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authorRandy Dunlap <rdunlap@infradead.org>2024-01-07 04:24:00 +0300
committerJonathan Corbet <corbet@lwn.net>2024-01-30 23:31:09 +0300
commit91a3d6be99e63f6b0a4b2983aef20bd3da2d1a74 (patch)
tree7c1a15fe1cf996a30ec1b08896c123dafd26cc87 /Documentation/doc-guide
parentd2a70e28ef738765f9226731dfdb3b6c06565456 (diff)
downloadlinux-91a3d6be99e63f6b0a4b2983aef20bd3da2d1a74.tar.xz
doc-guide: kernel-doc: tell about object-like macros
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@infradead.org> Cc: Jonathan Corbet <corbet@lwn.net> Cc: linux-doc@vger.kernel.org Acked-by: Daniel Vetter <daniel.vetter@ffwll.ch> Signed-off-by: Jonathan Corbet <corbet@lwn.net> Link: https://lore.kernel.org/r/20240107012400.32587-1-rdunlap@infradead.org
Diffstat (limited to 'Documentation/doc-guide')
-rw-r--r--Documentation/doc-guide/kernel-doc.rst45
1 files changed, 45 insertions, 0 deletions
diff --git a/Documentation/doc-guide/kernel-doc.rst b/Documentation/doc-guide/kernel-doc.rst
index 6ad72ac6861b..d6f7efefea42 100644
--- a/Documentation/doc-guide/kernel-doc.rst
+++ b/Documentation/doc-guide/kernel-doc.rst
@@ -341,6 +341,51 @@ Typedefs with function prototypes can also be documented::
*/
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
-------------------------------