| cmake_minimum_required(VERSION 3.8) | |
| project(dummy) | |
| find_package(PythonLibs 3 REQUIRED) | |
| find_package(PythonInterp ${PYTHONLIBS_VERSION_STRING} REQUIRED) | |
| find_package(SWIG REQUIRED) | |
| include(${SWIG_USE_FILE}) | |
| if(PYTHONLIBS_VERSION_STRING MATCHES "^2.*$" ) | |
| set(CMAKE_SWIG_FLAGS -classic) | |
| else() | |
| set(CMAKE_SWIG_FLAGS -py3) | |
| endif() | |
| message("PYTHONLIBS_VERSION_STRING: ${PYTHONLIBS_VERSION_STRING}") | |
| message("CMAKE_SWIG_FLAGS: ${CMAKE_SWIG_FLAGS}") | |
| include_directories(example ${PYTHON_INCLUDE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}) | |
| set_source_files_properties(example.i PROPERTIES CPLUSPLUS ON) | |
| swig_add_library(example TYPE SHARED LANGUAGE python SOURCES example.i) | |
| swig_link_libraries(example ${PYTHON_LIBRARIES}) | |
| enable_testing() | |
| add_test(test1 ${PYTHON_EXECUTABLE} ${CMAKE_CURRENT_SOURCE_DIR}/test_example_wrapper.py) |
| %module example | |
| // a typemap for the callback, it expects the argument to be an integer | |
| // whose value is the address of an appropriate callback function | |
| %typemap(in) void (*f)(int, const char*) { | |
| $1 = (void (*)(int i, const char*))PyLong_AsVoidPtr($input);; | |
| } | |
| %{ | |
| void use_callback(void (*f)(int i, const char* str)); | |
| %} | |
| %inline | |
| %{ | |
| // a C function that accepts a callback | |
| void use_callback(void (*f)(int i, const char* str)) | |
| { | |
| f(100, "callback arg"); | |
| } | |
| %} | |
| %pythoncode | |
| %{ | |
| import ctypes | |
| # a ctypes callback prototype | |
| py_callback_type = ctypes.CFUNCTYPE(None, ctypes.c_int, ctypes.c_char_p) | |
| def use_callback(py_callback): | |
| # wrap the python callback with a ctypes function pointer | |
| f = py_callback_type(py_callback) | |
| # get the function pointer of the ctypes wrapper by casting it to void* and taking its value | |
| f_ptr = ctypes.cast(f, ctypes.c_void_p).value | |
| _example.use_callback(f_ptr) | |
| %} |
| import example | |
| # python callback | |
| def py_callback(i, s): | |
| print('py_callback(%d, %s)'%(i, s)) | |
| example.use_callback(py_callback) |
| # add the location of the compiled module is in the module search path | |
| import sys | |
| sys.path.append('.') | |
| # run the actual example | |
| import test_example |