! An example of overloading subroutines.
! by James Van Buskirk as posted at comp.lang.fortran on 24 September
! 2007.
! This says to me that the code as given was nonconforming because the
! name FOO was used to identify the module procedure SUBROUTINE FOO
! from MODULE M1 as well as the module procedure SUBROUTINE FOO from
! MODULE M2.  The case of generic names says to me that any number of
! generic identifiers may have the same name as one module procedure
! provided any possible generic procedure reference is unambiguous
! (section 14.1.2.3).

MODULE M1
   INTERFACE FOO1
     MODULE PROCEDURE joe
   END INTERFACE

   INTERFACE FOO2
     MODULE PROCEDURE sue
   END INTERFACE
CONTAINS
   SUBROUTINE joe(I,I2,extra)
     integer extra
     INTEGER, INTENT(IN) :: I, I2
     WRITE(*,*) 'Joe INTEGER'
   END SUBROUTINE joe

   SUBROUTINE sue(I,I2,extra,onemore)
     integer extra, onemore
     INTEGER, INTENT(IN) :: I, I2
     WRITE(*,*) 'Sue INTEGER'
   END SUBROUTINE sue
END MODULE M1

MODULE M2
   INTERFACE FOO1
     MODULE PROCEDURE joe
   END INTERFACE

   INTERFACE FOO2
     MODULE PROCEDURE sue
   END INTERFACE
CONTAINS
   SUBROUTINE joe(R,R2,extra)
     integer extra
     REAL, INTENT(IN) :: R,R2
     WRITE(*,*) 'Joe REAL'
   END SUBROUTINE joe

   SUBROUTINE sue(R,R2,extra,onemore)
     integer extra, onemore
     REAL, INTENT(IN) :: R,R2
     WRITE(*,*) 'Sue REAL'
   END SUBROUTINE sue
END MODULE M2

MODULE M3
   INTERFACE FOO1
     MODULE PROCEDURE joe
   END INTERFACE

   INTERFACE FOO2
     MODULE PROCEDURE sue
   END INTERFACE
CONTAINS
   SUBROUTINE joe(D,D2,extra)
     integer extra
     DOUBLE PRECISION, INTENT(IN) :: D,D2
     WRITE(*,*) 'Joe DOUBLE'
   END SUBROUTINE joe

   SUBROUTINE sue(D,D2,extra,onemore)
     integer extra, onemore
     DOUBLE PRECISION, INTENT(IN) :: D,D2
     WRITE(*,*) 'Sue DOUBLE'
   END SUBROUTINE sue
END MODULE M3

PROGRAM P
! In PROGRAM P, there are three class 2 entities with the names 'joe',
! and sue; 'joe' and 'sue' are not generic names.
   USE M1
   USE M2
   USE M3
   CALL FOO1(10,9,1)
   CALL FOO1(10.,9.,1)
   CALL FOO1(10.0D0,9.0D0,1)

   CALL FOO2(10,9,2,3)
   CALL FOO2(10.,9.,2,3)
   CALL FOO2(10.0D0,9.0D0,2,3)

END PROGRAM P