OpenVMS Debugger Manual

The document is the OpenVMS Debugger Manual, published in April 2001. It explains the features of the OpenVMS Debugger for programmers using high-level languages and assembly language on OpenVMS Alpha and VAX systems (Version 7.3).

Key features and functionalities covered include:

• Locating and Fixing Bugs: The debugger helps identify run-time programming or logic errors by allowing interactive observation and manipulation of a program during execution.
• Language Support: It supports debugging programs written in various languages like Ada, BASIC, BLISS, C, C++, COBOL, DIBOL, Fortran, MACRO-32/64, PL/I, and SCAN.
• Debugging Interfaces: It offers three user interfaces: a command interface for terminals and workstations, a Compaq DECwindows Motif GUI for workstations, and a Microsoft Windows PC client interface for remote debugging.

• Core Debugging Capabilities:

  • Program Control: Start, resume, step through (line-by-line, instruction-by-instruction, semantic events), interrupt, and end program execution.
  • Eventpoints: Set breakpoints (to suspend execution), tracepoints (to report execution flow without stopping), and watchpoints (to suspend on variable modification).
  • Data Manipulation: Examine, display, and modify program variables, memory locations, and register values in various data types and radixes. Evaluate language expressions.
  • Source Code Management: Display source code, control source file location, and edit source code directly within the debugging session.
  • Symbol Management: Control access to and resolve ambiguities of symbolic information (variables, routines, modules, images).

• Advanced Debugging Topics: Includes specific techniques for debugging optimized code, screen-oriented programs, multilanguage programs, stack corruption, exceptions, exit handlers, AST-driven programs, translated images, multiprocess programs, vectorized programs (VAX only), and tasking (multithread) programs.

• Heap Analyzer: A tool providing a graphical representation of real-time memory usage to identify and resolve memory leaks, fragmentation, and other memory-related issues.
• Customization: The debugger's interface, key bindings, and display configurations are highly customizable.

This manual serves as a comprehensive guide for programmers to understand and effectively use the OpenVMS Debugger for various debugging scenarios across different programming languages and system architectures.