Revert r53997 as per
http://mail.python.org/pipermail/python-dev/2007-March/071796.html .
I've kept a couple of still-valid extra tests in test_descr, but didn't
bother to sort through the new comments and refactorings added in r53997
to see if some of them could be kept. If so, they could go in a
follow-up check-in.
diff --git a/Objects/typeobject.c b/Objects/typeobject.c
index 285bd67..a3b1476 100644
--- a/Objects/typeobject.c
+++ b/Objects/typeobject.c
@@ -127,7 +127,6 @@
return type->tp_bases;
}
-static PyTypeObject *most_derived_metaclass(PyTypeObject *, PyObject *);
static PyTypeObject *best_base(PyObject *);
static int mro_internal(PyTypeObject *);
static int compatible_for_assignment(PyTypeObject *, PyTypeObject *, char *);
@@ -188,7 +187,7 @@
Py_ssize_t i;
int r = 0;
PyObject *ob, *temp;
- PyTypeObject *new_base, *old_base, *metatype;
+ PyTypeObject *new_base, *old_base;
PyObject *old_bases, *old_mro;
if (!(type->tp_flags & Py_TPFLAGS_HEAPTYPE)) {
@@ -231,17 +230,6 @@
}
}
-
- metatype = most_derived_metaclass(type->ob_type, value);
- if (metatype == NULL)
- return -1;
- if (metatype != type->ob_type) {
- PyErr_SetString(PyExc_TypeError,
- "assignment to __bases__ may not change "
- "metatype");
- return -1;
- }
-
new_base = best_base(value);
if (!new_base) {
@@ -1367,14 +1355,7 @@
/* Calculate the best base amongst multiple base classes.
- This is the first one that's on the path to the "solid base".
-
- Requires that all base classes be types or classic classes.
-
- Will return NULL with TypeError set if
- 1) the base classes have conflicting layout instances, or
- 2) all the bases are classic classes.
-*/
+ This is the first one that's on the path to the "solid base". */
static PyTypeObject *
best_base(PyObject *bases)
@@ -1392,7 +1373,12 @@
base_proto = PyTuple_GET_ITEM(bases, i);
if (PyClass_Check(base_proto))
continue;
- assert(PyType_Check(base_proto));
+ if (!PyType_Check(base_proto)) {
+ PyErr_SetString(
+ PyExc_TypeError,
+ "bases must be types");
+ return NULL;
+ }
base_i = (PyTypeObject *)base_proto;
if (base_i->tp_dict == NULL) {
if (PyType_Ready(base_i) < 0)
@@ -1445,8 +1431,6 @@
return t_size != b_size;
}
-/* Return the type object that will determine the layout of the instance. */
-
static PyTypeObject *
solid_base(PyTypeObject *type)
{
@@ -1462,71 +1446,6 @@
return base;
}
-/* Determine the proper metatype to deal with this, and check some
- error cases while we're at it. Note that if some other metatype
- wins to contract, it's possible that its instances are not types.
-
- Error cases of interest: 1. The metaclass is not a subclass of a
- base class. 2. A non-type, non-classic base class appears before
- type.
-*/
-
-static PyTypeObject *
-most_derived_metaclass(PyTypeObject *metatype, PyObject *bases)
-{
- Py_ssize_t nbases, i;
- PyTypeObject *winner;
- /* types_ordered: One of three states possible:
- 0 type is in bases
- 1 non-types also in bases
- 2 type follows non-type in bases (error)
- */
- int types_ordered = 0;
-
- nbases = PyTuple_GET_SIZE(bases);
- winner = metatype;
- for (i = 0; i < nbases; i++) {
- PyObject *tmp = PyTuple_GET_ITEM(bases, i);
- PyTypeObject *tmptype = tmp->ob_type;
- if (tmptype == &PyClass_Type)
- continue; /* Special case classic classes */
- if (!PyType_Check(tmp)) {
- PyErr_SetString(PyExc_TypeError,
- "bases must be types");
- return NULL;
- }
- if (PyObject_IsSubclass(tmp, (PyObject*)&PyType_Type)) {
- if (types_ordered == 1) {
- types_ordered = 2;
- }
- }
- else if (!types_ordered)
- types_ordered = 1;
- if (winner == tmptype)
- continue;
- if (PyType_IsSubtype(winner, tmptype))
- continue;
- if (PyType_IsSubtype(tmptype, winner)) {
- winner = tmptype;
- continue;
- }
- PyErr_SetString(PyExc_TypeError,
- "metaclass conflict: "
- "the metaclass of a derived class "
- "must be a (non-strict) subclass "
- "of the metaclasses of all its bases");
- return NULL;
- }
- if (types_ordered == 2) {
- PyErr_SetString(PyExc_TypeError,
- "metaclass conflict: "
- "type must occur in bases before other "
- "non-classic base classes");
- return NULL;
- }
- return winner;
-}
-
static void object_dealloc(PyObject *);
static int object_init(PyObject *, PyObject *, PyObject *);
static int update_slot(PyTypeObject *, PyObject *);
@@ -1760,18 +1679,37 @@
&PyDict_Type, &dict))
return NULL;
- winner = most_derived_metaclass(metatype, bases);
- if (winner == NULL)
- return NULL;
- if (winner != metatype) {
- if (winner->tp_new != type_new) /* Pass it to the winner */ {
- return winner->tp_new(winner, args, kwds);
+ /* Determine the proper metatype to deal with this,
+ and check for metatype conflicts while we're at it.
+ Note that if some other metatype wins to contract,
+ it's possible that its instances are not types. */
+ nbases = PyTuple_GET_SIZE(bases);
+ winner = metatype;
+ for (i = 0; i < nbases; i++) {
+ tmp = PyTuple_GET_ITEM(bases, i);
+ tmptype = tmp->ob_type;
+ if (tmptype == &PyClass_Type)
+ continue; /* Special case classic classes */
+ if (PyType_IsSubtype(winner, tmptype))
+ continue;
+ if (PyType_IsSubtype(tmptype, winner)) {
+ winner = tmptype;
+ continue;
}
+ PyErr_SetString(PyExc_TypeError,
+ "metaclass conflict: "
+ "the metaclass of a derived class "
+ "must be a (non-strict) subclass "
+ "of the metaclasses of all its bases");
+ return NULL;
+ }
+ if (winner != metatype) {
+ if (winner->tp_new != type_new) /* Pass it to the winner */
+ return winner->tp_new(winner, args, kwds);
metatype = winner;
}
/* Adjust for empty tuple bases */
- nbases = PyTuple_GET_SIZE(bases);
if (nbases == 0) {
bases = PyTuple_Pack(1, &PyBaseObject_Type);
if (bases == NULL)