[Mesa-dev] swr forces c++11 for whole compilation

[Ilia Mirkin]

On Wed, Apr 13, 2016 at 10:11 AM, Jose Fonseca <jfonseca at vmware.com> wrote:
> On 13/04/16 14:21, Ilia Mirkin wrote:
>>
>> On Wed, Apr 13, 2016 at 8:48 AM, Jose Fonseca <jfonseca at vmware.com> wrote:
>>>
>>> On 13/04/16 11:43, Ilia Mirkin wrote:
>>>>
>>>>
>>>> Hi Tim,
>>>>
>>>> It seems like building swr forces c++11 mode for the whole build, even
>>>> other drivers being built that aren't necessarily ready for it.
>>>> Unfortunately c++11 isn't backwards compatible with c++03, so the switch
>>>> can't be made unilaterally. Could you have a look at why this is
>>>> happening?
>>>>
>>>> An example of something that does this properly is clover, which also
>>>> requires c++11 to be built.
>>>>
>>>> Thanks,
>>>>
>>>>     -ilia
>>>>
>>>
>>> Ilia,
>>>
>>> Even before SWR was merged and today's isinf fix was commited,
>>> nv50_ir_ra.cpp already has code to make it portable for C++11 (see
>>> below).
>>>
>>> I honestly don't understand what you're trying to achieve with this
>>> thread...
>>
>>
>> Build options required for a specific driver to stay with that driver
>> and not affect other drivers.
>>
>>>
>>> Are you seriously plan to require C++03 to build nouveau?  It would be
>>> insane try to do that once GCC 6 is widely available.
>>
>>
>> -std=c++03 (or something like that) will presumably work just fine?
>
>
> I wouldn't label it "just fine".  Soon everybody will be using C++11 or
> higher, either because it's the default (GCC 6.0, MSVC 2013/2015), or
> because some dependency uses it.  So if you use -std=c++03 only in a portion
> of the tree, you'll inherit the hassle of fixing mesa/include and
> mesa/src/util for C++03 when nobody else bothers...

Such an eventuality will probably make me reconsider these choices :)
When it happens, I guess we'll figure it out. Most util code is C-only
though.

Right now, including swr causes nouveau to be built differently than
if swr isn't built. I consider that to be a major issue.

  -ilia