cpython/Objects/classobject.c

664 lines
19 KiB
C

/* Class object implementation (dead now except for methods) */
#include "Python.h"
#include "pycore_object.h"
#include "pycore_pymem.h"
#include "pycore_pystate.h"
#include "structmember.h"
#define TP_DESCR_GET(t) ((t)->tp_descr_get)
/* Free list for method objects to safe malloc/free overhead
* The im_self element is used to chain the elements.
*/
static PyMethodObject *free_list;
static int numfree = 0;
#ifndef PyMethod_MAXFREELIST
#define PyMethod_MAXFREELIST 256
#endif
_Py_IDENTIFIER(__name__);
_Py_IDENTIFIER(__qualname__);
PyObject *
PyMethod_Function(PyObject *im)
{
if (!PyMethod_Check(im)) {
PyErr_BadInternalCall();
return NULL;
}
return ((PyMethodObject *)im)->im_func;
}
PyObject *
PyMethod_Self(PyObject *im)
{
if (!PyMethod_Check(im)) {
PyErr_BadInternalCall();
return NULL;
}
return ((PyMethodObject *)im)->im_self;
}
static PyObject *
method_vectorcall(PyObject *method, PyObject *const *args,
size_t nargsf, PyObject *kwnames)
{
assert(Py_TYPE(method) == &PyMethod_Type);
PyObject *self, *func, *result;
self = PyMethod_GET_SELF(method);
func = PyMethod_GET_FUNCTION(method);
Py_ssize_t nargs = PyVectorcall_NARGS(nargsf);
if (nargsf & PY_VECTORCALL_ARGUMENTS_OFFSET) {
/* PY_VECTORCALL_ARGUMENTS_OFFSET is set, so we are allowed to mutate the vector */
PyObject **newargs = (PyObject**)args - 1;
nargs += 1;
PyObject *tmp = newargs[0];
newargs[0] = self;
result = _PyObject_Vectorcall(func, newargs, nargs, kwnames);
newargs[0] = tmp;
}
else {
Py_ssize_t nkwargs = (kwnames == NULL) ? 0 : PyTuple_GET_SIZE(kwnames);
Py_ssize_t totalargs = nargs + nkwargs;
if (totalargs == 0) {
return _PyObject_Vectorcall(func, &self, 1, NULL);
}
PyObject *newargs_stack[_PY_FASTCALL_SMALL_STACK];
PyObject **newargs;
if (totalargs <= (Py_ssize_t)Py_ARRAY_LENGTH(newargs_stack) - 1) {
newargs = newargs_stack;
}
else {
newargs = PyMem_Malloc((totalargs+1) * sizeof(PyObject *));
if (newargs == NULL) {
PyErr_NoMemory();
return NULL;
}
}
/* use borrowed references */
newargs[0] = self;
/* bpo-37138: since totalargs > 0, it's impossible that args is NULL.
* We need this, since calling memcpy() with a NULL pointer is
* undefined behaviour. */
assert(args != NULL);
memcpy(newargs + 1, args, totalargs * sizeof(PyObject *));
result = _PyObject_Vectorcall(func, newargs, nargs+1, kwnames);
if (newargs != newargs_stack) {
PyMem_Free(newargs);
}
}
return result;
}
/* Method objects are used for bound instance methods returned by
instancename.methodname. ClassName.methodname returns an ordinary
function.
*/
PyObject *
PyMethod_New(PyObject *func, PyObject *self)
{
PyMethodObject *im;
if (self == NULL) {
PyErr_BadInternalCall();
return NULL;
}
im = free_list;
if (im != NULL) {
free_list = (PyMethodObject *)(im->im_self);
(void)PyObject_INIT(im, &PyMethod_Type);
numfree--;
}
else {
im = PyObject_GC_New(PyMethodObject, &PyMethod_Type);
if (im == NULL)
return NULL;
}
im->im_weakreflist = NULL;
Py_INCREF(func);
im->im_func = func;
Py_INCREF(self);
im->im_self = self;
im->vectorcall = method_vectorcall;
_PyObject_GC_TRACK(im);
return (PyObject *)im;
}
static PyObject *
method_reduce(PyMethodObject *im, PyObject *Py_UNUSED(ignored))
{
PyObject *self = PyMethod_GET_SELF(im);
PyObject *func = PyMethod_GET_FUNCTION(im);
PyObject *funcname;
_Py_IDENTIFIER(getattr);
funcname = _PyObject_GetAttrId(func, &PyId___name__);
if (funcname == NULL) {
return NULL;
}
return Py_BuildValue("N(ON)", _PyEval_GetBuiltinId(&PyId_getattr),
self, funcname);
}
static PyMethodDef method_methods[] = {
{"__reduce__", (PyCFunction)method_reduce, METH_NOARGS, NULL},
{NULL, NULL}
};
/* Descriptors for PyMethod attributes */
/* im_func and im_self are stored in the PyMethod object */
#define MO_OFF(x) offsetof(PyMethodObject, x)
static PyMemberDef method_memberlist[] = {
{"__func__", T_OBJECT, MO_OFF(im_func), READONLY|RESTRICTED,
"the function (or other callable) implementing a method"},
{"__self__", T_OBJECT, MO_OFF(im_self), READONLY|RESTRICTED,
"the instance to which a method is bound"},
{NULL} /* Sentinel */
};
/* Christian Tismer argued convincingly that method attributes should
(nearly) always override function attributes.
The one exception is __doc__; there's a default __doc__ which
should only be used for the class, not for instances */
static PyObject *
method_get_doc(PyMethodObject *im, void *context)
{
static PyObject *docstr;
if (docstr == NULL) {
docstr= PyUnicode_InternFromString("__doc__");
if (docstr == NULL)
return NULL;
}
return PyObject_GetAttr(im->im_func, docstr);
}
static PyGetSetDef method_getset[] = {
{"__doc__", (getter)method_get_doc, NULL, NULL},
{0}
};
static PyObject *
method_getattro(PyObject *obj, PyObject *name)
{
PyMethodObject *im = (PyMethodObject *)obj;
PyTypeObject *tp = obj->ob_type;
PyObject *descr = NULL;
{
if (tp->tp_dict == NULL) {
if (PyType_Ready(tp) < 0)
return NULL;
}
descr = _PyType_Lookup(tp, name);
}
if (descr != NULL) {
descrgetfunc f = TP_DESCR_GET(descr->ob_type);
if (f != NULL)
return f(descr, obj, (PyObject *)obj->ob_type);
else {
Py_INCREF(descr);
return descr;
}
}
return PyObject_GetAttr(im->im_func, name);
}
PyDoc_STRVAR(method_doc,
"method(function, instance)\n\
\n\
Create a bound instance method object.");
static PyObject *
method_new(PyTypeObject* type, PyObject* args, PyObject *kw)
{
PyObject *func;
PyObject *self;
if (!_PyArg_NoKeywords("method", kw))
return NULL;
if (!PyArg_UnpackTuple(args, "method", 2, 2,
&func, &self))
return NULL;
if (!PyCallable_Check(func)) {
PyErr_SetString(PyExc_TypeError,
"first argument must be callable");
return NULL;
}
if (self == NULL || self == Py_None) {
PyErr_SetString(PyExc_TypeError,
"self must not be None");
return NULL;
}
return PyMethod_New(func, self);
}
static void
method_dealloc(PyMethodObject *im)
{
_PyObject_GC_UNTRACK(im);
if (im->im_weakreflist != NULL)
PyObject_ClearWeakRefs((PyObject *)im);
Py_DECREF(im->im_func);
Py_XDECREF(im->im_self);
if (numfree < PyMethod_MAXFREELIST) {
im->im_self = (PyObject *)free_list;
free_list = im;
numfree++;
}
else {
PyObject_GC_Del(im);
}
}
static PyObject *
method_richcompare(PyObject *self, PyObject *other, int op)
{
PyMethodObject *a, *b;
PyObject *res;
int eq;
if ((op != Py_EQ && op != Py_NE) ||
!PyMethod_Check(self) ||
!PyMethod_Check(other))
{
Py_RETURN_NOTIMPLEMENTED;
}
a = (PyMethodObject *)self;
b = (PyMethodObject *)other;
eq = PyObject_RichCompareBool(a->im_func, b->im_func, Py_EQ);
if (eq == 1) {
eq = (a->im_self == b->im_self);
}
else if (eq < 0)
return NULL;
if (op == Py_EQ)
res = eq ? Py_True : Py_False;
else
res = eq ? Py_False : Py_True;
Py_INCREF(res);
return res;
}
static PyObject *
method_repr(PyMethodObject *a)
{
PyObject *self = a->im_self;
PyObject *func = a->im_func;
PyObject *funcname, *result;
const char *defname = "?";
if (_PyObject_LookupAttrId(func, &PyId___qualname__, &funcname) < 0 ||
(funcname == NULL &&
_PyObject_LookupAttrId(func, &PyId___name__, &funcname) < 0))
{
return NULL;
}
if (funcname != NULL && !PyUnicode_Check(funcname)) {
Py_DECREF(funcname);
funcname = NULL;
}
/* XXX Shouldn't use repr()/%R here! */
result = PyUnicode_FromFormat("<bound method %V of %R>",
funcname, defname, self);
Py_XDECREF(funcname);
return result;
}
static Py_hash_t
method_hash(PyMethodObject *a)
{
Py_hash_t x, y;
x = _Py_HashPointer(a->im_self);
y = PyObject_Hash(a->im_func);
if (y == -1)
return -1;
x = x ^ y;
if (x == -1)
x = -2;
return x;
}
static int
method_traverse(PyMethodObject *im, visitproc visit, void *arg)
{
Py_VISIT(im->im_func);
Py_VISIT(im->im_self);
return 0;
}
static PyObject *
method_descr_get(PyObject *meth, PyObject *obj, PyObject *cls)
{
Py_INCREF(meth);
return meth;
}
PyTypeObject PyMethod_Type = {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
"method",
sizeof(PyMethodObject),
0,
(destructor)method_dealloc, /* tp_dealloc */
offsetof(PyMethodObject, vectorcall), /* tp_vectorcall_offset */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_as_async */
(reprfunc)method_repr, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
(hashfunc)method_hash, /* tp_hash */
PyVectorcall_Call, /* tp_call */
0, /* tp_str */
method_getattro, /* tp_getattro */
PyObject_GenericSetAttr, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC |
_Py_TPFLAGS_HAVE_VECTORCALL, /* tp_flags */
method_doc, /* tp_doc */
(traverseproc)method_traverse, /* tp_traverse */
0, /* tp_clear */
method_richcompare, /* tp_richcompare */
offsetof(PyMethodObject, im_weakreflist), /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
method_methods, /* tp_methods */
method_memberlist, /* tp_members */
method_getset, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
method_descr_get, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */
method_new, /* tp_new */
};
/* Clear out the free list */
int
PyMethod_ClearFreeList(void)
{
int freelist_size = numfree;
while (free_list) {
PyMethodObject *im = free_list;
free_list = (PyMethodObject *)(im->im_self);
PyObject_GC_Del(im);
numfree--;
}
assert(numfree == 0);
return freelist_size;
}
void
PyMethod_Fini(void)
{
(void)PyMethod_ClearFreeList();
}
/* Print summary info about the state of the optimized allocator */
void
_PyMethod_DebugMallocStats(FILE *out)
{
_PyDebugAllocatorStats(out,
"free PyMethodObject",
numfree, sizeof(PyMethodObject));
}
/* ------------------------------------------------------------------------
* instance method
*/
PyObject *
PyInstanceMethod_New(PyObject *func) {
PyInstanceMethodObject *method;
method = PyObject_GC_New(PyInstanceMethodObject,
&PyInstanceMethod_Type);
if (method == NULL) return NULL;
Py_INCREF(func);
method->func = func;
_PyObject_GC_TRACK(method);
return (PyObject *)method;
}
PyObject *
PyInstanceMethod_Function(PyObject *im)
{
if (!PyInstanceMethod_Check(im)) {
PyErr_BadInternalCall();
return NULL;
}
return PyInstanceMethod_GET_FUNCTION(im);
}
#define IMO_OFF(x) offsetof(PyInstanceMethodObject, x)
static PyMemberDef instancemethod_memberlist[] = {
{"__func__", T_OBJECT, IMO_OFF(func), READONLY|RESTRICTED,
"the function (or other callable) implementing a method"},
{NULL} /* Sentinel */
};
static PyObject *
instancemethod_get_doc(PyObject *self, void *context)
{
static PyObject *docstr;
if (docstr == NULL) {
docstr = PyUnicode_InternFromString("__doc__");
if (docstr == NULL)
return NULL;
}
return PyObject_GetAttr(PyInstanceMethod_GET_FUNCTION(self), docstr);
}
static PyGetSetDef instancemethod_getset[] = {
{"__doc__", (getter)instancemethod_get_doc, NULL, NULL},
{0}
};
static PyObject *
instancemethod_getattro(PyObject *self, PyObject *name)
{
PyTypeObject *tp = self->ob_type;
PyObject *descr = NULL;
if (tp->tp_dict == NULL) {
if (PyType_Ready(tp) < 0)
return NULL;
}
descr = _PyType_Lookup(tp, name);
if (descr != NULL) {
descrgetfunc f = TP_DESCR_GET(descr->ob_type);
if (f != NULL)
return f(descr, self, (PyObject *)self->ob_type);
else {
Py_INCREF(descr);
return descr;
}
}
return PyObject_GetAttr(PyInstanceMethod_GET_FUNCTION(self), name);
}
static void
instancemethod_dealloc(PyObject *self) {
_PyObject_GC_UNTRACK(self);
Py_DECREF(PyInstanceMethod_GET_FUNCTION(self));
PyObject_GC_Del(self);
}
static int
instancemethod_traverse(PyObject *self, visitproc visit, void *arg) {
Py_VISIT(PyInstanceMethod_GET_FUNCTION(self));
return 0;
}
static PyObject *
instancemethod_call(PyObject *self, PyObject *arg, PyObject *kw)
{
return PyObject_Call(PyMethod_GET_FUNCTION(self), arg, kw);
}
static PyObject *
instancemethod_descr_get(PyObject *descr, PyObject *obj, PyObject *type) {
PyObject *func = PyInstanceMethod_GET_FUNCTION(descr);
if (obj == NULL) {
Py_INCREF(func);
return func;
}
else
return PyMethod_New(func, obj);
}
static PyObject *
instancemethod_richcompare(PyObject *self, PyObject *other, int op)
{
PyInstanceMethodObject *a, *b;
PyObject *res;
int eq;
if ((op != Py_EQ && op != Py_NE) ||
!PyInstanceMethod_Check(self) ||
!PyInstanceMethod_Check(other))
{
Py_RETURN_NOTIMPLEMENTED;
}
a = (PyInstanceMethodObject *)self;
b = (PyInstanceMethodObject *)other;
eq = PyObject_RichCompareBool(a->func, b->func, Py_EQ);
if (eq < 0)
return NULL;
if (op == Py_EQ)
res = eq ? Py_True : Py_False;
else
res = eq ? Py_False : Py_True;
Py_INCREF(res);
return res;
}
static PyObject *
instancemethod_repr(PyObject *self)
{
PyObject *func = PyInstanceMethod_Function(self);
PyObject *funcname, *result;
const char *defname = "?";
if (func == NULL) {
PyErr_BadInternalCall();
return NULL;
}
if (_PyObject_LookupAttrId(func, &PyId___name__, &funcname) < 0) {
return NULL;
}
if (funcname != NULL && !PyUnicode_Check(funcname)) {
Py_DECREF(funcname);
funcname = NULL;
}
result = PyUnicode_FromFormat("<instancemethod %V at %p>",
funcname, defname, self);
Py_XDECREF(funcname);
return result;
}
/*
static long
instancemethod_hash(PyObject *self)
{
long x, y;
x = (long)self;
y = PyObject_Hash(PyInstanceMethod_GET_FUNCTION(self));
if (y == -1)
return -1;
x = x ^ y;
if (x == -1)
x = -2;
return x;
}
*/
PyDoc_STRVAR(instancemethod_doc,
"instancemethod(function)\n\
\n\
Bind a function to a class.");
static PyObject *
instancemethod_new(PyTypeObject* type, PyObject* args, PyObject *kw)
{
PyObject *func;
if (!_PyArg_NoKeywords("instancemethod", kw))
return NULL;
if (!PyArg_UnpackTuple(args, "instancemethod", 1, 1, &func))
return NULL;
if (!PyCallable_Check(func)) {
PyErr_SetString(PyExc_TypeError,
"first argument must be callable");
return NULL;
}
return PyInstanceMethod_New(func);
}
PyTypeObject PyInstanceMethod_Type = {
PyVarObject_HEAD_INIT(&PyType_Type, 0)
"instancemethod", /* tp_name */
sizeof(PyInstanceMethodObject), /* tp_basicsize */
0, /* tp_itemsize */
instancemethod_dealloc, /* tp_dealloc */
0, /* tp_vectorcall_offset */
0, /* tp_getattr */
0, /* tp_setattr */
0, /* tp_as_async */
(reprfunc)instancemethod_repr, /* tp_repr */
0, /* tp_as_number */
0, /* tp_as_sequence */
0, /* tp_as_mapping */
0, /*(hashfunc)instancemethod_hash, tp_hash */
instancemethod_call, /* tp_call */
0, /* tp_str */
instancemethod_getattro, /* tp_getattro */
PyObject_GenericSetAttr, /* tp_setattro */
0, /* tp_as_buffer */
Py_TPFLAGS_DEFAULT
| Py_TPFLAGS_HAVE_GC, /* tp_flags */
instancemethod_doc, /* tp_doc */
instancemethod_traverse, /* tp_traverse */
0, /* tp_clear */
instancemethod_richcompare, /* tp_richcompare */
0, /* tp_weaklistoffset */
0, /* tp_iter */
0, /* tp_iternext */
0, /* tp_methods */
instancemethod_memberlist, /* tp_members */
instancemethod_getset, /* tp_getset */
0, /* tp_base */
0, /* tp_dict */
instancemethod_descr_get, /* tp_descr_get */
0, /* tp_descr_set */
0, /* tp_dictoffset */
0, /* tp_init */
0, /* tp_alloc */
instancemethod_new, /* tp_new */
};