I'm trying to wrap a legacy C library with cython. The C library
defines a custom data type with a 'typedef struct'. The Python
side of the code needs to initialize C variables having this
type but I haven't figured out how to declare the variables
correctly. Cython complains that
./library.c:2:6: note: expected ‘legacy_struct’ but argument is of type
‘__pyx_t_10new_module_legacy_struct’
Platform:
Python 2.7.3
Cython 0.17.1
Fedora 17 i686
Files that boil the problem down to the bare minimum are below and
also in the attached tar file. Anyone know where I'm going wrong?
-- Al
-------------- \/ cyth.pyx
#!/usr/bin/python
ctypedef struct legacy_struct:
int *S_start
double *N
char *data
cdef extern from "library.c":
int legacy_function(int nC ,
legacy_struct A)
import numpy as np
cimport numpy as np
np.import_array()
def Save():
cdef int nC = 0
cdef legacy_struct m
legacy_function( nC , <legacy_struct> m)
return
-------------- /\ cyth.pyx
-------------- \/ header.h
typedef struct {
int *S_start ;
double *N ;
char *data ;
} legacy_struct;
int legacy_function(int nC ,
legacy_struct A );
-------------- /\ header.h
-------------- \/ library.c
#include "header.h"
int legacy_function(int nC,
legacy_struct A ) {
A.S_start[nC] = 0;
return 1;
}
-------------- /\ library.c
-------------- \/ Makefile
CFLAGS= -g
LDFLAGS= -g
all: cyth.pyx library.c header.h
LDFLAGS=$(LDFLAGS) CFLAGS=$(CFLAGS) python setup.py build_ext --inplace
clean:
rm -rf build *.so cyth.c library.o
-------------- /\ Makefile
-------------- \/ setup.py
import numpy
from Cython.Distutils import build_ext
def configuration(parent_package='', top_path=None):
from numpy.distutils.misc_util import Configuration
config = Configuration('', parent_package, top_path)
config.add_extension('new_module',
sources=['cyth.pyx'],
depends=['cyth.c'],
extra_compile_args=["-g"],
extra_link_args=["-g"],
include_dirs=[numpy.get_include()])
return config
if __name__ == '__main__':
params = configuration(top_path='').todict()
params['cmdclass'] = dict(build_ext=build_ext)
from numpy.distutils.core import setup
setup(**params)
-------------- /\ setup.py
