From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.io!.POSTED.blaine.gmane.org!not-for-mail From: Pip Cet Newsgroups: gmane.emacs.devel Subject: Re: MPS: assertion failed: header_type (h) != IGC_OBJ_FWD Date: Tue, 16 Jul 2024 16:13:23 +0000 Message-ID: References: <86zfqhh2xv.fsf@gnu.org> <87msmhwhal.fsf@gmail.com> Mime-Version: 1.0 Content-Type: text/plain; charset=utf-8 Content-Transfer-Encoding: quoted-printable Injection-Info: ciao.gmane.io; posting-host="blaine.gmane.org:116.202.254.214"; logging-data="38854"; mail-complaints-to="usenet@ciao.gmane.io" Cc: Helmut Eller , Eli Zaretskii , Paul Eggert , emacs-devel@gnu.org To: =?utf-8?Q?Gerd_M=C3=B6llmann?= Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Tue Jul 16 20:16:30 2024 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 1sTmj0-0009j3-6z for ged-emacs-devel@m.gmane-mx.org; Tue, 16 Jul 2024 20:16:30 +0200 Original-Received: from localhost ([::1] helo=lists1p.gnu.org) by lists.gnu.org with esmtp (Exim 4.90_1) (envelope-from ) id 1sTmiF-0001HV-LM; Tue, 16 Jul 2024 14:15:43 -0400 Original-Received: from eggs.gnu.org ([2001:470:142:3::10]) by lists.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sTkoE-0005kE-Aj for emacs-devel@gnu.org; Tue, 16 Jul 2024 12:13:46 -0400 Original-Received: from mail-40131.protonmail.ch ([185.70.40.131]) by eggs.gnu.org with esmtps (TLS1.2:ECDHE_RSA_AES_256_GCM_SHA384:256) (Exim 4.90_1) (envelope-from ) id 1sTko9-0003JX-DR for emacs-devel@gnu.org; Tue, 16 Jul 2024 12:13:45 -0400 DKIM-Signature: v=1; a=rsa-sha256; c=relaxed/relaxed; d=protonmail.com; s=protonmail3; t=1721146417; x=1721405617; bh=WbwYhGwT0Op87WxU+mPoZ2sH00+gcE3+iz7barys8QE=; h=Date:To:From:Cc:Subject:Message-ID:In-Reply-To:References: Feedback-ID:From:To:Cc:Date:Subject:Reply-To:Feedback-ID: Message-ID:BIMI-Selector; b=dQvwfrGyHuGeeiICno1Tr9qVF1vcKOK9byrerUh30gvWvYRjMI2QuBIA6LkyI0AUb 9dlbAF9zy6uCXduYBaNgsJu6Ls148InIsRLBoh2ujn45N108UZlJq+ten1vc0BoXMd tf8YPCZL8bjAZ7EcVIA1tYNn2Dty25trDjcTELmOOL+G4YngryermdgWqghrqD0m8e Zxl3YkYSFsNQpLtIbUGlSya7W4sLy2NEW+R2YuYq5CwZPzcc8PimrPQKGXQ5GmGNRF vRm9NI950MAXufl+p5NMSvzjrtS4FzS8a6ZeChdhmosXDNjG1PtLMzCicxYOf2MKvi 9E5Y9eoBJ9exA== In-Reply-To: Feedback-ID: 112775352:user:proton X-Pm-Message-ID: c92075d6d21ef8fdbd995b90196b0166a3d3dc94 Received-SPF: pass client-ip=185.70.40.131; envelope-from=pipcet@protonmail.com; helo=mail-40131.protonmail.ch X-Spam_score_int: -27 X-Spam_score: -2.8 X-Spam_bar: -- X-Spam_report: (-2.8 / 5.0 requ) BAYES_00=-1.9, DKIM_SIGNED=0.1, DKIM_VALID=-0.1, DKIM_VALID_AU=-0.1, DKIM_VALID_EF=-0.1, FREEMAIL_FROM=0.001, RCVD_IN_DNSWL_LOW=-0.7, RCVD_IN_MSPIKE_H3=0.001, RCVD_IN_MSPIKE_WL=0.001, SPF_HELO_PASS=-0.001, SPF_PASS=-0.001 autolearn=ham autolearn_force=no X-Spam_action: no action X-Mailman-Approved-At: Tue, 16 Jul 2024 14:15:41 -0400 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-bounces+ged-emacs-devel=m.gmane-mx.org@gnu.org Xref: news.gmane.io gmane.emacs.devel:321732 Archived-At: On Tuesday, July 16th, 2024 at 14:48, Gerd M=C3=B6llmann wrote: > Helmut Eller eller.helmut@gmail.com writes: >=20 > > On Tue, Jul 16 2024, Gerd M=C3=B6llmann wrote: > >=20 > > > That's probably a misunderstanding. I'm thinking about a block of mem= ory > > > containing references, and the alignment of these references, not the > > > alignment of the block. > > >=20 > > > Example with sizeof(int) =3D 4, and sizeof(void *) =3D 8 > > >=20 > > > struct x > > > { > > > int x; > > > struct Lisp_Symbol *s; > > > }; > > >=20 > > > What about the offset of x::s? > >=20 > > That's not a problem because offsetof(struct x, s) =3D 8. There are 4 > > bytes padding after x. A problem could be if an unaligned void* is cast > > to a struct Lisp_Symbol*; let's hope that nobody does that. >=20 >=20 > If you're right, and the same holds for the control stack and anything > else a malloc'd block can contain, then we're safe. I'm pretty sure we are, though interior pointers might cause a problem. Any leads on where the crash happens yet? I've found a breakpoint on wrong_= type_argument helpful, since we usually hit that when memory moves and the = old pointer doesn't point to an object of the right type. By the way, I'm done with the code for making base =3D=3D client pointers a= nd giving (almost) every object a header. Since it's a major change and can= 't really be split that well, I'm not sure yet how to install it, though it= needs to be cleaned up still in any case... But when I do install it, it w= ill require rebuilding of all .eln files, or there will be weird segfaults.= (I guess we could bump the ABI constant in the nativecomp code to avoid th= at). Pip