HP 3000 Manuals

Getting Started as an MPE/iX Programmer Programmer's Guide

Chapter 4  HP Link Editor/XL 

HP Link Editor/XL is a software tool that prepares compiled programs for
execution on Series 900 HP 3000 computers and allows you to create and
maintain libraries containing subprograms that you frequently use.

Most MPE/iX compilers let you compile, link, and execute a program, all
in one step, or just compile and link in one step.  In these cases, you
do not directly execute HP Link Editor/XL to perform the linking
function; it is executed automatically.

This chapter describes the basic function of HP Link Editor/XL. For
detailed information on how to use HP Link Editor/XL, refer to Link 
Editor/XL Reference Manual (32650-90030).

HP Link Editor/XL uses one or more relocatable object modules produced by
one or more native compilers to create one of the following files:

   *   Relocatable library (RL), which is a collection of relocatable
       object modules that can be used by many programs at link time.

   *   Executable library (XL), which is a collection of executable
       modules that can be shared by many programs at run time.

   *   Executable program file, which is the result of merging all
       relocatable object modules associated with one program.

It can also operate on an existing RL or XL to update it.  Figure 4-1  
shows the role of :LINK and HP Link Editor/XL on the MPE/iX operating
system.


          Figure 4-1.  :LINK and HP Link Editor/XL on MPE/iX 

You automatically enter HP Link Editor/XL for the purpose of manipulating
relocatable object modules into an executable program file by using the
MPE/iX command :LINK. This command is especially useful in program
development, when you must link a large program that calls many
separately compiled routines or when you want to use values different
from standard HP Link Editor/XL defaults for this process.  For a :LINK
overview, refer to the "Linking a Program" subsection of Chapter 3.  For
detailed information on linking, refer to Link Editor/XL Reference Manual 
(32650-90030).

You can enter HP Link Editor/XL to:

   *   Create an executable program file (the executable form of a
       program), which includes several different modules that have been
       compiled separately.

   *   Change one or more of the default parameters associated with the
       program.  For example, you may need to change the execution stack
       size.

   *   Use one or more library routines in your program.  HP Link
       Editor/XL creates and maintains two kinds of libraries:
       relocatable libraries and executable libraries.  Routines in
       relocatable libraries are in their compiled format.  Routines in
       executable libraries are in executable form.  Libraries minimize
       duplication of programming effort, promote consistency and
       standardization in a programming organization, and help to produce
       easily maintained programs.

MPE/iX 5.0 Documentation