Lib/ctypes/test/test_prototypes.pyfrom ctypes import *
from ctypes.test import need_symbol
import unittest
# IMPORTANT INFO:
#
# Consider this call:
# func.restype = c_char_p
# func(c_char_p("123"))
# It returns
# "123"
#
# WHY IS THIS SO?
#
# argument tuple (c_char_p("123"), ) is destroyed after the function
# func is called, but NOT before the result is actually built.
#
# If the arglist would be destroyed BEFORE the result has been built,
# the c_char_p("123") object would already have a zero refcount,
# and the pointer passed to (and returned by) the function would
# probably point to deallocated space.
#
# In this case, there would have to be an additional reference to the argument...
import _ctypes_test
testdll = CDLL(_ctypes_test.__file__)
# Return machine address `a` as a (possibly long) non-negative integer.
# Starting with Python 2.5, id(anything) is always non-negative, and
# the ctypes addressof() inherits that via PyLong_FromVoidPtr().
def positive_address(a):
if a >= 0:
return a
# View the bits in `a` as unsigned instead.
import struct
num_bits = struct.calcsize("P") * 8 # num bits in native machine address
a += 1L << num_bits
assert a >= 0
return a
def c_wbuffer(init):
n = len(init) + 1
return (c_wchar * n)(*init)
class CharPointersTestCase(unittest.TestCase):
def setUp(self):
func = testdll._testfunc_p_p
func.restype = c_long
func.argtypes = None
def test_paramflags(self):
# function returns c_void_p result,
# and has a required parameter named 'input'
prototype = CFUNCTYPE(c_void_p, c_void_p)
func = prototype(("_testfunc_p_p", testdll),
((1, "input"),))
try:
func()
except TypeError, details:
self.assertEqual(str(details), "required argument 'input' missing")
else:
self.fail("TypeError not raised")
self.assertEqual(func(None), None)
self.assertEqual(func(input=None), None)
def test_int_pointer_arg(self):
func = testdll._testfunc_p_p
func.restype = c_long
self.assertEqual(0, func(0))
ci = c_int(0)
func.argtypes = POINTER(c_int),
self.assertEqual(positive_address(addressof(ci)),
positive_address(func(byref(ci))))
func.argtypes = c_char_p,
self.assertRaises(ArgumentError, func, byref(ci))
func.argtypes = POINTER(c_short),
self.assertRaises(ArgumentError, func, byref(ci))
func.argtypes = POINTER(c_double),
self.assertRaises(ArgumentError, func, byref(ci))
def test_POINTER_c_char_arg(self):
func = testdll._testfunc_p_p
func.restype = c_char_p
func.argtypes = POINTER(c_char),
self.assertEqual(None, func(None))
self.assertEqual("123", func("123"))
self.assertEqual(None, func(c_char_p(None)))
self.assertEqual("123", func(c_char_p("123")))
self.assertEqual("123", func(c_buffer("123")))
ca = c_char("a")
self.assertEqual("a", func(pointer(ca))[0])
self.assertEqual("a", func(byref(ca))[0])
def test_c_char_p_arg(self):
func = testdll._testfunc_p_p
func.restype = c_char_p
func.argtypes = c_char_p,
self.assertEqual(None, func(None))
self.assertEqual("123", func("123"))
self.assertEqual(None, func(c_char_p(None)))
self.assertEqual("123", func(c_char_p("123")))
self.assertEqual("123", func(c_buffer("123")))
ca = c_char("a")
self.assertEqual("a", func(pointer(ca))[0])
self.assertEqual("a", func(byref(ca))[0])
def test_c_void_p_arg(self):
func = testdll._testfunc_p_p
func.restype = c_char_p
func.argtypes = c_void_p,
self.assertEqual(None, func(None))
self.assertEqual("123", func("123"))
self.assertEqual("123", func(c_char_p("123")))
self.assertEqual(None, func(c_char_p(None)))
self.assertEqual("123", func(c_buffer("123")))
ca = c_char("a")
self.assertEqual("a", func(pointer(ca))[0])
self.assertEqual("a", func(byref(ca))[0])
func(byref(c_int()))
func(pointer(c_int()))
func((c_int * 3)())
@need_symbol('c_wchar_p')
def test_c_void_p_arg_with_c_wchar_p(self):
func = testdll._testfunc_p_p
func.restype = c_wchar_p
func.argtypes = c_void_p,
self.assertEqual(None, func(c_wchar_p(None)))
self.assertEqual(u"123", func(c_wchar_p(u"123")))
def test_instance(self):
func = testdll._testfunc_p_p
func.restype = c_void_p
class X:
_as_parameter_ = None
func.argtypes = c_void_p,
self.assertEqual(None, func(X()))
func.argtypes = None
self.assertEqual(None, func(X()))
@need_symbol('c_wchar')
class WCharPointersTestCase(unittest.TestCase):
def setUp(self):
func = testdll._testfunc_p_p
func.restype = c_int
func.argtypes = None
def test_POINTER_c_wchar_arg(self):
func = testdll._testfunc_p_p
func.restype = c_wchar_p
func.argtypes = POINTER(c_wchar),
self.assertEqual(None, func(None))
self.assertEqual(u"123", func(u"123"))
self.assertEqual(None, func(c_wchar_p(None)))
self.assertEqual(u"123", func(c_wchar_p(u"123")))
self.assertEqual(u"123", func(c_wbuffer(u"123")))
ca = c_wchar("a")
self.assertEqual(u"a", func(pointer(ca))[0])
self.assertEqual(u"a", func(byref(ca))[0])
def test_c_wchar_p_arg(self):
func = testdll._testfunc_p_p
func.restype = c_wchar_p
func.argtypes = c_wchar_p,
c_wchar_p.from_param(u"123")
self.assertEqual(None, func(None))
self.assertEqual("123", func(u"123"))
self.assertEqual(None, func(c_wchar_p(None)))
self.assertEqual("123", func(c_wchar_p("123")))
# XXX Currently, these raise TypeErrors, although they shouldn't:
self.assertEqual("123", func(c_wbuffer("123")))
ca = c_wchar("a")
self.assertEqual("a", func(pointer(ca))[0])
self.assertEqual("a", func(byref(ca))[0])
class ArrayTest(unittest.TestCase):
def test(self):
func = testdll._testfunc_ai8
func.restype = POINTER(c_int)
func.argtypes = c_int * 8,
func((c_int * 8)(1, 2, 3, 4, 5, 6, 7, 8))
# This did crash before:
def func(): pass
CFUNCTYPE(None, c_int * 3)(func)
################################################################
if __name__ == '__main__':
unittest.main()