM_COMPONENTS limit.  However, it
only has one "location" (as returned by glGetUniformLocation), so it
only counts 1 against the GL_MAX_UNIFORM_LOCATIONS limit.

> +
> +      /* 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;
> +      }
> +
> +      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 f28d853..6d42138 100644
> --- a/src/glsl/glcpp/glcpp-parse.y
> +++ b/src/glsl/glcpp/glcpp-parse.y
> @@ -2087,6 +2087,9 @@ _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 7602351..83f0b6d 100644
> --- a/src/glsl/glsl_lexer.ll
> +++ b/src/glsl/glsl_lexer.ll
> @@ -393,6 +393,7 @@ 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 c53c583..20879a0 100644
> --- a/src/glsl/glsl_parser_extras.h
> +++ b/src/glsl/glsl_parser_extras.h
> @@ -152,6 +152,20 @@ struct _mesa_glsl_parse_state {
>        return true;
>     }
>  
> +   bool check_explicit_uniform_location_allowed(YYLTYPE *locp,
> +                                                const ir_variable *var)
> +   {
> +      /* Requires OpenGL 3.3 or ARB_explicit_attrib_location. */
> +      if (ctx->Version < 33 && !ctx->Extensions.ARB_explicit_attrib_location) {
> +         _mesa_glsl_error(locp, this, "%s explicit location requires "
> +                          "GL_ARB_explicit_attrib_location extension "
> +                          "or OpenGL 3.3", mode_string(var));

Many copy-and-paste bugs. :) Explicit uniform locations aren't added
until 4.3.

> +         return false;
> +      }
> +
> +      return true;
> +   }
> +
>     bool has_explicit_attrib_location() const
>     {
>        return ARB_explicit_attrib_location_enable || is_version(330, 300);
>