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),
("is_package", c_bool),
("get_code", POINTER(c_ubyte)), # Function ptr
]
FrozenTable = POINTER(struct_frozen)
modules = []
for group in ["Bootstrap", "Stdlib", "Test"]:
ft = FrozenTable.in_dll(pythonapi, f"_PyImport_Frozen{group}")
# ft is a pointer to the struct_frozen entries:
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
modname = entry.name.decode("ascii")
modules.append(modname)
with self.subTest(modname):
if entry.size != 0:
# Do a sanity check on entry.size and entry.code.
self.assertGreater(abs(entry.size), 10)
self.assertTrue(
[entry.code[i] for i in range(abs(entry.size))])
# Check the module's package-ness.
with import_helper.frozen_modules():
spec = importlib.util.find_spec(modname)
if entry.is_package:
# It's a package.
self.assertIsNotNone(spec.submodule_search_locations)
else:
self.assertIsNone(spec.submodule_search_locations)
with import_helper.frozen_modules():
expected = _imp._frozen_module_names()
self.maxDiff = None
self.assertEqual(
modules, expected, "_PyImport_FrozenBootstrap example "
"in Doc/library/ctypes.rst may be out of date")
from ctypes import _pointer_type_cache
del _pointer_type_cache[struct_frozen]
def list_frozen(names):
submodules = set()
for name in _imp._frozen_module_names():
# To skip __hello__, __hello_alias__ and etc.
if name.startswith('__'):
continue
if '.' in name:
submodules.add(name)
else:
names.add(name)
# Make sure all frozen submodules have a known parent.
for name in list(submodules):
if name.partition('.')[0] in names:
submodules.remove(name)
if submodules:
raise Exception(f'unexpected frozen submodules: {sorted(submodules)}')