SWIG problems - "ImportError: dynamic module does not define......."

[Richard Sharp]

Hello,
I am not at my home office at the moment but you will probably find the 
following link helpful:

http://groups.google.de/groups?hl=de&lr=&ie=UTF-8&oe=utf-
8&threadm=mailman.999029862.20314.python-
list%40python.org&rnum=7&prev=/groups%3Fhl%3Dde%26ie%3DUTF-8%26oe%3Dutf-
8%26q%3Dpython%2Bdistutils%2Bexport%26sa%3DN%26tab%3Dwg

The content is:
Section 5.2 of the Extending and Embedding the Python Interpreter says:
"The problem is that some entry points are defined by the Python runtime
solely for extension modules to use. If the embedding application does not 
use any of these entry points, some linkers will not include those entries 
in the symbol table of the finished executable. Some additional options are 
needed to inform the linker not to remove these symbols.
Determining the right options to use for any given platform can be quite
difficult, but fortunately the Python configuration already has those 
values.
To retrieve them from an installed Python interpreter, start an interactive
interpreter and have a short session like this:
      >>> import distutils.sysconfig
      >>> distutils.sysconfig.get_config_var('LINKFORSHARED')
      '-Xlinker -export-dynamic'
The contents of the string presented will be the options that should be 
used.
If the string is empty, there's no need to add any additional options. The
LINKFORSHARED definition corresponds to the variable of the same name in
Python's top-level Makefile."
The '-Xlinker' tells gcc to pass '-export-dynamic' to ld. gcc itself seems 
to ignore it otherwise.

Richard Sharp

c.hodapp at softhome.net (Chris Hodapp) wrote in
<6e4c7e29.0312152000.229a9d3a at posting.google.com>: 

>I have seen messages posted about this before, and there is a clear
>reference to it in the manual, but I have been unable to find a
>solution.
>
>I'm on Slackware 9.1, kernel 2.6.0-test11, using Python 2.3.1 and
>GCC 3.2.3 (both installed by default with Slackware) and SWIG 1.3.19,
>compiled from source code.
>I messed around a little on my own and couldn't get things to work
>right,
>so I copied the examples from the book, nearly verbatim but with some
>minor changes to fit my configuration.
>
>I copied the example code exactly into example.i and example.c, and
>did
>the following commands: 
>swig -python example.i
>gcc -c example.c example_wrap.c -I/usr/include/python2.3
>ld -shared example.o example_wrap.o -o _example.so
>... and several other times in the last command I tried some other
>things like examplemodule.so and example.so. All of these worked
>without
>error, so I tried it from within Python, and got the usual error about
>"ImportError: dynamic module does not define init function" when I
>tried
>'import example'. It made no difference if I added the path with all
>the
>files to sys.path; the same error occurred.
>
>I tried this several times over, and I could never get it to work
>right. The last helpful suggestion I saw on here was that I did not
>make the init<whatever> function public by putting
>/EXPORT:init<whatever> on the linker line, but that doesn't seem to be
>what GNU ld understands
>
>Any suggestions?
>
>Thanks,
>-Chris
>