all messages for Emacs-related lists mirrored at yhetil.org
 help / color / mirror / code / Atom feed
From: "Eli Zaretskii" <eliz@elta.co.il>
Cc: emacs-devel@gnu.org
Subject: Re: Mac OSX running Carbon crash with today's CVS
Date: Wed, 23 Apr 2003 11:54:28 +0200	[thread overview]
Message-ID: <7999-Wed23Apr2003115428+0300-eliz@elta.co.il> (raw)
In-Reply-To: <37111A44-74D0-11D7-A77C-00039375B5CC@apple.com> (message from Gabriel Foster on Tue, 22 Apr 2003 07:39:25 -0700)

> Date: Tue, 22 Apr 2003 07:39:25 -0700
> From: Gabriel Foster <gabriel@apple.com>
> 
> In the most recent case, I had just hit the enter key.

Can you cause the same crash if you type "M-x garbage-collect RET"
right after starting Emacs?

> (gdb) print tail
> $2 = (struct gcpro *) 0xbfffde20
> (gdb) print *tail->var[i]
> Cannot access memory at address 0x1
> (gdb) print tail->var[i]
> Cannot access memory at address 0x1
> (gdb) print tail->var
> $3 = (volatile int *) 0x1

This is the problem, then: either tail->var or tail->nvars is garbled
(I'm guessing it's the latter).

Does anyone have a clue why this could happen on a Mac?

If no one comes up with a better idea, one way of attacking this bug
would be to put a hardware-assisted watchpoint on the nvars member,
like this:

   (gdb) watch ((struct gcpro *)0xbfffde20)->nvars

and when the watchpoint fires, look for the code that puts the
preposterously large value into nvars.  (If nvars changes its value
to something reasonable, like zero or 1, just type "cont" to let the
program resume its run.)

Before you do the above, it is highly recommended to find a simple
procedure that would predictably cause such a crash, and with the
same value of `tail', the GCPRO structure that is garbled.  Then use
that address instead of 0xbfffde20 above.

(I'm assuming that GDB on Mac OSX supports hardware-assisted
watchpoints, btw.)

  reply	other threads:[~2003-04-23  9:54 UTC|newest]

Thread overview: 5+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2003-04-21 22:21 Mac OSX running Carbon crash with today's CVS Gabriel Foster
2003-04-22  8:05 ` Eli Zaretskii
2003-04-22 14:39   ` Gabriel Foster
2003-04-23  9:54     ` Eli Zaretskii [this message]
2003-04-23 12:56       ` Andrew Choi

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

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

  git send-email \
    --in-reply-to=7999-Wed23Apr2003115428+0300-eliz@elta.co.il \
    --to=eliz@elta.co.il \
    --cc=emacs-devel@gnu.org \
    /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 external index

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

This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.