[Mesa-dev] [RFC PATCH 00/16] A new IR for Mesa

[Matt Turner]

On Wed, Aug 20, 2014 at 12:16 PM, Stéphane Marchesin
<stephane.marchesin at gmail.com> wrote:
> On Wed, Aug 20, 2014 at 11:56 AM, Matt Turner <mattst88 at gmail.com> wrote:
>> Having multiple versions installed in parallel breaks down pretty
>> easily. Where do the headers go? Where do all the executables go? Do
>> you version all of them and install one for each version? Do other
>> distros allow multiple versions of LLVM to be installed in parallel?
>> How do they manage?
>
> For Chrome OS we have multiple versions of LLVM, basically one for
> each consumer, and each consumer (except for the clang family) links
> to its version statically. It is tedious but less painful than having
> to change all the consumers at once (I certainly don't want to update
> our ASan tools because I upgraded mesa). It's wasteful and by no means
> ideal, but it's a pragmatic solution to a problem over which I have no
> control :)

Right. That solution would never be acceptable for Gentoo.

The LLVM maintainer in Gentoo also confirmed to me that we used to
allow multiple versions of LLVM to be installed side-by-side, but it
required a lot of patching and was a large pain.

The fundamental problem here seems to be that the intended usage model
for LLVM is that you just statically link it into your project. Seems
fine for proprietary software, not so fine for free software.