A Run Time Debugger for Oberon

Markus Hof
Johannes Kepler University Linz
Institute for Practical Computer Science
Altenbergerstr. 69, A-4040 Linz
hof@ssw.uni-linz.ac.at

Abstract

The Oberon environment offers only limited possibilities for inspecting run time data and for determining the cause for an exception. Only variables of basic types such as INTEGER or CHAR can be examined. It is not possible to execute a program step by step. This report describes a run time debugger that allows the inspection of structured types such as RECORD or ARRAY as well as step by step execution. The debugger supports views on local and global variables of any type. Run time types are supported as well as dynamic arrays. It is possible to follow pointers in order to traverse complex data structures. The debugger supports single stepping as well as breakpoints. Another goal was to embed the debugger into the Oberon environment as smoothly as possible. This results in a look and feel typical for Oberon. Many features of the Oberon system (text frames, text elements) have been reused, resulting in small and compact code. The run time debugger was implemented for PowerMac Oberon. Requires at least Macintosh System 7.5.

Published as technical report 5
Download here.