Next step in overload dispatcher refactoring.

tools/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 470 matching lines @@
 
       dart_declaration = '%s%s _%s(%s)' % (
           'static ' if operation.is_static else '',
           self.SecureOutputType(operation.type.id),
           overload_name, argument_list)
       cpp_callback_name = self._GenerateNativeBinding(
           overload_name, (0 if operation.is_static else 1) + argument_count,
           dart_declaration, 'Callback', False)
       self._GenerateOperationNativeCallback(operation, operation.arguments[:argument_count], cpp_callback_name)
 
-    def GenerateChecksAndCall(operation, argument_count):
-      GenerateCall(operation, argument_count,
-          self._OverloadChecks(operation, parameter_names, argument_count))
-
-    # TODO: Optimize the dispatch to avoid repeated checks.
-    if len(operations) > 1:
-      for operation in operations:
-        for position, argument in enumerate(operation.arguments):
-          if self._IsArgumentOptionalInWebCore(operation, argument):
-            GenerateChecksAndCall(operation, position)
-        GenerateChecksAndCall(operation, len(operation.arguments))
-      body.Emit('    throw "Incorrect number or type of arguments";\n');
-    else:
-      operation = operations[0]
-      argument_count = len(operation.arguments)
-      for position, argument in list(enumerate(operation.arguments))[::-1]:
-        if self._IsArgumentOptionalInWebCore(operation, argument):
-          check = '?%s' % parameter_names[position]
-          # argument_count instead of position + 1 is used here to cover one
-          # complicated case with the effectively optional argument in the middle.
-          # Consider foo(x, [Optional] y, [Optional=DefaultIsNullString] z)
-          # (as of now it's modelled after HTMLMediaElement.webkitAddKey).
-          # y is optional in WebCore, while z is not.
-          # In this case, if y was actually passed, we'd like to emit foo(x, y, z) invocation,
-          # not foo(x, y).
-          GenerateCall(operation, argument_count, [check])
-          argument_count = position
-      GenerateCall(operation, argument_count, [])
+    self._GenerateDispatcherBody(
+        body,
+        operations,
+        parameter_names,
+        GenerateCall,
+        self._IsArgumentOptionalInWebCore)
 
   def SecondaryContext(self, interface):
     pass
 
   def _GenerateOperationNativeCallback(self, operation, arguments, cpp_callback_name):
     webcore_function_name = operation.ext_attrs.get('ImplementedAs', operation.id)
     function_expression = self._GenerateWebCoreFunctionExpression(webcore_function_name, operation)
     self._GenerateNativeCallback(
         cpp_callback_name,
         not operation.is_static,
@@ skipping 378 matching lines @@
         LIBRARY_NAME=library_name)
 
       headers = self._library_headers[library_name]
       for header_file in headers:
         path = os.path.relpath(header_file, output_dir)
         includes_emitter.Emit('#include "$PATH"\n', PATH=path)
         body_emitter.Emit(
             '    if (Dart_NativeFunction func = $CLASS_NAME::resolver(name, argumentCount))\n'
             '        return func;\n',
             CLASS_NAME=os.path.splitext(os.path.basename(path))[0])