From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 14992 invoked by alias); 26 Nov 2014 16:18:18 -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 14981 invoked by uid 89); 26 Nov 2014 16:18:17 -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,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, 26 Nov 2014 16:18:16 +0000 Received: from int-mx09.intmail.prod.int.phx2.redhat.com (int-mx09.intmail.prod.int.phx2.redhat.com [10.5.11.22]) by mx1.redhat.com (8.14.4/8.14.4) with ESMTP id sAQGIF54019151 (version=TLSv1/SSLv3 cipher=DHE-RSA-AES256-GCM-SHA384 bits=256 verify=FAIL); Wed, 26 Nov 2014 11:18:15 -0500 Received: from [10.10.116.27] ([10.10.116.27]) by int-mx09.intmail.prod.int.phx2.redhat.com (8.14.4/8.14.4) with ESMTP id sAQGIEFl013722; Wed, 26 Nov 2014 11:18:14 -0500 Message-ID: <5475FD43.8040508@redhat.com> Date: Wed, 26 Nov 2014 16:35:00 -0000 From: Jason Merrill User-Agent: Mozilla/5.0 (X11; Linux x86_64; rv:31.0) Gecko/20100101 Thunderbird/31.2.0 MIME-Version: 1.0 To: Jakub Jelinek CC: Alexey Samsonov , Marek Polacek , gcc-patches@gcc.gnu.org Subject: Re: [PATCH] -fsanitize=vptr instrumentation (take 2) References: <20140916145644.GZ17454@tucnak.redhat.com> <54199A36.1080604@redhat.com> <20141027161605.GX10376@tucnak.redhat.com> <20141028124450.GJ10376@tucnak.redhat.com> In-Reply-To: <20141028124450.GJ10376@tucnak.redhat.com> Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit X-SW-Source: 2014-11/txt/msg03294.txt.bz2 On 10/28/2014 08:44 AM, Jakub Jelinek wrote: > +cp_ubsan_check_member_access_r (tree *stmt_p, int *walk_subtrees, void *data) This function needs a longer comment about exactly what forms it's trying to instrument. > + /* T t; t.foo (); doesn't need instrumentation, if the type is known. */ > + if (is_addr > + && TREE_CODE (op) == ADDR_EXPR > + && DECL_P (TREE_OPERAND (op, 0)) > + && same_type_p (type, > + TYPE_MAIN_VARIANT (TREE_TYPE (TREE_OPERAND (op, 0))))) > + return NULL_TREE; How do we know the decl's vptr hasn't been clobbered? This seems like one of the optimizations we decided to drop. > + if (TREE_CODE (base) == COMPONENT_REF > + && DECL_ARTIFICIAL (TREE_OPERAND (base, 1))) > + { > + tree base2 = TREE_OPERAND (base, 0); > + while (TREE_CODE (base2) == COMPONENT_REF > + || TREE_CODE (base2) == ARRAY_REF > + || TREE_CODE (base2) == ARRAY_RANGE_REF) > + base2 = TREE_OPERAND (base2, 0); > + if (TREE_CODE (base2) != INDIRECT_REF > + && TREE_CODE (base2) != MEM_REF) > + return; > + } > + else if (TREE_CODE (base) != INDIRECT_REF > + && TREE_CODE (base) != MEM_REF) > + return; Why do you look through ARRAY_REF here? An element of an array is its own complete object. Jason