cpython/Lib/test/test_exceptions.py
Miss Islington (bot) e064af564c
bpo-46442: improve and rename testExceptionCleanupNames (GH-30758)
The test tested that explicitly deleting the local variable bound to the exception
did not cause problems, but it did not test what it actually claimed to test, i.e.
that the variable is deleted automatically.
(cherry picked from commit 82c53229e1)

Co-authored-by: Yellow Dusk <yellow.dusk1590@fastmail.com>
2022-01-21 23:37:32 -08:00

1672 lines
58 KiB
Python

# Python test set -- part 5, built-in exceptions
import copy
import gc
import os
import sys
import unittest
import pickle
import weakref
import errno
from test.support import (TESTFN, captured_stderr, check_impl_detail,
check_warnings, cpython_only, gc_collect,
no_tracing, unlink, import_module, script_helper,
SuppressCrashReport)
from test import support
class NaiveException(Exception):
def __init__(self, x):
self.x = x
class SlottedNaiveException(Exception):
__slots__ = ('x',)
def __init__(self, x):
self.x = x
class BrokenStrException(Exception):
def __str__(self):
raise Exception("str() is broken")
# XXX This is not really enough, each *operation* should be tested!
class ExceptionTests(unittest.TestCase):
def raise_catch(self, exc, excname):
with self.subTest(exc=exc, excname=excname):
try:
raise exc("spam")
except exc as err:
buf1 = str(err)
try:
raise exc("spam")
except exc as err:
buf2 = str(err)
self.assertEqual(buf1, buf2)
self.assertEqual(exc.__name__, excname)
def testRaising(self):
self.raise_catch(AttributeError, "AttributeError")
self.assertRaises(AttributeError, getattr, sys, "undefined_attribute")
self.raise_catch(EOFError, "EOFError")
fp = open(TESTFN, 'w')
fp.close()
fp = open(TESTFN, 'r')
savestdin = sys.stdin
try:
try:
import marshal
marshal.loads(b'')
except EOFError:
pass
finally:
sys.stdin = savestdin
fp.close()
unlink(TESTFN)
self.raise_catch(OSError, "OSError")
self.assertRaises(OSError, open, 'this file does not exist', 'r')
self.raise_catch(ImportError, "ImportError")
self.assertRaises(ImportError, __import__, "undefined_module")
self.raise_catch(IndexError, "IndexError")
x = []
self.assertRaises(IndexError, x.__getitem__, 10)
self.raise_catch(KeyError, "KeyError")
x = {}
self.assertRaises(KeyError, x.__getitem__, 'key')
self.raise_catch(KeyboardInterrupt, "KeyboardInterrupt")
self.raise_catch(MemoryError, "MemoryError")
self.raise_catch(NameError, "NameError")
try: x = undefined_variable
except NameError: pass
self.raise_catch(OverflowError, "OverflowError")
x = 1
for dummy in range(128):
x += x # this simply shouldn't blow up
self.raise_catch(RuntimeError, "RuntimeError")
self.raise_catch(RecursionError, "RecursionError")
self.raise_catch(SyntaxError, "SyntaxError")
try: exec('/\n')
except SyntaxError: pass
self.raise_catch(IndentationError, "IndentationError")
self.raise_catch(TabError, "TabError")
try: compile("try:\n\t1/0\n \t1/0\nfinally:\n pass\n",
'<string>', 'exec')
except TabError: pass
else: self.fail("TabError not raised")
self.raise_catch(SystemError, "SystemError")
self.raise_catch(SystemExit, "SystemExit")
self.assertRaises(SystemExit, sys.exit, 0)
self.raise_catch(TypeError, "TypeError")
try: [] + ()
except TypeError: pass
self.raise_catch(ValueError, "ValueError")
self.assertRaises(ValueError, chr, 17<<16)
self.raise_catch(ZeroDivisionError, "ZeroDivisionError")
try: x = 1/0
except ZeroDivisionError: pass
self.raise_catch(Exception, "Exception")
try: x = 1/0
except Exception as e: pass
self.raise_catch(StopAsyncIteration, "StopAsyncIteration")
def testSyntaxErrorMessage(self):
# make sure the right exception message is raised for each of
# these code fragments
def ckmsg(src, msg):
with self.subTest(src=src, msg=msg):
try:
compile(src, '<fragment>', 'exec')
except SyntaxError as e:
if e.msg != msg:
self.fail("expected %s, got %s" % (msg, e.msg))
else:
self.fail("failed to get expected SyntaxError")
s = '''if 1:
try:
continue
except:
pass'''
ckmsg(s, "'continue' not properly in loop")
ckmsg("continue\n", "'continue' not properly in loop")
def testSyntaxErrorMissingParens(self):
def ckmsg(src, msg, exception=SyntaxError):
try:
compile(src, '<fragment>', 'exec')
except exception as e:
if e.msg != msg:
self.fail("expected %s, got %s" % (msg, e.msg))
else:
self.fail("failed to get expected SyntaxError")
s = '''print "old style"'''
ckmsg(s, "Missing parentheses in call to 'print'. "
"Did you mean print(\"old style\")?")
s = '''print "old style",'''
ckmsg(s, "Missing parentheses in call to 'print'. "
"Did you mean print(\"old style\", end=\" \")?")
s = '''exec "old style"'''
ckmsg(s, "Missing parentheses in call to 'exec'")
# should not apply to subclasses, see issue #31161
s = '''if True:\nprint "No indent"'''
ckmsg(s, "expected an indented block", IndentationError)
s = '''if True:\n print()\n\texec "mixed tabs and spaces"'''
ckmsg(s, "inconsistent use of tabs and spaces in indentation", TabError)
def check(self, src, lineno, offset, encoding='utf-8'):
with self.subTest(source=src, lineno=lineno, offset=offset):
with self.assertRaises(SyntaxError) as cm:
compile(src, '<fragment>', 'exec')
self.assertEqual(cm.exception.lineno, lineno)
self.assertEqual(cm.exception.offset, offset)
if cm.exception.text is not None:
if not isinstance(src, str):
src = src.decode(encoding, 'replace')
line = src.split('\n')[lineno-1]
self.assertIn(line, cm.exception.text)
def test_error_offset_continuation_characters(self):
check = self.check
check('"\\\n"(1 for c in I,\\\n\\', 3, 22)
def testSyntaxErrorOffset(self):
check = self.check
check('def fact(x):\n\treturn x!\n', 2, 10)
check('1 +\n', 1, 4)
check('def spam():\n print(1)\n print(2)', 3, 10)
check('Python = "Python" +', 1, 20)
check('Python = "\u1e54\xfd\u0163\u0125\xf2\xf1" +', 1, 20)
check(b'# -*- coding: cp1251 -*-\nPython = "\xcf\xb3\xf2\xee\xed" +',
2, 19, encoding='cp1251')
check(b'Python = "\xcf\xb3\xf2\xee\xed" +', 1, 18)
check('x = "a', 1, 7)
check('lambda x: x = 2', 1, 1)
check('f{a + b + c}', 1, 2)
# Errors thrown by compile.c
check('class foo:return 1', 1, 11)
check('def f():\n continue', 2, 3)
check('def f():\n break', 2, 3)
check('try:\n pass\nexcept:\n pass\nexcept ValueError:\n pass', 2, 3)
# Errors thrown by tokenizer.c
check('(0x+1)', 1, 3)
check('x = 0xI', 1, 6)
check('0010 + 2', 1, 4)
check('x = 32e-+4', 1, 8)
check('x = 0o9', 1, 6)
check('\u03b1 = 0xI', 1, 6)
check(b'\xce\xb1 = 0xI', 1, 6)
check(b'# -*- coding: iso8859-7 -*-\n\xe1 = 0xI', 2, 6,
encoding='iso8859-7')
check(b"""if 1:
def foo():
'''
def bar():
pass
def baz():
'''quux'''
""", 9, 20)
check("pass\npass\npass\n(1+)\npass\npass\npass", 4, 4)
check("(1+)", 1, 4)
check(b"\xef\xbb\xbf#coding: utf8\nprint('\xe6\x88\x91')\n", 0,
0 if support.use_old_parser() else -1)
# Errors thrown by symtable.c
check('x = [(yield i) for i in range(3)]', 1, 5)
check('def f():\n from _ import *', 1, 1)
check('def f(x, x):\n pass', 1, 1)
check('def f(x):\n nonlocal x', 2, 3)
check('def f(x):\n x = 1\n global x', 3, 3)
check('nonlocal x', 1, 1)
check('def f():\n global x\n nonlocal x', 2, 3)
# Errors thrown by future.c
check('from __future__ import doesnt_exist', 1, 1)
check('from __future__ import braces', 1, 1)
check('x=1\nfrom __future__ import division', 2, 1)
check('foo(1=2)', 1, 5)
check('def f():\n x, y: int', 2, 3)
check('[*x for x in xs]', 1, 2)
check('foo(x for x in range(10), 100)', 1, 5)
check('(yield i) = 2', 1, 1 if support.use_old_parser() else 2)
check('def f(*):\n pass', 1, 7 if support.use_old_parser() else 8)
check('for 1 in []: pass', 1, 5)
@cpython_only
def testSettingException(self):
# test that setting an exception at the C level works even if the
# exception object can't be constructed.
class BadException(Exception):
def __init__(self_):
raise RuntimeError("can't instantiate BadException")
class InvalidException:
pass
def test_capi1():
import _testcapi
try:
_testcapi.raise_exception(BadException, 1)
except TypeError as err:
exc, err, tb = sys.exc_info()
co = tb.tb_frame.f_code
self.assertEqual(co.co_name, "test_capi1")
self.assertTrue(co.co_filename.endswith('test_exceptions.py'))
else:
self.fail("Expected exception")
def test_capi2():
import _testcapi
try:
_testcapi.raise_exception(BadException, 0)
except RuntimeError as err:
exc, err, tb = sys.exc_info()
co = tb.tb_frame.f_code
self.assertEqual(co.co_name, "__init__")
self.assertTrue(co.co_filename.endswith('test_exceptions.py'))
co2 = tb.tb_frame.f_back.f_code
self.assertEqual(co2.co_name, "test_capi2")
else:
self.fail("Expected exception")
def test_capi3():
import _testcapi
self.assertRaises(SystemError, _testcapi.raise_exception,
InvalidException, 1)
if not sys.platform.startswith('java'):
test_capi1()
test_capi2()
test_capi3()
def test_WindowsError(self):
try:
WindowsError
except NameError:
pass
else:
self.assertIs(WindowsError, OSError)
self.assertEqual(str(OSError(1001)), "1001")
self.assertEqual(str(OSError(1001, "message")),
"[Errno 1001] message")
# POSIX errno (9 aka EBADF) is untranslated
w = OSError(9, 'foo', 'bar')
self.assertEqual(w.errno, 9)
self.assertEqual(w.winerror, None)
self.assertEqual(str(w), "[Errno 9] foo: 'bar'")
# ERROR_PATH_NOT_FOUND (win error 3) becomes ENOENT (2)
w = OSError(0, 'foo', 'bar', 3)
self.assertEqual(w.errno, 2)
self.assertEqual(w.winerror, 3)
self.assertEqual(w.strerror, 'foo')
self.assertEqual(w.filename, 'bar')
self.assertEqual(w.filename2, None)
self.assertEqual(str(w), "[WinError 3] foo: 'bar'")
# Unknown win error becomes EINVAL (22)
w = OSError(0, 'foo', None, 1001)
self.assertEqual(w.errno, 22)
self.assertEqual(w.winerror, 1001)
self.assertEqual(w.strerror, 'foo')
self.assertEqual(w.filename, None)
self.assertEqual(w.filename2, None)
self.assertEqual(str(w), "[WinError 1001] foo")
# Non-numeric "errno"
w = OSError('bar', 'foo')
self.assertEqual(w.errno, 'bar')
self.assertEqual(w.winerror, None)
self.assertEqual(w.strerror, 'foo')
self.assertEqual(w.filename, None)
self.assertEqual(w.filename2, None)
@unittest.skipUnless(sys.platform == 'win32',
'test specific to Windows')
def test_windows_message(self):
"""Should fill in unknown error code in Windows error message"""
ctypes = import_module('ctypes')
# this error code has no message, Python formats it as hexadecimal
code = 3765269347
with self.assertRaisesRegex(OSError, 'Windows Error 0x%x' % code):
ctypes.pythonapi.PyErr_SetFromWindowsErr(code)
def testAttributes(self):
# test that exception attributes are happy
exceptionList = [
(BaseException, (), {'args' : ()}),
(BaseException, (1, ), {'args' : (1,)}),
(BaseException, ('foo',),
{'args' : ('foo',)}),
(BaseException, ('foo', 1),
{'args' : ('foo', 1)}),
(SystemExit, ('foo',),
{'args' : ('foo',), 'code' : 'foo'}),
(OSError, ('foo',),
{'args' : ('foo',), 'filename' : None, 'filename2' : None,
'errno' : None, 'strerror' : None}),
(OSError, ('foo', 'bar'),
{'args' : ('foo', 'bar'),
'filename' : None, 'filename2' : None,
'errno' : 'foo', 'strerror' : 'bar'}),
(OSError, ('foo', 'bar', 'baz'),
{'args' : ('foo', 'bar'),
'filename' : 'baz', 'filename2' : None,
'errno' : 'foo', 'strerror' : 'bar'}),
(OSError, ('foo', 'bar', 'baz', None, 'quux'),
{'args' : ('foo', 'bar'), 'filename' : 'baz', 'filename2': 'quux'}),
(OSError, ('errnoStr', 'strErrorStr', 'filenameStr'),
{'args' : ('errnoStr', 'strErrorStr'),
'strerror' : 'strErrorStr', 'errno' : 'errnoStr',
'filename' : 'filenameStr'}),
(OSError, (1, 'strErrorStr', 'filenameStr'),
{'args' : (1, 'strErrorStr'), 'errno' : 1,
'strerror' : 'strErrorStr',
'filename' : 'filenameStr', 'filename2' : None}),
(SyntaxError, (), {'msg' : None, 'text' : None,
'filename' : None, 'lineno' : None, 'offset' : None,
'print_file_and_line' : None}),
(SyntaxError, ('msgStr',),
{'args' : ('msgStr',), 'text' : None,
'print_file_and_line' : None, 'msg' : 'msgStr',
'filename' : None, 'lineno' : None, 'offset' : None}),
(SyntaxError, ('msgStr', ('filenameStr', 'linenoStr', 'offsetStr',
'textStr')),
{'offset' : 'offsetStr', 'text' : 'textStr',
'args' : ('msgStr', ('filenameStr', 'linenoStr',
'offsetStr', 'textStr')),
'print_file_and_line' : None, 'msg' : 'msgStr',
'filename' : 'filenameStr', 'lineno' : 'linenoStr'}),
(SyntaxError, ('msgStr', 'filenameStr', 'linenoStr', 'offsetStr',
'textStr', 'print_file_and_lineStr'),
{'text' : None,
'args' : ('msgStr', 'filenameStr', 'linenoStr', 'offsetStr',
'textStr', 'print_file_and_lineStr'),
'print_file_and_line' : None, 'msg' : 'msgStr',
'filename' : None, 'lineno' : None, 'offset' : None}),
(UnicodeError, (), {'args' : (),}),
(UnicodeEncodeError, ('ascii', 'a', 0, 1,
'ordinal not in range'),
{'args' : ('ascii', 'a', 0, 1,
'ordinal not in range'),
'encoding' : 'ascii', 'object' : 'a',
'start' : 0, 'reason' : 'ordinal not in range'}),
(UnicodeDecodeError, ('ascii', bytearray(b'\xff'), 0, 1,
'ordinal not in range'),
{'args' : ('ascii', bytearray(b'\xff'), 0, 1,
'ordinal not in range'),
'encoding' : 'ascii', 'object' : b'\xff',
'start' : 0, 'reason' : 'ordinal not in range'}),
(UnicodeDecodeError, ('ascii', b'\xff', 0, 1,
'ordinal not in range'),
{'args' : ('ascii', b'\xff', 0, 1,
'ordinal not in range'),
'encoding' : 'ascii', 'object' : b'\xff',
'start' : 0, 'reason' : 'ordinal not in range'}),
(UnicodeTranslateError, ("\u3042", 0, 1, "ouch"),
{'args' : ('\u3042', 0, 1, 'ouch'),
'object' : '\u3042', 'reason' : 'ouch',
'start' : 0, 'end' : 1}),
(NaiveException, ('foo',),
{'args': ('foo',), 'x': 'foo'}),
(SlottedNaiveException, ('foo',),
{'args': ('foo',), 'x': 'foo'}),
]
try:
# More tests are in test_WindowsError
exceptionList.append(
(WindowsError, (1, 'strErrorStr', 'filenameStr'),
{'args' : (1, 'strErrorStr'),
'strerror' : 'strErrorStr', 'winerror' : None,
'errno' : 1,
'filename' : 'filenameStr', 'filename2' : None})
)
except NameError:
pass
for exc, args, expected in exceptionList:
try:
e = exc(*args)
except:
print("\nexc=%r, args=%r" % (exc, args), file=sys.stderr)
raise
else:
# Verify module name
if not type(e).__name__.endswith('NaiveException'):
self.assertEqual(type(e).__module__, 'builtins')
# Verify no ref leaks in Exc_str()
s = str(e)
for checkArgName in expected:
value = getattr(e, checkArgName)
self.assertEqual(repr(value),
repr(expected[checkArgName]),
'%r.%s == %r, expected %r' % (
e, checkArgName,
value, expected[checkArgName]))
# test for pickling support
for p in [pickle]:
for protocol in range(p.HIGHEST_PROTOCOL + 1):
s = p.dumps(e, protocol)
new = p.loads(s)
for checkArgName in expected:
got = repr(getattr(new, checkArgName))
want = repr(expected[checkArgName])
self.assertEqual(got, want,
'pickled "%r", attribute "%s' %
(e, checkArgName))
def testWithTraceback(self):
try:
raise IndexError(4)
except:
tb = sys.exc_info()[2]
e = BaseException().with_traceback(tb)
self.assertIsInstance(e, BaseException)
self.assertEqual(e.__traceback__, tb)
e = IndexError(5).with_traceback(tb)
self.assertIsInstance(e, IndexError)
self.assertEqual(e.__traceback__, tb)
class MyException(Exception):
pass
e = MyException().with_traceback(tb)
self.assertIsInstance(e, MyException)
self.assertEqual(e.__traceback__, tb)
def testInvalidTraceback(self):
try:
Exception().__traceback__ = 5
except TypeError as e:
self.assertIn("__traceback__ must be a traceback", str(e))
else:
self.fail("No exception raised")
def testInvalidAttrs(self):
self.assertRaises(TypeError, setattr, Exception(), '__cause__', 1)
self.assertRaises(TypeError, delattr, Exception(), '__cause__')
self.assertRaises(TypeError, setattr, Exception(), '__context__', 1)
self.assertRaises(TypeError, delattr, Exception(), '__context__')
def testNoneClearsTracebackAttr(self):
try:
raise IndexError(4)
except:
tb = sys.exc_info()[2]
e = Exception()
e.__traceback__ = tb
e.__traceback__ = None
self.assertEqual(e.__traceback__, None)
def testChainingAttrs(self):
e = Exception()
self.assertIsNone(e.__context__)
self.assertIsNone(e.__cause__)
e = TypeError()
self.assertIsNone(e.__context__)
self.assertIsNone(e.__cause__)
class MyException(OSError):
pass
e = MyException()
self.assertIsNone(e.__context__)
self.assertIsNone(e.__cause__)
def testChainingDescriptors(self):
try:
raise Exception()
except Exception as exc:
e = exc
self.assertIsNone(e.__context__)
self.assertIsNone(e.__cause__)
self.assertFalse(e.__suppress_context__)
e.__context__ = NameError()
e.__cause__ = None
self.assertIsInstance(e.__context__, NameError)
self.assertIsNone(e.__cause__)
self.assertTrue(e.__suppress_context__)
e.__suppress_context__ = False
self.assertFalse(e.__suppress_context__)
def testKeywordArgs(self):
# test that builtin exception don't take keyword args,
# but user-defined subclasses can if they want
self.assertRaises(TypeError, BaseException, a=1)
class DerivedException(BaseException):
def __init__(self, fancy_arg):
BaseException.__init__(self)
self.fancy_arg = fancy_arg
x = DerivedException(fancy_arg=42)
self.assertEqual(x.fancy_arg, 42)
@no_tracing
def testInfiniteRecursion(self):
def f():
return f()
self.assertRaises(RecursionError, f)
def g():
try:
return g()
except ValueError:
return -1
self.assertRaises(RecursionError, g)
def test_str(self):
# Make sure both instances and classes have a str representation.
self.assertTrue(str(Exception))
self.assertTrue(str(Exception('a')))
self.assertTrue(str(Exception('a', 'b')))
def test_exception_cleanup_names(self):
# Make sure the local variable bound to the exception instance by
# an "except" statement is only visible inside the except block.
try:
raise Exception()
except Exception as e:
self.assertIsInstance(e, Exception)
self.assertNotIn('e', locals())
with self.assertRaises(UnboundLocalError):
e
def test_exception_cleanup_names2(self):
# Make sure the cleanup doesn't break if the variable is explicitly deleted.
try:
raise Exception()
except Exception as e:
self.assertIsInstance(e, Exception)
del e
self.assertNotIn('e', locals())
with self.assertRaises(UnboundLocalError):
e
def testExceptionCleanupState(self):
# Make sure exception state is cleaned up as soon as the except
# block is left. See #2507
class MyException(Exception):
def __init__(self, obj):
self.obj = obj
class MyObj:
pass
def inner_raising_func():
# Create some references in exception value and traceback
local_ref = obj
raise MyException(obj)
# Qualified "except" with "as"
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except MyException as e:
pass
obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
# Qualified "except" without "as"
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except MyException:
pass
obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
# Bare "except"
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except:
pass
obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
# "except" with premature block leave
obj = MyObj()
wr = weakref.ref(obj)
for i in [0]:
try:
inner_raising_func()
except:
break
obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
# "except" block raising another exception
obj = MyObj()
wr = weakref.ref(obj)
try:
try:
inner_raising_func()
except:
raise KeyError
except KeyError as e:
# We want to test that the except block above got rid of
# the exception raised in inner_raising_func(), but it
# also ends up in the __context__ of the KeyError, so we
# must clear the latter manually for our test to succeed.
e.__context__ = None
obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
# guarantee no ref cycles on CPython (don't gc_collect)
if check_impl_detail(cpython=False):
gc_collect()
self.assertIsNone(obj)
# Some complicated construct
obj = MyObj()
wr = weakref.ref(obj)
try:
inner_raising_func()
except MyException:
try:
try:
raise
finally:
raise
except MyException:
pass
obj = None
if check_impl_detail(cpython=False):
gc_collect()
obj = wr()
self.assertIsNone(obj)
# Inside an exception-silencing "with" block
class Context:
def __enter__(self):
return self
def __exit__ (self, exc_type, exc_value, exc_tb):
return True
obj = MyObj()
wr = weakref.ref(obj)
with Context():
inner_raising_func()
obj = None
if check_impl_detail(cpython=False):
gc_collect()
obj = wr()
self.assertIsNone(obj)
def test_exception_target_in_nested_scope(self):
# issue 4617: This used to raise a SyntaxError
# "can not delete variable 'e' referenced in nested scope"
def print_error():
e
try:
something
except Exception as e:
print_error()
# implicit "del e" here
def test_generator_leaking(self):
# Test that generator exception state doesn't leak into the calling
# frame
def yield_raise():
try:
raise KeyError("caught")
except KeyError:
yield sys.exc_info()[0]
yield sys.exc_info()[0]
yield sys.exc_info()[0]
g = yield_raise()
self.assertEqual(next(g), KeyError)
self.assertEqual(sys.exc_info()[0], None)
self.assertEqual(next(g), KeyError)
self.assertEqual(sys.exc_info()[0], None)
self.assertEqual(next(g), None)
# Same test, but inside an exception handler
try:
raise TypeError("foo")
except TypeError:
g = yield_raise()
self.assertEqual(next(g), KeyError)
self.assertEqual(sys.exc_info()[0], TypeError)
self.assertEqual(next(g), KeyError)
self.assertEqual(sys.exc_info()[0], TypeError)
self.assertEqual(next(g), TypeError)
del g
self.assertEqual(sys.exc_info()[0], TypeError)
def test_generator_leaking2(self):
# See issue 12475.
def g():
yield
try:
raise RuntimeError
except RuntimeError:
it = g()
next(it)
try:
next(it)
except StopIteration:
pass
self.assertEqual(sys.exc_info(), (None, None, None))
def test_generator_leaking3(self):
# See issue #23353. When gen.throw() is called, the caller's
# exception state should be save and restored.
def g():
try:
yield
except ZeroDivisionError:
yield sys.exc_info()[1]
it = g()
next(it)
try:
1/0
except ZeroDivisionError as e:
self.assertIs(sys.exc_info()[1], e)
gen_exc = it.throw(e)
self.assertIs(sys.exc_info()[1], e)
self.assertIs(gen_exc, e)
self.assertEqual(sys.exc_info(), (None, None, None))
def test_generator_leaking4(self):
# See issue #23353. When an exception is raised by a generator,
# the caller's exception state should still be restored.
def g():
try:
1/0
except ZeroDivisionError:
yield sys.exc_info()[0]
raise
it = g()
try:
raise TypeError
except TypeError:
# The caller's exception state (TypeError) is temporarily
# saved in the generator.
tp = next(it)
self.assertIs(tp, ZeroDivisionError)
try:
next(it)
# We can't check it immediately, but while next() returns
# with an exception, it shouldn't have restored the old
# exception state (TypeError).
except ZeroDivisionError as e:
self.assertIs(sys.exc_info()[1], e)
# We used to find TypeError here.
self.assertEqual(sys.exc_info(), (None, None, None))
def test_generator_doesnt_retain_old_exc(self):
def g():
self.assertIsInstance(sys.exc_info()[1], RuntimeError)
yield
self.assertEqual(sys.exc_info(), (None, None, None))
it = g()
try:
raise RuntimeError
except RuntimeError:
next(it)
self.assertRaises(StopIteration, next, it)
def test_generator_finalizing_and_exc_info(self):
# See #7173
def simple_gen():
yield 1
def run_gen():
gen = simple_gen()
try:
raise RuntimeError
except RuntimeError:
return next(gen)
run_gen()
gc_collect()
self.assertEqual(sys.exc_info(), (None, None, None))
def _check_generator_cleanup_exc_state(self, testfunc):
# Issue #12791: exception state is cleaned up as soon as a generator
# is closed (reference cycles are broken).
class MyException(Exception):
def __init__(self, obj):
self.obj = obj
class MyObj:
pass
def raising_gen():
try:
raise MyException(obj)
except MyException:
yield
obj = MyObj()
wr = weakref.ref(obj)
g = raising_gen()
next(g)
testfunc(g)
g = obj = None
gc_collect() # For PyPy or other GCs.
obj = wr()
self.assertIsNone(obj)
def test_generator_throw_cleanup_exc_state(self):
def do_throw(g):
try:
g.throw(RuntimeError())
except RuntimeError:
pass
self._check_generator_cleanup_exc_state(do_throw)
def test_generator_close_cleanup_exc_state(self):
def do_close(g):
g.close()
self._check_generator_cleanup_exc_state(do_close)
def test_generator_del_cleanup_exc_state(self):
def do_del(g):
g = None
self._check_generator_cleanup_exc_state(do_del)
def test_generator_next_cleanup_exc_state(self):
def do_next(g):
try:
next(g)
except StopIteration:
pass
else:
self.fail("should have raised StopIteration")
self._check_generator_cleanup_exc_state(do_next)
def test_generator_send_cleanup_exc_state(self):
def do_send(g):
try:
g.send(None)
except StopIteration:
pass
else:
self.fail("should have raised StopIteration")
self._check_generator_cleanup_exc_state(do_send)
def test_3114(self):
# Bug #3114: in its destructor, MyObject retrieves a pointer to
# obsolete and/or deallocated objects.
class MyObject:
def __del__(self):
nonlocal e
e = sys.exc_info()
e = ()
try:
raise Exception(MyObject())
except:
pass
gc_collect() # For PyPy or other GCs.
self.assertEqual(e, (None, None, None))
def test_raise_does_not_create_context_chain_cycle(self):
class A(Exception):
pass
class B(Exception):
pass
class C(Exception):
pass
# Create a context chain:
# C -> B -> A
# Then raise A in context of C.
try:
try:
raise A
except A as a_:
a = a_
try:
raise B
except B as b_:
b = b_
try:
raise C
except C as c_:
c = c_
self.assertIsInstance(a, A)
self.assertIsInstance(b, B)
self.assertIsInstance(c, C)
self.assertIsNone(a.__context__)
self.assertIs(b.__context__, a)
self.assertIs(c.__context__, b)
raise a
except A as e:
exc = e
# Expect A -> C -> B, without cycle
self.assertIs(exc, a)
self.assertIs(a.__context__, c)
self.assertIs(c.__context__, b)
self.assertIsNone(b.__context__)
def test_no_hang_on_context_chain_cycle1(self):
# See issue 25782. Cycle in context chain.
def cycle():
try:
raise ValueError(1)
except ValueError as ex:
ex.__context__ = ex
raise TypeError(2)
try:
cycle()
except Exception as e:
exc = e
self.assertIsInstance(exc, TypeError)
self.assertIsInstance(exc.__context__, ValueError)
self.assertIs(exc.__context__.__context__, exc.__context__)
def test_no_hang_on_context_chain_cycle2(self):
# See issue 25782. Cycle at head of context chain.
class A(Exception):
pass
class B(Exception):
pass
class C(Exception):
pass
# Context cycle:
# +-----------+
# V |
# C --> B --> A
with self.assertRaises(C) as cm:
try:
raise A()
except A as _a:
a = _a
try:
raise B()
except B as _b:
b = _b
try:
raise C()
except C as _c:
c = _c
a.__context__ = c
raise c
self.assertIs(cm.exception, c)
# Verify the expected context chain cycle
self.assertIs(c.__context__, b)
self.assertIs(b.__context__, a)
self.assertIs(a.__context__, c)
def test_no_hang_on_context_chain_cycle3(self):
# See issue 25782. Longer context chain with cycle.
class A(Exception):
pass
class B(Exception):
pass
class C(Exception):
pass
class D(Exception):
pass
class E(Exception):
pass
# Context cycle:
# +-----------+
# V |
# E --> D --> C --> B --> A
with self.assertRaises(E) as cm:
try:
raise A()
except A as _a:
a = _a
try:
raise B()
except B as _b:
b = _b
try:
raise C()
except C as _c:
c = _c
a.__context__ = c
try:
raise D()
except D as _d:
d = _d
e = E()
raise e
self.assertIs(cm.exception, e)
# Verify the expected context chain cycle
self.assertIs(e.__context__, d)
self.assertIs(d.__context__, c)
self.assertIs(c.__context__, b)
self.assertIs(b.__context__, a)
self.assertIs(a.__context__, c)
def test_unicode_change_attributes(self):
# See issue 7309. This was a crasher.
u = UnicodeEncodeError('baz', 'xxxxx', 1, 5, 'foo')
self.assertEqual(str(u), "'baz' codec can't encode characters in position 1-4: foo")
u.end = 2
self.assertEqual(str(u), "'baz' codec can't encode character '\\x78' in position 1: foo")
u.end = 5
u.reason = 0x345345345345345345
self.assertEqual(str(u), "'baz' codec can't encode characters in position 1-4: 965230951443685724997")
u.encoding = 4000
self.assertEqual(str(u), "'4000' codec can't encode characters in position 1-4: 965230951443685724997")
u.start = 1000
self.assertEqual(str(u), "'4000' codec can't encode characters in position 1000-4: 965230951443685724997")
u = UnicodeDecodeError('baz', b'xxxxx', 1, 5, 'foo')
self.assertEqual(str(u), "'baz' codec can't decode bytes in position 1-4: foo")
u.end = 2
self.assertEqual(str(u), "'baz' codec can't decode byte 0x78 in position 1: foo")
u.end = 5
u.reason = 0x345345345345345345
self.assertEqual(str(u), "'baz' codec can't decode bytes in position 1-4: 965230951443685724997")
u.encoding = 4000
self.assertEqual(str(u), "'4000' codec can't decode bytes in position 1-4: 965230951443685724997")
u.start = 1000
self.assertEqual(str(u), "'4000' codec can't decode bytes in position 1000-4: 965230951443685724997")
u = UnicodeTranslateError('xxxx', 1, 5, 'foo')
self.assertEqual(str(u), "can't translate characters in position 1-4: foo")
u.end = 2
self.assertEqual(str(u), "can't translate character '\\x78' in position 1: foo")
u.end = 5
u.reason = 0x345345345345345345
self.assertEqual(str(u), "can't translate characters in position 1-4: 965230951443685724997")
u.start = 1000
self.assertEqual(str(u), "can't translate characters in position 1000-4: 965230951443685724997")
def test_unicode_errors_no_object(self):
# See issue #21134.
klasses = UnicodeEncodeError, UnicodeDecodeError, UnicodeTranslateError
for klass in klasses:
self.assertEqual(str(klass.__new__(klass)), "")
@no_tracing
def test_badisinstance(self):
# Bug #2542: if issubclass(e, MyException) raises an exception,
# it should be ignored
class Meta(type):
def __subclasscheck__(cls, subclass):
raise ValueError()
class MyException(Exception, metaclass=Meta):
pass
with captured_stderr() as stderr:
try:
raise KeyError()
except MyException as e:
self.fail("exception should not be a MyException")
except KeyError:
pass
except:
self.fail("Should have raised KeyError")
else:
self.fail("Should have raised KeyError")
def g():
try:
return g()
except RecursionError:
return sys.exc_info()
e, v, tb = g()
self.assertIsInstance(v, RecursionError, type(v))
self.assertIn("maximum recursion depth exceeded", str(v))
@cpython_only
def test_trashcan_recursion(self):
# See bpo-33930
def foo():
o = object()
for x in range(1_000_000):
# Create a big chain of method objects that will trigger
# a deep chain of calls when they need to be destructed.
o = o.__dir__
foo()
support.gc_collect()
@cpython_only
def test_recursion_normalizing_exception(self):
# Issue #22898.
# Test that a RecursionError is raised when tstate->recursion_depth is
# equal to recursion_limit in PyErr_NormalizeException() and check
# that a ResourceWarning is printed.
# Prior to #22898, the recursivity of PyErr_NormalizeException() was
# controlled by tstate->recursion_depth and a PyExc_RecursionErrorInst
# singleton was being used in that case, that held traceback data and
# locals indefinitely and would cause a segfault in _PyExc_Fini() upon
# finalization of these locals.
code = """if 1:
import sys
from _testinternalcapi import get_recursion_depth
class MyException(Exception): pass
def setrecursionlimit(depth):
while 1:
try:
sys.setrecursionlimit(depth)
return depth
except RecursionError:
# sys.setrecursionlimit() raises a RecursionError if
# the new recursion limit is too low (issue #25274).
depth += 1
def recurse(cnt):
cnt -= 1
if cnt:
recurse(cnt)
else:
generator.throw(MyException)
def gen():
f = open(%a, mode='rb', buffering=0)
yield
generator = gen()
next(generator)
recursionlimit = sys.getrecursionlimit()
depth = get_recursion_depth()
try:
# Upon the last recursive invocation of recurse(),
# tstate->recursion_depth is equal to (recursion_limit - 1)
# and is equal to recursion_limit when _gen_throw() calls
# PyErr_NormalizeException().
recurse(setrecursionlimit(depth + 2) - depth)
finally:
sys.setrecursionlimit(recursionlimit)
print('Done.')
""" % __file__
rc, out, err = script_helper.assert_python_failure("-Wd", "-c", code)
# Check that the program does not fail with SIGABRT.
self.assertEqual(rc, 1)
self.assertIn(b'RecursionError', err)
self.assertIn(b'ResourceWarning', err)
self.assertIn(b'Done.', out)
@cpython_only
def test_recursion_normalizing_infinite_exception(self):
# Issue #30697. Test that a RecursionError is raised when
# PyErr_NormalizeException() maximum recursion depth has been
# exceeded.
code = """if 1:
import _testcapi
try:
raise _testcapi.RecursingInfinitelyError
finally:
print('Done.')
"""
rc, out, err = script_helper.assert_python_failure("-c", code)
self.assertEqual(rc, 1)
self.assertIn(b'RecursionError: maximum recursion depth exceeded '
b'while normalizing an exception', err)
self.assertIn(b'Done.', out)
def test_recursion_in_except_handler(self):
def set_relative_recursion_limit(n):
depth = 1
while True:
try:
sys.setrecursionlimit(depth)
except RecursionError:
depth += 1
else:
break
sys.setrecursionlimit(depth+n)
def recurse_in_except():
try:
1/0
except:
recurse_in_except()
def recurse_after_except():
try:
1/0
except:
pass
recurse_after_except()
def recurse_in_body_and_except():
try:
recurse_in_body_and_except()
except:
recurse_in_body_and_except()
recursionlimit = sys.getrecursionlimit()
try:
set_relative_recursion_limit(10)
for func in (recurse_in_except, recurse_after_except, recurse_in_body_and_except):
with self.subTest(func=func):
try:
func()
except RecursionError:
pass
else:
self.fail("Should have raised a RecursionError")
finally:
sys.setrecursionlimit(recursionlimit)
@cpython_only
def test_recursion_normalizing_with_no_memory(self):
# Issue #30697. Test that in the abort that occurs when there is no
# memory left and the size of the Python frames stack is greater than
# the size of the list of preallocated MemoryError instances, the
# Fatal Python error message mentions MemoryError.
code = """if 1:
import _testcapi
class C(): pass
def recurse(cnt):
cnt -= 1
if cnt:
recurse(cnt)
else:
_testcapi.set_nomemory(0)
C()
recurse(16)
"""
with SuppressCrashReport():
rc, out, err = script_helper.assert_python_failure("-c", code)
self.assertIn(b'Fatal Python error: _PyErr_NormalizeException: '
b'Cannot recover from MemoryErrors while '
b'normalizing exceptions.', err)
@cpython_only
def test_MemoryError(self):
# PyErr_NoMemory always raises the same exception instance.
# Check that the traceback is not doubled.
import traceback
from _testcapi import raise_memoryerror
def raiseMemError():
try:
raise_memoryerror()
except MemoryError as e:
tb = e.__traceback__
else:
self.fail("Should have raises a MemoryError")
return traceback.format_tb(tb)
tb1 = raiseMemError()
tb2 = raiseMemError()
self.assertEqual(tb1, tb2)
@cpython_only
def test_exception_with_doc(self):
import _testcapi
doc2 = "This is a test docstring."
doc4 = "This is another test docstring."
self.assertRaises(SystemError, _testcapi.make_exception_with_doc,
"error1")
# test basic usage of PyErr_NewException
error1 = _testcapi.make_exception_with_doc("_testcapi.error1")
self.assertIs(type(error1), type)
self.assertTrue(issubclass(error1, Exception))
self.assertIsNone(error1.__doc__)
# test with given docstring
error2 = _testcapi.make_exception_with_doc("_testcapi.error2", doc2)
self.assertEqual(error2.__doc__, doc2)
# test with explicit base (without docstring)
error3 = _testcapi.make_exception_with_doc("_testcapi.error3",
base=error2)
self.assertTrue(issubclass(error3, error2))
# test with explicit base tuple
class C(object):
pass
error4 = _testcapi.make_exception_with_doc("_testcapi.error4", doc4,
(error3, C))
self.assertTrue(issubclass(error4, error3))
self.assertTrue(issubclass(error4, C))
self.assertEqual(error4.__doc__, doc4)
# test with explicit dictionary
error5 = _testcapi.make_exception_with_doc("_testcapi.error5", "",
error4, {'a': 1})
self.assertTrue(issubclass(error5, error4))
self.assertEqual(error5.a, 1)
self.assertEqual(error5.__doc__, "")
@cpython_only
def test_memory_error_cleanup(self):
# Issue #5437: preallocated MemoryError instances should not keep
# traceback objects alive.
from _testcapi import raise_memoryerror
class C:
pass
wr = None
def inner():
nonlocal wr
c = C()
wr = weakref.ref(c)
raise_memoryerror()
# We cannot use assertRaises since it manually deletes the traceback
try:
inner()
except MemoryError as e:
self.assertNotEqual(wr(), None)
else:
self.fail("MemoryError not raised")
gc_collect() # For PyPy or other GCs.
self.assertEqual(wr(), None)
@no_tracing
def test_recursion_error_cleanup(self):
# Same test as above, but with "recursion exceeded" errors
class C:
pass
wr = None
def inner():
nonlocal wr
c = C()
wr = weakref.ref(c)
inner()
# We cannot use assertRaises since it manually deletes the traceback
try:
inner()
except RecursionError as e:
self.assertNotEqual(wr(), None)
else:
self.fail("RecursionError not raised")
gc_collect() # For PyPy or other GCs.
self.assertEqual(wr(), None)
def test_errno_ENOTDIR(self):
# Issue #12802: "not a directory" errors are ENOTDIR even on Windows
with self.assertRaises(OSError) as cm:
os.listdir(__file__)
self.assertEqual(cm.exception.errno, errno.ENOTDIR, cm.exception)
def test_unraisable(self):
# Issue #22836: PyErr_WriteUnraisable() should give sensible reports
class BrokenDel:
def __del__(self):
exc = ValueError("del is broken")
# The following line is included in the traceback report:
raise exc
obj = BrokenDel()
with support.catch_unraisable_exception() as cm:
del obj
gc_collect() # For PyPy or other GCs.
self.assertEqual(cm.unraisable.object, BrokenDel.__del__)
self.assertIsNotNone(cm.unraisable.exc_traceback)
def test_unhandled(self):
# Check for sensible reporting of unhandled exceptions
for exc_type in (ValueError, BrokenStrException):
with self.subTest(exc_type):
try:
exc = exc_type("test message")
# The following line is included in the traceback report:
raise exc
except exc_type:
with captured_stderr() as stderr:
sys.__excepthook__(*sys.exc_info())
report = stderr.getvalue()
self.assertIn("test_exceptions.py", report)
self.assertIn("raise exc", report)
self.assertIn(exc_type.__name__, report)
if exc_type is BrokenStrException:
self.assertIn("<exception str() failed>", report)
else:
self.assertIn("test message", report)
self.assertTrue(report.endswith("\n"))
@cpython_only
def test_memory_error_in_PyErr_PrintEx(self):
code = """if 1:
import _testcapi
class C(): pass
_testcapi.set_nomemory(0, %d)
C()
"""
# Issue #30817: Abort in PyErr_PrintEx() when no memory.
# Span a large range of tests as the CPython code always evolves with
# changes that add or remove memory allocations.
for i in range(1, 20):
rc, out, err = script_helper.assert_python_failure("-c", code % i)
self.assertIn(rc, (1, 120))
self.assertIn(b'MemoryError', err)
def test_yield_in_nested_try_excepts(self):
#Issue #25612
class MainError(Exception):
pass
class SubError(Exception):
pass
def main():
try:
raise MainError()
except MainError:
try:
yield
except SubError:
pass
raise
coro = main()
coro.send(None)
with self.assertRaises(MainError):
coro.throw(SubError())
def test_generator_doesnt_retain_old_exc2(self):
#Issue 28884#msg282532
def g():
try:
raise ValueError
except ValueError:
yield 1
self.assertEqual(sys.exc_info(), (None, None, None))
yield 2
gen = g()
try:
raise IndexError
except IndexError:
self.assertEqual(next(gen), 1)
self.assertEqual(next(gen), 2)
def test_raise_in_generator(self):
#Issue 25612#msg304117
def g():
yield 1
raise
yield 2
with self.assertRaises(ZeroDivisionError):
i = g()
try:
1/0
except:
next(i)
next(i)
@unittest.skipUnless(__debug__, "Won't work if __debug__ is False")
def test_assert_shadowing(self):
# Shadowing AssertionError would cause the assert statement to
# misbehave.
global AssertionError
AssertionError = TypeError
try:
assert False, 'hello'
except BaseException as e:
del AssertionError
self.assertIsInstance(e, AssertionError)
self.assertEqual(str(e), 'hello')
else:
del AssertionError
self.fail('Expected exception')
def test_memory_error_subclasses(self):
# bpo-41654: MemoryError instances use a freelist of objects that are
# linked using the 'dict' attribute when they are inactive/dead.
# Subclasses of MemoryError should not participate in the freelist
# schema. This test creates a MemoryError object and keeps it alive
# (therefore advancing the freelist) and then it creates and destroys a
# subclass object. Finally, it checks that creating a new MemoryError
# succeeds, proving that the freelist is not corrupted.
class TestException(MemoryError):
pass
try:
raise MemoryError
except MemoryError as exc:
inst = exc
try:
raise TestException
except Exception:
pass
for _ in range(10):
try:
raise MemoryError
except MemoryError as exc:
pass
gc_collect()
class ImportErrorTests(unittest.TestCase):
def test_attributes(self):
# Setting 'name' and 'path' should not be a problem.
exc = ImportError('test')
self.assertIsNone(exc.name)
self.assertIsNone(exc.path)
exc = ImportError('test', name='somemodule')
self.assertEqual(exc.name, 'somemodule')
self.assertIsNone(exc.path)
exc = ImportError('test', path='somepath')
self.assertEqual(exc.path, 'somepath')
self.assertIsNone(exc.name)
exc = ImportError('test', path='somepath', name='somename')
self.assertEqual(exc.name, 'somename')
self.assertEqual(exc.path, 'somepath')
msg = "'invalid' is an invalid keyword argument for ImportError"
with self.assertRaisesRegex(TypeError, msg):
ImportError('test', invalid='keyword')
with self.assertRaisesRegex(TypeError, msg):
ImportError('test', name='name', invalid='keyword')
with self.assertRaisesRegex(TypeError, msg):
ImportError('test', path='path', invalid='keyword')
with self.assertRaisesRegex(TypeError, msg):
ImportError(invalid='keyword')
with self.assertRaisesRegex(TypeError, msg):
ImportError('test', invalid='keyword', another=True)
def test_reset_attributes(self):
exc = ImportError('test', name='name', path='path')
self.assertEqual(exc.args, ('test',))
self.assertEqual(exc.msg, 'test')
self.assertEqual(exc.name, 'name')
self.assertEqual(exc.path, 'path')
# Reset not specified attributes
exc.__init__()
self.assertEqual(exc.args, ())
self.assertEqual(exc.msg, None)
self.assertEqual(exc.name, None)
self.assertEqual(exc.path, None)
def test_non_str_argument(self):
# Issue #15778
with check_warnings(('', BytesWarning), quiet=True):
arg = b'abc'
exc = ImportError(arg)
self.assertEqual(str(arg), str(exc))
def test_copy_pickle(self):
for kwargs in (dict(),
dict(name='somename'),
dict(path='somepath'),
dict(name='somename', path='somepath')):
orig = ImportError('test', **kwargs)
for proto in range(pickle.HIGHEST_PROTOCOL + 1):
exc = pickle.loads(pickle.dumps(orig, proto))
self.assertEqual(exc.args, ('test',))
self.assertEqual(exc.msg, 'test')
self.assertEqual(exc.name, orig.name)
self.assertEqual(exc.path, orig.path)
for c in copy.copy, copy.deepcopy:
exc = c(orig)
self.assertEqual(exc.args, ('test',))
self.assertEqual(exc.msg, 'test')
self.assertEqual(exc.name, orig.name)
self.assertEqual(exc.path, orig.path)
if __name__ == '__main__':
unittest.main()