From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: Help please! To track down GC trying to free an already freed object. Date: Wed, 03 Apr 2019 13:12:12 +0300 Message-ID: <83ftqze6tf.fsf@gnu.org> References: <20190402112537.GA6212@ACM> <835zrwfc21.fsf@gnu.org> <20190402204653.GC25792@ACM> <831s2jg0s8.fsf@gnu.org> <20190403100113.GA11372@ACM> Injection-Info: blaine.gmane.org; posting-host="blaine.gmane.org:195.159.176.226"; logging-data="257186"; mail-complaints-to="usenet@blaine.gmane.org" Cc: dancol@dancol.org, emacs-devel@gnu.org To: Alan Mackenzie Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Wed Apr 03 12:12:16 2019 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([209.51.188.17]) by blaine.gmane.org with esmtps (TLS1.0:RSA_AES_256_CBC_SHA1:256) (Exim 4.89) (envelope-from ) id 1hBcsQ-0014fq-Sz for ged-emacs-devel@m.gmane.org; Wed, 03 Apr 2019 12:12:15 +0200 Original-Received: from localhost ([127.0.0.1]:50891 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBcsH-0003zD-H3 for ged-emacs-devel@m.gmane.org; Wed, 03 Apr 2019 06:12:05 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:36568) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBcsB-0003z4-3V for emacs-devel@gnu.org; Wed, 03 Apr 2019 06:11:59 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:51116) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1hBcsA-0001wK-0z; Wed, 03 Apr 2019 06:11:58 -0400 Original-Received: from [176.228.60.248] (port=1755 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1hBcs9-0005Yx-Fo; Wed, 03 Apr 2019 06:11:57 -0400 In-reply-to: <20190403100113.GA11372@ACM> (message from Alan Mackenzie on Wed, 3 Apr 2019 10:01:13 +0000) X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 Precedence: list List-Id: "Emacs development discussions." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.org gmane.emacs.devel:234916 Archived-At: > Date: Wed, 3 Apr 2019 10:01:13 +0000 > Cc: dancol@dancol.org, emacs-devel@gnu.org > From: Alan Mackenzie > > The problem I think I'm up against is that the symbol-with-pos object is > not being marked at a particular garbage_collect_1, and thus gets freed > prematurely. > > I intend to get the hex values of the Lisp_Objects which constitute the > list in which the symbol-with-pos is embedded and search for these in > last_marked. Putting a conditional breakpoint on Fcons slows down Emacs > somewhat. ;-) GDB has memory-search commands, see the node "Searching Memory" in the GDB manual. Maybe this can help.