From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 16139 invoked by alias); 15 May 2002 10:46:39 -0000 Mailing-List: contact gdb-patches-help@sources.redhat.com; run by ezmlm Precedence: bulk List-Subscribe: List-Archive: List-Post: List-Help: , Sender: gdb-patches-owner@sources.redhat.com Received: (qmail 16123 invoked from network); 15 May 2002 10:46:36 -0000 Received: from unknown (HELO fw-cam.cambridge.arm.com) (193.131.176.3) by sources.redhat.com with SMTP; 15 May 2002 10:46:36 -0000 Received: by fw-cam.cambridge.arm.com; id LAA12894; Wed, 15 May 2002 11:46:34 +0100 (BST) Received: from unknown(172.16.1.2) by fw-cam.cambridge.arm.com via smap (V5.5) id xma012249; Wed, 15 May 02 11:46:01 +0100 Received: from cam-mail2.cambridge.arm.com (cam-mail2.cambridge.arm.com [172.16.1.91]) by cam-admin0.cambridge.arm.com (8.9.3/8.9.3) with ESMTP id LAA22135; Wed, 15 May 2002 11:46:00 +0100 (BST) Received: from sun18.cambridge.arm.com (sun18.cambridge.arm.com [172.16.2.18]) by cam-mail2.cambridge.arm.com (8.9.3/8.9.3) with ESMTP id LAA02092; Wed, 15 May 2002 11:45:59 +0100 (BST) Message-Id: <200205151045.LAA02092@cam-mail2.cambridge.arm.com> To: Andrew Cagney cc: gdb-patches@sources.redhat.com, Richard.Earnshaw@arm.com Reply-To: Richard.Earnshaw@arm.com Organization: ARM Ltd. X-Telephone: +44 1223 400569 (direct+voicemail), +44 1223 400400 (switchbd) X-Fax: +44 1223 400410 X-Address: ARM Ltd., 110 Fulbourn Road, Cherry Hinton, Cambridge CB1 9NJ. X-Url: http://www.arm.com/ Subject: Re: [patch/rfc] Revise REGISTER_SIM_REGNO() In-reply-to: Your message of "Tue, 14 May 2002 18:48:16 EDT." <3CE19430.8030201@cygnus.com> Mime-Version: 1.0 Content-Type: text/plain; charset=us-ascii Date: Wed, 15 May 2002 03:46:00 -0000 From: Richard Earnshaw X-SW-Source: 2002-05/txt/msg00588.txt.bz2 > Hello, > > The attached, per comments from RichardE, revises the definition and use > of REGISTER_SIM_REGNO. I think I've managed to preserve existing behavour. > > Briefly, REGISTER_SIM_REGNO() [Hmm, do I doco `legacy' behavour?] > returns a cardinal indicating the simulators register number, or > SIM_REGNO_UNAVAILABLE/-1 when the register isn't there. > > To preserve current behavour on existing targets, > LEGACY_SIM_REGNO_IGNORE is returned by the default > legacy_register_sim_regno() function. I'd like to see a target have a way to report that it is permanently unable to recover a register -- because there's nothing in the protocol to allow its recovery. For example, I've added the privileged mode registers to my ARM target code; when the target is using a ptrace() interface for debugging a user program, then these registers are never available and it's pointless having gdb report them. Note -- again this is not an ABI issue, the same ABI can be in use when debugging kernel code; it's clearly a property of the target interface. Now to the point of why I'm saying this in response to this patch :-) LEGACY_SIM_REGNO_IGNORE seems to be saying almost exactly the same thing. So why "legacy"? R.