[Mesa-dev] [PATCH v3 25/25] configure.ac: Add required LLVM versions to the top

[Michel Dänzer]

On 13/10/16 03:37 AM, Tobias Droste wrote:
> Am Mittwoch, 12. Oktober 2016, 11:53:50 CEST schrieb Emil Velikov:
>>>
>>> +LLVM_VERSION_REQUIRED_OPENCL=3.6.0
>>> +LLVM_VERSION_REQUIRED_R600=3.6.0
>>> +LLVM_VERSION_REQUIRED_RADEONSI=3.6.0
>>
>> There's a small related gotcha: as-is at build time we get the
>> different codepaths thus, as people build against shared LLVM (hello
>> Archlinux, I'm looking at you) and update their LLVM without
>> rebuilding mesa (Arch I'm looking at you again) things go funny.

What exactly happened there? LLVM upstream generates shared libraries
named libLLVM-<major>.<minor>.so*, so it shouldn't be possible for a
simple LLVM package update to break Mesa, unless Arch did something
really stupid.


>> Tl;Dr; We really want to enable static linking by default and prod
>> distros to use it.
> 
> I'm all in favor of statically linking LLVM (that's the way I'm doing this on 
> my pc). 
> I think the only reason this is not done is because people (also here on the 
> list) don't want any static linkg of external libraries because of size or 
> whatever.
> So changing the default to static is easy, but I doubt it will make everyone 
> happy ;-)

Indeed, it'd probably make many distro packagers unhappy, because
they'll just have to re-enable shared linking, because packaging
policies generally strongly discourage if not outright forbid static
linking.


-- 
Earthling Michel Dänzer               |               http://www.amd.com
Libre software enthusiast             |             Mesa and X developer