diff options
| -rw-r--r-- | Lib/test/test_compile.py | 10 | ||||
| -rw-r--r-- | Misc/NEWS.d/next/Core and Builtins/2022-02-14-14-44-06.bpo-46724.jym_K6.rst | 2 | ||||
| -rw-r--r-- | Python/compile.c | 5 |
3 files changed, 17 insertions, 0 deletions
diff --git a/Lib/test/test_compile.py b/Lib/test/test_compile.py index 096501513c1..7ebe837fce1 100644 --- a/Lib/test/test_compile.py +++ b/Lib/test/test_compile.py @@ -1008,6 +1008,16 @@ if 1: elif instr.opname in HANDLED_JUMPS: self.assertNotEqual(instr.arg, (line + 1)*INSTR_SIZE) + def test_no_wraparound_jump(self): + # See https://bugs.python.org/issue46724 + + def while_not_chained(a, b, c): + while not (a < b < c): + pass + + for instr in dis.Bytecode(while_not_chained): + self.assertNotEqual(instr.opname, "EXTENDED_ARG") + @requires_debug_ranges() class TestSourcePositions(unittest.TestCase): # Ensure that compiled code snippets have correct line and column numbers diff --git a/Misc/NEWS.d/next/Core and Builtins/2022-02-14-14-44-06.bpo-46724.jym_K6.rst b/Misc/NEWS.d/next/Core and Builtins/2022-02-14-14-44-06.bpo-46724.jym_K6.rst new file mode 100644 index 00000000000..7324182677a --- /dev/null +++ b/Misc/NEWS.d/next/Core and Builtins/2022-02-14-14-44-06.bpo-46724.jym_K6.rst @@ -0,0 +1,2 @@ +Make sure that all backwards jumps use the ``JUMP_ABSOLUTE`` instruction, rather +than ``JUMP_FORWARD`` with an argument of ``(2**32)+offset``. diff --git a/Python/compile.c b/Python/compile.c index 1cf20d3a36a..786ef4e8ad3 100644 --- a/Python/compile.c +++ b/Python/compile.c @@ -7534,6 +7534,11 @@ normalize_jumps(struct assembler *a) last->i_opcode = JUMP_FORWARD; } } + if (last->i_opcode == JUMP_FORWARD) { + if (last->i_target->b_visited == 1) { + last->i_opcode = JUMP_ABSOLUTE; + } + } } } |