From mboxrd@z Thu Jan 1 00:00:00 1970 Return-Path: Received: from mail-io1-f66.google.com (mail-io1-f66.google.com [209.85.166.66]) by mail09.linbit.com (LINBIT Mail Daemon) with ESMTP id 951A8103B4AA for ; Mon, 17 Dec 2018 18:29:42 +0100 (CET) Received: by mail-io1-f66.google.com with SMTP id t24so10622013ioi.0 for ; Mon, 17 Dec 2018 09:29:42 -0800 (PST) To: Nathan Chancellor , Philipp Reisner , Lars Ellenberg References: <20181002171447.10765-1-natechancellor@gmail.com> <20181004200912.32348-1-natechancellor@gmail.com> <20181217172401.GA30635@flashbox> From: Jens Axboe Message-ID: <0110d874-7595-1786-77e3-e2b0daec2327@kernel.dk> Date: Mon, 17 Dec 2018 10:29:38 -0700 MIME-Version: 1.0 In-Reply-To: <20181217172401.GA30635@flashbox> Content-Type: text/plain; charset=utf-8 Content-Language: en-US Content-Transfer-Encoding: 7bit Cc: linux-block@vger.kernel.org, Nick Desaulniers , linux-kernel@vger.kernel.org, Arnd Bergmann , drbd-dev@lists.linbit.com Subject: Re: [Drbd-dev] [PATCH v2] drbd: Avoid Clang warning about pointless switch statment List-Id: "*Coordination* of development, patches, contributions -- *Questions* \(even to developers\) go to drbd-user, please." List-Unsubscribe: , List-Archive: List-Post: List-Help: List-Subscribe: , On 12/17/18 10:24 AM, Nathan Chancellor wrote: > On Thu, Oct 04, 2018 at 01:09:13PM -0700, Nathan Chancellor wrote: >> There are several warnings from Clang about no case statement matching >> the constant 0: >> >> In file included from drivers/block/drbd/drbd_receiver.c:48: >> In file included from drivers/block/drbd/drbd_int.h:48: >> In file included from ./include/linux/drbd_genl_api.h:54: >> In file included from ./include/linux/genl_magic_struct.h:236: >> ./include/linux/drbd_genl.h:321:1: warning: no case matching constant >> switch condition '0' >> GENL_struct(DRBD_NLA_HELPER, 24, drbd_helper_info, >> ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~ >> ./include/linux/genl_magic_struct.h:220:10: note: expanded from macro >> 'GENL_struct' >> switch (0) { >> ^ >> >> Silence this warning by adding a 'case 0:' statement. Additionally, >> adjust the alignment of the statements in the ct_assert_unique macro to >> avoid a checkpatch warning. >> >> This solution was originally sent by Arnd Bergmann with a default case >> statement: https://lore.kernel.org/patchwork/patch/756723/ >> >> Link: https://github.com/ClangBuiltLinux/linux/issues/43 >> Suggested-by: Lars Ellenberg >> Signed-off-by: Nathan Chancellor >> --- >> >> Since this is not the same as Arnd's patch, I took authorship for it >> while leaving a link to the original patch in the commit message. If >> this is not how it should have been done, please let me know. >> >> include/linux/genl_magic_struct.h | 5 ++++- >> 1 file changed, 4 insertions(+), 1 deletion(-) >> >> diff --git a/include/linux/genl_magic_struct.h b/include/linux/genl_magic_struct.h >> index 5972e4969197..eeae59d3ceb7 100644 >> --- a/include/linux/genl_magic_struct.h >> +++ b/include/linux/genl_magic_struct.h >> @@ -191,6 +191,7 @@ static inline void ct_assert_unique_operations(void) >> { >> switch (0) { >> #include GENL_MAGIC_INCLUDE_FILE >> + case 0: >> ; >> } >> } >> @@ -209,6 +210,7 @@ static inline void ct_assert_unique_top_level_attributes(void) >> { >> switch (0) { >> #include GENL_MAGIC_INCLUDE_FILE >> + case 0: >> ; >> } >> } >> @@ -218,7 +220,8 @@ static inline void ct_assert_unique_top_level_attributes(void) >> static inline void ct_assert_unique_ ## s_name ## _attributes(void) \ >> { \ >> switch (0) { \ >> - s_fields \ >> + s_fields \ >> + case 0: \ >> ; \ >> } \ >> } >> -- >> 2.19.0 >> > > Hi Lars and Philipp, > > Could you please make sure that this patch and the other one I sent make > it into 4.21/5.0? I am not sure when you were planning on sending the > pull request to Jens that you mentioned in the other thread but I've > noticed most maintainers typically send their requests for the impending > merge window around -rc7 or so and I wanted to make sure it was on your > radar. It needs to get here now, but drbd hasn't really sent anything in for about a year, so I'm starting to doubt how maintained it is at this point. -- Jens Axboe