A breakpoint causes the execution of a Natural object to be interrupted at a specific statement line. This section describes how and when to set breakpoints. Note that the maintenance functions described here may also be invoked from an object source by using the function.
To invoke Breakpoint Maintenance
In the Debug Main Menu, enter function code
B.
Or:
Enter the following direct command:
BM
The Breakpoint Maintenance menu appears.
This section describes conditions for using breakpoint maintenance, the functions provided in the Breakpoint Maintenance menu and the fields and columns contained in a breakpoint screen.
A breakpoint is set by specifying the name of the Natural object to be processed and the line number in the object's source code where the breakpoint is to be executed.
Once a breakpoint has been specified, it remains set for the entire Natural session, unless you delete it.
A breakpoint refers to a specific line number in source code. A subsequent change of the source code itself may therefore lead to the breakpoint no longer applying to the desired statement, and thus the Natural object not being interrupted at the desired position. To circumvent this problem with program loops, labels can be set within these loops. Breakpoints set for these labels are adjusted to the correct line number if statement lines are inserted or deleted.
The unique identifier for a breakpoint is the spy number as assigned by the debugger.
Breakpoints cannot be set on comment lines, on any statement line other than the first one (if a single statement occupies more than one program line), and on lines that contain one of the following statements only:
AT BREAK OF
AT END OF DATA
AT END OF PAGE
AT START OF DATA
AT TOP OF PAGE
BEFORE BREAK
DECIDE
See also the usage restrictions described in
Operational
Requirements.
DEFINE SUBROUTINE
DEFINE WINDOW
FORMAT
IF NO RECORDS FOUND
ON ERROR
OPTIONS
Whether it is possible or not to set breakpoints for lines compiled with
the Natural Optimizer Compiler depends on the NODBG option of the
OPTIONS
statement described in Switching on the Optimizer Compiler
in the Natural Optimizer Compiler documentation.
See the section Switch Test Mode On and Off.
To set the current state of specified breakpoints to active
In the Breakpoint Maintenance menu, enter
function code A, an object name and/or a line number.
Or:
Use the direct command ACTIVATE, the syntax
of which is described in the section Command Summary and
Syntax.
If you do not specify an object name or a line number, all breakpoints are activated.
To set the current state of specified breakpoints to inactive
In the Breakpoint Maintenance menu, enter
function code B, an object name and/or a line number.
Or:
Use the direct command DEACTIVATE, the
syntax of which is described in the section Command Summary and
Syntax.
If you do not specify an object name or a line number, all breakpoints are deactivated.
To delete specified breakpoints
In the Breakpoint Maintenance menu, enter
function code C, an object name and/or a line number.
Or:
Use the direct command DELETE, the syntax of
which is described in the section Command Summary and
Syntax.
If you do not specify an object name or a line number, all breakpoints are deleted.
To display a breakpoint
In the Breakpoint Maintenance menu, enter
function code D, an object name and a line number.
If you do not enter an object name, the default object (if specified) is used.
Or:
Use the direct command DISPLAY, the syntax of
which is described in the section Command Summary and
Syntax.
If a breakpoint has been set for the specified object and line number, a Display Breakpoint screen with all breakpoint definitions appears similar to the example below:
11:16:12 ***** NATURAL TEST UTILITIES ***** 2006-02-07
Test Mode ON - Display Breakpoint - Object
Spy number .............. 1
Initial state ........... active Current state .. active
Breakpoint name ......... BRK0130 DBID/FNR ....... 10/32
Object name ............. DEBPGM1 Library ........ SAG
Line number ............. 0130
Label ...................
Skips before execution .. 0
Max number executions ... 0
Number of activations ... 0
Error in definition ..... - none -
Commands ... BREAK
Command ===>
Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12---
Help Exit Last Mod Flip Canc |
If no unique breakpoint is found, the List Breakpoints screen described below appears.
The fields on the Display Breakpoint screen are described in Fields and Columns on Breakpoint Screens.
To list breakpoints
In the Breakpoint Maintenance menu, enter
function code D, an object name or a line number. You can use
asterisk (*) notation to specify a range of object names, for example,
ABC*. If you enter an asterisk (*) only, all object names are
selected. If you do not enter an object name, the
default object (if specified) is
used.
Or:
Use the direct command DISPLAY, the syntax of
which is described in the section Command Summary and
Syntax.
A List Breakpoints screen similar to the example below appears which lists all breakpoints set for the specified object(s) or line number:
11:41:56 ***** NATURAL TEST UTILITIES ***** 2006-01-30
Test Mode ON - List Breakpoints - Object
All
Co No. BP Name Library Object Line DBID FNR Stat Skips Execs Count E
*___________ *_______ *_______ 0000 I C
__ 1 BRK0130 SAG DEBPGM1 0130 10 32 A A 0 0 0
__ 2 BRKPGM3-END SAG DEBPGM3 END 10 32 A A 0 0 0
__ 3 BRKPGM3-300 SAG DEBPGM3 0300 10 32 A A 0 0 0
__ 4 BRKPGM2-400 SAG DEBPGM2 0400 10 32 A A 0 0 0
__ 5 BRKPGM2-430 SAG DEBPGM2 0430 10 32 A A 0 0 0
__ 6 BRKPGM1-END SAG DEBPGM1 END 10 32 A A 0 0 0
__ 7 BRKPGM1-ALL SAG DEBPGM1 ALL 10 32 A A 0 0 0
Command ===>
Enter-PF1---PF2---PF3---PF4---PF5---PF6---PF7---PF8---PF9---PF10--PF11--PF12---
Help Exit Last Flip - + Canc |
The list is sorted in ascending order by the spy numbers contained in the No. column.
For details on the columns contained in the List Breakpoints screen and the line commands that can be executed on any list item, refer to Fields and Columns on Breakpoint Screens.
To modify a breakpoint
In the Breakpoint Maintenance menu, enter
function code M, an object name and a line number. If you do not
enter an object name, the default
object (if specified) is used.
Or:
Use the direct command MODIFY, the syntax of
which is described in the section Command Summary and
Syntax.
If a unique breakpoint has been specified, the Modify Breakpoint screen appears where you can change the field entries. The fields on the Modify Breakpoint screen are described in Fields and Columns on Breakpoint Screens.
If no unique breakpoint is found, the List Breakpoints screen (see Display Breakpoint) appears.
When you have finished editing the breakpoint definitions, choose PF3 (Exit) or PF5 (Save) to save any modification. See also Maintenance and Validation for information on validity checks of debug entries. If you choose PF12 (Canc), the breakpoint remains unchanged.
To add a breakpoint for a session
In the Breakpoint Maintenance menu, enter
function code S, an object name and/or a line number.
Or:
Use the direct command SET, the syntax of which
is described in the section Command Summary and Syntax.
If you specify not an object name but a valid line number, the name of the default object (see the section Start the Debugger) is assumed. If no default object is specified, a selection window appears that displays all objects available in the current library.
If object name and line number are specified correctly, the breakpoint is usually set and confirmed immediately.
However, a breakpoint set for copycode can only be validated when a program that contains the copycode is executed. See also Maintenance and Validation for information on validity checks of debug entries.
The breakpoint receives the default command
(BREAK), its initial and current state are set to
active and no execution restrictions are specified. Note that if you delete the
command BREAK when setting a breakpoint and you do
not enter any command that issues a dialog, there is no way for the debugger to
receive control during program interruption.
The fields contained in a Display Breakpoint or a Modify Breakpoint screen and the columns of a List Breakpoints screen are described in the following table:
| Field | Column | Explanation | ||||||||||||||
|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|---|
| Test Mode | Indicates whether test mode is set to ON or
OFF.
|
|||||||||||||||
| Object | Displays the name of the default object (see Start the Debugger) if specified. | |||||||||||||||
| Co | Input field for any of the following line commands:
|
|||||||||||||||
| Spy number | No. | A unique number assigned by the debugger when setting the breakpoint. | ||||||||||||||
| Initial state | Stat I | Specifies the initial state and the current state
of the breakpoint: active (A) or inactive (I).
|
||||||||||||||
| Current state | Stat C | |||||||||||||||
| Breakpoint name | BP Name | The name of the breakpoint.
Valid values: 1 to 12 characters. The default name for a breakpoint consists of the object name and the line number. |
||||||||||||||
| DBID/FNR | DBID | The database ID (DBID) and file number (FNR) of the system file where the Natural object is stored. | ||||||||||||||
| FNR | ||||||||||||||||
| Library | Library | The name of the library that contains the object. | ||||||||||||||
| Object name | Object | The name of the object available in the current library or one of its steplibs. | ||||||||||||||
| Line number | Line | The line number of a statement in the object source code. See
also Conditions of
Use above.
You can also specify
|
||||||||||||||
| Label | Refers to a label set earlier in the source code of an object
for statements that define processing loops: see also
Conditions of
Use above.
Valid values: 1 to 32 characters. |
|||||||||||||||
| Skips before execution | Skips | Determines that the breakpoint is not to be executed until the
corresponding statement line has been executed a certain number of times.
Valid values: 0 (default) to 32767. |
||||||||||||||
| Max number executions | Execs | Any value greater than zero (0) determines the maximum number
of breakpoint executions.
Valid values: 0 (default) to 32767. |
||||||||||||||
| Number of activations | Count | Indicates how many times a breakpoint was activated for the
relevant statement line.
The counter is reset when a program is started at Level 1. |
||||||||||||||
| Error in definition | E | Indicates that the statement line in the breakpoint definition
cannot be found in the cataloged object during program execution.
This error can be caused if the source of an object is changed and recataloged during debugging. |
||||||||||||||
| Commands | Up to six debug commands. Enter one command per line. For a
summary of all available commands, see Command Summary and
Syntax.
Caution: |