[Bug fortran/37937] New: Bind(C) diagnostic when using c_double for COMPLEX variables

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

REAL(c_double)     matches "double" and is OK. However,
COMPLEX(c_double)  is invalid as the proper kind parameter
                   is c_double_complex matching "double _Complex"

Internally, both yield the same value and also sizeof(0.0_c_double) and
sizeof(real(cmplx(0.0, c_double_cmpl)) is the same. Thus one could simply
accept c_double as synonym for c_double_complex.

gfortran, however, has checks build in which ensure the right KIND is used;
there is room for improvement however:

! ------------------------------
use iso_c_binding
implicit none
real(c_double) :: r
complex(c_double) :: c ! << Wrong
type(c_ptr) :: ptr
ptr = c_loc(c) ! <<< ERROR here
end
! ------------------------------

Error: C kind parameter is for type REAL but symbol 'c' at (1) is of type
COMPLEX


Expected: The error is printed in the "COMPLEX(c_double)" line and not in the
"c_loc" line. The other question is whether a WARNING is enough or whether one
wants to have an ERROR.


PS: Found at
http://www.lrz-muenchen.de/services/software/mathematik/gsl/fortran/README
"    - gfortran 4.3.x does not support complex(c_double)."


-- 
           Summary: Bind(C) diagnostic when using c_double for COMPLEX
                    variables
           Product: gcc
           Version: 4.4.0
            Status: UNCONFIRMED
          Keywords: diagnostic
          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=37937