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

[Paolo Bonzini]

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.

Paolo

> 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.)