• Arnd Bergmann's avatar
    btrfs: use BUG() instead of BUG_ON(1) · 290342f6
    Arnd Bergmann authored
    BUG_ON(1) leads to bogus warnings from clang when
    CONFIG_PROFILE_ANNOTATED_BRANCHES is set:
    
    fs/btrfs/volumes.c:5041:3: error: variable 'max_chunk_size' is used uninitialized whenever 'if' condition is false
          [-Werror,-Wsometimes-uninitialized]
                    BUG_ON(1);
                    ^~~~~~~~~
    include/asm-generic/bug.h:61:36: note: expanded from macro 'BUG_ON'
     #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                       ^~~~~~~~~~~~~~~~~~~
    include/linux/compiler.h:48:23: note: expanded from macro 'unlikely'
     #  define unlikely(x)   (__branch_check__(x, 0, __builtin_constant_p(x)))
                            ^~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~~
    fs/btrfs/volumes.c:5046:9: note: uninitialized use occurs here
                                 max_chunk_size);
                                 ^~~~~~~~~~~~~~
    include/linux/kernel.h:860:36: note: expanded from macro 'min'
     #define min(x, y)       __careful_cmp(x, y, <)
                                             ^
    include/linux/kernel.h:853:17: note: expanded from macro '__careful_cmp'
                    __cmp_once(x, y, __UNIQUE_ID(__x), __UNIQUE_ID(__y), op))
                                  ^
    include/linux/kernel.h:847:25: note: expanded from macro '__cmp_once'
                    typeof(y) unique_y = (y);               \
                                          ^
    fs/btrfs/volumes.c:5041:3: note: remove the 'if' if its condition is always true
                    BUG_ON(1);
                    ^
    include/asm-generic/bug.h:61:32: note: expanded from macro 'BUG_ON'
     #define BUG_ON(condition) do { if (unlikely(condition)) BUG(); } while (0)
                                   ^
    fs/btrfs/volumes.c:4993:20: note: initialize the variable 'max_chunk_size' to silence this warning
            u64 max_chunk_size;
                              ^
                               = 0
    
    Change it to BUG() so clang can see that this code path can never
    continue.
    Reviewed-by: default avatarNikolay Borisov <nborisov@suse.com>
    Reviewed-by: default avatarDavid Sterba <dsterba@suse.com>
    Signed-off-by: default avatarArnd Bergmann <arnd@arndb.de>
    Signed-off-by: default avatarDavid Sterba <dsterba@suse.com>
    290342f6
file.c 87.3 KB