[libvirt] [PATCH] util: Make virStringArrayHasString() const-correct

Andrea Bolognani abologna at redhat.com
Tue Aug 16 17:55:11 UTC 2016

On Tue, 2016-08-16 at 18:49 +0200, Michal Privoznik wrote:
> On 16.08.2016 13:40, Andrea Bolognani wrote:
>> > The first argument should be const char ** instead of
> > char **, because this is a search function and as such it
> > doesn't, and shouldn't, alter the haystack in any way.
>> > This change means we no longer have to cast arrays of
> > immutable strings to arrays of mutable strings; we still
> > have to do the opposite, though, but that's reasonable.
> Is it? I mean, we are restricting ourselves and compiler fails to see
> that. To me 'const char **' is more restrictive than 'char **' therefore
> there should be no typecast required. But this is the discussion I
> should have with gcc devels. For some reason, gcc does automatic
> typecasting to const just for the fist level pointers and not the second
> one. That's why compilers errors out.

The reason for this behavior is explained in the C FAQ:


It's unfortunate, and very annoying. But I'd rather have
to perform arguably redundant casts than being bitten by
that kind of bug down the line :)


Pushed, thanks!

Andrea Bolognani / Red Hat / Virtualization

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