Replace PyObject_CallFunctionObjArgs() with fastcall

* PyObject_CallFunctionObjArgs(func, NULL) => _PyObject_CallNoArg(func)
* PyObject_CallFunctionObjArgs(func, arg, NULL) => _PyObject_CallArg1(func, arg)

PyObject_CallFunctionObjArgs() allocates 40 bytes on the C stack and requires
extra work to "parse" C arguments to build a C array of PyObject*.

_PyObject_CallNoArg() and _PyObject_CallArg1() are simpler and don't allocate
memory on the C stack.

This change is part of the fastcall project. The change on listsort() is
related to the issue #23507.

11 files changed, 31 insertions, 33 deletions

diff --git a/Modules/_asynciomodule.c b/Modules/_asynciomodule.c
index b65fc02..19503a8 100644
--- a/Modules/_asynciomodule.c
+++ b/Modules/_asynciomodule.c
@@ -721,8 +721,7 @@ static PyObject *
 _asyncio_Future__repr_info_impl(FutureObj *self)
 /*[clinic end generated code: output=fa69e901bd176cfb input=f21504d8e2ae1ca2]*/
 {
-    return PyObject_CallFunctionObjArgs(
-        asyncio_future_repr_info_func, self, NULL);
+    return _PyObject_CallArg1(asyncio_future_repr_info_func, self);
 }
 
 /*[clinic input]
@@ -1535,8 +1534,7 @@ static PyObject *
 _asyncio_Task__repr_info_impl(TaskObj *self)
 /*[clinic end generated code: output=6a490eb66d5ba34b input=3c6d051ed3ddec8b]*/
 {
-    return PyObject_CallFunctionObjArgs(
-        asyncio_task_repr_info_func, self, NULL);
+    return _PyObject_CallArg1(asyncio_task_repr_info_func, self);
 }
 
 /*[clinic input]
@@ -1896,7 +1894,7 @@ task_set_error_soon(TaskObj *task, PyObject *et, const char *format, ...)
         return NULL;
     }
 
-    PyObject *e = PyObject_CallFunctionObjArgs(et, msg, NULL);
+    PyObject *e = _PyObject_CallArg1(et, msg);
     Py_DECREF(msg);
     if (e == NULL) {
         return NULL;
@@ -1946,7 +1944,7 @@ task_step_impl(TaskObj *task, PyObject *exc)
 
         if (!exc) {
             /* exc was not a CancelledError */
-            exc = PyObject_CallFunctionObjArgs(asyncio_CancelledError, NULL);
+            exc = _PyObject_CallNoArg(asyncio_CancelledError);
             if (!exc) {
                 goto fail;
             }
@@ -2176,7 +2174,7 @@ task_step_impl(TaskObj *task, PyObject *exc)
     }
 
     /* Check if `result` is a generator */
-    o = PyObject_CallFunctionObjArgs(inspect_isgenerator, result, NULL);
+    o = _PyObject_CallArg1(inspect_isgenerator, result);
     if (o == NULL) {
         /* An exception in inspect.isgenerator */
         goto fail;
diff --git a/Modules/_csv.c b/Modules/_csv.c
index e5324ae..08907db 100644
--- a/Modules/_csv.c
+++ b/Modules/_csv.c
@@ -1259,7 +1259,7 @@ csv_writerow(WriterObj *self, PyObject *seq)
                                      (void *) self->rec, self->rec_len);
     if (line == NULL)
         return NULL;
-    result = PyObject_CallFunctionObjArgs(self->writeline, line, NULL);
+    result = _PyObject_CallArg1(self->writeline, line);
     Py_DECREF(line);
     return result;
 }
diff --git a/Modules/_elementtree.c b/Modules/_elementtree.c
index 71245c2..f3e1e9f 100644
--- a/Modules/_elementtree.c
+++ b/Modules/_elementtree.c
@@ -2457,7 +2457,7 @@ treebuilder_append_event(TreeBuilderObject *self, PyObject *action,
         PyObject *event = PyTuple_Pack(2, action, node);
         if (event == NULL)
             return -1;
-        res = PyObject_CallFunctionObjArgs(self->events_append, event, NULL);
+        res = _PyObject_CallArg1(self->events_append, event);
         Py_DECREF(event);
         if (res == NULL)
             return -1;
diff --git a/Modules/_json.c b/Modules/_json.c
index d3dbf98..da7b2ed 100644
--- a/Modules/_json.c
+++ b/Modules/_json.c
@@ -813,14 +813,14 @@ _parse_object_unicode(PyScannerObject *s, PyObject *pystr, Py_ssize_t idx, Py_ss
     *next_idx_ptr = idx + 1;
 
     if (has_pairs_hook) {
-        val = PyObject_CallFunctionObjArgs(s->object_pairs_hook, rval, NULL);
+        val = _PyObject_CallArg1(s->object_pairs_hook, rval);
         Py_DECREF(rval);
         return val;
     }
 
     /* if object_hook is not None: rval = object_hook(rval) */
     if (s->object_hook != Py_None) {
-        val = PyObject_CallFunctionObjArgs(s->object_hook, rval, NULL);
+        val = _PyObject_CallArg1(s->object_hook, rval);
         Py_DECREF(rval);
         return val;
     }
@@ -924,7 +924,7 @@ _parse_constant(PyScannerObject *s, const char *constant, Py_ssize_t idx, Py_ssi
         return NULL;
 
     /* rval = parse_constant(constant) */
-    rval = PyObject_CallFunctionObjArgs(s->parse_constant, cstr, NULL);
+    rval = _PyObject_CallArg1(s->parse_constant, cstr);
     idx += PyUnicode_GET_LENGTH(cstr);
     Py_DECREF(cstr);
     *next_idx_ptr = idx;
@@ -1023,7 +1023,7 @@ _match_number_unicode(PyScannerObject *s, PyObject *pystr, Py_ssize_t start, Py_
                                            idx - start);
         if (numstr == NULL)
             return NULL;
-        rval = PyObject_CallFunctionObjArgs(custom_func, numstr, NULL);
+        rval = _PyObject_CallArg1(custom_func, numstr);
     }
     else {
         Py_ssize_t i, n;
@@ -1475,7 +1475,7 @@ encoder_encode_string(PyEncoderObject *s, PyObject *obj)
     if (s->fast_encode)
         return s->fast_encode(NULL, obj);
     else
-        return PyObject_CallFunctionObjArgs(s->encoder, obj, NULL);
+        return _PyObject_CallArg1(s->encoder, obj);
 }
 
 static int
@@ -1553,7 +1553,7 @@ encoder_listencode_obj(PyEncoderObject *s, _PyAccu *acc,
                 return -1;
             }
         }
-        newobj = PyObject_CallFunctionObjArgs(s->defaultfn, obj, NULL);
+        newobj = _PyObject_CallArg1(s->defaultfn, obj);
         if (newobj == NULL) {
             Py_XDECREF(ident);
             return -1;
diff --git a/Modules/_ssl.c b/Modules/_ssl.c
index b198857..6003476 100644
--- a/Modules/_ssl.c
+++ b/Modules/_ssl.c
@@ -3197,7 +3197,7 @@ _password_callback(char *buf, int size, int rwflag, void *userdata)
     PySSL_END_ALLOW_THREADS_S(pw_info->thread_state);
 
     if (pw_info->callable) {
-        fn_ret = PyObject_CallFunctionObjArgs(pw_info->callable, NULL);
+        fn_ret = _PyObject_CallNoArg(pw_info->callable);
         if (!fn_ret) {
             /* TODO: It would be nice to move _ctypes_add_traceback() into the
                core python API, so we could use it to add a frame here */
diff --git a/Modules/_struct.c b/Modules/_struct.c
index 1d7a935..4ef5c89 100644
--- a/Modules/_struct.c
+++ b/Modules/_struct.c
@@ -2046,7 +2046,7 @@ cache_struct(PyObject *fmt)
         return s_object;
     }
 
-    s_object = PyObject_CallFunctionObjArgs((PyObject *)(&PyStructType), fmt, NULL);
+    s_object = _PyObject_CallArg1((PyObject *)(&PyStructType), fmt);
     if (s_object != NULL) {
         if (PyDict_Size(cache) >= MAXCACHE)
             PyDict_Clear(cache);
diff --git a/Modules/_testbuffer.c b/Modules/_testbuffer.c
index 13d3ccc..bf22f29 100644
--- a/Modules/_testbuffer.c
+++ b/Modules/_testbuffer.c
@@ -312,7 +312,7 @@ pack_from_list(PyObject *obj, PyObject *items, PyObject *format,
     assert(PyObject_CheckBuffer(obj));
     assert(PyList_Check(items) || PyTuple_Check(items));
 
-    structobj = PyObject_CallFunctionObjArgs(Struct, format, NULL);
+    structobj = _PyObject_CallArg1(Struct, format);
     if (structobj == NULL)
         return -1;
 
@@ -406,7 +406,7 @@ pack_single(char *ptr, PyObject *item, const char *fmt, Py_ssize_t itemsize)
     if (format == NULL)
         goto out;
 
-    structobj = PyObject_CallFunctionObjArgs(Struct, format, NULL);
+    structobj = _PyObject_CallArg1(Struct, format);
     if (structobj == NULL)
         goto out;
 
@@ -620,7 +620,7 @@ unpack_rec(PyObject *unpack_from, char *ptr, PyObject *mview, char *item,
 
     if (ndim == 0) {
         memcpy(item, ptr, itemsize);
-        x = PyObject_CallFunctionObjArgs(unpack_from, mview, NULL);
+        x = _PyObject_CallArg1(unpack_from, mview);
         if (x == NULL)
             return NULL;
         if (PyTuple_GET_SIZE(x) == 1) {
@@ -696,7 +696,7 @@ ndarray_as_list(NDArrayObject *nd)
     if (format == NULL)
         goto out;
 
-    structobj = PyObject_CallFunctionObjArgs(Struct, format, NULL);
+    structobj = _PyObject_CallArg1(Struct, format);
     Py_DECREF(format);
     if (structobj == NULL)
         goto out;
@@ -788,7 +788,7 @@ get_itemsize(PyObject *format)
     PyObject *tmp;
     Py_ssize_t itemsize;
 
-    tmp = PyObject_CallFunctionObjArgs(calcsize, format, NULL);
+    tmp = _PyObject_CallArg1(calcsize, format);
     if (tmp == NULL)
         return -1;
     itemsize = PyLong_AsSsize_t(tmp);
diff --git a/Modules/gcmodule.c b/Modules/gcmodule.c
index 754348e..a53cf20 100644
--- a/Modules/gcmodule.c
+++ b/Modules/gcmodule.c
@@ -709,7 +709,7 @@ handle_weakrefs(PyGC_Head *unreachable, PyGC_Head *old)
         assert(callback != NULL);
 
         /* copy-paste of weakrefobject.c's handle_callback() */
-        temp = PyObject_CallFunctionObjArgs(callback, wr, NULL);
+        temp = _PyObject_CallArg1(callback, wr);
         if (temp == NULL)
             PyErr_WriteUnraisable(callback);
         else
diff --git a/Modules/itertoolsmodule.c b/Modules/itertoolsmodule.c
index 6bf04cb..5ea69a0 100644
--- a/Modules/itertoolsmodule.c
+++ b/Modules/itertoolsmodule.c
@@ -101,7 +101,7 @@ groupby_next(groupbyobject *gbo)
             newkey = newvalue;
             Py_INCREF(newvalue);
         } else {
-            newkey = PyObject_CallFunctionObjArgs(gbo->keyfunc, newvalue, NULL);
+            newkey = _PyObject_CallArg1(gbo->keyfunc, newvalue);
             if (newkey == NULL) {
                 Py_DECREF(newvalue);
                 return NULL;
@@ -293,7 +293,7 @@ _grouper_next(_grouperobject *igo)
             newkey = newvalue;
             Py_INCREF(newvalue);
         } else {
-            newkey = PyObject_CallFunctionObjArgs(gbo->keyfunc, newvalue, NULL);
+            newkey = _PyObject_CallArg1(gbo->keyfunc, newvalue);
             if (newkey == NULL) {
                 Py_DECREF(newvalue);
                 return NULL;
@@ -1130,7 +1130,7 @@ dropwhile_next(dropwhileobject *lz)
         if (lz->start == 1)
             return item;
 
-        good = PyObject_CallFunctionObjArgs(lz->func, item, NULL);
+        good = _PyObject_CallArg1(lz->func, item);
         if (good == NULL) {
             Py_DECREF(item);
             return NULL;
@@ -1296,7 +1296,7 @@ takewhile_next(takewhileobject *lz)
     if (item == NULL)
         return NULL;
 
-    good = PyObject_CallFunctionObjArgs(lz->func, item, NULL);
+    good = _PyObject_CallArg1(lz->func, item);
     if (good == NULL) {
         Py_DECREF(item);
         return NULL;
@@ -3824,7 +3824,7 @@ filterfalse_next(filterfalseobject *lz)
             ok = PyObject_IsTrue(item);
         } else {
             PyObject *good;
-            good = PyObject_CallFunctionObjArgs(lz->func, item, NULL);
+            good = _PyObject_CallArg1(lz->func, item);
             if (good == NULL) {
                 Py_DECREF(item);
                 return NULL;
diff --git a/Modules/mathmodule.c b/Modules/mathmodule.c
index 95ea4f7..e7e34ef 100644
--- a/Modules/mathmodule.c
+++ b/Modules/mathmodule.c
@@ -951,7 +951,7 @@ static PyObject * math_ceil(PyObject *self, PyObject *number) {
             return NULL;
         return math_1_to_int(number, ceil, 0);
     }
-    result = PyObject_CallFunctionObjArgs(method, NULL);
+    result = _PyObject_CallNoArg(method);
     Py_DECREF(method);
     return result;
 }
@@ -991,7 +991,7 @@ static PyObject * math_floor(PyObject *self, PyObject *number) {
             return NULL;
         return math_1_to_int(number, floor, 0);
     }
-    result = PyObject_CallFunctionObjArgs(method, NULL);
+    result = _PyObject_CallNoArg(method);
     Py_DECREF(method);
     return result;
 }
@@ -1542,7 +1542,7 @@ math_trunc(PyObject *self, PyObject *number)
                          Py_TYPE(number)->tp_name);
         return NULL;
     }
-    result = PyObject_CallFunctionObjArgs(trunc, NULL);
+    result = _PyObject_CallNoArg(trunc);
     Py_DECREF(trunc);
     return result;
 }
diff --git a/Modules/posixmodule.c b/Modules/posixmodule.c
index 2e9eb9e..129ff1c 100644
--- a/Modules/posixmodule.c
+++ b/Modules/posixmodule.c
@@ -902,7 +902,7 @@ path_converter(PyObject *o, void *p)
             goto error_exit;
         }
 
-        o = to_cleanup = PyObject_CallFunctionObjArgs(func, NULL);
+        o = to_cleanup = _PyObject_CallNoArg(func);
         Py_DECREF(func);
         if (NULL == o) {
             goto error_exit;
@@ -12041,7 +12041,7 @@ PyOS_FSPath(PyObject *path)
                             Py_TYPE(path)->tp_name);
     }
 
-    path_repr = PyObject_CallFunctionObjArgs(func, NULL);
+    path_repr = _PyObject_CallNoArg(func);
     Py_DECREF(func);
     if (NULL == path_repr) {
         return NULL;