1 files changed, 59 insertions, 2 deletions
diff --git a/Doc/c-api/gcsupport.rst b/Doc/c-api/gcsupport.rst
index d1f0982b818..f6fa52b36c5 100644
--- a/Doc/c-api/gcsupport.rst
+++ b/Doc/c-api/gcsupport.rst
@@ -57,11 +57,49 @@ rules:
    Analogous to :c:macro:`PyObject_New` but for container objects with the
    :c:macro:`Py_TPFLAGS_HAVE_GC` flag set.
 
+   Do not call this directly to allocate memory for an object; call the type's
+   :c:member:`~PyTypeObject.tp_alloc` slot instead.
+
+   When populating a type's :c:member:`~PyTypeObject.tp_alloc` slot,
+   :c:func:`PyType_GenericAlloc` is preferred over a custom function that
+   simply calls this macro.
+
+   Memory allocated by this macro must be freed with
+   :c:func:`PyObject_GC_Del` (usually called via the object's
+   :c:member:`~PyTypeObject.tp_free` slot).
+
+   .. seealso::
+
+      * :c:func:`PyObject_GC_Del`
+      * :c:macro:`PyObject_New`
+      * :c:func:`PyType_GenericAlloc`
+      * :c:member:`~PyTypeObject.tp_alloc`
+
+
 .. c:macro:: PyObject_GC_NewVar(TYPE, typeobj, size)
 
    Analogous to :c:macro:`PyObject_NewVar` but for container objects with the
    :c:macro:`Py_TPFLAGS_HAVE_GC` flag set.
 
+   Do not call this directly to allocate memory for an object; call the type's
+   :c:member:`~PyTypeObject.tp_alloc` slot instead.
+
+   When populating a type's :c:member:`~PyTypeObject.tp_alloc` slot,
+   :c:func:`PyType_GenericAlloc` is preferred over a custom function that
+   simply calls this macro.
+
+   Memory allocated by this macro must be freed with
+   :c:func:`PyObject_GC_Del` (usually called via the object's
+   :c:member:`~PyTypeObject.tp_free` slot).
+
+   .. seealso::
+
+      * :c:func:`PyObject_GC_Del`
+      * :c:macro:`PyObject_NewVar`
+      * :c:func:`PyType_GenericAlloc`
+      * :c:member:`~PyTypeObject.tp_alloc`
+
+
 .. c:function:: PyObject* PyUnstable_Object_GC_NewWithExtraData(PyTypeObject *type, size_t extra_size)
 
    Analogous to :c:macro:`PyObject_GC_New` but allocates *extra_size*
@@ -73,6 +111,10 @@ rules:
    The extra data will be deallocated with the object, but otherwise it is
    not managed by Python.
 
+   Memory allocated by this function must be freed with
+   :c:func:`PyObject_GC_Del` (usually called via the object's
+   :c:member:`~PyTypeObject.tp_free` slot).
+
    .. warning::
       The function is marked as unstable because the final mechanism
       for reserving extra data after an instance is not yet decided.
@@ -136,6 +178,21 @@ rules:
    Releases memory allocated to an object using :c:macro:`PyObject_GC_New` or
    :c:macro:`PyObject_GC_NewVar`.
 
+   Do not call this directly to free an object's memory; call the type's
+   :c:member:`~PyTypeObject.tp_free` slot instead.
+
+   Do not use this for memory allocated by :c:macro:`PyObject_New`,
+   :c:macro:`PyObject_NewVar`, or related allocation functions; use
+   :c:func:`PyObject_Free` instead.
+
+   .. seealso::
+
+      * :c:func:`PyObject_Free` is the non-GC equivalent of this function.
+      * :c:macro:`PyObject_GC_New`
+      * :c:macro:`PyObject_GC_NewVar`
+      * :c:func:`PyType_GenericAlloc`
+      * :c:member:`~PyTypeObject.tp_free`
+
 
 .. c:function:: void PyObject_GC_UnTrack(void *op)
 
@@ -180,9 +237,9 @@ provided.  In order to use this macro, the :c:member:`~PyTypeObject.tp_traverse`
 must name its arguments exactly *visit* and *arg*:
 
 
-.. c:function:: void Py_VISIT(PyObject *o)
+.. c:macro:: Py_VISIT(o)
 
-   If *o* is not ``NULL``, call the *visit* callback, with arguments *o*
+   If the :c:expr:`PyObject *` *o* is not ``NULL``, call the *visit* callback, with arguments *o*
    and *arg*.  If *visit* returns a non-zero value, then return it.
    Using this macro, :c:member:`~PyTypeObject.tp_traverse` handlers
    look like::