bitbake: tinfoil: add a parse_recipe_file function

Parsing a recipe is such a common task for tinfoil-using scripts, and is
a little awkward to do properly, so add an API function to do it. This
should also isolate scripts a little from future changes to the internal
code. The first user of this will be the OpenEmbedded layer index update
script.

Part of the fix for [YOCTO #10192].

(Bitbake rev: 39780b1ccbd76579db0fc6fb9369c848a3bafa9d)

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

bitbake/lib/bb/tinfoil.py

@@ -90,6 +90,42 @@ class Tinfoil:
             else:
                 self.parseRecipes()
 
+    def parse_recipe_file(self, fn, appends=True, appendlist=None, config_data=None):
+        """
+        Parse the specified recipe file (with or without bbappends)
+        and return a datastore object representing the environment
+        for the recipe.
+        Parameters:
+            fn: recipe file to parse - can be a file path or virtual
+                specification
+            appends: True to apply bbappends, False otherwise
+            appendlist: optional list of bbappend files to apply, if you
+                        want to filter them
+            config_data: custom config datastore to use. NOTE: if you
+                         specify config_data then you cannot use a virtual
+                         specification for fn.
+        """
+        if appends and appendlist == []:
+            appends = False
+        if appends:
+            if appendlist:
+                appendfiles = appendlist
+            else:
+                if not hasattr(self.cooker, 'collection'):
+                    raise Exception('You must call tinfoil.prepare() with config_only=False in order to get bbappends')
+                appendfiles = self.cooker.collection.get_file_appends(fn)
+        else:
+            appendfiles = None
+        if config_data:
+            # We have to use a different function here if we're passing in a datastore
+            localdata = bb.data.createCopy(config_data)
+            envdata = bb.cache.parse_recipe(localdata, fn, appendfiles)['']
+        else:
+            # Use the standard path
+            parser = bb.cache.NoCache(self.cooker.databuilder)
+            envdata = parser.loadDataFull(fn, appendfiles)
+        return envdata
+
     def shutdown(self):
         self.cooker.shutdown(force=True)
         self.cooker.post_serve()