[PATCH] kernel-doc: document object-like preprocessor macros

[Alex Deucher]

On Tue, Jan 9, 2024 at 9:16 AM Daniel Vetter <daniel.vetter at ffwll.ch> wrote:
>
> I had no idea this exists, but Randy pointed out it's been added quite
> a long time ago in cbb4d3e6510b ("scripts/kernel-doc: handle
> object-like macros"). Definitely way before I started to write all the
> drm docs sadly, so there's a few things where I skipped writing
> kernel-doc since I didn't know it was possible.
>
> Fix this asap by documenting the two possible kernel-doc flavours for
> preprocessor definitions.
>
> References: https://lore.kernel.org/dri-devel/dd917333-9ae8-4e76-991d-39b6229ba8ce@infradead.org/
> Cc: Randy Dunlap <rdunlap at infradead.org>
> Cc: Thomas Zimmermann <tzimmermann at suse.de>
> Cc: Maxime Ripard <mripard at kernel.org>
> Cc: Daniel Vetter <daniel.vetter at ffwll.ch>
> Cc: "Steven Rostedt (Google)" <rostedt at goodmis.org>
> Cc: Jonathan Corbet <corbet at lwn.net>
> Cc: linux-doc at vger.kernel.org
> Signed-off-by: Daniel Vetter <daniel.vetter at intel.com>

News to me as well.
Acked-by: Alex Deucher <alexander.deucher at amd.com>

> ---
>  Documentation/doc-guide/kernel-doc.rst | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)
>
> diff --git a/Documentation/doc-guide/kernel-doc.rst b/Documentation/doc-guide/kernel-doc.rst
> index 6ad72ac6861b..a966f1fd5c30 100644
> --- a/Documentation/doc-guide/kernel-doc.rst
> +++ b/Documentation/doc-guide/kernel-doc.rst
> @@ -341,6 +341,32 @@ Typedefs with function prototypes can also be documented::
>     */
>     typedef void (*type_name)(struct v4l2_ctrl *arg1, void *arg2);
>
> +Preprocessor defines documentation
> +----------------------------------
> +
> +There are two ways to document preprocessor defines. The first works more or
> +less like kernel-doc for functions, including parameters::
> +
> +  /**
> +   * FUNC_NAME() - Brief description
> +   * @arg1: description of arg1
> +   * @arg2: description of arg2
> +   *
> +   * Description of the preprocessor function, may have multiple paragraphs.
> +   */
> +  #define FUNC_NAME(arg1, arg2)
> +
> +The second type is different and for object-like preprocessor macros without any
> +parameters::
> +
> +  /**
> +   * define MACRO - Brief description
> +   *
> +   * Description of the object-like preprocessor macro, may have multiple
> +   * paragraphs.
> +   */
> +   #define MACRO
> +
>  Highlights and cross-references
>  -------------------------------
>
> --
> 2.43.0
>