This is a verifier for the binary code used by the _sre module (this
is often called bytecode, though to distinguish it from Python bytecode
I put it in quotes).
I wrote this for Google App Engine, and am making the patch available as
open source under the Apache 2 license. Below are the copyright
statement and license, for completeness.
# Copyright 2008 Google Inc.
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.
It's not necessary to include these copyrights and bytecode in the
source file. Google has signed a contributor's agreement with the PSF
already.
If a PyTokenizer_FromString() is called with an empty string, the
tokenizer's line_start member never gets initialized. Later, it is
compared with the token pointer 'a' in parsetok.c:193 and that behavior
can result in undefined behavior.
long raise ValueError instead of returning 0. Also, change the error
message for conversion of an infinity to an integer, replacing 'long' by
'integer', so that it's appropriate for both long(float('inf')) and
int(float('inf')).
key list data structure in the thread startup path.
This change is a companion to r60148 which already successfully dealt with a
similar issue on thread shutdown.
In particular this loop has been observed happening from this call path:
#0 in find_key ()
#1 in PyThread_set_key_value ()
#2 in _PyGILState_NoteThreadState ()
#3 in PyThreadState_New ()
#4 in t_bootstrap ()
#5 in pthread_start_thread ()
I don't know how this happens but it does, *very* rarely. On more than
one hardware platform. I have not been able to reproduce it manually.
(A flaky mutex implementation on the system in question is one hypothesis).
As with r60148, the spinning we managed to observe in the wild was due to a
single list element pointing back upon itself.
Guido van Rossum
Antoine Pitrou
Andrew M. Kuchling
Brett Cannon
Mark Dickinson
Georg Brandl
Gregory P. Smith
Nick Coghlan