From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 19446 invoked by alias); 23 Apr 2008 12:48:21 -0000 Received: (qmail 19434 invoked by uid 22791); 23 Apr 2008 12:48:20 -0000 X-Spam-Check-By: sourceware.org Received: from viper.snap.net.nz (HELO viper.snap.net.nz) (202.37.101.25) by sourceware.org (qpsmtpd/0.31) with ESMTP; Wed, 23 Apr 2008 12:47:52 +0000 Received: from kahikatea.snap.net.nz (135.31.255.123.static.snap.net.nz [123.255.31.135]) by viper.snap.net.nz (Postfix) with ESMTP id 3E2AC3D8343; Thu, 24 Apr 2008 00:47:49 +1200 (NZST) Received: by kahikatea.snap.net.nz (Postfix, from userid 1000) id 765118FC6D; Thu, 24 Apr 2008 00:47:42 +1200 (NZST) From: Nick Roberts MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Transfer-Encoding: 7bit Message-ID: <18447.12269.389044.431822@kahikatea.snap.net.nz> Date: Wed, 23 Apr 2008 13:23:00 -0000 To: Vladimir Prus Cc: gdb-patches@sourceware.org Subject: Re: [PATCH] -stack-info-frame/-stack-list-frames In-Reply-To: <200804231349.35190.vladimir@codesourcery.com> References: <18446.45778.889114.789630@kahikatea.snap.net.nz> <200804230933.04964.vladimir@codesourcery.com> <18446.63716.779534.2827@kahikatea.snap.net.nz> <200804231349.35190.vladimir@codesourcery.com> X-Mailer: VM 7.19 under Emacs 22.2.50.2 X-IsSubscribed: yes Mailing-List: contact gdb-patches-help@sourceware.org; run by ezmlm Precedence: bulk List-Id: List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sourceware.org X-SW-Source: 2008-04/txt/msg00517.txt.bz2 >... > > I mean the window showing a variable's value (represented in Gdb as a > > variable object). > > Does that window shows: > > 1. Value of variable named XXX in the frame where that variable was > added to the window? > 2. Value of variable named XXX in the current frame > 3. Something else? It doesn't really matter how it was created. > > > > In any case, the extra field comes at almost no cost and a frontend > > > > can choose to ignore it. > > > > > > I supposed you don't plan to write documentation that say "these fields > > > are just in case you need them, feel free to ignore"? > > > > Not really because that applies equally to all the other fields, already > > present, that a front end might not use. > > Well, for other frames I know what they are used for. (by frames you mean fields?) Really? In the output of -stack-list-frames what are the pc address field for the outer frames used for? >... > Well, I still fail to see what further "understanding" the user might get > from that information, but I'd be happy to be told :-) I've already given a reason why I think it would be useful. > My biggest worry about this is that we'll be providing some information > which is highly compiler dependent and which we cannot document in any way > other that "it is hex number". I don't think a random frontend author knows > what DWARF CFI is :-) If it was just a hex number, the concept of frame address presumably wouldn't exist. To me, it refers to the start of the frame and if a variable has an address below that value, it belongs to that frame or a higher one. Maybe on some architectures, the stack grows in the other direction, and maybe there are other anomalies, but a user could understand this and interpret such numbers. -- Nick http://www.inet.net.nz/~nickrob