The correct CMakeLists.txt file to call a MAXON libarary in a Python script using pybind11

Question

I\'m very new to the whole CMake. Following this and this posts, now I want to call a MAXON function inside Python, using pybind11. What I have done so far:

• The

Answer 1

Thanks to abhilb post and his kind followup in the comments I was able to figure the problem out. well, at least find a temporary workaround:

• According to this post, the last two lines of the CMakeLists.txt file should change to

# this line can be removed
# add_executable(${PROJECT_NAME} HelloEposCmd.cpp)

target_link_libraries(${PROJECT_NAME} PRIVATE -lEposCmd)

• and then because according to this post pybind11 doesn't support double pointers we change the run function to:

int run() {

    int argc = 1;
    char* argv[] = {"./HelloEposCmd"};

...
}

which I suppose to be a horrible workaround (inspired by information from this page). Now running cmake ., make and python3 HelloEposCmd.py should work properly (except a small c++ warning!).

P.S.1. Maybe someone could use std::vector<std::string> as suggested here. This idea was proposed here and there are already some answers worth investigating.

P.S.2. Following this discussion, another workaround could be something like:

#include <stdio.h>
#include <stdlib.h>

void myFunc(int argc, char* argv[]) {
    for (int i = 0; i < argc; ++i) {
        printf("%s\n", argv[i]);
    }
}

int run(int argc, long* argv_) {

    char** argv = (char**)malloc(argc * sizeof(char*));

    for (int i = 0; i < argc; ++i) {
        argv[i] = (char*)(argv_[i]);
    }

    myFunc(argc, argv);

    free(argv);

    return 0;
}

Answer 2

pybind11_add_module already creates a target for you. So you don't need add_executable anymore. Just remove that line and when you will build you will get a library with the name HelloEposCmd

add_executable is needed if you are building an executable (.exe), which I believe is not what you want.

Documenation of pybind11 says.

This function behaves very much like CMake’s builtin add_library (in fact, it’s a wrapper function around that command).