Some random notes below ... > -----Original Message----- > From: [EMAIL PROTECTED] > [mailto:[EMAIL PROTECTED] > g] On Behalf Of [EMAIL PROTECTED] > Sent: Wednesday, January 10, 2007 1:26 AM > Subject: dynamic library loading, missing symbols > > The reason for the complication is that I don't have control over how > the library does dlopen() or how the code that calls dlopen was > compiled. I am, however, able to control the build process for the > Boost.Python wrapper and the original C++ code that the Boost.Python > wraps. I've tried as many linker tricks as I can think of to get this > to work. Both the boost wrapper and the C++ code that it wraps are > built using --export-dynamic.
* Make sure the exported symbols are marked "extern C" * Otherwise (you export C++ symbols), make sure the exporting component uses *exactly* the same compiler (version, ABI-influencing flags and all) as the importing component. * IMHO, C++ .sos are principally painful and almost unbearable, if you have (non-source) third party components involved. * Use nm to find the exact names of the exported and imported symbols (as already suggested). > > Is there a way to set at runtime what directories or libraries the > linker should search for these symbols? I have set LD_LIBRARY_PATH > correctly, but that didn't seem to affect anything. > > For reference, I am running on Gentoo linux 2.6.11.12 with gcc 3.4.4 > > I'm interested in any ideas that might help, but the ideal one should > work on any *nix system and not just linux. * You might read http://people.redhat.com/drepper/dsohowto.pdf, which I found very useful. There are ways described, how to control the way, the dynamic loader resolves symbols, all with their resp. caveats. * Nevertheless it only describes ELF-based systems, and mostly systems using Drepper's own .so-loader. * Portability to e.g. Windows is a almost impossible for you, because it doesn't support undefined symbols in .sos (and Drepper suggests on ELF-based systems this should only be used if absolutely unavoidable, IIRC). NB: There is a project on SF which claimes to provide this feature on Windows, but I haven't tried and it limits your choice of tools (http://edll.sf.net/). cheers, aa -- Andreas Ames | Programmer | Comergo GmbH | Voice: +49 711 13586 7789 | ames AT avaya DOT com -- http://mail.python.org/mailman/listinfo/python-list
