From mboxrd@z Thu Jan  1 00:00:00 1970
Return-Path: <gcc-prs-return-26775-listarch-gcc-prs=gcc.gnu.org@gcc.gnu.org>
Received: (qmail 28064 invoked by alias); 26 Dec 2002 23:46:01 -0000
Mailing-List: contact gcc-prs-help@gcc.gnu.org; run by ezmlm
Precedence: bulk
List-Archive: <http://gcc.gnu.org/ml/gcc-prs/>
List-Post: <mailto:gcc-prs@gcc.gnu.org>
List-Help: <mailto:gcc-prs-help@gcc.gnu.org>
Sender: gcc-prs-owner@gcc.gnu.org
Received: (qmail 28050 invoked by uid 71); 26 Dec 2002 23:46:01 -0000
Date: Thu, 26 Dec 2002 15:46:00 -0000
Message-ID: <20021226234601.28049.qmail@sources.redhat.com>
To: nobody@gcc.gnu.org
Cc: gcc-prs@gcc.gnu.org,
From: Manfred Spraul <manfred@colorfullife.com>
Subject: Re: c/9058: structure with flexible array member: offsetof() != sizeof()
Reply-To: Manfred Spraul <manfred@colorfullife.com>
X-SW-Source: 2002-12/txt/msg01304.txt.bz2
List-Id: <gcc-prs.sourceware.org>

The following reply was made to PR c/9058; it has been noted by GNATS.

From: Manfred Spraul <manfred@colorfullife.com>
To: "Joseph S. Myers" <jsm28@cam.ac.uk>
Cc: gcc-gnats@gcc.gnu.org, gcc-bugs@gcc.gnu.org
Subject: Re: c/9058: structure with flexible array member: offsetof() != sizeof()
Date: Fri, 27 Dec 2002 00:37:54 +0100

 Joseph S. Myers wrote:
 
 >On Thu, 26 Dec 2002, Manfred Spraul wrote:
 >
 >  
 >
 >>Thanks, I found the thread "C99 conformance bug in gcc-3.1" after filing 
 >>the bug report.
 >>What's the recommended approach to calculate the size for malloc calls? Is
 >>
 >>    struct a {int a; char b; short c[]; };
 >>
 >>    len = offsetof(struct a, c[nr_entries]);
 >>    
 >>
 >
 >You mean offsetof(struct a, c) + nr_entries * sizeof(short).
 >  
 >
 No, I meant what I wrote - is that valid? It would be less error prone, 
 e.g. if the type of the flexible array member is changed.
 linux kernel, i.e gcc portability across platforms.
 
 --
     Manfred