Don't use helper that processes entire stack

Author: DinoV

Include/internal/pycore_setobject.h

@@ -35,9 +35,6 @@ extern void _PySet_ClearInternal(PySetObject *so);
 
 PyAPI_FUNC(int) _PySet_AddTakeRef(PySetObject *so, PyObject *key);
 
-PyAPI_FUNC(PyObject *)
-_PySet_FromStackRefSteal(const _PyStackRef *src, Py_ssize_t n);
-
 
 
 #ifdef __cplusplus

Objects/setobject.c

@@ -208,52 +208,22 @@ set_add_entry(PySetObject *so, PyObject *key, Py_hash_t hash)
 {
     _Py_CRITICAL_SECTION_ASSERT_OBJECT_LOCKED(so);
 
-    /* Pre-increment is necessary to prevent arbitrary code in the rich
-       comparison from deallocating the key just before the insertion. */
-    Py_INCREF(key);
-
-    return set_add_entry_takeref(so, key, hash);
+    return set_add_entry_takeref(so, Py_NewRef(key), hash);
 }
 
 int
 _PySet_AddTakeRef(PySetObject *so, PyObject *key)
 {
     Py_hash_t hash = _PyObject_HashFast(key);
     if (hash == -1) {
+        Py_DECREF(key);
         return -1;
     }
     // We don't pre-increment here, the caller holds a strong
     // reference to the object which we are stealing.
     return set_add_entry_takeref(so, key, hash);
 }
 
-PyObject *
-_PySet_FromStackRefSteal(const _PyStackRef *src, Py_ssize_t n)
-{
-    PySetObject *set = (PySetObject *)PySet_New(NULL);
-    if (n == 0) {
-        return (PyObject *)set;
-    }
-
-    if (set_table_resize(set, n*2) != 0) {
-        return NULL;
-    }
-
-    int err = 0;
-    for (Py_ssize_t i = 0; i < n; i++) {
-        if (err == 0) {
-            err = _PySet_AddTakeRef(set, PyStackRef_AsPyObjectSteal(src[i]));
-        } else {
-            PyStackRef_CLOSE(src[i]);
-        }
-    }
-    if (err) {
-        Py_CLEAR(set);
-    }
-
-    return (PyObject *)set;
-}
-
 /*
 Internal routine used by set_table_resize() to insert an item which is
 known to be absent from the set.  Besides the performance benefit,

Python/bytecodes.c

@@ -1910,10 +1910,28 @@ dummy_func(
         }
 
         inst(BUILD_SET, (values[oparg] -- set)) {
-            PyObject *set_o = _PySet_FromStackRefSteal(values, oparg);
+            PyObject *set_o = PySet_New(NULL);
             if (set_o == NULL) {
+                DECREF_INPUTS();
                 ERROR_IF(true, error);
             }
+
+            int err = 0;
+            for (Py_ssize_t i = 0; i < oparg; i++) {
+                _PyStackRef value = values[i];
+                values[i] = PyStackRef_NULL;
+                if (err == 0) {
+                    err = _PySet_AddTakeRef((PySetObject *)set_o, PyStackRef_AsPyObjectSteal(value));
+                }
+                else {
+                    PyStackRef_CLOSE(value);
+                }
+            }
+            if (err) {
+                Py_DECREF(set_o);
+                ERROR_IF(true, error);
+            }
+
             INPUTS_DEAD();
             set = PyStackRef_FromPyObjectStealMortal(set_o);
         }