bitbake: lib/bb/utils: add function to get layer containing a file

In certain contexts it can be useful to find the layer that a file (e.g.
a recipe) appears in.

Implements [YOCTO #7723].

(Bitbake master rev: 3bf9c8830c5d5eea5502230d5af84ebd87ad5849)

(Bitbake rev: 8dcd83e5edb1cf3307b610d3bb8d54733ea7356d)

Signed-off-by: Paul Eggleton <paul.eggleton@linux.intel.com>
Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/utils.py

@@ -1097,3 +1097,19 @@ def edit_bblayers_conf(bblayers_conf, add, remove):
 
     return (notadded, notremoved)
 
+
+def get_file_layer(filename, d):
+    """Determine the collection (as defined by a layer's layer.conf file) containing the specified file"""
+    collections = (d.getVar('BBFILE_COLLECTIONS', True) or '').split()
+    collection_res = {}
+    for collection in collections:
+        collection_res[collection] = d.getVar('BBFILE_PATTERN_%s' % collection, True) or ''
+
+    # Use longest path so we handle nested layers
+    matchlen = 0
+    match = None
+    for collection, regex in collection_res.iteritems():
+        if len(regex) > matchlen and re.match(regex, filename):
+            matchlen = len(regex)
+            match = collection
+    return match