[Mesa-dev] [PATCH mesa 0/5] egl/wayland: Make wl_egl_window a versioned struct

[Emil Velikov]

On 21 July 2017 at 14:37, Daniel Stone <daniel at fooishbar.org> wrote:
> Hi Miguel,
>
> On 18 July 2017 at 21:49, Miguel A. Vico <mvicomoya at nvidia.com> wrote:
>> Although we've always made backwards compatible changes to wl_egl_window, we
>> are lacking of a versioning mechanism for EGL drivers that take a native
>> wl_egl_window to check what set of features are exposed/available by the given
>> struct.
>>
>> This series of patches aim to make wl_egl_window a versioned struct in a
>> backwards compatible way.
>>
>> Along the way, a wl_egl_window ABI checker program has been added that runs
>> at 'make check' time.
>>
>> Also, _eglPointerIsDereferencable() is fixed to return whether is
>> dereferencable, regardless of memory residency.
>
> Thanks for doing this. I do have a weak preference for this being in
> libwayland - given that we're effectively declaring this
> implementation to be part of the wayland-egl ABI with this patchset -
> but I can see it would be annoying to migrate the implementation
> between patches. *shrug*
>
That's a _very_ good point Dan. I think we can get this in atm, and
address that as follow-up since it is a bit fiddly.

Key things to be careful about:
 - user and backend API/ABI are kept separate
 - Mesa/Nvidia/others don't randomly dive into the wayland source code.

Thus a separate "package" which provides the wayland-egl-backend.pc +
headers sounds perfectly reasonable IMHO.
This is pretty much what we do with GLVND.

Thanks
Emil