Re: [PATCH v3 1/1] coding-style: recommend split headers instead of kernel.h

Yueh-Shun Li
2024-05-06T23:18:02Z

On 2024-01-28 14:26, Randy Dunlap wrote:
> On 1/8/24 12:22, Yueh-Shun Li wrote:
> > In section "18) Don't re-invent the kernel macros" in "Linux kernel
> > coding style":
> >
> > Recommend reusing macros from headers inside include/linux, instead of
> > the obsolete include/linux/kernel.h
> >
> > Change wording
> >
> > - "The header file contains macros" -> "the header files provide macros"
> > Some macros are intended to use inside the header file only, or are
> > considered the implementation detail of other facilities. Developers
> > are expected to determine if a macro is meant to be used outside the
> > header file.
> >
> > Signed-off-by: Yueh-Shun Li <shamrocklee@posteo.net>
>
> Acked-by: Randy Dunlap <rdunlap@infradead.org>
> Thanks.
>

Thank you for acknowledging.

Anything I could help to push it forward?

> > ---
> > Documentation/process/coding-style.rst | 24 +++++++++++++-----------
> > 1 file changed, 13 insertions(+), 11 deletions(-)
> >
> > diff --git a/Documentation/process/coding-style.rst b/Documentation/process/coding-style.rst
> > index 6db37a46d305..2a5c4f4c568c 100644
> > --- a/Documentation/process/coding-style.rst
> > +++ b/Documentation/process/coding-style.rst
> > @@ -1048,27 +1048,29 @@ readable alternative if the call-sites have naked true/false constants.
> > Otherwise limited use of bool in structures and arguments can improve
> > readability.
> >
> > +
> > 18) Don't re-invent the kernel macros
> > -------------------------------------
> >
> > -The header file include/linux/kernel.h contains a number of macros that
> > -you should use, rather than explicitly coding some variant of them yourself.
> > +The header files in the ``include/linux`` directory provide a number of macros
> > +that you should use, rather than explicitly coding some variant of them
> > +yourself.
> > +
> > For example, if you need to calculate the length of an array, take advantage
> > -of the macro
> > +of the macro ``ARRAY_SIZE()`` from ``include/linux/array_size.h`` by
> >
> > .. code-block:: c
> >
> > - #define ARRAY_SIZE(x) (sizeof(x) / sizeof((x)[0]))
> > + #include <linux/array_size.h>
> > + ARRAY_SIZE(x) // The size of array x
> >
> > Similarly, if you need to calculate the size of some structure member, use
> > +``sizeof_field()`` from ``include/linux/stddef.h``.
> >
> > -.. code-block:: c
> > -
> > - #define sizeof_field(t, f) (sizeof(((t*)0)->f))
> > -
> > -There are also min() and max() macros that do strict type checking if you
> > -need them. Feel free to peruse that header file to see what else is already
> > -defined that you shouldn't reproduce in your code.
> > +There are also ``min()`` and ``max()`` macros in ``include/linux/minmax.h``
> > +that do strict type checking if you need them. Feel free to search across and
> > +peruse the header files to see what else is already defined that you shouldn't
> > +reproduce in your code.
> >
> >
> > 19) Editor modelines and other cruft

Best regards,

Yueh-Shun