[geos-devel] Using SWIG to interface with GEOS, undefined symbols

[strk]

On Mon, Jul 12, 2004 at 12:15:58PM -0600, Sean Gillies wrote:
> 
> On Jul 12, 2004, at 9:39 AM, strk wrote:
> 
> >On Mon, Jul 12, 2004 at 09:10:53AM -0600, Sean Gillies wrote:
> >>On Jul 12, 2004, at 9:00 AM, strk wrote:
> >>
> >>>On Mon, Jul 12, 2004 at 08:41:07AM -0600, Sean Gillies wrote:
> >>>>Hi all,
> >>>>
> >>>>Yesterday I began to try to use SWIG to generate a Python
> >>>>GEOS module using the CVS GEOS.  To start, I am only wrapping
> >>>>the classes in geom.h and precision.h.
> >>>
> >>>precision.h does not really contain 'basic' classes.
> >>>PrecisionModel class is in geom.h.
> >>>
> >>>>SWIG 1.3.20 generates wrapper code with only a few warnings
> >>>>and the module does build, resulting in geos.py and a very
> >>>>large _geos.so (I have statically linked against libgeos.a).
> >>>>
> >>>>On import of the geos module, an import error is raised:
> >>>>
> >>>> ImportError:
> >>>>/home/sean/projects/PyGEOS/build/lib.linux-i686-2.3/_geos.so:
> >>>> undefined symbol: _ZN4geos14PrecisionModel19maximumPreciseValueE
> >>>
> >>>Could you have built _geos.so and the geos.py in at different times ?
> >>>CVS api is changing , and you get those kind of errors for every 
> >>>simple
> >>>'const' addition.
> >>>
> >>>--strk;
> >>>
> >>
> >>Thanks for the reply!  _geos.so and geos.py are synchronous, no 
> >>problem
> >>there.  I was having this same issue with GEOS 1.0 and SWIG, so I am
> >>ruling out API changes.  It's either my lack of knowledge of C++, some
> >>undocumented SWIG issue or a combination of these.
> >>
> >>Sean
> >
> >I've checked the code. It seems a bug in both GEOS-1.0 and GEOS-CVS
> >PrecisionModel::maximumPreciseValue is never given a value.
> >
> >geos::maximumPreciseValue is, but the header declare
> >geos::PrecisionModel::maximumPreciseValue, which is not.
> >
> >I've fixed it, please try now.
> >
> >--strk;
> >
> 
> Yes, that one bug seems to be fixed.
> 
> Now there is exposed another one :)
> 
>   ImportError: 
> /home/sean/projects/PyGEOS/build/lib.linux-i686-2.3/_geos.so:
>   undefined symbol:   _ZNK4geos14CoordinateList17toCoordinateArrayEv
> 
> If I direct SWIG to ignore the toCoordinateArray() method of 
> CoordinateList,
> then there is yet another undefined symbol:
> 
>   ImportError: 
> /home/sean/projects/PyGEOS/build/lib.linux-i686-2.3/_geos.so:
>   undefined symbol: 
> _ZN4geos14CoordinateList3addEPSt6vectorINS_10CoordinateESaIS2_EEb
> 
> Strk, I appreciate that you have taken the time to look into it,
> but this might be more time consuming.  I don't know if it will
> be possible to SWIG GEOS or if it is in the project's interest to
> be altered so that a SWIG module is possible.
> 
> cheers,
> Sean

Sean, no problem, you might help us as well, as we are redefining
the API, so every feedback is appreciated.
The problem here is with CoordinateList being currently removed
from interface. CoordinateList class reference is still in the
geom.h file, but the corresponding module is not built into
the library. We are still discussing wheter to keep or not that
class. In the meanwhile, I commented out the definition,
this should fix your problem.

--strk;

> 
> --
> Sean Gillies
> sgillies at frii dot com
> http://users.frii.com/sgillies