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Re: [Xen-devel] [PATCH] Add -Wcast-qual flag

To: "Christoph Egger" <Christoph.Egger@xxxxxxx>, <xen-devel@xxxxxxxxxxxxxxxxxxx>, "Keir Fraser" <keir@xxxxxxxxxxxxx>
Subject: Re: [Xen-devel] [PATCH] Add -Wcast-qual flag
From: "Jan Beulich" <jbeulich@xxxxxxxxxx>
Date: Thu, 21 Dec 2006 12:51:23 +0000
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>>> Keir Fraser <keir@xxxxxxxxxxxxx> 21.12.06 11:41 >>>
>On 21/12/06 10:05, "Christoph Egger" <Christoph.Egger@xxxxxxx> wrote:
>
>> The xen-cast.diff adds the -Wcast-qual flag.
>
>We don't enable this flag precisely because we end up needing to scatter
>const all over the place like confetti. I'm not convinced that use of const
>improves code quality. I fear we'd end up with 'const foo * const bar' all
>over the place -- ugly and confusing to most programmers (who frequently
>mess up const placement, in my experience).

While I'd really like to see all Xen code become const-correct (because I do
believe this helps with code quality, like does marking read only data read
only in the page tables), I don't think adding the warning here is
appropriate - after all, in C this is one of the purposes of adding explicit
casts (although I agree it's questionable to use casts for this purpose).
And no, I don't think that many people screwing up const placement is a
proper argument for not using const where possible.

Jan

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