Historically, -m added the empty string as sys.path
zero, meaning it resolved imports against the current
working directory, the same way -c and the interactive
prompt do.
This changes the sys.path initialisation to add the
*starting* working directory as sys.path[0] instead,
such that changes to the working directory while the
program is running will have no effect on imports
when using the -m switch.
- new test case for pre-initialization of sys.warnoptions and sys._xoptions
- restored ability to call these APIs prior to Py_Initialize
- updated the docs for the affected APIs to make it clear they can be
called before Py_Initialize
- also enhanced the existing embedding test cases
to check for expected settings in the sys module
* Added new opcode END_ASYNC_FOR.
* Setting global StopAsyncIteration no longer breaks "async for" loops.
* Jumping into an "async for" loop is now disabled.
* Jumping out of an "async for" loop no longer corrupts the stack.
* Simplify the compiler.
fstat may block for long time if the file descriptor is on a
non-responsive NFS server, hanging all threads. Most fstat() calls are
handled by _Py_fstat(), releasing the GIL internally, but but
_Py_fstat_noraise() does not release the GIL, and most calls release the
GIL explicitly around it.
This patch fixes last 2 calls to _Py_fstat_no_raise(), avoiding hangs
when calling:
- mmap.mmap()
- os.urandom()
- random.seed()
Fix a crash on fork when using a custom memory allocator (ex: using
PYTHONMALLOC env var).
_PyGILState_Reinit() and _PyInterpreterState_Enable() now use the
default RAW memory allocator to allocate a new interpreters mutex on
fork.
The length in strncpy is one char too short and as a result it leads
to a build warning with gcc 8. Comment out the strncpy since the
interpreter aborts immediately after anyway.
When comprehensions switched to using a nested scope, the old
code for generating a temporary name to hold the accumulation
target became redundant, but was never actually removed.
Patch by Nitish Chandra.
The CPython runtime assumes that there is a one-to-one relationship (for a given interpreter) between PyThreadState and OS threads. Sending and receiving on a channel in the same interpreter was causing crashes because of this (specifically due to a check in PyThreadState_Swap()). The solution is to not switch threads if the interpreter is the same.
Fix a rare but potential pre-exec child process deadlock in subprocess on POSIX systems when marking file descriptors inheritable on exec in the child process. This bug appears to have been introduced in 3.4 with the inheritable file descriptors support.
This also changes Python/fileutils.c `set_inheritable` to use the "slow" two `fcntl` syscall path instead of the "fast" single `ioctl` syscall path when asked to be async signal safe (by way of being asked not to raise exceptions). `ioctl` is not a POSIX async-signal-safe approved function.
ref: http://pubs.opengroup.org/onlinepubs/9699919799/functions/V2_chap02.html
Clarify that the level argument is used to determine whether to
perform absolute or relative imports: 0 is absolute, while a positive number
is the number of parent directories to search relative to the current module.
When an unawaited coroutine is collected very late in shutdown --
like, during the final GC at the end of PyImport_Cleanup -- then it
was triggering an interpreter abort, because we'd try to look up the
"warnings" module and not only was it missing (we were prepared for
that), but the entire module system was missing (which we were not
prepared for).
I've tried to fix this at the source, by making the utility function
get_warnings_attr robust against this in general. Note that it already
has the convention that it can return NULL without setting an error,
which is how it signals that the attribute it was asked to fetch is
missing, and that all callers already check for NULL returns.
There's a similar check for being late in shutdown at the top of
warn_explicit, which might be unnecessary after this fix, but I'm not
sure so I'm going to leave it.
* Document `from __future__ import annotations`
* Provide plumbing and tests for `from __future__ import annotations`
* Implement unparsing the AST back to string form
This is required for PEP 563 and as such only implements a part of the
unparsing process that covers expressions.
Zackery Spytz
Brett Cannon
Marcel Plch
INADA Naoki
Serhiy Storchaka
Nick Coghlan
Xiang Zhang
Nir Soffer
Siddhesh Poyarekar
Victor Stinner
Thomas Nyberg
Nitish Chandra
Eric Snow
Alexey Izbyshev
Leo Arias
Barry Warsaw
oldk
Yury Selivanov
Dmitry Alimov
Stéphane Wirtel
Mark Shannon
Benjamin Peterson
Nathaniel J. Smith
Guido van Rossum