From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 127338 invoked by alias); 1 Sep 2015 16:26:08 -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 127323 invoked by uid 89); 1 Sep 2015 16:26:08 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.3 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,SPF_HELO_PASS,T_RP_MATCHES_RCVD autolearn=no 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; Tue, 01 Sep 2015 16:26:07 +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 (Postfix) with ESMTPS id E2208461E2 for ; Tue, 1 Sep 2015 16:26:05 +0000 (UTC) Received: from localhost (unused-10-15-17-51.yyz.redhat.com [10.15.17.51]) by int-mx10.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id t81GQ4Ci008790 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=NO); Tue, 1 Sep 2015 12:26:05 -0400 From: Sergio Durigan Junior To: Gary Benson Cc: GDB Patches Subject: Re: [PATCH 2/2] Catching errors on probes-based dynamic linker interface References: <1440200253-28603-1-git-send-email-sergiodj@redhat.com> <1440200253-28603-3-git-send-email-sergiodj@redhat.com> <20150824084255.GA16508@blade.nx> <87r3msd5xr.fsf@redhat.com> <20150825124748.GA6948@blade.nx> <87wpwjgrmt.fsf@redhat.com> <87lhcq7raj.fsf@redhat.com> <20150901092449.GA6172@blade.nx> X-URL: http://blog.sergiodj.net Date: Tue, 01 Sep 2015 16:26:00 -0000 In-Reply-To: <20150901092449.GA6172@blade.nx> (Gary Benson's message of "Tue, 1 Sep 2015 10:24:49 +0100") Message-ID: <87h9ne6r8j.fsf@redhat.com> User-Agent: Gnus/5.13 (Gnus v5.13) Emacs/24.5 (gnu/linux) MIME-Version: 1.0 Content-Type: text/plain X-IsSubscribed: yes X-SW-Source: 2015-09/txt/msg00018.txt.bz2 On Tuesday, September 01 2015, Gary Benson wrote: >> > On Tuesday, August 25 2015, Gary Benson wrote: >> > > Sergio Durigan Junior wrote: >> > > > On Monday, August 24 2015, Gary Benson wrote: >> > > > > Maybe this would be clearer and more robust: >> > > > > >> > > > > TRY >> > > > > { >> > > > > unsigned probe_argc; >> > > > > >> > > > > probe_argc = get_probe_argument_count (pa->probe, frame); >> > > > > >> > > > > if (probe_argc == 2) >> > > > > action = FULL_RELOAD; >> > > > > else if (probe_argc < 2) >> > > > > action = PROBES_INTERFACE_FAILED; >> > > > > } >> > > > > CATCH (ex, RETURN_MASK_ERROR) >> > > > > { >> > > > > exception_print (gdb_stderr, ex); >> > > > > action = PROBES_INTERFACE_FAILED; >> > > > > } >> > > > > END_CATCH >> > > > >> > > > Maybe it's a matter of preference, but I don't like this (and >> > > > I don't see why it is more robust). I prefer to have as >> > > > little code as possible running on the TRY block, and handle >> > > > everything else outside of it. I think it also makes things a >> > > > bit more confuse because you have two places where action can >> > > > be PROBES_INTERFACE_FAILED. >> > > >> > > Well, there are two different failures: >> > > >> > > 1) get_probe_argument_count failed >> > > 2) get_probe_argument_count returned < 2 >> > >> > Yes, and both are covered by the proposed patch. It is not really >> > important to distinguish between these failures today: what really >> > matters is that GDB recognizes both as failures and acts >> > accordingly. > > That matters. It also matters that future maintainers do not trip > over this. > > I am ok with doing this: > > TRY > { > probe_argc = get_probe_argument_count (pa->probe, frame); > } > CATCH (ex, RETURN_MASK_ERROR) > { > exception_print (gdb_stderr, ex); > probe_argc = 0; > } > END_CATCH > > If you put a big fat comment above the following block, e.g.: > > /* Note that failure of get_probe_argument_count will > set probe_argc == 0. This must result in returning > action = PROBES_INTERFACE_FAILED. */ > if (probe_argc == 2) > action = FULL_RELOAD; > else if (probe_argc < 2) > action = PROBES_INTERFACE_FAILED; Great, that works for me as well. I will update the patch here to address this. Thanks, Gary. -- Sergio GPG key ID: 237A 54B1 0287 28BF 00EF 31F4 D0EB 7628 65FC 5E36 Please send encrypted e-mail if possible http://sergiodj.net/