From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 15854 invoked by alias); 10 Dec 2014 11:25:05 -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 15843 invoked by uid 89); 10 Dec 2014 11:25:04 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.5 required=5.0 tests=AWL,BAYES_00,SPF_HELO_PASS,SPF_PASS,T_RP_MATCHES_RCVD autolearn=ham version=3.3.2 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 (AES256-GCM-SHA384 encrypted) ESMTPS; Wed, 10 Dec 2014 11:25:03 +0000 Received: from int-mx10.intmail.prod.int.phx2.redhat.com (int-mx10.intmail.prod.int.phx2.redhat.com [10.5.11.23]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sBABOwEY010910 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 10 Dec 2014 06:24:58 -0500 Received: from bordewijk.wildebeest.org (ovpn-116-48.ams2.redhat.com [10.36.116.48]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id sBABOva4009679 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Wed, 10 Dec 2014 06:24:58 -0500 Received: by bordewijk.wildebeest.org (Postfix, from userid 1000) id 08CAD8133831; Wed, 10 Dec 2014 12:24:56 +0100 (CET) Message-ID: <1418210696.5011.10.camel@bordewijk.wildebeest.org> Subject: Re: [PATCH] Use GCC5/DWARF5 DW_AT_noreturn to mark functions that don't return normally. From: Mark Wielaard To: Stan Shebs Cc: gdb-patches@sourceware.org Date: Wed, 10 Dec 2014 11:25:00 -0000 In-Reply-To: <548745FD.40000@earthlink.net> References: <1417099980-31834-1-git-send-email-mjw@redhat.com> <5480696F.1060308@redhat.com> <1418122161.18974.42.camel@bordewijk.wildebeest.org> <548745FD.40000@earthlink.net> Content-Type: text/plain; charset="UTF-8" Content-Transfer-Encoding: quoted-printable Mime-Version: 1.0 X-SW-Source: 2014-12/txt/msg00205.txt.bz2 Hi Stan, On Tue, 2014-12-09 at 10:57 -0800, Stan Shebs wrote: > On 12/9/14, 2:49 AM, Mark Wielaard wrote: > > On Thu, 2014-12-04 at 14:02 +0000, Pedro Alves wrote: > >> I wonder if we could have a test? Could e.g., make sure we don't > >> crash when the user confirms a return in a noreturn function. > >=20 > > I am not sure how to write such a test. This is mainly interactive code, > > which will only trigger from_tty. I also am not sure such a test really > > tests this new feature. Trying to return from a noreturn function > > triggers undefined behavior. GDB probably won't crash, but the inferior > > might since the result is unpredictable (that is precisely why I added > > this, you forcibly return from a function and end up somewhere > > unexpected). Which makes testing the expected output of the user > > ignoring the warning somewhat hard. >=20 > Chiming in here, just write the test so that it passes whether or not > the inferior crashes - as you note, its behavior is undefined anyway. > If GDB crashes or hangs, on any platform, that's a bug that we have to > fix in GDB. I am afraid I still don't understand what we would be testing (whether the user if there is a tty gets to say yes or no?) or how to write such a test where we don't seem interested in the actual result. Is there an example to follow? Thanks, Mark