COBOL for OS/390 & VM

Expanding the possibilities
New and enhanced compiler options simplify common programming tasks, expand capabilities, and improve the performance of your COBOL applications. Using the new compiler option, ARITH, support for decimal data is enhanced, raising the maximum precision from 18 to 31 digits and providing an extended-precision mode for intermediate result calculations in arithmetic statements.

The TRUNC(BIN) compiler option was redesigned to help improve the performance of operations on binary data that require binary truncation rather than the standard COBOL truncation at base-10 picture descriptions. The performance benefit applies primarily to halfword and fullword binary data and to COBOL applications running on CMOS processors.

Data items declared with the new USAGE COMP-5 data type are represented in storage as binary data and can contain values of magnitude up to the capacity of the native binary representation (2, 4, or 8 bytes). With USAGE COMP-5, data values are no longer limited to the value implied by the number of 9s in the picture for the item. These enhancements help your COBOL applications to exploit the open, network-computing environment, making COBOL a more powerful application development tool.

Enhanced debugging
Production debugging capability is now available in the MVS/TSO, OS/390 UNIX, and CICS® environments. Debug Tool, a robust mainframe interactive (MFI)interlanguage tool, supports COBOL, PL/I, and C/C++. When you use Debug Tool and the remote interface, debugging COBOL applications that run in the OS/390 UNIX environment is much easier. Also, you can improve performance by enabling COBOL programs to use overlay hooks rather than compiled-in hooks. By choosing to generate the COBOL symbolic debugging information in a file separate from the object module, you can avoid large memory requirements for load modules in production.

DB2 coprocessor integration
COBOL programs that contain SQL statements no longer require precompilation with the DB2 precompiler. The COBOL compiler can now handle both native COBOL and embedded SQL statements in the source program. When the compiler encounters SQL statements, it inter- faces with the DB2 coprocessor. The DB2 coprocessor takes appropriate action and returns to the compiler any native language statements that must be generated. The coprocessor helps improve usability, particularly interactive debugging with Debug Tool because the application can be debugged at the original source level, instead of at the level of the expanded source produced by the DB2 precompiler. Additional enhancements include allowing SQL statements to be used in COPY books and removing the restriction that REPLACE statements have no effect on SQL statements.

OS/390 UNIX System Services support
COBOL for OS/390 & VM now supports application development and execution in the OS/390 UNIX System Services environment, enabling your development process to be more productive. COBOL programs running under OS/390 UNIX can access both HFS files and MVS data sets. HFS support during development is provided for COBOL source files, COPY books, object modules, listings, IDL files, ADATA files, and executable modules. HFS files can be used in COPY and BASIS statements. The cob2 command compiles and links COBOL programs within the OS/390 UNIX shell.

You can run an OS/390 UNIX COBOL application in the following OS/390 UNIX execution environments: OS/390 shell, OS/390 ISPF shell, TSO/E, and OS/390 batch. COBOL programs can call the standard UNIX/Posix functions, which are shipped as part of the OS/390 Language Environment® component. The DISPLAY statement is enhanced to optionally route the DISPLAY output to the HFS, stdout, or stderr. The format-1 ACCEPT statement is enhanced to optionally obtain input from the HFS or stdin.

Improved application development productivity
IBM COBOL for OS/390 & VM provides a set of intrinsic functions including string handling, financial capabilities, statistical functions, and mathematical formulas. You can use the COBOL CALL statement to take advantage of Language Environment services for everything from storage management to condition handling. The condition-handling support enables you to write programs in which error handling is done in a separate routine that is loaded only when needed. You no longer have to write the error-handling routines in Assembler; Language Environment allows you to write them in COBOL.

IBM COBOL for OS/390 & VM offers support for recursive calls in COBOL, structured programming, improved interoperability with other languages, and dynamic link library support. The IBM COBOL for OS/390 & VM run-time library, Language Environment, also supports PL/I, C/C++, or FORTRAN programs.