2008/9/12 Andy Wingo <[EMAIL PROTECTED]>:
> On Thu 11 Sep 2008 23:06, "Neil Jerram" <[EMAIL PROTECTED]> 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
