Cobol

Enterprise COBOL for z/OS and OS/390

Compiler and Run-Time Migration Guide
V ersion 3 Release 1

GC27-1409-00

Enterprise COBOL for z/OS and OS/390

Compiler and Run-Time Migration Guide
V ersion 3 Release 1

GC27-1409-00

Note!: Before using this information and the product it supports, be sure to read the general information under “Appendix N. Notices” on page 323.

FirstEdition (November 2001) This new edition replaces and makes obsolete the previous edition, GC26-4764-05. The technical changes for this edition are summarized under “Summary of Changes” and are indicated by a vertical bar to the left of a change. This edition applies to IBM Enterprise COBOL for z/OS and OS/390 Version 3 Release 1 (5655-G53) and to any subsequent releases until otherwise indicated innew editions or technical newsletters. Make sure you are using the correct edition for the level of the product. You can order publications online at www.ibm.com/shop/publications/order, or order by phone or fax. IBM Software Manufacturing Solutions takes publication orders between 8:30 a.m. and 7:00 p.m. EST (Eastern Standard Time). The phone number is (800)879-2755. The fax number is(800)445-9269. Order publications through your IBM representative or the IBM branch office serving your locality. When you send information to IBM, you grant IBM a nonexclusive right to use or distribute the information in any way it believes appropriate without incurring any obligation to you. © Copyright International Business Machines Corporation 1991, 2001. All rights reserved. US Government UsersRestricted Rights – Use, duplication or disclosure restricted by GSA ADP Schedule Contract with IBM Corp.

Contents
About this book . . . . . . . . . . . ix
Acknowledgement . . . . . . . . . . . Using your documentation . . . . . . . . Enterprise COBOL for z/OS and OS/390 . . . Language Environment element of z/OS Version Release 1 or later . . . . . . . . . . . Language Environment element ofOS/390 Version 2 Release 10 . . . . . . . . . How to send your comments . . . . . . . ix . x . x 1 . x . xi . xi

Chapter 3. Planning the move to Language Environment . . . . . . . 23
Preparing to move to the Language Environment run-time library . . . . . . . . . . . . . Installing Language Environment . . . . . . Assessing storage requirements . . . . . . . Educating your programmers aboutLanguage Environment . . . . . . . . . . . . . Taking an inventory of your applications . . . . Vendor tools, packages, and products. . . . . COBOL applications . . . . . . . . . . Assigning complexity ratings . . . . . . . Setting up conversion/no-conversion categories Deciding how to phase Language Environment into production mode . . . . . . . . . . . . Multilanguage conversion . . . . . . . .Determining how applications will have access to the library . . . . . . . . . . . . . . Setting up a regression testing procedure . . . . Take performance measurements . . . . . . Cutting over to production use . . . . . . . . 23 23 23 26 27 27 27 28 30 30 30 31 33 34 35

Summary of changes . . . . . . . . xiii
| | |
Changes to the Migration Guide . . . . . . Changes in GC27-1409-00, November2001. . Changes in GC26-4764-05, September 2000. . Summary of changes to the COBOL compilers . Changes in IBM Enterprise COBOL for z/OS and OS/390 . . . . . . . . . . . . Changes in COBOL for OS/390 & VM Version Release 2 . . . . . . . . . . . . . Changes in COBOL for OS/390 & VM Version Release 1 . . . . . . . . . . . . . . . . . xiii xiii xiii xiv

. xiv 2 . xiv 2 . xvi

Part 1. Overview . . . .. . . . . . 1
Chapter 1. Do I need to recompile? . . . 3
Migration basics . . . . . . . . Run-time migration . . . . . . Source migration . . . . . . . Service support for OS/VS COBOL and programs . . . . . . . . . . Changing OS/VS COBOL programs . . . VS . . . . . . . . . . . . . . COBOL II . . . . . . . . 3 3 4 4 5

Chapter 4. Planning to upgrade source programs . . . . . . . . . . . . ....