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Differential D2866

contrib: fix a subtle bug in check-code's regex rewriting
ClosedPublic

Authored by durin42 on Mar 14 2018, 3:53 PM.

Details

Reviewers
pulkit
Group Reviewers
hg-reviewers
Commits
rHGa8d540d2628c: contrib: fix a subtle bug in check-code's regex rewriting
rHGac635637ed2f: contrib: fix a subtle bug in check-code's regex rewriting
Summary

We rewrite \s to [ \t] when preparing our regular expressions, but
we previously weren't working to avoid having nested sets. Previously,
Python let this slide without incident, but in Python 3.7 wants to
make sure you meant an actual [ in a set, and so this warns. This
appears to be fortunate for us, because [\s(] was getting rewritten
to be [[ \t](] which doesn't actually match what we expected. See
preceding changes that were revealed to be necessary after
implementing this fix.

Diff Detail

Repository
rHG Mercurial
Lint
Automatic diff as part of commit; lint not applicable.
Unit
Automatic diff as part of commit; unit tests not applicable.

Event Timeline

durin42 created this revision.Mar 14 2018, 3:53 PM
pulkit accepted this revision.Mar 15 2018, 8:32 AM
pulkit added a subscriber: pulkit.

Looks good to me but I am not feeling confident enough to push this. Queued the first three.

Closed by commit rHGac635637ed2f: contrib: fix a subtle bug in check-code's regex rewriting (authored by durin42). · Explain WhyMar 15 2018, 10:43 AM
This revision was automatically updated to reflect the committed changes.

Revision Contents
Changeset List

PathPackages
Mcontrib/check-code.py (7 lines)

Diff 7066

contrib/check-code.py

def _preparepats(): def _preparepats():
for c in checks: for c in checks:
failandwarn = c[-1] failandwarn = c[-1]
for pats in failandwarn: for pats in failandwarn:
for i, pseq in enumerate(pats): for i, pseq in enumerate(pats):
# fix-up regexes for multi-line searches # fix-up regexes for multi-line searches
p = pseq[0] p = pseq[0]
# \s doesn't match \n # \s doesn't match \n (done in two steps)
p = re.sub(r'(?<!\\)\\s', r'[ \\t]', p) # first, we replace \s that appears in a set already
p = re.sub(r'\[\\s', r'[ \\t', p)
# now we replace other \s instances.
p = re.sub(r'(?<!(\\|\[))\\s', r'[ \\t]', p)
# [^...] doesn't match newline # [^...] doesn't match newline
p = re.sub(r'(?<!\\)\[\^', r'[^\\n', p) p = re.sub(r'(?<!\\)\[\^', r'[^\\n', p)
pats[i] = (re.compile(p, re.MULTILINE),) + pseq[1:] pats[i] = (re.compile(p, re.MULTILINE),) + pseq[1:]
filters = c[3] filters = c[3]
for i, flt in enumerate(filters): for i, flt in enumerate(filters):
filters[i] = re.compile(flt[0]), flt[1] filters[i] = re.compile(flt[0]), flt[1]