[Bug fortran/49802] [F2008] Handle VALUE with arrays (DIMENSION)

["burnus at gcc dot gnu.org" <gcc-bugzilla at gcc dot gnu dot org>]

http://gcc.gnu.org/bugzilla/show_bug.cgi?id=49802

--- Comment #2 from Tobias Burnus <burnus at gcc dot gnu.org> 2011-07-21 09:55:16 UTC ---
Created attachment 24803
  --> http://gcc.gnu.org/bugzilla/attachment.cgi?id=24803
Patch for the resolver/parse part - not for the actual implementation

Implementation strategy:

* For scalar types, continue to pass by value (for optimization purpose)

* For strings, arrays, and complicated DT: Copy the data and pass by reference.

* For VALUE + OPTIONAL - also for scalars: copy and pass by reference

Note: For generating a copy one needs - as already currently - do a deep copy
to capture also the allocatable components.

Example for alloc components with VALUE. The example fails (wrong result) with
NAG, ifort, gfortran and g95; pgi gets an ICE and crayftn states "The array
syntax statement is not conformable", which also looks bogus.

I believe that the test case is valid Fortran 2003.

implicit none
type t
  integer, allocatable :: A(:)
end type t

integer :: i
type(t) :: x

allocate(x%A(8))
x%A = [(i, i = 1, 8)]

call by_value(x)
print *, x%A

if (any (x%A /= [(i, i = 1, 8)])) call abort()

contains
  subroutine by_value(y)
    type(t), value :: y
    y%A = [(-10*i, i=1,9)]
    print *, y%A
  end subroutine
end