Debugging Facilities

GT.M provides a number of debugging features, many of them through language extensions.

These features include the ability to:

The following table summarizes the GT.M language extensions that facilitate debugging.

GT.M Debugging Tools

EXTENSION

EXPLANATION

ZBreak

Establishes a temporary breakpoint, with optional M action and/or activation count.

ZCOMpile

Invokes the GT.M compiler without a corresponding ZLINK.

ZContinue

Continues routine execution from a BREAK.

ZEDit

Invokes a VMS editor.

ZGoto

Removes zero or more levels from the M invocation stack and, optionally, transfers control.

ZLink

Includes a new or modified M routine in the current M process, automatically recompiling it if necessary.

ZMessage

Signals the specified condition.

ZPrint

Displays lines of source code.

ZSHow

Displays information about the M environment.

ZSTep

Executes a routine incrementally to the beginning of the next line of the specified type.

ZWRite

Displays all or some of the local or global symbols.

$ZCSTATUS

Holds the status code value for the last compilation performed by a ZCOMPILE command.

$ZEDit

Contains the status code for the last ZEDit.

$ZJOBEXAM()

Performs a ZSHOW "*" to a default file location and name, or the one optionally specified by the argument.

$ZLEVel

Contains the current level of DO/XECUTE nesting.

$ZMessage()

Translates an error condition code into text form.

$ZPOSition

Contains a string indicating the current execution location.

$ZPROmpt

Controls the direct mode prompt.

$ZSOurce

Contains the name of the most recently ZLINKed or ZEDITed M source program; provides the default name for next ZEDIT or ZLINK.

$ZStatus

Contains error condition code and location of the last exception condition occurring during routine execution.

$ZSTep

Controls the default ZSTep action.