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

Gaius Mulley
2015-01-20T22:25:17Z

Doug Evans <xdje42@gmail.com> writes:

> 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. :-)

Hi Doug,

feel free to clean up the code and make it comply with other languages.
I've a feeling that this code will need an overhaul against gm2-1.1.1
(grafted on gcc-4.7.4). The gcc/gm2 interface has pretty much all
been rewritten since gm2-1.0 (which was grafted onto gcc-4.1.2).

> 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, "]");
> }
> }

regards,
Gaius