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from ctypes import *
import unittest
import os
import ctypes
import _ctypes_test
class BITS(Structure):
_fields_ = [("A", c_int, 1),
("B", c_int, 2),
("C", c_int, 3),
("D", c_int, 4),
("E", c_int, 5),
("F", c_int, 6),
("G", c_int, 7),
("H", c_int, 8),
("I", c_int, 9),
("M", c_short, 1),
("N", c_short, 2),
("O", c_short, 3),
("P", c_short, 4),
("Q", c_short, 5),
("R", c_short, 6),
("S", c_short, 7)]
func = CDLL(_ctypes_test.__file__).unpack_bitfields
func.argtypes = POINTER(BITS), c_char
##for n in "ABCDEFGHIMNOPQRS":
## print n, hex(getattr(BITS, n).size), getattr(BITS, n).offset
class C_Test(unittest.TestCase):
def test_ints(self):
for i in range(512):
for name in "ABCDEFGHI":
b = BITS()
setattr(b, name, i)
self.assertEqual((name, i, getattr(b, name)), (name, i, func(byref(b), name)))
def test_shorts(self):
for i in range(256):
for name in "MNOPQRS":
b = BITS()
setattr(b, name, i)
self.assertEqual((name, i, getattr(b, name)), (name, i, func(byref(b), name)))
signed_int_types = (c_byte, c_short, c_int, c_long, c_longlong)
unsigned_int_types = (c_ubyte, c_ushort, c_uint, c_ulong, c_ulonglong)
int_types = unsigned_int_types + signed_int_types
class BitFieldTest(unittest.TestCase):
def test_longlong(self):
class X(Structure):
_fields_ = [("a", c_longlong, 1),
("b", c_longlong, 62),
("c", c_longlong, 1)]
self.assertEqual(sizeof(X), sizeof(c_longlong))
x = X()
x.a, x.b, x.c = -1, 7, -1
self.assertEqual((x.a, x.b, x.c), (-1, 7, -1))
def test_ulonglong(self):
class X(Structure):
_fields_ = [("a", c_ulonglong, 1),
("b", c_ulonglong, 62),
("c", c_ulonglong, 1)]
self.assertEqual(sizeof(X), sizeof(c_longlong))
x = X()
self.assertEqual((x.a, x.b, x.c), (0, 0, 0))
x.a, x.b, x.c = 7, 7, 7
self.assertEqual((x.a, x.b, x.c), (1, 7, 1))
def test_signed(self):
for c_typ in signed_int_types:
class X(Structure):
_fields_ = [("dummy", c_typ),
("a", c_typ, 3),
("b", c_typ, 3),
("c", c_typ, 1)]
self.assertEqual(sizeof(X), sizeof(c_typ)*2)
x = X()
self.assertEqual((c_typ, x.a, x.b, x.c), (c_typ, 0, 0, 0))
x.a = -1
self.assertEqual((c_typ, x.a, x.b, x.c), (c_typ, -1, 0, 0))
x.a, x.b = 0, -1
self.assertEqual((c_typ, x.a, x.b, x.c), (c_typ, 0, -1, 0))
def test_unsigned(self):
for c_typ in unsigned_int_types:
class X(Structure):
_fields_ = [("a", c_typ, 3),
("b", c_typ, 3),
("c", c_typ, 1)]
self.assertEqual(sizeof(X), sizeof(c_typ))
x = X()
self.assertEqual((c_typ, x.a, x.b, x.c), (c_typ, 0, 0, 0))
x.a = -1
self.assertEqual((c_typ, x.a, x.b, x.c), (c_typ, 7, 0, 0))
x.a, x.b = 0, -1
self.assertEqual((c_typ, x.a, x.b, x.c), (c_typ, 0, 7, 0))
def fail_fields(self, *fields):
return self.get_except(type(Structure), "X", (),
{"_fields_": fields})
def test_nonint_types(self):
# bit fields are not allowed on non-integer types.
result = self.fail_fields(("a", c_char_p, 1))
self.assertEqual(result, (TypeError, 'bit fields not allowed for type c_char_p'))
result = self.fail_fields(("a", c_void_p, 1))
self.assertEqual(result, (TypeError, 'bit fields not allowed for type c_void_p'))
if c_int != c_long:
result = self.fail_fields(("a", POINTER(c_int), 1))
self.assertEqual(result, (TypeError, 'bit fields not allowed for type LP_c_int'))
result = self.fail_fields(("a", c_char, 1))
self.assertEqual(result, (TypeError, 'bit fields not allowed for type c_char'))
try:
c_wchar
except NameError:
pass
else:
result = self.fail_fields(("a", c_wchar, 1))
self.assertEqual(result, (TypeError, 'bit fields not allowed for type c_wchar'))
class Dummy(Structure):
_fields_ = []
result = self.fail_fields(("a", Dummy, 1))
self.assertEqual(result, (TypeError, 'bit fields not allowed for type Dummy'))
def test_single_bitfield_size(self):
for c_typ in int_types:
result = self.fail_fields(("a", c_typ, -1))
self.assertEqual(result, (ValueError, 'number of bits invalid for bit field'))
result = self.fail_fields(("a", c_typ, 0))
self.assertEqual(result, (ValueError, 'number of bits invalid for bit field'))
class X(Structure):
_fields_ = [("a", c_typ, 1)]
self.assertEqual(sizeof(X), sizeof(c_typ))
class X(Structure):
_fields_ = [("a", c_typ, sizeof(c_typ)*8)]
self.assertEqual(sizeof(X), sizeof(c_typ))
result = self.fail_fields(("a", c_typ, sizeof(c_typ)*8 + 1))
self.assertEqual(result, (ValueError, 'number of bits invalid for bit field'))
def test_multi_bitfields_size(self):
class X(Structure):
_fields_ = [("a", c_short, 1),
("b", c_short, 14),
("c", c_short, 1)]
self.assertEqual(sizeof(X), sizeof(c_short))
class X(Structure):
_fields_ = [("a", c_short, 1),
("a1", c_short),
("b", c_short, 14),
("c", c_short, 1)]
self.assertEqual(sizeof(X), sizeof(c_short)*3)
self.assertEqual(X.a.offset, 0)
self.assertEqual(X.a1.offset, sizeof(c_short))
self.assertEqual(X.b.offset, sizeof(c_short)*2)
self.assertEqual(X.c.offset, sizeof(c_short)*2)
class X(Structure):
_fields_ = [("a", c_short, 3),
("b", c_short, 14),
("c", c_short, 14)]
self.assertEqual(sizeof(X), sizeof(c_short)*3)
self.assertEqual(X.a.offset, sizeof(c_short)*0)
self.assertEqual(X.b.offset, sizeof(c_short)*1)
self.assertEqual(X.c.offset, sizeof(c_short)*2)
def get_except(self, func, *args, **kw):
try:
func(*args, **kw)
except Exception as detail:
return detail.__class__, str(detail)
def test_mixed_1(self):
class X(Structure):
_fields_ = [("a", c_byte, 4),
("b", c_int, 4)]
if os.name in ("nt", "ce"):
self.assertEqual(sizeof(X), sizeof(c_int)*2)
else:
self.assertEqual(sizeof(X), sizeof(c_int))
def test_mixed_2(self):
class X(Structure):
_fields_ = [("a", c_byte, 4),
("b", c_int, 32)]
self.assertEqual(sizeof(X), sizeof(c_int)*2)
def test_mixed_3(self):
class X(Structure):
_fields_ = [("a", c_byte, 4),
("b", c_ubyte, 4)]
self.assertEqual(sizeof(X), sizeof(c_byte))
def test_mixed_4(self):
class X(Structure):
_fields_ = [("a", c_short, 4),
("b", c_short, 4),
("c", c_int, 24),
("d", c_short, 4),
("e", c_short, 4),
("f", c_int, 24)]
# MSVC does NOT combine c_short and c_int into one field, GCC
# does (unless GCC is run with '-mms-bitfields' which
# produces code compatible with MSVC).
if os.name in ("nt", "ce"):
self.assertEqual(sizeof(X), sizeof(c_int) * 4)
else:
self.assertEqual(sizeof(X), sizeof(c_int) * 2)
def test_anon_bitfields(self):
# anonymous bit-fields gave a strange error message
class X(Structure):
_fields_ = [("a", c_byte, 4),
("b", c_ubyte, 4)]
class Y(Structure):
_anonymous_ = ["_"]
_fields_ = [("_", X)]
if __name__ == "__main__":
unittest.main()
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