From: Alan Mackenzie <acm@muc.de>
To: 18577@debbugs.gnu.org
Subject: bug#18577: Regexp I-search: [(error Stack overflow in regexp matcher)]
Date: Sun, 28 Sep 2014 08:55:55 +0000 [thread overview]
Message-ID: <20140928085554.GA3157@acm.acm> (raw)
Hi, Emacs.
In the trunk, emacs -Q. Visit our favourite big file, xdisp.c.
With point at BOB, do C-M-s and enter this regular expression at the
prompt:
/\*\(\([^'*]\|\*[^/']\)*\*?'\([^'*]\|\*[^/']\)*\*?'\)*\([^'*]\|\*[^'/]\)*\*?'\([^'*]\|\*[^/']\)*\*?\*/
Press C-s. This gives the error message "[(error Stack overflow in
regexp matcher)]".
This feels like a bug. Regexp searching with this expression (which
finds a block comment containing an odd number of apostrophes) works fine
in the rest of the buffer. Only in the second (large) comment in xdisp.c
does it trigger this error. Surely an iterative regexp (which all
regexps are, surely?) shouldn't be triggering unbounded recursive
behaviour in the search engine.
[N.B. the regexp when parsed a bit looks like this:
/\*\( \)*\( \| \)*\*?'\( \| \)*\*?\*/
\( \| \)*\*?'\( \| \)*\*?' [^'*] \*[^'/] [^'*] \*[^/']
[^'*] \*[^/'] [^'*] \*[^/']
].
--
Alan Mackenzie (Nuremberg, Germany).
next reply other threads:[~2014-09-28 8:55 UTC|newest]
Thread overview: 13+ messages / expand[flat|nested] mbox.gz Atom feed top
2014-09-28 8:55 Alan Mackenzie [this message]
2014-09-28 10:56 ` bug#18577: Regexp I-search: [(error Stack overflow in regexp matcher)] Andreas Schwab
2014-09-28 12:37 ` Alan Mackenzie
2014-09-28 12:48 ` Andreas Schwab
2014-09-28 17:35 ` Stefan Monnier
2014-11-27 8:44 ` Tassilo Horn
2021-10-23 2:47 ` Stefan Kangas
2021-10-23 7:32 ` Eli Zaretskii
2021-10-23 8:30 ` Stefan Kangas
2021-10-23 8:39 ` Eli Zaretskii
2021-10-23 9:32 ` Stefan Kangas
2021-10-23 11:27 ` Eli Zaretskii
2021-10-24 22:08 ` Stefan Kangas
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