Since 2014 kernel-doc has supported describing object-like macros
but it is not documented anywhere. I should have required some
documentation for it when I merged the patch. :(
There are currently only 3 uses of this (all in DRM headers, in
include/drm/*.h).
Add object-like macro kernel-doc documentation now so that more may
know about it and use it.
Fixes: cbb4d3e6510b ("scripts/kernel-doc: handle object-like macros")
Signed-off-by: Randy Dunlap <rdunlap@xxxxxxxxxxxxx>
Cc: Jonathan Corbet <corbet@xxxxxxx>
Cc: linux-doc@xxxxxxxxxxxxxxx
---
v2: Previous attempts to use kernel-doc were for data definitions,
not macros, so remove that comment.
Remove a duplicate word in the patch description.
Add examples.
Documentation/doc-guide/kernel-doc.rst | 45 +++++++++++++++++++++++
1 file changed, 45 insertions(+)
diff -- a/Documentation/doc-guide/kernel-doc.rst b/Documentation/doc-guide/kernel-doc.rst
--- a/Documentation/doc-guide/kernel-doc.rst
+++ b/Documentation/doc-guide/kernel-doc.rst
@@ -341,6 +341,51 @@ Typedefs with function prototypes can al
*/
typedef void (*type_name)(struct v4l2_ctrl *arg1, void *arg2);
+Object-like macro documentation
+-------------------------------
+
+Object-like macros are distinct from function-like macros. They are
+differentiated by whether the macro name is immediately followed by a
+left parenthesis ('(') for function-like macros or not followed by one
+for object-like macros.
+
+Function-like macros are handled like functions by ``scripts/kernel-doc``.
+They may have a parameter list. Object-like macros have do not have a
+parameter list.
+
+The general format of an object-like macro kernel-doc comment is::
+
+ /**
+ * define object_name - Brief description.
+ *
+ * Description of the object.
+ */
+
+Example::
+
+ /**
+ * define MAX_ERRNO - maximum errno value that is supported
+ *
+ * Kernel pointers have redundant information, so we can use a
+ * scheme where we can return either an error code or a normal
+ * pointer with the same return value.
+ */
+ #define MAX_ERRNO 4095
+
+Example::
+
+ /**
+ * define DRM_GEM_VRAM_PLANE_HELPER_FUNCS - \
+ * Initializes struct drm_plane_helper_funcs for VRAM handling
+ *
+ * This macro initializes struct drm_plane_helper_funcs to use the
+ * respective helper functions.
+ */
+ #define DRM_GEM_VRAM_PLANE_HELPER_FUNCS \
+ .prepare_fb = drm_gem_vram_plane_helper_prepare_fb, \
+ .cleanup_fb = drm_gem_vram_plane_helper_cleanup_fb
+
+
Highlights and cross-references
-------------------------------
