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Date: Mon, 23 Sep 2013 15:44:02 +0200
From: Laszlo Ersek <lersek@redhat.com>
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Subject: Re: [Qemu-devel] [PATCH v4 12/23] acpi: add rules to compile ASL
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To: "Michael S. Tsirkin" <mst@redhat.com>
Cc: Paolo Bonzini <pbonzini@redhat.com>, qemu-devel@nongnu.org, Anthony Liguori <anthony@codemonkey.ws>, afaerber@suse.de

On 09/23/13 15:39, Michael S. Tsirkin wrote:
> On Mon, Sep 23, 2013 at 02:36:41PM +0200, Paolo Bonzini wrote:
>> Il 22/09/2013 15:37, Michael S. Tsirkin ha scritto:
>>> Detect presence of IASL compiler and use it
>>> to process ASL source. If not there, use pre-compiled
>>> files in-tree. Add script to update the in-tree files.
>>>
>>> Note: distros are known to silently update iasl
>>> so detect correct iasl flags for the installed version on each run as
>>> opposed to at configure time.
>>
>> This is not any different from a C compiler, which is likely updated
>> much much more often than iasl.
> 
> Yes but it's not a theoretical issue:
> we did catch iasl changing flags semantics on the fly, once.
> 
> I think compilers don't do this as a norm :)

(Fully tangentially... gcc and clang emit warnings for a new set of code
constructs every other week. When combined with -Werror, it's super
annoying; valid and intentional code can stop to build unexpectedly.
Good thing we have --disable-werror for this.)

Laszlo