test_c.py

from __future__ import annotations

import contextlib
import traceback
import unittest.mock

import pytest
import sys
import typing as t

is_musl = False
if sys.platform == 'linux':
    try:
        from packaging.tags import platform_tags
        is_musl = any(t.startswith('musllinux') for t in platform_tags())
        del platform_tags
    except ImportError:
        pass

def _setup_path():
    import os, sys
    sys.path.insert(0, os.path.join(os.path.dirname(__file__), '..'))
_setup_path()
from _cffi_backend import *
from _cffi_backend import _get_types, _get_common_types
try:
    from _cffi_backend import _testfunc
except ImportError:
    def _testfunc(num):
        pytest.skip("_testunc() not available")
from _cffi_backend import __version__


@contextlib.contextmanager
def _assert_unraisable(error_type: type[Exception] | None, message: str = '', traceback_tokens: list[str] | None = None):
    """Assert that a given sys.unraisablehook interaction occurred (or did not occur, if error_type is None) while this context was active"""
    raised_errors: list[Exception] = []
    raised_traceback: str = ''

    # sys.unraisablehook is called more than once for chained exceptions; accumulate the errors and tracebacks for inspection
    def _capture_unraisable_hook(ur_args):
        nonlocal raised_traceback
        raised_errors.append(ur_args.exc_value)

        # NB: need to use the old etype/value/tb form until 3.10 is the minimum
        raised_traceback += (ur_args.err_msg or '' + '\n') + ''.join(traceback.format_exception(None, ur_args.exc_value, ur_args.exc_traceback))


    with pytest.MonkeyPatch.context() as mp:
        mp.setattr(sys, 'unraisablehook', _capture_unraisable_hook)
        yield

    if error_type is None:
        assert not raised_errors
        assert not raised_traceback
        return

    assert any(type(raised_error) is error_type for raised_error in raised_errors)
    assert any(message in str(raised_error) for raised_error in raised_errors)
    for t in traceback_tokens or []:
        assert t in raised_traceback

# ____________________________________________________________

import sys
assert __version__ == "1.17.1", ("This test_c.py file is for testing a version"
                                 " of cffi that differs from the one that we"
                                 " get from 'import _cffi_backend'")
if sys.version_info < (3,):
    type_or_class = "type"
    mandatory_b_prefix = ''
    mandatory_u_prefix = 'u'
    bytechr = chr
    bitem2bchr = lambda x: x
    class U(object):
        def __add__(self, other):
            return eval('u'+repr(other).replace(r'\\u', r'\u')
                                       .replace(r'\\U', r'\U'))
    u = U()
    str2bytes = str
    strict_compare = False
else:
    type_or_class = "class"
    long = int
    unicode = str
    unichr = chr
    mandatory_b_prefix = 'b'
    mandatory_u_prefix = ''
    bytechr = lambda n: bytes([n])
    bitem2bchr = bytechr
    u = ""
    str2bytes = lambda s: bytes(s, "ascii")
    strict_compare = True

def size_of_int():
    BInt = new_primitive_type("int")
    return sizeof(BInt)

def size_of_long():
    BLong = new_primitive_type("long")
    return sizeof(BLong)

def size_of_ptr():
    BInt = new_primitive_type("int")
    BPtr = new_pointer_type(BInt)
    return sizeof(BPtr)


def find_and_load_library(name, flags=RTLD_NOW):
    import ctypes.util
    if name is None:
        path = None
    else:
        path = ctypes.util.find_library(name)
        if path is None and sys.platform == 'darwin' and sys.version_info[:2] == (3, 8):
            pytest.xfail("find_library usually broken on MacOS Python 3.8")
        if path is None and name == 'c':
            assert sys.platform == 'win32'
            assert (sys.version_info >= (3,) or
                    '__pypy__' in sys.builtin_module_names)
            pytest.skip("dlopen(None) cannot work on Windows "
                         "with PyPy or Python 3")
    return load_library(path, flags)

def test_load_library():
    x = find_and_load_library('c')
    assert repr(x).startswith("<clibrary '")
    x = find_and_load_library('c', RTLD_NOW | RTLD_GLOBAL)
    assert repr(x).startswith("<clibrary '")
    x = find_and_load_library('c', RTLD_LAZY)
    assert repr(x).startswith("<clibrary '")

def test_all_rtld_symbols():
    import sys
    FFI_DEFAULT_ABI        # these symbols must be defined
    FFI_CDECL
    RTLD_LAZY
    RTLD_NOW
    RTLD_GLOBAL
    RTLD_LOCAL
    if sys.platform.startswith("linux"):
        RTLD_NODELETE
        RTLD_NOLOAD
        if not is_musl:
            RTLD_DEEPBIND

def test_new_primitive_type():
    pytest.raises(KeyError, new_primitive_type, "foo")
    p = new_primitive_type("signed char")
    assert repr(p) == "<ctype 'signed char'>"

def check_dir(p, expected):
    got = [name for name in dir(p) if not name.startswith('_')]
    assert got == sorted(expected)

def test_inspect_primitive_type():
    p = new_primitive_type("signed char")
    assert p.kind == "primitive"
    assert p.cname == "signed char"
    check_dir(p, ['cname', 'kind'])

def test_cast_to_signed_char():
    p = new_primitive_type("signed char")
    x = cast(p, -65 + 17*256)
    assert repr(x) == "<cdata 'signed char' -65>"
    assert repr(type(x)) == "<%s '_cffi_backend._CDataBase'>" % type_or_class
    assert int(x) == -65
    x = cast(p, -66 + (1<<199)*256)
    assert repr(x) == "<cdata 'signed char' -66>"
    assert int(x) == -66
    assert (x == cast(p, -66)) is True
    assert (x != cast(p, -66)) is False
    q = new_primitive_type("short")
    assert (x == cast(q, -66)) is True
    assert (x != cast(q, -66)) is False

def test_sizeof_type():
    pytest.raises(TypeError, sizeof, 42.5)
    p = new_primitive_type("short")
    assert sizeof(p) == 2

def test_integer_types():
    for name in ['signed char', 'short', 'int', 'long', 'long long']:
        p = new_primitive_type(name)
        size = sizeof(p)
        min = -(1 << (8*size-1))
        max = (1 << (8*size-1)) - 1
        assert int(cast(p, min)) == min
        assert int(cast(p, max)) == max
        assert int(cast(p, min - 1)) == max
        assert int(cast(p, max + 1)) == min
        pytest.raises(TypeError, cast, p, None)
        assert long(cast(p, min - 1)) == max
        assert int(cast(p, b'\x08')) == 8
        assert int(cast(p, u+'\x08')) == 8
    for name in ['char', 'short', 'int', 'long', 'long long']:
        p = new_primitive_type('unsigned ' + name)
        size = sizeof(p)
        max = (1 << (8*size)) - 1
        assert int(cast(p, 0)) == 0
        assert int(cast(p, max)) == max
        assert int(cast(p, -1)) == max
        assert int(cast(p, max + 1)) == 0
        assert long(cast(p, -1)) == max
        assert int(cast(p, b'\xFE')) == 254
        assert int(cast(p, u+'\xFE')) == 254

def test_no_float_on_int_types():
    p = new_primitive_type('long')
    pytest.raises(TypeError, float, cast(p, 42))
    pytest.raises(TypeError, complex, cast(p, 42))

def test_float_types():
    INF = 1E200 * 1E200
    for name in ["float", "double"]:
        p = new_primitive_type(name)
        assert bool(cast(p, 0)) is False      # since 1.7
        assert bool(cast(p, -0.0)) is False   # since 1.7
        assert bool(cast(p, 1e-42)) is True
        assert bool(cast(p, -1e-42)) is True
        assert bool(cast(p, INF))
        assert bool(cast(p, -INF))
        assert bool(cast(p, float("nan")))
        assert int(cast(p, -150)) == -150
        assert int(cast(p, 61.91)) == 61
        assert long(cast(p, 61.91)) == 61
        assert type(int(cast(p, 61.91))) is int
        assert type(int(cast(p, 1E22))) is long
        assert type(long(cast(p, 61.91))) is long
        assert type(long(cast(p, 1E22))) is long
        pytest.raises(OverflowError, int, cast(p, INF))
        pytest.raises(OverflowError, int, cast(p, -INF))
        assert float(cast(p, 1.25)) == 1.25
        assert float(cast(p, INF)) == INF
        assert float(cast(p, -INF)) == -INF
        if name == "float":
            assert float(cast(p, 1.1)) != 1.1     # rounding error
            assert float(cast(p, 1E200)) == INF   # limited range

        assert cast(p, -1.1) == cast(p, -1.1)
        assert repr(float(cast(p, -0.0))) == '-0.0'
        assert float(cast(p, b'\x09')) == 9.0
        assert float(cast(p, u+'\x09')) == 9.0
        assert float(cast(p, True)) == 1.0
        pytest.raises(TypeError, cast, p, None)

def test_complex_types():
    INF = 1E200 * 1E200
    for name in ["float", "double"]:
        p = new_primitive_type("_cffi_" + name + "_complex_t")
        assert bool(cast(p, 0)) is False
        assert bool(cast(p, INF))
        assert bool(cast(p, -INF))
        assert bool(cast(p, 0j)) is False
        assert bool(cast(p, INF*1j))
        assert bool(cast(p, -INF*1j))
        # "can't convert complex to float", like CPython's "float(0j)"
        pytest.raises(TypeError, int, cast(p, -150))
        pytest.raises(TypeError, long, cast(p, -150))
        pytest.raises(TypeError, float, cast(p, -150))
        assert complex(cast(p, 1.25)) == 1.25
        assert complex(cast(p, 1.25j)) == 1.25j
        assert complex(cast(p, complex(0,INF))) == complex(0,INF)
        assert complex(cast(p, -INF)) == -INF
        if name == "float":
            assert complex(cast(p, 1.1j)) != 1.1j         # rounding error
            assert complex(cast(p, 1E200+3j)) == INF+3j   # limited range
            assert complex(cast(p, complex(3,1E200))) == complex(3,INF) # limited range

        assert cast(p, -1.1j) == cast(p, -1.1j)
        assert repr(complex(cast(p, -0.0)).real) == '-0.0'
        #assert repr(complex(cast(p, -0j))) == '-0j'   # http://bugs.python.org/issue29602
        assert complex(cast(p, b'\x09')) == 9.0 + 0j
        assert complex(cast(p, u+'\x09')) == 9.0 + 0j
        assert complex(cast(p, True)) == 1.0 + 0j
        pytest.raises(TypeError, cast, p, None)
        #
        pytest.raises(TypeError, cast, new_primitive_type(name), 1+0j)
        #
        for basetype in ["char", "int", "uint64_t", "float",
                         "double", "long double"]:
            baseobj = cast(new_primitive_type(basetype), 65)
            pytest.raises(TypeError, complex, baseobj)
        #
        BArray = new_array_type(new_pointer_type(p), 10)
        x = newp(BArray, None)
        x[5] = 12.34 + 56.78j
        assert type(x[5]) is complex
        assert abs(x[5] - (12.34 + 56.78j)) < 1e-5
        assert (x[5] == 12.34 + 56.78j) == (name == "double")  # rounding error
        #
        class Foo:
            def __complex__(self):
                return 2 + 3j
        assert complex(Foo()) == 2 + 3j
        assert complex(cast(p, Foo())) == 2 + 3j
    pytest.raises(TypeError, cast, new_primitive_type("int"), 1+0j)

def test_character_type():
    p = new_primitive_type("char")
    assert bool(cast(p, 'A')) is True
    assert bool(cast(p, '\x00')) is False    # since 1.7
    assert cast(p, '\x00') == cast(p, -17*256)
    assert int(cast(p, 'A')) == 65
    assert long(cast(p, 'A')) == 65
    assert type(int(cast(p, 'A'))) is int
    assert type(long(cast(p, 'A'))) is long
    assert str(cast(p, 'A')) == repr(cast(p, 'A'))
    assert repr(cast(p, 'A')) == "<cdata 'char' %s'A'>" % mandatory_b_prefix
    assert repr(cast(p, 255)) == r"<cdata 'char' %s'\xff'>" % mandatory_b_prefix
    assert repr(cast(p, 0)) == r"<cdata 'char' %s'\x00'>" % mandatory_b_prefix

def test_pointer_type():
    p = new_primitive_type("int")
    assert repr(p) == "<ctype 'int'>"
    p = new_pointer_type(p)
    assert repr(p) == "<ctype 'int *'>"
    p = new_pointer_type(p)
    assert repr(p) == "<ctype 'int * *'>"
    p = new_pointer_type(p)
    assert repr(p) == "<ctype 'int * * *'>"

def test_inspect_pointer_type():
    p1 = new_primitive_type("int")
    p2 = new_pointer_type(p1)
    assert p2.kind == "pointer"
    assert p2.cname == "int *"
    assert p2.item is p1
    check_dir(p2, ['cname', 'kind', 'item'])
    p3 = new_pointer_type(p2)
    assert p3.item is p2

def test_pointer_to_int():
    BInt = new_primitive_type("int")
    pytest.raises(TypeError, newp, BInt)
    pytest.raises(TypeError, newp, BInt, None)
    BPtr = new_pointer_type(BInt)
    p = newp(BPtr)
    assert repr(p) == "<cdata 'int *' owning %d bytes>" % size_of_int()
    p = newp(BPtr, None)
    assert repr(p) == "<cdata 'int *' owning %d bytes>" % size_of_int()
    p = newp(BPtr, 5000)
    assert repr(p) == "<cdata 'int *' owning %d bytes>" % size_of_int()
    q = cast(BPtr, p)
    assert repr(q).startswith("<cdata 'int *' 0x")
    assert p == q
    assert hash(p) == hash(q)
    e = pytest.raises(TypeError, newp, new_array_type(BPtr, None), None)
    assert str(e.value) == (
        "expected new array length or list/tuple/str, not NoneType")

def test_pointer_bool():
    BInt = new_primitive_type("int")
    BPtr = new_pointer_type(BInt)
    p = cast(BPtr, 0)
    assert bool(p) is False
    p = cast(BPtr, 42)
    assert bool(p) is True

def test_pointer_to_pointer():
    BInt = new_primitive_type("int")
    BPtr = new_pointer_type(BInt)
    BPtrPtr = new_pointer_type(BPtr)
    p = newp(BPtrPtr, None)
    assert repr(p) == "<cdata 'int * *' owning %d bytes>" % size_of_ptr()

def test_reading_pointer_to_int():
    BInt = new_primitive_type("int")
    BPtr = new_pointer_type(BInt)
    p = newp(BPtr, None)
    assert p[0] == 0
    p = newp(BPtr, 5000)
    assert p[0] == 5000
    with pytest.raises(IndexError):
        p[1]
    with pytest.raises(IndexError):
        p[-1]

def test_reading_pointer_to_float():
    BFloat = new_primitive_type("float")
    pytest.raises(TypeError, newp, BFloat, None)
    BPtr = new_pointer_type(BFloat)
    p = newp(BPtr, None)
    assert p[0] == 0.0 and type(p[0]) is float
    p = newp(BPtr, 1.25)
    assert p[0] == 1.25 and type(p[0]) is float
    p = newp(BPtr, 1.1)
    assert p[0] != 1.1 and abs(p[0] - 1.1) < 1E-5   # rounding errors

def test_cast_float_to_int():
    for type in ["int", "unsigned int", "long", "unsigned long",
                 "long long", "unsigned long long"]:
        p = new_primitive_type(type)
        assert int(cast(p, 4.2)) == 4
        pytest.raises(TypeError, newp, new_pointer_type(p), 4.2)

def test_newp_integer_types():
    for name in ['signed char', 'short', 'int', 'long', 'long long']:
        p = new_primitive_type(name)
        pp = new_pointer_type(p)
        size = sizeof(p)
        min = -(1 << (8*size-1))
        max = (1 << (8*size-1)) - 1
        assert newp(pp, min)[0] == min
        assert newp(pp, max)[0] == max
        pytest.raises(OverflowError, newp, pp, min - 2 ** 32)
        pytest.raises(OverflowError, newp, pp, min - 2 ** 64)
        pytest.raises(OverflowError, newp, pp, max + 2 ** 32)
        pytest.raises(OverflowError, newp, pp, max + 2 ** 64)
        pytest.raises(OverflowError, newp, pp, min - 1)
        pytest.raises(OverflowError, newp, pp, max + 1)
        pytest.raises(OverflowError, newp, pp, min - 1 - 2 ** 32)
        pytest.raises(OverflowError, newp, pp, min - 1 - 2 ** 64)
        pytest.raises(OverflowError, newp, pp, max + 1)
        pytest.raises(OverflowError, newp, pp, max + 1 + 2 ** 32)
        pytest.raises(OverflowError, newp, pp, max + 1 + 2 ** 64)
        pytest.raises(TypeError, newp, pp, 1.0)
    for name in ['char', 'short', 'int', 'long', 'long long']:
        p = new_primitive_type('unsigned ' + name)
        pp = new_pointer_type(p)
        size = sizeof(p)
        max = (1 << (8*size)) - 1
        assert newp(pp, 0)[0] == 0
        assert newp(pp, max)[0] == max
        pytest.raises(OverflowError, newp, pp, -1)
        pytest.raises(OverflowError, newp, pp, max + 1)

def test_reading_pointer_to_char():
    BChar = new_primitive_type("char")
    pytest.raises(TypeError, newp, BChar, None)
    BPtr = new_pointer_type(BChar)
    p = newp(BPtr, None)
    assert p[0] == b'\x00'
    p = newp(BPtr, b'A')
    assert p[0] == b'A'
    pytest.raises(TypeError, newp, BPtr, 65)
    pytest.raises(TypeError, newp, BPtr, b"foo")
    pytest.raises(TypeError, newp, BPtr, u+"foo")
    c = cast(BChar, b'A')
    assert str(c) == repr(c)
    assert int(c) == ord(b'A')
    pytest.raises(TypeError, cast, BChar, b'foo')
    pytest.raises(TypeError, cast, BChar, u+'foo')
    e = pytest.raises(TypeError, newp, new_array_type(BPtr, None), 12.3)
    assert str(e.value) == (
        "expected new array length or list/tuple/str, not float")

def test_reading_pointer_to_pointer():
    BVoidP = new_pointer_type(new_void_type())
    BCharP = new_pointer_type(new_primitive_type("char"))
    BInt = new_primitive_type("int")
    BIntPtr = new_pointer_type(BInt)
    BIntPtrPtr = new_pointer_type(BIntPtr)
    q = newp(BIntPtr, 42)
    assert q[0] == 42
    p = newp(BIntPtrPtr, None)
    assert p[0] is not None
    assert p[0] == cast(BVoidP, 0)
    assert p[0] == cast(BCharP, 0)
    assert p[0] != None
    assert repr(p[0]) == "<cdata 'int *' NULL>"
    p[0] = q
    assert p[0] != cast(BVoidP, 0)
    assert p[0] != cast(BCharP, 0)
    assert p[0][0] == 42
    q[0] += 1
    assert p[0][0] == 43
    p = newp(BIntPtrPtr, q)
    assert p[0][0] == 43

def test_load_standard_library():
    if sys.platform == "win32":
        pytest.raises(OSError, find_and_load_library, None)
        return
    x = find_and_load_library(None)
    BVoidP = new_pointer_type(new_void_type())
    assert x.load_function(BVoidP, 'strcpy')
    pytest.raises(AttributeError, x.load_function,
                   BVoidP, 'xxx_this_function_does_not_exist')
    # the next one is from 'libm', not 'libc', but we assume
    # that it is already loaded too, so it should work
    assert x.load_function(BVoidP, 'sqrt')
    #
    x.close_lib()
    pytest.raises(ValueError, x.load_function, BVoidP, 'sqrt')
    x.close_lib()

def test_no_len_on_nonarray():
    p = new_primitive_type("int")
    pytest.raises(TypeError, len, cast(p, 42))

def test_cmp_none():
    p = new_primitive_type("int")
    x = cast(p, 42)
    assert (x == None) is False
    assert (x != None) is True
    assert (x == ["hello"]) is False
    assert (x != ["hello"]) is True
    y = cast(p, 0)
    assert (y == None) is False

def test_invalid_indexing():
    p = new_primitive_type("int")
    x = cast(p, 42)
    with pytest.raises(TypeError):
        x[0]

def test_default_str():
    BChar = new_primitive_type("char")
    x = cast(BChar, 42)
    assert str(x) == repr(x)
    BInt = new_primitive_type("int")
    x = cast(BInt, 42)
    assert str(x) == repr(x)
    BArray = new_array_type(new_pointer_type(BInt), 10)
    x = newp(BArray, None)
    assert str(x) == repr(x)

def test_default_unicode():
    BInt = new_primitive_type("int")
    x = cast(BInt, 42)
    assert unicode(x) == unicode(repr(x))
    BArray = new_array_type(new_pointer_type(BInt), 10)
    x = newp(BArray, None)
    assert unicode(x) == unicode(repr(x))

def test_cast_from_cdataint():
    BInt = new_primitive_type("int")
    x = cast(BInt, 0)
    y = cast(new_pointer_type(BInt), x)
    assert bool(y) is False
    #
    x = cast(BInt, 42)
    y = cast(BInt, x)
    assert int(y) == 42
    y = cast(new_primitive_type("char"), x)
    assert int(y) == 42
    y = cast(new_primitive_type("float"), x)
    assert float(y) == 42.0
    #
    z = cast(BInt, 42.5)
    assert int(z) == 42
    z = cast(BInt, y)
    assert int(z) == 42

def test_void_type():
    p = new_void_type()
    assert p.kind == "void"
    assert p.cname == "void"
    check_dir(p, ['kind', 'cname'])

def test_array_type():
    p = new_primitive_type("int")
    assert repr(p) == "<ctype 'int'>"
    #
    pytest.raises(TypeError, new_array_type, new_pointer_type(p), "foo")
    pytest.raises(ValueError, new_array_type, new_pointer_type(p), -42)
    #
    p1 = new_array_type(new_pointer_type(p), None)
    assert repr(p1) == "<ctype 'int[]'>"
    pytest.raises(ValueError, new_array_type, new_pointer_type(p1), 42)
    #
    p1 = new_array_type(new_pointer_type(p), 42)
    p2 = new_array_type(new_pointer_type(p1), 25)
    assert repr(p2) == "<ctype 'int[25][42]'>"
    p2 = new_array_type(new_pointer_type(p1), None)
    assert repr(p2) == "<ctype 'int[][42]'>"
    #
    pytest.raises(OverflowError,
                   new_array_type, new_pointer_type(p), sys.maxsize+1)
    pytest.raises(OverflowError,
                   new_array_type, new_pointer_type(p), sys.maxsize // 3)

def test_inspect_array_type():
    p = new_primitive_type("int")
    p1 = new_array_type(new_pointer_type(p), None)
    assert p1.kind == "array"
    assert p1.cname == "int[]"
    assert p1.item is p
    assert p1.length is None
    check_dir(p1, ['cname', 'kind', 'item', 'length'])
    p1 = new_array_type(new_pointer_type(p), 42)
    assert p1.kind == "array"
    assert p1.cname == "int[42]"
    assert p1.item is p
    assert p1.length == 42
    check_dir(p1, ['cname', 'kind', 'item', 'length'])

def test_array_instance():
    LENGTH = 1423
    p = new_primitive_type("int")
    p1 = new_array_type(new_pointer_type(p), LENGTH)
    a = newp(p1, None)
    assert repr(a) == "<cdata 'int[%d]' owning %d bytes>" % (
        LENGTH, LENGTH * size_of_int())
    assert len(a) == LENGTH
    for i in range(LENGTH):
        assert a[i] == 0
    with pytest.raises(IndexError):
        a[LENGTH]
    with pytest.raises(IndexError):
        a[-1]
    for i in range(LENGTH):
        a[i] = i * i + 1
    for i in range(LENGTH):
        assert a[i] == i * i + 1
    with pytest.raises(IndexError) as e:
        a[LENGTH+100] = 500
    assert ('(expected %d < %d)' % (LENGTH+100, LENGTH)) in str(e.value)
    pytest.raises(TypeError, int, a)

def test_array_of_unknown_length_instance():
    p = new_primitive_type("int")
    p1 = new_array_type(new_pointer_type(p), None)
    pytest.raises(TypeError, newp, p1, None)
    pytest.raises(ValueError, newp, p1, -42)
    a = newp(p1, 42)
    assert len(a) == 42
    for i in range(42):
        a[i] -= i
    for i in range(42):
        assert a[i] == -i
    with pytest.raises(IndexError):
        a[42]
    with pytest.raises(IndexError):
        a[-1]
    with pytest.raises(IndexError):
        a[42] = 123
    with pytest.raises(IndexError):
        a[-1] = 456

def test_array_of_unknown_length_instance_with_initializer():
    p = new_primitive_type("int")
    p1 = new_array_type(new_pointer_type(p), None)
    a = newp(p1, list(range(42)))
    assert len(a) == 42
    a = newp(p1, tuple(range(142)))
    assert len(a) == 142

def test_array_initializer():
    p = new_primitive_type("int")
    p1 = new_array_type(new_pointer_type(p), None)
    a = newp(p1, list(range(100, 142)))
    for i in range(42):
        assert a[i] == 100 + i
    #
    p2 = new_array_type(new_pointer_type(p), 43)
    a = newp(p2, tuple(range(100, 142)))
    for i in range(42):
        assert a[i] == 100 + i
    assert a[42] == 0      # extra uninitialized item

def test_array_add():
    p = new_primitive_type("int")
    p1 = new_array_type(new_pointer_type(p), 5)    # int[5]
    p2 = new_array_type(new_pointer_type(p1), 3)   # int[3][5]
    a = newp(p2, [list(range(n, n+5)) for n in [100, 200, 300]])
    assert repr(a) == "<cdata 'int[3][5]' owning %d bytes>" % (
        3*5*size_of_int(),)
    assert repr(a + 0).startswith("<cdata 'int(*)[5]' 0x")
    assert 0 + a == a + 0 != 1 + a == a + 1
    assert repr(a[0]).startswith("<cdata 'int[5]' 0x")
    assert repr((a + 0)[0]).startswith("<cdata 'int[5]' 0x")
    assert repr(a[0] + 0).startswith("<cdata 'int *' 0x")
    assert type(a[0][0]) is int
    assert type((a[0] + 0)[0]) is int

def test_array_sub():
    BInt = new_primitive_type("int")
    BArray = new_array_type(new_pointer_type(BInt), 5)   # int[5]
    a = newp(BArray, None)
    p = a + 1
    assert p - a == 1
    assert p - (a+0) == 1
    assert a == (p - 1)
    BPtr = new_pointer_type(new_primitive_type("short"))
    q = newp(BPtr, None)
    with pytest.raises(TypeError):
        p - q
    with pytest.raises(TypeError):
        q - p
    with pytest.raises(TypeError):
        a - q
    with pytest.raises(TypeError) as e:
        q - a
    assert str(e.value) == "cannot subtract cdata 'short *' and cdata 'int *'"

def test_ptr_sub_unaligned():
    BInt = new_primitive_type("int")
    BIntPtr = new_pointer_type(BInt)
    a = cast(BIntPtr, 1240)
    for bi in range(1430, 1438):
        b = cast(BIntPtr, bi)
        if ((bi - 1240) % size_of_int()) == 0:
            assert b - a == (bi - 1240) // size_of_int()
            assert a - b == (1240 - bi) // size_of_int()
        else:
            with pytest.raises(ValueError):
                b - a
            with pytest.raises(ValueError):
                a - b

def test_cast_primitive_from_cdata():
    p = new_primitive_type("int")
    n = cast(p, cast(p, -42))
    assert int(n) == -42
    #
    p = new_primitive_type("unsigned int")
    n = cast(p, cast(p, 42))
    assert int(n) == 42
    #
    p = new_primitive_type("long long")
    n = cast(p, cast(p, -(1<<60)))
    assert int(n) == -(1<<60)
    #
    p = new_primitive_type("unsigned long long")
    n = cast(p, cast(p, 1<<63))
    assert int(n) == 1<<63
    #
    p = new_primitive_type("float")
    n = cast(p, cast(p, 42.5))
    assert float(n) == 42.5
    #
    p = new_primitive_type("char")
    n = cast(p, cast(p, "A"))
    assert int(n) == ord("A")

def test_new_primitive_from_cdata():
    p = new_primitive_type("int")
    p1 = new_pointer_type(p)
    n = newp(p1, cast(p, -42))
    assert n[0] == -42
    #
    p = new_primitive_type("unsigned int")
    p1 = new_pointer_type(p)
    n = newp(p1, cast(p, 42))
    assert n[0] == 42
    #
    p = new_primitive_type("float")
    p1 = new_pointer_type(p)
    n = newp(p1, cast(p, 42.5))
    assert n[0] == 42.5
    #
    p = new_primitive_type("char")
    p1 = new_pointer_type(p)
    n = newp(p1, cast(p, "A"))
    assert n[0] == b"A"

def test_cast_between_pointers():
    BIntP = new_pointer_type(new_primitive_type("int"))
    BIntA = new_array_type(BIntP, None)
    a = newp(BIntA, [40, 41, 42, 43, 44])
    BShortP = new_pointer_type(new_primitive_type("short"))
    b = cast(BShortP, a)
    c = cast(BIntP, b)
    assert c[3] == 43
    BLongLong = new_primitive_type("long long")
    d = cast(BLongLong, c)
    e = cast(BIntP, d)
    assert e[3] == 43
    f = cast(BIntP, int(d))
    assert f[3] == 43
    #
    b = cast(BShortP, 0)
    assert not b
    c = cast(BIntP, b)
    assert not c
    assert int(cast(BLongLong, c)) == 0

def test_alignof():
    BInt = new_primitive_type("int")
    assert alignof(BInt) == sizeof(BInt)
    BPtr = new_pointer_type(BInt)
    assert alignof(BPtr) == sizeof(BPtr)
    BArray = new_array_type(BPtr, None)
    assert alignof(BArray) == alignof(BInt)

def test_new_struct_type():
    BStruct = new_struct_type("foo")
    assert repr(BStruct) == "<ctype 'foo'>"
    BStruct = new_struct_type("struct foo")
    assert repr(BStruct) == "<ctype 'struct foo'>"
    BPtr = new_pointer_type(BStruct)
    assert repr(BPtr) == "<ctype 'struct foo *'>"
    pytest.raises(ValueError, sizeof, BStruct)
    pytest.raises(ValueError, alignof, BStruct)

def test_new_union_type():
    BUnion = new_union_type("union foo")
    assert repr(BUnion) == "<ctype 'union foo'>"
    BPtr = new_pointer_type(BUnion)
    assert repr(BPtr) == "<ctype 'union foo *'>"

def test_complete_struct():
    BLong = new_primitive_type("long")
    BChar = new_primitive_type("char")
    BShort = new_primitive_type("short")
    BStruct = new_struct_type("struct foo")
    assert BStruct.kind == "struct"
    assert BStruct.cname == "struct foo"
    assert BStruct.fields is None
    check_dir(BStruct, ['cname', 'kind', 'fields'])
    #
    complete_struct_or_union(BStruct, [('a1', BLong, -1),
                                       ('a2', BChar, -1),
                                       ('a3', BShort, -1)])
    d = BStruct.fields
    assert len(d) == 3
    assert d[0][0] == 'a1'
    assert d[0][1].type is BLong
    assert d[0][1].offset == 0
    assert d[0][1].bitshift == -1
    assert d[0][1].bitsize == -1
    assert d[1][0] == 'a2'
    assert d[1][1].type is BChar
    assert d[1][1].offset == sizeof(BLong)
    assert d[1][1].bitshift == -1
    assert d[1][1].bitsize == -1
    assert d[2][0] == 'a3'
    assert d[2][1].type is BShort
    assert d[2][1].offset == sizeof(BLong) + sizeof(BShort)
    assert d[2][1].bitshift == -1
    assert d[2][1].bitsize == -1
    assert sizeof(BStruct) == 2 * sizeof(BLong)
    assert alignof(BStruct) == alignof(BLong)

def test_complete_union():
    BLong = new_primitive_type("long")
    BChar = new_primitive_type("char")
    BUnion = new_union_type("union foo")
    assert BUnion.kind == "union"
    assert BUnion.cname == "union foo"
    assert BUnion.fields is None
    complete_struct_or_union(BUnion, [('a1', BLong, -1),
                                      ('a2', BChar, -1)])
    d = BUnion.fields
    assert len(d) == 2
    assert d[0][0] == 'a1'
    assert d[0][1].type is BLong
    assert d[0][1].offset == 0
    assert d[1][0] == 'a2'
    assert d[1][1].type is BChar
    assert d[1][1].offset == 0
    assert sizeof(BUnion) == sizeof(BLong)
    assert alignof(BUnion) == alignof(BLong)

def test_struct_instance():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    p = cast(BStructPtr, 42)
    with pytest.raises(AttributeError) as e:
        p.a1    # opaque
    assert str(e.value) == ("cdata 'struct foo *' points to an opaque type: "
                            "cannot read fields")
    with pytest.raises(AttributeError) as e:
        p.a1 = 10    # opaque
    assert str(e.value) == ("cdata 'struct foo *' points to an opaque type: "
                            "cannot write fields")

    complete_struct_or_union(BStruct, [('a1', BInt, -1),
                                       ('a2', BInt, -1)])
    p = newp(BStructPtr, None)
    s = p[0]
    assert s.a1 == 0
    s.a2 = 123
    assert s.a1 == 0
    assert s.a2 == 123
    with pytest.raises(OverflowError):
        s.a1 = sys.maxsize+1
    assert s.a1 == 0
    with pytest.raises(AttributeError) as e:
        p.foobar
    assert str(e.value) == "cdata 'struct foo *' has no field 'foobar'"
    with pytest.raises(AttributeError) as e:
        p.foobar = 42
    assert str(e.value) == "cdata 'struct foo *' has no field 'foobar'"
    with pytest.raises(AttributeError) as e:
        s.foobar
    assert str(e.value) == "cdata 'struct foo' has no field 'foobar'"
    with pytest.raises(AttributeError) as e:
        s.foobar = 42
    assert str(e.value) == "cdata 'struct foo' has no field 'foobar'"
    j = cast(BInt, 42)
    with pytest.raises(AttributeError) as e:
        j.foobar
    assert str(e.value) == "cdata 'int' has no attribute 'foobar'"
    with pytest.raises(AttributeError) as e:
        j.foobar = 42
    assert str(e.value) == "cdata 'int' has no attribute 'foobar'"
    j = cast(new_pointer_type(BInt), 42)
    with pytest.raises(AttributeError) as e:
        j.foobar
    assert str(e.value) == "cdata 'int *' has no attribute 'foobar'"
    with pytest.raises(AttributeError) as e:
        j.foobar = 42
    assert str(e.value) == "cdata 'int *' has no attribute 'foobar'"
    pp = newp(new_pointer_type(BStructPtr), p)
    with pytest.raises(AttributeError) as e:
        pp.a1
    assert str(e.value) == "cdata 'struct foo * *' has no attribute 'a1'"
    with pytest.raises(AttributeError) as e:
        pp.a1 = 42
    assert str(e.value) == "cdata 'struct foo * *' has no attribute 'a1'"

def test_union_instance():
    BInt = new_primitive_type("int")
    BUInt = new_primitive_type("unsigned int")
    BUnion = new_union_type("union bar")
    complete_struct_or_union(BUnion, [('a1', BInt, -1), ('a2', BUInt, -1)])
    p = newp(new_pointer_type(BUnion), [-42])
    bigval = -42 + (1 << (8*size_of_int()))
    assert p.a1 == -42
    assert p.a2 == bigval
    p = newp(new_pointer_type(BUnion), {'a2': bigval})
    assert p.a1 == -42
    assert p.a2 == bigval
    pytest.raises(OverflowError, newp, new_pointer_type(BUnion),
                   {'a1': bigval})
    p = newp(new_pointer_type(BUnion), [])
    assert p.a1 == p.a2 == 0

def test_struct_pointer():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BInt, -1),
                                       ('a2', BInt, -1)])
    p = newp(BStructPtr, None)
    assert p.a1 == 0      # read/write via the pointer (C equivalent: '->')
    p.a2 = 123
    assert p.a1 == 0
    assert p.a2 == 123

def test_struct_init_list():
    BVoidP = new_pointer_type(new_void_type())
    BInt = new_primitive_type("int")
    BIntPtr = new_pointer_type(BInt)
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BInt, -1),
                                       ('a2', BInt, -1),
                                       ('a3', BInt, -1),
                                       ('p4', BIntPtr, -1)])
    s = newp(BStructPtr, [123, 456])
    assert s.a1 == 123
    assert s.a2 == 456
    assert s.a3 == 0
    assert s.p4 == cast(BVoidP, 0)
    assert s.p4 != 0
    #
    s = newp(BStructPtr, {'a2': 41122, 'a3': -123})
    assert s.a1 == 0
    assert s.a2 == 41122
    assert s.a3 == -123
    assert s.p4 == cast(BVoidP, 0)
    #
    pytest.raises(KeyError, newp, BStructPtr, {'foobar': 0})
    #
    p = newp(BIntPtr, 14141)
    s = newp(BStructPtr, [12, 34, 56, p])
    assert s.p4 == p
    assert s.p4
    #
    s = newp(BStructPtr, [12, 34, 56, cast(BVoidP, 0)])
    assert s.p4 == cast(BVoidP, 0)
    assert not s.p4
    #
    pytest.raises(TypeError, newp, BStructPtr, [12, 34, 56, None])

def test_array_in_struct():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    BArrayInt5 = new_array_type(new_pointer_type(BInt), 5)
    complete_struct_or_union(BStruct, [('a1', BArrayInt5, -1)])
    s = newp(new_pointer_type(BStruct), [[20, 24, 27, 29, 30]])
    assert s.a1[2] == 27
    assert repr(s.a1).startswith("<cdata 'int[5]' 0x")

def test_offsetof():
    def offsetof(BType, fieldname):
        return typeoffsetof(BType, fieldname)[1]
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    pytest.raises(TypeError, offsetof, BInt, "abc")
    pytest.raises(TypeError, offsetof, BStruct, "abc")
    complete_struct_or_union(BStruct, [('abc', BInt, -1), ('def', BInt, -1)])
    assert offsetof(BStruct, 'abc') == 0
    assert offsetof(BStruct, 'def') == size_of_int()
    pytest.raises(KeyError, offsetof, BStruct, "ghi")
    assert offsetof(new_pointer_type(BStruct), "def") == size_of_int()

def test_function_type():
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BInt, BInt), BInt, False)
    assert repr(BFunc) == "<ctype 'int(*)(int, int)'>"
    BFunc2 = new_function_type((), BFunc, False)
    assert repr(BFunc2) == "<ctype 'int(*(*)())(int, int)'>"

def test_inspect_function_type():
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BInt, BInt), BInt, False)
    assert BFunc.kind == "function"
    assert BFunc.cname == "int(*)(int, int)"
    assert BFunc.args == (BInt, BInt)
    assert BFunc.result is BInt
    assert BFunc.ellipsis is False
    assert BFunc.abi == FFI_DEFAULT_ABI

def test_function_type_taking_struct():
    BChar = new_primitive_type("char")
    BShort = new_primitive_type("short")
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('a1', BChar, -1),
                                       ('a2', BShort, -1)])
    BFunc = new_function_type((BStruct,), BShort, False)
    assert repr(BFunc) == "<ctype 'short(*)(struct foo)'>"

def test_function_void_result():
    BVoid = new_void_type()
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BInt, BInt), BVoid, False)
    assert repr(BFunc) == "<ctype 'void(*)(int, int)'>"

def test_function_void_arg():
    BVoid = new_void_type()
    BInt = new_primitive_type("int")
    pytest.raises(TypeError, new_function_type, (BVoid,), BInt, False)

def test_call_function_0():
    BSignedChar = new_primitive_type("signed char")
    BFunc0 = new_function_type((BSignedChar, BSignedChar), BSignedChar, False)
    f = cast(BFunc0, _testfunc(0))
    assert f(40, 2) == 42
    assert f(-100, -100) == -200 + 256
    pytest.raises(OverflowError, f, 128, 0)
    pytest.raises(OverflowError, f, 0, 128)

def test_call_function_0_pretend_bool_result():
    BSignedChar = new_primitive_type("signed char")
    BBool = new_primitive_type("_Bool")
    BFunc0 = new_function_type((BSignedChar, BSignedChar), BBool, False)
    f = cast(BFunc0, _testfunc(0))
    assert f(40, -39) is True
    assert f(40, -40) is False
    pytest.raises(ValueError, f, 40, 2)

def test_call_function_1():
    BInt = new_primitive_type("int")
    BLong = new_primitive_type("long")
    BFunc1 = new_function_type((BInt, BLong), BLong, False)
    f = cast(BFunc1, _testfunc(1))
    assert f(40, 2) == 42
    assert f(-100, -100) == -200
    int_max = (1 << (8*size_of_int()-1)) - 1
    long_max = (1 << (8*size_of_long()-1)) - 1
    if int_max == long_max:
        assert f(int_max, 1) == - int_max - 1
    else:
        assert f(int_max, 1) == int_max + 1

def test_call_function_2():
    BLongLong = new_primitive_type("long long")
    BFunc2 = new_function_type((BLongLong, BLongLong), BLongLong, False)
    f = cast(BFunc2, _testfunc(2))
    longlong_max = (1 << (8*sizeof(BLongLong)-1)) - 1
    assert f(longlong_max - 42, 42) == longlong_max
    assert f(43, longlong_max - 42) == - longlong_max - 1

def test_call_function_3():
    BFloat = new_primitive_type("float")
    BDouble = new_primitive_type("double")
    BFunc3 = new_function_type((BFloat, BDouble), BDouble, False)
    f = cast(BFunc3, _testfunc(3))
    assert f(1.25, 5.1) == 1.25 + 5.1     # exact
    res = f(1.3, 5.1)
    assert res != 6.4 and abs(res - 6.4) < 1E-5    # inexact

def test_call_function_4():
    BFloat = new_primitive_type("float")
    BDouble = new_primitive_type("double")
    BFunc4 = new_function_type((BFloat, BDouble), BFloat, False)
    f = cast(BFunc4, _testfunc(4))
    res = f(1.25, 5.1)
    assert res != 6.35 and abs(res - 6.35) < 1E-5    # inexact

def test_call_function_5():
    BVoid = new_void_type()
    BFunc5 = new_function_type((), BVoid, False)
    f = cast(BFunc5, _testfunc(5))
    f()   # did not crash

def test_call_function_6():
    BInt = new_primitive_type("int")
    BIntPtr = new_pointer_type(BInt)
    BFunc6 = new_function_type((BIntPtr,), BIntPtr, False)
    f = cast(BFunc6, _testfunc(6))
    x = newp(BIntPtr, 42)
    res = f(x)
    assert typeof(res) is BIntPtr
    assert res[0] == 42 - 1000
    #
    BIntArray = new_array_type(BIntPtr, None)
    BFunc6bis = new_function_type((BIntArray,), BIntPtr, False)
    f = cast(BFunc6bis, _testfunc(6))
    #
    res = f([142])
    assert typeof(res) is BIntPtr
    assert res[0] == 142 - 1000
    #
    res = f((143,))
    assert typeof(res) is BIntPtr
    assert res[0] == 143 - 1000
    #
    x = newp(BIntArray, [242])
    res = f(x)
    assert typeof(res) is BIntPtr
    assert res[0] == 242 - 1000
    #
    pytest.raises(TypeError, f, 123456)
    pytest.raises(TypeError, f, "foo")
    pytest.raises(TypeError, f, u+"bar")

def test_call_function_7():
    BChar = new_primitive_type("char")
    BShort = new_primitive_type("short")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BChar, -1),
                                       ('a2', BShort, -1)])
    BFunc7 = new_function_type((BStruct,), BShort, False)
    f = cast(BFunc7, _testfunc(7))
    res = f({'a1': b'A', 'a2': -4042})
    assert res == -4042 + ord(b'A')
    #
    x = newp(BStructPtr, {'a1': b'A', 'a2': -4042})
    res = f(x[0])
    assert res == -4042 + ord(b'A')

def test_call_function_20():
    BChar = new_primitive_type("char")
    BShort = new_primitive_type("short")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BChar, -1),
                                       ('a2', BShort, -1)])
    BFunc20 = new_function_type((BStructPtr,), BShort, False)
    f = cast(BFunc20, _testfunc(20))
    x = newp(BStructPtr, {'a1': b'A', 'a2': -4042})
    # can't pass a 'struct foo'
    pytest.raises(TypeError, f, x[0])

def test_call_function_21():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('a', BInt, -1),
                                       ('b', BInt, -1),
                                       ('c', BInt, -1),
                                       ('d', BInt, -1),
                                       ('e', BInt, -1),
                                       ('f', BInt, -1),
                                       ('g', BInt, -1),
                                       ('h', BInt, -1),
                                       ('i', BInt, -1),
                                       ('j', BInt, -1)])
    BFunc21 = new_function_type((BStruct,), BInt, False)
    f = cast(BFunc21, _testfunc(21))
    res = f(list(range(13, 3, -1)))
    lst = [(n << i) for (i, n) in enumerate(range(13, 3, -1))]
    assert res == sum(lst)

def test_call_function_22():
    BInt = new_primitive_type("int")
    BArray10 = new_array_type(new_pointer_type(BInt), 10)
    BStruct = new_struct_type("struct foo")
    BStructP = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a', BArray10, -1)])
    BFunc22 = new_function_type((BStruct, BStruct), BStruct, False)
    f = cast(BFunc22, _testfunc(22))
    p1 = newp(BStructP, {'a': list(range(100, 110))})
    p2 = newp(BStructP, {'a': list(range(1000, 1100, 10))})
    res = f(p1[0], p2[0])
    for i in range(10):
        assert res.a[i] == p1.a[i] - p2.a[i]

def test_call_function_23():
    BVoid = new_void_type()          # declaring the function as int(void*)
    BVoidP = new_pointer_type(BVoid)
    BInt = new_primitive_type("int")
    BFunc23 = new_function_type((BVoidP,), BInt, False)
    f = cast(BFunc23, _testfunc(23))
    res = f(b"foo")
    assert res == 1000 * ord(b'f')
    res = f(cast(BVoidP, 0))        # NULL
    assert res == -42
    pytest.raises(TypeError, f, None)
    pytest.raises(TypeError, f, 0)
    pytest.raises(TypeError, f, 0.0)

def test_call_function_23_bis():
    # declaring the function as int(unsigned char*)
    BUChar = new_primitive_type("unsigned char")
    BUCharP = new_pointer_type(BUChar)
    BInt = new_primitive_type("int")
    BFunc23 = new_function_type((BUCharP,), BInt, False)
    f = cast(BFunc23, _testfunc(23))
    res = f(b"foo")
    assert res == 1000 * ord(b'f')

def test_call_function_23_bool_array():
    # declaring the function as int(_Bool*)
    BBool = new_primitive_type("_Bool")
    BBoolP = new_pointer_type(BBool)
    BInt = new_primitive_type("int")
    BFunc23 = new_function_type((BBoolP,), BInt, False)
    f = cast(BFunc23, _testfunc(23))
    res = f(b"\x01\x01")
    assert res == 1000
    pytest.raises(ValueError, f, b"\x02\x02")

def test_cannot_pass_struct_with_array_of_length_0():
    BInt = new_primitive_type("int")
    BArray0 = new_array_type(new_pointer_type(BInt), 0)
    BStruct = new_struct_type("struct foo")
    BStructP = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a', BArray0)])
    BFunc = new_function_type((BStruct,), BInt, False)
    pytest.raises(NotImplementedError, cast(BFunc, 123), cast(BStructP, 123))
    BFunc2 = new_function_type((BInt,), BStruct, False)
    pytest.raises(NotImplementedError, cast(BFunc2, 123), 123)

def test_call_function_9():
    BInt = new_primitive_type("int")
    BFunc9 = new_function_type((BInt,), BInt, True)    # vararg
    f = cast(BFunc9, _testfunc(9))
    assert f(0) == 0
    assert f(1, cast(BInt, 42)) == 42
    assert f(2, cast(BInt, 40), cast(BInt, 2)) == 42
    pytest.raises(TypeError, f, 1, 42)
    pytest.raises(TypeError, f, 2, None)
    # promotion of chars and shorts to ints
    BSChar = new_primitive_type("signed char")
    BUChar = new_primitive_type("unsigned char")
    BSShort = new_primitive_type("short")
    assert f(3, cast(BSChar, -3), cast(BUChar, 200), cast(BSShort, -5)) == 192

def test_call_function_24():
    BFloat = new_primitive_type("float")
    BFloatComplex = new_primitive_type("_cffi_float_complex_t")
    BFunc3 = new_function_type((BFloat, BFloat), BFloatComplex, False)
    if 0:   # libffi returning nonsense silently, so logic disabled for now
        f = cast(BFunc3, _testfunc(24))
        result = f(1.25, 5.1)
        assert type(result) == complex
        assert result.real == 1.25   # exact
        assert (result.imag != 2*5.1) and (abs(result.imag - 2*5.1) < 1e-5) # inexact
    else:
        f = cast(BFunc3, _testfunc(9))
        pytest.raises(NotImplementedError, f, 12.3, 34.5)

def test_call_function_25():
    BDouble = new_primitive_type("double")
    BDoubleComplex = new_primitive_type("_cffi_double_complex_t")
    BFunc3 = new_function_type((BDouble, BDouble), BDoubleComplex, False)
    if 0:   # libffi returning nonsense silently, so logic disabled for now
        f = cast(BFunc3, _testfunc(25))
        result = f(1.25, 5.1)
        assert type(result) == complex
        assert result.real == 1.25   # exact
        assert (result.imag != 2*5.1) and (abs(result.imag - 2*5.1) < 1e-10) # inexact
    else:
        f = cast(BFunc3, _testfunc(9))
        pytest.raises(NotImplementedError, f, 12.3, 34.5)

def test_cannot_call_with_a_autocompleted_struct():
    BSChar = new_primitive_type("signed char")
    BDouble = new_primitive_type("double")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('c', BDouble, -1, 8),
                                       ('a', BSChar, -1, 2),
                                       ('b', BSChar, -1, 0)])
    BFunc = new_function_type((BStruct,), BDouble)   # internally not callable
    dummy_func = cast(BFunc, 42)
    e = pytest.raises(NotImplementedError, dummy_func, "?")
    msg = ("ctype 'struct foo' not supported as argument.  It is a struct "
           'declared with "...;", but the C calling convention may depend '
           "on the missing fields; or, it contains anonymous struct/unions.  "
           "Such structs are only supported as argument if the function is "
           "'API mode' and non-variadic (i.e. declared inside ffibuilder."
           "cdef()+ffibuilder.set_source() and not taking a final '...' "
           "argument)")
    assert str(e.value) == msg

def test_new_charp():
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    x = newp(BCharA, 42)
    assert len(x) == 42
    x = newp(BCharA, b"foobar")
    assert len(x) == 7

def test_load_and_call_function():
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BLong = new_primitive_type("long")
    BFunc = new_function_type((BCharP,), BLong, False)
    ll = find_and_load_library('c')
    strlen = ll.load_function(BFunc, "strlen")
    input = newp(new_array_type(BCharP, None), b"foobar")
    assert strlen(input) == 6
    #
    assert strlen(b"foobarbaz") == 9
    #
    BVoidP = new_pointer_type(new_void_type())
    strlenaddr = ll.load_function(BVoidP, "strlen")
    assert strlenaddr == cast(BVoidP, strlen)

def test_read_variable():
    ## FIXME: this test assumes glibc specific behavior, it's not compliant with C standard
    ## https://bugs.pypy.org/issue1643
    if not sys.platform.startswith("linux"):
        pytest.skip("untested")
    BVoidP = new_pointer_type(new_void_type())
    ll = find_and_load_library('c')
    stderr = ll.read_variable(BVoidP, "stderr")
    assert stderr == cast(BVoidP, _testfunc(8))
    #
    ll.close_lib()
    pytest.raises(ValueError, ll.read_variable, BVoidP, "stderr")

def test_read_variable_as_unknown_length_array():
    ## FIXME: this test assumes glibc specific behavior, it's not compliant with C standard
    ## https://bugs.pypy.org/issue1643
    if not sys.platform.startswith("linux"):
        pytest.skip("untested")
    BCharP = new_pointer_type(new_primitive_type("char"))
    BArray = new_array_type(BCharP, None)
    ll = find_and_load_library('c')
    stderr = ll.read_variable(BArray, "stderr")
    assert repr(stderr).startswith("<cdata 'char *' 0x")
    # ^^ and not 'char[]', which is basically not allowed and would crash

def test_write_variable():
    ## FIXME: this test assumes glibc specific behavior, it's not compliant with C standard
    ## https://bugs.pypy.org/issue1643
    if not sys.platform.startswith("linux") or is_musl:
        pytest.skip("untested")
    BVoidP = new_pointer_type(new_void_type())
    ll = find_and_load_library('c')
    stderr = ll.read_variable(BVoidP, "stderr")
    ll.write_variable(BVoidP, "stderr", cast(BVoidP, 0))
    assert ll.read_variable(BVoidP, "stderr") is not None
    assert not ll.read_variable(BVoidP, "stderr")
    ll.write_variable(BVoidP, "stderr", stderr)
    assert ll.read_variable(BVoidP, "stderr") == stderr
    #
    ll.close_lib()
    pytest.raises(ValueError, ll.write_variable, BVoidP, "stderr", stderr)


def test_callback():
    BInt = new_primitive_type("int")
    def make_callback():
        def cb(n):
            return n + 1
        BFunc = new_function_type((BInt,), BInt, False)
        return callback(BFunc, cb, 42)    # 'cb' and 'BFunc' go out of scope
    f = make_callback()
    assert f(-142) == -141
    assert repr(f).startswith(
        "<cdata 'int(*)(int)' calling <function ")
    assert "cb at 0x" in repr(f)
    e = pytest.raises(TypeError, f)
    assert str(e.value) == "'int(*)(int)' expects 1 arguments, got 0"


def test_callback_exception():
    def check_value(x):
        if x == 10000:
            raise ValueError(42)
    def Zcb1(x):
        check_value(x)
        return x * 3
    BShort = new_primitive_type("short")
    BFunc = new_function_type((BShort,), BShort, False)

    f = callback(BFunc, Zcb1, -42)
    seen = []
    oops_result = None
    def oops(*args):
        seen.append(args)
        return oops_result
    ff = callback(BFunc, Zcb1, -42, oops)
    with _assert_unraisable(None):
        assert f(100) == 300
    with _assert_unraisable(ValueError, '42', ['in Zcb1', 'in check_value']):
        assert f(10000) == -42

    bigvalue = 20000
    with _assert_unraisable(OverflowError, "integer 60000 does not fit 'short'", ['callback', 'Zcb1']):
        assert f(bigvalue) == -42
    assert len(seen) == 0

    with _assert_unraisable(None):
        assert ff(bigvalue) == -42
    assert len(seen) == 1
    exc, val, tb = seen[0]
    assert exc is OverflowError
    assert str(val) == "integer 60000 does not fit 'short'"

    del seen[:]
    oops_result = 81
    with _assert_unraisable(None):
        assert ff(bigvalue) == 81

    assert len(seen) == 1
    exc, val, tb = seen[0]
    assert exc is OverflowError
    assert str(val) == "integer 60000 does not fit 'short'"

    del seen[:]
    oops_result = "xy"     # not None and not an int!

    with _assert_unraisable(TypeError, "an integer is required", ["integer 60000 does not fit 'short'"]):
        assert ff(bigvalue) == -42

    seen = "not a list"    # this makes the oops() function crash
    oops_result = None
    with _assert_unraisable(AttributeError, "'str' object has no attribute 'append", ['Zcb1', 'ff', 'oops']):
        assert ff(bigvalue) == -42


def test_callback_return_type():
    for rettype in ["signed char", "short", "int", "long", "long long",
                    "unsigned char", "unsigned short", "unsigned int",
                    "unsigned long", "unsigned long long"]:
        BRet = new_primitive_type(rettype)
        def cb(n):
            return n + 1
        BFunc = new_function_type((BRet,), BRet)
        f = callback(BFunc, cb, 42)
        assert f(41) == 42
        if rettype.startswith("unsigned "):
            min = 0
            max = (1 << (8*sizeof(BRet))) - 1
        else:
            min = -(1 << (8*sizeof(BRet)-1))
            max = (1 << (8*sizeof(BRet)-1)) - 1
        assert f(min) == min + 1
        assert f(max - 1) == max
        assert f(max) == 42

def test_a_lot_of_callbacks():
    BIGNUM = 10000
    if 'PY_DOT_PY' in globals(): BIGNUM = 100   # tests on py.py
    #
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BInt,), BInt, False)
    def make_callback(m):
        def cb(n):
            return n + m
        return callback(BFunc, cb, 42)    # 'cb' goes out of scope
    #
    flist = [make_callback(i) for i in range(BIGNUM)]
    for i, f in enumerate(flist):
        assert f(-142) == -142 + i

def test_callback_receiving_tiny_struct():
    BSChar = new_primitive_type("signed char")
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a', BSChar, -1),
                                       ('b', BSChar, -1)])
    def cb(s):
        return s.a + 10 * s.b
    BFunc = new_function_type((BStruct,), BInt)
    f = callback(BFunc, cb)
    p = newp(BStructPtr, [-2, -4])
    n = f(p[0])
    assert n == -42

def test_callback_returning_tiny_struct():
    BSChar = new_primitive_type("signed char")
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a', BSChar, -1),
                                       ('b', BSChar, -1)])
    def cb(n):
        return newp(BStructPtr, [-n, -3*n])[0]
    BFunc = new_function_type((BInt,), BStruct)
    f = callback(BFunc, cb)
    s = f(10)
    assert typeof(s) is BStruct
    assert repr(s) == "<cdata 'struct foo' owning 2 bytes>"
    assert s.a == -10
    assert s.b == -30

def test_callback_receiving_struct():
    BSChar = new_primitive_type("signed char")
    BInt = new_primitive_type("int")
    BDouble = new_primitive_type("double")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a', BSChar, -1),
                                       ('b', BDouble, -1)])
    def cb(s):
        return s.a + int(s.b)
    BFunc = new_function_type((BStruct,), BInt)
    f = callback(BFunc, cb)
    p = newp(BStructPtr, [-2, 44.444])
    n = f(p[0])
    assert n == 42

def test_callback_returning_struct():
    BSChar = new_primitive_type("signed char")
    BInt = new_primitive_type("int")
    BDouble = new_primitive_type("double")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a', BSChar, -1),
                                       ('b', BDouble, -1)])
    def cb(n):
        return newp(BStructPtr, [-n, 1E-42])[0]
    BFunc = new_function_type((BInt,), BStruct)
    f = callback(BFunc, cb)
    s = f(10)
    assert typeof(s) is BStruct
    assert repr(s) in ["<cdata 'struct foo' owning 12 bytes>",
                       "<cdata 'struct foo' owning 16 bytes>"]
    assert s.a == -10
    assert s.b == 1E-42

def test_callback_receiving_big_struct():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a', BInt, -1),
                                       ('b', BInt, -1),
                                       ('c', BInt, -1),
                                       ('d', BInt, -1),
                                       ('e', BInt, -1),
                                       ('f', BInt, -1),
                                       ('g', BInt, -1),
                                       ('h', BInt, -1),
                                       ('i', BInt, -1),
                                       ('j', BInt, -1)])
    def cb(s):
        for i, name in enumerate("abcdefghij"):
            assert getattr(s, name) == 13 - i
        return 42
    BFunc = new_function_type((BStruct,), BInt)
    f = callback(BFunc, cb)
    p = newp(BStructPtr, list(range(13, 3, -1)))
    n = f(p[0])
    assert n == 42

def test_callback_returning_big_struct():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a', BInt, -1),
                                       ('b', BInt, -1),
                                       ('c', BInt, -1),
                                       ('d', BInt, -1),
                                       ('e', BInt, -1),
                                       ('f', BInt, -1),
                                       ('g', BInt, -1),
                                       ('h', BInt, -1),
                                       ('i', BInt, -1),
                                       ('j', BInt, -1)])
    def cb():
        return newp(BStructPtr, list(range(13, 3, -1)))[0]
    BFunc = new_function_type((), BStruct)
    f = callback(BFunc, cb)
    s = f()
    assert typeof(s) is BStruct
    assert repr(s) in ["<cdata 'struct foo' owning 40 bytes>",
                       "<cdata 'struct foo' owning 80 bytes>"]
    for i, name in enumerate("abcdefghij"):
        assert getattr(s, name) == 13 - i

def test_callback_returning_void():
    BVoid = new_void_type()
    BFunc = new_function_type((), BVoid, False)
    def cb():
        seen.append(42)
    f = callback(BFunc, cb)
    seen = []
    f()
    assert seen == [42]
    pytest.raises(TypeError, callback, BFunc, cb, -42)

def test_enum_type():
    BUInt = new_primitive_type("unsigned int")
    BEnum = new_enum_type("foo", (), (), BUInt)
    assert repr(BEnum) == "<ctype 'foo'>"
    assert BEnum.kind == "enum"
    assert BEnum.cname == "foo"
    assert BEnum.elements == {}
    #
    BInt = new_primitive_type("int")
    BEnum = new_enum_type("enum foo", ('def', 'c', 'ab'), (0, 1, -20), BInt)
    assert BEnum.kind == "enum"
    assert BEnum.cname == "enum foo"
    assert BEnum.elements == {-20: 'ab', 0: 'def', 1: 'c'}
    # 'elements' is not the real dict, but merely a copy
    BEnum.elements[2] = '??'
    assert BEnum.elements == {-20: 'ab', 0: 'def', 1: 'c'}
    #
    BEnum = new_enum_type("enum bar", ('ab', 'cd'), (5, 5), BUInt)
    assert BEnum.elements == {5: 'ab'}
    assert BEnum.relements == {'ab': 5, 'cd': 5}

def test_cast_to_enum():
    BInt = new_primitive_type("int")
    BEnum = new_enum_type("enum foo", ('def', 'c', 'ab'), (0, 1, -20), BInt)
    assert sizeof(BEnum) == sizeof(BInt)
    e = cast(BEnum, 0)
    assert repr(e) == "<cdata 'enum foo' 0: def>"
    assert repr(cast(BEnum, -42)) == "<cdata 'enum foo' -42>"
    assert repr(cast(BEnum, -20)) == "<cdata 'enum foo' -20: ab>"
    assert string(e) == 'def'
    assert string(cast(BEnum, -20)) == 'ab'
    assert int(cast(BEnum, 1)) == 1
    assert int(cast(BEnum, 0)) == 0
    assert int(cast(BEnum, -242 + 2**128)) == -242
    assert string(cast(BEnum, -242 + 2**128)) == '-242'
    #
    BUInt = new_primitive_type("unsigned int")
    BEnum = new_enum_type("enum bar", ('def', 'c', 'ab'), (0, 1, 20), BUInt)
    e = cast(BEnum, -1)
    assert repr(e) == "<cdata 'enum bar' 4294967295>"     # unsigned int
    #
    BLong = new_primitive_type("long")
    BEnum = new_enum_type("enum baz", (), (), BLong)
    assert sizeof(BEnum) == sizeof(BLong)
    e = cast(BEnum, -1)
    assert repr(e) == "<cdata 'enum baz' -1>"

def test_enum_with_non_injective_mapping():
    BInt = new_primitive_type("int")
    BEnum = new_enum_type("enum foo", ('ab', 'cd'), (7, 7), BInt)
    e = cast(BEnum, 7)
    assert repr(e) == "<cdata 'enum foo' 7: ab>"
    assert string(e) == 'ab'

def test_enum_in_struct():
    BInt = new_primitive_type("int")
    BEnum = new_enum_type("enum foo", ('def', 'c', 'ab'), (0, 1, -20), BInt)
    BStruct = new_struct_type("struct bar")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BEnum, -1)])
    p = newp(BStructPtr, [-20])
    assert p.a1 == -20
    p = newp(BStructPtr, [12])
    assert p.a1 == 12
    e = pytest.raises(TypeError, newp, BStructPtr, [None])
    msg = str(e.value)
    assert ("an integer is required" in msg or  # CPython
            "unsupported operand type for int(): 'NoneType'" in msg or  # old PyPys
            "expected integer, got NoneType object" in msg) # newer PyPys
    with pytest.raises(TypeError):
        p.a1 = "def"
    if sys.version_info < (3,):
        BEnum2 = new_enum_type(unicode("foo"), (unicode('abc'),), (5,), BInt)
        assert string(cast(BEnum2, 5)) == 'abc'
        assert type(string(cast(BEnum2, 5))) is str

def test_enum_overflow():
    max_uint = 2 ** (size_of_int()*8) - 1
    max_int = max_uint // 2
    max_ulong = 2 ** (size_of_long()*8) - 1
    max_long = max_ulong // 2
    for BPrimitive in [new_primitive_type("int"),
                       new_primitive_type("unsigned int"),
                       new_primitive_type("long"),
                       new_primitive_type("unsigned long")]:
        for x in [max_uint, max_int, max_ulong, max_long]:
            for testcase in [x, x+1, -x-1, -x-2]:
                if int(cast(BPrimitive, testcase)) == testcase:
                    # fits
                    BEnum = new_enum_type("foo", ("AA",), (testcase,),
                                          BPrimitive)
                    assert int(cast(BEnum, testcase)) == testcase
                else:
                    # overflows
                    pytest.raises(OverflowError, new_enum_type,
                                   "foo", ("AA",), (testcase,), BPrimitive)

def test_callback_returning_enum():
    BInt = new_primitive_type("int")
    BEnum = new_enum_type("foo", ('def', 'c', 'ab'), (0, 1, -20), BInt)
    def cb(n):
        if n & 1:
            return cast(BEnum, n)
        else:
            return n
    BFunc = new_function_type((BInt,), BEnum)
    f = callback(BFunc, cb)
    assert f(0) == 0
    assert f(1) == 1
    assert f(-20) == -20
    assert f(20) == 20
    assert f(21) == 21

def test_callback_returning_enum_unsigned():
    BInt = new_primitive_type("int")
    BUInt = new_primitive_type("unsigned int")
    BEnum = new_enum_type("foo", ('def', 'c', 'ab'), (0, 1, 20), BUInt)
    def cb(n):
        if n & 1:
            return cast(BEnum, n)
        else:
            return n
    BFunc = new_function_type((BInt,), BEnum)
    f = callback(BFunc, cb)
    assert f(0) == 0
    assert f(1) == 1
    assert f(-21) == 2**32 - 21
    assert f(20) == 20
    assert f(21) == 21

def test_callback_returning_char():
    BInt = new_primitive_type("int")
    BChar = new_primitive_type("char")
    def cb(n):
        return bytechr(n)
    BFunc = new_function_type((BInt,), BChar)
    f = callback(BFunc, cb)
    assert f(0) == b'\x00'
    assert f(255) == b'\xFF'

def _hacked_pypy_uni4():
    pyuni4 = {1: True, 2: False}[len(u+'\U00012345')]
    return 'PY_DOT_PY' in globals() and not pyuni4

def test_callback_returning_wchar_t():
    BInt = new_primitive_type("int")
    BWChar = new_primitive_type("wchar_t")
    def cb(n):
        if n == -1:
            return u+'\U00012345'
        if n == -2:
            raise ValueError
        return unichr(n)
    BFunc = new_function_type((BInt,), BWChar)
    f = callback(BFunc, cb)
    assert f(0) == unichr(0)
    assert f(255) == unichr(255)
    assert f(0x1234) == u+'\u1234'
    if sizeof(BWChar) == 4 and not _hacked_pypy_uni4():
        assert f(-1) == u+'\U00012345'
    assert f(-2) == u+'\x00'   # and an exception printed to stderr

def test_struct_with_bitfields():
    BLong = new_primitive_type("long")
    BStruct = new_struct_type("struct foo")
    LONGBITS = 8 * sizeof(BLong)
    complete_struct_or_union(BStruct, [('a1', BLong, 1),
                                       ('a2', BLong, 2),
                                       ('a3', BLong, 3),
                                       ('a4', BLong, LONGBITS - 5)])
    d = BStruct.fields
    assert d[0][1].offset == d[1][1].offset == d[2][1].offset == 0
    assert d[3][1].offset == sizeof(BLong)
    def f(m, r):
        if sys.byteorder == 'little':
            return r
        else:
            return LONGBITS - m - r
    assert d[0][1].bitshift == f(1, 0)
    assert d[0][1].bitsize == 1
    assert d[1][1].bitshift == f(2, 1)
    assert d[1][1].bitsize == 2
    assert d[2][1].bitshift == f(3, 3)
    assert d[2][1].bitsize == 3
    assert d[3][1].bitshift == f(LONGBITS - 5, 0)
    assert d[3][1].bitsize == LONGBITS - 5
    assert sizeof(BStruct) == 2 * sizeof(BLong)
    assert alignof(BStruct) == alignof(BLong)

def test_bitfield_instance():
    BInt = new_primitive_type("int")
    BUnsignedInt = new_primitive_type("unsigned int")
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('a1', BInt, 1),
                                       ('a2', BUnsignedInt, 2),
                                       ('a3', BInt, 3)])
    p = newp(new_pointer_type(BStruct), None)
    p.a1 = -1
    assert p.a1 == -1
    p.a1 = 0
    with pytest.raises(OverflowError):
        p.a1 = 2
    assert p.a1 == 0
    #
    p.a1 = -1
    p.a2 = 3
    p.a3 = -4
    with pytest.raises(OverflowError):
        p.a3 = 4
    with pytest.raises(OverflowError) as e:
        p.a3 = -5
    assert str(e.value) == ("value -5 outside the range allowed by the "
                            "bit field width: -4 <= x <= 3")
    assert p.a1 == -1 and p.a2 == 3 and p.a3 == -4
    #
    # special case for convenience: "int x:1", while normally signed,
    # allows also setting the value "1" (it still gets read back as -1)
    p.a1 = 1
    assert p.a1 == -1
    with pytest.raises(OverflowError) as e:
        p.a1 = -2
    assert str(e.value) == ("value -2 outside the range allowed by the "
                            "bit field width: -1 <= x <= 1")

def test_bitfield_instance_init():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('a1', BInt, 1)])
    p = newp(new_pointer_type(BStruct), [-1])
    assert p.a1 == -1
    p = newp(new_pointer_type(BStruct), {'a1': -1})
    assert p.a1 == -1
    #
    BUnion = new_union_type("union bar")
    complete_struct_or_union(BUnion, [('a1', BInt, 1)])
    p = newp(new_pointer_type(BUnion), [-1])
    assert p.a1 == -1

def test_weakref():
    import _weakref
    BInt = new_primitive_type("int")
    BPtr = new_pointer_type(BInt)
    rlist = [_weakref.ref(BInt),
             _weakref.ref(newp(BPtr, 42)),
             _weakref.ref(cast(BPtr, 42)),
             _weakref.ref(cast(BInt, 42)),
             _weakref.ref(buffer(newp(BPtr, 42))),
             ]
    for i in range(5):
        import gc; gc.collect()
        if [r() for r in rlist] == [None for r in rlist]:
            break

def test_no_inheritance():
    BInt = new_primitive_type("int")
    try:
        class foo(type(BInt)): pass
    except TypeError:
        pass
    else:
        raise AssertionError
    x = cast(BInt, 42)
    try:
        class foo(type(x)): pass
    except TypeError:
        pass
    else:
        raise AssertionError

def test_assign_string():
    BChar = new_primitive_type("char")
    BArray1 = new_array_type(new_pointer_type(BChar), 5)
    BArray2 = new_array_type(new_pointer_type(BArray1), 5)
    a = newp(BArray2, [b"abc", b"de", b"ghij"])
    assert string(a[1]) == b"de"
    assert string(a[2]) == b"ghij"
    a[2] = b"."
    assert string(a[2]) == b"."
    a[2] = b"12345"
    assert string(a[2]) == b"12345"
    with pytest.raises(IndexError) as e:
        a[2] = b"123456"
    assert 'char[5]' in str(e.value)
    assert 'got 6 characters' in str(e.value)

def test_add_error():
    x = cast(new_primitive_type("int"), 42)
    with pytest.raises(TypeError):
        x + 1
    with pytest.raises(TypeError):
        x - 1

def test_void_errors():
    pytest.raises(ValueError, alignof, new_void_type())
    pytest.raises(TypeError, newp, new_pointer_type(new_void_type()), None)

def test_too_many_items():
    BChar = new_primitive_type("char")
    BArray = new_array_type(new_pointer_type(BChar), 5)
    pytest.raises(IndexError, newp, BArray, tuple(b'123456'))
    pytest.raises(IndexError, newp, BArray, list(b'123456'))
    pytest.raises(IndexError, newp, BArray, b'123456')
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [])
    pytest.raises(TypeError, newp, new_pointer_type(BStruct), b'')
    pytest.raises(ValueError, newp, new_pointer_type(BStruct), [b'1'])

def test_more_type_errors():
    BInt = new_primitive_type("int")
    BChar = new_primitive_type("char")
    BArray = new_array_type(new_pointer_type(BChar), 5)
    pytest.raises(TypeError, newp, BArray, 12.34)
    BArray = new_array_type(new_pointer_type(BInt), 5)
    pytest.raises(TypeError, newp, BArray, 12.34)
    BFloat = new_primitive_type("float")
    pytest.raises(TypeError, cast, BFloat, newp(BArray, None))

def test_more_overflow_errors():
    BUInt = new_primitive_type("unsigned int")
    pytest.raises(OverflowError, newp, new_pointer_type(BUInt), -1)
    pytest.raises(OverflowError, newp, new_pointer_type(BUInt), 2**32)

def test_newp_copying():
    """Test that we can do newp(<type>, <cdata of the given type>) for most
    types, including same-type arrays.
    """
    BInt = new_primitive_type("int")
    p = newp(new_pointer_type(BInt), cast(BInt, 42))
    assert p[0] == 42
    #
    BUInt = new_primitive_type("unsigned int")
    p = newp(new_pointer_type(BUInt), cast(BUInt, 42))
    assert p[0] == 42
    #
    BChar = new_primitive_type("char")
    p = newp(new_pointer_type(BChar), cast(BChar, '!'))
    assert p[0] == b'!'
    #
    BFloat = new_primitive_type("float")
    p = newp(new_pointer_type(BFloat), cast(BFloat, 12.25))
    assert p[0] == 12.25
    #
    BStruct = new_struct_type("struct foo_s")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BInt, -1)])
    s1 = newp(BStructPtr, [42])
    p1 = newp(new_pointer_type(BStructPtr), s1)
    assert p1[0] == s1
    #
    BArray = new_array_type(new_pointer_type(BInt), None)
    a1 = newp(BArray, [1, 2, 3, 4])
    pytest.raises(TypeError, newp, BArray, a1)
    BArray6 = new_array_type(new_pointer_type(BInt), 6)
    a1 = newp(BArray6, [10, 20, 30])
    a2 = newp(BArray6, a1)
    assert list(a2) == [10, 20, 30, 0, 0, 0]
    #
    s1 = newp(BStructPtr, [42])
    s2 = newp(BStructPtr, s1[0])
    assert s2.a1 == 42
    #
    BUnion = new_union_type("union foo_u")
    BUnionPtr = new_pointer_type(BUnion)
    complete_struct_or_union(BUnion, [('a1', BInt, -1)])
    u1 = newp(BUnionPtr, [42])
    u2 = newp(BUnionPtr, u1[0])
    assert u2.a1 == 42
    #
    BFunc = new_function_type((BInt,), BUInt)
    p1 = cast(BFunc, 42)
    p2 = newp(new_pointer_type(BFunc), p1)
    assert p2[0] == p1

def test_string():
    BChar = new_primitive_type("char")
    assert string(cast(BChar, 42)) == b'*'
    assert string(cast(BChar, 0)) == b'\x00'
    BCharP = new_pointer_type(BChar)
    BArray = new_array_type(BCharP, 10)
    a = newp(BArray, b"hello")
    assert len(a) == 10
    assert string(a) == b"hello"
    p = a + 2
    assert string(p) == b"llo"
    assert string(newp(new_array_type(BCharP, 4), b"abcd")) == b"abcd"
    pytest.raises(RuntimeError, string, cast(BCharP, 0))
    assert string(a, 4) == b"hell"
    assert string(a, 5) == b"hello"
    assert string(a, 6) == b"hello"

def test_string_byte():
    BByte = new_primitive_type("signed char")
    assert string(cast(BByte, 42)) == b'*'
    assert string(cast(BByte, 0)) == b'\x00'
    BArray = new_array_type(new_pointer_type(BByte), None)
    a = newp(BArray, [65, 66, 67])
    assert type(string(a)) is bytes and string(a) == b'ABC'
    #
    BByte = new_primitive_type("unsigned char")
    assert string(cast(BByte, 42)) == b'*'
    assert string(cast(BByte, 0)) == b'\x00'
    BArray = new_array_type(new_pointer_type(BByte), None)
    a = newp(BArray, [65, 66, 67])
    assert type(string(a)) is bytes and string(a) == b'ABC'
    if 'PY_DOT_PY' not in globals() and sys.version_info < (3,):
        assert string(a, 8).startswith(b'ABC')  # may contain additional garbage

def test_string_wchar():
    for typename in ["wchar_t", "char16_t", "char32_t"]:
        _test_string_wchar_variant(typename)

def _test_string_wchar_variant(typename):
    BWChar = new_primitive_type(typename)
    assert string(cast(BWChar, 42)) == u+'*'
    assert string(cast(BWChar, 0x4253)) == u+'\u4253'
    assert string(cast(BWChar, 0)) == u+'\x00'
    BArray = new_array_type(new_pointer_type(BWChar), None)
    a = newp(BArray, [u+'A', u+'B', u+'C'])
    assert type(string(a)) is unicode and string(a) == u+'ABC'
    if 'PY_DOT_PY' not in globals() and sys.version_info < (3,):
        try:
            # may contain additional garbage
            assert string(a, 8).startswith(u+'ABC')
        except ValueError:    # garbage contains values > 0x10FFFF
            assert sizeof(BWChar) == 4

def test_string_typeerror():
    BShort = new_primitive_type("short")
    BArray = new_array_type(new_pointer_type(BShort), None)
    a = newp(BArray, [65, 66, 67])
    pytest.raises(TypeError, string, a)

def test_bug_convert_to_ptr():
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BDouble = new_primitive_type("double")
    x = cast(BDouble, 42)
    pytest.raises(TypeError, newp, new_pointer_type(BCharP), x)

def test_set_struct_fields():
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharArray10 = new_array_type(BCharP, 10)
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BCharArray10, -1)])
    p = newp(BStructPtr, None)
    assert string(p.a1) == b''
    p.a1 = b'foo'
    assert string(p.a1) == b'foo'
    assert list(p.a1) == [b'f', b'o', b'o'] + [b'\x00'] * 7
    p.a1 = [b'x', b'y']
    assert string(p.a1) == b'xyo'

def test_invalid_function_result_types():
    BFunc = new_function_type((), new_void_type())
    BArray = new_array_type(new_pointer_type(BFunc), 5)        # works
    new_function_type((), BFunc)    # works
    new_function_type((), new_primitive_type("int"))
    new_function_type((), new_pointer_type(BFunc))
    BUnion = new_union_type("union foo_u")
    complete_struct_or_union(BUnion, [])
    BFunc = new_function_type((), BUnion)
    pytest.raises(NotImplementedError, cast(BFunc, 123))
    pytest.raises(TypeError, new_function_type, (), BArray)

def test_struct_return_in_func():
    BChar = new_primitive_type("char")
    BShort = new_primitive_type("short")
    BFloat = new_primitive_type("float")
    BDouble = new_primitive_type("double")
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo_s")
    complete_struct_or_union(BStruct, [('a1', BChar, -1),
                                       ('a2', BShort, -1)])
    BFunc10 = new_function_type((BInt,), BStruct)
    f = cast(BFunc10, _testfunc(10))
    s = f(40)
    assert repr(s) == "<cdata 'struct foo_s' owning 4 bytes>"
    assert s.a1 == bytechr(40)
    assert s.a2 == 40 * 40
    #
    BStruct11 = new_struct_type("struct test11")
    complete_struct_or_union(BStruct11, [('a1', BInt, -1),
                                         ('a2', BInt, -1)])
    BFunc11 = new_function_type((BInt,), BStruct11)
    f = cast(BFunc11, _testfunc(11))
    s = f(40)
    assert repr(s) == "<cdata 'struct test11' owning 8 bytes>"
    assert s.a1 == 40
    assert s.a2 == 40 * 40
    #
    BStruct12 = new_struct_type("struct test12")
    complete_struct_or_union(BStruct12, [('a1', BDouble, -1),
                                         ])
    BFunc12 = new_function_type((BInt,), BStruct12)
    f = cast(BFunc12, _testfunc(12))
    s = f(40)
    assert repr(s) == "<cdata 'struct test12' owning 8 bytes>"
    assert s.a1 == 40.0
    #
    BStruct13 = new_struct_type("struct test13")
    complete_struct_or_union(BStruct13, [('a1', BInt, -1),
                                         ('a2', BInt, -1),
                                         ('a3', BInt, -1)])
    BFunc13 = new_function_type((BInt,), BStruct13)
    f = cast(BFunc13, _testfunc(13))
    s = f(40)
    assert repr(s) == "<cdata 'struct test13' owning 12 bytes>"
    assert s.a1 == 40
    assert s.a2 == 40 * 40
    assert s.a3 == 40 * 40 * 40
    #
    BStruct14 = new_struct_type("struct test14")
    complete_struct_or_union(BStruct14, [('a1', BFloat, -1),
                                         ])
    BFunc14 = new_function_type((BInt,), BStruct14)
    f = cast(BFunc14, _testfunc(14))
    s = f(40)
    assert repr(s) == "<cdata 'struct test14' owning 4 bytes>"
    assert s.a1 == 40.0
    #
    BStruct15 = new_struct_type("struct test15")
    complete_struct_or_union(BStruct15, [('a1', BFloat, -1),
                                         ('a2', BInt, -1)])
    BFunc15 = new_function_type((BInt,), BStruct15)
    f = cast(BFunc15, _testfunc(15))
    s = f(40)
    assert repr(s) == "<cdata 'struct test15' owning 8 bytes>"
    assert s.a1 == 40.0
    assert s.a2 == 40 * 40
    #
    BStruct16 = new_struct_type("struct test16")
    complete_struct_or_union(BStruct16, [('a1', BFloat, -1),
                                         ('a2', BFloat, -1)])
    BFunc16 = new_function_type((BInt,), BStruct16)
    f = cast(BFunc16, _testfunc(16))
    s = f(40)
    assert repr(s) == "<cdata 'struct test16' owning 8 bytes>"
    assert s.a1 == 40.0
    assert s.a2 == -40.0
    #
    BStruct17 = new_struct_type("struct test17")
    complete_struct_or_union(BStruct17, [('a1', BInt, -1),
                                         ('a2', BFloat, -1)])
    BFunc17 = new_function_type((BInt,), BStruct17)
    f = cast(BFunc17, _testfunc(17))
    s = f(40)
    assert repr(s) == "<cdata 'struct test17' owning 8 bytes>"
    assert s.a1 == 40
    assert s.a2 == 40.0 * 40.0
    #
    BStruct17Ptr = new_pointer_type(BStruct17)
    BFunc18 = new_function_type((BStruct17Ptr,), BInt)
    f = cast(BFunc18, _testfunc(18))
    x = f([[40, 2.5]])
    assert x == 42
    x = f([{'a2': 43.1}])
    assert x == 43

def test_cast_with_functionptr():
    BFunc = new_function_type((), new_void_type())
    BFunc2 = new_function_type((), new_primitive_type("short"))
    BCharP = new_pointer_type(new_primitive_type("char"))
    BIntP = new_pointer_type(new_primitive_type("int"))
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BFunc, -1)])
    newp(BStructPtr, [cast(BFunc, 0)])
    newp(BStructPtr, [cast(BCharP, 0)])
    pytest.raises(TypeError, newp, BStructPtr, [cast(BIntP, 0)])
    pytest.raises(TypeError, newp, BStructPtr, [cast(BFunc2, 0)])

def test_wchar():
    _test_wchar_variant("wchar_t")
    if sys.platform.startswith("linux"):
        BWChar = new_primitive_type("wchar_t")
        assert sizeof(BWChar) == 4
        # wchar_t is often signed on Linux, but not always (e.g. on ARM)
        assert int(cast(BWChar, -1)) in (-1, 4294967295)

def test_char16():
    BChar16 = new_primitive_type("char16_t")
    assert sizeof(BChar16) == 2
    _test_wchar_variant("char16_t")
    assert int(cast(BChar16, -1)) == 0xffff       # always unsigned

def test_char32():
    BChar32 = new_primitive_type("char32_t")
    assert sizeof(BChar32) == 4
    _test_wchar_variant("char32_t")
    assert int(cast(BChar32, -1)) == 0xffffffff   # always unsigned

def _test_wchar_variant(typename):
    BWChar = new_primitive_type(typename)
    BInt = new_primitive_type("int")
    pyuni4 = {1: True, 2: False}[len(u+'\U00012345')]
    wchar4 = {2: False, 4: True}[sizeof(BWChar)]
    assert str(cast(BWChar, 0x45)) == "<cdata '%s' %s'E'>" % (
        typename, mandatory_u_prefix)
    assert str(cast(BWChar, 0x1234)) == "<cdata '%s' %s'\u1234'>" % (
        typename, mandatory_u_prefix)
    if not _hacked_pypy_uni4():
        if wchar4:
            x = cast(BWChar, 0x12345)
            assert str(x) == "<cdata '%s' %s'\U00012345'>" % (
                typename, mandatory_u_prefix)
            assert int(x) == 0x12345
        else:
            x = cast(BWChar, 0x18345)
            assert str(x) == "<cdata '%s' %s'\u8345'>" % (
                typename, mandatory_u_prefix)
            assert int(x) == 0x8345
    #
    BWCharP = new_pointer_type(BWChar)
    BStruct = new_struct_type("struct foo_s")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BWChar, -1),
                                       ('a2', BWCharP, -1)])
    s = newp(BStructPtr)
    s.a1 = u+'\x00'
    assert s.a1 == u+'\x00'
    with pytest.raises(TypeError):
        s.a1 = b'a'
    with pytest.raises(TypeError):
        s.a1 = bytechr(0xFF)
    s.a1 = u+'\u1234'
    assert s.a1 == u+'\u1234'
    if pyuni4:
        if wchar4:
            s.a1 = u+'\U00012345'
            assert s.a1 == u+'\U00012345'
    elif wchar4:
        if not _hacked_pypy_uni4():
            s.a1 = cast(BWChar, 0x12345)
            assert s.a1 == u+'\ud808\udf45'
            s.a1 = u+'\ud807\udf44'
            assert s.a1 == u+'\U00011f44'
    else:
        with pytest.raises(TypeError):
            s.a1 = u+'\U00012345'
    #
    BWCharArray = new_array_type(BWCharP, None)
    a = newp(BWCharArray, u+'hello \u1234 world')
    assert len(a) == 14   # including the final null
    assert string(a) == u+'hello \u1234 world'
    a[13] = u+'!'
    assert string(a) == u+'hello \u1234 world!'
    assert str(a) == repr(a)
    assert a[6] == u+'\u1234'
    a[6] = u+'-'
    assert string(a) == u+'hello - world!'
    assert str(a) == repr(a)
    #
    if wchar4 and not _hacked_pypy_uni4():
        u1 = u+'\U00012345\U00012346\U00012347'
        a = newp(BWCharArray, u1)
        assert len(a) == 4
        assert string(a) == u1
        assert len(list(a)) == 4
        expected = [u+'\U00012345', u+'\U00012346', u+'\U00012347', unichr(0)]
        assert list(a) == expected
        got = [a[i] for i in range(4)]
        assert got == expected
        with pytest.raises(IndexError):
            a[4]
    #
    w = cast(BWChar, 'a')
    assert repr(w) == "<cdata '%s' %s'a'>" % (typename, mandatory_u_prefix)
    assert str(w) == repr(w)
    assert string(w) == u+'a'
    assert int(w) == ord('a')
    w = cast(BWChar, 0x1234)
    assert repr(w) == "<cdata '%s' %s'\u1234'>" % (typename, mandatory_u_prefix)
    assert str(w) == repr(w)
    assert string(w) == u+'\u1234'
    assert int(w) == 0x1234
    w = cast(BWChar, u+'\u8234')
    assert repr(w) == "<cdata '%s' %s'\u8234'>" % (typename, mandatory_u_prefix)
    assert str(w) == repr(w)
    assert string(w) == u+'\u8234'
    assert int(w) == 0x8234
    w = cast(BInt, u+'\u1234')
    assert repr(w) == "<cdata 'int' 4660>"
    if wchar4 and not _hacked_pypy_uni4():
        w = cast(BWChar, u+'\U00012345')
        assert repr(w) == "<cdata '%s' %s'\U00012345'>" % (
            typename, mandatory_u_prefix)
        assert str(w) == repr(w)
        assert string(w) == u+'\U00012345'
        assert int(w) == 0x12345
        w = cast(BInt, u+'\U00012345')
        assert repr(w) == "<cdata 'int' 74565>"
    pytest.raises(TypeError, cast, BInt, u+'')
    pytest.raises(TypeError, cast, BInt, u+'XX')
    assert int(cast(BInt, u+'a')) == ord('a')
    #
    a = newp(BWCharArray, u+'hello - world')
    p = cast(BWCharP, a)
    assert string(p) == u+'hello - world'
    p[6] = u+'\u2345'
    assert string(p) == u+'hello \u2345 world'
    #
    s = newp(BStructPtr, [u+'\u1234', p])
    assert s.a1 == u+'\u1234'
    assert s.a2 == p
    assert str(s.a2) == repr(s.a2)
    assert string(s.a2) == u+'hello \u2345 world'
    #
    q = cast(BWCharP, 0)
    assert str(q) == repr(q)
    pytest.raises(RuntimeError, string, q)
    #
    def cb(p):
        assert repr(p).startswith("<cdata '%s *' 0x" % typename)
        return len(string(p))
    BFunc = new_function_type((BWCharP,), BInt, False)
    f = callback(BFunc, cb, -42)
    assert f(u+'a\u1234b') == 3
    #
    if wchar4 and not pyuni4 and not _hacked_pypy_uni4():
        # try out-of-range wchar_t values
        x = cast(BWChar, 1114112)
        pytest.raises(ValueError, string, x)
        x = cast(BWChar, -1)
        pytest.raises(ValueError, string, x)

def test_wchar_variants_mix():
    BWChar  = new_primitive_type("wchar_t")
    BChar16 = new_primitive_type("char16_t")
    BChar32 = new_primitive_type("char32_t")
    assert int(cast(BChar32, cast(BChar16, -2))) == 0xfffe
    assert int(cast(BWChar, cast(BChar16, -2))) == 0xfffe
    assert int(cast(BChar16, cast(BChar32, 0x0001f345))) == 0xf345
    assert int(cast(BChar16, cast(BWChar, 0x0001f345))) == 0xf345
    #
    BChar16A = new_array_type(new_pointer_type(BChar16), None)
    BChar32A = new_array_type(new_pointer_type(BChar32), None)
    x = cast(BChar32, 'A')
    pytest.raises(TypeError, newp, BChar16A, [x])
    x = cast(BChar16, 'A')
    pytest.raises(TypeError, newp, BChar32A, [x])
    #
    a = newp(BChar16A, u+'\U00012345')
    assert len(a) == 3
    a = newp(BChar32A, u+'\U00012345')
    assert len(a) == 2   # even if the Python unicode string above is 2 chars

def test_keepalive_struct():
    # exception to the no-keepalive rule: p=newp(BStructPtr) returns a
    # pointer owning the memory, and p[0] returns a pointer to the
    # struct that *also* owns the memory
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', new_primitive_type("int"), -1),
                                       ('a2', new_primitive_type("int"), -1),
                                       ('a3', new_primitive_type("int"), -1)])
    p = newp(BStructPtr)
    assert repr(p) == "<cdata 'struct foo *' owning 12 bytes>"
    q = p[0]
    assert repr(q) == "<cdata 'struct foo' owning 12 bytes>"
    q.a1 = 123456
    assert p.a1 == 123456
    r = cast(BStructPtr, p)
    assert repr(r[0]).startswith("<cdata 'struct foo &' 0x")
    del p
    import gc; gc.collect()
    assert q.a1 == 123456
    assert repr(q) == "<cdata 'struct foo' owning 12 bytes>"
    assert q.a1 == 123456

def test_nokeepalive_struct():
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    BStructPtrPtr = new_pointer_type(BStructPtr)
    complete_struct_or_union(BStruct, [('a1', new_primitive_type("int"), -1)])
    p = newp(BStructPtr)
    pp = newp(BStructPtrPtr)
    pp[0] = p
    s = pp[0][0]
    assert repr(s).startswith("<cdata 'struct foo &' 0x")

def test_owning_repr():
    BInt = new_primitive_type("int")
    BArray = new_array_type(new_pointer_type(BInt), None)   # int[]
    p = newp(BArray, 7)
    assert repr(p) == "<cdata 'int[]' owning 28 bytes>"
    assert sizeof(p) == 28
    #
    BArray = new_array_type(new_pointer_type(BInt), 7)   # int[7]
    p = newp(BArray, None)
    assert repr(p) == "<cdata 'int[7]' owning 28 bytes>"
    assert sizeof(p) == 28

def test_cannot_dereference_void():
    BVoidP = new_pointer_type(new_void_type())
    p = cast(BVoidP, 123456)
    with pytest.raises(TypeError):
        p[0]
    p = cast(BVoidP, 0)
    with pytest.raises((TypeError, RuntimeError)):
        p[0]

def test_iter():
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BArray = new_array_type(BIntP, None)   # int[]
    p = newp(BArray, 7)
    assert list(p) == list(iter(p)) == [0] * 7
    #
    pytest.raises(TypeError, iter, cast(BInt, 5))
    pytest.raises(TypeError, iter, cast(BIntP, 123456))

def test_cmp():
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BVoidP = new_pointer_type(new_void_type())
    p = newp(BIntP, 123)
    q = cast(BInt, 124)
    assert (p == q) is False
    assert (p != q) is True
    assert (q == p) is False
    assert (q != p) is True
    if strict_compare:
        with pytest.raises(TypeError): p < q
        with pytest.raises(TypeError): p <= q
        with pytest.raises(TypeError): q < p
        with pytest.raises(TypeError): q <= p
        with pytest.raises(TypeError): p > q
        with pytest.raises(TypeError): p >= q
    r = cast(BVoidP, p)
    assert (p <  r) is False
    assert (p <= r) is True
    assert (p == r) is True
    assert (p != r) is False
    assert (p >  r) is False
    assert (p >= r) is True
    s = newp(BIntP, 125)
    assert (p == s) is False
    assert (p != s) is True
    assert (p < s) is (p <= s) is (s > p) is (s >= p)
    assert (p > s) is (p >= s) is (s < p) is (s <= p)
    assert (p < s) ^ (p > s)

def test_buffer():
    try:
        import __builtin__
    except ImportError:
        import builtins as __builtin__
    BShort = new_primitive_type("short")
    s = newp(new_pointer_type(BShort), 100)
    assert sizeof(s) == size_of_ptr()
    assert sizeof(BShort) == 2
    assert len(buffer(s)) == 2
    #
    BChar = new_primitive_type("char")
    BCharArray = new_array_type(new_pointer_type(BChar), None)
    c = newp(BCharArray, b"hi there")
    #
    buf = buffer(c)
    assert repr(buf).startswith('<_cffi_backend.buffer object at 0x')
    assert bytes(buf) == b"hi there\x00"
    assert type(buf) is buffer
    if sys.version_info < (3,):
        assert str(buf) == "hi there\x00"
        assert unicode(buf) == u+"hi there\x00"
    else:
        assert str(buf) == repr(buf)
    # --mb_length--
    assert len(buf) == len(b"hi there\x00")
    # --mb_item--
    for i in range(-12, 12):
        try:
            expected = b"hi there\x00"[i]
        except IndexError:
            with pytest.raises(IndexError):
                buf[i]
        else:
            assert buf[i] == bitem2bchr(expected)
    # --mb_slice--
    assert buf[:] == b"hi there\x00"
    for i in range(-12, 12):
        assert buf[i:] == b"hi there\x00"[i:]
        assert buf[:i] == b"hi there\x00"[:i]
        for j in range(-12, 12):
            assert buf[i:j] == b"hi there\x00"[i:j]
    # --misc--
    assert list(buf) == list(map(bitem2bchr, b"hi there\x00"))
    # --mb_as_buffer--
    if hasattr(__builtin__, 'buffer'):          # Python <= 2.7
        pytest.raises(TypeError, __builtin__.buffer, c)
        bf1 = __builtin__.buffer(buf)
        assert len(bf1) == len(buf) and bf1[3] == "t"
    if hasattr(__builtin__, 'memoryview'):      # Python >= 2.7
        pytest.raises(TypeError, memoryview, c)
        mv1 = memoryview(buf)
        assert len(mv1) == len(buf) and mv1[3] in (b"t", ord(b"t"))
    # --mb_ass_item--
    expected = list(map(bitem2bchr, b"hi there\x00"))
    for i in range(-12, 12):
        try:
            expected[i] = bytechr(i & 0xff)
        except IndexError:
            with pytest.raises(IndexError):
                buf[i] = bytechr(i & 0xff)
        else:
            buf[i] = bytechr(i & 0xff)
        assert list(buf) == expected
    # --mb_ass_slice--
    buf[:] = b"hi there\x00"
    assert list(buf) == list(c) == list(map(bitem2bchr, b"hi there\x00"))
    with pytest.raises(ValueError):
        buf[:] = b"shorter"
    with pytest.raises(ValueError):
        buf[:] = b"this is much too long!"
    buf[4:2] = b""   # no effect, but should work
    assert buf[:] == b"hi there\x00"
    buf[:2] = b"HI"
    assert buf[:] == b"HI there\x00"
    buf[:2] = b"hi"
    expected = list(map(bitem2bchr, b"hi there\x00"))
    x = 0
    for i in range(-12, 12):
        for j in range(-12, 12):
            start = i if i >= 0 else i + len(buf)
            stop  = j if j >= 0 else j + len(buf)
            start = max(0, min(len(buf), start))
            stop  = max(0, min(len(buf), stop))
            sample = bytechr(x & 0xff) * (stop - start)
            x += 1
            buf[i:j] = sample
            expected[i:j] = map(bitem2bchr, sample)
            assert list(buf) == expected

def test_getcname():
    BUChar = new_primitive_type("unsigned char")
    BArray = new_array_type(new_pointer_type(BUChar), 123)
    assert getcname(BArray, "<-->") == "unsigned char<-->[123]"

def test_errno():
    BVoid = new_void_type()
    BFunc5 = new_function_type((), BVoid)
    f = cast(BFunc5, _testfunc(5))
    set_errno(50)
    f()
    assert get_errno() == 65
    f(); f()
    assert get_errno() == 95

def test_errno_callback():
    if globals().get('PY_DOT_PY'):
        pytest.skip("cannot run this test on py.py (e.g. fails on Windows)")
    set_errno(95)
    def cb():
        e = get_errno()
        set_errno(e - 6)
    BVoid = new_void_type()
    BFunc5 = new_function_type((), BVoid)
    f = callback(BFunc5, cb)
    f()
    assert get_errno() == 89
    f(); f()
    assert get_errno() == 77

def test_cast_to_array():
    # not valid in C!  extension to get a non-owning <cdata 'int[3]'>
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BArray = new_array_type(BIntP, 3)
    x = cast(BArray, 0)
    assert repr(x) == "<cdata 'int[3]' NULL>"

def test_cast_invalid():
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [])
    p = cast(new_pointer_type(BStruct), 123456)
    s = p[0]
    pytest.raises(TypeError, cast, BStruct, s)

def test_bug_float_convertion():
    BDouble = new_primitive_type("double")
    BDoubleP = new_pointer_type(BDouble)
    pytest.raises(TypeError, newp, BDoubleP, "foobar")

def test_bug_delitem():
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    x = newp(BCharP)
    with pytest.raises(TypeError):
        del x[0]

def test_bug_delattr():
    BLong = new_primitive_type("long")
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('a1', BLong, -1)])
    x = newp(new_pointer_type(BStruct))
    with pytest.raises(AttributeError):
        del x.a1

def test_variable_length_struct():
    pytest.skip("later")
    BLong = new_primitive_type("long")
    BArray = new_array_type(new_pointer_type(BLong), None)
    BStruct = new_struct_type("struct foo")
    BStructP = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BLong, -1),
                                       ('a2', BArray, -1)])
    assert sizeof(BStruct) == size_of_long()
    assert alignof(BStruct) == alignof(BLong)
    #
    pytest.raises(TypeError, newp, BStructP, None)
    x = newp(BStructP, 5)
    assert sizeof(x) == 6 * size_of_long()
    x[4] = 123
    assert x[4] == 123
    with pytest.raises(IndexError):
        x[5]
    assert len(x.a2) == 5
    #
    pytest.raises(TypeError, newp, BStructP, [123])
    x = newp(BStructP, [123, 5])
    assert x.a1 == 123
    assert len(x.a2) == 5
    assert list(x.a2) == [0] * 5
    #
    x = newp(BStructP, {'a2': 5})
    assert x.a1 == 0
    assert len(x.a2) == 5
    assert list(x.a2) == [0] * 5
    #
    x = newp(BStructP, [123, (4, 5)])
    assert x.a1 == 123
    assert len(x.a2) == 2
    assert list(x.a2) == [4, 5]
    #
    x = newp(BStructP, {'a2': (4, 5)})
    assert x.a1 == 0
    assert len(x.a2) == 2
    assert list(x.a2) == [4, 5]

def test_autocast_int():
    BInt = new_primitive_type("int")
    BIntPtr = new_pointer_type(BInt)
    BLongLong = new_primitive_type("long long")
    BULongLong = new_primitive_type("unsigned long long")
    BULongLongPtr = new_pointer_type(BULongLong)
    x = newp(BIntPtr, cast(BInt, 42))
    assert x[0] == 42
    x = newp(BIntPtr, cast(BLongLong, 42))
    assert x[0] == 42
    x = newp(BIntPtr, cast(BULongLong, 42))
    assert x[0] == 42
    x = newp(BULongLongPtr, cast(BInt, 42))
    assert x[0] == 42
    pytest.raises(OverflowError, newp, BULongLongPtr, cast(BInt, -42))
    x = cast(BInt, cast(BInt, 42))
    assert int(x) == 42
    x = cast(BInt, cast(BLongLong, 42))
    assert int(x) == 42
    x = cast(BInt, cast(BULongLong, 42))
    assert int(x) == 42
    x = cast(BULongLong, cast(BInt, 42))
    assert int(x) == 42
    x = cast(BULongLong, cast(BInt, -42))
    assert int(x) == 2 ** 64 - 42
    x = cast(BIntPtr, cast(BInt, 42))
    assert int(cast(BInt, x)) == 42

def test_autocast_float():
    BFloat = new_primitive_type("float")
    BDouble = new_primitive_type("float")
    BFloatPtr = new_pointer_type(BFloat)
    x = newp(BFloatPtr, cast(BDouble, 12.5))
    assert x[0] == 12.5
    x = cast(BFloat, cast(BDouble, 12.5))
    assert float(x) == 12.5

def test_longdouble():
    py_py = 'PY_DOT_PY' in globals()
    BInt = new_primitive_type("int")
    BLongDouble = new_primitive_type("long double")
    BLongDoublePtr = new_pointer_type(BLongDouble)
    BLongDoubleArray = new_array_type(BLongDoublePtr, None)
    a = newp(BLongDoubleArray, 1)
    x = a[0]
    if not py_py:
        assert repr(x).startswith("<cdata 'long double' 0.0")
    assert float(x) == 0.0
    assert int(x) == 0
    #
    b = newp(BLongDoubleArray, [1.23])
    x = b[0]
    if not py_py:
        assert repr(x).startswith("<cdata 'long double' 1.23")
    assert float(x) == 1.23
    assert int(x) == 1
    #
    BFunc19 = new_function_type((BLongDouble, BInt), BLongDouble)
    f = cast(BFunc19, _testfunc(19))
    start = lstart = 1.5
    for i in range(107):
        start = 4 * start - start * start
        lstart = f(lstart, 1)
    lother = f(1.5, 107)
    if not py_py:
        assert float(lstart) == float(lother)
        assert repr(lstart) == repr(lother)
        if sizeof(BLongDouble) > sizeof(new_primitive_type("double")):
            assert float(lstart) != start
            assert repr(lstart).startswith("<cdata 'long double' ")
    #
    c = newp(BLongDoubleArray, [lstart])
    x = c[0]
    assert float(f(lstart, 107)) == float(f(x, 107))

def test_get_array_of_length_zero():
    for length in [0, 5, 10]:
        BLong = new_primitive_type("long")
        BLongP = new_pointer_type(BLong)
        BArray0 = new_array_type(BLongP, length)
        BStruct = new_struct_type("struct foo")
        BStructPtr = new_pointer_type(BStruct)
        complete_struct_or_union(BStruct, [('a1', BArray0, -1)])
        p = newp(BStructPtr, None)
        if length == 0:
            assert repr(p.a1).startswith("<cdata 'long *' 0x")
        else:
            assert repr(p.a1).startswith("<cdata 'long[%d]' 0x" % length)

def test_nested_anonymous_struct():
    BInt = new_primitive_type("int")
    BChar = new_primitive_type("char")
    BStruct = new_struct_type("struct foo")
    BInnerStruct = new_struct_type("struct foo")
    complete_struct_or_union(BInnerStruct, [('a1', BInt, -1),
                                            ('a2', BChar, -1)])
    complete_struct_or_union(BStruct, [('', BInnerStruct, -1),
                                       ('a3', BChar, -1)])
    assert sizeof(BInnerStruct) == sizeof(BInt) * 2   # with alignment
    assert sizeof(BStruct) == sizeof(BInt) * 3        # 'a3' is placed after
    d = BStruct.fields
    assert len(d) == 3
    assert d[0][0] == 'a1'
    assert d[0][1].type is BInt
    assert d[0][1].offset == 0
    assert d[0][1].bitshift == -1
    assert d[0][1].bitsize == -1
    assert d[1][0] == 'a2'
    assert d[1][1].type is BChar
    assert d[1][1].offset == sizeof(BInt)
    assert d[1][1].bitshift == -1
    assert d[1][1].bitsize == -1
    assert d[2][0] == 'a3'
    assert d[2][1].type is BChar
    assert d[2][1].offset == sizeof(BInt) * 2
    assert d[2][1].bitshift == -1
    assert d[2][1].bitsize == -1

def test_nested_anonymous_struct_2():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    BInnerUnion = new_union_type("union bar")
    complete_struct_or_union(BInnerUnion, [('a1', BInt, -1),
                                           ('a2', BInt, -1)])
    complete_struct_or_union(BStruct, [('b1', BInt, -1),
                                       ('', BInnerUnion, -1),
                                       ('b2', BInt, -1)])
    assert sizeof(BInnerUnion) == sizeof(BInt)
    assert sizeof(BStruct) == sizeof(BInt) * 3
    fields = [(name, fld.offset, fld.flags) for (name, fld) in BStruct.fields]
    assert fields == [
        ('b1', 0 * sizeof(BInt), 0),
        ('a1', 1 * sizeof(BInt), 0),
        ('a2', 1 * sizeof(BInt), 1),
        ('b2', 2 * sizeof(BInt), 0),
    ]

def test_sizeof_union():
    # a union has the largest alignment of its members, and a total size
    # that is the largest of its items *possibly further aligned* if
    # another smaller item has a larger alignment...
    BChar = new_primitive_type("char")
    BShort = new_primitive_type("short")
    assert sizeof(BShort) == alignof(BShort) == 2
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('a1', BChar),
                                       ('a2', BChar),
                                       ('a3', BChar)])
    assert sizeof(BStruct) == 3 and alignof(BStruct) == 1
    BUnion = new_union_type("union u")
    complete_struct_or_union(BUnion, [('s', BStruct),
                                      ('i', BShort)])
    assert sizeof(BUnion) == 4
    assert alignof(BUnion) == 2

def test_unaligned_struct():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('b', BInt, -1, 1)],
                             None, 5, 1)

def test_CData_CType():
    CData, CType = _get_types()
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    nullchr = cast(BChar, 0)
    chrref = newp(BCharP, None)
    assert isinstance(nullchr, CData)
    assert isinstance(chrref, CData)
    assert not isinstance(BChar, CData)
    assert not isinstance(nullchr, CType)
    assert not isinstance(chrref, CType)
    assert isinstance(BChar, CType)

def test_no_cdata_float():
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BUInt = new_primitive_type("unsigned int")
    BUIntP = new_pointer_type(BUInt)
    BFloat = new_primitive_type("float")
    pytest.raises(TypeError, newp, BIntP, cast(BFloat, 0.0))
    pytest.raises(TypeError, newp, BUIntP, cast(BFloat, 0.0))

def test_bool():
    BBool = new_primitive_type("_Bool")
    BBoolP = new_pointer_type(BBool)
    assert int(cast(BBool, False)) == 0
    assert int(cast(BBool, True)) == 1
    assert bool(cast(BBool, False)) is False    # since 1.7
    assert bool(cast(BBool, True)) is True
    assert int(cast(BBool, 3)) == 1
    assert int(cast(BBool, long(3))) == 1
    assert int(cast(BBool, long(10)**4000)) == 1
    assert int(cast(BBool, -0.1)) == 1
    assert int(cast(BBool, -0.0)) == 0
    assert int(cast(BBool, '\x00')) == 0
    assert int(cast(BBool, '\xff')) == 1
    assert newp(BBoolP, False)[0] == 0
    assert newp(BBoolP, True)[0] == 1
    assert newp(BBoolP, 0)[0] == 0
    assert newp(BBoolP, 1)[0] == 1
    pytest.raises(TypeError, newp, BBoolP, 1.0)
    pytest.raises(TypeError, newp, BBoolP, '\x00')
    pytest.raises(OverflowError, newp, BBoolP, 2)
    pytest.raises(OverflowError, newp, BBoolP, -1)
    BCharP = new_pointer_type(new_primitive_type("char"))
    p = newp(BCharP, b'\x01')
    q = cast(BBoolP, p)
    assert q[0] is True
    p = newp(BCharP, b'\x00')
    q = cast(BBoolP, p)
    assert q[0] is False
    pytest.raises(TypeError, string, cast(BBool, False))
    BDouble = new_primitive_type("double")
    assert int(cast(BBool, cast(BDouble, 0.1))) == 1
    assert int(cast(BBool, cast(BDouble, 0.0))) == 0
    BBoolA = new_array_type(BBoolP, None)
    p = newp(BBoolA, b'\x01\x00')
    assert p[0] is True
    assert p[1] is False

def test_bool_forbidden_cases():
    BBool = new_primitive_type("_Bool")
    BBoolP = new_pointer_type(BBool)
    BBoolA = new_array_type(BBoolP, None)
    BCharP = new_pointer_type(new_primitive_type("char"))
    p = newp(BCharP, b'X')
    q = cast(BBoolP, p)
    with pytest.raises(ValueError):
        q[0]
    pytest.raises(TypeError, newp, BBoolP, b'\x00')
    assert newp(BBoolP, 0)[0] is False
    assert newp(BBoolP, 1)[0] is True
    pytest.raises(OverflowError, newp, BBoolP, 2)
    pytest.raises(OverflowError, newp, BBoolP, -1)
    pytest.raises(ValueError, newp, BBoolA, b'\x00\x01\x02')
    pytest.raises(OverflowError, newp, BBoolA, [0, 1, 2])
    pytest.raises(TypeError, string, newp(BBoolP, 1))
    pytest.raises(TypeError, string, newp(BBoolA, [1]))

def test_typeoffsetof():
    BChar = new_primitive_type("char")
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BChar, -1),
                                       ('a2', BChar, -1),
                                       ('a3', BChar, -1)])
    pytest.raises(TypeError, typeoffsetof, BStructPtr, None)
    pytest.raises(TypeError, typeoffsetof, BStruct, None)
    assert typeoffsetof(BStructPtr, 'a1') == (BChar, 0)
    assert typeoffsetof(BStruct, 'a1') == (BChar, 0)
    assert typeoffsetof(BStructPtr, 'a2') == (BChar, 1)
    assert typeoffsetof(BStruct, 'a3') == (BChar, 2)
    assert typeoffsetof(BStructPtr, 'a2', 0) == (BChar, 1)
    assert typeoffsetof(BStruct, u+'a3') == (BChar, 2)
    pytest.raises(TypeError, typeoffsetof, BStructPtr, 'a2', 1)
    pytest.raises(KeyError, typeoffsetof, BStructPtr, 'a4')
    pytest.raises(KeyError, typeoffsetof, BStruct, 'a5')
    pytest.raises(TypeError, typeoffsetof, BStruct, 42)
    pytest.raises(TypeError, typeoffsetof, BChar, 'a1')

def test_typeoffsetof_array():
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BArray = new_array_type(BIntP, None)
    pytest.raises(TypeError, typeoffsetof, BArray, None)
    pytest.raises(TypeError, typeoffsetof, BArray, 'a1')
    assert typeoffsetof(BArray, 51) == (BInt, 51 * size_of_int())
    assert typeoffsetof(BIntP, 51) == (BInt, 51 * size_of_int())
    assert typeoffsetof(BArray, -51) == (BInt, -51 * size_of_int())
    MAX = sys.maxsize // size_of_int()
    assert typeoffsetof(BArray, MAX) == (BInt, MAX * size_of_int())
    assert typeoffsetof(BIntP, MAX) == (BInt, MAX * size_of_int())
    pytest.raises(OverflowError, typeoffsetof, BArray, MAX + 1)

def test_typeoffsetof_no_bitfield():
    BInt = new_primitive_type("int")
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('a1', BInt, 4)])
    pytest.raises(TypeError, typeoffsetof, BStruct, 'a1')

def test_rawaddressof():
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BStruct = new_struct_type("struct foo")
    BStructPtr = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('a1', BChar, -1),
                                       ('a2', BChar, -1),
                                       ('a3', BChar, -1)])
    p = newp(BStructPtr)
    assert repr(p) == "<cdata 'struct foo *' owning 3 bytes>"
    s = p[0]
    assert repr(s) == "<cdata 'struct foo' owning 3 bytes>"
    a = rawaddressof(BStructPtr, s, 0)
    assert repr(a).startswith("<cdata 'struct foo *' 0x")
    pytest.raises(TypeError, rawaddressof, BStruct, s, 0)
    b = rawaddressof(BCharP, s, 0)
    assert b == cast(BCharP, p)
    c = rawaddressof(BStructPtr, a, 0)
    assert c == a
    pytest.raises(TypeError, rawaddressof, BStructPtr, cast(BChar, '?'), 0)
    #
    d = rawaddressof(BCharP, s, 1)
    assert d == cast(BCharP, p) + 1
    #
    e = cast(BCharP, 109238)
    f = rawaddressof(BCharP, e, 42)
    assert f == e + 42
    #
    BCharA = new_array_type(BCharP, None)
    e = newp(BCharA, 50)
    f = rawaddressof(BCharP, e, 42)
    assert f == e + 42

def test_newp_signed_unsigned_char():
    BCharArray = new_array_type(
        new_pointer_type(new_primitive_type("char")), None)
    p = newp(BCharArray, b"foo")
    assert len(p) == 4
    assert list(p) == [b"f", b"o", b"o", b"\x00"]
    #
    BUCharArray = new_array_type(
        new_pointer_type(new_primitive_type("unsigned char")), None)
    p = newp(BUCharArray, b"fo\xff")
    assert len(p) == 4
    assert list(p) == [ord("f"), ord("o"), 0xff, 0]
    #
    BSCharArray = new_array_type(
        new_pointer_type(new_primitive_type("signed char")), None)
    p = newp(BSCharArray, b"fo\xff")
    assert len(p) == 4
    assert list(p) == [ord("f"), ord("o"), -1, 0]

def test_newp_from_bytearray_doesnt_work():
    BCharArray = new_array_type(
        new_pointer_type(new_primitive_type("char")), None)
    pytest.raises(TypeError, newp, BCharArray, bytearray(b"foo"))
    p = newp(BCharArray, 5)
    buffer(p)[:] = bytearray(b"foo.\x00")
    assert len(p) == 5
    assert list(p) == [b"f", b"o", b"o", b".", b"\x00"]
    p[1:3] = bytearray(b"XY")
    assert list(p) == [b"f", b"X", b"Y", b".", b"\x00"]

def test_string_assignment_to_byte_array():
    BByteArray = new_array_type(
        new_pointer_type(new_primitive_type("unsigned char")), None)
    p = newp(BByteArray, 5)
    p[0:3] = bytearray(b"XYZ")
    assert list(p) == [ord("X"), ord("Y"), ord("Z"), 0, 0]

# XXX hack
if sys.version_info >= (3,):
    try:
        import posix, io
        posix.fdopen = io.open
    except ImportError:
        pass   # win32

def test_FILE():
    if sys.platform == "win32":
        pytest.skip("testing FILE not implemented")
    #
    BFILE = new_struct_type("struct _IO_FILE")
    BFILEP = new_pointer_type(BFILE)
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BCharP, BFILEP), BInt, False)
    BFunc2 = new_function_type((BFILEP, BCharP), BInt, True)
    ll = find_and_load_library('c')
    fputs = ll.load_function(BFunc, "fputs")
    fscanf = ll.load_function(BFunc2, "fscanf")
    #
    import posix
    fdr, fdw = posix.pipe()
    fr1 = posix.fdopen(fdr, 'rb', 256)
    fw1 = posix.fdopen(fdw, 'wb', 256)
    #
    fw1.write(b"X")
    res = fputs(b"hello world\n", fw1)
    assert res >= 0
    fw1.flush()     # should not be needed
    #
    p = newp(new_array_type(BCharP, 100), None)
    res = fscanf(fr1, b"%s\n", p)
    assert res == 1
    assert string(p) == b"Xhello"
    fr1.close()
    fw1.close()

def test_FILE_only_for_FILE_arg():
    if sys.platform == "win32":
        pytest.skip("testing FILE not implemented")
    #
    B_NOT_FILE = new_struct_type("struct NOT_FILE")
    B_NOT_FILEP = new_pointer_type(B_NOT_FILE)
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BCharP, B_NOT_FILEP), BInt, False)
    ll = find_and_load_library('c')
    fputs = ll.load_function(BFunc, "fputs")
    #
    import posix
    fdr, fdw = posix.pipe()
    fr1 = posix.fdopen(fdr, 'r')
    fw1 = posix.fdopen(fdw, 'w')
    #
    e = pytest.raises(TypeError, fputs, b"hello world\n", fw1)
    assert str(e.value).startswith(
        "initializer for ctype 'struct NOT_FILE *' must "
        "be a cdata pointer, not ")

def test_FILE_object():
    if sys.platform == "win32":
        pytest.skip("testing FILE not implemented")
    #
    BFILE = new_struct_type("FILE")
    BFILEP = new_pointer_type(BFILE)
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BCharP, BFILEP), BInt, False)
    BFunc2 = new_function_type((BFILEP,), BInt, False)
    ll = find_and_load_library('c')
    fputs = ll.load_function(BFunc, "fputs")
    fileno = ll.load_function(BFunc2, "fileno")
    #
    import posix
    fdr, fdw = posix.pipe()
    fw1 = posix.fdopen(fdw, 'wb', 256)
    #
    fw1p = cast(BFILEP, fw1)
    fw1.write(b"X")
    fw1.flush()
    res = fputs(b"hello\n", fw1p)
    assert res >= 0
    res = fileno(fw1p)
    assert (res == fdw) == (sys.version_info < (3,))
    fw1.close()
    #
    data = posix.read(fdr, 256)
    assert data == b"Xhello\n"
    posix.close(fdr)

def test_errno_saved():
    set_errno(42)
    # a random function that will reset errno to 0 (at least on non-windows)
    import os; os.stat('.')
    #
    res = get_errno()
    assert res == 42

def test_GetLastError():
    if sys.platform != "win32":
        pytest.skip("GetLastError(): only for Windows")
    #
    lib = find_and_load_library('KERNEL32.DLL')
    BInt = new_primitive_type("int")
    BVoid = new_void_type()
    BFunc1 = new_function_type((BInt,), BVoid, False)
    BFunc2 = new_function_type((), BInt, False)
    SetLastError = lib.load_function(BFunc1, "SetLastError")
    GetLastError = lib.load_function(BFunc2, "GetLastError")
    #
    SetLastError(42)
    # a random function that will reset the real GetLastError() to 0
    import nt; nt.stat('.')
    #
    res = GetLastError()
    assert res == 42
    #
    SetLastError(2)
    code, message = getwinerror()
    assert code == 2
    assert message == "The system cannot find the file specified"
    #
    code, message = getwinerror(1155)
    assert code == 1155
    assert message == ("No application is associated with the "
                       "specified file for this operation")

def test_nonstandard_integer_types():
    for typename in ['int8_t', 'uint8_t', 'int16_t', 'uint16_t', 'int32_t',
                     'uint32_t', 'int64_t', 'uint64_t', 'intptr_t',
                     'uintptr_t', 'ptrdiff_t', 'size_t', 'ssize_t',
                     'int_least8_t',  'uint_least8_t',
                     'int_least16_t', 'uint_least16_t',
                     'int_least32_t', 'uint_least32_t',
                     'int_least64_t', 'uint_least64_t',
                     'int_fast8_t',  'uint_fast8_t',
                     'int_fast16_t', 'uint_fast16_t',
                     'int_fast32_t', 'uint_fast32_t',
                     'int_fast64_t', 'uint_fast64_t',
                     'intmax_t', 'uintmax_t']:
        new_primitive_type(typename)    # works

def test_cannot_convert_unicode_to_charp():
    BCharP = new_pointer_type(new_primitive_type("char"))
    BCharArray = new_array_type(BCharP, None)
    pytest.raises(TypeError, newp, BCharArray, u+'foobar')

def test_buffer_keepalive():
    BCharP = new_pointer_type(new_primitive_type("char"))
    BCharArray = new_array_type(BCharP, None)
    buflist = []
    for i in range(20):
        c = newp(BCharArray, str2bytes("hi there %d" % i))
        buflist.append(buffer(c))
    import gc; gc.collect()
    for i in range(20):
        buf = buflist[i]
        assert buf[:] == str2bytes("hi there %d\x00" % i)

def test_slice():
    BIntP = new_pointer_type(new_primitive_type("int"))
    BIntArray = new_array_type(BIntP, None)
    c = newp(BIntArray, 5)
    assert len(c) == 5
    assert repr(c) == "<cdata 'int[]' owning 20 bytes>"
    d = c[1:4]
    assert len(d) == 3
    assert repr(d) == "<cdata 'int[]' sliced length 3>"
    d[0] = 123
    d[2] = 456
    assert c[1] == 123
    assert c[3] == 456
    assert d[2] == 456
    with pytest.raises(IndexError):
        d[3]
    with pytest.raises(IndexError):
        d[-1]

def test_slice_ptr():
    BIntP = new_pointer_type(new_primitive_type("int"))
    BIntArray = new_array_type(BIntP, None)
    c = newp(BIntArray, 5)
    d = (c+1)[0:2]
    assert len(d) == 2
    assert repr(d) == "<cdata 'int[]' sliced length 2>"
    d[1] += 50
    assert c[2] == 50

def test_slice_array_checkbounds():
    BIntP = new_pointer_type(new_primitive_type("int"))
    BIntArray = new_array_type(BIntP, None)
    c = newp(BIntArray, 5)
    c[0:5]
    assert len(c[5:5]) == 0
    with pytest.raises(IndexError):
        c[-1:1]
    cp = c + 0
    cp[-1:1]

def test_nonstandard_slice():
    BIntP = new_pointer_type(new_primitive_type("int"))
    BIntArray = new_array_type(BIntP, None)
    c = newp(BIntArray, 5)
    with pytest.raises(IndexError) as e:
        c[:5]
    assert str(e.value) == "slice start must be specified"
    with pytest.raises(IndexError) as e:
        c[4:]
    assert str(e.value) == "slice stop must be specified"
    with pytest.raises(IndexError) as e:
        c[1:2:3]
    assert str(e.value) == "slice with step not supported"
    with pytest.raises(IndexError) as e:
        c[1:2:1]
    assert str(e.value) == "slice with step not supported"
    with pytest.raises(IndexError) as e:
        c[4:2]
    assert str(e.value) == "slice start > stop"
    with pytest.raises(IndexError) as e:
        c[6:6]
    assert str(e.value) == "index too large (expected 6 <= 5)"

def test_setslice():
    BIntP = new_pointer_type(new_primitive_type("int"))
    BIntArray = new_array_type(BIntP, None)
    c = newp(BIntArray, 5)
    c[1:3] = [100, 200]
    assert list(c) == [0, 100, 200, 0, 0]
    cp = c + 3
    cp[-1:1] = [300, 400]
    assert list(c) == [0, 100, 300, 400, 0]
    cp[-1:1] = iter([500, 600])
    assert list(c) == [0, 100, 500, 600, 0]
    with pytest.raises(ValueError):
        cp[-1:1] = [1000]
    assert list(c) == [0, 100, 1000, 600, 0]
    with pytest.raises(ValueError):
        cp[-1:1] = (700, 800, 900)
    assert list(c) == [0, 100, 700, 800, 0]

def test_setslice_array():
    BIntP = new_pointer_type(new_primitive_type("int"))
    BIntArray = new_array_type(BIntP, None)
    c = newp(BIntArray, 5)
    d = newp(BIntArray, [10, 20, 30])
    c[1:4] = d
    assert list(c) == [0, 10, 20, 30, 0]
    #
    BShortP = new_pointer_type(new_primitive_type("short"))
    BShortArray = new_array_type(BShortP, None)
    d = newp(BShortArray, [40, 50])
    c[1:3] = d
    assert list(c) == [0, 40, 50, 30, 0]

def test_cdata_name_module_doc():
    p = new_primitive_type("signed char")
    x = cast(p, 17)
    assert x.__module__ == '_cffi_backend'
    assert x.__name__ == '<cdata>'
    assert hasattr(x, '__doc__')

def test_different_types_of_ptr_equality():
    BVoidP = new_pointer_type(new_void_type())
    BIntP = new_pointer_type(new_primitive_type("int"))
    x = cast(BVoidP, 12345)
    assert x == cast(BIntP, 12345)
    assert x != cast(BIntP, 12344)
    assert hash(x) == hash(cast(BIntP, 12345))

def test_new_handle():
    import _weakref
    BVoidP = new_pointer_type(new_void_type())
    BCharP = new_pointer_type(new_primitive_type("char"))
    class mylist(list):
        pass
    o = mylist([2, 3, 4])
    x = newp_handle(BVoidP, o)
    assert repr(x) == "<cdata 'void *' handle to [2, 3, 4]>"
    assert x
    assert from_handle(x) is o
    assert from_handle(cast(BCharP, x)) is o
    wr = _weakref.ref(o)
    del o
    import gc; gc.collect()
    assert wr() is not None
    assert from_handle(x) == list((2, 3, 4))
    assert from_handle(cast(BCharP, x)) == list((2, 3, 4))
    del x
    for i in range(3):
        if wr() is not None:
            import gc; gc.collect()
    assert wr() is None
    pytest.raises(RuntimeError, from_handle, cast(BCharP, 0))

def test_new_handle_cycle():
    import _weakref
    BVoidP = new_pointer_type(new_void_type())
    class A(object):
        pass
    o = A()
    o.cycle = newp_handle(BVoidP, o)
    wr = _weakref.ref(o)
    del o
    for i in range(3):
        if wr() is not None:
            import gc; gc.collect()
    assert wr() is None

def _test_bitfield_details(flag):
    BChar = new_primitive_type("char")
    BShort = new_primitive_type("short")
    BInt = new_primitive_type("int")
    BUInt = new_primitive_type("unsigned int")
    BStruct = new_struct_type("struct foo1")
    complete_struct_or_union(BStruct, [('a', BChar, -1),
                                       ('b1', BInt, 9),
                                       ('b2', BUInt, 7),
                                       ('c', BChar, -1)], -1, -1, -1, flag)
    if not (flag & SF_MSVC_BITFIELDS):   # gcc, any variant
        assert typeoffsetof(BStruct, 'c') == (BChar, 3)
        assert sizeof(BStruct) == 4
    else:               # msvc
        assert typeoffsetof(BStruct, 'c') == (BChar, 8)
        assert sizeof(BStruct) == 12
    assert alignof(BStruct) == 4
    #
    p = newp(new_pointer_type(BStruct), None)
    p.a = b'A'
    p.b1 = -201
    p.b2 = 99
    p.c = b'\x9D'
    raw = buffer(p)[:]
    if sys.byteorder == 'little':
        if flag & SF_MSVC_BITFIELDS:
            assert raw == b'A\x00\x00\x007\xC7\x00\x00\x9D\x00\x00\x00'
        elif flag & SF_GCC_LITTLE_ENDIAN:
            assert raw == b'A7\xC7\x9D'
        elif flag & SF_GCC_BIG_ENDIAN:
            assert raw == b'A\xE3\x9B\x9D'
        else:
            raise AssertionError("bad flag")
    else:
        if flag & SF_MSVC_BITFIELDS:
            assert raw == b'A\x00\x00\x00\x00\x00\xC77\x9D\x00\x00\x00'
        elif flag & SF_GCC_LITTLE_ENDIAN:
            assert raw == b'A\xC77\x9D'
        elif flag & SF_GCC_BIG_ENDIAN:
            assert raw == b'A\x9B\xE3\x9D'
        else:
            raise AssertionError("bad flag")
    #
    BStruct = new_struct_type("struct foo2")
    complete_struct_or_union(BStruct, [('a', BChar, -1),
                                       ('',  BShort, 9),
                                       ('c', BChar, -1)], -1, -1, -1, flag)
    assert typeoffsetof(BStruct, 'c') == (BChar, 4)
    if flag & SF_MSVC_BITFIELDS:
        assert sizeof(BStruct) == 6
        assert alignof(BStruct) == 2
    elif flag & SF_GCC_X86_BITFIELDS:
        assert sizeof(BStruct) == 5
        assert alignof(BStruct) == 1
    elif flag & SF_GCC_ARM_BITFIELDS:
        assert sizeof(BStruct) == 6
        assert alignof(BStruct) == 2
    else:
        raise AssertionError("bad flag")
    #
    BStruct = new_struct_type("struct foo2")
    complete_struct_or_union(BStruct, [('a', BChar, -1),
                                       ('',  BInt, 0),
                                       ('',  BInt, 0),
                                       ('c', BChar, -1)], -1, -1, -1, flag)
    if flag & SF_MSVC_BITFIELDS:
        assert typeoffsetof(BStruct, 'c') == (BChar, 1)
        assert sizeof(BStruct) == 2
        assert alignof(BStruct) == 1
    elif flag & SF_GCC_X86_BITFIELDS:
        assert typeoffsetof(BStruct, 'c') == (BChar, 4)
        assert sizeof(BStruct) == 5
        assert alignof(BStruct) == 1
    elif flag & SF_GCC_ARM_BITFIELDS:
        assert typeoffsetof(BStruct, 'c') == (BChar, 4)
        assert sizeof(BStruct) == 8
        assert alignof(BStruct) == 4
    else:
        raise AssertionError("bad flag")


SF_MSVC_BITFIELDS     = 0x01
SF_GCC_ARM_BITFIELDS  = 0x02
SF_GCC_X86_BITFIELDS  = 0x10

SF_GCC_BIG_ENDIAN     = 0x04
SF_GCC_LITTLE_ENDIAN  = 0x40

SF_PACKED             = 0x08

def test_bitfield_as_x86_gcc():
    _test_bitfield_details(flag=SF_GCC_X86_BITFIELDS|SF_GCC_LITTLE_ENDIAN)

def test_bitfield_as_msvc():
    _test_bitfield_details(flag=SF_MSVC_BITFIELDS|SF_GCC_LITTLE_ENDIAN)

def test_bitfield_as_arm_gcc():
    _test_bitfield_details(flag=SF_GCC_ARM_BITFIELDS|SF_GCC_LITTLE_ENDIAN)

def test_bitfield_as_ppc_gcc():
    # PowerPC uses the same format as X86, but is big-endian
    _test_bitfield_details(flag=SF_GCC_X86_BITFIELDS|SF_GCC_BIG_ENDIAN)


def buffer_warning(cdata):
    import warnings
    buf = buffer(cdata)
    bytes = len(buf)
    with warnings.catch_warnings(record=True) as w:
        warnings.simplefilter("always")
        buffer(cdata, bytes)
        assert len(w) == 0
        buffer(cdata, bytes + 1)
        assert len(w) <= 1
        return len(w) == 1

def test_struct_array_no_length():
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BArray = new_array_type(BIntP, None)
    BStruct = new_struct_type("foo")
    pytest.raises(TypeError, complete_struct_or_union,
                   BStruct, [('x', BArray),
                             ('y', BInt)])
    #
    BStruct = new_struct_type("foo")
    complete_struct_or_union(BStruct, [('x', BInt),
                                       ('y', BArray)])
    assert sizeof(BStruct) == size_of_int()
    d = BStruct.fields
    assert len(d) == 2
    assert d[0][0] == 'x'
    assert d[0][1].type is BInt
    assert d[0][1].offset == 0
    assert d[0][1].bitshift == -1
    assert d[0][1].bitsize == -1
    assert d[1][0] == 'y'
    assert d[1][1].type is BArray
    assert d[1][1].offset == size_of_int()
    assert d[1][1].bitshift == -2
    assert d[1][1].bitsize == -1
    #
    p = newp(new_pointer_type(BStruct))
    p.x = 42
    assert p.x == 42
    assert typeof(p.y) is BArray
    assert len(p.y) == 0
    assert p.y == cast(BIntP, p) + 1
    #
    p = newp(new_pointer_type(BStruct), [100])
    assert p.x == 100
    assert len(p.y) == 0
    #
    # Tests for
    #    ffi.new("struct_with_var_array *", [field.., [the_array_items..]])
    #    ffi.new("struct_with_var_array *", [field.., array_size])
    plist = []
    for i in range(20):
        if i % 2 == 0:
            p = newp(new_pointer_type(BStruct), [100, [200, i, 400]])
        else:
            p = newp(new_pointer_type(BStruct), [100, 3])
            p.y[1] = i
            p.y[0] = 200
            assert p.y[2] == 0
            p.y[2] = 400
        assert len(p.y) == 3
        assert len(p[0].y) == 3
        assert len(buffer(p)) == sizeof(BInt) * 4
        assert sizeof(p[0]) == sizeof(BInt) * 4
        plist.append(p)
    for i in range(20):
        p = plist[i]
        assert p.x == 100
        assert p.y[0] == 200
        assert p.y[1] == i
        assert p.y[2] == 400
        assert list(p.y) == [200, i, 400]
    #
    # the following assignment works, as it normally would, for any array field
    p.y = [501, 601]
    assert list(p.y) == [501, 601, 400]
    p[0].y = [500, 600]
    assert list(p[0].y) == [500, 600, 400]
    assert repr(p) == "<cdata 'foo *' owning %d bytes>" % (
        sizeof(BStruct) + 3 * sizeof(BInt),)
    assert repr(p[0]) == "<cdata 'foo' owning %d bytes>" % (
        sizeof(BStruct) + 3 * sizeof(BInt),)
    assert sizeof(p[0]) == sizeof(BStruct) + 3 * sizeof(BInt)
    #
    # from a non-owning pointer, we can't get the length
    q = cast(new_pointer_type(BStruct), p)
    assert q.y[0] == 500
    assert q[0].y[0] == 500
    pytest.raises(TypeError, len, q.y)
    pytest.raises(TypeError, len, q[0].y)
    assert typeof(q.y) is BIntP
    assert typeof(q[0].y) is BIntP
    assert sizeof(q[0]) == sizeof(BStruct)
    #
    # error cases
    with pytest.raises(IndexError):
        p.y[4]
    with pytest.raises(TypeError):
        p.y = cast(BIntP, 0)
    with pytest.raises(TypeError):
        p.y = 15
    with pytest.raises(TypeError):
        p.y = None
    #
    # accepting this may be specified by the C99 standard,
    # or a GCC strangeness...
    BStruct2 = new_struct_type("bar")
    complete_struct_or_union(BStruct2, [('f', BStruct),
                                        ('n', BInt)])
    p = newp(new_pointer_type(BStruct2), {'n': 42})
    assert p.n == 42
    #
    # more error cases
    pytest.raises(TypeError, newp, new_pointer_type(BStruct), [100, None])
    BArray4 = new_array_type(BIntP, 4)
    BStruct4 = new_struct_type("test4")
    complete_struct_or_union(BStruct4, [('a', BArray4)])   # not varsized
    pytest.raises(TypeError, newp, new_pointer_type(BStruct4), [None])
    pytest.raises(TypeError, newp, new_pointer_type(BStruct4), [4])
    p = newp(new_pointer_type(BStruct4), [[10, 20, 30]])
    assert p.a[0] == 10
    assert p.a[1] == 20
    assert p.a[2] == 30
    assert p.a[3] == 0
    assert buffer_warning(p)
    #
    # struct of struct of varsized array
    BStruct2 = new_struct_type("bar")
    complete_struct_or_union(BStruct2, [('head', BInt),
                                        ('tail', BStruct)])
    for i in range(2):   # try to detect heap overwrites
        p = newp(new_pointer_type(BStruct2), [100, [200, list(range(50))]])
        assert p.tail.y[49] == 49
    assert buffer_warning(p)
    assert not buffer_warning(cast(new_pointer_type(BStruct2), p))
    assert not buffer_warning(cast(BIntP, p))

def test_more_buffer_warning():
    BChar = new_primitive_type("unsigned char")
    BCharP = new_pointer_type(BChar)
    BArray = new_array_type(BCharP, 10)   # char[10]
    p = newp(BArray)
    assert buffer_warning(p)
    assert not buffer_warning(cast(BCharP, p))
    p = newp(BCharP)
    assert buffer_warning(p)
    assert not buffer_warning(cast(BCharP, p))


def test_struct_array_no_length_explicit_position():
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BArray = new_array_type(BIntP, None)
    BStruct = new_struct_type("foo")
    complete_struct_or_union(BStruct, [('x', BArray, -1, 0), # actually 3 items
                                       ('y', BInt, -1, 12)])
    p = newp(new_pointer_type(BStruct), [[10, 20], 30])
    assert p.x[0] == 10
    assert p.x[1] == 20
    assert p.x[2] == 0
    assert p.y == 30
    p = newp(new_pointer_type(BStruct), {'x': [40], 'y': 50})
    assert p.x[0] == 40
    assert p.x[1] == 0
    assert p.x[2] == 0
    assert p.y == 50
    p = newp(new_pointer_type(BStruct), {'y': 60})
    assert p.x[0] == 0
    assert p.x[1] == 0
    assert p.x[2] == 0
    assert p.y == 60
    #
    # This "should" work too, allocating a larger structure
    # (a bit strange in this case, but useful in general)
    plist = []
    for i in range(20):
        p = newp(new_pointer_type(BStruct), [[10, 20, 30, 40, 50, 60, 70]])
        plist.append(p)
    for i in range(20):
        p = plist[i]
        assert p.x[0] == 10
        assert p.x[1] == 20
        assert p.x[2] == 30
        assert p.x[3] == 40 == p.y
        assert p.x[4] == 50
        assert p.x[5] == 60
        assert p.x[6] == 70

def test_struct_array_not_aligned():
    # struct a { int x; char y; char z[]; };
    # ends up of size 8, but 'z' is at offset 5
    BChar = new_primitive_type("char")
    BInt = new_primitive_type("int")
    BCharP = new_pointer_type(BChar)
    BArray = new_array_type(BCharP, None)
    BStruct = new_struct_type("foo")
    complete_struct_or_union(BStruct, [('x', BInt),
                                       ('y', BChar),
                                       ('z', BArray)])
    assert sizeof(BStruct) == 2 * size_of_int()
    def offsetof(BType, fieldname):
        return typeoffsetof(BType, fieldname)[1]
    base = offsetof(BStruct, 'z')
    assert base == size_of_int() + 1
    #
    p = newp(new_pointer_type(BStruct), {'z': 3})
    assert sizeof(p[0]) == base + 3
    q = newp(new_pointer_type(BStruct), {'z': size_of_int()})
    assert sizeof(q) == size_of_ptr()
    assert sizeof(q[0]) == base + size_of_int()
    assert len(p.z) == 3
    assert len(p[0].z) == 3
    assert len(q.z) == size_of_int()
    assert len(q[0].z) == size_of_int()

def test_ass_slice():
    BChar = new_primitive_type("char")
    BArray = new_array_type(new_pointer_type(BChar), None)
    p = newp(BArray, b"foobar")
    p[2:5] = [b"*", b"Z", b"T"]
    p[1:3] = b"XY"
    assert list(p) == [b"f", b"X", b"Y", b"Z", b"T", b"r", b"\x00"]
    with pytest.raises(TypeError):
        p[1:5] = u+'XYZT'
    with pytest.raises(TypeError):
        p[1:5] = [1, 2, 3, 4]
    #
    for typename in ["wchar_t", "char16_t", "char32_t"]:
        BUniChar = new_primitive_type(typename)
        BArray = new_array_type(new_pointer_type(BUniChar), None)
        p = newp(BArray, u+"foobar")
        p[2:5] = [u+"*", u+"Z", u+"T"]
        p[1:3] = u+"XY"
        assert list(p) == [u+"f", u+"X", u+"Y", u+"Z", u+"T", u+"r", u+"\x00"]
        with pytest.raises(TypeError):
            p[1:5] = b'XYZT'
        with pytest.raises(TypeError):
            p[1:5] = [1, 2, 3, 4]

def test_void_p_arithmetic():
    BVoid = new_void_type()
    BInt = new_primitive_type("intptr_t")
    p = cast(new_pointer_type(BVoid), 100000)
    assert int(cast(BInt, p)) == 100000
    assert int(cast(BInt, p + 42)) == 100042
    assert int(cast(BInt, p - (-42))) == 100042
    assert (p + 42) - p == 42
    q = cast(new_pointer_type(new_primitive_type("char")), 100000)
    with pytest.raises(TypeError):
        p - q
    with pytest.raises(TypeError):
        q - p
    with pytest.raises(TypeError):
        p + cast(new_primitive_type('int'), 42)
    with pytest.raises(TypeError):
        p - cast(new_primitive_type('int'), 42)

def test_sizeof_sliced_array():
    BInt = new_primitive_type("int")
    BArray = new_array_type(new_pointer_type(BInt), 10)
    p = newp(BArray, None)
    assert sizeof(p[2:9]) == 7 * sizeof(BInt)

def test_packed():
    BLong = new_primitive_type("long")
    BChar = new_primitive_type("char")
    BShort = new_primitive_type("short")
    for extra_args in [(SF_PACKED,), (0, 1)]:
        BStruct = new_struct_type("struct foo")
        complete_struct_or_union(BStruct, [('a1', BLong, -1),
                                           ('a2', BChar, -1),
                                           ('a3', BShort, -1)],
                                 None, -1, -1, *extra_args)
        d = BStruct.fields
        assert len(d) == 3
        assert d[0][0] == 'a1'
        assert d[0][1].type is BLong
        assert d[0][1].offset == 0
        assert d[0][1].bitshift == -1
        assert d[0][1].bitsize == -1
        assert d[1][0] == 'a2'
        assert d[1][1].type is BChar
        assert d[1][1].offset == sizeof(BLong)
        assert d[1][1].bitshift == -1
        assert d[1][1].bitsize == -1
        assert d[2][0] == 'a3'
        assert d[2][1].type is BShort
        assert d[2][1].offset == sizeof(BLong) + sizeof(BChar)
        assert d[2][1].bitshift == -1
        assert d[2][1].bitsize == -1
        assert sizeof(BStruct) == sizeof(BLong) + sizeof(BChar) + sizeof(BShort)
        assert alignof(BStruct) == 1
    #
    BStruct2 = new_struct_type("struct foo")
    complete_struct_or_union(BStruct2, [('b1', BChar, -1),
                                        ('b2', BLong, -1)],
                             None, -1, -1, 0, 2)
    d = BStruct2.fields
    assert len(d) == 2
    assert d[0][0] == 'b1'
    assert d[0][1].type is BChar
    assert d[0][1].offset == 0
    assert d[0][1].bitshift == -1
    assert d[0][1].bitsize == -1
    assert d[1][0] == 'b2'
    assert d[1][1].type is BLong
    assert d[1][1].offset == 2
    assert d[1][1].bitshift == -1
    assert d[1][1].bitsize == -1
    assert sizeof(BStruct2) == 2 + sizeof(BLong)
    assert alignof(BStruct2) == 2

def test_packed_with_bitfields():
    if sys.platform == "win32":
        pytest.skip("testing gcc behavior")
    BLong = new_primitive_type("long")
    BChar = new_primitive_type("char")
    BStruct = new_struct_type("struct foo")
    pytest.raises(NotImplementedError,
                   complete_struct_or_union,
                   BStruct, [('a1', BLong, 30),
                             ('a2', BChar, 5)],
                   None, -1, -1, SF_PACKED)

def test_from_buffer():
    import array
    a = array.array('H', [10000, 20000, 30000])
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    c = from_buffer(BCharA, a)
    assert typeof(c) is BCharA
    assert len(c) == 6
    assert repr(c) == "<cdata 'char[]' buffer len 6 from 'array.array' object>"
    p = new_pointer_type(new_primitive_type("unsigned short"))
    cast(p, c)[1] += 500
    assert list(a) == [10000, 20500, 30000]

def test_from_buffer_not_str_unicode():
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    p1 = from_buffer(BCharA, b"foo")
    assert p1 == from_buffer(BCharA, b"foo")
    import gc; gc.collect()
    assert p1 == from_buffer(BCharA, b"foo")
    pytest.raises(TypeError, from_buffer, BCharA, u+"foo")
    try:
        from __builtin__ import buffer
    except ImportError:
        pass
    else:
        # Python 2 only
        contents = from_buffer(BCharA, buffer(b"foo"))
        assert len(contents) == len(p1)
        for i in range(len(contents)):
            assert contents[i] == p1[i]
        p4 = buffer(u+"foo")
        contents = from_buffer(BCharA, buffer(u+"foo"))
        assert len(contents) == len(p4)
        for i in range(len(contents)):
            assert contents[i] == p4[i]
    try:
        from __builtin__ import memoryview
    except ImportError:
        pass
    else:
        contents = from_buffer(BCharA, memoryview(b"foo"))
        assert len(contents) == len(p1)
        for i in range(len(contents)):
            assert contents[i] == p1[i]


def test_from_buffer_bytearray():
    a = bytearray(b"xyz")
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    p = from_buffer(BCharA, a)
    assert typeof(p) is BCharA
    assert len(p) == 3
    assert repr(p) == "<cdata 'char[]' buffer len 3 from 'bytearray' object>"
    assert p[2] == b"z"
    p[2] = b"."
    assert a[2] == ord(".")
    a[2] = ord("?")
    assert p[2] == b"?"

def test_from_buffer_more_cases():
    try:
        from _cffi_backend import _testbuff
    except ImportError:
        pytest.skip("not for pypy")
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    #
    def check1(bufobj, expected):
        c = from_buffer(BCharA, bufobj)
        assert typeof(c) is BCharA
        if sys.version_info >= (3,):
            expected = [bytes(c, "ascii") for c in expected]
        assert list(c) == list(expected)
    #
    def check(methods, expected, expected_for_memoryview=None):
        if sys.version_info >= (3,):
            if methods <= 7:
                return
            if expected_for_memoryview is not None:
                expected = expected_for_memoryview
        class X(object):
            pass
        _testbuff(X, methods)
        bufobj = X()
        check1(bufobj, expected)
        try:
            from __builtin__ import buffer
            bufobjb = buffer(bufobj)
        except (TypeError, ImportError):
            pass
        else:
            check1(bufobjb, expected)
        try:
            bufobjm = memoryview(bufobj)
        except (TypeError, NameError):
            pass
        else:
            check1(bufobjm, expected_for_memoryview or expected)
    #
    check(1, "RDB")
    check(2, "WRB")
    check(4, "CHB")
    check(8, "GTB")
    check(16, "ROB")
    #
    check(1 | 2,  "RDB")
    check(1 | 4,  "RDB")
    check(2 | 4,  "CHB")
    check(1 | 8,  "RDB", "GTB")
    check(1 | 16, "RDB", "ROB")
    check(2 | 8,  "WRB", "GTB")
    check(2 | 16, "WRB", "ROB")
    check(4 | 8,  "CHB", "GTB")
    check(4 | 16, "CHB", "ROB")

def test_from_buffer_require_writable():
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    p1 = from_buffer(BCharA, b"foo", False)
    assert p1 == from_buffer(BCharA, b"foo", False)
    pytest.raises((TypeError, BufferError), from_buffer, BCharA, b"foo", True)
    ba = bytearray(b"foo")
    p1 = from_buffer(BCharA, ba, True)
    p1[0] = b"g"
    assert ba == b"goo"

def test_from_buffer_types():
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BIntA = new_array_type(BIntP, None)
    lst = [-12345678, 87654321, 489148]
    bytestring = bytearray(buffer(newp(BIntA, lst))[:] + b'XYZ')
    lst2 = lst + [42, -999999999]
    bytestring2 = bytearray(buffer(newp(BIntA, lst2))[:] + b'XYZ')
    #
    p1 = from_buffer(BIntA, bytestring)      # int[]
    assert typeof(p1) is BIntA
    assert len(p1) == 3
    assert p1[0] == lst[0]
    assert p1[1] == lst[1]
    assert p1[2] == lst[2]
    with pytest.raises(IndexError):
        p1[3]
    with pytest.raises(IndexError):
        p1[-1]
    #
    pytest.raises(TypeError, from_buffer, BInt, bytestring)
    #
    p2 = from_buffer(BIntP, bytestring)      # int *
    assert p2 == p1 or 'PY_DOT_PY' in globals()
    # note: on py.py ^^^, bytearray buffers are not emulated well enough
    assert typeof(p2) is BIntP
    assert p2[0] == lst[0]
    assert p2[1] == lst[1]
    assert p2[2] == lst[2]
    # hopefully does not crash, but doesn't raise an exception:
    p2[3]
    p2[-1]
    # not enough data even for one, but this is not enforced:
    from_buffer(BIntP, b"")
    #
    BIntA2 = new_array_type(BIntP, 2)
    p2 = from_buffer(BIntA2, bytestring)     # int[2]
    assert typeof(p2) is BIntA2
    assert len(p2) == 2
    assert p2[0] == lst[0]
    assert p2[1] == lst[1]
    with pytest.raises(IndexError):
        p2[2]
    with pytest.raises(IndexError):
        p2[-1]
    assert p2 == p1 or 'PY_DOT_PY' in globals()
    #
    BIntA4 = new_array_type(BIntP, 4)        # int[4]: too big
    pytest.raises(ValueError, from_buffer, BIntA4, bytestring)
    #
    BStruct = new_struct_type("foo")
    complete_struct_or_union(BStruct, [('a1', BInt, -1),
                                       ('a2', BInt, -1)])
    BStructP = new_pointer_type(BStruct)
    BStructA = new_array_type(BStructP, None)
    p1 = from_buffer(BStructA, bytestring2)   # struct[]
    assert len(p1) == 2
    assert typeof(p1) is BStructA
    assert p1[0].a1 == lst2[0]
    assert p1[0].a2 == lst2[1]
    assert p1[1].a1 == lst2[2]
    assert p1[1].a2 == lst2[3]
    with pytest.raises(IndexError):
        p1[2]
    with pytest.raises(IndexError):
        p1[-1]
    assert repr(p1) == "<cdata 'foo[]' buffer len 2 from 'bytearray' object>"
    #
    p2 = from_buffer(BStructP, bytestring2)    # 'struct *'
    assert p2 == p1 or 'PY_DOT_PY' in globals()
    assert typeof(p2) is BStructP
    assert p2.a1 == lst2[0]
    assert p2.a2 == lst2[1]
    assert p2[0].a1 == lst2[0]
    assert p2[0].a2 == lst2[1]
    assert p2[1].a1 == lst2[2]
    assert p2[1].a2 == lst2[3]
    # does not crash:
    p2[2]
    p2[-1]
    # not enough data even for one, but this is not enforced:
    from_buffer(BStructP, b"")
    from_buffer(BStructP, b"1234567")
    #
    release(p1)
    assert repr(p1) == "<cdata 'foo[]' buffer RELEASED>"
    #
    BEmptyStruct = new_struct_type("empty")
    complete_struct_or_union(BEmptyStruct, [], Ellipsis, 0)
    assert sizeof(BEmptyStruct) == 0
    BEmptyStructP = new_pointer_type(BEmptyStruct)
    BEmptyStructA = new_array_type(BEmptyStructP, None)
    pytest.raises(ZeroDivisionError, from_buffer,      # empty[]
                                      BEmptyStructA, bytestring)
    #
    BEmptyStructA5 = new_array_type(BEmptyStructP, 5)
    p1 = from_buffer(BEmptyStructA5, bytestring)   # struct empty[5]
    assert typeof(p1) is BEmptyStructA5
    assert len(p1) == 5
    assert (cast(BIntP, p1) == from_buffer(BIntA, bytestring)
            or 'PY_DOT_PY' in globals())
    #
    BVarStruct = new_struct_type("varfoo")
    BVarStructP = new_pointer_type(BVarStruct)
    complete_struct_or_union(BVarStruct, [('a1', BInt, -1),
                                          ('va', BIntA, -1)])
    with pytest.raises(TypeError):
        from_buffer(BVarStruct, bytestring)
    pv = from_buffer(BVarStructP, bytestring)    # varfoo *
    assert pv.a1 == lst[0]
    assert pv.va[0] == lst[1]
    assert pv.va[1] == lst[2]
    assert sizeof(pv[0]) == 1 * size_of_int()
    with pytest.raises(TypeError):
        len(pv.va)
    # hopefully does not crash, but doesn't raise an exception:
    pv.va[2]
    pv.va[-1]
    # not enough data even for one, but this is not enforced:
    from_buffer(BVarStructP, b"")
    assert repr(pv) == "<cdata 'varfoo *' buffer from 'bytearray' object>"
    assert repr(pv[0]).startswith("<cdata 'varfoo &' ")
    #
    release(pv)
    assert repr(pv) == "<cdata 'varfoo *' buffer RELEASED>"
    assert repr(pv[0]).startswith("<cdata 'varfoo &' ")
    #
    pv = from_buffer(BVarStructP, bytestring)    # make a fresh one
    with pytest.raises(ValueError):
        release(pv[0])

def test_issue483():
    BInt = new_primitive_type("int")
    BIntP = new_pointer_type(BInt)
    BIntA = new_array_type(BIntP, None)
    lst = list(range(25))
    bytestring = bytearray(buffer(newp(BIntA, lst))[:] + b'XYZ')
    p1 = from_buffer(BIntA, bytestring)      # int[]
    assert len(buffer(p1)) == 25 * size_of_int()
    assert sizeof(p1) == 25 * size_of_int()
    #
    p2 = from_buffer(BIntP, bytestring)
    assert sizeof(p2) == size_of_ptr()
    assert len(buffer(p2)) == size_of_int()  # first element only, by default

def test_memmove():
    Short = new_primitive_type("short")
    ShortA = new_array_type(new_pointer_type(Short), None)
    Char = new_primitive_type("char")
    CharA = new_array_type(new_pointer_type(Char), None)
    p = newp(ShortA, [-1234, -2345, -3456, -4567, -5678])
    memmove(p, p + 1, 4)
    assert list(p) == [-2345, -3456, -3456, -4567, -5678]
    p[2] = 999
    memmove(p + 2, p, 6)
    assert list(p) == [-2345, -3456, -2345, -3456, 999]
    memmove(p + 4, newp(CharA, b"\x71\x72"), 2)
    if sys.byteorder == 'little':
        assert list(p) == [-2345, -3456, -2345, -3456, 0x7271]
    else:
        assert list(p) == [-2345, -3456, -2345, -3456, 0x7172]

def test_memmove_buffer():
    import array
    Short = new_primitive_type("short")
    ShortA = new_array_type(new_pointer_type(Short), None)
    a = array.array('H', [10000, 20000, 30000])
    p = newp(ShortA, 5)
    memmove(p, a, 6)
    assert list(p) == [10000, 20000, 30000, 0, 0]
    memmove(p + 1, a, 6)
    assert list(p) == [10000, 10000, 20000, 30000, 0]
    b = array.array('h', [-1000, -2000, -3000])
    memmove(b, a, 4)
    assert b.tolist() == [10000, 20000, -3000]
    assert a.tolist() == [10000, 20000, 30000]
    p[0] = 999
    p[1] = 998
    p[2] = 997
    p[3] = 996
    p[4] = 995
    memmove(b, p, 2)
    assert b.tolist() == [999, 20000, -3000]
    memmove(b, p + 2, 4)
    assert b.tolist() == [997, 996, -3000]
    p[2] = -p[2]
    p[3] = -p[3]
    memmove(b, p + 2, 6)
    assert b.tolist() == [-997, -996, 995]

def test_memmove_readonly_readwrite():
    SignedChar = new_primitive_type("signed char")
    SignedCharA = new_array_type(new_pointer_type(SignedChar), None)
    p = newp(SignedCharA, 5)
    memmove(p, b"abcde", 3)
    assert list(p) == [ord("a"), ord("b"), ord("c"), 0, 0]
    memmove(p, bytearray(b"ABCDE"), 2)
    assert list(p) == [ord("A"), ord("B"), ord("c"), 0, 0]
    pytest.raises((TypeError, BufferError), memmove, b"abcde", p, 3)
    ba = bytearray(b"xxxxx")
    memmove(dest=ba, src=p, n=3)
    assert ba == bytearray(b"ABcxx")
    memmove(ba, b"EFGH", 4)
    assert ba == bytearray(b"EFGHx")

def test_memmove_sign_check():
    SignedChar = new_primitive_type("signed char")
    SignedCharA = new_array_type(new_pointer_type(SignedChar), None)
    p = newp(SignedCharA, 5)
    pytest.raises(ValueError, memmove, p, p + 1, -1)   # not segfault

def test_memmove_bad_cdata():
    BInt = new_primitive_type("int")
    p = cast(BInt, 42)
    pytest.raises(TypeError, memmove, p, bytearray(b'a'), 1)
    pytest.raises(TypeError, memmove, bytearray(b'a'), p, 1)

def test_dereference_null_ptr():
    BInt = new_primitive_type("int")
    BIntPtr = new_pointer_type(BInt)
    p = cast(BIntPtr, 0)
    with pytest.raises(RuntimeError):
        p[0]
    with pytest.raises(RuntimeError):
        p[0] = 42
    with pytest.raises(RuntimeError):
        p[42]
    with pytest.raises(RuntimeError):
        p[42] = -1

def test_mixup():
    BStruct1 = new_struct_type("foo")
    BStruct2 = new_struct_type("foo")   # <= same name as BStruct1
    BStruct3 = new_struct_type("bar")
    BStruct1Ptr = new_pointer_type(BStruct1)
    BStruct2Ptr = new_pointer_type(BStruct2)
    BStruct3Ptr = new_pointer_type(BStruct3)
    BStruct1PtrPtr = new_pointer_type(BStruct1Ptr)
    BStruct2PtrPtr = new_pointer_type(BStruct2Ptr)
    BStruct3PtrPtr = new_pointer_type(BStruct3Ptr)
    pp1 = newp(BStruct1PtrPtr)
    pp2 = newp(BStruct2PtrPtr)
    pp3 = newp(BStruct3PtrPtr)
    pp1[0] = pp1[0]
    with pytest.raises(TypeError) as e:
        pp3[0] = pp1[0]
    assert str(e.value).startswith("initializer for ctype 'bar *' must be a ")
    assert str(e.value).endswith(", not cdata 'foo *'")
    with pytest.raises(TypeError) as e:
        pp2[0] = pp1[0]
    assert str(e.value) == ("initializer for ctype 'foo *' appears indeed to "
                            "be 'foo *', but the types are different (check "
                            "that you are not e.g. mixing up different ffi "
                            "instances)")

def test_stdcall_function_type():
    assert FFI_CDECL == FFI_DEFAULT_ABI
    try:
        stdcall = FFI_STDCALL
    except NameError:
        stdcall = FFI_DEFAULT_ABI
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BInt, BInt), BInt, False, stdcall)
    if stdcall != FFI_DEFAULT_ABI:
        assert repr(BFunc) == "<ctype 'int(__stdcall *)(int, int)'>"
    else:
        assert repr(BFunc) == "<ctype 'int(*)(int, int)'>"

def test_get_common_types():
    d = {}
    _get_common_types(d)
    assert d['bool'] == '_Bool'

def test_unpack():
    BChar = new_primitive_type("char")
    BArray = new_array_type(new_pointer_type(BChar), 10)   # char[10]
    p = newp(BArray, b"abc\x00def")
    p0 = p
    assert unpack(p, 10) == b"abc\x00def\x00\x00\x00"
    assert unpack(p+1, 5) == b"bc\x00de"

    for typename in ["wchar_t", "char16_t", "char32_t"]:
        BWChar = new_primitive_type(typename)
        BArray = new_array_type(new_pointer_type(BWChar), 10)   # wchar_t[10]
        p = newp(BArray, u"abc\x00def")
        assert unpack(p, 10) == u"abc\x00def\x00\x00\x00"

    for typename, samples in [
            ("uint8_t",  [0, 2**8-1]),
            ("uint16_t", [0, 2**16-1]),
            ("uint32_t", [0, 2**32-1]),
            ("uint64_t", [0, 2**64-1]),
            ("int8_t",  [-2**7, 2**7-1]),
            ("int16_t", [-2**15, 2**15-1]),
            ("int32_t", [-2**31, 2**31-1]),
            ("int64_t", [-2**63, 2**63-1]),
            ("_Bool", [False, True]),
            ("float", [0.0, 10.5]),
            ("double", [12.34, 56.78]),
            ]:
        BItem = new_primitive_type(typename)
        BArray = new_array_type(new_pointer_type(BItem), 10)
        p = newp(BArray, samples)
        result = unpack(p, len(samples))
        assert result == samples
        for i in range(len(samples)):
            assert result[i] == p[i] and type(result[i]) is type(p[i])
            assert (type(result[i]) is bool) == (type(samples[i]) is bool)
    #
    BInt = new_primitive_type("int")
    pytest.raises(TypeError, unpack, p)
    pytest.raises(TypeError, unpack, b"foobar", 6)
    pytest.raises(TypeError, unpack, cast(BInt, 42), 1)
    #
    BPtr = new_pointer_type(BInt)
    random_ptr = cast(BPtr, -424344)
    other_ptr = cast(BPtr, 54321)
    BArray = new_array_type(new_pointer_type(BPtr), None)
    lst = unpack(newp(BArray, [random_ptr, other_ptr]), 2)
    assert lst == [random_ptr, other_ptr]
    #
    BFunc = new_function_type((BInt, BInt), BInt, False)
    BFuncPtr = new_pointer_type(BFunc)
    lst = unpack(newp(new_array_type(BFuncPtr, None), 2), 2)
    assert len(lst) == 2
    assert not lst[0] and not lst[1]
    assert typeof(lst[0]) is BFunc
    #
    BStruct = new_struct_type("foo")
    BStructPtr = new_pointer_type(BStruct)
    e = pytest.raises(ValueError, unpack, cast(BStructPtr, 42), 5)
    assert str(e.value) == "'foo *' points to items of unknown size"
    complete_struct_or_union(BStruct, [('a1', BInt, -1),
                                       ('a2', BInt, -1)])
    array_of_structs = newp(new_array_type(BStructPtr, None), [[4,5], [6,7]])
    lst = unpack(array_of_structs, 2)
    assert typeof(lst[0]) is BStruct
    assert lst[0].a1 == 4 and lst[1].a2 == 7
    #
    pytest.raises(RuntimeError, unpack, cast(new_pointer_type(BChar), 0), 0)
    pytest.raises(RuntimeError, unpack, cast(new_pointer_type(BChar), 0), 10)
    #
    pytest.raises(ValueError, unpack, p0, -1)
    pytest.raises(ValueError, unpack, p, -1)

def test_cdata_dir():
    BInt = new_primitive_type("int")
    p = cast(BInt, 42)
    check_dir(p, [])
    p = newp(new_array_type(new_pointer_type(BInt), None), 5)
    check_dir(p, [])
    BStruct = new_struct_type("foo")
    p = cast(new_pointer_type(BStruct), 0)
    check_dir(p, [])    # opaque
    complete_struct_or_union(BStruct, [('a2', BInt, -1),
                                       ('a1', BInt, -1)])
    check_dir(p, ['a1', 'a2'])   # always sorted
    p = newp(new_pointer_type(BStruct), None)
    check_dir(p, ['a1', 'a2'])
    check_dir(p[0], ['a1', 'a2'])
    pp = newp(new_pointer_type(new_pointer_type(BStruct)), p)
    check_dir(pp, [])
    check_dir(pp[0], ['a1', 'a2'])
    check_dir(pp[0][0], ['a1', 'a2'])

def test_char_pointer_conversion():
    import warnings
    assert __version__.startswith("1."), (
        "the warning will be an error if we ever release cffi 2.x")
    BCharP = new_pointer_type(new_primitive_type("char"))
    BIntP = new_pointer_type(new_primitive_type("int"))
    BVoidP = new_pointer_type(new_void_type())
    BUCharP = new_pointer_type(new_primitive_type("unsigned char"))
    z1 = cast(BCharP, 0)
    z2 = cast(BIntP, 0)
    z3 = cast(BVoidP, 0)
    z4 = cast(BUCharP, 0)
    with warnings.catch_warnings(record=True) as w:
        warnings.simplefilter("always")
        newp(new_pointer_type(BIntP), z1)    # warn
        assert len(w) == 1
        newp(new_pointer_type(BVoidP), z1)   # fine
        assert len(w) == 1
        newp(new_pointer_type(BCharP), z2)   # warn
        assert len(w) == 2
        newp(new_pointer_type(BVoidP), z2)   # fine
        assert len(w) == 2
        newp(new_pointer_type(BCharP), z3)   # fine
        assert len(w) == 2
        newp(new_pointer_type(BIntP), z3)    # fine
        assert len(w) == 2
        newp(new_pointer_type(BCharP), z4)   # fine (ignore signedness here)
        assert len(w) == 2
        newp(new_pointer_type(BUCharP), z1)  # fine (ignore signedness here)
        assert len(w) == 2
        newp(new_pointer_type(BUCharP), z3)  # fine
        assert len(w) == 2
    # check that the warnings are associated with lines in this file
    assert w[1].lineno == w[0].lineno + 4

def test_primitive_comparison():
    def assert_eq(a, b):
        assert (a == b) is True
        assert (b == a) is True
        assert (a != b) is False
        assert (b != a) is False
        assert (a < b) is False
        assert (a <= b) is True
        assert (a > b) is False
        assert (a >= b) is True
        assert (b < a) is False
        assert (b <= a) is True
        assert (b > a) is False
        assert (b >= a) is True
        assert hash(a) == hash(b)
    def assert_lt(a, b, check_hash=True):
        assert (a == b) is False
        assert (b == a) is False
        assert (a != b) is True
        assert (b != a) is True
        assert (a < b) is True
        assert (a <= b) is True
        assert (a > b) is False
        assert (a >= b) is False
        assert (b < a) is False
        assert (b <= a) is False
        assert (b > a) is True
        assert (b >= a) is True
        if check_hash:
            assert hash(a) != hash(b)    # (or at least, it is unlikely)
    def assert_gt(a, b, check_hash=True):
        assert_lt(b, a, check_hash)
    def assert_ne(a, b):
        assert (a == b) is False
        assert (b == a) is False
        assert (a != b) is True
        assert (b != a) is True
        if strict_compare:
            with pytest.raises(TypeError): a < b
            with pytest.raises(TypeError): a <= b
            with pytest.raises(TypeError): a > b
            with pytest.raises(TypeError): a >= b
            with pytest.raises(TypeError): b < a
            with pytest.raises(TypeError): b <= a
            with pytest.raises(TypeError): b > a
            with pytest.raises(TypeError): b >= a
        elif a < b:
            assert_lt(a, b)
        else:
            assert_lt(b, a)
    assert_eq(5, 5)
    assert_lt(3, 5)
    assert_ne('5', 5)
    #
    t1 = new_primitive_type("char")
    t2 = new_primitive_type("int")
    t3 = new_primitive_type("unsigned char")
    t4 = new_primitive_type("unsigned int")
    t5 = new_primitive_type("float")
    t6 = new_primitive_type("double")
    assert_eq(cast(t1, 65), b'A')
    assert_lt(cast(t1, 64), b'\x99')
    assert_gt(cast(t1, 200), b'A')
    assert_ne(cast(t1, 65), 65)
    assert_eq(cast(t2, -25), -25)
    assert_lt(cast(t2, -25), -24)
    assert_gt(cast(t2, -25), -26)
    assert_eq(cast(t3, 65), 65)
    assert_ne(cast(t3, 65), b'A')
    assert_ne(cast(t3, 65), cast(t1, 65))
    assert_gt(cast(t4, -1), -1, check_hash=False)
    assert_gt(cast(t4, -1), cast(t2, -1), check_hash=False)
    assert_gt(cast(t4, -1), 99999)
    assert_eq(cast(t4, -1), 256 ** size_of_int() - 1)
    assert_eq(cast(t5, 3.0), 3)
    assert_eq(cast(t5, 3.5), 3.5)
    assert_lt(cast(t5, 3.3), 3.3)   # imperfect rounding
    assert_eq(cast(t6, 3.3), 3.3)
    assert_eq(cast(t5, 3.5), cast(t6, 3.5))
    assert_lt(cast(t5, 3.1), cast(t6, 3.1))   # imperfect rounding
    assert_eq(cast(t5, 7.0), cast(t3, 7))
    assert_lt(cast(t5, 3.1), 3.101)
    assert_gt(cast(t5, 3.1), 3)

def test_explicit_release_new():
    # release() on a ffi.new() object has no effect on CPython, but
    # really releases memory on PyPy.  We can't test that effect
    # though, because a released cdata is not marked.
    BIntP = new_pointer_type(new_primitive_type("int"))
    p = newp(BIntP)
    p[0] = 42
    with pytest.raises(IndexError):
        p[1]
    release(p)
    # here, reading p[0] might give garbage or segfault...
    release(p)   # no effect
    #
    BStruct = new_struct_type("struct foo")
    BStructP = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('p', BIntP, -1)])
    pstruct = newp(BStructP)
    assert pstruct.p == cast(BIntP, 0)
    release(pstruct)
    # here, reading pstruct.p might give garbage or segfault...
    release(pstruct)   # no effect

def test_explicit_release_new_contextmgr():
    BIntP = new_pointer_type(new_primitive_type("int"))
    with newp(BIntP) as p:
        p[0] = 42
        assert p[0] == 42
    # here, reading p[0] might give garbage or segfault...
    release(p)   # no effect

def test_explicit_release_badtype():
    BIntP = new_pointer_type(new_primitive_type("int"))
    p = cast(BIntP, 12345)
    pytest.raises(ValueError, release, p)
    pytest.raises(ValueError, release, p)
    BStruct = new_struct_type("struct foo")
    BStructP = new_pointer_type(BStruct)
    complete_struct_or_union(BStruct, [('p', BIntP, -1)])
    pstruct = newp(BStructP)
    pytest.raises(ValueError, release, pstruct[0])

def test_explicit_release_badtype_contextmgr():
    BIntP = new_pointer_type(new_primitive_type("int"))
    p = cast(BIntP, 12345)
    with pytest.raises(ValueError):
        with p:
            pass
    with pytest.raises(ValueError):
        with p:
            pass

def test_explicit_release_gc():
    BIntP = new_pointer_type(new_primitive_type("int"))
    seen = []
    intp1 = newp(BIntP, 12345)
    p1 = cast(BIntP, intp1)
    p = gcp(p1, seen.append)
    assert seen == []
    release(p)
    assert seen == [p1]
    assert p1[0] == 12345
    assert p[0] == 12345  # true so far, but might change to raise RuntimeError
    release(p)   # no effect

def test_explicit_release_gc_contextmgr():
    BIntP = new_pointer_type(new_primitive_type("int"))
    seen = []
    intp1 = newp(BIntP, 12345)
    p1 = cast(BIntP, intp1)
    p = gcp(p1, seen.append)
    with p:
        assert p[0] == 12345
        assert seen == []
    assert seen == [p1]
    assert p1[0] == 12345
    assert p[0] == 12345  # true so far, but might change to raise RuntimeError
    release(p)   # no effect

def test_explicit_release_from_buffer():
    a = bytearray(b"xyz")
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    p = from_buffer(BCharA, a)
    assert p[2] == b"z"
    assert repr(p) == "<cdata 'char[]' buffer len 3 from 'bytearray' object>"
    release(p)
    assert p[2] == b"z"  # true so far, but might change to raise RuntimeError
    assert repr(p) == "<cdata 'char[]' buffer RELEASED>"
    release(p)   # no effect

def test_explicit_release_from_buffer_contextmgr():
    a = bytearray(b"xyz")
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    p = from_buffer(BCharA, a)
    with p:
        assert p[2] == b"z"
    assert p[2] == b"z"  # true so far, but might change to raise RuntimeError
    assert repr(p) == "<cdata 'char[]' buffer RELEASED>"
    release(p)   # no effect

def test_explicit_release_bytearray_on_cpython():
    if '__pypy__' in sys.builtin_module_names:
        pytest.skip("pypy's bytearray are never locked")
    a = bytearray(b"xyz")
    BChar = new_primitive_type("char")
    BCharP = new_pointer_type(BChar)
    BCharA = new_array_type(BCharP, None)
    a += b't' * 10
    p = from_buffer(BCharA, a)
    with pytest.raises(BufferError):
        a += b'u' * 100
    release(p)
    a += b'v' * 100
    release(p)   # no effect
    a += b'w' * 1000
    assert a == bytearray(b"xyz" + b't' * 10 + b'v' * 100 + b'w' * 1000)

def test_int_doesnt_give_bool():
    BBool = new_primitive_type("_Bool")
    x = int(cast(BBool, 42))
    assert type(x) is int and x == 1
    x = long(cast(BBool, 42))
    assert type(x) is long and x == 1
    with pytest.raises(TypeError):
        float(cast(BBool, 42))
    with pytest.raises(TypeError):
        complex(cast(BBool, 42))

def test_cannot_call_null_function_pointer():
    BInt = new_primitive_type("int")
    BFunc = new_function_type((BInt, BInt), BInt, False)
    f = cast(BFunc, 0)
    with pytest.raises(RuntimeError):
        f(40, 2)

def test_huge_structure():
    BChar = new_primitive_type("char")
    BArray = new_array_type(new_pointer_type(BChar), sys.maxsize)
    assert sizeof(BArray) == sys.maxsize
    BStruct = new_struct_type("struct foo")
    complete_struct_or_union(BStruct, [('a1', BArray, -1)])
    assert sizeof(BStruct) == sys.maxsize

def test_get_types():
    import _cffi_backend
    CData, CType = _get_types()
    assert CData is _cffi_backend._CDataBase
    assert CType is _cffi_backend.CType

def test_type_available_with_correct_names():
    import _cffi_backend
    check_names = [
        'CType',
        'CField',
        'CLibrary',
        '_CDataBase',
        'FFI',
        'Lib',
        'buffer',
    ]
    if '__pypy__' in sys.builtin_module_names:
        check_names += [
            '__CData_iterator',
            '__FFIGlobSupport',
            '__FFIAllocator',
            '__FFIFunctionWrapper',
        ]
    else:
        check_names += [
            '__CDataOwn',
            '__CDataOwnGC',
            '__CDataFromBuf',
            '__CDataGCP',
            '__CData_iterator',
            '__FFIGlobSupport',
        ]
    for name in check_names:
        tp = getattr(_cffi_backend, name)
        assert isinstance(tp, type)
        assert (tp.__module__, tp.__name__) == ('_cffi_backend', name)

def test_unaligned_types():
    BByteArray = new_array_type(
        new_pointer_type(new_primitive_type("unsigned char")), None)
    pbuf = newp(BByteArray, 40)
    buf = buffer(pbuf)
    #
    for name in ['short', 'int', 'long', 'long long', 'float', 'double',
                 '_cffi_float_complex_t', '_cffi_double_complex_t']:
        p = new_primitive_type(name)
        if name.endswith('_complex_t'):
            num = cast(p, 1.23 - 4.56j)
        else:
            num = cast(p, 0x0123456789abcdef)
        size = sizeof(p)
        buf[0:40] = b"\x00" * 40
        pbuf1 = cast(new_pointer_type(p), pbuf + 1)
        pbuf1[0] = num
        assert pbuf1[0] == num
        assert buf[0] == b'\x00'
        assert buf[1 + size] == b'\x00'