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

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

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 <philmd@redhat.com>
>> ---
>>   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.