The debug component of OS/2 Version 2.0 consists of a set of system services which make it possible to trace and locate problems in programs, in order to increase productivity during the testing phase of the application development process. These services make use of the debug registers present in the Intel 80386 processor to implement features such as data watchpoints and soft instruction breakpoints. By using these registers, it becomes possible to implement watchpoints and breakpoints without making modifications to the code being debugged.
The debug component does not provide a complete debugging tool, but merely provides a mechanism whereby one process may control and monitor the execution of one or more related processes. It provides the services which are used by debugging tools such as the C Set/2 debugger. Debug provides functions such as single-stepping through a program, interrogation of processor registers and locations in memory and changing the contents of registers and locations in memory. The debugging tool provides the user interface which displays source code listings, allows the user to set breakpoints, start execution of a program and to monitor changes in the value of program variables.