From c41418751fcef0a42f336ba91871827b45d558a7 Mon Sep 17 00:00:00 2001 From: Guido van Rossum Date: Thu, 30 Aug 2001 04:43:35 +0000 Subject: 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. --- Objects/typeobject.c | 10 +++++++++- 1 file changed, 9 insertions(+), 1 deletion(-) diff --git a/Objects/typeobject.c b/Objects/typeobject.c index 559c41b..719a0a4 100644 --- a/Objects/typeobject.c +++ b/Objects/typeobject.c @@ -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++; } -- cgit v0.12