Staging
v0.5.1
v0.5.1
https://github.com/python/cpython
Tip revision: 1da43e5e916949c8e849e656d9d05fa4b9d6836c authored by Benjamin Peterson on 26 June 2009, 13:21:52 UTC
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
rearrange the sections of the README, so they'll hopefully be more in the order people will interested in
Tip revision: 1da43e5
test_prototypes.py
from ctypes import *
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 += 1 << 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 as details:
self.failUnlessEqual(str(details), "required argument 'input' missing")
else:
self.fail("TypeError not raised")
self.failUnlessEqual(func(None), None)
self.failUnlessEqual(func(input=None), None)
def test_int_pointer_arg(self):
func = testdll._testfunc_p_p
func.restype = c_long
self.failUnlessEqual(0, func(0))
ci = c_int(0)
func.argtypes = POINTER(c_int),
self.failUnlessEqual(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.failUnlessEqual(None, func(None))
self.failUnlessEqual("123", func("123"))
self.failUnlessEqual(None, func(c_char_p(None)))
self.failUnlessEqual("123", func(c_char_p("123")))
self.failUnlessEqual("123", func(c_buffer("123")))
ca = c_char("a")
self.failUnlessEqual("a", func(pointer(ca))[0])
self.failUnlessEqual("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.failUnlessEqual(None, func(None))
self.failUnlessEqual("123", func("123"))
self.failUnlessEqual(None, func(c_char_p(None)))
self.failUnlessEqual("123", func(c_char_p("123")))
self.failUnlessEqual("123", func(c_buffer("123")))
ca = c_char("a")
self.failUnlessEqual("a", func(pointer(ca))[0])
self.failUnlessEqual("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.failUnlessEqual(None, func(None))
self.failUnlessEqual("123", func(b"123"))
self.failUnlessEqual("123", func(c_char_p("123")))
self.failUnlessEqual(None, func(c_char_p(None)))
self.failUnlessEqual("123", func(c_buffer("123")))
ca = c_char("a")
self.failUnlessEqual("a", func(pointer(ca))[0])
self.failUnlessEqual("a", func(byref(ca))[0])
func(byref(c_int()))
func(pointer(c_int()))
func((c_int * 3)())
try:
func.restype = c_wchar_p
except NameError:
pass
else:
self.failUnlessEqual(None, func(c_wchar_p(None)))
self.failUnlessEqual("123", func(c_wchar_p("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.failUnlessEqual(None, func(X()))
func.argtypes = None
self.failUnlessEqual(None, func(X()))
try:
c_wchar
except NameError:
pass
else:
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.failUnlessEqual(None, func(None))
self.failUnlessEqual("123", func("123"))
self.failUnlessEqual(None, func(c_wchar_p(None)))
self.failUnlessEqual("123", func(c_wchar_p("123")))
self.failUnlessEqual("123", func(c_wbuffer("123")))
ca = c_wchar("a")
self.failUnlessEqual("a", func(pointer(ca))[0])
self.failUnlessEqual("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("123")
self.failUnlessEqual(None, func(None))
self.failUnlessEqual("123", func("123"))
self.failUnlessEqual(None, func(c_wchar_p(None)))
self.failUnlessEqual("123", func(c_wchar_p("123")))
# XXX Currently, these raise TypeErrors, although they shouldn't:
self.failUnlessEqual("123", func(c_wbuffer("123")))
ca = c_wchar("a")
self.failUnlessEqual("a", func(pointer(ca))[0])
self.failUnlessEqual("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()