[Thuban-list] Implementation of GDAL

[Bernhard Herzog]

Stephan Holl <sholl at gmx.net> writes:

> ~/cvs/thuban/Lib > python -c "import gdalwarp"
> Traceback (most recent call last):
>   File "<string>", line 1, in ?
> ImportError: ./gdalwarp.so: undefined symbol: __gxx_personality_v0

This looks like some library was missing when linking gdalwarp.so.
According to google this is probably because gdalwarp.cpp is compiled as
c++ but linked by gcc which doesn't automatically include libstdc++. We
don't have problem because we still mostly use gcc 2.95.

This seems to be a bug in distutils in Python < 2.3. There doesn't seem
to be an easy fix, unfortunately, but there are several options:

 - Use the distutils from Python 2.3 which automatically use the c++
   compiler for linking extensions written in C++

   I just tried this by creating a symbolic link to the directory
   containing distutils in the thuban source directory and then running
   the setup.py script normally (after removing the build subdirectory
   to make sure everything is rebuilt properly)

   ln -s path/to/python/lib/python2.3/distutils/ .
   rm -r build/
   python2.2 setup.py build

   This works for me but all I can easily check is it does indeed call
   the c++ compiler. I don't have a system with gcc 3.0 where all the
   other stuff Thuban requires is already available. The distutils of
   Python 2.3 work fine with Python 2.2 apparently.

 - Do the link step of gdalwarp manually by copying the commandline
   printed by setup.py and replacing the gcc with g++

 - Add "stdc++" to the libraries list in the Extension call for
   Lib.gdalwarp in setup.py (line 1089 or thereabouts)

  Bernhard

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