-qsave

Purpose

Specifies the default storage class for local variables.

Syntax


>>- -q--+-nosave-----------------------+-----------------------><
        '-save--+--------------------+-'   
                '-=--+-all---------+-'     
                     '-defaultinit-'

@PROCESS:

@PROCESS SAVE[({ALL | DEFAULTINIT})] | NOSAVE

Defaults

The default for this option depends on the invocation command used:

When xlf is used to compile the .f, .F, .f77, or .F77 files, the default is -qsave=all.
For the f77 and fort77 invocation commands, the default is -qsave=all.
For all the other invocation commands, the default is -qnosave.

Parameters

The -qsave suboptions include:

all: The default storage class is STATIC.
defaultinit: The default storage class is STATIC for variables of derived type that have default initialization specified, and AUTOMATIC otherwise.

The all and defaultinit suboptions are mutually exclusive.

Usage

The -qnosave option sets the default storage class to AUTOMATIC. This usage is usually necessary for multithreaded applications and subprograms that are compiled with the -qrecur option.

You can specify the -qsave option to duplicate the behavior of FORTRAN 77 programs. The xlf, f77 and fort77 commands have -qsave listed as a default option in the configuration file to preserve the previous behavior. The default configuration file path is /opt/IBM/xlf/15.1.0/etc/xlf.cfg.nn

Examples

The following example illustrates the impact of the -qsave option on derived data type:

        PROGRAM P
          CALL SUB
          CALL SUB
        END PROGRAM P

        SUBROUTINE SUB
          LOGICAL, SAVE :: FIRST_TIME = .TRUE.
          STRUCTURE /S/
            INTEGER I/17/
          END STRUCTURE
          RECORD /S/ LOCAL_STRUCT
          INTEGER LOCAL_VAR

          IF (FIRST_TIME) THEN
            LOCAL_STRUCT.I = 13
            LOCAL_VAR = 19
            FIRST_TIME = .FALSE.
          ELSE
            ! Prints " 13" if compiled with -qsave or -qsave=all
            ! Prints " 13" if compiled with -qsave=defaultinit
            ! Prints " 17" if compiled with -qnosave
            PRINT *, LOCAL_STRUCT
            ! Prints " 19" if compiled with -qsave or -qsave=all
            ! Value of LOCAL_VAR is undefined otherwise
            PRINT *, LOCAL_VAR
          END IF
        END SUBROUTINE SUB

Related information

-qrecur
See Storage classes for variables for information on how this option affects the storage class of variables.