[Mesa-stable] [PATCH] scons: update for LLVM 4.0

[Jose Fonseca]

On 06/05/17 21:23, Ben Boeckel wrote:
> On Sat, May 06, 2017 at 21:08:23 +0300, Andres Gomez wrote:
>> I'm not picking this for 17.0 since the changes that need LLVM 4.0 are
>> only getting into 17.1 and beyond, and because, IMHO, it doesn't make
>> sense to increase the version of a dependency in a stable release.
>>
>> I hope that's OK with you.
>
> This isn't increasing the version of a dependency, it is just supporting
> a newer version of that dependency (which is already supported in the
> autoconf build).
>
> --Ben
>

Unfortunately things often get broken with newer LLVM versions. 
Especially because LLVM does not always keep backwards compatibility. 
Fixing the build is just scratching the surface.

This is why we avoid backporting support for newer LLVM versions on old 
stable branches.  Even if we crossported every little change that's 
necessary, there's not enough testing going on those branches to be sure 
things didn't go awfully wrong.

This policy shouldn't be a problem in practice: if people are determined 
to use a newer LLVM, then using a newer Mesa shouldn't be particularly 
onerous.

Jose