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

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

[Daniel Vetter]

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@infradead.org>
Cc: Thomas Zimmermann <tzimmermann@suse.de>
Cc: Maxime Ripard <mripard@kernel.org>
Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
Cc: "Steven Rostedt (Google)" <rostedt@goodmis.org>
Cc: Jonathan Corbet <corbet@lwn.net>
Cc: linux-doc@vger.kernel.org
Signed-off-by: Daniel Vetter <daniel.vetter@intel.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

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

[Alex Deucher]

On Tue, Jan 9, 2024 at 9:16 AM Daniel Vetter <daniel.vetter@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@infradead.org>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: "Steven Rostedt (Google)" <rostedt@goodmis.org>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: linux-doc@vger.kernel.org
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>

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

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

[Jonathan Corbet]

Daniel Vetter <daniel.vetter@ffwll.ch> writes:

> 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@infradead.org>
> Cc: Thomas Zimmermann <tzimmermann@suse.de>
> Cc: Maxime Ripard <mripard@kernel.org>
> Cc: Daniel Vetter <daniel.vetter@ffwll.ch>
> Cc: "Steven Rostedt (Google)" <rostedt@goodmis.org>
> Cc: Jonathan Corbet <corbet@lwn.net>
> Cc: linux-doc@vger.kernel.org
> Signed-off-by: Daniel Vetter <daniel.vetter@intel.com>
> ---
>  Documentation/doc-guide/kernel-doc.rst | 26 ++++++++++++++++++++++++++
>  1 file changed, 26 insertions(+)

Applied, thanks.

jon