python / cpython

…8360)

…ild (GH-18357)

…-18369)

_Py_AddToAllObjects() is used in bltinmodule.c and typeobject.c when
Py_TRACE_REFS is defined.

Fix Py_TRACE_REFS build.

Add a fast-path for UTF-8 encoding in PyUnicode_EncodeFSDefault()
and PyUnicode_DecodeFSDefaultAndSize().

Add _PyUnicode_FiniEncodings() helper function for _PyUnicode_Fini().

Replace "struct _typeobject" with PyTypeObject in object.h.

Convert PyType_HasFeature(), PyType_Check() and PyType_CheckExact()
macros to static inline functions.

In the limited C API, PyObject_INIT() and PyObject_INIT_VAR() are now
defined as aliases to PyObject_Init() and PyObject_InitVar() to make
their implementation opaque. It avoids to leak implementation details
in the limited C API.

Exclude the following functions from the limited C API, move them
from object.h to cpython/object.h:

* _Py_NewReference()
* _Py_ForgetReference()
* _PyTraceMalloc_NewReference()
* _Py_GetRefTotal()

Exclude trashcan mechanism from the limited C API: it requires access to
PyTypeObject and PyThreadState structure fields, whereas these structures
are opaque in the limited C API.

The trashcan mechanism never worked with the limited C API. Move it
from object.h to cpython/object.h.

The macro is defined after Py_DECREF() and so is no longer used by
Py_DECREF().

Moving _Py_Dealloc() macro back from cpython/object.h to object.h
would require to move a lot of definitions as well: PyTypeObject and
many related types used by PyTypeObject.

Keep _Py_Dealloc() as an opaque function call to avoid leaking
implementation details in the limited C API (object.h): remove
_Py_Dealloc() macro from cpython/object.h.

https://bugs.python.org/issue39553



Automerge-Triggered-By: @zooba

* bpo-39491: Merge PEP 593 (typing.Annotated) support

PEP 593 has been accepted some time ago. I got a green light for merging
this from Till, so I went ahead and combined the code contributed to
typing_extensions[1] and the documentation from the PEP 593 text[2].

My changes were limited to:

* removing code designed for typing_extensions to run on older Python
  versions
* removing some irrelevant parts of the PEP text when copying it over as
  documentation and otherwise changing few small bits to better serve
  the purpose
* changing the get_type_hints signature to match reality (parameter
  names)

I wasn't entirely sure how to go about crediting the authors but I used
my best judgment, let me know if something needs changing in this
regard.

[1] https://github.com/python/typing/blob/8280de241fd8c8afe727c7860254b753e383b360/typing_extensions/src_py3/typing_extensions.py
[2] https://github.com/python/peps/blob/17710b879882454d55f82c2d44596e8e9f8e4bff/pep-0593.rst

…GH-17791)

…pty modules (GH-17824)

_Py_NewReference() becomes a regular opaque function, rather than a
static inline function in the C API (object.h), to better hide
implementation details.

Move _Py_tracemalloc_config from public pymem.h to internal
pycore_pymem.h header.

Make _Py_AddToAllObjects() private.

To print the exports to stdout, the gendef command requires the option "-". Without this option, no output is generated.

…-18295)

When called on a closed object, readinto() segfaults on account
of a write to a freed buffer:

    ==220553== Process terminating with default action of signal 11 (SIGSEGV): dumping core
    ==220553==  Access not within mapped region at address 0x2A
    ==220553==    at 0x48408A0: memmove (vg_replace_strmem.c:1272)
    ==220553==    by 0x58DB0C: _buffered_readinto_generic (bufferedio.c:972)
    ==220553==    by 0x58DCBA: _io__Buffered_readinto_impl (bufferedio.c:1053)
    ==220553==    by 0x58DCBA: _io__Buffered_readinto (bufferedio.c.h:253)

Reproducer:

    reader = open ("/dev/zero", "rb")
    _void  = reader.read (42)
    reader.close ()
    reader.readinto (bytearray (42)) ### BANG!

The problem exists since 2012 when commit dc46945 added code
to free the read buffer on close().

Signed-off-by: Philipp Gesang <philipp.gesang@intra2net.com>

…l names in distutils (GH-18150)

Make it export the correct init symbol also on Windows.



https://bugs.python.org/issue39432

Restore PyObject_IsInstance() comment explaining why only tuples of
types are accepted, but not general sequence. Comment written by
Guido van Rossum in commit 03290ec
which implements isinstance(x, (A, B, ...)). The comment was lost in
a PyObject_IsInstance() optimization:
commit ec569b7.

Cleanup also the code. recursive_isinstance() is no longer recursive,
so rename it to object_isinstance(), whereas object_isinstance() is
recursive and so rename it to object_recursive_isinstance().

…als (GH-18039)

Currently, during runtime destruction, `_PyImport_Cleanup` is clearing the interpreter state before clearing out the modules themselves. This leads to a segfault on modules that rely on the module state to clear themselves up.

For example, let's take the small snippet added in the issue by @DinoV :
```
import _struct

class C:
    def __init__(self):
        self.pack = _struct.pack
    def __del__(self):
        self.pack('I', -42)

_struct.x = C()
```

The module `_struct` uses the module state to run `pack`. Therefore, the module state has to be alive until after the module has been cleared out to successfully run `C.__del__`. This happens at line 606, when `_PyImport_Cleanup` calls `_PyModule_Clear`. In fact, the loop that calls `_PyModule_Clear` has in its comments: 

> Now, if there are any modules left alive, clear their globals to minimize potential leaks.  All C extension modules actually end up here, since they are kept alive in the interpreter state.

That means that we can't clear the module state (which is used by C Extensions) before we run that loop.

Moving `_PyInterpreterState_ClearModules` until after it, fixes the segfault in the code snippet.

Finally, this updates a test in `io` to correctly assert the error that it now throws (since it now finds the io module state). The test that uses this is: `test_create_at_shutdown_without_encoding`. Given this test is now working is a proof that the module state now stays alive even when `__del__` is called at module destruction time. Thus, I didn't add a new tests for this.


https://bugs.python.org/issue38076

…ial (GH-16973)

* Remove _Py_INC_REFTOTAL and _Py_DEC_REFTOTAL macros: modify
  directly _Py_RefTotal.
* _Py_ForgetReference() is no longer defined if the Py_TRACE_REFS
  macro is not defined.
* Remove _Py_NewReference() implementation from object.c:
  unify the two implementations in object.h inline function.
* Fix Py_TRACE_REFS build: _Py_INC_TPALLOCS() macro has been removed.

Improvements in listsort.txt and a comment in sortperf.py.

Automerge-Triggered-By: @csabella

Move the following functions from the public C API to the internal C
API:

* _PyDebug_PrintTotalRefs(),
* _Py_PrintReferenceAddresses()
* _Py_PrintReferences()

Remove:

* COUNT_ALLOCS macro
* sys.getcounts() function
* SHOW_ALLOC_COUNT code in listobject.c
* SHOW_TRACK_COUNT code in tupleobject.c
* PyConfig.show_alloc_count field
* -X showalloccount command line option
* @test.support.requires_type_collecting decorator

…e.shortDescription (GH-18175)

…er instance (GH-18266)

This also needs a backport to 3.8


https://bugs.python.org/issue39492



Automerge-Triggered-By: @pitrou