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Various programming productivity tools can help you increase your productivity as a Compaq COBOL programmer. These include the following:
Compaq FUSE is the Compaq integrated software development environment for UNIX workstations. Compaq FUSE is available in two variations: the Compaq FUSE base system, and FUSElite, a subset of Compaq FUSE (used for C program development), which is upgradable to the full base system.
Compaq FUSE supports basic software development activities including coding, building, debugging, performance analysis and code management. Some of the Compaq FUSE tools are layered on commonly used UNIX tools including make , prof , rcs , and sccs . The default integrated debugger is Ladebug Debugger. These Compaq FUSE tools provide easy-to-use Motif graphic interfaces, plus benefits achieved through integration with other Compaq FUSE tools and through extensions to the capabilities of the base tools.
Compaq FUSE also provides an integrated text editor with a Motif user interface as well as integrated emacs and vi . Other Compaq FUSE tools provide integrated static analysis and browsing capabilities, including program source cross-referencing and call-graph browsing.
Additional tools (such as the Code Manager, Profiler, and Compare---all based on standard UNIX utilities---and the Cross-Referencer and Call Graph Browser) are available with the Compaq FUSE base system.
The Compaq FUSE integration framework allows tools to invoke one another and trigger operations. Programming tasks are automated and streamlined, reducing some operations to a single mouse button click.
With Compaq FUSE you can:
See the Compaq FUSE documentation for additional, detailed information. <>
With certain COBOL programs in the Compaq FUSE environment a problem will manifest itself by displaying the wrong file in the Compaq FUSE Editor tool for certain COBOL items which are clicked on from the Cross-Referencer tool. This can only happen for COBOL programs with successive COPY statements where there are no intervening data item references or declarations. To work around this problem, insert an extra declaration between successive COPY statements in the DATA DIVISION as follows:
COPY "LIBRARY-1". 01 EXTRA-ITEM PIC X. COPY "LIBRARY-2". |
You should also insert an extra reference to a data item between successive COPY statements in the PROCEDURE DIVISION as follows:
DISPLAY "TEST 7". COPY "LIBRARY-1". move 1 to extra-item. COPY "LIBRARY-2". |
<>
C.2 Debugging Tools for Compaq COBOL Programs
This appendix includes representative debugging sessions that demonstrate debugger features for both the OpenVMS Debugger and the Tru64 UNIX Ladebug Debugger. These tools are source-level, symbolic debuggers that support Compaq COBOL data types and use.
Both the OpenVMS Debugger and the Tru64 UNIX Ladebug Debugger let you:
The debugging examples in Section C.3 and Section C.4 focus on a sample program, shown in Example C-1. One common program has been used, to emphasize the portability of Compaq COBOL.
As you read the debugging sections that follow, refer to the code in Example C-1 to identify source lines.
The program, TESTA, accepts a character string from the terminal and passes it to contained program TESTB. TESTB reverses the character string and returns it (and its length) to TESTA.
| Example C-1 Source Code Used in the Sample Debug Sessions |
|---|
module TESTA
1: IDENTIFICATION DIVISION.
2: PROGRAM-ID. TESTA.
3: DATA DIVISION.
4: WORKING-STORAGE SECTION.
5: 01 TESTA-DATA GLOBAL.
6: 02 LET-CNT PIC 9(2)V9(2).
7: 02 IN-WORD PIC X(20).
8: 02 DISP-COUNT PIC 9(2).
9: PROCEDURE DIVISION.
10: BEGINIT.
11: DISPLAY "ENTER WORD:".
12: MOVE SPACES TO IN-WORD.
13: ACCEPT IN-WORD.
14: CALL "TESTB" USING IN-WORD LET-CNT.
15: PERFORM SHOW-IT.
16: STOP RUN.
17: SHOW-IT.
18: DISPLAY IN-WORD.
19: MOVE LET-CNT TO DISP-COUNT.
20: DISPLAY DISP-COUNT " CHARACTERS".
21: IDENTIFICATION DIVISION.
22: PROGRAM-ID. TESTB INITIAL.
23: DATA DIVISION.
24: WORKING-STORAGE SECTION.
25: 01 SUB-1 PIC 9(2) COMP.
26: 01 SUB-2 PIC S9(2) COMP-3.
27: 01 HOLD-WORD.
28: 03 HOLD-CHAR PIC X OCCURS 20 TIMES.
29: 01 HOLD-CHARS-REHOLD-WORD.
30: 03 CHARS PIC X(20).
31: LINKAGE SECTION.
32: 01 TEMP-WORD.
33: 03 TEMP-CHAR PIC X OCCURS 20 TIMES.
34: 01 TEMP-CHARS REDEFINES TEMP-WORD.
35: 03 CHARS PIC X(20).
36: 01 CHARCT PIC 99V99.
37: PROCEDURE DIVISION USING TEMP-WORD, CHARCT.
38: STARTUP.
39: IF TEMP-WORD = SPACES
40: MOVE 0 TO CHARCT
41: EXIT PROGRAM.
42: MOVE SPACES TO HOLD-WORD.
43: PERFORM LOOK-BACK VARYING SUB-1 FROM 20 BY -1
44: UNTIL TEMP-CHAR (SUB-1) NOT = SPACE.
45: MOVE SUB-1 TO CHARCT.
46: PERFORM MOVE-IT VARYING SUB-2 FROM 1 BY 1 UNTIL SUB-1 = 0.
47: MOVE HOLD-WORD TO TEMP-WORD.
48: MOVE-IT.
49: MOVE TEMP-CHAR (SUB-1) TO HOLD-CHAR (SUB-2).
50: SUBTRACT 1 FROM SUB-1.
51: LOOK-BACK.
52: EXIT.
53: END PROGRAM TESTB.
54: END PROGRAM TESTA.
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The Ladebug Debugger is used to debug Compaq COBOL programs on the Tru64 UNIX operating system.
This section provides a representative debugging session that is designed to demonstrate the use of debugger features. For complete reference information on the Ladebug Debugger, you should refer to the Ladebug Debugger Manual in the Tru64 UNIX operating system documentation set. Online help is immediately available to you during a debugging session when you type help command at the debugger prompt (ladebug) . Additional information about the flags shown in this section is available in the man page. For example, you can type man cobol , and page to the appropriate topic to read information about the flags ( -g , -o ) used at the beginning of the example in this section.
% cobol -g -o testa testa.cob cobol: Warning: file not optimized; use -g3 for debug with optimize % |
% ladebug testa Welcome to the Ladebug Debugger Version 2.0.8 eft ------------------ object file name: testa Reading symbolic information ...done (ladebug) |
(ladebug) stop at 43 [#2: stop at "testa.cob":43 ] |
(ladebug) run ENTER WORD |
abc
[2] stopped at [TESTB:43 0x120001aa4]
43 PERFORM LOOK-BACK VARYING SUB-1 FROM 20 BY -1
|
(ladebug) stop at 47
[#2: stop at "testa.cob":47 ]
(ladebug) when at 50 { print chars of hold-chars; print SUB-1; cont; }
[#3: when at "testa.cob":50 { print CHARS of HOLD-CHARS; print SUB-1; ; cont ; } ]
|
(ladebug) status
#1 PC==0x120001e14 in testa "testa.cob":2 { break }
#2 PC==0x120001ba4 in TESTB "testa.cob":47 { break }
#3 PC==0x120001c1c in TESTB "testa.cob":50
{ ; print CHARS of HOLD-CHARS; print SUB-1; ; cont ; ; }
|
(ladebug) list 43,50
43 PERFORM LOOK-BACK VARYING SUB-1 FROM 20 BY -1
44 UNTIL TEMP-CHAR (SUB-1) NOT = SPACE.
45 MOVE SUB-1 TO CHARCT.
46 PERFORM MOVE-IT VARYING SUB-2 FROM 1 BY 1 UNTIL SUB-1 = 0.
47 MOVE HOLD-WORD TO TEMP-WORD.
48 MOVE-IT.
49 MOVE TEMP-CHAR (SUB-1) TO HOLD-CHAR (SUB-2).
50 SUBTRACT 1 FROM SUB-1.
|
(ladebug) trace at 15 [#3: trace at "testa.cob":15 ] |
(ladebug) stop disp-count of testa-data [#4: stop if DISP-COUNT of TESTA-DATA changes ] |
(ladebug) cont
[3] when [TESTB:50 0x120001c1c]
"c "
3
[3] when [TESTB:50 0x120001c1c]
"cb "
2
[3] when [TESTB:50 0x120001c1c]
"cba "
1
[2] stopped at [TESTB:47 0x120001ba4]
47 MOVE HOLD-WORD TO TEMP-WORD.
|
(ladebug) whatis sub-1 unsigned short SUB-1 (ladebug) print sub-1 0 |
(ladebug) whatis sub-2 pic s99 usage comp-3 SUB-2 (ladebug) assign sub-2=-42 |
(ladebug) print sub-2 -42 |
(ladebug) whatis charct pic 99v99 usage display charct (ladebug) print charct 3.00 |
(ladebug) assign charct=15.95 |
(ladebug) print charct 15.95 |
(ladebug) print temp-char of temp-word(2) "b" |
(ladebug) print in-word of testa-data "abc " |
(ladebug) assign charct=3.00 |
(ladebug) cont
[3] [calling testa from main cob_main.c:253 0x3ff8181f054]
cba
[4] The value of DISP-COUNT of TESTA-DATA was changed in testa,
before entering cob_acc_display
Old value = 0
New value = 3
[4] stopped at [cob_acc_display:349 0x3ff81808744]
(Cannot find source file cob_accdis.c)
|
(ladebug) where >0 0x3ff81808744 in cob_acc_display() cob_accdis.c:349 #1 0x120001fbc in testa() testa.cob:20 #2 0x3ff8181f054 in main() cob_main.c:253 (ladebug) file testa.cob (ladebug) stop at 20 [#6: stop at "testa.cob":20 ] |
(ladebug) cont 03 CHARACTERS Thread has finished executing |
(ladebug) q <> |
This section provides an introduction to using the OpenVMS debugger with Compaq COBOL programs. It includes the following:
For complete reference information on the OpenVMS debugger, see
the OpenVMS Debugger Manual in the OpenVMS documentation set. Online help
is immediately available to you during a
debugging session when you type the HELP command at the debugger prompt
(DBG>).
C.4.1 Notes on Compaq COBOL Support
In general, the OpenVMS debugger supports the data types and operators of Compaq COBOL and other debugger-supported languages. However, there are important language-specific limitations. (To get information about the supported data types and operators for a language, type the HELP LANGUAGE command at the DBG\> prompt.)
The debugger shows source text included in a program with the COBOL COPY file statement or the COPY module of library statement. However, the debugger does not show text which was created with the COPY REPLACING or REPLACE statement, or included by the COPY text FROM DICTIONARY statement.
The debugger cannot show the original source lines associated with the
code for a REPORT section. You can see the DATA SECTION source lines
associated with a report, but no source lines are associated with the
compiled code that generates the report.
C.4.2 Notes on Debugging Optimized Programs
The Compaq COBOL compiler is a highly optimizing compiler. Several of the optimizations it performs, such as instruction scheduling and label deletion, can cause unexpected behavior in the OpenVMS Debugger.
Instruction scheduling can make the debugger appear to execute statements out of order. A single COBOL source statement can often result in several machine instructions. A RISC architecture machine, like the Alpha processor, can start working on a new instruction every machine cycle, but not all instructions can complete within one machine cycle. If the output from one machine instruction is used as the input to a subsequent machine instruction, the machine cannot begin processing the second instruction until it has finished processing the first. In many cases an entirely separate instruction can execute in parallel with the first instruction to perform a related computation.
During instruction scheduling, instructions are reordered to minimize waiting time. As a result an instruction resulting from a subsequent COBOL statement can be scheduled in the middle of (or even before) a sequence of instructions from a preceding statement. This reordering NEVER changes the meaning of your program, but it can make your program's execution in the debugger seem incorrect. The most common symptom of instruction scheduling is that the pointer in the debugger source window jumps back and forth between lines when you use the debugger STEP command.
When the compiler performs label deletion, it deletes paragraph and section labels that you do not explicitly reference in your source program. This prevents you from setting breakpoints on the affected labels which can make the analysis and optimization of your program more difficult.
Because of these and other Compaq COBOL compiler optimizations, Compaq recommends that you use the /NOOPTIMIZE qualifier in conjunction with the /DEBUG qualifier when you are debugging your COBOL programs. Using /NOOPTIMIZE qualifier disables most of the Compaq COBOL optimizations. In particular it suppresses most instruction scheduling and all label deletion optimizations.
The following OpenVMS Alpha debugging session does not show the location of program errors; it is designed to show only the use of debugger features.
$ COBOL/DEBUG/NOOPTIMIZE TESTA $ LINK/DEBUG TESTA |
$ RUN TESTA
OpenVMS Alpha DEBUG Version V7.1-000
%DEBUG-I-INITIAL, Language: COBOL, Module: TESTA
%DEBUG-I-NOTATMAIN, type GO to get reach MAIN program
DBG>
|
DBG> GO
break at routine TESTA
11: DISPLAY "ENTER WORD"
|
DBG> SET BREAK %LINE 43 |
DBG> GO ENTER WORD: |
abc
break at TESTA\TESTB\%LINE 43
43: PERFORM LOOK-BACK VARYING SUB-1 FROM 20 BY -1
|
DBG> SET BREAK %LINE 47 DBG> SET BREAK %LINE 50 DO (EXAMINE HOLD-CHARS;EXAMINE SUB-1;GO) |
DBG> SHOW BREAK breakpoint at TESTA\TESTB\%LINE 43 breakpoint at TESTA\TESTB\%LINE 47 breakpoint at TESTA\TESTB\%LINE 50 do (EXAMINE HOLD-CHARS;EXAMINE SUB-1;GO) |
DBG> TYPE 43:50
module TESTA
43: PERFORM LOOK-BACK VARYING SUB-1 FROM 20 BY -1
44: UNTIL TEMP_CHAR (SUB-1) NOT = SPACE.
45: MOVE SUB-1 TO CHARCT.
46: PERFORM MOVE-IT VARYING SUB-2 FROM 1 BY 1 UNTIL SUB-1 = 0.
47: MOVE HOLD-WORD TO TEMP-WORD.
48: MOVE-IT.
49: MOVE TEMP-CHAR (SUB-1) TO HOLD-CHAR (SUB-2).
50: SUBTRACT 1 FROM SUB-1.
|
DBG> SET TRACE %LINE 15 |
DBG> SET WATCH DISP-COUNT DEBUG-I-WPTTRACE, non-static watchpoint, tracing every instruction |
DBG> GO
break at TESTA\TESTB\%LINE 50
50: SUBTRACT 1 FROM SUB-1.
TESTA\TESTB\HOLD-CHARS:
CHARS: "c "
TESTA\TESTB\SUB-1: 3
break at TESTA\TESTB\%LINE 50
50: SUBTRACT 1 FROM SUB-1.
TESTA\TESTB\HOLD-CHARS
CHARS: "cb "
TESTA\TESTB\SUB-1: 2
break at TESTA\TESTB\%LINE 50
50: SUBTRACT 1 FROM SUB-1.
TESTA\TESTB\HOLD-CHARS
CHARS: "cba "
TESTA\TESTB\SUB-1: 1
break at TESTA\TESTB\%LINE 47
47: MOVE HOLD-WORD TO TEMP-WORD.
DBG>
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