From mboxrd@z Thu Jan 1 00:00:00 1970 Path: news.gmane.org!not-for-mail From: Paul Eggert Newsgroups: gmane.emacs.devel Subject: Re: [RFC] Omit all GCPRO stuff if GC_MAKE_GCPROS_NOOPS Date: Sun, 15 Jul 2012 23:41:05 -0700 Organization: UCLA Computer Science Department Message-ID: <5003B781.7080006@cs.ucla.edu> References: <5002FF32.2090308@yandex.ru> NNTP-Posting-Host: plane.gmane.org Mime-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 7bit X-Trace: dough.gmane.org 1342420857 470 80.91.229.3 (16 Jul 2012 06:40:57 GMT) X-Complaints-To: usenet@dough.gmane.org NNTP-Posting-Date: Mon, 16 Jul 2012 06:40:57 +0000 (UTC) Cc: Emacs development discussions To: Dmitry Antipov Original-X-From: emacs-devel-bounces+ged-emacs-devel=m.gmane.org@gnu.org Mon Jul 16 08:40:57 2012 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 1SqezH-00029s-4y for ged-emacs-devel@m.gmane.org; Mon, 16 Jul 2012 08:40:55 +0200 Original-Received: from localhost ([::1]:54707 helo=lists.gnu.org) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SqezG-0004Ls-Gl for ged-emacs-devel@m.gmane.org; Mon, 16 Jul 2012 02:40:54 -0400 Original-Received: from eggs.gnu.org ([208.118.235.92]:54139) by lists.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SqezE-0004L1-5P for emacs-devel@gnu.org; Mon, 16 Jul 2012 02:40:52 -0400 Original-Received: from Debian-exim by eggs.gnu.org with spam-scanned (Exim 4.71) (envelope-from ) id 1SqezC-0005lA-Er for emacs-devel@gnu.org; Mon, 16 Jul 2012 02:40:52 -0400 Original-Received: from smtp.cs.ucla.edu ([131.179.128.62]:36977) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1SqezC-0005kn-9P for emacs-devel@gnu.org; Mon, 16 Jul 2012 02:40:50 -0400 Original-Received: from localhost (localhost.localdomain [127.0.0.1]) by smtp.cs.ucla.edu (Postfix) with ESMTP id 7A725A60003; Sun, 15 Jul 2012 23:40:48 -0700 (PDT) X-Virus-Scanned: amavisd-new at smtp.cs.ucla.edu Original-Received: from smtp.cs.ucla.edu ([127.0.0.1]) by localhost (smtp.cs.ucla.edu [127.0.0.1]) (amavisd-new, port 10024) with ESMTP id CEtRELLa6bRp; Sun, 15 Jul 2012 23:40:48 -0700 (PDT) Original-Received: from [192.168.1.4] (pool-108-23-119-2.lsanca.fios.verizon.net [108.23.119.2]) by smtp.cs.ucla.edu (Postfix) with ESMTPSA id D416BA60001; Sun, 15 Jul 2012 23:40:47 -0700 (PDT) User-Agent: Mozilla/5.0 (X11; Linux i686; rv:13.0) Gecko/20120615 Thunderbird/13.0.1 In-Reply-To: <5002FF32.2090308@yandex.ru> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.6 (newer, 3) X-Received-From: 131.179.128.62 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:151652 Archived-At: Could you please explain the point of the patch? Is it to simplify debugging, or improve performance, or what? I don't see the advantage over the current approach. > +#define DEFGCPRO1 void *__dummy ATTRIBUTE_UNUSED = &__dummy This would be cleaner if DEFGCPRO1 etc were either empty, or expanded to something that ended in ";". Then the caller can just do "DEFGCPRO1" (without the semicolon) and there's no need for dummy declarations. > +#define IF_GCPRO(code) do { } while (0) ... > +#define IF_GCPRO(code) do { code; } while (0) IF_GCPRO should act more like a function, i.e., its argument should be an expression and it should expand to an expression. This is more consistent with how typical macro-like functions work. The above should be: #define IF_GCPRO(expr) ((void) 0) ... #define IF_GCPRO(expr) (expr, (void) 0) and calls like this: IF_GCPRO (gcpro3.nvars = nargs; gcpro4.nvars = nargs); should be replaced by: IF_GCPRO ((gcpro3.nvars = nargs, gcpro4.nvars = nargs));