From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Stefan Monnier Newsgroups: gmane.emacs.bugs Subject: bug#12215: CSET is unnecessarily confusing Date: Thu, 23 Aug 2012 08:26:27 -0400 Message-ID: References: <502D8A95.7060609@cs.ucla.edu> <5034511B.7010409@cs.ucla.edu> <50350A4C.5050103@cs.ucla.edu> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain X-Trace: ger.gmane.org 1345724871 24710 80.91.229.3 (23 Aug 2012 12:27:51 GMT) X-Complaints-To: usenet@ger.gmane.org NNTP-Posting-Date: Thu, 23 Aug 2012 12:27:51 +0000 (UTC) Cc: Dmitry Antipov , 12215@debbugs.gnu.org To: Paul Eggert Original-X-From: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Thu Aug 23 14:27:50 2012 Return-path: Envelope-to: geb-bug-gnu-emacs@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 1T4WVl-0003oA-G3 for geb-bug-gnu-emacs@m.gmane.org; Thu, 23 Aug 2012 14:27:45 +0200 Original-Received: from localhost ([::1]:55413 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4WVf-00027F-H4 for geb-bug-gnu-emacs@m.gmane.org; Thu, 23 Aug 2012 08:27:39 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:40753) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4WVZ-0001z8-Vo for bug-gnu-emacs@gnu.org; Thu, 23 Aug 2012 08:27:37 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1T4WVY-0007Gy-8X for bug-gnu-emacs@gnu.org; Thu, 23 Aug 2012 08:27:33 -0400 Original-Received: from debbugs.gnu.org ([140.186.70.43]:35185) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1T4WVY-0007Gt-5C for bug-gnu-emacs@gnu.org; Thu, 23 Aug 2012 08:27:32 -0400 Original-Received: from Debian-debbugs by debbugs.gnu.org with local (Exim 4.72) (envelope-from ) id 1T4WW1-0008Mf-SN for bug-gnu-emacs@gnu.org; Thu, 23 Aug 2012 08:28:02 -0400 X-Loop: help-debbugs@gnu.org Resent-From: Stefan Monnier Original-Sender: debbugs-submit-bounces@debbugs.gnu.org Resent-CC: bug-gnu-emacs@gnu.org Resent-Date: Thu, 23 Aug 2012 12:28:01 +0000 Resent-Message-ID: Resent-Sender: help-debbugs@gnu.org X-GNU-PR-Message: followup 12215 X-GNU-PR-Package: emacs X-GNU-PR-Keywords: patch Original-Received: via spool by 12215-submit@debbugs.gnu.org id=B12215.134572482332082 (code B ref 12215); Thu, 23 Aug 2012 12:28:01 +0000 Original-Received: (at 12215) by debbugs.gnu.org; 23 Aug 2012 12:27:03 +0000 Original-Received: from localhost ([127.0.0.1]:44731 helo=debbugs.gnu.org) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1T4WV4-0008LO-Uu for submit@debbugs.gnu.org; Thu, 23 Aug 2012 08:27:03 -0400 Original-Received: from ironport2-out.teksavvy.com ([206.248.154.182]:30674) by debbugs.gnu.org with esmtp (Exim 4.72) (envelope-from ) id 1T4WV0-0008Ky-Qe for 12215@debbugs.gnu.org; Thu, 23 Aug 2012 08:26:59 -0400 X-IronPort-Anti-Spam-Filtered: true X-IronPort-Anti-Spam-Result: Av0EAG6Zu09FpZ+X/2dsb2JhbABEDrQDgQiCFQEBBAFWIwULCzQSFBgNJIgcBboJkEQDozOBWIIwVQ X-IronPort-AV: E=Sophos;i="4.75,637,1330923600"; d="scan'208";a="196507918" Original-Received: from 69-165-159-151.dsl.teksavvy.com (HELO pastel.home) ([69.165.159.151]) by ironport2-out.teksavvy.com with ESMTP/TLS/ADH-AES256-SHA; 23 Aug 2012 08:26:27 -0400 Original-Received: by pastel.home (Postfix, from userid 20848) id 4787958ADD; Thu, 23 Aug 2012 08:26:27 -0400 (EDT) In-Reply-To: <50350A4C.5050103@cs.ucla.edu> (Paul Eggert's message of "Wed, 22 Aug 2012 09:35:24 -0700") User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.2.50 (gnu/linux) X-BeenThere: debbugs-submit@debbugs.gnu.org X-Mailman-Version: 2.1.13 Precedence: list X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 2) X-Received-From: 140.186.70.43 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.org@gnu.org Original-Sender: bug-gnu-emacs-bounces+geb-bug-gnu-emacs=m.gmane.org@gnu.org Xref: news.gmane.org gmane.emacs.bugs:63425 Archived-At: > True in both cases. I suppose the notation could grow on one. Yes, I didn't like it much when I first thought about it, but I'm beginning to think it's the least bad option (the next one is to use another preprocessor than cpp ;-). > Second, why does the setter need the pointer to the start of > the object, as well as a pointer to the field that's changing? Depends on how the write barrier works; more specifically, depends on where the write-barrier writes the "this was modified" info. One choice is to have a flag in the object (like gcmarkbit) that says "this object was modified since last scan"; and for that you need a pointer to the start of the object rather than only to the field. Of course, there are also many other choices which don't require such a pointer (e.g. you can add the field's address to a list of "modified fields"; or you can have a flag covering all objects in a "page", ...). Stefan