Issue #10181: Add warning that structure layouts in memoryobject.h and
object.h have changed.
diff --git a/Doc/whatsnew/3.3.rst b/Doc/whatsnew/3.3.rst
index f1f79d6..7799ade 100644
--- a/Doc/whatsnew/3.3.rst
+++ b/Doc/whatsnew/3.3.rst
@@ -102,6 +102,7 @@
now returns an integer (in accordance with the struct module syntax).
For returning a bytes object the view must be cast to 'c' first.
+* For further changes see `Build and C API Changes`_ and `Porting C code`_ .
.. _pep-393:
@@ -1049,6 +1050,14 @@
Porting C code
--------------
+* In the course of changes to the buffer API the undocumented
+ :c:member:`~Py_buffer.smalltable` member of the
+ :c:type:`Py_buffer` structure has been removed and the
+ layout of the :c:type:`PyMemoryViewObject` has changed.
+
+ All extensions relying on the relevant parts in ``memoryobject.h``
+ or ``object.h`` must be rebuilt.
+
* Due to :ref:`PEP 393 <pep-393>`, the :c:type:`Py_UNICODE` type and all
functions using this type are deprecated (but will stay available for
at least five years). If you were using low-level Unicode APIs to