[sane-devel] How to avoid gcc warnings (was: hs2p backend)

[jazz_johnson at verizon.net]

On Tuesday 20 November 2007, Mattias Ellert wrote:
> 20 nov 2007 kl. 12.32 skrev Volker Grabsch:
> > On Mon, Nov 19, 2007 at 11:36:20AM -0500, m. allan noah wrote:
> >> ok, lets start by saying that lots of other sane backends produce
> >> warnings, and i am probably running a newer version of gcc than you,
> >> so it's not a requirement that we remove all of them. it's just a pet
> >> peev of mine.
> >>
> >> 1. if you put a little 'arg = arg;' line in the function, gcc will
> >> shutup about the param.
> >
> > I'd rather recommend:
> >
> >    (void)arg;
> >
> > because this command has no "action". ('arg = arg;' is an assigment)
> > This solution also works better for 'const' arguments.
>
> You can also leave the parameter unnamed in the declaration:
>
> sense_handler (int scsi_fd, u_char * result, void*)
>
> This will also get rid of the warning.
>
> 	Mattias

Leaving out the parameter name  gives me an error:

In file included from hs2p.c:95:
hs2p-scsi.c: In function 'sense_handler':
hs2p-scsi.c:384: error: parameter name omitted
make[1]: *** [hs2p.lo] Error 1
make[1]: Leaving directory `/var/tmp/portage/sane-backends-1.0.18/backend'
make: *** [all-recursive] Error 1

But the noop statement worked:
(void)arg;