- 1 year ago
How to export C functions from a Cython DLL?
To export C functions from a Cython DLL, you can follow these steps:
Step 1: Create a Cython module file (e.g., mymodule.pyx
) that contains the functions you want to export. Decorate the functions with the cdef
keyword to indicate that they are C functions.
cython# mymodule.pyx
cdef void my_function() nogil:
# Implementation of your C function
cdef int another_function(int arg1, double arg2) nogil:
# Implementation of another C function
return 42
Step 2: Create a Cython configuration file (e.g., setup.py
) to build the Cython module as a DLL and specify the exported symbols.
python# setup.py
from distutils.core import setup
from Cython.Build import cythonize
setup(
ext_modules=cythonize(
"mymodule.pyx",
language="c",
compiler_directives={"embedsignature": True},
pyrex_c_in_temp=True,
),
)
In the setup.py
file, we use cythonize
to build the Cython module as a DLL. The compiler_directives
parameter is used to enable the embedsignature
directive, which includes function signatures in the generated C code. The pyrex_c_in_temp
parameter is used to compile the generated C code in a temporary directory.
Step 3: Build the DLL using the Cython configuration file.
bash$ python setup.py build_ext --inplace
This command will generate a DLL file containing the exported C functions.
Step 4: Use the exported DLL in a C/C++ program by including the appropriate headers and linking against the DLL.
c// main.c
#include <stdio.h>
// Function prototypes
void my_function();
int another_function(int arg1, double arg2);
int main() {
my_function();
int result = another_function(10, 3.14);
printf("Result: %d\n", result);
return 0;
}
Ensure that you have the necessary header files (e.g., mymodule.h
) generated during the Cython build process to include in your C/C++ program.
Step 5: Compile and link your C/C++ program against the exported DLL.
bash$ gcc main.c -o main.exe -L. -lmymodule
Make sure to adjust the compilation command according to your specific build environment and filenames.
By following these steps, you can export C functions from a Cython DLL and use them in other C/C++ programs.