Upgrade COBOL compiler to 6.x in mixed Gen version HE environment

Products

• Gen
• Gen - Host Encyclopedia

Issue/Introduction

There is a requirement to start using COBOL 6.3 with Gen Host Encyclopedia (HE) instances.
However, the JCL generated by the product for compiles does not have all the DDs or the COBOL 6.3 options required.
We can set some libraries and such for COBOL 6.3 but the JCL and options are still generated for COBOL 4.x and compiles in foreground are not possible.
Where are the JCL and options templates?  

Also, a Gen 8.6 Host Encyclopedia is used to build both 7.6 and 8.6 applications from the corresponding models in that HE using customized data sets and logon procs per application/environment. How can the compiler be changed to use COBOL 6.3 for 8.6 without impacting 7.6?

Environment

Release : 8.6

Resolution

1. Per the Gen™ 8.6 > Technical Requirements > Third-Party Software Version page and Gen Compatibility Matrix, Gen 8.6 supports up to and including COBOL version 6.4.

2. For Host Encyclopedia/Construction:
a. The relevant COBOL version settings are in member TIRHE of the TIUPARML data set.
Change TIRC2LIB to point to the COBOL 6.3 library name and change TIRC2VER to have the correct COBOL version which in this case would be V6R3M0. 
This knowledge article covers the details: Using Gen 8.x with COBOL V5 or COBOL V6 compiler
b. For the actual compiler options there is clist TICCMPL in data set CEHBCLS0. That clist was also updated in PTF LU01885 (September 2021). If Gen 8.6 was installed using the Service Update Level 2111 PAX file then it includes that PTF (Gen™ 8.6 > Release Notes > New Features).
Relevant knowledge article: Tailoring TICCMPL delivered in Gen 8.6 PTF LU01885

3. If the Gen 7.6/8.6 customized data sets already include the PARMLIB data set then changes can be made to the 8.6 version of TIRHE without impacting 7.6.
However, if that data set is not already part of the customized environments then it would be required to create 2 distinct PARMLIBs for each COBOL version and include each one in the appropriate logon proc. The member TIRHE in each PARMLIB would then need to have different content according to the required COBOL version to be used i.e. COBOL 4.x (for 7.6) and COBOL 6.3 (for 8.6).
Relevant doc. page: Gen™ 8.6 > Installing > Install Gen on z/OS > Configuring Host Encyclopedia and Host Construction > Establish an ISPF Library Concatenation
NOTE: It should not be required to create a customized data set CEHBCLS0 for TICCMPL because it just uses the TIRC2VER variable set in TIRHE to set the appropriate compiler options for each supported COBOL version.

Additional Information

NOTE: It is not possible to compile/build Gen 7.6 generated applications with COBOL 6.3 or indeed any COBOL version greater than COBOL 4.x.