Workaround for C_F_POINTER

Paul Thanks for providing me with a working example. It allowed me to create a reproducer for error 1251 at compile time using FTN95 v.9.10 x64. The reproducer compiles with ifort.

program main
  use iso_c_binding,only:c_ptr,c_f_pointer
  implicit none
  interface
    subroutine c_f_pointer_test$(q) bind(c,name='__c_f_pointer_test')
      import :: c_ptr
      type(c_ptr), intent(out) :: q
    end subroutine
  end interface
  type(c_ptr) :: cptr
  REAL :: X
  
  call c_f_pointer_test$(cptr)
  X=TEST(cptr)
  PRINT*, X
  
  CONTAINS
  
  REAL FUNCTION TEST(J)
  implicit none
  type(c_ptr), INTENT(IN) :: J
  real,pointer :: a(:)
  real,pointer :: b(:,:)
  real,pointer :: c
  real::ss1,ss2
  integer s(1)
  s = [12]
  call c_f_pointer(J, a, s)
  ss1 = sum(a)
  call c_f_pointer(J, b, [3,4])
  ss2 = sum(b)
  call c_f_pointer(J, c)
  if(ss1 == ss2 .and. c == 1.0) print*, 'Success'
  TEST=a(12)
  END FUNCTION TEST
  
end program main

jlb

Thank you for the bug report. I have logged this for investigation.

This failure has now been fixed for the next release of FTN95.

Paul

Thank you for your prompt assistance. Is this an interim release or a full release of FTN95?

It will probably be an interim release following the full release of the personal edition of FTN95 v9.10.

Paul

Compiling your working example with FTN95 version 9.11 fails now with the following error

error 463 - Invalid characters(s) after SUBROUTINE expression

pointing at

subroutine c_f_pointer_test$(p) bind(c,name='__c_f_pointer_test')

jlb

There is a regression at v9.11 regarding BIND(C...). I will aim to upload a fix shortly.

Hi all, I am reaching out to ask if there are any updates regarding support for C_F_POINTER and C_LOC in subroutines. Currently, I am unable to use these features within subroutines, although they seem to work fine in a program context, as shown below:

       program main
       use,intrinsic::iso_c_binding

      implicit none
      
	   interface
      subroutine c_f_pointer_test(p) 
     & bind(c,name='__c_f_pointer_test')
      import :: c_ptr
      type(c_ptr), intent(out) :: p
      end subroutine
      end interface
      
      type(c_ptr) :: cptr
      real,pointer :: a(:)
      real,pointer :: b(:,:)
      real,pointer :: c


      logical L(6)
      
      L(1) = .not.c_associated(cptr)

      call c_f_pointer_test(cptr)      ! Create cptr
      shp = 12
      
      call c_f_pointer(cptr, a, [12])  ! 'a' points to cptr.
      call c_f_pointer(cptr, b, [3,4]) ! 'b' has the same target as 'a' but different shape.
      call c_f_pointer(cptr, c)        ! 'c' is just the first element of the cptr array.
      L(3) = c_associated(cptr)
      L(4) = c_associated(cptr, c_loc(a))
      L(5) = c_associated(cptr, c_loc(b))
      L(6) = c_associated(cptr, c_loc(c))

      if(all(L)) print*, 'Success'
      end program main 

I am currently working with version 9.10. Is there a planned release that will extend support for these features in subroutines?