gh-99300: Use Py_NewRef() in Objects/listobject.c (#99336)

Replace Py_INCREF() and Py_XINCREF() with Py_NewRef() and
Py_XNewRef() in Objects/listobject.c.

Author: vstinner

Objects/listobject.c

@@ -299,8 +299,7 @@ ins1(PyListObject *self, Py_ssize_t where, PyObject *v)
     items = self->ob_item;
     for (i = n; --i >= where; )
         items[i+1] = items[i];
-    Py_INCREF(v);
-    items[where] = v;
+    items[where] = Py_NewRef(v);
     return 0;
 }
 
@@ -332,8 +331,7 @@ int
 PyList_Append(PyObject *op, PyObject *newitem)
 {
     if (PyList_Check(op) && (newitem != NULL)) {
-        Py_INCREF(newitem);
-        return _PyList_AppendTakeRef((PyListObject *)op, newitem);
+        return _PyList_AppendTakeRef((PyListObject *)op, Py_NewRef(newitem));
     }
     PyErr_BadInternalCall();
     return -1;
@@ -461,8 +459,7 @@ list_item(PyListObject *a, Py_ssize_t i)
         PyErr_SetObject(PyExc_IndexError, &_Py_STR(list_err));
         return NULL;
     }
-    Py_INCREF(a->ob_item[i]);
-    return a->ob_item[i];
+    return Py_NewRef(a->ob_item[i]);
 }
 
 static PyObject *
@@ -483,8 +480,7 @@ list_slice(PyListObject *a, Py_ssize_t ilow, Py_ssize_t ihigh)
     dest = np->ob_item;
     for (i = 0; i < len; i++) {
         PyObject *v = src[i];
-        Py_INCREF(v);
-        dest[i] = v;
+        dest[i] = Py_NewRef(v);
     }
     Py_SET_SIZE(np, len);
     return (PyObject *)np;
@@ -539,15 +535,13 @@ list_concat(PyListObject *a, PyObject *bb)
     dest = np->ob_item;
     for (i = 0; i < Py_SIZE(a); i++) {
         PyObject *v = src[i];
-        Py_INCREF(v);
-        dest[i] = v;
+        dest[i] = Py_NewRef(v);
     }
     src = b->ob_item;
     dest = np->ob_item + Py_SIZE(a);
     for (i = 0; i < Py_SIZE(b); i++) {
         PyObject *v = src[i];
-        Py_INCREF(v);
-        dest[i] = v;
+        dest[i] = Py_NewRef(v);
     }
     Py_SET_SIZE(np, size);
     return (PyObject *)np;
@@ -716,8 +710,7 @@ list_ass_slice(PyListObject *a, Py_ssize_t ilow, Py_ssize_t ihigh, PyObject *v)
     }
     for (k = 0; k < n; k++, ilow++) {
         PyObject *w = vitem[k];
-        Py_XINCREF(w);
-        item[ilow] = w;
+        item[ilow] = Py_XNewRef(w);
     }
     for (k = norig - 1; k >= 0; --k)
         Py_XDECREF(recycle[k]);
@@ -745,14 +738,12 @@ list_inplace_repeat(PyListObject *self, Py_ssize_t n)
 {
     Py_ssize_t input_size = PyList_GET_SIZE(self);
     if (input_size == 0 || n == 1) {
-        Py_INCREF(self);
-        return (PyObject *)self;
+        return Py_NewRef(self);
     }
 
     if (n < 1) {
         (void)_list_clear(self);
-        Py_INCREF(self);
-        return (PyObject *)self;
+        return Py_NewRef(self);
     }
 
     if (input_size > PY_SSIZE_T_MAX / n) {
@@ -770,8 +761,7 @@ list_inplace_repeat(PyListObject *self, Py_ssize_t n)
     _Py_memory_repeat((char *)items, sizeof(PyObject *)*output_size,
                       sizeof(PyObject *)*input_size);
 
-    Py_INCREF(self);
-    return (PyObject *)self;
+    return Py_NewRef(self);
 }
 
 static int
@@ -784,8 +774,7 @@ list_ass_item(PyListObject *a, Py_ssize_t i, PyObject *v)
     }
     if (v == NULL)
         return list_ass_slice(a, i, i+1, v);
-    Py_INCREF(v);
-    Py_SETREF(a->ob_item[i], v);
+    Py_SETREF(a->ob_item[i], Py_NewRef(v));
     return 0;
 }
 
@@ -913,8 +902,7 @@ list_extend(PyListObject *self, PyObject *iterable)
         dest = self->ob_item + m;
         for (i = 0; i < n; i++) {
             PyObject *o = src[i];
-            Py_INCREF(o);
-            dest[i] = o;
+            dest[i] = Py_NewRef(o);
         }
         Py_DECREF(iterable);
         Py_RETURN_NONE;
@@ -1002,8 +990,7 @@ list_inplace_concat(PyListObject *self, PyObject *other)
     if (result == NULL)
         return result;
     Py_DECREF(result);
-    Py_INCREF(self);
-    return (PyObject *)self;
+    return Py_NewRef(self);
 }
 
 /*[clinic input]
@@ -2512,8 +2499,7 @@ list_sort_impl(PyListObject *self, PyObject *keyfunc, int reverse)
         }
         PyMem_Free(final_ob_item);
     }
-    Py_XINCREF(result);
-    return result;
+    return Py_XNewRef(result);
 }
 #undef IFLT
 #undef ISLT
@@ -2901,8 +2887,7 @@ list_subscript(PyListObject* self, PyObject* item)
             dest = ((PyListObject *)result)->ob_item;
             for (cur = start, i = 0; i < slicelength;
                  cur += (size_t)step, i++) {
-                it = src[cur];
-                Py_INCREF(it);
+                it = Py_NewRef(src[cur]);
                 dest[i] = it;
             }
             Py_SET_SIZE(result, slicelength);
@@ -3057,8 +3042,7 @@ list_ass_subscript(PyListObject* self, PyObject* item, PyObject* value)
             for (cur = start, i = 0; i < slicelength;
                  cur += (size_t)step, i++) {
                 garbage[i] = selfitems[cur];
-                ins = seqitems[i];
-                Py_INCREF(ins);
+                ins = Py_NewRef(seqitems[i]);
                 selfitems[cur] = ins;
             }
 
@@ -3199,8 +3183,7 @@ list_iter(PyObject *seq)
     if (it == NULL)
         return NULL;
     it->it_index = 0;
-    Py_INCREF(seq);
-    it->it_seq = (PyListObject *)seq;
+    it->it_seq = (PyListObject *)Py_NewRef(seq);
     _PyObject_GC_TRACK(it);
     return (PyObject *)it;
 }
@@ -3235,8 +3218,7 @@ listiter_next(_PyListIterObject *it)
     if (it->it_index < PyList_GET_SIZE(seq)) {
         item = PyList_GET_ITEM(seq, it->it_index);
         ++it->it_index;
-        Py_INCREF(item);
-        return item;
+        return Py_NewRef(item);
     }
 
     it->it_seq = NULL;
@@ -3350,8 +3332,7 @@ list___reversed___impl(PyListObject *self)
         return NULL;
     assert(PyList_Check(self));
     it->it_index = PyList_GET_SIZE(self) - 1;
-    Py_INCREF(self);
-    it->it_seq = self;
+    it->it_seq = (PyListObject*)Py_NewRef(self);
     PyObject_GC_Track(it);
     return (PyObject *)it;
 }
@@ -3389,8 +3370,7 @@ listreviter_next(listreviterobject *it)
     if (index>=0 && index < PyList_GET_SIZE(seq)) {
         item = PyList_GET_ITEM(seq, index);
         it->it_index--;
-        Py_INCREF(item);
-        return item;
+        return Py_NewRef(item);
     }
     it->it_index = -1;
     it->it_seq = NULL;