HP 3000 Manuals

HPTOOLSET XL Reference Manual

DATATRACE 

Monitors the value of a data item.

Syntax 

     DA[TATRACE] data-item [DO command-list [NOMESSAGE] ]
                           [OFF                         ]

Parameters 

Data-item        Any COBOL data name or index name defined in the COBOL
(COBOL)          source program.  A data item may be qualified with:

                   (1) OF,
                   (2) IN,
                   (3) subscript (must be an integer value), or
                   (4) periods separating the data names, where the most
                   significant data name is specified first.

                 You cannot reference a data item in a program other than
                 the one that is currently executing.

Data-item        Any Pascal data name defined in the source program.
(Pascal)         Standard Pascal selectors are used to qualify arrays and
                 records.  In addition, TOOLSET/XL allows commas when
                 selecting Array elements.  OF or IN may be used to
                 select record elements.

Data-item        Any FORTRAN data name defined in the source program.
(FORTRAN)        Standard FORTRAN delimiters are used in referencing
                 array elements.

DO Command List  Specifies a list of TOOLSET/XL commands you want
                 automatically executed when the value of a data item
                 changes.  Takes the form:

                 (command [; command]...)

NOMESSAGE        Suppresses an identifying message when DATATRACE is
                 executed.

OFF              Disables the DATATRACE. You may also use the Clear
                 function key which is available when the Show Debug menu
                 is displayed.

Description 

The DATATRACE command saves the value of the data item you specify.
TOOLSET/XL compares the saved value with the current value of the data
item at the beginning of each paragraph, section, or procedure in your
program.  If the value has changed, the new value will be saved and a
message containing the location and the new value will be displayed.  Any
commands that you have specified will be executed.  If there is no
command list, the program will continue running.

The maximum number of data items that can be traced is three.

If all the commands in your command list have executed, Symbolic Debug
will execute a RESUME command.  If you include a BREAK or SYSDEBUG
command in the command list, the list will terminate.

Pascal 

As with COBOL, only three data items can be traced at one time in a
Pascal program.  In addition, a variable cannot be referenced outside of
the level of the procedure that it is declared in, nor can it be
explicitly turned off when your are working outside of its procedure
level.

If you need to set another datatrace and are outside of the procedure
where the first three are set, you can:

  (1) Go back to the procedure level where the datatraces are set and
  explicitly turn any or all of the datatraces off.
  (2) Enter a SHOW DEBUG command.  This produces a menu from which you
  can mark any or all of the datatraces set and clear them by pressing
  the Clear function key available when the Show Debug menu is on the
  terminal screen.

The values of rows, elements, or entire arrays can be traced.

The RESUME command should not be included in a command list.

FORTRAN 

As with COBOL and Pascal, only three data items can be traced at one time
in a FORTRAN program.  To reference a variable outside the currently
executing subroutine or function, the variable must be in a common block.


          Figure 4-4.  Datatrace Command Screen 


NOTE  One cannot DISPLAY, MOVE, or DATATRACE Pascal local variables or
      parameters that reference global types that have not been included
      in the main outer block compile.  In other words, variables or
      parameters that reference newly added global types in their
      subprogram compile.  This may be a problem with mixed languages.

MPE/iX 5.0 Documentation