Issue #20440: Cleaning up the code by using Py_SETREF.

Modules/_datetimemodule.c

@@ -1057,10 +1057,8 @@ format_utcoffset(char *buf, size_t buflen, const char *sep,
     }
     /* Offset is normalized, so it is negative if days < 0 */
     if (GET_TD_DAYS(offset) < 0) {
-        PyObject *temp = offset;
         sign = '-';
-        offset = delta_negative((PyDateTime_Delta *)offset);
+        Py_SETREF(offset, delta_negative((PyDateTime_Delta *)offset));
-        Py_DECREF(temp);
         if (offset == NULL)
             return -1;
     }
@@ -3047,10 +3045,8 @@ tzinfo_fromutc(PyDateTime_TZInfo *self, PyObject *dt)
     if (dst == Py_None)
         goto Inconsistent;
     if (delta_bool((PyDateTime_Delta *)dst) != 0) {
-        PyObject *temp = result;
+        Py_SETREF(result, add_datetime_timedelta((PyDateTime_DateTime *)result,
-        result = add_datetime_timedelta((PyDateTime_DateTime *)result,
+                                                 (PyDateTime_Delta *)dst, 1));
-                                        (PyDateTime_Delta *)dst, 1);
-        Py_DECREF(temp);
         if (result == NULL)
             goto Fail;
     }
@@ -4157,10 +4153,7 @@ datetime_datetime_now_impl(PyTypeObject *type, PyObject *tz)
                                   tz);
     if (self != NULL && tz != Py_None) {
         /* Convert UTC to tzinfo's zone. */
-        PyObject *temp = self;
+        self = _PyObject_CallMethodId(tz, &PyId_fromutc, "N", self);
-
-        self = _PyObject_CallMethodId(tz, &PyId_fromutc, "O", self);
-        Py_DECREF(temp);
     }
     return self;
 }
@@ -4195,10 +4188,7 @@ datetime_fromtimestamp(PyObject *cls, PyObject *args, PyObject *kw)
                                    tzinfo);
     if (self != NULL && tzinfo != Py_None) {
         /* Convert UTC to tzinfo's zone. */
-        PyObject *temp = self;
+        self = _PyObject_CallMethodId(tzinfo, &PyId_fromutc, "N", self);
-
-        self = _PyObject_CallMethodId(tzinfo, &PyId_fromutc, "O", self);
-        Py_DECREF(temp);
     }
     return self;
 }
@@ -4421,9 +4411,7 @@ datetime_subtract(PyObject *left, PyObject *right)
                 return NULL;
 
             if (offdiff != NULL) {
-                PyObject *temp = result;
+                Py_SETREF(result, delta_subtract(result, offdiff));
-                result = delta_subtract(result, offdiff);
-                Py_DECREF(temp);
                 Py_DECREF(offdiff);
             }
         }

Modules/_elementtree.c

@@ -396,10 +396,8 @@ element_init(PyObject *self, PyObject *args, PyObject *kwds)
     Py_XDECREF(attrib);
 
     /* Replace the objects already pointed to by tag, text and tail. */
-    tmp = self_elem->tag;
     Py_INCREF(tag);
-    self_elem->tag = tag;
+    Py_SETREF(self_elem->tag, tag);
-    Py_DECREF(tmp);
 
     tmp = self_elem->text;
     Py_INCREF(Py_None);

Modules/_lsprof.c

@@ -762,7 +762,6 @@ profiler_dealloc(ProfilerObject *op)
 static int
 profiler_init(ProfilerObject *pObj, PyObject *args, PyObject *kw)
 {
-    PyObject *o;
     PyObject *timer = NULL;
     double timeunit = 0.0;
     int subcalls = 1;
@@ -777,11 +776,9 @@ profiler_init(ProfilerObject *pObj, PyObject *args, PyObject *kw)
 
     if (setSubcalls(pObj, subcalls) < 0 || setBuiltins(pObj, builtins) < 0)
         return -1;
-    o = pObj->externalTimer;
-    pObj->externalTimer = timer;
-    Py_XINCREF(timer);
-    Py_XDECREF(o);
     pObj->externalTimerUnit = timeunit;
+    Py_XINCREF(timer);
+    Py_SETREF(pObj->externalTimer, timer);
     return 0;
 }
 

Modules/_pickle.c

@@ -4494,8 +4494,6 @@ Pickler_get_persid(PicklerObject *self)
 static int
 Pickler_set_persid(PicklerObject *self, PyObject *value)
 {
-    PyObject *tmp;
-
     if (value == NULL) {
         PyErr_SetString(PyExc_TypeError,
                         "attribute deletion is not supported");
@@ -4507,10 +4505,8 @@ Pickler_set_persid(PicklerObject *self, PyObject *value)
         return -1;
     }
 
-    tmp = self->pers_func;
     Py_INCREF(value);
-    self->pers_func = value;
+    Py_SETREF(self->pers_func, value);
-    Py_XDECREF(tmp);      /* self->pers_func can be NULL, so be careful. */
 
     return 0;
 }
@@ -6946,8 +6942,6 @@ Unpickler_get_persload(UnpicklerObject *self)
 static int
 Unpickler_set_persload(UnpicklerObject *self, PyObject *value)
 {
-    PyObject *tmp;
-
     if (value == NULL) {
         PyErr_SetString(PyExc_TypeError,
                         "attribute deletion is not supported");
@@ -6960,10 +6954,8 @@ Unpickler_set_persload(UnpicklerObject *self, PyObject *value)
         return -1;
     }
 
-    tmp = self->pers_func;
     Py_INCREF(value);
-    self->pers_func = value;
+    Py_SETREF(self->pers_func, value);
-    Py_XDECREF(tmp);      /* self->pers_func can be NULL, so be careful. */
 
     return 0;
 }

Modules/readline.c

@@ -321,10 +321,8 @@ set_hook(const char *funcname, PyObject **hook_var, PyObject *args)
         Py_CLEAR(*hook_var);
     }
     else if (PyCallable_Check(function)) {
-        PyObject *tmp = *hook_var;
         Py_INCREF(function);
-        *hook_var = function;
+        Py_SETREF(*hook_var, function);
-        Py_XDECREF(tmp);
     }
     else {
         PyErr_Format(PyExc_TypeError,

Objects/exceptions.c

@@ -59,15 +59,11 @@ BaseException_new(PyTypeObject *type, PyObject *args, PyObject *kwds)
 static int
 BaseException_init(PyBaseExceptionObject *self, PyObject *args, PyObject *kwds)
 {
-    PyObject *tmp;
-
     if (!_PyArg_NoKeywords(Py_TYPE(self)->tp_name, kwds))
         return -1;
 
-    tmp = self->args;
+    Py_INCREF(args);
-    self->args = args;
+    Py_SETREF(self->args, args);
-    Py_INCREF(self->args);
-    Py_XDECREF(tmp);
 
     return 0;
 }
@@ -328,11 +324,10 @@ PyException_GetCause(PyObject *self) {
 
 /* Steals a reference to cause */
 void
-PyException_SetCause(PyObject *self, PyObject *cause) {
+PyException_SetCause(PyObject *self, PyObject *cause)
-    PyObject *old_cause = ((PyBaseExceptionObject *)self)->cause;
+{
-    ((PyBaseExceptionObject *)self)->cause = cause;
     ((PyBaseExceptionObject *)self)->suppress_context = 1;
-    Py_XDECREF(old_cause);
+    Py_SETREF(((PyBaseExceptionObject *)self)->cause, cause);
 }
 
 PyObject *
@@ -344,10 +339,9 @@ PyException_GetContext(PyObject *self) {
 
 /* Steals a reference to context */
 void
-PyException_SetContext(PyObject *self, PyObject *context) {
+PyException_SetContext(PyObject *self, PyObject *context)
-    PyObject *old_context = ((PyBaseExceptionObject *)self)->context;
+{
-    ((PyBaseExceptionObject *)self)->context = context;
+    Py_SETREF(((PyBaseExceptionObject *)self)->context, context);
-    Py_XDECREF(old_context);
 }
 
 

Objects/frameobject.c

@@ -349,15 +349,11 @@ frame_gettrace(PyFrameObject *f, void *closure)
 static int
 frame_settrace(PyFrameObject *f, PyObject* v, void *closure)
 {
-    PyObject* old_value;
-
     /* We rely on f_lineno being accurate when f_trace is set. */
     f->f_lineno = PyFrame_GetLineNumber(f);
 
-    old_value = f->f_trace;
     Py_XINCREF(v);
-    f->f_trace = v;
+    Py_SETREF(f->f_trace, v);
-    Py_XDECREF(old_value);
 
     return 0;
 }

Objects/funcobject.c

@@ -249,7 +249,6 @@ func_get_code(PyFunctionObject *op)
 static int
 func_set_code(PyFunctionObject *op, PyObject *value)
 {
-    PyObject *tmp;
     Py_ssize_t nfree, nclosure;
 
     /* Not legal to del f.func_code or to set it to anything
@@ -270,10 +269,8 @@ func_set_code(PyFunctionObject *op, PyObject *value)
                      nclosure, nfree);
         return -1;
     }
-    tmp = op->func_code;
     Py_INCREF(value);
-    op->func_code = value;
+    Py_SETREF(op->func_code, value);
-    Py_DECREF(tmp);
     return 0;
 }
 
@@ -287,8 +284,6 @@ func_get_name(PyFunctionObject *op)
 static int
 func_set_name(PyFunctionObject *op, PyObject *value)
 {
-    PyObject *tmp;
-
     /* Not legal to del f.func_name or to set it to anything
      * other than a string object. */
     if (value == NULL || !PyUnicode_Check(value)) {
@@ -296,10 +291,8 @@ func_set_name(PyFunctionObject *op, PyObject *value)
                         "__name__ must be set to a string object");
         return -1;
     }
-    tmp = op->func_name;
     Py_INCREF(value);
-    op->func_name = value;
+    Py_SETREF(op->func_name, value);
-    Py_DECREF(tmp);
     return 0;
 }
 
@@ -313,8 +306,6 @@ func_get_qualname(PyFunctionObject *op)
 static int
 func_set_qualname(PyFunctionObject *op, PyObject *value)
 {
-    PyObject *tmp;
-
     /* Not legal to del f.__qualname__ or to set it to anything
      * other than a string object. */
     if (value == NULL || !PyUnicode_Check(value)) {
@@ -322,10 +313,8 @@ func_set_qualname(PyFunctionObject *op, PyObject *value)
                         "__qualname__ must be set to a string object");
         return -1;
     }
-    tmp = op->func_qualname;
     Py_INCREF(value);
-    op->func_qualname = value;
+    Py_SETREF(op->func_qualname, value);
-    Py_DECREF(tmp);
     return 0;
 }
 
@@ -343,8 +332,6 @@ func_get_defaults(PyFunctionObject *op)
 static int
 func_set_defaults(PyFunctionObject *op, PyObject *value)
 {
-    PyObject *tmp;
-
     /* Legal to del f.func_defaults.
      * Can only set func_defaults to NULL or a tuple. */
     if (value == Py_None)
@@ -354,10 +341,8 @@ func_set_defaults(PyFunctionObject *op, PyObject *value)
                         "__defaults__ must be set to a tuple object");
         return -1;
     }
-    tmp = op->func_defaults;
     Py_XINCREF(value);
-    op->func_defaults = value;
+    Py_SETREF(op->func_defaults, value);
-    Py_XDECREF(tmp);
     return 0;
 }
 
@@ -375,8 +360,6 @@ func_get_kwdefaults(PyFunctionObject *op)
 static int
 func_set_kwdefaults(PyFunctionObject *op, PyObject *value)
 {
-    PyObject *tmp;
-
     if (value == Py_None)
         value = NULL;
     /* Legal to del f.func_kwdefaults.
@@ -386,10 +369,8 @@ func_set_kwdefaults(PyFunctionObject *op, PyObject *value)
             "__kwdefaults__ must be set to a dict object");
         return -1;
     }
-    tmp = op->func_kwdefaults;
     Py_XINCREF(value);
-    op->func_kwdefaults = value;
+    Py_SETREF(op->func_kwdefaults, value);
-    Py_XDECREF(tmp);
     return 0;
 }
 
@@ -408,8 +389,6 @@ func_get_annotations(PyFunctionObject *op)
 static int
 func_set_annotations(PyFunctionObject *op, PyObject *value)
 {
-    PyObject *tmp;
-
     if (value == Py_None)
         value = NULL;
     /* Legal to del f.func_annotations.
@@ -420,10 +399,8 @@ func_set_annotations(PyFunctionObject *op, PyObject *value)
             "__annotations__ must be set to a dict object");
         return -1;
     }
-    tmp = op->func_annotations;
     Py_XINCREF(value);
-    op->func_annotations = value;
+    Py_SETREF(op->func_annotations, value);
-    Py_XDECREF(tmp);
     return 0;
 }
 

Objects/genobject.c

@@ -510,8 +510,6 @@ gen_get_name(PyGenObject *op)
 static int
 gen_set_name(PyGenObject *op, PyObject *value)
 {
-    PyObject *tmp;
-
     /* Not legal to del gen.gi_name or to set it to anything
      * other than a string object. */
     if (value == NULL || !PyUnicode_Check(value)) {
@@ -519,10 +517,8 @@ gen_set_name(PyGenObject *op, PyObject *value)
                         "__name__ must be set to a string object");
         return -1;
     }
-    tmp = op->gi_name;
     Py_INCREF(value);
-    op->gi_name = value;
+    Py_SETREF(op->gi_name, value);
-    Py_DECREF(tmp);
     return 0;
 }
 
@@ -536,8 +532,6 @@ gen_get_qualname(PyGenObject *op)
 static int
 gen_set_qualname(PyGenObject *op, PyObject *value)
 {
-    PyObject *tmp;
-
     /* Not legal to del gen.__qualname__ or to set it to anything
      * other than a string object. */
     if (value == NULL || !PyUnicode_Check(value)) {
@@ -545,10 +539,8 @@ gen_set_qualname(PyGenObject *op, PyObject *value)
                         "__qualname__ must be set to a string object");
         return -1;
     }
-    tmp = op->gi_qualname;
     Py_INCREF(value);
-    op->gi_qualname = value;
+    Py_SETREF(op->gi_qualname, value);
-    Py_DECREF(tmp);
     return 0;
 }
 

Objects/object.c

@@ -1203,7 +1203,7 @@ PyObject_GenericSetAttr(PyObject *obj, PyObject *name, PyObject *value)
 int
 PyObject_GenericSetDict(PyObject *obj, PyObject *value, void *context)
 {
-    PyObject *dict, **dictptr = _PyObject_GetDictPtr(obj);
+    PyObject **dictptr = _PyObject_GetDictPtr(obj);
     if (dictptr == NULL) {
         PyErr_SetString(PyExc_AttributeError,
                         "This object has no __dict__");
@@ -1219,10 +1219,8 @@ PyObject_GenericSetDict(PyObject *obj, PyObject *value, void *context)
                      "not a '%.200s'", Py_TYPE(value)->tp_name);
         return -1;
     }
-    dict = *dictptr;
+    Py_INCREF(value);
-    Py_XINCREF(value);
+    Py_SETREF(*dictptr, value);
-    *dictptr = value;
-    Py_XDECREF(dict);
     return 0;
 }
 

Objects/typeobject.c

@@ -2092,7 +2092,7 @@ subtype_dict(PyObject *obj, void *context)
 static int
 subtype_setdict(PyObject *obj, PyObject *value, void *context)
 {
-    PyObject *dict, **dictptr;
+    PyObject **dictptr;
     PyTypeObject *base;
 
     base = get_builtin_base_with_dict(Py_TYPE(obj));
@@ -2123,10 +2123,8 @@ subtype_setdict(PyObject *obj, PyObject *value, void *context)
                      "not a '%.200s'", Py_TYPE(value)->tp_name);
         return -1;
     }
-    dict = *dictptr;
     Py_XINCREF(value);
-    *dictptr = value;
+    Py_SETREF(*dictptr, value);
-    Py_XDECREF(dict);
     return 0;
 }
 

Python/import.c

@@ -879,10 +879,8 @@ update_code_filenames(PyCodeObject *co, PyObject *oldname, PyObject *newname)
     if (PyUnicode_Compare(co->co_filename, oldname))
         return;
 
-    tmp = co->co_filename;
+    Py_INCREF(newname);
-    co->co_filename = newname;
+    Py_SETREF(co->co_filename, newname);
-    Py_INCREF(co->co_filename);
-    Py_DECREF(tmp);
 
     constants = co->co_consts;
     n = PyTuple_GET_SIZE(constants);
@@ -1327,10 +1325,8 @@ remove_importlib_frames(void)
             (always_trim ||
              PyUnicode_CompareWithASCIIString(code->co_name,
                                               remove_frames) == 0)) {
-            PyObject *tmp = *outer_link;
-            *outer_link = next;
             Py_XINCREF(next);
-            Py_DECREF(tmp);
+            Py_SETREF(*outer_link, next);
             prev_link = outer_link;
         }
         else {

Python/peephole.c

@@ -118,9 +118,7 @@ tuple_of_constants(unsigned char *codestr, Py_ssize_t n,
     /* If it's a BUILD_SET, use the PyTuple we just built to create a
       PyFrozenSet, and use that as the constant instead: */
     if (codestr[0] == BUILD_SET) {
-        PyObject *tuple = newconst;
+        Py_SETREF(newconst, PyFrozenSet_New(newconst));
-        newconst = PyFrozenSet_New(tuple);
-        Py_DECREF(tuple);
         if (newconst == NULL)
             return 0;
     }

Python/sysmodule.c

@@ -436,10 +436,7 @@ trace_trampoline(PyObject *self, PyFrameObject *frame,
         return -1;
     }
     if (result != Py_None) {
-        PyObject *temp = frame->f_trace;
+        Py_SETREF(frame->f_trace, result);
-        frame->f_trace = NULL;
-        Py_XDECREF(temp);
-        frame->f_trace = result;
     }
     else {
         Py_DECREF(result);