[Bug fortran/31668] New: %VAL rejected for PROC_MODULE and PROC_INTERNAL procedures

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

Reported by Arjan van Dijk,
http://gcc.gnu.org/ml/fortran/2007-04/msg00367.html

gfortran rejects the following code with the error:
  "By-value argument at (1) is not allowed in this context"

This is because the following check is matched: resolve.c,
resolve_actual_arglist():

              /* Intrinsics are still PROC_UNKNOWN here.  However,
                 since same file external procedures are not resolvable
                 in gfortran, it is a good deal easier to leave them to
                 intrinsic.c.  */
              if (ptype != PROC_UNKNOWN
                  && ptype != PROC_DUMMY
                  && ptype != PROC_EXTERNAL)

However, in this case: ptype == PROC_MODULE.

The following values are possible:
  PROC_UNKNOWN, PROC_MODULE, PROC_INTERNAL, PROC_DUMMY,
  PROC_INTRINSIC, PROC_ST_FUNCTION, PROC_EXTERNAL

I have to think about which cases make sense and which don't.
What speaks against allowing PROC_INTRINSIC, PROC_INTERNAL, PROC_ST_FUNCTION?
Is there one which needs always be rejected? If yes, a test case would be nice.

For PROC_INTERNAL I would argue it should be allowed:

   SUBROUTINE Grid2BMP(NX)
   INTEGER, INTENT(IN) :: NX
   call bmp_write(%val(nx))
   contains
       subroutine bmp_write(nx)
         integer, intent(in) :: nx
       end subroutine bmp_write
   END SUBROUTINE Grid2BMP
end

For statement functions, I agree it should be invalid (for %VAL, %REF, %DESCR):
   SUBROUTINE Grid2BMP(NX)
   INTEGER, INTENT(IN) :: NX
   integer :: i,f
   f(i)=i**2  ! statement function
   i = f(%VAL(i))
   END SUBROUTINE Grid2BMP
This agrees with ifort which also rejects it.

And for PROC_INTRINSIC: ifort rejects sin(%VAL(x)) as above (%VAL/%REF/%DESCR
invalid in this context), gfortran has the error:
"Argument list function at (1) is not allowed in this context".
(I prefer Intel's error message.)

At the moment, I don't see any intrinsic which would work with %VAL, but maybe
I miss something. Is there an example for PROC_INTRINSIC or PROC_UNKNOWN which
needs to be supported?

Example:
a) Longer example, see follow up email (URL above)
b) short example (works if one moves the interface into the procedure body):

module x
   interface
       subroutine bmp_write(nx)
         integer, intent(in) :: nx
       end subroutine bmp_write
   end interface
contains
   SUBROUTINE Grid2BMP(NX)
   INTEGER, INTENT(IN) :: NX
   call bmp_write(%val(nx))
   END SUBROUTINE Grid2BMP
END module
end


-- 
           Summary: %VAL rejected for PROC_MODULE and PROC_INTERNAL
                    procedures
           Product: gcc
           Version: 4.3.0
            Status: UNCONFIRMED
          Keywords: rejects-valid
          Severity: normal
          Priority: P3
         Component: fortran
        AssignedTo: unassigned at gcc dot gnu dot org
        ReportedBy: burnus at gcc dot gnu dot org


http://gcc.gnu.org/bugzilla/show_bug.cgi?id=31668