[Mesa-dev] [PATCH] configure.ac: Respect LLVM_CFLAGS in LLVM version detection

[Tomasz Figa]

On Mon, Dec 19, 2016 at 8:06 PM, Emil Velikov <emil.l.velikov at gmail.com> wrote:
> On 19 December 2016 at 08:52, Tomasz Figa <tfiga at chromium.org> wrote:
>> Hi Tobias,
>>
>> On Sat, Dec 17, 2016 at 2:15 AM, Tobias Droste <tdroste at gmx.de> wrote:
>>> Hi Tomasz,
>>>
>>> does this actually fix anything?
>>>
>>> Because right now llvm-config.h does not include anything and I doubt it will
>>> in the future, as it's just a collection of defines.
>>> The path to the header file itself is given by llvm-config ($LLVM_INCLUDEDIR).
>>>
>>> Did you just happen to see this or do you get an error without this patch?
>>
>> We happen to have the setup exactly as described in the patch
>> description, i.e. LLVM in a non-standard directory and with
>> llvm-config.h that includes another header. Without the patch
>> ./configure fails because of LLVM version detection errors.
>>
> I believe you're spot on - be that due to missing include [directives]
> or conditional header inclusion one would need to have the respective
> CFLAGS. Thus the patch is
> Reviewed-by: Emil Velikov <emil.velikov at collabora.com>
>
> At the same time - I seems to be lucky enough to have the headers sane
> [neither includes nor defines are required] on my Arch setup.
> Wondering if it's not something specific to the Android way of
> building LLVM

Yeah, that's very likely. :)

Although I can imagine distributors creating a wrapper including one
or another real header, depending on some setting. I might have seen
something like this in Gentoo, but I think it used absolute paths,
which made it compile without any flags.

> - IIRC the Android-x86 guys were explaining some
> interesting things.
> ... but that for another day. I'll commit your patch once I
> double-check Tobias' fixes.

Thanks!

Best regards,
Tomasz