Re: [Qemu-devel] [PATCH 02/10] qdev: add creation function that may fail

[Blue Swirl]

On Sat, Feb 12, 2011 at 7:10 PM, Markus Armbruster <address@hidden> wrote:
> Blue Swirl <address@hidden> writes:
>
>> Signed-off-by: Blue Swirl <address@hidden>
>> ---
>>  hw/qdev.c |   14 +++++++++++++-
>>  hw/qdev.h |    1 +
>>  2 files changed, 14 insertions(+), 1 deletions(-)
>>
>> diff --git a/hw/qdev.c b/hw/qdev.c
>> index c7fec44..1aa1ea0 100644
>> --- a/hw/qdev.c
>> +++ b/hw/qdev.c
>> @@ -106,6 +106,18 @@ static DeviceState
>> *qdev_create_from_info(BusState *bus, DeviceInfo *info)
>>     initialize the actual device emulation.  */
>>  DeviceState *qdev_create(BusState *bus, const char *name)
>>  {
>> +    DeviceState *dev;
>> +
>> +    dev = qdev_try_create(bus, name);
>> +    if (!dev) {
>> +        hw_error("Unknown device '%s' for bus '%s'\n", name, 
>> bus->info->name);
>
> Aside: I never liked the use hw_error() for this purpose.  Dumping CPU
> state isn't helpful when the problem is a bad device name in board setup
> code.

Right, perhaps hw_error shouldn't dump CPU state. Instead there should
be a new function (cpu_error) for that.

>> +    }
>> +
>> +    return dev;
>> +}
>> +
>> +DeviceState *qdev_try_create(BusState *bus, const char *name)
>> +{
>>      DeviceInfo *info;
>>
>>      if (!bus) {
>> @@ -114,7 +126,7 @@ DeviceState *qdev_create(BusState *bus, const char *name)
>>
>>      info = qdev_find_info(bus->info, name);
>>      if (!info) {
>> -        hw_error("Unknown device '%s' for bus '%s'\n", name, 
>> bus->info->name);
>> +        return NULL;
>>      }
>>
>>      return qdev_create_from_info(bus, info);
>> diff --git a/hw/qdev.h b/hw/qdev.h
>> index 9808f85..8a13ec9 100644
>> --- a/hw/qdev.h
>> +++ b/hw/qdev.h
>> @@ -122,6 +122,7 @@ typedef struct GlobalProperty {
>>  /*** Board API.  This should go away once we have a machine config file.  
>> ***/
>>
>>  DeviceState *qdev_create(BusState *bus, const char *name);
>> +DeviceState *qdev_try_create(BusState *bus, const char *name);
>>  int qdev_device_help(QemuOpts *opts);
>>  DeviceState *qdev_device_add(QemuOpts *opts);
>>  int qdev_init(DeviceState *dev) QEMU_WARN_UNUSED_RESULT;
>
> I'd prefer these to follow qdev_init() / qdev_init_nofail() precedence,
> for consistency, i.e. rename existing qdev_create() to
> qdev_create_nofail(), call your new function qdev_create().

That would be a big rename operation. Care to submit a patch?