# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1382835351 -7200
# Node ID 7aec95a715a8c85867fe77ae581d6bcbbc2cb618
# Parent  108075b4c4c41daf4beaea85fbdfd86d313e9e90
Removed "reverse" branches, since generation of local assignment information
should now be deferred until after attribute usage has been determined and
complete name/user definition information has become available.

diff -r 108075b4c4c4 -r 7aec95a715a8 docs/annotations.txt
--- a/docs/annotations.txt	Sun Oct 27 02:39:45 2013 +0200
+++ b/docs/annotations.txt	Sun Oct 27 02:55:51 2013 +0200
@@ -67,8 +67,6 @@
                     branch
 _attrbranches       indicates the immediate contributors to attribute usage
                     known to a node
-_attrrevbranches    indicates the immediate recipients of attribute usage known
-                    to a node (and is thus the inverse of _attrbranches)
 _attrcontributors   defines nodes contributing to combined attribute usage known
                     to a node (and is thus the accumulation of all contributors
                     via branches)
diff -r 108075b4c4c4 -r 7aec95a715a8 micropython/branch.py
--- a/micropython/branch.py	Sun Oct 27 02:39:45 2013 +0200
+++ b/micropython/branch.py	Sun Oct 27 02:55:51 2013 +0200
@@ -381,11 +381,6 @@
         if node._attrbranches is None:
             node._attrbranches = []
 
-        # Branches receiving usage from this node.
-
-        if node._attrrevbranches is None:
-            node._attrrevbranches = []
-
         # Definitions receiving usage from this node.
 
         if node._attrdefs is None:
@@ -542,7 +537,6 @@
         for user in all_users:
             self._init_attribute_user(user)
             user._attrbranches.append(node)
-            node._attrrevbranches.append(user)
 
     def _abandon_branch(self, retain_branch=True):
 
diff -r 108075b4c4c4 -r 7aec95a715a8 micropython/data.py
--- a/micropython/data.py	Sun Oct 27 02:39:45 2013 +0200
+++ b/micropython/data.py	Sun Oct 27 02:55:51 2013 +0200
@@ -574,29 +574,15 @@
         self.users = None
 
     def _get_defining_users(self):
-
-        # NOTE: Re-evaluation may be necessary in places like loops where more
-        # NOTE: branch information may be added.
-
         if self.users is None:
             users = set()
-            visited = set()
             for node in self.nodes:
-                self._get_defining_users_for_node(node, visited, users)
+                for user in node._attrdefs or [node]:
+                    if user._values and user._values.has_key(self.name):
+                        users.add(user)
             self.users = users
         return self.users
 
-    def _get_defining_users_for_node(self, node, visited, users):
-        if node in visited:
-            return
-        visited.add(node)
-        if not node._attrrevbranches:
-            if node._values and node._values.has_key(self.name):
-                users.add(node)
-            return
-        for n in node._attrrevbranches:
-            self._get_defining_users_for_node(n, visited, users)
-
     def get_assignments(self):
         return len(self._get_defining_users())