From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from us-smtp-1.mimecast.com (us-smtp-2.mimecast.com [205.139.110.61]) by sourceware.org (Postfix) with ESMTP id 656053939C35 for ; Tue, 23 Jun 2020 11:45:33 +0000 (GMT) DMARC-Filter: OpenDMARC Filter v1.3.2 sourceware.org 656053939C35 Received: from mimecast-mx01.redhat.com (mimecast-mx01.redhat.com [209.132.183.4]) (Using TLS) by relay.mimecast.com with ESMTP id us-mta-354-3ZIPTCW4OFe-CI86i2-URA-1; Tue, 23 Jun 2020 07:45:31 -0400 X-MC-Unique: 3ZIPTCW4OFe-CI86i2-URA-1 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 mimecast-mx01.redhat.com (Postfix) with ESMTPS id 889132C21 for ; Tue, 23 Jun 2020 11:45:30 +0000 (UTC) Received: from blade.nx (ovpn-112-118.ams2.redhat.com [10.36.112.118]) by smtp.corp.redhat.com (Postfix) with ESMTP id 592DF5DAA0; Tue, 23 Jun 2020 11:45:30 +0000 (UTC) Received: by blade.nx (Postfix, from userid 1000) id 872F9816CCA9; Tue, 23 Jun 2020 12:45:29 +0100 (BST) Date: Tue, 23 Jun 2020 12:45:29 +0100 From: Gary Benson To: Pedro Alves Cc: gdb-patches@sourceware.org Subject: Re: [OB PATCH] Avoid testcase build failures with -Wunused-value Message-ID: <20200623114529.GA5308@blade.nx> References: <1592911602-4914-1-git-send-email-gbenson@redhat.com> <27d9d693-8afb-d07f-6d14-d867d42babdd@redhat.com> MIME-Version: 1.0 In-Reply-To: <27d9d693-8afb-d07f-6d14-d867d42babdd@redhat.com> X-Scanned-By: MIMEDefang 2.79 on 10.5.11.14 X-Mimecast-Spam-Score: 0 X-Mimecast-Originator: redhat.com Content-Type: text/plain; charset=us-ascii Content-Disposition: inline X-Spam-Status: No, score=-10.1 required=5.0 tests=BAYES_00, DKIMWL_WL_HIGH, DKIM_SIGNED, DKIM_VALID, DKIM_VALID_AU, DKIM_VALID_EF, RCVD_IN_DNSWL_NONE, RCVD_IN_MSPIKE_H3, RCVD_IN_MSPIKE_WL, SPF_HELO_NONE, SPF_PASS, TXREP autolearn=ham autolearn_force=no version=3.4.2 X-Spam-Checker-Version: SpamAssassin 3.4.2 (2018-09-13) on server2.sourceware.org X-BeenThere: gdb-patches@sourceware.org X-Mailman-Version: 2.1.29 Precedence: list List-Id: Gdb-patches mailing list List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 23 Jun 2020 11:45:34 -0000 Pedro Alves wrote: > On 6/23/20 12:26 PM, Gary Benson via Gdb-patches wrote: > > --- a/gdb/testsuite/gdb.cp/namespace.cc > > +++ b/gdb/testsuite/gdb.cp/namespace.cc > > @@ -150,22 +150,22 @@ namespace C > > // plan to have GDB try to print out, just to make sure that the > > // compiler and I agree which ones should be legal! It's easy > > // to screw up when testing the boundaries of namespace stuff. > > - c; > > + int unused1 = c; > > It looks like such a fix will only work until the compiler decides > to enable -Wunused-variable by default too: > > testsuite/gdb.cp/namespace.cc:153:11: warning: unused variable 'unused' [-Wunused-variable] > int unused = c; > ^ > > Try compiling the testcase with -Wall, with both g++ and clang++: > > $ clang++ testsuite/gdb.cp/namespace.cc -Wall > > I think we should fix this with the more usual cast-to-void way: > > (void) c; Ok, but, out of interest, what stops the compiler ignoring that? Thanks, Gary