[Mesa-dev] [PATCH 03/13] isl: Don't use designated initializers in the header

[Emil Velikov]

On 16 April 2016 at 20:45, Jason Ekstrand <jason at jlekstrand.net> wrote:
> C++ doesn't support designated initializers and g++ in particular doesn't
> handle them when the struct gets complicated, i.e. has a union.
> ---
>  src/intel/isl/isl.h | 32 ++++++++++++++++++++------------
>  1 file changed, 20 insertions(+), 12 deletions(-)
>
> diff --git a/src/intel/isl/isl.h b/src/intel/isl/isl.h
> index 33d43d7..c3a1106 100644
> --- a/src/intel/isl/isl.h
> +++ b/src/intel/isl/isl.h
> @@ -988,25 +988,35 @@ isl_surf_info_is_z32_float(const struct isl_surf_init_info *info)
>  static inline struct isl_extent2d
>  isl_extent2d(uint32_t width, uint32_t height)
>  {
> -   return (struct isl_extent2d) { .w = width, .h = height };
> +   struct isl_extent2d e = {
> +      { width, },
> +      { height, },
> +   };
> +   return e;
>  }
>
Please use something like the following

   struct isl_extent2d e;

   memset(&e, 0, sizeof(e));
   e.w = width;
   e.h = height;

   return e;

It is a bit over expressive to write/look at, although it will give
you exactly what you want _all_ the time.
Otherwise you risk feeding garbage and/or setting the wrong struct
member as isl_extent2d change.

Hunting bugs that this may cause, is not what you want to do. Plus the
compiler will optimise it to the exact same code.

-Emil