m2-typeprint.c:m2_range's use of TYPE_DOMAIN_TYPE: Eh?

[Doug Evans <xdje42@gmail.com>]

Hi.

Does anyone know why m2_range uses TYPE_DOMAIN_TYPE here?

AFAICT, use of TYPE_DOMAIN_TYPE is wrong here.
It is only used for TYPE_CODE_{MEMBERPTR,METHODPTR,METHOD}.

ref: gdbtypes.h:

  /* * For types with virtual functions (TYPE_CODE_STRUCT),
     VPTR_BASETYPE is the base class which defined the virtual
     function table pointer.

     For types that are pointer to member types (TYPE_CODE_METHODPTR,
     TYPE_CODE_MEMBERPTR), VPTR_BASETYPE is the type that this pointer
     is a member of.

     For method types (TYPE_CODE_METHOD), VPTR_BASETYPE is the aggregate
     type that contains the method.

     Unused otherwise.  */

  struct type *vptr_basetype;

I ask because one symbol table improvement I want to make
may be best implemented if I add a new field to struct main_type.
However, this struct is space-critical, so I'm trying to find
some cleanup that can be done.
Question: Why doesn't vptr_fieldno, vptr_basetype live in
type_specific.cplus_specific?

Alas, vptr_basetype is overloaded and is used also for TYPE_DOMAIN_TYPE:

#define TYPE_DOMAIN_TYPE(thistype) TYPE_MAIN_TYPE(thistype)->vptr_basetype

hence wondering why in the world m2_range is using it. :-)

For TYPE_CODE_{MEMBERPTR,METHODPTR,METHOD},
any reason why their "domain type" (I'll want to rename that)
cannot live in type_specific?

---

void
m2_range (struct type *type, struct ui_file *stream, int show,
	  int level, const struct type_print_options *flags)
{
  if (TYPE_HIGH_BOUND (type) == TYPE_LOW_BOUND (type))
    m2_print_type (TYPE_DOMAIN_TYPE (type), "", stream, show, level,
		   flags);
  else
    {
      struct type *target = TYPE_TARGET_TYPE (type);

      fprintf_filtered (stream, "[");
      print_type_scalar (target, TYPE_LOW_BOUND (type), stream);
      fprintf_filtered (stream, "..");
      print_type_scalar (target, TYPE_HIGH_BOUND (type), stream);
      fprintf_filtered (stream, "]");
    }
}