Support overloaded constructors.

tools/dom/scripts/idlnode.py

 #!/usr/bin/python
 # Copyright (c) 2011, 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.
 
 import os
 import sys
 
 
 class IDLNode(object):
@@ skipping 198 matching lines @@
 
   def __contains__(self, key):
     return key in self.__map
 
   def __iter__(self):
     return self.__map.__iter__()
 
   def get(self, key, default=None):
     return self.__map.get(key, default)
 
+  def setdefault(self, key, value=None):
+    return self.__map.setdefault(key, value)
+
   def items(self):
     return self.__map.items()
 
   def keys(self):
     return self.__map.keys()
 
   def values(self):
     return self.__map.values()
 
   def clear(self):
@@ skipping 51 matching lines @@
     IDLDictNode.__init__(self, None)
     if not ast:
       return
     ext_attrs_ast = self._find_first(ast, 'ExtAttrs')
     if not ext_attrs_ast:
       return
     for ext_attr in self._find_all(ext_attrs_ast, 'ExtAttr'):
       name = self._find_first(ext_attr, 'Id')
       value = self._find_first(ext_attr, 'ExtAttrValue')
 
+      if name == 'Constructor':
+        # There might be multiple constructor attributes, collect them
+        # as a list.  Represent plain Constructor attribute
+        # (without any signature) as None.
+        assert value is None
+        func_value = None
+        ctor_args = self._find_first(ext_attr, 'ExtAttrArgList')
+        if ctor_args:
+          func_value = IDLExtAttrFunctionValue(None, ctor_args)
+        self.setdefault('Constructor', []).append(func_value)
+        continue
+
       func_value = self._find_first(value, 'ExtAttrFunctionValue')
       if func_value:
         # E.g. NamedConstructor=Audio(in [Optional] DOMString src)
         self[name] = IDLExtAttrFunctionValue(
             func_value,
             self._find_first(func_value, 'ExtAttrArgList'))
         continue
 
-      ctor_args = not value and self._find_first(ext_attr, 'ExtAttrArgList')
-      if ctor_args:
-        # E.g. Constructor(Element host)
-        self[name] = IDLExtAttrFunctionValue(None, ctor_args)
-        continue
-
       self[name] = value
 
   def _all_subnodes(self):
     # Extended attributes may contain IDLNodes, e.g. IDLExtAttrFunctionValue
     return self.values()
 
 
 class IDLExtAttrFunctionValue(IDLNode):
   """IDLExtAttrFunctionValue."""
   def __init__(self, func_value_ast, arg_list_ast):
@@ skipping 201 matching lines @@
   """IDLDictNode specialization for one annotation."""
   def __init__(self, ast=None):
     IDLDictNode.__init__(self, ast)
     self.id = None
     if not ast:
       return
     for arg in self._find_all(ast, 'AnnotationArg'):
       name = self._find_first(arg, 'Id')
       value = self._find_first(arg, 'AnnotationArgValue')
       self[name] = value