CRE Programmer's Guide

Compiling and Binding Programs for the TNS CRE
Common Run-Time Environment (CRE) Programmer’s Guide—528146-004
3-2
Specifying a Run-Time Environment
All language features are available to routines that run in user code space. The ENV
directive restricts the availability of certain language features to enable routines to run
in user library and system library code spaces. Table 3-2
on page 3-2 shows the
availability of language features, depending on the specified ENV option:
Use the ENV directive options as follows:
Table 3-1. ENV Options and the Availability of Run-Time Libraries
ENV Option Available Run-Time Library
COMMON CRE library
OLD A COBOL and FORTRAN run-time library
LIBRARY CRE library
NEUTRAL None
EMBEDDED None
LIBSPACE None
Table 3-2. ENV Options and the Availability of Language Features
Language Feature
OLD COMMON LIBRARY NEUTRAL EMBEDDED LIBSPACE
High-level language
I/O operations
Yes Yes Yes* No No No
User heap operations Yes Yes Yes No No No
Main routine Yes Yes No Yes** No No
Relocatable data
blocks
Yes Yes No Yes Yes No
* LIBRARY permits the use of high-level language I/O facilities if direct access to relocatable data blocks is not
needed for the operations.
** NEUTRAL cannot be used for a main routine if the program uses run-time library resources.
Table 3-3. Determining Which ENV Options to Use (page 1 of 2)
ENV Option Use for
COMMON C, COBOL, and FORTRAN user code routines that run in the CRE
TAL main routines that run in the CRE
LIBRARY C or COBOL user library routines that run in the CRE