Breakpoint Activities › The Backtrace Facility › Access the Backtrace Facility

Access the Backtrace Facility

To access the Backtrace facility from the source listing facility and to view the Backtrace Summary, enter BTRACE on the command line and press Enter, or press PF11 from the Source Listing Breakpoint screen. CA InterTest for CICS positions the Backtrace Summary at the last executed statement, which is the current breakpoint location. To view your program's backtrace statement‑by‑statement, press PF2 from the Backtrace Summary to access the Source Listing Backtrace.

Note: While you are using the Backtrace facility, the execution PF keys are disabled and replaced with special forward and backward tracing PF keys.

From the Backtrace Summary, perform the following actions:

• Access the Source Listing Backtrace to view statement‑by‑statement details of the program's execution path by:
  • Pressing PF2
  • Marking a statement block with S to indicate a starting position, and then pressing Enter
• Assign a bookmark, consisting of one to four characters, to one or more backtrace positions for faster and easier navigation through the Backtrace Summary

  The following screen shows the Backtrace Summary.

                 CA InterTest  BACKTRACE SUMMARY                            
  COMMAND ===>                                                                 
  Program= COBDEMO                                  Œ  From 0001 To 0011 Of 0011
                                                                                 
  Specify S then ENTER to display Source Listing BACKTRACE                 
  --------------------------------------------------------------------------------
  PFKS 1 Help      2 Backtrace 3 End        4            5 1st Stmt   6 Last Stmt
       7 Backward  8 Forward   9           10           11 Prev Bloc 12 Next Bloc
  --------------------------------------------------------------------------------
    Ž      Ž        
   S Bkmk       Stmt Block  | Source Listing                                     
   _ ____    #790.0...#791.0|  PROCEDURE DIVISION USING DFHEIBLK DFHCOMMAREA.    
   _ ____    #791.0...#801.0|      CALL 'DFHEI1'.                                
   _ ____    #801.0...#802.0|      CALL 'DFHEI1' USING DFHEIV0                   
   _ ____    #804.0...#804.0|      IF EIBAID = DFHCLEAR                          
   s ____    #812.0...#813.0|       MOVE '  Y    i 00557   ' TO DFHEIV0          
   _ ____    #813.0...#818.0|      CALL 'DFHEI1' USING DFHEIV0  TSQNAME TASKSTR
   _ ____    #822.0...#823.0|      IF EIBCALEN = 0                               
   _ ____    #878.0...#881.0|       MOVE '  }            00598   ' TO DFHEIV0    
   _ ____    #881.0...#887.0|      CALL 'DFHEI1' USING DFHEIV0  DFHC0070 DFHEICB 
   _ ____    #887.0...#888.1|      CALL 'DFHEI1' USING DFHEIV0.                  
   * ____    #897.0... Bkpt |      ADD +1 TO TASKNUM.                            
                                                                                 
   CAIN2988 First and Last Backtrace Stmt Block
  

Œ

From field indicates the relative backtrace statement blocks displayed on the screen. There are a maximum of 580 backtrace statement blocks that record a program's execution path. The oldest statement blocks are re-used as needed.

To reposition the Source Backtrace Summary, overtype the information in the From field with a relative statement block number or with a one‑ to four‑byte user‑specified tag or bookmark.



Select (S) column positions a display of the Source Listing Backtrace at a selected backtrace statement. Enter S next to any entry and press Enter. The Source Listing Backtrace displays from the specified backtrace position. Only one S is allowed.

Note: An * in the Select column indicates the current backtrace position.

Ž

Bookmark (Bkmk) column is used to assign a unique tag or ID to one or more backtrace positions.

• Specify multiple bookmarks.
• Each bookmark must contain at least one non‑numeric character. For example, P103, UB7, T1, A, and so on.
• Each bookmark must be unique.
• Once a bookmark is assigned to a specific backtrace position, it remains attached to that backtrace position until the bookmark is replaced or removed by subsequent program execution.
  • There are 580 backtrace positions, and the oldest entries are replaced.
  • If a backtrace position is not replaced between breakpoints, use the bookmark to reposition your Backtrace Summary by specifying the bookmark name in the From field of the Backtrace Summary screen.



Statement (Stmt) Block column identifies a block of contiguously executed statement numbers.

• Each line entry is a pair of program locations identifying the first and last statement numbers or offsets for a piece of sequentially executed code.
• For COBOL programs, the decimal value of the statement number indicates a specific verb in a statement. The first verb is 0, the second is 1, and so on.
• The top left entry was executed first, and the bottom right entry was executed most recently.
• After each statement number or offset in the right column there was a break in sequential execution, such as a CALL to CICS or a branch to another location in the program. Each break results in a new line entry.
• Plus signs indicate offsets; for example, +204.



Source Listing Summary column displays the source code associated with the first statement executed in the statement block, which is identified by the statement number in the left column. The left margin default is 01 for COBOL and PL/I programs, and 34 for Assembler programs.

Note: For display purposes, the starting column is either the left margin default or the Margin= value that was specified on the Source Listing Breakpoint screen, whichever is greater.

‘

Message Line displays any messages about the section of backtrace that you are currently viewing.