Add more tests

Add comment to _PyOS_GetOpt().

Author: vstinner

Lib/test/test_cmd_line.py

@@ -1458,6 +1458,26 @@ def check_ignored(option):
 
         # -c, -h, -m, -V and -? are tested elsewhere
 
+    def test_unknown_options(self):
+        for option in ('-a', '--long-option'):
+            with self.subTest(option=option):
+                proc = assert_python_failure(option)
+                errmsg = f'Unknown option: {option}'
+                self.assertStartsWith(proc.err.rstrip(), errmsg.encode())
+
+    def test_missing_argument(self):
+        def check_missing_arg(option):
+            proc = assert_python_failure(option)
+            self.assertEqual(proc.rc, 2)
+            errmsg = f"Argument expected for the {option} option"
+            self.assertStartsWith(proc.err.rstrip(), errmsg.encode())
+
+        check_missing_arg('-c')
+        check_missing_arg('-m')
+        check_missing_arg('-W')
+        check_missing_arg('-X')
+        check_missing_arg('--check-hash-based-pycs')
+
     def test_long_options(self):
         # Test long command line options
 
@@ -1469,8 +1489,17 @@ def test_long_options(self):
                 proc = assert_python_ok(opt, value, "-c", code)
                 self.assertEqual(proc.out.rstrip(), value.encode())
 
-        # Other long options --help-all, --help-env and --help-xoptions
-        # are tested elsewhere
+        # Other long options --help-all, --help-env, --help-xoptions
+        # and --version are tested elsewhere
+
+    def test_dash_option(self):
+        # Test -- in the command line
+        code = (
+            'import sys; '
+            'print(sys.flags.isolated, sys.flags.optimize, sys.argv)'
+        )
+        proc = assert_python_ok('-I', '-c', code, '--', '-O')
+        self.assertEqual(proc.out.rstrip(), b"1 0 ['-c', '--', '-O']")
 
 
 @unittest.skipIf(interpreter_requires_environment(),

Python/getopt.c

@@ -62,6 +62,17 @@ _PyOS_GetOpt_Init(struct _PyOS_GetOpt *getopt,
     getopt->argv = argv;
 }
 
+// Parse a command line option.
+//
+// Return a character for short option (ex: return 'h' for -h).
+// Return a number for long options (see 'longopts' array).
+// Return '_' on unknown option or missing argument.
+// Return -1 when done.
+//
+// Return 'h' for --help and return 'V' for --version.
+//
+// If an option has an argument, set getopt->arg to the argument.
+// If getopt->error is non-error, write error messages to stderr.
 int
 _PyOS_GetOpt(struct _PyOS_GetOpt *getopt)
 {

Python/initconfig.c

@@ -3013,7 +3013,7 @@ config_parse_cmdline(PyConfig *config, PyWideStringList *warnoptions,
     _PyOS_GetOpt_Init(&getopt, argv->length, argv->items);
     do {
         int c = _PyOS_GetOpt(&getopt);
-        if (c == EOF) {
+        if (c == -1) {
             break;
         }
 
@@ -3257,6 +3257,9 @@ _PyConfig_ProcessDeferredCmdlineOption(PyConfig *config)
         config_xoptions_usage();
         return 0;
 
+    case '_':
+        // Unknown option or missing argument
+        _Py_FALLTHROUGH;
     default:
         config_usage(1, program);
         return 2;

Python/preconfig.c

@@ -194,8 +194,7 @@ precmdline_parse_cmdline(_PyPreCmdline *cmdline)
     getopt.error = 0;
     do {
         int c = _PyOS_GetOpt(&getopt);
-
-        if (c == EOF || c == 'c' || c == 'm') {
+        if (c == -1 || c == 'c' || c == 'm') {
             break;
         }