From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 10378 invoked by alias); 16 Jan 2019 17:04:30 -0000 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 Received: (qmail 10366 invoked by uid 89); 16 Jan 2019 17:04:29 -0000 Authentication-Results: sourceware.org; auth=none X-Spam-SWARE-Status: No, score=-1.9 required=5.0 tests=BAYES_00,SPF_PASS autolearn=ham version=3.3.2 spammy=H*r:sk:RSA_AES X-HELO: eggs.gnu.org Received: from eggs.gnu.org (HELO eggs.gnu.org) (209.51.188.92) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Wed, 16 Jan 2019 17:04:27 +0000 Received: from fencepost.gnu.org ([2001:470:142:3::e]:39936) by eggs.gnu.org with esmtp (Exim 4.71) (envelope-from ) id 1gjobs-0002Sb-F4; Wed, 16 Jan 2019 12:04:14 -0500 Received: from [176.228.60.248] (port=3991 helo=home-c4e4a596f7) by fencepost.gnu.org with esmtpsa (TLS1.2:RSA_AES_256_CBC_SHA1:256) (Exim 4.82) (envelope-from ) id 1gjobr-00037R-Ga; Wed, 16 Jan 2019 12:04:12 -0500 Date: Wed, 16 Jan 2019 17:04:00 -0000 Message-Id: <83pnswcz5t.fsf@gnu.org> From: Eli Zaretskii To: Simon Marchi CC: simon.marchi@ericsson.com, gdb-patches@sourceware.org In-reply-to: (message from Simon Marchi on Tue, 15 Jan 2019 15:37:45 -0500) Subject: Re: [PATCH] doc: Add table of MI versions References: <20190114203902.11490-1-simon.marchi@ericsson.com> <831s5despw.fsf@gnu.org> <83va2pd8yv.fsf@gnu.org> X-detected-operating-system: by eggs.gnu.org: GNU/Linux 2.2.x-3.x [generic] X-IsSubscribed: yes X-SW-Source: 2019-01/txt/msg00375.txt.bz2 > Date: Tue, 15 Jan 2019 15:37:45 -0500 > From: Simon Marchi > Cc: simon.marchi@ericsson.com, gdb-patches@sourceware.org > > Since @sc{gdb/mi} is used by a variety of front ends to > @value{GDBN}, changes to the MI interface may break existing usage. > This section describes how the protocol changes and how to request > previous version of the protocol when it does. OK, thanks. > > new versions of the MI protocol are not compatible with the old > > versions > > I thought this was quite obvious by the fact that we say that we > introduce a new version when we make breaking changes. But I can add > this sentence, which would result in this: > > If the changes are likely to break front ends, the MI version level > will be increased by one. The new versions of the MI protocol are not > compatible > with the old versions. Old versions of MI remain available, allowing > front ends > to keep using them until they are modified to use the latest MI version. Fine by me. > >> About the idea itself, I don't think we need to implement this. > > > > We don't need to agree with it, we just need to preserve the > > suggestion. > > I have opened [1], is it fine to remove the comment from gdb.texinfo? No objections from me. > >> If front ends request a specific version of MI (which is good > >> practice, in my experience), they won't need to query it. > > > > What if a front end can support several versions, provided that it > > knows the latest version which is provided? Why require such a front > > end to request the lowest common denominator, instead of adapting to > > the latest version it can support? > > I don't think we require front ends to use the lowest common > denominator. Instead, it should request > max(version_known_by_the_front_end, version_known_by_gdb). And I think version_known_by_gdb needs this command, doesn't it? Thanks.