cache: don't write out the cache unnecessarily

If the only recipes's we reparsed this run were those flagged as not to be
cached, there's no point in re-saving the cache, as those items won't be
included anyway.

(Bitbake rev: 1e0c4dbcbec886a30b89f8b4bb365c3c927ef609)

Signed-off-by: Chris Larson <chris_larson@mentor.com>
Signed-off-by: Richard Purdie <rpurdie@linux.intel.com>

bitbake/lib/bb/cache.py

@@ -247,7 +247,6 @@ class Cache(object):
 
         cached = self.cacheValid(fn)
         if not cached:
-            self.cacheclean = False
             logger.debug(1, "Parsing %s", fn)
             datastores = self.load_bbfile(fn, appends, cfgData)
             depends = set()
@@ -259,6 +258,11 @@ class Cache(object):
                 if depends and not variant:
                     data.setVar("__depends", depends)
                 info = RecipeInfo.from_metadata(fn, data)
+                if not info.nocache:
+                    # The recipe was parsed, and is not marked as being
+                    # uncacheable, so we need to ensure that we write out the
+                    # new cache data.
+                    self.cacheclean = False
                 self.depends_cache[virtualfn] = info
 
         info = self.depends_cache[fn]