From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 21577 invoked by alias); 30 Oct 2013 16:15:12 -0000 Mailing-List: contact gcc-patches-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-patches-owner@gcc.gnu.org Received: (qmail 21554 invoked by uid 89); 30 Oct 2013 16:15:11 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-3.7 required=5.0 tests=AWL,BAYES_00,RP_MATCHES_RCVD,SPF_HELO_PASS,SPF_PASS 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 ESMTP; Wed, 30 Oct 2013 16:15:11 +0000 Received: from int-mx11.intmail.prod.int.phx2.redhat.com (int-mx11.intmail.prod.int.phx2.redhat.com [10.5.11.24]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id r9UGF88c029683 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-SHA bits=256 verify=OK); Wed, 30 Oct 2013 12:15:09 -0400 Received: from redhat.com (ovpn-116-47.ams2.redhat.com [10.36.116.47]) by int-mx11.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id r9UGF4GR005901 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO); Wed, 30 Oct 2013 12:15:07 -0400 Date: Wed, 30 Oct 2013 16:20:00 -0000 From: Marek Polacek To: Jason Merrill Cc: GCC Patches , Jakub Jelinek , "Joseph S. Myers" Subject: Re: [PATCH][ubsan] Add VLA bound instrumentation Message-ID: <20131030161504.GC31396@redhat.com> References: <20130912122655.GN23899@redhat.com> <20130925124132.GJ12296@redhat.com> <52697B9D.9000502@redhat.com> <20131025165803.GF27400@redhat.com> <526AB5CC.60408@redhat.com> <20131025190356.GG27400@redhat.com> <526AC0C9.1050003@redhat.com> <20131030145253.GB31396@redhat.com> <52712C29.3010206@redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <52712C29.3010206@redhat.com> User-Agent: Mutt/1.5.20 (2009-06-14) X-SW-Source: 2013-10/txt/msg02562.txt.bz2 On Wed, Oct 30, 2013 at 11:56:25AM -0400, Jason Merrill wrote: > On 10/30/2013 10:52 AM, Marek Polacek wrote: > >+ if ((flag_sanitize & SANITIZE_VLA) > >+ && !processing_template_decl > > You don't need to check processing_template_decl; the template case > was already handled above. Right, removed. > >+ tree x = cp_save_expr (size); > >+ x = build2 (COMPOUND_EXPR, TREE_TYPE (x), > >+ ubsan_instrument_vla (input_location, x), x); > >+ finish_expr_stmt (x); > > Saving 'size' here doesn't help since it's already been used above. > Could you use itype instead of size here? I already experimented with that and I think I can't, since we call the finish_expr_stmt too soon, which results in: int x = 1; int a[0:(sizetype) SAVE_EXPR ]; <>; < <= 0) { __builtin___ubsan_handle_vla_bound_not_positive (&*.Lubsan_data0, (unsigned long) SAVE_EXPR ); } else { 0 }, (void) SAVE_EXPR ; >>>>>; ssizetype D.2143; <>>>>; and that ICEs in gimplify_var_or_parm_decl, presumably because the if (SAVE_EXPR <= 0) { ... } should be emitted *after* that cleanup_point. When we generated the C++1y check in cp_finish_decl, we emitted the check after the cleanup_point, and everything was OK. I admit I don't understand the cleanup_points very much and I don't know exactly where they are coming from, because normally I don't see them coming out of C FE. :) Thanks. Marek