unofficial mirror of bug-gnu-emacs@gnu.org 
 help / color / mirror / code / Atom feed
From: "Chris Hecker" <checker@d6.com>
To: "Alan Mackenzie" <acm@muc.de>, "Eli Zaretskii" <eliz@gnu.org>
Cc: psainty@orcon.net.nz, gerd.moellmann@gmail.com,
	Gregory Heytings <gregory@heytings.org>,
	59038@debbugs.gnu.org
Subject: bug#59038: Re[2]: bug#59038: loading this base64 file makes emacs -Q 28.2 peg a core infinitely
Date: Sun, 06 Nov 2022 19:46:01 +0000	[thread overview]
Message-ID: <eme92b7378-31ef-4318-a343-1b2fdf5166cb@checker-blade15> (raw)
In-Reply-To: <Y2fiMTlfuNqae7zp@acm>


Yay!  Go team!

Thanks,
Chris

------ Original Message ------
From: "Alan Mackenzie" <acm@muc.de>
To: "Eli Zaretskii" <eliz@gnu.org>
Cc: "Gregory Heytings" <gregory@heytings.org>; psainty@orcon.net.nz; 
gerd.moellmann@gmail.com; 59038@debbugs.gnu.org; checker@d6.com
Sent: 2022-11-06 08:34:57
Subject: Re: bug#59038: loading this base64 file makes emacs -Q 28.2 peg 
a core infinitely

>Hello, Eli.
>
>On Sun, Nov 06, 2022 at 15:52:33 +0200, Eli Zaretskii wrote:
>>  > Date: Sun, 06 Nov 2022 09:18:23 +0000
>>  > From: Gregory Heytings <gregory@heytings.org>
>>  > cc: Eli Zaretskii <eliz@gnu.org>,
>>  >     Gerd Möllmann <gerd.moellmann@gmail.com>,
>>  >     59038@debbugs.gnu.org, checker@d6.com, acm@muc.de
>
>
>>  > >> That file opens just fine in other modes
>
>>  > > It also opens fine in c-mode, with global-font-lock-mode disabled.
>
>
>>  > Indeed, obviously it's a c-mode font-locking related bug.
>
>>  > >> Note that this bug has nothing to do with long lines.
>
>>  > > I imagine that the font-lock issue is related to the line being in
>>  > > excess of 21,000 chars (but general redisplay obviously doesn't have
>>  > > problems with lines this 'small').
>
>>  > > Reduced to 10,208 chars that file opens instantly under emacs -Q in
>>  > > c-mode with font-lock enabled; but at 10,209 chars it hangs Emacs (I
>>  > > killed it after waiting 4 minutes).
>
>
>>  > Interesting, thanks for the bisection!
>
>>  It's an infloop in c-brace-stack-at.
>
>>  What happens is that c-brace-stack-at calls c-update-brace-stack with
>>  arguments: (nil 1) 8160 13160.  c-update-brace-stack then calls
>>  c-syntactic-re-search-forward, which finds nothing interesting and
>>  returns with point at 13160, but then c-update-brace-stack calls
>>  c-beginning-of-current-token, which returns point back to 8160.  And
>>  it goes on and on and on...
>
>Thanks for the debugging.
>
>>  Alan, what can be done with this?
>
>This:
>
>
>diff -r 53717eda724c cc-engine.el
>--- a/cc-engine.el	Sat Oct 29 09:42:47 2022 +0000
>+++ b/cc-engine.el	Sun Nov 06 16:26:09 2022 +0000
>@@ -6177,9 +6177,10 @@
>  	    (setq s (cdr s))))
>  	 ((c-keyword-member kwd-sym 'c-flat-decl-block-kwds)
>  	  (push 0 s))))
>-      ;; The failing `c-syntactic-re-search-forward' may have left us in the
>-      ;; middle of a token, which might be a significant token.  Fix this!
>-      (c-beginning-of-current-token)
>+      (when (> prev-match-pos 1)      ; Has the search matched at least once?
>+	;; The failing `c-syntactic-re-search-forward' may have left us in the
>+	;; middle of a token, which might be a significant token.  Fix this!
>+	(c-beginning-of-current-token))
>        (cons (point)
>  	    (cons bound-<> s)))))
>
>
>--
>Alan Mackenzie (Nuremberg, Germany).






  parent reply	other threads:[~2022-11-06 19:46 UTC|newest]

Thread overview: 28+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2022-11-05  2:48 bug#59038: loading this base64 file makes emacs -Q 28.2 peg a core infinitely Chris Hecker
2022-11-05  5:12 ` Gerd Möllmann
2022-11-05  7:01   ` Eli Zaretskii
2022-11-05  7:50     ` Gerd Möllmann
2022-11-05  8:21       ` Chris Hecker
2022-11-05  8:45         ` Gerd Möllmann
2022-11-05  9:30         ` Eli Zaretskii
2022-11-05 10:39           ` bug#59038: Re[2]: " Chris Hecker
2022-11-05 11:29         ` Po Lu via Bug reports for GNU Emacs, the Swiss army knife of text editors
2022-11-05 15:01           ` Chris Hecker
2022-11-06  5:17             ` Gerd Möllmann
2022-11-05 22:03           ` Alan Mackenzie
2022-11-06  6:00             ` Eli Zaretskii
2022-11-05  9:28       ` Eli Zaretskii
2022-11-06  5:18         ` Gerd Möllmann
2022-11-05 22:27     ` Gregory Heytings
2022-11-05 23:41       ` Gregory Heytings
2022-11-06  3:58         ` Phil Sainty
2022-11-06  5:20           ` Gerd Möllmann
2022-11-06 13:54             ` Alan Mackenzie
2022-11-06  9:18           ` Gregory Heytings
2022-11-06 13:52             ` Eli Zaretskii
2022-11-06 16:34               ` Alan Mackenzie
2022-11-07  7:55                 ` Gerd Möllmann
     [not found]               ` <Y2fiMTlfuNqae7zp@acm>
2022-11-06 19:46                 ` Chris Hecker [this message]
2022-11-07 12:25                   ` Alan Mackenzie
2022-11-05  6:52 ` Eli Zaretskii
2022-11-05 10:45 ` Phil Sainty

Reply instructions:

You may reply publicly to this message via plain-text email
using any one of the following methods:

* Save the following mbox file, import it into your mail client,
  and reply-to-all from there: mbox

  Avoid top-posting and favor interleaved quoting:
  https://en.wikipedia.org/wiki/Posting_style#Interleaved_style

  List information: https://www.gnu.org/software/emacs/

* Reply using the --to, --cc, and --in-reply-to
  switches of git-send-email(1):

  git send-email \
    --in-reply-to=eme92b7378-31ef-4318-a343-1b2fdf5166cb@checker-blade15 \
    --to=checker@d6.com \
    --cc=59038@debbugs.gnu.org \
    --cc=acm@muc.de \
    --cc=eliz@gnu.org \
    --cc=gerd.moellmann@gmail.com \
    --cc=gregory@heytings.org \
    --cc=psainty@orcon.net.nz \
    /path/to/YOUR_REPLY

  https://kernel.org/pub/software/scm/git/docs/git-send-email.html

* If your mail client supports setting the In-Reply-To header
  via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line before the message body.
Code repositories for project(s) associated with this public inbox

	https://git.savannah.gnu.org/cgit/emacs.git

This is a public inbox, see mirroring instructions
for how to clone and mirror all data and code used for this inbox;
as well as URLs for read-only IMAP folder(s) and NNTP newsgroup(s).