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/bit_vector.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/disassembler.h"
#include "vm/double_conversion.h"
#include "vm/exceptions.h"
#include "vm/flow_graph_builder.h"
#include "vm/flow_graph_compiler.h"
#include "vm/growable_array.h"
#include "vm/hash_table.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/profiler.h"
#include "vm/report.h"
#include "vm/reusable_handles.h"
#include "vm/runtime_entry.h"
#include "vm/scopes.h"
#include "vm/stack_frame.h"
#include "vm/symbols.h"
#include "vm/tags.h"
#include "vm/timer.h"
#include "vm/unicode.h"
#include "vm/verified_memory.h"
#include "vm/weak_code.h"

namespace dart {

DEFINE_FLAG(int, huge_method_cutoff_in_code_size, 200000,
    "Huge method cutoff in unoptimized code size (in bytes).");
DEFINE_FLAG(int, huge_method_cutoff_in_tokens, 20000,
    "Huge method cutoff in tokens: Disables optimizations for huge methods.");
DEFINE_FLAG(bool, overlap_type_arguments, true,
    "When possible, partially or fully overlap the type arguments of a type "
    "with the type arguments of its super type.");
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, throw_on_javascript_int_overflow, false,
    "Throw an exception when the result of an integer calculation will not "
    "fit into a javascript integer.");
DEFINE_FLAG(bool, trace_cha, false, "Trace CHA operations");
DEFINE_FLAG(bool, use_field_guards, true, "Guard field cids.");
DEFINE_FLAG(bool, use_lib_cache, true, "Use library name cache");
DEFINE_FLAG(bool, trace_field_guards, false, "Trace changes in field's cids.");
DEFINE_FLAG(bool, ignore_patch_signature_mismatch, false,
            "Ignore patch file member signature mismatch.");

DECLARE_FLAG(charp, coverage_dir);
DECLARE_FLAG(bool, load_deferred_eagerly);
DECLARE_FLAG(bool, show_invisible_frames);
DECLARE_FLAG(bool, trace_compiler);
DECLARE_FLAG(bool, trace_deoptimization);
DECLARE_FLAG(bool, trace_deoptimization_verbose);
DECLARE_FLAG(bool, write_protect_code);


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
Object* Object::null_object_ = NULL;
Array* Object::null_array_ = NULL;
String* Object::null_string_ = NULL;
Instance* Object::null_instance_ = NULL;
TypeArguments* Object::null_type_arguments_ = NULL;
Array* Object::empty_array_ = NULL;
Array* Object::zero_array_ = NULL;
ContextScope* Object::empty_context_scope_ = NULL;
ObjectPool* Object::empty_object_pool_ = NULL;
PcDescriptors* Object::empty_descriptors_ = NULL;
LocalVarDescriptors* Object::empty_var_descriptors_ = NULL;
ExceptionHandlers* Object::empty_exception_handlers_ = NULL;
Array* Object::extractor_parameter_types_ = NULL;
Array* Object::extractor_parameter_names_ = NULL;
Instance* Object::sentinel_ = NULL;
Instance* Object::transition_sentinel_ = NULL;
Instance* Object::unknown_constant_ = NULL;
Instance* Object::non_constant_ = NULL;
Bool* Object::bool_true_ = NULL;
Bool* Object::bool_false_ = NULL;
Smi* Object::smi_illegal_cid_ = NULL;
LanguageError* Object::snapshot_writer_error_ = NULL;
LanguageError* Object::branch_offset_error_ = NULL;
Array* Object::vm_isolate_snapshot_object_table_ = NULL;

RawObject* Object::null_ = reinterpret_cast<RawObject*>(RAW_NULL);
RawClass* Object::class_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::dynamic_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::void_class_ = reinterpret_cast<RawClass*>(RAW_NULL);
RawType* Object::dynamic_type_ = reinterpret_cast<RawType*>(RAW_NULL);
RawType* Object::void_type_ = reinterpret_cast<RawType*>(RAW_NULL);
RawClass* Object::unresolved_class_class_ =
    reinterpret_cast<RawClass*>(RAW_NULL);
RawClass* Object::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::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::object_pool_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::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);


const double MegamorphicCache::kLoadFactor = 0.75;


static void AppendSubString(Zone* zone,
                            GrowableArray<const char*>* segments,
                            const char* name,
                            intptr_t start_pos, intptr_t len) {
  char* segment = zone->Alloc<char>(len + 1);  // '\0'-terminated.
  memmove(segment, name + start_pos, len);
  segment[len] = '\0';
  segments->Add(segment);
}


static const char* MergeSubStrings(Zone* zone,
                                   const GrowableArray<const char*>& segments,
                                   intptr_t alloc_len) {
  char* result = zone->Alloc<char>(alloc_len + 1);  // '\0'-terminated
  intptr_t pos = 0;
  for (intptr_t k = 0; k < segments.length(); k++) {
    const char* piece = segments[k];
    const intptr_t piece_len = strlen(segments[k]);
    memmove(result + pos, piece, piece_len);
    pos += piece_len;
    ASSERT(pos <= alloc_len);
  }
  result[pos] = '\0';
  return result;
}


// 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 multiple times:
//
//   _ReceivePortImpl@709387912 -> _ReceivePortImpl
//   _ReceivePortImpl@709387912._internal@709387912 ->
//      _ReceivePortImpl._internal
//   _C@6328321&_E@6328321&_F@6328321 -> _C&_E&_F
//
// The trailing . on the default constructor name is dropped:
//
//   List. -> List
//
// And so forth:
//
//   get:foo@6328321 -> foo
//   _MyClass@6328321. -> _MyClass
//   _MyClass@6328321.named -> _MyClass.named
//
RawString* String::IdentifierPrettyName(const String& name) {
  Zone* zone = Thread::Current()->zone();
  if (name.Equals(Symbols::TopLevel())) {
    // Name of invisible top-level class.
    return Symbols::Empty().raw();
  }

  const char* cname = name.ToCString();
  ASSERT(strlen(cname) == static_cast<size_t>(name.Length()));
  const intptr_t name_len = name.Length();
  // First remove all private name mangling.
  intptr_t start_pos = 0;
  GrowableArray<const char*> unmangled_segments;
  intptr_t sum_segment_len = 0;
  for (intptr_t i = 0; i < name_len; i++) {
    if ((cname[i] == '@') && ((i + 1) < name_len) &&
        (cname[i + 1] >= '0') && (cname[i + 1] <= '9')) {
      // Append the current segment to the unmangled name.
      const intptr_t segment_len = i - start_pos;
      sum_segment_len += segment_len;
      AppendSubString(zone, &unmangled_segments, cname, start_pos, segment_len);
      // Advance until past the name mangling. The private keys are only
      // numbers so we skip until the first non-number.
      i++;  // Skip the '@'.
      while ((i < name.Length()) &&
             (name.CharAt(i) >= '0') &&
             (name.CharAt(i) <= '9')) {
        i++;
      }
      start_pos = i;
      i--;  // Account for for-loop increment.
    }
  }

  const char* unmangled_name = NULL;
  if (start_pos == 0) {
    // No name unmangling needed, reuse the name that was passed in.
    unmangled_name = cname;
    sum_segment_len = name_len;
  } else if (name.Length() != start_pos) {
    // Append the last segment.
    const intptr_t segment_len = name.Length() - start_pos;
    sum_segment_len += segment_len;
    AppendSubString(zone, &unmangled_segments, cname, start_pos, segment_len);
  }
  if (unmangled_name == NULL) {
    // Merge unmangled_segments.
    unmangled_name = MergeSubStrings(zone, unmangled_segments, sum_segment_len);
  }

  intptr_t len = sum_segment_len;
  intptr_t start = 0;
  intptr_t dot_pos = -1;  // Position of '.' in the name, if any.
  bool is_setter = false;
  for (intptr_t i = start; i < len; i++) {
    if (unmangled_name[i] == ':') {
      if (start != 0) {
        // Reset and break.
        start = 0;
        dot_pos = -1;
        break;
      }
      ASSERT(start == 0);  // Only one : is possible in getters or setters.
      if (unmangled_name[0] == 's') {
        is_setter = true;
      }
      start = i + 1;
    } else if (unmangled_name[i] == '.') {
      if (dot_pos != -1) {
        // Reset and break.
        start = 0;
        dot_pos = -1;
        break;
      }
      ASSERT(dot_pos == -1);  // Only one dot is supported.
      dot_pos = i;
    }
  }

  if ((start == 0) && (dot_pos == -1)) {
    // This unmangled_name is fine as it is.
    return Symbols::New(unmangled_name, sum_segment_len);
  }

  // Drop the trailing dot if needed.
  intptr_t end = ((dot_pos + 1) == len) ? dot_pos : len;

  unmangled_segments.Clear();
  intptr_t final_len = end - start;
  AppendSubString(zone, &unmangled_segments, unmangled_name, start, final_len);
  if (is_setter) {
    const char* equals = Symbols::Equals().ToCString();
    const intptr_t equals_len = strlen(equals);
    AppendSubString(zone, &unmangled_segments, equals, 0, equals_len);
    final_len += equals_len;
  }

  unmangled_name = MergeSubStrings(zone, unmangled_segments, final_len);

  return Symbols::New(unmangled_name);
}


RawString* String::IdentifierPrettyNameRetainPrivate(const String& name) {
  intptr_t len = name.Length();
  intptr_t start = 0;
  intptr_t at_pos = -1;  // Position of '@' in the name, if any.
  bool is_setter = false;

  for (intptr_t i = start; i < len; i++) {
    if (name.CharAt(i) == ':') {
      ASSERT(start == 0);  // Only one : is possible in getters or setters.
      if (name.CharAt(0) == 's') {
        is_setter = true;
      }
      start = i + 1;
    } else if (name.CharAt(i) == '@') {
      // Setters should have only one @ so we know where to put the =.
      ASSERT(!is_setter || (at_pos == -1));
      at_pos = i;
    }
  }

  if (start == 0) {
    // This unmangled_name is fine as it is.
    return name.raw();
  }

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

  if (is_setter) {
    // Setters need to end with '='.
    if (at_pos == -1) {
      return String::Concat(result, Symbols::Equals());
    } else {
      const String& pre_at =
          String::Handle(String::SubString(result, 0, at_pos - 4));
      const String& post_at =
          String::Handle(String::SubString(name, at_pos, len - at_pos));
      result = String::Concat(pre_at, Symbols::Equals());
      result = String::Concat(result, post_at);
    }
  }

  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 == '$'));
}


static inline bool IsAsciiNonprintable(int32_t c) {
  return ((0 <= c) && (c < 32)) || (c == 127);
}


static inline bool NeedsEscapeSequence(int32_t c) {
  return (c == '"')  ||
         (c == '\\') ||
         (c == '$')  ||
         IsAsciiNonprintable(c);
}


static int32_t EscapeOverhead(int32_t c) {
  if (IsSpecialCharacter(c)) {
    return 1;  // 1 additional byte for the backslash.
  } else if (IsAsciiNonprintable(c)) {
    return 3;  // 3 additional bytes to encode c as \x00.
  }
  return 0;
}


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';
}


void Object::InitNull(Isolate* isolate) {
  // Should only be run by the vm isolate.
  ASSERT(isolate == Dart::vm_isolate());

  // TODO(iposva): NoSafepointScope needs to be added here.
  ASSERT(class_class() == null_);

  Heap* heap = isolate->heap();

  // 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(), true);
  }
}


void Object::InitOnce(Isolate* isolate) {
  // Should only be run by the vm isolate.
  ASSERT(isolate == Dart::vm_isolate());

  // Initialize the static vtable values.
  {
    Object fake_object;
    Smi fake_smi;
    Object::handle_vtable_ = fake_object.vtable();
    Smi::handle_vtable_ = fake_smi.vtable();
  }

  Heap* heap = isolate->heap();

  // Allocate the read only object handles here.
  null_object_ = Object::ReadOnlyHandle();
  null_array_ = Array::ReadOnlyHandle();
  null_string_ = String::ReadOnlyHandle();
  null_instance_ = Instance::ReadOnlyHandle();
  null_type_arguments_ = TypeArguments::ReadOnlyHandle();
  empty_array_ = Array::ReadOnlyHandle();
  zero_array_ = Array::ReadOnlyHandle();
  empty_context_scope_ = ContextScope::ReadOnlyHandle();
  empty_object_pool_ = ObjectPool::ReadOnlyHandle();
  empty_descriptors_ = PcDescriptors::ReadOnlyHandle();
  empty_var_descriptors_ = LocalVarDescriptors::ReadOnlyHandle();
  empty_exception_handlers_ = ExceptionHandlers::ReadOnlyHandle();
  extractor_parameter_types_ = Array::ReadOnlyHandle();
  extractor_parameter_names_ = Array::ReadOnlyHandle();
  sentinel_ = Instance::ReadOnlyHandle();
  transition_sentinel_ = Instance::ReadOnlyHandle();
  unknown_constant_ =  Instance::ReadOnlyHandle();
  non_constant_ =  Instance::ReadOnlyHandle();
  bool_true_ = Bool::ReadOnlyHandle();
  bool_false_ = Bool::ReadOnlyHandle();
  smi_illegal_cid_ = Smi::ReadOnlyHandle();
  snapshot_writer_error_ = LanguageError::ReadOnlyHandle();
  branch_offset_error_ = LanguageError::ReadOnlyHandle();
  vm_isolate_snapshot_object_table_ = Array::ReadOnlyHandle();

  *null_object_ = Object::null();
  *null_array_ = Array::null();
  *null_string_ = String::null();
  *null_instance_ = Instance::null();
  *null_type_arguments_ = TypeArguments::null();

  // Initialize the empty and zero array handles to null_ in order to be able to
  // check if the empty and zero arrays were allocated (RAW_NULL is not
  // available).
  *empty_array_ = Array::null();
  *zero_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, true);

    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::NextFieldOffset());
    cls.set_id(Class::kClassId);
    cls.set_state_bits(0);
    cls.set_is_finalized();
    cls.set_is_type_finalized();
    cls.set_type_arguments_field_offset_in_words(Class::kNoTypeArguments);
    cls.set_num_type_arguments(0);
    cls.set_num_own_type_arguments(0);
    cls.set_num_native_fields(0);
    cls.InitEmptyFields();
    isolate->RegisterClass(cls);
  }

  // Allocate and initialize the null class.
  cls = Class::New<Instance>(kNullCid);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  isolate->object_store()->set_null_class(cls);

  // Allocate and initialize the free list element class.
  cls = Class::New<FreeListElement::FakeInstance>(kFreeListElement);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_finalized();
  cls.set_is_type_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);
  }

  // Allocate and initialize optimizing compiler constants.
  {
    *unknown_constant_ ^=
        Object::Allocate(kNullCid, Instance::InstanceSize(), Heap::kOld);
    *non_constant_ ^=
        Object::Allocate(kNullCid, Instance::InstanceSize(), Heap::kOld);
  }

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

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

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

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

  cls = Class::New<ObjectPool>();
  object_pool_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<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.set_num_type_arguments(1);
  cls.set_num_own_type_arguments(1);
  cls = Class::New<Array>(kImmutableArrayCid);
  isolate->object_store()->set_immutable_array_class(cls);
  cls.set_type_arguments_field_offset(Array::type_arguments_offset());
  cls.set_num_type_arguments(1);
  cls.set_num_own_type_arguments(1);
  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);
  cls = Class::New<Mint>();
  isolate->object_store()->set_mint_class(cls);
  cls = Class::New<Bigint>();
  isolate->object_store()->set_bigint_class(cls);
  cls = Class::New<Double>();
  isolate->object_store()->set_double_class(cls);

  // Ensure that class kExternalTypedDataUint8ArrayCid is registered as we
  // need it when reading in the token stream of bootstrap classes in the VM
  // isolate.
  Class::NewExternalTypedDataClass(kExternalTypedDataUint8ArrayCid);

  // Needed for object pools of VM isolate stubs.
  Class::NewTypedDataClass(kTypedDataInt8ArrayCid);

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

  Smi& smi = Smi::Handle();
  // Allocate and initialize the zero_array instance.
  {
    uword address = heap->Allocate(Array::InstanceSize(1), Heap::kOld);
    InitializeObject(address, kImmutableArrayCid, Array::InstanceSize(1), true);
    Array::initializeHandle(
        zero_array_,
        reinterpret_cast<RawArray*>(address + kHeapObjectTag));
    zero_array_->StoreSmi(&zero_array_->raw_ptr()->length_, Smi::New(1));
    smi = Smi::New(0);
    zero_array_->SetAt(0, smi);
  }

  // Allocate and initialize the canonical empty context scope object.
  {
    uword address = heap->Allocate(ContextScope::InstanceSize(0), Heap::kOld);
    InitializeObject(address,
                     kContextScopeCid,
                     ContextScope::InstanceSize(0),
                     true);
    ContextScope::initializeHandle(
        empty_context_scope_,
        reinterpret_cast<RawContextScope*>(address + kHeapObjectTag));
    empty_context_scope_->StoreNonPointer(
        &empty_context_scope_->raw_ptr()->num_variables_, 0);
    empty_context_scope_->StoreNonPointer(
        &empty_context_scope_->raw_ptr()->is_implicit_, true);
  }

  // Allocate and initialize the canonical empty object pool object.
  {
    uword address =
        heap->Allocate(ObjectPool::InstanceSize(0), Heap::kOld);
    InitializeObject(address,
                     kObjectPoolCid,
                     ObjectPool::InstanceSize(0),
                     true);
    ObjectPool::initializeHandle(
        empty_object_pool_,
        reinterpret_cast<RawObjectPool*>(address + kHeapObjectTag));
    empty_object_pool_->StoreNonPointer(
        &empty_object_pool_->raw_ptr()->length_, 0);
  }

  // Allocate and initialize the empty_descriptors instance.
  {
    uword address = heap->Allocate(PcDescriptors::InstanceSize(0), Heap::kOld);
    InitializeObject(address, kPcDescriptorsCid,
                     PcDescriptors::InstanceSize(0),
                     true);
    PcDescriptors::initializeHandle(
        empty_descriptors_,
        reinterpret_cast<RawPcDescriptors*>(address + kHeapObjectTag));
    empty_descriptors_->StoreNonPointer(&empty_descriptors_->raw_ptr()->length_,
                                        0);
  }

  // Allocate and initialize the canonical empty variable descriptor object.
  {
    uword address =
        heap->Allocate(LocalVarDescriptors::InstanceSize(0), Heap::kOld);
    InitializeObject(address,
                     kLocalVarDescriptorsCid,
                     LocalVarDescriptors::InstanceSize(0),
                     true);
    LocalVarDescriptors::initializeHandle(
        empty_var_descriptors_,
        reinterpret_cast<RawLocalVarDescriptors*>(address + kHeapObjectTag));
    empty_var_descriptors_->StoreNonPointer(
        &empty_var_descriptors_->raw_ptr()->num_entries_, 0);
  }

  // Allocate and initialize the canonical empty exception handler info object.
  // The vast majority of all functions do not contain an exception handler
  // and can share this canonical descriptor.
  {
    uword address =
        heap->Allocate(ExceptionHandlers::InstanceSize(0), Heap::kOld);
    InitializeObject(address,
                     kExceptionHandlersCid,
                     ExceptionHandlers::InstanceSize(0),
                     true);
    ExceptionHandlers::initializeHandle(
        empty_exception_handlers_,
        reinterpret_cast<RawExceptionHandlers*>(address + kHeapObjectTag));
    empty_exception_handlers_->StoreNonPointer(
        &empty_exception_handlers_->raw_ptr()->num_entries_, 0);
  }

  // The VM isolate snapshot object table is initialized to an empty array
  // as we do not have any VM isolate snapshot at this time.
  *vm_isolate_snapshot_object_table_ = Object::empty_array().raw();

  cls = Class::New<Instance>(kDynamicCid);
  cls.set_is_abstract();
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_type_finalized();
  cls.set_is_finalized();
  dynamic_class_ = cls.raw();

  cls = Class::New<Instance>(kVoidCid);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_type_finalized();
  cls.set_is_finalized();
  void_class_ = cls.raw();

  cls = Class::New<Type>();
  cls.set_is_type_finalized();
  cls.set_is_finalized();

  cls = dynamic_class_;
  dynamic_type_ = Type::NewNonParameterizedType(cls);

  cls = void_class_;
  void_type_ = Type::NewNonParameterizedType(cls);

  // 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);

  *smi_illegal_cid_ = Smi::New(kIllegalCid);

  String& error_str = String::Handle();
  error_str = String::New("SnapshotWriter Error", Heap::kOld);
  *snapshot_writer_error_ = LanguageError::New(error_str,
                                               Report::kError,
                                               Heap::kOld);
  error_str = String::New("Branch offset overflow", Heap::kOld);
  *branch_offset_error_ = LanguageError::New(error_str,
                                             Report::kBailout,
                                             Heap::kOld);

  ASSERT(!null_object_->IsSmi());
  ASSERT(!null_array_->IsSmi());
  ASSERT(null_array_->IsArray());
  ASSERT(!null_string_->IsSmi());
  ASSERT(null_string_->IsString());
  ASSERT(!null_instance_->IsSmi());
  ASSERT(null_instance_->IsInstance());
  ASSERT(!null_type_arguments_->IsSmi());
  ASSERT(null_type_arguments_->IsTypeArguments());
  ASSERT(!empty_array_->IsSmi());
  ASSERT(empty_array_->IsArray());
  ASSERT(!zero_array_->IsSmi());
  ASSERT(zero_array_->IsArray());
  ASSERT(!empty_context_scope_->IsSmi());
  ASSERT(empty_context_scope_->IsContextScope());
  ASSERT(!empty_descriptors_->IsSmi());
  ASSERT(empty_descriptors_->IsPcDescriptors());
  ASSERT(!empty_var_descriptors_->IsSmi());
  ASSERT(empty_var_descriptors_->IsLocalVarDescriptors());
  ASSERT(!empty_exception_handlers_->IsSmi());
  ASSERT(empty_exception_handlers_->IsExceptionHandlers());
  ASSERT(!sentinel_->IsSmi());
  ASSERT(sentinel_->IsInstance());
  ASSERT(!transition_sentinel_->IsSmi());
  ASSERT(transition_sentinel_->IsInstance());
  ASSERT(!unknown_constant_->IsSmi());
  ASSERT(unknown_constant_->IsInstance());
  ASSERT(!non_constant_->IsSmi());
  ASSERT(non_constant_->IsInstance());
  ASSERT(!bool_true_->IsSmi());
  ASSERT(bool_true_->IsBool());
  ASSERT(!bool_false_->IsSmi());
  ASSERT(bool_false_->IsBool());
  ASSERT(smi_illegal_cid_->IsSmi());
  ASSERT(!snapshot_writer_error_->IsSmi());
  ASSERT(snapshot_writer_error_->IsLanguageError());
  ASSERT(!branch_offset_error_->IsSmi());
  ASSERT(branch_offset_error_->IsLanguageError());
  ASSERT(!vm_isolate_snapshot_object_table_->IsSmi());
  ASSERT(vm_isolate_snapshot_object_table_->IsArray());
}


// An object visitor which will mark all visited objects. This is used to
// premark all objects in the vm_isolate_ heap.
class PremarkingVisitor : public ObjectVisitor {
 public:
  explicit PremarkingVisitor(Isolate* isolate) : ObjectVisitor(isolate) {}

  void VisitObject(RawObject* obj) {
    // Free list elements should never be marked.
    if (!obj->IsFreeListElement()) {
      ASSERT(obj->IsVMHeapObject());
      if (obj->IsMarked()) {
        // Precompiled instructions are loaded pre-marked.
        ASSERT(Dart::IsRunningPrecompiledCode());
        ASSERT(obj->IsInstructions());
      } else {
        obj->SetMarkBitUnsynchronized();
      }
    }
  }
};


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

void Object::FinalizeVMIsolate(Isolate* isolate) {
  // Should only be run by the vm isolate.
  ASSERT(isolate == Dart::vm_isolate());

  // Allocate the parameter arrays for method extractor types and names.
  *extractor_parameter_types_ = Array::New(1, Heap::kOld);
  extractor_parameter_types_->SetAt(0, Type::Handle(Type::DynamicType()));
  *extractor_parameter_names_ = Array::New(1, Heap::kOld);
  extractor_parameter_names_->SetAt(0, Symbols::This());

  ASSERT(!extractor_parameter_types_->IsSmi());
  ASSERT(extractor_parameter_types_->IsArray());
  ASSERT(!extractor_parameter_names_->IsSmi());
  ASSERT(extractor_parameter_names_->IsArray());


  // Set up names for all VM singleton classes.
  Class& cls = Class::Handle();

  SET_CLASS_NAME(class, Class);
  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(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(namespace, Namespace);
  SET_CLASS_NAME(code, Code);
  SET_CLASS_NAME(instructions, Instructions);
  SET_CLASS_NAME(object_pool, ObjectPool);
  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(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 = isolate->object_store()->array_class();
  cls.set_name(Symbols::_List());
  cls = isolate->object_store()->one_byte_string_class();
  cls.set_name(Symbols::OneByteString());

  {
    ASSERT(isolate == Dart::vm_isolate());
    WritableVMIsolateScope scope(Thread::Current());
    PremarkingVisitor premarker(isolate);
    ASSERT(isolate->heap()->UsedInWords(Heap::kNew) == 0);
    isolate->heap()->IterateOldObjects(&premarker);
    // Make the VM isolate read-only again after setting all objects as marked.
  }
}


void Object::InitVmIsolateSnapshotObjectTable(intptr_t len) {
  ASSERT(Isolate::Current() == Dart::vm_isolate());
  *vm_isolate_snapshot_object_table_ = Array::New(len, Heap::kOld);
}


// 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(Thread::Current()->no_safepoint_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 a TypedDataInt8Array object.
      RawTypedData* raw =
          reinterpret_cast<RawTypedData*>(RawObject::FromAddr(addr));
      uword new_tags = RawObject::ClassIdTag::update(kTypedDataInt8ArrayCid, 0);
      new_tags = RawObject::SizeTag::update(leftover_size, new_tags);
      uword tags = raw->ptr()->tags_;
      uword old_tags;
      // TODO(iposva): Investigate whether CompareAndSwapWord is necessary.
      do {
        old_tags = tags;
        tags = AtomicOperations::CompareAndSwapWord(
            &raw->ptr()->tags_, old_tags, new_tags);
      } while (tags != old_tags);

      intptr_t leftover_len = (leftover_size - TypedData::InstanceSize(0));
      ASSERT(TypedData::InstanceSize(leftover_len) == leftover_size);
      raw->InitializeSmi(&(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 new_tags = RawObject::ClassIdTag::update(kInstanceCid, 0);
      new_tags = RawObject::SizeTag::update(leftover_size, new_tags);
      uword tags = raw->ptr()->tags_;
      uword old_tags;
      // TODO(iposva): Investigate whether CompareAndSwapWord is necessary.
      do {
        old_tags = tags;
        tags = AtomicOperations::CompareAndSwapWord(
            &raw->ptr()->tags_, old_tags, new_tags);
      } while (tags != old_tags);
    }
  }
}


void Object::VerifyBuiltinVtables() {
#if defined(DEBUG)
  Thread* thread = Thread::Current();
  Isolate* isolate = thread->isolate();
  Class& cls = Class::Handle(thread->zone(), 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_);
    }
  }
  ASSERT(builtin_vtables_[kFreeListElement] == 0);
#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);
}


RawError* Object::Init(Isolate* isolate) {
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  ASSERT(isolate == thread->isolate());
  TimelineDurationScope tds(thread,
                            isolate->GetIsolateStream(),
                            "Object::Init");

#if defined(DART_NO_SNAPSHOT)
  // Object::Init version when we are running in a version of dart that does
  // not have a full snapshot linked in.
  ObjectStore* object_store = isolate->object_store();

  Class& cls = Class::Handle(zone);
  Type& type = Type::Handle(zone);
  Array& array = Array::Handle(zone);
  Library& lib = Library::Handle(zone);

  // 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);

  // VM classes that are parameterized (Array, ImmutableArray,
  // GrowableObjectArray, and LinkedHashMap) are also pre-finalized,
  // so CalculateFieldOffsets() is not called, so we need to set the
  // offset of their type_arguments_ field, which is explicitly
  // declared in their respective Raw* classes.
  cls.set_type_arguments_field_offset(Array::type_arguments_offset());
  cls.set_num_type_arguments(1);

  // 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());
  cls.set_num_type_arguments(1);

  // 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(zone, Smi::New(0)));
  object_store->set_canonical_type_arguments(array);

  // Setup type class early in the process.
  const Class& type_cls = Class::Handle(zone, Class::New<Type>());
  const Class& type_ref_cls = Class::Handle(zone, Class::New<TypeRef>());
  const Class& type_parameter_cls = Class::Handle(zone,
                                                  Class::New<TypeParameter>());
  const Class& bounded_type_cls = Class::Handle(zone,
                                                Class::New<BoundedType>());
  const Class& mixin_app_type_cls = Class::Handle(zone,
                                                  Class::New<MixinAppType>());
  const Class& library_prefix_cls = Class::Handle(zone,
                                                  Class::New<LibraryPrefix>());

  // 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(
      zone, 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.
  const Library& core_lib = Library::Handle(zone, Library::CoreLibrary());
  ASSERT(!core_lib.IsNull());

  const GrowableObjectArray& pending_classes =
      GrowableObjectArray::Handle(zone, GrowableObjectArray::New());
  object_store->set_pending_classes(pending_classes);

  Context& context = Context::Handle(zone, 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(zone);
  cls = object_store->array_class();  // Was allocated above.
  RegisterPrivateClass(cls, Symbols::_List(), core_lib);
  pending_classes.Add(cls);
  // We cannot use NewNonParameterizedType(cls), because Array is parameterized.
  // Warning: class _List has not been patched yet. Its declared number of type
  // parameters is still 0. It will become 1 after patching. The array type
  // allocated below represents the raw type _List and not _List<E> as we
  // could expect. Use with caution.
  type ^= Type::New(Object::Handle(zone, cls.raw()),
                    TypeArguments::Handle(zone),
                    Scanner::kNoSourcePos);
  type.SetIsFinalized();
  type ^= type.Canonicalize();
  object_store->set_array_type(type);

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

  cls = Class::New<Array>(kImmutableArrayCid);
  object_store->set_immutable_array_class(cls);
  cls.set_type_arguments_field_offset(Array::type_arguments_offset());
  cls.set_num_type_arguments(1);
  ASSERT(object_store->immutable_array_class() != object_store->array_class());
  cls.set_is_prefinalized();
  RegisterPrivateClass(cls, Symbols::_ImmutableList(), core_lib);
  pending_classes.Add(cls);

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

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

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

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

  // Pre-register the isolate library so the native class implementations
  // can be hooked up before compiling it.
  Library& isolate_lib =
      Library::Handle(zone, Library::LookupLibrary(Symbols::DartIsolate()));
  if (isolate_lib.IsNull()) {
    isolate_lib = Library::NewLibraryHelper(Symbols::DartIsolate(), true);
    isolate_lib.SetLoadRequested();
    isolate_lib.Register();
    object_store->set_bootstrap_library(ObjectStore::kIsolate, isolate_lib);
  }
  ASSERT(!isolate_lib.IsNull());
  ASSERT(isolate_lib.raw() == Library::IsolateLibrary());

  cls = Class::New<Capability>();
  RegisterPrivateClass(cls, Symbols::_CapabilityImpl(), isolate_lib);
  pending_classes.Add(cls);

  cls = Class::New<ReceivePort>();
  RegisterPrivateClass(cls, Symbols::_RawReceivePortImpl(), isolate_lib);
  pending_classes.Add(cls);

  cls = Class::New<SendPort>();
  RegisterPrivateClass(cls, Symbols::_SendPortImpl(), isolate_lib);
  pending_classes.Add(cls);

  const Class& stacktrace_cls = Class::Handle(zone,
                                              Class::New<Stacktrace>());
  RegisterPrivateClass(stacktrace_cls, Symbols::_StackTrace(), core_lib);
  pending_classes.Add(stacktrace_cls);
  // Super type set below, after Object is allocated.

  cls = Class::New<JSRegExp>();
  RegisterPrivateClass(cls, Symbols::JSSyntaxRegExp(), core_lib);
  pending_classes.Add(cls);

  // Initialize the base interfaces used by the core VM classes.

  // Allocate and initialize the pre-allocated classes in the core library.
  // The script and token index of these pre-allocated classes is set up in
  // the parser when the corelib script is compiled (see
  // Parser::ParseClassDefinition).
  cls = Class::New<Instance>(kInstanceCid);
  object_store->set_object_class(cls);
  cls.set_name(Symbols::Object());
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  core_lib.AddClass(cls);
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_object_type(type);

  cls = Class::New<Bool>();
  object_store->set_bool_class(cls);
  RegisterClass(cls, Symbols::Bool(), core_lib);
  pending_classes.Add(cls);

  cls = Class::New<Instance>(kNullCid);
  object_store->set_null_class(cls);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  RegisterClass(cls, Symbols::Null(), core_lib);
  pending_classes.Add(cls);

  ASSERT(!library_prefix_cls.IsNull());
  RegisterPrivateClass(library_prefix_cls, Symbols::_LibraryPrefix(), core_lib);
  pending_classes.Add(library_prefix_cls);

  RegisterPrivateClass(type_cls, Symbols::Type(), core_lib);
  pending_classes.Add(type_cls);

  RegisterPrivateClass(type_ref_cls, Symbols::TypeRef(), core_lib);
  pending_classes.Add(type_ref_cls);

  RegisterPrivateClass(type_parameter_cls, Symbols::TypeParameter(), core_lib);
  pending_classes.Add(type_parameter_cls);

  RegisterPrivateClass(bounded_type_cls, Symbols::BoundedType(), core_lib);
  pending_classes.Add(bounded_type_cls);

  RegisterPrivateClass(mixin_app_type_cls, Symbols::MixinAppType(), core_lib);
  pending_classes.Add(mixin_app_type_cls);

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

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

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

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

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

  // Abstract super class for all signature classes.
  cls = Class::New<Instance>(kIllegalCid);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  RegisterPrivateClass(cls, Symbols::FunctionImpl(), core_lib);
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_function_impl_type(type);

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

  // Pre-register the mirrors library so we can place the vm class
  // MirrorReference there rather than the core library.
  lib = Library::LookupLibrary(Symbols::DartMirrors());
  if (lib.IsNull()) {
    lib = Library::NewLibraryHelper(Symbols::DartMirrors(), true);
    lib.SetLoadRequested();
    lib.Register();
    object_store->set_bootstrap_library(ObjectStore::kMirrors, lib);
  }
  ASSERT(!lib.IsNull());
  ASSERT(lib.raw() == Library::MirrorsLibrary());

  cls = Class::New<MirrorReference>();
  RegisterPrivateClass(cls, Symbols::_MirrorReference(), lib);

  // Pre-register the collection library so we can place the vm class
  // LinkedHashMap there rather than the core library.
  lib = Library::LookupLibrary(Symbols::DartCollection());
  if (lib.IsNull()) {
    lib = Library::NewLibraryHelper(Symbols::DartCollection(), true);
    lib.SetLoadRequested();
    lib.Register();
    object_store->set_bootstrap_library(ObjectStore::kCollection, lib);
  }
  ASSERT(!lib.IsNull());
  ASSERT(lib.raw() == Library::CollectionLibrary());
  cls = Class::New<LinkedHashMap>();
  object_store->set_linked_hash_map_class(cls);
  cls.set_type_arguments_field_offset(LinkedHashMap::type_arguments_offset());
  cls.set_num_type_arguments(2);
  cls.set_num_own_type_arguments(2);
  RegisterPrivateClass(cls, Symbols::_LinkedHashMap(), lib);
  pending_classes.Add(cls);

  // Pre-register the developer library so we can place the vm class
  // UserTag there rather than the core library.
  lib = Library::LookupLibrary(Symbols::DartDeveloper());
  if (lib.IsNull()) {
    lib = Library::NewLibraryHelper(Symbols::DartDeveloper(), true);
    lib.SetLoadRequested();
    lib.Register();
    object_store->set_bootstrap_library(ObjectStore::kDeveloper, lib);
  }
  ASSERT(!lib.IsNull());
  ASSERT(lib.raw() == Library::DeveloperLibrary());

  lib = Library::LookupLibrary(Symbols::DartDeveloper());
  ASSERT(!lib.IsNull());
  cls = Class::New<UserTag>();
  RegisterPrivateClass(cls, Symbols::_UserTag(), lib);
  pending_classes.Add(cls);

  // Setup some default native field classes which can be extended for
  // specifying native fields in dart classes.
  Library::InitNativeWrappersLibrary(isolate);
  ASSERT(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.
  lib = Library::LookupLibrary(Symbols::DartTypedData());
  if (lib.IsNull()) {
    lib = Library::NewLibraryHelper(Symbols::DartTypedData(), true);
    lib.SetLoadRequested();
    lib.Register();
    object_store->set_bootstrap_library(ObjectStore::kTypedData, lib);
  }
  ASSERT(!lib.IsNull());
  ASSERT(lib.raw() == Library::TypedDataLibrary());
#define REGISTER_TYPED_DATA_CLASS(clazz)                                       \
  cls = Class::NewTypedDataClass(kTypedData##clazz##Cid);                      \
  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);              \
  RegisterPrivateClass(cls, Symbols::_##clazz##View(), lib);                   \
  pending_classes.Add(cls);                                                    \

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

  cls = Class::New<Instance>(kByteBufferCid);
  cls.set_instance_size(0);
  cls.set_next_field_offset(-kWordSize);
  RegisterPrivateClass(cls, Symbols::_ByteBuffer(), lib);
  pending_classes.Add(cls);

  CLASS_LIST_TYPED_DATA(REGISTER_EXT_TYPED_DATA_CLASS);
#undef REGISTER_EXT_TYPED_DATA_CLASS
  // Register Float32x4 and Int32x4 in the object store.
  cls = Class::New<Float32x4>();
  object_store->set_float32x4_class(cls);
  RegisterPrivateClass(cls, Symbols::_Float32x4(), lib);
  cls = Class::New<Int32x4>();
  object_store->set_int32x4_class(cls);
  RegisterPrivateClass(cls, Symbols::_Int32x4(), lib);
  cls = Class::New<Float64x2>();
  object_store->set_float64x2_class(cls);
  RegisterPrivateClass(cls, Symbols::_Float64x2(), lib);

  cls = Class::New<Instance>(kIllegalCid);
  RegisterClass(cls, Symbols::Float32x4(), lib);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_float32x4_type(type);

  cls = Class::New<Instance>(kIllegalCid);
  RegisterClass(cls, Symbols::Int32x4(), lib);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_int32x4_type(type);

  cls = Class::New<Instance>(kIllegalCid);
  RegisterClass(cls, Symbols::Float64x2(), lib);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_float64x2_type(type);

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

  // Abstract class that represents the Dart class Function.
  cls = Class::New<Instance>(kIllegalCid);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  RegisterClass(cls, Symbols::Function(), core_lib);
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_function_type(type);

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

  cls = Class::New<Instance>(kIllegalCid);
  RegisterClass(cls, Symbols::Int(), core_lib);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_int_type(type);

  cls = Class::New<Instance>(kIllegalCid);
  RegisterClass(cls, Symbols::Double(), core_lib);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_double_type(type);

  name = Symbols::New("String");
  cls = Class::New<Instance>(kIllegalCid);
  RegisterClass(cls, name, core_lib);
  cls.set_num_type_arguments(0);
  cls.set_num_own_type_arguments(0);
  cls.set_is_prefinalized();
  pending_classes.Add(cls);
  type = Type::NewNonParameterizedType(cls);
  object_store->set_string_type(type);

  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 'void' and 'dynamic' are phoney classes to make type checking
  // more regular; they live in the VM isolate. The class 'void' is not
  // registered in the class dictionary because its name is a reserved word.
  // The class 'dynamic' is registered in the class dictionary because its name
  // is a built-in identifier (this is wrong).
  // The corresponding types are stored in the object store.
  cls = object_store->null_class();
  type = Type::NewNonParameterizedType(cls);
  object_store->set_null_type(type);

  // Consider removing when/if Null becomes an ordinary class.
  type = object_store->object_type();
  cls.set_super_type(type);

  // Finish the initialization by compiling the bootstrap scripts containing the
  // base interfaces and the implementation of the internal classes.
  const Error& error = Error::Handle(Bootstrap::LoadandCompileScripts());
  if (!error.IsNull()) {
    return error.raw();
  }

  ClassFinalizer::VerifyBootstrapClasses();

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

  // Set up recognized state of all functions (core, math and typed data).
  MethodRecognizer::InitializeState();

  // Adds static const fields (class ids) to the class 'ClassID');
  lib = Library::LookupLibrary(Symbols::DartInternal());
  ASSERT(!lib.IsNull());
  cls = lib.LookupClassAllowPrivate(Symbols::ClassID());
  ASSERT(!cls.IsNull());
  Field& field = Field::Handle(zone);
  Smi& value = Smi::Handle(zone);
  String& field_name = String::Handle(zone);

#define CLASS_LIST_WITH_NULL(V)                                                \
  V(Null)                                                                      \
  CLASS_LIST_NO_OBJECT(V)

#define ADD_SET_FIELD(clazz)                                                   \
  field_name = Symbols::New("cid"#clazz);                                      \
  field = Field::New(field_name, true, false, true, false, cls, 0);            \
  value = Smi::New(k##clazz##Cid);                                             \
  field.SetStaticValue(value, true);                                           \
  field.set_type(Type::Handle(Type::IntType()));                               \
  cls.AddField(field);                                                         \

  CLASS_LIST_WITH_NULL(ADD_SET_FIELD)
#undef ADD_SET_FIELD

  isolate->object_store()->InitKnownObjects();

  return Error::null();
#else  // defined(DART_NO_SNAPSHOT).
  // Object::Init version when we are running in a version of dart that has
  // a full snapshot linked in and an isolate is initialized using the full
  // snapshot.
  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.
  // 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<Instance>(kInstanceCid);
  object_store->set_object_class(cls);

  cls = Class::New<LibraryPrefix>();
  cls = Class::New<Type>();
  cls = Class::New<TypeRef>();
  cls = Class::New<TypeParameter>();
  cls = Class::New<BoundedType>();
  cls = Class::New<MixinAppType>();

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

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

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

  cls = Class::New<LinkedHashMap>();
  object_store->set_linked_hash_map_class(cls);

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

  cls = Class::New<Int32x4>();
  object_store->set_int32x4_class(cls);

  cls = Class::New<Float64x2>();
  object_store->set_float64x2_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<Instance>(kByteBufferCid);

  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<Instance>(kNullCid);
  object_store->set_null_class(cls);

  cls = Class::New<Capability>();
  cls = Class::New<ReceivePort>();
  cls = Class::New<SendPort>();
  cls = Class::New<Stacktrace>();
  cls = Class::New<JSRegExp>();
  cls = Class::New<Number>();

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

  cls = Class::New<MirrorReference>();
  cls = Class::New<UserTag>();

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

#endif  // defined(DART_NO_SNAPSHOT).

  return Error::null();
}


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


static void AddNameProperties(JSONObject* jsobj,
                              const String& name,
                              const String& vm_name) {
  jsobj->AddProperty("name", name.ToCString());
  if (!name.Equals(vm_name)) {
    jsobj->AddProperty("_vmName", vm_name.ToCString());
  }
}


void Object::AddCommonObjectProperties(JSONObject* jsobj,
                                       const char* protocol_type,
                                       bool ref) const {
  const char* vm_type = JSONType();
  bool same_type = (strcmp(protocol_type, vm_type) == 0);
  if (ref) {
    jsobj->AddPropertyF("type", "@%s", protocol_type);
  } else {
    jsobj->AddProperty("type", protocol_type);
  }
  if (!same_type) {
    jsobj->AddProperty("_vmType", vm_type);
  }
  if (!ref || IsInstance() || IsNull()) {
    // TODO(turnidge): Provide the type arguments here too?
    const Class& cls = Class::Handle(this->clazz());
    jsobj->AddProperty("class", cls);
  }
  if (!ref) {
    if (raw()->IsHeapObject()) {
      jsobj->AddProperty("size", raw()->Size());
    } else {
      jsobj->AddProperty("size", (intptr_t)0);
    }
  }
}


void Object::PrintJSON(JSONStream* stream, bool ref) const {
  if (IsNull()) {
    JSONObject jsobj(stream);
    AddCommonObjectProperties(&jsobj, "Instance", ref);
    jsobj.AddProperty("kind", "Null");
    jsobj.AddFixedServiceId("objects/null");
    jsobj.AddProperty("valueAsString", "null");
  } else {
    PrintJSONImpl(stream, ref);
  }
}


void Object::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Object", ref);
  jsobj.AddServiceId(*this);
  if (ref) {
    return;
  }
}


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


void Object::InitializeObject(uword address,
                              intptr_t class_id,
                              intptr_t size,
                              bool is_vm_object) {
  const uword break_instruction_value = Assembler::GetBreakInstructionFiller();
  const uword null_value = reinterpret_cast<uword>(null_);
  const bool is_instructions = class_id == kInstructionsCid;
  uword initial_value =
      is_instructions ? break_instruction_value : null_value;
  uword cur = address;
  uword end = address + size;
  if (is_instructions) {
    // Fill the header with null. The remainder of the Instructions object will
    // be filled with the break_instruction_value.
    uword header_end = address + Instructions::HeaderSize();
    while (cur < header_end) {
      *reinterpret_cast<uword*>(cur) = null_value;
      cur += kWordSize;
    }
  }
  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);
  tags = RawObject::VMHeapObjectTag::update(is_vm_object, tags);
  reinterpret_cast<RawObject*>(address)->tags_ = tags;
  ASSERT(is_vm_object == RawObject::IsVMHeapObject(tags));
  VerifiedMemory::Accept(address, size);
}


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));
  Thread* thread = Thread::Current();
  Isolate* isolate = thread->isolate();
  // New space allocation allowed only in mutator thread (Dart thread);
  ASSERT(isolate->MutatorThreadIsCurrentThread() || (space != Heap::kNew));
  ASSERT(thread->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(thread, exception);
    UNREACHABLE();
  }
  ClassTable* class_table = isolate->class_table();
  if (space == Heap::kNew) {
    class_table->UpdateAllocatedNew(cls_id, size);
  } else {
    class_table->UpdateAllocatedOld(cls_id, size);
  }
  const Class& cls = Class::Handle(class_table->At(cls_id));
  if (cls.TraceAllocation(isolate)) {
    Profiler::RecordAllocation(thread, cls_id);
  }
  NoSafepointScope no_safepoint;
  InitializeObject(address, cls_id, size, (isolate == Dart::vm_isolate()));
  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(Thread* thread, RawObject* obj) :
      ObjectPointerVisitor(thread->isolate()), thread_(thread), 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()) {
        old_obj_->SetRememberedBit();
        thread_->StoreBufferAddObject(old_obj_);
        // Remembered this object. There is no need to continue searching.
        return;
      }
    }
  }

 private:
  Thread* thread_;
  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& orig, Heap::Space space) {
  const Class& cls = Class::Handle(orig.clazz());
  intptr_t size = orig.raw()->Size();
  RawObject* raw_clone = Object::Allocate(cls.id(), size, space);
  NoSafepointScope no_safepoint;
  // TODO(koda): This will trip when we start allocating black.
  // Revisit code below at that point, to account for the new write barrier.
  ASSERT(!raw_clone->IsMarked());
  // Copy the body of the original into the clone.
  uword orig_addr = RawObject::ToAddr(orig.raw());
  uword clone_addr = RawObject::ToAddr(raw_clone);
  static const intptr_t kHeaderSizeInBytes = sizeof(RawObject);
  memmove(reinterpret_cast<uint8_t*>(clone_addr + kHeaderSizeInBytes),
          reinterpret_cast<uint8_t*>(orig_addr + kHeaderSizeInBytes),
          size - kHeaderSizeInBytes);
  VerifiedMemory::Accept(clone_addr, size);
  // Add clone to store buffer, if needed.
  if (!raw_clone->IsOldObject()) {
    // No need to remember an object in new space.
    return raw_clone;
  } else if (orig.raw()->IsOldObject() && !orig.raw()->IsRemembered()) {
    // Old original doesn't need to be remembered, so neither does the clone.
    return raw_clone;
  }
  StoreBufferUpdateVisitor visitor(Thread::Current(), raw_clone);
  raw_clone->VisitPointers(&visitor);
  return raw_clone;
}


RawString* Class::Name() const {
  // TODO(turnidge): This assert fails for the fake kFreeListElement class.
  // Fix this.
  ASSERT(raw_ptr()->name_ != String::null());
  return raw_ptr()->name_;
}


RawString* Class::PrettyName() const {
  return GeneratePrettyName();
}


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


bool Class::IsInFullSnapshot() const {
  NoSafepointScope no_safepoint;
  return raw_ptr()->library_->ptr()->is_in_fullsnapshot_;
}


RawType* Class::SignatureType() const {
  ASSERT(IsSignatureClass());
  Zone* zone = Thread::Current()->zone();
  const Function& function = Function::Handle(zone, 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_signature_class =
        Class::Handle(zone, function.signature_class());
    return canonical_signature_class.SignatureType();
  }
  const Type& signature_type = Type::Handle(zone, CanonicalType());
  if (!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(zone, type_parameters());
  // Return the still unfinalized signature type.
  return Type::New(*this, signature_type_arguments, token_pos());
}


RawAbstractType* Class::RareType() const {
  const Type& type = Type::Handle(Type::New(
      *this,
      Object::null_type_arguments(),
      Scanner::kNoSourcePos));
  return ClassFinalizer::FinalizeType(*this,
                                      type,
                                      ClassFinalizer::kCanonicalize);
}


RawAbstractType* Class::DeclarationType() const {
  const TypeArguments& args = TypeArguments::Handle(type_parameters());
  const Type& type = Type::Handle(Type::New(
      *this,
      args,
      Scanner::kNoSourcePos));
  return ClassFinalizer::FinalizeType(*this,
                                      type,
                                      ClassFinalizer::kCanonicalize);
}


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);
    NoSafepointScope no_safepoint;
    result ^= raw;
  }
  FakeObject fake;
  result.set_handle_vtable(fake.vtable());
  result.set_instance_size(FakeObject::InstanceSize());
  result.set_next_field_offset(FakeObject::NextFieldOffset());
  COMPILE_ASSERT((FakeObject::kClassId != kInstanceCid));
  result.set_id(FakeObject::kClassId);
  result.set_state_bits(0);
  if (FakeObject::kClassId < kInstanceCid) {
    // VM internal classes are done. There is no finalization needed or
    // possible in this case.
    result.set_is_finalized();
  } else {
    // VM backed classes are almost ready: run checks and resolve class
    // references, but do not recompute size.
    result.set_is_prefinalized();
  }
  result.set_type_arguments_field_offset_in_words(kNoTypeArguments);
  result.set_num_type_arguments(0);
  result.set_num_own_type_arguments(0);
  result.set_num_native_fields(0);
  result.set_token_pos(Scanner::kNoSourcePos);
  result.InitEmptyFields();
  Isolate::Current()->RegisterClass(result);
  return result.raw();
}



static void ReportTooManyTypeArguments(const Class& cls) {
  Report::MessageF(Report::kError,
                   Script::Handle(cls.script()),
                   cls.token_pos(),
                   "too many type parameters declared in class '%s' or in its "
                   "super classes",
                   String::Handle(cls.Name()).ToCString());
  UNREACHABLE();
}


void Class::set_num_type_arguments(intptr_t value) const {
  if (!Utils::IsInt(16, value)) {
    ReportTooManyTypeArguments(*this);
  }
  StoreNonPointer(&raw_ptr()->num_type_arguments_, value);
}


void Class::set_num_own_type_arguments(intptr_t value) const {
  if (!Utils::IsInt(16, value)) {
    ReportTooManyTypeArguments(*this);
  }
  StoreNonPointer(&raw_ptr()->num_own_type_arguments_, value);
}


// 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()->functions_, Object::empty_array().raw());
  StorePointer(&raw_ptr()->fields_, Object::empty_array().raw());
  StorePointer(&raw_ptr()->invocation_dispatcher_cache_,
               Object::empty_array().raw());
}


RawArray* Class::OffsetToFieldMap() const {
  Array& array = Array::Handle(raw_ptr()->offset_in_words_to_field_);
  if (array.IsNull()) {
    ASSERT(is_finalized());
    const intptr_t length = raw_ptr()->instance_size_in_words_;
    array = Array::New(length, Heap::kOld);
    Class& cls = Class::Handle(this->raw());
    Array& fields = Array::Handle();
    Field& f = Field::Handle();
    while (!cls.IsNull()) {
      fields = cls.fields();
      for (intptr_t i = 0; i < fields.Length(); ++i) {
        f ^= fields.At(i);
        if (!f.is_static()) {
          array.SetAt(f.Offset() >> kWordSizeLog2, f);
        }
      }
      cls = cls.SuperClass();
    }
    StorePointer(&raw_ptr()->offset_in_words_to_field_, array.raw());
  }
  return 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;
}


class FunctionName {
 public:
  FunctionName(const String& name, String* tmp_string)
      : name_(name), tmp_string_(tmp_string) {}
  bool Matches(const Function& function) const {
    if (name_.IsSymbol()) {
      return name_.raw() == function.name();
    } else {
      *tmp_string_ = function.name();
      return name_.Equals(*tmp_string_);
    }
  }
  intptr_t Hash() const { return name_.Hash(); }
 private:
  const String& name_;
  String* tmp_string_;
};


// Traits for looking up Functions by name.
class ClassFunctionsTraits {
 public:
  // Called when growing the table.
  static bool IsMatch(const Object& a, const Object& b) {
    ASSERT(a.IsFunction() && b.IsFunction());
    // Function objects are always canonical.
    return a.raw() == b.raw();
  }
  static bool IsMatch(const FunctionName& name, const Object& obj) {
    return name.Matches(Function::Cast(obj));
  }
  static uword Hash(const Object& key) {
    return String::HashRawSymbol(Function::Cast(key).name());
  }
  static uword Hash(const FunctionName& name) {
    return name.Hash();
  }
};
typedef UnorderedHashSet<ClassFunctionsTraits> ClassFunctionsSet;


void Class::SetFunctions(const Array& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->functions_, value.raw());
  const intptr_t len = value.Length();
  ClassFunctionsSet set(HashTables::New<ClassFunctionsSet>(len, Heap::kOld));
  if (len >= kFunctionLookupHashTreshold) {
    Function& func = Function::Handle();
    for (intptr_t i = 0; i < len; ++i) {
      func ^= value.At(i);
      // Verify that all the functions in the array have this class as owner.
      ASSERT(func.Owner() == raw());
      set.Insert(func);
    }
  }
  StorePointer(&raw_ptr()->functions_hash_table_, set.Release().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, Heap::kOld));
  new_arr.SetAt(arr.Length(), function);
  StorePointer(&raw_ptr()->functions_, new_arr.raw());
  // Add to hash table, if any.
  const intptr_t new_len = new_arr.Length();
  if (new_len == kFunctionLookupHashTreshold) {
    // Transition to using hash table.
    SetFunctions(new_arr);
  } else if (new_len > kFunctionLookupHashTreshold) {
    ClassFunctionsSet set(raw_ptr()->functions_hash_table_);
    set.Insert(function);
    StorePointer(&raw_ptr()->functions_hash_table_, set.Release().raw());
  }
}


void Class::RemoveFunction(const Function& function) const {
  const Array& arr = Array::Handle(functions());
  StorePointer(&raw_ptr()->functions_, Object::empty_array().raw());
  Function& entry = Function::Handle();
  for (intptr_t i = 0; i < arr.Length(); i++) {
    entry ^= arr.At(i);
    if (function.raw() != entry.raw()) {
      AddFunction(entry);
    }
  }
}


intptr_t Class::FindFunctionIndex(const Function& needle) const {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return -1;
  }
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_FUNCTION_HANDLESCOPE(thread);
  Array& funcs = thread->ArrayHandle();
  Function& function = thread->FunctionHandle();
  funcs ^= functions();
  ASSERT(!funcs.IsNull());
  const intptr_t len = funcs.Length();
  for (intptr_t i = 0; i < len; i++) {
    function ^= funcs.At(i);
    if (function.raw() == needle.raw()) {
      return i;
    }
  }
  // No function found.
  return -1;
}


RawFunction* Class::FunctionFromIndex(intptr_t idx) const {
  const Array& funcs = Array::Handle(functions());
  if ((idx < 0) || (idx >= funcs.Length())) {
    return Function::null();
  }
  Function& func = Function::Handle();
  func ^= funcs.At(idx);
  ASSERT(!func.IsNull());
  return func.raw();
}


RawFunction* Class::ImplicitClosureFunctionFromIndex(intptr_t idx) const {
  const Array& funcs = Array::Handle(functions());
  if ((idx < 0) || (idx >= funcs.Length())) {
    return Function::null();
  }
  Function& func = Function::Handle();
  func ^= funcs.At(idx);
  ASSERT(!func.IsNull());
  if (!func.HasImplicitClosureFunction()) {
    return Function::null();
  }
  const Function& closure_func =
      Function::Handle(func.ImplicitClosureFunction());
  ASSERT(!closure_func.IsNull());
  return closure_func.raw();
}


intptr_t Class::FindImplicitClosureFunctionIndex(const Function& needle) const {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return -1;
  }
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_FUNCTION_HANDLESCOPE(thread);
  Array& funcs = thread->ArrayHandle();
  Function& function = thread->FunctionHandle();
  funcs ^= functions();
  ASSERT(!funcs.IsNull());
  Function& implicit_closure = Function::Handle(thread->zone());
  const intptr_t len = funcs.Length();
  for (intptr_t i = 0; i < len; i++) {
    function ^= funcs.At(i);
    implicit_closure ^= function.implicit_closure_function();
    if (implicit_closure.IsNull()) {
      // Skip non-implicit closure functions.
      continue;
    }
    if (needle.raw() == implicit_closure.raw()) {
      return i;
    }
  }
  // No function found.
  return -1;
}



intptr_t Class::FindInvocationDispatcherFunctionIndex(
    const Function& needle) const {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return -1;
  }
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_OBJECT_HANDLESCOPE(thread);
  Array& funcs = thread->ArrayHandle();
  Object& object = thread->ObjectHandle();
  funcs ^= invocation_dispatcher_cache();
  ASSERT(!funcs.IsNull());
  const intptr_t len = funcs.Length();
  for (intptr_t i = 0; i < len; i++) {
    object = funcs.At(i);
    // The invocation_dispatcher_cache is a table with some entries that
    // are functions.
    if (object.IsFunction()) {
      if (Function::Cast(object).raw() == needle.raw()) {
        return i;
      }
    }
  }
  // No function found.
  return -1;
}



RawFunction* Class::InvocationDispatcherFunctionFromIndex(intptr_t idx) const {
  Thread* thread = Thread::Current();
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_OBJECT_HANDLESCOPE(thread);
  Array& dispatcher_cache = thread->ArrayHandle();
  Object& object = thread->ObjectHandle();
  dispatcher_cache ^= invocation_dispatcher_cache();
  object = dispatcher_cache.At(idx);
  if (!object.IsFunction()) {
    return Function::null();
  }
  return Function::Cast(object).raw();
}


void Class::set_closures(const GrowableObjectArray& value) const {
  StorePointer(&raw_ptr()->closure_functions_, value.raw());
}


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


// 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();
}

intptr_t Class::FindClosureIndex(const Function& needle) const {
  if (closures() == GrowableObjectArray::null()) {
    return -1;
  }
  Thread* thread = Thread::Current();
  const GrowableObjectArray& closures_array =
      GrowableObjectArray::Handle(thread->zone(), closures());
  REUSABLE_FUNCTION_HANDLESCOPE(thread);
  Function& closure = thread->FunctionHandle();
  intptr_t num_closures = closures_array.Length();
  for (intptr_t i = 0; i < num_closures; i++) {
    closure ^= closures_array.At(i);
    ASSERT(!closure.IsNull());
    if (closure.raw() == needle.raw()) {
      return i;
    }
  }
  return -1;
}


RawFunction* Class::ClosureFunctionFromIndex(intptr_t idx) const {
  const GrowableObjectArray& closures_array =
      GrowableObjectArray::Handle(closures());
  if ((idx < 0) || (idx >= closures_array.Length())) {
    return Function::null();
  }
  Function& func = Function::Handle();
  func ^= closures_array.At(idx);
  ASSERT(!func.IsNull());
  return func.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_state_bits(intptr_t bits) const {
  StoreNonPointer(&raw_ptr()->state_bits_, static_cast<uint16_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(Thread* thread) const {
  if (IsMixinApplication() && !is_mixin_type_applied()) {
    ClassFinalizer::ApplyMixinType(*this);
  }
  if (type_parameters() == TypeArguments::null()) {
    return 0;
  }
  REUSABLE_TYPE_ARGUMENTS_HANDLESCOPE(thread);
  TypeArguments& type_params = thread->TypeArgumentsHandle();
  type_params = type_parameters();
  return type_params.Length();
}


intptr_t Class::NumOwnTypeArguments() const {
  // Return cached value if already calculated.
  if (num_own_type_arguments() != kUnknownNumTypeArguments) {
    return num_own_type_arguments();
  }
  Thread* thread = Thread::Current();
  Isolate* isolate = thread->isolate();
  Zone* zone = thread->zone();
  const intptr_t num_type_params = NumTypeParameters();
  if (!FLAG_overlap_type_arguments ||
      (num_type_params == 0) ||
      (super_type() == AbstractType::null()) ||
      (super_type() == isolate->object_store()->object_type())) {
    set_num_own_type_arguments(num_type_params);
    return num_type_params;
  }
  ASSERT(!IsMixinApplication() || is_mixin_type_applied());
  const AbstractType& sup_type = AbstractType::Handle(zone, super_type());
  const TypeArguments& sup_type_args =
      TypeArguments::Handle(zone, sup_type.arguments());
  if (sup_type_args.IsNull()) {
    // The super type is raw or the super class is non generic.
    // In either case, overlapping is not possible.
    set_num_own_type_arguments(num_type_params);
    return num_type_params;
  }
  const intptr_t num_sup_type_args = sup_type_args.Length();
  // At this point, the super type may or may not be finalized. In either case,
  // the result of this function must remain the same.
  // The value of num_sup_type_args may increase when the super type is
  // finalized, but the last num_sup_type_args type arguments will not be
  // modified by finalization, only shifted to higher indices in the vector.
  // They may however get wrapped in a BoundedType, which we skip.
  // The super type may not even be resolved yet. This is not necessary, since
  // we only check for matching type parameters, which are resolved by default.
  const TypeArguments& type_params =
      TypeArguments::Handle(zone, type_parameters());
  // Determine the maximum overlap of a prefix of the vector consisting of the
  // type parameters of this class with a suffix of the vector consisting of the
  // type arguments of the super type of this class.
  // The number of own type arguments of this class is the number of its type
  // parameters minus the number of type arguments in the overlap.
  // Attempt to overlap the whole vector of type parameters; reduce the size
  // of the vector (keeping the first type parameter) until it fits or until
  // its size is zero.
  TypeParameter& type_param = TypeParameter::Handle(zone);
  AbstractType& sup_type_arg = AbstractType::Handle(zone);
  for (intptr_t num_overlapping_type_args =
           (num_type_params < num_sup_type_args) ?
               num_type_params : num_sup_type_args;
       num_overlapping_type_args > 0; num_overlapping_type_args--) {
    intptr_t i = 0;
    for (; i < num_overlapping_type_args; i++) {
      type_param ^= type_params.TypeAt(i);
      sup_type_arg = sup_type_args.TypeAt(
          num_sup_type_args - num_overlapping_type_args + i);
      // BoundedType can nest in case the finalized super type has bounded type
      // arguments that overlap multiple times in its own super class chain.
      while (sup_type_arg.IsBoundedType()) {
        sup_type_arg = BoundedType::Cast(sup_type_arg).type();
      }
      if (!type_param.Equals(sup_type_arg)) break;
    }
    if (i == num_overlapping_type_args) {
      // Overlap found.
      set_num_own_type_arguments(num_type_params - num_overlapping_type_args);
      return num_type_params - num_overlapping_type_args;
    }
  }
  // No overlap found.
  set_num_own_type_arguments(num_type_params);
  return num_type_params;
}


bool Class::IsGeneric() const {
  return NumTypeParameters() != 0;
}


intptr_t Class::NumTypeArguments() const {
  // Return cached value if already calculated.
  if (num_type_arguments() != kUnknownNumTypeArguments) {
    return num_type_arguments();
  }
  // To work properly, this call requires the super class of this class to be
  // resolved, which is checked by the type_class() call on the super type.
  // Note that calling type_class() on a MixinAppType fails.
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  Isolate* isolate = thread->isolate();
  Class& cls = Class::Handle(zone);
  AbstractType& sup_type = AbstractType::Handle(zone);
  cls = raw();
  intptr_t num_type_args = 0;
  do {
    if (cls.IsSignatureClass()) {
      Function& signature_fun = Function::Handle(zone);
      signature_fun ^= cls.signature_function();
      if (!signature_fun.is_static() &&
          !signature_fun.HasInstantiatedSignature()) {
        cls = signature_fun.Owner();
      }
    }
    // Calling NumOwnTypeArguments() on a mixin application class will setup the
    // type parameters if not already done.
    num_type_args += cls.NumOwnTypeArguments();
    // Super type of Object class is null.
    if ((cls.super_type() == AbstractType::null()) ||
        (cls.super_type() == isolate->object_store()->object_type())) {
      break;
    }
    sup_type = cls.super_type();
    ClassFinalizer::ResolveTypeClass(cls, sup_type);
    cls = sup_type.type_class();
  } while (true);
  set_num_type_arguments(num_type_args);
  return num_type_args;
}


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


void Class::set_super_type(const AbstractType& value) const {
  ASSERT(value.IsNull() ||
         (value.IsType() && !value.IsDynamicType()) ||
         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) const {
  ASSERT(!type_name.IsNull());
  Thread* thread = Thread::Current();
  REUSABLE_TYPE_ARGUMENTS_HANDLESCOPE(thread);
  REUSABLE_TYPE_PARAMETER_HANDLESCOPE(thread);
  REUSABLE_STRING_HANDLESCOPE(thread);
  TypeArguments& type_params = thread->TypeArgumentsHandle();
  TypeParameter&  type_param = thread->TypeParameterHandle();
  String& type_param_name = thread->StringHandle();

  type_params ^= type_parameters();
  if (!type_params.IsNull()) {
    const intptr_t num_type_params = type_params.Length();
    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 = Instance::NextFieldOffset();
    ASSERT(offset > 0);
  } else {
    ASSERT(super.is_finalized() || super.is_prefinalized());
    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,
  // otherwise, if this class is the first in the super chain to be
  // parameterized, introduce a new 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);
}


RawFunction* Class::GetInvocationDispatcher(const String& target_name,
                                            const Array& args_desc,
                                            RawFunction::Kind kind,
                                            bool create_if_absent) const {
  enum {
    kNameIndex = 0,
    kArgsDescIndex,
    kFunctionIndex,
    kEntrySize
  };

  ASSERT(kind == RawFunction::kNoSuchMethodDispatcher ||
         kind == RawFunction::kInvokeFieldDispatcher);
  Function& dispatcher = Function::Handle();
  Array& cache = Array::Handle(invocation_dispatcher_cache());
  ASSERT(!cache.IsNull());
  String& name = String::Handle();
  Array& desc = Array::Handle();
  intptr_t i = 0;
  for (; i < cache.Length(); i += kEntrySize) {
    name ^= cache.At(i + kNameIndex);
    if (name.IsNull()) break;  // Reached last entry.
    if (!name.Equals(target_name)) continue;
    desc ^= cache.At(i + kArgsDescIndex);
    if (desc.raw() != args_desc.raw()) continue;
    dispatcher ^= cache.At(i + kFunctionIndex);
    if (dispatcher.kind() == kind) {
      // Found match.
      ASSERT(dispatcher.IsFunction());
      break;
    }
  }

  if (dispatcher.IsNull() && create_if_absent) {
    if (i == cache.Length()) {
      // Allocate new larger cache.
      intptr_t new_len = (cache.Length() == 0)
          ? static_cast<intptr_t>(kEntrySize)
          : cache.Length() * 2;
      cache ^= Array::Grow(cache, new_len);
      set_invocation_dispatcher_cache(cache);
    }
    dispatcher ^= CreateInvocationDispatcher(target_name, args_desc, kind);
    cache.SetAt(i + kNameIndex, target_name);
    cache.SetAt(i + kArgsDescIndex, args_desc);
    cache.SetAt(i + kFunctionIndex, dispatcher);
  }
  return dispatcher.raw();
}


RawFunction* Class::CreateInvocationDispatcher(const String& target_name,
                                               const Array& args_desc,
                                               RawFunction::Kind kind) const {
  Function& invocation = Function::Handle(
      Function::New(String::Handle(Symbols::New(target_name)),
                    kind,
                    false,  // Not static.
                    false,  // Not const.
                    false,  // Not abstract.
                    false,  // Not external.
                    false,  // Not native.
                    *this,
                    0));  // No token position.
  ArgumentsDescriptor desc(args_desc);
  invocation.set_num_fixed_parameters(desc.PositionalCount());
  invocation.SetNumOptionalParameters(desc.NamedCount(),
                                      false);  // Not positional.
  invocation.set_parameter_types(Array::Handle(Array::New(desc.Count(),
                                                          Heap::kOld)));
  invocation.set_parameter_names(Array::Handle(Array::New(desc.Count(),
                                                          Heap::kOld)));
  // Receiver.
  invocation.SetParameterTypeAt(0, Type::Handle(Type::DynamicType()));
  invocation.SetParameterNameAt(0, Symbols::This());
  // Remaining positional parameters.
  intptr_t i = 1;
  for (; i < desc.PositionalCount(); i++) {
    invocation.SetParameterTypeAt(i, Type::Handle(Type::DynamicType()));
    char name[64];
    OS::SNPrint(name, 64, ":p%" Pd, i);
    invocation.SetParameterNameAt(i, String::Handle(Symbols::New(name)));
  }

  // Named parameters.
  for (; i < desc.Count(); i++) {
    invocation.SetParameterTypeAt(i, Type::Handle(Type::DynamicType()));
    intptr_t index = i - desc.PositionalCount();
    invocation.SetParameterNameAt(i, String::Handle(desc.NameAt(index)));
  }
  invocation.set_result_type(Type::Handle(Type::DynamicType()));
  invocation.set_is_debuggable(false);
  invocation.set_is_visible(false);
  invocation.set_is_reflectable(false);
  invocation.set_saved_args_desc(args_desc);

  return invocation.raw();
}


RawArray* Class::invocation_dispatcher_cache() const {
  return raw_ptr()->invocation_dispatcher_cache_;
}


void Class::set_invocation_dispatcher_cache(const Array& cache) const {
  StorePointer(&raw_ptr()->invocation_dispatcher_cache_, cache.raw());
}


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();
}


class CHACodeArray : public WeakCodeReferences {
 public:
  explicit CHACodeArray(const Class& cls)
      : WeakCodeReferences(Array::Handle(cls.cha_codes())), cls_(cls) {
  }

  virtual void UpdateArrayTo(const Array& value) {
    // TODO(fschneider): Fails for classes in the VM isolate.
    cls_.set_cha_codes(value);
  }

  virtual void ReportDeoptimization(const Code& code) {
    if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
      Function& function = Function::Handle(code.function());
      THR_Print("Deoptimizing %s because CHA optimized (%s).\n",
          function.ToFullyQualifiedCString(),
          cls_.ToCString());
    }
  }

  virtual void ReportSwitchingCode(const Code& code) {
    if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
      Function& function = Function::Handle(code.function());
      THR_Print("Switching %s to unoptimized code because CHA invalid"
                " (%s)\n",
                function.ToFullyQualifiedCString(),
                cls_.ToCString());
    }
  }

 private:
  const Class& cls_;
  DISALLOW_COPY_AND_ASSIGN(CHACodeArray);
};


void Class::RegisterCHACode(const Code& code) {
  if (FLAG_trace_cha) {
    THR_Print("RegisterCHACode %s class %s\n",
        Function::Handle(code.function()).ToQualifiedCString(), ToCString());
  }
  ASSERT(code.is_optimized());
  CHACodeArray a(*this);
  a.Register(code);
}


void Class::DisableCHAOptimizedCode() {
  CHACodeArray a(*this);
  a.DisableCode();
}


bool Class::TraceAllocation(Isolate* isolate) const {
  ClassTable* class_table = isolate->class_table();
  return class_table->TraceAllocationFor(id());
}


void Class::SetTraceAllocation(bool trace_allocation) const {
  Isolate* isolate = Isolate::Current();
  const bool changed = trace_allocation != this->TraceAllocation(isolate);
  if (changed) {
    ClassTable* class_table = isolate->class_table();
    class_table->SetTraceAllocationFor(id(), trace_allocation);
    DisableAllocationStub();
  }
}


void Class::set_cha_codes(const Array& cache) const {
  StorePointer(&raw_ptr()->cha_codes_, cache.raw());
}


// Apply the members from the patch class to the original class.
bool Class::ApplyPatch(const Class& patch, Error* error) const {
  ASSERT(error != NULL);
  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();
  // Lookup the original implicit constructor, if any.
  member_name = Name();
  member_name = String::Concat(member_name, Symbols::Dot());
  Function& orig_implicit_ctor = Function::Handle(LookupFunction(member_name));
  if (!orig_implicit_ctor.IsNull() &&
      !orig_implicit_ctor.IsImplicitConstructor()) {
    // Not an implicit constructor, but a user declared one.
    orig_implicit_ctor = Function::null();
  }
  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.
      // However, an implicitly created constructor should not be preserved if
      // the patch provides a constructor or a factory. Wait for now.
      if (orig_func.raw() != orig_implicit_ctor.raw()) {
        new_functions.Add(orig_func);
      }
    } else if (func.UserVisibleSignature() !=
               orig_func.UserVisibleSignature()
               && !FLAG_ignore_patch_signature_mismatch) {
      // Compare user visible signatures to ignore different implicit parameters
      // when patching a constructor with a factory.
      *error = LanguageError::NewFormatted(
          *error,  // No previous error.
          Script::Handle(patch.script()),
          func.token_pos(),
          Report::kError,
          Heap::kNew,
          "signature mismatch: '%s'", member_name.ToCString());
      return false;
    }
  }
  for (intptr_t i = 0; i < patch_len; i++) {
    func ^= patch_list.At(i);
    if (func.IsGenerativeConstructor() || func.IsFactory()) {
      // Do not preserve the original implicit constructor, if any.
      orig_implicit_ctor = Function::null();
    }
    func.set_owner(patch_class);
    new_functions.Add(func);
  }
  if (!orig_implicit_ctor.IsNull()) {
    // Preserve the original implicit constructor.
    new_functions.Add(orig_implicit_ctor);
  }
  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(patch_class);
    member_name = field.name();
    // TODO(iposva): Verify non-public fields only.

    // Verify no duplicate additions.
    orig_field ^= LookupField(member_name);
    if (!orig_field.IsNull()) {
      *error = LanguageError::NewFormatted(
          *error,  // No previous error.
          Script::Handle(patch.script()),
          field.token_pos(),
          Report::kError,
          Heap::kNew,
          "duplicate field: %s", member_name.ToCString());
      return false;
    }
    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 true;
}


static RawString* BuildClosureSource(const Array& formal_params,
                                     const String& expr) {
  const GrowableObjectArray& src_pieces =
      GrowableObjectArray::Handle(GrowableObjectArray::New());
  String& piece = String::Handle();
  src_pieces.Add(Symbols::LParen());
  // Add formal parameters.
  intptr_t num_formals = formal_params.Length();
  for (intptr_t i = 0; i < num_formals; i++) {
    if (i > 0) {
      src_pieces.Add(Symbols::CommaSpace());
    }
    piece ^= formal_params.At(i);
    src_pieces.Add(piece);
  }
  src_pieces.Add(Symbols::RParenArrow());
  src_pieces.Add(expr);
  src_pieces.Add(Symbols::Semicolon());
  return String::ConcatAll(Array::Handle(Array::MakeArray(src_pieces)));
}


static RawFunction* EvaluateHelper(const Class& cls,
                                   const String& expr,
                                   const Array& param_names,
                                   bool is_static) {
  const String& func_src =
      String::Handle(BuildClosureSource(param_names, expr));
  Script& script = Script::Handle();
  script = Script::New(Symbols::EvalSourceUri(),
                       func_src,
                       RawScript::kEvaluateTag);
  // In order to tokenize the source, we need to get the key to mangle
  // private names from the library from which the class originates.
  const Library& lib = Library::Handle(cls.library());
  ASSERT(!lib.IsNull());
  const String& lib_key = String::Handle(lib.private_key());
  script.Tokenize(lib_key);

  const Function& func = Function::Handle(
       Function::NewEvalFunction(cls, script, is_static));
  func.set_result_type(Type::Handle(Type::DynamicType()));
  const intptr_t num_implicit_params = is_static ? 0 : 1;
  func.set_num_fixed_parameters(num_implicit_params + param_names.Length());
  func.SetNumOptionalParameters(0, true);
  func.SetIsOptimizable(false);
  return func.raw();
}


RawObject* Class::Evaluate(const String& expr,
                           const Array& param_names,
                           const Array& param_values) const {
  const Function& eval_func =
      Function::Handle(EvaluateHelper(*this, expr, param_names, true));
  const Object& result =
      Object::Handle(DartEntry::InvokeFunction(eval_func, param_values));
  return result.raw();
}


// Ensure that top level parsing of the class has been done.
// TODO(24109): Migrate interface to Thread*.
RawError* Class::EnsureIsFinalized(Thread* thread) const {
  // Finalized classes have already been parsed.
  if (is_finalized()) {
    return Error::null();
  }
  ASSERT(thread != NULL);
  const Error& error = Error::Handle(
      thread->zone(), Compiler::CompileClass(*this));
  if (!error.IsNull()) {
    ASSERT(thread == Thread::Current());
    if (thread->long_jump_base() != NULL) {
      Report::LongJump(error);
      UNREACHABLE();
    }
  }
  return error.raw();
}


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());
}


void Class::AddField(const Field& field) const {
  const Array& arr = Array::Handle(fields());
  const Array& new_arr = Array::Handle(Array::Grow(arr, arr.Length() + 1));
  new_arr.SetAt(arr.Length(), field);
  SetFields(new_arr);
}


void Class::AddFields(const GrowableArray<const Field*>& new_fields) const {
  const intptr_t num_new_fields = new_fields.length();
  if (num_new_fields == 0) return;
  const Array& arr = Array::Handle(fields());
  const intptr_t num_old_fields = arr.Length();
  const Array& new_arr = Array::Handle(
      Array::Grow(arr, num_old_fields + num_new_fields, Heap::kOld));
  for (intptr_t i = 0; i < num_new_fields; i++) {
    new_arr.SetAt(i + num_old_fields, *new_fields.At(i));
  }
  SetFields(new_arr);
}


intptr_t Class::FindFieldIndex(const Field& needle) const {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return -1;
  }
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_FIELD_HANDLESCOPE(thread);
  REUSABLE_STRING_HANDLESCOPE(thread);
  Array& fields_array = thread->ArrayHandle();
  Field& field = thread->FieldHandle();
  String& field_name = thread->StringHandle();
  fields_array ^= fields();
  ASSERT(!fields_array.IsNull());
  String& needle_name = String::Handle(thread->zone());
  needle_name ^= needle.name();
  const intptr_t len = fields_array.Length();
  for (intptr_t i = 0; i < len; i++) {
    field ^= fields_array.At(i);
    field_name ^= field.name();
    if (field_name.Equals(needle_name)) {
      return i;
    }
  }
  // No field found.
  return -1;
}


RawField* Class::FieldFromIndex(intptr_t idx) const {
  const Array& flds = Array::Handle(fields());
  if ((idx < 0) || (idx >= flds.Length())) {
    return Field::null();
  }
  Field& field = Field::Handle();
  field ^= flds.At(idx);
  ASSERT(!field.IsNull());
  return field.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);
    NoSafepointScope no_safepoint;
    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::NextFieldOffset());
  result.set_id(index);
  result.set_state_bits(0);
  result.set_type_arguments_field_offset_in_words(kNoTypeArguments);
  result.set_num_type_arguments(kUnknownNumTypeArguments);
  result.set_num_own_type_arguments(kUnknownNumTypeArguments);
  result.set_num_native_fields(0);
  result.set_token_pos(Scanner::kNoSourcePos);
  result.InitEmptyFields();
  Isolate::Current()->RegisterClass(result);
  return result.raw();
}


RawClass* Class::New(const String& name,
                     const Script& script,
                     intptr_t token_pos) {
  Class& result = Class::Handle(New<Instance>(kIllegalCid));
  result.set_name(name);
  result.set_script(script);
  result.set_token_pos(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(name, script, token_pos));
  // Instances of a signature class can only be closures.
  result.set_instance_size(Closure::InstanceSize());
  result.set_next_field_offset(Closure::NextFieldOffset());
  // Signature classes extend the _FunctionImpl class.
  result.set_super_type(Type::Handle(
      Isolate::Current()->object_store()->function_impl_type()));
  result.set_is_synthesized_class();
  result.set_type_arguments_field_offset(Closure::type_arguments_offset());
  if (!signature_function.IsNull()) {
    result.PatchSignatureFunction(signature_function);
  }
  return result.raw();
}


void Class::PatchSignatureFunction(const Function& signature_function) const {
  ASSERT(!signature_function.IsNull());
  set_signature_function(signature_function);
  const Class& owner_class = Class::Handle(signature_function.Owner());
  ASSERT(!owner_class.IsNull());
  // A signature class extends class Instance and is either not parameterized or
  // parameterized with exactly the same list of type parameters as the owner
  // class of its function.
  // In case of a function type alias, the function owner is the alias class,
  // which is also the signature class. The signature class is therefore
  // parameterized according to the alias class declaration, even if the
  // function type is not generic.
  // Otherwise, if the function is static or if its signature type is
  // non-generic, i.e. it does not depend on any type parameter of the owner
  // class, then the signature class is not parameterized, although the owner
  // class may be.
  if (owner_class.raw() == raw()) {
    // This signature class is an alias, which cannot be the canonical
    // signature class for this signature function.
    ASSERT(!IsCanonicalSignatureClass());
    // Do not modify the declared type parameters of the alias, even if unused.
  } else {
    // Copy the type parameters only for an instance function type that is not
    // instantiated, i.e. that depends on the type parameters of the owner
    // class.
    // TODO(regis): Verify that it is not a problem for the copied type
    // parameters to refer to the owner class rather than to the signature
    // class. In other words, uninstantiated function types should only get
    // instantiated by the owner class as instantiator and never by the
    // signature class itself.
    TypeArguments& type_parameters = TypeArguments::Handle();
    if (!signature_function.is_static() &&
        (owner_class.NumTypeParameters() > 0) &&
        !signature_function.HasInstantiatedSignature()) {
      type_parameters = owner_class.type_parameters();
    }
    set_type_parameters(type_parameters);
    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(name, Script::Handle(), Scanner::kNoSourcePos);
    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(RawInstance) + 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();
    cls.set_is_type_finalized();
    cls.set_is_synthesized_class();
    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(String::NextFieldOffset());
  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(TypedData::NextFieldOffset());
  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(-kWordSize);
  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(ExternalTypedData::NextFieldOffset());
  result.set_is_prefinalized();
  return result.raw();
}


void Class::set_name(const String& value) const {
  ASSERT(value.IsSymbol());
  StorePointer(&raw_ptr()->name_, value.raw());
  if (raw_ptr()->user_name_ == String::null()) {
    // TODO(johnmccutchan): Eagerly set user name for VM isolate classes,
    // lazily set user name for the other classes.
    // Generate and set user_name.
    const String& user_name = String::Handle(GenerateUserVisibleName());
    set_user_name(user_name);
  }
}


void Class::set_user_name(const String& value) const {
  StorePointer(&raw_ptr()->user_name_, value.raw());
}


RawString* Class::GeneratePrettyName() const {
  if (!IsCanonicalSignatureClass()) {
    const String& name = String::Handle(Name());
    return String::IdentifierPrettyName(name);
  } else {
    return Name();
  }
}


RawString* Class::GenerateUserVisibleName() const {
  if (FLAG_show_internal_names) {
    return Name();
  }
  switch (id()) {
    case kNullCid:
      return Symbols::Null().raw();
    case kDynamicCid:
      return Symbols::Dynamic().raw();
    case kVoidCid:
      return Symbols::Void().raw();
    case kClassCid:
      return Symbols::Class().raw();
    case kUnresolvedClassCid:
      return Symbols::UnresolvedClass().raw();
    case kTypeArgumentsCid:
      return Symbols::TypeArguments().raw();
    case kPatchClassCid:
      return Symbols::PatchClass().raw();
    case kFunctionCid:
      return Symbols::Function().raw();
    case kClosureDataCid:
      return Symbols::ClosureData().raw();
    case kRedirectionDataCid:
      return Symbols::RedirectionData().raw();
    case kFieldCid:
      return Symbols::Field().raw();
    case kLiteralTokenCid:
      return Symbols::LiteralToken().raw();
    case kTokenStreamCid:
      return Symbols::TokenStream().raw();
    case kScriptCid:
      return Symbols::Script().raw();
    case kLibraryCid:
      return Symbols::Library().raw();
    case kLibraryPrefixCid:
      return Symbols::LibraryPrefix().raw();
    case kNamespaceCid:
      return Symbols::Namespace().raw();
    case kCodeCid:
      return Symbols::Code().raw();
    case kInstructionsCid:
      return Symbols::Instructions().raw();
    case kObjectPoolCid:
      return Symbols::ObjectPool().raw();
    case kPcDescriptorsCid:
      return Symbols::PcDescriptors().raw();
    case kStackmapCid:
      return Symbols::Stackmap().raw();
    case kLocalVarDescriptorsCid:
      return Symbols::LocalVarDescriptors().raw();
    case kExceptionHandlersCid:
      return Symbols::ExceptionHandlers().raw();
    case kContextCid:
      return Symbols::Context().raw();
    case kContextScopeCid:
      return Symbols::ContextScope().raw();
    case kICDataCid:
      return Symbols::ICData().raw();
    case kMegamorphicCacheCid:
      return Symbols::MegamorphicCache().raw();
    case kSubtypeTestCacheCid:
      return Symbols::SubtypeTestCache().raw();
    case kApiErrorCid:
      return Symbols::ApiError().raw();
    case kLanguageErrorCid:
      return Symbols::LanguageError().raw();
    case kUnhandledExceptionCid:
      return Symbols::UnhandledException().raw();
    case kUnwindErrorCid:
      return Symbols::UnwindError().raw();
    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::_String().raw();
    case kArrayCid:
    case kImmutableArrayCid:
    case kGrowableObjectArrayCid:
      return Symbols::List().raw();
    case kFloat32x4Cid:
      return Symbols::Float32x4().raw();
    case kInt32x4Cid:
      return Symbols::Int32x4().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 kTypedDataInt32x4ArrayCid:
    case kExternalTypedDataInt32x4ArrayCid:
      return Symbols::Int32x4List().raw();
    case kTypedDataFloat32x4ArrayCid:
    case kExternalTypedDataFloat32x4ArrayCid:
      return Symbols::Float32x4List().raw();
    case kTypedDataFloat64x2ArrayCid:
    case kExternalTypedDataFloat64x2ArrayCid:
      return Symbols::Float64x2List().raw();
    case kTypedDataFloat32ArrayCid:
    case kExternalTypedDataFloat32ArrayCid:
      return Symbols::Float32List().raw();
    case kTypedDataFloat64ArrayCid:
    case kExternalTypedDataFloat64ArrayCid:
      return Symbols::Float64List().raw();
    default:
      if (!IsCanonicalSignatureClass()) {
        const String& name = String::Handle(Name());
        return String::IdentifierPrettyName(name);
      } else {
        return Name();
      }
  }
  UNREACHABLE();
}


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);
  StoreNonPointer(&raw_ptr()->token_pos_, token_pos);
}


intptr_t Class::ComputeEndTokenPos() const {
  // Return the begin token for synthetic classes.
  if (IsSignatureClass() || IsMixinApplication() || IsTopLevel()) {
    return token_pos();
  }
  const Script& scr = Script::Handle(script());
  ASSERT(!scr.IsNull());
  const TokenStream& tkns = TokenStream::Handle(scr.tokens());
  TokenStream::Iterator tkit(
      tkns, token_pos(), TokenStream::Iterator::kNoNewlines);
  intptr_t level = 0;
  while (tkit.CurrentTokenKind() != Token::kEOS) {
    if (tkit.CurrentTokenKind() == Token::kLBRACE) {
      level++;
    } else if (tkit.CurrentTokenKind() == Token::kRBRACE) {
      if (--level == 0) {
        return tkit.CurrentPosition();
      }
    }
    tkit.Advance();
  }
  UNREACHABLE();
  return 0;
}


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_type_finalized() const {
  set_state_bits(TypeFinalizedBit::update(true, raw_ptr()->state_bits_));
}


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


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


void Class::set_is_enum_class() const {
  set_state_bits(EnumBit::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_mixin_app_alias() const {
  set_state_bits(MixinAppAliasBit::update(true, raw_ptr()->state_bits_));
}


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


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


void Class::set_is_cycle_free() const {
  ASSERT(!is_cycle_free());
  set_state_bits(CycleFreeBit::update(true, raw_ptr()->state_bits_));
}


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


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


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


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


void Class::reset_is_marked_for_parsing() const {
  set_state_bits(MarkedForParsingBit::update(false, raw_ptr()->state_bits_));
}


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


void Class::set_mixin(const Type& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->mixin_, value.raw());
}


bool Class::IsMixinApplication() const {
  return mixin() != Type::null();
}


void Class::set_patch_class(const Class& cls) const {
  ASSERT(patch_class() == Class::null());
  StorePointer(&raw_ptr()->patch_class_, cls.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, Heap::kOld);
}


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());
}


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


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


RawType* Class::CanonicalType() const {
  if (NumTypeArguments() == 0) {
    return reinterpret_cast<RawType*>(raw_ptr()->canonical_types_);
  }
  Array& types = Array::Handle();
  types ^= canonical_types();
  if (!types.IsNull() && (types.Length() > 0)) {
    return reinterpret_cast<RawType*>(types.At(0));
  }
  return reinterpret_cast<RawType*>(Object::null());
}


void Class::SetCanonicalType(const Type& type) const {
  ASSERT(type.IsCanonical());
  if (NumTypeArguments() == 0) {
    ASSERT((canonical_types() == Object::null()) ||
           (canonical_types() == type.raw()));  // Set during own finalization.
    set_canonical_types(type);
  } else {
    Array& types = Array::Handle();
    types ^= canonical_types();
    ASSERT(!types.IsNull() && (types.Length() > 1));
    ASSERT((types.At(0) == Object::null()) || (types.At(0) == type.raw()));
    types.SetAt(0, type);
  }
}


intptr_t Class::FindCanonicalTypeIndex(const Type& needle) const {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return -1;
  }
  if (needle.raw() == CanonicalType()) {
    // For a generic type or signature type, there exists another index with the
    // same type. It will never be returned by this function.
    return 0;
  }
  REUSABLE_OBJECT_HANDLESCOPE(thread);
  Object& types = thread->ObjectHandle();
  types = canonical_types();
  if (types.IsNull()) {
    return -1;
  }
  const intptr_t len = Array::Cast(types).Length();
  REUSABLE_ABSTRACT_TYPE_HANDLESCOPE(thread);
  AbstractType& type = thread->AbstractTypeHandle();
  for (intptr_t i = 0; i < len; i++) {
    type ^= Array::Cast(types).At(i);
    if (needle.raw() == type.raw()) {
      return i;
    }
  }
  // No type found.
  return -1;
}


RawType* Class::CanonicalTypeFromIndex(intptr_t idx) const {
  Type& type = Type::Handle();
  if (idx == 0) {
    type = CanonicalType();
    if (!type.IsNull()) {
      return type.raw();
    }
  }
  Object& types = Object::Handle(canonical_types());
  if (types.IsNull() || !types.IsArray()) {
    return Type::null();
  }
  if ((idx < 0) || (idx >= Array::Cast(types).Length())) {
    return Type::null();
  }
  type ^= Array::Cast(types).At(idx);
  ASSERT(!type.IsNull());
  return type.raw();
}


void Class::set_allocation_stub(const Code& value) const {
  // Never clear the stub as it may still be a target, but will be GC-d if
  // not referenced.
  ASSERT(!value.IsNull());
  ASSERT(raw_ptr()->allocation_stub_ == Code::null());
  StorePointer(&raw_ptr()->allocation_stub_, value.raw());
}


void Class::DisableAllocationStub() const {
  const Code& existing_stub = Code::Handle(allocation_stub());
  if (existing_stub.IsNull()) {
    return;
  }
  ASSERT(!existing_stub.IsDisabled());
  // Change the stub so that the next caller will regenerate the stub.
  existing_stub.DisableStubCode();
  // Disassociate the existing stub from class.
  StorePointer(&raw_ptr()->allocation_stub_, Code::null());
}


bool Class::IsFunctionClass() const {
  return raw() == Type::Handle(Type::Function()).type_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::TypeTestNonRecursive(const Class& cls,
                                 Class::TypeTestKind test_kind,
                                 const TypeArguments& type_arguments,
                                 const Class& other,
                                 const TypeArguments& other_type_arguments,
                                 Error* bound_error,
                                 Heap::Space space) {
  // Use the thsi object as if it was the receiver of this method, but instead
  // of recursing reset it to the super class and loop.
  Zone* zone = Thread::Current()->zone();
  Class& thsi = Class::Handle(zone, cls.raw());
  while (true) {
    ASSERT(!thsi.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 (thsi.IsDynamicClass()) {
      return test_kind == Class::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 (thsi.IsNullClass()) {
      // We already checked for other.IsDynamicClass() above.
      return (test_kind == Class::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 (thsi.raw() == other.raw()) {
      const intptr_t num_type_args = thsi.NumTypeArguments();
      if (num_type_args == 0) {
        return true;
      }
      const intptr_t num_type_params = thsi.NumTypeParameters();
      const intptr_t from_index = num_type_args - num_type_params;
      // Since we do not truncate the type argument vector of a subclass (see
      // below), we only check a subvector of the proper length.
      // Check for covariance.
      if (other_type_arguments.IsNull() ||
          other_type_arguments.IsRaw(from_index, num_type_params)) {
        return true;
      }
      if (type_arguments.IsNull() ||
          type_arguments.IsRaw(from_index, num_type_params)) {
        // 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 == Class::kIsSubtypeOf;
      }
      return type_arguments.TypeTest(test_kind,
                                     other_type_arguments,
                                     from_index,
                                     num_type_params,
                                     bound_error,
                                     space);
    }
    const bool other_is_function_class = other.IsFunctionClass();
    if (other.IsSignatureClass() || other_is_function_class) {
      const Function& other_fun = Function::Handle(zone,
                                                   other.signature_function());
      if (thsi.IsSignatureClass()) {
        if (other_is_function_class) {
          return true;
        }
        // Check for two function types.
        const Function& fun =
            Function::Handle(zone, thsi.signature_function());
        return fun.TypeTest(test_kind,
                            type_arguments,
                            other_fun,
                            other_type_arguments,
                            bound_error,
                            space);
      }
      // Check if type S has a call() method of function type T.
      Function& function =
          Function::Handle(zone, thsi.LookupDynamicFunction(Symbols::Call()));
      if (function.IsNull()) {
        // Walk up the super_class chain.
        Class& cls = Class::Handle(zone, thsi.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,
                              bound_error,
                              space)) {
              return true;
            }
      }
    }
    // Check for 'direct super type' specified in the implements clause
    // and check for transitivity at the same time.
    Array& interfaces = Array::Handle(zone, thsi.interfaces());
    AbstractType& interface = AbstractType::Handle(zone);
    Class& interface_class = Class::Handle(zone);
    TypeArguments& interface_args = TypeArguments::Handle(zone);
    Error& error = Error::Handle(zone);
    for (intptr_t i = 0; i < interfaces.Length(); i++) {
      interface ^= interfaces.At(i);
      if (!interface.IsFinalized()) {
        // We may be checking bounds at finalization time and can encounter
        // a still unfinalized interface.
        ClassFinalizer::FinalizeType(
            thsi, interface, ClassFinalizer::kCanonicalize);
        interfaces.SetAt(i, interface);
      }
      if (interface.IsMalbounded()) {
        // Return the first bound error to the caller if it requests it.
        if ((bound_error != NULL) && bound_error->IsNull()) {
          *bound_error = interface.error();
        }
        continue;  // Another interface may work better.
      }
      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.
        error = Error::null();
        interface_args =
            interface_args.InstantiateFrom(type_arguments, &error, NULL, space);
        if (!error.IsNull()) {
          // Return the first bound error to the caller if it requests it.
          if ((bound_error != NULL) && bound_error->IsNull()) {
            *bound_error = error.raw();
          }
          continue;  // Another interface may work better.
        }
      }
      if (interface_class.TypeTest(test_kind,
                                   interface_args,
                                   other,
                                   other_type_arguments,
                                   bound_error,
                                   space)) {
        return true;
      }
    }
    // "Recurse" up the class hierarchy until we have reached the top.
    thsi = thsi.SuperClass();
    if (thsi.IsNull()) {
      return false;
    }
  }
  UNREACHABLE();
  return false;
}


// 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 TypeArguments& type_arguments,
                     const Class& other,
                     const TypeArguments& other_type_arguments,
                     Error* bound_error,
                     Heap::Space space) const {
  return TypeTestNonRecursive(*this,
                              test_kind,
                              type_arguments,
                              other,
                              other_type_arguments,
                              bound_error,
                              space);
}


bool Class::IsTopLevel() const {
  return Name() == Symbols::TopLevel().raw();
}


bool Class::IsPrivate() const {
  return Library::IsPrivate(String::Handle(Name()));
}


RawFunction* Class::LookupDynamicFunction(const String& name) const {
  return LookupFunction(name, kInstance);
}


RawFunction* Class::LookupDynamicFunctionAllowPrivate(
    const String& name) const {
  return LookupFunctionAllowPrivate(name, kInstance);
}


RawFunction* Class::LookupStaticFunction(const String& name) const {
  return LookupFunction(name, kStatic);
}


RawFunction* Class::LookupStaticFunctionAllowPrivate(const String& name) const {
  return LookupFunctionAllowPrivate(name, kStatic);
}


RawFunction* Class::LookupConstructor(const String& name) const {
  return LookupFunction(name, kConstructor);
}


RawFunction* Class::LookupConstructorAllowPrivate(const String& name) const {
  return LookupFunctionAllowPrivate(name, kConstructor);
}


RawFunction* Class::LookupFactory(const String& name) const {
  return LookupFunction(name, kFactory);
}


RawFunction* Class::LookupFactoryAllowPrivate(const String& name) const {
  return LookupFunctionAllowPrivate(name, kFactory);
}


RawFunction* Class::LookupFunction(const String& name) const {
  return LookupFunction(name, kAny);
}


RawFunction* Class::LookupFunctionAllowPrivate(const String& name) const {
  return LookupFunctionAllowPrivate(name, kAny);
}


// 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::CheckFunctionType(const Function& func, MemberKind kind) {
  if (kind == kInstance) {
    if (func.IsDynamicFunction()) {
      return func.raw();
    }
  } else if (kind == kStatic) {
    if (func.IsStaticFunction()) {
      return func.raw();
    }
  } else if (kind == kConstructor) {
    if (func.IsGenerativeConstructor()) {
      ASSERT(!func.is_static());
      return func.raw();
    }
  } else if (kind == kFactory) {
    if (func.IsFactory()) {
      ASSERT(func.is_static());
      return func.raw();
    }
  } else if (kind == kAny) {
    return func.raw();
  }
  return Function::null();
}


RawFunction* Class::LookupFunction(const String& name, MemberKind kind) const {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return Function::null();
  }
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_FUNCTION_HANDLESCOPE(thread);
  Array& funcs = thread->ArrayHandle();
  funcs ^= functions();
  ASSERT(!funcs.IsNull());
  const intptr_t len = funcs.Length();
  Function& function = thread->FunctionHandle();
  if (len >= kFunctionLookupHashTreshold) {
    ClassFunctionsSet set(raw_ptr()->functions_hash_table_);
    REUSABLE_STRING_HANDLESCOPE(thread);
    function ^= set.GetOrNull(FunctionName(name, &(thread->StringHandle())));
    // No mutations.
    ASSERT(set.Release().raw() == raw_ptr()->functions_hash_table_);
    return function.IsNull() ? Function::null()
                             : CheckFunctionType(function, kind);
  }
  if (name.IsSymbol()) {
    // Quick Symbol compare.
    NoSafepointScope no_safepoint;
    for (intptr_t i = 0; i < len; i++) {
      function ^= funcs.At(i);
      if (function.name() == name.raw()) {
        return CheckFunctionType(function, kind);
      }
    }
  } else {
    REUSABLE_STRING_HANDLESCOPE(thread);
    String& function_name = thread->StringHandle();
    for (intptr_t i = 0; i < len; i++) {
      function ^= funcs.At(i);
      function_name ^= function.name();
      if (function_name.Equals(name)) {
        return CheckFunctionType(function, kind);
      }
    }
  }
  // No function found.
  return Function::null();
}


RawFunction* Class::LookupFunctionAllowPrivate(const String& name,
                                               MemberKind kind) const {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return Function::null();
  }
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_FUNCTION_HANDLESCOPE(thread);
  REUSABLE_STRING_HANDLESCOPE(thread);
  Array& funcs = thread->ArrayHandle();
  funcs ^= functions();
  ASSERT(!funcs.IsNull());
  const intptr_t len = funcs.Length();
  Function& function = thread->FunctionHandle();
  String& function_name = thread->StringHandle();
  for (intptr_t i = 0; i < len; i++) {
    function ^= funcs.At(i);
    function_name ^= function.name();
    if (String::EqualsIgnoringPrivateKey(function_name, name)) {
      return CheckFunctionType(function, kind);
    }
  }
  // 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 {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return Function::null();
  }
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_FUNCTION_HANDLESCOPE(thread);
  REUSABLE_STRING_HANDLESCOPE(thread);
  Array& funcs = thread->ArrayHandle();
  funcs ^= functions();
  intptr_t len = funcs.Length();
  Function& function = thread->FunctionHandle();
  String& function_name = thread->StringHandle();
  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.
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return Function::null();
  }
  Function& func = Function::Handle(zone);
  func = LookupClosureFunction(token_pos);
  if (!func.IsNull()) {
    return func.raw();
  }
  Array& funcs = Array::Handle(zone, 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 {
  return LookupField(name, kInstance);
}


RawField* Class::LookupStaticField(const String& name) const {
  return LookupField(name, kStatic);
}


RawField* Class::LookupField(const String& name) const {
  return LookupField(name, kAny);
}


RawField* Class::LookupField(const String& name, MemberKind kind) const {
  Thread* thread = Thread::Current();
  if (EnsureIsFinalized(thread) != Error::null()) {
    return Field::null();
  }
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_FIELD_HANDLESCOPE(thread);
  REUSABLE_STRING_HANDLESCOPE(thread);
  Array& flds = thread->ArrayHandle();
  flds ^= fields();
  ASSERT(!flds.IsNull());
  intptr_t len = flds.Length();
  Field& field = thread->FieldHandle();
  String& field_name = thread->StringHandle();
  for (intptr_t i = 0; i < len; i++) {
    field ^= flds.At(i);
    field_name ^= field.name();
    if (String::EqualsIgnoringPrivateKey(field_name, name)) {
      if (kind == kInstance) {
        if (!field.is_static()) {
          return field.raw();
        }
      } else if (kind == kStatic) {
        if (field.is_static()) {
          return field.raw();
        }
      } else if (kind == kAny) {
        return field.raw();
      }
      return Field::null();
    }
  }
  // No field found.
  return Field::null();
}


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


const char* Class::ToCString() const {
  const Library& lib = Library::Handle(library());
  const char* library_name = lib.IsNull() ? "" : lib.ToCString();
  const char* patch_prefix = is_patch() ? "Patch " : "";
  const char* class_name = String::Handle(Name()).ToCString();
  return OS::SCreate(Thread::Current()->zone(),
      "%s %sClass: %s", library_name, patch_prefix, class_name);
}


void Class::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Isolate* isolate = Isolate::Current();
  JSONObject jsobj(stream);
  if ((raw() == Class::null()) || (id() == kFreeListElement)) {
    // TODO(turnidge): This is weird and needs to be changed.
    jsobj.AddProperty("type", "null");
    return;
  }
  AddCommonObjectProperties(&jsobj, "Class", ref);
  jsobj.AddFixedServiceId("classes/%" Pd "", id());
  const String& user_name = String::Handle(PrettyName());
  const String& vm_name = String::Handle(Name());
  AddNameProperties(&jsobj, user_name, vm_name);
  if (ref) {
    return;
  }

  const Error& err = Error::Handle(EnsureIsFinalized(Thread::Current()));
  if (!err.IsNull()) {
    jsobj.AddProperty("error", err);
  }
  jsobj.AddProperty("abstract", is_abstract());
  jsobj.AddProperty("const", is_const());
  jsobj.AddProperty("_finalized", is_finalized());
  jsobj.AddProperty("_implemented", is_implemented());
  jsobj.AddProperty("_patch", is_patch());
  jsobj.AddProperty("_traceAllocations", TraceAllocation(isolate));
  const Class& superClass = Class::Handle(SuperClass());
  if (!superClass.IsNull()) {
    jsobj.AddProperty("super", superClass);
  }
  jsobj.AddProperty("library", Object::Handle(library()));
  const Script& script = Script::Handle(this->script());
  if (!script.IsNull()) {
    jsobj.AddLocation(script, token_pos(), ComputeEndTokenPos());
  }
  {
    JSONArray interfaces_array(&jsobj, "interfaces");
    const Array& interface_array = Array::Handle(interfaces());
    Type& interface_type = Type::Handle();
    if (!interface_array.IsNull()) {
      for (intptr_t i = 0; i < interface_array.Length(); ++i) {
        interface_type ^= interface_array.At(i);
        interfaces_array.AddValue(interface_type);
      }
    }
  }
  {
    JSONArray fields_array(&jsobj, "fields");
    const Array& field_array = Array::Handle(fields());
    Field& field = Field::Handle();
    if (!field_array.IsNull()) {
      for (intptr_t i = 0; i < field_array.Length(); ++i) {
        field ^= field_array.At(i);
        fields_array.AddValue(field);
      }
    }
  }
  {
    JSONArray functions_array(&jsobj, "functions");
    const Array& function_array = Array::Handle(functions());
    Function& function = Function::Handle();
    if (!function_array.IsNull()) {
      for (intptr_t i = 0; i < function_array.Length(); i++) {
        function ^= function_array.At(i);
        functions_array.AddValue(function);
      }
    }
  }
  {
    JSONArray subclasses_array(&jsobj, "subclasses");
    const GrowableObjectArray& subclasses =
        GrowableObjectArray::Handle(direct_subclasses());
    if (!subclasses.IsNull()) {
      Class& subclass = Class::Handle();
      for (intptr_t i = 0; i < subclasses.Length(); ++i) {
        // TODO(turnidge): Use the Type directly once regis has added
        // types to the vmservice.
        subclass ^= subclasses.At(i);
        subclasses_array.AddValue(subclass);
      }
    }
  }
  {
    ClassTable* class_table = Isolate::Current()->class_table();
    const ClassHeapStats* stats = class_table->StatsWithUpdatedSize(id());
    if (stats != NULL) {
      JSONObject allocation_stats(&jsobj, "_allocationStats");
      stats->PrintToJSONObject(*this, &allocation_stats);
    }
  }
}


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);
  StoreNonPointer(&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.
    Zone* zone = Thread::Current()->zone();
    GrowableHandlePtrArray<const String> strs(zone, 3);
    strs.Add(name);
    strs.Add(Symbols::Dot());
    strs.Add(String::Handle(zone, ident()));
    return Symbols::FromConcatAll(strs);
  } else {
    return ident();
  }
}


const char* UnresolvedClass::ToCString() const {
  const char* cname =  String::Handle(Name()).ToCString();
  return OS::SCreate(Thread::Current()->zone(),
      "unresolved class '%s'", cname);
}


void UnresolvedClass::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


static uint32_t CombineHashes(uint32_t hash, uint32_t other_hash) {
  hash += other_hash;
  hash += hash << 10;
  hash ^= hash >> 6;  // Logical shift, unsigned hash.
  return hash;
}


static uint32_t FinalizeHash(uint32_t hash) {
  hash += hash << 3;
  hash ^= hash >> 11;  // Logical shift, unsigned hash.
  hash += hash << 15;
  return hash;
}


intptr_t TypeArguments::Hash() const {
  if (IsNull()) return 0;
  const intptr_t num_types = Length();
  if (IsRaw(0, num_types)) return 0;
  uint32_t result = 0;
  AbstractType& type = AbstractType::Handle();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    // The hash may be calculated during type finalization (for debugging
    // purposes only) while a type argument is still temporarily null.
    result = CombineHashes(result, type.IsNull() ? 0 : type.Hash());
  }
  return FinalizeHash(result);
}


RawString* TypeArguments::SubvectorName(intptr_t from_index,
                                        intptr_t len,
                                        NameVisibility name_visibility) const {
  Zone* zone = Thread::Current()->zone();
  ASSERT(from_index + len <= Length());
  String& name = String::Handle(zone);
  const intptr_t num_strings = (len == 0) ? 2 : 2*len + 1;  // "<""T"", ""T"">".
  GrowableHandlePtrArray<const String> pieces(zone, num_strings);
  pieces.Add(Symbols::LAngleBracket());
  AbstractType& type = AbstractType::Handle();
  for (intptr_t i = 0; i < len; i++) {
    type = TypeAt(from_index + i);
    name = type.BuildName(name_visibility);
    pieces.Add(name);
    if (i < len - 1) {
      pieces.Add(Symbols::CommaSpace());
    }
  }
  pieces.Add(Symbols::RAngleBracket());
  ASSERT(pieces.length() == num_strings);
  return Symbols::FromConcatAll(pieces);
}


bool TypeArguments::IsSubvectorEquivalent(const TypeArguments& other,
                                          intptr_t from_index,
                                          intptr_t len,
                                          TrailPtr trail) const {
  if (this->raw() == other.raw()) {
    return true;
  }
  if (IsNull() || other.IsNull()) {
    return false;
  }
  const 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 = from_index; i < from_index + len; i++) {
    type = TypeAt(i);
    other_type = other.TypeAt(i);
    if (!type.IsEquivalent(other_type, trail)) {
      return false;
    }
  }
  return true;
}


bool TypeArguments::IsRecursive() const {
  if (IsNull()) return false;
  const intptr_t num_types = Length();
  AbstractType& type = AbstractType::Handle();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    // If this type argument is null, the type parameterized with this type
    // argument is still being finalized and is definitely recursive. The null
    // type argument will be replaced by a non-null type before the type is
    // marked as finalized.
    if (type.IsNull() || type.IsRecursive()) {
      return true;
    }
  }
  return false;
}


bool TypeArguments::IsDynamicTypes(bool raw_instantiated,
                                   intptr_t from_index,
                                   intptr_t len) const {
  ASSERT(Length() >= (from_index + len));
  AbstractType& type = AbstractType::Handle();
  Class& type_class = Class::Handle();
  for (intptr_t i = 0; i < len; i++) {
    type = TypeAt(from_index + i);
    if (!type.HasResolvedTypeClass()) {
      if (raw_instantiated && type.IsTypeParameter()) {
        // An uninstantiated type parameter is equivalent to dynamic (even in
        // the presence of a malformed bound in checked mode).
        continue;
      }
      return false;
    }
    type_class = type.type_class();
    if (!type_class.IsDynamicClass()) {
      return false;
    }
  }
  return true;
}


bool TypeArguments::TypeTest(TypeTestKind test_kind,
                             const TypeArguments& other,
                             intptr_t from_index,
                             intptr_t len,
                             Error* bound_error,
                             Heap::Space space) const {
  ASSERT(Length() >= (from_index + len));
  ASSERT(!other.IsNull());
  ASSERT(other.Length() >= (from_index + len));
  AbstractType& type = AbstractType::Handle();
  AbstractType& other_type = AbstractType::Handle();
  for (intptr_t i = 0; i < len; i++) {
    type = TypeAt(from_index + i);
    ASSERT(!type.IsNull());
    other_type = other.TypeAt(from_index + i);
    ASSERT(!other_type.IsNull());
    if (!type.TypeTest(test_kind, other_type, bound_error, space)) {
      return false;
    }
  }
  return true;
}


void TypeArguments::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  // The index in the canonical_type_arguments table cannot be used as part of
  // the object id (as in typearguments/id), because the indices are not
  // preserved when the table grows and the entries get rehashed. Use the ring.
  Isolate* isolate = Isolate::Current();
  ObjectStore* object_store = isolate->object_store();
  const Array& table = Array::Handle(object_store->canonical_type_arguments());
  ASSERT(table.Length() > 0);
  AddCommonObjectProperties(&jsobj, "TypeArguments", ref);
  jsobj.AddServiceId(*this);
  const String& user_name = String::Handle(PrettyName());
  const String& vm_name = String::Handle(Name());
  AddNameProperties(&jsobj, user_name, vm_name);
  if (ref) {
    return;
  }
  {
    JSONArray jsarr(&jsobj, "types");
    AbstractType& type_arg = AbstractType::Handle();
    for (intptr_t i = 0; i < Length(); i++) {
      type_arg = TypeAt(i);
      jsarr.AddValue(type_arg);
    }
  }
  if (!IsInstantiated()) {
    JSONArray jsarr(&jsobj, "_instantiations");
    Array& prior_instantiations = Array::Handle(instantiations());
    ASSERT(prior_instantiations.Length() > 0);  // Always at least a sentinel.
    TypeArguments& type_args = TypeArguments::Handle();
    intptr_t i = 0;
    while (true) {
      if (prior_instantiations.At(i) == Smi::New(StubCode::kNoInstantiator)) {
        break;
      }
      JSONObject instantiation(&jsarr);
      type_args ^= prior_instantiations.At(i);
      instantiation.AddProperty("instantiator", type_args, true);
      type_args ^= prior_instantiations.At(i + 1);
      instantiation.AddProperty("instantiated", type_args, true);
      i += 2;
    }
  }
}


bool TypeArguments::HasInstantiations() const {
  const Array& prior_instantiations = Array::Handle(instantiations());
  ASSERT(prior_instantiations.Length() > 0);  // Always at least a sentinel.
  return prior_instantiations.Length() > 1;
}


intptr_t TypeArguments::NumInstantiations() const {
  const Array& prior_instantiations = Array::Handle(instantiations());
  ASSERT(prior_instantiations.Length() > 0);  // Always at least a sentinel.
  intptr_t i = 0;
  while (prior_instantiations.At(i) != Smi::New(StubCode::kNoInstantiator)) {
    i += 2;
  }
  return i/2;
}


RawArray* TypeArguments::instantiations() const {
  return raw_ptr()->instantiations_;
}


void TypeArguments::set_instantiations(const Array& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->instantiations_, value.raw());
}


intptr_t TypeArguments::Length() const {
  ASSERT(!IsNull());
  return Smi::Value(raw_ptr()->length_);
}


RawAbstractType* TypeArguments::TypeAt(intptr_t index) const {
  return *TypeAddr(index);
}


void TypeArguments::SetTypeAt(intptr_t index,
                                const AbstractType& value) const {
  StorePointer(TypeAddr(index), value.raw());
}


bool TypeArguments::IsResolved() const {
  AbstractType& type = AbstractType::Handle();
  const intptr_t num_types = Length();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    if (!type.IsResolved()) {
      return false;
    }
  }
  return true;
}


bool TypeArguments::IsSubvectorInstantiated(intptr_t from_index,
                                            intptr_t len,
                                            TrailPtr trail) const {
  ASSERT(!IsNull());
  AbstractType& type = AbstractType::Handle();
  for (intptr_t i = 0; i < len; i++) {
    type = TypeAt(from_index + i);
    // If the type argument is null, the type parameterized with this type
    // argument is still being finalized. Skip this null type argument.
    if (!type.IsNull() && !type.IsInstantiated(trail)) {
      return false;
    }
  }
  return true;
}


bool TypeArguments::IsUninstantiatedIdentity() const {
  ASSERT(!IsInstantiated());
  AbstractType& type = AbstractType::Handle();
  const intptr_t num_types = Length();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    if (!type.IsTypeParameter()) {
      return false;
    }
    const TypeParameter& type_param = TypeParameter::Cast(type);
    ASSERT(type_param.IsFinalized());
    if ((type_param.index() != i)) {
      return false;
    }
    // If this type parameter specifies an upper bound, then the type argument
    // vector does not really represent the identity vector. It cannot be
    // substituted by the instantiator's type argument vector without checking
    // the upper bound.
    const AbstractType& bound = AbstractType::Handle(type_param.bound());
    ASSERT(bound.IsResolved());
    if (!bound.IsObjectType() && !bound.IsDynamicType()) {
      return false;
    }
  }
  return true;
  // Note that it is not necessary to verify at runtime that the instantiator
  // type vector is long enough, since this uninstantiated vector contains as
  // many different type parameters as it is long.
}


// Return true if this uninstantiated type argument vector, once instantiated
// at runtime, is a prefix of the type argument vector of its instantiator.
bool TypeArguments::CanShareInstantiatorTypeArguments(
      const Class& instantiator_class) const {
  ASSERT(!IsInstantiated());
  const intptr_t num_type_args = Length();
  const intptr_t num_instantiator_type_args =
      instantiator_class.NumTypeArguments();
  if (num_type_args > num_instantiator_type_args) {
    // This vector cannot be a prefix of a shorter vector.
    return false;
  }
  const intptr_t num_instantiator_type_params =
      instantiator_class.NumTypeParameters();
  const intptr_t first_type_param_offset =
      num_instantiator_type_args - num_instantiator_type_params;
  // At compile time, the type argument vector of the instantiator consists of
  // the type argument vector of its super type, which may refer to the type
  // parameters of the instantiator class, followed by (or overlapping partially
  // or fully with) the type parameters of the instantiator class in declaration
  // order.
  // In other words, the only variables are the type parameters of the
  // instantiator class.
  // This uninstantiated type argument vector is also expressed in terms of the
  // type parameters of the instantiator class. Therefore, in order to be a
  // prefix once instantiated at runtime, every one of its type argument must be
  // equal to the type argument of the instantiator vector at the same index.

  // As a first requirement, the last num_instantiator_type_params type
  // arguments of this type argument vector must refer to the corresponding type
  // parameters of the instantiator class.
  AbstractType& type_arg = AbstractType::Handle();
  for (intptr_t i = first_type_param_offset; i < num_type_args; i++) {
    type_arg = TypeAt(i);
    if (!type_arg.IsTypeParameter()) {
      return false;
    }
    const TypeParameter& type_param = TypeParameter::Cast(type_arg);
    ASSERT(type_param.IsFinalized());
    if ((type_param.index() != i)) {
      return false;
    }
  }
  // As a second requirement, the type arguments corresponding to the super type
  // must be identical. Overlapping ones have already been checked starting at
  // first_type_param_offset.
  if (first_type_param_offset == 0) {
    return true;
  }
  AbstractType& super_type = AbstractType::Handle(
      instantiator_class.super_type());
  const TypeArguments& super_type_args = TypeArguments::Handle(
      super_type.arguments());
  if (super_type_args.IsNull()) {
    return false;
  }
  AbstractType& super_type_arg = AbstractType::Handle();
  for (intptr_t i = 0;
       (i < first_type_param_offset) && (i < num_type_args); i++) {
    type_arg = TypeAt(i);
    super_type_arg = super_type_args.TypeAt(i);
    if (!type_arg.Equals(super_type_arg)) {
      return false;
    }
  }
  return true;
}


bool TypeArguments::IsFinalized() const {
  ASSERT(!IsNull());
  AbstractType& type = AbstractType::Handle();
  const intptr_t num_types = Length();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    if (!type.IsFinalized()) {
      return false;
    }
  }
  return true;
}


bool TypeArguments::IsBounded() const {
  AbstractType& type = AbstractType::Handle();
  const intptr_t num_types = Length();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    if (type.IsBoundedType()) {
      return true;
    }
    if (type.IsTypeParameter()) {
      const AbstractType& bound = AbstractType::Handle(
          TypeParameter::Cast(type).bound());
      if (!bound.IsObjectType() && !bound.IsDynamicType()) {
        return true;
      }
      continue;
    }
    const TypeArguments& type_args = TypeArguments::Handle(
        Type::Cast(type).arguments());
    if (!type_args.IsNull() && type_args.IsBounded()) {
      return true;
    }
  }
  return false;
}


RawTypeArguments* TypeArguments::InstantiateFrom(
    const TypeArguments& instantiator_type_arguments,
    Error* bound_error,
    TrailPtr trail,
    Heap::Space space) const {
  ASSERT(!IsInstantiated());
  if (!instantiator_type_arguments.IsNull() &&
      IsUninstantiatedIdentity() &&
      (instantiator_type_arguments.Length() == Length())) {
    return instantiator_type_arguments.raw();
  }
  const intptr_t num_types = Length();
  TypeArguments& instantiated_array =
      TypeArguments::Handle(TypeArguments::New(num_types, space));
  AbstractType& type = AbstractType::Handle();
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    // If this type argument T is null, the type A containing T in its flattened
    // type argument vector V is recursive and is still being finalized.
    // T is the type argument of a super type of A. T is being instantiated
    // during finalization of V, which is also the instantiator. T depends
    // solely on the type parameters of A and will be replaced by a non-null
    // type before A is marked as finalized.
    if (!type.IsNull() && !type.IsInstantiated()) {
      type = type.InstantiateFrom(instantiator_type_arguments,
                                  bound_error,
                                  trail,
                                  space);
    }
    instantiated_array.SetTypeAt(i, type);
  }
  return instantiated_array.raw();
}


RawTypeArguments* TypeArguments::InstantiateAndCanonicalizeFrom(
    const TypeArguments& instantiator_type_arguments,
    Error* bound_error) const {
  ASSERT(!IsInstantiated());
  ASSERT(instantiator_type_arguments.IsNull() ||
         instantiator_type_arguments.IsCanonical());
  // Lookup instantiator and, if found, return paired instantiated result.
  Array& prior_instantiations = Array::Handle(instantiations());
  ASSERT(!prior_instantiations.IsNull() && prior_instantiations.IsArray());
  // The instantiations cache is initialized with Object::zero_array() and is
  // therefore guaranteed to contain kNoInstantiator. No length check needed.
  ASSERT(prior_instantiations.Length() > 0);  // Always at least a sentinel.
  intptr_t index = 0;
  while (true) {
    if (prior_instantiations.At(index) == instantiator_type_arguments.raw()) {
      return TypeArguments::RawCast(prior_instantiations.At(index + 1));
    }
    if (prior_instantiations.At(index) == Smi::New(StubCode::kNoInstantiator)) {
      break;
    }
    index += 2;
  }
  // Cache lookup failed. Instantiate the type arguments.
  TypeArguments& result = TypeArguments::Handle();
  result = InstantiateFrom(instantiator_type_arguments, bound_error);
  if ((bound_error != NULL) && !bound_error->IsNull()) {
    return result.raw();
  }
  // Instantiation did not result in bound error. Canonicalize type arguments.
  result = result.Canonicalize();
  // InstantiateAndCanonicalizeFrom is not reentrant. It cannot have been called
  // indirectly, so the prior_instantiations array cannot have grown.
  ASSERT(prior_instantiations.raw() == instantiations());
  // Add instantiator and result to instantiations array.
  intptr_t length = prior_instantiations.Length();
  if ((index + 2) >= length) {
    // Grow the instantiations array.
    // The initial array is Object::zero_array() of length 1.
    length = (length > 64) ?
        (length + 64) :
        ((length == 1) ? 3 : ((length - 1) * 2 + 1));
    prior_instantiations =
        Array::Grow(prior_instantiations, length, Heap::kOld);
    set_instantiations(prior_instantiations);
    ASSERT((index + 2) < length);
  }
  prior_instantiations.SetAt(index, instantiator_type_arguments);
  prior_instantiations.SetAt(index + 1, result);
  prior_instantiations.SetAt(index + 2,
                             Smi::Handle(Smi::New(StubCode::kNoInstantiator)));
  return result.raw();
}


RawTypeArguments* TypeArguments::New(intptr_t len, Heap::Space space) {
  if (len < 0 || len > kMaxElements) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in TypeArguments::New: invalid len %" Pd "\n", len);
  }
  TypeArguments& result = TypeArguments::Handle();
  {
    RawObject* raw = Object::Allocate(TypeArguments::kClassId,
                                      TypeArguments::InstanceSize(len),
                                      space);
    NoSafepointScope no_safepoint;
    result ^= raw;
    // Length must be set before we start storing into the array.
    result.SetLength(len);
  }
  // The zero array should have been initialized.
  ASSERT(Object::zero_array().raw() != Array::null());
  COMPILE_ASSERT(StubCode::kNoInstantiator == 0);
  result.set_instantiations(Object::zero_array());
  return result.raw();
}



RawAbstractType* const* TypeArguments::TypeAddr(intptr_t index) const {
  // TODO(iposva): Determine if we should throw an exception here.
  ASSERT((index >= 0) && (index < Length()));
  return &raw_ptr()->types()[index];
}


void TypeArguments::SetLength(intptr_t value) const {
  ASSERT(!IsCanonical());
  // This is only safe because we create a new Smi, which does not cause
  // heap allocation.
  StoreSmi(&raw_ptr()->length_, Smi::New(value));
}


static void GrowCanonicalTypeArguments(Thread* thread, const Array& table) {
  Isolate* isolate = thread->isolate();
  Zone* zone = thread->zone();
  // Last element of the array is the number of used elements.
  const intptr_t table_size = table.Length() - 1;
  const intptr_t new_table_size = table_size * 2;
  Array& new_table = Array::Handle(zone, Array::New(new_table_size + 1));
  // Copy all elements from the original table to the newly allocated
  // array.
  TypeArguments& element = TypeArguments::Handle(zone);
  Object& new_element = Object::Handle(zone);
  for (intptr_t i = 0; i < table_size; i++) {
    element ^= table.At(i);
    if (!element.IsNull()) {
      const intptr_t hash = element.Hash();
      ASSERT(Utils::IsPowerOfTwo(new_table_size));
      intptr_t index = hash & (new_table_size - 1);
      new_element = new_table.At(index);
      while (!new_element.IsNull()) {
        index = (index + 1) & (new_table_size - 1);  // Move to next element.
        new_element = new_table.At(index);
      }
      new_table.SetAt(index, element);
    }
  }
  // Copy used count.
  new_element = table.At(table_size);
  new_table.SetAt(new_table_size, new_element);
  // Remember the new table now.
  isolate->object_store()->set_canonical_type_arguments(new_table);
}


static void InsertIntoCanonicalTypeArguments(Thread* thread,
                                             const Array& table,
                                             const TypeArguments& arguments,
                                             intptr_t index) {
  Zone* zone = thread->zone();
  arguments.SetCanonical();  // Mark object as being canonical.
  table.SetAt(index, arguments);  // Remember the new element.
  // Update used count.
  // Last element of the array is the number of used elements.
  const intptr_t table_size = table.Length() - 1;
  const intptr_t used_elements =
      Smi::Value(Smi::RawCast(table.At(table_size))) + 1;
  const Smi& used = Smi::Handle(zone, Smi::New(used_elements));
  table.SetAt(table_size, used);

#ifdef DEBUG
  // Verify that there are no duplicates.
  // Duplicates could appear if hash values are not kept constant across
  // snapshots, e.g. if class ids are not preserved by the snapshots.
  TypeArguments& other_arguments = TypeArguments::Handle();
  for (intptr_t i = 0; i < table_size; i++) {
    if ((i != index) && (table.At(i) != TypeArguments::null())) {
      other_arguments ^= table.At(i);
      if (arguments.Equals(other_arguments)) {
        // Recursive types may be equal, but have different hashes.
        ASSERT(arguments.IsRecursive());
        ASSERT(other_arguments.IsRecursive());
        ASSERT(arguments.Hash() != other_arguments.Hash());
      }
    }
  }
#endif

  // Rehash if table is 75% full.
  if (used_elements > ((table_size / 4) * 3)) {
    GrowCanonicalTypeArguments(thread, table);
  }
}


static intptr_t FindIndexInCanonicalTypeArguments(
    Zone* zone,
    const Array& table,
    const TypeArguments& arguments,
    intptr_t hash) {
  // Last element of the array is the number of used elements.
  const intptr_t table_size = table.Length() - 1;
  ASSERT(Utils::IsPowerOfTwo(table_size));
  intptr_t index = hash & (table_size - 1);

  TypeArguments& current = TypeArguments::Handle(zone);
  current ^= table.At(index);
  while (!current.IsNull() && !current.Equals(arguments)) {
    index = (index + 1) & (table_size - 1);  // Move to next element.
    current ^= table.At(index);
  }
  return index;  // Index of element if found or slot into which to add it.
}


RawTypeArguments* TypeArguments::CloneUnfinalized() const {
  if (IsNull() || IsFinalized()) {
    return raw();
  }
  ASSERT(IsResolved());
  AbstractType& type = AbstractType::Handle();
  const intptr_t num_types = Length();
  const TypeArguments& clone = TypeArguments::Handle(
      TypeArguments::New(num_types));
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    type = type.CloneUnfinalized();
    clone.SetTypeAt(i, type);
  }
  ASSERT(clone.IsResolved());
  return clone.raw();
}


RawTypeArguments* TypeArguments::CloneUninstantiated(
    const Class& new_owner,
    TrailPtr trail) const {
  ASSERT(!IsNull());
  ASSERT(IsFinalized());
  ASSERT(!IsInstantiated());
  AbstractType& type = AbstractType::Handle();
  const intptr_t num_types = Length();
  const TypeArguments& clone = TypeArguments::Handle(
      TypeArguments::New(num_types));
  for (intptr_t i = 0; i < num_types; i++) {
    type = TypeAt(i);
    if (!type.IsInstantiated()) {
      type = type.CloneUninstantiated(new_owner, trail);
    }
    clone.SetTypeAt(i, type);
  }
  ASSERT(clone.IsFinalized());
  return clone.raw();
}


RawTypeArguments* TypeArguments::Canonicalize(TrailPtr trail) const {
  if (IsNull() || IsCanonical()) {
    ASSERT(IsOld());
    return this->raw();
  }
  const intptr_t num_types = Length();
  if (IsRaw(0, num_types)) {
    return TypeArguments::null();
  }
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  Isolate* isolate = thread->isolate();
  ObjectStore* object_store = isolate->object_store();
  Array& table = Array::Handle(zone,
                               object_store->canonical_type_arguments());
  // Last element of the array is the number of used elements.
  const intptr_t num_used =
      Smi::Value(Smi::RawCast(table.At(table.Length() - 1)));
  const intptr_t hash = Hash();
  intptr_t index = FindIndexInCanonicalTypeArguments(zone, table, *this, hash);
  TypeArguments& result = TypeArguments::Handle(zone);
  result ^= table.At(index);
  if (result.IsNull()) {
    // Canonicalize each type argument.
    AbstractType& type_arg = AbstractType::Handle(zone);
    for (intptr_t i = 0; i < num_types; i++) {
      type_arg = TypeAt(i);
      type_arg = type_arg.Canonicalize(trail);
      SetTypeAt(i, type_arg);
    }
    // Canonicalization of a recursive type may change its hash.
    intptr_t canonical_hash = hash;
    if (IsRecursive()) {
      canonical_hash = Hash();
    }
    // Canonicalization of the type argument's own type arguments may add an
    // entry to the table, or even grow the table, and thereby change the
    // previously calculated index.
    table = object_store->canonical_type_arguments();
    if ((canonical_hash != hash) ||
        (Smi::Value(Smi::RawCast(table.At(table.Length() - 1))) != num_used)) {
      index = FindIndexInCanonicalTypeArguments(
          zone, table, *this, canonical_hash);
      result ^= table.At(index);
    }
    if (result.IsNull()) {
      // Make sure we have an old space object and add it to the table.
      if (this->IsNew()) {
        result ^= Object::Clone(*this, Heap::kOld);
      } else {
        result ^= this->raw();
      }
      ASSERT(result.IsOld());
      InsertIntoCanonicalTypeArguments(thread, table, result, index);
    }
  }
  ASSERT(result.Equals(*this));
  ASSERT(!result.IsNull());
  ASSERT(result.IsTypeArguments());
  ASSERT(result.IsCanonical());
  return result.raw();
}


const char* TypeArguments::ToCString() const {
  if (IsNull()) {
    return "NULL TypeArguments";
  }
  const char* prev_cstr = "TypeArguments:";
  for (int i = 0; i < Length(); i++) {
    const AbstractType& type_at = AbstractType::Handle(TypeAt(i));
    const char* type_cstr = type_at.IsNull() ? "null" : type_at.ToCString();
    char* chars = OS::SCreate(Thread::Current()->zone(),
        "%s [%s]", prev_cstr, type_cstr);
    prev_cstr = chars;
  }
  return prev_cstr;
}


const char* PatchClass::ToCString() const {
  const Class& cls = Class::Handle(patched_class());
  const char* cls_name = cls.ToCString();
  return OS::SCreate(Thread::Current()->zone(),
      "PatchClass for %s", cls_name);
}


void PatchClass::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


RawPatchClass* PatchClass::New(const Class& patched_class,
                               const Class& source_class) {
  const PatchClass& result = PatchClass::Handle(PatchClass::New());
  result.set_patched_class(patched_class);
  result.set_source_class(source_class);
  return result.raw();
}


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


RawScript* PatchClass::Script() const {
  const Class& source_class = Class::Handle(this->source_class());
  return source_class.script();
}


void PatchClass::set_patched_class(const Class& value) const {
  StorePointer(&raw_ptr()->patched_class_, value.raw());
}


void PatchClass::set_source_class(const Class& value) const {
  StorePointer(&raw_ptr()->source_class_, value.raw());
}


bool Function::HasBreakpoint() const {
  return Isolate::Current()->debugger()->HasBreakpoint(*this);
}


void Function::SetInstructions(const Code& value) const {
  StorePointer(&raw_ptr()->code_, value.raw());
  StoreNonPointer(&raw_ptr()->entry_point_, value.EntryPoint());
}

void Function::AttachCode(const Code& value) const {
  SetInstructions(value);
  ASSERT(Function::Handle(value.function()).IsNull() ||
    (value.function() == this->raw()));
  value.set_owner(*this);
}


bool Function::HasCode() const {
  ASSERT(raw_ptr()->code_ != Code::null());
  return raw_ptr()->code_ != StubCode::LazyCompile_entry()->code();
}


void Function::ClearCode() const {
  ASSERT((usage_counter() != 0) || (ic_data_array() == Array::null()));
  StorePointer(&raw_ptr()->unoptimized_code_, Code::null());
  SetInstructions(Code::Handle(StubCode::LazyCompile_entry()->code()));
}


void Function::SwitchToUnoptimizedCode() const {
  ASSERT(HasOptimizedCode());
  Thread* thread = Thread::Current();
  Isolate* isolate = thread->isolate();
  Zone* zone = thread->zone();
  const Code& current_code = Code::Handle(zone, CurrentCode());

  if (FLAG_trace_deoptimization_verbose) {
    THR_Print("Disabling optimized code: '%s' entry: %#" Px "\n",
      ToFullyQualifiedCString(),
      current_code.EntryPoint());
  }
  current_code.DisableDartCode();
  const Error& error = Error::Handle(zone,
      Compiler::EnsureUnoptimizedCode(thread, *this));
  if (!error.IsNull()) {
    Exceptions::PropagateError(error);
  }
  const Code& unopt_code = Code::Handle(zone, unoptimized_code());
  AttachCode(unopt_code);
  unopt_code.Enable();
  isolate->TrackDeoptimizedCode(current_code);
}


void Function::set_unoptimized_code(const Code& value) const {
  ASSERT(value.IsNull() || !value.is_optimized());
  StorePointer(&raw_ptr()->unoptimized_code_, value.raw());
}


RawContextScope* Function::context_scope() const {
  if (IsClosureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(!obj.IsNull());
    return ClosureData::Cast(obj).context_scope();
  }
  return ContextScope::null();
}


void Function::set_context_scope(const ContextScope& value) const {
  if (IsClosureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(!obj.IsNull());
    ClosureData::Cast(obj).set_context_scope(value);
    return;
  }
  UNREACHABLE();
}


RawInstance* Function::implicit_static_closure() const {
  if (IsImplicitStaticClosureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(!obj.IsNull());
    return ClosureData::Cast(obj).implicit_static_closure();
  }
  return Instance::null();
}


void Function::set_implicit_static_closure(const Instance& closure) const {
  if (IsImplicitStaticClosureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(!obj.IsNull());
    ClosureData::Cast(obj).set_implicit_static_closure(closure);
    return;
  }
  UNREACHABLE();
}


RawScript* Function::eval_script() const {
  const Object& obj = Object::Handle(raw_ptr()->data_);
  if (obj.IsScript()) {
    return Script::Cast(obj).raw();
  }
  return Script::null();
}


void Function::set_eval_script(const Script& script) const {
  ASSERT(token_pos() == 0);
  ASSERT(raw_ptr()->data_ == Object::null());
  set_data(script);
}


RawFunction* Function::extracted_method_closure() const {
  ASSERT(kind() == RawFunction::kMethodExtractor);
  const Object& obj = Object::Handle(raw_ptr()->data_);
  ASSERT(obj.IsFunction());
  return Function::Cast(obj).raw();
}


void Function::set_extracted_method_closure(const Function& value) const {
  ASSERT(kind() == RawFunction::kMethodExtractor);
  ASSERT(raw_ptr()->data_ == Object::null());
  set_data(value);
}


RawArray* Function::saved_args_desc() const {
  ASSERT(kind() == RawFunction::kNoSuchMethodDispatcher ||
         kind() == RawFunction::kInvokeFieldDispatcher);
  const Object& obj = Object::Handle(raw_ptr()->data_);
  ASSERT(obj.IsArray());
  return Array::Cast(obj).raw();
}


void Function::set_saved_args_desc(const Array& value) const {
  ASSERT(kind() == RawFunction::kNoSuchMethodDispatcher ||
         kind() == RawFunction::kInvokeFieldDispatcher);
  ASSERT(raw_ptr()->data_ == Object::null());
  set_data(value);
}


RawFunction* Function::parent_function() const {
  if (IsClosureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(!obj.IsNull());
    return ClosureData::Cast(obj).parent_function();
  }
  return Function::null();
}


void Function::set_parent_function(const Function& value) const {
  if (IsClosureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(!obj.IsNull());
    ClosureData::Cast(obj).set_parent_function(value);
    return;
  }
  UNREACHABLE();
}


RawFunction* Function::implicit_closure_function() const {
  if (IsClosureFunction() ||
      IsSignatureFunction() ||
      IsFactory()) {
    return Function::null();
  }
  const Object& obj = Object::Handle(raw_ptr()->data_);
  ASSERT(obj.IsNull() || obj.IsScript() || obj.IsFunction());
  return (obj.IsNull() || obj.IsScript()) ? Function::null()
                                          : Function::Cast(obj).raw();
}


void Function::set_implicit_closure_function(const Function& value) const {
  ASSERT(!IsClosureFunction() && !IsSignatureFunction());
  ASSERT(raw_ptr()->data_ == Object::null());
  set_data(value);
}


RawClass* Function::signature_class() const {
  if (IsSignatureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(obj.IsNull() || obj.IsClass());
    return (obj.IsNull()) ? Class::null() : Class::Cast(obj).raw();
  }
  if (IsClosureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(!obj.IsNull());
    return ClosureData::Cast(obj).signature_class();
  }
  return Class::null();
}


void Function::set_signature_class(const Class& value) const {
  if (IsSignatureFunction()) {
    set_data(value);
    return;
  }
  if (IsClosureFunction()) {
    const Object& obj = Object::Handle(raw_ptr()->data_);
    ASSERT(!obj.IsNull());
    ClosureData::Cast(obj).set_signature_class(value);
    return;
  }
  UNREACHABLE();
}


bool Function::IsRedirectingFactory() const {
  if (!IsFactory() || (raw_ptr()->data_ == Object::null())) {
    return false;
  }
  ASSERT(!IsClosureFunction());  // A factory cannot also be a closure.
  return true;
}


RawType* Function::RedirectionType() const {
  ASSERT(IsRedirectingFactory());
  const Object& obj = Object::Handle(raw_ptr()->data_);
  ASSERT(!obj.IsNull());
  return RedirectionData::Cast(obj).type();
}


const char* Function::KindToCString(RawFunction::Kind kind) {
  switch (kind) {
    case RawFunction::kRegularFunction:
      return "RegularFunction";
      break;
    case RawFunction::kClosureFunction:
      return "ClosureFunction";
      break;
    case RawFunction::kSignatureFunction:
      return "SignatureFunction";
      break;
    case RawFunction::kGetterFunction:
      return "GetterFunction";
      break;
    case RawFunction::kSetterFunction:
      return "SetterFunction";
      break;
    case RawFunction::kConstructor:
      return "Constructor";
      break;
    case RawFunction::kImplicitGetter:
      return "ImplicitGetter";
      break;
    case RawFunction::kImplicitSetter:
      return "ImplicitSetter";
      break;
    case RawFunction::kImplicitStaticFinalGetter:
      return "ImplicitStaticFinalGetter";
      break;
    case RawFunction::kMethodExtractor:
      return "MethodExtractor";
      break;
    case RawFunction::kNoSuchMethodDispatcher:
      return "NoSuchMethodDispatcher";
      break;
    case RawFunction::kInvokeFieldDispatcher:
      return "InvokeFieldDispatcher";
      break;
    case RawFunction::kIrregexpFunction:
      return "IrregexpFunction";
      break;
    default:
      UNREACHABLE();
      return NULL;
  }
}


void Function::SetRedirectionType(const Type& type) const {
  ASSERT(IsFactory());
  Object& obj = Object::Handle(raw_ptr()->data_);
  if (obj.IsNull()) {
    obj = RedirectionData::New();
    set_data(obj);
  }
  RedirectionData::Cast(obj).set_type(type);
}


RawString* Function::RedirectionIdentifier() const {
  ASSERT(IsRedirectingFactory());
  const Object& obj = Object::Handle(raw_ptr()->data_);
  ASSERT(!obj.IsNull());
  return RedirectionData::Cast(obj).identifier();
}


void Function::SetRedirectionIdentifier(const String& identifier) const {
  ASSERT(IsFactory());
  Object& obj = Object::Handle(raw_ptr()->data_);
  if (obj.IsNull()) {
    obj = RedirectionData::New();
    set_data(obj);
  }
  RedirectionData::Cast(obj).set_identifier(identifier);
}


RawFunction* Function::RedirectionTarget() const {
  ASSERT(IsRedirectingFactory());
  const Object& obj = Object::Handle(raw_ptr()->data_);
  ASSERT(!obj.IsNull());
  return RedirectionData::Cast(obj).target();
}


void Function::SetRedirectionTarget(const Function& target) const {
  ASSERT(IsFactory());
  Object& obj = Object::Handle(raw_ptr()->data_);
  if (obj.IsNull()) {
    obj = RedirectionData::New();
    set_data(obj);
  }
  RedirectionData::Cast(obj).set_target(target);
}


void Function::set_data(const Object& value) const {
  StorePointer(&raw_ptr()->data_, value.raw());
}


bool Function::IsInFactoryScope() const {
  if (!IsLocalFunction()) {
    return IsFactory();
  }
  Function& outer_function = Function::Handle(parent_function());
  while (outer_function.IsLocalFunction()) {
    outer_function = outer_function.parent_function();
  }
  return outer_function.IsFactory();
}


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


void Function::set_owner(const Object& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->owner_, value.raw());
}


RawJSRegExp* Function::regexp() const {
  ASSERT(kind() == RawFunction::kIrregexpFunction);
  const Array& pair = Array::Cast(Object::Handle(raw_ptr()->data_));
  return JSRegExp::RawCast(pair.At(0));
}


intptr_t Function::string_specialization_cid() const {
  ASSERT(kind() == RawFunction::kIrregexpFunction);
  const Array& pair = Array::Cast(Object::Handle(raw_ptr()->data_));
  return Smi::Value(Smi::RawCast(pair.At(1)));
}


void Function::SetRegExpData(const JSRegExp& regexp,
                             intptr_t string_specialization_cid) const {
  ASSERT(kind() == RawFunction::kIrregexpFunction);
  ASSERT(RawObject::IsStringClassId(string_specialization_cid));
  ASSERT(raw_ptr()->data_ == Object::null());
  const Array& pair = Array::Handle(Array::New(2, Heap::kOld));
  pair.SetAt(0, regexp);
  pair.SetAt(1, Smi::Handle(Smi::New(string_specialization_cid)));
  set_data(pair);
}


void Function::set_result_type(const AbstractType& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->result_type_, value.raw());
}


RawAbstractType* Function::ParameterTypeAt(intptr_t index) const {
  const Array& parameter_types = Array::Handle(raw_ptr()->parameter_types_);
  return AbstractType::RawCast(parameter_types.At(index));
}


void Function::SetParameterTypeAt(
    intptr_t index, const AbstractType& value) const {
  ASSERT(!value.IsNull());
  // Method extractor parameters are shared and are in the VM heap.
  ASSERT(kind() != RawFunction::kMethodExtractor);
  const Array& parameter_types = Array::Handle(raw_ptr()->parameter_types_);
  parameter_types.SetAt(index, value);
}


void Function::set_parameter_types(const Array& value) const {
  StorePointer(&raw_ptr()->parameter_types_, value.raw());
}


RawString* Function::ParameterNameAt(intptr_t index) const {
  const Array& parameter_names = Array::Handle(raw_ptr()->parameter_names_);
  return String::RawCast(parameter_names.At(index));
}


void Function::SetParameterNameAt(intptr_t index, const String& value) const {
  ASSERT(!value.IsNull() && value.IsSymbol());
  const Array& parameter_names = Array::Handle(raw_ptr()->parameter_names_);
  parameter_names.SetAt(index, value);
}


void Function::set_parameter_names(const Array& value) const {
  StorePointer(&raw_ptr()->parameter_names_, value.raw());
}


void Function::set_kind(RawFunction::Kind value) const {
  set_kind_tag(KindBits::update(value, raw_ptr()->kind_tag_));
}


void Function::set_modifier(RawFunction::AsyncModifier value) const {
  set_kind_tag(ModifierBits::update(value, raw_ptr()->kind_tag_));
}


void Function::set_recognized_kind(MethodRecognizer::Kind value) const {
  // Prevent multiple settings of kind.
  ASSERT((value == MethodRecognizer::kUnknown) || !IsRecognized());
  set_kind_tag(RecognizedBits::update(value, raw_ptr()->kind_tag_));
}


void Function::set_token_pos(intptr_t value) const {
  ASSERT(value >= 0);
  StoreNonPointer(&raw_ptr()->token_pos_, value);
}


void Function::set_kind_tag(intptr_t value) const {
  StoreNonPointer(&raw_ptr()->kind_tag_, static_cast<uint32_t>(value));
}


void Function::set_num_fixed_parameters(intptr_t value) const {
  ASSERT(value >= 0);
  ASSERT(Utils::IsInt(16, value));
  StoreNonPointer(&raw_ptr()->num_fixed_parameters_,
                  static_cast<int16_t>(value));
}


void Function::set_num_optional_parameters(intptr_t value) const {
  // A positive value indicates positional params, a negative one named params.
  ASSERT(Utils::IsInt(16, value));
  StoreNonPointer(&raw_ptr()->num_optional_parameters_,
                  static_cast<int16_t>(value));
}


void Function::SetNumOptionalParameters(intptr_t num_optional_parameters,
                                        bool are_optional_positional) const {
  ASSERT(num_optional_parameters >= 0);
  set_num_optional_parameters(are_optional_positional ?
                              num_optional_parameters :
                              -num_optional_parameters);
}


bool Function::IsOptimizable() const {
  if (FLAG_coverage_dir != NULL) {
    // Do not optimize if collecting coverage data.
    return false;
  }
  if (is_native()) {
    // Native methods don't need to be optimized.
    return false;
  }
  if (is_optimizable() && (script() != Script::null()) &&
      ((end_token_pos() - token_pos()) < FLAG_huge_method_cutoff_in_tokens)) {
    // Additional check needed for implicit getters.
    return (unoptimized_code() == Object::null()) ||
           (Code::Handle(unoptimized_code()).Size() <
            FLAG_huge_method_cutoff_in_code_size);
  }
  return false;
}


bool Function::IsNativeAutoSetupScope() const {
  return is_native() ? is_optimizable() : false;
}


void Function::SetIsOptimizable(bool value) const {
  ASSERT(!is_native());
  set_is_optimizable(value);
  if (!value) {
    set_is_inlinable(false);
  }
}


void Function::SetIsNativeAutoSetupScope(bool value) const {
  ASSERT(is_native());
  set_is_optimizable(value);
}


bool Function::CanBeInlined() const {
  return is_inlinable() &&
         !is_generated_body() &&
         HasCode() &&
         !Isolate::Current()->debugger()->HasBreakpoint(*this);
}


intptr_t Function::NumParameters() const {
  return num_fixed_parameters() + NumOptionalParameters();
}


intptr_t Function::NumImplicitParameters() const {
  if (kind() == RawFunction::kConstructor) {
    if (is_static()) {
      ASSERT(IsFactory());
      return 1;  // Type arguments.
    } else {
      ASSERT(IsGenerativeConstructor());
      return 2;  // Instance, phase.
    }
  }
  if ((kind() == RawFunction::kClosureFunction) ||
      (kind() == RawFunction::kSignatureFunction)) {
    return 1;  // Closure object.
  }
  if (!is_static()) {
    // Closure functions defined inside instance (i.e. non-static) functions are
    // marked as non-static, but they do not have a receiver.
    // Closures are handled above.
    ASSERT((kind() != RawFunction::kClosureFunction) &&
           (kind() != RawFunction::kSignatureFunction));
    return 1;  // Receiver.
  }
  return 0;  // No implicit parameters.
}


bool Function::AreValidArgumentCounts(intptr_t num_arguments,
                                      intptr_t num_named_arguments,
                                      String* error_message) const {
  if (num_named_arguments > NumOptionalNamedParameters()) {
    if (error_message != NULL) {
      const intptr_t kMessageBufferSize = 64;
      char message_buffer[kMessageBufferSize];
      OS::SNPrint(message_buffer,
                  kMessageBufferSize,
                  "%" Pd " named passed, at most %" Pd " expected",
                  num_named_arguments,
                  NumOptionalNamedParameters());
      // Allocate in old space because it can be invoked in background
      // optimizing compilation.
      *error_message = String::New(message_buffer, Heap::kOld);
    }
    return false;  // Too many named arguments.
  }
  const intptr_t num_pos_args = num_arguments - num_named_arguments;
  const intptr_t num_opt_pos_params = NumOptionalPositionalParameters();
  const intptr_t num_pos_params = num_fixed_parameters() + num_opt_pos_params;
  if (num_pos_args > num_pos_params) {
    if (error_message != NULL) {
      const intptr_t kMessageBufferSize = 64;
      char message_buffer[kMessageBufferSize];
      // Hide implicit parameters to the user.
      const intptr_t num_hidden_params = NumImplicitParameters();
      OS::SNPrint(message_buffer,
                  kMessageBufferSize,
                  "%" Pd "%s passed, %s%" Pd " expected",
                  num_pos_args - num_hidden_params,
                  num_opt_pos_params > 0 ? " positional" : "",
                  num_opt_pos_params > 0 ? "at most " : "",
                  num_pos_params - num_hidden_params);
      // Allocate in old space because it can be invoked in background
      // optimizing compilation.
      *error_message = String::New(message_buffer, Heap::kOld);
    }
    return false;  // Too many fixed and/or positional arguments.
  }
  if (num_pos_args < num_fixed_parameters()) {
    if (error_message != NULL) {
      const intptr_t kMessageBufferSize = 64;
      char message_buffer[kMessageBufferSize];
      // Hide implicit parameters to the user.
      const intptr_t num_hidden_params = NumImplicitParameters();
      OS::SNPrint(message_buffer,
                  kMessageBufferSize,
                  "%" Pd "%s passed, %s%" Pd " expected",
                  num_pos_args - num_hidden_params,
                  num_opt_pos_params > 0 ? " positional" : "",
                  num_opt_pos_params > 0 ? "at least " : "",
                  num_fixed_parameters() - num_hidden_params);
      // Allocate in old space because it can be invoked in background
      // optimizing compilation.
      *error_message = String::New(message_buffer, Heap::kOld);
    }
    return false;  // Too few fixed and/or positional arguments.
  }
  return true;
}


bool Function::AreValidArguments(intptr_t num_arguments,
                                 const Array& argument_names,
                                 String* error_message) const {
  const intptr_t num_named_arguments =
      argument_names.IsNull() ? 0 : argument_names.Length();
  if (!AreValidArgumentCounts(num_arguments,
                              num_named_arguments,
                              error_message)) {
    return false;
  }
  // Verify that all argument names are valid parameter names.
  Zone* zone = Thread::Current()->zone();
  String& argument_name = String::Handle(zone);
  String& parameter_name = String::Handle(zone);
  for (intptr_t i = 0; i < num_named_arguments; i++) {
    argument_name ^= argument_names.At(i);
    ASSERT(argument_name.IsSymbol());
    bool found = false;
    const intptr_t num_positional_args = num_arguments - num_named_arguments;
    const intptr_t num_parameters = NumParameters();
    for (intptr_t j = num_positional_args;
         !found && (j < num_parameters);
         j++) {
      parameter_name = ParameterNameAt(j);
      ASSERT(argument_name.IsSymbol());
      if (argument_name.Equals(parameter_name)) {
        found = true;
      }
    }
    if (!found) {
      if (error_message != NULL) {
        const intptr_t kMessageBufferSize = 64;
        char message_buffer[kMessageBufferSize];
        OS::SNPrint(message_buffer,
                    kMessageBufferSize,
                    "no optional formal parameter named '%s'",
                    argument_name.ToCString());
        // Allocate in old space because it can be invoked in background
        // optimizing compilation.
        *error_message = String::New(message_buffer, Heap::kOld);
      }
      return false;
    }
  }
  return true;
}


bool Function::AreValidArguments(const ArgumentsDescriptor& args_desc,
                                 String* error_message) const {
  const intptr_t num_arguments = args_desc.Count();
  const intptr_t num_named_arguments = args_desc.NamedCount();

  if (!AreValidArgumentCounts(num_arguments,
                              num_named_arguments,
                              error_message)) {
    return false;
  }
  // Verify that all argument names are valid parameter names.
  Zone* zone = Thread::Current()->zone();
  String& argument_name = String::Handle(zone);
  String& parameter_name = String::Handle(zone);
  for (intptr_t i = 0; i < num_named_arguments; i++) {
    argument_name ^= args_desc.NameAt(i);
    ASSERT(argument_name.IsSymbol());
    bool found = false;
    const intptr_t num_positional_args = num_arguments - num_named_arguments;
    const int num_parameters = NumParameters();
    for (intptr_t j = num_positional_args;
         !found && (j < num_parameters);
         j++) {
      parameter_name = ParameterNameAt(j);
      ASSERT(argument_name.IsSymbol());
      if (argument_name.Equals(parameter_name)) {
        found = true;
      }
    }
    if (!found) {
      if (error_message != NULL) {
        const intptr_t kMessageBufferSize = 64;
        char message_buffer[kMessageBufferSize];
        OS::SNPrint(message_buffer,
                    kMessageBufferSize,
                    "no optional formal parameter named '%s'",
                    argument_name.ToCString());
        // Allocate in old space because it can be invoked in background
        // optimizing compilation.
        *error_message = String::New(message_buffer, Heap::kOld);
      }
      return false;
    }
  }
  return true;
}


// Helper allocating a C string buffer in the zone, printing the fully qualified
// name of a function in it, and replacing ':' by '_' to make sure the
// constructed name is a valid C++ identifier for debugging purpose.
// Set 'chars' to allocated buffer and return number of written characters.

enum QualifiedFunctionLibKind {
  kQualifiedFunctionLibKindLibUrl,
  kQualifiedFunctionLibKindLibName
};


static intptr_t ConstructFunctionFullyQualifiedCString(
    const Function& function,
    char** chars,
    intptr_t reserve_len,
    bool with_lib,
    QualifiedFunctionLibKind lib_kind) {
  const char* name = String::Handle(function.name()).ToCString();
  const char* function_format = (reserve_len == 0) ? "%s" : "%s_";
  reserve_len += OS::SNPrint(NULL, 0, function_format, name);
  const Function& parent = Function::Handle(function.parent_function());
  intptr_t written = 0;
  if (parent.IsNull()) {
    const Class& function_class = Class::Handle(function.Owner());
    ASSERT(!function_class.IsNull());
    const char* class_name = String::Handle(function_class.Name()).ToCString();
    ASSERT(class_name != NULL);
    const Library& library = Library::Handle(function_class.library());
    ASSERT(!library.IsNull());
    const char* library_name = NULL;
    const char* lib_class_format = NULL;
    if (with_lib) {
      switch (lib_kind) {
        case kQualifiedFunctionLibKindLibUrl:
          library_name = String::Handle(library.url()).ToCString();
          break;
        case kQualifiedFunctionLibKindLibName:
          library_name = String::Handle(library.name()).ToCString();
          break;
        default:
          UNREACHABLE();
      }
      ASSERT(library_name != NULL);
      lib_class_format = (library_name[0] == '\0') ? "%s%s_" : "%s_%s_";
    } else {
      library_name = "";
      lib_class_format = "%s%s.";
    }
    reserve_len +=
        OS::SNPrint(NULL, 0, lib_class_format, library_name, class_name);
    ASSERT(chars != NULL);
    *chars = Thread::Current()->zone()->Alloc<char>(reserve_len + 1);
    written = OS::SNPrint(
        *chars, reserve_len + 1, lib_class_format, library_name, class_name);
  } else {
    written = ConstructFunctionFullyQualifiedCString(parent,
                                                     chars,
                                                     reserve_len,
                                                     with_lib,
                                                     lib_kind);
  }
  ASSERT(*chars != NULL);
  char* next = *chars + written;
  written += OS::SNPrint(next, reserve_len + 1, function_format, name);
  // Replace ":" with "_".
  while (true) {
    next = strchr(next, ':');
    if (next == NULL) break;
    *next = '_';
  }
  return written;
}


const char* Function::ToFullyQualifiedCString() const {
  char* chars = NULL;
  ConstructFunctionFullyQualifiedCString(*this, &chars, 0, true,
                                         kQualifiedFunctionLibKindLibUrl);
  return chars;
}


const char* Function::ToLibNamePrefixedQualifiedCString() const {
  char* chars = NULL;
  ConstructFunctionFullyQualifiedCString(*this, &chars, 0, true,
                                         kQualifiedFunctionLibKindLibName);
  return chars;
}


const char* Function::ToQualifiedCString() const {
  char* chars = NULL;
  ConstructFunctionFullyQualifiedCString(*this, &chars, 0, false,
                                         kQualifiedFunctionLibKindLibUrl);
  return chars;
}


bool Function::HasCompatibleParametersWith(const Function& other,
                                           Error* bound_error) const {
  ASSERT(Isolate::Current()->flags().error_on_bad_override());
  ASSERT((bound_error != NULL) && bound_error->IsNull());
  // Check that this function's signature type is a subtype of the other
  // function's signature type.
  if (!TypeTest(kIsSubtypeOf, Object::null_type_arguments(),
                other, Object::null_type_arguments(), bound_error,
                Heap::kOld)) {
    // For more informative error reporting, use the location of the other
    // function here, since the caller will use the location of this function.
    *bound_error = LanguageError::NewFormatted(
        *bound_error,  // A bound error if non null.
        Script::Handle(other.script()),
        other.token_pos(),
        Report::kError,
        Heap::kNew,
        "signature type '%s' of function '%s' is not a subtype of signature "
        "type '%s' of function '%s'",
        String::Handle(UserVisibleSignature()).ToCString(),
        String::Handle(UserVisibleName()).ToCString(),
        String::Handle(other.UserVisibleSignature()).ToCString(),
        String::Handle(other.UserVisibleName()).ToCString());
    return false;
  }
  // We should also check that if the other function explicitly specifies a
  // default value for a formal parameter, this function does not specify a
  // different default value for the same parameter. However, this check is not
  // possible in the current implementation, because the default parameter
  // values are not stored in the Function object, but discarded after a
  // function is compiled.
  return true;
}


// If test_kind == kIsSubtypeOf, checks if the type of the specified parameter
// of this function is a subtype or a supertype of the type of the specified
// parameter of the other function.
// If test_kind == kIsMoreSpecificThan, checks if the type of the specified
// parameter of this function is more specific than the type of the specified
// parameter of the other function.
// Note that we do not apply contravariance of parameter types, but covariance
// of both parameter types and result type.
bool Function::TestParameterType(
    TypeTestKind test_kind,
    intptr_t parameter_position,
    intptr_t other_parameter_position,
    const TypeArguments& type_arguments,
    const Function& other,
    const TypeArguments& other_type_arguments,
    Error* bound_error,
    Heap::Space space) const {
  AbstractType& other_param_type =
      AbstractType::Handle(other.ParameterTypeAt(other_parameter_position));
  if (!other_param_type.IsInstantiated()) {
    other_param_type = other_param_type.InstantiateFrom(other_type_arguments,
                                                        bound_error,
                                                        NULL,  // trail
                                                        space);
    ASSERT((bound_error == NULL) || bound_error->IsNull());
  }
  if (other_param_type.IsDynamicType()) {
    return true;
  }
  AbstractType& param_type =
      AbstractType::Handle(ParameterTypeAt(parameter_position));
  if (!param_type.IsInstantiated()) {
    param_type = param_type.InstantiateFrom(
        type_arguments, bound_error, NULL /*trail*/, space);
    ASSERT((bound_error == NULL) || bound_error->IsNull());
  }
  if (param_type.IsDynamicType()) {
    return test_kind == kIsSubtypeOf;
  }
  if (test_kind == kIsSubtypeOf) {
    if (!param_type.IsSubtypeOf(other_param_type, bound_error, space) &&
        !other_param_type.IsSubtypeOf(param_type, bound_error, space)) {
      return false;
    }
  } else {
    ASSERT(test_kind == kIsMoreSpecificThan);
    if (!param_type.IsMoreSpecificThan(other_param_type, bound_error, space)) {
      return false;
    }
  }
  return true;
}


bool Function::TypeTest(TypeTestKind test_kind,
                        const TypeArguments& type_arguments,
                        const Function& other,
                        const TypeArguments& other_type_arguments,
                        Error* bound_error,
                        Heap::Space space) const {
  const intptr_t num_fixed_params = num_fixed_parameters();
  const intptr_t num_opt_pos_params = NumOptionalPositionalParameters();
  const intptr_t num_opt_named_params = NumOptionalNamedParameters();
  const intptr_t other_num_fixed_params = other.num_fixed_parameters();
  const intptr_t other_num_opt_pos_params =
      other.NumOptionalPositionalParameters();
  const intptr_t other_num_opt_named_params =
      other.NumOptionalNamedParameters();
  // This function requires the same arguments or less and accepts the same
  // arguments or more.
  // A generative constructor may be compared to a redirecting factory and be
  // compatible although it has an additional phase parameter.
  // More generally, we can ignore implicit parameters.
  const intptr_t num_ignored_params = NumImplicitParameters();
  const intptr_t other_num_ignored_params = other.NumImplicitParameters();
  if (((num_fixed_params - num_ignored_params) >
       (other_num_fixed_params - other_num_ignored_params)) ||
      ((num_fixed_params - num_ignored_params + num_opt_pos_params) <
       (other_num_fixed_params - other_num_ignored_params +
        other_num_opt_pos_params)) ||
      (num_opt_named_params < other_num_opt_named_params)) {
    return false;
  }
  // Check the result type.
  AbstractType& other_res_type = AbstractType::Handle(other.result_type());
  if (!other_res_type.IsInstantiated()) {
    other_res_type = other_res_type.InstantiateFrom(other_type_arguments,
                                                    bound_error);
    ASSERT((bound_error == NULL) || bound_error->IsNull());
  }
  if (!other_res_type.IsDynamicType() && !other_res_type.IsVoidType()) {
    AbstractType& res_type = AbstractType::Handle(result_type());
    if (!res_type.IsInstantiated()) {
      res_type = res_type.InstantiateFrom(type_arguments, bound_error);
      ASSERT((bound_error == NULL) || bound_error->IsNull());
    }
    if (res_type.IsVoidType()) {
      return false;
    }
    if (test_kind == kIsSubtypeOf) {
      if (!res_type.IsSubtypeOf(other_res_type, bound_error) &&
          !other_res_type.IsSubtypeOf(res_type, bound_error)) {
        return false;
      }
    } else {
      ASSERT(test_kind == kIsMoreSpecificThan);
      if (!res_type.IsMoreSpecificThan(other_res_type, bound_error)) {
        return false;
      }
    }
  }
  // Check the types of fixed and optional positional parameters.
  for (intptr_t i = 0; i < (other_num_fixed_params - other_num_ignored_params +
                            other_num_opt_pos_params); i++) {
    if (!TestParameterType(test_kind,
                           i + num_ignored_params, i + other_num_ignored_params,
                           type_arguments, other, other_type_arguments,
                           bound_error,
                           space)) {
      return false;
    }
  }
  // Check the names and types of optional named parameters.
  if (other_num_opt_named_params == 0) {
    return true;
  }
  // Check that for each optional named parameter of type T of the other
  // function type, there exists an optional named parameter of this function
  // type with an identical name and with a type S that is a either a subtype
  // or supertype of T (if test_kind == kIsSubtypeOf) or that is more specific
  // than T (if test_kind == kIsMoreSpecificThan).
  // Note that SetParameterNameAt() guarantees that names are symbols, so we
  // can compare their raw pointers.
  const int num_params = num_fixed_params + num_opt_named_params;
  const int other_num_params =
      other_num_fixed_params + other_num_opt_named_params;
  bool found_param_name;
  String& other_param_name = String::Handle();
  for (intptr_t i = other_num_fixed_params; i < other_num_params; i++) {
    other_param_name = other.ParameterNameAt(i);
    ASSERT(other_param_name.IsSymbol());
    found_param_name = false;
    for (intptr_t j = num_fixed_params; j < num_params; j++) {
      ASSERT(String::Handle(ParameterNameAt(j)).IsSymbol());
      if (ParameterNameAt(j) == other_param_name.raw()) {
        found_param_name = true;
        if (!TestParameterType(test_kind,
                               j, i,
                               type_arguments, other, other_type_arguments,
                               bound_error,
                               space)) {
          return false;
        }
        break;
      }
    }
    if (!found_param_name) {
      return false;
    }
  }
  return true;
}


// The compiler generates an implicit constructor if a class definition
// does not contain an explicit constructor or factory. The implicit
// constructor has the same token position as the owner class.
bool Function::IsImplicitConstructor() const {
  return IsGenerativeConstructor() && (token_pos() == end_token_pos());
}


bool Function::IsImplicitClosureFunction() const {
  if (!IsClosureFunction()) {
    return false;
  }
  const Function& parent = Function::Handle(parent_function());
  return (parent.implicit_closure_function() == raw());
}


bool Function::IsImplicitStaticClosureFunction(RawFunction* func) {
  NoSafepointScope no_safepoint;
  uint32_t kind_tag = func->ptr()->kind_tag_;
  if (KindBits::decode(kind_tag) != RawFunction::kClosureFunction) {
    return false;
  }
  if (!StaticBit::decode(kind_tag)) {
    return false;
  }
  RawClosureData* data = reinterpret_cast<RawClosureData*>(func->ptr()->data_);
  RawFunction* parent_function = data->ptr()->parent_function_;
  return (parent_function->ptr()->data_ == reinterpret_cast<RawObject*>(func));
}


bool Function::IsConstructorClosureFunction() const {
  return IsClosureFunction() &&
      String::Handle(name()).StartsWith(Symbols::ConstructorClosurePrefix());
}


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


RawFunction* Function::New(const String& name,
                           RawFunction::Kind kind,
                           bool is_static,
                           bool is_const,
                           bool is_abstract,
                           bool is_external,
                           bool is_native,
                           const Object& owner,
                           intptr_t token_pos) {
  ASSERT(!owner.IsNull());
  const Function& result = Function::Handle(Function::New());
  result.set_parameter_types(Object::empty_array());
  result.set_parameter_names(Object::empty_array());
  result.set_name(name);
  result.set_kind(kind);
  result.set_recognized_kind(MethodRecognizer::kUnknown);
  result.set_modifier(RawFunction::kNoModifier);
  result.set_is_static(is_static);
  result.set_is_const(is_const);
  result.set_is_abstract(is_abstract);
  result.set_is_external(is_external);
  result.set_is_native(is_native);
  result.set_is_reflectable(true);  // Will be computed later.
  result.set_is_visible(true);  // Will be computed later.
  result.set_is_debuggable(true);  // Will be computed later.
  result.set_is_intrinsic(false);
  result.set_is_redirecting(false);
  result.set_is_generated_body(false);
  result.set_always_inline(false);
  result.set_is_polymorphic_target(false);
  result.set_owner(owner);
  result.set_token_pos(token_pos);
  result.set_end_token_pos(token_pos);
  result.set_num_fixed_parameters(0);
  result.set_num_optional_parameters(0);
  result.set_usage_counter(0);
  result.set_deoptimization_counter(0);
  result.set_optimized_instruction_count(0);
  result.set_optimized_call_site_count(0);
  result.set_is_optimizable(is_native ? false : true);
  result.set_is_inlinable(true);
  result.set_allows_hoisting_check_class(true);
  result.set_allows_bounds_check_generalization(true);
  result.SetInstructions(Code::Handle(StubCode::LazyCompile_entry()->code()));
  if (kind == RawFunction::kClosureFunction) {
    const ClosureData& data = ClosureData::Handle(ClosureData::New());
    result.set_data(data);
  }
  return result.raw();
}


RawFunction* Function::Clone(const Class& new_owner) const {
  ASSERT(!IsGenerativeConstructor());
  Function& clone = Function::Handle();
  clone ^= Object::Clone(*this, Heap::kOld);
  const Class& origin = Class::Handle(this->origin());
  const PatchClass& clone_owner =
      PatchClass::Handle(PatchClass::New(new_owner, origin));
  clone.set_owner(clone_owner);
  clone.ClearICDataArray();
  clone.ClearCode();
  clone.set_usage_counter(0);
  clone.set_deoptimization_counter(0);
  clone.set_optimized_instruction_count(0);
  clone.set_optimized_call_site_count(0);
  if (new_owner.NumTypeParameters() > 0) {
    // Adjust uninstantiated types to refer to type parameters of the new owner.
    AbstractType& type = AbstractType::Handle(clone.result_type());
    type ^= type.CloneUninstantiated(new_owner);
    clone.set_result_type(type);
    const intptr_t num_params = clone.NumParameters();
    Array& array = Array::Handle(clone.parameter_types());
    array ^= Object::Clone(array, Heap::kOld);
    clone.set_parameter_types(array);
    for (intptr_t i = 0; i < num_params; i++) {
      type = clone.ParameterTypeAt(i);
      type ^= type.CloneUninstantiated(new_owner);
      clone.SetParameterTypeAt(i, type);
    }
  }
  return clone.raw();
}


RawFunction* Function::NewClosureFunction(const String& name,
                                          const Function& parent,
                                          intptr_t token_pos) {
  ASSERT(!parent.IsNull());
  // Use the owner defining the parent function and not the class containing it.
  const Object& parent_owner = Object::Handle(parent.raw_ptr()->owner_);
  ASSERT(!parent_owner.IsNull());
  const Function& result = Function::Handle(
      Function::New(name,
                    RawFunction::kClosureFunction,
                    /* is_static = */ parent.is_static(),
                    /* is_const = */ false,
                    /* is_abstract = */ false,
                    /* is_external = */ false,
                    parent.is_native(),
                    parent_owner,
                    token_pos));
  result.set_parent_function(parent);
  return result.raw();
}


RawFunction* Function::NewEvalFunction(const Class& owner,
                                       const Script& script,
                                       bool is_static) {
  const Function& result = Function::Handle(
      Function::New(String::Handle(Symbols::New(":Eval")),
                    RawFunction::kRegularFunction,
                    is_static,
                    /* is_const = */ false,
                    /* is_abstract = */ false,
                    /* is_external = */ false,
                    /* is_native = */ false,
                    owner,
                    0));
  ASSERT(!script.IsNull());
  result.set_is_debuggable(false);
  result.set_is_visible(true);
  result.set_eval_script(script);
  return result.raw();
}

RawFunction* Function::ImplicitClosureFunction() const {
  // Return the existing implicit closure function if any.
  if (implicit_closure_function() != Function::null()) {
    return implicit_closure_function();
  }
  ASSERT(!IsSignatureFunction() && !IsClosureFunction());
  // Create closure function.
  const String& closure_name = String::Handle(name());
  const Function& closure_function = Function::Handle(
      NewClosureFunction(closure_name, *this, token_pos()));

  // Set closure function's context scope.
  if (is_static()) {
    closure_function.set_context_scope(Object::empty_context_scope());
  } else {
    const ContextScope& context_scope =
        ContextScope::Handle(LocalScope::CreateImplicitClosureScope(*this));
    closure_function.set_context_scope(context_scope);
  }

  // Set closure function's result type to this result type.
  closure_function.set_result_type(AbstractType::Handle(result_type()));

  // Set closure function's end token to this end token.
  closure_function.set_end_token_pos(end_token_pos());

  // The closurized method stub just calls into the original method and should
  // therefore be skipped by the debugger and in stack traces.
  closure_function.set_is_debuggable(false);
  closure_function.set_is_visible(false);

  // Set closure function's formal parameters to this formal parameters,
  // removing the receiver if this is an instance method and adding the closure
  // object as first parameter.
  const int kClosure = 1;
  const int has_receiver = is_static() ? 0 : 1;
  const int num_fixed_params = kClosure - has_receiver + num_fixed_parameters();
  const int num_opt_params = NumOptionalParameters();
  const bool has_opt_pos_params = HasOptionalPositionalParameters();
  const int num_params = num_fixed_params + num_opt_params;
  closure_function.set_num_fixed_parameters(num_fixed_params);
  closure_function.SetNumOptionalParameters(num_opt_params, has_opt_pos_params);
  closure_function.set_parameter_types(Array::Handle(Array::New(num_params,
                                                                Heap::kOld)));
  closure_function.set_parameter_names(Array::Handle(Array::New(num_params,
                                                                Heap::kOld)));
  AbstractType& param_type = AbstractType::Handle();
  String& param_name = String::Handle();
  // Add implicit closure object parameter.
  param_type = Type::DynamicType();
  closure_function.SetParameterTypeAt(0, param_type);
  closure_function.SetParameterNameAt(0, Symbols::ClosureParameter());
  for (int i = kClosure; i < num_params; i++) {
    param_type = ParameterTypeAt(has_receiver - kClosure + i);
    closure_function.SetParameterTypeAt(i, param_type);
    param_name = ParameterNameAt(has_receiver - kClosure + i);
    closure_function.SetParameterNameAt(i, param_name);
  }

  // Lookup or create a new signature class for the closure function in the
  // library of the owner class.
  const Class& owner_class = Class::Handle(Owner());
  ASSERT(!owner_class.IsNull() && (Owner() == closure_function.Owner()));
  const Library& library = Library::Handle(owner_class.library());
  ASSERT(!library.IsNull());
  const String& signature = String::Handle(closure_function.Signature());
  Class& signature_class = Class::ZoneHandle(
      library.LookupLocalClass(signature));
  if (signature_class.IsNull()) {
    const Script& script = Script::Handle(this->script());
    signature_class = Class::NewSignatureClass(signature,
                                               closure_function,
                                               script,
                                               closure_function.token_pos());
    library.AddClass(signature_class);
  } else {
    closure_function.set_signature_class(signature_class);
  }
  // Finalize types in signature class here, so that the
  // signature type is not computed twice.
  ClassFinalizer::FinalizeTypesInClass(signature_class);
  const Type& signature_type = Type::Handle(signature_class.SignatureType());
  if (!signature_type.IsFinalized()) {
    ClassFinalizer::FinalizeType(
        signature_class, signature_type, ClassFinalizer::kCanonicalize);
  }
  ASSERT(closure_function.signature_class() == signature_class.raw());
  set_implicit_closure_function(closure_function);
  ASSERT(closure_function.IsImplicitClosureFunction());
  return closure_function.raw();
}


RawString* Function::UserVisibleFormalParameters() const {
  // Typically 3, 5,.. elements in 'pieces', e.g.:
  // '_LoadRequest', CommaSpace, '_LoadError'.
  GrowableHandlePtrArray<const String> pieces(Thread::Current()->zone(), 5);
  const TypeArguments& instantiator = TypeArguments::Handle();
  BuildSignatureParameters(false, kUserVisibleName, instantiator, &pieces);
  return Symbols::FromConcatAll(pieces);
}


void Function::BuildSignatureParameters(
    bool instantiate,
    NameVisibility name_visibility,
    const TypeArguments& instantiator,
    GrowableHandlePtrArray<const String>* pieces) const {
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();

  AbstractType& param_type = AbstractType::Handle(zone);
  const intptr_t num_params = NumParameters();
  const intptr_t num_fixed_params = num_fixed_parameters();
  const intptr_t num_opt_pos_params = NumOptionalPositionalParameters();
  const intptr_t num_opt_named_params = NumOptionalNamedParameters();
  const intptr_t num_opt_params = num_opt_pos_params + num_opt_named_params;
  ASSERT((num_fixed_params + num_opt_params) == num_params);
  intptr_t i = 0;
  if (name_visibility == kUserVisibleName) {
    // Hide implicit parameters.
    i = NumImplicitParameters();
  }
  String& name = String::Handle(zone);
  while (i < num_fixed_params) {
    param_type = ParameterTypeAt(i);
    ASSERT(!param_type.IsNull());
    if (instantiate && !param_type.IsInstantiated()) {
      param_type = param_type.InstantiateFrom(instantiator, NULL);
    }
    name = param_type.BuildName(name_visibility);
    pieces->Add(name);
    if (i != (num_params - 1)) {
      pieces->Add(Symbols::CommaSpace());
    }
    i++;
  }
  if (num_opt_params > 0) {
    if (num_opt_pos_params > 0) {
      pieces->Add(Symbols::LBracket());
    } else {
      pieces->Add(Symbols::LBrace());
    }
    for (intptr_t i = num_fixed_params; i < num_params; i++) {
      // The parameter name of an optional positional parameter does not need
      // to be part of the signature, since it is not used.
      if (num_opt_named_params > 0) {
        name = ParameterNameAt(i);
        pieces->Add(name);
        pieces->Add(Symbols::ColonSpace());
      }
      param_type = ParameterTypeAt(i);
      if (instantiate && !param_type.IsInstantiated()) {
        param_type = param_type.InstantiateFrom(instantiator, NULL);
      }
      ASSERT(!param_type.IsNull());
      name = param_type.BuildName(name_visibility);
      pieces->Add(name);
      if (i != (num_params - 1)) {
        pieces->Add(Symbols::CommaSpace());
      }
    }
    if (num_opt_pos_params > 0) {
      pieces->Add(Symbols::RBracket());
    } else {
      pieces->Add(Symbols::RBrace());
    }
  }
}


RawInstance* Function::ImplicitStaticClosure() const {
  if (implicit_static_closure() == Instance::null()) {
    Thread* thread = Thread::Current();
    Isolate* isolate = thread->isolate();
    Zone* zone = thread->zone();
    ObjectStore* object_store = isolate->object_store();
    const Context& context =
        Context::Handle(zone, object_store->empty_context());
    Instance& closure =
        Instance::Handle(zone, Closure::New(*this, context, Heap::kOld));
    const char* error_str = NULL;
    closure ^= closure.CheckAndCanonicalize(&error_str);
    ASSERT(!closure.IsNull());
    set_implicit_static_closure(closure);
  }
  return implicit_static_closure();
}


RawInstance* Function::ImplicitInstanceClosure(const Instance& receiver) const {
  ASSERT(IsImplicitClosureFunction());
  const Class& cls = Class::Handle(signature_class());
  const Context& context = Context::Handle(Context::New(1));
  context.SetAt(0, receiver);
  const Instance& result = Instance::Handle(Closure::New(*this, context));
  if (cls.NumTypeArguments() > 0) {
    const TypeArguments& type_arguments =
        TypeArguments::Handle(receiver.GetTypeArguments());
    result.SetTypeArguments(type_arguments);
  }
  return result.raw();
}


RawString* Function::BuildSignature(bool instantiate,
                                    NameVisibility name_visibility,
                                    const TypeArguments& instantiator) const {
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  GrowableHandlePtrArray<const String> pieces(zone, 4);
  String& name = String::Handle(zone);
  if (!instantiate && !is_static() && (name_visibility == kInternalName)) {
    // Prefix the signature with its signature class and type parameters, if any
    // (e.g. "Map<K, V>(K) => bool"). In case of a function type alias, the
    // signature class name is the alias name.
    // The signature of static functions cannot be type parameterized.
    const Class& function_class = Class::Handle(zone, Owner());
    ASSERT(!function_class.IsNull());
    const TypeArguments& type_parameters = TypeArguments::Handle(
        zone, function_class.type_parameters());
    if (!type_parameters.IsNull()) {
      const String& function_class_name =
          String::Handle(zone, function_class.Name());
      pieces.Add(function_class_name);
      const intptr_t num_type_parameters = type_parameters.Length();
      pieces.Add(Symbols::LAngleBracket());
      TypeParameter& type_parameter = TypeParameter::Handle(zone);
      AbstractType& bound = AbstractType::Handle(zone);
      for (intptr_t i = 0; i < num_type_parameters; i++) {
        type_parameter ^= type_parameters.TypeAt(i);
        name = type_parameter.name();
        pieces.Add(name);
        bound = type_parameter.bound();
        if (!bound.IsNull() && !bound.IsObjectType()) {
          pieces.Add(Symbols::SpaceExtendsSpace());
          name = bound.BuildName(name_visibility);
          pieces.Add(name);
        }
        if (i < num_type_parameters - 1) {
          pieces.Add(Symbols::CommaSpace());
        }
      }
      pieces.Add(Symbols::RAngleBracket());
    }
  }
  pieces.Add(Symbols::LParen());
  BuildSignatureParameters(instantiate,
                           name_visibility,
                           instantiator,
                           &pieces);
  pieces.Add(Symbols::RParenArrow());
  AbstractType& res_type = AbstractType::Handle(zone, result_type());
  if (instantiate && !res_type.IsInstantiated()) {
    res_type = res_type.InstantiateFrom(instantiator, NULL);
  }
  name = res_type.BuildName(name_visibility);
  pieces.Add(name);
  return Symbols::FromConcatAll(pieces);
}


bool Function::HasInstantiatedSignature() const {
  AbstractType& type = AbstractType::Handle(result_type());
  if (!type.IsInstantiated()) {
    return false;
  }
  const intptr_t num_parameters = NumParameters();
  for (intptr_t i = 0; i < num_parameters; i++) {
    type = ParameterTypeAt(i);
    if (!type.IsInstantiated()) {
      return false;
    }
  }
  return true;
}


RawClass* Function::Owner() const {
  const Object& obj = Object::Handle(raw_ptr()->owner_);
  if (obj.IsClass()) {
    return Class::Cast(obj).raw();
  }
  ASSERT(obj.IsPatchClass());
  return PatchClass::Cast(obj).patched_class();
}


RawClass* Function::origin() const {
  const Object& obj = Object::Handle(raw_ptr()->owner_);
  if (obj.IsClass()) {
    return Class::Cast(obj).raw();
  }
  ASSERT(obj.IsPatchClass());
  return PatchClass::Cast(obj).source_class();
}


RawScript* Function::script() const {
  if (token_pos() == 0) {
    // Testing for position 0 is an optimization that relies on temporary
    // eval functions having token position 0.
    const Script& script = Script::Handle(eval_script());
    if (!script.IsNull()) {
      return script.raw();
    }
  }
  if (IsClosureFunction()) {
    return Function::Handle(parent_function()).script();
  }
  const Object& obj = Object::Handle(raw_ptr()->owner_);
  if (obj.IsClass()) {
    return Class::Cast(obj).script();
  }
  ASSERT(obj.IsPatchClass());
  return PatchClass::Cast(obj).Script();
}


bool Function::HasOptimizedCode() const {
  return HasCode() && Code::Handle(CurrentCode()).is_optimized();
}


RawString* Function::PrettyName() const {
  const String& str = String::Handle(name());
  return String::IdentifierPrettyName(str);
}


const char* Function::QualifiedUserVisibleNameCString() const {
  const String& str = String::Handle(QualifiedUserVisibleName());
  return str.ToCString();
}


RawString* Function::UserVisibleName() const {
  return PrettyName();
}


RawString* Function::QualifiedPrettyName() const {
  String& tmp = String::Handle();
  const Class& cls = Class::Handle(Owner());

  if (IsClosureFunction()) {
    if (IsLocalFunction() && !IsImplicitClosureFunction()) {
      const Function& parent = Function::Handle(parent_function());
      tmp = parent.QualifiedPrettyName();
    } else {
      return PrettyName();
    }
  } else {
    if (cls.IsTopLevel()) {
      return PrettyName();
    } else {
      tmp = cls.PrettyName();
    }
  }
  tmp = String::Concat(tmp, Symbols::Dot(), Heap::kOld);
  const String& suffix = String::Handle(PrettyName());
  return String::Concat(tmp, suffix, Heap::kOld);
}


RawString* Function::QualifiedUserVisibleName() const {
  String& tmp = String::Handle();
  const Class& cls = Class::Handle(Owner());

  if (IsClosureFunction()) {
    if (IsLocalFunction() && !IsImplicitClosureFunction()) {
      const Function& parent = Function::Handle(parent_function());
      tmp = parent.QualifiedUserVisibleName();
    } else {
      return UserVisibleName();
    }
  } else {
    if (cls.IsTopLevel()) {
      return UserVisibleName();
    } else {
      tmp = cls.UserVisibleName();
    }
  }
  tmp = String::Concat(tmp, Symbols::Dot());
  const String& suffix = String::Handle(UserVisibleName());
  return String::Concat(tmp, suffix);
}


RawString* Function::GetSource() const {
  if (IsImplicitConstructor() || IsSignatureFunction()) {
    // We may need to handle more cases when the restrictions on mixins are
    // relaxed. In particular we might start associating some source with the
    // forwarding constructors when it becomes possible to specify a particular
    // constructor from the mixin to use.
    return String::null();
  }
  const Script& func_script = Script::Handle(script());
  const TokenStream& stream = TokenStream::Handle(func_script.tokens());
  if (!func_script.HasSource()) {
    // When source is not available, avoid printing the whole token stream and
    // doing expensive position calculations.
    return stream.GenerateSource(token_pos(), end_token_pos() + 1);
  }

  const TokenStream::Iterator tkit(stream, end_token_pos());
  intptr_t from_line;
  intptr_t from_col;
  intptr_t to_line;
  intptr_t to_col;
  func_script.GetTokenLocation(token_pos(), &from_line, &from_col);
  func_script.GetTokenLocation(end_token_pos(), &to_line, &to_col);
  intptr_t last_tok_len = String::Handle(tkit.CurrentLiteral()).Length();
  // Handle special cases for end tokens of closures (where we exclude the last
  // token):
  // (1) "foo(() => null, bar);": End token is `,', but we don't print it.
  // (2) "foo(() => null);": End token is ')`, but we don't print it.
  // (3) "var foo = () => null;": End token is `;', but in this case the token
  // semicolon belongs to the assignment so we skip it.
  if ((tkit.CurrentTokenKind() == Token::kCOMMA) ||                   // Case 1.
      (tkit.CurrentTokenKind() == Token::kRPAREN) ||                  // Case 2.
      (tkit.CurrentTokenKind() == Token::kSEMICOLON &&
       String::Handle(name()).Equals("<anonymous closure>"))) {  // Case 3.
    last_tok_len = 0;
  }
  const String& result = String::Handle(func_script.GetSnippet(
      from_line, from_col, to_line, to_col + last_tok_len));
  ASSERT(!result.IsNull());
  return result.raw();
}


// Construct fingerprint from token stream. The token stream contains also
// arguments.
int32_t Function::SourceFingerprint() const {
  uint32_t result = IsImplicitClosureFunction()
      ? String::Handle(Function::Handle(parent_function()).Signature()).Hash()
      : String::Handle(Signature()).Hash();
  TokenStream::Iterator tokens_iterator(TokenStream::Handle(
      Script::Handle(script()).tokens()), token_pos());
  Object& obj = Object::Handle();
  String& literal = String::Handle();
  while (tokens_iterator.CurrentPosition() < end_token_pos()) {
    uint32_t val = 0;
    obj = tokens_iterator.CurrentToken();
    if (obj.IsSmi()) {
      val = Smi::Cast(obj).Value();
    } else {
      literal = tokens_iterator.MakeLiteralToken(obj);
      val = literal.Hash();
    }
    result = 31 * result + val;
    tokens_iterator.Advance();
  }
  result = result & ((static_cast<uint32_t>(1) << 31) - 1);
  ASSERT(result <= static_cast<uint32_t>(kMaxInt32));
  return result;
}


void Function::SaveICDataMap(
    const ZoneGrowableArray<const ICData*>& deopt_id_to_ic_data,
    const Array& edge_counters_array) const {
  // Compute number of ICData objects to save.
  // Store edge counter array in the first slot.
  intptr_t count = 1;
  for (intptr_t i = 0; i < deopt_id_to_ic_data.length(); i++) {
    if (deopt_id_to_ic_data[i] != NULL) {
      count++;
    }
  }
  const Array& array = Array::Handle(Array::New(count, Heap::kOld));
  INC_STAT(Thread::Current(), total_code_size, count * sizeof(uword));
  count = 1;
  for (intptr_t i = 0; i < deopt_id_to_ic_data.length(); i++) {
    if (deopt_id_to_ic_data[i] != NULL) {
      array.SetAt(count++, *deopt_id_to_ic_data[i]);
    }
  }
  array.SetAt(0, edge_counters_array);
  set_ic_data_array(array);
}


void Function::RestoreICDataMap(
    ZoneGrowableArray<const ICData*>* deopt_id_to_ic_data) const {
  ASSERT(deopt_id_to_ic_data->is_empty());
  Zone* zone = Thread::Current()->zone();
  const Array& saved_ic_data = Array::Handle(zone, ic_data_array());
  if (saved_ic_data.IsNull()) {
    return;
  }
  const intptr_t saved_length = saved_ic_data.Length();
  ASSERT(saved_length > 0);
  if (saved_length > 1) {
    const intptr_t restored_length = ICData::Cast(Object::Handle(
        zone, saved_ic_data.At(saved_length - 1))).deopt_id() + 1;
    deopt_id_to_ic_data->SetLength(restored_length);
    for (intptr_t i = 0; i < restored_length; i++) {
      (*deopt_id_to_ic_data)[i] = NULL;
    }
    for (intptr_t i = 1; i < saved_length; i++) {
      ICData& ic_data = ICData::ZoneHandle(zone);
      ic_data ^= saved_ic_data.At(i);
      (*deopt_id_to_ic_data)[ic_data.deopt_id()] = &ic_data;
    }
  }
}


void Function::set_ic_data_array(const Array& value) const {
  StorePointer(&raw_ptr()->ic_data_array_, value.raw());
}


RawArray* Function::ic_data_array() const {
  return raw_ptr()->ic_data_array_;
}


void Function::ClearICDataArray() const {
  set_ic_data_array(Array::null_array());
}


void Function::SetDeoptReasonForAll(intptr_t deopt_id,
                                    ICData::DeoptReasonId reason) {
  const Array& array = Array::Handle(ic_data_array());
  ICData& ic_data = ICData::Handle();
  for (intptr_t i = 1; i < array.Length(); i++) {
    ic_data ^= array.At(i);
    if (ic_data.deopt_id() == deopt_id) {
      ic_data.AddDeoptReason(reason);
    }
  }
}


bool Function::CheckSourceFingerprint(const char* prefix, int32_t fp) const {
  if (SourceFingerprint() != fp) {
    const bool recalculatingFingerprints = false;
    if (recalculatingFingerprints) {
      // This output can be copied into a file, then used with sed
      // to replace the old values.
      // sed -i .bak -f /tmp/newkeys runtime/vm/method_recognizer.h
      // sed -i .bak -f /tmp/newkeys runtime/vm/flow_graph_builder.h
      THR_Print("s/V(%s, %d)/V(%s, %d)/\n",
                prefix, fp, prefix, SourceFingerprint());
    } else {
      THR_Print("FP mismatch while recognizing method %s:"
                " expecting %d found %d\n",
                ToFullyQualifiedCString(),
                fp,
                SourceFingerprint());
      return false;
    }
  }
  return true;
}


const char* Function::ToCString() const {
  const char* static_str = is_static() ? " static" : "";
  const char* abstract_str = is_abstract() ? " abstract" : "";
  const char* kind_str = NULL;
  const char* const_str = is_const() ? " const" : "";
  switch (kind()) {
    case RawFunction::kRegularFunction:
    case RawFunction::kClosureFunction:
    case RawFunction::kGetterFunction:
    case RawFunction::kSetterFunction:
      kind_str = "";
      break;
    case RawFunction::kSignatureFunction:
      kind_str = " signature";
      break;
    case RawFunction::kConstructor:
      kind_str = is_static() ? " factory" : " constructor";
      break;
    case RawFunction::kImplicitGetter:
      kind_str = " getter";
      break;
    case RawFunction::kImplicitSetter:
      kind_str = " setter";
      break;
    case RawFunction::kImplicitStaticFinalGetter:
      kind_str = " static-final-getter";
      break;
    case RawFunction::kMethodExtractor:
      kind_str = " method-extractor";
      break;
    case RawFunction::kNoSuchMethodDispatcher:
      kind_str = " no-such-method-dispatcher";
      break;
    case RawFunction::kInvokeFieldDispatcher:
      kind_str = "invoke-field-dispatcher";
      break;
    case RawFunction::kIrregexpFunction:
      kind_str = "irregexp-function";
      break;
    default:
      UNREACHABLE();
  }
  const char* function_name = String::Handle(name()).ToCString();
  return OS::SCreate(Thread::Current()->zone(),
      "Function '%s':%s%s%s%s.",
      function_name, static_str, abstract_str, kind_str, const_str);
}


static void AddFunctionServiceId(const JSONObject& jsobj,
                                 const Function& f,
                                 const Class& cls) {
  // Special kinds of functions use indices in their respective lists.
  intptr_t id = -1;
  const char* selector = NULL;
  if (f.IsNonImplicitClosureFunction()) {
    id = cls.FindClosureIndex(f);
    selector = "closures";
  } else if (f.IsImplicitClosureFunction()) {
    id = cls.FindImplicitClosureFunctionIndex(f);
    selector = "implicit_closures";
  } else if (f.IsNoSuchMethodDispatcher() || f.IsInvokeFieldDispatcher()) {
    id = cls.FindInvocationDispatcherFunctionIndex(f);
    selector = "dispatchers";
  }
  if (id != -1) {
    ASSERT(selector != NULL);
    jsobj.AddFixedServiceId("classes/%" Pd "/%s/%" Pd "",
                            cls.id(), selector, id);
    return;
  }
  // Regular functions known to their owner use their name (percent-encoded).
  String& name = String::Handle(f.name());
  if (cls.LookupFunction(name) == f.raw()) {
    name = String::EncodeIRI(name);
    jsobj.AddFixedServiceId("classes/%" Pd "/functions/%s",
                            cls.id(), name.ToCString());
    return;
  }
  // Oddball functions (not known to their owner) fall back to use the object
  // id ring. Current known examples are signature functions of closures
  // and stubs like 'megamorphic_miss'.
  jsobj.AddServiceId(f);
}


void Function::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Class& cls = Class::Handle(Owner());
  ASSERT(!cls.IsNull());
  Error& err = Error::Handle();
  err ^= cls.EnsureIsFinalized(Thread::Current());
  ASSERT(err.IsNull());
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Function", ref);
  AddFunctionServiceId(jsobj, *this, cls);
  const String& user_name = String::Handle(PrettyName());
  const String& vm_name = String::Handle(name());
  AddNameProperties(&jsobj, user_name, vm_name);
  const Function& parent = Function::Handle(parent_function());
  if (!parent.IsNull()) {
    jsobj.AddProperty("owner", parent);
  } else if (cls.IsTopLevel()) {
    const Library& library = Library::Handle(cls.library());
    jsobj.AddProperty("owner", library);
  } else {
    jsobj.AddProperty("owner", cls);
  }

  const char* kind_string = Function::KindToCString(kind());
  jsobj.AddProperty("_kind", kind_string);
  jsobj.AddProperty("static", is_static());
  jsobj.AddProperty("const", is_const());
  if (ref) {
    return;
  }
  Code& code = Code::Handle(CurrentCode());
  if (!code.IsNull()) {
    jsobj.AddProperty("code", code);
  }
  Array& ics = Array::Handle(ic_data_array());
  if (!ics.IsNull()) {
    jsobj.AddProperty("_icDataArray", ics);
  }
  jsobj.AddProperty("_optimizable", is_optimizable());
  jsobj.AddProperty("_inlinable", is_inlinable());
  code = unoptimized_code();
  if (!code.IsNull()) {
    jsobj.AddProperty("_unoptimizedCode", code);
  }
  jsobj.AddProperty("_usageCounter", usage_counter());
  jsobj.AddProperty("_optimizedCallSiteCount", optimized_call_site_count());
  jsobj.AddProperty("_deoptimizations",
                    static_cast<intptr_t>(deoptimization_counter()));

  const Script& script = Script::Handle(this->script());
  if (!script.IsNull()) {
    jsobj.AddLocation(script, token_pos(), end_token_pos());
  }
}


void ClosureData::set_context_scope(const ContextScope& value) const {
  StorePointer(&raw_ptr()->context_scope_, value.raw());
}


void ClosureData::set_implicit_static_closure(const Instance& closure) const {
  ASSERT(!closure.IsNull());
  ASSERT(raw_ptr()->closure_ == Instance::null());
  StorePointer(&raw_ptr()->closure_, closure.raw());
}


void ClosureData::set_parent_function(const Function& value) const {
  StorePointer(&raw_ptr()->parent_function_, value.raw());
}


void ClosureData::set_signature_class(const Class& value) const {
  StorePointer(&raw_ptr()->signature_class_, value.raw());
}


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


const char* ClosureData::ToCString() const {
  return "ClosureData class";
}


void ClosureData::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


void RedirectionData::set_type(const Type& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->type_, value.raw());
}


void RedirectionData::set_identifier(const String& value) const {
  StorePointer(&raw_ptr()->identifier_, value.raw());
}


void RedirectionData::set_target(const Function& value) const {
  StorePointer(&raw_ptr()->target_, value.raw());
}


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


const char* RedirectionData::ToCString() const {
  return "RedirectionData class";
}


void RedirectionData::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


RawString* Field::GetterName(const String& field_name) {
  return String::Concat(Symbols::GetterPrefix(), field_name);
}


RawString* Field::GetterSymbol(const String& field_name) {
  return Symbols::FromConcat(Symbols::GetterPrefix(), field_name);
}


RawString* Field::LookupGetterSymbol(const String& field_name) {
  return Symbols::LookupFromConcat(Symbols::GetterPrefix(), field_name);
}


RawString* Field::SetterName(const String& field_name) {
  return String::Concat(Symbols::SetterPrefix(), field_name);
}


RawString* Field::SetterSymbol(const String& field_name) {
  return Symbols::FromConcat(Symbols::SetterPrefix(), field_name);
}


RawString* Field::LookupSetterSymbol(const String& field_name) {
  return Symbols::LookupFromConcat(Symbols::SetterPrefix(), field_name);
}


RawString* Field::NameFromGetter(const String& getter_name) {
  return Symbols::New(getter_name, kGetterPrefixLength,
      getter_name.Length() - kGetterPrefixLength);
}


RawString* Field::NameFromSetter(const String& setter_name) {
  return Symbols::New(setter_name, kSetterPrefixLength,
      setter_name.Length() - kSetterPrefixLength);
}


bool Field::IsGetterName(const String& function_name) {
  return function_name.StartsWith(Symbols::GetterPrefix());
}


bool Field::IsSetterName(const String& function_name) {
  return function_name.StartsWith(Symbols::SetterPrefix());
}


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


RawClass* Field::owner() const {
  const Object& obj = Object::Handle(raw_ptr()->owner_);
  if (obj.IsClass()) {
    return Class::Cast(obj).raw();
  }
  ASSERT(obj.IsPatchClass());
  return PatchClass::Cast(obj).patched_class();
}


RawClass* Field::origin() const {
  const Object& obj = Object::Handle(raw_ptr()->owner_);
  if (obj.IsClass()) {
    return Class::Cast(obj).raw();
  }
  ASSERT(obj.IsPatchClass());
  return PatchClass::Cast(obj).source_class();
}


void Field::set_type(const AbstractType& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->type_, value.raw());
}


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


RawField* Field::New(const String& name,
                     bool is_static,
                     bool is_final,
                     bool is_const,
                     bool is_reflectable,
                     const Class& owner,
                     intptr_t token_pos) {
  ASSERT(!owner.IsNull());
  const Field& result = Field::Handle(Field::New());
  result.set_name(name);
  result.set_is_static(is_static);
  if (!is_static) {
    result.SetOffset(0);
  }
  result.set_is_final(is_final);
  result.set_is_const(is_const);
  result.set_is_reflectable(is_reflectable);
  result.set_is_double_initialized(false);
  result.set_owner(owner);
  result.set_token_pos(token_pos);
  result.set_has_initializer(false);
  result.set_is_unboxing_candidate(true);
  result.set_guarded_cid(FLAG_use_field_guards ? kIllegalCid : kDynamicCid);
  result.set_is_nullable(FLAG_use_field_guards ? false : true);
  result.set_guarded_list_length_in_object_offset(Field::kUnknownLengthOffset);
  // Presently, we only attempt to remember the list length for final fields.
  if (is_final && FLAG_use_field_guards) {
    result.set_guarded_list_length(Field::kUnknownFixedLength);
  } else {
    result.set_guarded_list_length(Field::kNoFixedLength);
  }
  return result.raw();
}



RawField* Field::Clone(const Class& new_owner) const {
  Field& clone = Field::Handle();
  clone ^= Object::Clone(*this, Heap::kOld);
  const Class& owner = Class::Handle(this->owner());
  const PatchClass& clone_owner =
      PatchClass::Handle(PatchClass::New(new_owner, owner));
  clone.set_owner(clone_owner);
  if (!clone.is_static()) {
    clone.SetOffset(0);
  }
  if (new_owner.NumTypeParameters() > 0) {
    // Adjust the field type to refer to type parameters of the new owner.
    AbstractType& type = AbstractType::Handle(clone.type());
    type ^= type.CloneUninstantiated(new_owner);
    clone.set_type(type);
  }
  return clone.raw();
}


RawString* Field::PrettyName() const {
  const String& str = String::Handle(name());
  return String::IdentifierPrettyName(str);
}


RawString* Field::UserVisibleName() const {
  return PrettyName();
}


intptr_t Field::guarded_list_length() const {
  return Smi::Value(raw_ptr()->guarded_list_length_);
}


void Field::set_guarded_list_length(intptr_t list_length) const {
  StoreSmi(&raw_ptr()->guarded_list_length_, Smi::New(list_length));
}


intptr_t Field::guarded_list_length_in_object_offset() const {
  return raw_ptr()->guarded_list_length_in_object_offset_ + kHeapObjectTag;
}


void Field::set_guarded_list_length_in_object_offset(
    intptr_t list_length_offset) const {
  StoreNonPointer(&raw_ptr()->guarded_list_length_in_object_offset_,
                  static_cast<int8_t>(list_length_offset - kHeapObjectTag));
  ASSERT(guarded_list_length_in_object_offset() == list_length_offset);
}


bool Field::IsUnboxedField() const {
  bool valid_class = (FlowGraphCompiler::SupportsUnboxedDoubles() &&
                      (guarded_cid() == kDoubleCid)) ||
                     (FlowGraphCompiler::SupportsUnboxedSimd128() &&
                      (guarded_cid() == kFloat32x4Cid)) ||
                     (FlowGraphCompiler::SupportsUnboxedSimd128() &&
                      (guarded_cid() == kFloat64x2Cid));
  return is_unboxing_candidate() && !is_final() && !is_nullable() &&
         valid_class;
}


bool Field::IsPotentialUnboxedField() const {
  return is_unboxing_candidate() &&
         (IsUnboxedField() || (!is_final() && (guarded_cid() == kIllegalCid)));
}


const char* Field::ToCString() const {
  if (IsNull()) {
    return "Field::null";
  }
  const char* kF0 = is_static() ? " static" : "";
  const char* kF1 = is_final() ? " final" : "";
  const char* kF2 = is_const() ? " const" : "";
  const char* field_name = String::Handle(name()).ToCString();
  const Class& cls = Class::Handle(owner());
  const char* cls_name = String::Handle(cls.Name()).ToCString();
  return OS::SCreate(Thread::Current()->zone(),
      "Field <%s.%s>:%s%s%s", cls_name, field_name, kF0, kF1, kF2);
}

void Field::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  Class& cls = Class::Handle(owner());
  intptr_t id = cls.FindFieldIndex(*this);
  ASSERT(id >= 0);
  intptr_t cid = cls.id();
  AddCommonObjectProperties(&jsobj, "Field", ref);
  jsobj.AddFixedServiceId("classes/%" Pd "/fields/%" Pd "", cid, id);
  const String& user_name = String::Handle(PrettyName());
  const String& vm_name = String::Handle(name());
  AddNameProperties(&jsobj, user_name, vm_name);
  if (cls.IsTopLevel()) {
    const Library& library = Library::Handle(cls.library());
    jsobj.AddProperty("owner", library);
  } else {
    jsobj.AddProperty("owner", cls);
  }

  AbstractType& declared_type = AbstractType::Handle(type());
  jsobj.AddProperty("declaredType", declared_type);
  jsobj.AddProperty("static", is_static());
  jsobj.AddProperty("final", is_final());
  jsobj.AddProperty("const", is_const());
  if (ref) {
    return;
  }
  if (is_static()) {
    const Instance& valueObj = Instance::Handle(StaticValue());
    jsobj.AddProperty("staticValue", valueObj);
  }

  jsobj.AddProperty("_guardNullable", is_nullable());
  if (guarded_cid() == kIllegalCid) {
    jsobj.AddProperty("_guardClass", "unknown");
  } else if (guarded_cid() == kDynamicCid) {
    jsobj.AddProperty("_guardClass", "dynamic");
  } else {
    ClassTable* table = Isolate::Current()->class_table();
    ASSERT(table->IsValidIndex(guarded_cid()));
    cls ^= table->At(guarded_cid());
    jsobj.AddProperty("_guardClass", cls);
  }
  if (guarded_list_length() == kUnknownFixedLength) {
    jsobj.AddProperty("_guardLength", "unknown");
  } else if (guarded_list_length() == kNoFixedLength) {
    jsobj.AddProperty("_guardLength", "variable");
  } else {
    jsobj.AddProperty("_guardLength", guarded_list_length());
  }
  const Class& origin_cls = Class::Handle(origin());
  const Script& script = Script::Handle(origin_cls.script());
  if (!script.IsNull()) {
    jsobj.AddLocation(script, token_pos());
  }
}


// Build a closure object that gets (or sets) the contents of a static
// field f and cache the closure in a newly created static field
// named #f (or #f= in case of a setter).
RawInstance* Field::AccessorClosure(bool make_setter) const {
  ASSERT(is_static());
  const Class& field_owner = Class::Handle(owner());

  String& closure_name = String::Handle(this->name());
  closure_name = Symbols::FromConcat(Symbols::HashMark(), closure_name);
  if (make_setter) {
    closure_name = Symbols::FromConcat(Symbols::HashMark(), closure_name);
  }

  Field& closure_field = Field::Handle();
  closure_field = field_owner.LookupStaticField(closure_name);
  if (!closure_field.IsNull()) {
    ASSERT(closure_field.is_static());
    const Instance& closure =
        Instance::Handle(closure_field.StaticValue());
    ASSERT(!closure.IsNull());
    ASSERT(closure.IsClosure());
    return closure.raw();
  }

  // This is the first time a closure for this field is requested.
  // Create the closure and a new static field in which it is stored.
  const char* field_name = String::Handle(name()).ToCString();
  String& expr_src = String::Handle();
  if (make_setter) {
    expr_src =
        String::NewFormatted("(%s_) { return %s = %s_; }",
                             field_name, field_name, field_name);
  } else {
    expr_src = String::NewFormatted("() { return %s; }", field_name);
  }
  Object& result =
      Object::Handle(field_owner.Evaluate(expr_src,
                                          Object::empty_array(),
                                          Object::empty_array()));
  ASSERT(result.IsInstance());
  // The caller may expect the closure to be allocated in old space. Copy
  // the result here, since Object::Clone() is a private method.
  result = Object::Clone(result, Heap::kOld);

  closure_field = Field::New(closure_name,
                             true,  // is_static
                             true,  // is_final
                             true,  // is_const
                             false,  // is_reflectable
                             field_owner,
                             this->token_pos());
  closure_field.SetStaticValue(Instance::Cast(result), true);
  closure_field.set_type(Type::Handle(Type::DynamicType()));
  field_owner.AddField(closure_field);

  return Instance::RawCast(result.raw());
}


RawInstance* Field::GetterClosure() const {
  return AccessorClosure(false);
}


RawInstance* Field::SetterClosure() const {
  return AccessorClosure(true);
}


RawArray* Field::dependent_code() const {
  return raw_ptr()->dependent_code_;
}


void Field::set_dependent_code(const Array& array) const {
  StorePointer(&raw_ptr()->dependent_code_, array.raw());
}


class FieldDependentArray : public WeakCodeReferences {
 public:
  explicit FieldDependentArray(const Field& field)
      : WeakCodeReferences(Array::Handle(field.dependent_code())),
                           field_(field) {}

  virtual void UpdateArrayTo(const Array& value) {
    field_.set_dependent_code(value);
  }

  virtual void ReportDeoptimization(const Code& code) {
    if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
      Function& function = Function::Handle(code.function());
      THR_Print("Deoptimizing %s because guard on field %s failed.\n",
                function.ToFullyQualifiedCString(), field_.ToCString());
    }
  }

  virtual void ReportSwitchingCode(const Code& code) {
    if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
      Function& function = Function::Handle(code.function());
      THR_Print("Switching %s to unoptimized code because guard"
                " on field %s was violated.\n",
                function.ToFullyQualifiedCString(),
                field_.ToCString());
    }
  }

 private:
  const Field& field_;
  DISALLOW_COPY_AND_ASSIGN(FieldDependentArray);
};


void Field::RegisterDependentCode(const Code& code) const {
  ASSERT(code.is_optimized());
  FieldDependentArray a(*this);
  a.Register(code);
}


void Field::DeoptimizeDependentCode() const {
  FieldDependentArray a(*this);
  a.DisableCode();
}


bool Field::IsUninitialized() const {
  const Instance& value = Instance::Handle(raw_ptr()->value_.static_value_);
  ASSERT(value.raw() != Object::transition_sentinel().raw());
  return value.raw() == Object::sentinel().raw();
}


void Field::SetPrecompiledInitializer(const Function& initializer) const {
  StorePointer(&raw_ptr()->initializer_.precompiled_, initializer.raw());
}


bool Field::HasPrecompiledInitializer() const {
  return raw_ptr()->initializer_.precompiled_->IsHeapObject() &&
         raw_ptr()->initializer_.precompiled_->IsFunction();
}


void Field::SetSavedInitialStaticValue(const Instance& value) const {
  ASSERT(!HasPrecompiledInitializer());
  StorePointer(&raw_ptr()->initializer_.saved_value_, value.raw());
}


void Field::EvaluateInitializer() const {
  ASSERT(is_static());
  if (StaticValue() == Object::sentinel().raw()) {
    SetStaticValue(Object::transition_sentinel());
    Object& value = Object::Handle(Compiler::EvaluateStaticInitializer(*this));
    if (value.IsError()) {
      SetStaticValue(Object::null_instance());
      Exceptions::PropagateError(Error::Cast(value));
      UNREACHABLE();
    }
    ASSERT(value.IsNull() || value.IsInstance());
    SetStaticValue(value.IsNull() ? Instance::null_instance()
                                  : Instance::Cast(value));
    return;
  } else if (StaticValue() == Object::transition_sentinel().raw()) {
    SetStaticValue(Object::null_instance());
    const Array& ctor_args = Array::Handle(Array::New(1));
    const String& field_name = String::Handle(name());
    ctor_args.SetAt(0, field_name);
    Exceptions::ThrowByType(Exceptions::kCyclicInitializationError, ctor_args);
    UNREACHABLE();
    return;
  }
  UNREACHABLE();
}


static intptr_t GetListLength(const Object& value) {
  if (value.IsTypedData()) {
    const TypedData& list = TypedData::Cast(value);
    return list.Length();
  } else if (value.IsArray()) {
    const Array& list = Array::Cast(value);
    return list.Length();
  } else if (value.IsGrowableObjectArray()) {
    // List length is variable.
    return Field::kNoFixedLength;
  } else if (value.IsExternalTypedData()) {
    // TODO(johnmccutchan): Enable for external typed data.
    return Field::kNoFixedLength;
  } else if (RawObject::IsTypedDataViewClassId(value.GetClassId())) {
    // TODO(johnmccutchan): Enable for typed data views.
    return Field::kNoFixedLength;
  }
  return Field::kNoFixedLength;
}


static intptr_t GetListLengthOffset(intptr_t cid) {
  if (RawObject::IsTypedDataClassId(cid)) {
    return TypedData::length_offset();
  } else if (cid == kArrayCid || cid == kImmutableArrayCid) {
    return Array::length_offset();
  } else if (cid == kGrowableObjectArrayCid) {
    // List length is variable.
    return Field::kUnknownLengthOffset;
  } else if (RawObject::IsExternalTypedDataClassId(cid)) {
    // TODO(johnmccutchan): Enable for external typed data.
    return Field::kUnknownLengthOffset;
  } else if (RawObject::IsTypedDataViewClassId(cid)) {
    // TODO(johnmccutchan): Enable for typed data views.
    return Field::kUnknownLengthOffset;
  }
  return Field::kUnknownLengthOffset;
}


const char* Field::GuardedPropertiesAsCString() const {
  if (guarded_cid() == kIllegalCid) {
    return "<?>";
  } else if (guarded_cid() == kDynamicCid) {
    return "<*>";
  }

  const Class& cls = Class::Handle(
      Isolate::Current()->class_table()->At(guarded_cid()));
  const char* class_name = String::Handle(cls.Name()).ToCString();

  if (RawObject::IsBuiltinListClassId(guarded_cid()) &&
      !is_nullable() &&
      is_final()) {
    ASSERT(guarded_list_length() != kUnknownFixedLength);
    if (guarded_list_length() == kNoFixedLength) {
      return Thread::Current()->zone()->PrintToString(
          "<%s [*]>", class_name);
    } else {
      return Thread::Current()->zone()->PrintToString(
          "<%s [%" Pd " @%" Pd "]>",
          class_name,
          guarded_list_length(),
          guarded_list_length_in_object_offset());
    }
  }

  return Thread::Current()->zone()->PrintToString("<%s %s>",
    is_nullable() ? "nullable" : "not-nullable",
    class_name);
}


void Field::InitializeGuardedListLengthInObjectOffset() const {
  if (needs_length_check() &&
      (guarded_list_length() != Field::kUnknownFixedLength)) {
    const intptr_t offset = GetListLengthOffset(guarded_cid());
    set_guarded_list_length_in_object_offset(offset);
    ASSERT(offset != Field::kUnknownLengthOffset);
  } else {
    set_guarded_list_length_in_object_offset(Field::kUnknownLengthOffset);
  }
}


bool Field::UpdateGuardedCidAndLength(const Object& value) const {
  const intptr_t cid = value.GetClassId();

  if (guarded_cid() == kIllegalCid) {
    // Field is assigned first time.
    set_guarded_cid(cid);
    set_is_nullable(cid == kNullCid);

    // Start tracking length if needed.
    ASSERT((guarded_list_length() == Field::kUnknownFixedLength) ||
           (guarded_list_length() == Field::kNoFixedLength));
    if (needs_length_check()) {
      ASSERT(guarded_list_length() == Field::kUnknownFixedLength);
      set_guarded_list_length(GetListLength(value));
      InitializeGuardedListLengthInObjectOffset();
    }

    if (FLAG_trace_field_guards) {
      THR_Print("    => %s\n", GuardedPropertiesAsCString());
    }

    return false;
  }

  if ((cid == guarded_cid()) || ((cid == kNullCid) && is_nullable())) {
    // Class id of the assigned value matches expected class id and nullability.

    // If we are tracking length check if it has matches.
    if (needs_length_check() &&
        (guarded_list_length() != GetListLength(value))) {
      ASSERT(guarded_list_length() != Field::kUnknownFixedLength);
      set_guarded_list_length(Field::kNoFixedLength);
      set_guarded_list_length_in_object_offset(Field::kUnknownLengthOffset);
      return true;
    }

    // Everything matches.
    return false;
  }

  if ((cid == kNullCid) && !is_nullable()) {
    // Assigning null value to a non-nullable field makes it nullable.
    set_is_nullable(true);
  } else if ((cid != kNullCid) && (guarded_cid() == kNullCid)) {
    // Assigning non-null value to a field that previously contained only null
    // turns it into a nullable field with the given class id.
    ASSERT(is_nullable());
    set_guarded_cid(cid);
  } else {
    // Give up on tracking class id of values contained in this field.
    ASSERT(guarded_cid() != cid);
    set_guarded_cid(kDynamicCid);
    set_is_nullable(true);
  }

  // If we were tracking length drop collected feedback.
  if (needs_length_check()) {
    ASSERT(guarded_list_length() != Field::kUnknownFixedLength);
    set_guarded_list_length(Field::kNoFixedLength);
    set_guarded_list_length_in_object_offset(Field::kUnknownLengthOffset);
  }

  // Expected class id or nullability of the field changed.
  return true;
}


void Field::RecordStore(const Object& value) const {
  if (!FLAG_use_field_guards) {
    return;
  }

  if (FLAG_trace_field_guards) {
    THR_Print("Store %s %s <- %s\n",
              ToCString(),
              GuardedPropertiesAsCString(),
              value.ToCString());
  }

  if (UpdateGuardedCidAndLength(value)) {
    if (FLAG_trace_field_guards) {
      THR_Print("    => %s\n", GuardedPropertiesAsCString());
    }

    DeoptimizeDependentCode();
  }
}


void LiteralToken::set_literal(const String& literal) const {
  StorePointer(&raw_ptr()->literal_, literal.raw());
}


void LiteralToken::set_value(const Object& value) const {
  StorePointer(&raw_ptr()->value_, value.raw());
}


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


RawLiteralToken* LiteralToken::New(Token::Kind kind, const String& literal) {
  const LiteralToken& result = LiteralToken::Handle(LiteralToken::New());
  result.set_kind(kind);
  result.set_literal(literal);
  if (kind == Token::kINTEGER) {
    const Integer& value = Integer::Handle(Integer::NewCanonical(literal));
    ASSERT(value.IsSmi() || value.IsOld());
    result.set_value(value);
  } else if (kind == Token::kDOUBLE) {
    const Double& value = Double::Handle(Double::NewCanonical(literal));
    result.set_value(value);
  } else {
    ASSERT(Token::NeedsLiteralToken(kind));
    result.set_value(literal);
  }
  return result.raw();
}


const char* LiteralToken::ToCString() const {
  const String& token = String::Handle(literal());
  return token.ToCString();
}


void LiteralToken::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


RawArray* TokenStream::TokenObjects() const {
  return raw_ptr()->token_objects_;
}


void TokenStream::SetTokenObjects(const Array& value) const {
  StorePointer(&raw_ptr()->token_objects_, value.raw());
}


RawExternalTypedData* TokenStream::GetStream() const {
  return raw_ptr()->stream_;
}


void TokenStream::SetStream(const ExternalTypedData& value) const {
  StorePointer(&raw_ptr()->stream_, value.raw());
}


void TokenStream::DataFinalizer(void* isolate_callback_data,
                                Dart_WeakPersistentHandle handle,
                                void *peer) {
  ASSERT(peer != NULL);
  ::free(peer);
}


RawString* TokenStream::PrivateKey() const {
  return raw_ptr()->private_key_;
}


void TokenStream::SetPrivateKey(const String& value) const {
  StorePointer(&raw_ptr()->private_key_, value.raw());
}

RawString* TokenStream::GenerateSource() const {
  return GenerateSource(0, kMaxElements);
}

RawString* TokenStream::GenerateSource(intptr_t start_pos,
                                       intptr_t end_pos) const {
  Iterator iterator(*this, start_pos, Iterator::kAllTokens);
  const ExternalTypedData& data = ExternalTypedData::Handle(GetStream());
  const GrowableObjectArray& literals =
      GrowableObjectArray::Handle(GrowableObjectArray::New(data.Length()));
  const String& private_key = String::Handle(PrivateKey());
  intptr_t private_len = private_key.Length();

  Token::Kind curr = iterator.CurrentTokenKind();
  Token::Kind prev = Token::kILLEGAL;
  // Handles used in the loop.
  Object& obj = Object::Handle();
  String& literal = String::Handle();
  // Current indentation level.
  int indent = 0;

  while ((curr != Token::kEOS) && (iterator.CurrentPosition() < end_pos)) {
    // Remember current values for this token.
    obj = iterator.CurrentToken();
    literal = iterator.MakeLiteralToken(obj);
    // Advance to be able to use next token kind.
    iterator.Advance();
    Token::Kind next = iterator.CurrentTokenKind();

    // Handle the current token.
    if (curr == Token::kSTRING) {
      bool escape_characters = false;
      for (intptr_t i = 0; i < literal.Length(); i++) {
        if (NeedsEscapeSequence(literal.CharAt(i))) {
          escape_characters = true;
        }
      }
      if ((prev != Token::kINTERPOL_VAR) && (prev != Token::kINTERPOL_END)) {
        literals.Add(Symbols::DoubleQuotes());
      }
      if (escape_characters) {
        literal = String::EscapeSpecialCharacters(literal);
        literals.Add(literal);
      } else {
        literals.Add(literal);
      }
      if ((next != Token::kINTERPOL_VAR) && (next != Token::kINTERPOL_START)) {
        literals.Add(Symbols::DoubleQuotes());
      }
    } else if (curr == Token::kINTERPOL_VAR) {
      literals.Add(Symbols::Dollar());
      if (literal.CharAt(0) == Library::kPrivateIdentifierStart) {
        literal = String::SubString(literal, 0, literal.Length() - private_len);
      }
      literals.Add(literal);
    } else if (curr == Token::kIDENT) {
      if (literal.CharAt(0) == Library::kPrivateIdentifierStart) {
        literal = String::SubString(literal, 0, literal.Length() - private_len);
      }
      literals.Add(literal);
    } else {
      literals.Add(literal);
    }
    // Determine the separation text based on this current token.
    const String* separator = NULL;
    switch (curr) {
      case Token::kLBRACE:
      case Token::kRBRACE:
        if (next != Token::kNEWLINE) {
          separator = &Symbols::Blank();
        }
        break;
      case Token::kPERIOD:
      case Token::kLBRACK:
      case Token::kINTERPOL_VAR:
      case Token::kINTERPOL_START:
      case Token::kINTERPOL_END:
      case Token::kBIT_NOT:
      case Token::kNOT:
        break;
      // In case we see an opening parentheses '(' we increase the indent to
      // align multi-line parameters accordingly. The indent will be removed as
      // soon as we see the matching closing parentheses ')'.
      //
      // Example:
      // SomeVeryLongMethod(
      //     "withVeryLongParameter",
      //     "andAnotherVeryLongParameter",
      //     "andAnotherVeryLongParameter2") { ...
      case Token::kLPAREN:
        indent += 2;
        break;
      case Token::kRPAREN:
        indent -= 2;
        separator = &Symbols::Blank();
        break;
      case Token::kNEWLINE:
        if (prev == Token::kLBRACE) {
          indent++;
        }
        if (next == Token::kRBRACE) {
          indent--;
        }
        break;
      default:
        separator = &Symbols::Blank();
        break;
    }

    // Determine whether the separation text needs to be updated based on the
    // next token.
    switch (next) {
      case Token::kRBRACE:
        break;
      case Token::kNEWLINE:
      case Token::kSEMICOLON:
      case Token::kPERIOD:
      case Token::kCOMMA:
      case Token::kRPAREN:
      case Token::kLBRACK:
      case Token::kRBRACK:
      case Token::kINTERPOL_VAR:
      case Token::kINTERPOL_START:
      case Token::kINTERPOL_END:
        separator = NULL;
        break;
      case Token::kLPAREN:
        if (curr == Token::kCATCH) {
          separator = &Symbols::Blank();
        } else {
          separator = NULL;
        }
        break;
      case Token::kELSE:
        separator = &Symbols::Blank();
        break;
      default:
        // Do nothing.
        break;
    }

    // Update the few cases where both tokens need to be taken into account.
    if (((curr == Token::kIF) || (curr == Token::kFOR)) &&
        (next == Token::kLPAREN)) {
      separator = &Symbols::Blank();
    } else if ((curr == Token::kASSIGN) && (next == Token::kLPAREN)) {
      separator = &Symbols::Blank();
    } else if ((curr == Token::kRETURN  ||
                curr == Token::kCONDITIONAL ||
                Token::IsBinaryOperator(curr) ||
                Token::IsEqualityOperator(curr)) && (next == Token::kLPAREN)) {
      separator = &Symbols::Blank();
    } else if ((curr == Token::kLBRACE) && (next == Token::kRBRACE)) {
      separator = NULL;
    } else if ((curr == Token::kSEMICOLON) && (next != Token::kNEWLINE)) {
      separator = &Symbols::Blank();
    }

    // Add the separator.
    if (separator != NULL) {
      literals.Add(*separator);
    }

    // Account for indentation in case we printed a newline.
    if (curr == Token::kNEWLINE) {
        for (int i = 0; i < indent; i++) {
          literals.Add(Symbols::TwoSpaces());
        }
    }

    // Setup for next iteration.
    prev = curr;
    curr = next;
  }
  const Array& source = Array::Handle(Array::MakeArray(literals));
  return String::ConcatAll(source);
}


intptr_t TokenStream::ComputeSourcePosition(intptr_t tok_pos) const {
  Iterator iterator(*this, 0, Iterator::kAllTokens);
  intptr_t src_pos = 0;
  Token::Kind kind = iterator.CurrentTokenKind();
  while (iterator.CurrentPosition() < tok_pos && kind != Token::kEOS) {
    iterator.Advance();
    kind = iterator.CurrentTokenKind();
    src_pos += 1;
  }
  return src_pos;
}


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


RawTokenStream* TokenStream::New(intptr_t len) {
  if (len < 0 || len > kMaxElements) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in TokenStream::New: invalid len %" Pd "\n", len);
  }
  uint8_t* data = reinterpret_cast<uint8_t*>(::malloc(len));
  ASSERT(data != NULL);
  Zone* zone = Thread::Current()->zone();
  const ExternalTypedData& stream = ExternalTypedData::Handle(
      zone,
      ExternalTypedData::New(kExternalTypedDataUint8ArrayCid,
                             data, len, Heap::kOld));
  stream.AddFinalizer(data, DataFinalizer);
  const TokenStream& result = TokenStream::Handle(zone, TokenStream::New());
  result.SetStream(stream);
  return result.raw();
}


// CompressedTokenMap maps String and LiteralToken keys to Smi values.
// It also supports lookup by Scanner::TokenDescriptor.
class CompressedTokenTraits {
 public:
  static bool IsMatch(const Scanner::TokenDescriptor& descriptor,
                      const Object& key) {
    if (!key.IsLiteralToken()) {
      return false;
    }
    const LiteralToken& token = LiteralToken::Cast(key);
    return (token.literal() == descriptor.literal->raw()) &&
           (token.kind() == descriptor.kind);
  }

  // Only for non-descriptor lookup and table expansion.
  static bool IsMatch(const Object& a, const Object& b) {
    return a.raw() == b.raw();
  }

  static uword Hash(const Scanner::TokenDescriptor& descriptor) {
    return descriptor.literal->Hash();
  }

  static uword Hash(const Object& key) {
    if (key.IsLiteralToken()) {
      return String::HashRawSymbol(LiteralToken::Cast(key).literal());
    } else {
      return String::Cast(key).Hash();
    }
  }

  static RawObject* NewKey(const Scanner::TokenDescriptor& descriptor) {
    return LiteralToken::New(descriptor.kind, *descriptor.literal);
  }
};
typedef UnorderedHashMap<CompressedTokenTraits> CompressedTokenMap;


// Helper class for creation of compressed token stream data.
class CompressedTokenStreamData : public ValueObject {
 public:
  static const intptr_t kInitialBufferSize = 16 * KB;
  CompressedTokenStreamData() :
      buffer_(NULL),
      stream_(&buffer_, Reallocate, kInitialBufferSize),
      tokens_(HashTables::New<CompressedTokenMap>(kInitialTableSize)) {
  }
  ~CompressedTokenStreamData() {
    // Safe to discard the hash table now.
    tokens_.Release();
  }

  // Add an IDENT token into the stream and the token hash map.
  void AddIdentToken(const String* ident) {
    ASSERT(ident->IsSymbol());
    const intptr_t fresh_index = tokens_.NumOccupied();
    intptr_t index = Smi::Value(Smi::RawCast(
        tokens_.InsertOrGetValue(*ident,
                                 Smi::Handle(Smi::New(fresh_index)))));
    WriteIndex(index);
  }

  // Add a LITERAL token into the stream and the token hash map.
  void AddLiteralToken(const Scanner::TokenDescriptor& descriptor) {
    ASSERT(descriptor.literal->IsSymbol());
    const intptr_t fresh_index = tokens_.NumOccupied();
    intptr_t index = Smi::Value(Smi::RawCast(
        tokens_.InsertNewOrGetValue(descriptor,
                                    Smi::Handle(Smi::New(fresh_index)))));
    WriteIndex(index);
  }

  // Add a simple token into the stream.
  void AddSimpleToken(intptr_t kind) {
    stream_.WriteUnsigned(kind);
  }

  // Return the compressed token stream.
  uint8_t* GetStream() const { return buffer_; }

  // Return the compressed token stream length.
  intptr_t Length() const { return stream_.bytes_written(); }

  // Generate and return the token objects array.
  RawArray* MakeTokenObjectsArray() const {
    Array& result = Array::Handle(
        Array::New(tokens_.NumOccupied(), Heap::kOld));
    CompressedTokenMap::Iterator it(&tokens_);
    Object& key = Object::Handle();
    while (it.MoveNext()) {
      intptr_t entry = it.Current();
      key = tokens_.GetKey(entry);
      result.SetAt(Smi::Value(Smi::RawCast(tokens_.GetPayload(entry, 0))), key);
    }
    return result.raw();
  }

 private:
  void WriteIndex(intptr_t value) {
    stream_.WriteUnsigned(value + Token::kNumTokens);
  }

  static uint8_t* Reallocate(uint8_t* ptr,
                             intptr_t old_size,
                             intptr_t new_size) {
    void* new_ptr = ::realloc(reinterpret_cast<void*>(ptr), new_size);
    return reinterpret_cast<uint8_t*>(new_ptr);
  }

  static const intptr_t kInitialTableSize = 32;

  uint8_t* buffer_;
  WriteStream stream_;
  CompressedTokenMap tokens_;

  DISALLOW_COPY_AND_ASSIGN(CompressedTokenStreamData);
};


RawTokenStream* TokenStream::New(const Scanner::GrowableTokenStream& tokens,
                                 const String& private_key) {
  Zone* zone = Thread::Current()->zone();
  // Copy the relevant data out of the scanner into a compressed stream of
  // tokens.
  CompressedTokenStreamData data;
  intptr_t len = tokens.length();
  for (intptr_t i = 0; i < len; i++) {
    Scanner::TokenDescriptor token = tokens[i];
    if (token.kind == Token::kIDENT) {  // Identifier token.
      data.AddIdentToken(token.literal);
    } else if (Token::NeedsLiteralToken(token.kind)) {  // Literal token.
      data.AddLiteralToken(token);
    } else {  // Keyword, pseudo keyword etc.
      ASSERT(token.kind < Token::kNumTokens);
      data.AddSimpleToken(token.kind);
    }
  }
  data.AddSimpleToken(Token::kEOS);  // End of stream.

  // Create and setup the token stream object.
  const ExternalTypedData& stream = ExternalTypedData::Handle(
      zone,
      ExternalTypedData::New(kExternalTypedDataUint8ArrayCid,
                             data.GetStream(), data.Length(), Heap::kOld));
  stream.AddFinalizer(data.GetStream(), DataFinalizer);
  const TokenStream& result = TokenStream::Handle(zone, New());
  result.SetPrivateKey(private_key);
  const Array& token_objects =
      Array::Handle(zone, data.MakeTokenObjectsArray());
  {
    NoSafepointScope no_safepoint;
    result.SetStream(stream);
    result.SetTokenObjects(token_objects);
  }
  return result.raw();
}


const char* TokenStream::ToCString() const {
  return "TokenStream";
}


void TokenStream::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Object", ref);
  // TODO(johnmccutchan): Generate a stable id. TokenStreams hang off
  // a Script object but do not have a back reference to generate a stable id.
  jsobj.AddServiceId(*this);
  if (ref) {
    return;
  }
  const String& private_key = String::Handle(PrivateKey());
  jsobj.AddProperty("privateKey", private_key);
  // TODO(johnmccutchan): Add support for printing LiteralTokens and add
  // them to members array.
  JSONArray members(&jsobj, "members");
}


TokenStream::Iterator::Iterator(const TokenStream& tokens,
                                intptr_t token_pos,
                                Iterator::StreamType stream_type)
    : tokens_(TokenStream::Handle(tokens.raw())),
      data_(ExternalTypedData::Handle(tokens.GetStream())),
      stream_(reinterpret_cast<uint8_t*>(data_.DataAddr(0)), data_.Length()),
      token_objects_(Array::Handle(tokens.TokenObjects())),
      obj_(Object::Handle()),
      cur_token_pos_(token_pos),
      cur_token_kind_(Token::kILLEGAL),
      cur_token_obj_index_(-1),
      stream_type_(stream_type) {
  SetCurrentPosition(token_pos);
}


void TokenStream::Iterator::SetStream(const TokenStream& tokens,
                                      intptr_t token_pos) {
  tokens_ = tokens.raw();
  data_ = tokens.GetStream();
  stream_.SetStream(reinterpret_cast<uint8_t*>(data_.DataAddr(0)),
                    data_.Length());
  token_objects_ = tokens.TokenObjects();
  obj_ = Object::null();
  cur_token_pos_ = token_pos;
  cur_token_kind_ = Token::kILLEGAL;
  cur_token_obj_index_ = -1;
  SetCurrentPosition(token_pos);
}


bool TokenStream::Iterator::IsValid() const {
  return !tokens_.IsNull();
}


Token::Kind TokenStream::Iterator::LookaheadTokenKind(intptr_t num_tokens) {
  intptr_t saved_position = stream_.Position();
  Token::Kind kind = Token::kILLEGAL;
  intptr_t value = -1;
  intptr_t count = 0;
  while (count < num_tokens && value != Token::kEOS) {
    value = ReadToken();
    if ((stream_type_ == kAllTokens) ||
        (static_cast<Token::Kind>(value) != Token::kNEWLINE)) {
      count += 1;
    }
  }
  if (value < Token::kNumTokens) {
    kind = static_cast<Token::Kind>(value);
  } else {
    value = value - Token::kNumTokens;
    obj_ = token_objects_.At(value);
    if (obj_.IsLiteralToken()) {
      const LiteralToken& literal_token = LiteralToken::Cast(obj_);
      kind = literal_token.kind();
    } else {
      ASSERT(obj_.IsString());  // Must be an identifier.
      kind = Token::kIDENT;
    }
  }
  stream_.SetPosition(saved_position);
  return kind;
}


intptr_t TokenStream::Iterator::CurrentPosition() const {
  return cur_token_pos_;
}


void TokenStream::Iterator::SetCurrentPosition(intptr_t value) {
  stream_.SetPosition(value);
  Advance();
}


void TokenStream::Iterator::Advance() {
  intptr_t value;
  do {
    cur_token_pos_ = stream_.Position();
    value = ReadToken();
  } while ((stream_type_ == kNoNewlines) &&
           (static_cast<Token::Kind>(value) == Token::kNEWLINE));
  if (value < Token::kNumTokens) {
    cur_token_kind_ = static_cast<Token::Kind>(value);
    cur_token_obj_index_ = -1;
    return;
  }
  cur_token_obj_index_ = value - Token::kNumTokens;
  obj_ = token_objects_.At(cur_token_obj_index_);
  if (obj_.IsLiteralToken()) {
    const LiteralToken& literal_token = LiteralToken::Cast(obj_);
    cur_token_kind_ = literal_token.kind();
    return;
  }
  ASSERT(obj_.IsString());  // Must be an identifier.
  cur_token_kind_ = Token::kIDENT;
}


RawObject* TokenStream::Iterator::CurrentToken() const {
  if (cur_token_obj_index_ != -1) {
    return token_objects_.At(cur_token_obj_index_);
  } else {
    return Smi::New(cur_token_kind_);
  }
}


RawString* TokenStream::Iterator::CurrentLiteral() const {
  obj_ = CurrentToken();
  return MakeLiteralToken(obj_);
}


RawString* TokenStream::Iterator::MakeLiteralToken(const Object& obj) const {
  if (obj.IsString()) {
    return reinterpret_cast<RawString*>(obj.raw());
  } else if (obj.IsSmi()) {
    Token::Kind kind = static_cast<Token::Kind>(
        Smi::Value(reinterpret_cast<RawSmi*>(obj.raw())));
    ASSERT(kind < Token::kNumTokens);
    if (Token::IsPseudoKeyword(kind) || Token::IsKeyword(kind)) {
      return Symbols::Keyword(kind).raw();
    }
    return Symbols::New(Token::Str(kind));
  } else {
    ASSERT(obj.IsLiteralToken());  // Must be a literal token.
    const LiteralToken& literal_token = LiteralToken::Cast(obj);
    return literal_token.literal();
  }
}


bool Script::HasSource() const {
  return raw_ptr()->source_ != String::null();
}


RawString* Script::Source() const {
  String& source = String::Handle(raw_ptr()->source_);
  if (source.IsNull()) {
    return GenerateSource();
  }
  return raw_ptr()->source_;
}


RawString* Script::GenerateSource() const {
  const TokenStream& token_stream = TokenStream::Handle(tokens());
  return token_stream.GenerateSource();
}


RawGrowableObjectArray* Script::GenerateLineNumberArray() const {
  Zone* zone = Thread::Current()->zone();
  const GrowableObjectArray& info =
      GrowableObjectArray::Handle(zone, GrowableObjectArray::New());
  const String& source = String::Handle(zone, Source());
  const String& key = Symbols::Empty();
  const Object& line_separator = Object::Handle(zone);
  const TokenStream& tkns = TokenStream::Handle(zone, tokens());
  Smi& value = Smi::Handle(zone);
  String& tokenValue = String::Handle(zone);
  ASSERT(!tkns.IsNull());
  TokenStream::Iterator tkit(tkns, 0, TokenStream::Iterator::kAllTokens);
  int current_line = -1;
  Scanner s(source, key);
  s.Scan();
  bool skippedNewline = false;
  while (tkit.CurrentTokenKind() != Token::kEOS) {
    if (tkit.CurrentTokenKind() == Token::kNEWLINE) {
      // Skip newlines from the token stream.
      skippedNewline = true;
      tkit.Advance();
      continue;
    }
    if (s.current_token().kind != tkit.CurrentTokenKind()) {
      // Suppose we have a multiline string with interpolation:
      //
      // 10    '''
      // 11    bar
      // 12    baz
      // 13    foo is $foo
      // 14    '''
      //
      // In the token stream, this becomes something like:
      //
      // 10    string('bar\nbaz\nfoo is\n')
      // 11    newline
      // 12    newline
      // 13    string('') interpol_var(foo) string('\n')
      // 14
      //
      // In order to keep the token iterator and the scanner in sync,
      // we need to skip the extra empty string before the
      // interpolation.
      if (skippedNewline &&
          (s.current_token().kind == Token::kINTERPOL_VAR ||
           s.current_token().kind == Token::kINTERPOL_START) &&
          tkit.CurrentTokenKind() == Token::kSTRING) {
        tokenValue = tkit.CurrentLiteral();
        if (tokenValue.Length() == 0) {
          tkit.Advance();
        }
      }
    }
    skippedNewline = false;
    ASSERT(s.current_token().kind == tkit.CurrentTokenKind());
    int token_line = s.current_token().position.line;
    if (token_line != current_line) {
      // emit line
      info.Add(line_separator);
      value = Smi::New(token_line + line_offset());
      info.Add(value);
      current_line = token_line;
    }
    // TODO(hausner): Could optimize here by not reporting tokens
    // that will never be a location used by the debugger, e.g.
    // braces, semicolons, most keywords etc.
    value = Smi::New(tkit.CurrentPosition());
    info.Add(value);
    int column = s.current_token().position.column;
    // On the first line of the script we must add the column offset.
    if (token_line == 1) {
      column += col_offset();
    }
    value = Smi::New(column);
    info.Add(value);
    tkit.Advance();
    s.Scan();
  }
  return info.raw();
}


const char* Script::GetKindAsCString() const {
  switch (kind()) {
    case RawScript::kScriptTag:
      return "script";
    case RawScript::kLibraryTag:
      return "library";
    case RawScript::kSourceTag:
      return "source";
    case RawScript::kPatchTag:
      return "patch";
    case RawScript::kEvaluateTag:
      return "evaluate";
    default:
      UNIMPLEMENTED();
  }
  UNREACHABLE();
  return NULL;
}


void Script::set_url(const String& value) const {
  StorePointer(&raw_ptr()->url_, value.raw());
}


void Script::set_source(const String& value) const {
  StorePointer(&raw_ptr()->source_, value.raw());
}


void Script::set_kind(RawScript::Kind value) const {
  StoreNonPointer(&raw_ptr()->kind_, value);
}


void Script::set_tokens(const TokenStream& value) const {
  StorePointer(&raw_ptr()->tokens_, value.raw());
}


void Script::Tokenize(const String& private_key) const {
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  const TokenStream& tkns = TokenStream::Handle(zone, tokens());
  if (!tkns.IsNull()) {
    // Already tokenized.
    return;
  }
  // Get the source, scan and allocate the token stream.
  VMTagScope tagScope(thread, VMTag::kCompileScannerTagId);
  CSTAT_TIMER_SCOPE(thread, scanner_timer);
  const String& src = String::Handle(zone, Source());
  Scanner scanner(src, private_key);
  const Scanner::GrowableTokenStream& ts = scanner.GetStream();
  INC_STAT(thread, num_tokens_scanned, ts.length());
  set_tokens(TokenStream::Handle(zone, TokenStream::New(ts, private_key)));
  INC_STAT(thread, src_length, src.Length());
}


void Script::SetLocationOffset(intptr_t line_offset,
                               intptr_t col_offset) const {
  ASSERT(line_offset >= 0);
  ASSERT(col_offset >= 0);
  StoreNonPointer(&raw_ptr()->line_offset_, line_offset);
  StoreNonPointer(&raw_ptr()->col_offset_, col_offset);
}


void Script::GetTokenLocation(intptr_t token_pos,
                              intptr_t* line,
                              intptr_t* column,
                              intptr_t* token_len) const {
  ASSERT(line != NULL);
  const TokenStream& tkns = TokenStream::Handle(tokens());
  if (column == NULL) {
    TokenStream::Iterator tkit(tkns, 0, TokenStream::Iterator::kAllTokens);
    intptr_t cur_line = line_offset() + 1;
    while (tkit.CurrentPosition() < token_pos &&
           tkit.CurrentTokenKind() != Token::kEOS) {
      if (tkit.CurrentTokenKind() == Token::kNEWLINE) {
        cur_line++;
      }
      tkit.Advance();
    }
    *line = cur_line;
  } else {
    const String& src = String::Handle(Source());
    intptr_t src_pos = tkns.ComputeSourcePosition(token_pos);
    Scanner scanner(src, Symbols::Empty());
    scanner.ScanTo(src_pos);
    intptr_t relative_line = scanner.CurrentPosition().line;
    *line = relative_line + line_offset();
    *column = scanner.CurrentPosition().column;
    if (token_len != NULL) {
      if (scanner.current_token().literal != NULL) {
        *token_len = scanner.current_token().literal->Length();
      } else {
        *token_len = 1;
      }
    }
    // On the first line of the script we must add the column offset.
    if (relative_line == 1) {
      *column += col_offset();
    }
  }
}


void Script::TokenRangeAtLine(intptr_t line_number,
                              intptr_t* first_token_index,
                              intptr_t* last_token_index) const {
  ASSERT(first_token_index != NULL && last_token_index != NULL);
  ASSERT(line_number > 0);
  *first_token_index = -1;
  *last_token_index = -1;
  const TokenStream& tkns = TokenStream::Handle(tokens());
  line_number -= line_offset();
  if (line_number < 1) line_number = 1;
  TokenStream::Iterator tkit(tkns, 0, TokenStream::Iterator::kAllTokens);
  // Scan through the token stream to the required line.
  intptr_t cur_line = 1;
  while (cur_line < line_number && tkit.CurrentTokenKind() != Token::kEOS) {
    if (tkit.CurrentTokenKind() == Token::kNEWLINE) {
      cur_line++;
    }
    tkit.Advance();
  }
  if (tkit.CurrentTokenKind() == Token::kEOS) {
    // End of token stream before reaching required line.
    return;
  }
  if (tkit.CurrentTokenKind() == Token::kNEWLINE) {
    // No tokens on the current line. If there is a valid token afterwards, put
    // it into first_token_index.
    while (tkit.CurrentTokenKind() == Token::kNEWLINE &&
           tkit.CurrentTokenKind() != Token::kEOS) {
      tkit.Advance();
    }
    if (tkit.CurrentTokenKind() != Token::kEOS) {
      *first_token_index = tkit.CurrentPosition();
    }
    return;
  }
  *first_token_index = tkit.CurrentPosition();
  // We cannot do "CurrentPosition() - 1" for the last token, because we do not
  // know whether the previous token is a simple one or not.
  intptr_t end_pos = *first_token_index;
  while (tkit.CurrentTokenKind() != Token::kNEWLINE &&
         tkit.CurrentTokenKind() != Token::kEOS) {
    end_pos = tkit.CurrentPosition();
    tkit.Advance();
  }
  *last_token_index = end_pos;
}


RawString* Script::GetLine(intptr_t line_number, Heap::Space space) const {
  const String& src = String::Handle(Source());
  intptr_t relative_line_number = line_number - line_offset();
  intptr_t current_line = 1;
  intptr_t line_start_idx = -1;
  intptr_t last_char_idx = -1;
  for (intptr_t ix = 0;
       (ix < src.Length()) && (current_line <= relative_line_number);
       ix++) {
    if ((current_line == relative_line_number) && (line_start_idx < 0)) {
      line_start_idx = ix;
    }
    if (src.CharAt(ix) == '\n') {
      current_line++;
    } else if (src.CharAt(ix) == '\r') {
      if ((ix + 1 != src.Length()) && (src.CharAt(ix + 1) != '\n')) {
        current_line++;
      }
    } else {
      last_char_idx = ix;
    }
  }
  // Guarantee that returned string is never NULL.

  if (line_start_idx >= 0) {
    return String::SubString(src,
                             line_start_idx,
                             last_char_idx - line_start_idx + 1,
                             space);
  } else {
    return Symbols::Empty().raw();
  }
}


RawString* Script::GetSnippet(intptr_t from_line,
                              intptr_t from_column,
                              intptr_t to_line,
                              intptr_t to_column) const {
  const String& src = String::Handle(Source());
  intptr_t length = src.Length();
  intptr_t line = 1 + line_offset();
  intptr_t column = 1;
  intptr_t scan_position = 0;
  intptr_t snippet_start = -1;
  intptr_t snippet_end = -1;
  if (from_line - line_offset() == 1) {
    column += col_offset();
  }

  while (scan_position != length) {
    if (snippet_start == -1) {
      if ((line == from_line) && (column == from_column)) {
        snippet_start = scan_position;
      }
    }

    char c = src.CharAt(scan_position);
    if (c == '\n') {
      line++;
      column = 0;
    } else if (c == '\r') {
      line++;
      column = 0;
      if ((scan_position + 1 != length) &&
          (src.CharAt(scan_position + 1) == '\n')) {
        scan_position++;
      }
    }
    scan_position++;
    column++;

    if ((line == to_line) && (column == to_column)) {
      snippet_end = scan_position;
      break;
    }
  }
  String& snippet = String::Handle();
  if ((snippet_start != -1) && (snippet_end != -1)) {
    snippet =
        String::SubString(src, snippet_start, snippet_end - snippet_start);
  }
  return snippet.raw();
}


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


RawScript* Script::New(const String& url,
                       const String& source,
                       RawScript::Kind kind) {
  const Script& result = Script::Handle(Script::New());
  result.set_url(String::Handle(Symbols::New(url)));
  result.set_source(source);
  result.set_kind(kind);
  result.SetLocationOffset(0, 0);
  return result.raw();
}


const char* Script::ToCString() const {
  return "Script";
}


RawLibrary* Script::FindLibrary() const {
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  Isolate* isolate = thread->isolate();
  const GrowableObjectArray& libs = GrowableObjectArray::Handle(
      zone, isolate->object_store()->libraries());
  Library& lib = Library::Handle();
  Array& scripts = Array::Handle();
  for (intptr_t i = 0; i < libs.Length(); i++) {
    lib ^= libs.At(i);
    scripts = lib.LoadedScripts();
    for (intptr_t j = 0; j < scripts.Length(); j++) {
      if (scripts.At(j) == raw()) {
        return lib.raw();
      }
    }
  }
  return Library::null();
}


// See also Dart_ScriptGetTokenInfo.
void Script::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Script", ref);
  const String& uri = String::Handle(url());
  ASSERT(!uri.IsNull());
  const String& encoded_uri = String::Handle(String::EncodeIRI(uri));
  ASSERT(!encoded_uri.IsNull());
  const Library& lib = Library::Handle(FindLibrary());
  if (kind() == RawScript::kEvaluateTag) {
    jsobj.AddServiceId(*this);
  } else {
    ASSERT(!lib.IsNull());
    jsobj.AddFixedServiceId("libraries/%" Pd "/scripts/%s",
        lib.index(), encoded_uri.ToCString());
  }
  jsobj.AddPropertyStr("uri", uri);
  jsobj.AddProperty("_kind", GetKindAsCString());
  if (ref) {
    return;
  }
  if (!lib.IsNull()) {
    jsobj.AddProperty("library", lib);
  }
  const String& source = String::Handle(Source());
  jsobj.AddProperty("lineOffset", line_offset());
  jsobj.AddProperty("columnOffset", col_offset());
  jsobj.AddPropertyStr("source", source);

  // Print the line number table
  {
    JSONArray tokenPosTable(&jsobj, "tokenPosTable");

    const GrowableObjectArray& lineNumberArray =
        GrowableObjectArray::Handle(GenerateLineNumberArray());
    Object& value = Object::Handle();
    intptr_t pos = 0;

    // Skip leading null.
    ASSERT(lineNumberArray.Length() > 0);
    value = lineNumberArray.At(pos);
    ASSERT(value.IsNull());
    pos++;

    while (pos < lineNumberArray.Length()) {
      JSONArray lineInfo(&tokenPosTable);
      while (pos < lineNumberArray.Length()) {
        value = lineNumberArray.At(pos);
        pos++;
        if (value.IsNull()) {
          break;
        }
        const Smi& smi = Smi::Cast(value);
        lineInfo.AddValue(smi.Value());
      }
    }
  }
}


DictionaryIterator::DictionaryIterator(const Library& library)
    : array_(Array::Handle(library.dictionary())),
      // Last element in array is a Smi indicating the number of entries used.
      size_(Array::Handle(library.dictionary()).Length() - 1),
      next_ix_(0) {
  MoveToNextObject();
}


RawObject* DictionaryIterator::GetNext() {
  ASSERT(HasNext());
  int ix = next_ix_++;
  MoveToNextObject();
  ASSERT(array_.At(ix) != Object::null());
  return array_.At(ix);
}


void DictionaryIterator::MoveToNextObject() {
  Object& obj = Object::Handle(array_.At(next_ix_));
  while (obj.IsNull() && HasNext()) {
    next_ix_++;
    obj = array_.At(next_ix_);
  }
}


ClassDictionaryIterator::ClassDictionaryIterator(const Library& library,
                                                 IterationKind kind)
    : DictionaryIterator(library),
      anon_array_((kind == kIteratePrivate) ?
          Array::Handle(library.anonymous_classes()) : Object::empty_array()),
      anon_size_((kind == kIteratePrivate) ?
                 library.num_anonymous_classes() : 0),
      anon_ix_(0) {
  MoveToNextClass();
}


RawClass* ClassDictionaryIterator::GetNextClass() {
  ASSERT(HasNext());
  Class& cls = Class::Handle();
  if (next_ix_ < size_) {
    int ix = next_ix_++;
    cls ^= array_.At(ix);
    MoveToNextClass();
    return cls.raw();
  }
  ASSERT(anon_ix_ < anon_size_);
  cls ^= anon_array_.At(anon_ix_++);
  return cls.raw();
}


void ClassDictionaryIterator::MoveToNextClass() {
  Object& obj = Object::Handle();
  while (next_ix_ < size_) {
    obj = array_.At(next_ix_);
    if (obj.IsClass()) {
      return;
    }
    next_ix_++;
  }
}


LibraryPrefixIterator::LibraryPrefixIterator(const Library& library)
    : DictionaryIterator(library) {
  Advance();
}


RawLibraryPrefix* LibraryPrefixIterator::GetNext() {
  ASSERT(HasNext());
  int ix = next_ix_++;
  Object& obj = Object::Handle(array_.At(ix));
  Advance();
  return LibraryPrefix::Cast(obj).raw();
}


void LibraryPrefixIterator::Advance() {
  Object& obj = Object::Handle(array_.At(next_ix_));
  while (!obj.IsLibraryPrefix() && HasNext()) {
    next_ix_++;
    obj = array_.At(next_ix_);
  }
}


static void ReportTooManyImports(const Library& lib) {
  const String& url = String::Handle(lib.url());
  Report::MessageF(Report::kError,
                   Script::Handle(lib.LookupScript(url)),
                   Scanner::kNoSourcePos,
                   "too many imports in library '%s'",
                   url.ToCString());
  UNREACHABLE();
}


void Library::set_num_imports(intptr_t value) const {
  if (!Utils::IsUint(16, value)) {
    ReportTooManyImports(*this);
  }
  StoreNonPointer(&raw_ptr()->num_imports_, value);
}


void Library::SetName(const String& name) const {
  // Only set name once.
  ASSERT(!Loaded());
  ASSERT(name.IsSymbol());
  StorePointer(&raw_ptr()->name_, name.raw());
}


void Library::SetLoadInProgress() const {
  // Must not already be in the process of being loaded.
  ASSERT(raw_ptr()->load_state_ <= RawLibrary::kLoadRequested);
  StoreNonPointer(&raw_ptr()->load_state_, RawLibrary::kLoadInProgress);
}


void Library::SetLoadRequested() const {
  // Must not be already loaded.
  ASSERT(raw_ptr()->load_state_ == RawLibrary::kAllocated);
  StoreNonPointer(&raw_ptr()->load_state_, RawLibrary::kLoadRequested);
}


void Library::SetLoaded() const {
  // Should not be already loaded or just allocated.
  ASSERT(LoadInProgress() || LoadRequested());
  StoreNonPointer(&raw_ptr()->load_state_, RawLibrary::kLoaded);
}


void Library::SetLoadError(const Instance& error) const {
  // Should not be already successfully loaded or just allocated.
  ASSERT(LoadInProgress() || LoadRequested() || LoadFailed());
  StoreNonPointer(&raw_ptr()->load_state_, RawLibrary::kLoadError);
  StorePointer(&raw_ptr()->load_error_, error.raw());
}


// Traits for looking up Libraries by url in a hash set.
class LibraryUrlTraits {
 public:
  // Called when growing the table.
  static bool IsMatch(const Object& a, const Object& b) {
    ASSERT(a.IsLibrary() && b.IsLibrary());
    // Library objects are always canonical.
    return a.raw() == b.raw();
  }
  static uword Hash(const Object& key) {
    return Library::Cast(key).UrlHash();
  }
};


typedef UnorderedHashSet<LibraryUrlTraits> LibraryLoadErrorSet;


RawInstance* Library::TransitiveLoadError() const {
  if (LoadError() != Instance::null()) {
    return LoadError();
  }
  Thread* thread = Thread::Current();
  Isolate* isolate = thread->isolate();
  Zone* zone = thread->zone();
  ObjectStore* object_store = isolate->object_store();
  LibraryLoadErrorSet set(object_store->library_load_error_table());
  bool present = false;
  if (set.GetOrNull(*this, &present) != Object::null()) {
    object_store->set_library_load_error_table(set.Release());
    return Instance::null();
  }
  // Ensure we don't repeatedly visit the same library again.
  set.Insert(*this);
  object_store->set_library_load_error_table(set.Release());
  intptr_t num_imp = num_imports();
  Library& lib = Library::Handle(zone);
  Instance& error = Instance::Handle(zone);
  for (intptr_t i = 0; i < num_imp; i++) {
    HANDLESCOPE(thread);
    lib = ImportLibraryAt(i);
    error = lib.TransitiveLoadError();
    if (!error.IsNull()) {
      break;
    }
  }
  return error.raw();
}


static RawString* MakeClassMetaName(const Class& cls) {
  return Symbols::FromConcat(Symbols::At(), String::Handle(cls.Name()));
}


static RawString* MakeFieldMetaName(const Field& field) {
  const String& cname =
      String::Handle(MakeClassMetaName(Class::Handle(field.origin())));
  GrowableHandlePtrArray<const String> pieces(Thread::Current()->zone(), 3);
  pieces.Add(cname);
  pieces.Add(Symbols::At());
  pieces.Add(String::Handle(field.name()));
  return Symbols::FromConcatAll(pieces);
}


static RawString* MakeFunctionMetaName(const Function& func) {
  const String& cname =
      String::Handle(MakeClassMetaName(Class::Handle(func.origin())));
  GrowableHandlePtrArray<const String> pieces(Thread::Current()->zone(), 3);
  pieces.Add(cname);
  pieces.Add(Symbols::At());
  pieces.Add(String::Handle(func.QualifiedPrettyName()));
  return Symbols::FromConcatAll(pieces);
}


static RawString* MakeTypeParameterMetaName(const TypeParameter& param) {
  const String& cname = String::Handle(
      MakeClassMetaName(Class::Handle(param.parameterized_class())));
  GrowableHandlePtrArray<const String> pieces(Thread::Current()->zone(), 3);
  pieces.Add(cname);
  pieces.Add(Symbols::At());
  pieces.Add(String::Handle(param.name()));
  return Symbols::FromConcatAll(pieces);
}


void Library::AddMetadata(const Class& cls,
                          const String& name,
                          intptr_t token_pos) const {
  const String& metaname = String::Handle(Symbols::New(name));
  Field& field = Field::Handle(Field::New(metaname,
                                          true,   // is_static
                                          false,  // is_final
                                          false,  // is_const
                                          false,  // is_reflectable
                                          cls,
                                          token_pos));
  field.set_type(Type::Handle(Type::DynamicType()));
  field.SetStaticValue(Array::empty_array(), true);
  GrowableObjectArray& metadata =
      GrowableObjectArray::Handle(this->metadata());
  metadata.Add(field, Heap::kOld);
  cls.AddField(field);
}


void Library::AddClassMetadata(const Class& cls,
                               const Class& toplevel_class,
                               intptr_t token_pos) const {
  // We use the toplevel class as the owner of a class's metadata field because
  // a class's metadata is in scope of the library, not the class.
  AddMetadata(toplevel_class,
              String::Handle(MakeClassMetaName(cls)),
              token_pos);
}


void Library::AddFieldMetadata(const Field& field,
                               intptr_t token_pos) const {
  AddMetadata(Class::Handle(field.origin()),
              String::Handle(MakeFieldMetaName(field)),
              token_pos);
}


void Library::AddFunctionMetadata(const Function& func,
                                  intptr_t token_pos) const {
  AddMetadata(Class::Handle(func.origin()),
              String::Handle(MakeFunctionMetaName(func)),
              token_pos);
}


void Library::AddTypeParameterMetadata(const TypeParameter& param,
                                       intptr_t token_pos) const {
  AddMetadata(Class::Handle(param.parameterized_class()),
              String::Handle(MakeTypeParameterMetaName(param)),
              token_pos);
}


void Library::AddLibraryMetadata(const Class& cls, intptr_t token_pos) const {
  AddMetadata(cls, Symbols::TopLevel(), token_pos);
}


RawString* Library::MakeMetadataName(const Object& obj) const {
  if (obj.IsClass()) {
    return MakeClassMetaName(Class::Cast(obj));
  } else if (obj.IsField()) {
    return MakeFieldMetaName(Field::Cast(obj));
  } else if (obj.IsFunction()) {
    return MakeFunctionMetaName(Function::Cast(obj));
  } else if (obj.IsLibrary()) {
    return Symbols::TopLevel().raw();
  } else if (obj.IsTypeParameter()) {
    return MakeTypeParameterMetaName(TypeParameter::Cast(obj));
  }
  UNIMPLEMENTED();
  return String::null();
}


RawField* Library::GetMetadataField(const String& metaname) const {
  const GrowableObjectArray& metadata =
      GrowableObjectArray::Handle(this->metadata());
  Field& entry = Field::Handle();
  String& entryname = String::Handle();
  intptr_t num_entries = metadata.Length();
  for (intptr_t i = 0; i < num_entries; i++) {
    entry ^= metadata.At(i);
    entryname = entry.name();
    if (entryname.Equals(metaname)) {
      return entry.raw();
    }
  }
  return Field::null();
}


RawObject* Library::GetMetadata(const Object& obj) const {
  if (!obj.IsClass() && !obj.IsField() && !obj.IsFunction() &&
      !obj.IsLibrary() && !obj.IsTypeParameter()) {
    return Object::null();
  }
  const String& metaname = String::Handle(MakeMetadataName(obj));
  Field& field = Field::Handle(GetMetadataField(metaname));
  if (field.IsNull()) {
    // There is no metadata for this object.
    return Object::empty_array().raw();
  }
  Object& metadata = Object::Handle();
  metadata = field.StaticValue();
  if (field.StaticValue() == Object::empty_array().raw()) {
    metadata = Parser::ParseMetadata(Class::Handle(field.owner()),
                                     field.token_pos());
    if (metadata.IsArray()) {
      ASSERT(Array::Cast(metadata).raw() != Object::empty_array().raw());
      field.SetStaticValue(Array::Cast(metadata), true);
    }
  }
  return metadata.raw();
}


static bool ShouldBePrivate(const String& name) {
  return
      (name.Length() >= 1 &&
       name.CharAt(0) == '_') ||
      (name.Length() >= 5 &&
       (name.CharAt(4) == '_' &&
        (name.CharAt(0) == 'g' || name.CharAt(0) == 's') &&
        name.CharAt(1) == 'e' &&
        name.CharAt(2) == 't' &&
        name.CharAt(3) == ':'));
}


RawObject* Library::ResolveName(const String& name) const {
  Object& obj = Object::Handle();
  if (FLAG_use_lib_cache && LookupResolvedNamesCache(name, &obj)) {
    return obj.raw();
  }
  obj = LookupLocalObject(name);
  if (!obj.IsNull()) {
    // Names that are in this library's dictionary and are unmangled
    // are not cached. This reduces the size of the the cache.
    return obj.raw();
  }
  String& accessor_name = String::Handle(Field::GetterName(name));
  obj = LookupLocalObject(accessor_name);
  if (obj.IsNull()) {
    accessor_name = Field::SetterName(name);
    obj = LookupLocalObject(accessor_name);
    if (obj.IsNull() && !ShouldBePrivate(name)) {
      obj = LookupImportedObject(name);
    }
  }
  AddToResolvedNamesCache(name, obj);
  return obj.raw();
}


class StringEqualsTraits {
 public:
  static bool IsMatch(const Object& a, const Object& b) {
    return String::Cast(a).Equals(String::Cast(b));
  }
  static uword Hash(const Object& obj) {
    return String::Cast(obj).Hash();
  }
};
typedef UnorderedHashMap<StringEqualsTraits> ResolvedNamesMap;


// Returns true if the name is found in the cache, false no cache hit.
// obj is set to the cached entry. It may be null, indicating that the
// name does not resolve to anything in this library.
bool Library::LookupResolvedNamesCache(const String& name,
                                       Object* obj) const {
  ResolvedNamesMap cache(resolved_names());
  bool present = false;
  *obj = cache.GetOrNull(name, &present);
  ASSERT(cache.Release().raw() == resolved_names());
  return present;
}


// Add a name to the resolved name cache. This name resolves to the
// given object in this library scope. obj may be null, which means
// the name does not resolve to anything in this library scope.
void Library::AddToResolvedNamesCache(const String& name,
                                      const Object& obj) const {
  if (!FLAG_use_lib_cache) {
    return;
  }
  ResolvedNamesMap cache(resolved_names());
  cache.UpdateOrInsert(name, obj);
  StorePointer(&raw_ptr()->resolved_names_, cache.Release().raw());
}


void Library::InvalidateResolvedName(const String& name) const {
  Object& entry = Object::Handle();
  if (LookupResolvedNamesCache(name, &entry)) {
    // TODO(koda): Support deleted sentinel in snapshots and remove only 'name'.
    InvalidateResolvedNamesCache();
  }
}


void Library::InvalidateResolvedNamesCache() const {
  const intptr_t kInvalidatedCacheSize = 16;
  InitResolvedNamesCache(kInvalidatedCacheSize);
}


void Library::GrowDictionary(const Array& dict, intptr_t dict_size) const {
  // TODO(iposva): Avoid exponential growth.
  intptr_t new_dict_size = dict_size * 2;
  const Array& new_dict =
      Array::Handle(Array::New(new_dict_size + 1, Heap::kOld));
  // Rehash all elements from the original dictionary
  // to the newly allocated array.
  Object& entry = Class::Handle();
  String& entry_name = String::Handle();
  Object& new_entry = Object::Handle();
  for (intptr_t i = 0; i < dict_size; i++) {
    entry = dict.At(i);
    if (!entry.IsNull()) {
      entry_name = entry.DictionaryName();
      ASSERT(!entry_name.IsNull());
      const intptr_t hash = entry_name.Hash();
      intptr_t index = hash % new_dict_size;
      new_entry = new_dict.At(index);
      while (!new_entry.IsNull()) {
        index = (index + 1) % new_dict_size;  // Move to next element.
        new_entry = new_dict.At(index);
      }
      new_dict.SetAt(index, entry);
    }
  }
  // Copy used count.
  new_entry = dict.At(dict_size);
  new_dict.SetAt(new_dict_size, new_entry);
  // Remember the new dictionary now.
  StorePointer(&raw_ptr()->dictionary_, new_dict.raw());
}


void Library::AddObject(const Object& obj, const String& name) const {
  ASSERT(obj.IsClass() ||
         obj.IsFunction() ||
         obj.IsField() ||
         obj.IsLibraryPrefix());
  ASSERT(name.Equals(String::Handle(obj.DictionaryName())));
  ASSERT(LookupLocalObject(name) == Object::null());
  const Array& dict = Array::Handle(dictionary());
  intptr_t dict_size = dict.Length() - 1;
  intptr_t index = name.Hash() % dict_size;

  Object& entry = Object::Handle();
  entry = dict.At(index);
  // An empty spot will be found because we keep the hash set at most 75% full.
  while (!entry.IsNull()) {
    index = (index + 1) % dict_size;
    entry = dict.At(index);
  }

  // Insert the object at the empty slot.
  dict.SetAt(index, obj);
  // One more element added.
  intptr_t used_elements = Smi::Value(Smi::RawCast(dict.At(dict_size))) + 1;
  const Smi& used = Smi::Handle(Smi::New(used_elements));
  dict.SetAt(dict_size, used);  // Update used count.

  // Rehash if symbol_table is 75% full.
  if (used_elements > ((dict_size / 4) * 3)) {
    GrowDictionary(dict, dict_size);
  }

  // Invalidate the cache of loaded scripts.
  if (loaded_scripts() != Array::null()) {
    StorePointer(&raw_ptr()->loaded_scripts_, Array::null());
  }
}


// Lookup a name in the library's re-export namespace. The name is
// unmangled, i.e. no getter or setter names should be looked up.
RawObject* Library::LookupReExport(const String& name) const {
  if (HasExports()) {
    const Array& exports = Array::Handle(this->exports());
    // Break potential export cycle while looking up name.
    StorePointer(&raw_ptr()->exports_, Object::empty_array().raw());
    Namespace& ns = Namespace::Handle();
    Object& obj = Object::Handle();
    for (int i = 0; i < exports.Length(); i++) {
      ns ^= exports.At(i);
      obj = ns.Lookup(name);
      if (!obj.IsNull()) {
        break;
      }
    }
    StorePointer(&raw_ptr()->exports_, exports.raw());
    return obj.raw();
  }
  return Object::null();
}


RawObject* Library::LookupEntry(const String& name, intptr_t *index) const {
  Thread* thread = Thread::Current();
  REUSABLE_ARRAY_HANDLESCOPE(thread);
  REUSABLE_OBJECT_HANDLESCOPE(thread);
  REUSABLE_STRING_HANDLESCOPE(thread);
  Array& dict = thread->ArrayHandle();
  dict ^= dictionary();
  intptr_t dict_size = dict.Length() - 1;
  *index = name.Hash() % dict_size;
  Object& entry = thread->ObjectHandle();
  String& entry_name = thread->StringHandle();
  entry = dict.At(*index);
  // Search the entry in the hash set.
  while (!entry.IsNull()) {
    entry_name = entry.DictionaryName();
    ASSERT(!entry_name.IsNull());
     if (entry_name.Equals(name)) {
      return entry.raw();
    }
    *index = (*index + 1) % dict_size;
    entry = dict.At(*index);
  }
  return Object::null();
}


void Library::ReplaceObject(const Object& obj, const String& name) const {
  ASSERT(obj.IsClass() || obj.IsFunction() || obj.IsField());
  ASSERT(LookupLocalObject(name) != Object::null());

  intptr_t index;
  LookupEntry(name, &index);
  // The value is guaranteed to be found.
  const Array& dict = Array::Handle(dictionary());
  dict.SetAt(index, obj);
}


void Library::AddClass(const Class& cls) const {
  const String& class_name = String::Handle(cls.Name());
  AddObject(cls, class_name);
  // Link class to this library.
  cls.set_library(*this);
  InvalidateResolvedName(class_name);
}

static void AddScriptIfUnique(const GrowableObjectArray& scripts,
                              const Script& candidate) {
  if (candidate.IsNull()) {
    return;
  }
  Script& script_obj = Script::Handle();

  for (int i = 0; i < scripts.Length(); i++) {
    script_obj ^= scripts.At(i);
    if (script_obj.raw() == candidate.raw()) {
      // We already have a reference to this script.
      return;
    }
  }
  // Add script to the list of scripts.
  scripts.Add(candidate);
}

RawArray* Library::LoadedScripts() const {
  // We compute the list of loaded scripts lazily. The result is
  // cached in loaded_scripts_.
  if (loaded_scripts() == Array::null()) {
    // Iterate over the library dictionary and collect all scripts.
    const GrowableObjectArray& scripts =
        GrowableObjectArray::Handle(GrowableObjectArray::New(8));
    Object& entry = Object::Handle();
    Class& cls = Class::Handle();
    Class& patch_cls = Class::Handle();
    Script& owner_script = Script::Handle();
    Script& patch_script = Script::Handle();
    DictionaryIterator it(*this);
    while (it.HasNext()) {
      entry = it.GetNext();
      if (entry.IsClass()) {
        owner_script = Class::Cast(entry).script();
        patch_cls = Class::Cast(entry).patch_class();
        if (!patch_cls.IsNull()) {
          patch_script = patch_cls.script();
          AddScriptIfUnique(scripts, patch_script);
        }
      } else if (entry.IsFunction()) {
        owner_script = Function::Cast(entry).script();
      } else if (entry.IsField()) {
        cls = Field::Cast(entry).owner();
        owner_script = cls.script();
      } else {
        continue;
      }
      AddScriptIfUnique(scripts, owner_script);
    }

    // Special case: Scripts that only contain external top-level functions are
    // not included above, but can be referenced through a library's anonymous
    // classes. Example: dart-core:identical.dart.
    Array& anon_classes = Array::Handle(anonymous_classes());
    Function& func = Function::Handle();
    Array& functions = Array::Handle();
    for (intptr_t i = 0; i < anon_classes.Length(); i++) {
      cls ^= anon_classes.At(i);
      if (cls.IsNull()) continue;
      owner_script = cls.script();
      AddScriptIfUnique(scripts, owner_script);
      functions = cls.functions();
      for (intptr_t j = 0; j < functions.Length(); j++) {
        func ^= functions.At(j);
        owner_script = func.script();
        AddScriptIfUnique(scripts, owner_script);
      }
    }

    // Create the array of scripts and cache it in loaded_scripts_.
    const Array& scripts_array = Array::Handle(Array::MakeArray(scripts));
    StorePointer(&raw_ptr()->loaded_scripts_, scripts_array.raw());
  }
  return loaded_scripts();
}


// TODO(hausner): we might want to add a script dictionary to the
// library class to make this lookup faster.
RawScript* Library::LookupScript(const String& url) const {
  const intptr_t url_length = url.Length();
  if (url_length == 0) {
    return Script::null();
  }
  const Array& scripts = Array::Handle(LoadedScripts());
  Script& script = Script::Handle();
  String& script_url = String::Handle();
  const intptr_t num_scripts = scripts.Length();
  for (int i = 0; i < num_scripts; i++) {
    script ^= scripts.At(i);
    script_url = script.url();
    const intptr_t start_idx = script_url.Length() - url_length;
    if ((start_idx == 0) && url.Equals(script_url)) {
      return script.raw();
    } else if (start_idx > 0) {
      // If we do a suffix match, only match if the partial path
      // starts at or immediately after the path separator.
      if (((url.CharAt(0) == '/') ||
          (script_url.CharAt(start_idx - 1) == '/')) &&
          url.Equals(script_url, start_idx, url_length)) {
        return script.raw();
      }
    }
  }
  return Script::null();
}


RawFunction* Library::LookupFunctionInScript(const Script& script,
                                             intptr_t token_pos) const {
  Class& cls = Class::Handle();
  Function& func = Function::Handle();
  ClassDictionaryIterator it(*this, ClassDictionaryIterator::kIteratePrivate);
  while (it.HasNext()) {
    cls = it.GetNextClass();
    if (script.raw() == cls.script()) {
      func = cls.LookupFunctionAtToken(token_pos);
      if (!func.IsNull()) {
        return func.raw();
      }
    }
  }
  return Function::null();
}


RawObject* Library::LookupLocalObject(const String& name) const {
  intptr_t index;
  return LookupEntry(name, &index);
}


RawField* Library::LookupFieldAllowPrivate(const String& name) const {
  Object& obj = Object::Handle(LookupObjectAllowPrivate(name));
  if (obj.IsField()) {
    return Field::Cast(obj).raw();
  }
  return Field::null();
}


RawField* Library::LookupLocalField(const String& name) const {
  Object& obj = Object::Handle(LookupLocalObjectAllowPrivate(name));
  if (obj.IsField()) {
    return Field::Cast(obj).raw();
  }
  return Field::null();
}


RawFunction* Library::LookupFunctionAllowPrivate(const String& name) const {
  Object& obj = Object::Handle(LookupObjectAllowPrivate(name));
  if (obj.IsFunction()) {
    return Function::Cast(obj).raw();
  }
  return Function::null();
}


RawFunction* Library::LookupLocalFunction(const String& name) const {
  Object& obj = Object::Handle(LookupLocalObjectAllowPrivate(name));
  if (obj.IsFunction()) {
    return Function::Cast(obj).raw();
  }
  return Function::null();
}


RawObject* Library::LookupLocalObjectAllowPrivate(const String& name) const {
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  Object& obj = Object::Handle(zone, Object::null());
  obj = LookupLocalObject(name);
  if (obj.IsNull() && ShouldBePrivate(name)) {
    String& private_name = String::Handle(zone, PrivateName(name));
    obj = LookupLocalObject(private_name);
  }
  return obj.raw();
}


RawObject* Library::LookupObjectAllowPrivate(const String& name) const {
  // First check if name is found in the local scope of the library.
  Object& obj = Object::Handle(LookupLocalObjectAllowPrivate(name));
  if (!obj.IsNull()) {
    return obj.raw();
  }

  // Do not look up private names in imported libraries.
  if (ShouldBePrivate(name)) {
    return Object::null();
  }

  // Now check if name is found in any imported libs.
  return LookupImportedObject(name);
}


RawObject* Library::LookupImportedObject(const String& name) const {
  Object& obj = Object::Handle();
  Namespace& import = Namespace::Handle();
  Library& import_lib = Library::Handle();
  String& import_lib_url = String::Handle();
  String& first_import_lib_url = String::Handle();
  Object& found_obj = Object::Handle();
  String& found_obj_name = String::Handle();
  ASSERT(!ShouldBePrivate(name));
  for (intptr_t i = 0; i < num_imports(); i++) {
    import ^= ImportAt(i);
    obj = import.Lookup(name);
    if (!obj.IsNull()) {
      import_lib = import.library();
      import_lib_url = import_lib.url();
      if (found_obj.raw() != obj.raw()) {
        if (first_import_lib_url.IsNull() ||
            first_import_lib_url.StartsWith(Symbols::DartScheme())) {
          // This is the first object we found, or the
          // previously found object is exported from a Dart
          // system library. The newly found object hides the one
          // from the Dart library.
          first_import_lib_url = import_lib.url();
          found_obj = obj.raw();
          found_obj_name = obj.DictionaryName();
        } else if (import_lib_url.StartsWith(Symbols::DartScheme())) {
          // The newly found object is exported from a Dart system
          // library. It is hidden by the previously found object.
          // We continue to search.
        } else {
          // We found two different objects with the same name.
          // Note that we need to compare the names again because
          // looking up an unmangled name can return a getter or a
          // setter. A getter name is the same as the unmangled name,
          // but a setter name is different from an unmangled name or a
          // getter name.
          if (Field::IsGetterName(found_obj_name)) {
            found_obj_name = Field::NameFromGetter(found_obj_name);
          }
          String& second_obj_name = String::Handle(obj.DictionaryName());
          if (Field::IsGetterName(second_obj_name)) {
            second_obj_name = Field::NameFromGetter(second_obj_name);
          }
          if (found_obj_name.Equals(second_obj_name)) {
            return Object::null();
          }
        }
      }
    }
  }
  return found_obj.raw();
}


RawClass* Library::LookupClass(const String& name) const {
  Object& obj = Object::Handle(ResolveName(name));
  if (obj.IsClass()) {
    return Class::Cast(obj).raw();
  }
  return Class::null();
}


RawClass* Library::LookupLocalClass(const String& name) const {
  Object& obj = Object::Handle(LookupLocalObject(name));
  if (obj.IsClass()) {
    return Class::Cast(obj).raw();
  }
  return Class::null();
}


RawClass* Library::LookupClassAllowPrivate(const String& name) const {
  // See if the class is available in this library or in the top level
  // scope of any imported library.
  Zone* zone = Thread::Current()->zone();
  const Class& cls = Class::Handle(zone, LookupClass(name));
  if (!cls.IsNull()) {
    return cls.raw();
  }

  // Now try to lookup the class using its private name, but only in
  // this library (not in imported libraries).
  if (ShouldBePrivate(name)) {
    String& private_name = String::Handle(zone, PrivateName(name));
    const Object& obj = Object::Handle(LookupLocalObject(private_name));
    if (obj.IsClass()) {
      return Class::Cast(obj).raw();
    }
  }
  return Class::null();
}


RawLibraryPrefix* Library::LookupLocalLibraryPrefix(const String& name) const {
  const Object& obj = Object::Handle(LookupLocalObject(name));
  if (obj.IsLibraryPrefix()) {
    return LibraryPrefix::Cast(obj).raw();
  }
  return LibraryPrefix::null();
}


void Library::AddAnonymousClass(const Class& cls) const {
  intptr_t num_anonymous = this->raw_ptr()->num_anonymous_;
  Array& anon_array = Array::Handle(this->raw_ptr()->anonymous_classes_);
  if (num_anonymous == anon_array.Length()) {
    intptr_t new_len = (num_anonymous == 0) ? 4 : num_anonymous * 2;
    anon_array = Array::Grow(anon_array, new_len);
    StorePointer(&raw_ptr()->anonymous_classes_, anon_array.raw());
  }
  anon_array.SetAt(num_anonymous, cls);
  num_anonymous++;
  StoreNonPointer(&raw_ptr()->num_anonymous_, num_anonymous);
}


RawLibrary* Library::ImportLibraryAt(intptr_t index) const {
  Namespace& import = Namespace::Handle(ImportAt(index));
  if (import.IsNull()) {
    return Library::null();
  }
  return import.library();
}


RawNamespace* Library::ImportAt(intptr_t index) const {
  if ((index < 0) || index >= num_imports()) {
    return Namespace::null();
  }
  const Array& import_list = Array::Handle(imports());
  return Namespace::RawCast(import_list.At(index));
}


bool Library::ImportsCorelib() const {
  Zone* zone = Thread::Current()->zone();
  Library& imported = Library::Handle(zone);
  intptr_t count = num_imports();
  for (int i = 0; i < count; i++) {
    imported = ImportLibraryAt(i);
    if (imported.IsCoreLibrary()) {
      return true;
    }
  }
  LibraryPrefix& prefix = LibraryPrefix::Handle(zone);
  LibraryPrefixIterator it(*this);
  while (it.HasNext()) {
    prefix = it.GetNext();
    count = prefix.num_imports();
    for (int i = 0; i < count; i++) {
      imported = prefix.GetLibrary(i);
      if (imported.IsCoreLibrary()) {
        return true;
      }
    }
  }
  return false;
}


void Library::AddImport(const Namespace& ns) const {
  Array& imports = Array::Handle(this->imports());
  intptr_t capacity = imports.Length();
  if (num_imports() == capacity) {
    capacity = capacity + kImportsCapacityIncrement;
    imports = Array::Grow(imports, capacity);
    StorePointer(&raw_ptr()->imports_, imports.raw());
  }
  intptr_t index = num_imports();
  imports.SetAt(index, ns);
  set_num_imports(index + 1);
}


// Convenience function to determine whether the export list is
// non-empty.
bool Library::HasExports() const {
  return exports() != Object::empty_array().raw();
}


// We add one namespace at a time to the exports array and don't
// pre-allocate any unused capacity. The assumption is that
// re-exports are quite rare.
void Library::AddExport(const Namespace& ns) const {
  Array &exports = Array::Handle(this->exports());
  intptr_t num_exports = exports.Length();
  exports = Array::Grow(exports, num_exports + 1);
  StorePointer(&raw_ptr()->exports_, exports.raw());
  exports.SetAt(num_exports, ns);
}


static RawArray* NewDictionary(intptr_t initial_size) {
  const Array& dict = Array::Handle(Array::New(initial_size + 1, Heap::kOld));
  // The last element of the dictionary specifies the number of in use slots.
  dict.SetAt(initial_size, Smi::Handle(Smi::New(0)));
  return dict.raw();
}


void Library::InitResolvedNamesCache(intptr_t size) const {
  const Array& cache = Array::Handle(HashTables::New<ResolvedNamesMap>(size));
  StorePointer(&raw_ptr()->resolved_names_, cache.raw());
}


void Library::InitClassDictionary() const {
  // TODO(iposva): Find reasonable initial size.
  const int kInitialElementCount = 16;
  StorePointer(&raw_ptr()->dictionary_, NewDictionary(kInitialElementCount));
}


void Library::InitImportList() const {
  const Array& imports =
      Array::Handle(Array::New(kInitialImportsCapacity, Heap::kOld));
  StorePointer(&raw_ptr()->imports_, imports.raw());
  StoreNonPointer(&raw_ptr()->num_imports_, 0);
}


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


RawLibrary* Library::NewLibraryHelper(const String& url,
                                      bool import_core_lib) {
  const Library& result = Library::Handle(Library::New());
  result.StorePointer(&result.raw_ptr()->name_, Symbols::Empty().raw());
  result.StorePointer(&result.raw_ptr()->url_, url.raw());
  result.StorePointer(&result.raw_ptr()->resolved_names_,
                      Object::empty_array().raw());
  result.StorePointer(&result.raw_ptr()->dictionary_,
                      Object::empty_array().raw());
  result.StorePointer(&result.raw_ptr()->metadata_,
                      GrowableObjectArray::New(4, Heap::kOld));
  result.StorePointer(&result.raw_ptr()->anonymous_classes_,
                      Object::empty_array().raw());
  result.StoreNonPointer(&result.raw_ptr()->num_anonymous_, 0);
  result.StorePointer(&result.raw_ptr()->imports_, Object::empty_array().raw());
  result.StorePointer(&result.raw_ptr()->exports_, Object::empty_array().raw());
  result.StorePointer(&result.raw_ptr()->loaded_scripts_, Array::null());
  result.StorePointer(&result.raw_ptr()->load_error_, Instance::null());
  result.set_native_entry_resolver(NULL);
  result.set_native_entry_symbol_resolver(NULL);
  result.set_is_in_fullsnapshot(false);
  result.StoreNonPointer(&result.raw_ptr()->corelib_imported_, true);
  result.set_debuggable(false);
  result.set_is_dart_scheme(url.StartsWith(Symbols::DartScheme()));
  result.StoreNonPointer(&result.raw_ptr()->load_state_,
                         RawLibrary::kAllocated);
  result.StoreNonPointer(&result.raw_ptr()->index_, -1);
  const intptr_t kInitialNameCacheSize = 64;
  result.InitResolvedNamesCache(kInitialNameCacheSize);
  result.InitClassDictionary();
  result.InitImportList();
  result.AllocatePrivateKey();
  if (import_core_lib) {
    const Library& core_lib = Library::Handle(Library::CoreLibrary());
    ASSERT(!core_lib.IsNull());
    const Namespace& ns = Namespace::Handle(
        Namespace::New(core_lib, Object::null_array(), Object::null_array()));
    result.AddImport(ns);
  }
  return result.raw();
}


RawLibrary* Library::New(const String& url) {
  return NewLibraryHelper(url, false);
}


void Library::InitCoreLibrary(Isolate* isolate) {
  const String& core_lib_url = Symbols::DartCore();
  const Library& core_lib =
      Library::Handle(Library::NewLibraryHelper(core_lib_url, false));
  core_lib.SetLoadRequested();
  core_lib.Register();
  isolate->object_store()->set_bootstrap_library(ObjectStore::kCore, core_lib);
  isolate->object_store()->set_root_library(Library::Handle());

  // Hook up predefined classes without setting their library pointers. These
  // classes are coming from the VM isolate, and are shared between multiple
  // isolates so setting their library pointers would be wrong.
  const Class& cls = Class::Handle(Object::dynamic_class());
  core_lib.AddObject(cls, String::Handle(cls.Name()));
}


RawObject* Library::Evaluate(const String& expr,
                             const Array& param_names,
                             const Array& param_values) const {
  // Take or make a fake top-level class and evaluate the expression
  // as a static function of the class.
  Class& top_level_class = Class::Handle();
  Array& top_level_classes = Array::Handle(anonymous_classes());
  ASSERT(top_level_classes.Length() > 0);
  top_level_class ^= top_level_classes.At(0);
  ASSERT(top_level_class.is_finalized());
  return top_level_class.Evaluate(expr, param_names, param_values);
}


void Library::InitNativeWrappersLibrary(Isolate* isolate) {
  static const int kNumNativeWrappersClasses = 4;
  ASSERT(kNumNativeWrappersClasses > 0 && kNumNativeWrappersClasses < 10);
  const String& native_flds_lib_url = Symbols::DartNativeWrappers();
  const Library& native_flds_lib = Library::Handle(
      Library::NewLibraryHelper(native_flds_lib_url, false));
  const String& native_flds_lib_name = Symbols::DartNativeWrappersLibName();
  native_flds_lib.SetName(native_flds_lib_name);
  native_flds_lib.SetLoadRequested();
  native_flds_lib.Register();
  native_flds_lib.SetLoadInProgress();
  isolate->object_store()->set_native_wrappers_library(native_flds_lib);
  static const char* const kNativeWrappersClass = "NativeFieldWrapperClass";
  static const int kNameLength = 25;
  ASSERT(kNameLength == (strlen(kNativeWrappersClass) + 1 + 1));
  char name_buffer[kNameLength];
  String& cls_name = String::Handle();
  for (int fld_cnt = 1; fld_cnt <= kNumNativeWrappersClasses; fld_cnt++) {
    OS::SNPrint(name_buffer,
                kNameLength,
                "%s%d",
                kNativeWrappersClass,
                fld_cnt);
    cls_name = Symbols::New(name_buffer);
    Class::NewNativeWrapper(native_flds_lib, cls_name, fld_cnt);
  }
  native_flds_lib.SetLoaded();
}


// Returns library with given url in current isolate, or NULL.
RawLibrary* Library::LookupLibrary(const String &url) {
  Thread* thread = Thread::Current();
  Zone* zone = thread->zone();
  Isolate* isolate = thread->isolate();
  Library& lib = Library::Handle(zone, Library::null());
  String& lib_url = String::Handle(zone, String::null());
  GrowableObjectArray& libs = GrowableObjectArray::Handle(
      zone, isolate->object_store()->libraries());
  for (int i = 0; i < libs.Length(); i++) {
    lib ^= libs.At(i);
    lib_url ^= lib.url();
    if (lib_url.Equals(url)) {
      return lib.raw();
    }
  }
  return Library::null();
}


RawError* Library::Patch(const Script& script) const {
  ASSERT(script.kind() == RawScript::kPatchTag);
  return Compiler::Compile(*this, script);
}


bool Library::IsPrivate(const String& name) {
  if (ShouldBePrivate(name)) return true;
  // Factory names: List._fromLiteral.
  for (intptr_t i = 1; i < name.Length() - 1; i++) {
    if (name.CharAt(i) == '.') {
      if (name.CharAt(i + 1) == '_') {
        return true;
      }
    }
  }
  return false;
}


bool Library::IsKeyUsed(intptr_t key) {
  intptr_t lib_key;
  const GrowableObjectArray& libs = GrowableObjectArray::Handle(
      Isolate::Current()->object_store()->libraries());
  Library& lib = Library::Handle();
  String& lib_url = String::Handle();
  for (int i = 0; i < libs.Length(); i++) {
    lib ^= libs.At(i);
    lib_url ^= lib.url();
    lib_key = lib_url.Hash();
    if (lib_key == key) {
      return true;
    }
  }
  return false;
}


void Library::AllocatePrivateKey() const {
  const String& url = String::Handle(this->url());
  intptr_t key_value = url.Hash() & kIntptrMax;
  while ((key_value == 0) || Library::IsKeyUsed(key_value)) {
    key_value = (key_value + 1) & kIntptrMax;
  }
  ASSERT(key_value > 0);
  char private_key[32];
  OS::SNPrint(private_key, sizeof(private_key),
              "%c%" Pd "", kPrivateKeySeparator, key_value);
  StorePointer(&raw_ptr()->private_key_, String::New(private_key, Heap::kOld));
}


const String& Library::PrivateCoreLibName(const String& member) {
  const Library& core_lib = Library::Handle(Library::CoreLibrary());
  const String& private_name = String::ZoneHandle(core_lib.PrivateName(member));
  return private_name;
}


RawClass* Library::LookupCoreClass(const String& class_name) {
  const Library& core_lib = Library::Handle(Library::CoreLibrary());
  String& name = String::Handle(class_name.raw());
  if (class_name.CharAt(0) == kPrivateIdentifierStart) {
    // Private identifiers are mangled on a per library basis.
    name = Symbols::FromConcat(name, String::Handle(core_lib.private_key()));
  }
  return core_lib.LookupClass(name);
}


// Cannot handle qualified names properly as it only appends private key to
// the end (e.g. _Alfa.foo -> _Alfa.foo@...).
RawString* Library::PrivateName(const String& name) const {
  ASSERT(IsPrivate(name));
  // ASSERT(strchr(name, '@') == NULL);
  String& str = String::Handle();
  str = name.raw();
  str = Symbols::FromConcat(str, String::Handle(this->private_key()));
  return str.raw();
}


RawLibrary* Library::GetLibrary(intptr_t index) {
  Isolate* isolate = Isolate::Current();
  const GrowableObjectArray& libs =
      GrowableObjectArray::Handle(isolate->object_store()->libraries());
  ASSERT(!libs.IsNull());
  if ((0 <= index) && (index < libs.Length())) {
    Library& lib = Library::Handle();
    lib ^= libs.At(index);
    return lib.raw();
  }
  return Library::null();
}


void Library::Register() const {
  ASSERT(Library::LookupLibrary(String::Handle(url())) == Library::null());
  ObjectStore* object_store = Isolate::Current()->object_store();
  GrowableObjectArray& libs =
      GrowableObjectArray::Handle(object_store->libraries());
  ASSERT(!libs.IsNull());
  set_index(libs.Length());
  libs.Add(*this);
}


RawLibrary* Library::AsyncLibrary() {
  return Isolate::Current()->object_store()->async_library();
}


RawLibrary* Library::ConvertLibrary() {
  return Isolate::Current()->object_store()->convert_library();
}


RawLibrary* Library::CoreLibrary() {
  return Isolate::Current()->object_store()->core_library();
}


RawLibrary* Library::CollectionLibrary() {
  return Isolate::Current()->object_store()->collection_library();
}


RawLibrary* Library::DeveloperLibrary() {
  return Isolate::Current()->object_store()->developer_library();
}


RawLibrary* Library::InternalLibrary() {
  return Isolate::Current()->object_store()->internal_library();
}


RawLibrary* Library::IsolateLibrary() {
  return Isolate::Current()->object_store()->isolate_library();
}


RawLibrary* Library::MathLibrary() {
  return Isolate::Current()->object_store()->math_library();
}


RawLibrary* Library::MirrorsLibrary() {
  return Isolate::Current()->object_store()->mirrors_library();
}


RawLibrary* Library::NativeWrappersLibrary() {
  return Isolate::Current()->object_store()->native_wrappers_library();
}


RawLibrary* Library::ProfilerLibrary() {
  return Isolate::Current()->object_store()->profiler_library();
}


RawLibrary* Library::TypedDataLibrary() {
  return Isolate::Current()->object_store()->typed_data_library();
}


RawLibrary* Library::VMServiceLibrary() {
  return Isolate::Current()->object_store()->vmservice_library();
}


const char* Library::ToCString() const {
  const String& name = String::Handle(url());
  return OS::SCreate(Thread::Current()->zone(),
      "Library:'%s'", name.ToCString());
}


void Library::PrintJSONImpl(JSONStream* stream, bool ref) const {
  intptr_t id = index();
  ASSERT(id >= 0);
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Library", ref);
  jsobj.AddFixedServiceId("libraries/%" Pd "", id);
  const String& vm_name = String::Handle(name());
  const String& user_name =
      String::Handle(String::IdentifierPrettyName(vm_name));
  AddNameProperties(&jsobj, user_name, vm_name);
  const String& library_url = String::Handle(url());
  jsobj.AddPropertyStr("uri", library_url);
  if (ref) {
    return;
  }
  jsobj.AddProperty("debuggable", IsDebuggable());
  {
    JSONArray jsarr(&jsobj, "classes");
    ClassDictionaryIterator class_iter(*this);
    Class& klass = Class::Handle();
    while (class_iter.HasNext()) {
      klass = class_iter.GetNextClass();
      if (!klass.IsCanonicalSignatureClass() &&
          !klass.IsMixinApplication()) {
        jsarr.AddValue(klass);
      }
    }
  }
  {
    JSONArray jsarr(&jsobj, "dependencies");

    Array& ports = Array::Handle();
    Namespace& ns = Namespace::Handle();
    Library& target = Library::Handle();

    // Unprefixed imports.
    ports = imports();
    for (intptr_t i = 0; i < ports.Length(); i++) {
      ns ^= ports.At(i);
      if (ns.IsNull()) continue;

      JSONObject jsdep(&jsarr);
      jsdep.AddProperty("isDeferred", false);
      jsdep.AddProperty("isExport", false);
      jsdep.AddProperty("isImport", true);
      target = ns.library();
      jsdep.AddProperty("target", target);
    }

    // Exports.
    ports = exports();
    for (intptr_t i = 0; i < ports.Length(); i++) {
      ns ^= ports.At(i);
      if (ns.IsNull()) continue;

      JSONObject jsdep(&jsarr);
      jsdep.AddProperty("isDeferred", false);
      jsdep.AddProperty("isExport", true);
      jsdep.AddProperty("isImport", false);
      target = ns.library();
      jsdep.AddProperty("target", target);
    }

    // Prefixed imports.
    DictionaryIterator entries(*this);
    Object& entry = Object::Handle();
    LibraryPrefix& prefix = LibraryPrefix::Handle();
    String& prefixName = String::Handle();
    while (entries.HasNext()) {
      entry = entries.GetNext();
      if (entry.IsLibraryPrefix()) {
        prefix ^= entry.raw();
        ports = prefix.imports();
        for (intptr_t i = 0; i < ports.Length(); i++) {
          ns ^= ports.At(i);
          if (ns.IsNull()) continue;

          JSONObject jsdep(&jsarr);
          jsdep.AddProperty("isDeferred", prefix.is_deferred_load());
          jsdep.AddProperty("isExport", false);
          jsdep.AddProperty("isImport", true);
          prefixName = prefix.name();
          ASSERT(!prefixName.IsNull());
          jsdep.AddProperty("prefix", prefixName.ToCString());
          target = ns.library();
          jsdep.AddProperty("target", target);
        }
      }
    }
  }
  {
    JSONArray jsarr(&jsobj, "variables");
    DictionaryIterator entries(*this);
    Object& entry = Object::Handle();
    while (entries.HasNext()) {
      entry = entries.GetNext();
      if (entry.IsField()) {
        jsarr.AddValue(entry);
      }
    }
  }
  {
    JSONArray jsarr(&jsobj, "functions");
    DictionaryIterator entries(*this);
    Object& entry = Object::Handle();
    while (entries.HasNext()) {
      entry = entries.GetNext();
      if (entry.IsFunction()) {
        const Function& func = Function::Cast(entry);
        if (func.kind() == RawFunction::kRegularFunction ||
            func.kind() == RawFunction::kGetterFunction ||
            func.kind() == RawFunction::kSetterFunction) {
          jsarr.AddValue(func);
        }
      }
    }
  }
  {
    JSONArray jsarr(&jsobj, "scripts");
    Array& scripts = Array::Handle(LoadedScripts());
    Script& script = Script::Handle();
    for (intptr_t i = 0; i < scripts.Length(); i++) {
      script ^= scripts.At(i);
      jsarr.AddValue(script);
    }
  }
}


RawLibrary* LibraryPrefix::GetLibrary(int index) const {
  if ((index >= 0) || (index < num_imports())) {
    const Array& imports = Array::Handle(this->imports());
    Namespace& import = Namespace::Handle();
    import ^= imports.At(index);
    return import.library();
  }
  return Library::null();
}


RawInstance* LibraryPrefix::LoadError() const {
  Thread* thread = Thread::Current();
  Isolate* isolate = thread->isolate();
  Zone* zone = thread->zone();
  ObjectStore* object_store = isolate->object_store();
  GrowableObjectArray& libs =
      GrowableObjectArray::Handle(zone, object_store->libraries());
  ASSERT(!libs.IsNull());
  LibraryLoadErrorSet set(HashTables::New<LibraryLoadErrorSet>(libs.Length()));
  object_store->set_library_load_error_table(set.Release());
  Library& lib = Library::Handle(zone);
  Instance& error = Instance::Handle(zone);
  for (int32_t i = 0; i < num_imports(); i++) {
    lib = GetLibrary(i);
    ASSERT(!lib.IsNull());
    HANDLESCOPE(thread);
    error = lib.TransitiveLoadError();
    if (!error.IsNull()) {
      break;
    }
  }
  object_store->set_library_load_error_table(Object::empty_array());
  return error.raw();
}


bool LibraryPrefix::ContainsLibrary(const Library& library) const {
  int32_t num_current_imports = num_imports();
  if (num_current_imports > 0) {
    Library& lib = Library::Handle();
    const String& url = String::Handle(library.url());
    String& lib_url = String::Handle();
    for (int32_t i = 0; i < num_current_imports; i++) {
      lib = GetLibrary(i);
      ASSERT(!lib.IsNull());
      lib_url = lib.url();
      if (url.Equals(lib_url)) {
        return true;
      }
    }
  }
  return false;
}


void LibraryPrefix::AddImport(const Namespace& import) const {
  intptr_t num_current_imports = num_imports();

  // Prefixes with deferred libraries can only contain one library.
  ASSERT((num_current_imports == 0) || !is_deferred_load());

  // The library needs to be added to the list.
  Array& imports = Array::Handle(this->imports());
  const intptr_t length = (imports.IsNull()) ? 0 : imports.Length();
  // Grow the list if it is full.
  if (num_current_imports >= length) {
    const intptr_t new_length = length + kIncrementSize;
    imports = Array::Grow(imports, new_length, Heap::kOld);
    set_imports(imports);
  }
  imports.SetAt(num_current_imports, import);
  set_num_imports(num_current_imports + 1);
}


RawObject* LibraryPrefix::LookupObject(const String& name) const {
  if (!is_loaded() && !FLAG_load_deferred_eagerly) {
    return Object::null();
  }
  Array& imports = Array::Handle(this->imports());
  Object& obj = Object::Handle();
  Namespace& import = Namespace::Handle();
  Library& import_lib = Library::Handle();
  String& import_lib_url = String::Handle();
  String& first_import_lib_url = String::Handle();
  Object& found_obj = Object::Handle();
  for (intptr_t i = 0; i < num_imports(); i++) {
    import ^= imports.At(i);
    obj = import.Lookup(name);
    if (!obj.IsNull()) {
      import_lib = import.library();
      import_lib_url = import_lib.url();
      if (found_obj.raw() != obj.raw()) {
        if (first_import_lib_url.IsNull() ||
            first_import_lib_url.StartsWith(Symbols::DartScheme())) {
          // This is the first object we found, or the
          // previously found object is exported from a Dart
          // system library. The newly found object hides the one
          // from the Dart library.
          first_import_lib_url = import_lib.url();
          found_obj = obj.raw();
        } else if (import_lib_url.StartsWith(Symbols::DartScheme())) {
          // The newly found object is exported from a Dart system
          // library. It is hidden by the previously found object.
          // We continue to search.
        } else {
          // We found two different objects with the same name.
          return Object::null();
        }
      }
    }
  }
  return found_obj.raw();
}


RawClass* LibraryPrefix::LookupClass(const String& class_name) const {
  const Object& obj = Object::Handle(LookupObject(class_name));
  if (obj.IsClass()) {
    return Class::Cast(obj).raw();
  }
  return Class::null();
}


void LibraryPrefix::set_is_loaded() const {
  StoreNonPointer(&raw_ptr()->is_loaded_, true);
}


bool LibraryPrefix::LoadLibrary() const {
  // Non-deferred prefixes are loaded.
  ASSERT(is_deferred_load() || is_loaded());
  if (is_loaded()) {
    return true;  // Load request has already completed.
  }
  ASSERT(is_deferred_load());
  ASSERT(num_imports() == 1);
  // This is a prefix for a deferred library. If the library is not loaded
  // yet and isn't being loaded, call the library tag handler to schedule
  // loading. Once all outstanding load requests have completed, the embedder
  // will call the core library to:
  // - invalidate dependent code of this prefix;
  // - mark this prefixes as loaded;
  // - complete the future associated with this prefix.
  const Library& deferred_lib = Library::Handle(GetLibrary(0));
  if (deferred_lib.Loaded()) {
    this->set_is_loaded();
    return true;
  } else if (deferred_lib.LoadNotStarted()) {
    Thread* thread = Thread::Current();
    Isolate* isolate = thread->isolate();
    Api::Scope api_scope(isolate);
    Zone* zone = thread->zone();
    deferred_lib.SetLoadRequested();
    const GrowableObjectArray& pending_deferred_loads =
        GrowableObjectArray::Handle(
            isolate->object_store()->pending_deferred_loads());
    pending_deferred_loads.Add(deferred_lib);
    const String& lib_url = String::Handle(zone, deferred_lib.url());
    Dart_LibraryTagHandler handler = isolate->library_tag_handler();
    handler(Dart_kImportTag,
            Api::NewHandle(isolate, importer()),
            Api::NewHandle(isolate, lib_url.raw()));
  } else {
    // Another load request is in flight.
    ASSERT(deferred_lib.LoadRequested());
  }
  return false;  // Load request not yet completed.
}


RawArray* LibraryPrefix::dependent_code() const {
  return raw_ptr()->dependent_code_;
}


void LibraryPrefix::set_dependent_code(const Array& array) const {
  StorePointer(&raw_ptr()->dependent_code_, array.raw());
}


class PrefixDependentArray : public WeakCodeReferences {
 public:
  explicit PrefixDependentArray(const LibraryPrefix& prefix)
      : WeakCodeReferences(Array::Handle(prefix.dependent_code())),
                           prefix_(prefix) {}

  virtual void UpdateArrayTo(const Array& value) {
    prefix_.set_dependent_code(value);
  }

  virtual void ReportDeoptimization(const Code& code) {
    // This gets called when the code object is on the stack
    // while nuking code that depends on a prefix. We don't expect
    // this to happen, so make sure we die loudly if we find
    // ourselves here.
    UNIMPLEMENTED();
  }

  virtual void ReportSwitchingCode(const Code& code) {
    if (FLAG_trace_deoptimization || FLAG_trace_deoptimization_verbose) {
      THR_Print("Prefix '%s': disabling %s code for %s function '%s'\n",
          String::Handle(prefix_.name()).ToCString(),
          code.is_optimized() ? "optimized" : "unoptimized",
          code.IsDisabled() ? "'patched'" : "'unpatched'",
          Function::Handle(code.function()).ToCString());
    }
  }

 private:
  const LibraryPrefix& prefix_;
  DISALLOW_COPY_AND_ASSIGN(PrefixDependentArray);
};


void LibraryPrefix::RegisterDependentCode(const Code& code) const {
  ASSERT(is_deferred_load());
  ASSERT(!is_loaded());
  PrefixDependentArray a(*this);
  a.Register(code);
}


void LibraryPrefix::InvalidateDependentCode() const {
  PrefixDependentArray a(*this);
  a.DisableCode();
  set_is_loaded();
}


RawLibraryPrefix* LibraryPrefix::New() {
  RawObject* raw = Object::Allocate(LibraryPrefix::kClassId,
                                    LibraryPrefix::InstanceSize(),
                                    Heap::kOld);
  return reinterpret_cast<RawLibraryPrefix*>(raw);
}


RawLibraryPrefix* LibraryPrefix::New(const String& name,
                                     const Namespace& import,
                                     bool deferred_load,
                                     const Library& importer) {
  const LibraryPrefix& result = LibraryPrefix::Handle(LibraryPrefix::New());
  result.set_name(name);
  result.set_num_imports(0);
  result.set_importer(importer);
  result.StoreNonPointer(&result.raw_ptr()->is_deferred_load_, deferred_load);
  result.StoreNonPointer(&result.raw_ptr()->is_loaded_, !deferred_load);
  result.set_imports(Array::Handle(Array::New(kInitialSize)));
  result.AddImport(import);
  return result.raw();
}


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


void LibraryPrefix::set_imports(const Array& value) const {
  StorePointer(&raw_ptr()->imports_, value.raw());
}


void LibraryPrefix::set_num_imports(intptr_t value) const {
  if (!Utils::IsUint(16, value)) {
    ReportTooManyImports(Library::Handle(importer()));
  }
  StoreNonPointer(&raw_ptr()->num_imports_, value);
}


void LibraryPrefix::set_importer(const Library& value) const {
  StorePointer(&raw_ptr()->importer_, value.raw());
}


const char* LibraryPrefix::ToCString() const {
  const String& prefix = String::Handle(name());
  return OS::SCreate(Thread::Current()->zone(),
      "LibraryPrefix:'%s'", prefix.ToCString());
}


void LibraryPrefix::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


void Namespace::set_metadata_field(const Field& value) const {
  StorePointer(&raw_ptr()->metadata_field_, value.raw());
}


void Namespace::AddMetadata(intptr_t token_pos, const Class& owner_class) {
  ASSERT(Field::Handle(metadata_field()).IsNull());
  Field& field = Field::Handle(Field::New(Symbols::TopLevel(),
                                          true,   // is_static
                                          false,  // is_final
                                          false,  // is_const
                                          false,  // is_reflectable
                                          owner_class,
                                          token_pos));
  field.set_type(Type::Handle(Type::DynamicType()));
  field.SetStaticValue(Array::empty_array(), true);
  set_metadata_field(field);
  owner_class.AddField(field);
}


RawObject* Namespace::GetMetadata() const {
  Field& field = Field::Handle(metadata_field());
  if (field.IsNull()) {
    // There is no metadata for this object.
    return Object::empty_array().raw();
  }
  Object& metadata = Object::Handle();
  metadata = field.StaticValue();
  if (field.StaticValue() == Object::empty_array().raw()) {
    metadata = Parser::ParseMetadata(Class::Handle(field.owner()),
                                     field.token_pos());
    if (metadata.IsArray()) {
      ASSERT(Array::Cast(metadata).raw() != Object::empty_array().raw());
      field.SetStaticValue(Array::Cast(metadata), true);
    }
  }
  return metadata.raw();
}


const char* Namespace::ToCString() const {
  const Library& lib = Library::Handle(library());
  return OS::SCreate(Thread::Current()->zone(),
      "Namespace for library '%s'", lib.ToCString());
}


void Namespace::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


bool Namespace::HidesName(const String& name) const {
  // Quick check for common case with no combinators.
  if (hide_names() == show_names()) {
    ASSERT(hide_names() == Array::null());
    return false;
  }
  const String* plain_name = &name;
  if (Field::IsGetterName(name)) {
    plain_name = &String::Handle(Field::NameFromGetter(name));
  } else if (Field::IsSetterName(name)) {
    plain_name = &String::Handle(Field::NameFromSetter(name));
  }
  // Check whether the name is in the list of explicitly hidden names.
  if (hide_names() != Array::null()) {
    const Array& names = Array::Handle(hide_names());
    String& hidden = String::Handle();
    intptr_t num_names = names.Length();
    for (intptr_t i = 0; i < num_names; i++) {
      hidden ^= names.At(i);
      if (plain_name->Equals(hidden)) {
        return true;
      }
    }
  }
  // The name is not explicitly hidden. Now check whether it is in the
  // list of explicitly visible names, if there is one.
  if (show_names() != Array::null()) {
    const Array& names = Array::Handle(show_names());
    String& shown = String::Handle();
    intptr_t num_names = names.Length();
    for (intptr_t i = 0; i < num_names; i++) {
      shown ^= names.At(i);
      if (plain_name->Equals(shown)) {
        return false;
      }
    }
    // There is a list of visible names. The name we're looking for is not
    // contained in the list, so it is hidden.
    return true;
  }
  // The name is not filtered out.
  return false;
}


// Look up object with given name in library and filter out hidden
// names. Also look up getters and setters.
RawObject* Namespace::Lookup(const String& name) const {
  Zone* zone = Thread::Current()->zone();
  const Library& lib = Library::Handle(zone, library());
  intptr_t ignore = 0;

  // Lookup the name in the library's symbols.
  Object& obj = Object::Handle(zone, lib.LookupEntry(name, &ignore));
  if (!Field::IsGetterName(name) &&
      !Field::IsSetterName(name) &&
      (obj.IsNull() || obj.IsLibraryPrefix())) {
    const String& getter_name = String::Handle(Field::LookupGetterSymbol(name));
    if (!getter_name.IsNull()) {
      obj = lib.LookupEntry(getter_name, &ignore);
    }
    if (obj.IsNull()) {
      const String& setter_name =
          String::Handle(Field::LookupSetterSymbol(name));
      if (!setter_name.IsNull()) {
        obj = lib.LookupEntry(setter_name, &ignore);
      }
    }
  }

  // Library prefixes are not exported.
  if (obj.IsNull() || obj.IsLibraryPrefix()) {
    // Lookup in the re-exported symbols.
    obj = lib.LookupReExport(name);
  }
  if (obj.IsNull() || HidesName(name) || obj.IsLibraryPrefix()) {
    return Object::null();
  }
  return obj.raw();
}


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


RawNamespace* Namespace::New(const Library& library,
                             const Array& show_names,
                             const Array& hide_names) {
  ASSERT(show_names.IsNull() || (show_names.Length() > 0));
  ASSERT(hide_names.IsNull() || (hide_names.Length() > 0));
  const Namespace& result = Namespace::Handle(Namespace::New());
  result.StorePointer(&result.raw_ptr()->library_, library.raw());
  result.StorePointer(&result.raw_ptr()->show_names_, show_names.raw());
  result.StorePointer(&result.raw_ptr()->hide_names_, hide_names.raw());
  return result.raw();
}


RawError* Library::CompileAll() {
  Error& error = Error::Handle();
  const GrowableObjectArray& libs = GrowableObjectArray::Handle(
      Isolate::Current()->object_store()->libraries());
  Library& lib = Library::Handle();
  Class& cls = Class::Handle();
  for (int i = 0; i < libs.Length(); i++) {
    lib ^= libs.At(i);
    ClassDictionaryIterator it(lib, ClassDictionaryIterator::kIteratePrivate);
    while (it.HasNext()) {
      cls = it.GetNextClass();
      error = cls.EnsureIsFinalized(Thread::Current());
      if (!error.IsNull()) {
        return error.raw();
      }
      error = Compiler::CompileAllFunctions(cls);
      if (!error.IsNull()) {
        return error.raw();
      }
    }
  }
  return error.raw();
}


// Return Function::null() if function does not exist in libs.
RawFunction* Library::GetFunction(const GrowableArray<Library*>& libs,
                                  const char* class_name,
                                  const char* function_name) {
  Function& func = Function::Handle();
  String& class_str = String::Handle();
  String& func_str = String::Handle();
  Class& cls = Class::Handle();
  for (intptr_t l = 0; l < libs.length(); l++) {
    const Library& lib = *libs[l];
    if (strcmp(class_name, "::") == 0) {
      func_str = Symbols::New(function_name);
      func = lib.LookupFunctionAllowPrivate(func_str);
    } else {
      class_str = String::New(class_name);
      cls = lib.LookupClassAllowPrivate(class_str);
      if (!cls.IsNull()) {
        func_str = String::New(function_name);
        if (function_name[0] == '.') {
          func_str = String::Concat(class_str, func_str);
        }
        func = cls.LookupFunctionAllowPrivate(func_str);
      }
    }
    if (!func.IsNull()) {
      return func.raw();
    }
  }
  return Function::null();
}


#if defined(DART_NO_SNAPSHOT)
void Library::CheckFunctionFingerprints() {
  GrowableArray<Library*> all_libs;
  Function& func = Function::Handle();
  bool has_errors = false;

#define CHECK_FINGERPRINTS(class_name, function_name, dest, fp)                \
  func = GetFunction(all_libs, #class_name, #function_name);                   \
  if (func.IsNull()) {                                                         \
    has_errors = true;                                                         \
    OS::Print("Function not found %s.%s\n", #class_name, #function_name);      \
  } else {                                                                     \
    CHECK_FINGERPRINT3(func, class_name, function_name, dest, fp);             \
  }                                                                            \

  all_libs.Add(&Library::ZoneHandle(Library::CoreLibrary()));
  CORE_LIB_INTRINSIC_LIST(CHECK_FINGERPRINTS);
  CORE_INTEGER_LIB_INTRINSIC_LIST(CHECK_FINGERPRINTS);

  all_libs.Add(&Library::ZoneHandle(Library::MathLibrary()));
  all_libs.Add(&Library::ZoneHandle(Library::TypedDataLibrary()));
  all_libs.Add(&Library::ZoneHandle(Library::CollectionLibrary()));
  OTHER_RECOGNIZED_LIST(CHECK_FINGERPRINTS);
  INLINE_WHITE_LIST(CHECK_FINGERPRINTS);
  INLINE_BLACK_LIST(CHECK_FINGERPRINTS);
  POLYMORPHIC_TARGET_LIST(CHECK_FINGERPRINTS);

  all_libs.Clear();
  all_libs.Add(&Library::ZoneHandle(Library::DeveloperLibrary()));
  DEVELOPER_LIB_INTRINSIC_LIST(CHECK_FINGERPRINTS);

  all_libs.Clear();
  all_libs.Add(&Library::ZoneHandle(Library::MathLibrary()));
  MATH_LIB_INTRINSIC_LIST(CHECK_FINGERPRINTS);

  all_libs.Clear();
  all_libs.Add(&Library::ZoneHandle(Library::TypedDataLibrary()));
  TYPED_DATA_LIB_INTRINSIC_LIST(CHECK_FINGERPRINTS);

#undef CHECK_FINGERPRINTS

Class& cls = Class::Handle();

#define CHECK_FACTORY_FINGERPRINTS(factory_symbol, cid, fp)                    \
  cls = Isolate::Current()->class_table()->At(cid);                            \
  func = cls.LookupFunctionAllowPrivate(Symbols::factory_symbol());            \
  if (func.IsNull()) {                                                         \
    has_errors = true;                                                         \
    OS::Print("Function not found %s.%s\n", cls.ToCString(),                   \
        Symbols::factory_symbol().ToCString());                                \
  } else {                                                                     \
    CHECK_FINGERPRINT2(func, factory_symbol, cid, fp);                         \
  }                                                                            \

  RECOGNIZED_LIST_FACTORY_LIST(CHECK_FACTORY_FINGERPRINTS);

#undef CHECK_FACTORY_FINGERPRINTS

  if (has_errors) {
    FATAL("Fingerprint mismatch.");
  }
}
#endif  // defined(DART_NO_SNAPSHOT).


RawInstructions* Instructions::New(intptr_t size) {
  ASSERT(Object::instructions_class() != Class::null());
  if (size < 0 || size > kMaxElements) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in Instructions::New: invalid size %" Pd "\n", size);
  }
  Instructions& result = Instructions::Handle();
  {
    uword aligned_size = Instructions::InstanceSize(size);
    RawObject* raw = Object::Allocate(Instructions::kClassId,
                                      aligned_size,
                                      Heap::kCode);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.set_size(size);
  }
  return result.raw();
}


const char* Instructions::ToCString() const {
  return "Instructions";
}


void Instructions::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Object", ref);
  jsobj.AddServiceId(*this);
  if (ref) {
    return;
  }
}


// Encode integer in SLEB128 format.
void PcDescriptors::EncodeInteger(GrowableArray<uint8_t>* data,
                                  intptr_t value) {
  bool is_last_part = false;
  while (!is_last_part) {
    intptr_t part = value & 0x7f;
    value >>= 7;
    if ((value == 0 && (part & 0x40) == 0) ||
        (value == -1 && (part & 0x40) != 0)) {
      is_last_part = true;
    } else {
      part |= 0x80;
    }
    data->Add(part);
  }
}


// Decode SLEB128 encoded integer. Update byte_index to the next integer.
intptr_t PcDescriptors::DecodeInteger(intptr_t* byte_index) const {
  NoSafepointScope no_safepoint;
  const uint8_t* data = raw_ptr()->data();
  ASSERT(*byte_index < Length());
  uword shift = 0;
  intptr_t value = 0;
  intptr_t part = 0;
  do {
    part = data[(*byte_index)++];
    value |= (part & 0x7f) << shift;
    shift += 7;
  } while ((part & 0x80) != 0);

  if (shift < sizeof(value) * 8 && (part & 0x40) != 0) {
    value |= -(1 << shift);
  }
  return value;
}


RawObjectPool* ObjectPool::New(intptr_t len) {
  ASSERT(Object::object_pool_class() != Class::null());
  if (len < 0 || len > kMaxElements) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in ObjectPool::New: invalid length %" Pd "\n", len);
  }
  ObjectPool& result = ObjectPool::Handle();
  {
    uword size = ObjectPool::InstanceSize(len);
    RawObject* raw = Object::Allocate(ObjectPool::kClassId,
                                      size,
                                      Heap::kOld);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.SetLength(len);
  }

  // TODO(fschneider): Compress info array to just use just enough bits for
  // the entry type enum.
  const TypedData& info_array = TypedData::Handle(
      TypedData::New(kTypedDataInt8ArrayCid, len, Heap::kOld));
  result.set_info_array(info_array);
  return result.raw();
}


void ObjectPool::set_info_array(const TypedData& info_array) const {
  StorePointer(&raw_ptr()->info_array_, info_array.raw());
}


ObjectPool::EntryType ObjectPool::InfoAt(intptr_t index) const {
  const TypedData& array = TypedData::Handle(info_array());
  return static_cast<EntryType>(array.GetInt8(index));
}


const char* ObjectPool::ToCString() const {
  Zone* zone = Thread::Current()->zone();
  return zone->PrintToString("ObjectPool len:%" Pd, Length());
}


void ObjectPool::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Object", ref);
  jsobj.AddServiceId(*this);
  jsobj.AddProperty("length", Length());
  if (ref) {
    return;
  }

  {
    JSONArray jsarr(&jsobj, "_entries");
    uword imm;
    Object& obj = Object::Handle();
    for (intptr_t i = 0; i < Length(); i++) {
      JSONObject jsentry(stream);
      jsentry.AddProperty("offset", OffsetFromIndex(i));
      switch (InfoAt(i)) {
      case ObjectPool::kTaggedObject:
        obj = ObjectAt(i);
        jsentry.AddProperty("kind", "Object");
        jsentry.AddProperty("value", obj);
        break;
      case ObjectPool::kImmediate:
        imm = RawValueAt(i);
        jsentry.AddProperty("kind", "Immediate");
        jsentry.AddProperty64("value", imm);
        break;
      case ObjectPool::kNativeEntry:
        imm = RawValueAt(i);
        jsentry.AddProperty("kind", "NativeEntry");
        jsentry.AddProperty64("value", imm);
        break;
      default:
        UNREACHABLE();
      }
    }
  }
}


void ObjectPool::DebugPrint() const {
  THR_Print("Object Pool: {\n");
  for (intptr_t i = 0; i < Length(); i++) {
    intptr_t offset = OffsetFromIndex(i);
    THR_Print("  %" Pd " PP+0x%" Px ": ", i, offset);
    if (InfoAt(i) == kTaggedObject) {
      RawObject* obj = ObjectAt(i);
      THR_Print("0x%" Px " %s (obj)\n",
          reinterpret_cast<uword>(obj),
          Object::Handle(obj).ToCString());
    } else if (InfoAt(i) == kNativeEntry) {
      THR_Print("0x%" Px " (native entry)\n", RawValueAt(i));
    } else {
      THR_Print("0x%" Px " (raw)\n", RawValueAt(i));
    }
  }
  THR_Print("}\n");
}


intptr_t PcDescriptors::Length() const {
  return raw_ptr()->length_;
}


void PcDescriptors::SetLength(intptr_t value) const {
  StoreNonPointer(&raw_ptr()->length_, value);
}


void PcDescriptors::CopyData(GrowableArray<uint8_t>* delta_encoded_data) {
  NoSafepointScope no_safepoint;
  uint8_t* data = UnsafeMutableNonPointer(&raw_ptr()->data()[0]);
  for (intptr_t i = 0; i < delta_encoded_data->length(); ++i) {
    data[i] = (*delta_encoded_data)[i];
  }
}


RawPcDescriptors* PcDescriptors::New(GrowableArray<uint8_t>* data) {
  ASSERT(Object::pc_descriptors_class() != Class::null());
  Thread* thread = Thread::Current();
  PcDescriptors& result = PcDescriptors::Handle(thread->zone());
  {
    uword size = PcDescriptors::InstanceSize(data->length());
    RawObject* raw = Object::Allocate(PcDescriptors::kClassId,
                                      size,
                                      Heap::kOld);
    INC_STAT(thread, total_code_size, size);
    INC_STAT(thread, pc_desc_size, size);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.SetLength(data->length());
    result.CopyData(data);
  }
  return result.raw();
}


RawPcDescriptors* PcDescriptors::New(intptr_t length) {
  ASSERT(Object::pc_descriptors_class() != Class::null());
  Thread* thread = Thread::Current();
  PcDescriptors& result = PcDescriptors::Handle(thread->zone());
  {
    uword size = PcDescriptors::InstanceSize(length);
    RawObject* raw = Object::Allocate(PcDescriptors::kClassId,
                                      size,
                                      Heap::kOld);
    INC_STAT(thread, total_code_size, size);
    INC_STAT(thread, pc_desc_size, size);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.SetLength(length);
  }
  return result.raw();
}


const char* PcDescriptors::KindAsStr(RawPcDescriptors::Kind kind) {
  switch (kind) {
    case RawPcDescriptors::kDeopt:           return "deopt        ";
    case RawPcDescriptors::kIcCall:          return "ic-call      ";
    case RawPcDescriptors::kUnoptStaticCall: return "unopt-call   ";
    case RawPcDescriptors::kRuntimeCall:     return "runtime-call ";
    case RawPcDescriptors::kOsrEntry:        return "osr-entry    ";
    case RawPcDescriptors::kOther:           return "other        ";
    case RawPcDescriptors::kAnyKind:         UNREACHABLE(); break;
  }
  UNREACHABLE();
  return "";
}


void PcDescriptors::PrintHeaderString() {
  // 4 bits per hex digit + 2 for "0x".
  const int addr_width = (kBitsPerWord / 4) + 2;
  // "*" in a printf format specifier tells it to read the field width from
  // the printf argument list.
  THR_Print("%-*s\tkind    \tdeopt-id\ttok-ix\ttry-ix\n",
            addr_width, "pc");
}


const char* PcDescriptors::ToCString() const {
  // "*" in a printf format specifier tells it to read the field width from
  // the printf argument list.
#define FORMAT "%#-*" Px "\t%s\t%" Pd "\t\t%" Pd "\t%" Pd "\n"
  if (Length() == 0) {
    return "empty PcDescriptors\n";
  }
  // 4 bits per hex digit.
  const int addr_width = kBitsPerWord / 4;
  // First compute the buffer size required.
  intptr_t len = 1;  // Trailing '\0'.
  {
    Iterator iter(*this, RawPcDescriptors::kAnyKind);
    while (iter.MoveNext()) {
      len += OS::SNPrint(NULL, 0, FORMAT, addr_width,
                         iter.PcOffset(),
                         KindAsStr(iter.Kind()),
                         iter.DeoptId(),
                         iter.TokenPos(),
                         iter.TryIndex());
    }
  }
  // Allocate the buffer.
  char* buffer = Thread::Current()->zone()->Alloc<char>(len);
  // Layout the fields in the buffer.
  intptr_t index = 0;
  Iterator iter(*this, RawPcDescriptors::kAnyKind);
  while (iter.MoveNext()) {
    index += OS::SNPrint((buffer + index), (len - index), FORMAT, addr_width,
                         iter.PcOffset(),
                         KindAsStr(iter.Kind()),
                         iter.DeoptId(),
                         iter.TokenPos(),
                         iter.TryIndex());
  }
  return buffer;
#undef FORMAT
}


void PcDescriptors::PrintToJSONObject(JSONObject* jsobj, bool ref) const {
  AddCommonObjectProperties(jsobj, "Object", ref);
  // TODO(johnmccutchan): Generate a stable id. PcDescriptors hang off a Code
  // object but do not have a back reference to generate an ID.
  jsobj->AddServiceId(*this);
  if (ref) {
    return;
  }
  JSONArray members(jsobj, "members");
  Iterator iter(*this, RawPcDescriptors::kAnyKind);
  while (iter.MoveNext()) {
    JSONObject descriptor(&members);
    descriptor.AddPropertyF("pcOffset", "%" Px "", iter.PcOffset());
    descriptor.AddProperty("kind", KindAsStr(iter.Kind()));
    descriptor.AddProperty("deoptId", iter.DeoptId());
    // TODO(turnidge): Use AddLocation instead.
    descriptor.AddProperty("tokenPos", iter.TokenPos());
    descriptor.AddProperty("tryIndex", iter.TryIndex());
  }
}


void PcDescriptors::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  PrintToJSONObject(&jsobj, ref);
}


// Verify assumptions (in debug mode only).
// - No two deopt descriptors have the same deoptimization id.
// - No two ic-call descriptors have the same deoptimization id (type feedback).
// A function without unique ids is marked as non-optimizable (e.g., because of
// finally blocks).
void PcDescriptors::Verify(const Function& function) const {
#if defined(DEBUG)
  // TODO(srdjan): Implement a more efficient way to check, currently drop
  // the check for too large number of descriptors.
  if (Length() > 3000) {
    if (FLAG_trace_compiler) {
      OS::Print("Not checking pc decriptors, length %" Pd "\n", Length());
    }
    return;
  }
  // Only check ids for unoptimized code that is optimizable.
  if (!function.IsOptimizable()) {
    return;
  }
  Iterator iter(*this, RawPcDescriptors::kDeopt | RawPcDescriptors::kIcCall);
  while (iter.MoveNext()) {
    // 'deopt_id' is set for kDeopt and kIcCall and must be unique for one kind.
    if (Thread::IsDeoptAfter(iter.DeoptId())) {
      // TODO(vegorov): some instructions contain multiple calls and have
      // multiple "after" targets recorded. Right now it is benign but might
      // lead to issues in the future. Fix that and enable verification.
      continue;
    }

    Iterator nested(iter);
    while (nested.MoveNext()) {
      if (iter.Kind() == nested.Kind()) {
        ASSERT(nested.DeoptId() != iter.DeoptId());
      }
    }
  }
#endif  // DEBUG
}


bool Stackmap::GetBit(intptr_t bit_index) const {
  ASSERT(InRange(bit_index));
  int byte_index = bit_index >> kBitsPerByteLog2;
  int bit_remainder = bit_index & (kBitsPerByte - 1);
  uint8_t byte_mask = 1U << bit_remainder;
  uint8_t byte = raw_ptr()->data()[byte_index];
  return (byte & byte_mask);
}


void Stackmap::SetBit(intptr_t bit_index, bool value) const {
  ASSERT(InRange(bit_index));
  int byte_index = bit_index >> kBitsPerByteLog2;
  int bit_remainder = bit_index & (kBitsPerByte - 1);
  uint8_t byte_mask = 1U << bit_remainder;
  NoSafepointScope no_safepoint;
  uint8_t* byte_addr = UnsafeMutableNonPointer(&raw_ptr()->data()[byte_index]);
  if (value) {
    *byte_addr |= byte_mask;
  } else {
    *byte_addr &= ~byte_mask;
  }
}


RawStackmap* Stackmap::New(intptr_t pc_offset,
                           BitmapBuilder* bmap,
                           intptr_t register_bit_count) {
  ASSERT(Object::stackmap_class() != Class::null());
  ASSERT(bmap != NULL);
  Stackmap& result = Stackmap::Handle();
  // Guard against integer overflow of the instance size computation.
  intptr_t length = bmap->Length();
  intptr_t payload_size =
      Utils::RoundUp(length, kBitsPerByte) / kBitsPerByte;
  if ((payload_size < 0) ||
      (payload_size > kMaxLengthInBytes)) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in Stackmap::New: invalid length %" Pd "\n",
           length);
  }
  {
    // Stackmap data objects are associated with a code object, allocate them
    // in old generation.
    RawObject* raw = Object::Allocate(Stackmap::kClassId,
                                      Stackmap::InstanceSize(length),
                                      Heap::kOld);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.SetLength(length);
  }
  // When constructing a stackmap we store the pc offset in the stackmap's
  // PC. StackmapTableBuilder::FinalizeStackmaps will replace it with the pc
  // address.
  ASSERT(pc_offset >= 0);
  result.SetPcOffset(pc_offset);
  for (intptr_t i = 0; i < length; ++i) {
    result.SetBit(i, bmap->Get(i));
  }
  result.SetRegisterBitCount(register_bit_count);
  return result.raw();
}


RawStackmap* Stackmap::New(intptr_t length,
                           intptr_t register_bit_count,
                           intptr_t pc_offset) {
  ASSERT(Object::stackmap_class() != Class::null());
  Stackmap& result = Stackmap::Handle();
  // Guard against integer overflow of the instance size computation.
  intptr_t payload_size =
  Utils::RoundUp(length, kBitsPerByte) / kBitsPerByte;
  if ((payload_size < 0) ||
      (payload_size > kMaxLengthInBytes)) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in Stackmap::New: invalid length %" Pd "\n",
           length);
  }
  {
    // Stackmap data objects are associated with a code object, allocate them
    // in old generation.
    RawObject* raw = Object::Allocate(Stackmap::kClassId,
                                      Stackmap::InstanceSize(length),
                                      Heap::kOld);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.SetLength(length);
  }
  // When constructing a stackmap we store the pc offset in the stackmap's
  // PC. StackmapTableBuilder::FinalizeStackmaps will replace it with the pc
  // address.
  ASSERT(pc_offset >= 0);
  result.SetPcOffset(pc_offset);
  result.SetRegisterBitCount(register_bit_count);
  return result.raw();
}


const char* Stackmap::ToCString() const {
#define FORMAT "%#x: "
  if (IsNull()) {
    return "{null}";
  } else {
    intptr_t fixed_length = OS::SNPrint(NULL, 0, FORMAT, PcOffset()) + 1;
    Thread* thread = Thread::Current();
    // Guard against integer overflow in the computation of alloc_size.
    //
    // TODO(kmillikin): We could just truncate the string if someone
    // tries to print a 2 billion plus entry stackmap.
    if (Length() > (kIntptrMax - fixed_length)) {
      FATAL1("Length() is unexpectedly large (%" Pd ")", Length());
    }
    intptr_t alloc_size = fixed_length + Length();
    char* chars = thread->zone()->Alloc<char>(alloc_size);
    intptr_t index = OS::SNPrint(chars, alloc_size, FORMAT, PcOffset());
    for (intptr_t i = 0; i < Length(); i++) {
      chars[index++] = IsObject(i) ? '1' : '0';
    }
    chars[index] = '\0';
    return chars;
  }
#undef FORMAT
}


void Stackmap::PrintJSONImpl(JSONStream* stream, bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


RawString* LocalVarDescriptors::GetName(intptr_t var_index) const {
  ASSERT(var_index < Length());
  ASSERT(Object::Handle(*raw()->nameAddrAt(var_index)).IsString());
  return *raw()->nameAddrAt(var_index);
}


void LocalVarDescriptors::SetVar(intptr_t var_index,
                                 const String& name,
                                 RawLocalVarDescriptors::VarInfo* info) const {
  ASSERT(var_index < Length());
  ASSERT(!name.IsNull());
  StorePointer(raw()->nameAddrAt(var_index), name.raw());
  raw()->data()[var_index] = *info;
}


void LocalVarDescriptors::GetInfo(intptr_t var_index,
                                  RawLocalVarDescriptors::VarInfo* info) const {
  ASSERT(var_index < Length());
  *info = raw()->data()[var_index];
}


static int PrintVarInfo(char* buffer, int len,
                        intptr_t i,
                        const String& var_name,
                        const RawLocalVarDescriptors::VarInfo& info) {
  const RawLocalVarDescriptors::VarInfoKind kind = info.kind();
  const int32_t index = info.index();
  if (kind == RawLocalVarDescriptors::kContextLevel) {
    return OS::SNPrint(buffer, len,
                       "%2" Pd " %-13s level=%-3d scope=%-3d"
                       " begin=%-3d end=%d\n",
                       i,
                       LocalVarDescriptors::KindToCString(kind),
                       index,
                       info.scope_id,
                       info.begin_pos,
                       info.end_pos);
  } else if (kind == RawLocalVarDescriptors::kContextVar) {
    return OS::SNPrint(buffer, len,
                       "%2" Pd " %-13s level=%-3d index=%-3d"
                       " begin=%-3d end=%-3d name=%s\n",
                       i,
                       LocalVarDescriptors::KindToCString(kind),
                       info.scope_id,
                       index,
                       info.begin_pos,
                       info.end_pos,
                       var_name.ToCString());
  } else {
    return OS::SNPrint(buffer, len,
                       "%2" Pd " %-13s scope=%-3d index=%-3d"
                       " begin=%-3d end=%-3d name=%s\n",
                       i,
                       LocalVarDescriptors::KindToCString(kind),
                       info.scope_id,
                       index,
                       info.begin_pos,
                       info.end_pos,
                       var_name.ToCString());
  }
}


const char* LocalVarDescriptors::ToCString() const {
  if (IsNull()) {
    return "LocalVarDescriptors(NULL)";
  }
  if (Length() == 0) {
    return "empty LocalVarDescriptors";
  }
  intptr_t len = 1;  // Trailing '\0'.
  String& var_name = String::Handle();
  for (intptr_t i = 0; i < Length(); i++) {
    RawLocalVarDescriptors::VarInfo info;
    var_name = GetName(i);
    GetInfo(i, &info);
    len += PrintVarInfo(NULL, 0, i, var_name, info);
  }
  char* buffer = Thread::Current()->zone()->Alloc<char>(len + 1);
  buffer[0] = '\0';
  intptr_t num_chars = 0;
  for (intptr_t i = 0; i < Length(); i++) {
    RawLocalVarDescriptors::VarInfo info;
    var_name = GetName(i);
    GetInfo(i, &info);
    num_chars += PrintVarInfo((buffer + num_chars),
                              (len - num_chars),
                              i, var_name, info);
  }
  return buffer;
}


void LocalVarDescriptors::PrintJSONImpl(JSONStream* stream,
                                        bool ref) const {
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Object", ref);
  // TODO(johnmccutchan): Generate a stable id. LocalVarDescriptors hang off
  // a Code object but do not have a back reference to generate an ID.
  jsobj.AddServiceId(*this);
  if (ref) {
    return;
  }
  JSONArray members(&jsobj, "members");
  String& var_name = String::Handle();
  for (intptr_t i = 0; i < Length(); i++) {
    RawLocalVarDescriptors::VarInfo info;
    var_name = GetName(i);
    GetInfo(i, &info);
    JSONObject var(&members);
    var.AddProperty("name", var_name.ToCString());
    var.AddProperty("index", static_cast<intptr_t>(info.index()));
    var.AddProperty("beginPos", static_cast<intptr_t>(info.begin_pos));
    var.AddProperty("endPos", static_cast<intptr_t>(info.end_pos));
    var.AddProperty("scopeId", static_cast<intptr_t>(info.scope_id));
    var.AddProperty("kind", KindToCString(info.kind()));
  }
}


const char* LocalVarDescriptors::KindToCString(
    RawLocalVarDescriptors::VarInfoKind kind) {
  switch (kind) {
    case RawLocalVarDescriptors::kStackVar:
      return "StackVar";
    case RawLocalVarDescriptors::kContextVar:
      return "ContextVar";
    case RawLocalVarDescriptors::kContextLevel:
      return "ContextLevel";
    case RawLocalVarDescriptors::kSavedCurrentContext:
      return "CurrentCtx";
    default:
      UNIMPLEMENTED();
      return NULL;
  }
}

RawLocalVarDescriptors* LocalVarDescriptors::New(intptr_t num_variables) {
  ASSERT(Object::var_descriptors_class() != Class::null());
  if (num_variables < 0 || num_variables > kMaxElements) {
    // This should be caught before we reach here.
    FATAL2("Fatal error in LocalVarDescriptors::New: "
           "invalid num_variables %" Pd ". Maximum is: %d\n",
           num_variables, RawLocalVarDescriptors::kMaxIndex);
  }
  LocalVarDescriptors& result = LocalVarDescriptors::Handle();
  {
    uword size = LocalVarDescriptors::InstanceSize(num_variables);
    RawObject* raw = Object::Allocate(LocalVarDescriptors::kClassId,
                                      size,
                                      Heap::kOld);
    INC_STAT(Thread::Current(), total_code_size, size);
    INC_STAT(Thread::Current(), vardesc_size, size);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.StoreNonPointer(&result.raw_ptr()->num_entries_, num_variables);
  }
  return result.raw();
}


intptr_t LocalVarDescriptors::Length() const {
  return raw_ptr()->num_entries_;
}


intptr_t ExceptionHandlers::num_entries() const {
  return raw_ptr()->num_entries_;
}


void ExceptionHandlers::SetHandlerInfo(intptr_t try_index,
                                       intptr_t outer_try_index,
                                       uword handler_pc_offset,
                                       bool needs_stacktrace,
                                       bool has_catch_all) const {
  ASSERT((try_index >= 0) && (try_index < num_entries()));
  NoSafepointScope no_safepoint;
  RawExceptionHandlers::HandlerInfo* info =
      UnsafeMutableNonPointer(&raw_ptr()->data()[try_index]);
  info->outer_try_index = outer_try_index;
  // Some C compilers warn about the comparison always being true when using <=
  // due to limited range of data type.
  ASSERT((handler_pc_offset == static_cast<uword>(kMaxUint32)) ||
         (handler_pc_offset < static_cast<uword>(kMaxUint32)));
  info->handler_pc_offset = handler_pc_offset;
  info->needs_stacktrace = needs_stacktrace;
  info->has_catch_all = has_catch_all;
}

void ExceptionHandlers::GetHandlerInfo(
    intptr_t try_index,
    RawExceptionHandlers::HandlerInfo* info) const {
  ASSERT((try_index >= 0) && (try_index < num_entries()));
  ASSERT(info != NULL);
  *info = raw_ptr()->data()[try_index];
}


uword ExceptionHandlers::HandlerPCOffset(intptr_t try_index) const {
  ASSERT((try_index >= 0) && (try_index < num_entries()));
  return raw_ptr()->data()[try_index].handler_pc_offset;
}


intptr_t ExceptionHandlers::OuterTryIndex(intptr_t try_index) const {
  ASSERT((try_index >= 0) && (try_index < num_entries()));
  return raw_ptr()->data()[try_index].outer_try_index;
}


bool ExceptionHandlers::NeedsStacktrace(intptr_t try_index) const {
  ASSERT((try_index >= 0) && (try_index < num_entries()));
  return raw_ptr()->data()[try_index].needs_stacktrace;
}


bool ExceptionHandlers::HasCatchAll(intptr_t try_index) const {
  ASSERT((try_index >= 0) && (try_index < num_entries()));
  return raw_ptr()->data()[try_index].has_catch_all;
}


void ExceptionHandlers::SetHandledTypes(intptr_t try_index,
                                        const Array& handled_types) const {
  ASSERT((try_index >= 0) && (try_index < num_entries()));
  const Array& handled_types_data =
      Array::Handle(raw_ptr()->handled_types_data_);
  handled_types_data.SetAt(try_index, handled_types);
}


RawArray* ExceptionHandlers::GetHandledTypes(intptr_t try_index) const {
  ASSERT((try_index >= 0) && (try_index < num_entries()));
  Array& array = Array::Handle(raw_ptr()->handled_types_data_);
  array ^= array.At(try_index);
  return array.raw();
}


void ExceptionHandlers::set_handled_types_data(const Array& value) const {
  StorePointer(&raw_ptr()->handled_types_data_, value.raw());
}


RawExceptionHandlers* ExceptionHandlers::New(intptr_t num_handlers) {
  ASSERT(Object::exception_handlers_class() != Class::null());
  if ((num_handlers < 0) || (num_handlers >= kMaxHandlers)) {
    FATAL1("Fatal error in ExceptionHandlers::New(): "
           "invalid num_handlers %" Pd "\n",
           num_handlers);
  }
  ExceptionHandlers& result = ExceptionHandlers::Handle();
  {
    uword size = ExceptionHandlers::InstanceSize(num_handlers);
    RawObject* raw = Object::Allocate(ExceptionHandlers::kClassId,
                                      size,
                                      Heap::kOld);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.StoreNonPointer(&result.raw_ptr()->num_entries_, num_handlers);
  }
  const Array& handled_types_data = (num_handlers == 0) ?
      Object::empty_array() :
      Array::Handle(Array::New(num_handlers, Heap::kOld));
  result.set_handled_types_data(handled_types_data);
  return result.raw();
}


RawExceptionHandlers* ExceptionHandlers::New(const Array& handled_types_data) {
  ASSERT(Object::exception_handlers_class() != Class::null());
  const intptr_t num_handlers = handled_types_data.Length();
  if ((num_handlers < 0) || (num_handlers >= kMaxHandlers)) {
    FATAL1("Fatal error in ExceptionHandlers::New(): "
           "invalid num_handlers %" Pd "\n",
           num_handlers);
  }
  ExceptionHandlers& result = ExceptionHandlers::Handle();
  {
    uword size = ExceptionHandlers::InstanceSize(num_handlers);
    RawObject* raw = Object::Allocate(ExceptionHandlers::kClassId,
                                      size,
                                      Heap::kOld);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.StoreNonPointer(&result.raw_ptr()->num_entries_, num_handlers);
  }
  result.set_handled_types_data(handled_types_data);
  return result.raw();
}


const char* ExceptionHandlers::ToCString() const {
#define FORMAT1 "%" Pd " => %#x  (%" Pd " types) (outer %d)\n"
#define FORMAT2 "  %d. %s\n"
  if (num_entries() == 0) {
    return "empty ExceptionHandlers\n";
  }
  Array& handled_types = Array::Handle();
  Type& type = Type::Handle();
  RawExceptionHandlers::HandlerInfo info;
  // First compute the buffer size required.
  intptr_t len = 1;  // Trailing '\0'.
  for (intptr_t i = 0; i < num_entries(); i++) {
    GetHandlerInfo(i, &info);
    handled_types = GetHandledTypes(i);
    const intptr_t num_types =
        handled_types.IsNull() ? 0 : handled_types.Length();
    len += OS::SNPrint(NULL, 0, FORMAT1,
                       i,
                       info.handler_pc_offset,
                       num_types,
                       info.outer_try_index);
    for (int k = 0; k < num_types; k++) {
      type ^= handled_types.At(k);
      ASSERT(!type.IsNull());
      len += OS::SNPrint(NULL, 0, FORMAT2, k, type.ToCString());
    }
  }
  // Allocate the buffer.
  char* buffer = Thread::Current()->zone()->Alloc<char>(len);
  // Layout the fields in the buffer.
  intptr_t num_chars = 0;
  for (intptr_t i = 0; i < num_entries(); i++) {
    GetHandlerInfo(i, &info);
    handled_types = GetHandledTypes(i);
    const intptr_t num_types =
        handled_types.IsNull() ? 0 : handled_types.Length();
    num_chars += OS::SNPrint((buffer + num_chars),
                             (len - num_chars),
                             FORMAT1,
                             i,
                             info.handler_pc_offset,
                             num_types,
                             info.outer_try_index);
    for (int k = 0; k < num_types; k++) {
      type ^= handled_types.At(k);
      num_chars += OS::SNPrint((buffer + num_chars),
                               (len - num_chars),
                               FORMAT2, k, type.ToCString());
    }
  }
  return buffer;
#undef FORMAT1
#undef FORMAT2
}


void ExceptionHandlers::PrintJSONImpl(JSONStream* stream,
                                      bool ref) const {
  Object::PrintJSONImpl(stream, ref);
}


intptr_t DeoptInfo::FrameSize(const TypedData& packed) {
  NoSafepointScope no_safepoint;
  typedef ReadStream::Raw<sizeof(intptr_t), intptr_t> Reader;
  ReadStream read_stream(reinterpret_cast<uint8_t*>(packed.DataAddr(0)),
                         packed.LengthInBytes());
  return Reader::Read(&read_stream);
}


intptr_t DeoptInfo::NumMaterializations(
    const GrowableArray<DeoptInstr*>& unpacked) {
  intptr_t num = 0;
  while (unpacked[num]->kind() == DeoptInstr::kMaterializeObject) {
    num++;
  }
  return num;
}


void DeoptInfo::UnpackInto(const Array& table,
                           const TypedData& packed,
                           GrowableArray<DeoptInstr*>* unpacked,
                           intptr_t length) {
  NoSafepointScope no_safepoint;
  typedef ReadStream::Raw<sizeof(intptr_t), intptr_t> Reader;
  ReadStream read_stream(reinterpret_cast<uint8_t*>(packed.DataAddr(0)),
                         packed.LengthInBytes());
  const intptr_t frame_size = Reader::Read(&read_stream);  // Skip frame size.
  USE(frame_size);

  const intptr_t suffix_length = Reader::Read(&read_stream);
  if (suffix_length != 0) {
    ASSERT(suffix_length > 1);
    const intptr_t info_number = Reader::Read(&read_stream);

    TypedData& suffix = TypedData::Handle();
    Smi& offset = Smi::Handle();
    Smi& reason_and_flags = Smi::Handle();
    DeoptTable::GetEntry(
      table, info_number, &offset, &suffix, &reason_and_flags);
    UnpackInto(table, suffix, unpacked, suffix_length);
  }

  while ((read_stream.PendingBytes() > 0) &&
         (unpacked->length() < length)) {
    const intptr_t instruction = Reader::Read(&read_stream);
    const intptr_t from_index = Reader::Read(&read_stream);
    unpacked->Add(DeoptInstr::Create(instruction, from_index));
  }
}


void DeoptInfo::Unpack(const Array& table,
                       const TypedData& packed,
                       GrowableArray<DeoptInstr*>* unpacked) {
  ASSERT(unpacked->is_empty());

  // Pass kMaxInt32 as the length to unpack all instructions from the
  // packed stream.
  UnpackInto(table, packed, unpacked, kMaxInt32);

  unpacked->Reverse();
}


const char* DeoptInfo::ToCString(const Array& deopt_table,
                                 const TypedData& packed) {
#define FORMAT "[%s]"
  GrowableArray<DeoptInstr*> deopt_instrs;
  Unpack(deopt_table, packed, &deopt_instrs);

  // Compute the buffer size required.
  intptr_t len = 1;  // Trailing '\0'.
  for (intptr_t i = 0; i < deopt_instrs.length(); i++) {
    len += OS::SNPrint(NULL, 0, FORMAT, deopt_instrs[i]->ToCString());
  }

  // Allocate the buffer.
  char* buffer = Thread::Current()->zone()->Alloc<char>(len);

  // Layout the fields in the buffer.
  intptr_t index = 0;
  for (intptr_t i = 0; i < deopt_instrs.length(); i++) {
    index += OS::SNPrint((buffer + index),
                         (len - index),
                         FORMAT,
                         deopt_instrs[i]->ToCString());
  }

  return buffer;
#undef FORMAT
}


// Returns a bool so it can be asserted.
bool DeoptInfo::VerifyDecompression(const GrowableArray<DeoptInstr*>& original,
                                    const Array& deopt_table,
                                    const TypedData& packed) {
  GrowableArray<DeoptInstr*> unpacked;
  Unpack(deopt_table, packed, &unpacked);
  ASSERT(unpacked.length() == original.length());
  for (intptr_t i = 0; i < unpacked.length(); ++i) {
    ASSERT(unpacked[i]->Equals(*original[i]));
  }
  return true;
}


const char* ICData::ToCString() const {
  const String& name = String::Handle(target_name());
  const intptr_t num_args = NumArgsTested();
  const intptr_t num_checks = NumberOfChecks();
  return OS::SCreate(Thread::Current()->zone(),
      "ICData target:'%s' num-args: %" Pd " num-checks: %" Pd "",
      name.ToCString(), num_args, num_checks);
}


void ICData::set_owner(const Function& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->owner_, value.raw());
}


void ICData::set_target_name(const String& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->target_name_, value.raw());
}


void ICData::set_arguments_descriptor(const Array& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->args_descriptor_, value.raw());
}

void ICData::set_deopt_id(intptr_t value) const {
  ASSERT(value <= kMaxInt32);
  StoreNonPointer(&raw_ptr()->deopt_id_, value);
}


void ICData::set_ic_data(const Array& value) const {
  ASSERT(!value.IsNull());
  StorePointer(&raw_ptr()->ic_data_, value.raw());
}


intptr_t ICData::NumArgsTested() const {
  return NumArgsTestedBits::decode(raw_ptr()->state_bits_);
}


void ICData::SetNumArgsTested(intptr_t value) const {
  ASSERT(Utils::IsUint(2, value));
  StoreNonPointer(&raw_ptr()->state_bits_,
                  NumArgsTestedBits::update(value, raw_ptr()->state_bits_));
}


uint32_t ICData::DeoptReasons() const {
  return DeoptReasonBits::decode(raw_ptr()->state_bits_);
}


void ICData::SetDeoptReasons(uint32_t reasons) const {
  StoreNonPointer(&raw_ptr()->state_bits_,
                  DeoptReasonBits::update(reasons, raw_ptr()->state_bits_));
}


bool ICData::HasDeoptReason(DeoptReasonId reason) const {
  ASSERT(reason <= kLastRecordedDeoptReason);
  return (DeoptReasons() & (1 << reason)) != 0;
}


void ICData::AddDeoptReason(DeoptReasonId reason) const {
  if (reason <= kLastRecordedDeoptReason) {
    SetDeoptReasons(DeoptReasons() | (1 << reason));
  }
}


bool ICData::IssuedJSWarning() const {
  return IssuedJSWarningBit::decode(raw_ptr()->state_bits_);
}


void ICData::SetIssuedJSWarning() const {
  StoreNonPointer(&raw_ptr()->state_bits_,
                  IssuedJSWarningBit::update(true, raw_ptr()->state_bits_));
}


bool ICData::MayCheckForJSWarning() const {
  const String& name = String::Handle(target_name());
  // Warning issued from native code.
  // Calling sequence is decoded to obtain ic data in order to check if a
  // warning has already been issued.
  if (name.Equals(Library::PrivateCoreLibName(Symbols::_instanceOf())) ||
      name.Equals(Library::PrivateCoreLibName(Symbols::_as()))) {
    return true;
  }
  // Warning issued in ic miss handler.
  // No decoding necessary, so allow optimization if warning already issued.
  if (name.Equals(Symbols::toString()) && !IssuedJSWarning()) {
    return true;
  }
  return false;
}


void ICData::set_state_bits(uint32_t bits) const {
  StoreNonPointer(&raw_ptr()->state_bits_, bits);
}


intptr_t ICData::TestEntryLengthFor(intptr_t num_args) {
  return num_args + 1 /* target function*/ + 1 /* frequency */;
}


intptr_t ICData::TestEntryLength() const {
  return TestEntryLengthFor(NumArgsTested());
}


intptr_t ICData::NumberOfChecks() const {
  // Do not count the sentinel;
  return (Smi::Value(ic_data()->ptr()->length_) / TestEntryLength()) - 1;
}


// Discounts any checks with usage of zero.
intptr_t ICData::NumberOfUsedChecks() const {
  intptr_t n = NumberOfChecks();
  if (n == 0) {
    return 0;
  }
  intptr_t count = 0;
  for (intptr_t i = 0; i < n; i++) {
    if (GetCountAt(i) > 0) {
      count++;
    }
  }
  return count;
}


void ICData::WriteSentinel(const Array& data) const {
  ASSERT(!data.IsNull());
  for (intptr_t i = 1; i <= TestEntryLength(); i++) {
    data.SetAt(data.Length() - i, smi_illegal_cid());
  }
}


#if defined(DEBUG)
// Used in asserts to verify that a check is not added twice.
bool ICData::HasCheck(const GrowableArray<intptr_t>& cids) const {
  const intptr_t len = NumberOfChecks();
  for (intptr_t i = 0; i < len; i++) {
    GrowableArray<intptr_t> class_ids;
    Function& target = Function::Handle();
    GetCheckAt(i, &class_ids, &target);
    bool matches = true;
    for (intptr_t k = 0; k < class_ids.length(); k++) {
      if (class_ids[k] != cids[k]) {
        matches = false;
        break;
      }
    }
    if (matches) {
      return true;
    }
  }
  return false;
}
#endif  // DEBUG


// Used for unoptimized static calls when no class-ids are checked.
void ICData::AddTarget(const Function& target) const {
  ASSERT(!target.IsNull());
  if (NumArgsTested() > 0) {
    // Create a fake cid entry, so that we can store the target.
    if (NumArgsTested() == 1) {
      AddReceiverCheck(kObjectCid, target, 1);
    } else {
      GrowableArray<intptr_t> class_ids(NumArgsTested());
      for (intptr_t i = 0; i < NumArgsTested(); i++) {
        class_ids.Add(kObjectCid);
      }
      AddCheck(class_ids, target);
    }
    return;
  }
  ASSERT(NumArgsTested() == 0);
  // Can add only once.
  const intptr_t old_num = NumberOfChecks();
  ASSERT(old_num == 0);
  Array& data = Array::Handle(ic_data());
  const intptr_t new_len = data.Length() + TestEntryLength();
  data = Array::Grow(data, new_len, Heap::kOld);
  set_ic_data(data);
  WriteSentinel(data);
  intptr_t data_pos = old_num * TestEntryLength();
  ASSERT(!target.IsNull());
  data.SetAt(data_pos++, target);
  // Set count to 0 as this is called during compilation, before the
  // call has been executed.
  const Smi& value = Smi::Handle(Smi::New(0));
  data.SetAt(data_pos, value);
}


void ICData::AddCheck(const GrowableArray<intptr_t>& class_ids,
                      const Function& target) const {
  ASSERT(!target.IsNull());
  ASSERT(target.name() == target_name());
  DEBUG_ASSERT(!HasCheck(class_ids));
  ASSERT(NumArgsTested() > 1);  // Otherwise use 'AddReceiverCheck'.
  ASSERT(class_ids.length() == NumArgsTested());
  const intptr_t old_num = NumberOfChecks();
  Array& data = Array::Handle(ic_data());
  // ICData of static calls with NumArgsTested() > 0 have initially a
  // dummy set of cids entered (see ICData::AddTarget). That entry is
  // overwritten by first real type feedback data.
  if (old_num == 1) {
    bool has_dummy_entry = true;
    for (intptr_t i = 0; i < NumArgsTested(); i++) {
      if (Smi::Value(Smi::RawCast(data.At(i))) != kObjectCid) {
        has_dummy_entry = false;
        break;
      }
    }
    if (has_dummy_entry) {
      ASSERT(target.raw() == data.At(NumArgsTested()));
      // Replace dummy entry.
      Smi& value = Smi::Handle();
      for (intptr_t i = 0; i < NumArgsTested(); i++) {
        ASSERT(class_ids[i] != kIllegalCid);
        value = Smi::New(class_ids[i]);
        data.SetAt(i, value);
      }
      return;
    }
  }
  const intptr_t new_len = data.Length() + TestEntryLength();
  data = Array::Grow(data, new_len, Heap::kOld);
  set_ic_data(data);
  WriteSentinel(data);
  intptr_t data_pos = old_num * TestEntryLength();
  Smi& value = Smi::Handle();
  for (intptr_t i = 0; i < class_ids.length(); i++) {
    // kIllegalCid is used as terminating value, do not add it.
    ASSERT(class_ids[i] != kIllegalCid);
    value = Smi::New(class_ids[i]);
    data.SetAt(data_pos++, value);
  }
  ASSERT(!target.IsNull());
  data.SetAt(data_pos++, target);
  value = Smi::New(1);
  data.SetAt(data_pos, value);
}


void ICData::AddReceiverCheck(intptr_t receiver_class_id,
                              const Function& target,
                              intptr_t count) const {
#if defined(DEBUG)
  GrowableArray<intptr_t> class_ids(1);
  class_ids.Add(receiver_class_id);
  ASSERT(!HasCheck(class_ids));
#endif  // DEBUG
  ASSERT(!target.IsNull());
  ASSERT(NumArgsTested() == 1);  // Otherwise use 'AddCheck'.
  ASSERT(receiver_class_id != kIllegalCid);

  const intptr_t old_num = NumberOfChecks();
  Array& data = Array::Handle(ic_data());
  const intptr_t new_len = data.Length() + TestEntryLength();
  data = Array::Grow(data, new_len, Heap::kOld);
  set_ic_data(data);
  WriteSentinel(data);
  intptr_t data_pos = old_num * TestEntryLength();
  if ((receiver_class_id == kSmiCid) && (data_pos > 0)) {
    ASSERT(GetReceiverClassIdAt(0) != kSmiCid);
    // Move class occupying position 0 to the data_pos.
    for (intptr_t i = 0; i < TestEntryLength(); i++) {
      data.SetAt(data_pos + i, Object::Handle(data.At(i)));
    }
    // Insert kSmiCid in position 0.
    data_pos = 0;
  }
  data.SetAt(data_pos, Smi::Handle(Smi::New(receiver_class_id)));
  data.SetAt(data_pos + 1, target);
  data.SetAt(data_pos + 2, Smi::Handle(Smi::New(count)));
}


void ICData::GetCheckAt(intptr_t index,
                        GrowableArray<intptr_t>* class_ids,
                        Function* target) const {
  ASSERT(index < NumberOfChecks());
  ASSERT(class_ids != NULL);
  ASSERT(target != NULL);
  class_ids->Clear();
  const Array& data = Array::Handle(ic_data());
  intptr_t data_pos = index * TestEntryLength();
  for (intptr_t i = 0; i < NumArgsTested(); i++) {
    class_ids->Add(Smi::Value(Smi::RawCast(data.At(data_pos++))));
  }
  (*target) ^= data.At(data_pos++);
}


void ICData::GetOneClassCheckAt(intptr_t index,
                                intptr_t* class_id,
                                Function* target) const {
  ASSERT(class_id != NULL);
  ASSERT(target != NULL);
  ASSERT(NumArgsTested() == 1);
  const Array& data = Array::Handle(ic_data());
  const intptr_t data_pos = index * TestEntryLength();
  *class_id = Smi::Value(Smi::RawCast(data.At(data_pos)));
  *target ^= data.At(data_pos + 1);
}


intptr_t ICData::GetCidAt(intptr_t index) const {
  ASSERT(NumArgsTested() == 1);
  const Array& data = Array::Handle(ic_data());
  const intptr_t data_pos = index * TestEntryLength();
  return Smi::Value(Smi::RawCast(data.At(data_pos)));
}


intptr_t ICData::GetClassIdAt(intptr_t index, intptr_t arg_nr) const {
  GrowableArray<intptr_t> class_ids;
  Function& target = Function::Handle();
  GetCheckAt(index, &class_ids, &target);
  return class_ids[arg_nr];
}


intptr_t ICData::GetReceiverClassIdAt(intptr_t index) const {
  ASSERT(index < NumberOfChecks());
  const intptr_t data_pos = index * TestEntryLength();
  NoSafepointScope no_safepoint;
  RawArray* raw_data = ic_data();
  return Smi::Value(Smi::RawCast(raw_data->ptr()->data()[data_pos]));
}


RawFunction* ICData::GetTargetAt(intptr_t index) const {
  const intptr_t data_pos = index * TestEntryLength() + NumArgsTested();
  ASSERT(Object::Handle(Array::Handle(ic_data()).At(data_pos)).IsFunction());

  NoSafepointScope no_safepoint;
  RawArray* raw_data = ic_data();
  return reinterpret_cast<RawFunction*>(raw_data->ptr()->data()[data_pos]);
}


void ICData::IncrementCountAt(intptr_t index, intptr_t value) const {
  ASSERT(0 <= value);
  ASSERT(value <= Smi::kMaxValue);
  SetCountAt(index, Utils::Minimum(GetCountAt(index) + value, Smi::kMaxValue));
}


void ICData::SetCountAt(intptr_t index, intptr_t value) const {
  ASSERT(0 <= value);
  ASSERT(value <= Smi::kMaxValue);

  const Array& data = Array::Handle(ic_data());
  const intptr_t data_pos = index * TestEntryLength() +
      CountIndexFor(NumArgsTested());
  data.SetAt(data_pos, Smi::Handle(Smi::New(value)));
}


intptr_t ICData::GetCountAt(intptr_t index) const {
  const Array& data = Array::Handle(ic_data());
  const intptr_t data_pos = index * TestEntryLength() +
      CountIndexFor(NumArgsTested());
  return Smi::Value(Smi::RawCast(data.At(data_pos)));
}


intptr_t ICData::AggregateCount() const {
  if (IsNull()) return 0;
  const intptr_t len = NumberOfChecks();
  intptr_t count = 0;
  for (intptr_t i = 0; i < len; i++) {
    count += GetCountAt(i);
  }
  return count;
}


RawFunction* ICData::GetTargetForReceiverClassId(intptr_t class_id) const {
  const intptr_t len = NumberOfChecks();
  for (intptr_t i = 0; i < len; i++) {
    if (GetReceiverClassIdAt(i) == class_id) {
      return GetTargetAt(i);
    }
  }
  return Function::null();
}


RawICData* ICData::AsUnaryClassChecksForCid(
    intptr_t cid, const Function& target) const {
  ASSERT(!IsNull());
  const intptr_t kNumArgsTested = 1;
  ICData& result = ICData::Handle(ICData::NewFrom(*this, kNumArgsTested));

  // Copy count so that we copy the state "count == 0" vs "count > 0".
  result.AddReceiverCheck(cid, target, GetCountAt(0));
  return result.raw();
}


RawICData* ICData::AsUnaryClassChecksForArgNr(intptr_t arg_nr) const {
  ASSERT(!IsNull());
  ASSERT(NumArgsTested() > arg_nr);
  if ((arg_nr == 0) && (NumArgsTested() == 1)) {
    // Frequent case.
    return raw();
  }
  const intptr_t kNumArgsTested = 1;
  ICData& result = ICData::Handle(ICData::NewFrom(*this, kNumArgsTested));
  const intptr_t len = NumberOfChecks();
  for (intptr_t i = 0; i < len; i++) {
    const intptr_t class_id = GetClassIdAt(i, arg_nr);
    const intptr_t count = GetCountAt(i);
    if (count == 0) {
      continue;
    }
    intptr_t duplicate_class_id = -1;
    const intptr_t result_len = result.NumberOfChecks();
    for (intptr_t k = 0; k < result_len; k++) {
      if (class_id == result.GetReceiverClassIdAt(k)) {
        duplicate_class_id = k;
        break;
      }
    }
    if (duplicate_class_id >= 0) {
      // This check is valid only when checking the receiver.
      ASSERT((arg_nr != 0) ||
             (result.GetTargetAt(duplicate_class_id) == GetTargetAt(i)));
      result.IncrementCountAt(duplicate_class_id, count);
    } else {
      // This will make sure that Smi is first if it exists.
      result.AddReceiverCheck(class_id,
                              Function::Handle(GetTargetAt(i)),
                              count);
    }
  }

  return result.raw();
}


bool ICData::AllTargetsHaveSameOwner(intptr_t owner_cid) const {
  if (NumberOfChecks() == 0) return false;
  Class& cls = Class::Handle();
  const intptr_t len = NumberOfChecks();
  for (intptr_t i = 0; i < len; i++) {
    if (IsUsedAt(i)) {
      cls = Function::Handle(GetTargetAt(i)).Owner();
      if (cls.id() != owner_cid) {
        return false;
      }
    }
  }
  return true;
}


bool ICData::HasReceiverClassId(intptr_t class_id) const {
  ASSERT(NumArgsTested() > 0);
  const intptr_t len = NumberOfChecks();
  for (intptr_t i = 0; i < len; i++) {
    if (IsUsedAt(i)) {
      const intptr_t test_class_id = GetReceiverClassIdAt(i);
      if (test_class_id == class_id) {
        return true;
      }
    }
  }
  return false;
}


// Returns true if all targets are the same.
// TODO(srdjan): if targets are native use their C_function to compare.
bool ICData::HasOneTarget() const {
  ASSERT(NumberOfChecks() > 0);
  const Function& first_target = Function::Handle(GetTargetAt(0));
  const intptr_t len = NumberOfChecks();
  for (intptr_t i = 1; i < len; i++) {
    if (IsUsedAt(i) && (GetTargetAt(i) != first_target.raw())) {
      return false;
    }
  }
  return true;
}


void ICData::GetUsedCidsForTwoArgs(GrowableArray<intptr_t>* first,
                                   GrowableArray<intptr_t>* second) const {
  ASSERT(NumArgsTested() == 2);
  first->Clear();
  second->Clear();
  Function& target = Function::Handle();
  GrowableArray<intptr_t> class_ids;
  const intptr_t len = NumberOfChecks();
  for (intptr_t i = 0; i < len; i++) {
    if (GetCountAt(i) > 0) {
      GetCheckAt(i, &class_ids, &target);
      ASSERT(class_ids.length() == 2);
      first->Add(class_ids[0]);
      second->Add(class_ids[1]);
    }
  }
}


bool ICData::IsUsedAt(intptr_t i) const {
  if (GetCountAt(i) <= 0) {
    // Do not mistake unoptimized static call ICData for unused.
    // See ICData::AddTarget.
    // TODO(srdjan): Make this test more robust.
    if (NumArgsTested() > 0) {
      const intptr_t cid = GetReceiverClassIdAt(i);
      if (cid == kObjectCid) {
        return true;
      }
    }
    return false;
  }
  return true;
}


RawICData* ICData::New() {
  ICData& result = ICData::Handle();
  {
    // IC data objects are long living objects, allocate them in old generation.
    RawObject* raw = Object::Allocate(ICData::kClassId,
                                      ICData::InstanceSize(),
                                      Heap::kOld);
    NoSafepointScope no_safepoint;
    result ^= raw;
  }
  result.set_deopt_id(Thread::kNoDeoptId);
  result.set_state_bits(0);
  return result.raw();
}


RawICData* ICData::New(const Function& owner,
                       const String& target_name,
                       const Array& arguments_descriptor,
                       intptr_t deopt_id,
                       intptr_t num_args_tested) {
  ASSERT(!owner.IsNull());
  ASSERT(!target_name.IsNull());
  ASSERT(!arguments_descriptor.IsNull());
  ASSERT(Object::icdata_class() != Class::null());
  ASSERT(num_args_tested >= 0);
  ICData& result = ICData::Handle();
  {
    // IC data objects are long living objects, allocate them in old generation.
    RawObject* raw = Object::Allocate(ICData::kClassId,
                                      ICData::InstanceSize(),
                                      Heap::kOld);
    NoSafepointScope no_safepoint;
    result ^= raw;
  }
  result.set_owner(owner);
  result.set_target_name(target_name);
  result.set_arguments_descriptor(arguments_descriptor);
  result.set_deopt_id(deopt_id);
  result.set_state_bits(0);
  result.SetNumArgsTested(num_args_tested);
  // Number of array elements in one test entry.
  intptr_t len = result.TestEntryLength();
  // IC data array must be null terminated (sentinel entry).
  const Array& ic_data = Array::Handle(Array::New(len, Heap::kOld));
  result.set_ic_data(ic_data);
  result.WriteSentinel(ic_data);
  return result.raw();
}


RawICData* ICData::NewFrom(const ICData& from, intptr_t num_args_tested) {
  const ICData& result = ICData::Handle(ICData::New(
      Function::Handle(from.owner()),
      String::Handle(from.target_name()),
      Array::Handle(from.arguments_descriptor()),
      from.deopt_id(),
      num_args_tested));
  // Copy deoptimization reasons.
  result.SetDeoptReasons(from.DeoptReasons());
  return result.raw();
}


void ICData::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Object", ref);
  jsobj.AddServiceId(*this);
  jsobj.AddProperty("_owner", Object::Handle(owner()));
  jsobj.AddProperty("_selector", String::Handle(target_name()).ToCString());
  if (ref) {
    return;
  }
  jsobj.AddProperty("_argumentsDescriptor",
                    Object::Handle(arguments_descriptor()));
  jsobj.AddProperty("_entries", Object::Handle(ic_data()));
}


void ICData::PrintToJSONArray(const JSONArray& jsarray,
                              intptr_t token_pos,
                              bool is_static_call) const {
  Isolate* isolate = Isolate::Current();
  Class& cls = Class::Handle();
  Function& func = Function::Handle();

  JSONObject jsobj(&jsarray);
  jsobj.AddProperty("name", String::Handle(target_name()).ToCString());
  // TODO(turnidge): Use AddLocation instead.
  jsobj.AddProperty("tokenPos", token_pos);
  // TODO(rmacnak): Figure out how to stringify DeoptReasons().
  // jsobj.AddProperty("deoptReasons", ...);

  JSONArray cache_entries(&jsobj, "cacheEntries");
  for (intptr_t i = 0; i < NumberOfChecks(); i++) {
    func = GetTargetAt(i);
    if (is_static_call) {
      cls ^= func.Owner();
    } else {
      intptr_t cid = GetReceiverClassIdAt(i);
      cls ^= isolate->class_table()->At(cid);
    }
    intptr_t count = GetCountAt(i);
    JSONObject cache_entry(&cache_entries);
    if (cls.IsTopLevel()) {
      cache_entry.AddProperty("receiverContainer",
                              Library::Handle(cls.library()));
    } else {
      cache_entry.AddProperty("receiverContainer", cls);
    }
    cache_entry.AddProperty("count", count);
    cache_entry.AddProperty("target", func);
  }
}


static Token::Kind RecognizeArithmeticOp(const String& name) {
  ASSERT(name.IsSymbol());
  if (name.raw() == Symbols::Plus().raw()) {
    return Token::kADD;
  } else if (name.raw() == Symbols::Minus().raw()) {
    return Token::kSUB;
  } else if (name.raw() == Symbols::Star().raw()) {
    return Token::kMUL;
  } else if (name.raw() == Symbols::Slash().raw()) {
    return Token::kDIV;
  } else if (name.raw() == Symbols::TruncDivOperator().raw()) {
    return Token::kTRUNCDIV;
  } else if (name.raw() == Symbols::Percent().raw()) {
    return Token::kMOD;
  } else if (name.raw() == Symbols::BitOr().raw()) {
    return Token::kBIT_OR;
  } else if (name.raw() == Symbols::Ampersand().raw()) {
    return Token::kBIT_AND;
  } else if (name.raw() == Symbols::Caret().raw()) {
    return Token::kBIT_XOR;
  } else if (name.raw() == Symbols::LeftShiftOperator().raw()) {
    return Token::kSHL;
  } else if (name.raw() == Symbols::RightShiftOperator().raw()) {
    return Token::kSHR;
  } else if (name.raw() == Symbols::Tilde().raw()) {
    return Token::kBIT_NOT;
  } else if (name.raw() == Symbols::UnaryMinus().raw()) {
    return Token::kNEGATE;
  }
  return Token::kILLEGAL;
}


bool ICData::HasRangeFeedback() const {
  const String& target = String::Handle(target_name());
  const Token::Kind token_kind = RecognizeArithmeticOp(target);
  if (!Token::IsBinaryArithmeticOperator(token_kind) &&
      !Token::IsUnaryArithmeticOperator(token_kind)) {
    return false;
  }

  bool initialized = false;
  Function& t = Function::Handle();
  const intptr_t len = NumberOfChecks();
  GrowableArray<intptr_t> class_ids;
  for (intptr_t i = 0; i < len; i++) {
    if (IsUsedAt(i)) {
      initialized = true;
      GetCheckAt(i, &class_ids, &t);
      for (intptr_t j = 0; j < class_ids.length(); j++) {
        const intptr_t cid = class_ids[j];
        if ((cid != kSmiCid) && (cid != kMintCid)) {
          return false;
        }
      }
    }
  }

  return initialized;
}


ICData::RangeFeedback ICData::DecodeRangeFeedbackAt(intptr_t idx) const {
  ASSERT((0 <= idx) && (idx < 3));
  const uint32_t raw_feedback =
      RangeFeedbackBits::decode(raw_ptr()->state_bits_);
  const uint32_t feedback =
      (raw_feedback >> (idx * kBitsPerRangeFeedback)) & kRangeFeedbackMask;
  if ((feedback & kInt64RangeBit) != 0) {
    return kInt64Range;
  }

  if ((feedback & kUint32RangeBit) != 0) {
    if ((feedback & kSignedRangeBit) == 0) {
      return kUint32Range;
    }

    // Check if Smi is large enough to accomodate Int33: a mixture of Uint32
    // and negative Int32 values.
    return (kSmiBits < 33) ? kInt64Range : kSmiRange;
  }

  if ((feedback & kInt32RangeBit) != 0) {
    return kInt32Range;
  }

  return kSmiRange;
}


Code::Comments& Code::Comments::New(intptr_t count) {
  Comments* comments;
  if (count < 0 || count > (kIntptrMax / kNumberOfEntries)) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in Code::Comments::New: invalid count %" Pd "\n",
           count);
  }
  if (count == 0) {
    comments = new Comments(Object::empty_array());
  } else {
    const Array& data =
        Array::Handle(Array::New(count * kNumberOfEntries, Heap::kOld));
    comments = new Comments(data);
  }
  return *comments;
}


intptr_t Code::Comments::Length() const {
  if (comments_.IsNull()) {
    return 0;
  }
  return comments_.Length() / kNumberOfEntries;
}


intptr_t Code::Comments::PCOffsetAt(intptr_t idx) const {
  return Smi::Value(Smi::RawCast(
      comments_.At(idx * kNumberOfEntries + kPCOffsetEntry)));
}


void Code::Comments::SetPCOffsetAt(intptr_t idx, intptr_t pc)  {
  comments_.SetAt(idx * kNumberOfEntries + kPCOffsetEntry,
                  Smi::Handle(Smi::New(pc)));
}


RawString* Code::Comments::CommentAt(intptr_t idx) const {
  return String::RawCast(comments_.At(idx * kNumberOfEntries + kCommentEntry));
}


void Code::Comments::SetCommentAt(intptr_t idx, const String& comment) {
  comments_.SetAt(idx * kNumberOfEntries + kCommentEntry, comment);
}


Code::Comments::Comments(const Array& comments)
    : comments_(comments) {
}


RawLocalVarDescriptors* Code::GetLocalVarDescriptors() const {
  const LocalVarDescriptors& v = LocalVarDescriptors::Handle(var_descriptors());
  if (v.IsNull()) {
    ASSERT(!is_optimized());
    const Function& f = Function::Handle(function());
    ASSERT(!f.IsIrregexpFunction());  // Not yet implemented.
    Compiler::ComputeLocalVarDescriptors(*this);
  }
  return var_descriptors();
}


void Code::set_state_bits(intptr_t bits) const {
  StoreNonPointer(&raw_ptr()->state_bits_, bits);
}


void Code::set_is_optimized(bool value) const {
  set_state_bits(OptimizedBit::update(value, raw_ptr()->state_bits_));
}


void Code::set_is_alive(bool value) const {
  set_state_bits(AliveBit::update(value, raw_ptr()->state_bits_));
}


void Code::set_stackmaps(const Array& maps) const {
  ASSERT(maps.IsOld());
  StorePointer(&raw_ptr()->stackmaps_, maps.raw());
  INC_STAT(Thread::Current(),
           total_code_size,
           maps.IsNull() ? 0 : maps.Length() * sizeof(uword));
}


void Code::set_deopt_info_array(const Array& array) const {
  ASSERT(array.IsOld());
  StorePointer(&raw_ptr()->deopt_info_array_, array.raw());
}


void Code::set_static_calls_target_table(const Array& value) const {
  StorePointer(&raw_ptr()->static_calls_target_table_, value.raw());
#if defined(DEBUG)
  // Check that the table is sorted by pc offsets.
  // FlowGraphCompiler::AddStaticCallTarget adds pc-offsets to the table while
  // emitting assembly. This guarantees that every succeeding pc-offset is
  // larger than the previously added one.
  for (intptr_t i = kSCallTableEntryLength;
      i < value.Length();
      i += kSCallTableEntryLength) {
    ASSERT(value.At(i - kSCallTableEntryLength) < value.At(i));
  }
#endif  // DEBUG
}


bool Code::HasBreakpoint() const {
  return Isolate::Current()->debugger()->HasBreakpoint(*this);
}


RawTypedData* Code::GetDeoptInfoAtPc(uword pc,
                                     ICData::DeoptReasonId* deopt_reason,
                                     uint32_t* deopt_flags) const {
  ASSERT(is_optimized());
  const Instructions& instrs = Instructions::Handle(instructions());
  uword code_entry = instrs.EntryPoint();
  const Array& table = Array::Handle(deopt_info_array());
  ASSERT(!table.IsNull());
  // Linear search for the PC offset matching the target PC.
  intptr_t length = DeoptTable::GetLength(table);
  Smi& offset = Smi::Handle();
  Smi& reason_and_flags = Smi::Handle();
  TypedData& info = TypedData::Handle();
  for (intptr_t i = 0; i < length; ++i) {
    DeoptTable::GetEntry(table, i, &offset, &info, &reason_and_flags);
    if (pc == (code_entry + offset.Value())) {
      ASSERT(!info.IsNull());
      *deopt_reason = DeoptTable::ReasonField::decode(reason_and_flags.Value());
      *deopt_flags = DeoptTable::FlagsField::decode(reason_and_flags.Value());
      return info.raw();
    }
  }
  *deopt_reason = ICData::kDeoptUnknown;
  return TypedData::null();
}


intptr_t Code::BinarySearchInSCallTable(uword pc) const {
  NoSafepointScope no_safepoint;
  const Array& table = Array::Handle(raw_ptr()->static_calls_target_table_);
  RawObject* key = reinterpret_cast<RawObject*>(Smi::New(pc - EntryPoint()));
  intptr_t imin = 0;
  intptr_t imax = table.Length() / kSCallTableEntryLength;
  while (imax >= imin) {
    const intptr_t imid = ((imax - imin) / 2) + imin;
    const intptr_t real_index = imid * kSCallTableEntryLength;
    RawObject* key_in_table = table.At(real_index);
    if (key_in_table < key) {
      imin = imid + 1;
    } else if (key_in_table > key) {
      imax = imid - 1;
    } else {
      return real_index;
    }
  }
  return -1;
}


RawFunction* Code::GetStaticCallTargetFunctionAt(uword pc) const {
  const intptr_t i = BinarySearchInSCallTable(pc);
  if (i < 0) {
    return Function::null();
  }
  const Array& array =
      Array::Handle(raw_ptr()->static_calls_target_table_);
  Function& function = Function::Handle();
  function ^= array.At(i + kSCallTableFunctionEntry);
  return function.raw();
}


RawCode* Code::GetStaticCallTargetCodeAt(uword pc) const {
  const intptr_t i = BinarySearchInSCallTable(pc);
  if (i < 0) {
    return Code::null();
  }
  const Array& array =
      Array::Handle(raw_ptr()->static_calls_target_table_);
  Code& code = Code::Handle();
  code ^= array.At(i + kSCallTableCodeEntry);
  return code.raw();
}


void Code::SetStaticCallTargetCodeAt(uword pc, const Code& code) const {
  const intptr_t i = BinarySearchInSCallTable(pc);
  ASSERT(i >= 0);
  const Array& array =
      Array::Handle(raw_ptr()->static_calls_target_table_);
  ASSERT(code.IsNull() ||
         (code.function() == array.At(i + kSCallTableFunctionEntry)));
  array.SetAt(i + kSCallTableCodeEntry, code);
}


void Code::SetStubCallTargetCodeAt(uword pc, const Code& code) const {
  const intptr_t i = BinarySearchInSCallTable(pc);
  ASSERT(i >= 0);
  const Array& array =
      Array::Handle(raw_ptr()->static_calls_target_table_);
#if defined(DEBUG)
  if (array.At(i + kSCallTableFunctionEntry) == Function::null()) {
    ASSERT(!code.IsNull() && Object::Handle(code.owner()).IsClass());
  } else {
    ASSERT(code.IsNull() ||
           (code.function() == array.At(i + kSCallTableFunctionEntry)));
  }
#endif
  array.SetAt(i + kSCallTableCodeEntry, code);
}


void Code::Disassemble(DisassemblyFormatter* formatter) const {
  const Instructions& instr = Instructions::Handle(instructions());
  uword start = instr.EntryPoint();
  if (formatter == NULL) {
    Disassembler::Disassemble(start, start + instr.size(), *this);
  } else {
    Disassembler::Disassemble(start, start + instr.size(), formatter, *this);
  }
}


const Code::Comments& Code::comments() const  {
  Comments* comments = new Code::Comments(Array::Handle(raw_ptr()->comments_));
  return *comments;
}


void Code::set_comments(const Code::Comments& comments) const {
  ASSERT(comments.comments_.IsOld());
  StorePointer(&raw_ptr()->comments_, comments.comments_.raw());
}


void Code::SetPrologueOffset(intptr_t offset) const {
  ASSERT(offset >= 0);
  StoreSmi(
      reinterpret_cast<RawSmi* const *>(&raw_ptr()->return_address_metadata_),
      Smi::New(offset));
}


intptr_t Code::GetPrologueOffset() const {
  const Object& object = Object::Handle(raw_ptr()->return_address_metadata_);
  // In the future we may put something other than a smi in
  // |return_address_metadata_|.
  if (object.IsNull() || !object.IsSmi()) {
    return -1;
  }
  return Smi::Cast(object).Value();
}


RawArray* Code::GetInlinedIntervals() const {
  const Array& metadata = Array::Handle(raw_ptr()->inlined_metadata_);
  if (metadata.IsNull()) {
    return metadata.raw();
  }
  return reinterpret_cast<RawArray*>(
      metadata.At(RawCode::kInlinedIntervalsIndex));
}


void Code::SetInlinedIntervals(const Array& value) const {
  if (raw_ptr()->inlined_metadata_ == Array::null()) {
    StorePointer(&raw_ptr()->inlined_metadata_,
                 Array::New(RawCode::kInlinedMetadataSize, Heap::kOld));
  }
  const Array& metadata = Array::Handle(raw_ptr()->inlined_metadata_);
  ASSERT(!metadata.IsNull());
  ASSERT(metadata.IsOld());
  ASSERT(value.IsOld());
  metadata.SetAt(RawCode::kInlinedIntervalsIndex, value);
}


RawArray* Code::GetInlinedIdToFunction() const {
  const Array& metadata = Array::Handle(raw_ptr()->inlined_metadata_);
  if (metadata.IsNull()) {
    return metadata.raw();
  }
  return reinterpret_cast<RawArray*>(
      metadata.At(RawCode::kInlinedIdToFunctionIndex));
}


void Code::SetInlinedIdToFunction(const Array& value) const {
  if (raw_ptr()->inlined_metadata_ == Array::null()) {
    StorePointer(&raw_ptr()->inlined_metadata_,
                 Array::New(RawCode::kInlinedMetadataSize, Heap::kOld));
  }
  const Array& metadata = Array::Handle(raw_ptr()->inlined_metadata_);
  ASSERT(!metadata.IsNull());
  ASSERT(metadata.IsOld());
  ASSERT(value.IsOld());
  metadata.SetAt(RawCode::kInlinedIdToFunctionIndex, value);
}


RawArray* Code::GetInlinedCallerIdMap() const {
  const Array& metadata = Array::Handle(raw_ptr()->inlined_metadata_);
  if (metadata.IsNull()) {
    return metadata.raw();
  }
  return reinterpret_cast<RawArray*>(
      metadata.At(RawCode::kInlinedCallerIdMapIndex));
}


void Code::SetInlinedCallerIdMap(const Array& value) const {
  if (raw_ptr()->inlined_metadata_ == Array::null()) {
    StorePointer(&raw_ptr()->inlined_metadata_,
                 Array::New(RawCode::kInlinedMetadataSize, Heap::kOld));
  }
  const Array& metadata = Array::Handle(raw_ptr()->inlined_metadata_);
  ASSERT(!metadata.IsNull());
  ASSERT(metadata.IsOld());
  ASSERT(value.IsOld());
  metadata.SetAt(RawCode::kInlinedCallerIdMapIndex, value);
}


RawCode* Code::New(intptr_t pointer_offsets_length) {
  if (pointer_offsets_length < 0 || pointer_offsets_length > kMaxElements) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in Code::New: invalid pointer_offsets_length %" Pd "\n",
           pointer_offsets_length);
  }
  ASSERT(Object::code_class() != Class::null());
  Code& result = Code::Handle();
  {
    uword size = Code::InstanceSize(pointer_offsets_length);
    RawObject* raw = Object::Allocate(Code::kClassId, size, Heap::kOld);
    NoSafepointScope no_safepoint;
    result ^= raw;
    result.set_pointer_offsets_length(pointer_offsets_length);
    result.set_is_optimized(false);
    result.set_is_alive(false);
    result.set_comments(Comments::New(0));
    result.set_compile_timestamp(0);
    result.set_lazy_deopt_pc_offset(kInvalidPc);
    result.set_pc_descriptors(Object::empty_descriptors());
  }
  return result.raw();
}


RawCode* Code::FinalizeCode(const char* name,
                            Assembler* assembler,
                            bool optimized) {
  Isolate* isolate = Isolate::Current();
  if (!isolate->compilation_allowed()) {
    FATAL1("Precompilation missed code %s\n", name);
  }

  ASSERT(assembler != NULL);
  const ObjectPool& object_pool =
      ObjectPool::Handle(assembler->object_pool_wrapper().MakeObjectPool());

  // Allocate the Code and Instructions objects.  Code is allocated first
  // because a GC during allocation of the code will leave the instruction
  // pages read-only.
  intptr_t pointer_offset_count = assembler->CountPointerOffsets();
  Code& code = Code::ZoneHandle(Code::New(pointer_offset_count));
#ifdef TARGET_ARCH_IA32
  assembler->set_code_object(code);
#endif
  Instructions& instrs =
      Instructions::ZoneHandle(Instructions::New(assembler->CodeSize()));
  INC_STAT(Thread::Current(), total_instr_size, assembler->CodeSize());
  INC_STAT(Thread::Current(), total_code_size, assembler->CodeSize());

  instrs.set_code(code.raw());
  // Copy the instructions into the instruction area and apply all fixups.
  // Embedded pointers are still in handles at this point.
  MemoryRegion region(reinterpret_cast<void*>(instrs.EntryPoint()),
                      instrs.size());
  assembler->FinalizeInstructions(region);
  VerifiedMemory::Accept(region.start(), region.size());
  CPU::FlushICache(instrs.EntryPoint(), instrs.size());

  code.set_compile_timestamp(OS::GetCurrentTimeMicros());
  CodeObservers::NotifyAll(name,
                           instrs.EntryPoint(),
                           assembler->prologue_offset(),
                           instrs.size(),
                           optimized);
  {
    NoSafepointScope no_safepoint;
    const ZoneGrowableArray<intptr_t>& pointer_offsets =
        assembler->GetPointerOffsets();
    ASSERT(pointer_offsets.length() == pointer_offset_count);
    ASSERT(code.pointer_offsets_length() == pointer_offsets.length());

    // Set pointer offsets list in Code object and resolve all handles in
    // the instruction stream to raw objects.
    for (intptr_t i = 0; i < pointer_offsets.length(); i++) {
      intptr_t offset_in_instrs = pointer_offsets[i];
      code.SetPointerOffsetAt(i, offset_in_instrs);
      uword addr = region.start() + offset_in_instrs;
      const Object* object = *reinterpret_cast<Object**>(addr);
      instrs.raw()->StorePointer(reinterpret_cast<RawObject**>(addr),
                                 object->raw());
    }

    // Hook up Code and Instructions objects.
    code.set_active_instructions(instrs.raw());
    code.set_instructions(instrs.raw());
    code.set_is_alive(true);

    // Set object pool in Instructions object.
    INC_STAT(Thread::Current(),
             total_code_size, object_pool.Length() * sizeof(uintptr_t));
    code.set_object_pool(object_pool.raw());

    if (FLAG_write_protect_code) {
      uword address = RawObject::ToAddr(instrs.raw());
      bool status = VirtualMemory::Protect(
          reinterpret_cast<void*>(address),
          instrs.raw()->Size(),
          VirtualMemory::kReadExecute);
      ASSERT(status);
    }
  }
  code.set_comments(assembler->GetCodeComments());
  if (assembler->prologue_offset() >= 0) {
    code.SetPrologueOffset(assembler->prologue_offset());
  } else {
    // No prologue was ever entered, optimistically assume nothing was ever
    // pushed onto the stack.
    code.SetPrologueOffset(assembler->CodeSize());
  }
  INC_STAT(Thread::Current(),
           total_code_size, code.comments().comments_.Length());
  return code.raw();
}


RawCode* Code::FinalizeCode(const Function& function,
                            Assembler* assembler,
                            bool optimized) {
  // Calling ToLibNamePrefixedQualifiedCString is very expensive,
  // try to avoid it.
  if (CodeObservers::AreActive()) {
    return FinalizeCode(function.ToLibNamePrefixedQualifiedCString(),
                        assembler,
                        optimized);
  } else {
    return FinalizeCode("", assembler);
  }
}


// Check if object matches find condition.
bool Code::FindRawCodeVisitor::FindObject(RawObject* raw_obj) const {
  uword tags = raw_obj->ptr()->tags_;
  if (RawObject::ClassIdTag::decode(tags) == kInstructionsCid) {
    RawInstructions* raw_insts = reinterpret_cast<RawInstructions*>(raw_obj);
    return RawInstructions::ContainsPC(raw_insts, pc_);
  }
  return false;
}


RawCode* Code::LookupCodeInIsolate(Isolate* isolate, uword pc) {
  ASSERT((isolate == Isolate::Current()) || (isolate == Dart::vm_isolate()));
  NoSafepointScope no_safepoint;
  FindRawCodeVisitor visitor(pc);
  RawInstructions* instr;
  if (Dart::IsRunningPrecompiledCode()) {
    // TODO(johnmccutchan): Make code lookup work when running precompiled.
    UNIMPLEMENTED();
    return Code::null();
  }
  if (isolate->heap() == NULL) {
    return Code::null();
  }
  instr = isolate->heap()->FindObjectInCodeSpace(&visitor);
  if (instr != Instructions::null()) {
    return Instructions::Handle(instr).code();
  }
  return Code::null();
}


RawCode* Code::LookupCode(uword pc) {
  return LookupCodeInIsolate(Isolate::Current(), pc);
}


RawCode* Code::LookupCodeInVmIsolate(uword pc) {
  return LookupCodeInIsolate(Dart::vm_isolate(), pc);
}


// Given a pc and a timestamp, lookup the code.
RawCode* Code::FindCode(uword pc, int64_t timestamp) {
  Code& code = Code::Handle(Code::LookupCode(pc));
  if (!code.IsNull() && (code.compile_timestamp() == timestamp) &&
      (code.EntryPoint() == pc)) {
    // Found code in isolate.
    return code.raw();
  }
  code ^= Code::LookupCodeInVmIsolate(pc);
  if (!code.IsNull() && (code.compile_timestamp() == timestamp) &&
      (code.EntryPoint() == pc)) {
    // Found code in VM isolate.
    return code.raw();
  }
  return Code::null();
}


intptr_t Code::GetTokenIndexOfPC(uword pc) const {
  uword pc_offset = pc - EntryPoint();
  const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
  PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kAnyKind);
  while (iter.MoveNext()) {
    if (iter.PcOffset() == pc_offset) {
      return iter.TokenPos();
    }
  }
  return -1;
}


uword Code::GetPcForDeoptId(intptr_t deopt_id,
                            RawPcDescriptors::Kind kind) const {
  const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
  PcDescriptors::Iterator iter(descriptors, kind);
  while (iter.MoveNext()) {
    if (iter.DeoptId() == deopt_id) {
      uword pc_offset = iter.PcOffset();
      uword pc = EntryPoint() + pc_offset;
      ASSERT(ContainsInstructionAt(pc));
      return pc;
    }
  }
  return 0;
}


intptr_t Code::GetDeoptIdForOsr(uword pc) const {
  uword pc_offset = pc - EntryPoint();
  const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
  PcDescriptors::Iterator iter(descriptors, RawPcDescriptors::kOsrEntry);
  while (iter.MoveNext()) {
    if (iter.PcOffset() == pc_offset) {
      return iter.DeoptId();
    }
  }
  return Thread::kNoDeoptId;
}


const char* Code::ToCString() const {
  Zone* zone = Thread::Current()->zone();
  if (IsStubCode()) {
    const char* name = StubCode::NameOfStub(EntryPoint());
    return zone->PrintToString("[stub: %s]", name);
  } else {
    return zone->PrintToString("Code entry:%" Px, EntryPoint());
  }
}


RawString* Code::Name() const {
  const Object& obj = Object::Handle(owner());
  if (obj.IsNull()) {
    // Regular stub.
    const char* name = StubCode::NameOfStub(EntryPoint());
    ASSERT(name != NULL);
    const String& stub_name = String::Handle(String::New(name));
    return String::Concat(Symbols::StubPrefix(), stub_name);
  } else if (obj.IsClass()) {
    // Allocation stub.
    const Class& cls = Class::Cast(obj);
    String& cls_name = String::Handle(cls.Name());
    ASSERT(!cls_name.IsNull());
    return String::Concat(Symbols::AllocationStubFor(), cls_name);
  } else {
    ASSERT(obj.IsFunction());
    // Dart function.
    return Function::Cast(obj).name();
  }
}


RawString* Code::PrettyName() const {
  const Object& obj = Object::Handle(owner());
  if (obj.IsNull()) {
    // Regular stub.
    const char* name = StubCode::NameOfStub(EntryPoint());
    ASSERT(name != NULL);
    const String& stub_name = String::Handle(String::New(name));
    return String::Concat(Symbols::StubPrefix(), stub_name);
  } else if (obj.IsClass()) {
    // Allocation stub.
    const Class& cls = Class::Cast(obj);
    String& cls_name = String::Handle(cls.Name());
    ASSERT(!cls_name.IsNull());
    return String::Concat(Symbols::AllocationStubFor(), cls_name);
  } else {
    ASSERT(obj.IsFunction());
    // Dart function.
    return Function::Cast(obj).QualifiedPrettyName();
  }
}


bool Code::IsAllocationStubCode() const {
  const Object& obj = Object::Handle(owner());
  return obj.IsClass();
}


bool Code::IsStubCode() const {
  const Object& obj = Object::Handle(owner());
  return obj.IsNull();
}


bool Code::IsFunctionCode() const {
  const Object& obj = Object::Handle(owner());
  return obj.IsFunction();
}


void Code::DisableDartCode() const {
  ASSERT(IsFunctionCode());
  ASSERT(instructions() == active_instructions());
  const Code& new_code =
      Code::Handle(StubCode::FixCallersTarget_entry()->code());
  set_active_instructions(new_code.instructions());
}


void Code::DisableStubCode() const {
ASSERT(IsAllocationStubCode());
  ASSERT(instructions() == active_instructions());
  const Code& new_code =
      Code::Handle(StubCode::FixAllocationStubTarget_entry()->code());
  set_active_instructions(new_code.instructions());
}


void Code::PrintJSONImpl(JSONStream* stream, bool ref) const {
  JSONObject jsobj(stream);
  AddCommonObjectProperties(&jsobj, "Code", ref);
  jsobj.AddFixedServiceId("code/%" Px64"-%" Px "",
                          compile_timestamp(),
                          EntryPoint());
  const String& user_name = String::Handle(PrettyName());
  const String& vm_name = String::Handle(Name());
  AddNameProperties(&jsobj, user_name, vm_name);
  const bool is_stub = IsStubCode() || IsAllocationStubCode();
  if (is_stub) {
    jsobj.AddProperty("kind", "Stub");
  } else {
    jsobj.AddProperty("kind", "Dart");
  }
  jsobj.AddProperty("_optimized", is_optimized());
  if (ref) {
    return;
  }
  const Object& obj = Object::Handle(owner());
  if (obj.IsFunction()) {
    jsobj.AddProperty("function", obj);
  } else {
    // Generate a fake function reference.
    JSONObject func(&jsobj, "function");
    func.AddProperty("type", "@Function");
    func.AddProperty("_kind", "Stub");
    func.AddProperty("name", user_name.ToCString());
    AddNameProperties(&func, user_name, vm_name);
  }
  jsobj.AddPropertyF("_startAddress", "%" Px "", EntryPoint());
  jsobj.AddPropertyF("_endAddress", "%" Px "", EntryPoint() + Size());
  jsobj.AddProperty("_alive", is_alive());
  const ObjectPool& object_pool = ObjectPool::Handle(GetObjectPool());
  jsobj.AddProperty("_objectPool", object_pool);
  {
    JSONArray jsarr(&jsobj, "_disassembly");
    if (is_alive()) {
      // Only disassemble alive code objects.
      DisassembleToJSONStream formatter(jsarr);
      Disassemble(&formatter);
    }
  }
  const PcDescriptors& descriptors = PcDescriptors::Handle(pc_descriptors());
  if (!descriptors.IsNull()) {
    JSONObject desc(&jsobj, "_descriptors");
    descriptors.PrintToJSONObject(&desc, false);
  }
  const Array& inlined_function_table = Array::Handle(GetInlinedIdToFunction());
  if (!inlined_function_table.IsNull() &&
      (inlined_function_table.Length() > 0)) {
    JSONArray inlined_functions(&jsobj, "_inlinedFunctions");
    Function& function = Function::Handle();
    for (intptr_t i = 0; i < inlined_function_table.Length(); i++) {
      function ^= inlined_function_table.At(i);
      ASSERT(!function.IsNull());
      inlined_functions.AddValue(function);
    }
  }
  const Array& intervals = Array::Handle(GetInlinedIntervals());
  if (!intervals.IsNull() && (intervals.Length() > 0)) {
    Smi& start = Smi::Handle();
    Smi& end = Smi::Handle();
    Smi& temp_smi = Smi::Handle();
    JSONArray inline_intervals(&jsobj, "_inlinedIntervals");
    for (intptr_t i = 0; i < intervals.Length() - Code::kInlIntNumEntries;
         i += Code::kInlIntNumEntries) {
      start ^= intervals.At(i + Code::kInlIntStart);
      if (start.IsNull()) {
        continue;
      }
      end ^= intervals.At(i + Code::kInlIntNumEntries + Code::kInlIntStart);

      // Format: [start, end, inline functions...]
      JSONArray inline_interval(&inline_intervals);
      inline_interval.AddValue(start.Value());
      inline_interval.AddValue(end.Value());

      temp_smi ^= intervals.At(i + Code::kInlIntInliningId);
      intptr_t inlining_id = temp_smi.Value();
      ASSERT(inlining_id >= 0);
      intptr_t caller_id = GetCallerId(inlining_id);
      while (inlining_id >= 0) {
        inline_interval.AddValue(inlining_id);
        inlining_id = caller_id;
        caller_id = GetCallerId(inlining_id);
      }
    }
  }
}


uword Code::GetLazyDeoptPc() const {
  return (lazy_deopt_pc_offset() != kInvalidPc)
      ? EntryPoint() + lazy_deopt_pc_offset() : 0;
}


RawStackmap* Code::GetStackmap(
    uint32_t pc_offset, Array* maps, Stackmap* map) const {
  // This code is used during iterating frames during a GC and hence it
  // should not in turn start a GC.
  NoSafepointScope no_safepoint;
  if (stackmaps() == Array::null()) {
    // No stack maps are present in the code object which means this
    // frame relies on tagged pointers.
    return Stackmap::null();
  }
  // A stack map is present in the code object, use the stack map to visit
  // frame slots which are marked as having objects.
  *maps = stackmaps();
  *map = Stackmap::null();
  for (intptr_t i = 0; i < maps->Length(); i++) {
    *map ^= maps->At(i);
    ASSERT(!map->IsNull());
    if (map->PcOffset() == pc_offset) {
      return map->raw();  // We found a stack map for this frame.
    }
  }
  ASSERT(!is_optimized());
  return Stackmap::null();
}


intptr_t Code::GetCallerId(intptr_t inlined_id) const {
  if (inlined_id < 0) {
    return -1;
  }
  const Array& map = Array::Handle(GetInlinedCallerIdMap());
  if (map.IsNull() || (map.Length() == 0)) {
    return -1;
  }
  Smi& smi = Smi::Handle();
  smi ^= map.At(inlined_id);
  return smi.Value();
}


void Code::GetInlinedFunctionsAt(
    intptr_t offset, GrowableArray<Function*>* fs) const {
  fs->Clear();
  const Array& intervals = Array::Handle(GetInlinedIntervals());
  if (intervals.IsNull() || (intervals.Length() == 0)) {
    // E.g., for code stubs.
    return;
  }
  // First find the right interval. TODO(srdjan): use binary search since
  // intervals are sorted.
  Smi& start = Smi::Handle();
  Smi& end = Smi::Handle();
  intptr_t found_interval_ix = intervals.Length() - Code::kInlIntNumEntries;
  for (intptr_t i = 0; i < intervals.Length() - Code::kInlIntNumEntries;
       i += Code::kInlIntNumEntries) {
    start ^= intervals.At(i + Code::kInlIntStart);
    if (!start.IsNull()) {
      end ^= intervals.At(i + Code::kInlIntNumEntries + Code::kInlIntStart);
      if ((start.Value() <= offset) && (offset < end.Value())) {
        found_interval_ix = i;
        break;
      }
    }
  }

  // Find all functions.
  const Array& id_map = Array::Handle(GetInlinedIdToFunction());
  Smi& temp_smi = Smi::Handle();
  temp_smi ^= intervals.At(found_interval_ix + Code::kInlIntInliningId);
  intptr_t inlining_id = temp_smi.Value();
  ASSERT(inlining_id >= 0);
  intptr_t caller_id = GetCallerId(inlining_id);
  while (inlining_id >= 0) {
    Function& function = Function::ZoneHandle();
    function  ^= id_map.At(inlining_id);
    fs->Add(&function);
    inlining_id = caller_id;
    caller_id = GetCallerId(inlining_id);
  }
}


void Code::DumpInlinedIntervals() const {
  LogBlock lb;
  THR_Print("Inlined intervals:\n");
  const Array& intervals = Array::Handle(GetInlinedIntervals());
  if (intervals.IsNull() || (intervals.Length() == 0)) return;
  Smi& start = Smi::Handle();
  Smi& inlining_id = Smi::Handle();
  GrowableArray<Function*> inlined_functions;
  const Function& inliner = Function::Handle(function());
  for (intptr_t i = 0; i < intervals.Length(); i += Code::kInlIntNumEntries) {
    start ^= intervals.At(i + Code::kInlIntStart);
    ASSERT(!start.IsNull());
    if (start.IsNull()) continue;
    inlining_id ^= intervals.At(i + Code::kInlIntInliningId);
    THR_Print("  %" Px " iid: %" Pd " ; ", start.Value(), inlining_id.Value());
    inlined_functions.Clear();

    THR_Print("inlined: ");
    GetInlinedFunctionsAt(start.Value(), &inlined_functions);

    for (intptr_t j = 0; j < inlined_functions.length(); j++) {
      const char* name = inlined_functions[j]->ToQualifiedCString();
      THR_Print("  %s <-", name);
    }
    if (inlined_functions[inlined_functions.length() - 1]->raw() !=
           inliner.raw()) {
      THR_Print(" (ERROR, missing inliner)\n");
    } else {
      THR_Print("\n");
    }
  }
  THR_Print("Inlined ids:\n");
  const Array& id_map = Array::Handle(GetInlinedIdToFunction());
  Function& function = Function::Handle();
  for (intptr_t i = 0; i < id_map.Length(); i++) {
    function ^= id_map.At(i);
    if (!function.IsNull()) {
      THR_Print("  %" Pd ": %s\n", i, function.ToQualifiedCString());
    }
  }
  THR_Print("Caller Inlining Ids:\n");
  const Array& caller_map = Array::Handle(GetInlinedCallerIdMap());
  Smi& smi = Smi::Handle();
  for (intptr_t i = 0; i < caller_map.Length(); i++) {
    smi ^= caller_map.At(i);
    THR_Print("  iid: %" Pd " caller iid: %" Pd "\n", i, smi.Value());
  }
}


RawContext* Context::New(intptr_t num_variables, Heap::Space space) {
  ASSERT(num_variables >= 0);
  ASSERT(Object::context_class() != Class::null());

  if (num_variables < 0 || num_variables > kMaxElements) {
    // This should be caught before we reach here.
    FATAL1("Fatal error in Context::New: invalid num_variables %" Pd "\n"