Building NLMs Using Watcom's IDE v10.6 and C

Articles and Tips: article

ADAM JEROME
Developer Support Engineer
Developer Support

01 Jan 1997

Outlines a method of building NLMs using Watcom's IDE 10.6 which is recommended and approved by Novell Developer Support.

Introduction
Installation Steps

Introduction

This DevNote outlines a method of building NLMs using Watcom's IDE v10.6. This method is recommended and approved by Novell Developer Support. Note that this method is specific to the C environment and is not suitable for the C++ environment.

Installation Steps

Install the Watcom development environment. Include Novell NLM as a target platform.
Install Novell's SDK CD. Include NWSDK in the installation process.
Modify your computer's path statement to include the SDKCD9\NWSDK\TOOLSdirectory.

Note: This must be done so that:
- Watcom's Linker will find Novell'sMAKEINITfile.
- Novell's NLM tools(such as MSGLIB.EXE) will be accessible.
Remove all files from the WATCOM\NOVI directory. Copy all .IMP files from the SDKCD9\NWSDK\IMPORTS to the WATCOM\NOVIdirectory. Example:

COPY c:\sdkcd9\nwsdk\imports\*.imp c:\watcom\novi

Note: The .imp files shipped with the Watcom 10.6 compiler are outdated. There is no known method of changing the IDE'spath to CLIB.IMP. Therefore, the only alternative is to update the files in the location that the IDE expects to find them.

Build a New NLM Project (Tutorial)

Create a directory for your project. (Example: C:\projects\hello)
Activate the Watcom IDE.
Select "File/New Project" from the menu bar.
Specify the project directory and a project name. (Example: HELLO.wpj)
A New Target window is displayed allowing you to specify a target name and an image type. (By default they should be set similar to the following: Target name = "hello", Image type = "NLM [.nlm]"). Press the OK button. A Source files window will appear.
Initially, the Source Files window is empty. Press <Insert<. An Add File(s) to ... window will appear. Enter the name of the projects first C source file in the File Name field. (Example: HELLO.C). You may add other C source files as needed.
Continue using the Add File(s) to window to specify the location of Novell's PRELUDE.OBJ file. Do this by first setting the List Files of Type field to All Files [*.*], then set the Drives field and Directories field to the SDKCD9\NWSDK\IMPORTSdirectory. Specify the file PRELUDE.OBJ and add it to the project. Close the Add File(s) to window.
Select Options / Link for NetWare Switches... from the menu bar. Select 2. Import, Export and Library Switches from the scrollbar.Check the box labeled No default libraries [op nod].

Specify .IMP files as needed in the Import files(,):[imp] field. (Example: For the "Hello world" example, you will have to specify the following in the Import files(,):[imp] field:

@$(nlm386imp)\threads.imp,@$(nlm386imp)\nlmlib.imp

Note: The macrovalue nlm386imp is defined in Novell's make init file, in the SDKCD9\TOOLSdirectory. The actual .imp file names (ie: threads, nlmlib, etc.)may vary depending on the SDK release you have installed. This article assumes that you have installed SDK CD Release 9.

Press the OK button.
Select Options / C Compiler Switches... from the menu bar. By default,1. File Option Switches will be selected on the scrollbar. Set the Include directories:[-i] field to $(nlm386hdr).

Note: The macro value nlm386hdr is defined in Novell's makeinit file, in the SDKCD9\TOOLS directory.

An IDE Request window may appear asking Mark all .c files in >...=for remake? If so, press the Yes button.
You may now wish to edit one (or more) of the previously specified C files. You may do so by double clicking on one of the files listed Source files: window. (Example: hello.c [n/a]). The following is a simple "Hello world" example:
```
#include <stdlib.h<#include<
        <stdio.h<void main(void){    printf("Hello<
        world.\n");    return;}
```
Add the following function to one of your C source files (for example, add it to HELLO.C):
```
void __WATCOM_Prelude(void){return;}
```
Note: The Watcom 10.6 compiler constructs OBJ files from C source files. When the Watcom compiler is invoked from the IDE, a reference is automatically implied to an external __WATCOM_Prelude symbol. Thereis no known method of disabling this behavior from the IDE (even though the reference is not needed or even referenced in the C source). Therefore, your application must provide its own reference as a "shim" or "stub." This function will not be called by Novell's PRELUDE.OBJ or Dynamic Linked Library NLMs.

(The example program HELLO.C will look something like this:)
```
#include <stdlib.h<#include<
    <stdio.h<void __WATCOM_Prelude(void)<
           {        return;        }        

                  void main(void)        {  

         printf("Hello world.\n");

           return;        }
```
(Save the file, then proceed to step 12.)
Select Targets / Make from the menu bar. If all went well, you will find a powerfuland highly efficient NLM in the target directory.

* Originally published in Novell AppNotes

Disclaimer

The origin of this information may be internal or external to Novell. While Novell makes all reasonable efforts to verify this information, Novell does not make explicit or implied claims to its validity.