[Intel-gfx] [PATCH 1/2] drm/i915: introduce GEM_WARN_ON

[Chris Wilson]

On Fri, Dec 02, 2016 at 03:11:05PM +0000, Matthew Auld wrote:
> On 2 December 2016 at 13:54, Chris Wilson <chris at chris-wilson.co.uk> wrote:
> > On Fri, Dec 02, 2016 at 01:23:13PM +0000, Matthew Auld wrote:
> >> In a similar spirit to GEM_BUG_ON we now also have GEM_WARN_ON, this
> >> will enable us to freely add warnings which our CI will hopefully catch
> >> but without fear of impacting production machines.
> >>
> >> Suggested-by: Chris Wilson <chris at chris-wilson.co.uk>
> >> Signed-off-by: Matthew Auld <matthew.auld at intel.com>
> >> ---
> >>  drivers/gpu/drm/i915/i915_gem.h | 2 ++
> >>  1 file changed, 2 insertions(+)
> >>
> >> diff --git a/drivers/gpu/drm/i915/i915_gem.h b/drivers/gpu/drm/i915/i915_gem.h
> >> index 51ec793f2e20..04c777e6d0bf 100644
> >> --- a/drivers/gpu/drm/i915/i915_gem.h
> >> +++ b/drivers/gpu/drm/i915/i915_gem.h
> >> @@ -27,8 +27,10 @@
> >>
> >>  #ifdef CONFIG_DRM_I915_DEBUG_GEM
> >>  #define GEM_BUG_ON(expr) BUG_ON(expr)
> >> +#define GEM_WARN_ON(expr) WARN_ON(expr)
> >>  #else
> >>  #define GEM_BUG_ON(expr) do { } while (0)
> >> +#define GEM_WARN_ON(expr) do { } while (0)
> >
> > #define GEM_WARN_ON 0
> Oops. As an alternative, would you be offended with something like:
> 
> #define GEM_WARN_ON(expr) (BUILD_BUG_ON_INVALID(expr), 0)
> 
> Then the compiler will still check the validity of the expression, but
> will still compile everything out, and then we don't accidentally
> break the build when compiling without DEBUG_GEM ?

Ooh, new shiny. Uses sizeof()! Can you prepare a patch to fixup
GEM_BUG_ON as well?
-Chris

-- 
Chris Wilson, Intel Open Source Technology Centre