Date: Mon, 2 Apr 2012 07:52:52 -0400 From: John Baldwin <jhb@freebsd.org> To: Dimitry Andric <dim@freebsd.org> Cc: src-committers@freebsd.org, svn-src-all@freebsd.org, Scott Long <scottl@freebsd.org>, Stefan Farfeleder <stefanf@freebsd.org>, David Xu <davidxu@freebsd.org>, svn-src-head@freebsd.org Subject: Re: svn commit: r233700 - head/sys/kern Message-ID: <201204020752.52596.jhb@freebsd.org> In-Reply-To: <4F760E5F.5030300@FreeBSD.org> References: <201203301257.q2UCvE4l042042@svn.freebsd.org> <20120330133045.GD1423@mole.fafoe.narf.at> <4F760E5F.5030300@FreeBSD.org>
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On Friday, March 30, 2012 3:49:51 pm Dimitry Andric wrote:
> On 2012-03-30 15:30, Stefan Farfeleder wrote:
> > here are a few similar cases.
>
> Hm, what about this one that clang warns about:
>
> sys/dev/asr/asr.c:2420:57: warning: for loop has empty body [-Wempty-
body]
> for (ha = &Asr_softc_list; *ha; ha = &((*ha)->ha_next));
> ^
> sys/dev/asr/asr.c:2420:57: note: put the semicolon on a separate line to
silence this warning [-Wempty-body]
>
> I'm not sure about it though, the code looks like this:
>
> static int
> asr_attach(device_t dev)
> {
> [...]
> Asr_softc_t *sc, **ha;
> [...]
> LIST_INIT(&(sc->ha_ccb));
> /* Link us into the HA list */
> for (ha = &Asr_softc_list; *ha; ha = &((*ha)->ha_next));
> *(ha) = sc;
>
> It seems the for loop walks the list until the end, then tacks 'sc' onto
> it.
>
> So to 'fix' the warning, and make the meaning more explicit, we should
> probably rewrite that fragment as:
>
> LIST_INIT(&(sc->ha_ccb));
> /* Link us into the HA list */
> for (ha = &Asr_softc_list; *ha; ha = &((*ha)->ha_next))
> ;
> *(ha) = sc;
>
> Is this OK?
Can we just make that code use a STAILQ() instead of doing it obscurely by
hand?
--
John Baldwin
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