Date: Mon, 1 Dec 1997 18:38:15 -0600 (CST)
From: Andrew Deren <aderen AT eecs DOT uic DOT edu>
To: George Foot <mert0407 AT sable DOT ox DOT ac DOT uk>
cc: djgpp AT delorie DOT com
Subject: Re: Debuging
In-Reply-To: <65tqpb$qhb$2@news.ox.ac.uk>
Message-ID: <Pine.SUN.3.95.971201183547.26529D-100000@ernie.eecs.uic.edu>
MIME-Version: 1.0
Content-Type: TEXT/PLAIN; charset=US-ASCII
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Thanks, but someone pointed before that the problem was with constructors
of the classes. I had some global instacnes of some classes where some
fields where initialized to null and they were calling text_length to
calculate something, in win95 dpmi host it's fine to do that but not in
cwsdpmi. So I just changed the allegro text_length functions and put:
if (!text) return 0;
and the program works fine now.

On 1 Dec 1997, George Foot wrote:

> On Mon, 1 Dec 1997 04:40:46 GMT in comp.os.msdos.djgpp Andrew Deren <aderen AT eecs DOT uic DOT edu> wrote:
> 
> : I have a relatively large C++ program and it works fine when using Windows
> : 95 DPMI host but when using pure DOS, it crashes. I tried using debuger in
> : RHIDE but the program crashes even before reaching to the main function.
> : And the error is in text_length function which is a part of allegro. 
> : Does anyone know how to find where that error occurs. When I try using
> : stepping in debugger, the first time I use step I get the SIGSEG error.
> 
> Do smaller programs work?  Do C programs work?  Does the compiler work?
> 
> Allegro shouldn't be doing anything before the start of your main
> function, so it looks like the stack trace you saw was corrupted.  If
> other programs (especially standard C programs) work, this points
> perhaps to the C++ features which can be run before the main function
> -- I don't know too much about this.  You'll probably have to give
> more information about what sort of C++ specialities your program is
> (ab)using ;).
> 
> Presumably you're using the standard compiling and linking tools
> (i.e. not rebuilt wrongly); in this case, your programs should run as
> reliably as the compiler itself.  Does the compiler work from your DOS
> setup?
> 
> -- 
> george DOT foot AT merton DOT oxford DOT ac DOT uk
> 


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