Welcome to IBM COBOL for OS/390 & VM, IBM's latest host COBOL compiler!
This version of IBM COBOL for OS/390 & VM is fully source and object compatible with COBOL for MVS & VM Version 1, with the exception of programs containing object-oriented language constructs, which must be recompiled to enable support for OS/390 SOMobjects(TM), as described below.
This version of IBM COBOL for OS/390 & VM is fully source and object compatible with COBOL for MVS & VM Version 1, with the exception of programs containing object-oriented language constructs, which must be recompiled to enable support for OS/390 SOMobjects(TM), as described below.
The following is a brief outline of the differences from the COBOL for MVS & VM product:
- Support has been added for Dynamic Link Libraries (DLLs). A DLL is a load module containing programs and data which can be accessed from other load modules. The DLL mechanism is the primary means used for packaging SOM class libraries. With this new support, object-oriented COBOL applications may be packaged using separate DLL load modules for the client programs and class definitions. Two new compiler options, DLLNODLL and EXPORTALLNOEXPORTALL, are used to control the creation of DLLs. For details, see Chapter 20, "Building and Using Dynamic Link Libraries (DLLs)" in topic 4.2.
- Due to changes in the SOMobjects product that are delivered with OS/390® Release 3, changes in the JCL for building object-oriented COBOL applications are required:
- The SOMobjects kernel and the SOMobjects class libraries must be accessed from the SOMobjects product DLLs, rather than being linked together with the COBOL application load module, as was required in the prior version. This requires changes to the JCL to specify appropriate COBOL compiler options for DLL support, the prelink step must specify (at least) the DLL definition side-decks for the SOM kernel and class libraries, and the SOM SGOSPLKD data set is no longer used in the SYSLIB concatenation of the prelink step.
- The format of the SOM profile data set has changed, and the profile is now specified via the SOMENV DD statement rather than the SOMPROF DD.
For further details, see the OS/390 SOMobjects Programmer's Guide, and Chapter 16, "Using System Object Model (SOM)" in topic 3.2.
The INTDATE compiler option is no longer an installation option only--it can now be specified as an option when invoking the compiler.