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typeobject.c
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typeobject.c
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/* Type object implementation */
#include "Python.h"
#include "structmember.h"
#include <ctype.h>
/* The *real* layout of a type object when allocated on the heap */
/* XXX Should we publish this in a header file? */
typedef struct {
/* Note: there's a dependency on the order of these members
in slotptr() below. */
PyTypeObject type;
PyNumberMethods as_number;
PyMappingMethods as_mapping;
PySequenceMethods as_sequence; /* as_sequence comes after as_mapping,
so that the mapping wins when both
the mapping and the sequence define
a given operator (e.g. __getitem__).
see add_operators() below. */
PyBufferProcs as_buffer;
PyObject *name, *slots;
PyMemberDef members[1];
} etype;
static PyMemberDef type_members[] = {
{"__basicsize__", T_INT, offsetof(PyTypeObject,tp_basicsize),READONLY},
{"__itemsize__", T_INT, offsetof(PyTypeObject, tp_itemsize), READONLY},
{"__flags__", T_LONG, offsetof(PyTypeObject, tp_flags), READONLY},
{"__weakrefoffset__", T_LONG,
offsetof(PyTypeObject, tp_weaklistoffset), READONLY},
{"__base__", T_OBJECT, offsetof(PyTypeObject, tp_base), READONLY},
{"__dictoffset__", T_LONG,
offsetof(PyTypeObject, tp_dictoffset), READONLY},
{"__bases__", T_OBJECT, offsetof(PyTypeObject, tp_bases), READONLY},
{"__mro__", T_OBJECT, offsetof(PyTypeObject, tp_mro), READONLY},
{0}
};
static PyObject *
type_name(PyTypeObject *type, void *context)
{
char *s;
s = strrchr(type->tp_name, '.');
if (s == NULL)
s = type->tp_name;
else
s++;
return PyString_FromString(s);
}
static PyObject *
type_module(PyTypeObject *type, void *context)
{
PyObject *mod;
char *s;
s = strrchr(type->tp_name, '.');
if (s != NULL)
return PyString_FromStringAndSize(type->tp_name,
(int)(s - type->tp_name));
if (!(type->tp_flags & Py_TPFLAGS_HEAPTYPE))
return PyString_FromString("__builtin__");
mod = PyDict_GetItemString(type->tp_dict, "__module__");
if (mod != NULL && PyString_Check(mod)) {
Py_INCREF(mod);
return mod;
}
PyErr_SetString(PyExc_AttributeError, "__module__");
return NULL;
}
static int
type_set_module(PyTypeObject *type, PyObject *value, void *context)
{
if (!(type->tp_flags & Py_TPFLAGS_HEAPTYPE) ||
strrchr(type->tp_name, '.')) {
PyErr_Format(PyExc_TypeError,
"can't set %s.__module__", type->tp_name);
return -1;
}
if (!value) {
PyErr_Format(PyExc_TypeError,
"can't delete %s.__module__", type->tp_name);
return -1;
}
return PyDict_SetItemString(type->tp_dict, "__module__", value);
}
static PyObject *
type_dict(PyTypeObject *type, void *context)
{
if (type->tp_dict == NULL) {
Py_INCREF(Py_None);
return Py_None;
}
return PyDictProxy_New(type->tp_dict);
}
static PyObject *
type_get_doc(PyTypeObject *type, void *context)
{
PyObject *result;
if (!(type->tp_flags & Py_TPFLAGS_HEAPTYPE) && type->tp_doc != NULL)
return PyString_FromString(type->tp_doc);
result = PyDict_GetItemString(type->tp_dict, "__doc__");
if (result == NULL) {
result = Py_None;
Py_INCREF(result);
}
else if (result->ob_type->tp_descr_get) {
result = result->ob_type->tp_descr_get(result, NULL,
(PyObject *)type);
}
else {
Py_INCREF(result);
}
return result;
}
static PyGetSetDef type_getsets[] = {
{"__name__", (getter)type_name, NULL, NULL},
{"__module__", (getter)type_module, (setter)type_set_module, NULL},
{"__dict__", (getter)type_dict, NULL, NULL},
{"__doc__", (getter)type_get_doc, NULL, NULL},
{0}
};
static int
type_compare(PyObject *v, PyObject *w)
{
/* This is called with type objects only. So we
can just compare the addresses. */
Py_uintptr_t vv = (Py_uintptr_t)v;
Py_uintptr_t ww = (Py_uintptr_t)w;
return (vv < ww) ? -1 : (vv > ww) ? 1 : 0;
}
static PyObject *
type_repr(PyTypeObject *type)
{
PyObject *mod, *name, *rtn;
char *kind;
mod = type_module(type, NULL);
if (mod == NULL)
PyErr_Clear();
else if (!PyString_Check(mod)) {
Py_DECREF(mod);
mod = NULL;
}
name = type_name(type, NULL);
if (name == NULL)
return NULL;
if (type->tp_flags & Py_TPFLAGS_HEAPTYPE)
kind = "class";
else
kind = "type";
if (mod != NULL && strcmp(PyString_AS_STRING(mod), "__builtin__")) {
rtn = PyString_FromFormat("<%s '%s.%s'>",
kind,
PyString_AS_STRING(mod),
PyString_AS_STRING(name));
}
else
rtn = PyString_FromFormat("<%s '%s'>", kind, type->tp_name);
Py_XDECREF(mod);
Py_DECREF(name);
return rtn;
}
static PyObject *
type_call(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
PyObject *obj;
if (type->tp_new == NULL) {
PyErr_Format(PyExc_TypeError,
"cannot create '%.100s' instances",
type->tp_name);
return NULL;
}
obj = type->tp_new(type, args, kwds);
if (obj != NULL) {
/* Ugly exception: when the call was type(something),
don't call tp_init on the result. */
if (type == &PyType_Type &&
PyTuple_Check(args) && PyTuple_GET_SIZE(args) == 1 &&
(kwds == NULL ||
(PyDict_Check(kwds) && PyDict_Size(kwds) == 0)))
return obj;
/* If the returned object is not an instance of type,
it won't be initialized. */
if (!PyType_IsSubtype(obj->ob_type, type))
return obj;
type = obj->ob_type;
if (PyType_HasFeature(type, Py_TPFLAGS_HAVE_CLASS) &&
type->tp_init != NULL &&
type->tp_init(obj, args, kwds) < 0) {
Py_DECREF(obj);
obj = NULL;
}
}
return obj;
}
PyObject *
PyType_GenericAlloc(PyTypeObject *type, int nitems)
{
PyObject *obj;
const size_t size = _PyObject_VAR_SIZE(type, nitems);
if (PyType_IS_GC(type))
obj = _PyObject_GC_Malloc(size);
else
obj = PyObject_MALLOC(size);
if (obj == NULL)
return PyErr_NoMemory();
memset(obj, '\0', size);
if (type->tp_flags & Py_TPFLAGS_HEAPTYPE)
Py_INCREF(type);
if (type->tp_itemsize == 0)
PyObject_INIT(obj, type);
else
(void) PyObject_INIT_VAR((PyVarObject *)obj, type, nitems);
if (PyType_IS_GC(type))
_PyObject_GC_TRACK(obj);
return obj;
}
PyObject *
PyType_GenericNew(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
return type->tp_alloc(type, 0);
}
/* Helpers for subtyping */
static int
traverse_slots(PyTypeObject *type, PyObject *self, visitproc visit, void *arg)
{
int i, n;
PyMemberDef *mp;
n = type->ob_size;
mp = ((etype *)type)->members;
for (i = 0; i < n; i++, mp++) {
if (mp->type == T_OBJECT_EX) {
char *addr = (char *)self + mp->offset;
PyObject *obj = *(PyObject **)addr;
if (obj != NULL) {
int err = visit(obj, arg);
if (err)
return err;
}
}
}
return 0;
}
static int
subtype_traverse(PyObject *self, visitproc visit, void *arg)
{
PyTypeObject *type, *base;
traverseproc basetraverse;
/* Find the nearest base with a different tp_traverse,
and traverse slots while we're at it */
type = self->ob_type;
base = type;
while ((basetraverse = base->tp_traverse) == subtype_traverse) {
if (base->ob_size) {
int err = traverse_slots(base, self, visit, arg);
if (err)
return err;
}
base = base->tp_base;
assert(base);
}
if (type->tp_dictoffset != base->tp_dictoffset) {
PyObject **dictptr = _PyObject_GetDictPtr(self);
if (dictptr && *dictptr) {
int err = visit(*dictptr, arg);
if (err)
return err;
}
}
if (type->tp_flags & Py_TPFLAGS_HEAPTYPE) {
/* For a heaptype, the instances count as references
to the type. Traverse the type so the collector
can find cycles involving this link. */
int err = visit((PyObject *)type, arg);
if (err)
return err;
}
if (basetraverse)
return basetraverse(self, visit, arg);
return 0;
}
static void
clear_slots(PyTypeObject *type, PyObject *self)
{
int i, n;
PyMemberDef *mp;
n = type->ob_size;
mp = ((etype *)type)->members;
for (i = 0; i < n; i++, mp++) {
if (mp->type == T_OBJECT_EX && !(mp->flags & READONLY)) {
char *addr = (char *)self + mp->offset;
PyObject *obj = *(PyObject **)addr;
if (obj != NULL) {
Py_DECREF(obj);
*(PyObject **)addr = NULL;
}
}
}
}
static int
subtype_clear(PyObject *self)
{
PyTypeObject *type, *base;
inquiry baseclear;
/* Find the nearest base with a different tp_clear
and clear slots while we're at it */
type = self->ob_type;
base = type;
while ((baseclear = base->tp_clear) == subtype_clear) {
if (base->ob_size)
clear_slots(base, self);
base = base->tp_base;
assert(base);
}
/* There's no need to clear the instance dict (if any);
the collector will call its tp_clear handler. */
if (baseclear)
return baseclear(self);
return 0;
}
static PyObject *lookup_maybe(PyObject *, char *, PyObject **);
static int
call_finalizer(PyObject *self)
{
static PyObject *del_str = NULL;
PyObject *del, *res;
PyObject *error_type, *error_value, *error_traceback;
/* Temporarily resurrect the object. */
assert(self->ob_refcnt == 0);
self->ob_refcnt = 1;
/* Save the current exception, if any. */
PyErr_Fetch(&error_type, &error_value, &error_traceback);
/* Execute __del__ method, if any. */
del = lookup_maybe(self, "__del__", &del_str);
if (del != NULL) {
res = PyEval_CallObject(del, NULL);
if (res == NULL)
PyErr_WriteUnraisable(del);
else
Py_DECREF(res);
Py_DECREF(del);
}
/* Restore the saved exception. */
PyErr_Restore(error_type, error_value, error_traceback);
/* Undo the temporary resurrection; can't use DECREF here, it would
* cause a recursive call.
*/
assert(self->ob_refcnt > 0);
if (--self->ob_refcnt == 0)
return 0; /* this is the normal path out */
/* __del__ resurrected it! Make it look like the original Py_DECREF
* never happened.
*/
{
int refcnt = self->ob_refcnt;
_Py_NewReference(self);
self->ob_refcnt = refcnt;
}
assert(_Py_AS_GC(self)->gc.gc_refs != _PyGC_REFS_UNTRACKED);
/* If Py_REF_DEBUG, the original decref dropped _Py_RefTotal, but
* _Py_NewReference bumped it again, so that's a wash.
* If Py_TRACE_REFS, _Py_NewReference re-added self to the object
* chain, so no more to do there either.
* If COUNT_ALLOCS, the original decref bumped tp_frees, and
* _Py_NewReference bumped tp_allocs: both of those need to be
* undone.
*/
#ifdef COUNT_ALLOCS
--self->ob_type->tp_frees;
--self->ob_type->tp_allocs;
#endif
return -1; /* __del__ added a reference; don't delete now */
}
static void
subtype_dealloc(PyObject *self)
{
PyTypeObject *type, *base;
destructor basedealloc;
/* This exists so we can DECREF self->ob_type */
if (call_finalizer(self) < 0)
return;
/* Find the nearest base with a different tp_dealloc
and clear slots while we're at it */
type = self->ob_type;
base = type;
while ((basedealloc = base->tp_dealloc) == subtype_dealloc) {
if (base->ob_size)
clear_slots(base, self);
base = base->tp_base;
assert(base);
}
/* If we added a dict, DECREF it */
if (type->tp_dictoffset && !base->tp_dictoffset) {
PyObject **dictptr = _PyObject_GetDictPtr(self);
if (dictptr != NULL) {
PyObject *dict = *dictptr;
if (dict != NULL) {
Py_DECREF(dict);
*dictptr = NULL;
}
}
}
/* If we added weaklist, we clear it */
if (type->tp_weaklistoffset && !base->tp_weaklistoffset)
PyObject_ClearWeakRefs(self);
/* Finalize GC if the base doesn't do GC and we do */
if (PyType_IS_GC(type) && !PyType_IS_GC(base))
_PyObject_GC_UNTRACK(self);
/* Call the base tp_dealloc() */
assert(basedealloc);
basedealloc(self);
/* Can't reference self beyond this point */
if (type->tp_flags & Py_TPFLAGS_HEAPTYPE) {
Py_DECREF(type);
}
}
static PyTypeObject *solid_base(PyTypeObject *type);
/* type test with subclassing support */
int
PyType_IsSubtype(PyTypeObject *a, PyTypeObject *b)
{
PyObject *mro;
if (!(a->tp_flags & Py_TPFLAGS_HAVE_CLASS))
return b == a || b == &PyBaseObject_Type;
mro = a->tp_mro;
if (mro != NULL) {
/* Deal with multiple inheritance without recursion
by walking the MRO tuple */
int i, n;
assert(PyTuple_Check(mro));
n = PyTuple_GET_SIZE(mro);
for (i = 0; i < n; i++) {
if (PyTuple_GET_ITEM(mro, i) == (PyObject *)b)
return 1;
}
return 0;
}
else {
/* a is not completely initilized yet; follow tp_base */
do {
if (a == b)
return 1;
a = a->tp_base;
} while (a != NULL);
return b == &PyBaseObject_Type;
}
}
/* Internal routines to do a method lookup in the type
without looking in the instance dictionary
(so we can't use PyObject_GetAttr) but still binding
it to the instance. The arguments are the object,
the method name as a C string, and the address of a
static variable used to cache the interned Python string.
Two variants:
- lookup_maybe() returns NULL without raising an exception
when the _PyType_Lookup() call fails;
- lookup_method() always raises an exception upon errors.
*/
static PyObject *
lookup_maybe(PyObject *self, char *attrstr, PyObject **attrobj)
{
PyObject *res;
if (*attrobj == NULL) {
*attrobj = PyString_InternFromString(attrstr);
if (*attrobj == NULL)
return NULL;
}
res = _PyType_Lookup(self->ob_type, *attrobj);
if (res != NULL) {
descrgetfunc f;
if ((f = res->ob_type->tp_descr_get) == NULL)
Py_INCREF(res);
else
res = f(res, self, (PyObject *)(self->ob_type));
}
return res;
}
static PyObject *
lookup_method(PyObject *self, char *attrstr, PyObject **attrobj)
{
PyObject *res = lookup_maybe(self, attrstr, attrobj);
if (res == NULL && !PyErr_Occurred())
PyErr_SetObject(PyExc_AttributeError, *attrobj);
return res;
}
/* A variation of PyObject_CallMethod that uses lookup_method()
instead of PyObject_GetAttrString(). This uses the same convention
as lookup_method to cache the interned name string object. */
static PyObject *
call_method(PyObject *o, char *name, PyObject **nameobj, char *format, ...)
{
va_list va;
PyObject *args, *func = 0, *retval;
va_start(va, format);
func = lookup_maybe(o, name, nameobj);
if (func == NULL) {
va_end(va);
if (!PyErr_Occurred())
PyErr_SetObject(PyExc_AttributeError, *nameobj);
return NULL;
}
if (format && *format)
args = Py_VaBuildValue(format, va);
else
args = PyTuple_New(0);
va_end(va);
if (args == NULL)
return NULL;
assert(PyTuple_Check(args));
retval = PyObject_Call(func, args, NULL);
Py_DECREF(args);
Py_DECREF(func);
return retval;
}
/* Clone of call_method() that returns NotImplemented when the lookup fails. */
static PyObject *
call_maybe(PyObject *o, char *name, PyObject **nameobj, char *format, ...)
{
va_list va;
PyObject *args, *func = 0, *retval;
va_start(va, format);
func = lookup_maybe(o, name, nameobj);
if (func == NULL) {
va_end(va);
if (!PyErr_Occurred()) {
Py_INCREF(Py_NotImplemented);
return Py_NotImplemented;
}
return NULL;
}
if (format && *format)
args = Py_VaBuildValue(format, va);
else
args = PyTuple_New(0);
va_end(va);
if (args == NULL)
return NULL;
assert(PyTuple_Check(args));
retval = PyObject_Call(func, args, NULL);
Py_DECREF(args);
Py_DECREF(func);
return retval;
}
/* Method resolution order algorithm from "Putting Metaclasses to Work"
by Forman and Danforth (Addison-Wesley 1999). */
static int
conservative_merge(PyObject *left, PyObject *right)
{
int left_size;
int right_size;
int i, j, r, ok;
PyObject *temp, *rr;
assert(PyList_Check(left));
assert(PyList_Check(right));
again:
left_size = PyList_GET_SIZE(left);
right_size = PyList_GET_SIZE(right);
for (i = 0; i < left_size; i++) {
for (j = 0; j < right_size; j++) {
if (PyList_GET_ITEM(left, i) ==
PyList_GET_ITEM(right, j)) {
/* found a merge point */
temp = PyList_New(0);
if (temp == NULL)
return -1;
for (r = 0; r < j; r++) {
rr = PyList_GET_ITEM(right, r);
ok = PySequence_Contains(left, rr);
if (ok < 0) {
Py_DECREF(temp);
return -1;
}
if (!ok) {
ok = PyList_Append(temp, rr);
if (ok < 0) {
Py_DECREF(temp);
return -1;
}
}
}
ok = PyList_SetSlice(left, i, i, temp);
Py_DECREF(temp);
if (ok < 0)
return -1;
ok = PyList_SetSlice(right, 0, j+1, NULL);
if (ok < 0)
return -1;
goto again;
}
}
}
return PyList_SetSlice(left, left_size, left_size, right);
}
static int
serious_order_disagreements(PyObject *left, PyObject *right)
{
return 0; /* XXX later -- for now, we cheat: "don't do that" */
}
static int
fill_classic_mro(PyObject *mro, PyObject *cls)
{
PyObject *bases, *base;
int i, n;
assert(PyList_Check(mro));
assert(PyClass_Check(cls));
i = PySequence_Contains(mro, cls);
if (i < 0)
return -1;
if (!i) {
if (PyList_Append(mro, cls) < 0)
return -1;
}
bases = ((PyClassObject *)cls)->cl_bases;
assert(bases && PyTuple_Check(bases));
n = PyTuple_GET_SIZE(bases);
for (i = 0; i < n; i++) {
base = PyTuple_GET_ITEM(bases, i);
if (fill_classic_mro(mro, base) < 0)
return -1;
}
return 0;
}
static PyObject *
classic_mro(PyObject *cls)
{
PyObject *mro;
assert(PyClass_Check(cls));
mro = PyList_New(0);
if (mro != NULL) {
if (fill_classic_mro(mro, cls) == 0)
return mro;
Py_DECREF(mro);
}
return NULL;
}
static PyObject *
mro_implementation(PyTypeObject *type)
{
int i, n, ok;
PyObject *bases, *result;
if(type->tp_dict == NULL) {
if(PyType_Ready(type) < 0)
return NULL;
}
bases = type->tp_bases;
n = PyTuple_GET_SIZE(bases);
result = Py_BuildValue("[O]", (PyObject *)type);
if (result == NULL)
return NULL;
for (i = 0; i < n; i++) {
PyObject *base = PyTuple_GET_ITEM(bases, i);
PyObject *parentMRO;
if (PyType_Check(base))
parentMRO = PySequence_List(
((PyTypeObject*)base)->tp_mro);
else
parentMRO = classic_mro(base);
if (parentMRO == NULL) {
Py_DECREF(result);
return NULL;
}
if (serious_order_disagreements(result, parentMRO)) {
Py_DECREF(result);
return NULL;
}
ok = conservative_merge(result, parentMRO);
Py_DECREF(parentMRO);
if (ok < 0) {
Py_DECREF(result);
return NULL;
}
}
return result;
}
static PyObject *
mro_external(PyObject *self)
{
PyTypeObject *type = (PyTypeObject *)self;
return mro_implementation(type);
}
static int
mro_internal(PyTypeObject *type)
{
PyObject *mro, *result, *tuple;
if (type->ob_type == &PyType_Type) {
result = mro_implementation(type);
}
else {
static PyObject *mro_str;
mro = lookup_method((PyObject *)type, "mro", &mro_str);
if (mro == NULL)
return -1;
result = PyObject_CallObject(mro, NULL);
Py_DECREF(mro);
}
if (result == NULL)
return -1;
tuple = PySequence_Tuple(result);
Py_DECREF(result);
type->tp_mro = tuple;
return 0;
}
/* Calculate the best base amongst multiple base classes.
This is the first one that's on the path to the "solid base". */
static PyTypeObject *
best_base(PyObject *bases)
{
int i, n;
PyTypeObject *base, *winner, *candidate, *base_i;
PyObject *base_proto;
assert(PyTuple_Check(bases));
n = PyTuple_GET_SIZE(bases);
assert(n > 0);
base = NULL;
winner = NULL;
for (i = 0; i < n; i++) {
base_proto = PyTuple_GET_ITEM(bases, i);
if (PyClass_Check(base_proto))
continue;
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)
return NULL;
}
candidate = solid_base(base_i);
if (winner == NULL) {
winner = candidate;
base = base_i;
}
else if (PyType_IsSubtype(winner, candidate))
;
else if (PyType_IsSubtype(candidate, winner)) {
winner = candidate;
base = base_i;
}
else {
PyErr_SetString(
PyExc_TypeError,
"multiple bases have "
"instance lay-out conflict");
return NULL;
}
}
if (base == NULL)
PyErr_SetString(PyExc_TypeError,
"a new-style class can't have only classic bases");
return base;
}
static int
extra_ivars(PyTypeObject *type, PyTypeObject *base)
{
size_t t_size = type->tp_basicsize;
size_t b_size = base->tp_basicsize;
assert(t_size >= b_size); /* Else type smaller than base! */
if (type->tp_itemsize || base->tp_itemsize) {
/* If itemsize is involved, stricter rules */
return t_size != b_size ||
type->tp_itemsize != base->tp_itemsize;
}
if (type->tp_weaklistoffset && base->tp_weaklistoffset == 0 &&
type->tp_weaklistoffset + sizeof(PyObject *) == t_size)
t_size -= sizeof(PyObject *);
if (type->tp_dictoffset && base->tp_dictoffset == 0 &&
type->tp_dictoffset + sizeof(PyObject *) == t_size)
t_size -= sizeof(PyObject *);
return t_size != b_size;
}
static PyTypeObject *
solid_base(PyTypeObject *type)
{
PyTypeObject *base;
if (type->tp_base)
base = solid_base(type->tp_base);
else
base = &PyBaseObject_Type;
if (extra_ivars(type, base))
return type;
else
return base;
}
static void object_dealloc(PyObject *);
static int object_init(PyObject *, PyObject *, PyObject *);
static int update_slot(PyTypeObject *, PyObject *);
static void fixup_slot_dispatchers(PyTypeObject *);
static PyObject *
subtype_dict(PyObject *obj, void *context)
{
PyObject **dictptr = _PyObject_GetDictPtr(obj);
PyObject *dict;
if (dictptr == NULL) {
PyErr_SetString(PyExc_AttributeError,
"This object has no __dict__");
return NULL;
}
dict = *dictptr;
if (dict == NULL)
*dictptr = dict = PyDict_New();
Py_XINCREF(dict);
return dict;
}
static int
subtype_setdict(PyObject *obj, PyObject *value, void *context)
{
PyObject **dictptr = _PyObject_GetDictPtr(obj);
PyObject *dict;
if (dictptr == NULL) {
PyErr_SetString(PyExc_AttributeError,
"This object has no __dict__");
return -1;
}
if (value != NULL && !PyDict_Check(value)) {
PyErr_SetString(PyExc_TypeError,
"__dict__ must be set to a dictionary");
return -1;
}
dict = *dictptr;
Py_XINCREF(value);
*dictptr = value;
Py_XDECREF(dict);
return 0;
}
static PyGetSetDef subtype_getsets[] = {
{"__dict__", subtype_dict, subtype_setdict, NULL},
{0},
};
/* bozo: __getstate__ that raises TypeError */
static PyObject *
bozo_func(PyObject *self, PyObject *args)
{
PyErr_SetString(PyExc_TypeError,
"a class that defines __slots__ without "
"defining __getstate__ cannot be pickled");
return NULL;
}
static PyMethodDef bozo_ml = {"__getstate__", bozo_func, METH_VARARGS};
static PyObject *bozo_obj = NULL;
static int
valid_identifier(PyObject *s)
{
unsigned char *p;
int i, n;
if (!PyString_Check(s)) {
PyErr_SetString(PyExc_TypeError,
"__slots__ must be strings");
return 0;
}
p = (unsigned char *) PyString_AS_STRING(s);
n = PyString_GET_SIZE(s);
/* We must reject an empty name. As a hack, we bump the
length to 1 so that the loop will balk on the trailing \0. */
if (n == 0)
n = 1;
for (i = 0; i < n; i++, p++) {
if (!(i == 0 ? isalpha(*p) : isalnum(*p)) && *p != '_') {
PyErr_SetString(PyExc_TypeError,
"__slots__ must be identifiers");
return 0;
}
}
return 1;
}
static PyObject *
type_new(PyTypeObject *metatype, PyObject *args, PyObject *kwds)
{
PyObject *name, *bases, *dict;
static char *kwlist[] = {"name", "bases", "dict", 0};
static char buffer[256];
PyObject *slots, *tmp, *newslots;
PyTypeObject *type, *base, *tmptype, *winner;
etype *et;
PyMemberDef *mp;
int i, nbases, nslots, slotoffset, add_dict, add_weak;