01               RTP.                                            AAADGRUP
           05           RTP1          PIC X VALUE '1'.                  AAADGRUP
       >>if maxNR > 1                                                   AAADGRUP
           05           RTP2          PIC X VALUE '1'.                  AAADGRUP
         >>if maxNR > 2                                                 AAADGRUP
           05           RTP3          PIC X VALUE '1'.                  AAADGRUP
           >>if maxNR > 3                                               AAADGRUP
           05           RTP4          PIC X VALUE '1'.                  AAADGRUP
             >>if maxNR > 4                                             AAADGRUP
           05           RTP5          PIC X VALUE '1'.                  AAADGRUP
               >>if maxNR > 5                                           AAADGRUP
           05           RTP6          PIC X VALUE '1'.                  AAADGRUP
                 >>if maxNR > 6                                         AAADGRUP
           05           RTP7          PIC X VALUE '1'.                  AAADGRUP
                   >>if maxNR > 7                                       AAADGRUP
           05           RTP8          PIC X VALUE '1'.                  AAADGRUP
                     >>if maxNR > 8                                     AAADGRUP
           05           RTP9          PIC X VALUE '1'.                  AAADGRUP
                     >>end-if                                           AAADGRUP
                   >>end-if                                             AAADGRUP
                 >>end-if                                               AAADGRUP
               >>end-if                                                 AAADGRUP
             >>end-if                                                   AAADGRUP
           >>end-if                                                     AAADGRUP
         >>end-if                                                       AAADGRUP
       >>end-if                                                         AAADGRUP​

The support we have now in the Enterprise COBOL compiler for conditional compilation is almost exactly as it is defined in the COBOL standard, including all of its limitations.  However, we on the COBOL team are actually interested in continuing to provide improvements and enhancements to our conditional compilation support beyond that, and have given significant thought to adding macro support, which may be a part of a future COBOL standard as well.  We do face significant time constraints,  though, and prioritizing work is a challenge.  But certainly, we will continue to support and improve this feature and encourage its use where appropriate -- you should not worry about that.

In terms of the general question of where conditional compilation is appropriate -- I would say it is appropriate wherever it helps you to maintain a single source file with code that can be built in different ways to produce slightly different programs.  This is much better than duplicating large pieces of code that may only differ in a few key places.  For example, I know some users may have both Db2 and IMS systems and may have some COBOL processing that is generally identical for both but just the embedded SQL statements are different -- so being able to add code that can be built for Db2 and IMS is a great way to avoid duplicating code and causing a maintenance issue.

For any language that supports actual macros (potentially COBOL in the future) I would advise against using the macros as a way to implement inline "subroutines", as opposed to using normal language features for writing subroutines.  I've seen this pattern used before too often in various code bases written in languages that support macros and, unfortunately, if macros are overused and used as merely a way to generate inline subroutines, then it results in a code maintenance problem whereby a lot of code is "hidden" behind these macros in various "answer strings" (e.g., PL/I macros).  This makes it hard for developers, language analysis tools, debuggers, etc.  to understand what is actually going on in the code until the code goes through some kind of pre-processing phase that expands macros and allows you to see what the actual final result is.

That's about all the advice that have on this topic.  Please let me know if you need more info, or have more questions.

Regards,
David

Hi David,

Thanks for your answer and these informations.

Regarding the possibility of simplifying the coding, please to consider COBOLVUE-I-28, directive >>PERFORM to manage a loop, and COBOLVUE-I-284, directive >>PUNCH to create a line of source code.

I also opened other RFEs and Ideas about conditional compilation.

Regards.

Denis

       01               RTP.                                            AAADGRUP           05           RTP1          PIC X VALUE '1'.                  AAADGRUP       >>if maxNR > 1                                                   AAADGRUP           05           RTP2          PIC X VALUE '1'.                  AAADGRUP         >>if maxNR > 2                                                 AAADGRUP           05           RTP3          PIC X VALUE '1'.                  AAADGRUP           >>if maxNR > 3                                               AAADGRUP           05           RTP4          PIC X VALUE '1'.                  AAADGRUP             >>if maxNR > 4                                             AAADGRUP           05           RTP5          PIC X VALUE '1'.                  AAADGRUP               >>if maxNR > 5                                           AAADGRUP           05           RTP6          PIC X VALUE '1'.                  AAADGRUP                 >>if maxNR > 6                                         AAADGRUP           05           RTP7          PIC X VALUE '1'.                  AAADGRUP                   >>if maxNR > 7                                       AAADGRUP           05           RTP8          PIC X VALUE '1'.                  AAADGRUP                     >>if maxNR > 8                                     AAADGRUP           05           RTP9          PIC X VALUE '1'.                  AAADGRUP                     >>end-if                                           AAADGRUP                   >>end-if                                             AAADGRUP                 >>end-if                                               AAADGRUP               >>end-if                                                 AAADGRUP             >>end-if                                                   AAADGRUP           >>end-if                                                     AAADGRUP         >>end-if                                                       AAADGRUP       >>end-if                                                         AAADGRUP​

Hi

(sorry for my bad english)
I did a dissertation on conditional compilation (2002 standard) in cobol.
It can provide variability, security, allow a certain emulation of OO  while remaining "good old cobol"  (which will therefore not frighten the "old cobolists")

If you understand French and would like to read it, I will gladly send it to you

Regards,
Joel

Hi Joel,

I will certainly not criticize your mastery of English, being French myself and using Google translate before any publication :-)

I will be happy to discuss with you the implementation of conditional compilation in COBOL, and I can illustrate with what we have implemented on this subject.

I will send you my professional email address by private message.

Thanks for your proposition.