[Intel-gfx] [PATCH] drm/i915: throw __must_check at GEM_WARN_ON

[Joonas Lahtinen]

Quoting Matthew Auld (2018-04-04 14:19:04)
> GEM_WARN_ON is intended to be used as:
> 
> if (GEM_WARN_ON(expr))
>         ...
> 
> However this isn't clear since we just wrap WARN_ON, therefore throw a
> warning if the result is ignored. For !DRM_I915_DEBUG_GEM builds this
> should already be the case.
> 
> Suggested-by: Jani Nikula <jani.nikula at linux.intel.com>
> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> Cc: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>
> Cc: Jani Nikula <jani.nikula at linux.intel.com>
> Cc: Chris Wilson <chris at chris-wilson.co.uk>

Reviewed-by: Joonas Lahtinen <joonas.lahtinen at linux.intel.com>

I think this would be a worthwhile improvement.

Regards, Joonas

> ---
>  drivers/gpu/drm/i915/i915_gem.h | 9 ++++++++-
>  1 file changed, 8 insertions(+), 1 deletion(-)
> 
> diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h
> index 8922344fc21b..760671119130 100644
> --- a/drivers/gpu/drm/i915/i915_gem.h
> +++ b/drivers/gpu/drm/i915/i915_gem.h
> @@ -36,7 +36,14 @@
>                 BUG(); \
>                 } \
>         } while(0)
> -#define GEM_WARN_ON(expr) WARN_ON(expr)
> +
> +static __always_inline bool __must_check __gem_warn_on(bool v)
> +{
> +       return WARN_ON(v);
> +}
> +
> +/* To be used as: if (GEM_WARN_ON(expr)) */
> +#define GEM_WARN_ON(expr) __gem_warn_on(expr)
>  
>  #define GEM_DEBUG_DECL(var) var
>  #define GEM_DEBUG_EXEC(expr) expr
> -- 
> 2.14.3
>