Using Fortran 90 syntax

Fortran 90 and up provide the appropriate syntax to specify a procedure interface. You create a module and define an interface block. In this interface block you create one or more interface bodies to define the interfaces of procedures. Each interface body should consist of the appropriate procedure statement (FUNCTION or SUBROUTINE) with the dummy argument list, a type specification statement for the result in case of a FUNCTION procedure and a type specification for each of the dummy arguments. If an argument is an input argument, supply the INTENT(IN) attribute, if it is an output argument supply the INTENT(OUT) attribute, and if it is an input/output argument supply the INTENT(INOUT) attribute, which is the default. For optional arguments specify the OPTIONAL attribute. Conclude the interface body with an END FUNCTION or END SUBROUTINE statement. For example:

MODULE PLOTLIB
   INTERFACE
     FUNCTION MYFUN(ARG1, ARG2)
       REAL MYFUN
       REAL, INTENT(IN) :: ARG1
       REAL, INTENT(IN), OPTIONAL :: ARG2
     END FUNCTION MYFUN
   END INTERFACE
END MODULE PLOTLIB

Include this module in the Coverity Fortran Syntax Analysis analysis by specifying it as an input source file or place it in a Coverity Fortran Syntax Analysis library file.

When using Fortran 90 or up you include the procedure interface in the program-unit analysis by referring the module which defines the interface. You do this with the USE statement, for example:

USE PLOTLIB

Even if you are still restricted to use FORTRAN 77, you can apply the Fortran 90 way for the Coverity Fortran Syntax Analysis analysis! Just enable Fortran 90 or up syntax in the Coverity Fortran Syntax Analysis configuration file to analyze the interface modules and enable extension 217, modules, for the analysis of the other program units. Place the USE statement in an INCLUDE file which you conditionally use for the Coverity Fortran Syntax Analysis analysis. For compilation you replace this INCLUDE file by one with an EXTERNAL statement specifying the procedure.

You can use the supplied utility interf to generate a module with interface bodies from a Coverity Fortran Syntax Analysis library file. See the Operation chapter.