Support generation of constructors in the most common case.

client/dom/scripts/dartgenerator.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 generates Dart APIs from the IDL database."""
 
 import emitter
 import idlnode
 import logging
@@ skipping 2686 matching lines @@
 
   def StartInterface(self):
     self._class_name = self._ImplClassName(self._interface.id)
     self._interface_type_info = GetIDLTypeInfoByName(self._interface.id)
     self._members_emitter = emitter.Emitter()
     self._cpp_declarations_emitter = emitter.Emitter()
     self._cpp_impl_includes = {}
     self._cpp_definitions_emitter = emitter.Emitter()
     self._cpp_resolver_emitter = emitter.Emitter()
 
-    # Generate constructor.
-    # FIXME: add proper support for non-custom constructors.
-    if ('CustomConstructor' in self._interface.ext_attrs or
-        'V8CustomConstructor' in self._interface.ext_attrs or
-        self._interface.id in ['FileReader', 'WebKitCSSMatrix', 'XSLTProcessor']):
-      self._cpp_resolver_emitter.Emit(
-          '    if (name == "$(INTERFACE_NAME)_constructor_Callback")\n'
-          '        return Dart$(INTERFACE_NAME)Internal::constructorCallback;\n',
-          INTERFACE_NAME=self._interface.id)
+    self._GenerateConstructors()
+
+  def _GenerateConstructors(self):
+    # WebKit IDLs may define constructors with arguments.  Currently this form is not supported
+    # (see b/1721).  There is custom implementation for some of them, the rest are just ignored
+    # for now.
+    SUPPORTED_CONSTRUCTORS_WITH_ARGS = [ 'WebKitCSSMatrix' ]
+    UNSUPPORTED_CONSTRUCTORS_WITH_ARGS = [
+        'EventSource',
+        'MediaStream',
+        'PeerConnection',
+        'ShadowRoot',
+        'SharedWorker',
+        'TextTrackCue',
+        'Worker' ]
+    if not self._IsConstructable() or self._interface.id in UNSUPPORTED_CONSTRUCTORS_WITH_ARGS:
+      return
+
+    # TODO(antonm): currently we don't have information about number of arguments expected by
+    # the constructor, so name only dispatch.
+    self._cpp_resolver_emitter.Emit(
+        '    if (name == "$(INTERFACE_NAME)_constructor_Callback")\n'
+        '        return Dart$(INTERFACE_NAME)Internal::constructorCallback;\n',
+        INTERFACE_NAME=self._interface.id)
+
+
+    if self._interface.id in SUPPORTED_CONSTRUCTORS_WITH_ARGS or 'Constructor' not in self._interface.ext_attrs:
+      # We have a custom implementation for it.
       self._cpp_declarations_emitter.Emit(
           '\n'
           'void constructorCallback(Dart_NativeArguments);\n')
+      return
+
+    raises_dom_exceptions = 'ConstructorRaisesException' in self._interface.ext_attrs
+    raises_dart_exceptions = raises_dom_exceptions
+    type_info = GetIDLTypeInfo(self._interface)
+    arguments = []
+    parameter_definitions = ''
+    if 'CallWith' in self._interface.ext_attrs:
+      call_with = self._interface.ext_attrs['CallWith']
+      if call_with == 'ScriptExecutionContext':
+        raises_dart_exceptions = True
+        parameter_definitions = (
+            '        ScriptExecutionContext* context = DartUtilities::scriptExecutionContext();\n'
+            '        if (!context) {\n'
+            '            exception = Dart_NewString("Failed to create an object");\n'
+            '            goto fail;\n'
+            '        }\n')
+        arguments = ['context']
+      else:
+        raise Exception('Unsupported CallWith=%s attribute' % call_with)
+
+    self._GenerateNativeCallback(
+        callback_name='constructorCallback',
+        idl_node=self._interface,
+        parameter_definitions=parameter_definitions,
+        needs_receiver=False, function_name='%s::create' % type_info.native_type(),
+        arguments=arguments,
+        idl_return_type=self._interface,
+        raises_dart_exceptions=raises_dart_exceptions,
+        raises_dom_exceptions=raises_dom_exceptions)
+
 
   def _ImplClassName(self, interface_name):
     return interface_name + 'Implementation'
 
+  def _IsConstructable(self):
+    # FIXME: support ConstructorTemplate.
+    return set(['CustomConstructor', 'V8CustomConstructor', 'Constructor']) & set(self._interface.ext_attrs)
+
   def FinishInterface(self):
     base = self._BaseClassName(self._interface)
     self._dart_impl_emitter.Emit(
         self._templates.Load('dart_implementation.darttemplate'),
         CLASS=self._class_name, BASE=base, INTERFACE=self._interface.id,
         MEMBERS=self._members_emitter.Fragments())
 
     self._GenerateCppHeader()
 
     self._cpp_impl_emitter.Emit(
@@ skipping 92 matching lines @@
         webcore_function_name = re.sub(r'^(HTML|URL|JS|XML|XSLT|\w)',
                                        lambda s: s.group(1).lower(),
                                        attr.id)
         webcore_function_name = re.sub(r'^(create|exclusive)',
                                        lambda s: 'is' + s.group(1).capitalize(),
                                        webcore_function_name)
       if attr.type.id.startswith('SVGAnimated'):
         webcore_function_name += 'Animated'
 
     self._GenerateNativeCallback(cpp_callback_name, attr, '',
-        webcore_function_name, arguments, idl_return_type=attr.type,
+        True, webcore_function_name, arguments, idl_return_type=attr.type,
         raises_dart_exceptions=attr.get_raises,
         raises_dom_exceptions=attr.get_raises)
 
   def _AddSetter(self, attr):
     dart_declaration = 'void set %s(%s)' % (attr.id, attr.type.id)
     is_custom = set(['Custom', 'CustomSetter', 'V8CustomSetter']) & set(attr.ext_attrs)
     cpp_callback_name = self._GenerateNativeBinding(attr.id, 2,
         dart_declaration, 'Setter', is_custom)
     if is_custom:
       return
 
     arguments = []
     if 'Reflect' in attr.ext_attrs:
       webcore_function_name = GetIDLTypeInfo(attr.type).webcore_setter_name()
       arguments.append(self._GenerateWebCoreReflectionAttributeName(attr))
     else:
       webcore_function_name = re.sub(r'^(xml(?=[A-Z])|\w)',
                                      lambda s: s.group(1).upper(),
                                      attr.id)
       webcore_function_name = 'set%s' % webcore_function_name
       if attr.type.id.startswith('SVGAnimated'):
         webcore_function_name += 'Animated'
 
     arguments.append(attr.id)
     parameter_definitions_emitter = emitter.Emitter()
     self._GenerateParameterAdapter(parameter_definitions_emitter, attr, 0)
     parameter_definitions = parameter_definitions_emitter.Fragments()
     self._GenerateNativeCallback(cpp_callback_name, attr, parameter_definitions,
-        webcore_function_name, arguments, idl_return_type=None,
+        True, webcore_function_name, arguments, idl_return_type=None,
         raises_dart_exceptions=True,
         raises_dom_exceptions=attr.set_raises)
 
   def _HasNativeIndexGetter(self, interface):
     return ('CustomIndexedGetter' in interface.ext_attrs or
             'NumericIndexedGetter' in interface.ext_attrs)
 
   def _EmitNativeIndexGetter(self, interface, element_type):
     dart_declaration = '%s operator[](int index)' % element_type
     self._GenerateNativeBinding('numericIndexGetter', 2, dart_declaration,
@@ skipping 144 matching lines @@
     if self._interface.id == 'CSSStyleDeclaration' and operation.id == 'setProperty':
       # CSSStyleDeclaration.setProperty priority parameter is optional in Dart
       # idl, but is not optional in webcore implementation.
       if len(operation.arguments) == 2:
         arguments.append('String()')
 
     if 'NeedsUserGestureCheck' in operation.ext_attrs:
       arguments.extend('DartUtilities::processingUserGesture')
 
     parameter_definitions = parameter_definitions_emitter.Fragments()
-    self._GenerateNativeCallback(cpp_callback_name, operation,
-        parameter_definitions, webcore_function_name, arguments,
-        idl_return_type=operation.type,
+    self._GenerateNativeCallback(cpp_callback_name, operation, parameter_definitions,
+        True, webcore_function_name, arguments, idl_return_type=operation.type,
         raises_dart_exceptions=raises_dart_exceptions,
         raises_dom_exceptions=operation.raises)
 
   def _GenerateNativeCallback(self, callback_name, idl_node,
-      parameter_definitions, function_name, arguments, idl_return_type,
+      parameter_definitions, needs_receiver, function_name, arguments, idl_return_type,
       raises_dart_exceptions, raises_dom_exceptions):
-    receiver = self._interface_type_info.receiver()
     if raises_dom_exceptions:
       arguments.append('ec')
-    callback = '%s%s(%s)' % (receiver, function_name, ', '.join(arguments))
+    prefix = ''
+    if needs_receiver: prefix = self._interface_type_info.receiver()
+    callback = '%s%s(%s)' % (prefix, function_name, ', '.join(arguments))
 
     nested_templates = []
     if idl_return_type and idl_return_type.id != 'void':
       return_type_info = GetIDLTypeInfo(idl_return_type)
       conversion_cast = return_type_info.conversion_cast('$BODY')
       if isinstance(return_type_info, SVGTearOffIDLTypeInfo):
         svg_primitive_types = ['SVGAngle', 'SVGLength', 'SVGMatrix',
             'SVGNumber', 'SVGPoint', 'SVGRect', 'SVGTransform']
         conversion_cast = '%s::create($BODY)'
         if self._interface.id.startswith('SVGAnimated'):
@@ skipping 25 matching lines @@
       nested_templates.append(
           '        ExceptionCode ec = 0;\n'
           '$BODY'
           '        if (UNLIKELY(ec)) {\n'
           '            exception = DartDOMWrapper::exceptionCodeToDartException(ec);\n'
           '            goto fail;\n'
           '        }\n')
 
     nested_templates.append(
         '    {\n'
-        '        $WEBCORE_CLASS_NAME* receiver = DartDOMWrapper::receiver< $WEBCORE_CLASS_NAME >(args);\n'
         '$PARAMETER_DEFINITIONS'
-        '\n'
         '$BODY'
         '        return;\n'
         '    }\n')
 
     if raises_dart_exceptions:
       nested_templates.append(
           '    Dart_Handle exception;\n'
           '$BODY'
           '\n'
           'fail:\n'
           '    Dart_ThrowException(exception);\n'
           '    ASSERT_NOT_REACHED();\n')
 
     nested_templates.append(
         '\n'
         'static void $CALLBACK_NAME(Dart_NativeArguments args)\n'
         '{\n'
         '    DartApiScope dartApiScope;\n'
         '$BODY'
         '}\n')
 
     template_parameters = {
         'CALLBACK_NAME': callback_name,
         'WEBCORE_CLASS_NAME': self._interface_type_info.native_type(),
         'PARAMETER_DEFINITIONS': parameter_definitions,
     }
+    if needs_receiver:
+      template_parameters['PARAMETER_DEFINITIONS'] = emitter.Format(
+          '        $WEBCORE_CLASS_NAME* receiver = DartDOMWrapper::receiver< $WEBCORE_CLASS_NAME >(args);\n'
+          '        $PARAMETER_DEFINITIONS\n',
+          **template_parameters)
+
     for template in nested_templates:
       template_parameters['BODY'] = callback
-      callback_emitter = emitter.Emitter()
-      callback_emitter.Emit(template, **template_parameters)
-      callback = ''.join(callback_emitter.Fragments())
+      callback = emitter.Format(template, **template_parameters)
 
     self._cpp_definitions_emitter.Emit(callback)
 
   def _GenerateParameterAdapter(self, emitter, idl_argument, index):
     type_info = GetIDLTypeInfo(idl_argument.type)
     (adapter_type, include_name) = type_info.parameter_adapter_info()
     if include_name:
       self._cpp_impl_includes[include_name] = 1
     emitter.Emit(
         '\n'
@@ skipping 35 matching lines @@
     namespace = 'HTMLNames'
     svg_exceptions = ['class', 'id', 'onabort', 'onclick', 'onerror', 'onload',
                       'onmousedown', 'onmousemove', 'onmouseout', 'onmouseover',
                       'onmouseup', 'onresize', 'onscroll', 'onunload']
     if self._interface.id.startswith('SVG') and not attr.id in svg_exceptions:
       namespace = 'SVGNames'
     self._cpp_impl_includes[namespace] = 1
 
     attribute_name = attr.ext_attrs['Reflect'] or attr.id.lower()
     return 'WebCore::%s::%sAttr' % (namespace, attribute_name)