delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2013/07/10/18:13:27

X-Recipient: archive-cygwin AT delorie DOT com
DomainKey-Signature: a=rsa-sha1; c=nofws; d=sourceware.org; h=list-id
:list-unsubscribe:list-subscribe:list-archive:list-post
:list-help:sender:message-id:date:from:mime-version:to:subject
:content-type:content-transfer-encoding; q=dns; s=default; b=ZcG
1wjaUFAjkEh+/5bbobXMBKJbJS2RJ4fdKF8FfE91k0ReHfd1ij8lFxUtv42Ravvc
PRFj1Qylg89HRuUij0/6yh3yy03TyXGNKvPz2lukuwibCvDhMlQ5lAQnMlERUM7o
jmvZcyDWL20/bgQW5TWKU6VDolx/q+Q628nAF9xg=
DKIM-Signature: v=1; a=rsa-sha1; c=relaxed; d=sourceware.org; h=list-id
:list-unsubscribe:list-subscribe:list-archive:list-post
:list-help:sender:message-id:date:from:mime-version:to:subject
:content-type:content-transfer-encoding; s=default; bh=peN4TTLFR
GSvl+KFMYLHB6cG8wo=; b=H9xLOzyqWB9UZ2gfB7NtBfr6cobEUHQeFrxTzhFk8
Ppn60kyJbS6inOtw3HF74mA+Gy2KWlhCscIirA1UBrf359qAB2fyURi/IjmRPDU0
Sb2O9nVTngSqF3eChCXyXmezCqPdDNlDd4KWnLHBoOU2lAEezU1i1up/l+3wLPL4
B4=
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Id: <cygwin.cygwin.com>
List-Subscribe: <mailto:cygwin-subscribe AT cygwin DOT com>
List-Archive: <http://sourceware.org/ml/cygwin/>
List-Post: <mailto:cygwin AT cygwin DOT com>
List-Help: <mailto:cygwin-help AT cygwin DOT com>, <http://sourceware.org/ml/#faqs>
Sender: cygwin-owner AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
Delivered-To: mailing list cygwin AT cygwin DOT com
X-Spam-SWARE-Status: No, score=-2.2 required=5.0 tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,RCVD_IN_HOSTKARMA_NO,RCVD_IN_HOSTKARMA_YE,RP_MATCHES_RCVD,UNPARSEABLE_RELAY autolearn=ham version=3.3.1
Message-ID: <51DDDC6B.3090401@t-online.de>
Date: Thu, 11 Jul 2013 00:12:59 +0200
From: Christian Franke <Christian DOT Franke AT t-online DOT de>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:22.0) Gecko/20100101 Firefox/22.0 SeaMonkey/2.19
MIME-Version: 1.0
To: cygwin AT cygwin DOT com
Subject: i686-w64-mingw32-gcc 4.7.3: ignores __attribute__((packed)), regression?

The new MinGW-w64 4.7.3 gcc apparently ignores __attribute__((packed)). 
Cygwin's gcc 4.7.3 and older MinGW-w64 4.5.3 work as expected.


Testcase:

$ cat packed.c
struct packed { char a; short b; } __attribute__((packed));
int size = sizeof(struct packed);


$ i686-w64-mingw32-gcc --version
i686-w64-mingw32-gcc (GCC) 4.7.3
...
$ i686-w64-mingw32-gcc -S packed.c

$ cat packed.s
...
_size:
         .long   4


$ gcc --version
gcc (GCC) 4.7.3
...
$ gcc -S packed.c

$ cat packed.s
...
_size:
         .long   3


$ x86_64-w64-mingw32-gcc --version
x86_64-w64-mingw32-gcc (GCC) 4.5.3
...
$ x86_64-w64-mingw32-gcc -S packed.c

$ cat packed.s
...
size:
         .long   3


If #pragma pack(1) is used instead, it works as expected also with 
i686-w64-mingw32-gcc 4.7.3.

(Upstream?) bug ?


Christian


--
Problem reports:       http://cygwin.com/problems.html
FAQ:                   http://cygwin.com/faq/
Documentation:         http://cygwin.com/docs.html
Unsubscribe info:      http://cygwin.com/ml/#unsubscribe-simple

- Raw text -


  webmaster     delorie software   privacy  
  Copyright © 2019   by DJ Delorie     Updated Jul 2019