From b7e4f1d97c6e784d2dee182d2b81541ddcff5751 Mon Sep 17 00:00:00 2001
From: Carl Meyer <carl@oddbird.net>
Date: Thu, 15 Dec 2022 04:26:08 -0700
Subject: [PATCH] GH-99767: update PyTypeObject docs for type watchers
 (GH-99928)

---
 Doc/c-api/typeobj.rst     | 9 +++++++++
 Doc/includes/typestruct.h | 3 +++
 2 files changed, 12 insertions(+)

diff --git a/Doc/c-api/typeobj.rst b/Doc/c-api/typeobj.rst
index 8f8869ec668..c7b318b2185 100644
--- a/Doc/c-api/typeobj.rst
+++ b/Doc/c-api/typeobj.rst
@@ -147,6 +147,8 @@ Quick Reference
    +------------------------------------------------+-----------------------------------+-------------------+---+---+---+---+
    | :c:member:`~PyTypeObject.tp_vectorcall`        | :c:type:`vectorcallfunc`          |                   |   |   |   |   |
    +------------------------------------------------+-----------------------------------+-------------------+---+---+---+---+
+   | :c:member:`~PyTypeObject.tp_watched`           | char                              |                   |   |   |   |   |
+   +------------------------------------------------+-----------------------------------+-------------------+---+---+---+---+
 
 .. [#slots]
 
@@ -2090,6 +2092,13 @@ and :c:type:`PyType_Type` effectively act as defaults.)
    .. versionadded:: 3.9 (the field exists since 3.8 but it's only used since 3.9)
 
 
+.. c:member:: char PyTypeObject.tp_watched
+
+   Internal. Do not use.
+
+   .. versionadded:: 3.12
+
+
 .. _static-types:
 
 Static Types
diff --git a/Doc/includes/typestruct.h b/Doc/includes/typestruct.h
index 02f8ccfe443..f0ad1e47cb0 100644
--- a/Doc/includes/typestruct.h
+++ b/Doc/includes/typestruct.h
@@ -80,4 +80,7 @@ typedef struct _typeobject {
 
     destructor tp_finalize;
     vectorcallfunc tp_vectorcall;
+
+    /* bitset of which type-watchers care about this type */
+    char tp_watched;
 } PyTypeObject;