# HG changeset patch
# User Paul Boddie <paul@boddie.org.uk>
# Date 1216592640 -7200
# Node ID ff6235ff830d7dcf8634212679854d5963ea0fac
# Parent  d4dd63e66f6cd71bc5de5d5d3aa5647e1c8278bb
Made module and class attribute storage forbidden via attribute access on
objects, since this is not generally detectable at compile-time. (There would be
a run-time test on other store instructions in order to protect guarantees about
class and module attributes.)
Added name-related instruction attributes to the Translation class.

diff -r d4dd63e66f6c -r ff6235ff830d micropython/ast.py
--- a/micropython/ast.py	Sun Jul 20 23:16:26 2008 +0200
+++ b/micropython/ast.py	Mon Jul 21 00:24:00 2008 +0200
@@ -34,7 +34,9 @@
     supported_optimisations = ["constant_storage", "known_target", "self_access", "temp_storage", "load_operations", "unused_results"]
 
     attribute_load_instructions = (LoadAddress, LoadAddressContext, LoadAttr, LoadAttrIndex)
-    attribute_store_instructions = (StoreAddress, None, StoreAttr, StoreAttrIndex)
+    attribute_store_instructions = (None, None, StoreAttr, StoreAttrIndex)
+    name_load_instructions = (LoadName, LoadAddress)
+    name_store_instructions = (StoreName, StoreAddress)
 
     def __init__(self, module, importer, optimisations=None):
 
@@ -568,7 +570,12 @@
 
                 # Produce a suitable instruction.
 
-                self.replace_op(AddressInstruction(pos))
+                if AddressInstruction is not None:
+                    self.replace_op(AddressInstruction(pos))
+                else:
+                    raise TranslateError(self.module.full_name(), node,
+                        "Storing of class or module attribute %r via an object is not permitted." % attrname)
+
                 return
 
         # Where the last operation involves the special 'self' name, check to
@@ -1118,7 +1125,7 @@
     def visitAssList(self, node): raise TranslationNotImplementedError(self.module.full_name(), node, "AssList")
 
     def visitAssName(self, node):
-        self._visitName(node, (StoreName, StoreAddress))
+        self._visitName(node, self.name_store_instructions)
         self.set_source()
 
     visitAssTuple = visitAssList
@@ -1161,7 +1168,7 @@
 
         self.new_op(LoadConst(node.unit))
         self.record_value()
-        self._visitName(node, (StoreName, StoreAddress))
+        self._visitName(node, self.name_store_instructions)
         self.set_source()
         self.discard_value()
 
@@ -1290,7 +1297,7 @@
             self.new_op(LoadConst(node.unit))
 
             self.record_value()
-            self._visitName(node, (StoreName, StoreAddress))
+            self._visitName(node, self.name_store_instructions)
             self.set_source()
             self.discard_value()
 
@@ -1380,7 +1387,7 @@
             const = self.module.constant_values[None]
             self.new_op(LoadConst(const))
         else:
-            self._visitName(node, (LoadName, LoadAddress))
+            self._visitName(node, self.name_load_instructions)
 
     def visitNot(self, node):
         next_label = self.new_label()
diff -r d4dd63e66f6c -r ff6235ff830d tests/attributes.py
--- a/tests/attributes.py	Sun Jul 20 23:16:26 2008 +0200
+++ b/tests/attributes.py	Mon Jul 21 00:24:00 2008 +0200
@@ -9,7 +9,7 @@
 
     def update(self, value):
         self.attr = value
-        C.clsattr = value
+        C.clsattr
 
 C
 C.clsattr