Upgrading from Enterprise COBOL Version 4

Programs that contain any of the following language features might need to be modified:

• Programs using DATE FORMAT and windowed date functions. For details, see Changes in millennium language extensions in IBM Enterprise COBOL for z/OS, Version 5 and Version 6.
• Label declaratives. To compile programs with Enterprise COBOL V5 or V6, you must remove any format 2 declarative syntax: USE...AFTER...LABEL PROCEDURE..., and the syntax: GO TO MORE-LABELS. The support for these was removed in Enterprise COBOL Version 5
• Programs that use new reserved words as user words. For details, see New reserved words.

There is a new compiler option, FLAGMIG4, available with PTF for APAR PM93450 for Enterprise COBOL V4.2 to help you migrate to Enterprise COBOL V5 or V6. It is also recommended that you install PTFs for APARs PI12240, PI26838, and PI58762 as these contain updates to the FLAGMIG4 option. The FLAGMIG4 option identifies language elements in Enterprise COBOL V4 programs that are not supported, or that are supported differently in Enterprise COBOL V5 or V6. The compiler will generate a warning diagnostic message for all such language elements.