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| author | Johannes Berg <johannes.berg@intel.com> | 2016-10-07 17:02:42 -0700 |
|---|---|---|
| committer | Linus Torvalds <torvalds@linux-foundation.org> | 2016-10-07 18:46:30 -0700 |
| commit | 589a9785ee3a7cb85f1dedc3dad1c9754c691880 (patch) | |
| tree | 2a58cb3d8c4c0e1c9e025750dd4801f99352d7f1 /include | |
| parent | 53aeee7a86620b4dca81f6b807b37f36e7f99b09 (diff) | |
| download | linux-589a9785ee3a7cb85f1dedc3dad1c9754c691880.tar.bz2 | |
min/max: remove sparse warnings when they're nested
Currently, when min/max are nested within themselves, sparse will warn:
warning: symbol '_min1' shadows an earlier one
originally declared here
warning: symbol '_min1' shadows an earlier one
originally declared here
warning: symbol '_min2' shadows an earlier one
originally declared here
This also immediately happens when min3() or max3() are used.
Since sparse implements __COUNTER__, we can use __UNIQUE_ID() to
generate unique variable names, avoiding this.
Link: http://lkml.kernel.org/r/1471519773-29882-1-git-send-email-johannes@sipsolutions.net
Signed-off-by: Johannes Berg <johannes.berg@intel.com>
Cc: Jens Axboe <axboe@kernel.dk>
Signed-off-by: Andrew Morton <akpm@linux-foundation.org>
Signed-off-by: Linus Torvalds <torvalds@linux-foundation.org>
Diffstat (limited to 'include')
| -rw-r--r-- | include/linux/kernel.h | 48 |
1 files changed, 28 insertions, 20 deletions
diff --git a/include/linux/kernel.h b/include/linux/kernel.h index 74fd6f05bc5b..bc6ed52a39b9 100644 --- a/include/linux/kernel.h +++ b/include/linux/kernel.h @@ -733,17 +733,25 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } * strict type-checking.. See the * "unnecessary" pointer comparison. */ -#define min(x, y) ({ \ - typeof(x) _min1 = (x); \ - typeof(y) _min2 = (y); \ - (void) (&_min1 == &_min2); \ - _min1 < _min2 ? _min1 : _min2; }) - -#define max(x, y) ({ \ - typeof(x) _max1 = (x); \ - typeof(y) _max2 = (y); \ - (void) (&_max1 == &_max2); \ - _max1 > _max2 ? _max1 : _max2; }) +#define __min(t1, t2, min1, min2, x, y) ({ \ + t1 min1 = (x); \ + t2 min2 = (y); \ + (void) (&min1 == &min2); \ + min1 < min2 ? min1 : min2; }) +#define min(x, y) \ + __min(typeof(x), typeof(y), \ + __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ + x, y) + +#define __max(t1, t2, max1, max2, x, y) ({ \ + t1 max1 = (x); \ + t2 max2 = (y); \ + (void) (&max1 == &max2); \ + max1 > max2 ? max1 : max2; }) +#define max(x, y) \ + __max(typeof(x), typeof(y), \ + __UNIQUE_ID(max1_), __UNIQUE_ID(max2_), \ + x, y) #define min3(x, y, z) min((typeof(x))min(x, y), z) #define max3(x, y, z) max((typeof(x))max(x, y), z) @@ -775,15 +783,15 @@ static inline void ftrace_dump(enum ftrace_dump_mode oops_dump_mode) { } * * Or not use min/max/clamp at all, of course. */ -#define min_t(type, x, y) ({ \ - type __min1 = (x); \ - type __min2 = (y); \ - __min1 < __min2 ? __min1: __min2; }) - -#define max_t(type, x, y) ({ \ - type __max1 = (x); \ - type __max2 = (y); \ - __max1 > __max2 ? __max1: __max2; }) +#define min_t(type, x, y) \ + __min(type, type, \ + __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ + x, y) + +#define max_t(type, x, y) \ + __max(type, type, \ + __UNIQUE_ID(min1_), __UNIQUE_ID(min2_), \ + x, y) /** * clamp_t - return a value clamped to a given range using a given type |