On Thu, Mar 7, 2019 at 9:54 AM David Sterba <dste...@suse.cz> wrote: > > On Thu, Mar 07, 2019 at 09:35:15AM -0700, Nathan Chancellor wrote: > > When building with -Wsometimes-uninitialized, Clang warns: > > > > fs/btrfs/uuid-tree.c:129:13: warning: variable 'eb' is used uninitialized > > whenever 'if' condition is false [-Wsometimes-uninitialized] > > fs/btrfs/uuid-tree.c:129:13: warning: variable 'offset' is used > > uninitialized whenever 'if' condition is false [-Wsometimes-uninitialized] > > > > Clang can't tell that all cases are covered with this final else if. > > The chain of conditions is > > if (ret >= 0) > else if (ret == -EEXIST) > else if (ret < 0)
In the few cases we looked at, it seemed that the compiler's heuristic for coverage doesn't try very hard. I assume once you start having more complicated expressions is gets quite difficult to prove. Thanks for the patch Nathan! -- Thanks, ~Nick Desaulniers
