Issue #23996: Added _PyGen_SetStopIterationValue for safe raising
StopIteration with value. More safely handle non-normalized exceptions
in -_PyGen_FetchStopIterationValue.
diff --git a/Include/genobject.h b/Include/genobject.h
index 1ff32a8..61e708a 100644
--- a/Include/genobject.h
+++ b/Include/genobject.h
@@ -41,6 +41,7 @@
PyAPI_FUNC(PyObject *) PyGen_NewWithQualName(struct _frame *,
PyObject *name, PyObject *qualname);
PyAPI_FUNC(int) PyGen_NeedsFinalizing(PyGenObject *);
+PyAPI_FUNC(int) _PyGen_SetStopIterationValue(PyObject *);
PyAPI_FUNC(int) _PyGen_FetchStopIterationValue(PyObject **);
PyObject *_PyGen_Send(PyGenObject *, PyObject *);
PyObject *_PyGen_yf(PyGenObject *);
diff --git a/Lib/test/test_coroutines.py b/Lib/test/test_coroutines.py
index e52654c..4a327b5 100644
--- a/Lib/test/test_coroutines.py
+++ b/Lib/test/test_coroutines.py
@@ -710,6 +710,21 @@
coro.close()
self.assertEqual(CHK, 1)
+ def test_coro_wrapper_send_tuple(self):
+ async def foo():
+ return (10,)
+
+ result = run_async__await__(foo())
+ self.assertEqual(result, ([], (10,)))
+
+ def test_coro_wrapper_send_stop_iterator(self):
+ async def foo():
+ return StopIteration(10)
+
+ result = run_async__await__(foo())
+ self.assertIsInstance(result[1], StopIteration)
+ self.assertEqual(result[1].value, 10)
+
def test_cr_await(self):
@types.coroutine
def a():
@@ -1537,6 +1552,52 @@
warnings.simplefilter("error")
run_async(foo())
+ def test_for_tuple(self):
+ class Done(Exception): pass
+
+ class AIter(tuple):
+ i = 0
+ def __aiter__(self):
+ return self
+ async def __anext__(self):
+ if self.i >= len(self):
+ raise StopAsyncIteration
+ self.i += 1
+ return self[self.i - 1]
+
+ result = []
+ async def foo():
+ async for i in AIter([42]):
+ result.append(i)
+ raise Done
+
+ with self.assertRaises(Done):
+ foo().send(None)
+ self.assertEqual(result, [42])
+
+ def test_for_stop_iteration(self):
+ class Done(Exception): pass
+
+ class AIter(StopIteration):
+ i = 0
+ def __aiter__(self):
+ return self
+ async def __anext__(self):
+ if self.i:
+ raise StopAsyncIteration
+ self.i += 1
+ return self.value
+
+ result = []
+ async def foo():
+ async for i in AIter(42):
+ result.append(i)
+ raise Done
+
+ with self.assertRaises(Done):
+ foo().send(None)
+ self.assertEqual(result, [42])
+
def test_copy(self):
async def func(): pass
coro = func()
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
index 3f82462..cd6a43d 100644
--- a/Lib/test/test_generators.py
+++ b/Lib/test/test_generators.py
@@ -277,6 +277,27 @@
# hence no warning.
next(g)
+ def test_return_tuple(self):
+ def g():
+ return (yield 1)
+
+ gen = g()
+ self.assertEqual(next(gen), 1)
+ with self.assertRaises(StopIteration) as cm:
+ gen.send((2,))
+ self.assertEqual(cm.exception.value, (2,))
+
+ def test_return_stopiteration(self):
+ def g():
+ return (yield 1)
+
+ gen = g()
+ self.assertEqual(next(gen), 1)
+ with self.assertRaises(StopIteration) as cm:
+ gen.send(StopIteration(2))
+ self.assertIsInstance(cm.exception.value, StopIteration)
+ self.assertEqual(cm.exception.value.value, 2)
+
class YieldFromTests(unittest.TestCase):
def test_generator_gi_yieldfrom(self):
diff --git a/Objects/genobject.c b/Objects/genobject.c
index 9172e6a..0d5d54f 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -154,12 +154,7 @@
/* Delay exception instantiation if we can */
PyErr_SetNone(PyExc_StopIteration);
} else {
- PyObject *e = PyObject_CallFunctionObjArgs(
- PyExc_StopIteration, result, NULL);
- if (e != NULL) {
- PyErr_SetObject(PyExc_StopIteration, e);
- Py_DECREF(e);
- }
+ _PyGen_SetStopIterationValue(result);
}
Py_CLEAR(result);
}
@@ -460,6 +455,43 @@
}
/*
+ * Set StopIteration with specified value. Value can be arbitrary object
+ * or NULL.
+ *
+ * Returns 0 if StopIteration is set and -1 if any other exception is set.
+ */
+int
+_PyGen_SetStopIterationValue(PyObject *value)
+{
+ PyObject *e;
+
+ if (value == NULL ||
+ (!PyTuple_Check(value) &&
+ !PyObject_TypeCheck(value, (PyTypeObject *) PyExc_StopIteration)))
+ {
+ /* Delay exception instantiation if we can */
+ PyErr_SetObject(PyExc_StopIteration, value);
+ return 0;
+ }
+ /* Construct an exception instance manually with
+ * PyObject_CallFunctionObjArgs and pass it to PyErr_SetObject.
+ *
+ * We do this to handle a situation when "value" is a tuple, in which
+ * case PyErr_SetObject would set the value of StopIteration to
+ * the first element of the tuple.
+ *
+ * (See PyErr_SetObject/_PyErr_CreateException code for details.)
+ */
+ e = PyObject_CallFunctionObjArgs(PyExc_StopIteration, value, NULL);
+ if (e == NULL) {
+ return -1;
+ }
+ PyErr_SetObject(PyExc_StopIteration, e);
+ Py_DECREF(e);
+ return 0;
+}
+
+/*
* If StopIteration exception is set, fetches its 'value'
* attribute if any, otherwise sets pvalue to None.
*
@@ -469,7 +501,8 @@
*/
int
-_PyGen_FetchStopIterationValue(PyObject **pvalue) {
+_PyGen_FetchStopIterationValue(PyObject **pvalue)
+{
PyObject *et, *ev, *tb;
PyObject *value = NULL;
@@ -481,8 +514,15 @@
value = ((PyStopIterationObject *)ev)->value;
Py_INCREF(value);
Py_DECREF(ev);
- } else if (et == PyExc_StopIteration) {
- /* avoid normalisation and take ev as value */
+ } else if (et == PyExc_StopIteration && !PyTuple_Check(ev)) {
+ /* Avoid normalisation and take ev as value.
+ *
+ * Normalization is required if the value is a tuple, in
+ * that case the value of StopIteration would be set to
+ * the first element of the tuple.
+ *
+ * (See _PyErr_CreateException code for details.)
+ */
value = ev;
} else {
/* normalisation required */
@@ -1012,7 +1052,7 @@
static PyObject *
aiter_wrapper_iternext(PyAIterWrapper *aw)
{
- PyErr_SetObject(PyExc_StopIteration, aw->aw_aiter);
+ _PyGen_SetStopIterationValue(aw->aw_aiter);
return NULL;
}