"""
A testcase which accesses *values* in a dll.
"""
import unittest
import sys
from ctypes import *
import _ctypes_test
class ValuesTestCase(unittest.TestCase):
def test_an_integer(self):
# This test checks and changes an integer stored inside the
# _ctypes_test dll/shared lib.
ctdll = CDLL(_ctypes_test.__file__)
an_integer = c_int.in_dll(ctdll, "an_integer")
x = an_integer.value
self.assertEqual(x, ctdll.get_an_integer())
an_integer.value *= 2
self.assertEqual(x*2, ctdll.get_an_integer())
# To avoid test failures when this test is repeated several
# times the original value must be restored
an_integer.value = x
self.assertEqual(x, ctdll.get_an_integer())
def test_undefined(self):
ctdll = CDLL(_ctypes_test.__file__)
self.assertRaises(ValueError, c_int.in_dll, ctdll, "Undefined_Symbol")
class PythonValuesTestCase(unittest.TestCase):
"""This test only works when python itself is a dll/shared library"""
def test_optimizeflag(self):
# This test accesses the Py_OptimizeFlag integer, which is
# exported by the Python dll and should match the sys.flags value
opt = c_int.in_dll(pythonapi, "Py_OptimizeFlag").value
self.assertEqual(opt, sys.flags.optimize)
def test_frozentable(self):
# Python exports a PyImport_FrozenModules symbol. This is a
# pointer to an array of struct _frozen entries. The end of the
# array is marked by an entry containing a NULL name and zero
# size.
# In standard Python, this table contains a __hello__
# module, and a __phello__ package containing a spam
# module.
class struct_frozen(Structure):
_fields_ = [("name", c_char_p),
("code", POINTER(c_ubyte)),
("size", c_int)]
FrozenTable = POINTER(struct_frozen)
ft = FrozenTable.in_dll(pythonapi, "PyImport_FrozenModules")
# ft is a pointer to the struct_frozen entries:
items = []
# _frozen_importlib changes size whenever importlib._bootstrap
# changes, so it gets a special case. We should make sure it's
# found, but don't worry about its size too much. The same
# applies to _frozen_importlib_external.
bootstrap_seen = []
bootstrap_expected = [
b'_frozen_importlib',
b'_frozen_importlib_external',
b'zipimport',
]
for entry in ft:
# This is dangerous. We *can* iterate over a pointer, but
# the loop will not terminate (maybe with an access
# violation;-) because the pointer instance has no size.
if entry.name is None:
break
if entry.name in bootstrap_expected:
bootstrap_seen.append(entry.name)
self.assertTrue(entry.size,
"{!r} was reported as having no size".format(entry.name))
continue
items.append((entry.name.decode("ascii"), entry.size))
expected = [("__hello__", 141),
("__phello__", -141),
("__phello__.spam", 141),
]
self.assertEqual(items, expected, "PyImport_FrozenModules example "
"in Doc/library/ctypes.rst may be out of date")
self.assertEqual(sorted(bootstrap_seen), bootstrap_expected,
"frozen bootstrap modules did not match PyImport_FrozenModules")
from ctypes import _pointer_type_cache
del _pointer_type_cache[struct_frozen]
def test_undefined(self):
self.assertRaises(ValueError, c_int.in_dll, pythonapi,
"Undefined_Symbol")
if __name__ == '__main__':
unittest.main()
