[Numpy-discussion] Moving to gcc 4.* for win32 installers ?

[David Cournapeau]

On Tue, Dec 13, 2011 at 3:43 PM, Ralf Gommers
<ralf.gommers at googlemail.com> wrote:
> On Sun, Oct 30, 2011 at 12:18 PM, David Cournapeau <cournape at gmail.com>
> wrote:
>>
>> On Thu, Oct 27, 2011 at 5:19 PM, Ralf Gommers
>> <ralf.gommers at googlemail.com> wrote:
>> > Hi David,
>> >
>> > On Thu, Oct 27, 2011 at 3:02 PM, David Cournapeau <cournape at gmail.com>
>> > wrote:
>> >>
>> >> Hi,
>> >>
>> >> I was wondering if we could finally move to a more recent version of
>> >> compilers for official win32 installers. This would of course concern
>> >> the next release cycle, not the ones where beta/rc are already in
>> >> progress.
>> >>
>> >> Basically, the pros:
>> >>  - we will have to move at some point
>> >>  - gcc 4.* seem less buggy, especially C++ and fortran.
>> >>  - no need to maintain msvcr90 vodoo
>> >> The cons:
>> >>  - it will most likely break the ABI
>> >>  - we need to recompile atlas (but I can take care of it)
>> >>  - the biggest: it is difficult to combine gfortran with visual
>> >> studio (more exactly you cannot link gfortran runtime to a visual
>> >> studio executable). The only solution I could think of would be to
>> >> recompile the gfortran runtime with Visual Studio, which for some
>> >> reason does not sound very appealing :)
>> >
>> > To get the datetime changes to work with MinGW, we already concluded
>> > that
>> > building with 4.x is more or less required (without recognizing some of
>> > the
>> > points you list above). Changes to mingw32ccompiler to fix compilation
>> > with
>> > 4.x went in in https://github.com/numpy/numpy/pull/156. It would be good
>> > if
>> > you could check those.
>>
>> I will look into it more carefully, but overall, it seems that
>> building atlas 3.8.4, numpy and scipy with gcc 4.x works quite well.
>> The main issue is that gcc 4.* adds some dependencies on mingw dlls.
>> There are two options:
>>  - adding the dlls in the installers
>>  - statically linking those, which seems to be a bad idea
>> (generalizing the dll boundaries problem to exception and things we
>> would rather not care about:
>> http://cygwin.com/ml/cygwin/2007-06/msg00332.html).
>>
>> > It probably makes sense make this move for numpy 1.7. If this breaks the
>> > ABI
>> > then it would be easiest to make numpy 1.7 the minimum required version
>> > for
>> > scipy 0.11.
>>
>> My thinking as well.
>>
>
> Hi David, what is the current status of this issue? I kind of forgot this is
> a prerequisite for the next release when starting the 1.7.0 release thread.

The only issue at this point is the distribution of mingw dlls. I have
not found a way to do it nicely (where nicely means something that is
distributed within numpy package). Given that those dlls are actually
versioned and seem to have a strong versioning policy, maybe we can
just install them inside the python installation ?

cheers,

David