From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.ciao.gmane.io!not-for-mail From: Eli Zaretskii Newsgroups: gmane.emacs.bugs Subject: bug#41321: 27.0.91; Emacs aborts due to invalid pseudovector objects Date: Sat, 30 May 2020 21:11:39 +0300 Message-ID: <83pnall2ck.fsf@gnu.org> References: <83zha8cgpi.fsf@gnu.org> <4bab5f55-95fe-cf34-e490-1d4319728395@cs.ucla.edu> <837dwyvi74.fsf@gnu.org> <1484f569-c260-9fb0-bfe1-67897de289d3@cs.ucla.edu> <83blm9tn4j.fsf@gnu.org> <4aeb8963-4fd1-fcd4-e6e1-be409ab54775@cs.ucla.edu> <83r1v5s2p1.fsf@gnu.org> <5351703b-1780-561b-7f68-cdd4ed45e599@cs.ucla.edu> <838shcseng.fsf@gnu.org> <309544a0-d857-13f3-e211-41a40966dcc5@cs.ucla.edu> <00884bff-c7ca-9f67-c3ec-cd3963ca1cb9@cs.ucla.edu> <6fa1ac99-c972-881e-180b-e49d0513504c@cs.ucla.edu> <83ftbim0ha.fsf@gnu.org> <137b759b-f8e0-3c8f-ca53-488559f3c29f@cs.ucla.edu> Injection-Info: ciao.gmane.io; posting-host="ciao.gmane.io:159.69.161.202"; logging-data="14324"; mail-complaints-to="usenet@ciao.gmane.io" Cc: 41321@debbugs.gnu.org, monnier@iro.umontreal.ca, pipcet@gmail.com To: Paul Eggert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane-mx.org@gnu.org Sat May 30 20:12:12 2020 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 1jf5xq-0003dA-N3 for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 30 May 2020 20:12:10 +0200 Original-Received: from localhost ([::1]:57112 helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jf5xp-0008E4-O6 for geb-bug-gnu-emacs@m.gmane-mx.org; Sat, 30 May 2020 14:12:09 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]:37966) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1jf5xi-0008Ds-4R for bug-gnu-emacs@gnu.org; Sat, 30 May 2020 14:12:02 -0400 Original-Received: from debbugs.gnu.org ([209.51.188.43]:47631) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_128_GCM_SHA256:128) (Exim 4.90_1) (envelope-from ) id 1jf5xh-0005bt-R4 for bug-gnu-emacs@gnu.org; Sat, 30 May 2020 14:12:01 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.84_2) (envelope-from ) id 1jf5xh-0002Vn-Lg for bug-gnu-emacs@gnu.org; Sat, 30 May 2020 14:12:01 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Eli Zaretskii Original-Sender: "Debbugs-submit" Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Sat, 30 May 2020 18:12:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 41321 X-GNU-PR-Package: emacs Original-Received: via spool by 41321-submit@debbugs.gnu.org id=B41321.15908623109636 (code B ref 41321); Sat, 30 May 2020 18:12:01 +0000 Original-Received: (at 41321) by debbugs.gnu.org; 30 May 2020 18:11:50 +0000 Original-Received: from localhost ([127.0.0.1]:59177 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jf5xW-0002VM-1U for submit@debbugs.gnu.org; Sat, 30 May 2020 14:11:50 -0400 Original-Received: from eggs.gnu.org ([209.51.188.92]:58716) by debbugs.gnu.org with esmtp (Exim 4.84_2) (envelope-from ) id 1jf5xU-0002V9-29 for 41321@debbugs.gnu.org; Sat, 30 May 2020 14:11:48 -0400 Original-Received: from fencepost.gnu.org ([2001:470:142:3::e]:39669) by eggs.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1jf5xO-0005HU-79; Sat, 30 May 2020 14:11:42 -0400 Original-Received: from [176.228.60.248] (port=1437 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1jf5xN-0007on-LI; Sat, 30 May 2020 14:11:42 -0400 In-Reply-To: <137b759b-f8e0-3c8f-ca53-488559f3c29f@cs.ucla.edu> (message from Paul Eggert on Sat, 30 May 2020 10:52:07 -0700) 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:181247 Archived-At: > Cc: monnier@iro.umontreal.ca, pipcet@gmail.com, 41321@debbugs.gnu.org > From: Paul Eggert > Date: Sat, 30 May 2020 10:52:07 -0700 > > On 5/29/20 10:54 PM, Eli Zaretskii wrote: > >> (USE_LSB_TAG > >> ? (uintptr_t) word % GCALIGNMENT == Lisp_Symbol > >> : (uintptr_t) word % alignof (struct Lisp_Symbol) == 0) > > I don't understand how this will work, given that Lisp object on the > > stack can be pushed as 2 non-contiguous 32-bit words. Can you > > explain? > > On a --with-wide-int host where !USE_LSB_TAG, the above test will work > correctly on the low-order word of a Lisp object that is a symbol, > because ((uintptr_t) word % alignof (struct Lisp_Symbol) == 0) must be > true on such a word. > > The test is only for symbols; it's not for other Lisp objects. So any pointer whose alignment is the same as 'struct Lisp_Symbol' will pass the test, regardless of the tag bits? That's basically most of the struct pointers on those architectures, no?