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

[Jose Fonseca]

On 13/04/16 15:26, Ilia Mirkin wrote:
> 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.

Fair enough.

Jose