HP OpenVMS Debugger Manual

This document is the OpenVMS Debugger Manual, published in June 2010 for OpenVMS Version 8.4 (Integrity servers and Alpha).

It serves as a comprehensive guide for programmers of all experience levels to locate and debug run-time errors in programs written in high-level languages and assembly language. The manual covers the debugger's features across three main interfaces:

• Command-line interface (for terminals and workstations)
• HP DECwindows Motif graphical user interface (GUI)
• Microsoft Windows PC client interface (for remote debugging)

Key features and capabilities explained include:

• Controlling Program Execution: Starting/resuming execution, stepping through code, and using breakpoints, tracepoints, and watchpoints to suspend or monitor program flow.
• Data Examination & Manipulation: Inspecting and modifying variables, memory locations, and registers, and evaluating language expressions.
• Source Code Management: Displaying and navigating source code, controlling symbol access, and handling symbol ambiguities.
• Advanced Debugging Topics: Debugging optimized code (including "semantic stepping" on Alpha systems), multilanguage programs, multiprocess programs, multithreaded (tasking) programs, and managing exceptions and condition handlers.
• Memory Analysis: Utilizing the Heap Analyzer (on Integrity servers and Alpha systems) for graphical, real-time representation of memory usage to identify leaks and optimize performance.
• Customization: Using command procedures, initialization files, log files, and customizing the debugger's interface.

The debugger supports 64-bit address space manipulation on OpenVMS Alpha systems and is internationalized for multibyte character support. A significant limitation is that it only debugs code in user mode, not in supervisor, executive, or kernel modes.