Reserve other numeric values for future use

Author: noahbkim

Lib/test/test_cmd_line.py

@@ -1074,12 +1074,21 @@ def test_import_time(self):
         self.assertRegex(res_err, r"import time: \s*\d+ \| \s*\d+ \| \s*os")
         self.assertNotRegex(res_err, r"import time: cached\s* \| cached\s* \| os")
 
+        code = "import os"
+        res = assert_python_ok('-X', 'importtime=true', '-c', code)
+        res_err = res.err.decode("utf-8")
+        self.assertRegex(res_err, r"import time: \s*\d+ \| \s*\d+ \| \s*os")
+        self.assertNotRegex(res_err, r"import time: cached\s* \| cached\s* \| os")
+
         code = "import os; import os"
         res = assert_python_ok('-X', 'importtime=2', '-c', code)
         res_err = res.err.decode("utf-8")
         self.assertRegex(res_err, r"import time: \s*\d+ \| \s*\d+ \| \s*os")
         self.assertRegex(res_err, r"import time: cached\s* \| cached\s* \| os")
 
+        assert_python_failure('-X', 'importtime=-1', '-c', code)
+        assert_python_failure('-X', 'importtime=3', '-c', code)
+
     def res2int(self, res):
         out = res.out.strip().decode("utf-8")
         return tuple(int(i) for i in out.split())

Python/initconfig.c

@@ -2251,16 +2251,26 @@ config_init_run_presite(PyConfig *config)
 static PyStatus
 config_set_import_time(PyConfig *config, const wchar_t *value)
 {
-    /* We recognize 2 as a special value: if the importtime flag is
-     * set to 2, we also print import cache hits. Otherwise, we fall
-     * back to standard -X importtime behavior. */
-    if (wcscmp(value, L"2") == 0) {
-        config->import_time = 2;
-    }
-    else if (value != NULL) {
+    int numeric_value;
+
+    // If no value is specified or the value is not an integer, use 1.
+    if (*value == 0 || config_wstr_to_int(value, &numeric_value) != 0) {
         config->import_time = 1;
     }
 
+    /* -Ximporttime=1 incurs the default behavior. -Ximporttime=2 also
+     * prints import cache hits. All other numeric values are reserved.
+     */
+    else if (0 <= numeric_value && numeric_value <= 2) {
+        config->import_time = numeric_value;
+    }
+
+    else {
+        return _PyStatus_ERR(
+                "-X importtime: numeric values other than 1 or 2 are "
+                "reserved for future use");
+    }
+
     return _PyStatus_OK();
 }