From: Tom Lane <tgl@sss.pgh.pa.us>
To: Andrew Dunstan <andrew@dunslane.net>
cc: Jeff Davis <pgsql@j-davis.com>, Alvaro Herrera <alvherre@alvh.no-ip.org>,
        pgsql-hackers@postgresql.org
Subject: Re: perl: unsafe empty pattern behavior
In-reply-to: <a2d160b7-ff67-41f1-5176-4b520a15ef4a@dunslane.net>
References: <202403121753.lw7u5b5fjsjw@alvherre.pgsql> <2385813054ce4e4b3e5998600da2ce95b9509dc7.camel@j-davis.com> <1941562.1710284344@sss.pgh.pa.us> <a2d160b7-ff67-41f1-5176-4b520a15ef4a@dunslane.net>
Comments: In-reply-to Andrew Dunstan <andrew@dunslane.net>
	message dated "Wed, 13 Mar 2024 00:04:49 -0400"
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Date: Wed, 13 Mar 2024 00:15:18 -0400
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Andrew Dunstan <andrew@dunslane.net> writes:
> On 2024-03-12 Tu 18:59, Tom Lane wrote:
>> I wonder whether perlcritic has sufficiently deep understanding of
>> Perl code that it could find these hazards.

> Yeah, that was my thought too. I'd start with ProhibitComplexRegexes.pm =

> as a template.

Oooh.  Taking a quick look at the source code:

https://metacpan.org/dist/Perl-Critic/source/lib/Perl/Critic/Policy/Regula=
rExpressions/ProhibitComplexRegexes.pm

it seems like it'd be pretty trivial to convert that from "complain if
regex contains more than N characters" to "complain if regex contains
zero characters".

			regards, tom lane