Better support for the case of typed arrays inheriting from other typed arrays.

lib/dom/scripts/systemnative.py

 #!/usr/bin/python
 # Copyright (c) 2012, the Dart project authors.  Please see the AUTHORS file
 # for details. All rights reserved. Use of this source code is governed by a
 # BSD-style license that can be found in the LICENSE file.
 
 """This module provides shared functionality for the systems to generate
 native binding from the IDL database."""
 
 import emitter
 import os
@@ skipping 583 matching lines @@
     #
     # In the non-root case we have to choose between:
     #
     #   class YImpl extends XImpl { add List<T> methods; }
     #
     # and
     #
     #   class YImpl extends ListBase<T> { copies of transitive XImpl methods; }
     #
     dart_element_type = DartType(element_type)
-    if ('CustomIndexedGetter' in self._interface.ext_attrs or
-        'NumericIndexedGetter' in self._interface.ext_attrs):
+    if self._HasNativeIndexGetter():
       self._EmitNativeIndexGetter(dart_element_type)
     else:
       self._members_emitter.Emit(
           '\n'
           '  $TYPE operator[](int index) {\n'
           '    return item(index);\n'
           '  }\n',
           TYPE=dart_element_type)
 
-    if 'CustomIndexedSetter' in self._interface.ext_attrs:
+    if self._HasNativeIndexSetter():
       self._EmitNativeIndexSetter(dart_element_type)
     else:
       self._members_emitter.Emit(
           '\n'
           '  void operator[]=(int index, $TYPE value) {\n'
           '    throw new UnsupportedOperationException("Cannot assign element of immutable List.");\n'
           '  }\n',
           TYPE=dart_element_type)
 
     self._members_emitter.Emit(
@@ skipping 78 matching lines @@
         '\n'
         '  bool isEmpty() {\n'
         '    return length == 0;\n'
         '  }\n'
         '\n'
         '  Iterator<$TYPE> iterator() {\n'
         '    return new _FixedSizeListIterator<$TYPE>(this);\n'
         '  }\n',
         TYPE=dart_element_type)
 
+  def AmendIndexer(self, element_type):
+    # If interface is marked as having native indexed
+    # getter or setter, we must emit overrides as it's not
+    # guaranteed that the corresponding methods in C++ would be
+    # virtual.  For example, as of time of writing, even though
+    # Uint8ClampedArray inherits from Uint8Array, ::set method
+    # is not virtual and accessing it through Uint8Array pointer
+    # would lead to wrong semantics (modulo vs. clamping.)
+    dart_element_type = DartType(element_type)
+
+    if self._HasNativeIndexGetter():
+      self._EmitNativeIndexGetter(dart_element_type)
+    if self._HasNativeIndexSetter():
+      self._EmitNativeIndexSetter(dart_element_type)
+
+  def _HasNativeIndexGetter(self):
+    ext_attrs = self._interface.ext_attrs
+    return ('CustomIndexedGetter' in ext_attrs or
+        'NumericIndexedGetter' in ext_attrs)
+
   def _EmitNativeIndexGetter(self, element_type):
     dart_declaration = '%s operator[](int index)' % element_type
     self._GenerateNativeBinding('numericIndexGetter', 2, dart_declaration,
         'Callback', True)
 
+  def _HasNativeIndexSetter(self):
+    return 'CustomIndexedSetter' in self._interface.ext_attrs
+
   def _EmitNativeIndexSetter(self, element_type):
     dart_declaration = 'void operator[]=(int index, %s value)' % element_type
     self._GenerateNativeBinding('numericIndexSetter', 3, dart_declaration,
         'Callback', True)
 
   def _AddOperation(self, info):
     """
     Arguments:
       info: An OperationInfo object.
     """
@@ skipping 392 matching lines @@
 def _InstanceOfNode(database, interface):
   if interface.id == 'Node':
     return True
   for parent in interface.parents:
     if not database.HasInterface(parent.type.id):
       continue
     parent_interface = database.GetInterface(parent.type.id)
     if _InstanceOfNode(database, parent_interface):
       return True
   return False