Re: [PULL 31/31] qemu-option: warn for short-form boolean options

[Peter Maydell]

On Tue, 16 Feb 2021 at 11:23, Paolo Bonzini <pbonzini@redhat.com> wrote:
> I agree, and that's why I have no plans to move -chardev off QemuOpts;
> warning is a different step than excising and sometimes years pass from
> one to the other.  However, that doesn't prevent introducing a warning
> so that users slowly move away from the problematic functionality.

If we want to continue to support the functionality then complaining
about it doesn't serve much purpose IMHO.

> Also, "-chardev" is not the way that most users will configure sockets.
>   The more common "-serial tcp:localhost:12345,server,nowait" will not
> trigger the warning; that was not clear at all from the the commit
> message.  It may even make sense to deprecate the *long* form in that
> case (which I am not planning to do, to be clear).   I'll fix the
> documentation for those uses that are affected, though; thanks for
> reporting that.

A bunch of my local scripts for running QEMU got hit by this new
deprecation warning; "git grep 'chardev.*nowait'" gets hits in
our documentation; if you google for 'chardev "server,nowait"' there
are plenty of in-the-wild uses.

Is there any other serious use of the 'no' prefix other than
'nowait' ? Perhaps we could get most of the benefit here by
banning the 'no' prefix and adding a compatibility 'nowait'
bool which had the inverse sense to the existing 'wait' bool ?
(TBH I had assumed that 'nowait' was already implemented that
way; 'nodelay' is.)

-- PMM