[Mesa-dev] configure fails to find llvm since recent llvm commit.

[Emil Velikov]

On 3 July 2017 at 22:51, Andy Furniss <adf.lists at gmail.com> wrote:
> Emil Velikov wrote:
>>
>> On 3 July 2017 at 16:31, Andy Furniss <adf.lists at gmail.com> wrote:
>>>
>>> Rafael Avila de Espindola wrote:
>>>>
>>>>
>>>> What check is configure doing?
>>>
>>>
>>>
>>> Not sure just a user.
>>>
>>>> Is the llvm build a clean one? What is the value of LLVM_APPEND_VC_REV?
>>>
>>>
>>>
>>> It is a clean build.
>>> A reply to the list advised to start using
>>>
>>> -DLLVM_APPEND_VC_REV=OFF
>>>
>>> With this it is OK.
>>>
>> Skimming through the LLVM it's not obvious what is the before/after
>> output of `llvm-config --version'. Can anyone share some examples?
>
>
> On current git head, well it was when I started the build from clean,
> probably not by now :-)
>
> Without -DLLVM_APPEND_VC_REV=OFF the output is
>
> 5.0.0git-5a8feb7
>
> With it, it's
>
> 5.0.0svn
>
So the version is FOOgit-$SHA while the DSO uses, FOOsvn. At the same
time at least 3.9.0/3.9.1 has broken llvm-config --libnames/libfiles,
so we cannot rely on that.
Doesn't seem like LLVM is giving us something robust to work with here.

LLVM users/devs (Rafael), I would suggest up-streaming a patch which
changes that toggle default value, for now.
As LLVM does a few releases where it has a reliable way of determining
the library name users can switch to it.

How does this sound?

Thanks
Emil