Do not pass tautology predicates into check list.

lib/html/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 455 matching lines @@
 
     body = self._members_emitter.Emit(
         '\n'
         '  $DECLARATION {\n'
         '$!BODY'
         '  }\n',
         DECLARATION=dart_declaration)
 
     version = [1]
     def GenerateCall(operation, argument_count, checks):
-      checks = filter(lambda e: e != 'true', checks)
       if checks:
         if operation.type.id != 'void':
           template = '    if ($CHECKS) {\n      return $CALL;\n    }\n'
         else:
           template = '    if ($CHECKS) {\n      $CALL;\n      return;\n    }\n'
       else:
         if operation.type.id != 'void':
           template = '    return $CALL;\n'
         else:
           template = '    $CALL;\n'
 
       overload_name = '%s_%s' % (operation.id, version[0])
       version[0] += 1
       argument_list = ', '.join(argument_names[:argument_count])
       call = '_%s(%s)' % (overload_name, argument_list)
       body.Emit(template, CHECKS=' && '.join(checks), CALL=call)
 
       dart_declaration = '%s%s _%s(%s)' % (
           'static ' if operation.is_static else '',
           SecureOutputType(self, 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):
-      checks = ['!?%s' % name for name in argument_names]
+      checks = []
       for i in range(0, argument_count):
         argument = operation.arguments[i]
         argument_name = argument_names[i]
         type = self._DartType(argument.type.id)
         if type not in ['dynamic', 'Object']:
-          checks[i] = '(%s is %s || %s == null)' % (argument_name, type, argument_name)
-        else:
-          checks[i] = 'true'
+          checks.append('(%s is %s || %s == null)' % (argument_name, type, argument_name))
+      checks.extend(['!?%s' % name for name in argument_names[argument_count:]])
       GenerateCall(operation, argument_count, checks)
 
     # 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');
@@ skipping 338 matching lines @@
   def EmitResolver(self, template, output_dir):
     file_path = os.path.join(output_dir, 'DartResolver.cpp')
     includes_emitter, body_emitter = self._emitters.FileEmitter(file_path).Emit(template)
     for header_file in self._headers_list:
       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])