ref-manual/classes.rst: document the relative_symlinks class

Added by commit e478550c8cd8 ("openssl/fontconfig/bzip2: Use relative
symlinks instead of absolute ones (using a new class)") in OE-Core.

(From yocto-docs rev: c0dc554eba7d421023ecc68a70b7a19df38628b0)

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 19 insertions, 0 deletions

diff --git a/documentation/ref-manual/classes.rst b/documentation/ref-manual/classes.rst
index 0e616420cf..2a69d2d59b 100644
--- a/documentation/ref-manual/classes.rst
+++ b/documentation/ref-manual/classes.rst
@@ -2498,6 +2498,25 @@ The :ref:`ref-classes-recipe_sanity` class checks for the presence of any host s
 recipe prerequisites that might affect the build (e.g. variables that
 are set or software that is present).
 
+.. _ref-classes-relative_symlinks:
+
+``relative_symlinks``
+=====================
+
+The :ref:`ref-classes-relative_symlinks` class walks the symbolic links in the
+:term:`D` directory and replaces links pointing to absolute paths to relative
+paths. This is occasionally used in some recipes that create wrong symbolic
+links when their :ref:`ref-classes-native` version is built, and/or would cause
+breakage in the :ref:`overview-manual/concepts:shared state cache`.
+
+For example, if the following symbolic link is found in :term:`D`::
+
+   /usr/bin/foo -> /sbin/bar
+
+It is replaced by::
+
+   /usr/bin/foo -> ../../sbin/bar
+
 .. _ref-classes-relocatable:
 
 ``relocatable``