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gh-103968: PyType_FromMetaclass: Allow metaclasses with tp_new=NULL (GH-105386)

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Petr Viktorin 2023-06-12 17:45:49 +02:00 • committed by GitHub
parent 58f0bda341
commit 2b90796be6
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5 changed files with 53 additions and 9 deletions
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43
Lib/test/test_capi/test_misc.py
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@ -671,31 +671,60 @@ class CAPITest(unittest.TestCase):
self.assertEqual(obj.pvalue, 0)
def test_heaptype_with_custom_metaclass(self):
self.assertTrue(issubclass(_testcapi.HeapCTypeMetaclass, type))
self.assertTrue(issubclass(_testcapi.HeapCTypeMetaclassCustomNew, type))
metaclass = _testcapi.HeapCTypeMetaclass
self.assertTrue(issubclass(metaclass, type))
t = _testcapi.pytype_fromspec_meta(_testcapi.HeapCTypeMetaclass)
# Class creation from C
t = _testcapi.pytype_fromspec_meta(metaclass)
self.assertIsInstance(t, type)
self.assertEqual(t.__name__, "HeapCTypeViaMetaclass")
self.assertIs(type(t), _testcapi.HeapCTypeMetaclass)
self.assertIs(type(t), metaclass)
# Class creation from Python
t = metaclass("PyClassViaMetaclass", (), {})
self.assertIsInstance(t, type)
self.assertEqual(t.__name__, "PyClassViaMetaclass")
def test_heaptype_with_custom_metaclass_null_new(self):
metaclass = _testcapi.HeapCTypeMetaclassNullNew
self.assertTrue(issubclass(metaclass, type))
# Class creation from C
t = _testcapi.pytype_fromspec_meta(metaclass)
self.assertIsInstance(t, type)
self.assertEqual(t.__name__, "HeapCTypeViaMetaclass")
self.assertIs(type(t), metaclass)
# Class creation from Python
with self.assertRaisesRegex(TypeError, "cannot create .* instances"):
metaclass("PyClassViaMetaclass", (), {})
def test_heaptype_with_custom_metaclass_custom_new(self):
metaclass = _testcapi.HeapCTypeMetaclassCustomNew
self.assertTrue(issubclass(_testcapi.HeapCTypeMetaclassCustomNew, type))
msg = "Metaclasses with custom tp_new are not supported."
with self.assertRaisesRegex(TypeError, msg):
t = _testcapi.pytype_fromspec_meta(_testcapi.HeapCTypeMetaclassCustomNew)
t = _testcapi.pytype_fromspec_meta(metaclass)
def test_heaptype_with_custom_metaclass_deprecation(self):
metaclass = _testcapi.HeapCTypeMetaclassCustomNew
# gh-103968: a metaclass with custom tp_new is deprecated, but still
# allowed for functions that existed in 3.11
# (PyType_FromSpecWithBases is used here).
class Base(metaclass=_testcapi.HeapCTypeMetaclassCustomNew):
class Base(metaclass=metaclass):
pass
# Class creation from C
with warnings_helper.check_warnings(
('.*custom tp_new.*in Python 3.14.*', DeprecationWarning),
):
sub = _testcapi.make_type_with_base(Base)
self.assertTrue(issubclass(sub, Base))
self.assertIsInstance(sub, _testcapi.HeapCTypeMetaclassCustomNew)
self.assertIsInstance(sub, metaclass)
def test_multiple_inheritance_ctypes_with_weakref_or_dict(self):