Re: [Bug: 21.4.14] Stack overflow in regexp matcher

Dres> With the latest xemacs I noticed REGEX_MALLOC is now the Dres> default. When I tried setting it with 21.4.13 the same Dres> problem occured. Dres> The error message is: Dres> Stack overflow in regexp matcher My feeling is that what is happening here is that a problem you wouldn't see when using ALLOCA is being exposed by using REGEX_MALLOC. Dres> And the value of compilation-error-regexp-alist is: Using multiline regexps is a clear sign of a pact with the Devil. I really don't know what to say; we don't have much choice about using such regexps at the moment. You have a very hard choice (as Debian maintainer): you can prevent crashes (ie, leave REGEX_MALLOC enabled) at the expense of forcing a lot of matches that would otherwise succeed to end in error. This patch should help, and I'd appreciate testing. But the logic regarding MATCH_MAY_ALLOCATE has changed a lot in 21.5, and the 21.4 usage seems real weird to me, especially in light of comments in 21.5. So watch out. Index: src/ChangeLog =================================================================== RCS file: /pack/xemacscvs/XEmacs/xemacs/src/ChangeLog,v retrieving revision 1.290.2.53 diff -u -U0 -r1.290.2.53 ChangeLog --- src/ChangeLog 4 Sep 2003 02:44:48 -0000 1.290.2.53 +++ src/ChangeLog 13 Sep 2003 07:16:06 -0000 ＠＠ -0,0 +1,4 ＠＠ +2003-09-13 Stephen J. Turnbull <stephen(a)xemacs.org&gt; + + * regex.c (re_max_failures): Bump to 20000 for REGEX_MALLOC, too. + Index: src/regex.c =================================================================== RCS file: /pack/xemacscvs/XEmacs/xemacs/src/regex.c,v retrieving revision 1.25.2.4 diff -u -r1.25.2.4 regex.c --- src/regex.c 19 Jun 2003 03:34:42 -0000 1.25.2.4 +++ src/regex.c 13 Sep 2003 07:16:15 -0000 ＠＠ -1135,7 +1135,7 ＠＠ exactly that if always used MAX_FAILURE_SPACE each time we failed. This is a variable only so users of regex can assign to it; we never change it ourselves. */ -#if defined (MATCH_MAY_ALLOCATE) +#if defined (MATCH_MAY_ALLOCATE) || defined (REGEX_MALLOC) /* 4400 was enough to cause a crash on Alpha OSF/1, whose default stack limit is 2mb. */ int re_max_failures = 20000; -- Institute of Policy and Planning Sciences http://turnbull.sk.tsukuba.ac.jp University of Tsukuba Tennodai 1-1-1 Tsukuba 305-8573 JAPAN Ask not how you can "do" free software business; ask what your business can "do for" free software.