From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 118455 invoked by alias); 8 Apr 2015 16:32:35 -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 118426 invoked by uid 89); 8 Apr 2015 16:32:34 -0000 Authentication-Results: sourceware.org; auth=none X-Virus-Found: No X-Spam-SWARE-Status: No, score=-1.5 required=5.0 tests=AWL,BAYES_00,KAM_LAZY_DOMAIN_SECURITY,T_RP_MATCHES_RCVD autolearn=no version=3.3.2 X-HELO: nikam.ms.mff.cuni.cz Received: from nikam.ms.mff.cuni.cz (HELO nikam.ms.mff.cuni.cz) (195.113.20.16) by sourceware.org (qpsmtpd/0.93/v0.84-503-g423c35a) with (AES256-GCM-SHA384 encrypted) ESMTPS; Wed, 08 Apr 2015 16:32:33 +0000 Received: by nikam.ms.mff.cuni.cz (Postfix, from userid 16202) id 2323F541487; Wed, 8 Apr 2015 18:32:29 +0200 (CEST) Date: Wed, 08 Apr 2015 16:32:00 -0000 From: Jan Hubicka To: Jakub Jelinek Cc: Jan Hubicka , Jason Merrill , gcc-patches@gcc.gnu.org Subject: Re: [C++ PATCH] Fix alignment handling in build_cplus_array_type/cp_build_qualified_type_real (PR c++/65690) Message-ID: <20150408163229.GA90713@kam.mff.cuni.cz> References: <20150408100239.GO19273@tucnak.redhat.com> <55253F73.1000902@redhat.com> <20150408162209.GC27929@kam.mff.cuni.cz> <20150408162756.GU19273@tucnak.redhat.com> MIME-Version: 1.0 Content-Type: text/plain; charset=us-ascii Content-Disposition: inline In-Reply-To: <20150408162756.GU19273@tucnak.redhat.com> User-Agent: Mutt/1.5.21 (2010-09-15) X-SW-Source: 2015-04/txt/msg00329.txt.bz2 > On Wed, Apr 08, 2015 at 06:22:10PM +0200, Jan Hubicka wrote: > > > On 04/08/2015 06:02 AM, Jakub Jelinek wrote: > > > > (cp_build_qualified_type_real): Use check_base_type. Build a > > > > variant and copy over even TYPE_CONTEXT and > > > > TYPE_ALIGN/TYPE_USER_ALIGN if any of those are different. > > > > > > This seems wrong. If there is an array with the same name, > > > attributes and element type, it should have the same alignment; if > > > > One of problems is that cp_build_qualified_type rebuilds the array from > > scratch and never copies the attribute list around (as oposed to > > build_qualified_type that just memcpy the type node) > > As I said earlier, TYPE_ATTRIBUTES is NULL here anyway, because the > attributes hang in DECL_ATTRIBUTES of TYPE_DECL. And, except for > config/sol2.c (which looks wrong), nothing ever calls lookup_attribute for > "aligned" anyway, the user aligned stuff is encoded in TYPE_USER_ALIGN > and/or DECL_USER_ALIGN and TYPE_ALIGN/DECL_ALIGN. This is interesting too. I did know that alignment is "lowered" into TYPE_USER_ALIGN/TYPE_ALIGN values, but there is a lot of other code that looks for type attributes by searching TYPE_ATTRIBUTES, not DECL_ATTRIBUTES of TYPE_DECL (such as nonnul_arg_p in tree-vrp) or alloc_object_size. Does it mean that those attributes are ignored for C++ produced types? Honza > > Jakub