DECLARE TARGET

extended-list

Is a list of one or more variables, functions, subroutines, or common blocks. If you specify more than one extended-list item, they must be separated by commas. A common block name must appear between slashes (/ /); you cannot specify a blank common block. The specified extended-list items can be used inside a target region that executes on the device.

If the extended-list item is a function or subroutine, it must not be a generic name, procedure pointer, or entry name. A device-specific version of the routine is created that can be called from a target region.

If the extended-list item is a variable:

• It is mapped to a corresponding variable in the device data environment. If the variable is initialized, the corresponding variable in the device data environment is initialized with the same value.

• It can only appear in the scope in which it is declared.

• It must be declared in the Fortran scope of a module, or it must have the SAVE attribute (explicitly or implicitly).

You cannot specify the following variables in the DECLARE TARGET directive:

• A THREADPRIVATE variable

• A variable that is part of another variable (for example, an element in an array or a field of a structure)

• A variable that is an element of a common block

• A variable that appears in an EQUIVALENCE statement

If the extended-list item is a common block:

• It must be declared to be a common block in the same scoping unit in which the DECLARE TARGET directive appears.

• If the DECLARE TARGET directive specifying the common block name appears in one program unit, a DECLARE TARGET directive must also appear in every other program unit that contains a COMMON statement specifying the same common block name. The directive must appear after the last relevant COMMON statement in the program unit.

clause

Is one of the following:

• TO (extended-list)

  Is a comma-separated collection of one or more list items or procedures.

  If a list item is a routine then a device-specific version of the routine is created that can be called from a target region.

  If a list item is a variable then the original variable is mapped to a corresponding variable in the device data environment as if it had appeared in a MAP clause with the map-type TO on the implicit TARGET DATA construct for each device.

  The list item is never removed from those device data environments.

• LINK (list)

  The list items of a LINK clause are not mapped by the DECLARE TARGET directive. Instead, their mapping occurs only when they are mapped by TARGET DATA or TARGET constructs.