[PATCH wayland 2/6] wayland-egl: make wayland-egl-backend.h C++ safe

[Arnaud Vrac]

On Fri, Feb 16, 2018 at 2:53 PM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> On 16 February 2018 at 10:49, Daniel Stone <daniel at fooishbar.org> wrote:
>> Hi Emil,
>>
>> On 16 February 2018 at 10:40, Emil Velikov <emil.l.velikov at gmail.com> wrote:
>>> On 15 February 2018 at 23:12, Derek Foreman <derekf at osg.samsung.com> wrote:
>>>> Maybe it's just me, but having different names for the same variable for C
>>>> vs C++ compilation seems really nasty and potentially surprising.
>>>>
>>> Indeed it is surprising. In practise nobody should be using C++.
>>> The guards are added just for lolz - but we can flip things the other
>>> way around.
>>> Namely, error out when using C++ ;-)
>>
>> I mean, effectively we did before the rename, by using a reserved keyword ...
>>
> Indeed.

I'm the one that complained about this compilation issue in the first
place because the proprietary driver I'm using is implemented in C++.
While I don't mind renaming the 'private' field in my branch, I'm just
saying there are EGL/wayland backend implementations in C++ in the
wild.

-Arnaud

>
>>>> Shouldn't old versions of Mesa already have internal versions of this header
>>>> anyway?  I didn't think it was publicly installed until now...
>>>>
>>> That's what Dan't patch did. Sadly as-is (before this series) every
>>> Mesa release under the sun - released or git will fail to build.
>>> I don't think we can retroactively go and fix the all :-(
>>
>> Every one? As far as I'm aware, it's only for 17.3.x. If we apply my
>> patch to explicitly pick the path, then all 18.x will be fine (since
>> they use an explicitly internal path), 17.2.x and below are all fine
>> (since the file was still called wayland-egl-priv.h), and presumably
>> 17.3.x will be seeing another stable release which could trivially fix
>> that as well.
>>
>> OTOH, if we keep releasing Mesa with ambiguous includes of
>> wayland-egl-backend.h, then we can't change API details inside that
>> struct, for as long as we want to support these releases. Hence why
>> I'd go with the patch to disambiguate the includes, or maybe renaming
>> wayland-egl-backend.h in Mesa to wayland-egl-mesa-backend.h or
>> something.
>>
> You're right - only 17.3.x and 18.0 will need fixing. The more I think
> about it, the more I'm inclined towards your solution.
> Consider 1/6 and 2/6 dropped.
>
> Thanks
> Emil