Re: [Qemu-devel] [libvirt] [PULL 25/26] block: Remove deprecated -drive option serial

[Kevin Wolf]

Am 12.07.2018 um 09:48 hat Cornelia Huck geschrieben:
> On Thu, 12 Jul 2018 08:51:16 +0200
> Markus Armbruster <address@hidden> wrote:
> 
> > Markus Armbruster <address@hidden> writes:
> > 
> > > Kevin Wolf <address@hidden> writes:
> > >  
> > >> Am 10.07.2018 um 16:22 hat Cornelia Huck geschrieben:  
> > >>> On Tue, 10 Jul 2018 07:59:15 +0200
> > >>> Markus Armbruster <address@hidden> wrote:
> > >>>   
> > >>> > In addition to actively pulling libvirt developers into review of
> > >>> > deprecation patches, we should pursue the idea to optionally let QEMU
> > >>> > fail on use of deprecated features, then have libvirt run its test 
> > >>> > suite
> > >>> > that way.  
> > >>> 
> > >>> What about the following:
> > >>> 
> > >>> qemu_deprecated_option("old_option", "modern_option");
> > >>> 
> > >>> Which would then print (in normal operation)
> > >>> 
> > >>> "WARNING: 'old_option' is deprecated and will be removed; use 
> > >>> 'modern_option' instead"
> > >>> 
> > >>> to the monitor (or to stderr? to both?).
> > >>> 
> > >>> If you start QEMU with a -no-deprecated-options switch, it would print
> > >>> 
> > >>> "ERROR: 'old_option' is deprecated and will be removed; use 
> > >>> 'modern_option' instead"
> > >>> 
> > >>> and do an exit(1).
> > >>> 
> > >>> Would that be workable?  
> > >>
> > >> I think the function should just take a message:
> > >>
> > >>     /* Works like error_report(), except for the WARNING/ERROR prefix
> > >>      * and exit(1) if -no-deprecated-options is set */
> > >>     void deprecation_report(const char *fmt, ...);  
> > >
> > > I like it.  The contract could use a bit of polish, but that's detail.  

Obviously, this comment wasn't meant to be copied into the source code,
but just to explain what I'm actually proposing there.

> > Suggest --deprecated={silent,warn,error}, default silent.
> 
> I like that, but I'd prefer to default to warn (so that command line
> users have a better chance to notice it).

I agree that warn is the better default. (It's also consistent with what
we have been doing for deprecations so far.)

Kevin