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

[Peter Maydell]

On Tue, 16 Feb 2021 at 13:30, Paolo Bonzini <pbonzini@redhat.com> wrote:
> On 16/02/21 12:58, Peter Maydell wrote:
> > 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.
>
> It depends.  I don't want to support it forever for all options;
> -machine, -accel and -object are those for which I do intend to remove
> support for short-form options after the two release deprecation period.
>
> My first submission of this patch even special cased "-chardev" to hide
> the warning, but this was dropped in response to reviews.
> (https://patchew.org/QEMU/20201103151452.416784-1-pbonzini@redhat.com/20201103151452.416784-5-pbonzini@redhat.com/).
>   I can add that back if you prefer, since it's very simple.

I agree with Daniel that it would be better to be consistent about
whether we like these short options or not, but disagree that
the answer is to deprecate everywhere :-)

Broadly, I think that being able to say 'foo' when foo is a
boolean option being set to true is obvious and nice-to-use
syntax, and I don't really want it to go away. 'nofoo' for
'foo=false' is much less obvious and I'm happy if we only
support it as a special-case for 'nowait'.

-- PMM