Re: [PATCH] KVM: arm64: Drop 'const' from argument of vq_present()

From: Dave Martin
Date: Tue Jun 04 2019 - 06:01:15 EST


On Tue, Jun 04, 2019 at 03:01:53PM +0530, Viresh Kumar wrote:
> On 04-06-19, 10:26, Dave Martin wrote:
> > I'm in two minds about whether this is worth fixing, but if you want to
> > post a patch to remove the extra const (or convert vq_present() to a
> > macro), I'll take a look at it.
>
> This patch already does what you are asking for (remove the extra
> const), isn't it ?

Yes, sorry -- I didn't scroll back far enough.

> I looked at my textbook (The C programming Language, By Brian W.
> Kernighan and Dennis M. Ritchie.) and it says:
>
> "
> The const declaration can also be used with array arguments, to
> indicate that the function does not change that array:
>
> int strlen(const char[]);
> "
>
> and so this patch isn't necessary for sure.

This is an array to which a pointer argument points, not an array
argument. I think that's how we hit the constified double-indirection
problem.

Cheers
---Dave