From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Dynamic loading progress Date: Sun, 13 Sep 2015 21:58:14 -0400 Message-ID: References: <87vbgpk1po.fsf@lifelogs.com> <85mw20gmeo.fsf@stephe-leake.org> <878u97nyjn.fsf@lifelogs.com> <86d1yirnqw.fsf@stephe-leake.org> <87si7977rs.fsf@tromey.com> <55DB7C3D.4090106@cs.ucla.edu> <55DE75FD.8020308@cs.ucla.edu> <55F5DD8C.70506@dancol.org> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1442195915 20815 80.91.229.3 (14 Sep 2015 01:58:35 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Mon, 14 Sep 2015 01:58:35 +0000 (UTC) Cc: Paul Eggert , Emacs development discussions , Philipp Stephani , =?windows-1252?Q?Aur=E9lien?= Aptel , Tom Tromey , Stephen Leake To: Daniel Colascione Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Sep 14 03:58:25 2015 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by plane.gmane.org with esmtp (Exim 4.69) (envelope-from ) id 1ZbJ2G-0003kF-Nt for ged-emacs-devel@m.gmane.org; Mon, 14 Sep 2015 03:58:24 +0200 Original-Received: from localhost ([::1]:37855 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZbJ2F-0007EQ-Rn for ged-emacs-devel@m.gmane.org; Sun, 13 Sep 2015 21:58:23 -0400 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:49938) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZbJ2C-0007EH-QN for emacs-devel@gnu.org; Sun, 13 Sep 2015 21:58:21 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1ZbJ29-0007E5-LR for emacs-devel@gnu.org; Sun, 13 Sep 2015 21:58:20 -0400 Original-Received: from ironport2-out.teksavvy.com ([206.248.154.181]:47381) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1ZbJ29-0007Dw-HX for emacs-devel@gnu.org; Sun, 13 Sep 2015 21:58:17 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: A0CXDQA731xV/0jo92hcgxCEAshgBAICgTw8EQEBAQEBAQGBCkEFg10BAQMBViMQCw4mEhQYDSSINwjPIwEBAQEGAgEfizqFBQeELQW1BCOBZoIuIoJ4AQEB X-IPAS-Result: A0CXDQA731xV/0jo92hcgxCEAshgBAICgTw8EQEBAQEBAQGBCkEFg10BAQMBViMQCw4mEhQYDSSINwjPIwEBAQEGAgEfizqFBQeELQW1BCOBZoIuIoJ4AQEB X-IronPort-AV: E=Sophos;i="5.13,465,1427774400"; d="scan'208";a="164746015" Original-Received: from 104-247-232-72.cpe.teksavvy.com (HELO ceviche.home) ([104.247.232.72]) by ironport2-out.teksavvy.com with ESMTP/TLS/DHE-RSA-AES256-SHA; 13 Sep 2015 21:58:15 -0400 Original-Received: by ceviche.home (Postfix, from userid 20848) id AFFDB661D2; Sun, 13 Sep 2015 21:58:14 -0400 (EDT) In-Reply-To: <55F5DD8C.70506@dancol.org> (Daniel Colascione's message of "Sun, 13 Sep 2015 13:33:16 -0700") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.0.50 (gnu/linux) X-detected-operating-system: by eggs.gnu.org: Genre and OS details not recognized. X-Received-From: 206.248.154.181 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.14 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-bounces+ged-emacs-devel=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.devel:189909 Archived-At: >>> It's not possible to skip frames in module code using longjmp, so >> Why not? > Because most C code isn't expecting to be unwound. > Forcing non-local flow control on module code is completely > unacceptable. Emacs needs to return with an error indication set. Hmm... I'm still not sure what's the issue. AFAICT, the only odd case I can think of is the following: 1- Emacs calls some module code via the new API. 2- This code (which is Emacs-specific) will know about Fthrow. 3- It may call some non-Emacs-specific code from some other library. 4- This non-Emacs-specific code calls back to some Emacs-specific function. 5- This Emacs-specific function calls Fthrow/Fsignal. Where the problem only shows if/when we reach point 5. This problem can be handled between 4 and 5 by using an appropriate internal_condition_case. Is there some other situation you're thinking of? Stefan