[Mesa-dev] [PATCH 1/5] glsl: prevent spurious Valgrind errors when serializing NIR

[Timothy Arceri]

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

On 11/04/18 20:56, Nicolai Hähnle wrote:
> From: Nicolai Hähnle <nicolai.haehnle at amd.com>
> 
> It looks as if the structure fields array is fully initialized below,
> but in fact at least gcc in debug builds will not actually overwrite
> the unused bits of bit fields.
> ---
>   src/compiler/glsl_types.cpp | 6 ++++--
>   1 file changed, 4 insertions(+), 2 deletions(-)
> 
> diff --git a/src/compiler/glsl_types.cpp b/src/compiler/glsl_types.cpp
> index 9d853caf721..9ebf6a433bd 100644
> --- a/src/compiler/glsl_types.cpp
> +++ b/src/compiler/glsl_types.cpp
> @@ -98,22 +98,24 @@ glsl_type::glsl_type(const glsl_struct_field *fields, unsigned num_fields,
>      vector_elements(0), matrix_columns(0),
>      length(num_fields)
>   {
>      unsigned int i;
>   
>      this->mem_ctx = ralloc_context(NULL);
>      assert(this->mem_ctx != NULL);
>   
>      assert(name != NULL);
>      this->name = ralloc_strdup(this->mem_ctx, name);
> -   this->fields.structure = ralloc_array(this->mem_ctx,
> -                                         glsl_struct_field, length);
> +   /* Zero-fill to prevent spurious Valgrind errors when serializing NIR
> +    * due to uninitialized unused bits in bit fields. */
> +   this->fields.structure = rzalloc_array(this->mem_ctx,
> +                                          glsl_struct_field, length);
>   
>      for (i = 0; i < length; i++) {
>         this->fields.structure[i] = fields[i];
>         this->fields.structure[i].name = ralloc_strdup(this->fields.structure,
>                                                        fields[i].name);
>      }
>   }
>   
>   glsl_type::glsl_type(const glsl_struct_field *fields, unsigned num_fields,
>                        enum glsl_interface_packing packing,
>