[PATCH] drm/fourcc: introduce DRM_FOURCC_STANDALONE guard

[James Park]

On Tue, Feb 2, 2021 at 4:57 PM Emil Velikov <emil.l.velikov at gmail.com>
wrote:

> On Tue, 2 Feb 2021 at 23:25, James Park <james.park at lagfreegames.com>
> wrote:
> >
> > On Tue, Feb 2, 2021 at 2:47 PM Emil Velikov <emil.l.velikov at gmail.com>
> wrote:
> > >
> > > Currently, the drm_fourcc.h header depends on drm.h for __u32 and
> __u64.
> > > At the same time drm.h pulls a lot of unneeded symbols.
> > >
> > > Add new guard DRM_FOURCC_STANDALONE, which when set will use local
> > > declaration of said symbols.
> > >
> > > When used on linux - this is a trivial but only when building in
> strict c99
> > > mode. One is welcome to ignore the warning, silence it or use c11. If
> neither
> > > of the three is an option, then do _not_  set the new guard.
> > >
> > > Cc: James Park <james.park at lagfreegames.com>
> > > Cc: Pekka Paalanen <pekka.paalanen at collabora.com>
> > > Cc: Simon Ser <contact at emersion.fr>
> > > Signed-off-by: Emil Velikov <emil.l.velikov at gmail.com>
> > > ---
> > > As mentioned before - there's little point in having yet another header
> > > since keeping those in sync has been a PITA in the past.
> > > ---
> > >  include/uapi/drm/drm_fourcc.h | 19 +++++++++++++++++++
> > >  1 file changed, 19 insertions(+)
> > >
> > > diff --git a/include/uapi/drm/drm_fourcc.h
> b/include/uapi/drm/drm_fourcc.h
> > > index 6f0628eb13a6..c1522902f6c9 100644
> > > --- a/include/uapi/drm/drm_fourcc.h
> > > +++ b/include/uapi/drm/drm_fourcc.h
> > > @@ -24,7 +24,26 @@
> > >  #ifndef DRM_FOURCC_H
> > >  #define DRM_FOURCC_H
> > >
> > > +/*
> > > + * Define DRM_FOURCC_STANDALONE you're interested only FOURCC and do
> not want
> > > + * to pull drm.h into your application.
> > > + */
> > > +#ifdef DRM_FOURCC_STANDALONE
> > > +#if defined(__linux__)
> > > +
> > > +#include <linux/types.h>
> > > +
> > > +#else /* One of the BSDs */
> > > +
> > > +#include <stdint.h>
> > > +typedef uint32_t __u32;
> > > +typedef uint64_t __u64;
> > > +
> > > +#endif /* __linux __ */
> > > +
> > > +#else
> > >  #include "drm.h"
> > > +#endif /* DRM_FOURCC_STANDALONE */
> > >
> > >  #if defined(__cplusplus)
> > >  extern "C" {
> > > --
> > > 2.30.0
> > >
> >
> > One of my earlier solutions similarly would have forced people to deal
> > with duplicate typedefs, and we arrived at the current solution
> > because we didn't want to burden anyone with that.
>
> As summed in the commit message the burden is only applicable when all
> of the following are set:
>  - non-linux
>  - force DRM_FOURCC_STANDALONE
>  - c99 -pedantic
>
> Even then, we're talking about a compilation warning. So yeah - let's
> keep things short and sweet.
>
> Side note: AFAICT MSVC will not trigger a warning so your logs should be
> clean.
>
> -Emil
>

I'm having trouble reading your commit message, this sentence in
particular: "When used on linux - this is a trivial but only when building
in strict c99 mode."

This asymmetric copy/paste grosses me out so much. I don't think a patch
like this should be opinionated about someone's build settings. Am I alone?
Doesn't this bother anyone else?

- James
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