diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst index 9c7cf73473943710cd77edffda19911f966bda68..7e768c65aa9262862a4681c80421c73b34a6e222 100644 --- a/Documentation/process/coding-style.rst +++ b/Documentation/process/coding-style.rst @@ -827,6 +827,29 @@ Macros with multiple statements should be enclosed in a do - while block: do_this(b, c); \ } while (0) +Function-like macros with unused parameters should be replaced by static +inline functions to avoid the issue of unused variables: + +.. code-block:: c + + static inline void fun(struct foo *foo) + { + } + +Due to historical practices, many files still employ the "cast to (void)" +approach to evaluate parameters. However, this method is not advisable. +Inline functions address the issue of "expression with side effects +evaluated more than once", circumvent unused-variable problems, and +are generally better documented than macros for some reason. + +.. code-block:: c + + /* + * Avoid doing this whenever possible and instead opt for static + * inline functions + */ + #define macrofun(foo) do { (void) (foo); } while (0) + Things to avoid when using macros: 1) macros that affect control flow: