On Fri, Jul 20, 2012 at 10:37:32AM +0200, Richard Guenther wrote:
> On Thu, Jul 19, 2012 at 6:53 PM, Jakub Jelinek <ja...@redhat.com> wrote:
> Hum. How hard would it be to merge the attributes?
IMHO hard and ugly. The thing is that you probably can do some hacks
easily in handle_nonnull_attribute, so that multiple nonnull attributes
on the same prototype get merged together (at the end of function when
returning without *no_add_attrs = true; before it, do
a = lookup_attribute ("nonnull", TYPE_ATTRIBUTES (type));
if (a != NULL)
{
merge stuff into a;
*no_add_attrs = true;
}
), but that handles just one of the cases, where multiple nonnull attributes
appear on the same prototype. But you can (and with builtins.def usually
do) have also
void foo (void *, void *, void *) __attribute__((nonnull (1)));
void foo (void *, void *, void *) __attribute__((nonnull (2)));
and for that case no attribute hook is called, so either merge_attributes
would need to special case this attribute (which would be a layering
violation, as nonnull is just C/C++ attribute), or each FE would need in its
merge_decls and similar call lookup_attribute ("nonnull", TYPE_ATTRIBUTES
(...));
twice and do the merging manually. As there are just two users of the
nonnull attribute, handling all of them there looked much shorter and easier
to me.
> > 2012-07-19 Jakub Jelinek <ja...@redhat.com>
> >
> > PR c++/28656
> > * tree-vrp.c (nonnull_arg_p): Handle all nonnull attributes instead
> > of just the first one.
> >
> > * c-common.c (check_function_nonnull): Handle multiple nonnull
> > attributes properly.
> >
> > * c-c++-common/pr28656.c: New test.
Jakub
