Figure 1 illustrates
the error of using a subscript value outside the range of an array.
This program was compiled with LIST, TEST, and SSRANGE. The SSRANGE
compiler option causes the compiler to generate code that checks (during
run time) for data that has been stored or referenced outside of its
defined area because of incorrect indexing and subscripting. The SSRANGE
option takes effect during run time. For COBOL V4R2 and prior releases,
you can disable the check by specifying the CHECK(OFF) runtime option.
For Enterprise COBOL V5.1 and later releases, the CHECK runtime option
is ignored.
The program was run with TERMTHDACT(TRACE) to generate the traceback information shown in Sections of Language Environment dump for COBOLX.
CBL LIST,SSRANGE,TEST
ID DIVISION.
PROGRAM-ID. COBOLX.
ENVIRONMENT DIVISION.
DATA DIVISION.
WORKING-STORAGE SECTION.
77 J PIC 9(4) USAGE COMP.
01 TABLE-X.
02 SLOT PIC 9(4) USAGE COMP OCCURS 8 TIMES.
PROCEDURE DIVISION.
MOVE 9 TO J.
MOVE 1 TO SLOT (J).
GOBACK.To understand the traceback information and debug this program, use the following steps:
- Locate the current error message in the Condition Information for Active Routines section of the Language Environment traceback, shown in Sections of Language Environment dump for COBOLX. The message is IGZ0006S The reference to table SLOT by verb number 01 on line 000011 addressed an area outside the region of the table. The message indicates that line 11 was the current COBOL statement when the error occurred. For more information about this message, see z/OS Language Environment Runtime Messages.
- Statement 11 in the traceback section of the dump occurred in program COBOLX.
- Find the statement on line 11 in the listing for program COBOLX,
shown in Figure 2. This statement
moves the 1 value to the array SLOT (J). Figure 2. COBOL listing for COBOLX
PP 5655-G53 IBM Enterprise COBOL for z/OS 3.4.1 COBOLX Date 02/14/2007 Time 14:58:58 Page 3 LineID PL SL ----+-*A-1-B--+----2----+----3----+----4----+----5----+----6----+----7-|--+----8 Map and Cross Reference /* COBOLX 000001 ID DIVISION. 000002 PROGRAM-ID. COBOLX. 000003 ENVIRONMENT DIVISION. 000004 DATA DIVISION. 000005 WORKING-STORAGE SECTION. 000006 77 J PIC 9(4) USAGE COMP. 000007 01 TABLE-X. 000008 02 SLOT PIC 9(4) USAGE COMP OCCURS 8 TIMES. 000009 PROCEDURE DIVISION. 000010 MOVE 9 TO J. 6 000011 MOVE 1 TO SLOT (J). 8 6 000012 GOBACK. */ COBOLX - Find the values of the local variables in the Parameters, Registers,
and Variables for Active Routines section of the traceback, shown
in Sections of Language Environment dump for COBOLX. J, which is
of type PIC 9(4) with usage COMP, has a 9 value. J is
the index to the array SLOT.
The array SLOT contains eight positions. When the program tries to move a value into the J or 9th element of the 8-element array named SLOT, the error of moving a value outside the area of the array occurs.