blob: 31776da698564ffc2aec956ea97aad2d08cc2974 [file] [log] [blame]
!! Illustrates a bug in IBM XL Fortran for AIX, V12.1 (5724-U82)
!! The function "identity" is an internal function which
!! is passed as a parameter to the "map" routine. However, when it is invoked as a callback,
!! the string it receives as its first parameter is not the string that was actually passed
!! as the first parameter by the invoking function.
!! Jeff Overbey (1/29/09)
module string_module
implicit none
type, public :: string
procedure :: map
procedure :: copy
end type string
! Applies function to each of the strings 'H', 'e', 'l', 'l', 'o'
subroutine map(self, function)
class(string), intent(in) :: self
character(len=1) function function(string)
character(len=1), intent(in) :: string
end function
end interface
character, dimension(5) :: hello = (/ 'H', 'e', 'l', 'l', 'o' /)
integer :: i
do i = 1, 5
print *, "Invoking callback with parameter ", hello(i)
hello(i) = function(hello(i))
end do
end subroutine
! Invokes map with the identity function (defined below)
subroutine copy(self)
class(string), intent(in) :: self
call self%map(identity)
!!!!! Error is demonstrated when this (internal) function is
!!!!! passed as an argument to the map procedure: The "ch"
!!!!! argument is a garbage string, not the one actually
!!!!! passed by map
character(len=1) function identity(ch) result(return)
character(len=1), intent(in) :: ch
print *, "Callback invoked with parameter ", ch
return = ch
end function
end subroutine
end module string_module
program string_test
use string_module
type(string) :: s
call s%copy()
end program string_test