Re: How to port to GNUstep ?

[Richard van Paasen]

Ok,

I found this on apple's site:

http://karchive.info.apple.com/article.html?artnum=72504

It explains how to move from NS3.3 to OS4.2.


Abstract:
==============================
                      Converting Your Code to OPENSTEP

                      This document describes how to convert your code from 
NEXTSTEP Release 3.x to
                      OPENSTEP for Mach Release 4.x.

                      Release 4.0 is NeXT's first OpenStep-compliant release. 
OpenStep is an API that
                      enables platform-independent development of client/server 
applications. The OpenStep
                      API includes the Application Kit, the DPSClient library, 
and a new kit called the
                      Foundation Framework, which provides an operating system 
independence layer. The
                      OpenStep Application Kit is functionally equivalent to 
the NEXTSTEP Release 3
                      Application Kit, but its API has been reworked to make 
use of the Foundation
                      Framework. Because Release 4.0 is OpenStep compliant, 
converting your code to it is a
                      good way to make your application an OpenStep application.

                      To convert your code, you run a series of scripts. These 
scripts use tops, a tool that
                      performs in-place substitutions on source files according 
to a set of rules. The script files
                      contain the rules that tops applies to your code. Most of 
the scripts are provided in the
                      release, but you must generate some of them before you 
start converting because they
                      work directly on the custom classes in your code. 
OPENSTEP for Mach provides a tool
                      that allows you to generate these scripts.

                      The scripts convert most of the NEXTSTEP API to the new 
OpenStep API. Some
                      methods, classes, and functions have been altered in such 
a way that an automated
                      conversion is not possible. For these, the conversion 
scripts produce an error message
                      that identifies the obsolete code and tells you how to 
convert it.

                      You run the conversion in six stages. Each stage runs a 
different set of scripts. After each
                      stage, you compile your code to identify places where the 
conversion was not automatic.
                      It is recommended that you run some additional scripts to 
replace the Common classes
                      with OpenStep API, making your code even more portable.

                      This document tells you how to set up your project for 
conversion and how to run the
                      conversion scripts. A separate document, the OpenStep 
Conversion Guide, describes
                      the changes made during each of the conversion stages and 
the reason for those
                      changes. Its location on-line is
                      
/NextLibrary/Documentation/NextDev/Conversion/ConversionGuide. Read the first
                      chapter of this guide (00_Intro.rtfd) for an overview of 
the differences between
                      NEXTSTEP 3.X and OpenStep and for a discussion of the 
different strategies you might
                      use when converting.


                      The Conversion Process


                      To convert your code, do the following:

                      1. Convert your project to a 4.0 project.

                      2. Generate the conversion scripts.

                      3. Run the six-stage conversion process and any optional 
conversions.

                      4. Convert your nib files.

                      5. Debug your application.

                      These steps are described further below. .....