[PATCH AUTOSEL 4.14 126/170] drbd: Avoid Clang warning about pointless switch statment

Sasha Levin
2019-01-28T16:56:44Z

From: Nathan Chancellor <natechancellor@gmail.com>

[ Upstream commit a52c5a16cf19d8a85831bb1b915a221dd4ffae3c ]

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>
Signed-off-by: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Sasha Levin <sashal@kernel.org>
---
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: \
; \
} \
}
--
2.19.1