XL Fortran Enterprise Edition for AIX : User's Guide - IBM

-qsave Option
Syntax
-qsave[={all|defaultinit}] | -qnosave
SAVE[({all|defaultinit})] NOSAVE
This specifies the default storage class for local variables.
If -qsave=all is specified, the default storage class is STATIC; if -qnosave is
specified, the default storage class is AUTOMATIC; if -qsave=defaultinit is
specified, the default storage class is STATIC for variables of derived type that
have default initialization specified, and AUTOMATIC otherwise. The default
suboption for the -qsave option is all. The two suboptions are mutually exclusive.
The default for this option depends on the invocation used. For example, you may
need to specify -qsave to duplicate the behavior of FORTRAN 77 programs. The
xlf, xlf_r, xlf_r7, f77, and fort77 commands have -qsave listed as a default option
in /etc/xlf.cfg to preserve the previous behavior.
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
The -qnosave option is usually necessary for multi-threaded applications and
subprograms that are compiled with the “-qrecur Option” on page 224.
See Storage Classes for Variables in the XL Fortran Enterprise Edition for AIX Language
Reference for information on how this option affects the storage class of variables.
228 XL Fortran Enterprise Edition for AIX : User’s Guide