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From: Hans Petter Selasky <hselasky@c2i.net>
To: freebsd-current@freebsd.org
Date: Mon, 9 Feb 2009 15:34:11 +0100
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Cc: usb@freebsd.org, Christoph Mallon <christoph.mallon@gmx.de>
Subject: Re: HEADSUP usb2/usb4bsd to become default in GENERIC
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On Monday 09 February 2009, Christoph Mallon wrote:
> Hans Petter Selasky schrieb:
> > On Monday 09 February 2009, Christoph Mallon wrote:
> >> Christoph Mallon schrieb:
> >>> are named "err" or "error". This should be investigated, so here's the
> >>> complete list:
> >>
> >> Sorry, my MUA seems to have damaged the list. You can get the list here:
> >> http://tron.homeunix.org/usb2.unread.log
> >
> > I think some of these errors depend if you have USB debugging compiled or
> > not. At least GCC does not warn?
>
> No, it does not depend on USB debugging.
> GCC has no warning at all for variables which are only assigned to.
> It only can warn about variables, which are only initialised.
>
> {
>    int x = 23; // GCC warns here ...
>    int y;      // ... but not here - cparser does
>    y = 42;
>    y++;
> }
>
> cparser has an analysis, which can warn about "y", too.
>
> I manually verified all 40 warnings and I cannot find any users (i.e.
> readers) for these variables.

What is the correct way to discard the return argument of a function? That's 
basically what most of the warnings are about.

1) (void)my_fn() cast
2) if (my_fn()) { }
3) err = my_fn();
4) my_fn();

--HPS