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cpython/Lib/test/support/__init__.py

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"""Supporting definitions for the Python regression tests."""
if __name__ != 'test.support':
raise ImportError('support must be imported from the test package')
import contextlib
import functools
import getpass
import opcode
import os
import re
import stat
import sys
import sysconfig
import time
import types
import unittest
import warnings
from .testresult import get_test_runner
try:
from _testcapi import unicode_legacy_string
except ImportError:
unicode_legacy_string = None
__all__ = [
# globals
"PIPE_MAX_SIZE", "verbose", "max_memuse", "use_resources", "failfast",
# exceptions
"Error", "TestFailed", "TestDidNotRun", "ResourceDenied",
# io
"record_original_stdout", "get_original_stdout", "captured_stdout",
"captured_stdin", "captured_stderr",
# unittest
"is_resource_enabled", "requires", "requires_freebsd_version",
"requires_linux_version", "requires_mac_ver",
"check_syntax_error",
"run_unittest", "run_doctest",
"requires_gzip", "requires_bz2", "requires_lzma",
"bigmemtest", "bigaddrspacetest", "cpython_only", "get_attribute",
"requires_IEEE_754", "requires_zlib",
"has_fork_support", "requires_fork",
"has_subprocess_support", "requires_subprocess",
"has_socket_support", "requires_working_socket",
"anticipate_failure", "load_package_tests", "detect_api_mismatch",
"check__all__", "skip_if_buggy_ucrt_strfptime",
"check_disallow_instantiation", "check_sanitizer", "skip_if_sanitizer",
"requires_limited_api", "requires_specialization",
# sys
"is_jython", "is_android", "is_emscripten", "is_wasi",
"check_impl_detail", "unix_shell", "setswitchinterval",
# os
"get_pagesize",
# network
"open_urlresource",
# processes
"reap_children",
# miscellaneous
"run_with_locale", "swap_item", "findfile", "infinite_recursion",
"swap_attr", "Matcher", "set_memlimit", "SuppressCrashReport", "sortdict",
"run_with_tz", "PGO", "missing_compiler_executable",
"ALWAYS_EQ", "NEVER_EQ", "LARGEST", "SMALLEST",
"LOOPBACK_TIMEOUT", "INTERNET_TIMEOUT", "SHORT_TIMEOUT", "LONG_TIMEOUT",
"Py_DEBUG", "EXCEEDS_RECURSION_LIMIT",
]
# Timeout in seconds for tests using a network server listening on the network
# local loopback interface like 127.0.0.1.
#
# The timeout is long enough to prevent test failure: it takes into account
# that the client and the server can run in different threads or even different
# processes.
#
# The timeout should be long enough for connect(), recv() and send() methods
# of socket.socket.
LOOPBACK_TIMEOUT = 5.0
if sys.platform == 'win32' and ' 32 bit (ARM)' in sys.version:
# bpo-37553: test_socket.SendfileUsingSendTest is taking longer than 2
# seconds on Windows ARM32 buildbot
LOOPBACK_TIMEOUT = 10
elif sys.platform == 'vxworks':
LOOPBACK_TIMEOUT = 10
# Timeout in seconds for network requests going to the internet. The timeout is
# short enough to prevent a test to wait for too long if the internet request
# is blocked for whatever reason.
#
# Usually, a timeout using INTERNET_TIMEOUT should not mark a test as failed,
# but skip the test instead: see transient_internet().
INTERNET_TIMEOUT = 60.0
# Timeout in seconds to mark a test as failed if the test takes "too long".
#
# The timeout value depends on the regrtest --timeout command line option.
#
# If a test using SHORT_TIMEOUT starts to fail randomly on slow buildbots, use
# LONG_TIMEOUT instead.
SHORT_TIMEOUT = 30.0
# Timeout in seconds to detect when a test hangs.
#
# It is long enough to reduce the risk of test failure on the slowest Python
# buildbots. It should not be used to mark a test as failed if the test takes
# "too long". The timeout value depends on the regrtest --timeout command line
# option.
LONG_TIMEOUT = 5 * 60.0
# TEST_HOME_DIR refers to the top level directory of the "test" package
# that contains Python's regression test suite
TEST_SUPPORT_DIR = os.path.dirname(os.path.abspath(__file__))
TEST_HOME_DIR = os.path.dirname(TEST_SUPPORT_DIR)
STDLIB_DIR = os.path.dirname(TEST_HOME_DIR)
REPO_ROOT = os.path.dirname(STDLIB_DIR)
class Error(Exception):
"""Base class for regression test exceptions."""
class TestFailed(Error):
"""Test failed."""
class TestFailedWithDetails(TestFailed):
"""Test failed."""
def __init__(self, msg, errors, failures):
self.msg = msg
self.errors = errors
self.failures = failures
super().__init__(msg, errors, failures)
def __str__(self):
return self.msg
class TestDidNotRun(Error):
"""Test did not run any subtests."""
class ResourceDenied(unittest.SkipTest):
"""Test skipped because it requested a disallowed resource.
This is raised when a test calls requires() for a resource that
has not be enabled. It is used to distinguish between expected
and unexpected skips.
"""
def anticipate_failure(condition):
"""Decorator to mark a test that is known to be broken in some cases
Any use of this decorator should have a comment identifying the
associated tracker issue.
"""
if condition:
return unittest.expectedFailure
return lambda f: f
def load_package_tests(pkg_dir, loader, standard_tests, pattern):
"""Generic load_tests implementation for simple test packages.
Most packages can implement load_tests using this function as follows:
def load_tests(*args):
return load_package_tests(os.path.dirname(__file__), *args)
"""
if pattern is None:
pattern = "test*"
top_dir = STDLIB_DIR
package_tests = loader.discover(start_dir=pkg_dir,
top_level_dir=top_dir,
pattern=pattern)
standard_tests.addTests(package_tests)
return standard_tests
def get_attribute(obj, name):
"""Get an attribute, raising SkipTest if AttributeError is raised."""
try:
attribute = getattr(obj, name)
except AttributeError:
raise unittest.SkipTest("object %r has no attribute %r" % (obj, name))
else:
return attribute
verbose = 1 # Flag set to 0 by regrtest.py
use_resources = None # Flag set to [] by regrtest.py
max_memuse = 0 # Disable bigmem tests (they will still be run with
# small sizes, to make sure they work.)
real_max_memuse = 0
junit_xml_list = None # list of testsuite XML elements
failfast = False
# _original_stdout is meant to hold stdout at the time regrtest began.
# This may be "the real" stdout, or IDLE's emulation of stdout, or whatever.
# The point is to have some flavor of stdout the user can actually see.
_original_stdout = None
def record_original_stdout(stdout):
global _original_stdout
_original_stdout = stdout
def get_original_stdout():
return _original_stdout or sys.stdout
def _force_run(path, func, *args):
try:
return func(*args)
except FileNotFoundError as err:
# chmod() won't fix a missing file.
if verbose >= 2:
print('%s: %s' % (err.__class__.__name__, err))
raise
except OSError as err:
if verbose >= 2:
print('%s: %s' % (err.__class__.__name__, err))
print('re-run %s%r' % (func.__name__, args))
os.chmod(path, stat.S_IRWXU)
return func(*args)
# Check whether a gui is actually available
def _is_gui_available():
if hasattr(_is_gui_available, 'result'):
return _is_gui_available.result
import platform
reason = None
if sys.platform.startswith('win') and platform.win32_is_iot():
reason = "gui is not available on Windows IoT Core"
elif sys.platform.startswith('win'):
# if Python is running as a service (such as the buildbot service),
# gui interaction may be disallowed
import ctypes
import ctypes.wintypes
UOI_FLAGS = 1
WSF_VISIBLE = 0x0001
class USEROBJECTFLAGS(ctypes.Structure):
_fields_ = [("fInherit", ctypes.wintypes.BOOL),
("fReserved", ctypes.wintypes.BOOL),
("dwFlags", ctypes.wintypes.DWORD)]
dll = ctypes.windll.user32
h = dll.GetProcessWindowStation()
if not h:
raise ctypes.WinError()
uof = USEROBJECTFLAGS()
needed = ctypes.wintypes.DWORD()
res = dll.GetUserObjectInformationW(h,
UOI_FLAGS,
ctypes.byref(uof),
ctypes.sizeof(uof),
ctypes.byref(needed))
if not res:
raise ctypes.WinError()
if not bool(uof.dwFlags & WSF_VISIBLE):
reason = "gui not available (WSF_VISIBLE flag not set)"
elif sys.platform == 'darwin':
# The Aqua Tk implementations on OS X can abort the process if
# being called in an environment where a window server connection
# cannot be made, for instance when invoked by a buildbot or ssh
# process not running under the same user id as the current console
# user. To avoid that, raise an exception if the window manager
# connection is not available.
from ctypes import cdll, c_int, pointer, Structure
from ctypes.util import find_library
app_services = cdll.LoadLibrary(find_library("ApplicationServices"))
if app_services.CGMainDisplayID() == 0:
reason = "gui tests cannot run without OS X window manager"
else:
class ProcessSerialNumber(Structure):
_fields_ = [("highLongOfPSN", c_int),
("lowLongOfPSN", c_int)]
psn = ProcessSerialNumber()
psn_p = pointer(psn)
if ( (app_services.GetCurrentProcess(psn_p) < 0) or
(app_services.SetFrontProcess(psn_p) < 0) ):
reason = "cannot run without OS X gui process"
# check on every platform whether tkinter can actually do anything
if not reason:
try:
from tkinter import Tk
root = Tk()
root.withdraw()
root.update()
root.destroy()
except Exception as e:
err_string = str(e)
if len(err_string) > 50:
err_string = err_string[:50] + ' [...]'
reason = 'Tk unavailable due to {}: {}'.format(type(e).__name__,
err_string)
_is_gui_available.reason = reason
_is_gui_available.result = not reason
return _is_gui_available.result
def is_resource_enabled(resource):
"""Test whether a resource is enabled.
Known resources are set by regrtest.py. If not running under regrtest.py,
all resources are assumed enabled unless use_resources has been set.
"""
return use_resources is None or resource in use_resources
def requires(resource, msg=None):
"""Raise ResourceDenied if the specified resource is not available."""
if not is_resource_enabled(resource):
if msg is None:
msg = "Use of the %r resource not enabled" % resource
raise ResourceDenied(msg)
if resource in {"network", "urlfetch"} and not has_socket_support:
raise ResourceDenied("No socket support")
if resource == 'gui' and not _is_gui_available():
raise ResourceDenied(_is_gui_available.reason)
def _requires_unix_version(sysname, min_version):
"""Decorator raising SkipTest if the OS is `sysname` and the version is less
than `min_version`.
For example, @_requires_unix_version('FreeBSD', (7, 2)) raises SkipTest if
the FreeBSD version is less than 7.2.
"""
import platform
min_version_txt = '.'.join(map(str, min_version))
version_txt = platform.release().split('-', 1)[0]
if platform.system() == sysname:
try:
version = tuple(map(int, version_txt.split('.')))
except ValueError:
skip = False
else:
skip = version < min_version
else:
skip = False
return unittest.skipIf(
skip,
f"{sysname} version {min_version_txt} or higher required, not "
f"{version_txt}"
)
def requires_freebsd_version(*min_version):
"""Decorator raising SkipTest if the OS is FreeBSD and the FreeBSD version is
less than `min_version`.
For example, @requires_freebsd_version(7, 2) raises SkipTest if the FreeBSD
version is less than 7.2.
"""
return _requires_unix_version('FreeBSD', min_version)
def requires_linux_version(*min_version):
"""Decorator raising SkipTest if the OS is Linux and the Linux version is
less than `min_version`.
For example, @requires_linux_version(2, 6, 32) raises SkipTest if the Linux
version is less than 2.6.32.
"""
return _requires_unix_version('Linux', min_version)
def requires_mac_ver(*min_version):
"""Decorator raising SkipTest if the OS is Mac OS X and the OS X
version if less than min_version.
For example, @requires_mac_ver(10, 5) raises SkipTest if the OS X version
is lesser than 10.5.
"""
def decorator(func):
@functools.wraps(func)
def wrapper(*args, **kw):
if sys.platform == 'darwin':
import platform
version_txt = platform.mac_ver()[0]
try:
version = tuple(map(int, version_txt.split('.')))
except ValueError:
pass
else:
if version < min_version:
min_version_txt = '.'.join(map(str, min_version))
raise unittest.SkipTest(
"Mac OS X %s or higher required, not %s"
% (min_version_txt, version_txt))
return func(*args, **kw)
wrapper.min_version = min_version
return wrapper
return decorator
def skip_if_buildbot(reason=None):
"""Decorator raising SkipTest if running on a buildbot."""
if not reason:
reason = 'not suitable for buildbots'
try:
isbuildbot = getpass.getuser().lower() == 'buildbot'
except (KeyError, EnvironmentError) as err:
warnings.warn(f'getpass.getuser() failed {err}.', RuntimeWarning)
isbuildbot = False
return unittest.skipIf(isbuildbot, reason)
def check_sanitizer(*, address=False, memory=False, ub=False):
"""Returns True if Python is compiled with sanitizer support"""
if not (address or memory or ub):
raise ValueError('At least one of address, memory, or ub must be True')
_cflags = sysconfig.get_config_var('CFLAGS') or ''
_config_args = sysconfig.get_config_var('CONFIG_ARGS') or ''
memory_sanitizer = (
'-fsanitize=memory' in _cflags or
'--with-memory-sanitizer' in _config_args
)
address_sanitizer = (
'-fsanitize=address' in _cflags or
'--with-memory-sanitizer' in _config_args
)
ub_sanitizer = (
'-fsanitize=undefined' in _cflags or
'--with-undefined-behavior-sanitizer' in _config_args
)
return (
(memory and memory_sanitizer) or
(address and address_sanitizer) or
(ub and ub_sanitizer)
)
def skip_if_sanitizer(reason=None, *, address=False, memory=False, ub=False):
"""Decorator raising SkipTest if running with a sanitizer active."""
if not reason:
reason = 'not working with sanitizers active'
skip = check_sanitizer(address=address, memory=memory, ub=ub)
return unittest.skipIf(skip, reason)
def system_must_validate_cert(f):
"""Skip the test on TLS certificate validation failures."""
@functools.wraps(f)
def dec(*args, **kwargs):
try:
f(*args, **kwargs)
except OSError as e:
if "CERTIFICATE_VERIFY_FAILED" in str(e):
raise unittest.SkipTest("system does not contain "
"necessary certificates")
raise
return dec
# A constant likely larger than the underlying OS pipe buffer size, to
# make writes blocking.
# Windows limit seems to be around 512 B, and many Unix kernels have a
# 64 KiB pipe buffer size or 16 * PAGE_SIZE: take a few megs to be sure.
# (see issue #17835 for a discussion of this number).
PIPE_MAX_SIZE = 4 * 1024 * 1024 + 1
# A constant likely larger than the underlying OS socket buffer size, to make
# writes blocking.
# The socket buffer sizes can usually be tuned system-wide (e.g. through sysctl
# on Linux), or on a per-socket basis (SO_SNDBUF/SO_RCVBUF). See issue #18643
# for a discussion of this number.
SOCK_MAX_SIZE = 16 * 1024 * 1024 + 1
# decorator for skipping tests on non-IEEE 754 platforms
requires_IEEE_754 = unittest.skipUnless(
float.__getformat__("double").startswith("IEEE"),
"test requires IEEE 754 doubles")
def requires_zlib(reason='requires zlib'):
try:
import zlib
except ImportError:
zlib = None
return unittest.skipUnless(zlib, reason)
def requires_gzip(reason='requires gzip'):
try:
import gzip
except ImportError:
gzip = None
return unittest.skipUnless(gzip, reason)
def requires_bz2(reason='requires bz2'):
try:
import bz2
except ImportError:
bz2 = None
return unittest.skipUnless(bz2, reason)
def requires_lzma(reason='requires lzma'):
try:
import lzma
except ImportError:
lzma = None
return unittest.skipUnless(lzma, reason)
def has_no_debug_ranges():
try:
import _testinternalcapi
except ImportError:
raise unittest.SkipTest("_testinternalcapi required")
config = _testinternalcapi.get_config()
return not bool(config['code_debug_ranges'])
def requires_debug_ranges(reason='requires co_positions / debug_ranges'):
return unittest.skipIf(has_no_debug_ranges(), reason)
requires_legacy_unicode_capi = unittest.skipUnless(unicode_legacy_string,
'requires legacy Unicode C API')
# Is not actually used in tests, but is kept for compatibility.
is_jython = sys.platform.startswith('java')
is_android = hasattr(sys, 'getandroidapilevel')
if sys.platform not in ('win32', 'vxworks'):
unix_shell = '/system/bin/sh' if is_android else '/bin/sh'
else:
unix_shell = None
# wasm32-emscripten and -wasi are POSIX-like but do not
# have subprocess or fork support.
is_emscripten = sys.platform == "emscripten"
is_wasi = sys.platform == "wasi"
has_fork_support = hasattr(os, "fork") and not is_emscripten and not is_wasi
def requires_fork():
return unittest.skipUnless(has_fork_support, "requires working os.fork()")
has_subprocess_support = not is_emscripten and not is_wasi
def requires_subprocess():
"""Used for subprocess, os.spawn calls, fd inheritance"""
return unittest.skipUnless(has_subprocess_support, "requires subprocess support")
# Emscripten's socket emulation and WASI sockets have limitations.
has_socket_support = not is_emscripten and not is_wasi
def requires_working_socket(*, module=False):
"""Skip tests or modules that require working sockets
Can be used as a function/class decorator or to skip an entire module.
"""
msg = "requires socket support"
if module:
if not has_socket_support:
raise unittest.SkipTest(msg)
else:
return unittest.skipUnless(has_socket_support, msg)
# Does strftime() support glibc extension like '%4Y'?
has_strftime_extensions = False
if sys.platform != "win32":
# bpo-47037: Windows debug builds crash with "Debug Assertion Failed"
try:
has_strftime_extensions = time.strftime("%4Y") != "%4Y"
except ValueError:
pass
# Define the URL of a dedicated HTTP server for the network tests.
# The URL must use clear-text HTTP: no redirection to encrypted HTTPS.
TEST_HTTP_URL = "http://www.pythontest.net"
# Set by libregrtest/main.py so we can skip tests that are not
# useful for PGO
PGO = False
# Set by libregrtest/main.py if we are running the extended (time consuming)
# PGO task. If this is True, PGO is also True.
PGO_EXTENDED = False
# TEST_DATA_DIR is used as a target download location for remote resources
TEST_DATA_DIR = os.path.join(TEST_HOME_DIR, "data")
def darwin_malloc_err_warning(test_name):
"""Assure user that loud errors generated by macOS libc's malloc are
expected."""
if sys.platform != 'darwin':
return
import shutil
msg = ' NOTICE '
detail = (f'{test_name} may generate "malloc can\'t allocate region"\n'
'warnings on macOS systems. This behavior is known. Do not\n'
'report a bug unless tests are also failing.\n'
'See https://github.com/python/cpython/issues/85100')
padding, _ = shutil.get_terminal_size()
print(msg.center(padding, '-'))
print(detail)
print('-' * padding)
def findfile(filename, subdir=None):
"""Try to find a file on sys.path or in the test directory. If it is not
found the argument passed to the function is returned (this does not
necessarily signal failure; could still be the legitimate path).
Setting *subdir* indicates a relative path to use to find the file
rather than looking directly in the path directories.
"""
if os.path.isabs(filename):
return filename
if subdir is not None:
filename = os.path.join(subdir, filename)
path = [TEST_HOME_DIR] + sys.path
for dn in path:
fn = os.path.join(dn, filename)
if os.path.exists(fn): return fn
return filename
def sortdict(dict):
"Like repr(dict), but in sorted order."
items = sorted(dict.items())
reprpairs = ["%r: %r" % pair for pair in items]
withcommas = ", ".join(reprpairs)
return "{%s}" % withcommas
def check_syntax_error(testcase, statement, errtext='', *, lineno=None, offset=None):
with testcase.assertRaisesRegex(SyntaxError, errtext) as cm:
compile(statement, '<test string>', 'exec')
err = cm.exception
testcase.assertIsNotNone(err.lineno)
if lineno is not None:
testcase.assertEqual(err.lineno, lineno)
testcase.assertIsNotNone(err.offset)
if offset is not None:
testcase.assertEqual(err.offset, offset)
def open_urlresource(url, *args, **kw):
import urllib.request, urllib.parse
from .os_helper import unlink
try:
import gzip
except ImportError:
gzip = None
check = kw.pop('check', None)
filename = urllib.parse.urlparse(url)[2].split('/')[-1] # '/': it's URL!
fn = os.path.join(TEST_DATA_DIR, filename)
def check_valid_file(fn):
f = open(fn, *args, **kw)
if check is None:
return f
elif check(f):
f.seek(0)
return f
f.close()
if os.path.exists(fn):
f = check_valid_file(fn)
if f is not None:
return f
unlink(fn)
# Verify the requirement before downloading the file
requires('urlfetch')
if verbose:
print('\tfetching %s ...' % url, file=get_original_stdout())
opener = urllib.request.build_opener()
if gzip:
opener.addheaders.append(('Accept-Encoding', 'gzip'))
f = opener.open(url, timeout=INTERNET_TIMEOUT)
if gzip and f.headers.get('Content-Encoding') == 'gzip':
f = gzip.GzipFile(fileobj=f)
try:
with open(fn, "wb") as out:
s = f.read()
while s:
out.write(s)
s = f.read()
finally:
f.close()
f = check_valid_file(fn)
if f is not None:
return f
raise TestFailed('invalid resource %r' % fn)
@contextlib.contextmanager
def captured_output(stream_name):
"""Return a context manager used by captured_stdout/stdin/stderr
that temporarily replaces the sys stream *stream_name* with a StringIO."""
import io
orig_stdout = getattr(sys, stream_name)
setattr(sys, stream_name, io.StringIO())
try:
yield getattr(sys, stream_name)
finally:
setattr(sys, stream_name, orig_stdout)
def captured_stdout():
"""Capture the output of sys.stdout:
with captured_stdout() as stdout:
print("hello")
self.assertEqual(stdout.getvalue(), "hello\\n")
"""
return captured_output("stdout")
def captured_stderr():
"""Capture the output of sys.stderr:
with captured_stderr() as stderr:
print("hello", file=sys.stderr)
self.assertEqual(stderr.getvalue(), "hello\\n")
"""
return captured_output("stderr")
def captured_stdin():
"""Capture the input to sys.stdin:
with captured_stdin() as stdin:
stdin.write('hello\\n')
stdin.seek(0)
# call test code that consumes from sys.stdin
captured = input()
self.assertEqual(captured, "hello")
"""
return captured_output("stdin")
def gc_collect():
"""Force as many objects as possible to be collected.
In non-CPython implementations of Python, this is needed because timely
deallocation is not guaranteed by the garbage collector. (Even in CPython
this can be the case in case of reference cycles.) This means that __del__
methods may be called later than expected and weakrefs may remain alive for
longer than expected. This function tries its best to force all garbage
objects to disappear.
"""
import gc
gc.collect()
gc.collect()
gc.collect()
@contextlib.contextmanager
def disable_gc():
import gc
have_gc = gc.isenabled()
gc.disable()
try:
yield
finally:
if have_gc:
gc.enable()
def python_is_optimized():
"""Find if Python was built with optimizations."""
cflags = sysconfig.get_config_var('PY_CFLAGS') or ''
final_opt = ""
for opt in cflags.split():
if opt.startswith('-O'):
final_opt = opt
return final_opt not in ('', '-O0', '-Og')
_header = 'nP'
_align = '0n'
if hasattr(sys, "getobjects"):
_header = '2P' + _header
_align = '0P'
_vheader = _header + 'n'
def calcobjsize(fmt):
import struct
return struct.calcsize(_header + fmt + _align)
def calcvobjsize(fmt):
import struct
return struct.calcsize(_vheader + fmt + _align)
_TPFLAGS_HAVE_GC = 1<<14
_TPFLAGS_HEAPTYPE = 1<<9
def check_sizeof(test, o, size):
try:
import _testinternalcapi
except ImportError:
raise unittest.SkipTest("_testinternalcapi required")
result = sys.getsizeof(o)
# add GC header size
if ((type(o) == type) and (o.__flags__ & _TPFLAGS_HEAPTYPE) or\
((type(o) != type) and (type(o).__flags__ & _TPFLAGS_HAVE_GC))):
size += _testinternalcapi.SIZEOF_PYGC_HEAD
msg = 'wrong size for %s: got %d, expected %d' \
% (type(o), result, size)
test.assertEqual(result, size, msg)
#=======================================================================
# Decorator for running a function in a different locale, correctly resetting
# it afterwards.
@contextlib.contextmanager
def run_with_locale(catstr, *locales):
try:
import locale
category = getattr(locale, catstr)
orig_locale = locale.setlocale(category)
except AttributeError:
# if the test author gives us an invalid category string
raise
except:
# cannot retrieve original locale, so do nothing
locale = orig_locale = None
else:
for loc in locales:
try:
locale.setlocale(category, loc)
break
except:
pass
try:
yield
finally:
if locale and orig_locale:
locale.setlocale(category, orig_locale)
#=======================================================================
# Decorator for running a function in a specific timezone, correctly
# resetting it afterwards.
def run_with_tz(tz):
def decorator(func):
def inner(*args, **kwds):
try:
tzset = time.tzset
except AttributeError:
raise unittest.SkipTest("tzset required")
if 'TZ' in os.environ:
orig_tz = os.environ['TZ']
else:
orig_tz = None
os.environ['TZ'] = tz
tzset()
# now run the function, resetting the tz on exceptions
try:
return func(*args, **kwds)
finally:
if orig_tz is None:
del os.environ['TZ']
else:
os.environ['TZ'] = orig_tz
time.tzset()
inner.__name__ = func.__name__
inner.__doc__ = func.__doc__
return inner
return decorator
#=======================================================================
# Big-memory-test support. Separate from 'resources' because memory use
# should be configurable.
# Some handy shorthands. Note that these are used for byte-limits as well
# as size-limits, in the various bigmem tests
_1M = 1024*1024
_1G = 1024 * _1M
_2G = 2 * _1G
_4G = 4 * _1G
MAX_Py_ssize_t = sys.maxsize
def set_memlimit(limit):
global max_memuse
global real_max_memuse
sizes = {
'k': 1024,
'm': _1M,
'g': _1G,
't': 1024*_1G,
}
m = re.match(r'(\d+(\.\d+)?) (K|M|G|T)b?$', limit,
re.IGNORECASE | re.VERBOSE)
if m is None:
raise ValueError('Invalid memory limit %r' % (limit,))
memlimit = int(float(m.group(1)) * sizes[m.group(3).lower()])
real_max_memuse = memlimit
if memlimit > MAX_Py_ssize_t:
memlimit = MAX_Py_ssize_t
if memlimit < _2G - 1:
raise ValueError('Memory limit %r too low to be useful' % (limit,))
max_memuse = memlimit
class _MemoryWatchdog:
"""An object which periodically watches the process' memory consumption
and prints it out.
"""
def __init__(self):
self.procfile = '/proc/{pid}/statm'.format(pid=os.getpid())
self.started = False
def start(self):
import warnings
try:
f = open(self.procfile, 'r')
except OSError as e:
warnings.warn('/proc not available for stats: {}'.format(e),
RuntimeWarning)
sys.stderr.flush()
return
import subprocess
with f:
watchdog_script = findfile("memory_watchdog.py")
self.mem_watchdog = subprocess.Popen([sys.executable, watchdog_script],
stdin=f,
stderr=subprocess.DEVNULL)
self.started = True
def stop(self):
if self.started:
self.mem_watchdog.terminate()
self.mem_watchdog.wait()
def bigmemtest(size, memuse, dry_run=True):
"""Decorator for bigmem tests.
'size' is a requested size for the test (in arbitrary, test-interpreted
units.) 'memuse' is the number of bytes per unit for the test, or a good
estimate of it. For example, a test that needs two byte buffers, of 4 GiB
each, could be decorated with @bigmemtest(size=_4G, memuse=2).
The 'size' argument is normally passed to the decorated test method as an
extra argument. If 'dry_run' is true, the value passed to the test method
may be less than the requested value. If 'dry_run' is false, it means the
test doesn't support dummy runs when -M is not specified.
"""
def decorator(f):
def wrapper(self):
size = wrapper.size
memuse = wrapper.memuse
if not real_max_memuse:
maxsize = 5147
else:
maxsize = size
if ((real_max_memuse or not dry_run)
and real_max_memuse < maxsize * memuse):
raise unittest.SkipTest(
"not enough memory: %.1fG minimum needed"
% (size * memuse / (1024 ** 3)))
if real_max_memuse and verbose:
print()
print(" ... expected peak memory use: {peak:.1f}G"
.format(peak=size * memuse / (1024 ** 3)))
watchdog = _MemoryWatchdog()
watchdog.start()
else:
watchdog = None
try:
return f(self, maxsize)
finally:
if watchdog:
watchdog.stop()
wrapper.size = size
wrapper.memuse = memuse
return wrapper
return decorator
def bigaddrspacetest(f):
"""Decorator for tests that fill the address space."""
def wrapper(self):
if max_memuse < MAX_Py_ssize_t:
if MAX_Py_ssize_t >= 2**63 - 1 and max_memuse >= 2**31:
raise unittest.SkipTest(
"not enough memory: try a 32-bit build instead")
else:
raise unittest.SkipTest(
"not enough memory: %.1fG minimum needed"
% (MAX_Py_ssize_t / (1024 ** 3)))
else:
return f(self)
return wrapper
#=======================================================================
# unittest integration.
def _id(obj):
return obj
def requires_resource(resource):
if resource == 'gui' and not _is_gui_available():
return unittest.skip(_is_gui_available.reason)
if is_resource_enabled(resource):
return _id
else:
return unittest.skip("resource {0!r} is not enabled".format(resource))
def cpython_only(test):
"""
Decorator for tests only applicable on CPython.
"""
return impl_detail(cpython=True)(test)
def impl_detail(msg=None, **guards):
if check_impl_detail(**guards):
return _id
if msg is None:
guardnames, default = _parse_guards(guards)
if default:
msg = "implementation detail not available on {0}"
else:
msg = "implementation detail specific to {0}"
guardnames = sorted(guardnames.keys())
msg = msg.format(' or '.join(guardnames))
return unittest.skip(msg)
def _parse_guards(guards):
# Returns a tuple ({platform_name: run_me}, default_value)
if not guards:
return ({'cpython': True}, False)
is_true = list(guards.values())[0]
assert list(guards.values()) == [is_true] * len(guards) # all True or all False
return (guards, not is_true)
# Use the following check to guard CPython's implementation-specific tests --
# or to run them only on the implementation(s) guarded by the arguments.
def check_impl_detail(**guards):
"""This function returns True or False depending on the host platform.
Examples:
if check_impl_detail(): # only on CPython (default)
if check_impl_detail(jython=True): # only on Jython
if check_impl_detail(cpython=False): # everywhere except on CPython
"""
guards, default = _parse_guards(guards)
return guards.get(sys.implementation.name, default)
def no_tracing(func):
"""Decorator to temporarily turn off tracing for the duration of a test."""
if not hasattr(sys, 'gettrace'):
return func
else:
@functools.wraps(func)
def wrapper(*args, **kwargs):
original_trace = sys.gettrace()
try:
sys.settrace(None)
return func(*args, **kwargs)
finally:
sys.settrace(original_trace)
return wrapper
def refcount_test(test):
"""Decorator for tests which involve reference counting.
To start, the decorator does not run the test if is not run by CPython.
After that, any trace function is unset during the test to prevent
unexpected refcounts caused by the trace function.
"""
return no_tracing(cpython_only(test))
def requires_limited_api(test):
try:
import _testcapi
except ImportError:
return unittest.skip('needs _testcapi module')(test)
return unittest.skipUnless(
_testcapi.LIMITED_API_AVAILABLE, 'needs Limited API support')(test)
def requires_specialization(test):
return unittest.skipUnless(
opcode.ENABLE_SPECIALIZATION, "requires specialization")(test)
def _filter_suite(suite, pred):
"""Recursively filter test cases in a suite based on a predicate."""
newtests = []
for test in suite._tests:
if isinstance(test, unittest.TestSuite):
_filter_suite(test, pred)
newtests.append(test)
else:
if pred(test):
newtests.append(test)
suite._tests = newtests
def _run_suite(suite):
"""Run tests from a unittest.TestSuite-derived class."""
runner = get_test_runner(sys.stdout,
verbosity=verbose,
capture_output=(junit_xml_list is not None))
result = runner.run(suite)
if junit_xml_list is not None:
junit_xml_list.append(result.get_xml_element())
if not result.testsRun and not result.skipped and not result.errors:
raise TestDidNotRun
if not result.wasSuccessful():
if len(result.errors) == 1 and not result.failures:
err = result.errors[0][1]
elif len(result.failures) == 1 and not result.errors:
err = result.failures[0][1]
else:
err = "multiple errors occurred"
if not verbose: err += "; run in verbose mode for details"
errors = [(str(tc), exc_str) for tc, exc_str in result.errors]
failures = [(str(tc), exc_str) for tc, exc_str in result.failures]
raise TestFailedWithDetails(err, errors, failures)
# By default, don't filter tests
_match_test_func = None
_accept_test_patterns = None
_ignore_test_patterns = None
def match_test(test):
# Function used by support.run_unittest() and regrtest --list-cases
if _match_test_func is None:
return True
else:
return _match_test_func(test.id())
def _is_full_match_test(pattern):
# If a pattern contains at least one dot, it's considered
# as a full test identifier.
# Example: 'test.test_os.FileTests.test_access'.
#
# ignore patterns which contain fnmatch patterns: '*', '?', '[...]'
# or '[!...]'. For example, ignore 'test_access*'.
return ('.' in pattern) and (not re.search(r'[?*\[\]]', pattern))
def set_match_tests(accept_patterns=None, ignore_patterns=None):
global _match_test_func, _accept_test_patterns, _ignore_test_patterns
if accept_patterns is None:
accept_patterns = ()
if ignore_patterns is None:
ignore_patterns = ()
accept_func = ignore_func = None
if accept_patterns != _accept_test_patterns:
accept_patterns, accept_func = _compile_match_function(accept_patterns)
if ignore_patterns != _ignore_test_patterns:
ignore_patterns, ignore_func = _compile_match_function(ignore_patterns)
# Create a copy since patterns can be mutable and so modified later
_accept_test_patterns = tuple(accept_patterns)
_ignore_test_patterns = tuple(ignore_patterns)
if accept_func is not None or ignore_func is not None:
def match_function(test_id):
accept = True
ignore = False
if accept_func:
accept = accept_func(test_id)
if ignore_func:
ignore = ignore_func(test_id)
return accept and not ignore
_match_test_func = match_function
def _compile_match_function(patterns):
if not patterns:
func = None
# set_match_tests(None) behaves as set_match_tests(())
patterns = ()
elif all(map(_is_full_match_test, patterns)):
# Simple case: all patterns are full test identifier.
# The test.bisect_cmd utility only uses such full test identifiers.
func = set(patterns).__contains__
else:
import fnmatch
regex = '|'.join(map(fnmatch.translate, patterns))
# The search *is* case sensitive on purpose:
# don't use flags=re.IGNORECASE
regex_match = re.compile(regex).match
def match_test_regex(test_id):
if regex_match(test_id):
# The regex matches the whole identifier, for example
# 'test.test_os.FileTests.test_access'.
return True
else:
# Try to match parts of the test identifier.
# For example, split 'test.test_os.FileTests.test_access'
# into: 'test', 'test_os', 'FileTests' and 'test_access'.
return any(map(regex_match, test_id.split(".")))
func = match_test_regex
return patterns, func
def run_unittest(*classes):
"""Run tests from unittest.TestCase-derived classes."""
valid_types = (unittest.TestSuite, unittest.TestCase)
loader = unittest.TestLoader()
suite = unittest.TestSuite()
for cls in classes:
if isinstance(cls, str):
if cls in sys.modules:
suite.addTest(loader.loadTestsFromModule(sys.modules[cls]))
else:
raise ValueError("str arguments must be keys in sys.modules")
elif isinstance(cls, valid_types):
suite.addTest(cls)
else:
suite.addTest(loader.loadTestsFromTestCase(cls))
_filter_suite(suite, match_test)
_run_suite(suite)
#=======================================================================
# Check for the presence of docstrings.
# Rather than trying to enumerate all the cases where docstrings may be
# disabled, we just check for that directly
def _check_docstrings():
"""Just used to check if docstrings are enabled"""
MISSING_C_DOCSTRINGS = (check_impl_detail() and
sys.platform != 'win32' and
not sysconfig.get_config_var('WITH_DOC_STRINGS'))
HAVE_DOCSTRINGS = (_check_docstrings.__doc__ is not None and
not MISSING_C_DOCSTRINGS)
requires_docstrings = unittest.skipUnless(HAVE_DOCSTRINGS,
"test requires docstrings")
#=======================================================================
# doctest driver.
def run_doctest(module, verbosity=None, optionflags=0):
"""Run doctest on the given module. Return (#failures, #tests).
If optional argument verbosity is not specified (or is None), pass
support's belief about verbosity on to doctest. Else doctest's
usual behavior is used (it searches sys.argv for -v).
"""
import doctest
if verbosity is None:
verbosity = verbose
else:
verbosity = None
f, t = doctest.testmod(module, verbose=verbosity, optionflags=optionflags)
if f:
raise TestFailed("%d of %d doctests failed" % (f, t))
if verbose:
print('doctest (%s) ... %d tests with zero failures' %
(module.__name__, t))
return f, t
#=======================================================================
# Support for saving and restoring the imported modules.
def flush_std_streams():
if sys.stdout is not None:
sys.stdout.flush()
if sys.stderr is not None:
sys.stderr.flush()
def print_warning(msg):
# bpo-45410: Explicitly flush stdout to keep logs in order
flush_std_streams()
stream = print_warning.orig_stderr
for line in msg.splitlines():
print(f"Warning -- {line}", file=stream)
stream.flush()
# bpo-39983: Store the original sys.stderr at Python startup to be able to
# log warnings even if sys.stderr is captured temporarily by a test.
print_warning.orig_stderr = sys.stderr
# Flag used by saved_test_environment of test.libregrtest.save_env,
# to check if a test modified the environment. The flag should be set to False
# before running a new test.
#
# For example, threading_helper.threading_cleanup() sets the flag is the function fails
# to cleanup threads.
environment_altered = False
def reap_children():
"""Use this function at the end of test_main() whenever sub-processes
are started. This will help ensure that no extra children (zombies)
stick around to hog resources and create problems when looking
for refleaks.
"""
global environment_altered
# Need os.waitpid(-1, os.WNOHANG): Windows is not supported
if not (hasattr(os, 'waitpid') and hasattr(os, 'WNOHANG')):
return
elif not has_subprocess_support:
return
# Reap all our dead child processes so we don't leave zombies around.
# These hog resources and might be causing some of the buildbots to die.
while True:
try:
# Read the exit status of any child process which already completed
pid, status = os.waitpid(-1, os.WNOHANG)
except OSError:
break
if pid == 0:
break
print_warning(f"reap_children() reaped child process {pid}")
environment_altered = True
@contextlib.contextmanager
def swap_attr(obj, attr, new_val):
"""Temporary swap out an attribute with a new object.
Usage:
with swap_attr(obj, "attr", 5):
...
This will set obj.attr to 5 for the duration of the with: block,
restoring the old value at the end of the block. If `attr` doesn't
exist on `obj`, it will be created and then deleted at the end of the
block.
The old value (or None if it doesn't exist) will be assigned to the
target of the "as" clause, if there is one.
"""
if hasattr(obj, attr):
real_val = getattr(obj, attr)
setattr(obj, attr, new_val)
try:
yield real_val
finally:
setattr(obj, attr, real_val)
else:
setattr(obj, attr, new_val)
try:
yield
finally:
if hasattr(obj, attr):
delattr(obj, attr)
@contextlib.contextmanager
def swap_item(obj, item, new_val):
"""Temporary swap out an item with a new object.
Usage:
with swap_item(obj, "item", 5):
...
This will set obj["item"] to 5 for the duration of the with: block,
restoring the old value at the end of the block. If `item` doesn't
exist on `obj`, it will be created and then deleted at the end of the
block.
The old value (or None if it doesn't exist) will be assigned to the
target of the "as" clause, if there is one.
"""
if item in obj:
real_val = obj[item]
obj[item] = new_val
try:
yield real_val
finally:
obj[item] = real_val
else:
obj[item] = new_val
try:
yield
finally:
if item in obj:
del obj[item]
def args_from_interpreter_flags():
"""Return a list of command-line arguments reproducing the current
settings in sys.flags and sys.warnoptions."""
import subprocess
return subprocess._args_from_interpreter_flags()
def optim_args_from_interpreter_flags():
"""Return a list of command-line arguments reproducing the current
optimization settings in sys.flags."""
import subprocess
return subprocess._optim_args_from_interpreter_flags()
class Matcher(object):
_partial_matches = ('msg', 'message')
def matches(self, d, **kwargs):
"""
Try to match a single dict with the supplied arguments.
Keys whose values are strings and which are in self._partial_matches
will be checked for partial (i.e. substring) matches. You can extend
this scheme to (for example) do regular expression matching, etc.
"""
result = True
for k in kwargs:
v = kwargs[k]
dv = d.get(k)
if not self.match_value(k, dv, v):
result = False
break
return result
def match_value(self, k, dv, v):
"""
Try to match a single stored value (dv) with a supplied value (v).
"""
if type(v) != type(dv):
result = False
elif type(dv) is not str or k not in self._partial_matches:
result = (v == dv)
else:
result = dv.find(v) >= 0
return result
_buggy_ucrt = None
def skip_if_buggy_ucrt_strfptime(test):
"""
Skip decorator for tests that use buggy strptime/strftime
If the UCRT bugs are present time.localtime().tm_zone will be
an empty string, otherwise we assume the UCRT bugs are fixed
See bpo-37552 [Windows] strptime/strftime return invalid
results with UCRT version 17763.615
"""
import locale
global _buggy_ucrt
if _buggy_ucrt is None:
if(sys.platform == 'win32' and
locale.getencoding() == 'cp65001' and
time.localtime().tm_zone == ''):
_buggy_ucrt = True
else:
_buggy_ucrt = False
return unittest.skip("buggy MSVC UCRT strptime/strftime")(test) if _buggy_ucrt else test
class PythonSymlink:
"""Creates a symlink for the current Python executable"""
def __init__(self, link=None):
from .os_helper import TESTFN
self.link = link or os.path.abspath(TESTFN)
self._linked = []
self.real = os.path.realpath(sys.executable)
self._also_link = []
self._env = None
self._platform_specific()
if sys.platform == "win32":
def _platform_specific(self):
import glob
import _winapi
if os.path.lexists(self.real) and not os.path.exists(self.real):
# App symlink appears to not exist, but we want the
# real executable here anyway
self.real = _winapi.GetModuleFileName(0)
dll = _winapi.GetModuleFileName(sys.dllhandle)
src_dir = os.path.dirname(dll)
dest_dir = os.path.dirname(self.link)
self._also_link.append((
dll,
os.path.join(dest_dir, os.path.basename(dll))
))
for runtime in glob.glob(os.path.join(glob.escape(src_dir), "vcruntime*.dll")):
self._also_link.append((
runtime,
os.path.join(dest_dir, os.path.basename(runtime))
))
self._env = {k.upper(): os.getenv(k) for k in os.environ}
self._env["PYTHONHOME"] = os.path.dirname(self.real)
if sysconfig.is_python_build():
self._env["PYTHONPATH"] = STDLIB_DIR
else:
def _platform_specific(self):
pass
def __enter__(self):
os.symlink(self.real, self.link)
self._linked.append(self.link)
for real, link in self._also_link:
os.symlink(real, link)
self._linked.append(link)
return self
def __exit__(self, exc_type, exc_value, exc_tb):
for link in self._linked:
try:
os.remove(link)
except IOError as ex:
if verbose:
print("failed to clean up {}: {}".format(link, ex))
def _call(self, python, args, env, returncode):
import subprocess
cmd = [python, *args]
p = subprocess.Popen(cmd, stdout=subprocess.PIPE,
stderr=subprocess.PIPE, env=env)
r = p.communicate()
if p.returncode != returncode:
if verbose:
print(repr(r[0]))
print(repr(r[1]), file=sys.stderr)
raise RuntimeError(
'unexpected return code: {0} (0x{0:08X})'.format(p.returncode))
return r
def call_real(self, *args, returncode=0):
return self._call(self.real, args, None, returncode)
def call_link(self, *args, returncode=0):
return self._call(self.link, args, self._env, returncode)
def skip_if_pgo_task(test):
"""Skip decorator for tests not run in (non-extended) PGO task"""
ok = not PGO or PGO_EXTENDED
msg = "Not run for (non-extended) PGO task"
return test if ok else unittest.skip(msg)(test)
def detect_api_mismatch(ref_api, other_api, *, ignore=()):
"""Returns the set of items in ref_api not in other_api, except for a
defined list of items to be ignored in this check.
By default this skips private attributes beginning with '_' but
includes all magic methods, i.e. those starting and ending in '__'.
"""
missing_items = set(dir(ref_api)) - set(dir(other_api))
if ignore:
missing_items -= set(ignore)
missing_items = set(m for m in missing_items
if not m.startswith('_') or m.endswith('__'))
return missing_items
def check__all__(test_case, module, name_of_module=None, extra=(),
not_exported=()):
"""Assert that the __all__ variable of 'module' contains all public names.
The module's public names (its API) are detected automatically based on
whether they match the public name convention and were defined in
'module'.
The 'name_of_module' argument can specify (as a string or tuple thereof)
what module(s) an API could be defined in in order to be detected as a
public API. One case for this is when 'module' imports part of its public
API from other modules, possibly a C backend (like 'csv' and its '_csv').
The 'extra' argument can be a set of names that wouldn't otherwise be
automatically detected as "public", like objects without a proper
'__module__' attribute. If provided, it will be added to the
automatically detected ones.
The 'not_exported' argument can be a set of names that must not be treated
as part of the public API even though their names indicate otherwise.
Usage:
import bar
import foo
import unittest
from test import support
class MiscTestCase(unittest.TestCase):
def test__all__(self):
support.check__all__(self, foo)
class OtherTestCase(unittest.TestCase):
def test__all__(self):
extra = {'BAR_CONST', 'FOO_CONST'}
not_exported = {'baz'} # Undocumented name.
# bar imports part of its API from _bar.
support.check__all__(self, bar, ('bar', '_bar'),
extra=extra, not_exported=not_exported)
"""
if name_of_module is None:
name_of_module = (module.__name__, )
elif isinstance(name_of_module, str):
name_of_module = (name_of_module, )
expected = set(extra)
for name in dir(module):
if name.startswith('_') or name in not_exported:
continue
obj = getattr(module, name)
if (getattr(obj, '__module__', None) in name_of_module or
(not hasattr(obj, '__module__') and
not isinstance(obj, types.ModuleType))):
expected.add(name)
test_case.assertCountEqual(module.__all__, expected)
def suppress_msvcrt_asserts(verbose=False):
try:
import msvcrt
except ImportError:
return
msvcrt.SetErrorMode(msvcrt.SEM_FAILCRITICALERRORS
| msvcrt.SEM_NOALIGNMENTFAULTEXCEPT
| msvcrt.SEM_NOGPFAULTERRORBOX
| msvcrt.SEM_NOOPENFILEERRORBOX)
# CrtSetReportMode() is only available in debug build
if hasattr(msvcrt, 'CrtSetReportMode'):
for m in [msvcrt.CRT_WARN, msvcrt.CRT_ERROR, msvcrt.CRT_ASSERT]:
if verbose:
msvcrt.CrtSetReportMode(m, msvcrt.CRTDBG_MODE_FILE)
msvcrt.CrtSetReportFile(m, msvcrt.CRTDBG_FILE_STDERR)
else:
msvcrt.CrtSetReportMode(m, 0)
class SuppressCrashReport:
"""Try to prevent a crash report from popping up.
On Windows, don't display the Windows Error Reporting dialog. On UNIX,
disable the creation of coredump file.
"""
old_value = None
old_modes = None
def __enter__(self):
"""On Windows, disable Windows Error Reporting dialogs using
SetErrorMode() and CrtSetReportMode().
On UNIX, try to save the previous core file size limit, then set
soft limit to 0.
"""
if sys.platform.startswith('win'):
# see http://msdn.microsoft.com/en-us/library/windows/desktop/ms680621.aspx
try:
import msvcrt
except ImportError:
return
self.old_value = msvcrt.GetErrorMode()
msvcrt.SetErrorMode(self.old_value | msvcrt.SEM_NOGPFAULTERRORBOX)
# bpo-23314: Suppress assert dialogs in debug builds.
# CrtSetReportMode() is only available in debug build.
if hasattr(msvcrt, 'CrtSetReportMode'):
self.old_modes = {}
for report_type in [msvcrt.CRT_WARN,
msvcrt.CRT_ERROR,
msvcrt.CRT_ASSERT]:
old_mode = msvcrt.CrtSetReportMode(report_type,
msvcrt.CRTDBG_MODE_FILE)
old_file = msvcrt.CrtSetReportFile(report_type,
msvcrt.CRTDBG_FILE_STDERR)
self.old_modes[report_type] = old_mode, old_file
else:
try:
import resource
self.resource = resource
except ImportError:
self.resource = None
if self.resource is not None:
try:
self.old_value = self.resource.getrlimit(self.resource.RLIMIT_CORE)
self.resource.setrlimit(self.resource.RLIMIT_CORE,
(0, self.old_value[1]))
except (ValueError, OSError):
pass
if sys.platform == 'darwin':
import subprocess
# Check if the 'Crash Reporter' on OSX was configured
# in 'Developer' mode and warn that it will get triggered
# when it is.
#
# This assumes that this context manager is used in tests
# that might trigger the next manager.
cmd = ['/usr/bin/defaults', 'read',
'com.apple.CrashReporter', 'DialogType']
proc = subprocess.Popen(cmd,
stdout=subprocess.PIPE,
stderr=subprocess.PIPE)
with proc:
stdout = proc.communicate()[0]
if stdout.strip() == b'developer':
print("this test triggers the Crash Reporter, "
"that is intentional", end='', flush=True)
return self
def __exit__(self, *ignore_exc):
"""Restore Windows ErrorMode or core file behavior to initial value."""
if self.old_value is None:
return
if sys.platform.startswith('win'):
import msvcrt
msvcrt.SetErrorMode(self.old_value)
if self.old_modes:
for report_type, (old_mode, old_file) in self.old_modes.items():
msvcrt.CrtSetReportMode(report_type, old_mode)
msvcrt.CrtSetReportFile(report_type, old_file)
else:
if self.resource is not None:
try:
self.resource.setrlimit(self.resource.RLIMIT_CORE, self.old_value)
except (ValueError, OSError):
pass
def patch(test_instance, object_to_patch, attr_name, new_value):
"""Override 'object_to_patch'.'attr_name' with 'new_value'.
Also, add a cleanup procedure to 'test_instance' to restore
'object_to_patch' value for 'attr_name'.
The 'attr_name' should be a valid attribute for 'object_to_patch'.
"""
# check that 'attr_name' is a real attribute for 'object_to_patch'
# will raise AttributeError if it does not exist
getattr(object_to_patch, attr_name)
# keep a copy of the old value
attr_is_local = False
try:
old_value = object_to_patch.__dict__[attr_name]
except (AttributeError, KeyError):
old_value = getattr(object_to_patch, attr_name, None)
else:
attr_is_local = True
# restore the value when the test is done
def cleanup():
if attr_is_local:
setattr(object_to_patch, attr_name, old_value)
else:
delattr(object_to_patch, attr_name)
test_instance.addCleanup(cleanup)
# actually override the attribute
setattr(object_to_patch, attr_name, new_value)
@contextlib.contextmanager
def patch_list(orig):
"""Like unittest.mock.patch.dict, but for lists."""
try:
saved = orig[:]
yield
finally:
orig[:] = saved
def run_in_subinterp(code):
"""
Run code in a subinterpreter. Raise unittest.SkipTest if the tracemalloc
module is enabled.
"""
_check_tracemalloc()
import _testcapi
return _testcapi.run_in_subinterp(code)
def run_in_subinterp_with_config(code, **config):
"""
Run code in a subinterpreter. Raise unittest.SkipTest if the tracemalloc
module is enabled.
"""
_check_tracemalloc()
import _testcapi
return _testcapi.run_in_subinterp_with_config(code, **config)
def _check_tracemalloc():
# Issue #10915, #15751: PyGILState_*() functions don't work with
# sub-interpreters, the tracemalloc module uses these functions internally
try:
import tracemalloc
except ImportError:
pass
else:
if tracemalloc.is_tracing():
raise unittest.SkipTest("run_in_subinterp() cannot be used "
"if tracemalloc module is tracing "
"memory allocations")
def check_free_after_iterating(test, iter, cls, args=()):
class A(cls):
def __del__(self):
nonlocal done
done = True
try:
next(it)
except StopIteration:
pass
done = False
it = iter(A(*args))
# Issue 26494: Shouldn't crash
test.assertRaises(StopIteration, next, it)
# The sequence should be deallocated just after the end of iterating
gc_collect()
test.assertTrue(done)
def missing_compiler_executable(cmd_names=[]):
"""Check if the compiler components used to build the interpreter exist.
Check for the existence of the compiler executables whose names are listed
in 'cmd_names' or all the compiler executables when 'cmd_names' is empty
and return the first missing executable or None when none is found
missing.
"""
# TODO (PEP 632): alternate check without using distutils
from distutils import ccompiler, sysconfig, spawn, errors
compiler = ccompiler.new_compiler()
sysconfig.customize_compiler(compiler)
if compiler.compiler_type == "msvc":
# MSVC has no executables, so check whether initialization succeeds
try:
compiler.initialize()
except errors.DistutilsPlatformError:
return "msvc"
for name in compiler.executables:
if cmd_names and name not in cmd_names:
continue
cmd = getattr(compiler, name)
if cmd_names:
assert cmd is not None, \
"the '%s' executable is not configured" % name
elif not cmd:
continue
if spawn.find_executable(cmd[0]) is None:
return cmd[0]
_is_android_emulator = None
def setswitchinterval(interval):
# Setting a very low gil interval on the Android emulator causes python
# to hang (issue #26939).
minimum_interval = 1e-5
if is_android and interval < minimum_interval:
global _is_android_emulator
if _is_android_emulator is None:
import subprocess
_is_android_emulator = (subprocess.check_output(
['getprop', 'ro.kernel.qemu']).strip() == b'1')
if _is_android_emulator:
interval = minimum_interval
return sys.setswitchinterval(interval)
def get_pagesize():
"""Get size of a page in bytes."""
try:
page_size = os.sysconf('SC_PAGESIZE')
except (ValueError, AttributeError):
try:
page_size = os.sysconf('SC_PAGE_SIZE')
except (ValueError, AttributeError):
page_size = 4096
return page_size
@contextlib.contextmanager
def disable_faulthandler():
import faulthandler
# use sys.__stderr__ instead of sys.stderr, since regrtest replaces
# sys.stderr with a StringIO which has no file descriptor when a test
# is run with -W/--verbose3.
fd = sys.__stderr__.fileno()
is_enabled = faulthandler.is_enabled()
try:
faulthandler.disable()
yield
finally:
if is_enabled:
faulthandler.enable(file=fd, all_threads=True)
class SaveSignals:
"""
Save and restore signal handlers.
This class is only able to save/restore signal handlers registered
by the Python signal module: see bpo-13285 for "external" signal
handlers.
"""
def __init__(self):
import signal
self.signal = signal
self.signals = signal.valid_signals()
# SIGKILL and SIGSTOP signals cannot be ignored nor caught
for signame in ('SIGKILL', 'SIGSTOP'):
try:
signum = getattr(signal, signame)
except AttributeError:
continue
self.signals.remove(signum)
self.handlers = {}
def save(self):
for signum in self.signals:
handler = self.signal.getsignal(signum)
if handler is None:
# getsignal() returns None if a signal handler was not
# registered by the Python signal module,
# and the handler is not SIG_DFL nor SIG_IGN.
#
# Ignore the signal: we cannot restore the handler.
continue
self.handlers[signum] = handler
def restore(self):
for signum, handler in self.handlers.items():
self.signal.signal(signum, handler)
def with_pymalloc():
import _testcapi
return _testcapi.WITH_PYMALLOC
class _ALWAYS_EQ:
"""
Object that is equal to anything.
"""
def __eq__(self, other):
return True
def __ne__(self, other):
return False
ALWAYS_EQ = _ALWAYS_EQ()
class _NEVER_EQ:
"""
Object that is not equal to anything.
"""
def __eq__(self, other):
return False
def __ne__(self, other):
return True
def __hash__(self):
return 1
NEVER_EQ = _NEVER_EQ()
@functools.total_ordering
class _LARGEST:
"""
Object that is greater than anything (except itself).
"""
def __eq__(self, other):
return isinstance(other, _LARGEST)
def __lt__(self, other):
return False
LARGEST = _LARGEST()
@functools.total_ordering
class _SMALLEST:
"""
Object that is less than anything (except itself).
"""
def __eq__(self, other):
return isinstance(other, _SMALLEST)
def __gt__(self, other):
return False
SMALLEST = _SMALLEST()
def maybe_get_event_loop_policy():
"""Return the global event loop policy if one is set, else return None."""
import asyncio.events
return asyncio.events._event_loop_policy
# Helpers for testing hashing.
NHASHBITS = sys.hash_info.width # number of bits in hash() result
assert NHASHBITS in (32, 64)
# Return mean and sdev of number of collisions when tossing nballs balls
# uniformly at random into nbins bins. By definition, the number of
# collisions is the number of balls minus the number of occupied bins at
# the end.
def collision_stats(nbins, nballs):
n, k = nbins, nballs
# prob a bin empty after k trials = (1 - 1/n)**k
# mean # empty is then n * (1 - 1/n)**k
# so mean # occupied is n - n * (1 - 1/n)**k
# so collisions = k - (n - n*(1 - 1/n)**k)
#
# For the variance:
# n*(n-1)*(1-2/n)**k + meanempty - meanempty**2 =
# n*(n-1)*(1-2/n)**k + meanempty * (1 - meanempty)
#
# Massive cancellation occurs, and, e.g., for a 64-bit hash code
# 1-1/2**64 rounds uselessly to 1.0. Rather than make heroic (and
# error-prone) efforts to rework the naive formulas to avoid those,
# we use the `decimal` module to get plenty of extra precision.
#
# Note: the exact values are straightforward to compute with
# rationals, but in context that's unbearably slow, requiring
# multi-million bit arithmetic.
import decimal
with decimal.localcontext() as ctx:
bits = n.bit_length() * 2 # bits in n**2
# At least that many bits will likely cancel out.
# Use that many decimal digits instead.
ctx.prec = max(bits, 30)
dn = decimal.Decimal(n)
p1empty = ((dn - 1) / dn) ** k
meanempty = n * p1empty
occupied = n - meanempty
collisions = k - occupied
var = dn*(dn-1)*((dn-2)/dn)**k + meanempty * (1 - meanempty)
return float(collisions), float(var.sqrt())
class catch_unraisable_exception:
"""
Context manager catching unraisable exception using sys.unraisablehook.
Storing the exception value (cm.unraisable.exc_value) creates a reference
cycle. The reference cycle is broken explicitly when the context manager
exits.
Storing the object (cm.unraisable.object) can resurrect it if it is set to
an object which is being finalized. Exiting the context manager clears the
stored object.
Usage:
with support.catch_unraisable_exception() as cm:
# code creating an "unraisable exception"
...
# check the unraisable exception: use cm.unraisable
...
# cm.unraisable attribute no longer exists at this point
# (to break a reference cycle)
"""
def __init__(self):
self.unraisable = None
self._old_hook = None
def _hook(self, unraisable):
# Storing unraisable.object can resurrect an object which is being
# finalized. Storing unraisable.exc_value creates a reference cycle.
self.unraisable = unraisable
def __enter__(self):
self._old_hook = sys.unraisablehook
sys.unraisablehook = self._hook
return self
def __exit__(self, *exc_info):
sys.unraisablehook = self._old_hook
del self.unraisable
def wait_process(pid, *, exitcode, timeout=None):
"""
Wait until process pid completes and check that the process exit code is
exitcode.
Raise an AssertionError if the process exit code is not equal to exitcode.
If the process runs longer than timeout seconds (LONG_TIMEOUT by default),
kill the process (if signal.SIGKILL is available) and raise an
AssertionError. The timeout feature is not available on Windows.
"""
if os.name != "nt":
import signal
if timeout is None:
timeout = LONG_TIMEOUT
start_time = time.monotonic()
for _ in sleeping_retry(timeout, error=False):
pid2, status = os.waitpid(pid, os.WNOHANG)
if pid2 != 0:
break
# rety: the process is still running
else:
try:
os.kill(pid, signal.SIGKILL)
os.waitpid(pid, 0)
except OSError:
# Ignore errors like ChildProcessError or PermissionError
pass
dt = time.monotonic() - start_time
raise AssertionError(f"process {pid} is still running "
f"after {dt:.1f} seconds")
else:
# Windows implementation: don't support timeout :-(
pid2, status = os.waitpid(pid, 0)
exitcode2 = os.waitstatus_to_exitcode(status)
if exitcode2 != exitcode:
raise AssertionError(f"process {pid} exited with code {exitcode2}, "
f"but exit code {exitcode} is expected")
# sanity check: it should not fail in practice
if pid2 != pid:
raise AssertionError(f"pid {pid2} != pid {pid}")
def skip_if_broken_multiprocessing_synchronize():
"""
Skip tests if the multiprocessing.synchronize module is missing, if there
is no available semaphore implementation, or if creating a lock raises an
OSError (on Linux only).
"""
from .import_helper import import_module
# Skip tests if the _multiprocessing extension is missing.
import_module('_multiprocessing')
# Skip tests if there is no available semaphore implementation:
# multiprocessing.synchronize requires _multiprocessing.SemLock.
synchronize = import_module('multiprocessing.synchronize')
if sys.platform == "linux":
try:
# bpo-38377: On Linux, creating a semaphore fails with OSError
# if the current user does not have the permission to create
# a file in /dev/shm/ directory.
synchronize.Lock(ctx=None)
except OSError as exc:
raise unittest.SkipTest(f"broken multiprocessing SemLock: {exc!r}")
def check_disallow_instantiation(testcase, tp, *args, **kwds):
"""
Check that given type cannot be instantiated using *args and **kwds.
See bpo-43916: Add Py_TPFLAGS_DISALLOW_INSTANTIATION type flag.
"""
mod = tp.__module__
name = tp.__name__
if mod != 'builtins':
qualname = f"{mod}.{name}"
else:
qualname = f"{name}"
msg = f"cannot create '{re.escape(qualname)}' instances"
testcase.assertRaisesRegex(TypeError, msg, tp, *args, **kwds)
@contextlib.contextmanager
def set_recursion_limit(limit):
"""Temporarily change the recursion limit."""
original_limit = sys.getrecursionlimit()
try:
sys.setrecursionlimit(limit)
yield
finally:
sys.setrecursionlimit(original_limit)
def infinite_recursion(max_depth=75):
"""Set a lower limit for tests that interact with infinite recursions
(e.g test_ast.ASTHelpers_Test.test_recursion_direct) since on some
debug windows builds, due to not enough functions being inlined the
stack size might not handle the default recursion limit (1000). See
bpo-11105 for details."""
return set_recursion_limit(max_depth)
def ignore_deprecations_from(module: str, *, like: str) -> object:
token = object()
warnings.filterwarnings(
"ignore",
category=DeprecationWarning,
module=module,
message=like + fr"(?#support{id(token)})",
)
return token
def clear_ignored_deprecations(*tokens: object) -> None:
if not tokens:
raise ValueError("Provide token or tokens returned by ignore_deprecations_from")
new_filters = []
endswith = tuple(rf"(?#support{id(token)})" for token in tokens)
for action, message, category, module, lineno in warnings.filters:
if action == "ignore" and category is DeprecationWarning:
if isinstance(message, re.Pattern):
msg = message.pattern
else:
msg = message or ""
if msg.endswith(endswith):
continue
new_filters.append((action, message, category, module, lineno))
if warnings.filters != new_filters:
warnings.filters[:] = new_filters
warnings._filters_mutated()
# Skip a test if venv with pip is known to not work.
def requires_venv_with_pip():
# ensurepip requires zlib to open ZIP archives (.whl binary wheel packages)
try:
import zlib
except ImportError:
return unittest.skipIf(True, "venv: ensurepip requires zlib")
# bpo-26610: pip/pep425tags.py requires ctypes.
# gh-92820: setuptools/windows_support.py uses ctypes (setuptools 58.1).
try:
import ctypes
except ImportError:
ctypes = None
return unittest.skipUnless(ctypes, 'venv: pip requires ctypes')
# True if Python is built with the Py_DEBUG macro defined: if
# Python is built in debug mode (./configure --with-pydebug).
Py_DEBUG = hasattr(sys, 'gettotalrefcount')
def late_deletion(obj):
"""
Keep a Python alive as long as possible.
Create a reference cycle and store the cycle in an object deleted late in
Python finalization. Try to keep the object alive until the very last
garbage collection.
The function keeps a strong reference by design. It should be called in a
subprocess to not mark a test as "leaking a reference".
"""
# Late CPython finalization:
# - finalize_interp_clear()
# - _PyInterpreterState_Clear(): Clear PyInterpreterState members
# (ex: codec_search_path, before_forkers)
# - clear os.register_at_fork() callbacks
# - clear codecs.register() callbacks
ref_cycle = [obj]
ref_cycle.append(ref_cycle)
# Store a reference in PyInterpreterState.codec_search_path
import codecs
def search_func(encoding):
return None
search_func.reference = ref_cycle
codecs.register(search_func)
if hasattr(os, 'register_at_fork'):
# Store a reference in PyInterpreterState.before_forkers
def atfork_func():
pass
atfork_func.reference = ref_cycle
os.register_at_fork(before=atfork_func)
def busy_retry(timeout, err_msg=None, /, *, error=True):
"""
Run the loop body until "break" stops the loop.
After *timeout* seconds, raise an AssertionError if *error* is true,
or just stop if *error is false.
Example:
for _ in support.busy_retry(support.SHORT_TIMEOUT):
if check():
break
Example of error=False usage:
for _ in support.busy_retry(support.SHORT_TIMEOUT, error=False):
if check():
break
else:
raise RuntimeError('my custom error')
"""
if timeout <= 0:
raise ValueError("timeout must be greater than zero")
start_time = time.monotonic()
deadline = start_time + timeout
while True:
yield
if time.monotonic() >= deadline:
break
if error:
dt = time.monotonic() - start_time
msg = f"timeout ({dt:.1f} seconds)"
if err_msg:
msg = f"{msg}: {err_msg}"
raise AssertionError(msg)
def sleeping_retry(timeout, err_msg=None, /,
*, init_delay=0.010, max_delay=1.0, error=True):
"""
Wait strategy that applies exponential backoff.
Run the loop body until "break" stops the loop. Sleep at each loop
iteration, but not at the first iteration. The sleep delay is doubled at
each iteration (up to *max_delay* seconds).
See busy_retry() documentation for the parameters usage.
Example raising an exception after SHORT_TIMEOUT seconds:
for _ in support.sleeping_retry(support.SHORT_TIMEOUT):
if check():
break
Example of error=False usage:
for _ in support.sleeping_retry(support.SHORT_TIMEOUT, error=False):
if check():
break
else:
raise RuntimeError('my custom error')
"""
delay = init_delay
for _ in busy_retry(timeout, err_msg, error=error):
yield
time.sleep(delay)
delay = min(delay * 2, max_delay)
@contextlib.contextmanager
def adjust_int_max_str_digits(max_digits):
"""Temporarily change the integer string conversion length limit."""
current = sys.get_int_max_str_digits()
try:
sys.set_int_max_str_digits(max_digits)
yield
finally:
sys.set_int_max_str_digits(current)
#For recursion tests, easily exceeds default recursion limit
EXCEEDS_RECURSION_LIMIT = 5000
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