Use PythonSetup

CMakeLists.txt

@@ -136,7 +136,8 @@ set(POSITION_INDEPENDENT_CODE True)
 enable_testing()
 
 # python.
-include(YACMAPythonSetup)
+# include(YACMAPythonSetup)
+include(PythonSetup)
 
 # # python version check.
 # if (${PYTHON_VERSION_MAJOR} LESS 3 OR (${PYTHON_VERSION_MAJOR} EQUAL 3 AND ${PYTHON_VERSION_MINOR} LESS 4))

cmake/PythonSetup.cmake

@@ -0,0 +1,170 @@
+if(YACMAPythonSetupIncluded)
+    return()
+endif()
+
+if (PREFIX)
+    message(STATUS "Using PREFIX: ${PREFIX}")
+elseif(CONDA_PREFIX)
+    message(STATUS "Using CONDA_PREFIX: ${CONDA_PREFIX}")
+    set(PREFIX ${CONDA_PREFIX})
+elseif(CMAKE_PREFIX_PATH)
+    message(STATUS "Using CMAKE_PREFIX_PATH: ${CMAKE_PREFIX_PATH}")
+    set(PREFIX ${CMAKE_PREFIX_PATH})
+else()
+    message(FATAL_ERROR "We need a prefix")
+endif()
+
+set(Python_ROOT ${PREFIX})
+find_package(Python REQUIRED COMPONENTS Interpreter Development)
+
+# Python include directory
+if (NOT Python_INCLUDE_DIRS)
+    message(FATAL_ERROR "Could not determine the Python include dir.")
+else()
+    set(
+        YACMA_PYTHON_INCLUDE_DIR "${Python_INCLUDE_DIRS}"
+        CACHE PATH "Path to the Python include dir."
+    )
+endif()
+add_library(YACMA::PythonIncludeDir INTERFACE IMPORTED)
+set_target_properties(
+    YACMA::PythonIncludeDir PROPERTIES
+    INTERFACE_INCLUDE_DIRECTORIES ${YACMA_PYTHON_INCLUDE_DIR}
+)
+
+# Python executable
+if (NOT Python_EXECUTABLE)
+    message(FATAL_ERROR "Could not determine the Python executable.")
+else()
+    set(PYTHON_EXECUTABLE "${Python_EXECUTABLE}")
+endif()
+
+# Python version
+if (NOT Python_VERSION)
+    message(FATAL_ERROR "Could not determine the Python version.")
+else()
+    set(PYTHON_VERSION_STRING "${Python_VERSION}")
+endif()
+
+# Python libraries
+if (WIN32)
+    if (NOT Python_LIBRARIES)
+        message(FATAL_ERROR "Could not determine the Python libraries.")
+    else()
+        set(PYTHON_LIBRARIES "${Python_LIBRARIES}")
+    endif()
+endif()
+
+
+# Platform-specific installation directory
+if (NOT Python_SITEARCH)
+    message(FATAL_ERROR "Could not determine the Python installation directory.")
+else()
+    string(REPLACE "/" ";" _install_dir ${Python_SITEARCH})
+    list(FIND _install_dir "lib" _lib_index)
+    list(SUBLIST _install_dir ${_lib_index} -1 _install_dir)
+    list(JOIN _install_dir "/" YACMA_PYTHON_MODULES_INSTALL_PATH)
+endif()
+
+# Display info
+message(STATUS "Python interpreter: ${PYTHON_EXECUTABLE}")
+message(STATUS "Python interpreter version: ${PYTHON_VERSION_STRING}")
+if (WIN32)
+    message(STATUS "Python libraries: ${PYTHON_LIBRARIES}")
+endif()
+message(STATUS "Python include dir: ${YACMA_PYTHON_INCLUDE_DIR}")
+message(STATUS "Python modules install path: ${YACMA_PYTHON_MODULES_INSTALL_PATH}")
+
+
+# Module extension
+if (UNIX)
+    if (APPLE)
+        message(STATUS "OS X platform detected: Extension is .so")
+        set(_YACMA_PY_MODULE_EXTENSION ".so")
+    else()
+        message(STATUS "Generic UNIX platform detected")
+    endif()
+
+    if(NOT YACMA_PYTHON_MODULES_INSTALL_PATH)
+        message(WARNING "THIS SHOULD NOT BE CALLED")
+        execute_process(
+            COMMAND ${PYTHON_EXECUTABLE} -c
+            "from __future__ import print_function\nimport distutils.sysconfig\nimport os\nprint(os.path.split(distutils.sysconfig.get_python_lib())[-1])"
+            OUTPUT_VARIABLE _YACMA_PY_PACKAGES_DIR
+            OUTPUT_STRIP_TRAILING_WHITESPACE
+        )
+        message(STATUS "Python packages dir is: ${_YACMA_PY_PACKAGES_DIR}")
+        set(
+            YACMA_PYTHON_MODULES_INSTALL_PATH
+            "lib/python${PYTHON_VERSION_MAJOR}.${PYTHON_VERSION_MINOR}/${_YACMA_PY_PACKAGES_DIR}"
+            CACHE PATH "Install path for Python modules."
+        )
+        mark_as_advanced(YACMA_PYTHON_MODULES_INSTALL_PATH)
+    endif()
+    elseif(WIN32)
+        message(STATUS "Windows platform detected.")
+        message(STATUS "Output extension for compiled modules will be '.pyd'.")
+        set(_YACMA_PY_MODULE_EXTENSION "pyd")
+        if(NOT YACMA_PYTHON_MODULES_INSTALL_PATH)
+            message(WARNING "THIS SHOULD NOT BE CALLED!")
+            # On Windows, we will install directly into the install path of the Python interpreter.
+            execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "from distutils.sysconfig import get_python_lib; print(get_python_lib())"
+                    OUTPUT_VARIABLE _YACMA_PYTHON_MODULES_INSTALL_PATH OUTPUT_STRIP_TRAILING_WHITESPACE)
+            set(YACMA_PYTHON_MODULES_INSTALL_PATH "${_YACMA_PYTHON_MODULES_INSTALL_PATH}" CACHE PATH "Install path for Python modules.")
+            mark_as_advanced(YACMA_PYTHON_MODULES_INSTALL_PATH)
+        endif()
+    else()
+        message(FATAL_ERROR "Platform not supported.")
+endif()
+
+# Check the install path was actually detected.
+if("${YACMA_PYTHON_MODULES_INSTALL_PATH}" STREQUAL "")
+    message(FATAL_ERROR "Python module install path not detected correctly.")
+endif()
+
+function(YACMA_PYTHON_MODULE name)
+    message(STATUS "Setting up the compilation of the Python module '${name}'.")
+    # If we need an explicit link to the Python library, we compile it as a normal shared library.
+    # Otherwise, we compile it as a module.
+    if(_YACMA_PYTHON_MODULE_NEED_LINK)
+        add_library("${name}" SHARED ${ARGN})
+    else()
+        add_library("${name}" MODULE ${ARGN})
+    endif()
+    # Any "lib" prefix normally added by CMake must be removed.
+    set_target_properties("${name}" PROPERTIES PREFIX "")
+    if(NOT ${_YACMA_PY_MODULE_EXTENSION} STREQUAL "")
+        # If needed, set a custom extension for the module.
+        message(STATUS "Setting up custom extension '${_YACMA_PY_MODULE_EXTENSION}' for the Python module '${name}'.")
+        set_target_properties("${name}" PROPERTIES SUFFIX ".${_YACMA_PY_MODULE_EXTENSION}")
+    endif()
+    # We need extra flags to be set when compiling Python modules, at least
+    # with clang and gcc. See:
+    # https://bugs.python.org/issue11149
+    # http://www.python.org/dev/peps/pep-3123/
+    # NOTE: do not use the yacma compiler linker settings bits, so this module
+    # can be used stand-alone.
+    if(CMAKE_COMPILER_IS_GNUCXX OR (${CMAKE_CXX_COMPILER_ID} MATCHES "Clang" AND NOT MSVC))
+        message(STATUS "Setting up extra compiler flag '-fwrapv' for the Python module '${name}'.")
+        target_compile_options(${name} PRIVATE "-fwrapv")
+    endif()
+    if(APPLE AND ${CMAKE_CXX_COMPILER_ID} MATCHES "Clang")
+        # On OSX + Clang this link flag is apparently necessary in order to avoid
+        # undefined references to symbols defined in the Python library. See also:
+        # https://github.com/potassco/clingo/issues/79
+        # https://stackoverflow.com/questions/25421479/clang-and-undefined-symbols-when-building-a-library
+        # https://cmake.org/pipermail/cmake/2017-March/065115.html
+        set_target_properties(${name} PROPERTIES LINK_FLAGS "-undefined dynamic_lookup")
+    endif()
+
+    # Add the Python include dirs.
+    target_include_directories("${name}" SYSTEM PRIVATE ${YACMA_PYTHON_INCLUDE_DIR})
+
+    # Link to the Python libs, if necessary.
+    if(_YACMA_PYTHON_MODULE_NEED_LINK)
+        target_link_libraries("${name}" PRIVATE ${PYTHON_LIBRARIES})
+    endif()
+endfunction()
+
+# Mark as included.
+set(YACMAPythonSetupIncluded YES)