Safety measures now that str and tuple are subclassable:

If tp_itemsize of the basetype is nonzero, only allow empty __slots__
(declaring that no __dict__ should be added), and don't add a weakref
offset.
This commit is contained in:
Guido van Rossum 2001-08-30 04:43:35 +00:00
parent 31bcff8815
commit c41418751f

View File

@ -712,6 +712,13 @@ type_new(PyTypeObject *metatype, PyObject *args, PyObject *kwds)
if (slots == NULL)
return NULL;
nslots = PyTuple_GET_SIZE(slots);
if (nslots > 0 && base->tp_itemsize != 0) {
PyErr_Format(PyExc_TypeError,
"nonempty __slots__ "
"not supported for subtype of '%s'",
base->tp_name);
return NULL;
}
for (i = 0; i < nslots; i++) {
if (!PyString_Check(PyTuple_GET_ITEM(slots, i))) {
PyErr_SetString(PyExc_TypeError,
@ -728,7 +735,8 @@ type_new(PyTypeObject *metatype, PyObject *args, PyObject *kwds)
nslots++;
add_dict++;
}
if (slots == NULL && base->tp_weaklistoffset == 0) {
if (slots == NULL && base->tp_weaklistoffset == 0 &&
base->tp_itemsize == 0) {
nslots++;
add_weak++;
}