[Mesa-dev] [PATCH 5/9] glsl: explicitly zero out padding to gl_shader_variable bitfield

[Timothy Arceri]

On 26/06/17 19:40, Nicolai Hähnle wrote:

> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
>
> Otherwise, the padding bits remain undefined, which leads to valgrind
> errors when storing the gl_shader_variable in the disk cache.
> ---
>   src/compiler/glsl/linker.cpp | 1 +
>   src/mesa/main/mtypes.h       | 2 ++
>   2 files changed, 3 insertions(+)
>
> diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
> index cfda263..691c4cb 100644
> --- a/src/compiler/glsl/linker.cpp
> +++ b/src/compiler/glsl/linker.cpp
> @@ -3755,20 +3755,21 @@ create_shader_variable(struct gl_shader_program *shProg,
>      out->type = type;
>      out->outermost_struct_type = outermost_struct_type;
>      out->interface_type = interface_type;
>      out->component = in->data.location_frac;
>      out->index = in->data.index;
>      out->patch = in->data.patch;
>      out->mode = in->data.mode;
>      out->interpolation = in->data.interpolation;
>      out->explicit_location = in->data.explicit_location;
>      out->precision = in->data.precision;
> +   out->padding = 0;
>   
>      return out;
>   }
>   
>   static bool
>   add_shader_variable(const struct gl_context *ctx,
>                       struct gl_shader_program *shProg,
>                       struct set *resource_set,
>                       unsigned stage_mask,
>                       GLenum programInterface, ir_variable *var,
> diff --git a/src/mesa/main/mtypes.h b/src/mesa/main/mtypes.h
> index 0cb0024..a1fc743 100644
> --- a/src/mesa/main/mtypes.h
> +++ b/src/mesa/main/mtypes.h
> @@ -2813,20 +2813,22 @@ struct gl_shader_variable
>       * If the location is explicitly set in the shader, it \b cannot be changed
>       * by the linker or by the API (e.g., calls to \c glBindAttribLocation have
>       * no effect).
>       */
>      unsigned explicit_location:1;
>   
>      /**
>       * Precision qualifier.
>       */
>      unsigned precision:2;
> +

Maybe add a comment to remind devs to update this when they make changes 
here?

> +   unsigned padding:19;
>   };
>   
>   /**
>    * Active resource in a gl_shader_program
>    */
>   struct gl_program_resource
>   {
>      GLenum Type; /** Program interface type. */
>      const void *Data; /** Pointer to resource associated data structure. */
>      uint8_t StageReferences; /** Bitmask of shader stage references. */