Re: [PATCH] vl: Abort if multiple machines are registered as default

[Philippe Mathieu-Daudé]

On 2/7/20 12:08 PM, Laurent Vivier wrote:
> Le 07/02/2020 à 12:02, Philippe Mathieu-Daudé a écrit :
> > It would be confusing to have multiple default machines.
> > Abort if this ever occurs.
> >
> > Signed-off-by: Philippe Mathieu-Daudé <address@hidden>
> > ---
> >   vl.c | 7 +++++++
> >   1 file changed, 7 insertions(+)
> >
> > diff --git a/vl.c b/vl.c
> > index 7dcb0879c4..da828188eb 100644
> > --- a/vl.c
> > +++ b/vl.c
> > @@ -2354,6 +2354,8 @@ static MachineClass *machine_parse(const char *name, 
> > GSList *machines)
> >       GSList *el;
> >   
> >       if (is_help_option(name)) {
> > +        int default_count = 0;
> > +
> >           printf("Supported machines are:\n");
> >           machines = g_slist_sort(machines, machine_class_cmp);
> >           for (el = machines; el; el = el->next) {
> > @@ -2364,6 +2366,11 @@ static MachineClass *machine_parse(const char *name, 
> > GSList *machines)
> >               printf("%-20s %s%s%s\n", mc->name, mc->desc,
> >                      mc->is_default ? " (default)" : "",
> >                      mc->deprecation_reason ? " (deprecated)" : "");
> > +            default_count += !!mc->is_default;
> > +        }
> > +        if (default_count > 1) {
> > +            error_printf("Multiple default machines available\n");
> > +            abort();
> >           }
> >           exit(0);
> >       }
>
> Does it really deserve an abort?
> Ideal solution would be to be able to check this at build or in the unit
> tests.

This is for developers, not for users. I'll use Marc-André suggestion 
and use an assertion.