[Mesa-dev] [PATCH 11/11] glsl: Reject linking shaders with too many uniform blocks.

[Brian Paul]

On 07/20/2012 04:33 PM, Eric Anholt wrote:
> Part of fixing piglit maxblocks.
> ---
>   src/glsl/linker.cpp |   34 ++++++++++++++++++++++++++++++++++
>   1 file changed, 34 insertions(+)
>
> diff --git a/src/glsl/linker.cpp b/src/glsl/linker.cpp
> index bfdde40..f4e578f 100644
> --- a/src/glsl/linker.cpp
> +++ b/src/glsl/linker.cpp
> @@ -2324,6 +2324,12 @@ check_resources(struct gl_context *ctx, struct gl_shader_program *prog)
>         0          /* FINISHME: Geometry shaders. */
>      };
>
> +   const unsigned max_uniform_blocks[MESA_SHADER_TYPES] = {
> +      ctx->Const.VertexProgram.MaxUniformBlocks,
> +      ctx->Const.FragmentProgram.MaxUniformBlocks,
> +      ctx->Const.GeometryProgram.MaxUniformBlocks,
> +   };
> +
>      for (unsigned i = 0; i<  MESA_SHADER_TYPES; i++) {
>         struct gl_shader *sh = prog->_LinkedShaders[i];
>
> @@ -2348,6 +2354,34 @@ check_resources(struct gl_context *ctx, struct gl_shader_program *prog)
>         }
>      }
>
> +   unsigned blocks[] = {0, 0, 0};

Should that be:
    unsigned blocks[MESA_SHADER_TYPES] = { 0, 0, 0 };

The idea would be to get a compiler warning if the blocks array isn't 
grown in the future for new shader types.


> +   unsigned total_uniform_blocks = 0;
> +
> +   for (unsigned i = 0; i<  prog->NumUniformBlocks; i++) {
> +      for (unsigned j = 0; j<  MESA_SHADER_TYPES; j++) {
> +	 if (prog->UniformBlockStageIndex[j][i] != -1) {
> +	    blocks[j]++;
> +	    total_uniform_blocks++;
> +	 }
> +      }
> +
> +      if (total_uniform_blocks>  ctx->Const.MaxCombinedUniformBlocks) {
> +	 linker_error(prog, "Too many combined uniform blocks (%d/%d)",
> +		      prog->NumUniformBlocks,
> +		      ctx->Const.MaxCombinedUniformBlocks);
> +      } else {
> +	 for (unsigned i = 0; i<  MESA_SHADER_TYPES; i++) {
> +	    if (blocks[i]>  max_uniform_blocks[i]) {
> +	       linker_error(prog, "Too many %s uniform blocks (%d/%d)",
> +			    shader_names[i],
> +			    blocks[i],
> +			    max_uniform_blocks[i]);
> +	       break;
> +	    }
> +	 }
> +      }
> +   }
> +
>      return prog->LinkStatus;
>   }
>