first time use of swig, python and c++ .. it's a mess ... please advice

[Eric von Horst]

On Feb 27, 9:44 pm, "Bronner, Gregory" <gregory.bron... at lehman.com>
wrote:
> The operator= stuff is usually innocuous.
> The compiler died because it couldn't find 'vector', which is reasonable, since it thought it was compiling a C file.
>
> Probably because you swigged the file without the magic "-c++" option -- I'm not sure how distutils passes arguments to swig, but if you do it from the command line, you'll do something like swig -c++ -python -I<path to python> <file> and it will generate a .cpp  file and a .py file, which will (hopefully) compile.
>
> I'd focus on doing it manually, then getting distutils to work properly.
>
> -----Original Message-----
> From: Hyuga [mailto:hyugaricd... at gmail.com]
> Sent: Wednesday, February 27, 2008 10:01 AM
> To: python-l... at python.org
> Subject: Re: first time use of swig, python and c++ .. it's a mess ... please advice
>
> On Feb 26, 3:38 pm, Eric von Horst <z80vsvi... at hotmail.com> wrote:
> > Hi,
>
> > we have a third-party product that has a C++ api on HP-UX.
>
> > I would like be able to use the API in Python (as I remember Python is
> > good at doing this).
>
> > I have no experience with this so I Googled and tried to find some
> > info on what I had to do.
>
> > So, I installed Python 2.4.4 and Swig 1.3.33
>
> > The header file to the library is '/opt/OV/include/opcsvcapi.h'.
>
> > I created a SWIG file with the following content:
> > "
> > %module opcsvcapi
> >  %{
> >  /* Includes the header in the wrapper code */
> >  #include "/opt/OV/include/opcsvcapi.h"
> >  %}
>
> >  /* Parse the header file to generate wrappers */
> >  %include "/opt/OV/include/opcsvcapi.h"
> > "
> > Then I ran the cmd:
> > # swig -c++ -python opcsvcapi.i
> > with output:
> > "
> > /opt/OV/include/opcsvcapi.h:41: Warning(362): operator= ignored
> > /opt/OV/include/opcsvcapi.h:46: Warning(503): Can't wrap 'operator
> > Type' unless renamed to a valid identifier.
> > "
>
> > The result are two files:
> > opcsvcapi.py
> > opcsvcapi_wrap.cxx
>
> > I created a 'setup.py' file with the following content:
> > "
> > import distutils
> > from distutils.core import setup, Extension
>
> > setup(name = "opcsvcapi",
> >       version = "1.0",
> >       ext_modules = [Extension("_opcsvcapi",
> > ["opcsvcapi.i","opcsvcapi.cxx"])])
> > "
>
> > Then I run: python setup.py build
>
> > This results in an extra file:
> > opcsvcapi_wrap.c and a 'build' directory
>
> > and the following errors:
> > "
> > running build
> > running build_ext
> > building '_opcsvcapi' extension
> > swigging opcsvcapi.i to opcsvcapi_wrap.c swig -python -o
> > opcsvcapi_wrap.c opcsvcapi.i creating build creating
> > build/temp.hp-ux-B.11.11-9000-800-2.4
> > gcc -pthread -fno-strict-aliasing -DNDEBUG -g -O3 -Wall -Wstrict-
> > prototypes -fPIC -I/usr/local/include/python2.4 -c opcsvcapi_wrap.c -o
> > build/temp.hp-ux-B.11.11-9000-800-2.4/opcsvcapi_wrap.o
> > In file included from /usr/local/include/python2.4/Python.h:8,
> >                  from opcsvcapi_wrap.c:118:
> > /usr/local/include/python2.4/pyconfig.h:851:1: warning:
> > "_POSIX_C_SOURCE" redefined
> > <command line>:1:1: warning: this is the location of the previous
> > definition In file included from opcsvcapi_wrap.c:2490:
> > /opt/OV/include/opcsvcapi.h:12:18: error: vector: No such file or
> > directory In file included from opcsvcapi_wrap.c:2490:
> > /opt/OV/include/opcsvcapi.h:15: error: expected '=', ',', ';', 'asm'
> > or '__attribute__' before 'SvcAPI'
> > opcsvcapi_wrap.c: In function 'Swig_var_SvcAPI_set':
> > opcsvcapi_wrap.c:2505: error: 'SvcAPI' undeclared (first use in this
> > function)
> > opcsvcapi_wrap.c:2505: error: (Each undeclared identifier is reported
> > only once
> > opcsvcapi_wrap.c:2505: error: for each function it appears in.)
> > opcsvcapi_wrap.c:2505: error: 'namespace' undeclared (first use in
> > this function)
> > opcsvcapi_wrap.c:2505: error: expected expression before ')' token
> > opcsvcapi_wrap.c: In function 'init_opcsvcapi':
> > opcsvcapi_wrap.c:3064: error: 'Swig_var_SvcAPI_get' undeclared (first
> > use in this function)
> > error: command 'gcc' failed with exit status 1 "
>
> > and that's it.
>
> > Any idea what I am doing wrong?
>
> > Any help much appreciated
>
> > Kris
>
> Well, the errors you got from the compiler are just confusing to me, but I suspect it goes back to the warning you got from SWIG.  Some class in there is overriding the = operator, but since that can't be done in Python, you need to give it some special instructions on how to handle that.
>
> For example, if you have Foo::operator=, in your SWIG header include a line like:
> %rename(assign) Foo::operator=
>
> Then in the Python module, the Foo class will have an assign method.
>
> Hyuga
>
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That is indeed what I did.

A do get .cpp file. The thin is that if I run setup, the library is
again swigged but without the -c++ option (see original post)

but honestly, I don't know what to do after I have the .cpp file.

I could not find any docs that explained clearly how to compile if you
are using C++

The only thing I found was that it was not so straightforward

So, again, any help is very much appreciated