From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 45786 invoked by alias); 22 Sep 2017 19:24:46 -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 45776 invoked by uid 89); 22 Sep 2017 19:24:46 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-0.9 required=5.0 tests=BAYES_00,KAM_LAZY_DOMAIN_SECURITY,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=no version=3.3.2 spammy=9999 X-HELO: mx1.redhat.com Received: from mx1.redhat.com (HELO mx1.redhat.com) (209.132.183.28) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with ESMTP; Fri, 22 Sep 2017 19:24:45 +0000 Received: from smtp.corp.redhat.com (int-mx04.intmail.prod.int.phx2.redhat.com [10.5.11.14]) (using TLSv1.2 with cipher AECDH-AES256-SHA (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 608F32C976F; Fri, 22 Sep 2017 19:24:44 +0000 (UTC) DMARC-Filter: OpenDMARC Filter v1.3.2 mx1.redhat.com 608F32C976F Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; dmarc=none (p=none dis=none) header.from=redhat.com Authentication-Results: ext-mx05.extmail.prod.ext.phx2.redhat.com; spf=fail smtp.mailfrom=palves@redhat.com Received: from [127.0.0.1] (ovpn04.gateway.prod.ext.ams2.redhat.com [10.39.146.4]) by smtp.corp.redhat.com (Postfix) with ESMTP id DC9F75D9CB; Fri, 22 Sep 2017 19:24:41 +0000 (UTC) Subject: Re: [PATCH v3 4/5] Implement "set cwd" command on GDB To: Eli Zaretskii , Sergio Durigan Junior References: <20170912042325.14927-1-sergiodj@redhat.com> <20170921225926.23132-1-sergiodj@redhat.com> <20170921225926.23132-5-sergiodj@redhat.com> <83poajcg9a.fsf@gnu.org> <878th64nqk.fsf@redhat.com> <838th6d0l1.fsf@gnu.org> Cc: gdb-patches@sourceware.org From: Pedro Alves Message-ID: Date: Fri, 22 Sep 2017 19:24:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.4.0 MIME-Version: 1.0 In-Reply-To: <838th6d0l1.fsf@gnu.org> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2017-09/txt/msg00695.txt.bz2 On 09/22/2017 07:56 PM, Eli Zaretskii wrote: > There's no contradiction between these two sides of this issue. For > native debugging, host == target, so the host can expand. For the > non-native debugging, you can ask the target to do the expansion and > store the result. You can't, not as the actual value of the setting, because the setting can be tweaked before GDB is even connected to a target. I.e., you can do: (gdb) set cwd ~ # I haven't even connected to a target yet. # Where should this be expanded? # On host may be incorrect. # '~' -> /home/pedro on this machine (gdb) target extended-remote foo:9999 (gdb) start error: /home/pedro does not exist # '~' is /mount/home/pedro on 'foo' (gdb) kill (gdb) target extended-remote bar:9999 (gdb) start error: /home/pedro does not exist # '~' is /nfs/home/palves on 'bar' It may be useful to display the expanded path as extra info, like in: (gdb) set cwd ~foo/bar (gdb) show cwd The current directory is ~foo/bar (/home/foo/bar) ^^^^^^^^^^^^^ though that'd require a new remote protocol packet. > Either way IMO is better than expanding at run > time, because the latter makes the expansion dependent on factors > which could be out of the user control, I don't see what the problem is here. > and also requires every use > of the value to call gdb_tilde_expand, thus wasting cycles. I don't think that significant, compared to all the other work / syscalls / remote protocol roundtrips that we have to do to start a process. Thanks, Pedro Alves