SWIG build debugging tools/tips

Question

I am trying to build M2Crypto 0.21.1 with OpenSSL 1.0.0c (or 0.9.7m) for Python 2.5.4 on windows, but SWIG is conspiring against me. I've tried both SWIG 2.0.1 and SWIG 1.3.40 and I get the same error:

swigging SWIG/_m2crypto.i to SWIG/_m2crypto_wrap.c
C:\Development\swigwin-1.3.40\swig.exe -python -IC:\Development\Python-2.5.4\include -IC:\Development\Python-2.5.4\PC -Ic:\Development\openssl-0.9.7m\include -includeall -o SWIG/_m2crypto_wrap.c SWIG/_m2crypto.i
c:\Development\openssl-0.9.7m\include\openssl\opensslv.h(1): Error: Syntax error in input(1).

All permutations of OpenSSL/SWIG show this error. I've tried invoking swig by hand and passing all the "extra verbose" options I could, but none of them are even close to informative. What else can I do to try to find the true source of this problem?

(There are suggestions on this site to edit the .i file for M2Crypto, but 0.21.1 already has the suggested changes integrated)

Answer 1

Actually the problem here isn't SWIG, but I'll leave this question/answer for the next M2Crypto user that comes along - maybe it will help them.

The problem is that the M2Crypto setup.py by default points to <your openssl dir>/include, but if that openssl directory is the source tree, include/ isn't the right place to look (on windows at least) - you need to be looking in inc32/, otherwise opensslv.h is just a line pointing to a different file, which is why SWIG bombs out on line 1.