commit b7215ffbae167b04d1c845c8f994eccfd19f5be1
Author: Victor Stinner <vstinner@python.org>
Date:   Wed Jan 26 02:06:30 2022 +0100

    Add PyDescr_New()

diff --git a/pythoncapi_compat.h b/pythoncapi_compat.h
index 3e55206..f4b2f30 100644
--- a/pythoncapi_compat.h
+++ b/pythoncapi_compat.h
@@ -33,6 +33,16 @@ extern "C" {
 #endif
 
 
+// Py_UNUSED() was added to Python 3.4.0b2.
+#if PY_VERSION_HEX < 0x030400B2 && !defined(Py_UNUSED)
+#  if defined(__GNUC__) || defined(__clang__)
+#    define Py_UNUSED(name) _unused_ ## name __attribute__((unused))
+#  else
+#    define Py_UNUSED(name) _unused_ ## name
+#  endif
+#endif
+
+
 // Cast argument to PyObject* type.
 #ifndef _PyObject_CAST
 #  define _PyObject_CAST(op) ((PyObject*)(op))
@@ -372,13 +382,40 @@ _Py_IS_TYPE(const PyObject *ob, const PyTypeObject *type) {
 #endif
 
 
-// Py_UNUSED() was added to Python 3.4.0b2.
-#if PY_VERSION_HEX < 0x030400B2 && !defined(Py_UNUSED)
-#  if defined(__GNUC__) || defined(__clang__)
-#    define Py_UNUSED(name) _unused_ ## name __attribute__((unused))
-#  else
-#    define Py_UNUSED(name) _unused_ ## name
-#  endif
+// bpo-45476 added PyDescr_New() to Python 3.11.0a5
+#if PY_VERSION_HEX < 0x030B00A5
+PyDescrObject *
+PyDescr_New(PyTypeObject *descr_type, PyTypeObject *type, const char *name)
+{
+    assert(descr_type != NULL);
+    assert(type != NULL);
+    assert(name != NULL);
+
+    PyObject *name_obj;
+#if PY_MAJOR_VERSION >= 3
+    name_obj = PyUnicode_InternFromString(name);
+#else
+    name_obj = PyString_InternFromString(name);
+#endif
+    if (name_obj == NULL) {
+        return NULL;
+    }
+
+    PyDescrObject *descr = (PyDescrObject *)PyType_GenericAlloc(descr_type, 0);
+    if (descr == NULL) {
+        Py_DECREF(name_obj);
+        return NULL;
+    }
+
+    
+    descr->d_type = (PyTypeObject*)Py_NewRef(type);
+    descr->d_name = name_obj;
+    // PyDescrObject.d_qualname was added to Python 3.3.0a1
+#if PY_VERSION_HEX >= 0x030300A1
+    descr->d_qualname = NULL;
+#endif
+    return descr;
+}
 #endif
 
 
diff --git a/tests/test_pythoncapi_compat.py b/tests/test_pythoncapi_compat.py
index ea93a77..12d44ba 100644
--- a/tests/test_pythoncapi_compat.py
+++ b/tests/test_pythoncapi_compat.py
@@ -40,7 +40,7 @@ def build_ext():
     display_title("Build the C extension")
     if os.path.exists("build"):
         shutil.rmtree("build")
-    os.environ['CFLAGS'] = "-I .."
+    os.environ['CFLAGS'] = "-I .. -O0 -Wp,-U_FORTIFY_SOURCE"
     cmd = [sys.executable, "setup.py", "build"]
     if VERBOSE:
         run_command(cmd)
diff --git a/tests/test_pythoncapi_compat_cext.c b/tests/test_pythoncapi_compat_cext.c
index a5fabf1..5ba00c7 100644
--- a/tests/test_pythoncapi_compat_cext.c
+++ b/tests/test_pythoncapi_compat_cext.c
@@ -395,6 +395,77 @@ error:
     return NULL;
 }
 
+static void
+mydescr_dealloc(PyDescrObject *descr) {
+  PyObject_GC_UnTrack(descr);
+#if PY_MAJOR_VERSION >= 3
+  Py_XDECREF(PyDescr_TYPE(descr));
+  Py_XDECREF(PyDescr_NAME(descr));
+#else
+  Py_XDECREF(descr->d_type);
+  Py_XDECREF(descr->d_name);
+#endif
+  Py_TYPE(descr)->tp_free(descr);
+}
+
+
+static int
+mydescr_traverse(
+#if PY_VERSION_HEX >= 0x03090000
+    PyObject *self, visitproc visit, void *arg
+#else
+    PyObject *Py_UNUSED(self), visitproc Py_UNUSED(visit), void *Py_UNUSED(arg)
+#endif
+    )
+{
+#if PY_VERSION_HEX >= 0x03090000
+    PyDescrObject *descr = (PyDescrObject *)self;
+    Py_VISIT(PyDescr_TYPE(descr));
+#endif
+    return 0;
+}
+
+PyTypeObject MyDescr_Type = {
+    PyVarObject_HEAD_INIT(&PyType_Type, 0)
+    .tp_name = "mydescr",
+    .tp_basicsize = sizeof(PyDescrObject),
+    .tp_dealloc = (destructor)mydescr_dealloc,
+    .tp_traverse = mydescr_traverse,
+    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC,
+};
+
+
+static PyObject *
+test_pydescr_new(PyObject *Py_UNUSED(module), PyObject* Py_UNUSED(ignored))
+{
+    // PyDescr_New()
+    PyTypeObject *descr_type = &MyDescr_Type;
+    PyTypeObject *type = &PyLong_Type;
+
+    if (PyType_Ready(&MyDescr_Type) < 0) {
+        return NULL;
+    }
+
+    PyDescrObject *descr = PyDescr_New(descr_type, type, "name");
+    if (descr == NULL) {
+        return NULL;
+    }
+    assert(Py_REFCNT(descr) == 1);
+#if !defined(PYPY_VERSION)
+    assert(PyObject_GC_IsTracked((PyObject*)descr));
+#endif
+#if PY_MAJOR_VERSION >= 3
+    assert(PyDescr_TYPE(descr) == type);
+    assert(PyUnicode_CompareWithASCIIString(PyDescr_NAME(descr), "name") == 0);
+#else
+    assert(descr->d_type == type);
+    assert(strcmp(PyString_AsString(descr->d_name), "name") == 0);
+#endif
+
+    Py_DECREF(descr);
+    Py_RETURN_NONE;
+}
+
 
 static struct PyMethodDef methods[] = {
     {"test_object", test_object, METH_NOARGS, NULL},
@@ -408,6 +479,7 @@ static struct PyMethodDef methods[] = {
     {"test_calls", test_calls, METH_NOARGS, NULL},
     {"test_gc", test_gc, METH_NOARGS, NULL},
     {"test_module", test_module, METH_NOARGS, NULL},
+    {"test_pydescr_new", test_pydescr_new, METH_NOARGS, NULL},
     {NULL, NULL, 0, NULL}
 };