[rtems-libbsd commit] doc: Update rules to modify FreeBSD code

[Sebastian Huber]

Module:    rtems-libbsd
Branch:    master
Commit:    a971614a9150ce906b8448fee544041f009117b8
Changeset: http://git.rtems.org/rtems-libbsd/commit/?id=a971614a9150ce906b8448fee544041f009117b8

Author:    Sebastian Huber <sebastian.huber at embedded-brains.de>
Date:      Fri Aug 19 11:18:52 2016 +0200

doc: Update rules to modify FreeBSD code

---

 libbsd.txt | 30 ++++++++++++++++++++++++++++++
 1 file changed, 30 insertions(+)

diff --git a/libbsd.txt b/libbsd.txt
index f4b0746..6b9e2a9 100644
--- a/libbsd.txt
+++ b/libbsd.txt
@@ -625,6 +625,36 @@ include a `__rtems__` in the guards to make searches easy, so use
 * `#else /* __rtems__ */`, and
 * `#endif /* __rtems__ */`.
 
+The guards must start at the begin of the line.  Examples for wrong guards:
+
+-------------------------------------------------------------------------------
+static void
+guards_must_start_at_the_begin_of_the_line(int j)
+{
+
+	#ifdef __rtems__
+	return (j + 1);
+	#else /* __rtems__ */
+	return (j + 2);
+	#endif /* __rtems__ */
+}
+
+static void
+missing_rtems_comments_in_the_guards(int j)
+{
+
+#ifdef __rtems__
+	return (j + 3);
+#else
+	return (j + 4);
+#endif
+}
+-------------------------------------------------------------------------------
+
+Do not disable option header includes via guards.  Instead, add an empty option
+header, e.g. `rtemsbsd/include/rtems/bsd/local/opt_xyz.h`.  In general, provide
+empty header files and do not guard includes.
+
 For new code use
 http://www.freebsd.org/cgi/man.cgi?query=style&apropos=0&sektion=9&manpath=FreeBSD+9.2-RELEASE&arch=default&format=html[STYLE(9)].
 Do not format original FreeBSD code.