view tests/filterpyflakes.py @ 38935:27a54096c92e

linelog: fix infinite loop vulnerability

Checking `len(lines)` is not a great way of detecting infinite loops, as
demonstrated in the added test. Therefore check instruction count instead.

The original C implementation does not have this problem. There are a few
other places where the C implementation enforces more strictly, like
`a1 <= a2`, `b1 <= b2`, `rev > 0`. But they are optional.

Test Plan:
Add a test. The old code forces the test to time out.

Differential Revision: https://phab.mercurial-scm.org/D4151

#!/usr/bin/env python

# Filter output by pyflakes to control which warnings we check

from __future__ import absolute_import, print_function

import re
import sys

lines = []
for line in sys.stdin:
    # We blacklist tests that are too noisy for us
    pats = [
        r"undefined name 'WindowsError'",
        r"redefinition of unused '[^']+' from line",
        # for cffi, allow re-exports from pure.*
        r"cffi/[^:]*:.*\bimport \*' used",
        r"cffi/[^:]*:.*\*' imported but unused",
    ]

    keep = True
    for pat in pats:
        if re.search(pat, line):
            keep = False
            break # pattern matches
    if keep:
        fn = line.split(':', 1)[0]
        f = open(fn)
        data = f.read()
        f.close()
        if 'no-' 'check-code' in data:
            continue
        lines.append(line)

for line in lines:
    sys.stdout.write(line)
print()