HP 3000 Manuals HP 3000 Manuals
USL Files and Relocatable Object Files
Compilers on both MPE V and MPE XL systems read source files and generate
object code for them, consisting of blocks of machine instructions. MPE
V compilers create relocatable binary modules (RBMs), which are placed in
USL files. MPE XL compilers create relocatable object modules, which are
placed in relocatable object files or relocatable libraries.
The primary differences between compiling into a USL file and a
relocatable object file are:
MPE V Segmenter HP Link Editor/XL
* Compilers produce one RBM for each * Unless you use the RLFILE compiler
procedure in a source file and place directive, compilers produce only
each of these RBMs into one USL one relocatable object module per
file. compilation unit (source file).
This module is placed into a
relocatable object file.
If you need to manipulate individual
procedures or subroutines contained
in a source file, use the RLFILE
directive or put the procedures in
separate source files. When you
compile from separate source files,a
relocatable object file is produced
for each and can be manipulated
separately.
* RBMs are the smallest units that the * Relocatable object modules are the
MPE V Segmenter can process. smallest unit that the HP Link
Editor/XL can process.
* You can use subset compilation to * Compilation replaces all procedures
selectively replace RBMs in a USL within a relocatable object file.
file.
* Version management is possible with * Version management is not available.
USL files. You access a The entire relocatable object file
de-activated RBM by using its index is replaced during each compilation.
number.