Re: [Qemu-devel] [PATCH] configure: make it possible to disable IASL

[Stefan Weil <sw@weilnetz.de>]

Am 25.11.2013 14:54, schrieb Marcel Apfelbaum:
> On Mon, 2013-11-25 at 13:26 +0200, Michael S. Tsirkin wrote:
>> On Sun, Nov 24, 2013 at 09:58:34PM +0100, Stefan Weil wrote:
>>>>>> --iasl=false works without further modifications (because test "false
>>>>>> -h" works and returns false). It also looks more natural than --iasl=.
>>>>>>
>>>>>> Cheers, Stefan
>>>>> It seems that some people try --iasl= as the more natural way
>>>>> to do this. It's not documented that a failing iasl will
>>>>> cause a fall-back and I'd rather document an explicit option
>>>>> than making it fail.
>>>> I'm also curious why would you say =false is natural:
>>>> it's a string option not a boolean one.
>>>>
>>> 'false' is a string here, namely the name of the executable which is
>>> normally found at /bin/false.
>>> It takes any number of parameters and always returns 1 (which is boolean
>>> false
>>> in shell conventions).
>>>
>>> You could also write --iasl=/bin/false.
>>>
>>> I suggest this kind of patch:
>>>
>>>  echo "  --iasl=IASL              use ACPI compiler IASL [$iasl]"
>>> +echo "                           iasl=false disables the ACPI compiler"
>> It's still not a natural interface.
>>
>> It works by chance because we run iasl and test the return code,
>> but we don't have to.
>> For example, a reasonable implementation might produce
>> an error if the user-specified iasl fails, breaking this hack.
>>
>> Interfaces should not follow implementation.
>> If you don't want iasl a reasonable syntax is '' or
>> --disable-iasl.
> +1 on --disable-iasl
>
> Marcel

I also prefer --disable-iasl because that's the usual QEMU way how to
disable features.

Cheers,
Stefan