Compiler migration

Compiler migration is not required for most programs and can occur after you have moved your OS/VS COBOL or VS COBOL II programs to run with Language Environment®. Compiler migration is required for OS/VS COBOL programs and VS COBOL II programs compiled with NORES.

Source code changes are not required for most programs when recompiling with Enterprise COBOL 5 or 6. Although we recommend recompiling all programs in each application as you migrate to Enterprise COBOL 5 or 6, it is not required. Source code changes will be required for programs that were compiled with OS/VS COBOL or were compiled with a later compiler using the old CMPR2 compiler option.

Compiler migration and recompilation is required for OS/VS COBOL programs and VS COBOL II NORES programs if they are to be called by (or need to call) Enterprise COBOL 5 or 6 programs. Enterprise COBOL 5 and 6 programs can dynamically call (and be dynamically called by) VS COBOL II RES programs.

Compiler migration usually consists of upgrading the source language level that is used (such as from 74 Standard COBOL supported by OS/VS COBOL to 85 Standard COBOL supported by Enterprise COBOL). Compiler migration is also required in a few instances to enable your applications to run under Language Environment.

Many conversion tools exist to aid in upgrading your source code. For details, see Conversion tools for source programs.