diff options
| -rw-r--r-- | Lib/test/test_typechecks.py | 21 | ||||
| -rw-r--r-- | Objects/abstract.c | 82 |
2 files changed, 42 insertions, 61 deletions
diff --git a/Lib/test/test_typechecks.py b/Lib/test/test_typechecks.py index 32aa660..64c4174 100644 --- a/Lib/test/test_typechecks.py +++ b/Lib/test/test_typechecks.py @@ -29,10 +29,6 @@ class SubInt(Integer): pass -class Evil: - def __instancecheck__(self, inst): return False - - class TypeChecksTest(unittest.TestCase): def testIsSubclassInternal(self): @@ -75,11 +71,18 @@ class TypeChecksTest(unittest.TestCase): self.assertEqual(isinstance(42, SubInt), False) self.assertEqual(isinstance(42, (SubInt,)), False) - def testInfiniteRecursionCaughtProperly(self): - e = Evil() - # This invokes isinstance() recursively, until the stack is exhausted. - self.assertRaises(RuntimeError, isinstance, e, Evil) - # XXX How to check the same situation for issubclass()? + def test_oldstyle(self): + # These should just be ignored. + class X: + def __instancecheck__(self, inst): + return True + def __subclasscheck__(self, cls): + return True + class Sub(X): pass + self.assertFalse(isinstance(3, X)) + self.assertTrue(isinstance(X(), X)) + self.assertFalse(issubclass(int, X)) + self.assertTrue(issubclass(Sub, X)) def test_main(): diff --git a/Objects/abstract.c b/Objects/abstract.c index 2266fa1..63b2041 100644 --- a/Objects/abstract.c +++ b/Objects/abstract.c @@ -2902,7 +2902,6 @@ int PyObject_IsInstance(PyObject *inst, PyObject *cls) { static PyObject *name = NULL; - PyObject *checker; /* Quick test for an exact match */ if (Py_TYPE(inst) == (PyTypeObject *)cls) @@ -2927,33 +2926,25 @@ PyObject_IsInstance(PyObject *inst, PyObject *cls) return r; } - if (PyClass_Check(cls) || PyInstance_Check(cls)) { - checker = PyObject_GetAttrString(cls, "__instancecheck__"); - if (checker == NULL) { - if (PyErr_ExceptionMatches(PyExc_AttributeError)) - PyErr_Clear(); - else - return -1; - } - } - else { + if (!(PyClass_Check(cls) || PyInstance_Check(cls))) { + PyObject *checker; checker = _PyObject_LookupSpecial(cls, "__instancecheck__", &name); - } - if (checker != NULL) { - PyObject *res; - int ok = -1; - if (Py_EnterRecursiveCall(" in __instancecheck__")) { + if (checker != NULL) { + PyObject *res; + int ok = -1; + if (Py_EnterRecursiveCall(" in __instancecheck__")) { + Py_DECREF(checker); + return ok; + } + res = PyObject_CallFunctionObjArgs(checker, inst, NULL); + Py_LeaveRecursiveCall(); Py_DECREF(checker); + if (res != NULL) { + ok = PyObject_IsTrue(res); + Py_DECREF(res); + } return ok; } - res = PyObject_CallFunctionObjArgs(checker, inst, NULL); - Py_LeaveRecursiveCall(); - Py_DECREF(checker); - if (res != NULL) { - ok = PyObject_IsTrue(res); - Py_DECREF(res); - } - return ok; } return recursive_isinstance(inst, cls); } @@ -2992,8 +2983,6 @@ int PyObject_IsSubclass(PyObject *derived, PyObject *cls) { static PyObject *name = NULL; - PyObject *t, *v, *tb; - PyObject *checker; if (PyTuple_Check(cls)) { Py_ssize_t i; @@ -3013,36 +3002,25 @@ PyObject_IsSubclass(PyObject *derived, PyObject *cls) Py_LeaveRecursiveCall(); return r; } - if (PyClass_Check(cls) || PyInstance_Check(cls)) { - PyErr_Fetch(&t, &v, &tb); - checker = PyObject_GetAttr(cls, name); - if (checker == NULL && - !PyErr_ExceptionMatches(PyExc_AttributeError)) { - Py_XDECREF(t); - Py_XDECREF(v); - Py_XDECREF(tb); - return -1; - } - PyErr_Restore(t, v, tb); - } - else { + if (!(PyClass_Check(cls) || PyInstance_Check(cls))) { + PyObject *checker; checker = _PyObject_LookupSpecial(cls, "__subclasscheck__", &name); - } - if (checker != NULL) { - PyObject *res; - int ok = -1; - if (Py_EnterRecursiveCall(" in __subclasscheck__")) { + if (checker != NULL) { + PyObject *res; + int ok = -1; + if (Py_EnterRecursiveCall(" in __subclasscheck__")) { + Py_DECREF(checker); + return ok; + } + res = PyObject_CallFunctionObjArgs(checker, derived, NULL); + Py_LeaveRecursiveCall(); Py_DECREF(checker); + if (res != NULL) { + ok = PyObject_IsTrue(res); + Py_DECREF(res); + } return ok; } - res = PyObject_CallFunctionObjArgs(checker, derived, NULL); - Py_LeaveRecursiveCall(); - Py_DECREF(checker); - if (res != NULL) { - ok = PyObject_IsTrue(res); - Py_DECREF(res); - } - return ok; } return recursive_issubclass(derived, cls); } |