Re: [Qemu-trivial] [PATCH v6] qdev: Add support for property type bool

[Jan Kiszka]

On 2012-01-24 18:38, Andreas Färber wrote:
> Am 24.01.2012 18:29, schrieb Jan Kiszka:
>> On 2012-01-24 18:17, Andreas Färber wrote:
>>> From: Andreas Färber <address@hidden>
>>>
>>> VMState supports the type bool but qdev instead supports bit, backed by
>>> uint32_t. Therefore let's add DEFINE_PROP_BOOL() and qdev_prop_set_bool().
>>>
>>> bool by definition is either true or false. Should the need arise to
>>> parse yes/no, on/off, 1/0 or whatever as well, we can still add that at
>>> a later point in time.
>>
>> To make it a real replacement for PROP_TYPE_BIT, let's use on/off, also
>> for printing. Not only programmers may use this interface. ;)
> 
> Actually non-programmers are the reason for this: cache=on/off makes a
> great deal of sense in English (noun), but not enabled=off (adjective),
> which was my use case of this patch for ISA devices.

Agreed, there are use cases for both.

> 
> I'm fine with accepting the whole range of possibilities for parsing.
> For printing I see no reason to, since there's no legacy users of this
> new type we could break. true/false seemed better than yes/no.

We have a few single-bit booleans I would like to convert to bool. So
the best option may be having control over what is printed. Could we
easily provide a PROP_TYPE_SWITCH based on bool?

> 
>>> +PropertyInfo qdev_prop_bool = {
>>> +    .name = "bool",
>>
>> Now we have "bool" and "boolean". Can we rename the latter to bit?
> 
> I'd be fine with that, just don't know if that would break anything
> elsewhere for qdev or QOM?

Hmm, to me it looks like it's only used for verbose error reporting. But
I may miss something.

Jan

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