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Date:   Fri, 14 Feb 2020 11:54:55 -0800
From:   Sean Christopherson <sean.j.christopherson@intel.com>
To:     Paolo Bonzini <pbonzini@redhat.com>
Cc:     Qian Cai <cai@lca.pw>, Jim Mattson <jmattson@google.com>,
        Vitaly Kuznetsov <vkuznets@redhat.com>,
        Wanpeng Li <wanpengli@tencent.com>,
        Joerg Roedel <joro@8bytes.org>, kvm list <kvm@vger.kernel.org>,
        LKML <linux-kernel@vger.kernel.org>
Subject: Re: [PATCH] kvm/emulate: fix a -Werror=cast-function-type
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On Fri, Feb 14, 2020 at 08:33:50PM +0100, Paolo Bonzini wrote:
> On 14/02/20 20:14, Qian Cai wrote:
> >> It seems misguided to define a local variable just to get an implicit
> >> cast from (void *) to (fastop_t). Sean's first suggestion gives you
> >> the same implicit cast without the local variable. The second
> >> suggestion makes both casts explicit.
> > 
> > OK, I'll do a v2 using the first suggestion which looks simpler once it passed
> > compilations.
> > 
> 
> Another interesting possibility is to use an unnamed union of a
> (*execute) function pointer and a (*fastop) function pointer.

I considered that when introducing fastop_t.  I don't remember why I
didn't go that route.  It's entirely possible I completely forgot that
anonymous unions are allowed and thought it would mean changing a bunch
of use sites.