http://groups.google.com/group/comp.lang.fortran/browse_thread/thread/c1d51d45d8779b90

Internal Compiler Error: in gfc_conv_string_parameter, at fortran/trans-expr.c:4009

--C program ----------------------
char cdir(void){return '/';}

--Fortran program ----------------
MODULE mod
  INTERFACE
    FUNCTION cdir() BIND(C,name="cdir") RESULT(r)
      USE iso_c_binding
      CHARACTER(kind=C_CHAR) :: r
    END FUNCTION
  END INTERFACE
END MODULE

PROGRAM test
  USE mod
  WRITE(*,*) cdir()
  WRITE(*,*) ICHAR(cdir())
END PROGRAM