GH-92678: Document that you shouldn't be doing your own dictionary offset calculations. (GH-95598)

Co-authored-by: Petr Viktorin <encukou@gmail.com>
Co-authored-by: Stanley <46876382+slateny@users.noreply.github.com>

1 files changed, 18 insertions, 0 deletions

diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst
index 07a625b..fb03366 100644
--- a/Doc/c-api/object.rst
+++ b/Doc/c-api/object.rst
@@ -126,6 +126,14 @@ Object Protocol
    A generic implementation for the getter of a ``__dict__`` descriptor. It
    creates the dictionary if necessary.
 
+   This function may also be called to get the :py:attr:`~object.__dict__`
+   of the object *o*. Pass ``NULL`` for *context* when calling it.
+   Since this function may need to allocate memory for the
+   dictionary, it may be more efficient to call :c:func:`PyObject_GetAttr`
+   when accessing an attribute on the object.
+
+   On failure, returns ``NULL`` with an exception set.
+
    .. versionadded:: 3.3
 
 
@@ -137,6 +145,16 @@ Object Protocol
    .. versionadded:: 3.3
 
 
+.. c:function:: PyObject** _PyObject_GetDictPtr(PyObject *obj)
+
+   Return a pointer to :py:attr:`~object.__dict__` of the object *obj*.
+   If there is no ``__dict__``, return ``NULL`` without setting an exception.
+
+   This function may need to allocate memory for the
+   dictionary, so it may be more efficient to call :c:func:`PyObject_GetAttr`
+   when accessing an attribute on the object.
+
+
 .. c:function:: PyObject* PyObject_RichCompare(PyObject *o1, PyObject *o2, int opid)
 
    Compare the values of *o1* and *o2* using the operation specified by *opid*,