https://github.com/python/cpython/commit/1071f7400ec6f3ffb63b48310440b2ae73c632b4
commit: 1071f7400ec6f3ffb63b48310440b2ae73c632b4
branch: main
author: An Long <[email protected]>
committer: markshannon <[email protected]>
date: 2026-10-01T12:08:48+01:00
summary:
gh-155823: Fix stale stack on _SEND_VIRTUAL_TIER_TWO exhausted exit (GH-155844)
files:
A
Misc/NEWS.d/next/Core_and_Builtins/2026-08-15-20-31-20.gh-issue-155823.OhNmzi.rst
M Lib/test/test_capi/test_opt.py
M Python/bytecodes.c
M Python/executor_cases.c.h
diff --git a/Lib/test/test_capi/test_opt.py b/Lib/test/test_capi/test_opt.py
index d387fc7a23da26..64b6e82936d2f1 100644
--- a/Lib/test/test_capi/test_opt.py
+++ b/Lib/test/test_capi/test_opt.py
@@ -5821,6 +5821,20 @@ def testfunc(n):
self.assertIn("_FOR_ITER_GEN_FRAME", uops)
self.assertIn("_SEND_VIRTUAL_TIER_TWO", uops)
+ def test_send_virtual_exhausted(self):
+ # gh-155823: warm up on a non-empty list, then take the exhausted exit.
+ def gen(x):
+ yield from x
+ def testfunc(n, x):
+ total = 0
+ for _ in range(n):
+ for v in gen(x):
+ total += v
+ return total
+
+ testfunc(TIER2_THRESHOLD * 10, [1])
+ self.assertEqual(testfunc(1000, []), 0)
+
def test_binary_op_subscr_init_frame(self):
class B:
def __getitem__(self, other):
diff --git
a/Misc/NEWS.d/next/Core_and_Builtins/2026-08-15-20-31-20.gh-issue-155823.OhNmzi.rst
b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-15-20-31-20.gh-issue-155823.OhNmzi.rst
new file mode 100644
index 00000000000000..7dfbaf02575fd6
--- /dev/null
+++
b/Misc/NEWS.d/next/Core_and_Builtins/2026-08-15-20-31-20.gh-issue-155823.OhNmzi.rst
@@ -0,0 +1,4 @@
+Fix a JIT bug where the side exit taken when a virtual iterator is exhausted
+left a stale value on the stack, so the tier one interpreter resumed with
+corrupted state and ``yield from`` raised :exc:`AttributeError` instead of
+finishing normally.
diff --git a/Python/bytecodes.c b/Python/bytecodes.c
index 8799c48b110976..8dfb76ef7884d1 100644
--- a/Python/bytecodes.c
+++ b/Python/bytecodes.c
@@ -1786,8 +1786,6 @@ dummy_func(
if (index < 0) {
ERROR_NO_POP();
}
- next = none;
- DEAD(none);
EXIT_IF(true);
}
DEAD(none);
diff --git a/Python/executor_cases.c.h b/Python/executor_cases.c.h
index 0f1acd7f6af160..b60e9b2b52daa8 100644
--- a/Python/executor_cases.c.h
+++ b/Python/executor_cases.c.h
@@ -9175,7 +9175,6 @@
SET_CURRENT_CACHED_VALUES(0);
JUMP_TO_ERROR();
}
- next = none;
if (true) {
UOP_STAT_INC(uopcode, miss);
SET_CURRENT_CACHED_VALUES(0);
@@ -9219,10 +9218,9 @@
SET_CURRENT_CACHED_VALUES(0);
JUMP_TO_ERROR();
}
- next = none;
if (true) {
UOP_STAT_INC(uopcode, miss);
- _tos_cache0 = stack_pointer[0];
+ _tos_cache0 = none;
SET_CURRENT_CACHED_VALUES(1);
JUMP_TO_JUMP_TARGET();
}
@@ -9266,10 +9264,9 @@
SET_CURRENT_CACHED_VALUES(0);
JUMP_TO_ERROR();
}
- next = none;
if (true) {
UOP_STAT_INC(uopcode, miss);
- _tos_cache1 = stack_pointer[1];
+ _tos_cache1 = none;
_tos_cache0 = null_or_index;
SET_CURRENT_CACHED_VALUES(2);
JUMP_TO_JUMP_TARGET();
@@ -9316,10 +9313,9 @@
SET_CURRENT_CACHED_VALUES(0);
JUMP_TO_ERROR();
}
- next = none;
if (true) {
UOP_STAT_INC(uopcode, miss);
- _tos_cache2 = stack_pointer[2];
+ _tos_cache2 = none;
_tos_cache1 = null_or_index;
_tos_cache0 = iter;
SET_CURRENT_CACHED_VALUES(3);
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