[Python-checkins] [3.10] bpo-46009: Do not exhaust generator when send() method raises (GH-29986). (GH-29988)
pablogsal
webhook-mailer at python.org
Wed Dec 8 09:46:41 EST 2021
https://github.com/python/cpython/commit/99c72326d245fb604609a87a51ef1ad0845467b7
commit: 99c72326d245fb604609a87a51ef1ad0845467b7
branch: 3.10
author: Mark Shannon <mark at hotpy.org>
committer: pablogsal <Pablogsal at gmail.com>
date: 2021-12-08T14:46:32Z
summary:
[3.10] bpo-46009: Do not exhaust generator when send() method raises (GH-29986). (GH-29988)
* [3.10] bpo-46009: Do not exhaust generator when send() method raises (GH-29986).
(cherry picked from commit 69806b9516dbe092381f3ef884c7c64bb9b8414a)
Co-authored-by: Mark Shannon <mark at hotpy.org>
* Rename variable after cherry-pick.
* Add NULL check.
files:
A Misc/NEWS.d/next/Core and Builtins/2021-12-08-11-06-53.bpo-46009.cL8pH0.rst
M Doc/library/dis.rst
M Lib/test/test_generators.py
M Objects/genobject.c
M Python/ceval.c
diff --git a/Doc/library/dis.rst b/Doc/library/dis.rst
index e7e67daae5254..74820f9bdb578 100644
--- a/Doc/library/dis.rst
+++ b/Doc/library/dis.rst
@@ -1252,9 +1252,8 @@ All of the following opcodes use their arguments.
.. opcode:: GEN_START (kind)
- Pops TOS. If TOS was not ``None``, raises an exception. The ``kind``
- operand corresponds to the type of generator or coroutine and determines
- the error message. The legal kinds are 0 for generator, 1 for coroutine,
+ Pops TOS. The ``kind`` operand corresponds to the type of generator or
+ coroutine. The legal kinds are 0 for generator, 1 for coroutine,
and 2 for async generator.
.. versionadded:: 3.10
diff --git a/Lib/test/test_generators.py b/Lib/test/test_generators.py
index d14c757c7b6e4..3bf5f3b7438e7 100644
--- a/Lib/test/test_generators.py
+++ b/Lib/test/test_generators.py
@@ -161,6 +161,14 @@ def f():
with self.assertRaises((TypeError, pickle.PicklingError)):
pickle.dumps(g, proto)
+ def test_send_non_none_to_new_gen(self):
+ def f():
+ yield 1
+ g = f()
+ with self.assertRaises(TypeError):
+ g.send(0)
+ self.assertEqual(next(g), 1)
+
class ExceptionTest(unittest.TestCase):
# Tests for the issue #23353: check that the currently handled exception
diff --git a/Misc/NEWS.d/next/Core and Builtins/2021-12-08-11-06-53.bpo-46009.cL8pH0.rst b/Misc/NEWS.d/next/Core and Builtins/2021-12-08-11-06-53.bpo-46009.cL8pH0.rst
new file mode 100644
index 0000000000000..a80e66b7c6451
--- /dev/null
+++ b/Misc/NEWS.d/next/Core and Builtins/2021-12-08-11-06-53.bpo-46009.cL8pH0.rst
@@ -0,0 +1,5 @@
+Restore behavior from 3.9 and earlier when sending non-None to newly started
+generator. In 3.9 this did not affect the state of the generator. In 3.10.0
+and 3.10.1 ``gen_func().send(0)`` is equivalent to
+``gen_func().throw(TypeError(...)`` which exhausts the generator. In 3.10.2
+onward, the behavior has been reverted to that of 3.9.
diff --git a/Objects/genobject.c b/Objects/genobject.c
index 3ac38de0c311b..33fc4a592492a 100644
--- a/Objects/genobject.c
+++ b/Objects/genobject.c
@@ -145,6 +145,19 @@ gen_send_ex2(PyGenObject *gen, PyObject *arg, PyObject **presult,
PyObject *result;
*presult = NULL;
+ if (f != NULL && f->f_lasti < 0 && arg && arg != Py_None) {
+ const char *msg = "can't send non-None value to a "
+ "just-started generator";
+ if (PyCoro_CheckExact(gen)) {
+ msg = NON_INIT_CORO_MSG;
+ }
+ else if (PyAsyncGen_CheckExact(gen)) {
+ msg = "can't send non-None value to a "
+ "just-started async generator";
+ }
+ PyErr_SetString(PyExc_TypeError, msg);
+ return PYGEN_ERROR;
+ }
if (f != NULL && _PyFrame_IsExecuting(f)) {
const char *msg = "generator already executing";
if (PyCoro_CheckExact(gen)) {
diff --git a/Python/ceval.c b/Python/ceval.c
index 624baf537518f..8ad1713b78c01 100644
--- a/Python/ceval.c
+++ b/Python/ceval.c
@@ -2649,25 +2649,9 @@ _PyEval_EvalFrameDefault(PyThreadState *tstate, PyFrameObject *f, int throwflag)
case TARGET(GEN_START): {
PyObject *none = POP();
+ assert(none == Py_None);
+ assert(oparg < 3);
Py_DECREF(none);
- if (!Py_IsNone(none)) {
- if (oparg > 2) {
- _PyErr_SetString(tstate, PyExc_SystemError,
- "Illegal kind for GEN_START");
- }
- else {
- static const char *gen_kind[3] = {
- "generator",
- "coroutine",
- "async generator"
- };
- _PyErr_Format(tstate, PyExc_TypeError,
- "can't send non-None value to a "
- "just-started %s",
- gen_kind[oparg]);
- }
- goto error;
- }
DISPATCH();
}
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