Wireshark-dev: Re: [Wireshark-dev] packet-ieee802154.c compilation error

From: "Maynard, Chris" <Christopher.Maynard@xxxxxxxxx>
Date: Tue, 2 Sep 2008 17:28:46 -0400

What about modifying the macro itself?

#define ieee802154_crc_tvb(tvb, offset)
((guint16)(crc16_ccitt_tvb_seed(tvb, offset, IEEE802154_CRC_SEED) ^
IEEE802154_CRC_XOROUT))


> -----Original Message-----
> From: wireshark-dev-bounces@xxxxxxxxxxxxx [mailto:wireshark-dev-
> bounces@xxxxxxxxxxxxx] On Behalf Of Jaap Keuter
> Sent: Tuesday, September 02, 2008 5:23 PM
> To: Developer support list for Wireshark
> Subject: Re: [Wireshark-dev] packet-ieee802154.c compilation error
> 
> Hi Chris,
> 
> Yes, that is the one.
> And no, that typecast doesn't solve it.
> And yes, it does hide it from the larger scope, which is a bug IMHO.
> 
> Thanx,
> Jaap
> 
> Maynard, Chris wrote:
> > Jaap,
> > I assume this is the line it's complaining about?:
> >
> > fcs_ok = (fcs == ieee802154_crc_tvb(tvb,
> > tvb_reported_length(tvb)-IEEE802154_FCS_LEN));
> >
> > At first glance, there doesn't seem to be anything wrong with the
> > comparison since fcs is a guint16 and that's exactly what
> > crc16_ccitt_tvb_seed() returns; however, because the comparison is
> > actually the following:
> >
> > fcs_ok = (fcs == (crc16_ccitt_tvb_seed(tvb,
> > tvb_reported_length(tvb)-IEEE802154_FCS_LEN, IEEE802154_CRC_SEED) ^
> > IEEE802154_CRC_XOROUT));
> >
> > I think the compiler is interpreting (blah ^ IEEE802154_CRC_XOROUT)
...
> > where IEEE802154_CRC_XOROUT is defined as 0xFFFF ... as the
equivalent
> > of (~blah) and that's where your warning is coming from.
> >
> > What if you try the following?
> > fcs_ok = (fcs == (guint16)(ieee802154_crc_tvb(tvb,
> > tvb_reported_length(tvb)-IEEE802154_FCS_LEN)));
> >
> > - Chris
> > BTW: I ran lint on that file in case you want to have a look.  Lint
> > doesn't complain about that line exactly, but it might have some
other
> > things worth at least looking over.  For example, line 703 where
fcs_ok
> > is redeclared, but the value of fcs_ok, although assigned within the
> > if() scope is not actually visible outside of that scope; yet fcs_ok
is
> > referenced later on (line 746, ...).
> >
> >
> >> -----Original Message-----
> >> From: wireshark-dev-bounces@xxxxxxxxxxxxx [mailto:wireshark-dev-
> >> bounces@xxxxxxxxxxxxx] On Behalf Of Jaap Keuter
> >> Sent: Tuesday, September 02, 2008 4:18 PM
> >> To: Developer support list for Wireshark
> >> Subject: [Wireshark-dev] packet-ieee802154.c compilation error
> >>
> >> Hi list,
> >>
> >> I'm running into this error for which I do not know the proper
> > solution:
> >> cc1: warnings being treated as errors
> >> packet-ieee802154.c: In function 'dissect_ieee802154_common':
> >> packet-ieee802154.c:709: error: comparison of promoted ~unsigned
with
> >> unsigned
> >> make[4]: *** [libdissectors_la-packet-ieee802154.lo] Error 1
> >>
> >> $ gcc -v
> >> Using built-in specs.
> >> Target: i486-linux-gnu
> >> Configured with: ../src/configure -v --with-pkgversion='Debian
> > 4.3.1-9'
> >> --with-bugurl=file:///usr/share/doc/gcc-4.3/README.Bugs
> >> --enable-languages=c,c++,fortran,objc,obj-c++ --prefix=/usr
--enable-
> >> shared
> >> --with-system-zlib --libexecdir=/usr/lib --without-included-gettext
> >> --enable-threads=posix --enable-nls --with-gxx-include-
> >> dir=/usr/include/c++/4.3
> >> --program-suffix=-4.3 --enable-clocale=gnu --enable-libstdcxx-debug
> >> --enable-objc-gc --enable-mpfr --enable-targets=all --enable-cld
> >> --enable-checking=release --build=i486-linux-gnu
--host=i486-linux-gnu
> >> --target=i486-linux-gnu
> >> Thread model: posix
> >> gcc version 4.3.1 (Debian 4.3.1-9)
> >>
> >> Any hints are welcome.
> >>
> >> Thanx,
> >> Jaap
> >> _______________________________________________
> 
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