From mboxrd@z Thu Jan  1 00:00:00 1970
From: Ben Hutchings <bhutchings@solarflare.com>
Subject: Re: [PATCH net-next] ipv4: use IS_ENABLED() macro to cleanup code
Date: Wed, 26 Oct 2011 10:00:54 +0200
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Cc: David Miller <davem@davemloft.net>, <netdev@vger.kernel.org>
To: Eric Dumazet <eric.dumazet@gmail.com>
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On Wed, 2011-10-26 at 08:34 +0200, Eric Dumazet wrote:
> Le mardi 25 octobre 2011 =C3=A0 19:30 -0400, David Miller a =C3=A9cri=
t :
>=20
> > net/ipv4/ip_sockglue.c: In function =E2=80=98do_ip_setsockopt=E2=80=
=99:
> > net/ipv4/ip_sockglue.c:523:29: error: =E2=80=98LOOPBACK4_IPV6=E2=80=
=99 undeclared (first use in this function)
> > net/ipv4/ip_sockglue.c:523:29: note: each undeclared identifier is =
reported only once for each function it appears in
> >=20
> > This fails because ip_sockglue.c guards the net/transp_v6.h header
> > inclusion with a real CPP guard.
>=20
> Yep, it seems compiler was not able to perform optimisation of dead
> code.
[...]

No, the compiler is just checking the code further than you wanted
before optimising it away.

Ben.

--=20
Ben Hutchings, Staff Engineer, Solarflare
Not speaking for my employer; that's the marketing department's job.
They asked us to note that Solarflare product names are trademarked.