TechPenguineer · pull · Nov 18, 2025 · Nov 18, 2025 · Nov 18, 2025 · Nov 18, 2025
diff --git a/.github/workflows/jit.yml b/.github/workflows/jit.yml
@@ -57,10 +57,9 @@ jobs:
       fail-fast: false
       matrix:
         target:
-# To re-enable later when we support these.
-#          - i686-pc-windows-msvc/msvc
-#          - x86_64-pc-windows-msvc/msvc
-#          - aarch64-pc-windows-msvc/msvc
+          - i686-pc-windows-msvc/msvc
+          - x86_64-pc-windows-msvc/msvc
+          - aarch64-pc-windows-msvc/msvc
           - x86_64-apple-darwin/clang
           - aarch64-apple-darwin/clang
           - x86_64-unknown-linux-gnu/gcc
@@ -71,16 +70,15 @@ jobs:
         llvm:
           - 21
         include:
-# To re-enable later when we support these.
-#          - target: i686-pc-windows-msvc/msvc
-#            architecture: Win32
-#            runner: windows-2022
-#          - target: x86_64-pc-windows-msvc/msvc
-#            architecture: x64
-#            runner: windows-2022
-#          - target: aarch64-pc-windows-msvc/msvc
-#            architecture: ARM64
-#            runner: windows-11-arm
+          - target: i686-pc-windows-msvc/msvc
+            architecture: Win32
+            runner: windows-2022
+          - target: x86_64-pc-windows-msvc/msvc
+            architecture: x64
+            runner: windows-2022
+          - target: aarch64-pc-windows-msvc/msvc
+            architecture: ARM64
+            runner: windows-11-arm
           - target: x86_64-apple-darwin/clang
             architecture: x86_64
             runner: macos-15-intel

diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst
@@ -85,6 +85,35 @@ Object Protocol
    instead of the :func:`repr`.
 
 
+.. c:function:: void PyUnstable_Object_Dump(PyObject *op)
+
+   Dump an object *op* to ``stderr``. This should only be used for debugging.
+
+   The output is intended to try dumping objects even after memory corruption:
+
+   * Information is written starting with fields that are the least likely to
+     crash when accessed.
+   * This function can be called without an :term:`attached thread state`, but
+     it's not recommended to do so: it can cause deadlocks.
+   * An object that does not belong to the current interpreter may be dumped,
+     but this may also cause crashes or unintended behavior.
+   * Implement a heuristic to detect if the object memory has been freed. Don't
+     display the object contents in this case, only its memory address.
+   * The output format may change at any time.
+
+   Example of output:
+
+   .. code-block:: output
+
+       object address  : 0x7f80124702c0
+       object refcount : 2
+       object type     : 0x9902e0
+       object type name: str
+       object repr     : 'abcdef'
+
+   .. versionadded:: next
+
+
 .. c:function:: int PyObject_HasAttrWithError(PyObject *o, PyObject *attr_name)
 
    Returns ``1`` if *o* has the attribute *attr_name*, and ``0`` otherwise.

diff --git a/Doc/c-api/structures.rst b/Doc/c-api/structures.rst
@@ -698,14 +698,12 @@ The following flags can be used with :c:member:`PyMemberDef.flags`:
    entry indicates an offset from the subclass-specific data, rather than
    from ``PyObject``.
 
-   Can only be used as part of :c:member:`Py_tp_members <PyTypeObject.tp_members>`
+   Can only be used as part of the :c:data:`Py_tp_members`
    :c:type:`slot <PyType_Slot>` when creating a class using negative
    :c:member:`~PyType_Spec.basicsize`.
    It is mandatory in that case.
-
-   This flag is only used in :c:type:`PyType_Slot`.
-   When setting :c:member:`~PyTypeObject.tp_members` during
-   class creation, Python clears it and sets
+   When setting :c:member:`~PyTypeObject.tp_members` from the slot during
+   class creation, Python clears the flag and sets
    :c:member:`PyMemberDef.offset` to the offset from the ``PyObject`` struct.
 
 .. index::

diff --git a/Doc/c-api/type.rst b/Doc/c-api/type.rst
@@ -383,8 +383,8 @@ The following functions and structs are used to create
 
    The *bases* argument can be used to specify base classes; it can either
    be only one class or a tuple of classes.
-   If *bases* is ``NULL``, the *Py_tp_bases* slot is used instead.
-   If that also is ``NULL``, the *Py_tp_base* slot is used instead.
+   If *bases* is ``NULL``, the :c:data:`Py_tp_bases` slot is used instead.
+   If that also is ``NULL``, the :c:data:`Py_tp_base` slot is used instead.
    If that also is ``NULL``, the new type derives from :class:`object`.
 
    The *module* argument can be used to record the module in which the new
@@ -590,9 +590,9 @@ The following functions and structs are used to create
       :c:type:`PyAsyncMethods` with an added ``Py_`` prefix.
       For example, use:
 
-      * ``Py_tp_dealloc`` to set :c:member:`PyTypeObject.tp_dealloc`
-      * ``Py_nb_add`` to set :c:member:`PyNumberMethods.nb_add`
-      * ``Py_sq_length`` to set :c:member:`PySequenceMethods.sq_length`
+      * :c:data:`Py_tp_dealloc` to set :c:member:`PyTypeObject.tp_dealloc`
+      * :c:data:`Py_nb_add` to set :c:member:`PyNumberMethods.nb_add`
+      * :c:data:`Py_sq_length` to set :c:member:`PySequenceMethods.sq_length`
 
       An additional slot is supported that does not correspond to a
       :c:type:`!PyTypeObject` struct field:
@@ -611,7 +611,7 @@ The following functions and structs are used to create
 
       If it is not possible to switch to a ``MANAGED`` flag (for example,
       for vectorcall or to support Python older than 3.12), specify the
-      offset in :c:member:`Py_tp_members <PyTypeObject.tp_members>`.
+      offset in :c:data:`Py_tp_members`.
       See :ref:`PyMemberDef documentation <pymemberdef-offsets>`
       for details.
 
@@ -639,7 +639,7 @@ The following functions and structs are used to create
 
       .. versionchanged:: 3.14
          The field :c:member:`~PyTypeObject.tp_vectorcall` can now set
-         using ``Py_tp_vectorcall``.  See the field's documentation
+         using :c:data:`Py_tp_vectorcall`.  See the field's documentation
          for details.
 
    .. c:member:: void *pfunc
@@ -649,7 +649,7 @@ The following functions and structs are used to create
 
       *pfunc* values may not be ``NULL``, except for the following slots:
 
-      * ``Py_tp_doc``
+      * :c:data:`Py_tp_doc`
       * :c:data:`Py_tp_token` (for clarity, prefer :c:data:`Py_TP_USE_SPEC`
         rather than ``NULL``)
 

diff --git a/Doc/c-api/typeobj.rst b/Doc/c-api/typeobj.rst
@@ -2273,7 +2273,7 @@ and :c:data:`PyType_Type` effectively act as defaults.)
    This field should be set to ``NULL`` and treated as read-only.
    Python will fill it in when the type is :c:func:`initialized <PyType_Ready>`.
 
-   For dynamically created classes, the ``Py_tp_bases``
+   For dynamically created classes, the :c:data:`Py_tp_bases`
    :c:type:`slot <PyType_Slot>` can be used instead of the *bases* argument
    of :c:func:`PyType_FromSpecWithBases`.
    The argument form is preferred.

diff --git a/Doc/deprecations/pending-removal-in-future.rst b/Doc/deprecations/pending-removal-in-future.rst
@@ -76,7 +76,7 @@ although there is currently no date scheduled for their removal.
 * :mod:`mailbox`: Use of StringIO input and text mode is deprecated, use
   BytesIO and binary mode instead.
 
-* :mod:`os`: Calling :func:`os.register_at_fork` in multi-threaded process.
+* :mod:`os`: Calling :func:`os.register_at_fork` in a multi-threaded process.
 
 * :class:`!pydoc.ErrorDuringImport`: A tuple value for *exc_info* parameter is
   deprecated, use an exception instance.

diff --git a/Doc/howto/isolating-extensions.rst b/Doc/howto/isolating-extensions.rst
@@ -353,7 +353,7 @@ garbage collection protocol.
 That is, heap types should:
 
 - Have the :c:macro:`Py_TPFLAGS_HAVE_GC` flag.
-- Define a traverse function using ``Py_tp_traverse``, which
+- Define a traverse function using :c:data:`Py_tp_traverse`, which
   visits the type (e.g. using ``Py_VISIT(Py_TYPE(self))``).
 
 Please refer to the documentation of

diff --git a/Doc/library/decimal.rst b/Doc/library/decimal.rst
@@ -264,7 +264,7 @@ allows the settings to be changed.  This approach meets the needs of most
 applications.
 
 For more advanced work, it may be useful to create alternate contexts using the
-Context() constructor.  To make an alternate active, use the :func:`setcontext`
+:meth:`Context` constructor.  To make an alternate active, use the :func:`setcontext`
 function.
 
 In accordance with the standard, the :mod:`decimal` module provides two ready to

diff --git a/Doc/library/os.rst b/Doc/library/os.rst
@@ -558,7 +558,7 @@ process and user.
 
 .. function:: initgroups(username, gid, /)
 
-   Call the system initgroups() to initialize the group access list with all of
+   Call the system ``initgroups()`` to initialize the group access list with all of
    the groups of which the specified username is a member, plus the specified
    group id.
 

diff --git a/Doc/whatsnew/3.15.rst b/Doc/whatsnew/3.15.rst
@@ -316,9 +316,7 @@ Other language changes
   and compression. Common code patterns which can be optimized with
   :func:`~bytearray.take_bytes` are listed below.
 
-  (Contributed by Cody Maloney in :gh:`139871`.)
-
-  .. list-table:: Suggested Optimizing Refactors
+  .. list-table:: Suggested optimizing refactors
       :header-rows: 1
 
       * - Description
@@ -387,10 +385,12 @@ Other language changes
               buffer.resize(n)
               data = buffer.take_bytes()
 
+  (Contributed by Cody Maloney in :gh:`139871`.)
+
 * Many functions related to compiling or parsing Python code, such as
   :func:`compile`, :func:`ast.parse`, :func:`symtable.symtable`,
-  and :func:`importlib.abc.InspectLoader.source_to_code`, now allow to pass
-  the module name. It is needed to unambiguous :ref:`filter <warning-filter>`
+  and :func:`importlib.abc.InspectLoader.source_to_code`, now allow the module
+  name to be passed. It is needed to unambiguously :ref:`filter <warning-filter>`
   syntax warnings by module name.
   (Contributed by Serhiy Storchaka in :gh:`135801`.)
 
@@ -776,6 +776,17 @@ unittest
   (Contributed by Garry Cairns in :gh:`134567`.)
 
 
+venv
+----
+
+* On POSIX platforms, platlib directories will be created if needed when
+  creating virtual environments, instead of using ``lib64 -> lib`` symlink.
+  This means purelib and platlib of virtual environments no longer share the
+  same ``lib`` directory on platforms where :data:`sys.platlibdir` is not
+  equal to ``lib``.
+  (Contributed by Rui Xi in :gh:`133951`.)
+
+
 warnings
 --------
 
@@ -788,17 +799,6 @@ warnings
   (Contributed by Serhiy Storchaka in :gh:`135801`.)
 
 
-venv
-----
-
-* On POSIX platforms, platlib directories will be created if needed when
-  creating virtual environments, instead of using ``lib64 -> lib`` symlink.
-  This means purelib and platlib of virtual environments no longer share the
-  same ``lib`` directory on platforms where :data:`sys.platlibdir` is not
-  equal to ``lib``.
-  (Contributed by Rui Xi in :gh:`133951`.)
-
-
 xml.parsers.expat
 -----------------
 
@@ -1084,19 +1084,23 @@ New features
 
   (Contributed by Victor Stinner in :gh:`129813`.)
 
+* Add a new :c:func:`PyImport_CreateModuleFromInitfunc` C-API for creating
+  a module from a *spec* and *initfunc*.
+  (Contributed by Itamar Oren in :gh:`116146`.)
+
 * Add :c:func:`PyTuple_FromArray` to create a :class:`tuple` from an array.
   (Contributed by Victor Stinner in :gh:`111489`.)
 
+* Add :c:func:`PyUnstable_Object_Dump` to dump an object to ``stderr``.
+  It should only be used for debugging.
+  (Contributed by Victor Stinner in :gh:`141070`.)
+
 * Add :c:func:`PyUnstable_ThreadState_SetStackProtection` and
   :c:func:`PyUnstable_ThreadState_ResetStackProtection` functions to set
   the stack protection base address and stack protection size of a Python
   thread state.
   (Contributed by Victor Stinner in :gh:`139653`.)
 
-* Add a new :c:func:`PyImport_CreateModuleFromInitfunc` C-API for creating
-  a module from a *spec* and *initfunc*.
-  (Contributed by Itamar Oren in :gh:`116146`.)
-
 
 Changed C APIs
 --------------
@@ -1242,7 +1246,7 @@ Porting to Python 3.15
 This section lists previously described changes and other bugfixes
 that may require changes to your code.
 
-* :class:`sqlite3.Connection` APIs has been cleaned up.
+* :class:`sqlite3.Connection` APIs have been cleaned up.
 
   * All parameters of :func:`sqlite3.connect` except *database* are now keyword-only.
   * The first three parameters of methods :meth:`~sqlite3.Connection.create_function`
@@ -1262,7 +1266,7 @@ that may require changes to your code.
 * :meth:`~mmap.mmap.resize` has been removed on platforms that don't support the
   underlying syscall, instead of raising a :exc:`SystemError`.
 
-* Resource warning is now emitted for unclosed
+* A resource warning is now emitted for an unclosed
   :func:`xml.etree.ElementTree.iterparse` iterator if it opened a file.
   Use its :meth:`!close` method or the :func:`contextlib.closing` context
   manager to close it.

diff --git a/Include/cpython/object.h b/Include/cpython/object.h
@@ -295,7 +295,10 @@ PyAPI_FUNC(PyObject *) PyType_GetDict(PyTypeObject *);
 
 PyAPI_FUNC(int) PyObject_Print(PyObject *, FILE *, int);
 PyAPI_FUNC(void) _Py_BreakPoint(void);
-PyAPI_FUNC(void) _PyObject_Dump(PyObject *);
+PyAPI_FUNC(void) PyUnstable_Object_Dump(PyObject *);
+
+// Alias for backward compatibility
+#define _PyObject_Dump PyUnstable_Object_Dump
 
 PyAPI_FUNC(PyObject*) _PyObject_GetAttrId(PyObject *, _Py_Identifier *);
 
@@ -387,10 +390,11 @@ PyAPI_FUNC(PyObject *) _PyObject_FunctionStr(PyObject *);
    process with a message on stderr if the given condition fails to hold,
    but compile away to nothing if NDEBUG is defined.
 
-   However, before aborting, Python will also try to call _PyObject_Dump() on
-   the given object.  This may be of use when investigating bugs in which a
-   particular object is corrupt (e.g. buggy a tp_visit method in an extension
-   module breaking the garbage collector), to help locate the broken objects.
+   However, before aborting, Python will also try to call
+   PyUnstable_Object_Dump() on the given object. This may be of use when
+   investigating bugs in which a particular object is corrupt (e.g. buggy a
+   tp_visit method in an extension module breaking the garbage collector), to
+   help locate the broken objects.
 
    The WITH_MSG variant allows you to supply an additional message that Python
    will attempt to print to stderr, after the object dump. */

diff --git a/Include/internal/pycore_global_objects_fini_generated.h b/Include/internal/pycore_global_objects_fini_generated.h
diff --git a/Include/internal/pycore_magic_number.h b/Include/internal/pycore_magic_number.h
@@ -286,6 +286,7 @@ Known values:
     Python 3.15a1 3653 (Fix handling of opcodes that may leave operands on the stack when optimizing LOAD_FAST)
     Python 3.15a1 3654 (Fix missing exception handlers in logical expression)
     Python 3.15a1 3655 (Fix miscompilation of some module-level annotations)
+    Python 3.15a1 3656 (Add TRACE_RECORD instruction, for platforms with switch based interpreter)
 
 
     Python 3.16 will start with 3700
@@ -299,7 +300,7 @@ PC/launcher.c must also be updated.
 
 */
 
-#define PYC_MAGIC_NUMBER 3655
+#define PYC_MAGIC_NUMBER 3656
 /* This is equivalent to converting PYC_MAGIC_NUMBER to 2 bytes
    (little-endian) and then appending b'\r\n'. */
 #define PYC_MAGIC_NUMBER_TOKEN \