Change how MorphologyLoader instances are created

Loading .morph files is becoming a bit more complicated, as we need to
deal with the VERSION file, and possibly soon with a DEFAULTS file as
well.

The logic of loading and parsing .morph files is done either in the
sourceresolver module, or the morphloader module. This change means that
all users of the latter module can use the get hold of a
MorphologyLoader instance with VERSION already parsed. If DEFAULTS is
added then it is also simple to parse DEFAULTS.

Change-Id: Ib33756e9dbd078e38f12dd7f776c89584b178959

1 files changed, 21 insertions, 5 deletions

diff --git a/morphlib/definitions_repo.py b/morphlib/definitions_repo.py
index c1381af6..301e5b86 100644
--- a/morphlib/definitions_repo.py
+++ b/morphlib/definitions_repo.py
@@ -124,10 +124,8 @@ class DefinitionsRepo(gitdir.GitDirectory):
             bb = morphlib.buildbranch.BuildBranch(
                 build_ref_prefix, uuid, definitions_repo=self)
 
-        loader = morphlib.morphloader.MorphologyLoader()
         pbb = morphlib.buildbranch.pushed_build_branch(
-            bb, loader=loader,
-            changes_need_pushing=push, name=git_user_name,
+            bb, changes_need_pushing=push, name=git_user_name,
             email=git_user_email, build_uuid=uuid,
             status=status_cb)
         return pbb   # (repo_url, commit, original_ref)
@@ -228,11 +226,29 @@ class DefinitionsRepo(gitdir.GitDirectory):
                     'to "origin", or use the --local-changes=include feature '
                     'of Morph.' % (e.ref, e.repo_url, ref))
 
-    def load_all_morphologies(self, loader):
+    def get_morphology_loader(self):
+        '''Return a MorphologyLoader instance.
+
+        This may read the VERSION and DEFAULTS file and pass appropriate
+        information to the MorphologyLoader constructor.
+
+        '''
+        mf = morphlib.morphologyfinder.MorphologyFinder(self)
+
+        version_text = mf.read_file('VERSION')
+        morphlib.definitions_version.check_version_file(version_text)
+
+        loader = morphlib.morphloader.MorphologyLoader()
+
+        return loader
+
+    def load_all_morphologies(self, loader=None):
+        loader = loader or self.get_morphology_loader()
+
         mf = morphlib.morphologyfinder.MorphologyFinder(self)
         for filename in (f for f in mf.list_morphologies()
                          if not self.is_symlink(f)):
-            text = mf.read_morphology(filename)
+            text = mf.read_file(filename)
             m = loader.load_from_string(text, filename=filename)
             m.repo_url = self.remote_url
             m.ref = self.HEAD