delorie.com/archives/browse.cgi   search  
Mail Archives: cygwin/2006/04/10/13:39:07

X-Spam-Check-By: sourceware.org
Date: Mon, 10 Apr 2006 13:38:50 -0400
From: Christopher Faylor <cgf-no-personal-reply-please AT cygwin DOT com>
To: cygwin AT cygwin DOT com
Subject: Re: Cygwin backwards compatibility break with WinMain and GetCommandLine (was Re: WinMain() not getting cl...)
Message-ID: <20060410173850.GA19752@trixie.casa.cgf.cx>
Reply-To: cygwin AT cygwin DOT com
Mail-Followup-To: cygwin AT cygwin DOT com
References: <20060404184447 DOT GA4824 AT tela DOT daveroth DOT dyndns DOT org> <20060410013414 DOT GA20557 AT trixie DOT casa DOT cgf DOT cx> <Pine DOT GSO DOT 4 DOT 63 DOT 0604100927270 DOT 20193 AT access1 DOT cims DOT nyu DOT edu>
Mime-Version: 1.0
In-Reply-To: <Pine.GSO.4.63.0604100927270.20193@access1.cims.nyu.edu>
User-Agent: Mutt/1.5.11
Mailing-List: contact cygwin-help AT cygwin DOT com; run by ezmlm
List-Unsubscribe: <mailto:cygwin-unsubscribe-archive-cygwin=delorie DOT com AT cygwin DOT 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

On Mon, Apr 10, 2006 at 09:48:10AM -0400, Igor Peshansky wrote:
>On Sun, 9 Apr 2006, Christopher Faylor wrote:
>
>> On Tue, Apr 04, 2006 at 11:44:47AM -0700, David Rothenberger wrote:
>> >WinMain() in a program compiled with cygwin1.dll is no longer
>> >getting passed the command-line from bash correctly with the
>> >20060403 snapshot. It works fine with the 20060329 snapshot.
>> >
>> >This is the same problem mentioned in
>> ><http://cygwin.com/ml/cygwin/2005-09/msg00298.html>.
>> >
>> >The same test case is attached here again (winCmdLine.c). I compile
>> >it with "gcc -o winCmdLine winCmdLine.c" (note no -mno-cygwin).
>>
>> This is due to recent changes which cause cygwin to stop filling out the
>> command-line for cygwin1.dll using programs.  We did this to fix the
>> "long command line" problem.
>>
>> There is a crude workaround for the problem which reinstates the
>> previous cygwin behavior but I really would rather not go that way.  It
>> would be nice if, just this once, we could make cygwin a little faster
>> at the expense of programs which are using a non-linux-like interface.
>>
>> So, I'm thinking that if you want your WinMain or GetCommandLine using
>> program to work with Cygwin 1.5.20 then you'll have to relink it.  I
>> realize that this is a major departure from previous stated goal of
>> maintaining backwards compatibility but we've already broken that once
>> in recent memory with the case of pure Windows environment variables so
>> I think we probably will just take the logical next step and break
>> things for WinMain and GetCommandLine as well.
>>
>> If there are a lot of programs out there which are using WinMain or
>> GetCommandLine then I guess we'll hear about it.  Otherwise, unless
>> someone can convince me that this is a bad idea, Cygwin will start
>> carrying a GetCommandLine substitute which regenerates the command line
>> from the argv list.  I have something ready to go in my sandbox now
>> but I thought I'd hold off doing this in case someone had a valid
>> objection to this approach.
>
>One argument against doing this is that people will now have to build and
>distribute 2 versions of each such program -- one that works on 1.5.20,
>and one that works on all previous versions of Cygwin.  However, I think
>there *is* a way of writing the program so that it will work on both
>versions, by using something like the following (untested) function:

This is not a problem.  GetCommandLine won't live in cygwin1.dll.  It
will live in libcygwin.a.  So, once linked, the binary will work with
any version of cygwin.

cgf

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

- Raw text -


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