On Mon, Oct 19, 2020 at 12:59:01AM +0100, Ramsay Jones wrote:
> On 17/10/2020 23:56, Luc Van Oostenryck wrote:
> > diff --git a/builtin.c b/builtin.c
> > index 880dd54f647e..5e490830e147 100644
> > --- a/builtin.c
> > +++ b/builtin.c
> > @@ -627,23 +627,23 @@ static const struct builtin_fn builtins_common[] = {
> > { "__builtin___vsnprintf_chk", &int_ctype, 0, { &string_ctype, size_t_ctype, &int_ctype, size_t_ctype, &const_string_ctype, va_list_ctype }},
> > { "__builtin___vsprintf_chk", &int_ctype, 0, { &string_ctype, &int_ctype, size_t_ctype, &const_string_ctype, va_list_ctype }},
> >
> > - { "__sync_add_and_fetch", &int_ctype, 1, { &ptr_ctype }},
> > - { "__sync_and_and_fetch", &int_ctype, 1, { &ptr_ctype }},
> > + { "__sync_add_and_fetch", NULL, 1, { vol_ptr, &dyntype }, .op = &atomic_op },
> > + { "__sync_and_and_fetch", NULL, 1, { vol_ptr, &dyntype }, .op = &atomic_op },
>
> Hmm, I get that the return type is derived from the type of the first
> argument, but I don't see where that return type is checked/assigned
> to the function return type. :( So, why are these set to NULL, but ...
>
> > { "__sync_bool_compare_and_swap", &bool_ctype, 1, { vol_ptr, &dyntype, &dyntype }, .op = &atomic_op},
>
> ... this one isn't?
Well, yes, __sync_bool_compare_and_swap() is defined as returning a bool,
so it can directly specified here. For the other functions, for example
__sync_add_and_fetch(), the return type must indeed be deduced form the
type of the first argument. It is set at the end of eval_atomic_common()
if (!expr->ctype) // __sync_val_compare_and_swap()
expr->ctype = ctype;
The comment should be removed or replaced by a real one.
I'll clarify that. Thanks for noticng this.
-- Luc
