text: # Copyright (c) 2012 The Chromium Authors. All rights reserved.
  # Use of this source code is governed by a BSD-style license that can be
  # found in the LICENSE file.
  
  from code import Code
  from model import PropertyType
  import cpp_util
  import schema_util
  import util_cc_helper
  
  class CCGenerator(object):
    def __init__(self, type_generator, cpp_namespace):
      self._type_generator = type_generator
      self._cpp_namespace = cpp_namespace
  
    def Generate(self, namespace):
      return _Generator(namespace,
                        self._type_generator,
                        self._cpp_namespace).Generate()
  
  
  class _Generator(object):
    """A .cc generator for a namespace.
    """
    def __init__(self, namespace, cpp_type_generator, cpp_namespace):
      self._namespace = namespace
      self._type_helper = cpp_type_generator
      self._cpp_namespace = cpp_namespace
      self._target_namespace = (
          self._type_helper.GetCppNamespaceName(self._namespace))
      self._util_cc_helper = (
          util_cc_helper.UtilCCHelper(self._type_helper))
      self._generate_error_messages = namespace.compiler_options.get(
          'generate_error_messages', False)
  
    def Generate(self):
      """Generates a Code object with the .cc for a single namespace.
      """
      c = Code()
      (c.Append(cpp_util.CHROMIUM_LICENSE)
        .Append()
        .Append(cpp_util.GENERATED_FILE_MESSAGE % self._namespace.source_file)
        .Append()
        .Append(self._util_cc_helper.GetIncludePath())
        .Append('#include "base/logging.h"')
        .Append('#include "base/strings/string_number_conversions.h"')
        .Append('#include "base/strings/utf_string_conversions.h"')
        .Append('#include "%s/%s.h"' %
            (self._namespace.source_file_dir, self._namespace.unix_name))
        .Cblock(self._type_helper.GenerateIncludes(include_soft=True))
        .Append()
        .Concat(cpp_util.OpenNamespace(self._cpp_namespace))
        .Cblock(self._type_helper.GetNamespaceStart())
      )
      if self._namespace.properties:
        (c.Append('//')
          .Append('// Properties')
          .Append('//')
          .Append()
        )
        for property in self._namespace.properties.values():
          property_code = self._type_helper.GeneratePropertyValues(
              property,
              'const %(type)s %(name)s = %(value)s;',
              nodoc=True)
          if property_code:
            c.Cblock(property_code)
      if self._namespace.types:
        (c.Append('//')
          .Append('// Types')
          .Append('//')
          .Append()
          .Cblock(self._GenerateTypes(None, self._namespace.types.values()))
        )
      if self._namespace.functions:
        (c.Append('//')
          .Append('// Functions')
          .Append('//')
          .Append()
        )
      for function in self._namespace.functions.values():
        c.Cblock(self._GenerateFunction(function))
      if self._namespace.events:
        (c.Append('//')
          .Append('// Events')
          .Append('//')
          .Append()
        )
        for event in self._namespace.events.values():
          c.Cblock(self._GenerateEvent(event))
      (c.Concat(self._type_helper.GetNamespaceEnd())
        .Cblock(cpp_util.CloseNamespace(self._cpp_namespace))
      )
      return c
  
    def _GenerateType(self, cpp_namespace, type_):
      """Generates the function definitions for a type.
      """
      classname = cpp_util.Classname(schema_util.StripNamespace(type_.name))
      c = Code()
  
      if type_.functions:
        # Wrap functions within types in the type's namespace.
        (c.Append('namespace %s {' % classname)
          .Append())
        for function in type_.functions.values():
          c.Cblock(self._GenerateFunction(function))
        c.Append('}  // namespace %s' % classname)
      elif type_.property_type == PropertyType.ARRAY:
        c.Cblock(self._GenerateType(cpp_namespace, type_.item_type))
      elif type_.property_type in (PropertyType.CHOICES,
                                   PropertyType.OBJECT):
        if cpp_namespace is None:
          classname_in_namespace = classname
        else:
          classname_in_namespace = '%s::%s' % (cpp_namespace, classname)
  
        if type_.property_type == PropertyType.OBJECT:
          c.Cblock(self._GeneratePropertyFunctions(classname_in_namespace,
                                                   type_.properties.values()))
        else:
          c.Cblock(self._GenerateTypes(classname_in_namespace, type_.choices))
  
        (c.Append('%s::%s()' % (classname_in_namespace, classname))
          .Cblock(self._GenerateInitializersAndBody(type_))
          .Append('%s::~%s() {}' % (classname_in_namespace, classname))
          .Append()
        )
        if type_.origin.from_json:
          c.Cblock(self._GenerateTypePopulate(classname_in_namespace, type_))
          if cpp_namespace is None:  # only generate for top-level types
            c.Cblock(self._GenerateTypeFromValue(classname_in_namespace, type_))
        if type_.origin.from_client:
          c.Cblock(self._GenerateTypeToValue(classname_in_namespace, type_))
      elif type_.property_type == PropertyType.ENUM:
        (c.Cblock(self._GenerateEnumToString(cpp_namespace, type_))
          .Cblock(self._GenerateEnumFromString(cpp_namespace, type_))
        )
  
      return c
  
    def _GenerateInitializersAndBody(self, type_):
      items = []
      for prop in type_.properties.values():
        if prop.optional:
          continue
  
        t = prop.type_
        if t.property_type == PropertyType.INTEGER:
          items.append('%s(0)' % prop.unix_name)
        elif t.property_type == PropertyType.DOUBLE:
          items.append('%s(0.0)' % prop.unix_name)
        elif t.property_type == PropertyType.BOOLEAN:
          items.append('%s(false)' % prop.unix_name)
        elif (t.property_type == PropertyType.ANY or
              t.property_type == PropertyType.ARRAY or
              t.property_type == PropertyType.BINARY or  # mapped to std::string
              t.property_type == PropertyType.CHOICES or
              t.property_type == PropertyType.ENUM or
              t.property_type == PropertyType.OBJECT or
              t.property_type == PropertyType.FUNCTION or
              t.property_type == PropertyType.REF or
              t.property_type == PropertyType.STRING):
          # TODO(miket): It would be nice to initialize CHOICES and ENUM, but we
          # don't presently have the semantics to indicate which one of a set
          # should be the default.
          continue
        else:
          raise TypeError(t)
  
      if items:
        s = ': %s' % (', '.join(items))
      else:
        s = ''
      s = s + ' {}'
      return Code().Append(s)
  
    def _GenerateTypePopulate(self, cpp_namespace, type_):
      """Generates the function for populating a type given a pointer to it.
  
      E.g for type "Foo", generates Foo::Populate()
      """
      classname = cpp_util.Classname(schema_util.StripNamespace(type_.name))
      c = Code()
      (c.Append('// static')
        .Append('bool %(namespace)s::Populate(')
        .Sblock('    %s) {' % self._GenerateParams(
            ('const base::Value& value', '%(name)s* out'))))
  
      if type_.property_type == PropertyType.CHOICES:
        for choice in type_.choices:
          (c.Sblock('if (%s) {' % self._GenerateValueIsTypeExpression('value',
                                                                      choice))
              .Concat(self._GeneratePopulateVariableFromValue(
                  choice,
                  '(&value)',
                  'out->as_%s' % choice.unix_name,
                  'false',
                  is_ptr=True))
              .Append('return true;')
            .Eblock('}')
          )
        (c.Concat(self._GenerateError(
            '"expected %s, got " +  %s' %
                (" or ".join(choice.name for choice in type_.choices),
                self._util_cc_helper.GetValueTypeString('value'))))
          .Append('return false;'))
      elif type_.property_type == PropertyType.OBJECT:
        (c.Sblock('if (!value.IsType(base::Value::TYPE_DICTIONARY)) {')
          .Concat(self._GenerateError(
            '"expected dictionary, got " + ' +
            self._util_cc_helper.GetValueTypeString('value')))
          .Append('return false;')
          .Eblock('}'))
  
        if type_.properties or type_.additional_properties is not None:
          c.Append('const base::DictionaryValue* dict = '
                       'static_cast<const base::DictionaryValue*>(&value);')
        for prop in type_.properties.values():
          c.Concat(self._InitializePropertyToDefault(prop, 'out'))
        for prop in type_.properties.values():
          c.Concat(self._GenerateTypePopulateProperty(prop, 'dict', 'out'))
        if type_.additional_properties is not None:
          if type_.additional_properties.property_type == PropertyType.ANY:
            c.Append('out->additional_properties.MergeDictionary(dict);')
          else:
            cpp_type = self._type_helper.GetCppType(type_.additional_properties,
                                                    is_in_container=True)
            (c.Append('for (base::DictionaryValue::Iterator it(*dict);')
              .Sblock('     !it.IsAtEnd(); it.Advance()) {')
                .Append('%s tmp;' % cpp_type)
                .Concat(self._GeneratePopulateVariableFromValue(
                    type_.additional_properties,
                    '(&it.value())',
                    'tmp',
                    'false'))
                .Append('out->additional_properties[it.key()] = tmp;')
              .Eblock('}')
            )
        c.Append('return true;')
      (c.Eblock('}')
        .Substitute({'namespace': cpp_namespace, 'name': classname}))
      return c
  
    def _GenerateValueIsTypeExpression(self, var, type_):
      real_type = self._type_helper.FollowRef(type_)
      if real_type.property_type is PropertyType.CHOICES:
        return '(%s)' % ' || '.join(self._GenerateValueIsTypeExpression(var,
                                                                        choice)
                                    for choice in real_type.choices)
      return '%s.IsType(%s)' % (var, cpp_util.GetValueType(real_type))
  
    def _GenerateTypePopulateProperty(self, prop, src, dst):
      """Generate the code to populate a single property in a type.
  
      src: base::DictionaryValue*
      dst: Type*
      """
      c = Code()
      value_var = prop.unix_name + '_value'
      c.Append('const base::Value* %(value_var)s = NULL;')
      if prop.optional:
        (c.Sblock(
            'if (%(src)s->GetWithoutPathExpansion("%(key)s", &%(value_var)s)) {')
          .Concat(self._GeneratePopulatePropertyFromValue(
              prop, value_var, dst, 'false')))
        underlying_type = self._type_helper.FollowRef(prop.type_)
        if underlying_type.property_type == PropertyType.ENUM:
          (c.Append('} else {')
            .Append('%%(dst)s->%%(name)s = %s;' %
                self._type_helper.GetEnumNoneValue(prop.type_)))
        c.Eblock('}')
      else:
        (c.Sblock(
            'if (!%(src)s->GetWithoutPathExpansion("%(key)s", &%(value_var)s)) {')
          .Concat(self._GenerateError('"\'%%(key)s\' is required"'))
          .Append('return false;')
          .Eblock('}')
          .Concat(self._GeneratePopulatePropertyFromValue(
              prop, value_var, dst, 'false'))
        )
      c.Append()
      c.Substitute({
        'value_var': value_var,
        'key': prop.name,
        'src': src,
        'dst': dst,
        'name': prop.unix_name
      })
      return c
  
    def _GenerateTypeFromValue(self, cpp_namespace, type_):
      classname = cpp_util.Classname(schema_util.StripNamespace(type_.name))
      c = Code()
      (c.Append('// static')
        .Append('scoped_ptr<%s> %s::FromValue(%s) {' % (classname,
          cpp_namespace, self._GenerateParams(('const base::Value& value',))))
        .Append('  scoped_ptr<%s> out(new %s());' % (classname, classname))
        .Append('  if (!Populate(%s))' % self._GenerateArgs(
            ('value', 'out.get()')))
        .Append('    return scoped_ptr<%s>();' % classname)
        .Append('  return out.Pass();')
        .Append('}')
      )
      return c
  
    def _GenerateTypeToValue(self, cpp_namespace, type_):
      """Generates a function that serializes the type into a base::Value.
      E.g. for type "Foo" generates Foo::ToValue()
      """
      if type_.property_type == PropertyType.OBJECT:
        return self._GenerateObjectTypeToValue(cpp_namespace, type_)
      elif type_.property_type == PropertyType.CHOICES:
        return self._GenerateChoiceTypeToValue(cpp_namespace, type_)
      else:
        raise ValueError("Unsupported property type %s" % type_.type_)
  
    def _GenerateObjectTypeToValue(self, cpp_namespace, type_):
      """Generates a function that serializes an object-representing type
      into a base::DictionaryValue.
      """
      c = Code()
      (c.Sblock('scoped_ptr<base::DictionaryValue> %s::ToValue() const {' %
            cpp_namespace)
          .Append('scoped_ptr<base::DictionaryValue> value('
                      'new base::DictionaryValue());')
          .Append()
      )
  
      for prop in type_.properties.values():
        if prop.optional:
          # Optional enum values are generated with a NONE enum value.
          underlying_type = self._type_helper.FollowRef(prop.type_)
          if underlying_type.property_type == PropertyType.ENUM:
            c.Sblock('if (%s != %s) {' %
                (prop.unix_name,
                 self._type_helper.GetEnumNoneValue(prop.type_)))
          else:
            c.Sblock('if (%s.get()) {' % prop.unix_name)
  
        # ANY is a base::Value which is abstract and cannot be a direct member, so
        # it will always be a pointer.
        is_ptr = prop.optional or prop.type_.property_type == PropertyType.ANY
        c.Append('value->SetWithoutPathExpansion("%s", %s);' % (
            prop.name,
            self._CreateValueFromType(prop.type_,
                                      'this->%s' % prop.unix_name,
                                      is_ptr=is_ptr)))
  
        if prop.optional:
          c.Eblock('}')
  
      if type_.additional_properties is not None:
        if type_.additional_properties.property_type == PropertyType.ANY:
          c.Append('value->MergeDictionary(&additional_properties);')
        else:
          # Non-copyable types will be wrapped in a linked_ptr for inclusion in
          # maps, so we need to unwrap them.
          needs_unwrap = (
              not self._type_helper.IsCopyable(type_.additional_properties))
          cpp_type = self._type_helper.GetCppType(type_.additional_properties,
                                                  is_in_container=True)
          (c.Sblock('for (std::map<std::string, %s>::const_iterator it =' %
                        cpp_util.PadForGenerics(cpp_type))
            .Append('       additional_properties.begin();')
            .Append('   it != additional_properties.end(); ++it) {')
            .Append('value->SetWithoutPathExpansion(it->first, %s);' %
                self._CreateValueFromType(
                    type_.additional_properties,
                    '%sit->second' % ('*' if needs_unwrap else '')))
            .Eblock('}')
          )
  
      return (c.Append()
               .Append('return value.Pass();')
             .Eblock('}'))
  
    def _GenerateChoiceTypeToValue(self, cpp_namespace, type_):
      """Generates a function that serializes a choice-representing type
      into a base::Value.
      """
      c = Code()
      c.Sblock('scoped_ptr<base::Value> %s::ToValue() const {' % cpp_namespace)
      c.Append('scoped_ptr<base::Value> result;')
      for choice in type_.choices:
        choice_var = 'as_%s' % choice.unix_name
        (c.Sblock('if (%s) {' % choice_var)
            .Append('DCHECK(!result) << "Cannot set multiple choices for %s";' %
                        type_.unix_name)
            .Append('result.reset(%s);' %
                        self._CreateValueFromType(choice, '*%s' % choice_var))
          .Eblock('}')
        )
      (c.Append('DCHECK(result) << "Must set at least one choice for %s";' %
                    type_.unix_name)
        .Append('return result.Pass();')
        .Eblock('}')
      )
      return c
  
    def _GenerateFunction(self, function):
      """Generates the definitions for function structs.
      """
      c = Code()
  
      # TODO(kalman): use function.unix_name not Classname.
      function_namespace = cpp_util.Classname(function.name)
      # Windows has a #define for SendMessage, so to avoid any issues, we need
      # to not use the name.
      if function_namespace == 'SendMessage':
        function_namespace = 'PassMessage'
      (c.Append('namespace %s {' % function_namespace)
        .Append()
      )
  
      # Params::Populate function
      if function.params:
        c.Concat(self._GeneratePropertyFunctions('Params', function.params))
        (c.Append('Params::Params() {}')
          .Append('Params::~Params() {}')
          .Append()
          .Cblock(self._GenerateFunctionParamsCreate(function))
        )
  
      # Results::Create function
      if function.callback:
        c.Concat(self._GenerateCreateCallbackArguments('Results',
                                                       function.callback))
  
      c.Append('}  // namespace %s' % function_namespace)
      return c
  
    def _GenerateEvent(self, event):
      # TODO(kalman): use event.unix_name not Classname.
      c = Code()
      event_namespace = cpp_util.Classname(event.name)
      (c.Append('namespace %s {' % event_namespace)
        .Append()
        .Cblock(self._GenerateEventNameConstant(None, event))
        .Cblock(self._GenerateCreateCallbackArguments(None, event))
        .Append('}  // namespace %s' % event_namespace)
      )
      return c
  
    def _CreateValueFromType(self, type_, var, is_ptr=False):
      """Creates a base::Value given a type. Generated code passes ownership
      to caller.
  
      var: variable or variable*
  
      E.g for std::string, generate new base::StringValue(var)
      """
      underlying_type = self._type_helper.FollowRef(type_)
      if (underlying_type.property_type == PropertyType.CHOICES or
          underlying_type.property_type == PropertyType.OBJECT):
        if is_ptr:
          return '(%s)->ToValue().release()' % var
        else:
          return '(%s).ToValue().release()' % var
      elif (underlying_type.property_type == PropertyType.ANY or
            underlying_type.property_type == PropertyType.FUNCTION):
        if is_ptr:
          vardot = '(%s)->' % var
        else:
          vardot = '(%s).' % var
        return '%sDeepCopy()' % vardot
      elif underlying_type.property_type == PropertyType.ENUM:
        return 'new base::StringValue(ToString(%s))' % var
      elif underlying_type.property_type == PropertyType.BINARY:
        if is_ptr:
          vardot = var + '->'
        else:
          vardot = var + '.'
        return ('base::BinaryValue::CreateWithCopiedBuffer(%sdata(), %ssize())' %
                (vardot, vardot))
      elif underlying_type.property_type == PropertyType.ARRAY:
        return '%s.release()' % self._util_cc_helper.CreateValueFromArray(
            underlying_type,
            var,
            is_ptr)
      elif underlying_type.property_type.is_fundamental:
        if is_ptr:
          var = '*%s' % var
        if underlying_type.property_type == PropertyType.STRING:
          return 'new base::StringValue(%s)' % var
        else:
          return 'new base::FundamentalValue(%s)' % var
      else:
        raise NotImplementedError('Conversion of %s to base::Value not '
                                  'implemented' % repr(type_.type_))
  
    def _GenerateParamsCheck(self, function, var):
      """Generates a check for the correct number of arguments when creating
      Params.
      """
      c = Code()
      num_required = 0
      for param in function.params:
        if not param.optional:
          num_required += 1
      if num_required == len(function.params):
        c.Sblock('if (%(var)s.GetSize() != %(total)d) {')
      elif not num_required:
        c.Sblock('if (%(var)s.GetSize() > %(total)d) {')
      else:
        c.Sblock('if (%(var)s.GetSize() < %(required)d'
            ' || %(var)s.GetSize() > %(total)d) {')
      (c.Concat(self._GenerateError(
          '"expected %%(total)d arguments, got " '
          '+ base::IntToString(%%(var)s.GetSize())'))
        .Append('return scoped_ptr<Params>();')
        .Eblock('}')
        .Substitute({
          'var': var,
          'required': num_required,
          'total': len(function.params),
      }))
      return c
  
    def _GenerateFunctionParamsCreate(self, function):
      """Generate function to create an instance of Params. The generated
      function takes a base::ListValue of arguments.
  
      E.g for function "Bar", generate Bar::Params::Create()
      """
      c = Code()
      (c.Append('// static')
        .Sblock('scoped_ptr<Params> Params::Create(%s) {' % self._GenerateParams(
          ['const base::ListValue& args']))
        .Concat(self._GenerateParamsCheck(function, 'args'))
        .Append('scoped_ptr<Params> params(new Params());'))
  
      for param in function.params:
        c.Concat(self._InitializePropertyToDefault(param, 'params'))
  
      for i, param in enumerate(function.params):
        # Any failure will cause this function to return. If any argument is
        # incorrect or missing, those following it are not processed. Note that
        # for optional arguments, we allow missing arguments and proceed because
        # there may be other arguments following it.
        failure_value = 'scoped_ptr<Params>()'
        c.Append()
        value_var = param.unix_name + '_value'
        (c.Append('const base::Value* %(value_var)s = NULL;')
          .Append('if (args.Get(%(i)s, &%(value_var)s) &&')
          .Sblock('    !%(value_var)s->IsType(base::Value::TYPE_NULL)) {')
          .Concat(self._GeneratePopulatePropertyFromValue(
              param, value_var, 'params', failure_value))
          .Eblock('}')
        )
        if not param.optional:
          (c.Sblock('else {')
            .Concat(self._GenerateError('"\'%%(key)s\' is required"'))
            .Append('return %s;' % failure_value)
            .Eblock('}'))
        c.Substitute({'value_var': value_var, 'i': i, 'key': param.name})
      (c.Append()
        .Append('return params.Pass();')
        .Eblock('}')
        .Append()
      )
  
      return c
  
    def _GeneratePopulatePropertyFromValue(self,
                                           prop,
                                           src_var,
                                           dst_class_var,
                                           failure_value):
      """Generates code to populate property |prop| of |dst_class_var| (a
      pointer) from a Value*. See |_GeneratePopulateVariableFromValue| for
      semantics.
      """
      return self._GeneratePopulateVariableFromValue(prop.type_,
                                                     src_var,
                                                     '%s->%s' % (dst_class_var,
                                                                 prop.unix_name),
                                                     failure_value,
                                                     is_ptr=prop.optional)
  
    def _GeneratePopulateVariableFromValue(self,
                                           type_,
                                           src_var,
                                           dst_var,
                                           failure_value,
                                           is_ptr=False):
      """Generates code to populate a variable |dst_var| of type |type_| from a
      Value* at |src_var|. The Value* is assumed to be non-NULL. In the generated
      code, if |dst_var| fails to be populated then Populate will return
      |failure_value|.
      """
      c = Code()
      c.Sblock('{')
  
      underlying_type = self._type_helper.FollowRef(type_)
  
      if underlying_type.property_type.is_fundamental:
        if is_ptr:
          (c.Append('%(cpp_type)s temp;')
            .Sblock('if (!%s) {' % cpp_util.GetAsFundamentalValue(
                        self._type_helper.FollowRef(type_), src_var, '&temp'))
            .Concat(self._GenerateError(
              '"\'%%(key)s\': expected ' + '%s, got " + %s' % (
                  type_.name,
                  self._util_cc_helper.GetValueTypeString(
                      '%%(src_var)s', True))))
            .Append('return %(failure_value)s;')
            .Eblock('}')
            .Append('%(dst_var)s.reset(new %(cpp_type)s(temp));')
          )
        else:
          (c.Sblock('if (!%s) {' % cpp_util.GetAsFundamentalValue(
                        self._type_helper.FollowRef(type_),
                        src_var,
                        '&%s' % dst_var))
            .Concat(self._GenerateError(
              '"\'%%(key)s\': expected ' + '%s, got " + %s' % (
                  type_.name,
                  self._util_cc_helper.GetValueTypeString(
                      '%%(src_var)s', True))))
            .Append('return %(failure_value)s;')
            .Eblock('}')
          )
      elif underlying_type.property_type == PropertyType.OBJECT:
        if is_ptr:
          (c.Append('const base::DictionaryValue* dictionary = NULL;')
            .Sblock('if (!%(src_var)s->GetAsDictionary(&dictionary)) {')
            .Concat(self._GenerateError(
              '"\'%%(key)s\': expected dictionary, got " + ' +
              self._util_cc_helper.GetValueTypeString('%%(src_var)s', True)))
            .Append('return %(failure_value)s;')
            .Eblock('}')
            .Append('scoped_ptr<%(cpp_type)s> temp(new %(cpp_type)s());')
            .Append('if (!%%(cpp_type)s::Populate(%s)) {' % self._GenerateArgs(
              ('*dictionary', 'temp.get()')))
            .Append('  return %(failure_value)s;')
            .Append('}')
            .Append('%(dst_var)s = temp.Pass();')
          )
        else:
          (c.Append('const base::DictionaryValue* dictionary = NULL;')
            .Sblock('if (!%(src_var)s->GetAsDictionary(&dictionary)) {')
            .Concat(self._GenerateError(
              '"\'%%(key)s\': expected dictionary, got " + ' +
              self._util_cc_helper.GetValueTypeString('%%(src_var)s', True)))
            .Append('return %(failure_value)s;')
            .Eblock('}')
            .Append('if (!%%(cpp_type)s::Populate(%s)) {' % self._GenerateArgs(
              ('*dictionary', '&%(dst_var)s')))
            .Append('  return %(failure_value)s;')
            .Append('}')
          )
      elif underlying_type.property_type == PropertyType.FUNCTION:
        if is_ptr:
          c.Append('%(dst_var)s.reset(new base::DictionaryValue());')
      elif underlying_type.property_type == PropertyType.ANY:
        c.Append('%(dst_var)s.reset(%(src_var)s->DeepCopy());')
      elif underlying_type.property_type == PropertyType.ARRAY:
        # util_cc_helper deals with optional and required arrays
        (c.Append('const base::ListValue* list = NULL;')
          .Sblock('if (!%(src_var)s->GetAsList(&list)) {')
            .Concat(self._GenerateError(
              '"\'%%(key)s\': expected list, got " + ' +
              self._util_cc_helper.GetValueTypeString('%%(src_var)s', True)))
            .Append('return %(failure_value)s;')
            .Eblock('}'))
        item_type = self._type_helper.FollowRef(underlying_type.item_type)
        if item_type.property_type == PropertyType.ENUM:
          c.Concat(self._GenerateListValueToEnumArrayConversion(
                       item_type,
                       'list',
                       dst_var,
                       failure_value,
                       is_ptr=is_ptr))
        else:
          (c.Sblock('if (!%s) {' % self._util_cc_helper.PopulateArrayFromList(
                underlying_type,
                'list',
                dst_var,
                is_ptr))
            .Concat(self._GenerateError(
              '"unable to populate array \'%%(parent_key)s\'"'))
            .Append('return %(failure_value)s;')
            .Eblock('}')
          )
      elif underlying_type.property_type == PropertyType.CHOICES:
        if is_ptr:
          (c.Append('scoped_ptr<%(cpp_type)s> temp(new %(cpp_type)s());')
            .Append('if (!%%(cpp_type)s::Populate(%s))' % self._GenerateArgs(
              ('*%(src_var)s', 'temp.get()')))
            .Append('  return %(failure_value)s;')
            .Append('%(dst_var)s = temp.Pass();')
          )
        else:
          (c.Append('if (!%%(cpp_type)s::Populate(%s))' % self._GenerateArgs(
              ('*%(src_var)s', '&%(dst_var)s')))
            .Append('  return %(failure_value)s;'))
      elif underlying_type.property_type == PropertyType.ENUM:
        c.Concat(self._GenerateStringToEnumConversion(type_,
                                                      src_var,
                                                      dst_var,
                                                      failure_value))
      elif underlying_type.property_type == PropertyType.BINARY:
        (c.Sblock('if (!%(src_var)s->IsType(base::Value::TYPE_BINARY)) {')
          .Concat(self._GenerateError(
            '"\'%%(key)s\': expected binary, got " + ' +
            self._util_cc_helper.GetValueTypeString('%%(src_var)s', True)))
          .Append('return %(failure_value)s;')
          .Eblock('}')
          .Append('const base::BinaryValue* binary_value =')
          .Append('    static_cast<const base::BinaryValue*>(%(src_var)s);')
        )
        if is_ptr:
          (c.Append('%(dst_var)s.reset(')
            .Append('    new std::string(binary_value->GetBuffer(),')
            .Append('                    binary_value->GetSize()));')
          )
        else:
          (c.Append('%(dst_var)s.assign(binary_value->GetBuffer(),')
            .Append('                   binary_value->GetSize());')
          )
      else:
        raise NotImplementedError(type_)
      return c.Eblock('}').Substitute({
        'cpp_type': self._type_helper.GetCppType(type_),
        'src_var': src_var,
        'dst_var': dst_var,
        'failure_value': failure_value,
        'key': type_.name,
        'parent_key': type_.parent.name
      })
  
    def _GenerateListValueToEnumArrayConversion(self,
                                                item_type,
                                                src_var,
                                                dst_var,
                                                failure_value,
                                                is_ptr=False):
      """Returns Code that converts a ListValue of string constants from
      |src_var| into an array of enums of |type_| in |dst_var|. On failure,
      returns |failure_value|.
      """
      c = Code()
      accessor = '.'
      if is_ptr:
        accessor = '->'
        cpp_type = self._type_helper.GetCppType(item_type, is_in_container=True)
        c.Append('%s.reset(new std::vector<%s>);' %
                     (dst_var, cpp_util.PadForGenerics(cpp_type)))
      (c.Sblock('for (base::ListValue::const_iterator it = %s->begin(); '
                     'it != %s->end(); ++it) {' % (src_var, src_var))
        .Append('%s tmp;' % self._type_helper.GetCppType(item_type))
        .Concat(self._GenerateStringToEnumConversion(item_type,
                                                     '(*it)',
                                                     'tmp',
                                                     failure_value))
        .Append('%s%spush_back(tmp);' % (dst_var, accessor))
        .Eblock('}')
      )
      return c
  
    def _GenerateStringToEnumConversion(self,
                                        type_,
                                        src_var,
                                        dst_var,
                                        failure_value):
      """Returns Code that converts a string type in |src_var| to an enum with
      type |type_| in |dst_var|. In the generated code, if |src_var| is not
      a valid enum name then the function will return |failure_value|.
      """
      c = Code()
      enum_as_string = '%s_as_string' % type_.unix_name
      (c.Append('std::string %s;' % enum_as_string)
        .Sblock('if (!%s->GetAsString(&%s)) {' % (src_var, enum_as_string))
        .Concat(self._GenerateError(
          '"\'%%(key)s\': expected string, got " + ' +
          self._util_cc_helper.GetValueTypeString('%%(src_var)s', True)))
        .Append('return %s;' % failure_value)
        .Eblock('}')
        .Append('%s = Parse%s(%s);' % (dst_var,
                                       self._type_helper.GetCppType(type_),
                                       enum_as_string))
        .Sblock('if (%s == %s) {' % (dst_var,
                                   self._type_helper.GetEnumNoneValue(type_)))
        .Concat(self._GenerateError(
          '\"\'%%(key)s\': expected \\"' +
          '\\" or \\"'.join(self._type_helper.FollowRef(type_).enum_values) +
          '\\", got \\"" + %s + "\\""' % enum_as_string))
        .Append('return %s;' % failure_value)
        .Eblock('}')
        .Substitute({'src_var': src_var, 'key': type_.name})
      )
      return c
  
    def _GeneratePropertyFunctions(self, namespace, params):
      """Generates the member functions for a list of parameters.
      """
      return self._GenerateTypes(namespace, (param.type_ for param in params))
  
    def _GenerateTypes(self, namespace, types):
      """Generates the member functions for a list of types.
      """
      c = Code()
      for type_ in types:
        c.Cblock(self._GenerateType(namespace, type_))
      return c
  
    def _GenerateEnumToString(self, cpp_namespace, type_):
      """Generates ToString() which gets the string representation of an enum.
      """
      c = Code()
      classname = cpp_util.Classname(schema_util.StripNamespace(type_.name))
  
      if cpp_namespace is not None:
        c.Append('// static')
      maybe_namespace = '' if cpp_namespace is None else '%s::' % cpp_namespace
  
      c.Sblock('std::string %sToString(%s enum_param) {' %
                   (maybe_namespace, classname))
      c.Sblock('switch (enum_param) {')
      for enum_value in self._type_helper.FollowRef(type_).enum_values:
        (c.Append('case %s: ' % self._type_helper.GetEnumValue(type_, enum_value))
          .Append('  return "%s";' % enum_value))
      (c.Append('case %s:' % self._type_helper.GetEnumNoneValue(type_))
        .Append('  return "";')
        .Eblock('}')
        .Append('NOTREACHED();')
        .Append('return "";')
        .Eblock('}')
      )
      return c
  
    def _GenerateEnumFromString(self, cpp_namespace, type_):
      """Generates FromClassNameString() which gets an enum from its string
      representation.
      """
      c = Code()
      classname = cpp_util.Classname(schema_util.StripNamespace(type_.name))
  
      if cpp_namespace is not None:
        c.Append('// static')
      maybe_namespace = '' if cpp_namespace is None else '%s::' % cpp_namespace
  
      c.Sblock('%s%s %sParse%s(const std::string& enum_string) {' %
                   (maybe_namespace, classname, maybe_namespace, classname))
      for i, enum_value in enumerate(
            self._type_helper.FollowRef(type_).enum_values):
        # This is broken up into all ifs with no else ifs because we get
        # "fatal error C1061: compiler limit : blocks nested too deeply"
        # on Windows.
        (c.Append('if (enum_string == "%s")' % enum_value)
          .Append('  return %s;' %
              self._type_helper.GetEnumValue(type_, enum_value)))
      (c.Append('return %s;' % self._type_helper.GetEnumNoneValue(type_))
        .Eblock('}')
      )
      return c
  
    def _GenerateCreateCallbackArguments(self, function_scope, callback):
      """Generate all functions to create Value parameters for a callback.
  
      E.g for function "Bar", generate Bar::Results::Create
      E.g for event "Baz", generate Baz::Create
  
      function_scope: the function scope path, e.g. Foo::Bar for the function
                      Foo::Bar::Baz(). May be None if there is no function scope.
      callback: the Function object we are creating callback arguments for.
      """
      c = Code()
      params = callback.params
      c.Concat(self._GeneratePropertyFunctions(function_scope, params))
  
      (c.Sblock('scoped_ptr<base::ListValue> %(function_scope)s'
                    'Create(%(declaration_list)s) {')
        .Append('scoped_ptr<base::ListValue> create_results('
                'new base::ListValue());')
      )
      declaration_list = []
      for param in params:
        declaration_list.append(cpp_util.GetParameterDeclaration(
            param, self._type_helper.GetCppType(param.type_)))
        c.Append('create_results->Append(%s);' %
            self._CreateValueFromType(param.type_, param.unix_name))
      c.Append('return create_results.Pass();')
      c.Eblock('}')
      c.Substitute({
          'function_scope': ('%s::' % function_scope) if function_scope else '',
          'declaration_list': ', '.join(declaration_list),
          'param_names': ', '.join(param.unix_name for param in params)
      })
      return c
  
    def _GenerateEventNameConstant(self, function_scope, event):
      """Generates a constant string array for the event name.
      """
      c = Code()
      c.Append('const char kEventName[] = "%s.%s";' % (
                   self._namespace.name, event.name))
      return c
  
    def _InitializePropertyToDefault(self, prop, dst):
      """Initialize a model.Property to its default value inside an object.
  
      E.g for optional enum "state", generate dst->state = STATE_NONE;
  
      dst: Type*
      """
      c = Code()
      underlying_type = self._type_helper.FollowRef(prop.type_)
      if (underlying_type.property_type == PropertyType.ENUM and
          prop.optional):
        c.Append('%s->%s = %s;' % (
          dst,
          prop.unix_name,
          self._type_helper.GetEnumNoneValue(prop.type_)))
      return c
  
    def _GenerateError(self, body):
      """Generates an error message pertaining to population failure.
  
      E.g 'expected bool, got int'
      """
      c = Code()
      if not self._generate_error_messages:
        return c
      (c.Append('if (error)')
        .Append('  *error = UTF8ToUTF16(' + body + ');'))
      return c
  
    def _GenerateParams(self, params):
      """Builds the parameter list for a function, given an array of parameters.
      """
      if self._generate_error_messages:
        params = list(params) + ['base::string16* error']
      return ', '.join(str(p) for p in params)
  
    def _GenerateArgs(self, args):
      """Builds the argument list for a function, given an array of arguments.
      """
      if self._generate_error_messages:
        args = list(args) + ['error']
      return ', '.join(str(a) for a in args)
  