test/cctest/test-heap.cc

// Copyright 2006-2008 the V8 project authors. All rights reserved.

#include <stdlib.h>

#include "v8.h"

#include "execution.h"
#include "factory.h"
#include "macro-assembler.h"
#include "global-handles.h"
#include "cctest.h"

using namespace v8::internal;

static v8::Persistent<v8::Context> env;

static void InitializeVM() {
  if (env.IsEmpty()) env = v8::Context::New();
  v8::HandleScope scope;
  env->Enter();
}


static void CheckMap(Map* map, int type, int instance_size) {
  CHECK(map->IsHeapObject());
#ifdef DEBUG
  CHECK(Heap::Contains(map));
#endif
  CHECK_EQ(Heap::meta_map(), map->map());
  CHECK_EQ(type, map->instance_type());
  CHECK_EQ(instance_size, map->instance_size());
}


TEST(HeapMaps) {
  InitializeVM();
  CheckMap(Heap::meta_map(), MAP_TYPE, Map::kSize);
  CheckMap(Heap::heap_number_map(), HEAP_NUMBER_TYPE, HeapNumber::kSize);
  CheckMap(Heap::fixed_array_map(), FIXED_ARRAY_TYPE, kVariableSizeSentinel);
  CheckMap(Heap::string_map(), STRING_TYPE, kVariableSizeSentinel);
}


static void CheckOddball(Object* obj, const char* string) {
  CHECK(obj->IsOddball());
  bool exc;
  Object* print_string = *Execution::ToString(Handle<Object>(obj), &exc);
  CHECK(String::cast(print_string)->IsEqualTo(CStrVector(string)));
}


static void CheckSmi(int value, const char* string) {
  bool exc;
  Object* print_string =
      *Execution::ToString(Handle<Object>(Smi::FromInt(value)), &exc);
  CHECK(String::cast(print_string)->IsEqualTo(CStrVector(string)));
}


static void CheckNumber(double value, const char* string) {
  Object* obj = Heap::NumberFromDouble(value);
  CHECK(obj->IsNumber());
  bool exc;
  Object* print_string = *Execution::ToString(Handle<Object>(obj), &exc);
  CHECK(String::cast(print_string)->IsEqualTo(CStrVector(string)));
}


static void CheckFindCodeObject() {
  // Test FindCodeObject
#define __ assm.

  Assembler assm(NULL, 0);

  __ nop();  // supported on all architectures

  CodeDesc desc;
  assm.GetCode(&desc);
  Object* code = Heap::CreateCode(desc,
                                  Code::ComputeFlags(Code::STUB),
                                  Handle<Object>(Heap::undefined_value()));
  CHECK(code->IsCode());

  HeapObject* obj = HeapObject::cast(code);
  Address obj_addr = obj->address();

  for (int i = 0; i < obj->Size(); i += kPointerSize) {
    Object* found = Heap::FindCodeObject(obj_addr + i);
    CHECK_EQ(code, found);
  }

  Object* copy = Heap::CreateCode(desc,
                                  Code::ComputeFlags(Code::STUB),
                                  Handle<Object>(Heap::undefined_value()));
  CHECK(copy->IsCode());
  HeapObject* obj_copy = HeapObject::cast(copy);
  Object* not_right = Heap::FindCodeObject(obj_copy->address() +
                                           obj_copy->Size() / 2);
  CHECK(not_right != code);
}


TEST(HeapObjects) {
  InitializeVM();

  v8::HandleScope sc;
  Object* value = Heap::NumberFromDouble(1.000123);
  CHECK(value->IsHeapNumber());
  CHECK(value->IsNumber());
  CHECK_EQ(1.000123, value->Number());

  value = Heap::NumberFromDouble(1.0);
  CHECK(value->IsSmi());
  CHECK(value->IsNumber());
  CHECK_EQ(1.0, value->Number());

  value = Heap::NumberFromInt32(1024);
  CHECK(value->IsSmi());
  CHECK(value->IsNumber());
  CHECK_EQ(1024.0, value->Number());

  value = Heap::NumberFromInt32(Smi::kMinValue);
  CHECK(value->IsSmi());
  CHECK(value->IsNumber());
  CHECK_EQ(Smi::kMinValue, Smi::cast(value)->value());

  value = Heap::NumberFromInt32(Smi::kMaxValue);
  CHECK(value->IsSmi());
  CHECK(value->IsNumber());
  CHECK_EQ(Smi::kMaxValue, Smi::cast(value)->value());

#ifndef V8_TARGET_ARCH_X64
  // TODO(lrn): We need a NumberFromIntptr function in order to test this.
  value = Heap::NumberFromInt32(Smi::kMinValue - 1);
  CHECK(value->IsHeapNumber());
  CHECK(value->IsNumber());
  CHECK_EQ(static_cast<double>(Smi::kMinValue - 1), value->Number());
#endif

  value = Heap::NumberFromUint32(static_cast<uint32_t>(Smi::kMaxValue) + 1);
  CHECK(value->IsHeapNumber());
  CHECK(value->IsNumber());
  CHECK_EQ(static_cast<double>(static_cast<uint32_t>(Smi::kMaxValue) + 1),
           value->Number());

  // nan oddball checks
  CHECK(Heap::nan_value()->IsNumber());
  CHECK(isnan(Heap::nan_value()->Number()));

  Handle<String> s = Factory::NewStringFromAscii(CStrVector("fisk hest "));
  CHECK(s->IsString());
  CHECK_EQ(10, s->length());

  String* object_symbol = String::cast(Heap::Object_symbol());
  CHECK(Top::context()->global()->HasLocalProperty(object_symbol));

  // Check ToString for oddballs
  CheckOddball(Heap::true_value(), "true");
  CheckOddball(Heap::false_value(), "false");
  CheckOddball(Heap::null_value(), "null");
  CheckOddball(Heap::undefined_value(), "undefined");

  // Check ToString for Smis
  CheckSmi(0, "0");
  CheckSmi(42, "42");
  CheckSmi(-42, "-42");

  // Check ToString for Numbers
  CheckNumber(1.1, "1.1");

  CheckFindCodeObject();
}


TEST(Tagging) {
  InitializeVM();
  int request = 24;
  CHECK_EQ(request, static_cast<int>(OBJECT_POINTER_ALIGN(request)));
  CHECK(Smi::FromInt(42)->IsSmi());
  CHECK(Failure::RetryAfterGC(NEW_SPACE)->IsFailure());
  CHECK_EQ(NEW_SPACE,
           Failure::RetryAfterGC(NEW_SPACE)->allocation_space());
  CHECK_EQ(OLD_POINTER_SPACE,
           Failure::RetryAfterGC(OLD_POINTER_SPACE)->allocation_space());
  CHECK(Failure::Exception()->IsFailure());
  CHECK(Smi::FromInt(Smi::kMinValue)->IsSmi());
  CHECK(Smi::FromInt(Smi::kMaxValue)->IsSmi());
}


TEST(GarbageCollection) {
  InitializeVM();

  v8::HandleScope sc;
  // Check GC.
  Heap::CollectGarbage(NEW_SPACE);

  Handle<String> name = Factory::LookupAsciiSymbol("theFunction");
  Handle<String> prop_name = Factory::LookupAsciiSymbol("theSlot");
  Handle<String> prop_namex = Factory::LookupAsciiSymbol("theSlotx");
  Handle<String> obj_name = Factory::LookupAsciiSymbol("theObject");

  {
    v8::HandleScope inner_scope;
    // Allocate a function and keep it in global object's property.
    Handle<JSFunction> function =
        Factory::NewFunction(name, Factory::undefined_value());
    Handle<Map> initial_map =
        Factory::NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
    function->set_initial_map(*initial_map);
    Top::context()->global()->SetProperty(*name, *function, NONE);
    // Allocate an object.  Unrooted after leaving the scope.
    Handle<JSObject> obj = Factory::NewJSObject(function);
    obj->SetProperty(*prop_name, Smi::FromInt(23), NONE);
    obj->SetProperty(*prop_namex, Smi::FromInt(24), NONE);

    CHECK_EQ(Smi::FromInt(23), obj->GetProperty(*prop_name));
    CHECK_EQ(Smi::FromInt(24), obj->GetProperty(*prop_namex));
  }

  Heap::CollectGarbage(NEW_SPACE);

  // Function should be alive.
  CHECK(Top::context()->global()->HasLocalProperty(*name));
  // Check function is retained.
  Object* func_value = Top::context()->global()->GetProperty(*name);
  CHECK(func_value->IsJSFunction());
  Handle<JSFunction> function(JSFunction::cast(func_value));

  {
    HandleScope inner_scope;
    // Allocate another object, make it reachable from global.
    Handle<JSObject> obj = Factory::NewJSObject(function);
    Top::context()->global()->SetProperty(*obj_name, *obj, NONE);
    obj->SetProperty(*prop_name, Smi::FromInt(23), NONE);
  }

  // After gc, it should survive.
  Heap::CollectGarbage(NEW_SPACE);

  CHECK(Top::context()->global()->HasLocalProperty(*obj_name));
  CHECK(Top::context()->global()->GetProperty(*obj_name)->IsJSObject());
  JSObject* obj =
      JSObject::cast(Top::context()->global()->GetProperty(*obj_name));
  CHECK_EQ(Smi::FromInt(23), obj->GetProperty(*prop_name));
}


static void VerifyStringAllocation(const char* string) {
  v8::HandleScope scope;
  Handle<String> s = Factory::NewStringFromUtf8(CStrVector(string));
  CHECK_EQ(StrLength(string), s->length());
  for (int index = 0; index < s->length(); index++) {
    CHECK_EQ(static_cast<uint16_t>(string[index]), s->Get(index));
  }
}


TEST(String) {
  InitializeVM();

  VerifyStringAllocation("a");
  VerifyStringAllocation("ab");
  VerifyStringAllocation("abc");
  VerifyStringAllocation("abcd");
  VerifyStringAllocation("fiskerdrengen er paa havet");
}


TEST(LocalHandles) {
  InitializeVM();

  v8::HandleScope scope;
  const char* name = "Kasper the spunky";
  Handle<String> string = Factory::NewStringFromAscii(CStrVector(name));
  CHECK_EQ(StrLength(name), string->length());
}


TEST(GlobalHandles) {
  InitializeVM();

  Handle<Object> h1;
  Handle<Object> h2;
  Handle<Object> h3;
  Handle<Object> h4;

  {
    HandleScope scope;

    Handle<Object> i = Factory::NewStringFromAscii(CStrVector("fisk"));
    Handle<Object> u = Factory::NewNumber(1.12344);

    h1 = GlobalHandles::Create(*i);
    h2 = GlobalHandles::Create(*u);
    h3 = GlobalHandles::Create(*i);
    h4 = GlobalHandles::Create(*u);
  }

  // after gc, it should survive
  Heap::CollectGarbage(NEW_SPACE);

  CHECK((*h1)->IsString());
  CHECK((*h2)->IsHeapNumber());
  CHECK((*h3)->IsString());
  CHECK((*h4)->IsHeapNumber());

  CHECK_EQ(*h3, *h1);
  GlobalHandles::Destroy(h1.location());
  GlobalHandles::Destroy(h3.location());

  CHECK_EQ(*h4, *h2);
  GlobalHandles::Destroy(h2.location());
  GlobalHandles::Destroy(h4.location());
}


static bool WeakPointerCleared = false;

static void TestWeakGlobalHandleCallback(v8::Persistent<v8::Value> handle,
                                         void* id) {
  if (1234 == reinterpret_cast<intptr_t>(id)) WeakPointerCleared = true;
  handle.Dispose();
}


TEST(WeakGlobalHandlesScavenge) {
  InitializeVM();

  WeakPointerCleared = false;

  Handle<Object> h1;
  Handle<Object> h2;

  {
    HandleScope scope;

    Handle<Object> i = Factory::NewStringFromAscii(CStrVector("fisk"));
    Handle<Object> u = Factory::NewNumber(1.12344);

    h1 = GlobalHandles::Create(*i);
    h2 = GlobalHandles::Create(*u);
  }

  GlobalHandles::MakeWeak(h2.location(),
                          reinterpret_cast<void*>(1234),
                          &TestWeakGlobalHandleCallback);

  // Scavenge treats weak pointers as normal roots.
  Heap::PerformScavenge();

  CHECK((*h1)->IsString());
  CHECK((*h2)->IsHeapNumber());

  CHECK(!WeakPointerCleared);
  CHECK(!GlobalHandles::IsNearDeath(h2.location()));
  CHECK(!GlobalHandles::IsNearDeath(h1.location()));

  GlobalHandles::Destroy(h1.location());
  GlobalHandles::Destroy(h2.location());
}


TEST(WeakGlobalHandlesMark) {
  InitializeVM();

  WeakPointerCleared = false;

  Handle<Object> h1;
  Handle<Object> h2;

  {
    HandleScope scope;

    Handle<Object> i = Factory::NewStringFromAscii(CStrVector("fisk"));
    Handle<Object> u = Factory::NewNumber(1.12344);

    h1 = GlobalHandles::Create(*i);
    h2 = GlobalHandles::Create(*u);
  }

  Heap::CollectGarbage(OLD_POINTER_SPACE);
  Heap::CollectGarbage(NEW_SPACE);
  // Make sure the object is promoted.

  GlobalHandles::MakeWeak(h2.location(),
                          reinterpret_cast<void*>(1234),
                          &TestWeakGlobalHandleCallback);
  CHECK(!GlobalHandles::IsNearDeath(h1.location()));
  CHECK(!GlobalHandles::IsNearDeath(h2.location()));

  Heap::CollectGarbage(OLD_POINTER_SPACE);

  CHECK((*h1)->IsString());

  CHECK(WeakPointerCleared);
  CHECK(!GlobalHandles::IsNearDeath(h1.location()));

  GlobalHandles::Destroy(h1.location());
}

TEST(DeleteWeakGlobalHandle) {
  InitializeVM();

  WeakPointerCleared = false;

  Handle<Object> h;

  {
    HandleScope scope;

    Handle<Object> i = Factory::NewStringFromAscii(CStrVector("fisk"));
    h = GlobalHandles::Create(*i);
  }

  GlobalHandles::MakeWeak(h.location(),
                          reinterpret_cast<void*>(1234),
                          &TestWeakGlobalHandleCallback);

  // Scanvenge does not recognize weak reference.
  Heap::PerformScavenge();

  CHECK(!WeakPointerCleared);

  // Mark-compact treats weak reference properly.
  Heap::CollectGarbage(OLD_POINTER_SPACE);

  CHECK(WeakPointerCleared);
}

static const char* not_so_random_string_table[] = {
  "abstract",
  "boolean",
  "break",
  "byte",
  "case",
  "catch",
  "char",
  "class",
  "const",
  "continue",
  "debugger",
  "default",
  "delete",
  "do",
  "double",
  "else",
  "enum",
  "export",
  "extends",
  "false",
  "final",
  "finally",
  "float",
  "for",
  "function",
  "goto",
  "if",
  "implements",
  "import",
  "in",
  "instanceof",
  "int",
  "interface",
  "long",
  "native",
  "new",
  "null",
  "package",
  "private",
  "protected",
  "public",
  "return",
  "short",
  "static",
  "super",
  "switch",
  "synchronized",
  "this",
  "throw",
  "throws",
  "transient",
  "true",
  "try",
  "typeof",
  "var",
  "void",
  "volatile",
  "while",
  "with",
  0
};


static void CheckSymbols(const char** strings) {
  for (const char* string = *strings; *strings != 0; string = *strings++) {
    Object* a = Heap::LookupAsciiSymbol(string);
    // LookupAsciiSymbol may return a failure if a GC is needed.
    if (a->IsFailure()) continue;
    CHECK(a->IsSymbol());
    Object* b = Heap::LookupAsciiSymbol(string);
    if (b->IsFailure()) continue;
    CHECK_EQ(b, a);
    CHECK(String::cast(b)->IsEqualTo(CStrVector(string)));
  }
}


TEST(SymbolTable) {
  InitializeVM();

  CheckSymbols(not_so_random_string_table);
  CheckSymbols(not_so_random_string_table);
}


TEST(FunctionAllocation) {
  InitializeVM();

  v8::HandleScope sc;
  Handle<String> name = Factory::LookupAsciiSymbol("theFunction");
  Handle<JSFunction> function =
      Factory::NewFunction(name, Factory::undefined_value());
  Handle<Map> initial_map =
      Factory::NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
  function->set_initial_map(*initial_map);

  Handle<String> prop_name = Factory::LookupAsciiSymbol("theSlot");
  Handle<JSObject> obj = Factory::NewJSObject(function);
  obj->SetProperty(*prop_name, Smi::FromInt(23), NONE);
  CHECK_EQ(Smi::FromInt(23), obj->GetProperty(*prop_name));
  // Check that we can add properties to function objects.
  function->SetProperty(*prop_name, Smi::FromInt(24), NONE);
  CHECK_EQ(Smi::FromInt(24), function->GetProperty(*prop_name));
}


TEST(ObjectProperties) {
  InitializeVM();

  v8::HandleScope sc;
  String* object_symbol = String::cast(Heap::Object_symbol());
  JSFunction* object_function =
      JSFunction::cast(Top::context()->global()->GetProperty(object_symbol));
  Handle<JSFunction> constructor(object_function);
  Handle<JSObject> obj = Factory::NewJSObject(constructor);
  Handle<String> first = Factory::LookupAsciiSymbol("first");
  Handle<String> second = Factory::LookupAsciiSymbol("second");

  // check for empty
  CHECK(!obj->HasLocalProperty(*first));

  // add first
  obj->SetProperty(*first, Smi::FromInt(1), NONE);
  CHECK(obj->HasLocalProperty(*first));

  // delete first
  CHECK(obj->DeleteProperty(*first, JSObject::NORMAL_DELETION));
  CHECK(!obj->HasLocalProperty(*first));

  // add first and then second
  obj->SetProperty(*first, Smi::FromInt(1), NONE);
  obj->SetProperty(*second, Smi::FromInt(2), NONE);
  CHECK(obj->HasLocalProperty(*first));
  CHECK(obj->HasLocalProperty(*second));

  // delete first and then second
  CHECK(obj->DeleteProperty(*first, JSObject::NORMAL_DELETION));
  CHECK(obj->HasLocalProperty(*second));
  CHECK(obj->DeleteProperty(*second, JSObject::NORMAL_DELETION));
  CHECK(!obj->HasLocalProperty(*first));
  CHECK(!obj->HasLocalProperty(*second));

  // add first and then second
  obj->SetProperty(*first, Smi::FromInt(1), NONE);
  obj->SetProperty(*second, Smi::FromInt(2), NONE);
  CHECK(obj->HasLocalProperty(*first));
  CHECK(obj->HasLocalProperty(*second));

  // delete second and then first
  CHECK(obj->DeleteProperty(*second, JSObject::NORMAL_DELETION));
  CHECK(obj->HasLocalProperty(*first));
  CHECK(obj->DeleteProperty(*first, JSObject::NORMAL_DELETION));
  CHECK(!obj->HasLocalProperty(*first));
  CHECK(!obj->HasLocalProperty(*second));

  // check string and symbol match
  static const char* string1 = "fisk";
  Handle<String> s1 = Factory::NewStringFromAscii(CStrVector(string1));
  obj->SetProperty(*s1, Smi::FromInt(1), NONE);
  Handle<String> s1_symbol = Factory::LookupAsciiSymbol(string1);
  CHECK(obj->HasLocalProperty(*s1_symbol));

  // check symbol and string match
  static const char* string2 = "fugl";
  Handle<String> s2_symbol = Factory::LookupAsciiSymbol(string2);
  obj->SetProperty(*s2_symbol, Smi::FromInt(1), NONE);
  Handle<String> s2 = Factory::NewStringFromAscii(CStrVector(string2));
  CHECK(obj->HasLocalProperty(*s2));
}


TEST(JSObjectMaps) {
  InitializeVM();

  v8::HandleScope sc;
  Handle<String> name = Factory::LookupAsciiSymbol("theFunction");
  Handle<JSFunction> function =
      Factory::NewFunction(name, Factory::undefined_value());
  Handle<Map> initial_map =
      Factory::NewMap(JS_OBJECT_TYPE, JSObject::kHeaderSize);
  function->set_initial_map(*initial_map);

  Handle<String> prop_name = Factory::LookupAsciiSymbol("theSlot");
  Handle<JSObject> obj = Factory::NewJSObject(function);

  // Set a propery
  obj->SetProperty(*prop_name, Smi::FromInt(23), NONE);
  CHECK_EQ(Smi::FromInt(23), obj->GetProperty(*prop_name));

  // Check the map has changed
  CHECK(*initial_map != obj->map());
}


TEST(JSArray) {
  InitializeVM();

  v8::HandleScope sc;
  Handle<String> name = Factory::LookupAsciiSymbol("Array");
  Handle<JSFunction> function = Handle<JSFunction>(
      JSFunction::cast(Top::context()->global()->GetProperty(*name)));

  // Allocate the object.
  Handle<JSObject> object = Factory::NewJSObject(function);
  Handle<JSArray> array = Handle<JSArray>::cast(object);
  Object* ok = array->Initialize(0);
  // We just initialized the VM, no heap allocation failure yet.
  CHECK(!ok->IsFailure());

  // Set array length to 0.
  ok = array->SetElementsLength(Smi::FromInt(0));
  CHECK(!ok->IsFailure());
  CHECK_EQ(Smi::FromInt(0), array->length());
  CHECK(array->HasFastElements());  // Must be in fast mode.

  // array[length] = name.
  ok = array->SetElement(0, *name);
  CHECK(!ok->IsFailure());
  CHECK_EQ(Smi::FromInt(1), array->length());
  CHECK_EQ(array->GetElement(0), *name);

  // Set array length with larger than smi value.
  Handle<Object> length =
      Factory::NewNumberFromUint(static_cast<uint32_t>(Smi::kMaxValue) + 1);
  ok = array->SetElementsLength(*length);
  CHECK(!ok->IsFailure());

  uint32_t int_length = 0;
  CHECK(length->ToArrayIndex(&int_length));
  CHECK_EQ(*length, array->length());
  CHECK(array->HasDictionaryElements());  // Must be in slow mode.

  // array[length] = name.
  ok = array->SetElement(int_length, *name);
  CHECK(!ok->IsFailure());
  uint32_t new_int_length = 0;
  CHECK(array->length()->ToArrayIndex(&new_int_length));
  CHECK_EQ(static_cast<double>(int_length), new_int_length - 1);
  CHECK_EQ(array->GetElement(int_length), *name);
  CHECK_EQ(array->GetElement(0), *name);
}


TEST(JSObjectCopy) {
  InitializeVM();

  v8::HandleScope sc;
  String* object_symbol = String::cast(Heap::Object_symbol());
  JSFunction* object_function =
      JSFunction::cast(Top::context()->global()->GetProperty(object_symbol));
  Handle<JSFunction> constructor(object_function);
  Handle<JSObject> obj = Factory::NewJSObject(constructor);
  Handle<String> first = Factory::LookupAsciiSymbol("first");
  Handle<String> second = Factory::LookupAsciiSymbol("second");

  obj->SetProperty(*first, Smi::FromInt(1), NONE);
  obj->SetProperty(*second, Smi::FromInt(2), NONE);

  Object* ok = obj->SetElement(0, *first);
  CHECK(!ok->IsFailure());

  ok = obj->SetElement(1, *second);
  CHECK(!ok->IsFailure());

  // Make the clone.
  Handle<JSObject> clone = Copy(obj);
  CHECK(!clone.is_identical_to(obj));

  CHECK_EQ(obj->GetElement(0), clone->GetElement(0));
  CHECK_EQ(obj->GetElement(1), clone->GetElement(1));

  CHECK_EQ(obj->GetProperty(*first), clone->GetProperty(*first));
  CHECK_EQ(obj->GetProperty(*second), clone->GetProperty(*second));

  // Flip the values.
  clone->SetProperty(*first, Smi::FromInt(2), NONE);
  clone->SetProperty(*second, Smi::FromInt(1), NONE);

  ok = clone->SetElement(0, *second);
  CHECK(!ok->IsFailure());
  ok = clone->SetElement(1, *first);
  CHECK(!ok->IsFailure());

  CHECK_EQ(obj->GetElement(1), clone->GetElement(0));
  CHECK_EQ(obj->GetElement(0), clone->GetElement(1));

  CHECK_EQ(obj->GetProperty(*second), clone->GetProperty(*first));
  CHECK_EQ(obj->GetProperty(*first), clone->GetProperty(*second));
}


TEST(StringAllocation) {
  InitializeVM();


  const unsigned char chars[] = { 0xe5, 0xa4, 0xa7 };
  for (int length = 0; length < 100; length++) {
    v8::HandleScope scope;
    char* non_ascii = NewArray<char>(3 * length + 1);
    char* ascii = NewArray<char>(length + 1);
    non_ascii[3 * length] = 0;
    ascii[length] = 0;
    for (int i = 0; i < length; i++) {
      ascii[i] = 'a';
      non_ascii[3 * i] = chars[0];
      non_ascii[3 * i + 1] = chars[1];
      non_ascii[3 * i + 2] = chars[2];
    }
    Handle<String> non_ascii_sym =
        Factory::LookupSymbol(Vector<const char>(non_ascii, 3 * length));
    CHECK_EQ(length, non_ascii_sym->length());
    Handle<String> ascii_sym =
        Factory::LookupSymbol(Vector<const char>(ascii, length));
    CHECK_EQ(length, ascii_sym->length());
    Handle<String> non_ascii_str =
        Factory::NewStringFromUtf8(Vector<const char>(non_ascii, 3 * length));
    non_ascii_str->Hash();
    CHECK_EQ(length, non_ascii_str->length());
    Handle<String> ascii_str =
        Factory::NewStringFromUtf8(Vector<const char>(ascii, length));
    ascii_str->Hash();
    CHECK_EQ(length, ascii_str->length());
    DeleteArray(non_ascii);
    DeleteArray(ascii);
  }
}


static int ObjectsFoundInHeap(Handle<Object> objs[], int size) {
  // Count the number of objects found in the heap.
  int found_count = 0;
  HeapIterator iterator;
  for (HeapObject* obj = iterator.next(); obj != NULL; obj = iterator.next()) {
    for (int i = 0; i < size; i++) {
      if (*objs[i] == obj) {
        found_count++;
      }
    }
  }
  return found_count;
}


TEST(Iteration) {
  InitializeVM();
  v8::HandleScope scope;

  // Array of objects to scan haep for.
  const int objs_count = 6;
  Handle<Object> objs[objs_count];
  int next_objs_index = 0;

  // Allocate a JS array to OLD_POINTER_SPACE and NEW_SPACE
  objs[next_objs_index++] = Factory::NewJSArray(10);
  objs[next_objs_index++] = Factory::NewJSArray(10, TENURED);

  // Allocate a small string to OLD_DATA_SPACE and NEW_SPACE
  objs[next_objs_index++] =
      Factory::NewStringFromAscii(CStrVector("abcdefghij"));
  objs[next_objs_index++] =
      Factory::NewStringFromAscii(CStrVector("abcdefghij"), TENURED);

  // Allocate a large string (for large object space).
  int large_size = Heap::MaxObjectSizeInPagedSpace() + 1;
  char* str = new char[large_size];
  for (int i = 0; i < large_size - 1; ++i) str[i] = 'a';
  str[large_size - 1] = '\0';
  objs[next_objs_index++] =
      Factory::NewStringFromAscii(CStrVector(str), TENURED);
  delete[] str;

  // Add a Map object to look for.
  objs[next_objs_index++] = Handle<Map>(HeapObject::cast(*objs[0])->map());

  CHECK_EQ(objs_count, next_objs_index);
  CHECK_EQ(objs_count, ObjectsFoundInHeap(objs, objs_count));
}


TEST(LargeObjectSpaceContains) {
  InitializeVM();

  Heap::CollectGarbage(NEW_SPACE);

  Address current_top = Heap::new_space()->top();
  Page* page = Page::FromAddress(current_top);
  Address current_page = page->address();
  Address next_page = current_page + Page::kPageSize;
  int bytes_to_page = static_cast<int>(next_page - current_top);
  if (bytes_to_page <= FixedArray::kHeaderSize) {
    // Alas, need to cross another page to be able to
    // put desired value.
    next_page += Page::kPageSize;
    bytes_to_page = static_cast<int>(next_page - current_top);
  }
  CHECK(bytes_to_page > FixedArray::kHeaderSize);

  intptr_t* flags_ptr = &Page::FromAddress(next_page)->flags_;
  Address flags_addr = reinterpret_cast<Address>(flags_ptr);

  int bytes_to_allocate =
      static_cast<int>(flags_addr - current_top) + kPointerSize;

  int n_elements = (bytes_to_allocate - FixedArray::kHeaderSize) /
      kPointerSize;
  CHECK_EQ(bytes_to_allocate, FixedArray::SizeFor(n_elements));
  FixedArray* array = FixedArray::cast(
      Heap::AllocateFixedArray(n_elements));

  int index = n_elements - 1;
  CHECK_EQ(flags_ptr,
           HeapObject::RawField(array, FixedArray::OffsetOfElementAt(index)));
  array->set(index, Smi::FromInt(0));
  // This chould have turned next page into LargeObjectPage:
  // CHECK(Page::FromAddress(next_page)->IsLargeObjectPage());

  HeapObject* addr = HeapObject::FromAddress(next_page + 2 * kPointerSize);
  CHECK(Heap::new_space()->Contains(addr));
  CHECK(!Heap::lo_space()->Contains(addr));
}


TEST(EmptyHandleEscapeFrom) {
  InitializeVM();

  v8::HandleScope scope;
  Handle<JSObject> runaway;

  {
      v8::HandleScope nested;
      Handle<JSObject> empty;
      runaway = empty.EscapeFrom(&nested);
  }

  CHECK(runaway.is_null());
}


static int LenFromSize(int size) {
  return (size - FixedArray::kHeaderSize) / kPointerSize;
}


TEST(Regression39128) {
  // Test case for crbug.com/39128.
  InitializeVM();

  // Increase the chance of 'bump-the-pointer' allocation in old space.
  bool force_compaction = true;
  Heap::CollectAllGarbage(force_compaction);

  v8::HandleScope scope;

  // The plan: create JSObject which references objects in new space.
  // Then clone this object (forcing it to go into old space) and check
  // that region dirty marks are updated correctly.

  // Step 1: prepare a map for the object.  We add 1 inobject property to it.
  Handle<JSFunction> object_ctor(Top::global_context()->object_function());
  CHECK(object_ctor->has_initial_map());
  Handle<Map> object_map(object_ctor->initial_map());
  // Create a map with single inobject property.
  Handle<Map> my_map = Factory::CopyMap(object_map, 1);
  int n_properties = my_map->inobject_properties();
  CHECK_GT(n_properties, 0);

  int object_size = my_map->instance_size();

  // Step 2: allocate a lot of objects so to almost fill new space: we need
  // just enough room to allocate JSObject and thus fill the newspace.

  int allocation_amount = Min(FixedArray::kMaxSize,
                              Heap::MaxObjectSizeInNewSpace());
  int allocation_len = LenFromSize(allocation_amount);
  NewSpace* new_space = Heap::new_space();
  Address* top_addr = new_space->allocation_top_address();
  Address* limit_addr = new_space->allocation_limit_address();
  while ((*limit_addr - *top_addr) > allocation_amount) {
    CHECK(!Heap::always_allocate());
    Object* array = Heap::AllocateFixedArray(allocation_len);
    CHECK(!array->IsFailure());
    CHECK(new_space->Contains(array));
  }

  // Step 3: now allocate fixed array and JSObject to fill the whole new space.
  int to_fill = static_cast<int>(*limit_addr - *top_addr - object_size);
  int fixed_array_len = LenFromSize(to_fill);
  CHECK(fixed_array_len < FixedArray::kMaxLength);

  CHECK(!Heap::always_allocate());
  Object* array = Heap::AllocateFixedArray(fixed_array_len);
  CHECK(!array->IsFailure());
  CHECK(new_space->Contains(array));

  Object* object = Heap::AllocateJSObjectFromMap(*my_map);
  CHECK(!object->IsFailure());
  CHECK(new_space->Contains(object));
  JSObject* jsobject = JSObject::cast(object);
  CHECK_EQ(0, FixedArray::cast(jsobject->elements())->length());
  CHECK_EQ(0, jsobject->properties()->length());
  // Create a reference to object in new space in jsobject.
  jsobject->FastPropertyAtPut(-1, array);

  CHECK_EQ(0, static_cast<int>(*limit_addr - *top_addr));

  // Step 4: clone jsobject, but force always allocate first to create a clone
  // in old pointer space.
  Address old_pointer_space_top = Heap::old_pointer_space()->top();
  AlwaysAllocateScope aa_scope;
  Object* clone_obj = Heap::CopyJSObject(jsobject);
  CHECK(!object->IsFailure());
  JSObject* clone = JSObject::cast(clone_obj);
  if (clone->address() != old_pointer_space_top) {
    // Alas, got allocated from free list, we cannot do checks.
    return;
  }
  CHECK(Heap::old_pointer_space()->Contains(clone->address()));

  // Step 5: verify validity of region dirty marks.
  Address clone_addr = clone->address();
  Page* page = Page::FromAddress(clone_addr);
  // Check that region covering inobject property 1 is marked dirty.
  CHECK(page->IsRegionDirty(clone_addr + (object_size - kPointerSize)));
}


TEST(TestCodeFlushing) {
  i::FLAG_allow_natives_syntax = true;
  // If we do not flush code this test is invalid.
  if (!FLAG_flush_code) return;
  InitializeVM();
  v8::HandleScope scope;
  const char* source = "function foo() {"
                       "  var x = 42;"
                       "  var y = 42;"
                       "  var z = x + y;"
                       "};"
                       "foo()";
  Handle<String> foo_name = Factory::LookupAsciiSymbol("foo");

  // This compile will add the code to the compilation cache.
  CompileRun(source);

  // Check function is compiled.
  Object* func_value = Top::context()->global()->GetProperty(*foo_name);
  CHECK(func_value->IsJSFunction());
  Handle<JSFunction> function(JSFunction::cast(func_value));
  CHECK(function->shared()->is_compiled());

  Heap::CollectAllGarbage(true);
  Heap::CollectAllGarbage(true);

  CHECK(function->shared()->is_compiled());

  Heap::CollectAllGarbage(true);
  Heap::CollectAllGarbage(true);
  Heap::CollectAllGarbage(true);
  Heap::CollectAllGarbage(true);
  Heap::CollectAllGarbage(true);
  Heap::CollectAllGarbage(true);

  // foo should no longer be in the compilation cache
  CHECK(!function->shared()->is_compiled());
  CHECK(!function->is_compiled());
  // Call foo to get it recompiled.
  CompileRun("foo()");
  CHECK(function->shared()->is_compiled());
  CHECK(function->is_compiled());
}


// Count the number of global contexts in the weak list of global contexts.
static int CountGlobalContexts() {
  int count = 0;
  Object* object = Heap::global_contexts_list();
  while (!object->IsUndefined()) {
    count++;
    object = Context::cast(object)->get(Context::NEXT_CONTEXT_LINK);
  }
  return count;
}


TEST(TestInternalWeakLists) {
  static const int kNumTestContexts = 10;

  v8::HandleScope scope;
  v8::Persistent<v8::Context> ctx[kNumTestContexts];

  CHECK_EQ(0, CountGlobalContexts());

  // Create a number of global contests which gets linked together.
  for (int i = 0; i < kNumTestContexts; i++) {
    ctx[i] = v8::Context::New();
    CHECK_EQ(i + 1, CountGlobalContexts());

    ctx[i]->Enter();
    ctx[i]->Exit();
  }

  // Force compilation cache cleanup.
  Heap::CollectAllGarbage(true);

  // Dispose the global contexts one by one.
  for (int i = 0; i < kNumTestContexts; i++) {
    ctx[i].Dispose();
    ctx[i].Clear();

    // Scavenge treats these references as strong.
    for (int j = 0; j < 10; j++) {
      Heap::PerformScavenge();
      CHECK_EQ(kNumTestContexts - i, CountGlobalContexts());
    }

    // Mark compact handles the weak references.
    Heap::CollectAllGarbage(true);
    CHECK_EQ(kNumTestContexts - i - 1, CountGlobalContexts());
  }

  CHECK_EQ(0, CountGlobalContexts());
}


// Count the number of global contexts in the weak list of global contexts
// causing a GC after the specified number of elements.
static int CountGlobalContextsWithGC(int n) {
  int count = 0;
  Handle<Object> object(Heap::global_contexts_list());
  while (!object->IsUndefined()) {
    count++;
    if (count == n) Heap::CollectAllGarbage(true);
    object =
        Handle<Object>(Context::cast(*object)->get(Context::NEXT_CONTEXT_LINK));
  }
  return count;
}


TEST(TestInternalWeakListsTraverseWithGC) {
  static const int kNumTestContexts = 10;

  v8::HandleScope scope;
  v8::Persistent<v8::Context> ctx[kNumTestContexts];

  CHECK_EQ(0, CountGlobalContexts());

  // Create an number of contexts and check the length of the weak list both
  // with and without GCs while iterating the list.
  for (int i = 0; i < kNumTestContexts; i++) {
    ctx[i] = v8::Context::New();
    CHECK_EQ(i + 1, CountGlobalContexts());
    CHECK_EQ(i + 1, CountGlobalContextsWithGC(i / 2 + 1));

    ctx[i]->Enter();
    ctx[i]->Exit();
  }
}