Specifications

Debugging and Testing Tools

9.1 OpenVMS Debugger

9.1.2 User-Interface Options

The debugger has the following user-interface options to accommodate different

needs and debugging styles:

• DECwindows interface for workstations

When using this interface, you interact with the debugger by manipulating a

mouse and pointer to choose items from menus, click on buttons, select names

in windows, and so on. This interface is the default interface. It provides the

basic debugging and convenience features that you will probably need most of

the time.

• Command interface for terminals and workstations

When using this interface, you interact with the debugger by entering

commands at a prompt. In addition to general-purpose debugging features,

the command interface provides special features not available through the

default DECwindows interface (for example, changing the radix for the

display of integer data).

The DECwindows interface also has a command-entry prompt. You can use

it as an alternative to the DECwindows interface for certain operations,

including debugging tasks not available through the DECwindows interface.

9.1.3 Functional Features of the Command Interface

The functional features of the command interface are highlighted in the following

paragraphs.

Symbolic Debugging

Because the OpenVMS Debugger is a symbolic debugger, you can refer to program

locations by the symbols you used for them in your program—the names of

variables, routines, labels, and so on. You do not need to specify memory

addresses or machine registers when referring to program locations, although

you can, if you want.

Support for All Data Types

The debugger understands all compiler generated data types, such as integer,

ﬂoating point, enumeration, record, array, and so on. It displays the values of

program variables according to their declared type.

Flexible Data Format

The debugger permits a variety of data forms and types for entry and display. By

default, the source language of the program determines the format used for the

entry and display of data. You can also impose other formats. For example, by

using a type or radix qualiﬁer with the EXAMINE command, you can display the

contents of a program location in ASCII, word-integer, or ﬂoating-point format.

Starting or Resuming Program Execution

You start or resume program execution with the GO or STEP commands. The

GO command causes the program to execute until a breakpoint is reached, a

watchpoint is modiﬁed, an exception is signaled, or the program terminates. The

STEP command enables you to execute a speciﬁed number of lines or instructions,

or up to the next instruction of a speciﬁed class.

9–3