From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20043 invoked by alias); 16 Jan 2004 18:57:50 -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 20030 invoked from network); 16 Jan 2004 18:57:48 -0000 Received: from unknown (HELO localhost.redhat.com) (216.129.200.20) by sources.redhat.com with SMTP; 16 Jan 2004 18:57:48 -0000 Received: from gnu.org (localhost [127.0.0.1]) by localhost.redhat.com (Postfix) with ESMTP id 7A3312B8F; Fri, 16 Jan 2004 13:57:40 -0500 (EST) Message-ID: <40083424.1000102@gnu.org> Date: Fri, 16 Jan 2004 18:57:00 -0000 From: Andrew Cagney User-Agent: Mozilla/5.0 (X11; U; NetBSD macppc; en-US; rv:1.0.2) Gecko/20030820 MIME-Version: 1.0 To: Daniel Jacobowitz Cc: gdb-patches@sources.redhat.com Subject: Re: RFA/ARM: Switch mode when setting PC References: <20040116035402.GA3215@nevyn.them.org> <40077A12.5040306@gnu.org> <20040116141040.GA8134@nevyn.them.org> <20040116173235.GA7498@nevyn.them.org> Content-Type: text/plain; charset=us-ascii; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2004-01/txt/msg00420.txt.bz2 > On Fri, Jan 16, 2004 at 09:10:40AM -0500, Daniel Jacobowitz wrote: > >> > The ari contains this yellow card: >> > >> > write pc >> > Replace write_pc() with get_frame_base_address or get_frame_id; at >> > present the inferior function call code still uses this when doing a >> > DECR_PC_AFTER_BREAK >> > >> > the concern is with the way write_pc is being called to perform two >> > different operations: >> > >> > - decrement the pc just after the target stops >> > Arrrg! >> > - jump to a specific address >> > As with an inferior function call or jump. >> > >> > I think it would be better to have two methods so that it's clear that >> > this case only applies when doing a jump. > >> >> Well, it'd be better to rip out the current DECR_PC_AFTER_BREAK and >> handle it completely within the four (roughly) affected targets, >> thereby removing the overloading of write_pc. IMVHO. It's been on everyones wish list for too long. Last time I tried I got bogged down due to a lack of ia32 doco - that's now been fixed though. > Hi Andrew, > > Is this patch OK (write_pc isn't deprecated yet!)? Cleaning up the > existing DECR_PC_AFTER_BREAK handling is going to be a touchy job, and > I don't really want to try it today :) I'll try to look into it later, > though. I was suggesting "two methods so that it's clear that this case only applies when doing a jump". This won't involve anything like deprecating /removing decr_pc_after_break _+ write_pc but will involve the addition of a new method like: set_resume_address (arch, targ or tpid or regs) that could somehow default to a legacy call to write_pc. Significantly, this will avoid making the changes conditional on the elimination of decr-pc (your concern). Why is this better? It clearly separates the [apparently] legetimate resume case from the decr-pc case. This in turn opens the way for the deprecate / delete decr-pc "write_pc" code while at the same time ensuring that the work can't break the arm. enjoy, Andrew