Re: Goops & Valgrind

[Andy Wingo <wingo@pobox.com>]

Hi,

Sorry for the spam, but I'm going through some backlog that I didn't
have the resources to deal with. Has this issue been addressed?

Andy

On Sun 14 Sep 2008 14:06, "Neil Jerram" <neiljerram@googlemail.com> writes:

> 2008/9/12 Andy Wingo <wingo@pobox.com>:
>> On Thu 11 Sep 2008 23:06, "Neil Jerram" <neiljerram@googlemail.com> writes:
>>
>>> Are you sure?  Surely that would require a call somewhere to
>>> scm_alloc_struct() with n_extra = 0, and I can't see any of those.
>>
>> I'm sure -- goops.c:1541 in master. Doesn't go through scm_alloc_struct
>> at all.
>
> Thanks, I see now.
>
>>> Also, is Mikael right with his error #1?  I'm thinking not, because I
>>> believe that instances are structs too, so surely it's OK to call
>>> SCM_STRUCT_DATA (x)[...] on them?
>>
>> I can't recall the mail at the moment. Please reply if you want me to
>> dig through this -- I'm happy to do so. But instances are structs, yes.
>> Calling SCM_STRUCT_DATA (x)[] does work. You have to know how many
>> fields there are, though -- you get that from the vtable.
>
> Agreed.  So I think the right fix here is along the lines of your
> second suggestion:
>
>> #define SCM_NUMBER_OF_FIELDS(x) (SCM_STRUCT_VTABLE (x)[scm_si_nfields])
>
> I propose specifically that we:
>
> - remove the SCM_NUMBER_OF_SLOTS macro - because it's never been
> right, so there can't be external code relying on it
>
> - change scm_sys_fast_slot_ref and scm_sys_fast_slot_set_x to say
>
>   i = scm_to_unsigned_integer (index, 0, SCM_SLOT (SCM_CLASS_OF (obj),
> scm_si_nfields) - 1);
>
> OK?  (There are way too many goops/struct macros already, so let's not
> introduce another one!)
>
> One last concern, though: I didn't understand what you meant by "would
> probably have a different purpose".  (In:
>
>> assumption. The other would be to use a different definition of
>> SCM_NUMBER_OF SLOTS, which would probably have a different purpose:
>
> )
>
> Regards,
>      Neil

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