From 33f166d4ca9535471b3d6ba2173237fafa900378 Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Fri, 29 Jul 2022 23:42:07 +0800
Subject: [PATCH 1/4] Document Py_TPFLAGS_MANAGED_DICT and friends

---
 Doc/c-api/gcsupport.rst | 23 +++++++++++++++++++++++
 Doc/c-api/typeobj.rst   | 14 ++++++++++++++
 Doc/whatsnew/3.11.rst   |  9 +++++++++
 3 files changed, 46 insertions(+)

diff --git a/Doc/c-api/gcsupport.rst b/Doc/c-api/gcsupport.rst
index 8c90d1e8991c10..451be99d63cd98 100644
--- a/Doc/c-api/gcsupport.rst
+++ b/Doc/c-api/gcsupport.rst
@@ -129,6 +129,29 @@ rules:
    The :c:func:`_PyObject_GC_TRACK` and :c:func:`_PyObject_GC_UNTRACK` macros
    have been removed from the public C API.
 
+.. c:function:: int _PyObject_VisitManagedDict(PyObject *self, visitproc visit, void *arg)
+
+   Visitor function for types with :const:`Py_TPFLAGS_MANAGED_DICT` bit set.
+   Call this function in c:member:`~PyTypeObject.tp_traverse`.  The arguments
+   share the same meaning as the arguments of c:member:`~PyTypeObject.tp_traverse`.
+   A non-zero return value indicates an error and that returned value should be
+   returned immediately.
+
+   .. warning:: This function is unstable and may change with time.
+
+   .. versionadded:: 3.11
+
+.. c:function:: void _PyObject_ClearManagedDict(PyObject *self)
+
+   Inquiry function for types with :const:`Py_TPFLAGS_MANAGED_DICT` bit set.
+   Call this function in c:member:`~PyTypeObject.tp_clear`.
+
+   This is analogous to the Python function :func:`gc.is_finalized`.
+
+   .. warning:: This function is unstable and may change with time.
+
+   .. versionadded:: 3.11
+
 The :c:member:`~PyTypeObject.tp_traverse` handler accepts a function parameter of this type:
 
 
diff --git a/Doc/c-api/typeobj.rst b/Doc/c-api/typeobj.rst
index 7514801f2d4d59..a07765b0eaa775 100644
--- a/Doc/c-api/typeobj.rst
+++ b/Doc/c-api/typeobj.rst
@@ -1260,6 +1260,20 @@ and :c:type:`PyType_Type` effectively act as defaults.)
 
       .. versionadded:: 3.10
 
+   .. data:: Py_TPFLAGS_MANAGED_DICT
+
+      Set this bit to allow CPython to automatically manage the ``__dict__``
+      of the instances of a type.  To tell CPython to clear the managed
+      dictionary, you must call
+      :c:func:`_PyObject_VisitManagedDict` in :c:member:`~PyTypeObject.tp_traverse`
+      and :c:func:`_PyObject_ClearManagedDict` in :c:member:`~PyTypeObject.tp_clear`
+      respectively.
+
+      **Inheritance:**
+
+      ???
+
+      .. versionadded:: 3.11
 
 .. c:member:: const char* PyTypeObject.tp_doc
 
diff --git a/Doc/whatsnew/3.11.rst b/Doc/whatsnew/3.11.rst
index 1b3a685dbacb91..52e99332599e45 100644
--- a/Doc/whatsnew/3.11.rst
+++ b/Doc/whatsnew/3.11.rst
@@ -1927,6 +1927,15 @@ Porting to Python 3.11
   paths and then modify them, finish initialization and use :c:func:`PySys_GetObject`
   to retrieve :data:`sys.path` as a Python list object and modify it directly.
 
+* CPython no longer assumes that a ``__dict__`` exists after an object. C extension
+  types with inheritance and ``__dict__`` may have MRO problems. To fix this, allow
+  CPython to manage the ``__dict__`` of instances of your type by setting
+  :const:`Py_TPFLAGS_MANAGED_DICT` in :c:member:`~PyTypeObject.tp_flags`.
+  You must call :c:func:`_PyObject_VisitManagedDict` and
+  :c:func:`_PyObject_ClearManagedDict` to support GC collection.  See the
+  respective functions for more information on how to use them.
+  (Contributed by Mark Shannon in :gh:`92678`.)
+
 Deprecated
 ----------
 

From 3e28e0f88605cdc49c72710a2c06a3ef56b6c801 Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Fri, 29 Jul 2022 23:43:38 +0800
Subject: [PATCH 2/4] remove unneeded line

---
 Doc/c-api/gcsupport.rst | 2 --
 1 file changed, 2 deletions(-)

diff --git a/Doc/c-api/gcsupport.rst b/Doc/c-api/gcsupport.rst
index 451be99d63cd98..c30a3ea12c9271 100644
--- a/Doc/c-api/gcsupport.rst
+++ b/Doc/c-api/gcsupport.rst
@@ -146,8 +146,6 @@ rules:
    Inquiry function for types with :const:`Py_TPFLAGS_MANAGED_DICT` bit set.
    Call this function in c:member:`~PyTypeObject.tp_clear`.
 
-   This is analogous to the Python function :func:`gc.is_finalized`.
-
    .. warning:: This function is unstable and may change with time.
 
    .. versionadded:: 3.11

From efd504c0fa5deed327fa91ecf267ac35c4a1ad52 Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Fri, 29 Jul 2022 23:55:59 +0800
Subject: [PATCH 3/4] fix invalid rst

---
 Doc/c-api/gcsupport.rst | 2 ++
 1 file changed, 2 insertions(+)

diff --git a/Doc/c-api/gcsupport.rst b/Doc/c-api/gcsupport.rst
index c30a3ea12c9271..c99f9f83fcf568 100644
--- a/Doc/c-api/gcsupport.rst
+++ b/Doc/c-api/gcsupport.rst
@@ -129,6 +129,7 @@ rules:
    The :c:func:`_PyObject_GC_TRACK` and :c:func:`_PyObject_GC_UNTRACK` macros
    have been removed from the public C API.
 
+
 .. c:function:: int _PyObject_VisitManagedDict(PyObject *self, visitproc visit, void *arg)
 
    Visitor function for types with :const:`Py_TPFLAGS_MANAGED_DICT` bit set.
@@ -141,6 +142,7 @@ rules:
 
    .. versionadded:: 3.11
 
+
 .. c:function:: void _PyObject_ClearManagedDict(PyObject *self)
 
    Inquiry function for types with :const:`Py_TPFLAGS_MANAGED_DICT` bit set.

From 5c2573c9a809e325d881e0c03678629be350fb47 Mon Sep 17 00:00:00 2001
From: Ken Jin <28750310+Fidget-Spinner@users.noreply.github.com>
Date: Sat, 30 Jul 2022 00:10:17 +0800
Subject: [PATCH 4/4] fix rst again

---
 Doc/c-api/gcsupport.rst | 6 +++---
 1 file changed, 3 insertions(+), 3 deletions(-)

diff --git a/Doc/c-api/gcsupport.rst b/Doc/c-api/gcsupport.rst
index c99f9f83fcf568..ce6ab2a62e38be 100644
--- a/Doc/c-api/gcsupport.rst
+++ b/Doc/c-api/gcsupport.rst
@@ -133,8 +133,8 @@ rules:
 .. c:function:: int _PyObject_VisitManagedDict(PyObject *self, visitproc visit, void *arg)
 
    Visitor function for types with :const:`Py_TPFLAGS_MANAGED_DICT` bit set.
-   Call this function in c:member:`~PyTypeObject.tp_traverse`.  The arguments
-   share the same meaning as the arguments of c:member:`~PyTypeObject.tp_traverse`.
+   Call this function in :c:member:`~PyTypeObject.tp_traverse`.  The arguments
+   share the same meaning as the arguments of :c:member:`~PyTypeObject.tp_traverse`.
    A non-zero return value indicates an error and that returned value should be
    returned immediately.
 
@@ -146,7 +146,7 @@ rules:
 .. c:function:: void _PyObject_ClearManagedDict(PyObject *self)
 
    Inquiry function for types with :const:`Py_TPFLAGS_MANAGED_DICT` bit set.
-   Call this function in c:member:`~PyTypeObject.tp_clear`.
+   Call this function in :c:member:`~PyTypeObject.tp_clear`.
 
    .. warning:: This function is unstable and may change with time.