[Kconfig] Replace find_executable by python module, moved python check before calling kconfig

CMakeLists.txt

@@ -143,6 +143,27 @@ set(CONFIG "px4_sitl_default" CACHE STRING "desired configuration")
 include(px4_add_module)
 set(config_module_list)
 
+# Find Python
+# If using catkin, Python 2 is found since it points
+# to the Python libs installed with the ROS distro
+if (NOT CATKIN_DEVEL_PREFIX)
+	find_package(PythonInterp 3)
+	# We have a custom error message to tell users how to install python3.
+	if (NOT PYTHONINTERP_FOUND)
+		message(FATAL_ERROR "Python 3 not found. Please install Python 3:\n"
+			"    Ubuntu: sudo apt install python3 python3-dev python3-pip\n"
+			"    macOS: brew install python")
+	endif()
+else()
+	find_package(PythonInterp REQUIRED)
+endif()
+
+option(PYTHON_COVERAGE "Python code coverage" OFF)
+if(PYTHON_COVERAGE)
+	message(STATUS "python coverage enabled")
+	set(PYTHON_EXECUTABLE coverage run -p)
+endif()
+
 include(px4_config)
 include(kconfig)
 message(STATUS "PX4 config: ${PX4_CONFIG}")
@@ -283,27 +304,6 @@ if (CATKIN_DEVEL_PREFIX)
 	endif()
 endif()
 
-# Python
-# If using catkin, Python 2 is found since it points
-# to the Python libs installed with the ROS distro
-if (NOT CATKIN_DEVEL_PREFIX)
-	find_package(PythonInterp 3)
-	# We have a custom error message to tell users how to install python3.
-	if (NOT PYTHONINTERP_FOUND)
-		message(FATAL_ERROR "Python 3 not found. Please install Python 3:\n"
-			"    Ubuntu: sudo apt install python3 python3-dev python3-pip\n"
-			"    macOS: brew install python")
-	endif()
-else()
-	find_package(PythonInterp REQUIRED)
-endif()
-
-option(PYTHON_COVERAGE "Python code coverage" OFF)
-if(PYTHON_COVERAGE)
-	message(STATUS "python coverage enabled")
-	set(PYTHON_EXECUTABLE coverage run -p)
-endif()
-
 #=============================================================================
 # get chip and chip manufacturer
 #

cmake/kconfig.cmake

@@ -1,15 +1,16 @@
 set(BOARD_DEFCONFIG ${PX4_CONFIG_FILE} CACHE FILEPATH "path to defconfig" FORCE)
 set(BOARD_CONFIG ${PX4_BINARY_DIR}/boardconfig CACHE FILEPATH "path to config" FORCE)
 
-find_program(MENUCONFIG_PATH menuconfig)
-find_program(GUICONFIG_PATH guiconfig)
-find_program(DEFCONFIG_PATH defconfig)
-find_program(SAVEDEFCONFIG_PATH savedefconfig)
-if(NOT MENUCONFIG_PATH OR NOT GUICONFIG_PATH OR NOT DEFCONFIG_PATH OR NOT SAVEDEFCONFIG_PATH)
-    message(STATUS "kconfiglib is not installed\n"
+execute_process(COMMAND ${PYTHON_EXECUTABLE} -c "import menuconfig" RESULT_VARIABLE ret)
+if(ret EQUAL "1")
+    message(FATAL_ERROR "kconfiglib is not installed or not in PATH\n"
                         "please install using \"pip3 install kconfiglib\"\n")
 endif()
 
+set(MENUCONFIG_PATH ${PYTHON_EXECUTABLE} -m menuconfig CACHE INTERNAL "menuconfig program" FORCE)
+set(GUICONFIG_PATH ${PYTHON_EXECUTABLE} -m guiconfig CACHE INTERNAL "guiconfig program" FORCE)
+set(DEFCONFIG_PATH ${PYTHON_EXECUTABLE} -m defconfig CACHE INTERNAL "defconfig program" FORCE)
+set(SAVEDEFCONFIG_PATH ${PYTHON_EXECUTABLE} -m savedefconfig CACHE INTERNAL "savedefconfig program" FORCE)
 
 set(COMMON_KCONFIG_ENV_SETTINGS
 	PYTHON_EXECUTABLE=${PYTHON_EXECUTABLE}