HP OpenVMS Delta/XDelta Debugger Manual
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  1. Breakpoint 1 is cleared using 0,[breakpoint #];B. (Never clear breakpoint 1 in XDELTA.)
  2. All breakpoints are listed again with ;B command.
  3. DELTA displays breakpoint 2 (breakpoint 1 cleared).
  4. Program execution continues using the ;P command.
  5. Breakpoint 2 is encountered; DELTA displays the breakpoint message and the instruction. The subroutine is executed with the O command and the subroutine output is displayed. The next instruction where the subroutine returns control is displayed. Program execution continues with the ;P command.
  6. Breakpoint 2 is encountered; DELTA displays the breakpoint message and the instruction. Program execution continues to the next breakpoint with the ;P command. The subroutine is executed, and the subroutine output is displayed.
  7. Breakpoint 2 is encountered again; the instruction at offset 4B9 (in the subroutine) is displayed using !. This instruction is part of the setup for the call to the system service $QIOW.
  8. Successive address locations are displayed by pressing the Linefeed key nine times. These instructions are the remainder of the setup and the call to the system service $QIOW.
  9. A breakpoint at X1+04D5 (the current address) is set using the ;B command. This breakpoint is in the subroutine. The . symbol represents the current address.
  10. The current breakpoints in the program are listed. The new breakpoint is assigned breakpoint 1.

C.2.4 DELTA Debugging Session Example on VAX - Part 4

In the final part of the example session, program execution continues and stops at the new breakpoint set in the previous example segment. DELTA executes the subroutine where the breakpoint was encountered and displays the output. The next breakpoint is reached and the use enters the ;O command to step over the subroutine. When there are no more breakpoints, the program completes and final exit status is displayed.

The callout list following the example provides details for this example segment.

Example C-6 DELTA Debugging Session Example on VAX - Part 4 

 
;P                                                                  (1)
1 BRK AT 000006D5
X1+04D5/CALLS    #0C,@#7FFEDE00              ;P                     (2)
        PID=  0006      LOGINTIME=  12:50:29.45
2 BRK AT 00000699
X1+0499/BSBB    X1+04A2       ;P                                    (3)
1 BRK AT 000006D5
X1+04D5/CALLS    #0C,@#7FFEDE00              ;P                     (4)
        PID=  0007      LOGINTIME=  12:50:37.08
2 BRK AT 00000699
X1+0499/BSBB    X1+04A2       O                                     (5)
1 BRK AT 000006D5
 
X1+04D5/CALLS    #0C,@#7FFEDE00              ;P                     (6)
        PID=  0008      LOGINTIME=  12:50:45.64
STEPOVER BRK AT 0000069B                                            (7)
X1+049B/BRB    X1+047A                       ;B                     (8)
1  000006D5
2  00000699                                                         (9)
0,2;B                                                               (10)
0,1;B                                                               (11)
;B                                                                  (12)
;P                                                                  (13)
        PID=  0009      LOGINTIME=  12:51:22.51
        PID=  000A      LOGINTIME=  12:51:30.26
        PID=  000B      LOGINTIME=  12:51:36.21
        PID=  000C      LOGINTIME=  12:51:58.86                     (14)
EXIT 00000001                                                       (15)
80187E7E/POPR    #03                         EXIT                   (16)

  1. Program execution continues with the ;P command.
  2. Program execution stops at the new breakpoint 1, which is in the subroutine GOT_IT. DELTA displays the breakpoint message and the instruction at the new breakpoint. Program execution continues with the ;P command.
  3. The subroutine completes and displays the output, and program execution continues until breakpoint 2. DELTA displays the breakpoint message and the breakpoint 2 instruction. Program execution continues with the ;P command.
  4. Program execution stops at breakpoint 1 in the subroutine. Program execution continues with the ;P command. The subroutine is executed, and the output is displayed.
  5. Program execution stops at breakpoint 2. The O command is entered to execute and step over the subroutine.
  6. Program execution stops at breakpoint 1 in the subroutine. Program execution continues with the ;P command.
  7. The subroutine completes execution and displays output. DELTA displays a STEPOVER break message to state that the O command has been completed, returning control at address 69B (an instruction in the main routine).
  8. The instruction where the subroutine returns is displayed, and program execution is halted. The ;B command is entered to display all current breakpoints.
  9. The two current breakpoints are listed.
  10. The command 0,2;B clears breakpoint 2.
  11. The command 0,1;B clears breakpoint 1.
  12. The ;B command is entered to display all current breakpoints. Because all breakpoints have been cleared, DELTA does not display any.
  13. Program execution continues with the ;P command. Because there are no longer any breakpoints, the program executes to the end.
  14. All current process login times are displayed.
  15. Final exit status is displayed.
  16. The DELTA EXIT command is entered to terminate the debugging session and leave DELTA.

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