bitbake: cooker/event: Add an event which lists all stamps reachable after parsing

The metadata can potentially use such an event to clean up any
"unreachable" data, solving several problems we currently have
where obsolete data may continue to exist in the shared areas.

(Bitbake rev: c5e6f929f3d5eeb7954660dea62611c58b795ff8)

Signed-off-by: Richard Purdie <richard.purdie@linuxfoundation.org>

bitbake/lib/bb/cooker.py

@@ -1477,6 +1477,11 @@ class BBCooker:
             self.handlePrefProviders()
             self.recipecache.bbfile_priority = self.collection.collection_priorities(self.recipecache.pkg_fn, self.data)
             self.state = state.running
+
+            # Send an event listing all stamps reachable after parsing
+            # which the metadata may use to clean up stale data
+            event = bb.event.ReachableStamps(self.recipecache.stamp)
+            bb.event.fire(event, self.expanded_data)
             return None
 
         return True

bitbake/lib/bb/event.py

@@ -497,6 +497,16 @@ class TargetsTreeGenerated(Event):
         Event.__init__(self)
         self._model = model
 
+class ReachableStamps(Event):
+    """
+    An event listing all stamps reachable after parsing
+    which the metadata may use to clean up stale data
+    """
+
+    def __init__(self, stamps):
+        Event.__init__(self)
+        self.stamps = stamps
+
 class FilesMatchingFound(Event):
     """
     Event when a list of files matching the supplied pattern has