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authorScott Rifenbark <srifenbark@gmail.com>2016-07-22 08:36:09 -0700
committerRichard Purdie <richard.purdie@linuxfoundation.org>2016-08-02 15:20:38 +0100
commit8006da3f229d0227215ccd59cd273edacf72f9ce (patch)
treec4f51f249f797a7e46531cf14ecba3c5006d4f2c /doc
parentd8ae3775eefe3f7b62fc26cae5b742ae83850c13 (diff)
downloadbitbake-contrib-8006da3f229d0227215ccd59cd273edacf72f9ce.tar.gz
bitbake-user-manual: Added non-existant variable expansion
Fixes [YOCTO #10003] I added a small paragraph explaining what happens when expansion of a variable that does not exist occurs. Signed-off-by: Scott Rifenbark <srifenbark@gmail.com>
Diffstat (limited to 'doc')
-rw-r--r--doc/bitbake-user-manual/bitbake-user-manual-metadata.xml11
1 files changed, 11 insertions, 0 deletions
diff --git a/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml b/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
index fe04103da..ce0e84db0 100644
--- a/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
+++ b/doc/bitbake-user-manual/bitbake-user-manual-metadata.xml
@@ -86,6 +86,17 @@
<link linkend='immediate-variable-expansion'>immediate variable expansion</link>
operator (i.e. ":=").
</para>
+
+ <para>
+ If the variable expansion syntax is used on a variable that
+ does not exist, the string is kept as is.
+ For example, given the following assignment,
+ <filename>BAR</filename> expands to the literal string
+ "${FOO}" as long as <filename>FOO</filename> does not exist.
+ <literallayout class='monospaced'>
+ BAR = "${FOO}"
+ </literallayout>
+ </para>
</section>
<section id='setting-a-default-value'>