runtime/vm/object.cc

// 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.

#include "vm/object.h"

#include "include/dart_api.h"
#include "platform/assert.h"
#include "vm/assembler.h"
#include "vm/cpu.h"
#include "vm/bigint_operations.h"
#include "vm/bootstrap.h"
#include "vm/class_finalizer.h"
#include "vm/code_generator.h"
#include "vm/code_observers.h"
#include "vm/code_patcher.h"
#include "vm/compiler.h"
#include "vm/compiler_stats.h"
#include "vm/dart.h"
#include "vm/dart_api_state.h"
#include "vm/dart_entry.h"
#include "vm/datastream.h"
#include "vm/debugger.h"
#include "vm/deopt_instructions.h"
#include "vm/double_conversion.h"
#include "vm/exceptions.h"
#include "vm/growable_array.h"
#include "vm/heap.h"
#include "vm/intermediate_language.h"
#include "vm/intrinsifier.h"
#include "vm/object_store.h"
#include "vm/parser.h"
#include "vm/runtime_entry.h"
#include "vm/scopes.h"
#include "vm/stack_frame.h"
#include "vm/symbols.h"
#include "vm/timer.h"
#include "vm/unicode.h"

namespace dart {

DEFINE_FLAG(bool, show_internal_names, false,
    "Show names of internal classes (e.g. \"OneByteString\") in error messages "
    "instead of showing the corresponding interface names (e.g. \"String\")");
DEFINE_FLAG(bool, trace_disabling_optimized_code, false,
    "Trace disabling optimized code.");
DEFINE_FLAG(int, huge_method_cutoff_in_tokens, 20000,
    "Huge method cutoff in tokens: Disables optimizations for huge methods.");
DEFINE_FLAG(int, huge_method_cutoff_in_code_size, 200000,
    "Huge method cutoff in unoptimized code size (in bytes).");
DECLARE_FLAG(bool, trace_compiler);
DECLARE_FLAG(bool, eliminate_type_checks);
DECLARE_FLAG(bool, enable_type_checks);

static const char* kGetterPrefix = "get:";
static const intptr_t kGetterPrefixLength = strlen(kGetterPrefix);
static const char* kSetterPrefix = "set:";
static const intptr_t kSetterPrefixLength = strlen(kSetterPrefix);

cpp_vtable Object::handle_vtable_ = 0;
cpp_vtable Object::builtin_vtables_[kNumPredefinedCids] = { 0 };
cpp_vtable Smi::handle_vtable_ = 0;

// These are initialized to a value that will force a illegal memory access if
// they are being used.
#if defined(RAW_NULL)
#error RAW_NULL should not be defined.
#endif
#define RAW_NULL kHeapObjectTag
Array* Object::empty_array_ = NULL;
Instance* Object::sentinel_ = NULL;
Instance* Object::transition_sentinel_ = NULL;
Bool* Object::bool_true_ = NULL;
Bool* Object::bool_false_ = NULL;
LanguageError* Object::snapshot_writer_error_ = NULL;

RawObject* Object::null_ = reinterpret_cast<RawObject*>(RAW_NULL);
RawClass* Object::class_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::null_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::dynamic_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::void_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::unresolved_class_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::type_arguments_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::instantiated_type_arguments_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::patch_class_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::function_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::closure_data_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::redirection_data_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::field_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::literal_token_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::token_stream_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::script_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::library_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::library_prefix_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::namespace_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::code_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::instructions_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::pc_descriptors_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::stackmap_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::var_descriptors_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::exception_handlers_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::deopt_info_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::context_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::context_scope_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::icdata_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::megamorphic_cache_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::subtypetestcache_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::api_error_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::language_error_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::unhandled_exception_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::unwind_error_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
#undef RAW_NULL


const double MegamorphicCache::kLoadFactor = 0.75;


// The following functions are marked as invisible, meaning they will be hidden
// in the stack trace.
// (Library, class name, method name)
#define INVISIBLE_LIST(V)                                                      \
  V(CoreLibrary, Object, _noSuchMethod)                                        \
  V(CoreLibrary, Object, _as)                                                  \
  V(CoreLibrary, Object, _instanceOf)                                          \
  V(CoreLibrary, _ObjectArray, _ObjectArray.)                                  \
  V(CoreLibrary, AssertionErrorImplementation, _throwNew)                      \
  V(CoreLibrary, TypeErrorImplementation, _throwNew)                           \
  V(CoreLibrary, FallThroughErrorImplementation, _throwNew)                    \
  V(CoreLibrary, AbstractClassInstantiationErrorImplementation, _throwNew)     \
  V(CoreLibrary, NoSuchMethodError, _throwNew)                                 \
  V(CoreLibrary, int, _throwFormatException)                                   \
  V(CoreLibrary, int, _parse)                                                  \
  V(CoreLibrary, StackTrace, _setupFullStackTrace)                             \


static void MarkFunctionAsInvisible(const Library& lib,
                                    const char* class_name,
                                    const char* function_name) {
  ASSERT(!lib.IsNull());
  const Class& cls = Class::Handle(
      lib.LookupClassAllowPrivate(String::Handle(String::New(class_name))));
  ASSERT(!cls.IsNull());
  const Function& function =
      Function::Handle(
          cls.LookupFunctionAllowPrivate(
              String::Handle(String::New(function_name))));
  ASSERT(!function.IsNull());
  function.set_is_visible(false);
}


static void MarkInvisibleFunctions() {
#define MARK_FUNCTION(lib, class_name, function_name)                          \
  MarkFunctionAsInvisible(Library::Handle(Library::lib()),                     \
      #class_name, #function_name);                                            \

INVISIBLE_LIST(MARK_FUNCTION)
#undef MARK_FUNCTION
}

// Takes a vm internal name and makes it suitable for external user.
//
// Examples:
//
// Internal getter and setter prefixes are changed:
//
//   get:foo -> foo
//   set:foo -> foo=
//
// Private name mangling is removed, possibly twice:
//
//   _ReceivePortImpl@6be832b -> _ReceivePortImpl
//   _ReceivePortImpl@6be832b._internal@6be832b -> +ReceivePortImpl._internal
//
// The trailing . on the default constructor name is dropped:
//
//   List. -> List
//
// And so forth:
//
//   get:foo@6be832b -> foo
//   _MyClass@6b3832b. -> _MyClass
//   _MyClass@6b3832b.named -> _MyClass.named
//
static RawString* IdentifierPrettyName(const String& name) {
  intptr_t len = name.Length();
  intptr_t start = 0;
  intptr_t at_pos = len;   // Position of '@' in the name.
  intptr_t dot_pos = len;  // Position of '.' in the name.
  bool is_setter = false;

  if (name.Equals(Symbols::TopLevel())) {
    // Name of invisible top-level class.
    return Symbols::Empty().raw();
  }
  for (int i = start; i < name.Length(); i++) {
    if (name.CharAt(i) == ':') {
      ASSERT(start == 0);
      if (name.CharAt(0) == 's') {
        is_setter = true;
      }
      start = i + 1;
    } else if (name.CharAt(i) == '@') {
      ASSERT(at_pos == len);
      at_pos = i;
    } else if (name.CharAt(i) == '.') {
      dot_pos = i;
      break;
    }
  }
  intptr_t limit = (at_pos < dot_pos ? at_pos : dot_pos);
  if (start == 0 && limit == len) {
    // This name is fine as it is.
    return name.raw();
  }

  const String& result =
      String::Handle(String::SubString(name, start, (limit - start)));

  // Look for a second '@' now to correctly handle names like
  // "_ReceivePortImpl@6be832b._internal@6be832b".
  at_pos = len;
  for (int i = dot_pos; i < name.Length(); i++) {
    if (name.CharAt(i) == '@') {
      ASSERT(at_pos == len);
      at_pos = i;
    }
  }

  intptr_t suffix_len = at_pos - dot_pos;
  if (suffix_len > 1) {
    // This is a named constructor.  Add the name back to the string.
    const String& suffix =
        String::Handle(String::SubString(name, dot_pos, suffix_len));
    return String::Concat(result, suffix);
  }

  if (is_setter) {
    // Setters need to end with '='.
    return String::Concat(result, Symbols::Equals());
  }

  return result.raw();
}


template<typename type>
static bool IsSpecialCharacter(type value) {
  return ((value == '"') ||
          (value == '\n') ||
          (value == '\f') ||
          (value == '\b') ||
          (value == '\t') ||
          (value == '\v') ||
          (value == '\r') ||
          (value == '\\') ||
          (value == '$'));
}


template<typename type>
static type SpecialCharacter(type value) {
  if (value == '"') {
    return '"';
  } else if (value == '\n') {
    return 'n';
  } else if (value == '\f') {
    return 'f';
  } else if (value == '\b') {
    return 'b';
  } else if (value == '\t') {
    return 't';
  } else if (value == '\v') {
    return 'v';
  } else if (value == '\r') {
    return 'r';
  } else if (value == '\\') {
    return '\\';
  } else if (value == '$') {
    return '$';
  }
  UNREACHABLE();
  return '\0';
}


static void DeleteWeakPersistentHandle(Dart_Handle handle) {
  ApiState* state = Isolate::Current()->api_state();
  ASSERT(state != NULL);
  FinalizablePersistentHandle* weak_ref =
      reinterpret_cast<FinalizablePersistentHandle*>(handle);
  ASSERT(state->IsValidWeakPersistentHandle(handle));
  state->weak_persistent_handles().FreeHandle(weak_ref);
}


void Object::InitOnce() {
  // TODO(iposva): NoGCScope needs to be added here.
  ASSERT(class_class() == null_);
  // Initialize the static vtable values.
  {
    Object fake_object;
    Smi fake_smi;
    Object::handle_vtable_ = fake_object.vtable();
    Smi::handle_vtable_ = fake_smi.vtable();
  }

  Isolate* isolate = Isolate::Current();
  Heap* heap = isolate->heap();

  // Allocate the read only object handles here.
  empty_array_ = Array::ReadOnlyHandle(isolate);
  sentinel_ = Instance::ReadOnlyHandle(isolate);
  transition_sentinel_ = Instance::ReadOnlyHandle(isolate);
  bool_true_ = Bool::ReadOnlyHandle(isolate);
  bool_false_ = Bool::ReadOnlyHandle(isolate);
  snapshot_writer_error_ = LanguageError::ReadOnlyHandle(isolate);

  // Allocate and initialize the null instance.
  // 'null_' must be the first object allocated as it is used in allocation to
  // clear the object.
  {
    uword address = heap->Allocate(Instance::InstanceSize(), Heap::kOld);
    null_ = reinterpret_cast<RawInstance*>(address + kHeapObjectTag);
    // The call below is using 'null_' to initialize itself.
    InitializeObject(address, kNullCid, Instance::InstanceSize());
  }

  // Initialize the empty array handle to null_ in order to be able to check
  // if the empty array was allocated (RAW_NULL is not available).
  *empty_array_ = Array::null();

  Class& cls = Class::Handle();

  // Allocate and initialize the class class.
  {
    intptr_t size = Class::InstanceSize();
    uword address = heap->Allocate(size, Heap::kOld);
    class_class_ = reinterpret_cast<RawClass*>(address + kHeapObjectTag);
    InitializeObject(address, Class::kClassId, size);

    Class fake;
    // Initialization from Class::New<Class>.
    // Directly set raw_ to break a circular dependency: SetRaw will attempt
    // to lookup class class in the class table where it is not registered yet.
    cls.raw_ = class_class_;
    cls.set_handle_vtable(fake.vtable());
    cls.set_instance_size(Class::InstanceSize());
    cls.set_next_field_offset(Class::InstanceSize());
    cls.set_id(Class::kClassId);
    cls.raw_ptr()->state_bits_ = 0;
    cls.set_is_finalized();
    cls.raw_ptr()->type_arguments_field_offset_in_words_ =
        Class::kNoTypeArguments;
    cls.raw_ptr()->num_native_fields_ = 0;
    cls.InitEmptyFields();
    isolate->class_table()->Register(cls);
  }

  // Allocate and initialize the null class.
  cls = Class::New<Instance>(kNullCid);
  cls.set_is_finalized();
  null_class_ = cls.raw();

  // Allocate and initialize the free list element class.
  cls = Class::New<FreeListElement::FakeInstance>(kFreeListElement);
  cls.set_is_finalized();

  // Allocate and initialize the sentinel values of Null class.
  {
    *sentinel_ ^=
        Object::Allocate(kNullCid, Instance::InstanceSize(), Heap::kOld);

    *transition_sentinel_ ^=
        Object::Allocate(kNullCid, Instance::InstanceSize(), Heap::kOld);
  }

  cls = Class::New<Instance>(kDynamicCid);
  cls.set_is_finalized();
  cls.set_is_abstract();
  dynamic_class_ = cls.raw();

  // Allocate the remaining VM internal classes.
  cls = Class::New<UnresolvedClass>();
  unresolved_class_class_ = cls.raw();

  cls = Class::New<Instance>(kVoidCid);
  cls.set_is_finalized();
  void_class_ = cls.raw();

  cls = Class::New<TypeArguments>();
  type_arguments_class_ = cls.raw();

  cls = Class::New<InstantiatedTypeArguments>();
  instantiated_type_arguments_class_ = cls.raw();

  cls = Class::New<PatchClass>();
  patch_class_class_ = cls.raw();

  cls = Class::New<Function>();
  function_class_ = cls.raw();

  cls = Class::New<ClosureData>();
  closure_data_class_ = cls.raw();

  cls = Class::New<RedirectionData>();
  redirection_data_class_ = cls.raw();

  cls = Class::New<Field>();
  field_class_ = cls.raw();

  cls = Class::New<LiteralToken>();
  literal_token_class_ = cls.raw();

  cls = Class::New<TokenStream>();
  token_stream_class_ = cls.raw();

  cls = Class::New<Script>();
  script_class_ = cls.raw();

  cls = Class::New<Library>();
  library_class_ = cls.raw();

  cls = Class::New<LibraryPrefix>();
  library_prefix_class_ = cls.raw();

  cls = Class::New<Namespace>();
  namespace_class_ = cls.raw();

  cls = Class::New<Code>();
  code_class_ = cls.raw();

  cls = Class::New<Instructions>();
  instructions_class_ = cls.raw();

  cls = Class::New<PcDescriptors>();
  pc_descriptors_class_ = cls.raw();

  cls = Class::New<Stackmap>();
  stackmap_class_ = cls.raw();

  cls = Class::New<LocalVarDescriptors>();
  var_descriptors_class_ = cls.raw();

  cls = Class::New<ExceptionHandlers>();
  exception_handlers_class_ = cls.raw();

  cls = Class::New<DeoptInfo>();
  deopt_info_class_ = cls.raw();

  cls = Class::New<Context>();
  context_class_ = cls.raw();

  cls = Class::New<ContextScope>();
  context_scope_class_ = cls.raw();

  cls = Class::New<ICData>();
  icdata_class_ = cls.raw();

  cls = Class::New<MegamorphicCache>();
  megamorphic_cache_class_ = cls.raw();

  cls = Class::New<SubtypeTestCache>();
  subtypetestcache_class_ = cls.raw();

  cls = Class::New<ApiError>();
  api_error_class_ = cls.raw();

  cls = Class::New<LanguageError>();
  language_error_class_ = cls.raw();

  cls = Class::New<UnhandledException>();
  unhandled_exception_class_ = cls.raw();

  cls = Class::New<UnwindError>();
  unwind_error_class_ = cls.raw();

  ASSERT(class_class() != null_);

  // Pre-allocate classes in the vm isolate so that we can for example create a
  // symbol table and populate it with some frequently used strings as symbols.
  cls = Class::New<Array>();
  isolate->object_store()->set_array_class(cls);
  cls.set_type_arguments_field_offset(Array::type_arguments_offset());
  cls = Class::New<ImmutableArray>();
  isolate->object_store()->set_immutable_array_class(cls);
  cls.set_type_arguments_field_offset(Array::type_arguments_offset());
  cls = Class::NewStringClass(kOneByteStringCid);
  isolate->object_store()->set_one_byte_string_class(cls);
  cls = Class::NewStringClass(kTwoByteStringCid);
  isolate->object_store()->set_two_byte_string_class(cls);

  // Allocate and initialize the empty_array instance.
  {
    uword address = heap->Allocate(Array::InstanceSize(0), Heap::kOld);
    InitializeObject(address, kArrayCid, Array::InstanceSize(0));
    Array::initializeHandle(
        empty_array_,
        reinterpret_cast<RawArray*>(address + kHeapObjectTag));
    empty_array_->raw()->ptr()->length_ = Smi::New(0);
  }

  // Allocate and initialize singleton true and false boolean objects.
  cls = Class::New<Bool>();
  isolate->object_store()->set_bool_class(cls);
  *bool_true_ = Bool::New(true);
  *bool_false_ = Bool::New(false);

  *snapshot_writer_error_ =
      LanguageError::New(String::Handle(String::New("SnapshotWriter Error")));

  ASSERT(!empty_array_->IsSmi());
  ASSERT(empty_array_->IsArray());
  ASSERT(!sentinel_->IsSmi());
  ASSERT(sentinel_->IsInstance());
  ASSERT(!transition_sentinel_->IsSmi());
  ASSERT(transition_sentinel_->IsInstance());
  ASSERT(!bool_true_->IsSmi());
  ASSERT(bool_true_->IsBool());
  ASSERT(!bool_false_->IsSmi());
  ASSERT(bool_false_->IsBool());
  ASSERT(!snapshot_writer_error_->IsSmi());
  ASSERT(snapshot_writer_error_->IsLanguageError());
}


#define SET_CLASS_NAME(class_name, name)                                       \
  cls = class_name##_class();                                                  \
  cls.set_name(Symbols::name());                                               \

void Object::RegisterSingletonClassNames() {
  Class& cls = Class::Handle();

  // Set up names for all VM singleton classes.
  SET_CLASS_NAME(class, Class);
  SET_CLASS_NAME(null, Null);
  SET_CLASS_NAME(dynamic, Dynamic);
  SET_CLASS_NAME(void, Void);
  SET_CLASS_NAME(unresolved_class, UnresolvedClass);
  SET_CLASS_NAME(type_arguments, TypeArguments);
  SET_CLASS_NAME(instantiated_type_arguments, InstantiatedTypeArguments);
  SET_CLASS_NAME(patch_class, PatchClass);
  SET_CLASS_NAME(function, Function);
  SET_CLASS_NAME(closure_data, ClosureData);
  SET_CLASS_NAME(redirection_data, RedirectionData);
  SET_CLASS_NAME(field, Field);
  SET_CLASS_NAME(literal_token, LiteralToken);
  SET_CLASS_NAME(token_stream, TokenStream);
  SET_CLASS_NAME(script, Script);
  SET_CLASS_NAME(library, LibraryClass);
  SET_CLASS_NAME(library_prefix, LibraryPrefix);
  SET_CLASS_NAME(namespace, Namespace);
  SET_CLASS_NAME(code, Code);
  SET_CLASS_NAME(instructions, Instructions);
  SET_CLASS_NAME(pc_descriptors, PcDescriptors);
  SET_CLASS_NAME(stackmap, Stackmap);
  SET_CLASS_NAME(var_descriptors, LocalVarDescriptors);
  SET_CLASS_NAME(exception_handlers, ExceptionHandlers);
  SET_CLASS_NAME(deopt_info, DeoptInfo);
  SET_CLASS_NAME(context, Context);
  SET_CLASS_NAME(context_scope, ContextScope);
  SET_CLASS_NAME(icdata, ICData);
  SET_CLASS_NAME(megamorphic_cache, MegamorphicCache);
  SET_CLASS_NAME(subtypetestcache, SubtypeTestCache);
  SET_CLASS_NAME(api_error, ApiError);
  SET_CLASS_NAME(language_error, LanguageError);
  SET_CLASS_NAME(unhandled_exception, UnhandledException);
  SET_CLASS_NAME(unwind_error, UnwindError);

  // Set up names for object array and one byte string class which are
  // pre-allocated in the vm isolate also.
  cls = Dart::vm_isolate()->object_store()->array_class();
  cls.set_name(Symbols::ObjectArray());
  cls = Dart::vm_isolate()->object_store()->one_byte_string_class();
  cls.set_name(Symbols::OneByteString());
}


void Object::CreateInternalMetaData() {
  // Initialize meta data for VM internal classes.
  Class& cls = Class::Handle();
  Array& fields = Array::Handle();
  Field& fld = Field::Handle();
  String& name = String::Handle();

  // TODO(iposva): Add more of the VM classes here.
  cls = context_class_;
  fields = Array::New(1);
  name = Symbols::New("@parent_");
  fld = Field::New(name, false, false, false, cls, 0);
  fields.SetAt(0, fld);
  cls.SetFields(fields);
}


// Make unused space in an object whose type has been transformed safe
// for traversing during GC.
// The unused part of the transformed object is marked as an TypedDataInt8Array
// object.
void Object::MakeUnusedSpaceTraversable(const Object& obj,
                                        intptr_t original_size,
                                        intptr_t used_size) {
  ASSERT(Isolate::Current()->no_gc_scope_depth() > 0);
  ASSERT(!obj.IsNull());
  ASSERT(original_size >= used_size);
  if (original_size > used_size) {
    intptr_t leftover_size = original_size - used_size;

    uword addr = RawObject::ToAddr(obj.raw()) + used_size;
    if (leftover_size >= TypedData::InstanceSize(0)) {
      // Update the leftover space as an TypedDataInt8Array object.
      RawTypedData* raw =
          reinterpret_cast<RawTypedData*>(RawObject::FromAddr(addr));
      uword tags = 0;
      tags = RawObject::SizeTag::update(leftover_size, tags);
      tags = RawObject::ClassIdTag::update(kTypedDataInt8ArrayCid, tags);
      raw->ptr()->tags_ = tags;
      intptr_t leftover_len = (leftover_size - TypedData::InstanceSize(0));
      ASSERT(TypedData::InstanceSize(leftover_len) == leftover_size);
      raw->ptr()->length_ = Smi::New(leftover_len);
    } else {
      // Update the leftover space as a basic object.
      ASSERT(leftover_size == Object::InstanceSize());
      RawObject* raw = reinterpret_cast<RawObject*>(RawObject::FromAddr(addr));
      uword tags = 0;
      tags = RawObject::SizeTag::update(leftover_size, tags);
      tags = RawObject::ClassIdTag::update(kInstanceCid, tags);
      raw->ptr()->tags_ = tags;
    }
  }
}


void Object::VerifyBuiltinVtables() {
#if defined(DEBUG)
  Isolate* isolate = Isolate::Current();
  ASSERT(isolate != NULL);
  Class& cls = Class::Handle(isolate, Class::null());
  for (intptr_t cid = (kIllegalCid + 1); cid < kNumPredefinedCids; cid++) {
    if (isolate->class_table()->HasValidClassAt(cid)) {
      cls ^= isolate->class_table()->At(cid);
      ASSERT(builtin_vtables_[cid] == cls.raw_ptr()->handle_vtable_);
    }
  }
#endif
}


void Object::RegisterClass(const Class& cls,
                           const String& name,
                           const Library& lib) {
  ASSERT(name.Length() > 0);
  ASSERT(name.CharAt(0) != '_');
  cls.set_name(name);
  lib.AddClass(cls);
}


void Object::RegisterPrivateClass(const Class& cls,
                                  const String& public_class_name,
                                  const Library& lib) {
  ASSERT(public_class_name.Length() > 0);
  ASSERT(public_class_name.CharAt(0) == '_');
  String& str = String::Handle();
  str = lib.PrivateName(public_class_name);
  cls.set_name(str);
  lib.AddClass(cls);
}


#define LOAD_LIBRARY(name, raw_name)                                           \
  url = Symbols::Dart##name().raw();                                           \
  lib = Library::LookupLibrary(url);                                           \
  if (lib.IsNull()) {                                                          \
    lib = Library::NewLibraryHelper(url, true);                                \
    lib.Register();                                                            \
  }                                                                            \
  isolate->object_store()->set_##raw_name##_library(lib);                      \

#define INIT_LIBRARY(name, raw_name, has_patch)                                \
  LOAD_LIBRARY(name, raw_name)                                                 \
  script = Bootstrap::Load##name##Script(false);                               \
  error = Bootstrap::Compile(lib, script);                                     \
  if (!error.IsNull()) {                                                       \
    return error.raw();                                                        \
  }                                                                            \
  if (has_patch) {                                                             \
    script = Bootstrap::Load##name##Script(true);                              \
    error = lib.Patch(script);                                                 \
    if (!error.IsNull()) {                                                     \
      return error.raw();                                                      \
    }                                                                          \
  }                                                                            \


RawError* Object::Init(Isolate* isolate) {
  TIMERSCOPE(time_bootstrap);
  ObjectStore* object_store = isolate->object_store();

  Class& cls = Class::Handle();
  Type& type = Type::Handle();
  Array& array = Array::Handle();
  String& url = String::Handle();
  Library& lib = Library::Handle();
  Script& script = Script::Handle();
  Error& error = Error::Handle();

  // All RawArray fields will be initialized to an empty array, therefore
  // initialize array class first.
  cls = Class::New<Array>();
  object_store->set_array_class(cls);

  // Array and ImmutableArray are the only VM classes that are parameterized.
  // Since they are pre-finalized, CalculateFieldOffsets() is not called, so we
  // need to set the offset of their type_arguments_ field, which is explicitly
  // declared in RawArray.
  cls.set_type_arguments_field_offset(Array::type_arguments_offset());

  // Set up the growable object array class (Has to be done after the array
  // class is setup as one of its field is an array object).
  cls = Class::New<GrowableObjectArray>();
  object_store->set_growable_object_array_class(cls);
  cls.set_type_arguments_field_offset(
      GrowableObjectArray::type_arguments_offset());

  // canonical_type_arguments_ are Smi terminated.
  // Last element contains the count of used slots.
  const intptr_t kInitialCanonicalTypeArgumentsSize = 4;
  array = Array::New(kInitialCanonicalTypeArgumentsSize + 1);
  array.SetAt(kInitialCanonicalTypeArgumentsSize, Smi::Handle(Smi::New(0)));
  object_store->set_canonical_type_arguments(array);

  // Setup type class early in the process.
  cls = Class::New<Type>();
  object_store->set_type_class(cls);

  cls = Class::New<TypeParameter>();
  object_store->set_type_parameter_class(cls);

  cls = Class::New<BoundedType>();
  object_store->set_bounded_type_class(cls);

  cls = Class::New<MixinAppType>();
  object_store->set_mixin_app_type_class(cls);

  // Pre-allocate the OneByteString class needed by the symbol table.
  cls = Class::NewStringClass(kOneByteStringCid);
  object_store->set_one_byte_string_class(cls);

  // Pre-allocate the TwoByteString class needed by the symbol table.
  cls = Class::NewStringClass(kTwoByteStringCid);
  object_store->set_two_byte_string_class(cls);

  // Setup the symbol table for the symbols created in the isolate.
  Symbols::SetupSymbolTable(isolate);

  // Set up the libraries array before initializing the core library.
  const GrowableObjectArray& libraries =
      GrowableObjectArray::Handle(GrowableObjectArray::New(Heap::kOld));
  object_store->set_libraries(libraries);

  // Pre-register the core library.
  Library::InitCoreLibrary(isolate);

  // Basic infrastructure has been setup, initialize the class dictionary.
  Library& core_lib = Library::Handle(Library::CoreLibrary());
  ASSERT(!core_lib.IsNull());

  const GrowableObjectArray& pending_classes =
      GrowableObjectArray::Handle(GrowableObjectArray::New(Heap::kOld));
  object_store->set_pending_classes(pending_classes);

  Context& context = Context::Handle(Context::New(0, Heap::kOld));
  object_store->set_empty_context(context);

  // Now that the symbol table is initialized and that the core dictionary as
  // well as the core implementation dictionary have been setup, preallocate
  // remaining classes and register them by name in the dictionaries.
  String& name = String::Handle();
  cls = Class::New<Bool>();
  object_store->set_bool_class(cls);
  RegisterClass(cls, Symbols::Bool(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = object_store->array_class();  // Was allocated above.
  RegisterPrivateClass(cls, Symbols::ObjectArray(), core_lib);
  pending_classes.Add(cls, Heap::kOld);
  // We cannot use NewNonParameterizedType(cls), because Array is parameterized.
  type ^= Type::New(Object::Handle(cls.raw()),
                    TypeArguments::Handle(),
                    Scanner::kDummyTokenIndex);
  type.SetIsFinalized();
  type ^= type.Canonicalize();
  object_store->set_array_type(type);

  cls = object_store->growable_object_array_class();  // Was allocated above.
  RegisterPrivateClass(cls, Symbols::GrowableObjectArray(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::New<ImmutableArray>();
  object_store->set_immutable_array_class(cls);
  cls.set_type_arguments_field_offset(Array::type_arguments_offset());
  ASSERT(object_store->immutable_array_class() != object_store->array_class());
  RegisterPrivateClass(cls, Symbols::ImmutableArray(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = object_store->one_byte_string_class();  // Was allocated above.
  RegisterPrivateClass(cls, Symbols::OneByteString(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = object_store->two_byte_string_class();  // Was allocated above.
  RegisterPrivateClass(cls, Symbols::TwoByteString(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::NewStringClass(kExternalOneByteStringCid);
  object_store->set_external_one_byte_string_class(cls);
  RegisterPrivateClass(cls, Symbols::ExternalOneByteString(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::NewStringClass(kExternalTwoByteStringCid);
  object_store->set_external_two_byte_string_class(cls);
  RegisterPrivateClass(cls, Symbols::ExternalTwoByteString(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::New<Stacktrace>();
  object_store->set_stacktrace_class(cls);
  RegisterClass(cls, Symbols::StackTrace(), core_lib);
  pending_classes.Add(cls, Heap::kOld);
  // Super type set below, after Object is allocated.

  cls = Class::New<JSRegExp>();
  object_store->set_jsregexp_class(cls);
  RegisterPrivateClass(cls, Symbols::JSSyntaxRegExp(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  // Initialize the base interfaces used by the core VM classes.
  script = Bootstrap::LoadCoreScript(false);

  // Allocate and initialize the pre-allocated classes in the core library.
  cls = Class::New<Instance>(kInstanceCid);
  object_store->set_object_class(cls);
  cls.set_name(Symbols::Object());
  cls.set_script(script);
  cls.set_is_prefinalized();
  core_lib.AddClass(cls);
  pending_classes.Add(cls, Heap::kOld);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_object_type(type);

  cls = object_store->type_class();
  RegisterPrivateClass(cls, Symbols::Type(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = object_store->type_parameter_class();
  RegisterPrivateClass(cls, Symbols::TypeParameter(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::New<Integer>();
  object_store->set_integer_implementation_class(cls);
  RegisterPrivateClass(cls, Symbols::IntegerImplementation(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::New<Smi>();
  object_store->set_smi_class(cls);
  RegisterPrivateClass(cls, Symbols::_Smi(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::New<Mint>();
  object_store->set_mint_class(cls);
  RegisterPrivateClass(cls, Symbols::_Mint(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::New<Bigint>();
  object_store->set_bigint_class(cls);
  RegisterPrivateClass(cls, Symbols::_Bigint(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::New<Double>();
  object_store->set_double_class(cls);
  RegisterPrivateClass(cls, Symbols::_Double(), core_lib);
  pending_classes.Add(cls, Heap::kOld);

  cls = Class::New<WeakProperty>();
  object_store->set_weak_property_class(cls);
  RegisterPrivateClass(cls, Symbols::_WeakProperty(), core_lib);

  // Setup some default native field classes which can be extended for
  // specifying native fields in dart classes.
  Library::InitNativeWrappersLibrary(isolate);
  ASSERT(isolate->object_store()->native_wrappers_library() != Library::null());

  // Pre-register the typed_data library so the native class implementations
  // can be hooked up before compiling it.
  LOAD_LIBRARY(TypedData, typed_data);
  ASSERT(!lib.IsNull());
  ASSERT(lib.raw() == Library::TypedDataLibrary());
  const intptr_t typed_data_class_array_length =
      RawObject::NumberOfTypedDataClasses();
  Array& typed_data_classes =
      Array::Handle(Array::New(typed_data_class_array_length));
  int index = 0;
#define REGISTER_TYPED_DATA_CLASS(clazz)                                       \
  cls = Class::NewTypedDataClass(kTypedData##clazz##Cid);                      \
  index = kTypedData##clazz##Cid - kTypedDataInt8ArrayCid;                     \
  typed_data_classes.SetAt(index, cls);                                        \
  RegisterPrivateClass(cls, Symbols::_##clazz(), lib);                         \

  CLASS_LIST_TYPED_DATA(REGISTER_TYPED_DATA_CLASS);
#undef REGISTER_TYPED_DATA_CLASS
#define REGISTER_TYPED_DATA_VIEW_CLASS(clazz)                                  \
  cls = Class::NewTypedDataViewClass(kTypedData##clazz##ViewCid);              \
  index = kTypedData##clazz##ViewCid - kTypedDataInt8ArrayCid;                 \
  typed_data_classes.SetAt(index, cls);                                        \
  RegisterPrivateClass(cls, Symbols::_##clazz##View(), lib);                   \
  pending_classes.Add(cls, Heap::kOld);                                        \

  CLASS_LIST_TYPED_DATA(REGISTER_TYPED_DATA_VIEW_CLASS);
  cls = Class::NewTypedDataViewClass(kByteDataViewCid);
  index = kByteDataViewCid - kTypedDataInt8ArrayCid;
  typed_data_classes.SetAt(index, cls);
  RegisterPrivateClass(cls, Symbols::_ByteDataView(), lib);
  pending_classes.Add(cls, Heap::kOld);
#undef REGISTER_TYPED_DATA_VIEW_CLASS
#define REGISTER_EXT_TYPED_DATA_CLASS(clazz)                                   \
  cls = Class::NewExternalTypedDataClass(kExternalTypedData##clazz##Cid);      \
  index = kExternalTypedData##clazz##Cid - kTypedDataInt8ArrayCid;             \
  typed_data_classes.SetAt(index, cls);                                        \
  RegisterPrivateClass(cls, Symbols::_External##clazz(), lib);                 \

  CLASS_LIST_TYPED_DATA(REGISTER_EXT_TYPED_DATA_CLASS);
#undef REGISTER_EXT_TYPED_DATA_CLASS
  // Register Float32x4 and Uint32x4 in the object store.
  cls = Class::New<Float32x4>();
  object_store->set_float32x4_class(cls);
  RegisterPrivateClass(cls, Symbols::_Float32x4(), lib);
  cls = Class::New<Uint32x4>();
  object_store->set_uint32x4_class(cls);
  RegisterPrivateClass(cls, Symbols::_Uint32x4(), lib);

  cls = Class::New<Instance>(Symbols::Float32x4(), script,
                             Scanner::kDummyTokenIndex);
  RegisterClass(cls, Symbols::Float32x4(), lib);
  pending_classes.Add(cls, Heap::kOld);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_float32x4_type(type);

  cls = Class::New<Instance>(Symbols::Uint32x4(), script,
                             Scanner::kDummyTokenIndex);
  pending_classes.Add(cls, Heap::kOld);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_uint32x4_type(type);

  object_store->set_typed_data_classes(typed_data_classes);

  // Set the super type of class Stacktrace to Object type so that the
  // 'toString' method is implemented.
  cls = object_store->stacktrace_class();
  cls.set_super_type(type);

  // Note: The abstract class Function is represented by VM class
  // DartFunction, not VM class Function.
  cls = Class::New<DartFunction>();
  RegisterClass(cls, Symbols::Function(), core_lib);
  pending_classes.Add(cls, Heap::kOld);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_function_type(type);

  cls = Class::New<Number>();
  RegisterClass(cls, Symbols::Number(), core_lib);
  pending_classes.Add(cls, Heap::kOld);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_number_type(type);

  cls = Class::New<Instance>(Symbols::Int(), script, Scanner::kDummyTokenIndex);
  RegisterClass(cls, Symbols::Int(), core_lib);
  pending_classes.Add(cls, Heap::kOld);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_int_type(type);

  cls = Class::New<Instance>(Symbols::Double(),
                             script,
                             Scanner::kDummyTokenIndex);
  RegisterClass(cls, Symbols::Double(), core_lib);
  pending_classes.Add(cls, Heap::kOld);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_double_type(type);

  name = Symbols::New("String");
  cls = Class::New<Instance>(name, script, Scanner::kDummyTokenIndex);
  RegisterClass(cls, name, core_lib);
  pending_classes.Add(cls, Heap::kOld);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_string_type(type);

  cls = Class::New<Instance>(Symbols::List(),
                             script,
                             Scanner::kDummyTokenIndex);
  RegisterClass(cls, Symbols::List(), core_lib);
  pending_classes.Add(cls, Heap::kOld);
  object_store->set_list_class(cls);

  cls = object_store->bool_class();
  type = Type::NewNonParameterizedType(cls);
  object_store->set_bool_type(type);

  cls = object_store->smi_class();
  type = Type::NewNonParameterizedType(cls);
  object_store->set_smi_type(type);

  cls = object_store->mint_class();
  type = Type::NewNonParameterizedType(cls);
  object_store->set_mint_type(type);

  // The classes 'Null' and 'void' are not registered in the class dictionary,
  // because their names are reserved keywords. Their names are not heap
  // allocated, because the classes reside in the VM isolate.
  // The corresponding types are stored in the object store.
  cls = null_class();
  type = Type::NewNonParameterizedType(cls);
  object_store->set_null_type(type);

  cls = void_class();
  type = Type::NewNonParameterizedType(cls);
  object_store->set_void_type(type);

  // The class 'dynamic' is registered in the class dictionary because its name
  // is a built-in identifier, rather than a reserved keyword. Its name is not
  // heap allocated, because the class resides in the VM isolate.
  // The corresponding type, the "unknown type", is stored in the object store.
  cls = dynamic_class();
  type = Type::NewNonParameterizedType(cls);
  object_store->set_dynamic_type(type);

  // Finish the initialization by compiling the bootstrap scripts containing the
  // base interfaces and the implementation of the internal classes.
  INIT_LIBRARY(Core, core, true);

  INIT_LIBRARY(Async, async, true);
  INIT_LIBRARY(Collection, collection, true);
  INIT_LIBRARY(CollectionDev, collection_dev, true);
  INIT_LIBRARY(Crypto, crypto, false);
  INIT_LIBRARY(Isolate, isolate, true);
  INIT_LIBRARY(Json, json, true);
  INIT_LIBRARY(Math, math, true);
  INIT_LIBRARY(Mirrors, mirrors, true);
  INIT_LIBRARY(TypedData, typed_data, true);
  INIT_LIBRARY(Utf, utf, false);
  INIT_LIBRARY(Uri, uri, false);

  Bootstrap::SetupNativeResolver();

  // Remove the Object superclass cycle by setting the super type to null (not
  // to the type of null).
  cls = object_store->object_class();
  cls.set_super_type(Type::Handle());

  ClassFinalizer::VerifyBootstrapClasses();
  MarkInvisibleFunctions();

  // Set up the intrinsic state of all functions (core, math and scalar list).
  Intrinsifier::InitializeState();

  return Error::null();
}


void Object::InitFromSnapshot(Isolate* isolate) {
  TIMERSCOPE(time_bootstrap);
  ObjectStore* object_store = isolate->object_store();

  Class& cls = Class::Handle();

  // Set up empty classes in the object store, these will get
  // initialized correctly when we read from the snapshot.
  // This is done to allow bootstrapping of reading classes from the snapshot.
  cls = Class::New<Instance>(kInstanceCid);
  object_store->set_object_class(cls);

  cls = Class::New<Type>();
  object_store->set_type_class(cls);

  cls = Class::New<TypeParameter>();
  object_store->set_type_parameter_class(cls);

  cls = Class::New<BoundedType>();
  object_store->set_bounded_type_class(cls);

  cls = Class::New<MixinAppType>();
  object_store->set_mixin_app_type_class(cls);

  cls = Class::New<Array>();
  object_store->set_array_class(cls);

  cls = Class::New<ImmutableArray>();
  object_store->set_immutable_array_class(cls);

  cls = Class::New<GrowableObjectArray>();
  object_store->set_growable_object_array_class(cls);

  cls = Class::New<Float32x4>();
  object_store->set_float32x4_class(cls);

  cls = Class::New<Uint32x4>();
  object_store->set_uint32x4_class(cls);

#define REGISTER_TYPED_DATA_CLASS(clazz)                                       \
  cls = Class::NewTypedDataClass(kTypedData##clazz##Cid);
  CLASS_LIST_TYPED_DATA(REGISTER_TYPED_DATA_CLASS);
#undef REGISTER_TYPED_DATA_CLASS
#define REGISTER_TYPED_DATA_VIEW_CLASS(clazz)                                  \
  cls = Class::NewTypedDataViewClass(kTypedData##clazz##ViewCid);
  CLASS_LIST_TYPED_DATA(REGISTER_TYPED_DATA_VIEW_CLASS);
  cls = Class::NewTypedDataViewClass(kByteDataViewCid);
#undef REGISTER_TYPED_DATA_VIEW_CLASS
#define REGISTER_EXT_TYPED_DATA_CLASS(clazz)                                   \
  cls = Class::NewExternalTypedDataClass(kExternalTypedData##clazz##Cid);
  CLASS_LIST_TYPED_DATA(REGISTER_EXT_TYPED_DATA_CLASS);
#undef REGISTER_EXT_TYPED_DATA_CLASS

  cls = Class::New<Integer>();
  object_store->set_integer_implementation_class(cls);

  cls = Class::New<Smi>();
  object_store->set_smi_class(cls);

  cls = Class::New<Mint>();
  object_store->set_mint_class(cls);

  cls = Class::New<Double>();
  object_store->set_double_class(cls);

  cls = Class::New<Bigint>();
  object_store->set_bigint_class(cls);

  cls = Class::NewStringClass(kOneByteStringCid);
  object_store->set_one_byte_string_class(cls);

  cls = Class::NewStringClass(kTwoByteStringCid);
  object_store->set_two_byte_string_class(cls);

  cls = Class::NewStringClass(kExternalOneByteStringCid);
  object_store->set_external_one_byte_string_class(cls);

  cls = Class::NewStringClass(kExternalTwoByteStringCid);
  object_store->set_external_two_byte_string_class(cls);

  cls = Class::New<Bool>();
  object_store->set_bool_class(cls);

  cls = Class::New<Stacktrace>();
  object_store->set_stacktrace_class(cls);

  cls = Class::New<JSRegExp>();
  object_store->set_jsregexp_class(cls);

  // Some classes are not stored in the object store. Yet we still need to
  // create their Class object so that they get put into the class_table
  // (as a side effect of Class::New()).
  cls = Class::New<DartFunction>();
  cls = Class::New<Number>();

  cls = Class::New<WeakProperty>();
  object_store->set_weak_property_class(cls);
}


void Object::Print() const {
  OS::Print("%s\n", ToCString());
}


RawString* Object::DictionaryName() const {
  return String::null();
}


void Object::InitializeObject(uword address, intptr_t class_id, intptr_t size) {
  // TODO(iposva): Get a proper halt instruction from the assembler which
  // would be needed here for code objects.
  uword initial_value = reinterpret_cast<uword>(null_);
  uword cur = address;
  uword end = address + size;
  while (cur < end) {
    *reinterpret_cast<uword*>(cur) = initial_value;
    cur += kWordSize;
  }
  uword tags = 0;
  ASSERT(class_id != kIllegalCid);
  tags = RawObject::ClassIdTag::update(class_id, tags);
  tags = RawObject::SizeTag::update(size, tags);
  reinterpret_cast<RawObject*>(address)->tags_ = tags;
}


void Object::CheckHandle() const {
#if defined(DEBUG)
  if (raw_ != Object::null()) {
    if ((reinterpret_cast<uword>(raw_) & kSmiTagMask) == kSmiTag) {
      ASSERT(vtable() == Smi::handle_vtable_);
      return;
    }
    intptr_t cid = raw_->GetClassId();
    if (cid >= kNumPredefinedCids) {
      cid = kInstanceCid;
    }
    ASSERT(vtable() == builtin_vtables_[cid]);
    if (FLAG_verify_handles) {
      Isolate* isolate = Isolate::Current();
      Heap* isolate_heap = isolate->heap();
      Heap* vm_isolate_heap = Dart::vm_isolate()->heap();
      ASSERT(isolate_heap->Contains(RawObject::ToAddr(raw_)) ||
             vm_isolate_heap->Contains(RawObject::ToAddr(raw_)));
    }
  }
#endif
}


RawObject* Object::Allocate(intptr_t cls_id,
                            intptr_t size,
                            Heap::Space space) {
  ASSERT(Utils::IsAligned(size, kObjectAlignment));
  Isolate* isolate = Isolate::Current();
  ASSERT(isolate->no_callback_scope_depth() == 0);
  Heap* heap = isolate->heap();

  uword address = heap->Allocate(size, space);
  if (address == 0) {
    // Use the preallocated out of memory exception to avoid calling
    // into dart code or allocating any code.
    const Instance& exception =
        Instance::Handle(isolate->object_store()->out_of_memory());
    Exceptions::Throw(exception);
    UNREACHABLE();
  }
  NoGCScope no_gc;
  InitializeObject(address, cls_id, size);
  RawObject* raw_obj = reinterpret_cast<RawObject*>(address + kHeapObjectTag);
  ASSERT(cls_id == RawObject::ClassIdTag::decode(raw_obj->ptr()->tags_));
  return raw_obj;
}


class StoreBufferUpdateVisitor : public ObjectPointerVisitor {
 public:
  explicit StoreBufferUpdateVisitor(Isolate* isolate, RawObject* obj) :
      ObjectPointerVisitor(isolate), old_obj_(obj) {
    ASSERT(old_obj_->IsOldObject());
  }

  void VisitPointers(RawObject** first, RawObject** last) {
    for (RawObject** curr = first; curr <= last; ++curr) {
      RawObject* raw_obj = *curr;
      if (raw_obj->IsHeapObject() && raw_obj->IsNewObject()) {
        uword ptr = reinterpret_cast<uword>(old_obj_);
        isolate()->store_buffer()->AddPointer(ptr);
        // Remembered this object. There is no need to continue searching.
        return;
      }
    }
  }

 private:
  RawObject* old_obj_;

  DISALLOW_COPY_AND_ASSIGN(StoreBufferUpdateVisitor);
};


bool Object::IsReadOnlyHandle() const {
  return Dart::IsReadOnlyHandle(reinterpret_cast<uword>(this));
}


bool Object::IsNotTemporaryScopedHandle() const {
  return (IsZoneHandle() || IsReadOnlyHandle());
}



RawObject* Object::Clone(const Object& src, Heap::Space space) {
  const Class& cls = Class::Handle(src.clazz());
  intptr_t size = src.raw()->Size();
  RawObject* raw_obj = Object::Allocate(cls.id(), size, space);
  NoGCScope no_gc;
  memmove(raw_obj->ptr(), src.raw()->ptr(), size);
  if (space == Heap::kOld) {
    StoreBufferUpdateVisitor visitor(Isolate::Current(), raw_obj);
    raw_obj->VisitPointers(&visitor);
  }
  return raw_obj;
}


RawString* Class::Name() const {
  ASSERT(raw_ptr()->name_ != String::null());
  return raw_ptr()->name_;
}


RawString* Class::UserVisibleName() const {
  if (FLAG_show_internal_names) {
    return Name();
  }
  switch (id()) {
    case kIntegerCid:
    case kSmiCid:
    case kMintCid:
    case kBigintCid:
      return Symbols::Int().raw();
    case kDoubleCid:
      return Symbols::Double().raw();
    case kOneByteStringCid:
    case kTwoByteStringCid:
    case kExternalOneByteStringCid:
    case kExternalTwoByteStringCid:
      return Symbols::New("String");
    case kArrayCid:
    case kImmutableArrayCid:
    case kGrowableObjectArrayCid:
      return Symbols::List().raw();
    case kFloat32x4Cid:
      return Symbols::Float32x4().raw();
    case kUint32x4Cid:
      return Symbols::Uint32x4().raw();
    case kTypedDataInt8ArrayCid:
    case kExternalTypedDataInt8ArrayCid:
      return Symbols::Int8List().raw();
    case kTypedDataUint8ArrayCid:
    case kExternalTypedDataUint8ArrayCid:
      return Symbols::Uint8List().raw();
    case kTypedDataUint8ClampedArrayCid:
    case kExternalTypedDataUint8ClampedArrayCid:
      return Symbols::Uint8ClampedList().raw();
    case kTypedDataInt16ArrayCid:
    case kExternalTypedDataInt16ArrayCid:
      return Symbols::Int16List().raw();
    case kTypedDataUint16ArrayCid:
    case kExternalTypedDataUint16ArrayCid:
      return Symbols::Uint16List().raw();
    case kTypedDataInt32ArrayCid:
    case kExternalTypedDataInt32ArrayCid:
      return Symbols::Int32List().raw();
    case kTypedDataUint32ArrayCid:
    case kExternalTypedDataUint32ArrayCid:
      return Symbols::Uint32List().raw();
    case kTypedDataInt64ArrayCid:
    case kExternalTypedDataInt64ArrayCid:
      return Symbols::Int64List().raw();
    case kTypedDataUint64ArrayCid:
    case kExternalTypedDataUint64ArrayCid:
      return Symbols::Uint64List().raw();
    case kTypedDataFloat32x4ArrayCid:
    case kExternalTypedDataFloat32x4ArrayCid:
      return Symbols::Float32x4List().raw();
    case kTypedDataFloat32ArrayCid:
    case kExternalTypedDataFloat32ArrayCid:
      return Symbols::Float32List().raw();
    case kTypedDataFloat64ArrayCid:
    case kExternalTypedDataFloat64ArrayCid:
      return Symbols::Float64List().raw();
    default:
      if (!IsSignatureClass()) {
        const String& name = String::Handle(Name());
        return IdentifierPrettyName(name);
      } else {
        return Name();
      }
  }
  UNREACHABLE();
}


RawType* Class::SignatureType() const {
  ASSERT(IsSignatureClass());
  const Function& function = Function::Handle(signature_function());
  ASSERT(!function.IsNull());
  if (function.signature_class() != raw()) {
    // This class is a function type alias. Return the canonical signature type.
    const Class& canonical_class = Class::Handle(function.signature_class());
    return canonical_class.SignatureType();
  }
  // Return the first canonical signature type if already computed.
  const Array& signature_types = Array::Handle(canonical_types());
  // The canonical_types array is initialized to the empty array.
  ASSERT(!signature_types.IsNull());
  if (signature_types.Length() > 0) {
    // At most one signature type per signature class.
    ASSERT((signature_types.Length() == 1) ||
           ((signature_types.Length() == 2) &&
            (signature_types.At(1) == Type::null())));
    Type& signature_type = Type::Handle();
    signature_type ^= signature_types.At(0);
    ASSERT(!signature_type.IsNull());
    return signature_type.raw();
  }
  // A signature class extends class Instance and is parameterized in the same
  // way as the owner class of its non-static signature function.
  // It is not type parameterized if its signature function is static.
  // See Class::NewSignatureClass() for the setup of its type parameters.
  // During type finalization, the type arguments of the super class of the
  // owner class of its signature function will be prepended to the type
  // argument vector. Therefore, we only need to set the type arguments
  // matching the type parameters here.
  const TypeArguments& signature_type_arguments =
      TypeArguments::Handle(type_parameters());
  const Type& signature_type = Type::Handle(
      Type::New(*this, signature_type_arguments, token_pos()));

  // Return the still unfinalized signature type.
  ASSERT(!signature_type.IsFinalized());
  return signature_type.raw();
}


template <class FakeObject>
RawClass* Class::New() {
  ASSERT(Object::class_class() != Class::null());
  Class& result = Class::Handle();
  {
    RawObject* raw = Object::Allocate(Class::kClassId,
                                      Class::InstanceSize(),
                                      Heap::kOld);
    NoGCScope no_gc;
    result ^= raw;
  }
  FakeObject fake;
  result.set_handle_vtable(fake.vtable());
  result.set_instance_size(FakeObject::InstanceSize());
  result.set_next_field_offset(FakeObject::InstanceSize());
  ASSERT((FakeObject::kClassId != kInstanceCid));
  result.set_id(FakeObject::kClassId);
  result.raw_ptr()->state_bits_ = 0;
  // VM backed classes are almost ready: run checks and resolve class
  // references, but do not recompute size.
  result.set_is_prefinalized();
  result.raw_ptr()->type_arguments_field_offset_in_words_ = kNoTypeArguments;
  result.raw_ptr()->num_native_fields_ = 0;
  result.raw_ptr()->token_pos_ = Scanner::kDummyTokenIndex;
  result.InitEmptyFields();
  Isolate::Current()->class_table()->Register(result);
  return result.raw();
}


// Initialize class fields of type Array with empty array.
void Class::InitEmptyFields() {
  if (Object::empty_array().raw() == Array::null()) {
    // The empty array has not been initialized yet.
    return;
  }
  StorePointer(&raw_ptr()->interfaces_, Object::empty_array().raw());
  StorePointer(&raw_ptr()->constants_, Object::empty_array().raw());
  StorePointer(&raw_ptr()->canonical_types_, Object::empty_array().raw());
  StorePointer(&raw_ptr()->functions_, Object::empty_array().raw());
  StorePointer(&raw_ptr()->fields_, Object::empty_array().raw());
}


bool Class::HasInstanceFields() const {
  const Array& field_array = Array::Handle(fields());
  Field& field = Field::Handle();
  for (intptr_t i = 0; i < field_array.Length(); ++i) {
    field ^= field_array.At(i);
    if (!field.is_static()) {
      return true;
    }
  }
  return false;
}


void Class::SetFunctions(const Array& value) const {
  ASSERT(!value.IsNull());
#if defined(DEBUG)
  // Verify that all the functions in the array have this class as owner.
  Function& func = Function::Handle();
  intptr_t len = value.Length();
  for (intptr_t i = 0; i < len; i++) {
    func ^= value.At(i);
    ASSERT(func.Owner() == raw());
  }
#endif
  StorePointer(&raw_ptr()->functions_, value.raw());
}


void Class::AddFunction(const Function& function) const {
  const Array& arr = Array::Handle(functions());
  const Array& new_arr = Array::Handle(Array::Grow(arr, arr.Length() + 1));
  new_arr.SetAt(arr.Length(), function);
  SetFunctions(new_arr);
}


void Class::AddClosureFunction(const Function& function) const {
  GrowableObjectArray& closures =
      GrowableObjectArray::Handle(raw_ptr()->closure_functions_);
  if (closures.IsNull()) {
    closures = GrowableObjectArray::New(4);
    StorePointer(&raw_ptr()->closure_functions_, closures.raw());
  }
  ASSERT(function.IsNonImplicitClosureFunction());
  closures.Add(function);
}


// Lookup the innermost closure function that contains token at token_pos.
RawFunction* Class::LookupClosureFunction(intptr_t token_pos) const {
  if (raw_ptr()->closure_functions_ == GrowableObjectArray::null()) {
    return Function::null();
  }
  const GrowableObjectArray& closures =
      GrowableObjectArray::Handle(raw_ptr()->closure_functions_);
  Function& closure = Function::Handle();
  intptr_t num_closures = closures.Length();
  intptr_t best_fit_token_pos = -1;
  intptr_t best_fit_index = -1;
  for (intptr_t i = 0; i < num_closures; i++) {
    closure ^= closures.At(i);
    ASSERT(!closure.IsNull());
    if ((closure.token_pos() <= token_pos) &&
        (token_pos < closure.end_token_pos()) &&
        (best_fit_token_pos < closure.token_pos())) {
      best_fit_index = i;
      best_fit_token_pos = closure.token_pos();
    }
  }
  closure = Function::null();
  if (best_fit_index >= 0) {
    closure ^= closures.At(best_fit_index);
  }
  return closure.raw();
}


void Class::set_signature_function(const Function& value) const {
  ASSERT(value.IsClosureFunction() || value.IsSignatureFunction());
  StorePointer(&raw_ptr()->signature_function_, value.raw());
}


void Class::set_class_state(RawClass::ClassState state) const {
  ASSERT((state == RawClass::kAllocated) ||
         (state == RawClass::kPreFinalized) ||
         (state == RawClass::kFinalized));
  set_state_bits(StateBits::update(state, raw_ptr()->state_bits_));
}


void Class::set_state_bits(intptr_t bits) const {
  raw_ptr()->state_bits_ = static_cast<uint8_t>(bits);
}


void Class::set_library(const Library& value) const {
  StorePointer(&raw_ptr()->library_, value.raw());
}


void Class::set_type_parameters(const TypeArguments& value) const {
  StorePointer(&raw_ptr()->type_parameters_, value.raw());
}


intptr_t Class::NumTypeParameters() const {
  const TypeArguments& type_params = TypeArguments::Handle(type_parameters());
  if (type_params.IsNull()) {
    return 0;
  } else {
    return type_params.Length();
  }
}


intptr_t Class::NumTypeArguments() const {
  // To work properly, this call requires the super class of this class to be
  // resolved, which is checked by the SuperClass() call.
  Class& cls = Class::Handle(raw());
  if (IsSignatureClass()) {
    const Function& signature_fun = Function::Handle(signature_function());
    if (!signature_fun.is_static() &&
        !signature_fun.HasInstantiatedSignature()) {
      cls = signature_fun.Owner();
    }
  }
  intptr_t num_type_args = NumTypeParameters();
  const Class& superclass = Class::Handle(cls.SuperClass());
  // Object is its own super class during bootstrap.
  if (!superclass.IsNull() && (superclass.raw() != raw())) {
    num_type_args += superclass.NumTypeArguments();
  }
  return num_type_args;
}


bool Class::HasTypeArguments() const {
  if (!IsSignatureClass() && (is_finalized() || is_prefinalized())) {
    // More efficient than calling NumTypeArguments().
    return type_arguments_field_offset() != kNoTypeArguments;
  } else {
    // No need to check NumTypeArguments() if class has type parameters.
    return (NumTypeParameters() > 0) || (NumTypeArguments() > 0);
  }
}


RawClass* Class::SuperClass() const {
  const AbstractType& sup_type = AbstractType::Handle(super_type());
  if (sup_type.IsNull()) {
    return Class::null();
  }
  return sup_type.type_class();
}


void Class::set_super_type(const AbstractType& value) const {
  ASSERT(value.IsNull() ||
         value.IsType() ||
         value.IsBoundedType() ||
         value.IsMixinAppType());
  StorePointer(&raw_ptr()->super_type_, value.raw());
}


// Return a TypeParameter if the type_name is a type parameter of this class.
// Return null otherwise.
RawTypeParameter* Class::LookupTypeParameter(const String& type_name,
                                             intptr_t token_pos) const {
  ASSERT(!type_name.IsNull());
  const TypeArguments& type_params = TypeArguments::Handle(type_parameters());
  if (!type_params.IsNull()) {
    intptr_t num_type_params = type_params.Length();
    TypeParameter& type_param = TypeParameter::Handle();
    String& type_param_name = String::Handle();
    for (intptr_t i = 0; i < num_type_params; i++) {
      type_param ^= type_params.TypeAt(i);
      type_param_name = type_param.name();
      if (type_param_name.Equals(type_name)) {
        return type_param.raw();
      }
    }
  }
  return TypeParameter::null();
}


void Class::CalculateFieldOffsets() const {
  Array& flds = Array::Handle(fields());
  const Class& super = Class::Handle(SuperClass());
  intptr_t offset = 0;
  intptr_t type_args_field_offset = kNoTypeArguments;
  if (super.IsNull()) {
    offset = sizeof(RawObject);
  } else {
    type_args_field_offset = super.type_arguments_field_offset();
    offset = super.next_field_offset();
    ASSERT(offset > 0);
    // We should never call CalculateFieldOffsets for native wrapper
    // classes, assert this.
    ASSERT(num_native_fields() == 0);
    set_num_native_fields(super.num_native_fields());
  }
  // If the super class is parameterized, use the same type_arguments field.
  if (type_args_field_offset == kNoTypeArguments) {
    const TypeArguments& type_params = TypeArguments::Handle(type_parameters());
    if (!type_params.IsNull()) {
      ASSERT(type_params.Length() > 0);
      // The instance needs a type_arguments field.
      type_args_field_offset = offset;
      offset += kWordSize;
    }
  }
  set_type_arguments_field_offset(type_args_field_offset);
  ASSERT(offset != 0);
  Field& field = Field::Handle();
  intptr_t len = flds.Length();
  for (intptr_t i = 0; i < len; i++) {
    field ^= flds.At(i);
    // Offset is computed only for instance fields.
    if (!field.is_static()) {
      ASSERT(field.Offset() == 0);
      field.SetOffset(offset);
      offset += kWordSize;
    }
  }
  set_instance_size(RoundedAllocationSize(offset));
  set_next_field_offset(offset);
}


void Class::Finalize() const {
  ASSERT(!is_finalized());
  // Prefinalized classes have a VM internal representation and no Dart fields.
  // Their instance size  is precomputed and field offsets are known.
  if (!is_prefinalized()) {
    // Compute offsets of instance fields and instance size.
    CalculateFieldOffsets();
  }
  set_is_finalized();
}


static const char* FormatPatchError(const char* format, const Object& obj) {
  const char* msg = obj.ToCString();
  intptr_t len = OS::SNPrint(NULL, 0, format, msg) + 1;
  char* result = Isolate::Current()->current_zone()->Alloc<char>(len);
  OS::SNPrint(result, len, format, msg);
  return result;
}


// Apply the members from the patch class to the original class.
const char* Class::ApplyPatch(const Class& patch) const {
  ASSERT(!is_finalized());
  // Shared handles used during the iteration.
  String& member_name = String::Handle();

  const PatchClass& patch_class =
      PatchClass::Handle(PatchClass::New(*this, patch));

  Array& orig_list = Array::Handle(functions());
  intptr_t orig_len = orig_list.Length();
  Array& patch_list = Array::Handle(patch.functions());
  intptr_t patch_len = patch_list.Length();

  // TODO(iposva): Verify that only patching existing methods and adding only
  // new private methods.
  Function& func = Function::Handle();
  Function& orig_func = Function::Handle();
  const GrowableObjectArray& new_functions = GrowableObjectArray::Handle(
      GrowableObjectArray::New(orig_len));
  for (intptr_t i = 0; i < orig_len; i++) {
    orig_func ^= orig_list.At(i);
    member_name ^= orig_func.name();
    func = patch.LookupFunction(member_name);
    if (func.IsNull()) {
      // Non-patched function is preserved, all patched functions are added in
      // the loop below.
      new_functions.Add(orig_func);
    } else if (!func.HasCompatibleParametersWith(orig_func) &&
               !(func.IsFactory() && orig_func.IsConstructor() &&
                 (func.num_fixed_parameters() + 1 ==
                  orig_func.num_fixed_parameters()))) {
      return FormatPatchError("mismatched parameters: %s", member_name);
    }
  }
  for (intptr_t i = 0; i < patch_len; i++) {
    func ^= patch_list.At(i);
    func.set_owner(patch_class);
    new_functions.Add(func);
  }
  Array& new_list = Array::Handle(Array::MakeArray(new_functions));
  SetFunctions(new_list);

  // Merge the two list of fields. Raise an error when duplicates are found or
  // when a public field is being added.
  orig_list = fields();
  orig_len = orig_list.Length();
  patch_list = patch.fields();
  patch_len = patch_list.Length();

  Field& field = Field::Handle();
  Field& orig_field = Field::Handle();
  new_list = Array::New(patch_len + orig_len);
  for (intptr_t i = 0; i < patch_len; i++) {
    field ^= patch_list.At(i);
    field.set_owner(*this);
    member_name = field.name();
    // TODO(iposva): Verify non-public fields only.

    // Verify no duplicate additions.
    orig_field ^= LookupField(member_name);
    if (!orig_field.IsNull()) {
      return FormatPatchError("duplicate field: %s", member_name);
    }
    new_list.SetAt(i, field);
  }
  for (intptr_t i = 0; i < orig_len; i++) {
    field ^= orig_list.At(i);
    new_list.SetAt(patch_len + i, field);
  }
  SetFields(new_list);

  // The functions and fields in the patch class are no longer needed.
  patch.SetFunctions(Object::empty_array());
  patch.SetFields(Object::empty_array());
  return NULL;
}


void Class::SetFields(const Array& value) const {
  ASSERT(!value.IsNull());
#if defined(DEBUG)
  // Verify that all the fields in the array have this class as owner.
  Field& field = Field::Handle();
  intptr_t len = value.Length();
  for (intptr_t i = 0; i < len; i++) {
    field ^= value.At(i);
    ASSERT(field.owner() == raw());
  }
#endif
  // The value of static fields is already initialized to null.
  StorePointer(&raw_ptr()->fields_, value.raw());
}


template <class FakeInstance>
RawClass* Class::New(intptr_t index) {
  ASSERT(Object::class_class() != Class::null());
  Class& result = Class::Handle();
  {
    RawObject* raw = Object::Allocate(Class::kClassId,
                                      Class::InstanceSize(),
                                      Heap::kOld);
    NoGCScope no_gc;
    result ^= raw;
  }
  FakeInstance fake;
  ASSERT(fake.IsInstance());
  result.set_handle_vtable(fake.vtable());
  result.set_instance_size(FakeInstance::InstanceSize());
  result.set_next_field_offset(FakeInstance::InstanceSize());
  result.set_id(index);
  result.raw_ptr()->state_bits_ = 0;
  result.raw_ptr()->type_arguments_field_offset_in_words_ = kNoTypeArguments;
  result.raw_ptr()->num_native_fields_ = 0;
  result.raw_ptr()->token_pos_ = Scanner::kDummyTokenIndex;
  result.InitEmptyFields();
  Isolate::Current()->class_table()->Register(result);
  return result.raw();
}


template <class FakeInstance>
RawClass* Class::New(const String& name,
                     const Script& script,
                     intptr_t token_pos) {
  Class& result = Class::Handle(New<FakeInstance>(kIllegalCid));
  result.set_name(name);
  result.set_script(script);
  result.set_token_pos(token_pos);
  return result.raw();
}


RawClass* Class::New(const String& name,
                     const Script& script,
                     intptr_t token_pos) {
  Class& result = Class::Handle(New<Instance>(name, script, token_pos));
  return result.raw();
}


RawClass* Class::NewSignatureClass(const String& name,
                                   const Function& signature_function,
                                   const Script& script,
                                   intptr_t token_pos) {
  const Class& result = Class::Handle(New<Instance>(name, script, token_pos));
  const Type& super_type = Type::Handle(Type::ObjectType());
  ASSERT(!super_type.IsNull());
  // Instances of a signature class can only be closures.
  result.set_instance_size(Closure::InstanceSize());
  result.set_next_field_offset(Closure::InstanceSize());
  result.set_super_type(super_type);
  result.set_type_arguments_field_offset(Closure::type_arguments_offset());
  // Implements interface "Function".
  const Type& function_type = Type::Handle(Type::Function());
  const Array& interfaces = Array::Handle(Array::New(1, Heap::kOld));
  interfaces.SetAt(0, function_type);
  result.set_interfaces(interfaces);
  if (!signature_function.IsNull()) {
    result.PatchSignatureFunction(signature_function);
  }
  return result.raw();
}


void Class::PatchSignatureFunction(const Function& signature_function) const {
  ASSERT(!signature_function.IsNull());
  const Class& owner_class = Class::Handle(signature_function.Owner());
  ASSERT(!owner_class.IsNull());
  TypeArguments& type_parameters = TypeArguments::Handle();
  // A signature class extends class Instance and is parameterized in the same
  // way as the owner class of its non-static signature function.
  // It is not type parameterized if its signature function is static.
  // In case of a function type alias, the function owner is the alias class
  // instead of the enclosing class.
  if (!signature_function.is_static() &&
      (owner_class.NumTypeParameters() > 0) &&
      !signature_function.HasInstantiatedSignature()) {
    type_parameters = owner_class.type_parameters();
  }
  set_signature_function(signature_function);
  set_type_parameters(type_parameters);
  if (owner_class.raw() == raw()) {
    // This signature class is an alias, which cannot be the canonical
    // signature class for this signature function.
    ASSERT(!IsCanonicalSignatureClass());
  } else if (signature_function.signature_class() == Object::null()) {
    // Make this signature class the canonical signature class.
    signature_function.set_signature_class(*this);
    ASSERT(IsCanonicalSignatureClass());
  }
  set_is_prefinalized();
}


RawClass* Class::NewNativeWrapper(const Library& library,
                                  const String& name,
                                  int field_count) {
  Class& cls = Class::Handle(library.LookupClass(name));
  if (cls.IsNull()) {
    cls = New<Instance>(name, Script::Handle(), Scanner::kDummyTokenIndex);
    cls.SetFields(Object::empty_array());
    cls.SetFunctions(Object::empty_array());
    // Set super class to Object.
    cls.set_super_type(Type::Handle(Type::ObjectType()));
    // Compute instance size. First word contains a pointer to a properly
    // sized typed array once the first native field has been set.
    intptr_t instance_size = sizeof(RawObject) + kWordSize;
    cls.set_instance_size(RoundedAllocationSize(instance_size));
    cls.set_next_field_offset(instance_size);
    cls.set_num_native_fields(field_count);
    cls.set_is_finalized();
    library.AddClass(cls);
    return cls.raw();
  } else {
    return Class::null();
  }
}


RawClass* Class::NewStringClass(intptr_t class_id) {
  intptr_t instance_size;
  if (class_id == kOneByteStringCid) {
    instance_size = OneByteString::InstanceSize();
  } else if (class_id == kTwoByteStringCid) {
    instance_size = TwoByteString::InstanceSize();
  } else if (class_id == kExternalOneByteStringCid) {
    instance_size = ExternalOneByteString::InstanceSize();
  } else {
    ASSERT(class_id == kExternalTwoByteStringCid);
    instance_size = ExternalTwoByteString::InstanceSize();
  }
  Class& result = Class::Handle(New<String>(class_id));
  result.set_instance_size(instance_size);
  result.set_next_field_offset(instance_size);
  result.set_is_prefinalized();
  return result.raw();
}


RawClass* Class::NewTypedDataClass(intptr_t class_id) {
  ASSERT(RawObject::IsTypedDataClassId(class_id));
  intptr_t instance_size = TypedData::InstanceSize();
  Class& result = Class::Handle(New<TypedData>(class_id));
  result.set_instance_size(instance_size);
  result.set_next_field_offset(instance_size);
  result.set_is_prefinalized();
  return result.raw();
}


RawClass* Class::NewTypedDataViewClass(intptr_t class_id) {
  ASSERT(RawObject::IsTypedDataViewClassId(class_id));
  Class& result = Class::Handle(New<Instance>(class_id));
  result.set_instance_size(0);
  result.set_next_field_offset(0);
  return result.raw();
}


RawClass* Class::NewExternalTypedDataClass(intptr_t class_id) {
  ASSERT(RawObject::IsExternalTypedDataClassId(class_id));
  intptr_t instance_size = ExternalTypedData::InstanceSize();
  Class& result = Class::Handle(New<ExternalTypedData>(class_id));
  result.set_instance_size(instance_size);
  result.set_next_field_offset(instance_size);
  result.set_is_prefinalized();
  return result.raw();
}


void Class::set_name(const String& value) const {
  ASSERT(value.IsSymbol());
  StorePointer(&raw_ptr()->name_, value.raw());
}


void Class::set_script(const Script& value) const {
  StorePointer(&raw_ptr()->script_, value.raw());
}


void Class::set_token_pos(intptr_t token_pos) const {
  ASSERT(token_pos >= 0);
  raw_ptr()->token_pos_ = token_pos;
}


void Class::set_is_implemented() const {
  set_state_bits(ImplementedBit::update(true, raw_ptr()->state_bits_));
}


void Class::set_is_abstract() const {
  set_state_bits(AbstractBit::update(true, raw_ptr()->state_bits_));
}


void Class::set_is_const() const {
  set_state_bits(ConstBit::update(true, raw_ptr()->state_bits_));
}


void Class::set_is_finalized() const {
  ASSERT(!is_finalized());
  set_state_bits(StateBits::update(RawClass::kFinalized,
                                   raw_ptr()->state_bits_));
}


void Class::set_is_prefinalized() const {
  ASSERT(!is_finalized());
  set_state_bits(StateBits::update(RawClass::kPreFinalized,
                                   raw_ptr()->state_bits_));
}


void Class::set_interfaces(const Array& value) const {
  // Verification and resolving of interfaces occurs in finalizer.
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->interfaces_, value.raw());
}


void Class::set_mixin(const Type& value) const {
  // Resolution and application of mixin type occurs in finalizer.
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->mixin_, value.raw());
}


void Class::AddDirectSubclass(const Class& subclass) const {
  ASSERT(!subclass.IsNull());
  ASSERT(subclass.SuperClass() == raw());
  // Do not keep track of the direct subclasses of class Object.
  ASSERT(!IsObjectClass());
  GrowableObjectArray& direct_subclasses =
      GrowableObjectArray::Handle(raw_ptr()->direct_subclasses_);
  if (direct_subclasses.IsNull()) {
    direct_subclasses = GrowableObjectArray::New(4, Heap::kOld);
    StorePointer(&raw_ptr()->direct_subclasses_, direct_subclasses.raw());
  }
#if defined(DEBUG)
  // Verify that the same class is not added twice.
  for (intptr_t i = 0; i < direct_subclasses.Length(); i++) {
    ASSERT(direct_subclasses.At(i) != subclass.raw());
  }
#endif
  direct_subclasses.Add(subclass);
}


RawArray* Class::constants() const {
  return raw_ptr()->constants_;
}

void Class::set_constants(const Array& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->constants_, value.raw());
}


RawArray* Class::canonical_types() const {
  return raw_ptr()->canonical_types_;
}

void Class::set_canonical_types(const Array& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->canonical_types_, value.raw());
}


void Class::set_allocation_stub(const Code& value) const {
  ASSERT(!value.IsNull());
  ASSERT(raw_ptr()->allocation_stub_ == Code::null());
  StorePointer(&raw_ptr()->allocation_stub_, value.raw());
}


bool Class::IsFunctionClass() const {
  return raw() == Type::Handle(Type::Function()).type_class();
}


bool Class::IsListClass() const {
  return raw() == Isolate::Current()->object_store()->list_class();
}


bool Class::IsCanonicalSignatureClass() const {
  const Function& function = Function::Handle(signature_function());
  return (!function.IsNull() && (function.signature_class() == raw()));
}


// If test_kind == kIsSubtypeOf, checks if type S is a subtype of type T.
// If test_kind == kIsMoreSpecificThan, checks if S is more specific than T.
// Type S is specified by this class parameterized with 'type_arguments', and
// type T by class 'other' parameterized with 'other_type_arguments'.
// This class and class 'other' do not need to be finalized, however, they must
// be resolved as well as their interfaces.
bool Class::TypeTest(
    TypeTestKind test_kind,
    const AbstractTypeArguments& type_arguments,
    const Class& other,
    const AbstractTypeArguments& other_type_arguments,
    Error* malformed_error) const {
  ASSERT(!IsVoidClass());
  // Check for DynamicType.
  // Each occurrence of DynamicType in type T is interpreted as the dynamic
  // type, a supertype of all types.
  if (other.IsDynamicClass()) {
    return true;
  }
  // In the case of a subtype test, each occurrence of DynamicType in type S is
  // interpreted as the bottom type, a subtype of all types.
  // However, DynamicType is not more specific than any type.
  if (IsDynamicClass()) {
    return test_kind == kIsSubtypeOf;
  }
  // Check for NullType, which is only a subtype of ObjectType, of DynamicType,
  // or of itself, and which is more specific than any type.
  if (IsNullClass()) {
    // We already checked for other.IsDynamicClass() above.
    return (test_kind == kIsMoreSpecificThan) ||
        other.IsObjectClass() || other.IsNullClass();
  }
  // Check for ObjectType. Any type that is not NullType or DynamicType (already
  // checked above), is more specific than ObjectType.
  if (other.IsObjectClass()) {
    return true;
  }
  // Check for reflexivity.
  if (raw() == other.raw()) {
    const intptr_t len = NumTypeArguments();
    if (len == 0) {
      return true;
    }
    // Since we do not truncate the type argument vector of a subclass (see
    // below), we only check a prefix of the proper length.
    // Check for covariance.
    if (other_type_arguments.IsNull() || other_type_arguments.IsRaw(len)) {
      return true;
    }
    if (type_arguments.IsNull() || type_arguments.IsRaw(len)) {
      // Other type can't be more specific than this one because for that
      // it would have to have all dynamic type arguments which is checked
      // above.
      return test_kind == kIsSubtypeOf;
    }
    return type_arguments.TypeTest(test_kind,
                                   other_type_arguments,
                                   len,
                                   malformed_error);
  }
  const bool other_is_function_class = other.IsFunctionClass();
  if (other.IsSignatureClass() || other_is_function_class) {
    const Function& other_fun = Function::Handle(other.signature_function());
    if (IsSignatureClass()) {
      if (other_is_function_class) {
        return true;
      }
      // Check for two function types.
      const Function& fun = Function::Handle(signature_function());
      return fun.TypeTest(test_kind,
                          type_arguments,
                          other_fun,
                          other_type_arguments,
                          malformed_error);
    }
    // Check if type S has a call() method of function type T.
    Function& function =
        Function::Handle(LookupDynamicFunction(Symbols::Call()));
    if (function.IsNull()) {
      // Walk up the super_class chain.
      Class& cls = Class::Handle(SuperClass());
      while (!cls.IsNull() && function.IsNull()) {
        function = cls.LookupDynamicFunction(Symbols::Call());
        cls = cls.SuperClass();
      }
    }
    if (!function.IsNull()) {
      if (other_is_function_class ||
          function.TypeTest(test_kind,
                            type_arguments,
                            other_fun,
                            other_type_arguments,
                            malformed_error)) {
        return true;
      }
    }
  }
  // Check for 'direct super type' specified in the implements clause
  // and check for transitivity at the same time.
  Array& interfaces = Array::Handle(this->interfaces());
  AbstractType& interface = AbstractType::Handle();
  Class& interface_class = Class::Handle();
  AbstractTypeArguments& interface_args = AbstractTypeArguments::Handle();
  Error& args_malformed_error = Error::Handle();
  for (intptr_t i = 0; i < interfaces.Length(); i++) {
    interface ^= interfaces.At(i);
    interface_class = interface.type_class();
    interface_args = interface.arguments();
    if (!interface_args.IsNull() && !interface_args.IsInstantiated()) {
      // This type class implements an interface that is parameterized with
      // generic type(s), e.g. it implements List<T>.
      // The uninstantiated type T must be instantiated using the type
      // parameters of this type before performing the type test.
      // The type arguments of this type that are referred to by the type
      // parameters of the interface are at the end of the type vector,
      // after the type arguments of the super type of this type.
      // The index of the type parameters is adjusted upon finalization.
      ASSERT(interface.IsFinalized());
      args_malformed_error = Error::null();
      interface_args = interface_args.InstantiateFrom(type_arguments,
                                                      &args_malformed_error);
      if (!args_malformed_error.IsNull()) {
        // Return the first malformed error to the caller if it requests it.
        if ((malformed_error != NULL) && malformed_error->IsNull()) {
          *malformed_error = args_malformed_error.raw();
        }
        continue;  // Another interface may work better.
      }
    }
    if (interface_class.TypeTest(test_kind,
                                 interface_args,
                                 other,
                                 other_type_arguments,
                                 malformed_error)) {
      return true;
    }
  }
  const Class& super_class = Class::Handle(SuperClass());
  if (super_class.IsNull()) {
    return false;
  }
  // Instead of truncating the type argument vector to the length of the super
  // type argument vector, we make sure that the code works with a vector that
  // is longer than necessary.
  return super_class.TypeTest(test_kind,
                              type_arguments,
                              other,
                              other_type_arguments,
                              malformed_error);
}


bool Class::IsTopLevel() const {
  return String::Handle(Name()).Equals("::");
}


RawFunction* Class::LookupDynamicFunction(const String& name) const {
  Function& function = Function::Handle(LookupFunction(name));
  if (function.IsNull() || !function.IsDynamicFunction()) {
    return Function::null();
  }
  return function.raw();
}


RawFunction* Class::LookupDynamicFunctionAllowPrivate(
    const String& name) const {
  Function& function = Function::Handle(LookupFunctionAllowPrivate(name));
  if (function.IsNull() || !function.IsDynamicFunction()) {
    return Function::null();
  }
  return function.raw();
}


RawFunction* Class::LookupStaticFunction(const String& name) const {
  Function& function = Function::Handle(LookupFunction(name));
  if (function.IsNull() || !function.IsStaticFunction()) {
    return Function::null();
  }
  return function.raw();
}


RawFunction* Class::LookupStaticFunctionAllowPrivate(const String& name) const {
  Function& function = Function::Handle(LookupFunctionAllowPrivate(name));
  if (function.IsNull() || !function.IsStaticFunction()) {
    return Function::null();
  }
  return function.raw();
}


RawFunction* Class::LookupConstructor(const String& name) const {
  Function& function = Function::Handle(LookupFunction(name));
  if (function.IsNull() || !function.IsConstructor()) {
    return Function::null();
  }
  ASSERT(!function.is_static());
  return function.raw();
}


RawFunction* Class::LookupConstructorAllowPrivate(const String& name) const {
  Function& function = Function::Handle(LookupFunctionAllowPrivate(name));
  if (function.IsNull() || !function.IsConstructor()) {
    return Function::null();
  }
  ASSERT(!function.is_static());
  return function.raw();
}


RawFunction* Class::LookupFactory(const String& name) const {
  Function& function = Function::Handle(LookupFunction(name));
  if (function.IsNull() || !function.IsFactory()) {
    return Function::null();
  }
  ASSERT(function.is_static());
  return function.raw();
}


// Returns true if 'prefix' and 'accessor_name' match 'name'.
static bool MatchesAccessorName(const String& name,
                                const char* prefix,
                                intptr_t prefix_length,
                                const String& accessor_name) {
  intptr_t name_len = name.Length();
  intptr_t accessor_name_len = accessor_name.Length();

  if (name_len != (accessor_name_len + prefix_length)) {
    return false;
  }
  for (intptr_t i = 0; i < prefix_length; i++) {
    if (name.CharAt(i) != prefix[i]) {
      return false;
    }
  }
  for (intptr_t i = 0, j = prefix_length; i < accessor_name_len; i++, j++) {
    if (name.CharAt(j) != accessor_name.CharAt(i)) {
      return false;
    }
  }
  return true;
}


RawFunction* Class::LookupFunction(const String& name) const {
  Isolate* isolate = Isolate::Current();
  Array& funcs = Array::Handle(isolate, functions());
  if (funcs.IsNull()) {
    // This can occur, e.g., for Null classes.
    return Function::null();
  }
  Function& function = Function::Handle(isolate, Function::null());
  const intptr_t len = funcs.Length();
  if (name.IsSymbol()) {
    // Quick Symbol compare.
    NoGCScope no_gc;
    for (intptr_t i = 0; i < len; i++) {
      function ^= funcs.At(i);
      if (function.name() == name.raw()) {
        return function.raw();
      }
    }
  } else {
    String& function_name = String::Handle(isolate, String::null());
    for (intptr_t i = 0; i < len; i++) {
      function ^= funcs.At(i);
      function_name ^= function.name();
      if (function_name.Equals(name)) {
        return function.raw();
      }
    }
  }
  // No function found.
  return Function::null();
}


RawFunction* Class::LookupFunctionAllowPrivate(const String& name) const {
  Isolate* isolate = Isolate::Current();
  Array& funcs = Array::Handle(isolate, functions());
  if (funcs.IsNull()) {
    // This can occur, e.g., for Null classes.
    return Function::null();
  }
  Function& function = Function::Handle(isolate, Function::null());
  String& function_name = String::Handle(isolate, String::null());
  intptr_t len = funcs.Length();
  for (intptr_t i = 0; i < len; i++) {
    function ^= funcs.At(i);
    function_name ^= function.name();
    if (String::EqualsIgnoringPrivateKey(function_name, name)) {
        return function.raw();
    }
  }
  // No function found.
  return Function::null();
}


RawFunction* Class::LookupGetterFunction(const String& name) const {
  return LookupAccessorFunction(kGetterPrefix, kGetterPrefixLength, name);
}


RawFunction* Class::LookupSetterFunction(const String& name) const {
  return LookupAccessorFunction(kSetterPrefix, kSetterPrefixLength, name);
}


RawFunction* Class::LookupAccessorFunction(const char* prefix,
                                           intptr_t prefix_length,
                                           const String& name) const {
  Isolate* isolate = Isolate::Current();
  Array& funcs = Array::Handle(isolate, functions());
  Function& function = Function::Handle(isolate, Function::null());
  String& function_name = String::Handle(isolate, String::null());
  intptr_t len = funcs.Length();
  for (intptr_t i = 0; i < len; i++) {
    function ^= funcs.At(i);
    function_name ^= function.name();
    if (MatchesAccessorName(function_name, prefix, prefix_length, name)) {
      return function.raw();
    }
  }

  // No function found.
  return Function::null();
}


RawFunction* Class::LookupFunctionAtToken(intptr_t token_pos) const {
  // TODO(hausner): we can shortcut the negative case if we knew the
  // beginning and end token position of the class.
  Function& func = Function::Handle();
  func = LookupClosureFunction(token_pos);
  if (!func.IsNull()) {
    return func.raw();
  }
  Array& funcs = Array::Handle(functions());
  intptr_t len = funcs.Length();
  for (intptr_t i = 0; i < len; i++) {
    func ^= funcs.At(i);
    if ((func.token_pos() <= token_pos) &&
        (token_pos <= func.end_token_pos())) {
      return func.raw();
    }
  }
  // No function found.
  return Function::null();
}


RawField* Class::LookupInstanceField(const String& name) const {
  ASSERT(is_finalized());
  const Field& field = Field::Handle(LookupField(name));
  if (!field.IsNull()) {
    if (field.is_static()) {
      // Name matches but it is not of the correct kind, return NULL.
      return Field::null();
    }
    return field.raw();
  }
  // No field found.
  return Field::null();
}


RawField* Class::LookupStaticField(const String& name) const {
  ASSERT(is_finalized());
  const Field& field = Field::Handle(LookupField(name));
  if (!field.IsNull()) {
    if (!field.is_static()) {
      // Name matches but it is not of the correct kind, return NULL.
      return Field::null();
    }
    return field.raw();
  }
  // No field found.
  return Field::null();
}


RawField* Class::LookupField(const String& name) const {
  Isolate* isolate = Isolate::Current();
  const Array& flds = Array::Handle(isolate, fields());
  Field& field = Field::Handle(isolate, Field::null());
  String& field_name = String::Handle(isolate, String::null());
  intptr_t len = flds.Length();
  for (intptr_t i = 0; i < len; i++) {
    field ^= flds.At(i);
    field_name ^= field.name();
    if (String::EqualsIgnoringPrivateKey(field_name, name)) {
        return field.raw();
    }
  }
  // No field found.
  return Field::null();
}


RawLibraryPrefix* Class::LookupLibraryPrefix(const String& name) const {
  Isolate* isolate = Isolate::Current();
  const Library& lib = Library::Handle(isolate, library());
  const Object& obj = Object::Handle(isolate, lib.LookupLocalObject(name));
  if (!obj.IsNull() && obj.IsLibraryPrefix()) {
    const LibraryPrefix& lib_prefix = LibraryPrefix::Cast(obj);
    return lib_prefix.raw();
  }
  return LibraryPrefix::null();
}


const char* Class::ToCString() const {
  const char* format = "%s Class: %s";
  const Library& lib = Library::Handle(library());
  const char* library_name = lib.IsNull() ? "" : lib.ToCString();
  const char* class_name = String::Handle(Name()).ToCString();
  intptr_t len = OS::SNPrint(NULL, 0, format, library_name, class_name) + 1;
  char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
  OS::SNPrint(chars, len, format, library_name, class_name);
  return chars;
}


void Class::InsertCanonicalConstant(intptr_t index,
                                    const Instance& constant) const {
  // The constant needs to be added to the list. Grow the list if it is full.
  Array& canonical_list = Array::Handle(constants());
  const intptr_t list_len = canonical_list.Length();
  if (index >= list_len) {
    const intptr_t new_length = (list_len == 0) ? 4 : list_len + 4;
    const Array& new_canonical_list =
        Array::Handle(Array::Grow(canonical_list, new_length, Heap::kOld));
    set_constants(new_canonical_list);
    new_canonical_list.SetAt(index, constant);
  } else {
    canonical_list.SetAt(index, constant);
  }
}


RawUnresolvedClass* UnresolvedClass::New(const LibraryPrefix& library_prefix,
                                         const String& ident,
                                         intptr_t token_pos) {
  const UnresolvedClass& type = UnresolvedClass::Handle(UnresolvedClass::New());
  type.set_library_prefix(library_prefix);
  type.set_ident(ident);
  type.set_token_pos(token_pos);
  return type.raw();
}


RawUnresolvedClass* UnresolvedClass::New() {
  ASSERT(Object::unresolved_class_class() != Class::null());
  RawObject* raw = Object::Allocate(UnresolvedClass::kClassId,
                                    UnresolvedClass::InstanceSize(),
                                    Heap::kOld);
  return reinterpret_cast<RawUnresolvedClass*>(raw);
}


void UnresolvedClass::set_token_pos(intptr_t token_pos) const {
  ASSERT(token_pos >= 0);
  raw_ptr()->token_pos_ = token_pos;
}


void UnresolvedClass::set_ident(const String& ident) const {
  StorePointer(&raw_ptr()->ident_, ident.raw());
}


void UnresolvedClass::set_library_prefix(
    const LibraryPrefix& library_prefix) const {
  StorePointer(&raw_ptr()->library_prefix_, library_prefix.raw());
}


RawString* UnresolvedClass::Name() const {
  if (library_prefix() != LibraryPrefix::null()) {
    const LibraryPrefix& lib_prefix = LibraryPrefix::Handle(library_prefix());
    String& name = String::Handle();
    name = lib_prefix.name();  // Qualifier.
    name = String::Concat(name, Symbols::Dot());
    const String& str = String::Handle(ident());
    name = String::Concat(name, str);
    return name.raw();
  } else {
    return ident();
  }
}


const char* UnresolvedClass::ToCString() const {
  const char* format = "unresolved class '%s'";
  const char* cname =  String::Handle(Name()).ToCString();
  intptr_t len = OS::SNPrint(NULL, 0, format, cname) + 1;
  char* chars = Isolate::Current()->current_zone()->Alloc<char>(len);
  OS::SNPrint(chars, len, format, cname);
  return chars;
}


intptr_t AbstractTypeArguments::Length() const  {
  // AbstractTypeArguments is an abstract class.
  UNREACHABLE();
  return -1;
}


RawAbstractType* AbstractTypeArguments::TypeAt(intptr_t index) const {
  // AbstractTypeArguments is an abstract class.
  UNREACHABLE();
  return NULL;
}


void AbstractTypeArguments::SetTypeAt(intptr_t index,
                                      const AbstractType& value) const {
  // AbstractTypeArguments is an abstract class.
  UNREACHABLE();
}


bool AbstractTypeArguments::IsResolved() const {
  // AbstractTypeArguments is an abstract class.
  UNREACHABLE();
  return false;
}


bool AbstractTypeArguments::IsInstantiated() const {
  // AbstractTypeArguments is an abstract class.
  UNREACHABLE();
  return false;
}


bool AbstractTypeArguments::IsUninstantiatedIdentity() const {
  // AbstractTypeArguments is an abstract class.
  UNREACHABLE();
  return false;
}


bool AbstractTypeArguments::IsBounded() const {
  // AbstractTypeArguments is an abstract class.
  UNREACHABLE();
  return false;
}


static intptr_t FinalizeHash(uword hash) {
  hash += hash << 3;
  hash ^= hash >> 11;
  hash += hash << 15;
  return hash;
}


intptr_t AbstractTypeArguments::Hash() const {
  if (IsNull()) return 0;
  uword result = 0;
  intptr_t num_types = Length();
  AbstractType& type = AbstractType::Handle();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    result += type.Hash();
    result += result << 10;
    result ^= result >> 6;
  }
  return FinalizeHash(result);
}


RawString* AbstractTypeArguments::SubvectorName(
    intptr_t from_index,
    intptr_t len,
    NameVisibility name_visibility) const {
  ASSERT(from_index + len <= Length());
  String& name = String::Handle();
  const intptr_t num_strings = 2*len + 1;  // "<""T"", ""T"">".
  const Array& strings = Array::Handle(Array::New(num_strings));
  intptr_t s = 0;
  strings.SetAt(s++, Symbols::LAngleBracket());
  AbstractType& type = AbstractType::Handle();
  for (intptr_t i = 0; i < len; i++) {
    type = TypeAt(from_index + i);
    name = type.BuildName(name_visibility);
    strings.SetAt(s++, name);
    if (i < len - 1) {
      strings.SetAt(s++, Symbols::CommaSpace());
    }
  }
  strings.SetAt(s++, Symbols::RAngleBracket());
  ASSERT(s == num_strings);
  name = String::ConcatAll(strings);
  return Symbols::New(name);
}


bool AbstractTypeArguments::Equals(const AbstractTypeArguments& other) const {
  ASSERT(!IsNull());  // Use AbstractTypeArguments::AreEqual().
  if (this->raw() == other.raw()) {
    return true;
  }
  if (other.IsNull()) {
    return false;
  }
  intptr_t num_types = Length();
  if (num_types != other.Length()) {
    return false;
  }
  AbstractType& type = AbstractType::Handle();
  AbstractType& other_type = AbstractType::Handle();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    other_type = other.TypeAt(i);
    if (!type.Equals(other_type)) {
      return false;
    }
  }
  return true;
}


bool AbstractTypeArguments::AreEqual(
    const AbstractTypeArguments& arguments,
    const AbstractTypeArguments& other_arguments) {
  if (arguments.raw() == other_arguments.raw()) {
    return true;
  }
  if (arguments.IsNull()) {
    return other_arguments.IsDynamicTypes(false, other_arguments.Length());
  }
  if (other_arguments.IsNull()) {
    return arguments.IsDynamicTypes(false, arguments.Length());
  }
  return arguments.Equals(other_arguments);
}


RawAbstractTypeArguments* AbstractTypeArguments::InstantiateFrom(
    const AbstractTypeArguments& instantiator_type_arguments,
    Error* malformed_error) const {
  // AbstractTypeArguments is an abstract class.
  UNREACHABLE();
  return NULL;
}


bool AbstractTypeArguments::IsDynamicTypes(bool raw_instantiated,
                                           intptr_t len) const {
  ASSERT(Length() >= len);
  AbstractType& type = AbstractType::Handle();