Date: Tue, 26 Oct 2021 22:24:42 -0700 From: Gleb Smirnoff <glebius@freebsd.org> To: Konstantin Belousov <kostikbel@gmail.com> Cc: mjg@freebsd.org, jhb@freebsd.org, jeff@freebsd.org, arch@freebsd.org Subject: Re: rwlock(9) and mutex(9) definitions Message-ID: <YXjimhWUYCwaYoWi@FreeBSD.org> In-Reply-To: <YXjfcclPCfbhYYCQ@kib.kiev.ua> References: <YXiw1afVlQyEhQyc@FreeBSD.org> <YXizhiRnByvyisXe@kib.kiev.ua> <YXi0PM6babQKFulv@kib.kiev.ua> <YXjS16MQZiKm4E/r@FreeBSD.org> <YXjYCj2zh0cjL/%2Bq@kib.kiev.ua> <YXjadvxmJRoXwWUj@FreeBSD.org> <YXjfcclPCfbhYYCQ@kib.kiev.ua>
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On Wed, Oct 27, 2021 at 08:11:13AM +0300, Konstantin Belousov wrote:
K> > Okay, let's put return aside. This would compile with true
K> > functions (e.g. WITNESS), otherwise not:
K> >
K> > void
K> > something(bool clue)
K> > {
K> > clue ? rw_rlock(lock) : rw_wlock(lock);
K> > }
K> >
K> > And this is correct code per 6.5.15.
K>
K> So why cannot you write it as
K> ...
K> if (clue)
K> rw_rlock(lock);
K> else
K> rw_wlock(lock);
Of course I can. But manual page rwlock(9) says I can treat them as functions, thus
use in conditional operator.
My point is that the fact that I can work around this, doesn't justify the
problem not being fixed.
What is a downside of wrapping them in "__extension__ ({ })"?
--
Gleb Smirnoff
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