bpo-40024: Add PyModule_AddType() helper function (GH-19088)

Doc/c-api/module.rst

@@ -441,7 +441,7 @@ state:
 
    Add an object to *module* as *name*.  This is a convenience function which can
    be used from the module's initialization function.  This steals a reference to
-   *value* on success.  Return ``-1`` on error, ``0`` on success.
+   *value* on success. Return ``-1`` on error, ``0`` on success.
 
    .. note::
 
@@ -484,6 +484,16 @@ state:
 
    Add a string constant to *module*.
 
+.. c:function:: int PyModule_AddType(PyObject *module, PyTypeObject *type)
+
+   Add a type object to *module*.
+   The type object is finalized by calling internally :c:func:`PyType_Ready`.
+   The name of the type object is taken from the last component of
+   :c:member:`~PyTypeObject.tp_name` after dot.
+   Return ``-1`` on error, ``0`` on success.
+
+   .. versionadded:: 3.9
+
 
 Module lookup
 ^^^^^^^^^^^^^

Doc/whatsnew/3.9.rst

@@ -538,6 +538,9 @@ Build and C API Changes
   by the internal C API. Remove also ``PyThreadFrameGetter`` type.
   (Contributed by Victor Stinner in :issue:`39946`.)
 
+* The :c:func:`PyModule_AddType` function is added to help adding a type to a module.
+  (Contributed by Dong-hee Na in :issue:`40024`.)
+
 Deprecated
 ==========
 

Include/modsupport.h

@@ -139,6 +139,10 @@ void _PyArg_Fini(void);
 PyAPI_FUNC(int) PyModule_AddObject(PyObject *, const char *, PyObject *);
 PyAPI_FUNC(int) PyModule_AddIntConstant(PyObject *, const char *, long);
 PyAPI_FUNC(int) PyModule_AddStringConstant(PyObject *, const char *, const char *);
+#if !defined(Py_LIMITED_API) || Py_LIMITED_API+0 >= 0x03090000
+/* New in 3.9 */
+PyAPI_FUNC(int) PyModule_AddType(PyObject *module, PyTypeObject *type);
+#endif /* Py_LIMITED_API */
 #define PyModule_AddIntMacro(m, c) PyModule_AddIntConstant(m, #c, c)
 #define PyModule_AddStringMacro(m, c) PyModule_AddStringConstant(m, #c, c)
 

Misc/NEWS.d/next/C API/2020-03-20-18-41-33.bpo-40024.9zHpve.rst

@@ -0,0 +1 @@
+Add :c:func:`PyModule_AddType` helper function: add a type to a module. Patch by Dong-hee Na.

Modules/_collectionsmodule.c

@@ -2565,21 +2565,13 @@ collections_exec(PyObject *module) {
         &PyODict_Type,
         &dequeiter_type,
         &dequereviter_type,
-        &tuplegetter_type,
+        &tuplegetter_type
-        NULL,
     };
 
     defdict_type.tp_base = &PyDict_Type;
 
-    for (int i = 0; typelist[i] != NULL; i++) {
+    for (size_t i = 0; i < Py_ARRAY_LENGTH(typelist); i++) {
-        PyTypeObject *type = typelist[i];
+        if (PyModule_AddType(module, typelist[i]) < 0) {
-        if (PyType_Ready(type) < 0) {
-            return -1;
-        }
-        const char *name = _PyType_Name(type);
-        Py_INCREF(type);
-        if (PyModule_AddObject(module, name, (PyObject *)type) < 0) {
-            Py_DECREF(type);
             return -1;
         }
     }

Modules/_functoolsmodule.c

@@ -1431,13 +1431,10 @@ static struct PyModuleDef _functoolsmodule = {
 PyMODINIT_FUNC
 PyInit__functools(void)
 {
-    int i;
     PyObject *m;
-    const char *name;
     PyTypeObject *typelist[] = {
         &partial_type,
-        &lru_cache_type,
+        &lru_cache_type
-        NULL
     };
 
     m = PyModule_Create(&_functoolsmodule);
@@ -1450,14 +1447,11 @@ PyInit__functools(void)
         return NULL;
     }
 
-    for (i=0 ; typelist[i] != NULL ; i++) {
+    for (size_t i = 0; i < Py_ARRAY_LENGTH(typelist); i++) {
-        if (PyType_Ready(typelist[i]) < 0) {
+        if (PyModule_AddType(m, typelist[i]) < 0) {
             Py_DECREF(m);
             return NULL;
         }
-        name = _PyType_Name(typelist[i]);
-        Py_INCREF(typelist[i]);
-        PyModule_AddObject(m, name, (PyObject *)typelist[i]);
     }
     return m;
 }

Modules/_lzmamodule.c

@@ -1486,19 +1486,13 @@ PyInit__lzma(void)
     if (PyModule_AddObject(m, "LZMAError", Error) == -1)
         return NULL;
 
-    if (PyType_Ready(&Compressor_type) == -1)
+    if (PyModule_AddType(m, &Compressor_type) < 0) {
-        return NULL;
-    Py_INCREF(&Compressor_type);
-    if (PyModule_AddObject(m, "LZMACompressor",
-                           (PyObject *)&Compressor_type) == -1)
         return NULL;
+    }
 
-    if (PyType_Ready(&Decompressor_type) == -1)
+    if (PyModule_AddType(m, &Decompressor_type) < 0) {
-        return NULL;
-    Py_INCREF(&Decompressor_type);
-    if (PyModule_AddObject(m, "LZMADecompressor",
-                           (PyObject *)&Decompressor_type) == -1)
         return NULL;
+    }
 
     return m;
 }

Modules/itertoolsmodule.c

@@ -4724,21 +4724,13 @@ itertoolsmodule_exec(PyObject *m)
         &groupby_type,
         &_grouper_type,
         &tee_type,
-        &teedataobject_type,
+        &teedataobject_type
-        NULL
     };
 
     Py_SET_TYPE(&teedataobject_type, &PyType_Type);
 
-    for (int i = 0; typelist[i] != NULL; i++) {
+    for (size_t i = 0; i < Py_ARRAY_LENGTH(typelist); i++) {
-        PyTypeObject *type = typelist[i];
+        if (PyModule_AddType(m, typelist[i]) < 0) {
-        if (PyType_Ready(type) < 0) {
-            return -1;
-        }
-        const char *name = _PyType_Name(type);
-        Py_INCREF(type);
-        if (PyModule_AddObject(m, name, (PyObject *)type) < 0) {
-            Py_DECREF(type);
             return -1;
         }
     }

Objects/typeobject.c

@@ -431,6 +431,7 @@ check_set_special_type_attr(PyTypeObject *type, PyObject *value, const char *nam
 const char *
 _PyType_Name(PyTypeObject *type)
 {
+    assert(type->tp_name != NULL);
     const char *s = strrchr(type->tp_name, '.');
     if (s == NULL) {
         s = type->tp_name;

Python/modsupport.c

@@ -678,3 +678,22 @@ PyModule_AddStringConstant(PyObject *m, const char *name, const char *value)
     Py_DECREF(o);
     return -1;
 }
+
+int
+PyModule_AddType(PyObject *module, PyTypeObject *type)
+{
+    if (PyType_Ready(type) < 0) {
+        return -1;
+    }
+
+    const char *name = _PyType_Name(type);
+    assert(name != NULL);
+
+    Py_INCREF(type);
+    if (PyModule_AddObject(module, name, (PyObject *)type) < 0) {
+        Py_DECREF(type);
+        return -1;
+    }
+
+    return 0;
+}