From mboxrd@z Thu Jan 1 00:00:00 1970 From: Dennis Dalessandro Subject: Re: [PATCH 02/47] IB/cm: Suppress gcc 7 fall-through complaints Date: Tue, 10 Oct 2017 15:49:22 -0400 Message-ID: <09736345-fb33-5cde-b571-862454334faf@intel.com> References: <20171006213333.6721-1-bart.vanassche@wdc.com> <20171006213333.6721-3-bart.vanassche@wdc.com> <849d304a-fa89-0d6a-6edb-cf34780e41a8@intel.com> <20171010193127.GK2106@mtr-leonro.local> Mime-Version: 1.0 Content-Type: text/plain; charset=windows-1252; format=flowed Content-Transfer-Encoding: 7bit Return-path: In-Reply-To: <20171010193127.GK2106-U/DQcQFIOTAAJjI8aNfphQ@public.gmane.org> Content-Language: en-US Sender: linux-rdma-owner-u79uwXL29TY76Z2rM5mHXA@public.gmane.org To: Leon Romanovsky Cc: Bart Van Assche , Doug Ledford , linux-rdma-u79uwXL29TY76Z2rM5mHXA@public.gmane.org, Sean Hefty List-Id: linux-rdma@vger.kernel.org On 10/10/2017 3:31 PM, Leon Romanovsky wrote: > 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 Ah, makes sense now, thanks Leon. -- 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