From owner-freebsd-arm@freebsd.org Tue Sep 26 04:55:45 2017 Return-Path: Delivered-To: freebsd-arm@mailman.ysv.freebsd.org Received: from mx1.freebsd.org (mx1.freebsd.org [IPv6:2001:1900:2254:206a::19:1]) by mailman.ysv.freebsd.org (Postfix) with ESMTP id 03456E2EE91 for ; Tue, 26 Sep 2017 04:55:45 +0000 (UTC) (envelope-from george+freebsd@m5p.com) Received: from mailhost.m5p.com (mailhost.m5p.com [207.172.210.101]) (using TLSv1.2 with cipher ECDHE-RSA-AES128-GCM-SHA256 (128/128 bits)) (Client CN "m5p.com", Issuer "Let's Encrypt Authority X3" (not verified)) by mx1.freebsd.org (Postfix) with ESMTPS id AEDF2762C4 for ; Tue, 26 Sep 2017 04:55:44 +0000 (UTC) (envelope-from george+freebsd@m5p.com) Received: from [IPv6:2001:470:1f07:15ff::1f] (haymarket.m5p.com [IPv6:2001:470:1f07:15ff::1f]) (authenticated bits=0) by mailhost.m5p.com (8.15.2/8.15.2) with ESMTPSA id v8Q4tIg1033977 (version=TLSv1.2 cipher=DHE-RSA-AES128-SHA bits=128 verify=NO) for ; Tue, 26 Sep 2017 00:55:24 -0400 (EDT) (envelope-from george+freebsd@m5p.com) Subject: Re: Why does this compile? To: freebsd-arm@freebsd.org References: From: George Mitchell Message-ID: <2b4d4179-9bda-c4ab-95af-5200463600cb@m5p.com> Date: Tue, 26 Sep 2017 00:55:11 -0400 User-Agent: Mozilla/5.0 (X11; FreeBSD amd64; rv:52.0) Gecko/20100101 Thunderbird/52.3.0 MIME-Version: 1.0 In-Reply-To: Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="chU1Pmv4FMIEBLRtL4DLfkWQ19nHDOQdt" X-Spam-Status: No, score=0.2 required=10.0 tests=HELO_MISC_IP, RP_MATCHES_RCVD autolearn=no autolearn_force=no version=3.4.1 X-Spam-Checker-Version: SpamAssassin 3.4.1 (2015-04-28) on mattapan.m5p.com X-Greylist: Sender succeeded SMTP AUTH, not delayed by milter-greylist-4.6.2 (mailhost.m5p.com [IPv6:2001:470:1f07:15ff::f7]); Tue, 26 Sep 2017 00:55:24 -0400 (EDT) X-BeenThere: freebsd-arm@freebsd.org X-Mailman-Version: 2.1.23 Precedence: list List-Id: "Porting FreeBSD to ARM processors." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , X-List-Received-Date: Tue, 26 Sep 2017 04:55:45 -0000 This is an OpenPGP/MIME signed message (RFC 4880 and 3156) --chU1Pmv4FMIEBLRtL4DLfkWQ19nHDOQdt Content-Type: multipart/mixed; boundary="97LRdo9QePb0oTx6t3RmG0uqkkASoxVsT"; protected-headers="v1" From: George Mitchell To: freebsd-arm@freebsd.org Message-ID: <2b4d4179-9bda-c4ab-95af-5200463600cb@m5p.com> Subject: Re: Why does this compile? References: In-Reply-To: --97LRdo9QePb0oTx6t3RmG0uqkkASoxVsT Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: quoted-printable On 09/26/17 00:38, Russell Haley wrote: > [...] > #include >=20 > int main() > { > struct in_pktinfo; > return 0; > } > [...] This is a perfectly valid forward declaration of a struct type. In most normal cases, you would follow this up with something that contains a pointer to a thing of that type, and later a full declaration of the type. As it stands, though, it's simply a statement to the compiler that you are possibly using (and fully declaring) the structure type later on in your program. -- George --97LRdo9QePb0oTx6t3RmG0uqkkASoxVsT-- --chU1Pmv4FMIEBLRtL4DLfkWQ19nHDOQdt Content-Type: application/pgp-signature; name="signature.asc" Content-Description: OpenPGP digital signature Content-Disposition: attachment; filename="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEENdM4ZHktsJW5kKZXwRES3m+p4fkFAlnJ3bYACgkQwRES3m+p 4fnZww//bc8w36PcQw0KJeZ6a8DjSGuJ6bhNEJ7wT17Eb8+68mk2re5No8yYPXc0 LbvM1BSYlNbk3nyhgfVo5exGC22B2rqzQu4Qgr/bNc7J8z0yNGJIwS0UorKy6P02 yHCVwVLoPRMjoD/jdYCNd+j5qJ0lVnvcny39uGg1y2o4KsCRG6L+IwmPGLyvwViP iJBcGuewmxc2BU0U+gxrq3Cw9uZTo5YYDBrc1hmre5S7pwBF94LgrFuFQVVGWOxH GQAtBE4lEVsfjnahFgixbisA3cPlmFRjdBNW22kOg0H7F92ixHRbSYwLLHjZB3pN NBR7BDlqWF5EfjhjJiz/jolFanta8XKB1QxuT1uDxPx48BnvuTpDwuYLkNJXObxE TMbnldrRso2Bj4fAWNNyiFF6v/Jt4wH3TfrrzqM6D1J8DK/adiUrdSYPVIBIVMTf uvp+kRidaS6DIywLeQexCZXgacgB6Kzy0DLWtS64k/jAYVkb57wU89t2bb4T86JL FiZFx901j5KZiWX3BZaI9bNzB6+1ppnkUZmxZeguxjXNLEqZOFDH4fXP0TjX76XA fIDmo1dlx/KuSgEmChduQAPjx9/dKFOkifqgYPkThNCH2wgNV+0qQ47+Ajrod+RX KC/6GdRyxhN53T3FQ+WyPfyTL2+9QgpIe19Xs4zsa24zhXK9WIE= =dpHX -----END PGP SIGNATURE----- --chU1Pmv4FMIEBLRtL4DLfkWQ19nHDOQdt--