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cpython/Lib/test/test_structseq.py
Sam Gross 4b63cd170e
gh-122527: Fix a crash on deallocation of PyStructSequence (GH-122577)
The `PyStructSequence` destructor would crash if it was deallocated after
its type's dictionary was cleared by the GC, because it couldn't compute
the "real size" of the instance. This could occur with relatively
straightforward code in the free-threaded build or with a reference
cycle involving the type in the default build, due to differing orders
in which `tp_clear()` was called.

Account for the non-sequence fields in `tp_basicsize` and use that,
along with `Py_SIZE()`, to compute the "real" size of a
`PyStructSequence` in the dealloc function. This avoids the accesses to
the type's dictionary during dealloc, which were unsafe.
2024-08-02 18:11:44 +02:00

361 lines
14 KiB
Python

import copy
import os
import pickle
import re
import textwrap
import time
import unittest
from test.support import script_helper
class StructSeqTest(unittest.TestCase):
def test_tuple(self):
t = time.gmtime()
self.assertIsInstance(t, tuple)
astuple = tuple(t)
self.assertEqual(len(t), len(astuple))
self.assertEqual(t, astuple)
# Check that slicing works the same way; at one point, slicing t[i:j] with
# 0 < i < j could produce NULLs in the result.
for i in range(-len(t), len(t)):
self.assertEqual(t[i:], astuple[i:])
for j in range(-len(t), len(t)):
self.assertEqual(t[i:j], astuple[i:j])
for j in range(-len(t), len(t)):
self.assertEqual(t[:j], astuple[:j])
self.assertRaises(IndexError, t.__getitem__, -len(t)-1)
self.assertRaises(IndexError, t.__getitem__, len(t))
for i in range(-len(t), len(t)-1):
self.assertEqual(t[i], astuple[i])
def test_repr(self):
t = time.gmtime()
self.assertTrue(repr(t))
t = time.gmtime(0)
self.assertEqual(repr(t),
"time.struct_time(tm_year=1970, tm_mon=1, tm_mday=1, tm_hour=0, "
"tm_min=0, tm_sec=0, tm_wday=3, tm_yday=1, tm_isdst=0)")
# os.stat() gives a complicated struct sequence.
st = os.stat(__file__)
rep = repr(st)
self.assertTrue(rep.startswith("os.stat_result"))
self.assertIn("st_mode=", rep)
self.assertIn("st_ino=", rep)
self.assertIn("st_dev=", rep)
def test_concat(self):
t1 = time.gmtime()
t2 = t1 + tuple(t1)
for i in range(len(t1)):
self.assertEqual(t2[i], t2[i+len(t1)])
def test_repeat(self):
t1 = time.gmtime()
t2 = 3 * t1
for i in range(len(t1)):
self.assertEqual(t2[i], t2[i+len(t1)])
self.assertEqual(t2[i], t2[i+2*len(t1)])
def test_contains(self):
t1 = time.gmtime()
for item in t1:
self.assertIn(item, t1)
self.assertNotIn(-42, t1)
def test_hash(self):
t1 = time.gmtime()
self.assertEqual(hash(t1), hash(tuple(t1)))
def test_cmp(self):
t1 = time.gmtime()
t2 = type(t1)(t1)
self.assertEqual(t1, t2)
self.assertTrue(not (t1 < t2))
self.assertTrue(t1 <= t2)
self.assertTrue(not (t1 > t2))
self.assertTrue(t1 >= t2)
self.assertTrue(not (t1 != t2))
def test_fields(self):
t = time.gmtime()
self.assertEqual(len(t), t.n_sequence_fields)
self.assertEqual(t.n_unnamed_fields, 0)
self.assertEqual(t.n_fields, time._STRUCT_TM_ITEMS)
def test_constructor(self):
t = time.struct_time
self.assertRaises(TypeError, t)
self.assertRaises(TypeError, t, None)
self.assertRaises(TypeError, t, "123")
self.assertRaises(TypeError, t, "123", dict={})
self.assertRaises(TypeError, t, "123456789", dict=None)
self.assertRaises(TypeError, t, seq="123456789", dict={})
self.assertEqual(t("123456789"), tuple("123456789"))
self.assertEqual(t("123456789", {}), tuple("123456789"))
self.assertEqual(t("123456789", dict={}), tuple("123456789"))
self.assertEqual(t(sequence="123456789", dict={}), tuple("123456789"))
self.assertEqual(t("1234567890"), tuple("123456789"))
self.assertEqual(t("1234567890").tm_zone, "0")
self.assertEqual(t("123456789", {"tm_zone": "some zone"}), tuple("123456789"))
self.assertEqual(t("123456789", {"tm_zone": "some zone"}).tm_zone, "some zone")
s = "123456789"
self.assertEqual("".join(t(s)), s)
def test_constructor_with_duplicate_fields(self):
t = time.struct_time
error_message = re.escape("got duplicate or unexpected field name(s)")
with self.assertRaisesRegex(TypeError, error_message):
t("1234567890", dict={"tm_zone": "some zone"})
with self.assertRaisesRegex(TypeError, error_message):
t("1234567890", dict={"tm_zone": "some zone", "tm_mon": 1})
with self.assertRaisesRegex(TypeError, error_message):
t("1234567890", dict={"error": 0, "tm_zone": "some zone"})
with self.assertRaisesRegex(TypeError, error_message):
t("1234567890", dict={"error": 0, "tm_zone": "some zone", "tm_mon": 1})
def test_constructor_with_duplicate_unnamed_fields(self):
assert os.stat_result.n_unnamed_fields > 0
n_visible_fields = os.stat_result.n_sequence_fields
r = os.stat_result(range(n_visible_fields), {'st_atime': -1.0})
self.assertEqual(r.st_atime, -1.0)
self.assertEqual(r, tuple(range(n_visible_fields)))
r = os.stat_result((*range(n_visible_fields), -1.0))
self.assertEqual(r.st_atime, -1.0)
self.assertEqual(r, tuple(range(n_visible_fields)))
with self.assertRaisesRegex(TypeError,
re.escape("got duplicate or unexpected field name(s)")):
os.stat_result((*range(n_visible_fields), -1.0), {'st_atime': -1.0})
def test_constructor_with_unknown_fields(self):
t = time.struct_time
error_message = re.escape("got duplicate or unexpected field name(s)")
with self.assertRaisesRegex(TypeError, error_message):
t("123456789", dict={"tm_year": 0})
with self.assertRaisesRegex(TypeError, error_message):
t("123456789", dict={"tm_year": 0, "tm_mon": 1})
with self.assertRaisesRegex(TypeError, error_message):
t("123456789", dict={"tm_zone": "some zone", "tm_mon": 1})
with self.assertRaisesRegex(TypeError, error_message):
t("123456789", dict={"tm_zone": "some zone", "error": 0})
with self.assertRaisesRegex(TypeError, error_message):
t("123456789", dict={"error": 0, "tm_zone": "some zone", "tm_mon": 1})
with self.assertRaisesRegex(TypeError, error_message):
t("123456789", dict={"error": 0})
with self.assertRaisesRegex(TypeError, error_message):
t("123456789", dict={"tm_zone": "some zone", "error": 0})
def test_eviltuple(self):
class Exc(Exception):
pass
# Devious code could crash structseqs' constructors
class C:
def __getitem__(self, i):
raise Exc
def __len__(self):
return 9
self.assertRaises(Exc, time.struct_time, C())
def test_pickling(self):
t = time.gmtime()
for proto in range(pickle.HIGHEST_PROTOCOL + 1):
p = pickle.dumps(t, proto)
t2 = pickle.loads(p)
self.assertEqual(t2.__class__, t.__class__)
self.assertEqual(t2, t)
self.assertEqual(t2.tm_year, t.tm_year)
self.assertEqual(t2.tm_zone, t.tm_zone)
def test_pickling_with_unnamed_fields(self):
assert os.stat_result.n_unnamed_fields > 0
r = os.stat_result(range(os.stat_result.n_sequence_fields),
{'st_atime': 1.0, 'st_atime_ns': 2.0})
for proto in range(pickle.HIGHEST_PROTOCOL + 1):
p = pickle.dumps(r, proto)
r2 = pickle.loads(p)
self.assertEqual(r2.__class__, r.__class__)
self.assertEqual(r2, r)
self.assertEqual(r2.st_mode, r.st_mode)
self.assertEqual(r2.st_atime, r.st_atime)
self.assertEqual(r2.st_atime_ns, r.st_atime_ns)
def test_copying(self):
n_fields = time.struct_time.n_fields
t = time.struct_time([[i] for i in range(n_fields)])
t2 = copy.copy(t)
self.assertEqual(t2.__class__, t.__class__)
self.assertEqual(t2, t)
self.assertEqual(t2.tm_year, t.tm_year)
self.assertEqual(t2.tm_zone, t.tm_zone)
self.assertIs(t2[0], t[0])
self.assertIs(t2.tm_year, t.tm_year)
t3 = copy.deepcopy(t)
self.assertEqual(t3.__class__, t.__class__)
self.assertEqual(t3, t)
self.assertEqual(t3.tm_year, t.tm_year)
self.assertEqual(t3.tm_zone, t.tm_zone)
self.assertIsNot(t3[0], t[0])
self.assertIsNot(t3.tm_year, t.tm_year)
def test_copying_with_unnamed_fields(self):
assert os.stat_result.n_unnamed_fields > 0
n_sequence_fields = os.stat_result.n_sequence_fields
r = os.stat_result([[i] for i in range(n_sequence_fields)],
{'st_atime': [1.0], 'st_atime_ns': [2.0]})
r2 = copy.copy(r)
self.assertEqual(r2.__class__, r.__class__)
self.assertEqual(r2, r)
self.assertEqual(r2.st_mode, r.st_mode)
self.assertEqual(r2.st_atime, r.st_atime)
self.assertEqual(r2.st_atime_ns, r.st_atime_ns)
self.assertIs(r2[0], r[0])
self.assertIs(r2.st_mode, r.st_mode)
self.assertIs(r2.st_atime, r.st_atime)
self.assertIs(r2.st_atime_ns, r.st_atime_ns)
r3 = copy.deepcopy(r)
self.assertEqual(r3.__class__, r.__class__)
self.assertEqual(r3, r)
self.assertEqual(r3.st_mode, r.st_mode)
self.assertEqual(r3.st_atime, r.st_atime)
self.assertEqual(r3.st_atime_ns, r.st_atime_ns)
self.assertIsNot(r3[0], r[0])
self.assertIsNot(r3.st_mode, r.st_mode)
self.assertIsNot(r3.st_atime, r.st_atime)
self.assertIsNot(r3.st_atime_ns, r.st_atime_ns)
def test_extended_getslice(self):
# Test extended slicing by comparing with list slicing.
t = time.gmtime()
L = list(t)
indices = (0, None, 1, 3, 19, 300, -1, -2, -31, -300)
for start in indices:
for stop in indices:
# Skip step 0 (invalid)
for step in indices[1:]:
self.assertEqual(list(t[start:stop:step]),
L[start:stop:step])
def test_match_args(self):
expected_args = ('tm_year', 'tm_mon', 'tm_mday', 'tm_hour', 'tm_min',
'tm_sec', 'tm_wday', 'tm_yday', 'tm_isdst')
self.assertEqual(time.struct_time.__match_args__, expected_args)
def test_match_args_with_unnamed_fields(self):
expected_args = ('st_mode', 'st_ino', 'st_dev', 'st_nlink', 'st_uid',
'st_gid', 'st_size')
self.assertEqual(os.stat_result.n_unnamed_fields, 3)
self.assertEqual(os.stat_result.__match_args__, expected_args)
def test_copy_replace_all_fields_visible(self):
assert os.times_result.n_unnamed_fields == 0
assert os.times_result.n_sequence_fields == os.times_result.n_fields
t = os.times()
# visible fields
self.assertEqual(copy.replace(t), t)
self.assertIsInstance(copy.replace(t), os.times_result)
self.assertEqual(copy.replace(t, user=1.5), (1.5, *t[1:]))
self.assertEqual(copy.replace(t, system=2.5), (t[0], 2.5, *t[2:]))
self.assertEqual(copy.replace(t, user=1.5, system=2.5), (1.5, 2.5, *t[2:]))
# unknown fields
with self.assertRaisesRegex(TypeError, 'unexpected field name'):
copy.replace(t, error=-1)
with self.assertRaisesRegex(TypeError, 'unexpected field name'):
copy.replace(t, user=1, error=-1)
def test_copy_replace_with_invisible_fields(self):
assert time.struct_time.n_unnamed_fields == 0
assert time.struct_time.n_sequence_fields < time.struct_time.n_fields
t = time.gmtime(0)
# visible fields
t2 = copy.replace(t)
self.assertEqual(t2, (1970, 1, 1, 0, 0, 0, 3, 1, 0))
self.assertIsInstance(t2, time.struct_time)
t3 = copy.replace(t, tm_year=2000)
self.assertEqual(t3, (2000, 1, 1, 0, 0, 0, 3, 1, 0))
self.assertEqual(t3.tm_year, 2000)
t4 = copy.replace(t, tm_mon=2)
self.assertEqual(t4, (1970, 2, 1, 0, 0, 0, 3, 1, 0))
self.assertEqual(t4.tm_mon, 2)
t5 = copy.replace(t, tm_year=2000, tm_mon=2)
self.assertEqual(t5, (2000, 2, 1, 0, 0, 0, 3, 1, 0))
self.assertEqual(t5.tm_year, 2000)
self.assertEqual(t5.tm_mon, 2)
# named invisible fields
self.assertTrue(hasattr(t, 'tm_zone'), f"{t} has no attribute 'tm_zone'")
with self.assertRaisesRegex(AttributeError, 'readonly attribute'):
t.tm_zone = 'some other zone'
self.assertEqual(t2.tm_zone, t.tm_zone)
self.assertEqual(t3.tm_zone, t.tm_zone)
self.assertEqual(t4.tm_zone, t.tm_zone)
t6 = copy.replace(t, tm_zone='some other zone')
self.assertEqual(t, t6)
self.assertEqual(t6.tm_zone, 'some other zone')
t7 = copy.replace(t, tm_year=2000, tm_zone='some other zone')
self.assertEqual(t7, (2000, 1, 1, 0, 0, 0, 3, 1, 0))
self.assertEqual(t7.tm_year, 2000)
self.assertEqual(t7.tm_zone, 'some other zone')
# unknown fields
with self.assertRaisesRegex(TypeError, 'unexpected field name'):
copy.replace(t, error=2)
with self.assertRaisesRegex(TypeError, 'unexpected field name'):
copy.replace(t, tm_year=2000, error=2)
with self.assertRaisesRegex(TypeError, 'unexpected field name'):
copy.replace(t, tm_zone='some other zone', error=2)
def test_copy_replace_with_unnamed_fields(self):
assert os.stat_result.n_unnamed_fields > 0
r = os.stat_result(range(os.stat_result.n_sequence_fields))
error_message = re.escape('__replace__() is not supported')
with self.assertRaisesRegex(TypeError, error_message):
copy.replace(r)
with self.assertRaisesRegex(TypeError, error_message):
copy.replace(r, st_mode=1)
with self.assertRaisesRegex(TypeError, error_message):
copy.replace(r, error=2)
with self.assertRaisesRegex(TypeError, error_message):
copy.replace(r, st_mode=1, error=2)
def test_reference_cycle(self):
# gh-122527: Check that a structseq that's part of a reference cycle
# with its own type doesn't crash. Previously, if the type's dictionary
# was cleared first, the structseq instance would crash in the
# destructor.
script_helper.assert_python_ok("-c", textwrap.dedent(r"""
import time
t = time.gmtime()
type(t).refcyle = t
"""))
if __name__ == "__main__":
unittest.main()