python / cpython

…19688)

Deprecate lib2to3 module in light of PEP 617.

We anticipate removal in the 3.12 timeframe.

Previously every test was building an extension module and
loading it into sys.modules. The tearDown function was thus
not able to clean up correctly, resulting in memory leaks.

With this commit, every test function now builds the extension
module and runs the actual test code in a new process
(using assert_python_ok), so that sys.modules stays intact
and no memory gets leaked.

Optimize the subprocess module on FreeBSD using closefrom().
A single close(fd) syscall is cheap, but when sysconf(_SC_OPEN_MAX)
is high, the loop calling close(fd) on each file descriptor can take
several milliseconds.

The workaround on FreeBSD to improve performance was to load and
mount the fdescfs kernel module, but this is not enabled by default.

Initial patch by Ed Maste (emaste), Conrad Meyer (cem), Kyle Evans
(kevans) and Kubilay Kocak (koobs):
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242274

On FreeBSD, os.closerange(fd_low, fd_high) now calls
closefrom(fd_low) if fd_high is greater than or equal to
sysconf(_SC_OPEN_MAX).

Initial patch by Ed Maste (emaste), Conrad Meyer (cem), Kyle Evans
(kevans) and Kubilay Kocak (koobs):
https://bugs.freebsd.org/bugzilla/show_bug.cgi?id=242274

If _PyCode_InitOpcache() fails in _PyEval_EvalFrameDefault(), use
"goto exit_eval_frame;" rather than "return NULL;" to exit the
function in a consistent state. For example, tstate->frame is now
reset properly.

We should use `$(MKDIR_P) <directory>`, not `$(MKDIR_P) -p <directory>`.

This is invoked by mypy, using ast.parse(source, "<func_type>", "func_type"). Since the new grammar doesn't yet support the func_type_input start symbol we must use the old compiler in this case to prevent a crash.

https://bugs.python.org/issue40334

Log "Warning -- ..." test warnings into sys.__stderr__ rather than
sys.stderr, to ensure to display them even if sys.stderr is captured.

test.libregrtest.utils.print_warning() now calls
test.support.print_warning().

…19679)

The changes in this commit are all related to @vstinner's original review comments of the initial PEP 617 implementation PR.

… in test_peg_generator (GH-19674)

Using `def` rather than `define` results in:

    Ambiguous command "def pu": define, define-prefix.

Automerge-Triggered-By: @csabella

)

* Rename PyConfig.use_peg to _use_peg_parser
* Document PyConfig._use_peg_parser and mark it a deprecated
* Mark -X oldparser option and PYTHONOLDPARSER env var as deprecated
  in the documentation.
* Add use_old_parser() and skip_if_new_parser() to test.support
* Remove sys.flags.use_peg: use_old_parser() uses
  _testinternalcapi.get_configs() instead.
* Enhance test_embed tests
* subprocess._args_from_interpreter_flags() copies -X oldparser

…oconf files (GH-19667)

Co-authored-by: Guido van Rossum <guido@python.org>
Co-authored-by: Lysandros Nikolaou <lisandrosnik@gmail.com>

Added str.removeprefix and str.removesuffix methods and corresponding
bytes, bytearray, and collections.UserString methods to remove affixes
from a string if present. See PEP 616 for a full description.

Because some people subclass this class and call undocumented methods, and we don't want to break them.

The constant values of future flags in the __future__ module
is updated in order to prevent collision with compiler flags.
Previously PyCF_ALLOW_TOP_LEVEL_AWAIT was clashing
with CO_FUTURE_DIVISION.

Fix the Windows implementation of os.waitpid() for exit code
larger than "INT_MAX >> 8". The exit status is now interpreted as an
unsigned number.

os.waitstatus_to_exitcode() now accepts wait status larger than
INT_MAX.

…-19650)

Previously, python.org macOS installers did not alter the Current version
symlink in /Library/Frameworks/Python.framework/Versions when installing
a version of Python 3.x, only when installing 2.x.  Now that Python 2 is
retired, it's time to change that.  This should make it a bit easier
to embed Python 3 into other macOS applications.

It is possible to use either '-isysroot /some/path' (with a space) or
'-isysroot/some/path' (no space in between). Support both forms in
places where special handling of -isysroot is done, rather than just
the first form.
Co-authored-by: Ned Deily <nad@python.org>