#include "Python.h"

#include "pycore_object.h" // _PyObject_GET_WEAKREFS_LISTPTR

#define GET_WEAKREFS_LISTPTR(o) \

((PyWeakReference **) _PyObject_GET_WEAKREFS_LISTPTR(o))

#include "clinic/_weakref.c.h"

static Py_ssize_t

_weakref_getweakrefcount_impl(PyObject *module, PyObject *object)

{

PyWeakReference **list;

if (!_PyType_SUPPORTS_WEAKREFS(Py_TYPE(object)))

return 0;

list = GET_WEAKREFS_LISTPTR(object);

return _PyWeakref_GetWeakrefCount(*list);

}

static int

is_dead_weakref(PyObject *value)

{

if (!PyWeakref_Check(value)) {

PyErr_SetString(PyExc_TypeError, "not a weakref");

return -1;

}

return PyWeakref_GET_OBJECT(value) == Py_None;

}

static PyObject *

_weakref__remove_dead_weakref_impl(PyObject *module, PyObject *dct,

PyObject *key)

{

if (_PyDict_DelItemIf(dct, key, is_dead_weakref) < 0) {

if (PyErr_ExceptionMatches(PyExc_KeyError))

/* This function is meant to allow safe weak-value dicts

PyErr_Clear();

else

return NULL;

}

Py_RETURN_NONE;

}

static PyObject *

_weakref_getweakrefs(PyObject *module, PyObject *object)

{

PyObject *result = NULL;

if (_PyType_SUPPORTS_WEAKREFS(Py_TYPE(object))) {

PyWeakReference **list = GET_WEAKREFS_LISTPTR(object);

Py_ssize_t count = _PyWeakref_GetWeakrefCount(*list);

result = PyList_New(count);

if (result != NULL) {

PyWeakReference *current = *list;

Py_ssize_t i;

for (i = 0; i < count; ++i) {

PyList_SET_ITEM(result, i, (PyObject *) current);

Py_INCREF(current);

current = current->wr_next;

}

}

}

else {

result = PyList_New(0);

}

return result;

}

static PyObject *

_weakref_proxy_impl(PyObject *module, PyObject *object, PyObject *callback)

{

return PyWeakref_NewProxy(object, callback);

}

static PyMethodDef

weakref_functions[] = {

_WEAKREF_GETWEAKREFCOUNT_METHODDEF

_WEAKREF__REMOVE_DEAD_WEAKREF_METHODDEF

_WEAKREF_GETWEAKREFS_METHODDEF

_WEAKREF_PROXY_METHODDEF

{NULL, NULL, 0, NULL}

};

static int

weakref_exec(PyObject *module)

{

Py_INCREF(&_PyWeakref_RefType);

if (PyModule_AddObject(module, "ref", (PyObject *) &_PyWeakref_RefType) < 0) {

Py_DECREF(&_PyWeakref_RefType);

return -1;

}

Py_INCREF(&_PyWeakref_RefType);

if (PyModule_AddObject(module, "ReferenceType",

(PyObject *) &_PyWeakref_RefType) < 0) {

Py_DECREF(&_PyWeakref_RefType);

return -1;

}

Py_INCREF(&_PyWeakref_ProxyType);

if (PyModule_AddObject(module, "ProxyType",

(PyObject *) &_PyWeakref_ProxyType) < 0) {

Py_DECREF(&_PyWeakref_ProxyType);

return -1;

}

Py_INCREF(&_PyWeakref_CallableProxyType);

if (PyModule_AddObject(module, "CallableProxyType",

(PyObject *) &_PyWeakref_CallableProxyType) < 0) {

Py_DECREF(&_PyWeakref_CallableProxyType);

return -1;

}

return 0;

}

static struct PyModuleDef_Slot weakref_slots[] = {

{Py_mod_exec, weakref_exec},

{0, NULL}

};

static struct PyModuleDef weakrefmodule = {

PyModuleDef_HEAD_INIT,

"_weakref",

"Weak-reference support module.",

0,

weakref_functions,

weakref_slots,

NULL,

NULL,

NULL

};

PyInit__weakref(void)

{

return PyModuleDef_Init(&weakrefmodule);

}