On 2019/3/8 6:10 上午, Nathan Chancellor wrote: > When building with -Wsometimes-uninitialized, Clang warns: > > drivers/md/bcache/alloc.c:333:4: warning: variable 'bucket' is used > uninitialized whenever 'if' condition is false > [-Wsometimes-uninitialized] > > fifo_pop expands to a conditional depending on '!fifo_empty(...)', which > is the same condition as the while loop. It seems Clang can't piece > together that this condition will never been false as long as we are in > the while loop because they are the same condition. It's easy enough to > silence this warning by just explicitly zero initializing bucket. > > Link: https://github.com/ClangBuiltLinux/linux/issues/396 > Signed-off-by: Nathan Chancellor <natechancellor@xxxxxxxxx> Hi Nathan, Nice catch, I will add it to my for-test. Thanks. Coly Li > --- > drivers/md/bcache/alloc.c | 2 +- > 1 file changed, 1 insertion(+), 1 deletion(-) > > diff --git a/drivers/md/bcache/alloc.c b/drivers/md/bcache/alloc.c > index 5002838ea476..c72094901ac6 100644 > --- a/drivers/md/bcache/alloc.c > +++ b/drivers/md/bcache/alloc.c > @@ -328,7 +328,7 @@ static int bch_allocator_thread(void *arg) > * the free list: > */ > while (!fifo_empty(&ca->free_inc)) { > - long bucket; > + long bucket = 0; > > fifo_pop(&ca->free_inc, bucket); > > -- Coly Li
