On Mon, Jan 25, 2021 at 20:28:52 +0300, Valery Ushakov wrote:
> On Mon, Jan 25, 2021 at 08:19:44 -0800, Jason Thorpe wrote:
>
> > > On Jan 25, 2021, at 6:22 AM, Kamil Rytarowski <ka...@netbsd.org> wrote:
> > >
> > > I have no problem with this change but I am curious why should we use "{
> > > }"? It's a C GNU extension and C++ syntax.
> >
> > Using { 0 } makes an assumption about the first member of the
> > structure which is not guaranteed to remain true.
>
> The commit message says:
>
> | Since we're using designated initialisers for compat data, we should
> | use a completely empty initializer for the sentinel.
>
> but that "should" is not true. The code that checks that sentinel
> uses some particular member to access it, so, pedantically speaking,
> the initialization must designate that member in the sentinel
> initialization. Yes, this is verbose and doesn't look as pretty, but
> that is what "should" happen here. Using non-standard {} extension
> makes it look nicer, but is not a "should" kind of necessity.
PS: Forgot to add that C++ doesn't have designated initializers (or at
least it didn't last time I looked), so they are in a different
situation here and need an empty initializer list. In C the only
difference it makes is, as far as I can tell, exactly this kind of an
array with a sentinel at the end and the difference is cosmetic.
-uwe
