[Mesa-dev] [PATCH v2 3/4] glsl: explicitly zero out padding to gl_shader_variable bitfield

[Timothy Arceri]

Reviewed-by: Timothy Arceri <tarceri at itsqueeze.com>

On 03/07/17 22:34, 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.
> 
> v2: use rzalloc instead of an explicit padding member variable
> ---
>   src/compiler/glsl/linker.cpp | 5 ++++-
>   1 file changed, 4 insertions(+), 1 deletion(-)
> 
> diff --git a/src/compiler/glsl/linker.cpp b/src/compiler/glsl/linker.cpp
> index 4aa4682..b406675 100644
> --- a/src/compiler/glsl/linker.cpp
> +++ b/src/compiler/glsl/linker.cpp
> @@ -3723,21 +3723,24 @@ build_stageref(struct gl_shader_program *shProg, const char *name,
>    * Create gl_shader_variable from ir_variable class.
>    */
>   static gl_shader_variable *
>   create_shader_variable(struct gl_shader_program *shProg,
>                          const ir_variable *in,
>                          const char *name, const glsl_type *type,
>                          const glsl_type *interface_type,
>                          bool use_implicit_location, int location,
>                          const glsl_type *outermost_struct_type)
>   {
> -   gl_shader_variable *out = ralloc(shProg, struct gl_shader_variable);
> +   /* Allocate zero-initialized memory to ensure that bitfield padding
> +    * is zero.
> +    */
> +   gl_shader_variable *out = rzalloc(shProg, struct gl_shader_variable);
>      if (!out)
>         return NULL;
>   
>      /* Since gl_VertexID may be lowered to gl_VertexIDMESA, but applications
>       * expect to see gl_VertexID in the program resource list.  Pretend.
>       */
>      if (in->data.mode == ir_var_system_value &&
>          in->data.location == SYSTEM_VALUE_VERTEX_ID_ZERO_BASE) {
>         out->name = ralloc_strdup(shProg, "gl_VertexID");
>      } else if ((in->data.mode == ir_var_shader_out &&
>