[Distutils] Proposed new Distutils API for compiler flag detection (Issue26689)

[Ned Deily]

Some months ago, Sylvain brought up a couple of proposals for Distutils.  The second proposal received some discussion but it appears that the first one got lost.  Here it is:

> From sylvain.corlay at gmail.com  Wed May 25 12:01:51 2016
> From: sylvain.corlay at gmail.com (Sylvain Corlay)
> Date: Wed, 25 May 2016 12:01:51 -0400
> Subject: [Distutils] Distutils improvements regarding header installation
>  and building C extension modules
> Message-ID: <CAK=Phk4tg_S2mVS2eAkLK514Aq_gq26yEg_vWwAEz8NnstypMg at mail.gmail.com>
> 
> Hello everyone,
> 
> This is my first post here so, apologies if I am breaking any rules.
> 
> Lately, I have been filing a few bug reports and patches to distutils on
> bugs.python.org that all concern the installation and build of C++
> extensions.
> 
> *1) The distutils.ccompiler has_flag method.*
> (http://bugs.python.org/issue26689)
> 
> When building C++ extension modules that require a certain compiler flag
> (such as enabling C++11 features), you may want to check if the compiler
> has such a flag available.
> 
> I proposed a patch adding a `has_flag` method to ccompiler. It is an
> equivalent to cmake' s CHECK_CXX_COMPILER_FLAG.
> 
> The implementation is similar to the one of has_function which by the way
> has a pending patch by minrk in issue (http://bugs.python.org/issue25544).

On python-dev and in the bug tracker, Sylvain has understandably asked for a review with an eye to adding this new feature to Python 3.6 whose feature code cutoff is scheduled for a few weeks from now.  As release manager, I am not opposed in general to adding new features to Distutils but I think we should be very cautious about modifying or adding new Distutils APIs, given that many third-party distribution authors want to support their packages on multiple versions.  So I want to make sure that there is some agreement that adding this new API starting with 3.6 is a good thing to do rather than having it go in under the radar.  If there are technical review issues with the implementation, it would probably be better to give those directly on the bug tracker.

Opinions?

Thanks!
--Ned

--
  Ned Deily
  nad at python.org -- []