bpo-1635741: Port _sha1, _sha512, _md5 to multiphase init (GH-21818)

Port the _sha1, _sha512, and _md5 extension modules
to multi-phase initialization API (PEP 489).

1 files changed, 92 insertions, 64 deletions

diff --git a/Modules/sha1module.c b/Modules/sha1module.c
index b0656d8..c22437d 100644
--- a/Modules/sha1module.c
+++ b/Modules/sha1module.c
@@ -295,13 +295,22 @@ sha1_done(struct sha1_state *sha1, unsigned char *out)
  * ------------------------------------------------------------------------
  */
 
-static PyTypeObject SHA1type;
+typedef struct {
+    PyTypeObject* sha1_type;
+} SHA1State;
 
+static inline SHA1State*
+sha1_get_state(PyObject *module)
+{
+    void *state = PyModule_GetState(module);
+    assert(state != NULL);
+    return (SHA1State *)state;
+}
 
 static SHA1object *
-newSHA1object(void)
+newSHA1object(SHA1State *st)
 {
-    return (SHA1object *)PyObject_New(SHA1object, &SHA1type);
+    return (SHA1object *)PyObject_New(SHA1object, st->sha1_type);
 }
 
 
@@ -310,7 +319,9 @@ newSHA1object(void)
 static void
 SHA1_dealloc(PyObject *ptr)
 {
+    PyTypeObject *tp = Py_TYPE(ptr);
     PyObject_Del(ptr);
+    Py_DECREF(tp);
 }
 
 
@@ -319,16 +330,19 @@ SHA1_dealloc(PyObject *ptr)
 /*[clinic input]
 SHA1Type.copy
 
+    cls: defining_class
+
 Return a copy of the hash object.
 [clinic start generated code]*/
 
 static PyObject *
-SHA1Type_copy_impl(SHA1object *self)
-/*[clinic end generated code: output=b4e001264620f02a input=b7eae10df6f89b36]*/
+SHA1Type_copy_impl(SHA1object *self, PyTypeObject *cls)
+/*[clinic end generated code: output=b32d4461ce8bc7a7 input=6c22e66fcc34c58e]*/
 {
-    SHA1object *newobj;
+    SHA1State *st = PyType_GetModuleState(cls);
 
-    if ((newobj = newSHA1object()) == NULL)
+    SHA1object *newobj;
+    if ((newobj = newSHA1object(st)) == NULL)
         return NULL;
 
     newobj->hash_state = self->hash_state;
@@ -422,7 +436,6 @@ sha1_get_digest_size(PyObject *self, void *closure)
     return PyLong_FromLong(SHA1_DIGESTSIZE);
 }
 
-
 static PyGetSetDef SHA1_getseters[] = {
     {"block_size",
      (getter)SHA1_get_block_size, NULL,
@@ -439,40 +452,19 @@ static PyGetSetDef SHA1_getseters[] = {
     {NULL}  /* Sentinel */
 };
 
-static PyTypeObject SHA1type = {
-    PyVarObject_HEAD_INIT(NULL, 0)
-    "_sha1.sha1",               /*tp_name*/
-    sizeof(SHA1object), /*tp_basicsize*/
-    0,                  /*tp_itemsize*/
-    /* methods */
-    SHA1_dealloc,       /*tp_dealloc*/
-    0,                  /*tp_vectorcall_offset*/
-    0,                  /*tp_getattr*/
-    0,                  /*tp_setattr*/
-    0,                  /*tp_as_async*/
-    0,                  /*tp_repr*/
-    0,                  /*tp_as_number*/
-    0,                  /*tp_as_sequence*/
-    0,                  /*tp_as_mapping*/
-    0,                  /*tp_hash*/
-    0,                  /*tp_call*/
-    0,                  /*tp_str*/
-    0,                  /*tp_getattro*/
-    0,                  /*tp_setattro*/
-    0,                  /*tp_as_buffer*/
-    Py_TPFLAGS_DEFAULT, /*tp_flags*/
-    0,                  /*tp_doc*/
-    0,                  /*tp_traverse*/
-    0,                  /*tp_clear*/
-    0,                  /*tp_richcompare*/
-    0,                  /*tp_weaklistoffset*/
-    0,                  /*tp_iter*/
-    0,                  /*tp_iternext*/
-    SHA1_methods,       /* tp_methods */
-    NULL,               /* tp_members */
-    SHA1_getseters,      /* tp_getset */
+static PyType_Slot sha1_type_slots[] = {
+    {Py_tp_dealloc, SHA1_dealloc},
+    {Py_tp_methods, SHA1_methods},
+    {Py_tp_getset, SHA1_getseters},
+    {0,0}
 };
 
+static PyType_Spec sha1_type_spec = {
+    .name = "_sha1.sha1",
+    .basicsize =  sizeof(SHA1object),
+    .flags = Py_TPFLAGS_DEFAULT,
+    .slots = sha1_type_slots
+};
 
 /* The single module-level function: new() */
 
@@ -496,7 +488,8 @@ _sha1_sha1_impl(PyObject *module, PyObject *string, int usedforsecurity)
     if (string)
         GET_BUFFER_VIEW_OR_ERROUT(string, &buf);
 
-    if ((new = newSHA1object()) == NULL) {
+    SHA1State *st = sha1_get_state(module);
+    if ((new = newSHA1object(st)) == NULL) {
         if (string)
             PyBuffer_Release(&buf);
         return NULL;
@@ -526,37 +519,72 @@ static struct PyMethodDef SHA1_functions[] = {
     {NULL,      NULL}            /* Sentinel */
 };
 
+static int
+_sha1_traverse(PyObject *module, visitproc visit, void *arg)
+{
+    SHA1State *state = sha1_get_state(module);
+    Py_VISIT(state->sha1_type);
+    return 0;
+}
+
+static int
+_sha1_clear(PyObject *module)
+{
+    SHA1State *state = sha1_get_state(module);
+    Py_CLEAR(state->sha1_type);
+    return 0;
+}
+
+static void
+_sha1_free(void *module)
+{
+    _sha1_clear((PyObject *)module);
+}
+
+static int
+_sha1_exec(PyObject *module)
+{
+    SHA1State* st = sha1_get_state(module);
+
+    st->sha1_type = (PyTypeObject *)PyType_FromModuleAndSpec(
+        module, &sha1_type_spec, NULL);
+
+    if (st->sha1_type == NULL) {
+        return -1;
+    }
+
+    Py_INCREF(st->sha1_type);
+    if (PyModule_AddObject(module, 
+                           "SHA1Type",
+                           (PyObject *)st->sha1_type) < 0) {
+        Py_DECREF(st->sha1_type);
+        return -1;
+    }
+
+    return 0;
+}
+
 
 /* Initialize this module. */
 
+static PyModuleDef_Slot _sha1_slots[] = {
+    {Py_mod_exec, _sha1_exec},
+    {0, NULL}
+};
+
 static struct PyModuleDef _sha1module = {
         PyModuleDef_HEAD_INIT,
-        "_sha1",
-        NULL,
-        -1,
-        SHA1_functions,
-        NULL,
-        NULL,
-        NULL,
-        NULL
+        .m_name = "_sha1",
+        .m_size = sizeof(SHA1State),
+        .m_methods = SHA1_functions,
+        .m_slots = _sha1_slots,
+        .m_traverse = _sha1_traverse,
+        .m_clear = _sha1_clear,
+        .m_free = _sha1_free
 };
 
 PyMODINIT_FUNC
 PyInit__sha1(void)
 {
-    PyObject *m;
-
-    Py_SET_TYPE(&SHA1type, &PyType_Type);
-    if (PyType_Ready(&SHA1type) < 0) {
-        return NULL;
-    }
-
-    m = PyModule_Create(&_sha1module);
-    if (m == NULL) {
-        return NULL;
-    }
-
-    Py_INCREF((PyObject *)&SHA1type);
-    PyModule_AddObject(m, "SHA1Type", (PyObject *)&SHA1type);
-    return m;
+    return PyModuleDef_Init(&_sha1module);
 }