From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 32792 invoked by alias); 22 Sep 2016 23:10:30 -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 32770 invoked by uid 89); 22 Sep 2016 23:10:29 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-5.0 required=5.0 tests=BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS autolearn=ham version=3.3.2 spammy=pierre, Pierre, learned, Hx-languages-length:1362 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; Thu, 22 Sep 2016 23:10:28 +0000 Received: from int-mx13.intmail.prod.int.phx2.redhat.com (int-mx13.intmail.prod.int.phx2.redhat.com [10.5.11.26]) (using TLSv1.2 with cipher ECDHE-RSA-AES256-GCM-SHA384 (256/256 bits)) (No client certificate requested) by mx1.redhat.com (Postfix) with ESMTPS id 621D0916C7; Thu, 22 Sep 2016 23:10:26 +0000 (UTC) Received: from [127.0.0.1] (ovpn01.gateway.prod.ext.ams2.redhat.com [10.39.146.11]) by int-mx13.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id u8MNAOf2015066; Thu, 22 Sep 2016 19:10:25 -0400 Subject: Re: [RFA 3/5] Use std::string, std::vector in rust-lang.c To: Pierre Muller , "'Tom Tromey'" References: <1474566656-15389-1-git-send-email-tom@tromey.com> <1474566656-15389-4-git-send-email-tom@tromey.com> <89b014ab-704c-bb8e-2e1a-6361efa5a644@redhat.com> <87bmzf21bf.fsf@tromey.com> <1b62c1c7-31ec-38c7-e4b4-25fdc560388c@redhat.com> <57e4328a.c3c4620a.59d5b.803fSMTPIN_ADDED_BROKEN@mx.google.com> Cc: gdb-patches@sourceware.org From: Pedro Alves Message-ID: <7ee42720-5b51-893e-b629-d39a573aa080@redhat.com> Date: Fri, 23 Sep 2016 09:44:00 -0000 User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:45.0) Gecko/20100101 Thunderbird/45.2.0 MIME-Version: 1.0 In-Reply-To: <57e4328a.c3c4620a.59d5b.803fSMTPIN_ADDED_BROKEN@mx.google.com> Content-Type: text/plain; charset=windows-1252 Content-Transfer-Encoding: 7bit X-SW-Source: 2016-09/txt/msg00301.txt.bz2 On 09/22/2016 08:35 PM, Pierre Muller wrote: > Just out of curiosity: > how are such variables treated by gcc regarding debug information? > > What is the scope of definition of those variables? > And is it correctly handled by current GDB? On my system, they look like as if declared at the top of the scope. Up until they're initialized, they'll have garbage contents, and that's what gdb will show. But that's no different from actually declaring a variable at the top of the scope and only initializing it after. It's not a big deal. There's a GNU extension that I think is meant to make it possible for the debugger to treat uninitialized variables specially (DW_OP_GNU_uninit), though I don't think we do much with it. Not sure gcc emits it, even. > > IIRC (but my knowledge about C++ if far > worse than for plain C.. which itself I only learned to be able to > contribute to GDB...) the reason why we can remove the cleanups is > that the compiler will insert auto--magically > the destructors of those local variables at the end of > their respective scope, is this correct? Correct. > >> So I think there's no ground for objection. > > Not that I want to raise an objection, > I just wonder if debugging GDB by itself will remain as easy as it was! Hope so too... Thanks, Pedro Alves