This exists to stop people from using the bits while the feature is in
active development. We had the same patch a few days (weeks?) ago.
* Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx> [240906 11:05]:
> A few functions defined but not used. This, in particular,
> prevents kernel builds with clang, `make W=1` and CONFIG_WERROR=y:
>
> lib/maple_tree.c:351:21: error: unused function 'mte_set_full' [-Werror,-Wunused-function]
> 351 | static inline void *mte_set_full(const struct maple_enode *node)
> | ^~~~~~~~~~~~
> lib/maple_tree.c:356:21: error: unused function 'mte_clear_full' [-Werror,-Wunused-function]
> 356 | static inline void *mte_clear_full(const struct maple_enode *node)
> | ^~~~~~~~~~~~~~
> lib/maple_tree.c:361:20: error: unused function 'mte_has_null' [-Werror,-Wunused-function]
> 361 | static inline bool mte_has_null(const struct maple_enode *node)
> | ^~~~~~~~~~~~
>
> Fix this by dropping unused functions.
>
> See also commit 6863f5643dd7 ("kbuild: allow Clang to find unused static
> inline functions for W=1 build").
>
> Fixes: 6e7ba8b5e238 ("maple_tree: mte_set_full() and mte_clear_full() clang-analyzer clean up")
> Fixes: 54a611b60590 ("Maple Tree: add new data structure")
> Signed-off-by: Andy Shevchenko <andriy.shevchenko@xxxxxxxxxxxxxxx>
> ---
> lib/maple_tree.c | 15 ---------------
> 1 file changed, 15 deletions(-)
>
> diff --git a/lib/maple_tree.c b/lib/maple_tree.c
> index aa3a5df15b8e..f7601aa470e0 100644
> --- a/lib/maple_tree.c
> +++ b/lib/maple_tree.c
> @@ -348,21 +348,6 @@ static inline void *mte_safe_root(const struct maple_enode *node)
> return (void *)((unsigned long)node & ~MAPLE_ROOT_NODE);
> }
>
> -static inline void *mte_set_full(const struct maple_enode *node)
> -{
> - return (void *)((unsigned long)node & ~MAPLE_ENODE_NULL);
> -}
> -
> -static inline void *mte_clear_full(const struct maple_enode *node)
> -{
> - return (void *)((unsigned long)node | MAPLE_ENODE_NULL);
> -}
> -
> -static inline bool mte_has_null(const struct maple_enode *node)
> -{
> - return (unsigned long)node & MAPLE_ENODE_NULL;
> -}
> -
> static __always_inline bool ma_is_root(struct maple_node *node)
> {
> return ((unsigned long)node->parent & MA_ROOT_PARENT);
> --
> 2.43.0.rc1.1336.g36b5255a03ac
>
