User`s guide

NOTE: You cannot single-step into a subroutine that was loaded from a protected disk
file. Thus, you must use Ctrl+Z to step across any CALL of such a routine.
NOTE: The execution pointer (->) is not displayed while the system is executing an
instruction. Do not type a Ctrl+X or Ctrl+Z until the execution pointer reappears.
PAUSE Instructions
Debug editor mode can be used to insert PAUSE instructions in the program at strategic
points. Execution pauses when those points are reached. After the pause has occurred, and
you are ready to have execution resume, you can use the PROCEED command.
The debugger Ctrl+P command provides a convenient means of issuing a PROCEED
command for the program being debugged.
The disadvantage of using PAUSE instructions, however, is that they must be explicitly
edited into the program and removed when debugging is completed. The following section
describes a more convenient way to achieve the same effect as is achieved when a PAUSE
instruction is used..
Program Breakpoints
The V+ BPT command can be used to attach a breakpoint to an instruction. The BPT allows
either or both of the following responses to occur when the breakpoint is encountered during
execution:
l Execution stops at the flagged instruction (before it is executed).
l Values are displayed on the system terminal, showing the current status of user-
specified expressions.
To set breakpoints at various points in the program, enter the appropriate BPT commands on
the debugger command line to place the breakpoints and to specify expressions to be
evaluated when the breakpoints are encountered.
If you do not need to have an expression evaluated at a breakpoint, you can use the
debugger Ctrl+B command to set a pausing breakpoint-that is, one that will cause execution
to stop. To use the Ctrl+B command you must position the typing cursor in the edit window
so it is on the instruction of interest. Once the cursor is positioned, you can type Ctrl+B to
have a breakpoint placed at that instruction.
NOTE:You can use Go To (F3) (and other editor commands) to change the program in
the edit window. Thus, you can move to any program you want before typing Ctrl+B to
set a breakpoint. (You do not have to explicitly switch to having the edit window show the
program currently stopped. The debugger will automatically display the appropriate
program the next time execution stops for any reason.)
The Program Debugger
(Undefined variable: Primary.Product_Name_V)Language User's Guide, version
17.x
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