From mboxrd@z Thu Jan 1 00:00:00 1970 From: Leon Romanovsky Subject: Re: [PATCH 02/47] IB/cm: Suppress gcc 7 fall-through complaints Date: Tue, 10 Oct 2017 22:31:27 +0300 Message-ID: <20171010193127.GK2106@mtr-leonro.local> References: <20171006213333.6721-1-bart.vanassche@wdc.com> <20171006213333.6721-3-bart.vanassche@wdc.com> <849d304a-fa89-0d6a-6edb-cf34780e41a8@intel.com> Mime-Version: 1.0 Content-Type: multipart/signed; micalg=pgp-sha256; protocol="application/pgp-signature"; boundary="PEfPc/DjvCj+JzNg" Return-path: Content-Disposition: inline In-Reply-To: <849d304a-fa89-0d6a-6edb-cf34780e41a8-ral2JQCrhuEAvxtiuMwx3w@public.gmane.org> Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Dennis Dalessandro Cc: Bart Van Assche , Doug Ledford , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sean Hefty List-Id: linux-rdma@vger.kernel.org --PEfPc/DjvCj+JzNg Content-Type: text/plain; charset=us-ascii Content-Disposition: inline On Tue, Oct 10, 2017 at 03:27:11PM -0400, Dennis Dalessandro wrote: > On 10/6/2017 5:32 PM, Bart Van Assche wrote: > > Avoid that gcc 7 reports the following warning when building with W=1: > > > > warning: this statement may fall through [-Wimplicit-fallthrough=] > > > > Signed-off-by: Bart Van Assche > > Cc: Sean Hefty > > --- > > drivers/infiniband/core/cm.c | 1 + > > 1 file changed, 1 insertion(+) > > > > diff --git a/drivers/infiniband/core/cm.c b/drivers/infiniband/core/cm.c > > index d80911d4abb7..5927ee4e57ca 100644 > > --- a/drivers/infiniband/core/cm.c > > +++ b/drivers/infiniband/core/cm.c > > @@ -2808,6 +2808,7 @@ int ib_send_cm_mra(struct ib_cm_id *cm_id, > > msg_response = CM_MSG_RESPONSE_OTHER; > > break; > > } > > + /* fall through */ > > default: > > ret = -EINVAL; > > goto error1; > > > > So adding the comment is enough to make gcc shut up? Or are you just > annotating the code so it's obvious it was intentional? GCC is looking for the specific comment. --- -Wimplicit-fallthrough warns when a switch case falls through. This warning has five different levels. The compiler is able to parse a wide range of fallthrough comments, depending on the level. It also handles control-flow statements, such as ifs. It's possible to suppress the warning by either adding a fallthrough comment, or by using a null statement: __attribute__ ((fallthrough)); (C, C++), or [[fallthrough]]; (C++17), or [[gnu::fallthrough]]; (C++11/C++14). --- https://gcc.gnu.org/gcc-7/changes.html Thanks > > -Dennis > -- > To unsubscribe from this list: send the line "unsubscribe linux-rdma" in > the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org > More majordomo info at http://vger.kernel.org/majordomo-info.html --PEfPc/DjvCj+JzNg Content-Type: application/pgp-signature; name="signature.asc" -----BEGIN PGP SIGNATURE----- iQIzBAEBCAAdFiEEkhr/r4Op1/04yqaB5GN7iDZyWKcFAlndIA8ACgkQ5GN7iDZy WKfTlg//UqQPd+x3EPDyZNFSX4Gs3EAXg62b8ZxTBBAXGzFgCIwiHHN4gLstpxqX O9exbuQ1wflvFognmwyW8O/52sp4QCP8POiJrugfjQP4L3cw9HoeqcMMF5AMIXc+ 5TZEBPhQYaCMm8wwQENRIsoobrajbPerL2GlIqxqeMOcVkxe6TWLUCkcSKS2CRwt SmIXfxDmhnQsEza6gZxId0TR6RK3NqrGtZmOlpj18tOjGBPiMjxIOL2vyKwiIqGt DKrgbOvotDcVuf8eT5ZRqeYAiBnC7a+jAh+nmbPocVLVcoFOOnfKeKyMEekIfyD8 /qHwKPetDFUmtFjWNfKItLSfUEmcwnUh0vhmjGJifFUKnUjA1ZI4y+ufwrjh3YnM iuYcCGhJ4BCpudfZCn+ybU6yJl92/ZGa30c/1/3FDYmmGFBVZO6PYyVK2s36u0rJ TW5diS8xZXPtceN+cRk1TVCGJqvTonwgITlIO8C0qCFcZvfqMFnf7b/k733V/gz0 W3L389FzHl5n0pJXcMWLMsA3q6jlTQWQbXSOZc724k3whUlj0kwvRUiQGyQ7SiXv t6fFumkMdzQua+S4wJWp+ZG3M6bnnWHM/vpKa6PErDz0yZlZd2JaT/pZPGuUGOsR Ag2M79JeDjDXa4zIbvJHLNxRmLMQoXeYVM/r6/UGIueJnjCGcY4= =2YLo -----END PGP SIGNATURE----- --PEfPc/DjvCj+JzNg-- -- To unsubscribe from this list: send the line "unsubscribe linux-rdma" in the body of a message to majordomo-u79uwXL29TY76Z2rM5mHXA@public.gmane.org More majordomo info at http://vger.kernel.org/majordomo-info.html