diff -r 1f3242fb0c9c Modules/md5module.c
--- a/Modules/md5module.c	Thu Jan 09 19:03:32 2014 -0500
+++ b/Modules/md5module.c	Fri Jan 10 17:27:30 2014 +0800
@@ -34,6 +34,17 @@
 #define MD5_BLOCKSIZE    64
 #define MD5_DIGESTSIZE   16
 
+/*[clinic input]
+module _md5
+class _md5.MD5
+[clinic start generated code]*/
+/*[clinic end generated code: checksum=da39a3ee5e6b4b0d3255bfef95601890afd80709]*/
+/*[python input]
+class MD5object_converter(self_converter):
+    type = "MD5object *"
+[python start generated code]*/
+/*[python end generated code: checksum=da39a3ee5e6b4b0d3255bfef95601890afd80709]*/
+
 /* The structure for storing MD5 info */
 
 struct md5_state {
@@ -401,18 +412,28 @@
     return retval;
 }
 
-PyDoc_STRVAR(MD5_update__doc__,
-"Update this hash object's state with the provided string.");
+/*[clinic input]
+_md5.MD5.update
+    self: MD5object
+    obj: object
+    /
+
+Update this hash object's state with the provided string.
+[clinic start generated code]*/
+
+PyDoc_STRVAR(_md5_MD5_update__doc__,
+"update(obj)\n"
+"Update this hash object\'s state with the provided string.");
+
+#define _MD5_MD5_UPDATE_METHODDEF    \
+    {"update", (PyCFunction)_md5_MD5_update, METH_O, _md5_MD5_update__doc__},
 
 static PyObject *
-MD5_update(MD5object *self, PyObject *args)
+_md5_MD5_update(MD5object *self, PyObject *obj)
+/*[clinic end generated code: checksum=2795c34ad0dccb2e2647c09b51c7bf7389613887]*/
 {
-    PyObject *obj;
     Py_buffer buf;
 
-    if (!PyArg_ParseTuple(args, "O:update", &obj))
-        return NULL;
-
     GET_BUFFER_VIEW_OR_ERROUT(obj, &buf);
 
     md5_process(&self->hash_state, buf.buf, buf.len);
@@ -426,7 +447,7 @@
     {"copy",      (PyCFunction)MD5_copy,      METH_NOARGS,  MD5_copy__doc__},
     {"digest",    (PyCFunction)MD5_digest,    METH_NOARGS,  MD5_digest__doc__},
     {"hexdigest", (PyCFunction)MD5_hexdigest, METH_NOARGS,  MD5_hexdigest__doc__},
-    {"update",    (PyCFunction)MD5_update,    METH_VARARGS, MD5_update__doc__},
+    _MD5_MD5_UPDATE_METHODDEF
     {NULL,        NULL}         /* sentinel */
 };
 
@@ -502,27 +523,53 @@
 
 /* The single module-level function: new() */
 
-PyDoc_STRVAR(MD5_new__doc__,
+/*[clinic input]
+_md5.MD5.md5
+
+    string: object = None
+
+Return a new MD5 hash object; optionally initialized with a string.
+[clinic start generated code]*/
+
+PyDoc_STRVAR(_md5_MD5_md5__doc__,
+"md5(string=None)\n"
 "Return a new MD5 hash object; optionally initialized with a string.");
 
+#define _MD5_MD5_MD5_METHODDEF    \
+    {"md5", (PyCFunction)_md5_MD5_md5, METH_VARARGS|METH_KEYWORDS, _md5_MD5_md5__doc__},
+
 static PyObject *
-MD5_new(PyObject *self, PyObject *args, PyObject *kwdict)
+_md5_MD5_md5_impl(PyObject *self, PyObject *string);
+
+static PyObject *
+_md5_MD5_md5(PyObject *self, PyObject *args, PyObject *kwargs)
 {
-    static char *kwlist[] = {"string", NULL};
+    PyObject *return_value = NULL;
+    static char *_keywords[] = {"string", NULL};
+    PyObject *string = Py_None;
+
+    if (!PyArg_ParseTupleAndKeywords(args, kwargs,
+        "|O:md5", _keywords,
+        &string))
+        goto exit;
+    return_value = _md5_MD5_md5_impl(self, string);
+
+exit:
+    return return_value;
+}
+
+static PyObject *
+_md5_MD5_md5_impl(PyObject *self, PyObject *string)
+/*[clinic end generated code: checksum=a4f98a1e8045ba48089b971b72bfe5a2d0b16c50]*/
+{
     MD5object *new;
-    PyObject *data_obj = NULL;
     Py_buffer buf;
 
-    if (!PyArg_ParseTupleAndKeywords(args, kwdict, "|O:new", kwlist,
-                                     &data_obj)) {
-        return NULL;
-    }
-
-    if (data_obj)
-        GET_BUFFER_VIEW_OR_ERROUT(data_obj, &buf);
+    if (string != Py_None)
+        GET_BUFFER_VIEW_OR_ERROUT(string, &buf);
 
     if ((new = newMD5object()) == NULL) {
-        if (data_obj)
+        if (string != Py_None)
             PyBuffer_Release(&buf);
         return NULL;
     }
@@ -531,11 +578,11 @@
 
     if (PyErr_Occurred()) {
         Py_DECREF(new);
-        if (data_obj)
+        if (string != Py_None)
             PyBuffer_Release(&buf);
         return NULL;
     }
-    if (data_obj) {
+    if (string != Py_None) {
         md5_process(&new->hash_state, buf.buf, buf.len);
         PyBuffer_Release(&buf);
     }
@@ -547,7 +594,7 @@
 /* List of functions exported by this module */
 
 static struct PyMethodDef MD5_functions[] = {
-    {"md5", (PyCFunction)MD5_new, METH_VARARGS|METH_KEYWORDS, MD5_new__doc__},
+    _MD5_MD5_MD5_METHODDEF
     {NULL,      NULL}            /* Sentinel */
 };