DEFAULT_VERSIONS+=llvm=90 ignored?

[Jan Beich]

Steve Kargl <sgk at troutmask.apl.washington.edu> writes:

> On Fri, Dec 04, 2020 at 11:41:41PM +0100, Jan Beich wrote:
>> devel/llvm10 is pinned by graphics/mesa-* likely to reduce QA after a
>> fiasco in bug 239682. Trying to unpin in bug 250869 was rejected.
>> 
>> graphics/mesa-dri/Makefile.common:
>> LLVM_DEFAULT=	10
>
> Well, I guess that pretty much kills LLVM_DEFAULT for any
> modern hardware (even a 8 year old laptop) that uses drm
> unless a user wants base-system llvm, llvm90, and llvm10 
> installed.  One will certainly be able to compile any
> c/c++ thrown ones way.

ports/ started as a collection of hacks, so just hack mesa* to override
LLVM_DEFAULT or switch to DEFAULT_VERSIONS+=llvm=10. Otherwise, use
binary packages for heavy dependencies.

I think, only AMD GPUs need LLVM support in Mesa. graphics/mesa-dri is not
flexible enough to choose which drivers to build. In graphics/mesa-devel it's
possible to disable AMD drivers and LLVM support. For example, "iris" driver
works fine on Intel HD530 (Skylake) with LLVM disabled.