Intel® Fortran Compiler 16.0 User and Reference Guide

ATTRIBUTES

General Compiler Directive: Declares properties for specified variables.

!DIR$ ATTRIBUTES att[,att]...:: object[,object]...

att

Is one of the following options (or properties):

object

Is the name of a data object or procedure.

The following table shows which ATTRIBUTES options can be used with various objects:

Option

Variable and Array Declarations

Common Block Names 1

Subprogram Specification and EXTERNAL Statements

ALIAS

No

Yes

Yes

ALIGN

Yes

No

No

ALLOCATABLE

Yes2

No

No

ALLOW_NULL

Yes

No

No

ARRAY_VISUALIZER

Yes2

No

No

C

No

Yes

Yes

CONCURRENCY_SAFE

No

No

Yes

CVF

No

Yes

Yes

DECORATE

No

No

Yes

DEFAULT

No

Yes

Yes

DLLEXPORT

Yes3

Yes

Yes

DLLIMPORT

Yes

Yes

Yes

EXTERN

Yes

No

No

FASTMEM

Yes

No

No

FORCEINLINE

No

No

Yes

IGNORE_LOC

Yes4

No

No

INLINE

No

No

Yes

MIXED_STR_LEN_ARG

No

No

Yes

NO_ARG_CHECK

Yes

No

Yes5

NOCLONE

No

No

Yes

NOINLINE

No

No

Yes

OFFLOAD

Yes

No

Yes

OPTIMIZATION_PARAMETER

No

No

Yes5, 6

REFERENCE

Yes

No

Yes

STDCALL

No

Yes

Yes

VALUE

Yes

No

No

VARYING

No

No

Yes

VECTOR

No

No

Yes5

1A common block name is specified as [/]common-block-name[/]

2This option can only be applied to arrays.

3Module-level variables and arrays only.

4This option can only be applied to INTERFACE blocks.

5This option cannot be applied to EXTERNAL statements.

6This option can be applied to named main programs.

These options can be used in function and subroutine definitions, in type declarations, and with the INTERFACE and ENTRY statements.

Options applied to entities available through use or host association are in effect during the association. For example, consider the following:

MODULE MOD1
  INTERFACE
    SUBROUTINE NEW_SUB
    !DIR$ ATTRIBUTES C, ALIAS:'othername' :: NEW_SUB
    END SUBROUTINE
  END INTERFACE
  CONTAINS
    SUBROUTINE SUB2
    CALL NEW_SUB
    END SUBROUTINE
END MODULE

In this case, the call to NEW_SUB within SUB2 uses the C and ALIAS options specified in the interface block.

Options C, STDCALL, REFERENCE, VALUE, and VARYING affect the calling conventions of routines:

Examples

INTERFACE
   SUBROUTINE For_Sub (I)
     !DIR$ ATTRIBUTES C, ALIAS:'_For_Sub' :: For_Sub
     INTEGER I
   END SUBROUTINE For_Sub
END INTERFACE

You can assign more than one option to multiple variables with the same compiler directive. All assigned options apply to all specified variables. For example:

 !DIR$ ATTRIBUTES REFERENCE, VARYING, C :: A, B, C 

In this case, the variables A, B, and C are assigned the REFERENCE, VARYING, and C options. The only restriction on the number of options and variables is that the entire compiler directive must fit on one line.

The identifier of the variable or procedure that is assigned one or more options must be a simple name. It cannot include initialization or array dimensions. For example, the following is not allowed:

 !DIR$ ATTRIBUTES C :: A(10)  ! This is illegal.  

The following shows another example:

SUBROUTINE ARRAYTEST(arr)
!DIR$ ATTRIBUTES DLLEXPORT :: ARRAYTEST
   REAL(4) arr(3, 7)
   INTEGER i, j
   DO i = 1, 3
     DO j = 1, 7
       arr (i, j) = 11.0 * i + j
     END DO
   END DO
END SUBROUTINE

See Also