# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1338854094 -7200
# Node ID 830194e3b6aba66ed25961c77c49010e9aa6e6a9
# Parent  6a5775a852482041a03ae000b2f86e3d518555d4
Reinstated tentative declarations of instance attributes from attribute usage
that can be overridden by the declaration of class attributes for classes in the
same hierarchy. Thus, "mix-in" classes whose methods employ self-based attribute
accesses will not cause instance attributes to be allocated if class attributes
are defined in descendant classes making use of such "mix-in" classes.

diff -r 6a5775a85248 -r 830194e3b6ab micropython/data.py
--- a/micropython/data.py	Tue Jun 05 01:30:05 2012 +0200
+++ b/micropython/data.py	Tue Jun 05 01:54:54 2012 +0200
@@ -1303,6 +1303,7 @@
         self.bases = []
         self.descendants = set()
         self.instattr = set()           # instance attributes
+        self.instattr_tentative = set() # tentative/suspected instance attributes
         self.relocated = set()          # attributes which do not have the same
                                         # position as those of the same name in
                                         # some superclasses
@@ -1446,8 +1447,11 @@
         self.bases.append(base)
         base.add_descendant(self)
 
-    def add_instance_attribute(self, name):
-        self.instattr.add(name)
+    def add_instance_attribute(self, name, tentative=False):
+        if tentative:
+            self.instattr_tentative.add(name)
+        else:
+            self.instattr.add(name)
 
     def add_descendant(self, cls):
         self.descendants.add(cls)
@@ -1553,6 +1557,21 @@
 
         "Make sure that the instance attributes are fully defined."
 
+        # Eliminate tentative instance attributes that are actually class
+        # attributes.
+
+        for attrname in self.all_class_attributes().keys():
+            if attrname in self.instattr_tentative:
+                self.instattr_tentative.remove(attrname)
+
+        for cls in self.descendants:
+            for attrname in cls.class_attribute_names():
+                if attrname in self.instattr_tentative:
+                    self.instattr_tentative.remove(attrname)
+
+        for attrname in self.instattr_tentative:
+            self.instattr.add(attrname)
+
         # Cache the attributes by converting the positioned attributes into a
         # dictionary.
 
diff -r 6a5775a85248 -r 830194e3b6ab micropython/inspect.py
--- a/micropython/inspect.py	Tue Jun 05 01:30:05 2012 +0200
+++ b/micropython/inspect.py	Tue Jun 05 01:54:54 2012 +0200
@@ -327,9 +327,13 @@
         cls.set(name, self.expr, 0)
         self.use_specific_attribute(cls.full_name(), name)
 
-    def store_instance_attr(self, name):
+    def store_instance_attr(self, name, tentative=False):
 
-        "Record instance attribute 'name' in the current class."
+        """
+        Record instance attribute 'name' in the current class. If 'tentative' is
+        set to a true value, the instance attribute will be discarded if a class
+        attribute is observed.
+        """
 
         if self.in_method:
 
@@ -337,7 +341,7 @@
             # Previous namespace is the class.
 
             cls = self.namespaces[-2]
-            cls.add_instance_attribute(name)
+            cls.add_instance_attribute(name, tentative)
 
             # NOTE: The instance attribute, although defined in a specific
             # NOTE: class, obviously appears in all descendant classes.
@@ -514,6 +518,12 @@
             # to be an instance.
 
             else:
+
+                # Record any instance attributes.
+
+                if expr.name == "self":
+                    self.store_instance_attr(attrname, tentative=True)
+
                 attr = make_instance()
 
                 # Note usage of the attribute where a local is involved.