bpo-45757: Fix bug where dis produced an incorrect oparg on EXTENDED_ARG before a no-arg opcode (GH-29480)

This commit is contained in:
Irit Katriel 2021-11-09 20:07:38 +00:00 committed by GitHub
parent bcc4e46832
commit cb414cf0e2
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3 changed files with 23 additions and 0 deletions

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@ -523,6 +523,7 @@ def _unpack_opargs(code):
extended_arg = (arg << 8) if op == EXTENDED_ARG else 0
else:
arg = None
extended_arg = 0
yield (i, op, arg)
def findlabels(code):

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@ -179,6 +179,23 @@ dis_bug42562 = """\
2 RETURN_VALUE
"""
# Extended arg followed by NOP
code_bug_45757 = bytes([
0x90, 0x01, # EXTENDED_ARG 0x01
0x09, 0xFF, # NOP 0xFF
0x90, 0x01, # EXTENDED_ARG 0x01
0x64, 0x29, # LOAD_CONST 0x29
0x53, 0x00, # RETURN_VALUE 0x00
])
dis_bug_45757 = """\
0 EXTENDED_ARG 1
2 NOP
4 EXTENDED_ARG 1
6 LOAD_CONST 297
8 RETURN_VALUE
"""
_BIG_LINENO_FORMAT = """\
%3d 0 LOAD_GLOBAL 0 (spam)
2 POP_TOP
@ -547,6 +564,10 @@ class DisTests(unittest.TestCase):
def test_bug_42562(self):
self.do_disassembly_test(bug42562, dis_bug42562)
def test_bug_45757(self):
# Extended arg followed by NOP
self.do_disassembly_test(code_bug_45757, dis_bug_45757)
def test_big_linenos(self):
def func(count):
namespace = {}

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@ -0,0 +1 @@
Fix bug where :mod:`dis` produced an incorrect oparg when :opcode:`EXTENDED_ARG` is followed by an opcode that does not use its argument.