mirrors/cpython
1
0
Fork 0
mirror of https://github.com/python/cpython.git synced 2025-07-23 03:05:38 +00:00
Code Issues Projects Releases Packages Wiki Activity Actions 15

Another step in the right direction: when a new class's attribute

Browse source 
corresponding to a dispatch slot (e.g. __getitem__ or __add__) is set,
calculate the proper dispatch slot and propagate the change to all
subclasses.  Because of multiple inheritance, there's no easy way to
avoid always recursing down the tree of subclasses.  Who cares?

(There's more to do, but this works.  There's also a test for this now.)
This commit is contained in:
Guido van Rossum 2001-10-11 18:33:53 +00:00
parent 9e4ca10ce4
commit 875eeaa193
2 changed files with 195 additions and 49 deletions
Download patch file Download diff file Expand all files Collapse all files

149
Objects/typeobject.c
View file

@ -676,7 +676,7 @@ solid_base(PyTypeObject *type)
staticforward void object_dealloc(PyObject *);
staticforward int object_init(PyObject *, PyObject *, PyObject *);
staticforward int update_slot(PyTypeObject *, PyObject *, PyObject *);
staticforward int update_slot(PyTypeObject *, PyObject *);
staticforward void fixup_slot_dispatchers(PyTypeObject *);
static PyObject *
@ -1107,7 +1107,7 @@ type_setattro(PyTypeObject *type, PyObject *name, PyObject *value)
if (type->tp_flags & Py_TPFLAGS_DYNAMICTYPE) {
if (PyObject_GenericSetAttr((PyObject *)type, name, value) < 0)
return -1;
return update_slot(type, name, value);
return update_slot(type, name);
}
PyErr_SetString(PyExc_TypeError, "can't set static type attributes");
return -1;
@ -3679,6 +3679,7 @@ typedef struct {
int offset;
void *function;
wrapperfunc wrapper;
PyObject *name_strobj;
} slotdef;
#undef TPSLOT
@ -3797,9 +3798,7 @@ static slotdef slotdefs[] = {
slot_nb_inplace_true_divide, wrap_binaryfunc),
TPSLOT("__str__", tp_str, slot_tp_str, wrap_unaryfunc),
TPSLOT("__str__", tp_print, NULL, NULL),
TPSLOT("__repr__", tp_repr, slot_tp_repr, wrap_unaryfunc),
TPSLOT("__repr__", tp_print, NULL, NULL),
TPSLOT("__cmp__", tp_compare, _PyObject_SlotCompare, wrap_cmpfunc),
TPSLOT("__hash__", tp_hash, slot_tp_hash, wrap_hashfunc),
TPSLOT("__call__", tp_call, slot_tp_call, wrap_call),
@ -3827,35 +3826,6 @@ static slotdef slotdefs[] = {
{NULL}
};
static int
update_slot(PyTypeObject *type, PyObject *name, PyObject *value)
{
char *s;
int n;
slotdef *p;
void **ptr;
assert(type->tp_flags & Py_TPFLAGS_HEAPTYPE);
if (value == NULL)
return 0; /* Can't unset a slot */
s = PyString_AsString(name);
n = PyString_Size(name);
if (s == NULL || n < 0) {
/* Shouldn't happen, but can't be bothered */
PyErr_Clear();
return 0;
}
if (!(s[0] == '_' && s[1] == '_' && s[n-1] == '_' && s[n-2] == '_'))
return 0;
for (p = slotdefs; p->name; p++) {
if (!strcmp(p->name, s)) {
ptr = (void **) ((char *)type + p->offset);
*ptr = p->function;
}
}
return 0;
}
static void **
slotptr(PyTypeObject *type, int offset)
{
@ -3883,6 +3853,119 @@ slotptr(PyTypeObject *type, int offset)
return (void **)ptr;
}
staticforward int recurse_down_subclasses(PyTypeObject *type, int offset);
static int
update_one_slot(PyTypeObject *type, int offset)
{
slotdef *p;
PyObject *descr;
PyWrapperDescrObject *d;
void *generic = NULL, *specific = NULL;
int use_generic = 0;
void **ptr;
for (p = slotdefs; p->name; p++) {
if (p->offset != offset)
continue;
descr = _PyType_Lookup(type, p->name_strobj);
if (descr == NULL)
continue;
ptr = slotptr(type, p->offset);
if (ptr == NULL)
continue;
generic = p->function;
if (descr->ob_type == &PyWrapperDescr_Type) {
d = (PyWrapperDescrObject *)descr;
if (d->d_base->wrapper == p->wrapper &&
PyType_IsSubtype(type, d->d_type)) {
if (specific == NULL ||
specific == d->d_wrapped)
specific = d->d_wrapped;
else
use_generic = 1;
}
}
else
use_generic = 1;
if (specific && !use_generic)
*ptr = specific;
else
*ptr = generic;
}
if (recurse_down_subclasses(type, offset) < 0)
return -1;
return 0;
}
static int
recurse_down_subclasses(PyTypeObject *type, int offset)
{
PyTypeObject *subclass;
PyObject *ref, *subclasses;
int i, n;
subclasses = type->tp_subclasses;
if (subclasses == NULL)
return 0;
assert(PyList_Check(subclasses));
n = PyList_GET_SIZE(subclasses);
for (i = 0; i < n; i++) {
ref = PyList_GET_ITEM(subclasses, i);
assert(PyWeakref_CheckRef(ref));
subclass = (PyTypeObject *)PyWeakref_GET_OBJECT(ref);
if (subclass == NULL)
continue;
assert(PyType_Check(subclass));
if (update_one_slot(subclass, offset) < 0)
return -1;
}
return 0;
}
static void
init_name_strobj(void)
{
slotdef *p;
static int initialized = 0;
if (initialized)
return;
for (p = slotdefs; p->name; p++) {
p->name_strobj = PyString_InternFromString(p->name);
if (!p->name_strobj)
Py_FatalError("XXX ouch");
}
initialized = 1;
}
static void
collect_offsets(PyObject *name, int offsets[])
{
slotdef *p;
init_name_strobj();
for (p = slotdefs; p->name; p++) {
if (name == p->name_strobj)
*offsets++ = p->offset;
}
*offsets = 0;
}
static int
update_slot(PyTypeObject *type, PyObject *name)
{
int offsets[10];
int *ip;
collect_offsets(name, offsets);
for (ip = offsets; *ip; ip++) {
if (update_one_slot(type, *ip) < 0)
return -1;
}
return 0;
}
static void
fixup_slot_dispatchers(PyTypeObject *type)
{