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// Copyright 2014 the V8 project authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.
#include "src/runtime/runtime-utils.h"
#include "src/arguments.h"
#include "src/code-stubs.h"
#include "src/conversions-inl.h"
#include "src/elements.h"
#include "src/factory.h"
#include "src/isolate-inl.h"
#include "src/keys.h"
#include "src/messages.h"
#include "src/prototype.h"
namespace v8 {
namespace internal {
RUNTIME_FUNCTION(Runtime_FinishArrayPrototypeSetup) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
CONVERT_ARG_HANDLE_CHECKED(JSArray, prototype, 0);
Object* length = prototype->length();
RUNTIME_ASSERT(length->IsSmi() && Smi::cast(length)->value() == 0);
RUNTIME_ASSERT(prototype->HasFastSmiOrObjectElements());
// This is necessary to enable fast checks for absence of elements
// on Array.prototype and below.
prototype->set_elements(isolate->heap()->empty_fixed_array());
return Smi::FromInt(0);
}
static void InstallCode(Isolate* isolate, Handle<JSObject> holder,
const char* name, Handle<Code> code) {
Handle<String> key = isolate->factory()->InternalizeUtf8String(name);
Handle<JSFunction> optimized =
isolate->factory()->NewFunctionWithoutPrototype(key, code);
optimized->shared()->DontAdaptArguments();
JSObject::AddProperty(holder, key, optimized, NONE);
}
static void InstallBuiltin(Isolate* isolate, Handle<JSObject> holder,
const char* name, Builtins::Name builtin_name) {
InstallCode(isolate, holder, name,
handle(isolate->builtins()->builtin(builtin_name), isolate));
}
RUNTIME_FUNCTION(Runtime_SpecialArrayFunctions) {
HandleScope scope(isolate);
DCHECK(args.length() == 0);
Handle<JSObject> holder =
isolate->factory()->NewJSObject(isolate->object_function());
InstallBuiltin(isolate, holder, "pop", Builtins::kArrayPop);
FastArrayPushStub stub(isolate);
InstallCode(isolate, holder, "push", stub.GetCode());
InstallBuiltin(isolate, holder, "shift", Builtins::kArrayShift);
InstallBuiltin(isolate, holder, "unshift", Builtins::kArrayUnshift);
InstallBuiltin(isolate, holder, "slice", Builtins::kArraySlice);
InstallBuiltin(isolate, holder, "splice", Builtins::kArraySplice);
return *holder;
}
RUNTIME_FUNCTION(Runtime_FixedArrayGet) {
SealHandleScope shs(isolate);
DCHECK(args.length() == 2);
CONVERT_ARG_CHECKED(FixedArray, object, 0);
CONVERT_SMI_ARG_CHECKED(index, 1);
return object->get(index);
}
RUNTIME_FUNCTION(Runtime_FixedArraySet) {
SealHandleScope shs(isolate);
DCHECK(args.length() == 3);
CONVERT_ARG_CHECKED(FixedArray, object, 0);
CONVERT_SMI_ARG_CHECKED(index, 1);
CONVERT_ARG_CHECKED(Object, value, 2);
object->set(index, value);
return isolate->heap()->undefined_value();
}
RUNTIME_FUNCTION(Runtime_TransitionElementsKind) {
HandleScope scope(isolate);
RUNTIME_ASSERT(args.length() == 2);
CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
CONVERT_ARG_HANDLE_CHECKED(Map, map, 1);
JSObject::TransitionElementsKind(array, map->elements_kind());
return *array;
}
// Moves all own elements of an object, that are below a limit, to positions
// starting at zero. All undefined values are placed after non-undefined values,
// and are followed by non-existing element. Does not change the length
// property.
// Returns the number of non-undefined elements collected.
// Returns -1 if hole removal is not supported by this method.
RUNTIME_FUNCTION(Runtime_RemoveArrayHoles) {
HandleScope scope(isolate);
DCHECK(args.length() == 2);
CONVERT_ARG_HANDLE_CHECKED(JSReceiver, object, 0);
CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[1]);
if (object->IsJSProxy()) return Smi::FromInt(-1);
return *JSObject::PrepareElementsForSort(Handle<JSObject>::cast(object),
limit);
}
// Move contents of argument 0 (an array) to argument 1 (an array)
RUNTIME_FUNCTION(Runtime_MoveArrayContents) {
HandleScope scope(isolate);
DCHECK(args.length() == 2);
CONVERT_ARG_HANDLE_CHECKED(JSArray, from, 0);
CONVERT_ARG_HANDLE_CHECKED(JSArray, to, 1);
JSObject::ValidateElements(from);
JSObject::ValidateElements(to);
Handle<FixedArrayBase> new_elements(from->elements());
ElementsKind from_kind = from->GetElementsKind();
Handle<Map> new_map = JSObject::GetElementsTransitionMap(to, from_kind);
JSObject::SetMapAndElements(to, new_map, new_elements);
to->set_length(from->length());
JSObject::ResetElements(from);
from->set_length(Smi::FromInt(0));
JSObject::ValidateElements(to);
return *to;
}
// How many elements does this object/array have?
RUNTIME_FUNCTION(Runtime_EstimateNumberOfElements) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);
Handle<FixedArrayBase> elements(array->elements(), isolate);
SealHandleScope shs(isolate);
if (elements->IsDictionary()) {
int result =
Handle<SeededNumberDictionary>::cast(elements)->NumberOfElements();
return Smi::FromInt(result);
} else {
DCHECK(array->length()->IsSmi());
// For packed elements, we know the exact number of elements
int length = elements->length();
ElementsKind kind = array->GetElementsKind();
if (IsFastPackedElementsKind(kind)) {
return Smi::FromInt(length);
}
// For holey elements, take samples from the buffer checking for holes
// to generate the estimate.
const int kNumberOfHoleCheckSamples = 97;
int increment = (length < kNumberOfHoleCheckSamples)
? 1
: static_cast<int>(length / kNumberOfHoleCheckSamples);
ElementsAccessor* accessor = array->GetElementsAccessor();
int holes = 0;
for (int i = 0; i < length; i += increment) {
if (!accessor->HasElement(array, i, elements)) {
++holes;
}
}
int estimate = static_cast<int>((kNumberOfHoleCheckSamples - holes) /
kNumberOfHoleCheckSamples * length);
return Smi::FromInt(estimate);
}
}
// Returns an array that tells you where in the [0, length) interval an array
// might have elements. Can either return an array of keys (positive integers
// or undefined) or a number representing the positive length of an interval
// starting at index 0.
// Intervals can span over some keys that are not in the object.
RUNTIME_FUNCTION(Runtime_GetArrayKeys) {
HandleScope scope(isolate);
DCHECK(args.length() == 2);
CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
CONVERT_NUMBER_CHECKED(uint32_t, length, Uint32, args[1]);
if (array->HasFastStringWrapperElements()) {
int string_length =
String::cast(Handle<JSValue>::cast(array)->value())->length();
int backing_store_length = array->elements()->length();
return *isolate->factory()->NewNumberFromUint(
Min(length,
static_cast<uint32_t>(Max(string_length, backing_store_length))));
}
if (!array->elements()->IsDictionary()) {
RUNTIME_ASSERT(array->HasFastSmiOrObjectElements() ||
array->HasFastDoubleElements());
uint32_t actual_length = static_cast<uint32_t>(array->elements()->length());
return *isolate->factory()->NewNumberFromUint(Min(actual_length, length));
}
KeyAccumulator accumulator(isolate, OWN_ONLY, ALL_PROPERTIES);
// No need to separate prototype levels since we only get element keys.
for (PrototypeIterator iter(isolate, array,
PrototypeIterator::START_AT_RECEIVER);
!iter.IsAtEnd(); iter.Advance()) {
if (PrototypeIterator::GetCurrent(iter)->IsJSProxy() ||
PrototypeIterator::GetCurrent<JSObject>(iter)
->HasIndexedInterceptor()) {
// Bail out if we find a proxy or interceptor, likely not worth
// collecting keys in that case.
return *isolate->factory()->NewNumberFromUint(length);
}
accumulator.NextPrototype();
Handle<JSObject> current = PrototypeIterator::GetCurrent<JSObject>(iter);
JSObject::CollectOwnElementKeys(current, &accumulator, ALL_PROPERTIES);
}
// Erase any keys >= length.
Handle<FixedArray> keys = accumulator.GetKeys(KEEP_NUMBERS);
int j = 0;
for (int i = 0; i < keys->length(); i++) {
if (NumberToUint32(keys->get(i)) >= length) continue;
if (i != j) keys->set(j, keys->get(i));
j++;
}
if (j != keys->length()) {
isolate->heap()->RightTrimFixedArray<Heap::CONCURRENT_TO_SWEEPER>(
*keys, keys->length() - j);
}
return *isolate->factory()->NewJSArrayWithElements(keys);
}
namespace {
Object* ArrayConstructorCommon(Isolate* isolate, Handle<JSFunction> constructor,
Handle<JSReceiver> new_target,
Handle<AllocationSite> site,
Arguments* caller_args) {
Factory* factory = isolate->factory();
// If called through new, new.target can be:
// - a subclass of constructor,
// - a proxy wrapper around constructor, or
// - the constructor itself.
// If called through Reflect.construct, it's guaranteed to be a constructor by
// REFLECT_CONSTRUCT_PREPARE.
DCHECK(new_target->IsConstructor());
bool holey = false;
bool can_use_type_feedback = !site.is_null();
bool can_inline_array_constructor = true;
if (caller_args->length() == 1) {
Handle<Object> argument_one = caller_args->at<Object>(0);
if (argument_one->IsSmi()) {
int value = Handle<Smi>::cast(argument_one)->value();
if (value < 0 ||
JSArray::SetLengthWouldNormalize(isolate->heap(), value)) {
// the array is a dictionary in this case.
can_use_type_feedback = false;
} else if (value != 0) {
holey = true;
if (value >= JSArray::kInitialMaxFastElementArray) {
can_inline_array_constructor = false;
}
}
} else {
// Non-smi length argument produces a dictionary
can_use_type_feedback = false;
}
}
Handle<Map> initial_map;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, initial_map,
JSFunction::GetDerivedMap(isolate, constructor, new_target));
ElementsKind to_kind = can_use_type_feedback ? site->GetElementsKind()
: initial_map->elements_kind();
if (holey && !IsFastHoleyElementsKind(to_kind)) {
to_kind = GetHoleyElementsKind(to_kind);
// Update the allocation site info to reflect the advice alteration.
if (!site.is_null()) site->SetElementsKind(to_kind);
}
// We should allocate with an initial map that reflects the allocation site
// advice. Therefore we use AllocateJSObjectFromMap instead of passing
// the constructor.
if (to_kind != initial_map->elements_kind()) {
initial_map = Map::AsElementsKind(initial_map, to_kind);
}
// If we don't care to track arrays of to_kind ElementsKind, then
// don't emit a memento for them.
Handle<AllocationSite> allocation_site;
if (AllocationSite::GetMode(to_kind) == TRACK_ALLOCATION_SITE) {
allocation_site = site;
}
Handle<JSArray> array = Handle<JSArray>::cast(
factory->NewJSObjectFromMap(initial_map, NOT_TENURED, allocation_site));
factory->NewJSArrayStorage(array, 0, 0, DONT_INITIALIZE_ARRAY_ELEMENTS);
ElementsKind old_kind = array->GetElementsKind();
RETURN_FAILURE_ON_EXCEPTION(
isolate, ArrayConstructInitializeElements(array, caller_args));
if (!site.is_null() &&
(old_kind != array->GetElementsKind() || !can_use_type_feedback ||
!can_inline_array_constructor)) {
// The arguments passed in caused a transition. This kind of complexity
// can't be dealt with in the inlined hydrogen array constructor case.
// We must mark the allocationsite as un-inlinable.
site->SetDoNotInlineCall();
}
return *array;
}
} // namespace
RUNTIME_FUNCTION(Runtime_NewArray) {
HandleScope scope(isolate);
DCHECK_LE(3, args.length());
int const argc = args.length() - 3;
// TODO(bmeurer): Remove this Arguments nonsense.
Arguments argv(argc, args.arguments() - 1);
CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, 0);
CONVERT_ARG_HANDLE_CHECKED(JSReceiver, new_target, argc + 1);
CONVERT_ARG_HANDLE_CHECKED(HeapObject, type_info, argc + 2);
// TODO(bmeurer): Use MaybeHandle to pass around the AllocationSite.
Handle<AllocationSite> site = type_info->IsAllocationSite()
? Handle<AllocationSite>::cast(type_info)
: Handle<AllocationSite>::null();
return ArrayConstructorCommon(isolate, constructor, new_target, site, &argv);
}
RUNTIME_FUNCTION(Runtime_ArrayConstructor) {
HandleScope scope(isolate);
// If we get 2 arguments then they are the stub parameters (constructor, type
// info). If we get 4, then the first one is a pointer to the arguments
// passed by the caller, and the last one is the length of the arguments
// passed to the caller (redundant, but useful to check on the deoptimizer
// with an assert).
Arguments empty_args(0, NULL);
bool no_caller_args = args.length() == 2;
DCHECK(no_caller_args || args.length() == 4);
int parameters_start = no_caller_args ? 0 : 1;
Arguments* caller_args =
no_caller_args ? &empty_args : reinterpret_cast<Arguments*>(args[0]);
CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, parameters_start);
CONVERT_ARG_HANDLE_CHECKED(Object, type_info, parameters_start + 1);
#ifdef DEBUG
if (!no_caller_args) {
CONVERT_SMI_ARG_CHECKED(arg_count, parameters_start + 2);
DCHECK(arg_count == caller_args->length());
}
#endif
Handle<AllocationSite> site;
if (!type_info.is_null() &&
*type_info != isolate->heap()->undefined_value()) {
site = Handle<AllocationSite>::cast(type_info);
DCHECK(!site->SitePointsToLiteral());
}
return ArrayConstructorCommon(isolate, constructor, constructor, site,
caller_args);
}
RUNTIME_FUNCTION(Runtime_InternalArrayConstructor) {
HandleScope scope(isolate);
Arguments empty_args(0, NULL);
bool no_caller_args = args.length() == 1;
DCHECK(no_caller_args || args.length() == 3);
int parameters_start = no_caller_args ? 0 : 1;
Arguments* caller_args =
no_caller_args ? &empty_args : reinterpret_cast<Arguments*>(args[0]);
CONVERT_ARG_HANDLE_CHECKED(JSFunction, constructor, parameters_start);
#ifdef DEBUG
if (!no_caller_args) {
CONVERT_SMI_ARG_CHECKED(arg_count, parameters_start + 1);
DCHECK(arg_count == caller_args->length());
}
#endif
return ArrayConstructorCommon(isolate, constructor, constructor,
Handle<AllocationSite>::null(), caller_args);
}
RUNTIME_FUNCTION(Runtime_NormalizeElements) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
RUNTIME_ASSERT(!array->HasFixedTypedArrayElements() &&
!array->IsJSGlobalProxy());
JSObject::NormalizeElements(array);
return *array;
}
// GrowArrayElements returns a sentinel Smi if the object was normalized.
RUNTIME_FUNCTION(Runtime_GrowArrayElements) {
HandleScope scope(isolate);
DCHECK(args.length() == 2);
CONVERT_ARG_HANDLE_CHECKED(JSObject, object, 0);
CONVERT_NUMBER_CHECKED(int, key, Int32, args[1]);
if (key < 0) {
return object->elements();
}
uint32_t capacity = static_cast<uint32_t>(object->elements()->length());
uint32_t index = static_cast<uint32_t>(key);
if (index >= capacity) {
if (object->WouldConvertToSlowElements(index)) {
// We don't want to allow operations that cause lazy deopt. Return a Smi
// as a signal that optimized code should eagerly deoptimize.
return Smi::FromInt(0);
}
uint32_t new_capacity = JSObject::NewElementsCapacity(index + 1);
object->GetElementsAccessor()->GrowCapacityAndConvert(object, new_capacity);
}
// On success, return the fixed array elements.
return object->elements();
}
RUNTIME_FUNCTION(Runtime_HasComplexElements) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
CONVERT_ARG_HANDLE_CHECKED(JSObject, array, 0);
for (PrototypeIterator iter(isolate, array,
PrototypeIterator::START_AT_RECEIVER);
!iter.IsAtEnd(); iter.Advance()) {
if (PrototypeIterator::GetCurrent(iter)->IsJSProxy()) {
return isolate->heap()->true_value();
}
Handle<JSObject> current = PrototypeIterator::GetCurrent<JSObject>(iter);
if (current->HasIndexedInterceptor()) {
return isolate->heap()->true_value();
}
if (!current->HasDictionaryElements()) continue;
if (current->element_dictionary()->HasComplexElements()) {
return isolate->heap()->true_value();
}
}
return isolate->heap()->false_value();
}
RUNTIME_FUNCTION(Runtime_IsArray) {
SealHandleScope shs(isolate);
DCHECK(args.length() == 1);
CONVERT_ARG_CHECKED(Object, obj, 0);
return isolate->heap()->ToBoolean(obj->IsJSArray());
}
RUNTIME_FUNCTION(Runtime_HasCachedArrayIndex) {
SealHandleScope shs(isolate);
DCHECK(args.length() == 1);
return isolate->heap()->false_value();
}
RUNTIME_FUNCTION(Runtime_GetCachedArrayIndex) {
// This can never be reached, because Runtime_HasCachedArrayIndex always
// returns false.
UNIMPLEMENTED();
return nullptr;
}
RUNTIME_FUNCTION(Runtime_ArraySpeciesConstructor) {
HandleScope scope(isolate);
DCHECK(args.length() == 1);
CONVERT_ARG_HANDLE_CHECKED(Object, original_array, 0);
Handle<Object> constructor;
ASSIGN_RETURN_FAILURE_ON_EXCEPTION(
isolate, constructor,
Object::ArraySpeciesConstructor(isolate, original_array));
return *constructor;
}
} // namespace internal
} // namespace v8