HelpersLists.c

//     Copyright 2026, Kay Hayen, mailto:kay.hayen@gmail.com find license text at end of file
 
/* This helpers is used to work with lists.
 
*/
 
// This file is included from another C file, help IDEs to still parse it on
// its own.
#ifdef __IDE_ONLY__
#include "nuitka/prelude.h"
#endif
 
// #include "richcomparisons.h"
 
static PyObject *Nuitka_LongFromCLong(long ival);
 
#ifdef Py_GIL_DISABLED
typedef struct {
    Py_ssize_t allocated;
    PyObject *ob_item[];
} _PyListArray;
 
static _PyListArray *Nuitka_AllocateListArray(size_t capacity) {
    if (unlikely(capacity > PY_SSIZE_T_MAX / sizeof(PyObject *) - 1)) {
        return NULL;
    }
 
    // TODO: API call to be removed.
    _PyListArray *list_array = PyMem_Malloc(sizeof(_PyListArray) + capacity * sizeof(PyObject *));
 
    if (unlikely(list_array == NULL)) {
        return NULL;
    }
 
    list_array->allocated = capacity;
    return list_array;
}
 
// spell-checker: ignore use_qsbr
static void Nuitka_FreeListArray(PyObject **items, bool use_qsbr) {
    _PyListArray *array = _Py_CONTAINER_OF(items, _PyListArray, ob_item);
 
    if (use_qsbr) {
        NuitkaMem_FreeDelayed(array);
    } else {
        NuitkaMem_Free(array);
    }
}
 
#endif
 
#if NUITKA_LIST_HAS_FREELIST
 
PyObject *MAKE_LIST_EMPTY(PyThreadState *tstate, Py_ssize_t size) {
    assert(size >= 0);
 
#if _NUITKA_EXPERIMENTAL_DISABLE_LIST_OPT
    return PyList_New(size);
#else
#if PYTHON_VERSION >= 0x3e0
    PyListObject *result_list = (PyListObject *)Nuitka_PyFreeList_Pop(&Nuitka_Py_freelists_GET(tstate)->lists);
 
    if (result_list == NULL) {
        result_list = (PyListObject *)Nuitka_GC_New(&PyList_Type);
    } else {
        Nuitka_Py_NewReference((PyObject *)result_list);
    }
#else
    // This is the CPython name, spell-checker: ignore numfree
#if PYTHON_VERSION < 0x3d0
    PyListObject **items = tstate->interp->list.free_list;
    int *numfree = &tstate->interp->list.numfree;
#else
    struct _Py_object_freelists *freelists = _Nuitka_object_freelists_GET(tstate);
    struct _Py_list_freelist *state = &freelists->lists;
    PyListObject **items = state->items;
    int *numfree = &state->numfree;
#endif
    assert(*numfree >= 0);
    PyListObject *result_list;
 
    if (*numfree) {
        (*numfree) -= 1;
        result_list = items[*numfree];
 
        Nuitka_Py_NewReference((PyObject *)result_list);
    } else {
        result_list = (PyListObject *)Nuitka_GC_New(&PyList_Type);
    }
#endif
    assert(result_list != NULL);
    assert(PyList_CheckExact(result_list));
 
    // Elements are allocated separately.
    if (size > 0) {
#ifdef Py_GIL_DISABLED
        _PyListArray *list_array = Nuitka_AllocateListArray(size);
 
        if (unlikely(list_array == NULL)) {
            Py_DECREF(result_list);
            return PyErr_NoMemory();
        }
 
        memset(list_array->ob_item, 0, size * sizeof(PyObject *));
        result_list->ob_item = list_array->ob_item;
#else
        result_list->ob_item = (PyObject **)NuitkaMem_Calloc(size, sizeof(PyObject *));
 
        if (unlikely(result_list->ob_item == NULL)) {
            Py_DECREF(result_list);
            return PyErr_NoMemory();
        }
#endif
    } else {
        result_list->ob_item = NULL;
    }
 
    Py_SET_SIZE(result_list, size);
    result_list->allocated = size;
 
    Nuitka_GC_Track(result_list);
 
    return (PyObject *)result_list;
#endif
}
#endif
 
PyObject *LIST_COPY(PyThreadState *tstate, PyObject *list) {
    CHECK_OBJECT(list);
    assert(PyList_CheckExact(list));
 
    Py_ssize_t size = PyList_GET_SIZE(list);
    PyObject *result = MAKE_LIST_EMPTY(tstate, size);
 
    if (unlikely(result == NULL)) {
        return NULL;
    }
 
    for (Py_ssize_t i = 0; i < size; i++) {
        PyObject *item = PyList_GET_ITEM(list, i);
        Py_INCREF(item);
        PyList_SET_ITEM(result, i, item);
    }
 
    return result;
}
 
static bool LIST_RESIZE(PyListObject *list, Py_ssize_t new_size) {
    CHECK_OBJECT(list);
    assert(new_size >= 0);
 
    Py_ssize_t allocated = list->allocated;
 
    if (allocated >= new_size && new_size >= (allocated >> 1)) {
        Py_SET_SIZE(list, new_size);
 
        return true;
    }
 
    size_t new_allocated;
 
    if (new_size == 0) {
        new_allocated = 0;
    } else {
        new_allocated = ((size_t)new_size + (new_size >> 3) + 6) & ~(size_t)3;
        assert(new_allocated >= (size_t)new_size);
    }
 
#ifdef Py_GIL_DISABLED
    _PyListArray *array = Nuitka_AllocateListArray(new_allocated);
 
    if (array == NULL) {
        PyErr_NoMemory();
        return -1;
    }
    PyObject **old_items = list->ob_item;
    if (list->ob_item != NULL) {
        size_t num_allocated_bytes;
        if (new_allocated < (size_t)allocated) {
            num_allocated_bytes = new_allocated * sizeof(PyObject *);
        } else {
            num_allocated_bytes = allocated * sizeof(PyObject *);
        }
        memcpy(array->ob_item, list->ob_item, num_allocated_bytes);
    }
    if (new_allocated > (size_t)allocated) {
        memset(array->ob_item + allocated, 0, sizeof(PyObject *) * (new_allocated - allocated));
    }
    _Py_atomic_store_ptr_release(&list->ob_item, &array->ob_item);
    list->allocated = new_allocated;
    Py_SET_SIZE(list, new_size);
    if (old_items != NULL) {
        Nuitka_FreeListArray(old_items, _PyObject_GC_IS_SHARED(list));
    }
#else
    size_t num_allocated_bytes = new_allocated * sizeof(PyObject *);
 
    // TODO: For Python3.13 No-GIL this is different code
    PyObject **items = (PyObject **)NuitkaMem_Realloc(list->ob_item, num_allocated_bytes);
    if (unlikely(items == NULL)) {
        PyErr_NoMemory();
        return false;
    }
 
    list->ob_item = items;
    Py_SET_SIZE(list, new_size);
    list->allocated = new_allocated;
#endif
 
    return true;
}
 
bool LIST_EXTEND_FROM_LIST(PyObject *list, PyObject *other) {
#if _NUITKA_EXPERIMENTAL_DISABLE_LIST_OPT
    PyObject *result = _PyList_Extend((PyListObject *)list, other);
    if (result != NULL) {
        Py_DECREF(result);
        return true;
    } else {
        return false;
    }
#else
    assert(PyList_CheckExact(list));
    assert(PyList_CheckExact(other));
 
    size_t n = PyList_GET_SIZE(other);
 
    if (n == 0) {
        return true;
    }
 
    size_t m = Py_SIZE(list);
 
    if (LIST_RESIZE((PyListObject *)list, m + n) == false) {
        return false;
    }
 
    PyObject **src = &PyList_GET_ITEM(other, 0);
    PyObject **dest = &PyList_GET_ITEM(list, m);
 
    for (size_t i = 0; i < n; i++) {
        PyObject *o = src[i];
        Py_INCREF(o);
 
        dest[i] = o;
    }
 
    return true;
#endif
}
 
bool LIST_EXTEND_FROM_ITERABLE(PyThreadState *tstate, PyObject *target, PyObject *other) {
    CHECK_OBJECT(target);
    assert(PyList_CheckExact(target));
 
    CHECK_OBJECT(other);
 
    PyListObject *list = (PyListObject *)target;
 
#if _NUITKA_EXPERIMENTAL_DISABLE_LIST_OPT
    PyObject *result = _PyList_Extend(list, other);
    if (result != NULL) {
        Py_DECREF(result);
        return true;
    } else {
        return false;
    }
#else
    // First attempt those things that occur most often. Keep in mind that
    // other might be the same object as list.
    PyObject **src;
    Py_ssize_t src_size;
 
    if (PyList_CheckExact(other)) { // this covers list == other too.
        src = _PyList_ITEMS(other);
        src_size = PyList_GET_SIZE(other);
    } else if (PyTuple_CheckExact(other)) {
        src = _PyTuple_ITEMS(other);
        src_size = PyTuple_GET_SIZE(other);
    } else {
        src = NULL;
#ifndef __NUITKA_NO_ASSERT__
        src_size = 0;
#endif
    }
 
    if (src != NULL) {
        if (src_size == 0) {
            return true;
        }
 
        Py_ssize_t list_size = PyList_GET_SIZE(list);
 
        // Overflow is not really realistic, so we only assert against it.
        assert(list_size <= PY_SSIZE_T_MAX - src_size);
        if (LIST_RESIZE(list, list_size + src_size) == false) {
            return false;
        }
 
        PyObject **target_items = _PyList_ITEMS(list) + list_size;
 
        for (Py_ssize_t i = 0; i < src_size; i++) {
            PyObject *value = src[i];
            Py_INCREF(value);
            *target_items++ = value;
        }
 
        return true;
    }
 
    // Slow path needs to use iterator. TODO:
    PyObject *iter = MAKE_ITERATOR(tstate, other);
 
    if (iter == NULL) {
        return false;
    }
    PyObject *(*iternext)(PyObject *) = *Py_TYPE(iter)->tp_iternext;
 
    Py_ssize_t cur_size = PyList_GET_SIZE(list);
 
#if PYTHON_VERSION >= 0x300
    // Guess a iterator size if possible
    src_size = PyObject_LengthHint(other, 8);
 
    if (src_size < 0) {
        Py_DECREF(iter);
        return false;
    }
 
    Py_ssize_t list_size = PyList_GET_SIZE(list);
 
    if (list_size > PY_SSIZE_T_MAX - src_size) {
        // Overflow is not really realistic, hope is, it will not come true.
    } else {
        // Allocate the space in one go.
        if (LIST_RESIZE(list, list_size + src_size) == false) {
            Py_DECREF(iter);
            return false;
        }
 
        // Restore validity of the object for the time being.
        Py_SET_SIZE(list, list_size);
    }
#endif
 
    for (;;) {
        PyObject *item = iternext(iter);
 
        if (item == NULL) {
            bool stop_iteration_error = CHECK_AND_CLEAR_STOP_ITERATION_OCCURRED(tstate);
 
            Py_DECREF(iter);
 
            if (unlikely(stop_iteration_error == false)) {
                if (cur_size < list->allocated) {
                    if (LIST_RESIZE(list, cur_size) == false) {
                        return false;
                    }
                }
 
                return false;
            }
 
            break;
        }
 
        CHECK_OBJECT(item);
 
        if (cur_size < list->allocated) {
            // Already allocated, so we can just set it.
            PyList_SET_ITEM(list, cur_size, item);
            Py_SET_SIZE(list, cur_size + 1);
        } else {
            assert(cur_size != PY_SSIZE_T_MAX);
 
            if (LIST_RESIZE(list, cur_size + 1) == false) {
                return false;
            }
 
            PyList_SET_ITEM(list, cur_size, item);
        }
        cur_size += 1;
    }
 
    /* Cut back result list if initial guess was too large. */
    assert(cur_size == PyList_GET_SIZE(list));
 
    if (cur_size < list->allocated) {
        if (LIST_RESIZE(list, cur_size) == false) {
            return false;
        }
    }
 
    return true;
#endif
}
 
#if PYTHON_VERSION >= 0x390
bool LIST_EXTEND_FOR_UNPACK(PyThreadState *tstate, PyObject *list, PyObject *other) {
    // TODO: For improved performance, inline this, but we probably wait
    // until code generation for this kind of helpers is there.
    bool result = LIST_EXTEND_FROM_ITERABLE(tstate, list, other);
 
    if (likely(result)) {
        return true;
    }
 
    PyObject *error = GET_ERROR_OCCURRED(tstate);
 
    assert(error != NULL);
 
    if (EXCEPTION_MATCH_BOOL_SINGLE(tstate, error, PyExc_TypeError) &&
        (Py_TYPE(other)->tp_iter == NULL && !PySequence_Check(other))) {
        CLEAR_ERROR_OCCURRED(tstate);
        PyErr_Format(PyExc_TypeError, "Value after * must be an iterable, not %s", Py_TYPE(other)->tp_name);
    }
 
    return false;
}
#endif
 
bool LIST_APPEND1(PyObject *target, PyObject *item) {
    CHECK_OBJECT(target);
    assert(PyList_CheckExact(target));
 
    CHECK_OBJECT(item);
 
#if _NUITKA_EXPERIMENTAL_DISABLE_LIST_OPT
    int res = PyList_Append(target, item);
    Py_DECREF(item);
    return res == 0;
#else
    PyListObject *list = (PyListObject *)target;
 
    Py_ssize_t cur_size = PyList_GET_SIZE(list);
 
    // Overflow is not really realistic, so we only assert against it.
    assert(cur_size <= PY_SSIZE_T_MAX);
 
    if (LIST_RESIZE(list, cur_size + 1) == false) {
        return false;
    }
 
    PyList_SET_ITEM(list, cur_size, item);
 
    return true;
#endif
}
 
bool LIST_APPEND0(PyObject *target, PyObject *item) {
    CHECK_OBJECT(target);
    assert(PyList_CheckExact(target));
 
    CHECK_OBJECT(item);
 
#if _NUITKA_EXPERIMENTAL_DISABLE_LIST_OPT
    int res = PyList_Append(target, item);
    return res == 0;
#else
    PyListObject *list = (PyListObject *)target;
 
    Py_ssize_t cur_size = PyList_GET_SIZE(list);
 
    // Overflow is not really realistic, so we only assert against it.
    assert(cur_size <= PY_SSIZE_T_MAX);
 
    if (LIST_RESIZE(list, cur_size + 1) == false) {
        return false;
    }
 
    PyList_SET_ITEM0(list, cur_size, item);
 
    return true;
#endif
}
 
bool LIST_REMOVE(PyObject *target, PyObject *item) {
    CHECK_OBJECT(target);
    assert(PyList_CheckExact(target));
 
    CHECK_OBJECT(item);
 
#if _NUITKA_EXPERIMENTAL_DISABLE_LIST_OPT && 0
    // TODO: This is not exposed, would need to delete as slice instead.
    int res = PyList_Remove(target, item);
    return res == 0;
#else
    PyListObject *list = (PyListObject *)target;
 
    Py_ssize_t cur_size = PyList_GET_SIZE(list);
 
    for (Py_ssize_t i = 0; i < cur_size; i++) {
        PyObject *element = list->ob_item[i];
 
        Py_INCREF(element);
        nuitka_bool cmp = RICH_COMPARE_EQ_NBOOL_OBJECT_OBJECT(element, item);
        Py_DECREF(element);
 
        if (cmp == NUITKA_BOOL_TRUE) {
            Py_DECREF(element);
            Py_SET_SIZE(list, cur_size - 1);
 
            memmove(list->ob_item + i, list->ob_item + i + 1, sizeof(PyObject *) * (cur_size - i - 1));
 
            return true;
        } else if (unlikely(cmp == NUITKA_BOOL_EXCEPTION)) {
            return false;
        }
    }
 
    PyThreadState *tstate = PyThreadState_GET();
 
    SET_CURRENT_EXCEPTION_TYPE0_STR(tstate, PyExc_ValueError, "list.remove(x): x not in list");
    return false;
#endif
}
 
void LIST_CLEAR(PyObject *target) {
    CHECK_OBJECT(target);
    assert(PyList_CheckExact(target));
 
    PyListObject *list = (PyListObject *)target;
 
    PyObject **items = list->ob_item;
 
    if (items != NULL) {
        // Make the list empty first, so the data we release is not accessible.
        Py_ssize_t i = Py_SIZE(list);
        Py_SET_SIZE(list, 0);
        list->ob_item = NULL;
        list->allocated = 0;
 
        while (--i >= 0) {
            Py_XDECREF(items[i]);
        }
 
        PyMem_Free(items);
    }
}
 
PyObject *getListIndexObject(Py_ssize_t value) {
#if PYTHON_VERSION < 0x300
    return PyInt_FromSsize_t(value);
#else
    // TODO: Actually to be fully correct, we will need a "Nuitka_LongFromCSsize_t" which
    // we do not have yet.
    return Nuitka_LongFromCLong((long)value);
#endif
}
 
PyObject *LIST_COUNT(PyObject *list, PyObject *item) {
    CHECK_OBJECT(list);
    assert(PyList_CheckExact(list));
 
    Py_ssize_t count = 0;
 
    for (Py_ssize_t i = 0; i < Py_SIZE(list); i++) {
        PyObject *element = PyList_GET_ITEM(list, i);
 
        // Fast path, is identical
        if (element == item) {
            count++;
            continue;
        }
 
        // Rich compare element while holding a reference. TODO: If we knew the type
        // of "item" we could be faster by picking variants that know stuff, but
        // maybe it is not as important.
        Py_INCREF(element);
        nuitka_bool nbool_res = RICH_COMPARE_EQ_NBOOL_OBJECT_OBJECT(element, item);
        Py_DECREF(element);
 
        if (nbool_res == NUITKA_BOOL_TRUE) {
            count++;
            continue;
        }
 
        // Pass on exceptions from comparisons.
        if (unlikely(nbool_res == NUITKA_BOOL_EXCEPTION)) {
            return NULL;
        }
    }
 
    return getListIndexObject(count);
}
 
static PyObject *_LIST_INDEX_COMMON(PyThreadState *tstate, PyListObject *list, PyObject *item, Py_ssize_t start,
                                    Py_ssize_t stop) {
    // Negative values for start/stop are handled here.
    if (start < 0) {
        start += Py_SIZE(list);
 
        if (start < 0) {
            start = 0;
        }
    }
 
    if (stop < 0) {
        stop += Py_SIZE(list);
 
        if (stop < 0) {
            stop = 0;
        }
    }
 
    for (Py_ssize_t i = start; i < stop && i < Py_SIZE(list); i++) {
        PyObject *element = list->ob_item[i];
 
        Py_INCREF(element);
        nuitka_bool nbool_res = RICH_COMPARE_EQ_NBOOL_OBJECT_OBJECT(element, item);
        Py_DECREF(element);
 
        if (nbool_res == NUITKA_BOOL_TRUE) {
            return getListIndexObject(i);
        }
 
        // Pass on exceptions from comparisons.
        if (unlikely(nbool_res == NUITKA_BOOL_EXCEPTION)) {
            return NULL;
        }
    }
 
#if PYTHON_VERSION < 0x300
    PyObject *err_format = PyString_FromString("%r is not in list");
    PyObject *format_tuple = MAKE_TUPLE1_0(tstate, item);
    PyObject *err_string = PyString_Format(err_format, format_tuple);
    Py_DECREF(format_tuple);
 
    if (err_string == NULL) {
        return NULL;
    }
 
    SET_CURRENT_EXCEPTION_TYPE0_VALUE1(tstate, PyExc_ValueError, err_string);
    return NULL;
#else
    PyErr_Format(PyExc_ValueError, "%R is not in list", item);
    return NULL;
#endif
}
 
PyObject *LIST_INDEX2(PyThreadState *tstate, PyObject *list, PyObject *item) {
    CHECK_OBJECT(list);
    assert(PyList_CheckExact(list));
 
    return _LIST_INDEX_COMMON(tstate, (PyListObject *)list, item, 0, Py_SIZE(list));
}
 
PyObject *LIST_INDEX3(PyThreadState *tstate, PyObject *list, PyObject *item, PyObject *start) {
    CHECK_OBJECT(list);
    assert(PyList_CheckExact(list));
 
    PyObject *start_index = Nuitka_Number_IndexAsLong(start);
 
    if (unlikely(start_index == NULL)) {
        // TODO: Clearing should be useless here.
        CLEAR_ERROR_OCCURRED(tstate);
 
        SET_CURRENT_EXCEPTION_TYPE0_STR(tstate, PyExc_TypeError,
                                        "slice indices must be integers or have an __index__ method");
        return NULL;
    }
 
    Py_ssize_t start_ssize;
#if PYTHON_VERSION < 0x300
    if (PyInt_CheckExact(start_index)) {
        start_ssize = PyInt_AS_LONG(start_index);
    } else {
        start_ssize = PyLong_AsSsize_t(start_index);
    }
#else
    start_ssize = PyLong_AsSsize_t(start_index);
#endif
 
    Py_DECREF(start_index);
 
    return _LIST_INDEX_COMMON(tstate, (PyListObject *)list, item, start_ssize, Py_SIZE(list));
}
 
PyObject *LIST_INDEX4(PyThreadState *tstate, PyObject *list, PyObject *item, PyObject *start, PyObject *stop) {
    CHECK_OBJECT(list);
    assert(PyList_CheckExact(list));
 
    PyObject *start_index = Nuitka_Number_IndexAsLong(start);
 
    if (unlikely(start_index == NULL)) {
        CLEAR_ERROR_OCCURRED(tstate);
 
        SET_CURRENT_EXCEPTION_TYPE0_STR(tstate, PyExc_TypeError,
                                        "slice indices must be integers or have an __index__ method");
        return NULL;
    }
 
    Py_ssize_t start_ssize;
#if PYTHON_VERSION < 0x300
    if (PyInt_CheckExact(start_index)) {
        start_ssize = PyInt_AS_LONG(start_index);
    } else {
        start_ssize = PyLong_AsSsize_t(start_index);
    }
#else
    start_ssize = PyLong_AsSsize_t(start_index);
#endif
 
    Py_DECREF(start_index);
 
    PyObject *stop_index = Nuitka_Number_IndexAsLong(stop);
 
    if (unlikely(stop_index == NULL)) {
        Py_DECREF(start_index);
 
        CLEAR_ERROR_OCCURRED(tstate);
 
        SET_CURRENT_EXCEPTION_TYPE0_STR(tstate, PyExc_TypeError,
                                        "slice indices must be integers or have an __index__ method");
        return NULL;
    }
 
    Py_ssize_t stop_ssize;
#if PYTHON_VERSION < 0x300
    if (PyInt_CheckExact(stop_index)) {
        stop_ssize = PyInt_AS_LONG(stop_index);
    } else {
        stop_ssize = PyLong_AsSsize_t(stop_index);
    }
#else
    stop_ssize = PyLong_AsSsize_t(stop_index);
#endif
 
    Py_DECREF(stop_index);
 
    return _LIST_INDEX_COMMON(tstate, (PyListObject *)list, item, start_ssize, stop_ssize);
}
 
bool LIST_INSERT(PyThreadState *tstate, PyObject *list, PyObject *index, PyObject *item) {
    CHECK_OBJECT(list);
    assert(PyList_CheckExact(list));
    CHECK_OBJECT(index);
    CHECK_OBJECT(item);
 
    // TODO: Avoid the clear, by having this as a variant that doesn't set the
    // exception to begin with
    PyObject *index_long = Nuitka_Number_IndexAsLong(index);
 
    if (unlikely(index_long == NULL)) {
        CLEAR_ERROR_OCCURRED(tstate);
 
        SET_CURRENT_EXCEPTION_TYPE_COMPLAINT("'%s' cannot be interpreted as an integer", index);
        return false;
    }
 
    Py_ssize_t index_ssize;
#if PYTHON_VERSION < 0x300
    if (PyInt_CheckExact(index_long)) {
        index_ssize = PyInt_AS_LONG(index_long);
    } else {
        index_ssize = PyLong_AsSsize_t(index_long);
    }
#else
    index_ssize = PyLong_AsSsize_t(index_long);
#endif
 
    Py_DECREF(index_long);
 
    LIST_INSERT_CONST(list, index_ssize, item);
    return true;
}
 
void LIST_INSERT_CONST(PyObject *list, Py_ssize_t index, PyObject *item) {
    CHECK_OBJECT(list);
    assert(PyList_CheckExact(list));
    CHECK_OBJECT(item);
 
    PyListObject *list_object = (PyListObject *)list;
 
    Py_ssize_t n = Py_SIZE(list_object);
 
    // Expand the list by needed space.
    if (LIST_RESIZE(list_object, n + 1) == false) {
        abort();
    }
 
    // Negative values and overflow for for index are handled here.
    if (index < 0) {
        index += n;
        if (index < 0) {
            index = 0;
        }
    }
    if (index > n) {
        index = n;
    }
 
    // Shift the items behind the insert index.
    PyObject **items = list_object->ob_item;
 
    for (Py_ssize_t i = n; --i >= index;) {
        items[i + 1] = items[i];
    }
 
    Py_INCREF(item);
    items[index] = item;
}
 
static void _Nuitka_ReverseObjectsSlice(PyObject **lo, PyObject **hi) {
    assert(lo != NULL && hi != NULL);
 
    hi -= 1;
 
    while (lo < hi) {
        {
            PyObject *t = *lo;
            *lo = *hi;
            *hi = t;
        }
 
        lo += 1;
        hi -= 1;
    }
}
 
void LIST_REVERSE(PyObject *list) {
    CHECK_OBJECT(list);
    assert(PyList_CheckExact(list));
 
    PyListObject *list_object = (PyListObject *)list;
 
    if (Py_SIZE(list_object) > 1) {
        _Nuitka_ReverseObjectsSlice(list_object->ob_item, list_object->ob_item + Py_SIZE(list_object));
    }
}
 
#if PYTHON_VERSION >= 0x300 && !defined(_NUITKA_EXPERIMENTAL_DISABLE_LIST_OPT)
static bool allocateListItems(PyListObject *list, Py_ssize_t size) {
    PyObject **items = PyMem_New(PyObject *, size);
 
    if (unlikely(items == NULL)) {
        PyErr_NoMemory();
        return false;
    }
 
    list->ob_item = items;
    list->allocated = size;
 
    return true;
}
 
#endif
 
PyObject *MAKE_LIST(PyThreadState *tstate, PyObject *iterable) {
    // Can leave the size hinting to later functions, because the list is allocated empty without
    // items, and when then extending, etc. length hints can be used.
    PyObject *list = MAKE_LIST_EMPTY(tstate, 0);
 
#if _NUITKA_EXPERIMENTAL_DISABLE_LIST_OPT
    PyObject *result = _PyList_Extend((PyListObject *)list, iterable);
    if (result == NULL) {
        Py_DECREF(list);
        return NULL;
    } else {
        Py_DECREF(result);
        return list;
    }
#else
    Py_INCREF(iterable);
 
#if PYTHON_VERSION >= 0x300
    if (Nuitka_PyObject_HasLen(iterable)) {
        Py_ssize_t iter_len = Nuitka_PyObject_Size(iterable);
 
        if (unlikely(iter_len == -1)) {
            if (!PyErr_ExceptionMatches(PyExc_TypeError)) {
                return NULL;
            }
 
            CLEAR_ERROR_OCCURRED(tstate);
        }
 
        if (iter_len > 0) {
            if (allocateListItems((PyListObject *)list, iter_len) == false) {
                return NULL;
            }
        }
    }
#endif
 
    bool res = LIST_EXTEND_FROM_ITERABLE(tstate, list, iterable);
 
    Py_DECREF(iterable);
 
    if (unlikely(res == false)) {
        Py_DECREF(list);
        return NULL;
    }
 
    return list;
#endif
}
 
#include "HelpersListsGenerated.c"
 
//     Part of "Nuitka", an optimizing Python compiler that is compatible and
//     integrates with CPython, but also works on its own.
//
//     Licensed under the GNU Affero General Public License, Version 3 (the "License");
//     you may not use this file except in compliance with the License.
//     You may obtain a copy of the License at
//
//        http://www.gnu.org/licenses/agpl.txt
//
//     Unless required by applicable law or agreed to in writing, software
//     distributed under the License is distributed on an "AS IS" BASIS,
//     WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//     See the License for the specific language governing permissions and
//     limitations under the License.