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From: "bonzini at gnu dot org" <sourceware-bugzilla@sourceware.org>
To: glibc-bugs-regex@sourceware.org
Subject: [Bug regex/52] Repeated and nested subexpressions (reproducible in most other engines)
Date: Thu, 04 Jul 2013 07:42:00 -0000	[thread overview]
Message-ID: <bug-52-132-lgFzXnrvPv@http.sourceware.org/bugzilla/> (raw)
In-Reply-To: <bug-52-132@http.sourceware.org/bugzilla/>

http://sourceware.org/bugzilla/show_bug.cgi?id=52

--- Comment #13 from Paolo Bonzini <bonzini at gnu dot org> ---
At the time I reported the bug, I'm pretty sure I checked a few proprietary
Unices.  Also, even though it is not POSIX RE, Perl regular expressions have
the same behavior.  While it is true that backreferences can make this bug
affect the overall outcome of the match, it is still a very weird regular
expression.

Thanks for mentioning musl's matcher, I'll check it out.  Matching
backreferences at a decent speed _and_ obeying the POSIX leftmost/longest rules
is very hard to do.  The glibc matcher unfortunately is very badly documented
and the backreference part of it is basically black magic. :(

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  parent reply	other threads:[~2013-07-04  7:42 UTC|newest]

Thread overview: 12+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
     [not found] <bug-52-132@http.sourceware.org/bugzilla/>
2012-03-08  4:59 ` carlos at systemhalted dot org
2013-07-03 21:25 ` eblake at redhat dot com
2013-07-04  0:28 ` bugdal at aerifal dot cx
2013-07-04  3:37 ` carlos at redhat dot com
2013-07-04  3:38 ` carlos at redhat dot com
2013-07-04  7:22 ` bonzini at gnu dot org
2013-07-04  7:35 ` bugdal at aerifal dot cx
2013-07-04  7:42 ` bonzini at gnu dot org [this message]
2013-07-04  7:51 ` bugdal at aerifal dot cx
2013-07-04  8:04 ` bonzini at gnu dot org
2013-07-04 15:05 ` eggert at gnu dot org
2014-01-31  9:15 ` afaq.ahmed at agilosoft dot com

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