Intel® Fortran Compiler Classic and Intel® Fortran Compiler Developer Guide and Reference

ID 767251
Date 11/07/2023
Public

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STATIC

Statement and Attribute: Controls the storage allocation of variables in subprograms (as does AUTOMATIC). Variables declared as STATIC and allocated in memory reside in the static storage area, rather than in the stack storage area.

The STATIC attribute can be specified in a type declaration statement or a STATIC statement, and takes one of the following forms:

Type Declaration Statement:

type, [att-ls,] STATIC [, att-ls] :: v[, v] ...

Statement:

STATIC[::] v[, v] ...

type

Is a data type specifier.

att-ls

Is an optional list of attribute specifiers.

v

Is the name of a variable or an array specification. It can be of any type.

STATIC declarations only affect how data is allocated in storage.

If you want to retain definitions of variables upon reentry to subprograms, you must use the SAVE attribute.

By default, the compiler allocates local scalar variables of non-recursive subprograms in the static storage area. Local arrays, except for allocatable arrays, are in the static storage area by default.

The compiler may choose to allocate a variable in temporary (stack or register) storage if it notices that the variable is always defined before use. Appropriate use of the SAVE attribute can prevent compiler warnings if a variable is used before it is defined.

To change the default for variables, specify them as AUTOMATIC or specify RECURSIVE in one of the following ways:

  • As a keyword in a FUNCTION or SUBROUTINE statement

  • As a compiler option

  • As an option in an OPTIONS statement

To override any compiler option that may affect variables, explicitly specify the variables as STATIC.

NOTE:

Variables that are data-initialized, and variables in COMMON and SAVE statements are always static. This is regardless of whether a compiler option specifies recursion.

A variable cannot be specified as STATIC more than once in the same scoping unit.

If the variable is a pointer, STATIC applies only to the pointer itself, not to any associated target.

Some variables cannot be specified as STATIC. The following table shows these restrictions:

Variable

STATIC

Dummy argument

No

Automatic object

No

Common block item

Yes

Use-associated item

No

Function result

No

Component of a derived type

No

A variable can be specified with both the STATIC and SAVE attributes.

If a variable is in a module's outer scope, it can be specified as STATIC.

Example

The following example shows a type declaration statement specifying the STATIC attribute:

INTEGER, STATIC :: ARRAY_A

The following example shows a STATIC statement:


...
CONTAINS
 INTEGER FUNCTION REDO_FUNC
   INTEGER I, J(10), K
   REAL C, D, E(30)
   AUTOMATIC I, J, K(20)
   STATIC C, D, E
   ...
 END FUNCTION
...
 INTEGER N1, N2
 N1 = -1
 DO WHILE (N1)
   N2 = N1*2
   call sub1(N1, N2)
   read *, N1
 END DO
 CONTAINS
 SUBROUTINE sub1 (iold, inew)
 INTEGER, intent(INOUT):: iold
 integer, STATIC ::N3
 integer, intent(IN) :: inew
 if (iold .eq. -1) then
   N3 = iold
 end if
 print *, 'New: ', inew, 'N3: ',N3
 END subroutine
 !
 END