[lkml]   [2008]   [May]   [30]   [last100]   RSS Feed
Views: [wrap][no wrap]   [headers]  [forward] 
Messages in this thread
Patch in this message
Subject[PATCH] doc: document the kernel-doc conventions for kernel hackers
From: Paul Jackson <>

Provide documentation of the kernel-doc documentation conventions
oriented to kernel hackers.

Since I figure that there will be more people reading this
kernel-doc-nano-HOWTO.txt file who are kernel developers focused
on the rest of the kernel, than there will be readers of this
file who are documentation developers extracting that embedded
kernel-doc documentation, I have taken the liberty of making
the new section added here:

How to format kernel-doc comments

the first section of the kernel-doc-nano-HOWTO.txt file.

This first section is intended to introduce, motivate and
provide basic usage of the kernel-doc mechanism for kernel
hackers developing other portions of the kernel.

Signed-off-by: Paul Jackson <>
Cc: Randy Dunlap <>
Cc: Alan Cox <>

Documentation/kernel-doc-nano-HOWTO.txt | 99 ++++++++++++++++++++++++++++++++
1 file changed, 99 insertions(+)

--- linux-2.6.orig/Documentation/kernel-doc-nano-HOWTO.txt 2008-05-30 08:47:13.000000000 -0700
+++ linux-2.6/Documentation/kernel-doc-nano-HOWTO.txt 2008-05-30 13:31:07.111325343 -0700
@@ -1,6 +1,105 @@
kernel-doc nano-HOWTO

+How to format kernel-doc comments
+In order to provide an embedded, 'C' friendly, easy to maintain,
+but consistent and extractable documentation of the functions and
+data structures in the Linux kernel, the Linux kernel has adopted
+a consistent style for documenting functions and their parameters,
+and structures and their members.
+The format for this documentation is called the kernel-doc format.
+It as documented in this Documentation/kernel-doc-nano-HOWTO.txt file.
+This style embeds the documentation within the source files, using
+a few simple conventions. The scripts/kernel-doc perl script, some
+SGML templates in Documentation/DocBook, and other tools understand
+these conventions, and are used to extract this embedded documentation
+into various documents.
+In order to provide good documentation of kernel functions and data
+structures, please use the following conventions to format your
+kernel-doc comments in Linux kernel source.
+We definitely need kernel-doc formatted documentation for functions
+that are exported to loadable modules using EXPORT_SYMBOL.
+We also look to provide kernel-doc formatted documentation for
+functions externally visible to other kernel files (not marked
+We also recommend providing kernel-doc formatted documentation
+for private (file "static") routines, for consistency of kernel
+source code layout. But this is lower priority and at the
+discretion of the MAINTAINER of that kernel source file.
+Data structures visible in kernel include files should also be
+documented using kernel-doc formatted comments.
+The opening comment mark "/**" is reserved for kernel-doc comments.
+Only comments so marked will be considered by the kernel-doc scripts,
+and any comment so marked must be in kernel-doc format. Do not use
+"/**" to be begin a comment block unless the comment block contains
+kernel-doc formatted comments. The closing comment marker for
+kernel-doc comments can be either "*/" or "**/".
+Kernel-doc comments should be placed just before the function
+or data structure being describe.
+Example kernel-doc function comment:
+ * foobar() - short function description of foobar
+ * @arg1: Describe the first argument to foobar.
+ * @arg2: Describe the second argument to foobar.
+ * One can provide multiple line descriptions
+ * for arguments.
+ *
+ * A longer description, with more discussion of the function foobar()
+ * that might be useful to those using or modifying it. Begins with
+ * empty comment line, and may include additional embedded empty
+ * comment lines.
+ *
+ * The longer description can have multiple paragraphs.
+ **/
+The first line, with the short description, must be on a single line.
+The @argument descriptions must begin on the very next line following
+this opening short function description line, with no intervening
+empty comment lines.
+Example kernel-doc data structure comment.
+ * struct blah - the basic blah structure
+ * @mem1: describe the first member of struct blah
+ * @mem2: describe the second member of struct blah,
+ * perhaps with more lines and words.
+ *
+ * Longer description of this structure.
+ **/
+The kernel-doc function comments describe each parameter to the
+function, in order, with the @name lines.
+The kernel-doc data structure comments describe each structure member
+in the data structure, with the @name lines.
+The longer description formatting is "reflowed", loosing your line
+breaks. So presenting carefully formatted lists within these
+descriptions won't work so well; derived documentation will loose
+the formatting.
+See the section below "How to add extractable documentation to your
+source files" for more details and notes on how to format kernel-doc
+Components of the kernel-doc system
Many places in the source tree have extractable documentation in the
form of block comments above functions. The components of this system
I won't rest till it's the best ...
Programmer, Linux Scalability
Paul Jackson <> 1.650.933.1373

 \ /
  Last update: 2008-05-30 22:37    [W:0.040 / U:0.156 seconds]
©2003-2020 Jasper Spaans|hosted at Digital Ocean and TransIP|Read the blog|Advertise on this site