lib/bb/utils: Add filter()

The bb.utils.filter() function can be used to filter a variable
containing whitespace separated words based on another set of words.
It has been modeled after the bb.utils.contains_any() function.

A typical example of how it can be used is to simplify constructs for
PACKAGECONFIG that depend on DISTRO_FEATURES:

-PACKAGECONFIG ?= "\
-    ${@bb.utils.contains('DISTRO_FEATURES', 'acl', 'acl', '', d)} \
-    ${@bb.utils.contains('DISTRO_FEATURES', 'selinux', 'selinux', '', d)} \
-"
+PACKAGECONFIG ?= "${@bb.utils.filter('DISTRO_FEATURES', 'acl selinux', d)}"

Signed-off-by: Peter Kjellerstedt <peter.kjellerstedt@axis.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

1 files changed, 24 insertions, 0 deletions

diff --git a/lib/bb/utils.py b/lib/bb/utils.py
index 284512629..d6bcfa37e 100644
--- a/lib/bb/utils.py
+++ b/lib/bb/utils.py
@@ -979,6 +979,30 @@ def contains_any(variable, checkvalues, truevalue, falsevalue, d):
         return truevalue
     return falsevalue
 
+def filter(variable, checkvalues, d):
+    """Return all words in the variable that are present in the checkvalues.
+
+    Arguments:
+
+    variable -- the variable name. This will be fetched and expanded (using
+    d.getVar(variable)) and then split into a set().
+
+    checkvalues -- if this is a string it is split on whitespace into a set(),
+    otherwise coerced directly into a set().
+
+    d -- the data store.
+    """
+
+    val = d.getVar(variable)
+    if not val:
+        return ''
+    val = set(val.split())
+    if isinstance(checkvalues, str):
+        checkvalues = set(checkvalues.split())
+    else:
+        checkvalues = set(checkvalues)
+    return ' '.join(sorted(checkvalues & val))
+
 def cpu_count():
     return multiprocessing.cpu_count()