gh-155503: Add more PyType C API tests

Add tests on functions:

* PyType_GenericAlloc()
* PyType_SUPPORTS_WEAKREFS()

Author: Amankumar-10012004

Lib/test/test_capi/test_type.py

@@ -495,3 +495,39 @@ class MyType:
 
         # CRASHES type_modified(NULL)
         # CRASHES type_modified({}): argument must be a type
+
+    def test_type_genericalloc(self):
+        # Test PyType_GenericAlloc()
+        type_genericalloc = _testlimitedcapi.type_genericalloc
+
+        class HeapType:
+            pass
+
+        obj = type_genericalloc(HeapType)
+        self.assertIsInstance(obj, HeapType)
+
+        obj2 = type_genericalloc(HeapType, 0)
+        self.assertIsInstance(obj2, HeapType)
+
+        # CRASHES type_genericalloc(NULL)
+        # CRASHES type_genericalloc(123): argument must be a type
+
+    def test_type_supports_weakrefs(self):
+        # Test PyType_SUPPORTS_WEAKREFS()
+        type_supports_weakrefs = _testcapi.type_supports_weakrefs
+
+        class WithWeakref:
+            pass
+
+        class NoWeakref:
+            __slots__ = ('x',)
+
+        self.assertTrue(type_supports_weakrefs(WithWeakref))
+        self.assertFalse(type_supports_weakrefs(NoWeakref))
+        self.assertFalse(type_supports_weakrefs(int))
+        self.assertFalse(type_supports_weakrefs(str))
+        self.assertFalse(type_supports_weakrefs(list))
+        self.assertFalse(type_supports_weakrefs(dict))
+
+        # CRASHES type_supports_weakrefs(NULL)
+        # CRASHES type_supports_weakrefs(123): argument must be a type

Modules/_testcapi/type.c

@@ -157,13 +157,26 @@ type_get_tp_mro(PyObject *self, PyObject *arg)
 }
 
 
+// Test PyType_SUPPORTS_WEAKREFS()
+static PyObject *
+type_supports_weakrefs(PyObject *self, PyObject *arg)
+{
+    NULLABLE(arg);
+    PyTypeObject *type = (PyTypeObject*)arg;
+
+    int res = PyType_SUPPORTS_WEAKREFS(type);
+    return PyLong_FromLong(res);
+}
+
+
 static PyMethodDef test_methods[] = {
     {"test_get_type_dict", test_get_type_dict, METH_NOARGS},
     {"test_get_statictype_slots", test_get_statictype_slots,     METH_NOARGS},
     {"type_get_version", type_get_version, METH_O, PyDoc_STR("type->tp_version_tag")},
     {"type_assign_version", type_assign_version, METH_O, PyDoc_STR("PyUnstable_Type_AssignVersionTag")},
     {"type_get_tp_bases", type_get_tp_bases, METH_O},
     {"type_get_tp_mro", type_get_tp_mro, METH_O},
+    {"type_supports_weakrefs", type_supports_weakrefs, METH_O, PyDoc_STR("PyType_SUPPORTS_WEAKREFS(type)")},
     {NULL},
 };
 

Modules/_testlimitedcapi/type.c

@@ -160,6 +160,22 @@ type_issubtype(PyObject *module, PyObject *args)
 }
 
 
+// Test PyType_GenericAlloc()
+static PyObject *
+type_genericalloc(PyObject *module, PyObject *args)
+{
+    PyObject *arg;
+    Py_ssize_t nitems = 0;
+    if (!PyArg_ParseTuple(args, "O|n", &arg, &nitems)) {
+        return NULL;
+    }
+    NULLABLE(arg);
+    PyTypeObject *type = (PyTypeObject *)arg;
+
+    return PyType_GenericAlloc(type, nitems);
+}
+
+
 static PyMethodDef test_methods[] = {
     {"get_heaptype_for_name", get_heaptype_for_name, METH_NOARGS},
     {"get_type_name", get_type_name, METH_O},
@@ -172,6 +188,7 @@ static PyMethodDef test_methods[] = {
     {"type_clearcache", type_clearcache, METH_NOARGS},
     {"type_getflags", type_getflags, METH_O},
     {"type_issubtype", type_issubtype, METH_VARARGS},
+    {"type_genericalloc", type_genericalloc, METH_VARARGS},
     {NULL},
 };