[Mesa-dev] [PATCH 1/3] mesa: remove obsolete and broken sampler code

[Timothy Arceri]

Please ignore the first two patches turns out the name generation is
used for structs (although there seems to be no piglit tests for this)
like:

struct S {
   sampler2D tex[2];
};

uniform S i[3];


Where name would become: i[2].tex

On Fri, 2015-05-29 at 23:16 +1000, Timothy Arceri wrote:
> The warning is now handled earlier in the ast to hir code,
> and the name was only generated for arrays of arrays in which
> case this just breaks the Uniform hash lookup.
> ---
>  src/mesa/program/sampler.cpp | 38 +++++++++++++-------------------------
>  1 file changed, 13 insertions(+), 25 deletions(-)
> 
> diff --git a/src/mesa/program/sampler.cpp b/src/mesa/program/sampler.cpp
> index ea3024d..34567d2 100644
> --- a/src/mesa/program/sampler.cpp
> +++ b/src/mesa/program/sampler.cpp
> @@ -38,14 +38,12 @@
>  class get_sampler_name : public ir_hierarchical_visitor
>  {
>  public:
> -   get_sampler_name(ir_dereference *last,
> -		    struct gl_shader_program *shader_program)
> +   get_sampler_name(struct gl_shader_program *shader_program)
>     {
>        this->mem_ctx = ralloc_context(NULL);
>        this->shader_program = shader_program;
>        this->name = NULL;
>        this->offset = 0;
> -      this->last = last;
>     }
>  
>     ~get_sampler_name()
> @@ -68,29 +66,20 @@ public:
>     virtual ir_visitor_status visit_leave(ir_dereference_array *ir)
>     {
>        ir_constant *index = ir->array_index->as_constant();
> -      int i;
> +
> +      /* GLSL 1.10 and 1.20 allowed variable sampler array indices,
> +       * while GLSL 1.30 requires that the array indices be
> +       * constant integer expressions.  We don't expect any driver
> +       * to actually work with a really variable array index, so
> +       * all that would work would be an unrolled loop counter so
> +       * the index must be constant at this point.
> +       */
> +      assert(index != NULL);
>  
>        if (index) {
> -	 i = index->value.i[0];
> -      } else {
> -	 /* GLSL 1.10 and 1.20 allowed variable sampler array indices,
> -	  * while GLSL 1.30 requires that the array indices be
> -	  * constant integer expressions.  We don't expect any driver
> -	  * to actually work with a really variable array index, so
> -	  * all that would work would be an unrolled loop counter that ends
> -	  * up being constant above.
> -	  */
> -	 ralloc_strcat(&shader_program->InfoLog,
> -		       "warning: Variable sampler array index unsupported.\n"
> -		       "This feature of the language was removed in GLSL 1.20 "
> -		       "and is unlikely to be supported for 1.10 in Mesa.\n");
> -	 i = 0;
> -      }
> -      if (ir != last) {
> -	 this->name = ralloc_asprintf(mem_ctx, "%s[%d]", name, i);
> -      } else {
> -	 offset = i;
> +	 offset = index->value.i[0];
>        }
> +
>        return visit_continue;
>     }
>  
> @@ -98,7 +87,6 @@ public:
>     const char *name;
>     void *mem_ctx;
>     int offset;
> -   ir_dereference *last;
>  };
>  
> 
> @@ -107,7 +95,7 @@ _mesa_get_sampler_uniform_value(class ir_dereference *sampler,
>  				struct gl_shader_program *shader_program,
>  				const struct gl_program *prog)
>  {
> -   get_sampler_name getname(sampler, shader_program);
> +   get_sampler_name getname(shader_program);
>  
>     GLuint shader = _mesa_program_enum_to_shader_stage(prog->Target);
>