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From: Lars Ellenberg <lars.ellenberg@linbit.com>
To: Jens Axboe <axboe@kernel.dk>,
	linux-kernel@vger.kernel.org, linux-block@vger.kernel.org
Cc: drbd-dev@lists.linbit.com
Subject: [PATCH 16/17] drbd: Avoid Clang warning about pointless switch statment
Date: Thu, 20 Dec 2018 17:23:43 +0100	[thread overview]
Message-ID: <20181220162344.8430-17-lars.ellenberg@linbit.com> (raw)
In-Reply-To: <20181220162344.8430-1-lars.ellenberg@linbit.com>

From: Nathan Chancellor <natechancellor@gmail.com>

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 <lars.ellenberg@linbit.com>
Signed-off-by: Nathan Chancellor <natechancellor@gmail.com>
---
 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:								\
 			;						\
 	}								\
 }
-- 
2.17.1


  parent reply	other threads:[~2018-12-20 16:44 UTC|newest]

Thread overview: 19+ messages / expand[flat|nested]  mbox.gz  Atom feed  top
2018-12-20 16:23 [PATCH 00/17] DRBD updates for 4.21 Lars Ellenberg
2018-12-20 16:23 ` [PATCH 01/17] drbd: narrow rcu_read_lock in drbd_sync_handshake Lars Ellenberg
2018-12-20 16:23 ` [PATCH 02/17] drbd: must not use connection after kref_put(&connection->kref) Lars Ellenberg
2018-12-20 16:23 ` [PATCH 03/17] drbd: centralize printk reporting of new size into drbd_set_my_capacity() Lars Ellenberg
2018-12-20 16:23 ` [PATCH 04/17] drbd: ignore "all zero" peer volume sizes in handshake Lars Ellenberg
2018-12-20 16:23 ` [PATCH 05/17] drbd: disconnect, if the wrong UUIDs are attached on a connected peer Lars Ellenberg
2018-12-20 16:23 ` [PATCH 06/17] drbd: fix confusing error message during attach Lars Ellenberg
2018-12-20 16:23 ` [PATCH 07/17] drbd: attach on connected diskless peer must not shrink a consistent device Lars Ellenberg
2018-12-20 16:23 ` [PATCH 08/17] drbd: reject attach of unsuitable uuids even if connected Lars Ellenberg
2018-12-20 16:23 ` [PATCH 09/17] drbd: fix comment typos Lars Ellenberg
2018-12-20 16:23 ` [PATCH 10/17] drbd: do not block when adjusting "disk-options" while IO is frozen Lars Ellenberg
2018-12-20 16:23 ` [PATCH 11/17] drbd: avoid spurious self-outdating with concurrent disconnect / down Lars Ellenberg
2018-12-20 16:23 ` [PATCH 12/17] drbd: fix print_st_err()'s prototype to match the definition Lars Ellenberg
2018-12-20 16:23 ` [PATCH 13/17] drbd: don't retry connection if peers do not agree on "authentication" settings Lars Ellenberg
2018-12-20 16:23 ` [PATCH 14/17] drbd: skip spurious timeout (ping-timeo) when failing promote Lars Ellenberg
2018-12-20 16:23 ` [PATCH 15/17] drbd: introduce P_ZEROES (REQ_OP_WRITE_ZEROES on the "wire") Lars Ellenberg
2018-12-20 16:23 ` Lars Ellenberg [this message]
2018-12-20 16:23 ` [PATCH 17/17] drbd: Change drbd_request_detach_interruptible's return type to int Lars Ellenberg
2018-12-20 16:27 ` [PATCH 00/17] DRBD updates for 4.21 Jens Axboe

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