Python 2.6 and wrapping C libraries on Windows

[Christian Heimes]

L. Lindstrom schrieb:
> I have read that Python extension modules must link to the same C
> run-time as the Python interpreter. This I can appreciate. But does this
> requirement extend to the C libraries an extension module wraps. The
> case in point is Pygame and SDL. The Pygame extension modules are built
> with distutils, so for Python 2.6 using Visual Studio 2008 should ensure
> the .pyd files link to msvcr90.dll. But SDL is built using Msys/MinGW
> and the configure/make tool chain. This fails when linking to
> msvcr90.dll since the small test programs configure builds lack manifest
> files. They fail to load msvcr90.dll, raising an R6034 error instead. So
> besides heap management and FILE pointers, is there any reason SDL, or
> any C dependency, needs to link to the same C run-time as Python? If I
> ensure SDL frees memory it allocates and does not directly access a file
> opened by Python can I just use another C run-time such as msvcrt?
>

Your analysis of the problem and the implication of mixing CRTs is
correct. However ...

It should be trivial to modify the build systemof SDL so that the
manifest is integrated into the DLLs. Everything else is a hack. It
*should* work and in reality it *does* work for most cases. But someday
you'll hit a solid wall and get strange and hard to debug segfaults.

It's in your own interest to get it right in the first place. And you'd
serve the Python community greatly by providing a nice tutorial how to
modify 3rd party builds. *hint* :)

If you need any help feel free to contact me. The new build system is
mostly my work with help from Martin, Amaury and other core developers.

Christian