From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.devel Subject: Re: fsanitize=bounds-strict caught potential error Date: Sun, 05 Dec 2021 17:23:30 +0200 Message-ID: <83r1ar2hzh.fsf@gnu.org> References: <87o85vp5hs.fsf.ref@yahoo.com> <87o85vp5hs.fsf@yahoo.com> <83wnkj2m21.fsf@gnu.org> <87r1arozgc.fsf@igel.home> Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="19690"; mail-complaints-to="usenet@ciao.gmane.io" Cc: luangruo@yahoo.com, emacs-devel@gnu.org To: Andreas Schwab Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Sun Dec 05 16:24:39 2021 Return-path: Envelope-to: ged-emacs-devel@m.gmane-mx.org Original-Received: from lists.gnu.org ([209.51.188.17]) by ciao.gmane.io with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.92) (envelope-from ) id 1mttNW-0004v5-T4 for ged-emacs-devel@m.gmane-mx.org; Sun, 05 Dec 2021 16:24:39 +0100 Original-Received: from localhost ([::1]:47436 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1mttNU-0004Ew-QW for ged-emacs-devel@m.gmane-mx.org; Sun, 05 Dec 2021 10:24:36 -0500 Original-Received: from eggs.gnu.org ([209.51.188.92]:38522) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mttMW-0003Yb-M9 for emacs-devel@gnu.org; Sun, 05 Dec 2021 10:23:37 -0500 Original-Received: from [2001:470:142:3::e] (port=41362 helo=fencepost.gnu.org) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mttMV-0002Mt-N3; Sun, 05 Dec 2021 10:23:35 -0500 DKIM-Signature: v=1; a=rsa-sha256; q=dns/txt; c=relaxed/relaxed; d=gnu.org; s=fencepost-gnu-org; h=References:Subject:In-Reply-To:To:From:Date: mime-version; bh=A4TDIvd6WKXFfHEhAaYQoDmJ5uGhwohk1blJb8siJWM=; b=apSjZmudqPZr H0tg+cJaUMOKI4gMmRRFehAHRk2860cXkkMtq3tfeb/IJFFVynnNHAP85WM7jF3XkjVjGcILCxEyO iUc+QPQ1JIpDMCHAEj+FWyyfFUPIhEkfBsCPja1TPpxMSLDoTmhxWhtzwXHtHygCyP+Sp2G2M5fZT 3D8m6b2L+XvrkfbpQLy0S/Bd8OTqGRSF5dkgWqQxpTK1eRodi4SVyUKd7NDikZwolkPmcqVTCHZvT Rhn2mS1jTE36cw8ZQgil65r/GXRL7MPQEx8dmUfKqYiqIPvCFF1aT191S06Uy600M7wD14J0M4/0B mlHXHesFtXCn9HxoXaQKfw==; Original-Received: from [87.69.77.57] (port=1718 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1mttMV-00013u-Fg; Sun, 05 Dec 2021 10:23:35 -0500 In-Reply-To: <87r1arozgc.fsf@igel.home> (message from Andreas Schwab on Sun, 05 Dec 2021 16:15:15 +0100) X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.29 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-mx.org@gnu.org Original-Sender: "Emacs-devel" Xref: news.gmane.io gmane.emacs.devel:281003 Archived-At: > From: Andreas Schwab > Cc: Po Lu , emacs-devel@gnu.org > Date: Sun, 05 Dec 2021 16:15:15 +0100 > > >> xdisp.c:30394:37: runtime error: index -1 out of bounds for type 'iterator_stack_entry [5]' > > > > The compiler doesn't know enough to realize that this code can never > > be executed with it->sp < 1. This code is there since 2003, and never > > gave us any trouble. > > It is a runtime error, thus the erroneous access is actually being > executed. Then let's put an assertion there and find the culprit. Maybe it's the min-width feature, which is new on master.