[Bug fortran/43696] [OOP] Bogus error: Passed-object dummy argument must not be POINTER

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

------- Comment #3 from burnus at gcc dot gnu dot org  2010-04-09 08:42 -------
(In reply to comment #0)
> Error: Passed-object dummy argument of 'error_read_formatted' at (1) must not
> be POINTER

The error message itself is OK as the constraint is (F2008 FDIS):

"C456 The passed-object dummy argument shall be a scalar, nonpointer,
nonallocatable dummy data object with the same declared type as the type being
defined; all of its length type parameters shall be assumed; it shall be
polymorphic (4.3.1.3) if and only if the type being defined is extensible
(4.5.7). It shall not have the VALUE attribute."

However, if one looks at the object:
  type,extends(serializable_class)::error_type
    [...]
  contains
    procedure :: read_formatted => error_read_formatted
[...]
  recursive subroutine
error_read_formatted(dtv,unit,iotype,v_list,iostat,iomsg)
    CLASS(error_type),INTENT(INOUT) :: dtv

The constraint seems to be fulfilled:
 "dtv" is a scalar, nonpointer, nonallocatable dummy. It does not have any
length type parameters and it is not VALUE. And its type (well, class) is
"error_type" as the type in which is it used - and CLASS is allows because
"error_type" is extensible.

The check itself in resolve.c also looks OK:
  me_arg->ts.u.derived->components->attr.class_pointer
but it seems as if either the first component is checked (which would be is
wrong) or as if the wrong type is used. One has:

  type,extends(serializable_class)::error_type
     class(error_type),pointer::next=>null()

The component is polymorphic and of the same type and it is a POINTER; I assume
that is the cause of the trouble.


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http://gcc.gnu.org/bugzilla/show_bug.cgi?id=43696