Python extensions using MinGW and CXX

[Gerhard Häring]

Reinhard Nadrchal <reinhard at proceryon.at> wrote:
> To create the python import library I did the following (with my 
> specific paths provided):
> 
> pexports /C/WINDOWS/system32/python20.dll > python20.def
> dlltool  --dllname /C/WINDOWS/system32/python20.dll --def python20.def 
> --output-lib libpython20.a
> and copied libpython20.a to the Python20/libs directory.

Try not to use any paths for python20.dll. I. e.:

$ pexports python20.dll >python20.def
$ dlltool --dllname python20.dll --def python20.def --output-lib libpython20.a

You'll need to have copied python20.dll in your working directory first.

I remember another user had weird problems when he used absolute paths and
the above method worked for him.

> If I, on the other hand, link in python20.dll I get no errors and ld 
> seems to be happy. The trouble starts when I execute 'import foo' from 
> the python interpreter -  it simply crashes without  any comment.
> 
> g++ -shared -lpython20 foo.o -ofoo.pyd
> 
> That's the way I've tried it so far. I've also tried to link without the 
> -shared option using -mdll,

Python's distutils uses -mdll, but I really don't know the meaning of
either one in the win32 context :-(

> but in this case Python doesn't recognize 
> the 'initfoo' entry point - maybe this is the key ?! Ho do I have to 
> declare/define the init function ???

With DL_EXPORT:

#v+
extern "C" {
DL_EXPORT(void) initfoo() {
    // ...
}
}
#v-

-- Gerhard