include_guard(DIRECTORY) set(prop_name DIR_SCRIPT_COUNT) get_property(count_is_set GLOBAL PROPERTY ${prop_name} SET) if(NOT count_is_set) set_property(GLOBAL PROPERTY ${prop_name} 1) else() get_property(count GLOBAL PROPERTY ${prop_name}) math(EXPR count "${count} + 1") set_property(GLOBAL PROPERTY ${prop_name} ${count}) endif()