Your program's defined limits

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IDF considers "your program" to be any location within your initial program module, and any extra program modules that you have defined.
  • When your program is loaded, IDF determines its limits from the operating system.
  • You can implicitly define extra modules as the result of triggering a deferred breakpoint established with a DBREAK command.
  • You can explicitly define extra modules with the IDF MODULE command:
    • If the module is described by a Contents Directory Entry (CDE) you can establish the module definition with a MODULE CDE command.
    • You can define an explicit module origin and size with the MODULE BASE and MODULE SIZE commands.
    • You can establish an explicit module's CSECT structure with a LOAD SYMBOLS command (see LOAD).

The origin and size of the programs known to IDF are displayed in the Target Status window, when open.

Whenever possible, IDF notifies you if your program is preparing to branch to a location outside its defined limits. This is often useful in locating a "wild branch", for example to location zero.

If you have specified the TRACEALL option, IDF considers the defined limits of your program to begin at location zero and extend upward to the end of storage. Thus when you specify TRACEALL, you can trace through all of virtual memory.

Care should be taken if you attempt to trace through protected (read only) storage.