X-Recipient: archive-cygwin AT delorie DOT com
X-SWARE-Spam-Status: No, hits=-1.7 required=5.0	tests=AWL,BAYES_00,RCVD_IN_DNSWL_NONE,T_RP_MATCHES_RCVD,UNPARSEABLE_RELAY
X-Spam-Check-By: sourceware.org
Message-ID: <4F321831.8070401@t-online.de>
Date: Wed, 08 Feb 2012 07:37:37 +0100
From: Christian Franke <Christian DOT Franke AT t-online DOT de>
User-Agent: Mozilla/5.0 (Windows NT 6.1; WOW64; rv:7.0.1) Gecko/20110928 Firefox/7.0.1 SeaMonkey/2.4.1
MIME-Version: 1.0
To: cygwin AT cygwin DOT com
Subject: Re: Bug in sys/wait.h with C++
References: <1328668786 DOT 8060 DOT 7 DOT camel AT YAAKOV04> <20120208061036 DOT GD7184 AT ednor DOT casa DOT cgf DOT cx>
In-Reply-To: <20120208061036.GD7184@ednor.casa.cgf.cx>
Content-Type: text/plain; charset=ISO-8859-1; format=flowed
Content-Transfer-Encoding: 7bit
X-IsSubscribed: yes
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

Christopher Faylor wrote:
> On Tue, Feb 07, 2012 at 08:39:46PM -0600, Yaakov (Cygwin/X) wrote:
>> Just came across an issue with<sys/wait.h>  in C++.  STC:
>>
>> $ cat test.c
>> #include<stddef.h>
>> #include<sys/wait.h>
>> int main(void) { wait(NULL); return 0; }
>>
>> $ gcc -Wall test.c
>>
>> $ gcc -x c++ -Wall test.c
>> test.c: In function ???int main()???:
>> test.c:2:27: error: call of overloaded ???wait(NULL)??? is ambiguous
>> /usr/include/sys/wait.h:37:7: note: candidates are: pid_t wait(int*)
>> /usr/include/sys/wait.h:82:14: note:                 pid_t wait(wait*)
>>
>> This code compiles cleanly on Linux.
> I guess we have to incorporate Linux's head-standing in
> /usr/include/sys/wait.h to allow both the use of union wait * and int as
> arguments to wait().

Yes. Unfortunately the typesafe approach from
http://cygwin.com/ml/cygwin-patches/2011-q4/msg00003.html
does not work with NULL (0 in C++), sorry.

Workaround: wait((int *)0) or wait((union wait *)0);


> Anyone want to send a patch to cygwin-patches?

I'll do soon.

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