added unit tests

Author: blhsing

Lib/test/test_builtin.py

@@ -1111,7 +1111,22 @@ def test_exec_filter_syntax_warnings_by_module(self):
             self.assertEqual(wm.filename, '<string>')
             self.assertIs(wm.category, SyntaxWarning)
 
-
+    def test_eval_exec_sync_fast_locals(self):
+        def func_assign():
+            a = 1
+
+        def func_read():
+            b = a + 1
+
+        for executor in eval, exec:
+            with self.subTest(executor=executor.__name__):
+                ns = {}
+                executor(func_assign.__code__, {}, ns, sync_fast_locals=True)
+                self.assertEqual(ns, {'a': 1})
+                ns = {'a': 1}
+                executor(func_read.__code__, {}, ns, sync_fast_locals=True)
+                self.assertEqual(ns, {'a': 1, 'b': 2})
+        
     def test_filter(self):
         self.assertEqual(list(filter(lambda c: 'a' <= c <= 'z', 'Hello World')), list('elloorld'))
         self.assertEqual(list(filter(None, [1, 'hello', [], [3], '', None, 9, 0])), [1, 'hello', [3], 9])

Python/bltinmodule.c

@@ -1041,7 +1041,7 @@ builtin_eval_impl(PyObject *module, PyObject *source, PyObject *globals,
         }
         if (!sync_fast_locals && ((PyCodeObject *)source)->co_flags & CO_OPTIMIZED) {
             Py_DECREF(locals);
-            locals = NULL;
+            locals = globals;
         }
         result = PyEval_EvalCode(source, globals, locals);
     }

Python/ceval.c

@@ -1530,7 +1530,7 @@ typedef struct {
 } _PyEntryFrame;
 
 static int
-_PyEval_SyncMappingToFast(_PyInterpreterFrame *frame)
+_PyEval_SyncLocalsToFast(_PyInterpreterFrame *frame)
 {
     PyObject *mapping = frame->f_locals;
     PyCodeObject *co = _PyFrame_GetCode(frame);
@@ -1543,14 +1543,14 @@ _PyEval_SyncMappingToFast(_PyInterpreterFrame *frame)
             frame->localsplus[i] = PyStackRef_FromPyObjectSteal(value);
         }
         else {
-            PyErr_Clear();
+            return -1;
         }
     }
     return 0;
 }
 
 static int
-_PyEval_SyncFastToMapping(_PyInterpreterFrame *frame)
+_PyEval_SyncFastToLocals(_PyInterpreterFrame *frame)
 {
     PyObject *mapping = frame->f_locals;
     PyCodeObject *co = _PyFrame_GetCode(frame);
@@ -1562,7 +1562,7 @@ _PyEval_SyncFastToMapping(_PyInterpreterFrame *frame)
             PyObject *name = PyTuple_GET_ITEM(names, i);
             PyObject *obj = PyStackRef_AsPyObjectSteal(sref);
             if (PyObject_SetItem(mapping, name, obj) < 0) {
-                PyErr_Clear();
+                return -1;
             }
         }
     }
@@ -1632,13 +1632,9 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, _PyInterpreterFrame *frame, int
     tstate->current_frame = frame;
     entry.frame.localsplus[0] = PyStackRef_NULL;
     PyCodeObject *co = _PyFrame_GetCode(frame);
-    if ((co->co_flags & CO_OPTIMIZED) && 
-        frame->f_locals != NULL && 
-        frame->f_locals != frame->f_globals) 
-    {
-        if (_PyEval_SyncMappingToFast(frame) < 0) {
-            goto early_exit;
-        }
+    if ((co->co_flags & CO_OPTIMIZED) && frame->f_locals != NULL &&
+        frame->f_locals != frame->f_globals && _PyEval_SyncLocalsToFast(frame) < 0) {
+        goto early_exit;
     }
 #ifdef _Py_TIER2
     if (tstate->current_executor != NULL) {
@@ -2427,13 +2423,10 @@ void
 _PyEval_FrameClearAndPop(PyThreadState *tstate, _PyInterpreterFrame * frame)
 {
     PyCodeObject *co = _PyFrame_GetCode(frame);
-    if ((co->co_flags & CO_OPTIMIZED) && 
-        frame->f_locals != NULL && 
-        frame->f_locals != frame->f_globals) 
-    {
-        if (_PyEval_SyncFastToMapping(frame) < 0) {
-            PyErr_WriteUnraisable(frame->f_locals);
-        }
+    if ((co->co_flags & CO_OPTIMIZED) && frame->f_locals != NULL &&
+        frame->f_locals != frame->f_globals && _PyEval_SyncFastToLocals(frame) < 0) {
+        /* Swallow the error while the frame is in a teardown state */
+        PyErr_WriteUnraisable(frame->f_locals);
     }
     // Update last_profiled_frame for remote profiler frame caching.
     // By this point, tstate->current_frame is already set to the parent frame.