Changing the defaults for the VS FORTRAN runtime option

Module AFH5GPRM contains the set of runtime option defaults for running with the VS FORTRAN compatibility library. You can accept the IBM®-supplied defaults or you can supply your own defaults. To customize AFBVGPRM for your site, use the IBM-supplied job AFHWVPRM, and modify the VSF2PARM macro instruction in an SMP/E USERMOD.

Use the AFH5PARM macro to change the IBM-supplied default values for VS FORTRAN runtime options. The default values that you assign are assumed if you do not override them.

There are no operands to set the default values for the runtime options AUTOTASK, PARALLEL, and PARTRACE; therefore, these options cannot be changed during installation. However, they can be changed at runtime.

There are no operands in the VSF2PARM macro to set the default values for the runtime options ERRUNIT, RDRUNIT, PRTUNIT, and PUNUNIT. The default I/O unit values for these units can be changed during installation through the Unit Attribute Table.

The IBM-supplied default values are underlined in the following option list. If an option is not specified, its default will be used, with the exception of the SCOPE option, which must always be specified.

SCOPE = GLOBAL

Required to replace the global runtime options table AFBVGPRM, which supplies default values for all users of the VS FORTRAN compatibility library.

There is no default value for this option. SCOPE=GLOBAL must always be specified.

ABSDUMP | NOABSDUMP

Specifies whether the post-abend symbolic dump information is printed.

ABSDUMP

Causes the post-abend symbolic dump information to be printed if an abnormal termination occurs.

NOABSDUMP

Suppresses the printing of the post-abend symbolic dump information.

NOABSDUMP is the default.

CNVIOERR | NOCNVIOERR

Specifies whether input conversion errors will be treated as I/O errors.

CNVIOERR

Causes ERR and IOSTAT to recognize conversion errors as I/O errors.

NOCNVIOERR

Causes conversion errors not to be treated as I/O errors. ERR and IOSTAT have no effect for these errors.

NOCNVIOERR is the default.

DEBUG | NODEBUG

Specifies whether interactive debug will be invoked. NODEBUG is the default.

Note: This option does not apply to the Language Environment® VS FORTRAN compatibility library. If you want to use the VS FORTRAN Interactive Debugger, then run your program with the VS FORTRAN Version 2 library rather than with Language Environment.

DEBUNIT | NODEBUNIT

Specifies whether Fortran unit numbers will be treated as if connected to a terminal device. NODEBUNIT

Note: This option does not apply to the Language Environment VS FORTRAN compatibility library. If you want to use the VS FORTRAN Interactive Debugger, then run your program with the VS FORTRAN Version 2 library rather than with Language Environment.

ECPACK | NOECPACK

Specifies whether a data space should be filled with as many extended common blocks as possible before a new data space is allocated.

ECPACK

Specifies extended common blocks be placed into the fewest possible number of data spaces. This option reduces some of the overhead that is associated with referencing data spaces.

ECPACK is the default.

NOECPACK

Specifies that each extended common block be placed into a separate data space. As a result, reference errors made beyond the bounds of an extended common block might be more easily detected.

FAIL (ABEND | RC | ABENDRC)

Indicates how applications that fail are to be terminated: either by a nonzero return or by an abnormal termination (ABEND). The suboption of the FAIL option might have the following meanings.

ABEND

Causes the program to end by an abnormal termination (ABEND) with a user completion code of 240.

RC

Causes the program to end normally but with a nonzero return code (16).

ABENDRC

Causes the program to end by abnormal termination (ABEND) when failure is because of a condition for which the operating system would usually cause an ABEND; and to end with a nonzero return code when failure is by some condition detected by VS FORTRAN.

ABENDRC is the default.

FILEHIST | NOFILEHIST

Specifies whether to allow the file definition of a file referred to by a ddname to be changed at run time.

FILEHIST

Causes the history of a file to be used in determining its existence. In particular it checks to see whether:

• The file was ever internally opened (in which case it exists), or
• The file was deleted by a CLOSE statement (in which case it does not exist).

When FILEHIST is specified, you cannot change the file definition of a file at runtime and have the same results produced as previous VS FORTRAN releases.

FILEHIST is the default.

NOFILEHIST

Causes the history of a file to be disregarded in determining its existence.

If you specify NOFILEHIST you should consider:

• If you change file definitions at run time file is treated as if it was being opened for the first time. Before the file definition can be changed, the existing file must be closed.
• If you do not change file definitions at run time, you must use STATUS='NEW' to reopen an empty file that has been closed with STATUS='KEEP', because the file does not appear to exist to Fortran.

INQPCOPN | NOINQPCOPN

Specifies whether a unit is connected to a file when executing an INQUIRE by unit.

INQPCOPN

Specifies that, if a unit is connected to a file, even if it was preconnected and no I/O statement has been executed, a value of true is returned in the variable or an array element given in the OPENED specifier from an INQUIRE by unit statement.

INQPCOPN is the default.

NOINQPCOPN

Indicates that, if and only if a unit is internally open, a value of true is returned in the variable or an array element given in the OPENED specifier for an INQUIRE by unit statement.

Internally open means that the unit is connected to a file by an OPEN statement, or if the unit has been preconnected, that a READ, WRITE, PRINT, REWIND, or ENDFILE statement has been successfully executed.

IOINIT | NOIOINIT

Specifies whether the normal initialization for I/O processing will occur during initialization of the runtime environment.

IOINIT

Causes the normal initialization for I/O processing to occur during initialization of the runtime environment. IOINIT is the default.

NOIOINIT

Suppresses initialization for I/O processing. This means that the error message unit is not opened during initialization of the runtime environment. However, this does not prevent I/O from occurring on this or on any other unit. (Such I/O might fail if proper DD statements are not given.)

OCSTATUS | NOOCSTATUS

Specifies whether file existence is checked during the running of OPEN statements, whether files are deleted from their storage media, and whether files that were closed can be reconnected without an OPEN statement.

OCSTATUS

Specifies:

1. File existence is checked for consistency with the OPEN statement specifiers STATUS='OLD' and STATUS='NEW'.
2. File deletion occurs when the CLOSE statement specifier STATUS='DELETE' is given (on devices which allow deletion).
3. A preconnected file is disconnected when a CLOSE statement is given or when another file is opened on the same unit. It can be reconnected only by an OPEN statement when there is no other file currently connected to that unit.

OCSTATUS is the default.

NOOCSTATUS

Specifies:

1. File existence is not checked for consistency with the OPEN statement specifiers STATUS='OLD' and STATUS='NEW'.
2. File deletion does not occur when the CLOSE statement specifier STATUS='DELETE' is given.
3. A preconnected file is disconnected when a CLOSE statement is given or when another file is opened on the same unit. It can be reconnected by a sequential READ or WRITE, BACKSPACE, OPEN, REWIND, or ENDFILE statement when there is no other file that is currently connected to that unit.

RECPAD[(ALL)] | NORECPAD

Specifies whether a formatted input record is padded with blanks.

RECPAD

Causes a formatted input record within an internal file or a varying/undefined length record (RECFM=U or V) external file to be padded with blanks when an input list and format specification require more data from the record than the record contains. Blanks added for padding are interpreted as though the input record actually contains blanks in those fields. If ALL is specified, a formatted input record is padded regardless of the record format of the file.

NORECPAD

Specifies that an input list and format specification must not require more data from an input record than the record contains. If more data is required, condition FOR1002E is raised.

NORECPAD is the default.

SPIE | NOSPIE

Specifies whether the runtime environment takes control when a program interrupt occurs.

SPIE

Specifies that the runtime environment takes control when a program interrupt occurs. SPIE is the default.

NOSPIE

Specifies that the runtime environment does not take control when a program interrupt occurs. If you specify NOSPIE, various runtime functions that depend on a return of control after a program interrupt are not available. These include the following:

• The messages and corrective action for a floating-point overflow.
• The messages and corrective action for a floating-point underflow interrupt (unless the underflow is to be handled by the hardware based upon the XUFLOW option).
• The messages and corrective action for a floating-point or fixed-point divide exception.
• The simulation of extended precision floating-point operations on processors that do not have these instructions.
• The realignment of vector operands that are not on the required storage boundaries and the rerunning of the failed instruction.

Instead of the corrective action, abnormal termination results. In this case, the STAE or NOSTAE option that is in effect governs whether the VS FORTRAN runtime environment gains control at the time of the abend.

STAE | NOSTAE

Specifies whether the runtime environment takes control if an abnormal termination occurs.

STAE

Specifies that the runtime environment will take control when an abnormal termination occurs. STAE is the default.

NOSTAE

Specifies that the runtime environment does not take control when an abnormal termination occurs. If NOSTAE is specified, abnormal termination is handled by the operating system rather than by the VS FORTRAN runtime environment. In this case the following occurs:

• Message AFB240I, which shows the PSW and register contents at the time of the abend, is not printed. However, this information will be provided by the operating system.
• The indication of which Fortran statement caused the failure will not be printed.
• The traceback of the routines will not be printed.
• The post-abend symbolic dump will not be printed even with the option ABSDUMP in effect.
• Certain exceptional conditions handled by the runtime environment or by the debugging device cause system abends rather than VS FORTRAN messages. For example, some errors that occur during running of an OPEN statement result in a system abend rather than the printing of message AFB219I, which allows the program to possibly continue running.
• An MTF subtask that terminates unexpectedly causes a user ABEND 922 in the main task rather than message AFB922I.

XUFLOW | NOXUFLOW

Specifies whether an exponent underflow will cause a program interrupt.

XUFLOW

Allows an exponent underflow to cause a program interrupt, followed by a message from the VS FORTRAN Version 2 Library, followed by a standard fixup. XUFLOW is the default.

NOXUFLOW

Suppresses the program interrupt that is caused by an exponent underflow. The hardware sets the result to zero.