modsys, unix: Add sys.exit(), should be implemented by a port.

py/modsys.c

@@ -36,6 +36,8 @@
 
 #if MICROPY_ENABLE_MOD_SYS
 
+MP_DECLARE_CONST_FUN_OBJ(mp_sys_exit_obj);
+
 // These should be implemented by ports, specific types don't matter,
 // only addresses.
 struct _dummy_t;
@@ -53,6 +55,9 @@ STATIC const MP_DEFINE_STR_OBJ(version_obj, "3.4.0");
 
 STATIC const mp_map_elem_t mp_module_sys_globals_table[] = {
     { MP_OBJ_NEW_QSTR(MP_QSTR___name__), MP_OBJ_NEW_QSTR(MP_QSTR_sys) },
+    // Should be implemented by port
+    { MP_OBJ_NEW_QSTR(MP_QSTR_exit), (mp_obj_t)&mp_sys_exit_obj },
+
     { MP_OBJ_NEW_QSTR(MP_QSTR_path), (mp_obj_t)&mp_sys_path_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_argv), (mp_obj_t)&mp_sys_argv_obj },
     { MP_OBJ_NEW_QSTR(MP_QSTR_version), (mp_obj_t)&version_obj },

py/qstrdefs.h

@@ -329,6 +329,7 @@ Q(utf-8)
 Q(argv)
 Q(byteorder)
 Q(big)
+Q(exit)
 Q(little)
 Q(stdin)
 Q(stdout)

unix/main.c

@@ -371,6 +371,15 @@ int main(int argc, char **argv) {
     return 0;
 }
 
+STATIC mp_obj_t mp_sys_exit(uint n_args, const mp_obj_t *args) {
+    int rc = 0;
+    if (n_args > 0) {
+        rc = mp_obj_get_int(args[0]);
+    }
+    exit(rc);
+}
+MP_DEFINE_CONST_FUN_OBJ_VAR_BETWEEN(mp_sys_exit_obj, 0, 1, mp_sys_exit);
+
 uint mp_import_stat(const char *path) {
     struct stat st;
     if (stat(path, &st) == 0) {