Prepare swig for building pyauto on win

Prepare swig for running pyauto on win.

Work around a weird python nag on win. Python.h uses a _DEBUG macro to conditionally load debug version of the python lib. This conflicts with MSVS which defines _DEBUG in Debug configuration.
This change works around this problem by including Python.h without the _DEBUG macro, since we don't want to debug python itself in any case. 

Accompanying CL in Cr src: http://codereview.chromium.org/661342

Committed: http://src.chromium.org/viewvc/chrome?view=rev&revision=40423

[John Grabowski, 2010-03-02 05:51:20]

LGTM


Hmm... can't view side by side diffs.  Check your patch carefully.

+// Include Python.h without _DEBUG macro. Or else it requires
+// pythonXX_d.lib instead of pythonXX.lib on windows which is unwanted
+// since we don't intend to debug python itself.

Use proper english.  E.g.:

// Resolve conflicting use of _DEBUG across projects.
// #defining _DEBUG causes Python.h to require pythonXX_d.lib.
// #defining _DEBUG is also the MSVC blah blah blah.
// Make sure our project, which uses the latter, doesn't trigger the former.

[John Grabowski, 2010-03-02 05:52:34]

Oh... shouldn't you try and upstream this?
And add notes to the README.chromium about deltas from the released python?

[Nirnimesh, 2010-03-02 19:53:07]

On 2010/03/02 05:52:34, John Grabowski wrote:
> Oh... shouldn't you try and upstream this?
> And add notes to the README.chromium about deltas from the released python?

Corrected the english [:)], and the patch on the server.

This specific swig+python+MSVC _DEBUG problem has been discussed a lot from what
I see on the internet. Their solution is to mangle with Python.h locally to
disable the use of pythonXX_d.lib. The python folks have refused to make changes
to Python.h in their tree since they _do_ want to debug python when compiling in
Debug config in MSVC. Editing the swig python bindings seems a better approach
to me.

If I use debug python, I'd have to use the debug versions of all the libraries
as well -- .pyd, which is a little more than what we want, since you'd have to
start using python_d.exe as well.

README.chromium lives in the Cr src and is therefore in the other CL.

Thanks for the quick reviews, John.

[John Grabowski, 2010-03-02 20:20:43]

This specific swig+python+MSVC _DEBUG problem has been discussed a lot from
> what
> I see on the internet. Their solution is to mangle with Python.h locally to
> disable the use of pythonXX_d.lib. The python folks have refused to make
> changes
> to Python.h in their tree since they _do_ want to debug python when
> compiling in
> Debug config in MSVC. Editing the swig python bindings seems a better
> approach
> to me.
>

Sigh.  I agree with your approach then.
If you can find one, perhaps add a link from a py dev saying "we won't take
this change because blah blah".

jrg


>
> If I use debug python, I'd have to use the debug versions of all the
> libraries
> as well -- .pyd, which is a little more than what we want, since you'd have
> to
> start using python_d.exe as well.
>
> README.chromium lives in the Cr src and is therefore in the other CL.
>
> Thanks for the quick reviews, John.
>
>
>
> http://codereview.chromium.org/661334
>