bpo-36427: Document that PyEval_RestoreThread and PyGILState_Ensure can terminate the calling thread (GH-12541)

Calling these function from a thread when the runtime is finalizing will terminate
the thread, even if the thread was not created by Python. Users can use 
_Py_IsFinalizing or sys.is_finalizing to check if the interpreter is in the process of
being finalized before calling this function to avoid unwanted termination.

After the removal of pgen, multiple header and function prototypes that lack implementation or are unused are still lying around.

Since bpo-30291 it is possible to specify the architecture of Python when using the launcher

Omit serialno field from debug hooks on Python memory allocators to
reduce the memory footprint by 5%.

Enable tracemalloc to get the traceback where a memory block has been
allocated when a fatal memory error is logged to decide where to put
a breakpoint.

Compile Python with PYMEM_DEBUG_SERIALNO defined to get back the
field.

Add a new _PyObject_CheckConsistency() function which can be used to
help debugging. The function is available in release mode.

Add a 'check_content' parameter to _PyDict_CheckConsistency().

Add -fmax-type-align=8 to CFLAGS when clang compiler is detected.

The pymalloc memory allocator aligns memory on 8 bytes. On x86-64,
clang expects alignment on 16 bytes by default and so uses MOVAPS
instruction which can lead to segmentation fault. Instruct clang that
Python is limited to alignemnt on 8 bytes to use MOVUPS instruction
instead: slower but don't trigger a SIGSEGV if the memory is not
aligned on 16 bytes.

Sadly, the flag must be expected to CFLAGS and not just
CFLAGS_NODIST, since third party C extensions can have the same
issue.

This enables using the `--preset-iot` option with the PC/layout script, but does not enable IoT builds as part of any normal release.

This reverts commit f13c5c8b (gh-12360).

For BufferedReader and BufferedWriter, seek and tell operations are
optional (they may or may not exist based on the underlying stream). For
BufferedRandom, they are mandatory: a BufferedRandom should not be
constructed over an unseekable underlying stream. Document this.

This is effectively an un-revert of #11617 and #12024 (reverted in #12159). Portions of those were merged in other PRs (with lower risk) and this represents the remainder. Note that I found 3 different bugs in the original PRs and have fixed them here.

In development mode (-X dev) and in debug build, the io.IOBase
destructor now logs close() exceptions. These exceptions are silent
by default in release mode.

On AIX, sys.platform doesn't contain the major version anymore.
Always return 'aix', instead of 'aix3' .. 'aix7'.  Since
older Python versions include the version number, it is recommended to
always use sys.platform.startswith('aix').

Fix test_sys.test_getallocatedblocks() when tracemalloc is enabled.
If the name of Python memory allocators cannot get read, consider
that pymalloc is disabled.

Fix the following error:

./python -X tracemalloc -m test test_sys -v -m test_getallocatedblocks

ERROR: test_getallocatedblocks (test.test_sys.SysModuleTest)
------------------------------------------------------------
Traceback (most recent call last):
  File "Lib/test/test_sys.py", line 770, in test_getallocatedblocks
    alloc_name = _testcapi.pymem_getallocatorsname()
RuntimeError: cannot get allocators name

"make tags" and "make TAGS" now also parse Modules/_io/*.c
and Modules/_io/*.h.

Modify CLEANBYTE, DEADDYTE and FORBIDDENBYTE constants: use 0xCD,
0xDD and 0xFD, rather than 0xCB, 0xBB and 0xFB, to use the same byte
patterns than Windows CRT debug malloc() and free().

Commit 57b1a286 fixed doctest, but example code is not
match with document.
Just skip doctest for the block.

Replace _PyMem_IsFreed() function with _PyMem_IsPtrFreed() inline
function. The function is now way more efficient, it became a simple
comparison on integers, rather than a short loop. It detects also
uninitialized bytes and "forbidden bytes" filled by debug hooks
on memory allocators.

Add unit tests on _PyObject_IsFreed().

Disable the job to unblock the CI until the issue is properly
understood.

* better __init__.py explanation in tutorial

* Update Doc/tutorial/modules.rst
Co-Authored-By: methane <songofacandy@gmail.com>

Set CUSTOMIZED_OSX_COMPILER to True to disable
_osx_support.customize_compiler().

The random module now prefers the lean internal _sha512 module over hashlib
for seed(version=2) to optimize import time.
Signed-off-by: Christian Heimes <christian@python.org>

The script needs to be updated to support win 10/ 1803 chcp.com command (output has trailing dot)





https://bugs.python.org/issue34144