bpo-37337: Add _PyObject_CallMethodNoArgs()

python · methane · Jul 8, 2019 · Jun 18, 2019 · Jul 5, 2019 · Jul 1, 2019
commit 338f5575ac80346e34fc4624c767fd2f43dd073a
diff --git a/Doc/c-api/object.rst b/Doc/c-api/object.rst
@@ -353,6 +353,17 @@ Object Protocol
    *NULL* on failure.
 
 
+.. c:function:: PyObject* _PyObject_CallMethodNoArgs(PyObject *obj, PyObject *name)
+
+   Call a method of the Python object *obj* without arguments,
+   where the name of the method is given as a Python string object in *name*.
+
+   Return the result of the call on success, or raise an exception and return
+   *NULL* on failure.
+
+   .. versionadded:: 3.9
+
+
 .. c:function:: PyObject* _PyObject_Vectorcall(PyObject *callable, PyObject *const *args, size_t nargsf, PyObject *kwnames)
 
    Call a callable Python object *callable*, using

diff --git a/Include/cpython/abstract.h b/Include/cpython/abstract.h
@@ -162,6 +162,14 @@ PyAPI_FUNC(PyObject *) _PyObject_VectorcallMethod(
     PyObject *name, PyObject *const *args,
     size_t nargsf, PyObject *kwnames);
 
+static inline PyObject *
+_PyObject_CallMethodNoArgs(PyObject *self, PyObject *name)
+{
+    PyObject *args[1] = {self};
+    return _PyObject_VectorcallMethod(name, args,
+           1 | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL);
+}
+
 /* Like PyObject_CallMethod(), but expect a _Py_Identifier*
    as the method name. */
 PyAPI_FUNC(PyObject *) _PyObject_CallMethodId(PyObject *obj,
@@ -190,6 +198,14 @@ _PyObject_VectorcallMethodId(
     return _PyObject_VectorcallMethod(oname, args, nargsf, kwnames);
 }
 
+static inline PyObject *
+_PyObject_CallMethodIdNoArgs(PyObject *self, _Py_Identifier *name)
+{
+    PyObject *args[1] = {self};
+    return _PyOb
EDBE
ject_VectorcallMethodId(name, args,
+           1 | PY_VECTORCALL_ARGUMENTS_OFFSET, NULL);
+}
+
 PyAPI_FUNC(int) _PyObject_HasLen(PyObject *o);
 
 /* Guess the size of object 'o' using len(o) or o.__length_hint__().

diff --git a/Misc/NEWS.d/next/C API/2019-06-19-12-06-31.bpo-37337.gXIGyU.rst b/Misc/NEWS.d/next/C API/2019-06-19-12-06-31.bpo-37337.gXIGyU.rst
@@ -1 +1,2 @@
-Add :c:func:`_PyObject_VectorcallMethod` for fast calling of methods.
+Add fast functions for calling methods: :c:func:`_PyObject_VectorcallMethod`
+and :c:func:`_PyObject_CallMethodNoArgs`
diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
@@ -333,7 +333,7 @@ get_event_loop(void)
         return NULL;
     }
 
-    loop = _PyObject_CallMethodId(policy, &PyId_get_event_loop, NULL);
+    loop = _PyObject_CallMethodIdNoArgs(policy, &PyId_get_event_loop);
     Py_DECREF(policy);
     return loop;
 }
@@ -494,7 +494,7 @@ future_init(FutureObj *fut, PyObject *loop)
     }
     fut->fut_loop = loop;
 
-    res = _PyObject_CallMethodId(fut->fut_loop, &PyId_get_debug, NULL);
+    res = _PyObject_CallMethodIdNoArgs(fut->fut_loop, &PyId_get_debug);
     if (res == NULL) {
         return -1;
     }
@@ -1297,9 +1297,8 @@ FutureObj_repr(FutureObj *fut)
 
     ENSURE_FUTURE_ALIVE(fut)
 
-    PyObject *rinfo = _PyObject_CallMethodIdObjArgs((PyObject*)fut,
-                                                    &PyId__repr_info,
-                                                    NULL);
+    PyObject *rinfo = _PyObject_CallMethodIdNoArgs((PyObject*)fut,
+                                                   &PyId__repr_info);
     if (rinfo == NULL) {
         return NULL;
     }
@@ -2200,8 +2199,7 @@ _asyncio_Task_cancel_impl(TaskObj *self)
         PyObject *res;
         int is_true;
 
-        res = _PyObject_CallMethodId(
-            self->task_fut_waiter, &PyId_cancel, NULL);
+        res = _PyObject_CallMethodIdNoArgs(self->task_fut_waiter, &PyId_cancel);
         if (res == NULL) {
             return NULL;
         }
@@ -2738,7 +2736,7 @@ task_step_impl(TaskObj *task, PyObject *exc)
         if (task->task_must_cancel) {
             PyObject *r;
             int is_true;
-            r = _PyObject_CallMethodId(result, &PyId_cancel, NULL);
+            r = _PyObject_CallMethodIdNoArgs(result, &PyId_cancel);
             if (r == NULL) {
                 return NULL;
             }
@@ -2829,7 +2827,7 @@ task_step_impl(TaskObj *task, PyObject *exc)
         if (task->task_must_cancel) {
             PyObject *r;
             int is_true;
-            r = _PyObject_CallMethodId(result, &PyId_cancel, NULL);
+            r = _PyObject_CallMethodIdNoArgs(result, &PyId_cancel);
             if (r == NULL) {
                 return NULL;
             }

diff --git a/Modules/_collectionsmodule.c b/Modules/_collectionsmodule.c
@@ -2040,7 +2040,7 @@ defdict_reduce(defdictobject *dd, PyObject *Py_UNUSED(ignored))
         args = PyTuple_Pack(1, dd->default_factory);
     if (args == NULL)
         return NULL;
-    items = _PyObject_CallMethodId((PyObject *)dd, &PyId_items, NULL);
+    items = _PyObject_CallMethodIdNoArgs((PyObject *)dd, &PyId_items);
     if (items == NULL) {
         Py_DECREF(args);
         return NULL;

diff --git a/Modules/_ctypes/_ctypes.c b/Modules/_ctypes/_ctypes.c
@@ -3974,7 +3974,7 @@ _build_result(PyObject *result, PyObject *callargs,
             _Py_IDENTIFIER(__ctypes_from_outparam__);
 
             v = PyTuple_GET_ITEM(callargs, i);
-            v = _PyObject_CallMethodId
10000
(v, &PyId___ctypes_from_outparam__, NULL);
+            v = _PyObject_CallMethodIdNoArgs(v, &PyId___ctypes_from_outparam__);
             if (v == NULL || numretvals == 1) {
                 Py_DECREF(callargs);
                 return v;

diff --git a/Modules/_cursesmodule.c b/Modules/_cursesmodule.c
@@ -2906,7 +2906,7 @@ _curses_getwin(PyObject *module, PyObject *file)
     if (_Py_set_inheritable(fileno(fp), 0, NULL) < 0)
         goto error;
 
-    data = _PyObject_CallMethodId(file, &PyId_read, NULL);
+    data = _PyObject_CallMethodIdNoArgs(file, &PyId_read);
     if (data == NULL)
         goto error;
     if (!PyBytes_Check(data)) {

diff --git a/Modules/_datetimemodule.c b/Modules/_datetimemodule.c
@@ -1659,7 +1659,7 @@ time_time(void)
     if (time != NULL) {
         _Py_IDENTIFIER(time);
 
-        result = _PyObject_CallMethodId(time, &PyId_time, NULL);
+        result = _PyObject_CallMethodIdNoArgs(time, &PyId_time);
         Py_DECREF(time);
     }
     return result;
@@ -1918,7 +1918,7 @@ get_float_as_integer_ratio(PyObject *floatobj)
     PyObject *ratio;
 
     assert(floatobj && PyFloat_Check(floatobj));
-    ratio = _PyObject_CallMethodId(floatobj, &PyId_as_integer_ratio, NULL);
+    ratio = _PyObject_CallMethodIdNoArgs(floatobj, &PyId_as_integer_ratio);
     if (ratio == NULL) {
         return NULL;
     }
@@ -3162,7 +3162,7 @@ date_isoformat(PyDateTime_Date *self, PyObject *Py_UNUSED(ignored))
 static PyObject *
 date_str(PyDateTime_Date *self)
 {
-    return _PyObject_CallMethodId((PyObject *)self, &PyId_isoformat, NULL);
+    return _PyObject_CallMethodIdNoArgs((PyObject *)self, &PyId_isoformat);
 }
 
 
@@ -3188,7 +3188,7 @@ date_strftime(PyDateTime_Date *self, PyObject *args, PyObject *kw)
                                       &format))
         return NULL;
 
-    tuple = _PyObject_CallMethodId((PyObject *)self, &PyId_timetuple, NULL);
+    tuple = _PyObject_CallMethodIdNoArgs((PyObject *)self, &PyId_timetuple);
     if (tuple == NULL)
         return NULL;
     result = wrap_strftime((PyObject *)self, format, tuple,
@@ -4175,7 +4175,7 @@ time_repr(PyDateTime_Time *self)
 static PyObject *
 time_str(PyDateTime_Time *self)
 {
-    return _PyObject_CallMethodId((PyObject *)self, &PyId_isoformat, NULL);
+    return _PyObject_CallMethodIdNoArgs((PyObject *)self, &PyId_isoformat);
 }
 
 static PyObject *

diff --git a/Modules/_dbmmodule.c b/Modules/_dbmmodule.c
@@ -370,7 +370,7 @@ static PyObject *
 dbm__exit__(PyObject *self, PyObject *args)
 {
     _Py_IDENTIFIER(close);
-    return _PyObject_CallMethodId(self, &PyId_close, NULL);
+    return _PyObject_CallMethodIdNoArgs(self, &PyId_close);
 }
 
 

diff --git a/Modules/_gdbmmodule.c b/Modules/_gdbmmodule.c
@@ -497,7 +497,7 @@ static PyObject *
 dbm__exit__(PyObject *self, PyObject *args)
 {
     _Py_IDENTIFIER(close);
-    return _PyObject_CallMethodId(self, &PyId_close, NULL);
+    return _PyObject_CallMethodIdNoArgs(self, &PyId_close);
 }
 
 static PyMethodDef dbm_methods[] = {

diff --git a/Modules/_io/_iomodule.c b/Modules/_io/_iomodule.c
@@ -400,7 +400,7 @@ _io_open_impl(PyObject *module, PyObject *file, const char *mode,
 
     /* buffering */
     if (buffering < 0) {
-        PyObject *res = _PyObject_CallMethodId(raw, &PyId_isatty, NULL);
+        PyObject *res = _PyObject_CallMethodIdNoArgs(raw, &PyId_isatty);
         if (res == NULL)
             goto error;
         isatty = PyLong_AsLong(res);
@@ -494,7 +494,7 @@ _io_open_impl(PyObject *module, PyObject *file, const char *mode,
     if (result != NULL) {
         PyObject *exc, *val, *tb, *close_result;
         PyErr_Fetch(&exc, &val, &tb);
-        close_result = _PyObject_CallMethodId(result, &PyId_close, NULL);
+        close_result = _PyObject_CallMethodIdNoArgs(result, &PyId_close);
         _PyErr_ChainExceptions(exc, val, tb);
         Py_XDECREF(close_result);
         Py_DECREF(result);

diff --git a/Modules/_io/bufferedio.c b/Modules/_io/bufferedio.c
@@ -461,7 +461,7 @@ static PyObject *
 buffered_simple_flush(buffered *self, PyObject *args)
 {
     CHECK_INITIALIZED(self)
-    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_flush, NULL);
+    return _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_flush);
 }
 
 static int
@@ -513,15 +513,15 @@ buffered_close(buffered *self, PyObject *args)
     }
     /* flush() will most probably re-take the lock, so drop it first */
     LEAVE_BUFFERED(self)
-    res = PyObject_CallMethodObjArgs((PyObject *)self, _PyIO_str_flush, NULL);
+    res = _PyObject_CallMethodNoArgs((PyObject *)self, _PyIO_str_flush);
     if (!ENTER_BUFFERED(self))
         return NULL;
     if (res == NULL)
         PyErr_Fetch(&exc, &val, &tb);
     else
         Py_DECREF(res);
 
-    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_close, NULL);
+    res = _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_close);
 
     if (self->buffer) {
         PyMem_Free(self->buffer);
@@ -545,7 +545,7 @@ buffered_detach(buffered *self, PyObject *Py_UNUSED(ignored))
 {
     PyObject *raw, *res;
     CHECK_INITIALIZED(self)
-    res = PyObject_CallMethodObjArgs((PyObject *)self, _PyIO_str_flush, NULL);
+    res = _PyObject_CallMethodNoArgs((PyObject *)self, _PyIO_str_flush);
     if (res == NULL)
         return NULL;
     Py_DECREF(res);
@@ -562,21 +562,21 @@ static PyObject *
 buffered_seekable(buffered *self, PyObject *Py_UNUSED(ignored))
 {
     CHECK_INITIALIZED(self)
-    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_seekable, NULL);
+    return _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_seekable);
 }
 
 static PyObject *
 buffered_readable(buffered *self, PyObject *Py_UNUSED(ignored))
 {
     CHECK_INITIALIZED(self)
-    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_readable, NULL);
+    return _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_readable);
 }
 
 static PyObject *
 buffered_writable(buffered *self, PyObject *Py_UNUSED(ignored))
 {
     CHECK_INITIALIZED(self)
-    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_writable, NULL);
+    return _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_writable);
 }
 
 static PyObject *
@@ -599,14 +599,14 @@ static PyObject *
 buffered_fileno(buffered *self, PyObject *Py_UNUSED(ignored))
 {
     CHECK_INITIALIZED(self)
-    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_fileno, NULL);
+    return _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_fileno);
 }
 
 static PyObject *
 buffered_isatty(buffered *self, PyObject *Py_UNUSED(ignored))
 {
     CHECK_INITIALIZED(self)
-    return PyObject_CallMethodObjArgs(self->raw, _PyIO_str_isatty, NULL);
+    return _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_isatty);
 }
 
 /* Forward decls */
@@ -670,7 +670,7 @@ _buffered_raw_tell(buffered *self)
 {
     Py_off_t n;
     PyObject *res;
-    res = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_tell, NULL);
+    res = _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_tell);
     if (res == NULL)
         return -1;
     n = PyNumber_AsOff_t(res, PyExc_ValueError);
@@ -1350,8 +1350,8 @@ buffered_iternext(buffered *self)
         line = _buffered_readline(self, -1);
     }
     else {
-        line = PyObject_CallMethodObjArgs((PyObject *)self,
-                                           _PyIO_str_readline, NULL);
+        line = _PyObject_CallMethodNoArgs((PyObject *)self,
+                                             _PyIO_str_readline);
         if (line && !PyBytes_Check(line)) {
             PyErr_Format(PyExc_OSError,
                          "readline() should have returned a bytes object, "
@@ -1566,7 +1566,7 @@ _bufferedreader_read_all(buffered *self)
         }
 
         /* Read until EOF or until read() would block. */
-        data = PyObject_CallMethodObjArgs(self->raw, _PyIO_str_read, NULL);
+        data = _PyObject_CallMethodNoArgs(self->raw, _PyIO_str_read);
         if (data == NULL)
             goto cleanup;
         if (data != Py_None && !PyBytes_Check(data)) {

diff --git a/Modules/_io/iobase.c b/Modules/_io/iobase.c
@@ -235,7 +235,7 @@ _io__IOBase_close_impl(PyObject *self)
         Py_RETURN_NONE;
     }
 
-    res = PyObject_CallMethodObjArgs(self, _PyIO_str_flush, NULL);
+    res = _PyObject_CallMethodNoArgs(self, _PyIO_str_flush);
 
     PyErr_Fetch(&exc, &val, &tb);
     rc = _PyObject_SetAttrId(self, &PyId___IOBase_closed, Py_True);
@@ -281,8 +281,7 @@ iobase_finalize(PyObject *self)
            finalization process. */
         if (_PyObject_SetAttrId(self, &PyId__finalizing, Py_True))
             PyErr_Clear();
-        res = PyObject_CallMethodObjArgs((PyObject *) self, _PyIO_str_close,
-                                          NULL);
+        res = _PyObject_CallMethodNoArgs((PyObject *)self, _PyIO_str_close);
         /* Silencing I/O errors is bad, but printing spurious tracebacks is
            equally as bad, and potentially more frequent (because of
            shutdown issues). */
@@ -383,7 +382,7 @@ _io__IOBase_seekable_impl(PyObject *self)
 PyObject *
 _PyIOBase_check_seekable(PyObject *self, PyObject *args)
 {
-    PyObject *res  = PyObject_CallMethodObjArgs(self, _PyIO_str_seekable, NULL);
+    PyObject *res  = _PyObject_CallMethodNoArgs(self, _PyIO_str_seekable);
     if (res == NULL)
         return NULL;
     if (res != Py_True) {
@@ -416,7 +415,7 @@ _io__IOBase_readable_impl(PyObject *self)
 PyObject *
 _PyIOBase_check_readable(PyObject *self, PyObject *args)
 {
-    PyObject *res  = PyObject_CallMethodObjArgs(self, _PyIO_str_readable, NULL);
+    PyObject *res = _PyObject_CallMethodNoArgs(self, _PyIO_str_readable);
     if (res == NULL)
         return NULL;
     if (res != Py_True) {
@@ -449,7 +448,7 @@ _io__IOBase_writable_impl(PyObject *self)
 PyObject *
 _PyIOBase_check_writable(PyObject *self, PyObject *args)
 {
-    PyObject *res  = PyObject_CallMethodObjArgs(self, _PyIO_str_writable, NULL);
+    PyObject *res = _PyObject_CallMethodNoArgs(self, _PyIO_str_writable);
     if (res == NULL)
         return NULL;
     if (res != Py_True) {
@@ -478,7 +477,7 @@ iobase_enter(PyObject *self, PyObject *args)
 static PyObject *
 iobase_exit(PyObject *self, PyObject *args)
 {
-    return PyObject_CallMethodObjArgs(self, _PyIO_str_close, NULL);
+    return _PyObject_CallMethodNoArgs(self, _PyIO_str_close);
 }
 
 /* Lower-level APIs */
@@ -656,7 +655,7 @@ iobase_iter(PyObject *self)
 static PyObject *
 iobase_iternext(PyObject *self)
 {
-    PyObject *line = PyObject_CallMethodObjArgs(self, _PyIO_str_readline, NULL);
+    PyObject *line = _PyObject_CallMethodNoArgs(self, _PyIO_str_readline);
 
     if (line == NULL)
         return NULL;
@@ -921,7 +920,7 @@ _io__RawIOBase_read_impl(PyObject *self, Py_ssize_t n)
     if (n < 0) {
         _Py_IDENTIFIER(readall);
 
-        return _PyObject_CallMethodId(self, &PyId_readall, NULL);
+        return _PyObject_CallMethodIdNoArgs(self, &PyId_readall);
     }
 
     /* TODO: allocate a bytes object directly instead and manually construct