Re: [Qemu-devel] [PATCH 5/4] vl: Clean up machine selection in main().

[Markus Armbruster]

Marcel Apfelbaum <address@hidden> writes:

> On 02/16/2016 04:57 PM, Markus Armbruster wrote:
>> We set machine_class to the default first, and update it to the real
>> one later.  Any use of machine_class in between is almost certainly
>> wrong.  Set it once and for all instead.
>>
>> Signed-off-by: Markus Armbruster <address@hidden>
>> ---
>>   vl.c | 11 ++++++-----
>>   1 file changed, 6 insertions(+), 5 deletions(-)
>>
>> diff --git a/vl.c b/vl.c
>> index 7918e9f..098728c 100644
>> --- a/vl.c
>> +++ b/vl.c
>> @@ -2748,8 +2748,9 @@ static const QEMUOption *lookup_opt(int argc, char 
>> **argv,
>>       return popt;
>>   }
>>
>> -static void set_machine_options(MachineClass **machine_class)
>> +static MachineClass *select_machine(MachineClass *dflt)
>
> Hi Markus,
>
> I am no fan of "dflt" naming, but I can live with it.
>
>>   {
>> +    MachineClass *machine_class = dflt;
>>       const char *optarg;
>>       QemuOpts *opts;
>>       Location loc;
>> @@ -2761,16 +2762,17 @@ static void set_machine_options(MachineClass 
>> **machine_class)
>>
>>       optarg = qemu_opt_get(opts, "type");
>>       if (optarg) {
>> -        *machine_class = machine_parse(optarg);
>> +        machine_class = machine_parse(optarg);
>>       }
>>
>> -    if (*machine_class == NULL) {
>> +    if (!machine_class) {
>>           error_report("No machine specified, and there is no default");
>>           error_printf("Use -machine help to list supported machines\n");
>>           exit(1);
>>       }
>>
>>       loc_pop(&loc);
>> +    return machine_class;
>>   }
>>
>>   static int machine_set_property(void *opaque,
>> @@ -3075,7 +3077,6 @@ int main(int argc, char **argv, char **envp)
>>       os_setup_early_signal_handling();
>>
>>       module_call_init(MODULE_INIT_MACHINE);
>> -    machine_class = find_default_machine();
>>       cpu_model = NULL;
>>       snapshot = 0;
>>       cyls = heads = secs = 0;
>> @@ -4066,7 +4067,7 @@ int main(int argc, char **argv, char **envp)
>>
>>       replay_configure(icount_opts);
>>
>> -    set_machine_options(&machine_class);
>> +    machine_class = select_machine(find_default_machine());
>
> I like the approach "going all the way", I would
> even hide the call to find_default_machine inside select_machine.

Good idea.  Squashing in:

diff --git a/vl.c b/vl.c
index 098728c..c0b6747 100644
--- a/vl.c
+++ b/vl.c
@@ -2748,9 +2748,9 @@ static const QEMUOption *lookup_opt(int argc, char **argv,
     return popt;
 }
 
-static MachineClass *select_machine(MachineClass *dflt)
+static MachineClass *select_machine(void)
 {
-    MachineClass *machine_class = dflt;
+    MachineClass *machine_class = find_default_machine();
     const char *optarg;
     QemuOpts *opts;
     Location loc;
@@ -4067,7 +4067,7 @@ int main(int argc, char **argv, char **envp)
 
     replay_configure(icount_opts);
 
-    machine_class = select_machine(find_default_machine());
+    machine_class = select_machine();
 
     set_memory_options(&ram_slots, &maxram_size, machine_class);
 
>
> Reviewed-by: Marcel Apfelbaum <address@hidden>

Thanks!