From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!.POSTED!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.devel Subject: Re: Conservative GC isn't safe Date: Sat, 26 Nov 2016 10:05:34 -0500 Message-ID: References: <66485157-00cd-4704-a421-cbfe84299cae@cs.ucla.edu> <69a1fdf3-7120-125b-8556-d74f5afc6b37@dancol.org> <8360na399k.fsf@gnu.org> NNTP-Posting-Host: blaine.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: blaine.gmane.org 1480173049 11834 195.159.176.226 (26 Nov 2016 15:10:49 GMT) X-Complaints-To: usenet@blaine.gmane.org NNTP-Posting-Date: Sat, 26 Nov 2016 15:10:49 +0000 (UTC) User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/25.1.50 (gnu/linux) To: emacs-devel@gnu.org Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Sat Nov 26 16:10:46 2016 Return-path: Envelope-to: ged-emacs-devel@m.gmane.org Original-Received: from lists.gnu.org ([208.118.235.17]) by blaine.gmane.org with esmtp (Exim 4.84_2) (envelope-from ) id 1cAecn-0002kG-A7 for ged-emacs-devel@m.gmane.org; Sat, 26 Nov 2016 16:10:45 +0100 Original-Received: from localhost ([::1]:50883 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cAecq-00033I-Uo for ged-emacs-devel@m.gmane.org; Sat, 26 Nov 2016 10:10:48 -0500 Original-Received: from eggs.gnu.org ([2001:4830:134:3::10]:60291) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1cAecJ-00033A-BB for emacs-devel@gnu.org; Sat, 26 Nov 2016 10:10:16 -0500 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1cAecG-000364-4n for emacs-devel@gnu.org; Sat, 26 Nov 2016 10:10:15 -0500 Original-Received: from [195.159.176.226] (port=52896 helo=blaine.gmane.org) by eggs.gnu.org with esmtps (TLS1.0:RSA_AES_128_CBC_SHA1:16) (Exim 4.71) (envelope-from ) id 1cAecF-00035p-U5 for emacs-devel@gnu.org; Sat, 26 Nov 2016 10:10:12 -0500 Original-Received: from list by blaine.gmane.org with local (Exim 4.84_2) (envelope-from ) id 1cAec8-00059C-Ut for emacs-devel@gnu.org; Sat, 26 Nov 2016 16:10:04 +0100 X-Injected-Via-Gmane: http://gmane.org/ Original-Lines: 13 Original-X-Complaints-To: usenet@blaine.gmane.org Cancel-Lock: sha1:jE6z7sGrHJrpAPjtk2VqOwt6INo= X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] [fuzzy] X-Received-From: 195.159.176.226 X-BeenThere: emacs-devel@gnu.org X-Mailman-Version: 2.1.21 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" Xref: news.gmane.org gmane.emacs.devel:209617 Archived-At: > How would you assert dynamically that if an interval is reachable, its > owning string or buffer must be too? You don't. You check it statically (by a human). > It's not enough for the variable holding the reference to the string > or buffer to be in scope: you have to be sure that the reference > isn't dead. It should be: if it's in scope, it's not dead. Stefan