same_slots_added

same_slots_added

static int same_slots_added(PyTypeObject* a, PyTypeObject* b) noexcept {
    PyTypeObject* base = a->tp_base;
    Py_ssize_t size;
    PyObject* slots_a, *slots_b;

    assert(base == b->tp_base);
    size = base->tp_basicsize;

    if (a->tp_dictoffset == size && b->tp_dictoffset == size)
        size += sizeof(PyObject*);

    // Pyston change: have to check attrs_offset
    if (a->attrs_offset == size && b->attrs_offset == size)
        size += sizeof(HCAttrs);

    if (a->tp_weaklistoffset == size && b->tp_weaklistoffset == size)
        size += sizeof(PyObject*);

    /* Check slots compliance */
    slots_a = ((PyHeapTypeObject*)a)->ht_slots;
    slots_b = ((PyHeapTypeObject*)b)->ht_slots;
    if (slots_a && slots_b) {
        if (PyObject_Compare(slots_a, slots_b) != 0)
            return 0;
        size += sizeof(PyObject*) * PyTuple_GET_SIZE(slots_a);
    }

    return size == a->tp_basicsize && size == b->tp_basicsize;
}