Merge branch 'main' into fix-pulldom-resource-leak-148428

Author: WYSIATI

Lib/test/test_capi/test_opt.py

@@ -2755,6 +2755,21 @@ def testfunc(n):
         self.assertNotIn("_GUARD_TOS_INT", uops)
         self.assertIn("_POP_TOP_NOP", uops)
 
+    def test_check_is_not_py_callable(self):
+        def testfunc(n):
+            total = 0
+            f = len
+            xs = (1, 2, 3)
+            for _ in range(n):
+                total += f(xs)
+            return total
+
+        res, ex = self._run_with_optimizer(testfunc, TIER2_THRESHOLD)
+        self.assertEqual(res, 3 * TIER2_THRESHOLD)
+        self.assertIsNotNone(ex)
+        uops = get_opnames(ex)
+        self.assertNotIn("_CHECK_IS_NOT_PY_CALLABLE", uops)
+
     def test_call_len_string(self):
         def testfunc(n):
             for _ in range(n):

Misc/NEWS.d/next/Core_and_Builtins/2026-04-11-15-12-53.gh-issue-148398.g62jCA.rst

@@ -0,0 +1 @@
+Fix a bug in the JIT optimizer where class attribute loads were not invalidated after type mutation.

Python/optimizer_bytecodes.c

@@ -226,6 +226,10 @@ dummy_func(void) {
             }
             else {
                 sym_set_const(owner, type);
+                if ((((PyTypeObject *)type)->tp_flags & Py_TPFLAGS_IMMUTABLETYPE) == 0) {
+                    PyType_Watch(TYPE_WATCHER_ID, type);
+                    _Py_BloomFilter_Add(dependencies, type);
+                }
             }
         }
     }
@@ -1213,6 +1217,13 @@ dummy_func(void) {
         (void)framesize;
     }
 
+    op(_CHECK_IS_NOT_PY_CALLABLE, (callable, unused, unused[oparg] -- callable, unused, unused[oparg])) {
+        PyTypeObject *type = sym_get_type(callable);
+        if (type && type != &PyFunction_Type && type != &PyMethod_Type) {
+            ADD_OP(_NOP, 0, 0);
+        }
+    }
+
     op(_PUSH_FRAME, (new_frame -- )) {
         SYNC_SP();
         if (!CURRENT_FRAME_IS_INIT_SHIM()) {