bpo-39965: Correctly raise SyntaxError if await is used outside async functions when PyCF_ALLOW_TOP_LEVEL_AWAIT is set (GH-19010)

Lib/test/test_builtin.py

@@ -421,6 +421,44 @@ class BuiltinTest(unittest.TestCase):
         finally:
             asyncio.set_event_loop_policy(policy)
 
+    def test_compile_top_level_await_invalid_cases(self):
+         # helper function just to check we can run top=level async-for
+        async def arange(n):
+            for i in range(n):
+                yield i
+
+        modes = ('single', 'exec')
+        code_samples = [
+            '''def f():  await arange(10)\n''',
+            '''def f():  [x async for x in arange(10)]\n''',
+            '''def f():  [await x async for x in arange(10)]\n''',
+            '''def f():
+                   async for i in arange(1):
+                       a = 1
+            ''',
+            '''def f():
+                   async with asyncio.Lock() as l:
+                       a = 1
+            '''
+        ]
+        policy = maybe_get_event_loop_policy()
+        try:
+            for mode, code_sample in product(modes, code_samples):
+                source = dedent(code_sample)
+                with self.assertRaises(
+                        SyntaxError, msg=f"source={source} mode={mode}"):
+                    compile(source, '?', mode)
+
+                with self.assertRaises(
+                        SyntaxError, msg=f"source={source} mode={mode}"):
+                    co = compile(source,
+                             '?',
+                             mode,
+                             flags=ast.PyCF_ALLOW_TOP_LEVEL_AWAIT)
+        finally:
+            asyncio.set_event_loop_policy(policy)
+
+
     def test_compile_async_generator(self):
         """
         With the PyCF_ALLOW_TOP_LEVEL_AWAIT flag added in 3.8, we want to