From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.bugs Subject: bug#49261: Segfault during loadup Date: Tue, 13 Jul 2021 18:12:00 -0500 Message-ID: References: <87o8bn7bie.fsf@gnus.org> <87zgv6vuon.fsf@gmx.de> <837di9lwbm.fsf@gnu.org> <87a6n5vuu4.fsf@gnus.org> <8735sqnmei.fsf@gnus.org> <87zguyf4ht.fsf@gmx.de> <87pmvum54p.fsf@gnus.org> <87v95mf2lj.fsf@gmx.de> <87pmvt3ob1.fsf@gnus.org> <83r1g9evoy.fsf@gnu.org> <83pmvtevgg.fsf@gnu.org> <87czrt3mj4.fsf@gnus.org> <878s2h3m1d.fsf@gnus.org> <874kd53lnl.fsf@gnus.org> <87zgux26ab.fsf@gnus.org> <87pmvt25uq.fsf@gnus.org> <87lf6h2294.fsf@gnus.org> <87h7h51x9y.fsf_-_@gnus.org> <83bl79b17n.fsf@gnu.org> <835yxgc1pm.fsf@gnu.org> <83wnpvag6z.fsf@gnu.org> <5608bf0a-7211-73a9-690f-c869a1cb3c9d@cs.ucla.edu> <83o8b7a5ow.fsf@gnu.org> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8; format=flowed Content-Transfer-Encoding: 7bit Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="39591"; mail-complaints-to="usenet@ciao.gmane.io" User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:78.0) Gecko/20100101 Thunderbird/78.11.0 Cc: larsi@gnus.org, 49261@debbugs.gnu.org To: Eli Zaretskii Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Wed Jul 14 01:13:11 2021 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1m3RaQ-000ABI-Tj for geb-bug-gnu-emacs@m.gmane-mx.org; Wed, 14 Jul 2021 01:13:10 +0200 Original-Received: from localhost ([::1]:47560 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1m3RaP-0000YN-Sg for geb-bug-gnu-emacs@m.gmane-mx.org; Tue, 13 Jul 2021 19:13:09 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:38838) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1m3RaI-0000Xu-Fr for bug-gnu-emacs@gnu.org; Tue, 13 Jul 2021 19:13:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:59100) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1m3RaI-00083q-7y for bug-gnu-emacs@gnu.org; Tue, 13 Jul 2021 19:13:02 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1m3RaI-0008Nm-3f for bug-gnu-emacs@gnu.org; Tue, 13 Jul 2021 19:13:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Paul Eggert Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Tue, 13 Jul 2021 23:13:02 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 49261 X-GNU-PR-Package: emacs Original-Received: via spool by 49261-submit@debbugs.gnu.org id=B49261.162621792932159 (code B ref 49261); Tue, 13 Jul 2021 23:13:02 +0000 Original-Received: (at 49261) by debbugs.gnu.org; 13 Jul 2021 23:12:09 +0000 Original-Received: from localhost ([127.0.0.1]:42413 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1m3RZQ-0008Md-UP for submit@debbugs.gnu.org; Tue, 13 Jul 2021 19:12:09 -0400 Original-Received: from zimbra.cs.ucla.edu ([131.179.128.68]:60988) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1m3RZP-0008MR-P9 for 49261@debbugs.gnu.org; Tue, 13 Jul 2021 19:12:08 -0400 Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id 5D5301600EF; Tue, 13 Jul 2021 16:12:02 -0700 (PDT) Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10032) with ESMTP id ADTQaidYxoW9; Tue, 13 Jul 2021 16:12:01 -0700 (PDT) Original-Received: from localhost (localhost [127.0.0.1]) by zimbra.cs.ucla.edu (Postfix) with ESMTP id AA2D61600F1; Tue, 13 Jul 2021 16:12:01 -0700 (PDT) X-Virus-Scanned: amavisd-new at zimbra.cs.ucla.edu Original-Received: from zimbra.cs.ucla.edu ([127.0.0.1]) by localhost (zimbra.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10026) with ESMTP id ykgbgCA_f1Sn; Tue, 13 Jul 2021 16:12:01 -0700 (PDT) Original-Received: from [192.168.0.205] (ip72-206-1-93.fv.ks.cox.net [72.206.1.93]) by zimbra.cs.ucla.edu (Postfix) with ESMTPSA id 4FD1D16006C; Tue, 13 Jul 2021 16:12:01 -0700 (PDT) In-Reply-To: <83o8b7a5ow.fsf@gnu.org> Content-Language: en-US X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.18 Precedence: list X-BeenThere: bug-gnu-emacs@gnu.org List-Id: "Bug reports for GNU Emacs, the Swiss army knife of text editors" List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , Errors-To: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Original-Sender: "bug-gnu-emacs" Xref: news.gmane.io gmane.emacs.bugs:209902 Archived-At: On 7/12/21 10:54 AM, Eli Zaretskii wrote: > Then what is the -Woverflow option for? Can you show an example of > code which -Woverflow would flag that doesn't produce a bogus warning? Sure: the GCC documentation says -Woverflow is supposed to warn about "compile-time overflow in constant expressions". So GCC should (and does) warn about this top-level declaration: int x = INT_MAX + 1; However, there is no overflow here: unsigned a = -1, b = INT_MIN, c = LLONG_MAX; and these declarations have well-defined behavior in C, so -Woverflow should not issue warnings for them even though they are unsigned conversions that change numeric values. It might be useful to some programmers to generate warnings about these unsigned conversions, but this should be a separate -W option not -Woverflow. There's no overflow here.