Don't use PY_CXX_CONST; add tests

Author: vstinner

Doc/c-api/arg.rst

@@ -527,7 +527,7 @@ API Functions
    .. versionadded:: next
 
 
-.. c:function:: int PyArg_ParseVectorAndKeywords(PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames, const char * const *kwlist, ...)
+.. c:function:: int PyArg_ParseVectorAndKeywords(PyObject *const *args, Py_ssize_t nargs, PyObject *kwnames, const char *format, const char * const *kwlist, ...)
 
    Parse the parameters of a function that takes both vector and keyword
    parameters into local variables (that is, a function using the

Include/cpython/modsupport.h

@@ -12,7 +12,7 @@ PyAPI_FUNC(int) PyArg_ParseVectorAndKeywords(
     Py_ssize_t nargs,
     PyObject *kwnames,
     const char *format,
-    PY_CXX_CONST char * const *kwlist,
+    const char * const *kwlist,
     ...);
 
 // A data structure that can be used to run initialization code once in a

Lib/test/test_capi/test_modsupport.py

@@ -152,3 +152,22 @@ def test_negative_freethreading(self, modname, minor, build):
             msg = "only compatible with free-threaded CPython"
         with self.assertRaisesRegex(ImportError, msg):
             _testcapi.pyabiinfo_check(modname, 1, minor, ft_flag, build, 0)
+
+
+class TestModsupport(unittest.TestCase):
+    def test_pyarg_parsevector(self):
+        func = _testcapi.pyarg_parsevector
+        self.assertEqual(func(1, 2), (1, 2, 0))
+        self.assertEqual(func(1, 2, 3), (1, 2, 3))
+        self.assertRaises(TypeError, func, 1)
+        self.assertRaises(TypeError, func, "str", 2)
+
+    def test_funcandkeywords(self):
+        func = _testcapi.pyarg_parsevectorandkeywords
+        self.assertEqual(func(1, 2), (1, 2, 0))
+        self.assertEqual(func(1, 2, 3), (1, 2, 3))
+        self.assertEqual(func(1, b=2), (1, 2, 0))
+        self.assertEqual(func(1, b=2, c=3), (1, 2, 3))
+        self.assertRaises(TypeError, func, 1)
+        self.assertRaises(TypeError, func, "str", 2)
+        self.assertRaises(TypeError, func, 1, z=2)

Modules/_testcapi/modsupport.c

@@ -25,8 +25,36 @@ pyabiinfo_check(PyObject *Py_UNUSED(module), PyObject *args)
     Py_RETURN_NONE;
 }
 
+static PyObject *
+pyarg_parsevector(PyObject* self, PyObject* const* args, Py_ssize_t nargs)
+{
+    int a, b, c = 0;
+    if (!PyArg_ParseVector(args, nargs, "ii|i", &a, &b, &c)) {
+        return NULL;
+    }
+    return Py_BuildValue("iii", a, b, c);
+}
+
+static PyObject *
+pyarg_parsevectorandkeywords(PyObject* self, PyObject* const* args,
+                             Py_ssize_t nargs, PyObject* kwnames)
+{
+    int a, b, c = 0;
+    const char *kwlist[] = {"a", "b", "c", NULL};
+    if (!PyArg_ParseVectorAndKeywords(args, nargs, kwnames,
+                                      "ii|i", kwlist,
+                                      &a, &b, &c)) {
+        return NULL;
+    }
+    return Py_BuildValue("iii", a, b, c);
+}
+
 static PyMethodDef TestMethods[] = {
     {"pyabiinfo_check", pyabiinfo_check, METH_VARARGS},
+    {"pyarg_parsevector", _PyCFunction_CAST(pyarg_parsevector), METH_FASTCALL},
+    {"pyarg_parsevectorandkeywords",
+     _PyCFunction_CAST(pyarg_parsevectorandkeywords),
+     METH_FASTCALL | METH_KEYWORDS},
     {NULL},
 };