Merge branch 'main' into revive-138569

Author: ambv

Doc/library/argparse.rst

@@ -753,7 +753,7 @@ upper-cased name. For example::
 
    >>> parser = argparse.ArgumentParser(prog='PROG')
    >>> parser.add_argument('--foo-bar')
-   >>> parser.parse_args(['--foo-bar', 'FOO-BAR']
+   >>> parser.parse_args(['--foo-bar', 'FOO-BAR'])
    Namespace(foo_bar='FOO-BAR')
    >>> parser.print_help()
    usage:  [-h] [--foo-bar FOO-BAR]

Doc/library/email.message.rst

@@ -57,7 +57,7 @@ message objects.
    :class:`~email.policy.default` policy, which follows the rules of the email
    RFCs except for line endings (instead of the RFC mandated ``\r\n``, it uses
    the Python standard ``\n`` line endings).  For more information see the
-   :mod:`~email.policy` documentation.
+   :mod:`~email.policy` documentation. [2]_
 
    .. method:: as_string(unixfrom=False, maxheaderlen=None, policy=None)
 
@@ -749,3 +749,9 @@ message objects.
 .. [1] Originally added in 3.4 as a :term:`provisional module <provisional
        package>`.  Docs for legacy message class moved to
        :ref:`compat32_message`.
+
+.. [2] The :class:`EmailMessage` class requires a policy that provides a
+       ``content_manager`` attribute for content management methods like
+       ``set_content()`` and ``get_content()`` to work. The legacy
+       :const:`~email.policy.compat32` policy does not support these methods
+       and should not be used with :class:`EmailMessage`.

Doc/library/email.policy.rst

@@ -662,6 +662,13 @@ The header objects and their attributes are described in
    An instance of :class:`Compat32`, providing  backward compatibility with the
    behavior of the email package in Python 3.2.
 
+   .. note::
+
+      The :const:`compat32` policy should not be used as a policy for
+      :class:`~email.message.EmailMessage` objects, and should only be used
+      to serialize messages that were created using the :const:`compat32`
+      policy.
+
 
 .. rubric:: Footnotes
 

Doc/library/os.rst

@@ -1556,6 +1556,15 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
    .. versionadded:: 3.15
 
 
+.. data:: RWF_ATOMIC
+
+   Write data atomically. Requires alignment to the device's atomic write unit.
+
+   .. availability:: Linux >= 6.11
+
+   .. versionadded:: next
+
+
 .. function:: ptsname(fd, /)
 
    Return the name of the slave pseudo-terminal device associated with the
@@ -1598,6 +1607,7 @@ or `the MSDN <https://msdn.microsoft.com/en-us/library/z0kc8e3z.aspx>`_ on Windo
    - :data:`RWF_SYNC`
    - :data:`RWF_APPEND`
    - :data:`RWF_DONTCACHE`
+   - :data:`RWF_ATOMIC`
 
    Return the total number of bytes actually written.
 
@@ -1969,7 +1979,8 @@ can be inherited by child processes.  Since Python 3.4, file descriptors
 created by Python are non-inheritable by default.
 
 On UNIX, non-inheritable file descriptors are closed in child processes at the
-execution of a new program, other file descriptors are inherited.
+execution of a new program, other file descriptors are inherited. Note that
+non-inheritable file descriptors are still *inherited* by child processes on :func:`os.fork`.
 
 On Windows, non-inheritable handles and file descriptors are closed in child
 processes, except for standard streams (file descriptors 0, 1 and 2: stdin, stdout

Doc/library/stdtypes.rst

@@ -2045,7 +2045,18 @@ expression support in the :mod:`re` module).
 .. method:: str.index(sub[, start[, end]])
 
    Like :meth:`~str.find`, but raise :exc:`ValueError` when the substring is
-   not found.
+   not found. For example:
+
+   .. doctest::
+
+      >>> 'spam, spam, spam'.index('eggs')
+      Traceback (most recent call last):
+        File "<python-input-0>", line 1, in <module>
+          'spam, spam, spam'.index('eggs')
+          ~~~~~~~~~~~~~~~~~~~~~~~~^^^^^^^^
+      ValueError: substring not found
+
+   See also :meth:`rindex`.
 
 
 .. method:: str.isalnum()
@@ -2190,6 +2201,15 @@ expression support in the :mod:`re` module).
    Nonprintable characters are those in group Separator or Other (Z or C),
    except the ASCII space.
 
+   For example:
+
+   .. doctest::
+
+      >>> ''.isprintable(), ' '.isprintable()
+      (True, True)
+      >>> '\t'.isprintable(), '\n'.isprintable()
+      (False, False)
+
 
 .. method:: str.isspace()
 

Doc/library/tempfile.rst

@@ -225,8 +225,9 @@ The module defines the following user-callable items:
    properly implements the :const:`os.O_EXCL` flag for :func:`os.open`.  The
    file is readable and writable only by the creating user ID.  If the
    platform uses permission bits to indicate whether a file is executable,
-   the file is executable by no one.  The file descriptor is not inherited
-   by child processes.
+   the file is executable by no one.
+
+   The file descriptor is :ref:`not inherited by child processes <fd_inheritance>`.
 
    Unlike :func:`TemporaryFile`, the user of :func:`mkstemp` is responsible
    for deleting the temporary file when done with it.

Doc/whatsnew/3.15.rst

@@ -891,7 +891,11 @@ Results from the `pyperformance <https://github.com/python/pyperformance>`__
 benchmark suite report
 `3-4% <https://github.com/facebookexperimental/free-threading-benchmarking/blob/main/results/bm-20251214-3.15.0a2%2B-6cddf04-JIT/bm-20251214-vultr-x86_64-python-6cddf04344a1e8ca9df5-3.15.0a2%2B-6cddf04-vs-base.svg>`__
 geometric mean performance improvement for the JIT over the standard CPython
-interpreter built with all optimizations enabled. The speedups for JIT
+interpreter built with all optimizations enabled on x86-64 Linux. On AArch64
+macOS, the JIT has a
+`7-8% <https://raw.githubusercontent.com/facebookexperimental/free-threading-benchmarking/refs/heads/main/results/bm-20260103-3.15.0a3%2B-9609574-JIT/bm-20260103-macm4pro-arm64-python-9609574e7fd36edfaa8b-3.15.0a3%2B-9609574-vs-base.svg>`__
+speedup over the :ref:`tail calling interpreter <whatsnew314-tail-call-interpreter>`
+with all optimizations enabled. The speedups for JIT
 builds versus no JIT builds range from roughly 20% slowdown to over
 100% speedup (ignoring the ``unpack_sequence`` microbenchmark) on
 x86-64 Linux and AArch64 macOS systems.

Include/internal/pycore_code.h

@@ -160,6 +160,12 @@ typedef struct {
 
 #define INLINE_CACHE_ENTRIES_CONTAINS_OP CACHE_ENTRIES(_PyContainsOpCache)
 
+typedef struct {
+    _Py_BackoffCounter counter;
+} _PyCallFunctionExCache;
+
+#define INLINE_CACHE_ENTRIES_CALL_FUNCTION_EX CACHE_ENTRIES(_PyCallFunctionExCache)
+
 /* "Locals plus" for a code object is the set of locals + cell vars +
  * free vars.  This relates to variable names as well as offsets into
  * the "fast locals" storage array of execution frames.  The compiler
@@ -326,6 +332,7 @@ PyAPI_FUNC(void) _Py_Specialize_Send(_PyStackRef receiver, _Py_CODEUNIT *instr);
 PyAPI_FUNC(void) _Py_Specialize_ToBool(_PyStackRef value, _Py_CODEUNIT *instr);
 PyAPI_FUNC(void) _Py_Specialize_ContainsOp(_PyStackRef value, _Py_CODEUNIT *instr);
 PyAPI_FUNC(void) _Py_GatherStats_GetIter(_PyStackRef iterable);
+PyAPI_FUNC(void) _Py_Specialize_CallFunctionEx(_PyStackRef func_st, _Py_CODEUNIT *instr);
 
 // Utility functions for reading/writing 32/64-bit values in the inline caches.
 // Great care should be taken to ensure that these functions remain correct and

Include/internal/pycore_interpframe.h

@@ -395,6 +395,10 @@ _PyEvalFramePushAndInit(PyThreadState *tstate, _PyStackRef func,
                         size_t argcount, PyObject *kwnames,
                         _PyInterpreterFrame *previous);
 
+PyAPI_FUNC(_PyInterpreterFrame *)
+_PyEvalFramePushAndInit_Ex(PyThreadState *tstate, _PyStackRef func,
+    PyObject *locals, Py_ssize_t nargs, PyObject *callargs, PyObject *kwargs, _PyInterpreterFrame *previous);
+
 #ifdef __cplusplus
 }
 #endif

Include/internal/pycore_magic_number.h

@@ -288,6 +288,8 @@ Known values:
     Python 3.15a1 3655 (Fix miscompilation of some module-level annotations)
     Python 3.15a2 3656 (Add TRACE_RECORD instruction, for platforms with switch based interpreter)
     Python 3.15a4 3657 (Add BINARY_OP_SUBSCR_USTR_INT)
+    Python 3.15a4 3658 (Optimize bytecode for list/set called on genexp)
+    Python 3.15a4 3659 (Add CALL_FUNCTION_EX specialization)
 
 
     Python 3.16 will start with 3700
@@ -301,7 +303,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3657
+#define PYC_MAGIC_NUMBER 3659
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \