If tracemalloc is not tracing Python memory allocations,
_PyMem_DumpTraceback() now suggests to enable tracemalloc
to get the traceback where the memory block has been allocated.

* Move "GC" macros together:

  * PyObject_IS_GC()
  * _Py_AS_GC()
  * _PyObject_GC_IS_TRACKED()
  * _PyObject_GC_MAY_BE_TRACKED()

* Mark other GC macros as internal (#ifdef Py_BUILD_CORE):

  * _PyGCHead_NEXT(g), _PyGCHead_SET_NEXT(g, p)
  * _PyGCHead_PREV(g), _PyGCHead_SET_PREV(g, p)
  * _PyGCHead_FINALIZED(g), _PyGCHead_SET_FINALIZED(g)
  * _PyGC_FINALIZED(o), _PyGC_SET_FINALIZED(o)
  * _PyObject_GC_TRACK(o), _PyObject_GC_UNTRACK(o)
  * _PyGC_PREV_MASK_FINALIZED
  * _PyGC_PREV_MASK_COLLECTING
  * _PyGC_PREV_SHIFT
  * _PyGC_PREV_MASK

* Replace _PyGC_generation0 with _PyRuntime.gc.generation0
* _queuemodule.c: replace _PyObject_GC_UNTRACK()
  with with PyObject_GC_UnTrack()
* Document that  _PyObject_GC_TRACK() _PyObject_GC_UNTRACK() macros
  have been removed from the public C API.

Datetime macros like PyDate_Check() have two implementations, one using
the C API capsule and one using direct access to the datetime type
symbols defined in _datetimemodule.c. Since the direct access versions
of the macros are only used in _datetimemodule.c, they have been moved
out of "datetime.h" and into _datetimemodule.c.

The _PY_DATETIME_IMPL macro is currently necessary in order to avoid
both duplicate definitions of these macros in _datetimemodule.c and
unnecessary declarations of C API capsule-related macros and varibles in
datetime.h.
Co-Authored-By: Victor Stinner <vstinner@redhat.com>

Rename our new MEMORY_SANITIZER define to _Py_MEMORY_SANITIZER.
Project based C Preprocessor namespacing at its finest. :P

reproduciblity -> reproducibility
PyPA are the group -> PyPA is the group

clang's MemorySanitizer understand getc() but does not understand
getc_unlocked().  Workaround: Don't use it on msan builds.

The warnings module now suggests to enable tracemalloc if the source
is specified, tracemalloc module is available, but tracemalloc is not
tracing memory allocations.

Adds configure flags for msan and ubsan builds to make it easier to enable.
These also encode the detail that address sanitizer and memory sanitizer
should disable pymalloc.

Define MEMORY_SANITIZER when appropriate at build time and adds workarounds
to existing code to mark things as initialized where the sanitizer is otherwise unable to
determine that.  This lets our build succeed under the memory sanitizer.  not all tests
pass without sanitizer failures yet but we're in pretty good shape after this.

a asynchronous generator -> an asynchronous generator

Rename Include/internal/ headers:

* pycore_hash.h -> pycore_pyhash.h
* pycore_lifecycle.h -> pycore_pylifecycle.h
* pycore_mem.h -> pycore_pymem.h
* pycore_state.h -> pycore_pystate.h

Add missing headers to Makefile.pre.in and PCbuild:

* pycore_condvar.h.
* pycore_hamt.h
* pycore_pyhash.h

Independently of -> Independent of

* universal_newlines defaulting to False would suggest, that not
  specifying universal_newlines explicitly and setting text to True
  should cause an error, which is not the case.
* The run function didn't have the universal_newlines parameter
  documented
* The check_output function didn't have its text parameter documented

The documentation was not covering multiple targets enclosed by
parenthesis nor multiple targets enclosed by brackets, adding them all
would be heavy, an else cover them all and is lighter to read.

* ast.h now includes Python-ast.h and node.h
* parsetok.h now includes node.h and grammar.h
* symtable.h now includes Python-ast.h
* Modify asdl_c.py to enhance Python-ast.h:

  * Add #ifndef/#define Py_PYTHON_AST_H to be able to include the header
    twice
  * Add "extern { ... }" for C++
  * Undefine "Yield" macro conflicting with winbase.h

* Remove "#undef Yield" from C files, it's now done in Python-ast.h
* Remove now useless includes in C files

This function may access memory which is mapped but is considered
free by libc allocator. It behaves so by design, therefore we
need to suppress sanitizer reports.

GCC doesn't support MSan, so disable only TSan for it.

Remove unneeded assertion (we already know so is a PySetObject *).

https://bugs.python.org/issue33699

The System Preferences Dock "prefer tabs always" setting disables some
IDLE features.  Menus are a bit different than as described for Windows
and Linux.

This also makes it consistent with other places like:

- https://docs.python.org/dev/copyright.html
- https://www.python.org/ footer
- https://github.com/python/cpython/blob/e42b705188271da108de42b55d9344642170aa2b/Python/getcopyright.c#L7

Co-Authored-By: maggyero <gery.ogam@gmail.com>

* _PyTuple_ITEMS() gives access to the tuple->ob_item field and cast the
  first argument to PyTupleObject*. This internal macro is only usable if
  Py_BUILD_CORE is defined.
* Replace &PyTuple_GET_ITEM(ob, 0) with _PyTuple_ITEMS(ob).
* Replace PyTuple_GET_ITEM(op, 1) with &_PyTuple_ITEMS(ob)[1].

* All internal header files now require Py_BUILD_CORE or
  Py_BUILD_CORE_BUILTIN to be defined.
* _json.c is now compiled with Py_BUILD_CORE_BUILTIN to access
  pycore_accu.h header.
* Add an example to Modules/Setup to show how to build _json
  as a built-in module; it requires non trivial compiler options.

Currently, the *n* and *total* variables get converted to floats each time they are multiplied by random().  This minor tweak does the conversion just once and gets a small speedup (approx 3%).

Gives approx 20% speed-up using clang depending on the number of elements in the set (the less dense the set, the more the speed-up).

Uses the same entry++ logic used elsewhere in the setobject.c code.

1) Convert weird field name "typ" to the more standard "type".
2) For the NUMBER type, convert the value to an int() or float().
3) Simplify ``group(kind)`` to the shorter and faster ``group()`` call.
4) Simplify logic go a single if-elif chain to make this easier to extend.
5) Reorder the tests to match the order the tokens are specified.
   This isn't necessary for correctness but does make the example
   easier to follow.
6) Move the "column" calculation before the if-elif chain so that
   users have the option of using this value in error messages.

Since the n==1 case just returns *max*, it cannot be larger
than the magnitude of the vector entry.

This typo doesn't affect the result because wrong bits are discarded
on implicit conversion to unsigned char, but it trips UBSan
with -fsanitize=implicit-integer-truncation.





https://bugs.python.org/issue35194

Fix an off by one error in the peephole optimizer when checking for unreachable code beyond a return.

Do a bounds check within find_op so it can return before going past the end as a safety measure.

https://github.com/python/cpython/commit/7db3c488335168993689ddae5914a28e16188447#diff-a33329ae6ae0bb295d742f0caf93c137
introduced this off by one error while fixing another one nearby.

This bug was shipped in all Python 3.6 and 3.7 releases.

The included unittest won't fail unless you do a clang msan build.

The call to `_untrack_reader` is performed too soon, causing the protocol
to forget about the reader before `connection_lost` can run and feed the
EOF to the reader. See bpo-35065.