frameobject.c

/* Frame object implementation */

#include "Python.h"
#include "pycore_cell.h"          // PyCell_GetRef()
#include "pycore_ceval.h"         // _PyEval_SetOpcodeTrace()
#include "pycore_code.h"          // CO_FAST_LOCAL
#include "pycore_dict.h"          // _PyDict_LoadBuiltinsFromGlobals()
#include "pycore_frame.h"         // PyFrameObject
#include "pycore_function.h"      // _PyFunction_FromConstructor()
#include "pycore_genobject.h"     // _PyGen_GetGeneratorFromFrame()
#include "pycore_interpframe.h"   // _PyFrame_GetLocalsArray()
#include "pycore_modsupport.h"    // _PyArg_CheckPositional()
#include "pycore_object.h"        // _PyObject_GC_UNTRACK()
#include "pycore_opcode_metadata.h" // _PyOpcode_Caches
#include "pycore_optimizer.h"     // _Py_Executors_InvalidateDependency()
#include "pycore_unicodeobject.h" // _PyUnicode_Equal()

#include "frameobject.h"          // PyFrameLocalsProxyObject
#include "opcode.h"               // EXTENDED_ARG

#include "clinic/frameobject.c.h"


#define PyFrameObject_CAST(op)  \
    (assert(PyObject_TypeCheck((op), &PyFrame_Type)), (PyFrameObject *)(op))

#define PyFrameLocalsProxyObject_CAST(op)                           \
    (                                                               \
        assert(PyObject_TypeCheck((op), &PyFrameLocalsProxy_Type)), \
        (PyFrameLocalsProxyObject *)(op)                            \
    )

#define OFF(x) offsetof(PyFrameObject, x)

/*[clinic input]
class frame "PyFrameObject *" "&PyFrame_Type"
[clinic start generated code]*/
/*[clinic end generated code: output=da39a3ee5e6b4b0d input=2d1dbf2e06cf351f]*/


// Returns new reference or NULL
static PyObject *
framelocalsproxy_getval(_PyInterpreterFrame *frame, PyCodeObject *co, int i)
{
    _PyStackRef *fast = _PyFrame_GetLocalsArray(frame);
    _PyLocals_Kind kind = _PyLocals_GetKind(co->co_localspluskinds, i);

    PyObject *value = PyStackRef_AsPyObjectBorrow(fast[i]);
    PyObject *cell = NULL;

    if (value == NULL) {
        return NULL;
    }

    if (kind == CO_FAST_FREE || kind & CO_FAST_CELL) {
        // The cell was set when the frame was created from
        // the function's closure.
        // GH-128396: With PEP 709, it's possible to have a fast variable in
        // an inlined comprehension that has the same name as the cell variable
        // in the frame, where the `kind` obtained from frame can not guarantee
        // that the variable is a cell.
        // If the variable is not a cell, we are okay with it and we can simply
        // return the value.
        if (PyCell_Check(value)) {
            cell = value;
        }
    }

    if (cell != NULL) {
        value = PyCell_GetRef((PyCellObject *)cell);
    }
    else {
        Py_XINCREF(value);
    }

    if (value == NULL) {
        return NULL;
    }

    return value;
}

static bool
framelocalsproxy_hasval(_PyInterpreterFrame *frame, PyCodeObject *co, int i)
{
    PyObject *value = framelocalsproxy_getval(frame, co, i);
    if (value == NULL) {
        return false;
    }
    Py_DECREF(value);
    return true;
}

static int
framelocalsproxy_getkeyindex(PyFrameObject *frame, PyObject *key, bool read, PyObject **value_ptr)
{
    /*
     * Returns -2 (!) if an error occurred; exception will be set.
     * Returns the fast locals index of the key on success:
     *   - if read == true, returns the index if the value is not NULL
     *   - if read == false, returns the index if the value is not hidden
     * Otherwise returns -1.
     *
     * If read == true and value_ptr is not NULL, *value_ptr is set to
     * the value of the key if it is found (with a new reference).
     */

    // value_ptr should only be given if we are reading the value
    assert(read || value_ptr == NULL);

    PyCodeObject *co = _PyFrame_GetCode(frame->f_frame);

    // Ensure that the key is hashable.
    Py_hash_t key_hash = PyObject_Hash(key);
    if (key_hash == -1) {
        return -2;
    }

    bool found = false;

    // We do 2 loops here because it's highly possible the key is interned
    // and we can do a pointer comparison.
    for (int i = 0; i < co->co_nlocalsplus; i++) {
        PyObject *name = PyTuple_GET_ITEM(co->co_localsplusnames, i);
        if (name == key) {
            if (read) {
                PyObject *value = framelocalsproxy_getval(frame->f_frame, co, i);
                if (value != NULL) {
                    if (value_ptr != NULL) {
                        *value_ptr = value;
                    }
                    else {
                        Py_DECREF(value);
                    }
                    return i;
                }
            } else {
                if (!(_PyLocals_GetKind(co->co_localspluskinds, i) & CO_FAST_HIDDEN)) {
                    return i;
                }
            }
            found = true;
        }
    }
    if (found) {
        // This is an attempt to read an unset local variable or
        // write to a variable that is hidden from regular write operations
        return -1;
    }
    // This is unlikely, but we need to make sure. This means the key
    // is not interned.
    for (int i = 0; i < co->co_nlocalsplus; i++) {
        PyObject *name = PyTuple_GET_ITEM(co->co_localsplusnames, i);
        Py_hash_t name_hash = PyObject_Hash(name);
        assert(name_hash != -1);  // keys are exact unicode
        if (name_hash != key_hash) {
            continue;
        }
        int same = PyObject_RichCompareBool(name, key, Py_EQ);
        if (same < 0) {
            return -2;
        }
        if (same) {
            if (read) {
                PyObject *value = framelocalsproxy_getval(frame->f_frame, co, i);
                if (value != NULL) {
                    if (value_ptr != NULL) {
                        *value_ptr = value;
                    }
                    else {
                        Py_DECREF(value);
                    }
                    return i;
                }
            } else {
                if (!(_PyLocals_GetKind(co->co_localspluskinds, i) & CO_FAST_HIDDEN)) {
                    return i;
                }
            }
        }
    }

    return -1;
}

static PyObject *
framelocalsproxy_getitem(PyObject *self, PyObject *key)
{
    PyFrameObject *frame = PyFrameLocalsProxyObject_CAST(self)->frame;
    PyObject *value = NULL;

    int i = framelocalsproxy_getkeyindex(frame, key, true, &value);
    if (i == -2) {
        return NULL;
    }
    if (i >= 0) {
        assert(value != NULL);
        return value;
    }
    assert(value == NULL);

    // Okay not in the fast locals, try extra locals

    PyObject *extra = frame->f_extra_locals;
    if (extra != NULL) {
        if (PyDict_GetItemRef(extra, key, &value) < 0) {
            return NULL;
        }
        if (value != NULL) {
            return value;
        }
    }

    PyErr_Format(PyExc_KeyError, "local variable '%R' is not defined", key);
    return NULL;
}

static int
add_overwritten_fast_local(PyFrameObject *frame, PyObject *obj)
{
    Py_ssize_t new_size;
    if (frame->f_overwritten_fast_locals == NULL) {
        new_size = 1;
    }
    else {
        Py_ssize_t size = PyTuple_Size(frame->f_overwritten_fast_locals);
        if (size == -1) {
            return -1;
        }
        new_size = size + 1;
    }
    PyObject *new_tuple = PyTuple_New(new_size);
    if (new_tuple == NULL) {
        return -1;
    }
    for (Py_ssize_t i = 0; i < new_size - 1; i++) {
        PyObject *o = PyTuple_GET_ITEM(frame->f_overwritten_fast_locals, i);
        PyTuple_SET_ITEM(new_tuple, i, Py_NewRef(o));
    }
    PyTuple_SET_ITEM(new_tuple, new_size - 1, Py_NewRef(obj));
    Py_XSETREF(frame->f_overwritten_fast_locals, new_tuple);
    return 0;
}

static int
framelocalsproxy_setitem(PyObject *self, PyObject *key, PyObject *value)
{
    /* Merge locals into fast locals */
    PyFrameObject *frame = PyFrameLocalsProxyObject_CAST(self)->frame;
    _PyStackRef *fast = _PyFrame_GetLocalsArray(frame->f_frame);
    PyCodeObject *co = _PyFrame_GetCode(frame->f_frame);

    int i = framelocalsproxy_getkeyindex(frame, key, false, NULL);
    if (i == -2) {
        return -1;
    }
    if (i >= 0) {
        if (value == NULL) {
            PyErr_SetString(PyExc_ValueError, "cannot remove local variables from FrameLocalsProxy");
            return -1;
        }

        _Py_Executors_InvalidateDependency(PyInterpreterState_Get(), co, 1);

        _PyLocals_Kind kind = _PyLocals_GetKind(co->co_localspluskinds, i);
        _PyStackRef oldvalue = fast[i];
        PyObject *cell = NULL;
        if (kind == CO_FAST_FREE) {
            // The cell was set when the frame was created from
            // the function's closure.
            assert(!PyStackRef_IsNull(oldvalue) && PyCell_Check(PyStackRef_AsPyObjectBorrow(oldvalue)));
            cell = PyStackRef_AsPyObjectBorrow(oldvalue);
        } else if (kind & CO_FAST_CELL && !PyStackRef_IsNull(oldvalue)) {
            PyObject *as_obj = PyStackRef_AsPyObjectBorrow(oldvalue);
            if (PyCell_Check(as_obj)) {
                cell = as_obj;
            }
        }
        if (cell != NULL) {
            Py_XINCREF(value);
            PyCell_SetTakeRef((PyCellObject *)cell, value);
        } else if (value != PyStackRef_AsPyObjectBorrow(oldvalue)) {
            PyObject *old_obj = PyStackRef_AsPyObjectBorrow(fast[i]);
            if (old_obj != NULL && !_Py_IsImmortal(old_obj)) {
                if (add_overwritten_fast_local(frame, old_obj) < 0) {
                    return -1;
                }
                PyStackRef_CLOSE(fast[i]);
            }
            fast[i] = PyStackRef_FromPyObjectNew(value);
        }
        return 0;
    }

    // Okay not in the fast locals, try extra locals

    PyObject *extra = frame->f_extra_locals;

    if (extra == NULL) {
        if (value == NULL) {
            _PyErr_SetKeyError(key);
            return -1;
        }
        extra = PyDict_New();
        if (extra == NULL) {
            return -1;
        }
        frame->f_extra_locals = extra;
    }

    assert(PyDict_Check(extra));

    if (value == NULL) {
        return PyDict_DelItem(extra, key);
    } else {
        return PyDict_SetItem(extra, key, value);
    }
}

static int
framelocalsproxy_merge(PyObject* self, PyObject* other)
{
    if (!PyDict_Check(other) && !PyFrameLocalsProxy_Check(other)) {
        return -1;
    }

    PyObject *keys = PyMapping_Keys(other);
    if (keys == NULL) {
        return -1;
    }

    PyObject *iter = PyObject_GetIter(keys);
    Py_DECREF(keys);
    if (iter == NULL) {
        return -1;
    }

    PyObject *key = NULL;
    PyObject *value = NULL;

    while ((key = PyIter_Next(iter)) != NULL) {
        value = PyObject_GetItem(other, key);
        if (value == NULL) {
            Py_DECREF(key);
            Py_DECREF(iter);
            return -1;
        }

        if (framelocalsproxy_setitem(self, key, value) < 0) {
            Py_DECREF(key);
            Py_DECREF(value);
            Py_DECREF(iter);
            return -1;
        }

        Py_DECREF(key);
        Py_DECREF(value);
    }

    Py_DECREF(iter);

    if (PyErr_Occurred()) {
        return -1;
    }

    return 0;
}

static PyObject *
framelocalsproxy_keys(PyObject *self, PyObject *Py_UNUSED(ignored))
{
    PyFrameObject *frame = PyFrameLocalsProxyObject_CAST(self)->frame;
    PyCodeObject *co = _PyFrame_GetCode(frame->f_frame);
    PyObject *names = PyList_New(0);
    if (names == NULL) {
        return NULL;
    }

    for (int i = 0; i < co->co_nlocalsplus; i++) {
        if (framelocalsproxy_hasval(frame->f_frame, co, i)) {
            PyObject *name = PyTuple_GET_ITEM(co->co_localsplusnames, i);
            if (PyList_Append(names, name) < 0) {
                Py_DECREF(names);
                return NULL;
            }
        }
    }

    // Iterate through the extra locals
    if (frame->f_extra_locals) {
        assert(PyDict_Check(frame->f_extra_locals));

        Py_ssize_t i = 0;
        PyObject *key = NULL;
        PyObject *value = NULL;

        while (PyDict_Next(frame->f_extra_locals, &i, &key, &value)) {
            if (PyList_Append(names, key) < 0) {
                Py_DECREF(names);
                return NULL;
            }
        }
    }

    return names;
}

static void
framelocalsproxy_dealloc(PyObject *self)
{
    PyFrameLocalsProxyObject *proxy = PyFrameLocalsProxyObject_CAST(self);
    PyObject_GC_UnTrack(self);
    Py_CLEAR(proxy->frame);
    Py_TYPE(self)->tp_free(self);
}

static PyObject *
framelocalsproxy_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
{
    if (PyTuple_GET_SIZE(args) != 1) {
        PyErr_Format(PyExc_TypeError,
                     "FrameLocalsProxy expected 1 argument, got %zd",
                     PyTuple_GET_SIZE(args));
        return NULL;
    }
    PyObject *item = PyTuple_GET_ITEM(args, 0);

    if (!PyFrame_Check(item)) {
        PyErr_Format(PyExc_TypeError, "expect frame, not %T", item);
        return NULL;
    }
    PyFrameObject *frame = (PyFrameObject*)item;

    if (kwds != NULL && PyDict_Size(kwds) != 0) {
        PyErr_SetString(PyExc_TypeError,
                        "FrameLocalsProxy takes no keyword arguments");
        return 0;
    }

    PyFrameLocalsProxyObject *self = (PyFrameLocalsProxyObject *)type->tp_alloc(type, 0);
    if (self == NULL) {
        return NULL;
    }

    ((PyFrameLocalsProxyObject*)self)->frame = (PyFrameObject*)Py_NewRef(frame);

    return (PyObject *)self;
}

static int
framelocalsproxy_tp_clear(PyObject *self)
{
    PyFrameLocalsProxyObject *proxy = PyFrameLocalsProxyObject_CAST(self);
    Py_CLEAR(proxy->frame);
    return 0;
}

static int
framelocalsproxy_visit(PyObject *self, visitproc visit, void *arg)
{
    PyFrameLocalsProxyObject *proxy = PyFrameLocalsProxyObject_CAST(self);
    Py_VISIT(proxy->frame);
    return 0;
}

static PyObject *
framelocalsproxy_iter(PyObject *self)
{
    PyObject* keys = framelocalsproxy_keys(self, NULL);
    if (keys == NULL) {
        return NULL;
    }

    PyObject* iter = PyObject_GetIter(keys);
    Py_XDECREF(keys);

    return iter;
}

static PyObject *
framelocalsproxy_richcompare(PyObject *lhs, PyObject *rhs, int op)
{
    PyFrameLocalsProxyObject *self = PyFrameLocalsProxyObject_CAST(lhs);
    if (PyFrameLocalsProxy_Check(rhs)) {
        PyFrameLocalsProxyObject *other = (PyFrameLocalsProxyObject *)rhs;
        bool result = self->frame == other->frame;
        if (op == Py_EQ) {
            return PyBool_FromLong(result);
        } else if (op == Py_NE) {
            return PyBool_FromLong(!result);
        }
    } else if (PyDict_Check(rhs)) {
        PyObject *dct = PyDict_New();
        if (dct == NULL) {
            return NULL;
        }

        if (PyDict_Update(dct, lhs) < 0) {
            Py_DECREF(dct);
            return NULL;
        }

        PyObject *result = PyObject_RichCompare(dct, rhs, op);
        Py_DECREF(dct);
        return result;
    }

    Py_RETURN_NOTIMPLEMENTED;
}

static PyObject *
framelocalsproxy_repr(PyObject *self)
{
    int i = Py_ReprEnter(self);
    if (i != 0) {
        return i > 0 ? PyUnicode_FromString("{...}") : NULL;
    }

    PyObject *dct = PyDict_New();
    if (dct == NULL) {
        Py_ReprLeave(self);
        return NULL;
    }

    if (PyDict_Update(dct, self) < 0) {
        Py_DECREF(dct);
        Py_ReprLeave(self);
        return NULL;
    }

    PyObject *repr = PyObject_Repr(dct);
    Py_DECREF(dct);

    Py_ReprLeave(self);

    return repr;
}

static PyObject*
framelocalsproxy_or(PyObject *self, PyObject *other)
{
    if (!PyDict_Check(other) && !PyFrameLocalsProxy_Check(other)) {
        Py_RETURN_NOTIMPLEMENTED;
    }

    PyObject *result = PyDict_New();
    if (result == NULL) {
        return NULL;
    }

    if (PyDict_Update(result, self) < 0) {
        Py_DECREF(result);
        return NULL;
    }

    if (PyDict_Update(result, other) < 0) {
        Py_DECREF(result);
        return NULL;
    }

    return result;
}

static PyObject*
framelocalsproxy_inplace_or(PyObject *self, PyObject *other)
{
    if (!PyDict_Check(other) && !PyFrameLocalsProxy_Check(other)) {
        Py_RETURN_NOTIMPLEMENTED;
    }

    if (framelocalsproxy_merge(self, other) < 0) {
        Py_RETURN_NOTIMPLEMENTED;
    }

    return Py_NewRef(self);
}

static PyObject *
framelocalsproxy_values(PyObject *self, PyObject *Py_UNUSED(ignored))
{
    PyFrameObject *frame = PyFrameLocalsProxyObject_CAST(self)->frame;
    PyCodeObject *co = _PyFrame_GetCode(frame->f_frame);
    PyObject *values = PyList_New(0);
    if (values == NULL) {
        return NULL;
    }

    for (int i = 0; i < co->co_nlocalsplus; i++) {
        PyObject *value = framelocalsproxy_getval(frame->f_frame, co, i);
        if (value) {
            if (PyList_Append(values, value) < 0) {
                Py_DECREF(values);
                Py_DECREF(value);
                return NULL;
            }
            Py_DECREF(value);
        }
    }

    // Iterate through the extra locals
    if (frame->f_extra_locals) {
        Py_ssize_t j = 0;
        PyObject *key = NULL;
        PyObject *value = NULL;
        while (PyDict_Next(frame->f_extra_locals, &j, &key, &value)) {
            if (PyList_Append(values, value) < 0) {
                Py_DECREF(values);
                return NULL;
            }
        }
    }

    return values;
}

static PyObject *
framelocalsproxy_items(PyObject *self, PyObject *Py_UNUSED(ignored))
{
    PyFrameObject *frame = PyFrameLocalsProxyObject_CAST(self)->frame;
    PyCodeObject *co = _PyFrame_GetCode(frame->f_frame);
    PyObject *items = PyList_New(0);
    if (items == NULL) {
        return NULL;
    }

    for (int i = 0; i < co->co_nlocalsplus; i++) {
        PyObject *name = PyTuple_GET_ITEM(co->co_localsplusnames, i);
        PyObject *value = framelocalsproxy_getval(frame->f_frame, co, i);

        if (value) {
            PyObject *pair = PyTuple_Pack(2, name, value);
            if (pair == NULL) {
                Py_DECREF(items);
                Py_DECREF(value);
                return NULL;
            }

            if (PyList_Append(items, pair) < 0) {
                Py_DECREF(items);
                Py_DECREF(pair);
                Py_DECREF(value);
                return NULL;
            }

            Py_DECREF(pair);
            Py_DECREF(value);
        }
    }

    // Iterate through the extra locals
    if (frame->f_extra_locals) {
        Py_ssize_t j = 0;
        PyObject *key = NULL;
        PyObject *value = NULL;
        while (PyDict_Next(frame->f_extra_locals, &j, &key, &value)) {
            PyObject *pair = PyTuple_Pack(2, key, value);
            if (pair == NULL) {
                Py_DECREF(items);
                return NULL;
            }

            if (PyList_Append(items, pair) < 0) {
                Py_DECREF(items);
                Py_DECREF(pair);
                return NULL;
            }

            Py_DECREF(pair);
        }
    }

    return items;
}

static Py_ssize_t
framelocalsproxy_length(PyObject *self)
{
    PyFrameObject *frame = PyFrameLocalsProxyObject_CAST(self)->frame;
    PyCodeObject *co = _PyFrame_GetCode(frame->f_frame);
    Py_ssize_t size = 0;

    if (frame->f_extra_locals != NULL) {
        assert(PyDict_Check(frame->f_extra_locals));
        size += PyDict_Size(frame->f_extra_locals);
    }

    for (int i = 0; i < co->co_nlocalsplus; i++) {
        if (framelocalsproxy_hasval(frame->f_frame, co, i)) {
            size++;
        }
    }
    return size;
}

static int
framelocalsproxy_contains(PyObject *self, PyObject *key)
{
    PyFrameObject *frame = PyFrameLocalsProxyObject_CAST(self)->frame;

    int i = framelocalsproxy_getkeyindex(frame, key, true, NULL);
    if (i == -2) {
        return -1;
    }
    if (i >= 0) {
        return 1;
    }

    PyObject *extra = frame->f_extra_locals;
    if (extra != NULL) {
        return PyDict_Contains(extra, key);
    }

    return 0;
}

static PyObject* framelocalsproxy___contains__(PyObject *self, PyObject *key)
{
    int result = framelocalsproxy_contains(self, key);
    if (result < 0) {
        return NULL;
    }
    return PyBool_FromLong(result);
}

static PyObject*
framelocalsproxy_update(PyObject *self, PyObject *other)
{
    if (framelocalsproxy_merge(self, other) < 0) {
        PyErr_SetString(PyExc_TypeError, "update() argument must be dict or another FrameLocalsProxy");
        return NULL;
    }

    Py_RETURN_NONE;
}

static PyObject*
framelocalsproxy_get(PyObject* self, PyObject *const *args, Py_ssize_t nargs)
{
    if (nargs < 1 || nargs > 2) {
        PyErr_SetString(PyExc_TypeError, "get expected 1 or 2 arguments");
        return NULL;
    }

    PyObject *key = args[0];
    PyObject *default_value = Py_None;

    if (nargs == 2) {
        default_value = args[1];
    }

    PyObject *result = framelocalsproxy_getitem(self, key);

    if (result == NULL) {
        if (PyErr_ExceptionMatches(PyExc_KeyError)) {
            PyErr_Clear();
            return Py_XNewRef(default_value);
        }
        return NULL;
    }

    return result;
}

static PyObject*
framelocalsproxy_setdefault(PyObject* self, PyObject *const *args, Py_ssize_t nargs)
{
    if (nargs < 1 || nargs > 2) {
        PyErr_SetString(PyExc_TypeError, "setdefault expected 1 or 2 arguments");
        return NULL;
    }

    PyObject *key = args[0];
    PyObject *default_value = Py_None;

    if (nargs == 2) {
        default_value = args[1];
    }

    PyObject *result = framelocalsproxy_getitem(self, key);

    if (result == NULL) {
        if (PyErr_ExceptionMatches(PyExc_KeyError)) {
            PyErr_Clear();
            if (framelocalsproxy_setitem(self, key, default_value) < 0) {
                return NULL;
            }
            return Py_XNewRef(default_value);
        }
        return NULL;
    }

    return result;
}

static PyObject*
framelocalsproxy_pop(PyObject* self, PyObject *const *args, Py_ssize_t nargs)
{
    if (!_PyArg_CheckPositional("pop", nargs, 1, 2)) {
        return NULL;
    }

    PyObject *key = args[0];
    PyObject *default_value = NULL;

    if (nargs == 2) {
        default_value = args[1];
    }

    PyFrameObject *frame = PyFrameLocalsProxyObject_CAST(self)->frame;

    int i = framelocalsproxy_getkeyindex(frame, key, false, NULL);
    if (i == -2) {
        return NULL;
    }

    if (i >= 0) {
        PyErr_SetString(PyExc_ValueError, "cannot remove local variables from FrameLocalsProxy");
        return NULL;
    }

    PyObject *result = NULL;

    if (frame->f_extra_locals == NULL) {
        if (default_value != NULL) {
            return Py_XNewRef(default_value);
        } else {
            _PyErr_SetKeyError(key);
            return NULL;
        }
    }

    if (PyDict_Pop(frame->f_extra_locals, key, &result) < 0) {
        return NULL;
    }

    if (result == NULL) {
        if (default_value != NULL) {
            return Py_XNewRef(default_value);
        } else {
            _PyErr_SetKeyError(key);
            return NULL;
        }
    }

    return result;
}

static PyObject*
framelocalsproxy_copy(PyObject *self, PyObject *Py_UNUSED(ignored))
{
    PyObject* result = PyDict_New();

    if (result == NULL) {
        return NULL;
    }

    if (PyDict_Update(result, self) < 0) {
        Py_DECREF(result);
        return NULL;
    }

    return result;
}

static PyObject*
framelocalsproxy_reversed(PyObject *self, PyObject *Py_UNUSED(ignored))
{
    PyObject *result = framelocalsproxy_keys(self, NULL);

    if (result == NULL) {
        return NULL;
    }

    if (PyList_Reverse(result) < 0) {
        Py_DECREF(result);
        return NULL;
    }
    return result;
}

static PyNumberMethods framelocalsproxy_as_number = {
    .nb_or = framelocalsproxy_or,
    .nb_inplace_or = framelocalsproxy_inplace_or,
};

static PySequenceMethods framelocalsproxy_as_sequence = {
    .sq_contains = framelocalsproxy_contains,
};

static PyMappingMethods framelocalsproxy_as_mapping = {
    .mp_length = framelocalsproxy_length,
    .mp_subscript = framelocalsproxy_getitem,
    .mp_ass_subscript = framelocalsproxy_setitem,
};

static PyMethodDef framelocalsproxy_methods[] = {
    {"__contains__", framelocalsproxy___contains__, METH_O | METH_COEXIST, NULL},
    {"__getitem__", framelocalsproxy_getitem, METH_O | METH_COEXIST, NULL},
    {"update", framelocalsproxy_update, METH_O, NULL},
    {"__reversed__", framelocalsproxy_reversed, METH_NOARGS, NULL},
    {"copy", framelocalsproxy_copy, METH_NOARGS, NULL},
    {"keys", framelocalsproxy_keys, METH_NOARGS, NULL},
    {"values", framelocalsproxy_values, METH_NOARGS, NULL},
    {"items", _PyCFunction_CAST(framelocalsproxy_items), METH_NOARGS, NULL},
    {"get", _PyCFunction_CAST(framelocalsproxy_get), METH_FASTCALL, NULL},
    {"pop", _PyCFunction_CAST(framelocalsproxy_pop), METH_FASTCALL, NULL},
    {
        "setdefault",
        _PyCFunction_CAST(framelocalsproxy_setdefault),
        METH_FASTCALL,
        NULL
    },
    {NULL, NULL}   /* sentinel */
};

PyTypeObject PyFrameLocalsProxy_Type = {
    PyVarObject_HEAD_INIT(&PyType_Type, 0)
    .tp_name = "FrameLocalsProxy",
    .tp_basicsize = sizeof(PyFrameLocalsProxyObject),
    .tp_dealloc = framelocalsproxy_dealloc,
    .tp_repr = &framelocalsproxy_repr,
    .tp_as_number = &framelocalsproxy_as_number,
    .tp_as_sequence = &framelocalsproxy_as_sequence,
    .tp_as_mapping = &framelocalsproxy_as_mapping,
    .tp_getattro = PyObject_GenericGetAttr,
    .tp_setattro = PyObject_GenericSetAttr,
    .tp_flags = Py_TPFLAGS_DEFAULT | Py_TPFLAGS_HAVE_GC | Py_TPFLAGS_MAPPING,
    .tp_traverse = framelocalsproxy_visit,
    .tp_clear = framelocalsproxy_tp_clear,
    .tp_richcompare = framelocalsproxy_richcompare,
    .tp_iter = framelocalsproxy_iter,
    .tp_methods = framelocalsproxy_methods,
    .tp_alloc = PyType_GenericAlloc,
    .tp_new = framelocalsproxy_new,
    .tp_free = PyObject_GC_Del,
};

PyObject *
_PyFrameLocalsProxy_New(PyFrameObject *frame)
{
    PyObject* args = PyTuple_Pack(1, frame);
    if (args == NULL) {
        return NULL;
    }

    PyObject* proxy = framelocalsproxy_new(&PyFrameLocalsProxy_Type, args, NULL);
    Py_DECREF(args);
    return proxy;
}

static PyMemberDef frame_memberlist[] = {
    {"f_trace_lines",   Py_T_BOOL,         OFF(f_trace_lines), 0},
    {NULL}      /* Sentinel */
};

/*[clinic input]
@critical_section
@getter
frame.f_locals as frame_locals

Return the mapping used by the frame to look up local variables.
[clinic start generated code]*/

static PyObject *
frame_locals_get_impl(PyFrameObject *self)
/*[clinic end generated code: output=b4ace8bb4cae71f4 input=7bd444d0dc8ddf44]*/
{
    assert(!_PyFrame_IsIncomplete(self->f_frame));

    PyCodeObject *co = _PyFrame_GetCode(self->f_frame);

    if (!(co->co_flags & CO_OPTIMIZED) && !_PyFrame_HasHiddenLocals(self->f_frame)) {
        if (self->f_frame->f_locals == NULL) {
            // We found cases when f_locals is NULL for non-optimized code.
            // We fill the f_locals with an empty dict to avoid crash until
            // we find the root cause.
            self->f_frame->f_locals = PyDict_New();
            if (self->f_frame->f_locals == NULL) {
                return NULL;
            }
        }
        return Py_NewRef(self->f_frame->f_locals);
    }

    return _PyFrameLocalsProxy_New(self);
}

int
PyFrame_GetLineNumber(PyFrameObject *f)
{
    assert(f != NULL);
    if (f->f_lineno == -1) {
        // We should calculate it once. If we can't get the line number,
        // set f->f_lineno to 0.
        f->f_lineno = PyUnstable_InterpreterFrame_GetLine(f->f_frame);
        if (f->f_lineno < 0) {
            f->f_lineno = 0;
            return -1;
        }
    }