def PyFrame_New(space, tstate, w_code, w_globals, w_locals):
    typedescr = get_typedescr(PyFrame.typedef)
    py_obj = typedescr.allocate(space, space.gettypeobject(PyFrame.typedef))
    py_frame = rffi.cast(PyFrameObject, py_obj)
    space.interp_w(PyCode, w_code) # sanity check
    py_frame.c_f_code = rffi.cast(PyCodeObject, make_ref(space, w_code))
    py_frame.c_f_globals = make_ref(space, w_globals)
    return py_frame

def type_attach(space, py_obj, w_type):
    """
    Fills a newly allocated PyTypeObject from an existing type.
    """
    from pypy.module.cpyext.object import PyObject_Del

    assert isinstance(w_type, W_TypeObject)

    pto = rffi.cast(PyTypeObjectPtr, py_obj)

    typedescr = get_typedescr(w_type.layout.typedef)

    # dealloc
    pto.c_tp_dealloc = typedescr.get_dealloc(space)
    # buffer protocol
    if space.is_w(w_type, space.w_str):
        setup_string_buffer_procs(space, pto)
    if space.is_w(w_type, space.w_buffer):
        setup_buffer_buffer_procs(space, pto)

    pto.c_tp_free = llhelper(PyObject_Del.api_func.functype,
            PyObject_Del.api_func.get_wrapper(space))
    pto.c_tp_alloc = llhelper(PyType_GenericAlloc.api_func.functype,
            PyType_GenericAlloc.api_func.get_wrapper(space))
    if pto.c_tp_flags & Py_TPFLAGS_HEAPTYPE:
        w_typename = space.getattr(w_type, space.wrap('__name__'))
        heaptype = rffi.cast(PyHeapTypeObject, pto)
        heaptype.c_ht_name = make_ref(space, w_typename)
        from pypy.module.cpyext.bytesobject import PyString_AsString
        pto.c_tp_name = PyString_AsString(space, heaptype.c_ht_name)
    else:
        pto.c_tp_name = rffi.str2charp(w_type.name)
    # uninitialized fields:
    # c_tp_print, c_tp_getattr, c_tp_setattr
    # XXX implement
    # c_tp_compare and the following fields (see http://docs.python.org/c-api/typeobj.html )
    w_base = best_base(space, w_type.bases_w)
    pto.c_tp_base = rffi.cast(PyTypeObjectPtr, make_ref(space, w_base))

    builder = space.fromcache(StaticObjectBuilder)
    if builder.cpyext_type_init is not None:
        builder.cpyext_type_init.append((pto, w_type))
    else:
        finish_type_1(space, pto)
        finish_type_2(space, pto, w_type)

    pto.c_tp_basicsize = rffi.sizeof(typedescr.basestruct)
    if pto.c_tp_base:
        if pto.c_tp_base.c_tp_basicsize > pto.c_tp_basicsize:
            pto.c_tp_basicsize = pto.c_tp_base.c_tp_basicsize

    # will be filled later on with the correct value
    # may not be 0
    if space.is_w(w_type, space.w_object):
        pto.c_tp_new = rffi.cast(newfunc, 1)
    update_all_slots(space, w_type, pto)
    pto.c_tp_flags |= Py_TPFLAGS_READY
    return pto

def _PyObject_NewVar(space, type, itemcount):
    w_type = from_ref(space, rffi.cast(PyObject, type))
    assert isinstance(w_type, W_TypeObject)
    typedescr = get_typedescr(w_type.instancetypedef)
    py_obj = typedescr.allocate(space, w_type, itemcount=itemcount)
    py_obj.c_ob_refcnt = 0
    if type.c_tp_itemsize == 0:
        w_obj = PyObject_Init(space, py_obj, type)
    else:
        py_objvar = rffi.cast(PyVarObject, py_obj)
        w_obj = PyObject_InitVar(space, py_objvar, type, itemcount)
    return py_obj

def new_empty_str(space, length):
    """
    Allocate a PyBytesObject and its ob_sval, but without a corresponding
    interpreter object.  The ob_sval may be mutated, until bytes_realize() is
    called.  Refcount of the result is 1.
    """
    typedescr = get_typedescr(space.w_str.layout.typedef)
    py_obj = typedescr.allocate(space, space.w_str, length)
    py_str = rffi.cast(PyBytesObject, py_obj)
    py_str.c_ob_shash = -1
    py_str.c_ob_sstate = rffi.cast(rffi.INT, 0) # SSTATE_NOT_INTERNED
    return py_str

def new_empty_tuple(space, length):
    """
    Allocate a PyTupleObject and its array of PyObject *, but without a
    corresponding interpreter object.  The array may be mutated, until
    tuple_realize() is called.  Refcount of the result is 1.
    """
    typedescr = get_typedescr(space.w_tuple.layout.typedef)
    py_obj = typedescr.allocate(space, space.w_tuple, length)
    py_tup = rffi.cast(PyTupleObject, py_obj)
    p = py_tup.c_ob_item
    for i in range(py_tup.c_ob_size):
        p[i] = lltype.nullptr(PyObject.TO)
    return py_obj

def new_empty_tuple(space, length):
    """
    Allocate a PyTupleObject and its array of PyObject *, but without a
    corresponding interpreter object.  The array may be mutated, until
    tuple_realize() is called.  Refcount of the result is 1.
    """
    typedescr = get_typedescr(space.w_tuple.layout.typedef)
    py_obj = typedescr.allocate(space, space.w_tuple)
    py_tup = rffi.cast(PyTupleObject, py_obj)

    py_tup.c_ob_item = lltype.malloc(ObjectItems, length,
                                     flavor='raw', zero=True)
    py_tup.c_ob_size = length
    return py_tup

def new_empty_str(space, length):
    """
    Allocate a PyStringObject and its buffer, but without a corresponding
    interpreter object.  The buffer may be mutated, until string_realize() is
    called.  Refcount of the result is 1.
    """
    typedescr = get_typedescr(space.w_str.layout.typedef)
    py_obj = typedescr.allocate(space, space.w_str)
    py_str = rffi.cast(PyStringObject, py_obj)

    buflen = length + 1
    py_str.c_size = length
    py_str.c_buffer = lltype.malloc(rffi.CCHARP.TO, buflen,
                                    flavor='raw', zero=True)
    return py_str

def new_empty_str(space, length):
    """
    Allocates a PyBytesObject and its buffer, but without a corresponding
    interpreter object.  The buffer may be mutated, until bytes_realize() is
    called.
    """
    typedescr = get_typedescr(space.w_bytes.instancetypedef)
    py_obj = typedescr.allocate(space, space.w_bytes)
    py_str = rffi.cast(PyBytesObject, py_obj)

    buflen = length + 1
    py_str.c_size = length
    py_str.c_buffer = lltype.malloc(rffi.CCHARP.TO, buflen,
                                    flavor='raw', zero=True)
    return py_str

def type_attach(space, py_obj, w_type):
    """
    Fills a newly allocated PyTypeObject from an existing type.
    """
    from pypy.module.cpyext.object import PyObject_Del

    assert isinstance(w_type, W_TypeObject)

    pto = rffi.cast(PyTypeObjectPtr, py_obj)

    typedescr = get_typedescr(w_type.instancetypedef)

    # dealloc
    pto.c_tp_dealloc = typedescr.get_dealloc(space)
    # buffer protocol
    if space.is_w(w_type, space.w_str):
        setup_string_buffer_procs(space, pto)

    pto.c_tp_flags |= Py_TPFLAGS_HEAPTYPE
    pto.c_tp_free = llhelper(PyObject_Del.api_func.functype,
            PyObject_Del.api_func.get_wrapper(space))
    pto.c_tp_alloc = llhelper(PyType_GenericAlloc.api_func.functype,
            PyType_GenericAlloc.api_func.get_wrapper(space))
    pto.c_tp_name = rffi.str2charp(w_type.getname(space))
    pto.c_tp_basicsize = -1 # hopefully this makes malloc bail out
    pto.c_tp_itemsize = 0
    # uninitialized fields:
    # c_tp_print, c_tp_getattr, c_tp_setattr
    # XXX implement
    # c_tp_compare and the following fields (see http://docs.python.org/c-api/typeobj.html )
    w_base = best_base(space, w_type.bases_w)
    pto.c_tp_base = rffi.cast(PyTypeObjectPtr, make_ref(space, w_base))

    finish_type_1(space, pto)
    finish_type_2(space, pto, w_type)

    pto.c_tp_basicsize = rffi.sizeof(typedescr.basestruct)
    if pto.c_tp_base:
        if pto.c_tp_base.c_tp_basicsize > pto.c_tp_basicsize:
            pto.c_tp_basicsize = pto.c_tp_base.c_tp_basicsize

    # will be filled later on with the correct value
    # may not be 0
    if space.is_w(w_type, space.w_object):
        pto.c_tp_new = rffi.cast(newfunc, 1)
    update_all_slots(space, w_type, pto)
    pto.c_tp_flags |= Py_TPFLAGS_READY
    return pto

def new_empty_unicode(space, length):
    """
    Allocate a PyUnicodeObject and its buffer, but without a corresponding
    interpreter object.  The buffer may be mutated, until unicode_realize() is
    called.  Refcount of the result is 1.
    """
    typedescr = get_typedescr(space.w_unicode.layout.typedef)
    py_obj = typedescr.allocate(space, space.w_unicode)
    py_uni = rffi.cast(PyUnicodeObject, py_obj)

    buflen = length + 1
    py_uni.c_length = length
    py_uni.c_str = lltype.malloc(rffi.CWCHARP.TO, buflen,
                                 flavor='raw', zero=True,
                                 add_memory_pressure=True)
    py_uni.c_hash = -1
    py_uni.c_defenc = lltype.nullptr(PyObject.TO)
    return py_uni

def type_attach(space, py_obj, w_type):
    """
    Fills a newly allocated PyTypeObject from an existing type.
    """
    from pypy.module.cpyext.object import PyObject_Free

    assert isinstance(w_type, W_TypeObject)

    pto = rffi.cast(PyTypeObjectPtr, py_obj)

    typedescr = get_typedescr(w_type.layout.typedef)

    # dealloc
    if space.gettypeobject(w_type.layout.typedef) is w_type:
        # only for the exact type, like 'space.w_tuple' or 'space.w_list'
        pto.c_tp_dealloc = typedescr.get_dealloc().get_llhelper(space)
    else:
        # for all subtypes, use subtype_dealloc()
        pto.c_tp_dealloc = llslot(space, subtype_dealloc)
    if space.is_w(w_type, space.w_str):
        pto.c_tp_itemsize = 1
    elif space.is_w(w_type, space.w_tuple):
        pto.c_tp_itemsize = rffi.sizeof(PyObject)
    # buffer protocol
    setup_buffer_procs(space, w_type, pto)

    pto.c_tp_free = llslot(space, PyObject_Free)
    pto.c_tp_alloc = llslot(space, PyType_GenericAlloc)
    builder = space.fromcache(StaticObjectBuilder)
    if ((pto.c_tp_flags & Py_TPFLAGS_HEAPTYPE) != 0
            and builder.cpyext_type_init is None):
            # this ^^^ is not None only during startup of cpyext.  At that
            # point we might get into troubles by doing make_ref() when
            # things are not initialized yet.  So in this case, simply use
            # str2charp() and "leak" the string.
        w_typename = space.getattr(w_type, space.wrap('__name__'))
        heaptype = rffi.cast(PyHeapTypeObject, pto)
        heaptype.c_ht_name = make_ref(space, w_typename)
        from pypy.module.cpyext.bytesobject import PyString_AsString
        pto.c_tp_name = PyString_AsString(space, heaptype.c_ht_name)
    else:
        pto.c_tp_name = rffi.str2charp(w_type.name)
    # uninitialized fields:
    # c_tp_print
    # XXX implement
    # c_tp_compare and more?
    w_base = best_base(space, w_type.bases_w)
    pto.c_tp_base = rffi.cast(PyTypeObjectPtr, make_ref(space, w_base))

    if builder.cpyext_type_init is not None:
        builder.cpyext_type_init.append((pto, w_type))
    else:
        finish_type_1(space, pto)
        finish_type_2(space, pto, w_type)

    pto.c_tp_basicsize = rffi.sizeof(typedescr.basestruct)
    if pto.c_tp_base:
        if pto.c_tp_base.c_tp_basicsize > pto.c_tp_basicsize:
            pto.c_tp_basicsize = pto.c_tp_base.c_tp_basicsize
        if pto.c_tp_itemsize < pto.c_tp_base.c_tp_itemsize:
            pto.c_tp_itemsize = pto.c_tp_base.c_tp_itemsize

    # will be filled later on with the correct value
    # may not be 0
    if space.is_w(w_type, space.w_object):
        pto.c_tp_new = rffi.cast(newfunc, 1)
    update_all_slots(space, w_type, pto)
    pto.c_tp_flags |= Py_TPFLAGS_READY
    return pto