mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-10-21 14:12:27 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 8

Manual forward port of 64962 - use PyObject_HashNotImplemented as a tp_hash level indicator that the default hash implementation has not been inherited

Browse source
This commit is contained in:
Nick Coghlan 2008-07-15 15:46:38 +00:00
parent e65282114e
commit d1abd25ed8
12 changed files with 122 additions and 94 deletions
Download patch file Download diff file Expand all files Collapse all files

36
Objects/typeobject.c
View file

@ -3810,13 +3810,15 @@ PyType_Ready(PyTypeObject *type)
/* Hack for tp_hash and __hash__.
If after all that, tp_hash is still NULL, and __hash__ is not in
tp_dict, set tp_dict['__hash__'] equal to None.
tp_dict, set tp_hash to PyObject_HashNotImplemented and
tp_dict['__hash__'] equal to None.
This signals that __hash__ is not inherited.
*/
if (type->tp_hash == NULL) {
if (PyDict_GetItemString(type->tp_dict, "__hash__") == NULL) {
if (PyDict_SetItemString(type->tp_dict, "__hash__", Py_None) < 0)
goto error;
type->tp_hash = PyObject_HashNotImplemented;
}
}
@ -4943,9 +4945,7 @@ slot_tp_hash(PyObject *self)
}
if (func == NULL) {
PyErr_Format(PyExc_TypeError, "unhashable type: '%.200s'",
Py_TYPE(self)->tp_name);
return -1;
return PyObject_HashNotImplemented(self);
}
res = PyEval_CallObject(func, NULL);
@ -5676,6 +5676,13 @@ update_one_slot(PyTypeObject *type, slotdef *p)
sanity checks. I'll buy the first person to
point out a bug in this reasoning a beer. */
}
else if (descr == Py_None &&
strcmp(p->name, "__hash__") == 0) {
/* We specifically allow __hash__ to be set to None
to prevent inheritance of the default
implementation from object.__hash__ */
specific = PyObject_HashNotImplemented;
}
else {
use_generic = 1;
generic = p->function;
@ -5889,12 +5896,21 @@ add_operators(PyTypeObject *type)
continue;
if (PyDict_GetItem(dict, p->name_strobj))
continue;
descr = PyDescr_NewWrapper(type, p, *ptr);
if (descr == NULL)
return -1;
if (PyDict_SetItem(dict, p->name_strobj, descr) < 0)
return -1;
Py_DECREF(descr);
if (*ptr == PyObject_HashNotImplemented) {
/* Classes may prevent the inheritance of the tp_hash
slot by storing PyObject_HashNotImplemented in it. Make it
visible as a None value for the __hash__ attribute. */
if (PyDict_SetItem(dict, p->name_strobj, Py_None) < 0)
return -1;
}
else {
descr = PyDescr_NewWrapper(type, p, *ptr);
if (descr == NULL)
return -1;
if (PyDict_SetItem(dict, p->name_strobj, descr) < 0)
return -1;
Py_DECREF(descr);
}
}
if (type->tp_new != NULL) {
if (add_tp_new_wrapper(type) < 0)