[PATCH v2 4/8] ref-manual/variables.rst: document the LTO variable

[Antonin Godard <antonin.godard@bootlin.com>]

Added by 228b5a91516c ("lto: Add global LTO distro policy file") in
OE-Core.

Signed-off-by: Antonin Godard <antonin.godard@bootlin.com>
---
 documentation/ref-manual/variables.rst | 7 +++++++
 1 file changed, 7 insertions(+)

diff --git a/documentation/ref-manual/variables.rst b/documentation/ref-manual/variables.rst
index 45542d715..6c779e42d 100644
--- a/documentation/ref-manual/variables.rst
+++ b/documentation/ref-manual/variables.rst
@@ -5890,6 +5890,13 @@ system and gives an overview of their function and contents.
       For the directory containing logs specific to each task, see the
       :term:`T` variable.
 
+   :term:`LTO`
+      The :term:`LTO` variable define the flags specific to the ``lto``
+      :term:`distro feature <DISTRO_FEATURES>`. The value of this variable is
+      appended to the :term:`TARGET_LDFLAGS` variable, adding `Link-Time
+      Optimisation <https://gcc.gnu.org/wiki/LinkTimeOptimization>`__ flags to
+      the linker in-use.
+
    :term:`MACHINE`
       Specifies the target device for which the image is built. You define
       :term:`MACHINE` in the ``local.conf`` file found in the

-- 
2.53.0