Re: Goops & Valgrind

["Neil Jerram" <neiljerram@googlemail.com>]

2009/1/4 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
>
> --
> http://wingolog.org/
>

Sorry, no.  I have the code change ready to go now; do you by any
chance have a convenient test for this?

       Neil