From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: (qmail 20263 invoked by alias); 5 Mar 2013 06:26:31 -0000 Received: (qmail 20255 invoked by uid 22791); 5 Mar 2013 06:26:30 -0000 X-SWARE-Spam-Status: No, hits=-1.3 required=5.0 tests=AWL,BAYES_00,KHOP_SPAMHAUS_DROP,KHOP_THREADED,RCVD_IN_HOSTKARMA_NO,RCVD_IN_HOSTKARMA_YE,RP_MATCHES_RCVD X-Spam-Check-By: sourceware.org Received: from g4t0017.houston.hp.com (HELO g4t0017.houston.hp.com) (15.201.24.20) by sourceware.org (qpsmtpd/0.43rc1) with ESMTP; Tue, 05 Mar 2013 06:26:23 +0000 Received: from G9W0364.americas.hpqcorp.net (g9w0364.houston.hp.com [16.216.193.45]) (using TLSv1 with cipher AES128-SHA (128/128 bits)) (No client certificate requested) by g4t0017.houston.hp.com (Postfix) with ESMTPS id 5190A3832A; Tue, 5 Mar 2013 06:26:22 +0000 (UTC) Received: from G9W3617.americas.hpqcorp.net (16.216.186.52) by G9W0364.americas.hpqcorp.net (16.216.193.45) with Microsoft SMTP Server (TLS) id 14.2.328.9; Tue, 5 Mar 2013 06:25:03 +0000 Received: from G9W0725.americas.hpqcorp.net ([169.254.8.216]) by G9W3617.americas.hpqcorp.net ([16.216.186.52]) with mapi id 14.02.0328.009; Tue, 5 Mar 2013 06:25:02 +0000 From: "Mailaripillai, Kannan Jeganathan" To: Bernard Leak , "gcc-help@gcc.gnu.org" Subject: RE: no warning even with -Wcast-align in windows/hp-ux Date: Tue, 05 Mar 2013 06:26:00 -0000 Message-ID: References: <51350B9A.20602@brenda-arkle.me.uk> Content-Type: text/plain; charset="us-ascii" Content-Transfer-Encoding: quoted-printable MIME-Version: 1.0 Mailing-List: contact gcc-help-help@gcc.gnu.org; run by ezmlm Precedence: bulk List-Id: List-Archive: List-Post: List-Help: Sender: gcc-help-owner@gcc.gnu.org X-SW-Source: 2013-03/txt/msg00028.txt.bz2 > > It ain't a 68000, you know! > Right. I get bus error for such misaligned int access. Correction. I didn't try with 68000.=20 I used ia64 hp server rx7640 HP-UX B.11.31. Regards, Kannan -----Original Message----- From: Mailaripillai, Kannan Jeganathan=20 Sent: Tuesday, March 05, 2013 9:22 AM To: 'Bernard Leak'; gcc-help@gcc.gnu.org Subject: RE: no warning even with -Wcast-align in windows/hp-ux > Do you *know* that char1, char2 are not both on appropriately-aligned=20 > int boundaries? Sorry. That was a incorrect example. Consider this: struct st1{ char c1, c2, c3, c4, c5; } ob1; int main(void) { int *ip; ip =3D &ob1.c1; // c1 at 404100 in cygwin ip =3D &ob1.c2; // c2 at 404101 in cygwin } > misaligned accesses to ints are not prohibited on. e.g., x86. Right. No abort / bus error for misaligned int ptr (value) access. > It ain't a 68000, you know! Right. I get bus error for such misaligned int access. Thanks Bernard Leak for the information. Regards, Kannan ----------------------------------------------------------------- From: Bernard Leak [mailto:bernard@brenda-arkle.me.uk]=20 Sent: Tuesday, March 05, 2013 2:31 AM To: gcc-help@gcc.gnu.org Cc: Mailaripillai, Kannan Jeganathan Subject: Re: no warning even with -Wcast-align in windows/hp-ux gcc-help.52314 (apologies if that doesn't thread properly...) >char char1; >char char2; >int *ip; >void foo(void) { > ip =3D &char1; // line 6 > *ip =3D 65; > ip =3D &char2; // line 8 > *ip =3D 66; > return; >} >No alignment warning at line 6, 8.=20 >Tried in windows (GCC 4.5.3), hp-ux (GCC 4.7.1). Um, why should there be an alignment warning? Do you *know* that char1, char2 are not both on appropriately-aligned int boundaries? Leaving aside the unofficial character of all Windows builds of GCC (are you using Cygwin or similar?), misaligned accesses to ints are not prohibited on. e.g., x86. It ain't a 68000, you know! On the other hand, I get a warning "assignment from incompatible pointer type", for each of the indicated lines, which is what I'd expect. Bernard Leak.