// 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/conversions.h"

#include "src/counters.h"

#include "src/objects-inl.h"

#include "src/regexp/jsregexp-inl.h"

#include "src/regexp/regexp-utils.h"

#include "src/string-builder.h"

#include "src/string-search.h"

namespace v8 {

namespace internal {

RUNTIME_FUNCTION(Runtime_GetSubstitution) {

HandleScope scope(isolate);

DCHECK_EQ(5, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, matched, 0);

CONVERT_ARG_HANDLE_CHECKED(String, subject, 1);

CONVERT_SMI_ARG_CHECKED(position, 2);

CONVERT_ARG_HANDLE_CHECKED(String, replacement, 3);

CONVERT_SMI_ARG_CHECKED(start_index, 4);

// A simple match without captures.

class SimpleMatch : public String::Match {

public:

SimpleMatch(Handle<String> match, Handle<String> prefix,

Handle<String> suffix)

: match_(match), prefix_(prefix), suffix_(suffix) {}

Handle<String> GetMatch() override { return match_; }

Handle<String> GetPrefix() override { return prefix_; }

Handle<String> GetSuffix() override { return suffix_; }

int CaptureCount() override { return 0; }

bool HasNamedCaptures() override { return false; }

MaybeHandle<String> GetCapture(int i, bool* capture_exists) override {

*capture_exists = false;

return match_; // Return arbitrary string handle.

}

MaybeHandle<String> GetNamedCapture(Handle<String> name,

CaptureState* state) override {

UNREACHABLE();

}

private:

Handle<String> match_, prefix_, suffix_;

};

Handle<String> prefix =

isolate->factory()->NewSubString(subject, 0, position);

Handle<String> suffix = isolate->factory()->NewSubString(

subject, position + matched->length(), subject->length());

SimpleMatch match(matched, prefix, suffix);

RETURN_RESULT_OR_FAILURE(

isolate,

String::GetSubstitution(isolate, &match, replacement, start_index));

}

// This may return an empty MaybeHandle if an exception is thrown or

// we abort due to reaching the recursion limit.

MaybeHandle<String> StringReplaceOneCharWithString(

Isolate* isolate, Handle<String> subject, Handle<String> search,

Handle<String> replace, bool* found, int recursion_limit) {

StackLimitCheck stackLimitCheck(isolate);

if (stackLimitCheck.HasOverflowed() || (recursion_limit == 0)) {

return MaybeHandle<String>();

}

recursion_limit--;

if (subject->IsConsString()) {

ConsString* cons = ConsString::cast(*subject);

Handle<String> first = Handle<String>(cons->first());

Handle<String> second = Handle<String>(cons->second());

Handle<String> new_first;

if (!StringReplaceOneCharWithString(isolate, first, search, replace, found,

recursion_limit).ToHandle(&new_first)) {

return MaybeHandle<String>();

}

if (*found) return isolate->factory()->NewConsString(new_first, second);

Handle<String> new_second;

if (!StringReplaceOneCharWithString(isolate, second, search, replace, found,

recursion_limit)

.ToHandle(&new_second)) {

return MaybeHandle<String>();

}

if (*found) return isolate->factory()->NewConsString(first, new_second);

return subject;

} else {

int index = String::IndexOf(isolate, subject, search, 0);

if (index == -1) return subject;

*found = true;

Handle<String> first = isolate->factory()->NewSubString(subject, 0, index);

Handle<String> cons1;

ASSIGN_RETURN_ON_EXCEPTION(

isolate, cons1, isolate->factory()->NewConsString(first, replace),

String);

Handle<String> second =

isolate->factory()->NewSubString(subject, index + 1, subject->length());

return isolate->factory()->NewConsString(cons1, second);

}

}

RUNTIME_FUNCTION(Runtime_StringReplaceOneCharWithString) {

HandleScope scope(isolate);

DCHECK_EQ(3, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);

CONVERT_ARG_HANDLE_CHECKED(String, search, 1);

CONVERT_ARG_HANDLE_CHECKED(String, replace, 2);

// If the cons string tree is too deep, we simply abort the recursion and

// retry with a flattened subject string.

const int kRecursionLimit = 0x1000;

bool found = false;

Handle<String> result;

if (StringReplaceOneCharWithString(isolate, subject, search, replace, &found,

kRecursionLimit).ToHandle(&result)) {

return *result;

}

if (isolate->has_pending_exception()) return isolate->heap()->exception();

subject = String::Flatten(subject);

if (StringReplaceOneCharWithString(isolate, subject, search, replace, &found,

kRecursionLimit).ToHandle(&result)) {

return *result;

}

if (isolate->has_pending_exception()) return isolate->heap()->exception();

// In case of empty handle and no pending exception we have stack overflow.

return isolate->StackOverflow();

}

RUNTIME_FUNCTION(Runtime_StringTrim) {

HandleScope scope(isolate);

DCHECK_EQ(2, args.length());

Handle<String> string = args.at<String>(0);

CONVERT_SMI_ARG_CHECKED(mode, 1);

String::TrimMode trim_mode = static_cast<String::TrimMode>(mode);

return *String::Trim(string, trim_mode);

}

// ES6 #sec-string.prototype.includes

// String.prototype.includes(searchString [, position])

RUNTIME_FUNCTION(Runtime_StringIncludes) {

HandleScope scope(isolate);

DCHECK_EQ(3, args.length());

Handle<Object> receiver = args.at(0);

if (receiver->IsNullOrUndefined(isolate)) {

THROW_NEW_ERROR_RETURN_FAILURE(

isolate, NewTypeError(MessageTemplate::kCalledOnNullOrUndefined,

isolate->factory()->NewStringFromAsciiChecked(

"String.prototype.includes")));

}

Handle<String> receiver_string;

ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, receiver_string,

Object::ToString(isolate, receiver));

// Check if the search string is a regExp and fail if it is.

Handle<Object> search = args.at(1);

Maybe<bool> is_reg_exp = RegExpUtils::IsRegExp(isolate, search);

if (is_reg_exp.IsNothing()) {

DCHECK(isolate->has_pending_exception());

return isolate->heap()->exception();

}

if (is_reg_exp.FromJust()) {

THROW_NEW_ERROR_RETURN_FAILURE(

isolate, NewTypeError(MessageTemplate::kFirstArgumentNotRegExp,

isolate->factory()->NewStringFromStaticChars(

"String.prototype.includes")));

}

Handle<String> search_string;

ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, search_string,

Object::ToString(isolate, args.at(1)));

Handle<Object> position;

ASSIGN_RETURN_FAILURE_ON_EXCEPTION(isolate, position,

Object::ToInteger(isolate, args.at(2)));

uint32_t index = receiver_string->ToValidIndex(*position);

int index_in_str =

String::IndexOf(isolate, receiver_string, search_string, index);

return *isolate->factory()->ToBoolean(index_in_str != -1);

}

// ES6 #sec-string.prototype.indexof

// String.prototype.indexOf(searchString [, position])

RUNTIME_FUNCTION(Runtime_StringIndexOf) {

HandleScope scope(isolate);

DCHECK_EQ(3, args.length());

return String::IndexOf(isolate, args.at(0), args.at(1), args.at(2));

}

// ES6 #sec-string.prototype.indexof

// String.prototype.indexOf(searchString, position)

// Fast version that assumes that does not perform conversions of the incoming

// arguments.

RUNTIME_FUNCTION(Runtime_StringIndexOfUnchecked) {

HandleScope scope(isolate);

DCHECK_EQ(3, args.length());

Handle<String> receiver_string = args.at<String>(0);

Handle<String> search_string = args.at<String>(1);

int index = std::min(std::max(args.smi_at(2), 0), receiver_string->length());

return Smi::FromInt(String::IndexOf(isolate, receiver_string, search_string,

static_cast<uint32_t>(index)));

}

RUNTIME_FUNCTION(Runtime_StringLastIndexOf) {

HandleScope handle_scope(isolate);

return String::LastIndexOf(isolate, args.at(0), args.at(1),

isolate->factory()->undefined_value());

}

RUNTIME_FUNCTION(Runtime_SubString) {

HandleScope scope(isolate);

DCHECK_EQ(3, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, string, 0);

int start, end;

// We have a fast integer-only case here to avoid a conversion to double in

// the common case where from and to are Smis.

if (args[1]->IsSmi() && args[2]->IsSmi()) {

CONVERT_SMI_ARG_CHECKED(from_number, 1);

CONVERT_SMI_ARG_CHECKED(to_number, 2);

start = from_number;

end = to_number;

} else if (args[1]->IsNumber() && args[2]->IsNumber()) {

CONVERT_DOUBLE_ARG_CHECKED(from_number, 1);

CONVERT_DOUBLE_ARG_CHECKED(to_number, 2);

start = FastD2IChecked(from_number);

end = FastD2IChecked(to_number);

} else {

return isolate->ThrowIllegalOperation();

}

// The following condition is intentionally robust because the SubStringStub

// delegates here and we test this in cctest/test-strings/RobustSubStringStub.

if (end < start || start < 0 || end > string->length()) {

return isolate->ThrowIllegalOperation();

}

isolate->counters()->sub_string_runtime()->Increment();

return *isolate->factory()->NewSubString(string, start, end);

}

RUNTIME_FUNCTION(Runtime_StringAdd) {

HandleScope scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, str1, 0);

CONVERT_ARG_HANDLE_CHECKED(String, str2, 1);

isolate->counters()->string_add_runtime()->Increment();

RETURN_RESULT_OR_FAILURE(isolate,

isolate->factory()->NewConsString(str1, str2));

}

RUNTIME_FUNCTION(Runtime_InternalizeString) {

HandleScope handles(isolate);

DCHECK_EQ(1, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, string, 0);

return *isolate->factory()->InternalizeString(string);

}

RUNTIME_FUNCTION(Runtime_StringCharCodeAt) {

HandleScope handle_scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, subject, 0);

CONVERT_NUMBER_CHECKED(uint32_t, i, Uint32, args[1]);

// Flatten the string. If someone wants to get a char at an index

// in a cons string, it is likely that more indices will be

// accessed.

subject = String::Flatten(subject);

if (i >= static_cast<uint32_t>(subject->length())) {

return isolate->heap()->nan_value();

}

return Smi::FromInt(subject->Get(i));

}

RUNTIME_FUNCTION(Runtime_StringCompare) {

HandleScope handle_scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, x, 0);

CONVERT_ARG_HANDLE_CHECKED(String, y, 1);

isolate->counters()->string_compare_runtime()->Increment();

switch (String::Compare(x, y)) {

case ComparisonResult::kLessThan:

return Smi::FromInt(LESS);

case ComparisonResult::kEqual:

return Smi::FromInt(EQUAL);

case ComparisonResult::kGreaterThan:

return Smi::FromInt(GREATER);

case ComparisonResult::kUndefined:

break;

}

UNREACHABLE();

}

RUNTIME_FUNCTION(Runtime_StringBuilderConcat) {

HandleScope scope(isolate);

DCHECK_EQ(3, args.length());

CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);

int32_t array_length;

if (!args[1]->ToInt32(&array_length)) {

THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());

}

CONVERT_ARG_HANDLE_CHECKED(String, special, 2);

size_t actual_array_length = 0;

CHECK(TryNumberToSize(array->length(), &actual_array_length));

CHECK(array_length >= 0);

CHECK(static_cast<size_t>(array_length) <= actual_array_length);

// This assumption is used by the slice encoding in one or two smis.

DCHECK(Smi::kMaxValue >= String::kMaxLength);

CHECK(array->HasFastElements());

JSObject::EnsureCanContainHeapObjectElements(array);

int special_length = special->length();

if (!array->HasObjectElements()) {

return isolate->Throw(isolate->heap()->illegal_argument_string());

}

int length;

bool one_byte = special->HasOnlyOneByteChars();

{

DisallowHeapAllocation no_gc;

FixedArray* fixed_array = FixedArray::cast(array->elements());

if (fixed_array->length() < array_length) {

array_length = fixed_array->length();

}

if (array_length == 0) {

return isolate->heap()->empty_string();

} else if (array_length == 1) {

Object* first = fixed_array->get(0);

if (first->IsString()) return first;

}

length = StringBuilderConcatLength(special_length, fixed_array,

array_length, &one_byte);

}

if (length == -1) {

return isolate->Throw(isolate->heap()->illegal_argument_string());

}

if (length == 0) {

return isolate->heap()->empty_string();

}

if (one_byte) {

Handle<SeqOneByteString> answer;

ASSIGN_RETURN_FAILURE_ON_EXCEPTION(

isolate, answer, isolate->factory()->NewRawOneByteString(length));

StringBuilderConcatHelper(*special, answer->GetChars(),

FixedArray::cast(array->elements()),

array_length);

return *answer;

} else {

Handle<SeqTwoByteString> answer;

ASSIGN_RETURN_FAILURE_ON_EXCEPTION(

isolate, answer, isolate->factory()->NewRawTwoByteString(length));

StringBuilderConcatHelper(*special, answer->GetChars(),

FixedArray::cast(array->elements()),

array_length);

return *answer;

}

}

RUNTIME_FUNCTION(Runtime_StringBuilderJoin) {

HandleScope scope(isolate);

DCHECK_EQ(3, args.length());

CONVERT_ARG_HANDLE_CHECKED(JSArray, array, 0);

int32_t array_length;

if (!args[1]->ToInt32(&array_length)) {

THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());

}

CONVERT_ARG_HANDLE_CHECKED(String, separator, 2);

CHECK(array->HasObjectElements());

CHECK(array_length >= 0);

Handle<FixedArray> fixed_array(FixedArray::cast(array->elements()));

if (fixed_array->length() < array_length) {

array_length = fixed_array->length();

}

if (array_length == 0) {

return isolate->heap()->empty_string();

} else if (array_length == 1) {

Object* first = fixed_array->get(0);

CHECK(first->IsString());

return first;

}

int separator_length = separator->length();

CHECK(separator_length > 0);

int max_nof_separators =

(String::kMaxLength + separator_length - 1) / separator_length;

if (max_nof_separators < (array_length - 1)) {

THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());

}

int length = (array_length - 1) * separator_length;

for (int i = 0; i < array_length; i++) {

Object* element_obj = fixed_array->get(i);

CHECK(element_obj->IsString());

String* element = String::cast(element_obj);

int increment = element->length();

if (increment > String::kMaxLength - length) {

STATIC_ASSERT(String::kMaxLength < kMaxInt);

length = kMaxInt; // Provoke exception;

break;

}

length += increment;

}

Handle<SeqTwoByteString> answer;

ASSIGN_RETURN_FAILURE_ON_EXCEPTION(

isolate, answer, isolate->factory()->NewRawTwoByteString(length));

DisallowHeapAllocation no_gc;

uc16* sink = answer->GetChars();

#ifdef DEBUG

uc16* end = sink + length;

#endif

CHECK(fixed_array->get(0)->IsString());

String* first = String::cast(fixed_array->get(0));

String* separator_raw = *separator;

int first_length = first->length();

String::WriteToFlat(first, sink, 0, first_length);

sink += first_length;

for (int i = 1; i < array_length; i++) {

DCHECK(sink + separator_length <= end);

String::WriteToFlat(separator_raw, sink, 0, separator_length);

sink += separator_length;

CHECK(fixed_array->get(i)->IsString());

String* element = String::cast(fixed_array->get(i));

int element_length = element->length();

DCHECK(sink + element_length <= end);

String::WriteToFlat(element, sink, 0, element_length);

sink += element_length;

}

DCHECK(sink == end);

// Use %_FastOneByteArrayJoin instead.

DCHECK(!answer->IsOneByteRepresentation());

return *answer;

}

template <typename sinkchar>

static void WriteRepeatToFlat(String* src, Vector<sinkchar> buffer, int cursor,

int repeat, int length) {

if (repeat == 0) return;

sinkchar* start = &buffer[cursor];

String::WriteToFlat<sinkchar>(src, start, 0, length);

int done = 1;

sinkchar* next = start + length;

while (done < repeat) {

int block = Min(done, repeat - done);

int block_chars = block * length;

CopyChars(next, start, block_chars);

next += block_chars;

done += block;

}

}

template <typename Char>

static void JoinSparseArrayWithSeparator(FixedArray* elements,

int elements_length,

uint32_t array_length,

String* separator,

Vector<Char> buffer) {

DisallowHeapAllocation no_gc;

int previous_separator_position = 0;

int separator_length = separator->length();

DCHECK_LT(0, separator_length);

int cursor = 0;

for (int i = 0; i < elements_length; i += 2) {

int position = NumberToInt32(elements->get(i));

String* string = String::cast(elements->get(i + 1));

int string_length = string->length();

if (string->length() > 0) {

int repeat = position - previous_separator_position;

WriteRepeatToFlat<Char>(separator, buffer, cursor, repeat,

separator_length);

cursor += repeat * separator_length;

previous_separator_position = position;

String::WriteToFlat<Char>(string, &buffer[cursor], 0, string_length);

cursor += string->length();

}

}

int last_array_index = static_cast<int>(array_length - 1);

// Array length must be representable as a signed 32-bit number,

// otherwise the total string length would have been too large.

DCHECK(array_length <= 0x7fffffff); // Is int32_t.

int repeat = last_array_index - previous_separator_position;

WriteRepeatToFlat<Char>(separator, buffer, cursor, repeat, separator_length);

cursor += repeat * separator_length;

DCHECK(cursor <= buffer.length());

}

RUNTIME_FUNCTION(Runtime_SparseJoinWithSeparator) {

HandleScope scope(isolate);

DCHECK_EQ(3, args.length());

CONVERT_ARG_HANDLE_CHECKED(JSArray, elements_array, 0);

CONVERT_NUMBER_CHECKED(uint32_t, array_length, Uint32, args[1]);

CONVERT_ARG_HANDLE_CHECKED(String, separator, 2);

// elements_array is fast-mode JSarray of alternating positions

// (increasing order) and strings.

CHECK(elements_array->HasSmiOrObjectElements());

// array_length is length of original array (used to add separators);

// separator is string to put between elements. Assumed to be non-empty.

CHECK(array_length > 0);

// Find total length of join result.

int string_length = 0;

bool is_one_byte = separator->IsOneByteRepresentation();

bool overflow = false;

CONVERT_NUMBER_CHECKED(int, elements_length, Int32, elements_array->length());

CHECK(elements_length <= elements_array->elements()->length());

CHECK((elements_length & 1) == 0); // Even length.

FixedArray* elements = FixedArray::cast(elements_array->elements());

{

DisallowHeapAllocation no_gc;

for (int i = 0; i < elements_length; i += 2) {

String* string = String::cast(elements->get(i + 1));

int length = string->length();

if (is_one_byte && !string->IsOneByteRepresentation()) {

is_one_byte = false;

}

if (length > String::kMaxLength ||

String::kMaxLength - length < string_length) {

overflow = true;

break;

}

string_length += length;

}

}

int separator_length = separator->length();

if (!overflow && separator_length > 0) {

if (array_length <= 0x7fffffffu) {

int separator_count = static_cast<int>(array_length) - 1;

int remaining_length = String::kMaxLength - string_length;

if ((remaining_length / separator_length) >= separator_count) {

string_length += separator_length * (array_length - 1);

} else {

// Not room for the separators within the maximal string length.

overflow = true;

}

} else {

// Nonempty separator and at least 2^31-1 separators necessary

// means that the string is too large to create.

STATIC_ASSERT(String::kMaxLength < 0x7fffffff);

overflow = true;

}

}

if (overflow) {

// Throw an exception if the resulting string is too large. See

// https://code.google.com/p/chromium/issues/detail?id=336820

// for details.

THROW_NEW_ERROR_RETURN_FAILURE(isolate, NewInvalidStringLengthError());

}

if (is_one_byte) {

Handle<SeqOneByteString> result = isolate->factory()

->NewRawOneByteString(string_length)

.ToHandleChecked();

JoinSparseArrayWithSeparator<uint8_t>(

FixedArray::cast(elements_array->elements()), elements_length,

array_length, *separator,

Vector<uint8_t>(result->GetChars(), string_length));

return *result;

} else {

Handle<SeqTwoByteString> result = isolate->factory()

->NewRawTwoByteString(string_length)

.ToHandleChecked();

JoinSparseArrayWithSeparator<uc16>(

FixedArray::cast(elements_array->elements()), elements_length,

array_length, *separator,

Vector<uc16>(result->GetChars(), string_length));

return *result;

}

}

// Copies Latin1 characters to the given fixed array looking up

// one-char strings in the cache. Gives up on the first char that is

// not in the cache and fills the remainder with smi zeros. Returns

// the length of the successfully copied prefix.

static int CopyCachedOneByteCharsToArray(Heap* heap, const uint8_t* chars,

FixedArray* elements, int length) {

DisallowHeapAllocation no_gc;

FixedArray* one_byte_cache = heap->single_character_string_cache();

Object* undefined = heap->undefined_value();

int i;

WriteBarrierMode mode = elements->GetWriteBarrierMode(no_gc);

for (i = 0; i < length; ++i) {

Object* value = one_byte_cache->get(chars[i]);

if (value == undefined) break;

elements->set(i, value, mode);

}

if (i < length) {

DCHECK(Smi::kZero == 0);

memset(elements->data_start() + i, 0, kPointerSize * (length - i));

}

#ifdef DEBUG

for (int j = 0; j < length; ++j) {

Object* element = elements->get(j);

DCHECK(element == Smi::kZero ||

(element->IsString() && String::cast(element)->LooksValid()));

}

#endif

return i;

}

// Converts a String to JSArray.

// For example, "foo" => ["f", "o", "o"].

RUNTIME_FUNCTION(Runtime_StringToArray) {

HandleScope scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, s, 0);

CONVERT_NUMBER_CHECKED(uint32_t, limit, Uint32, args[1]);

s = String::Flatten(s);

const int length = static_cast<int>(Min<uint32_t>(s->length(), limit));

Handle<FixedArray> elements;

int position = 0;

if (s->IsFlat() && s->IsOneByteRepresentation()) {

// Try using cached chars where possible.

elements = isolate->factory()->NewUninitializedFixedArray(length);

DisallowHeapAllocation no_gc;

String::FlatContent content = s->GetFlatContent();

if (content.IsOneByte()) {

Vector<const uint8_t> chars = content.ToOneByteVector();

// Note, this will initialize all elements (not only the prefix)

// to prevent GC from seeing partially initialized array.

position = CopyCachedOneByteCharsToArray(isolate->heap(), chars.start(),

*elements, length);

} else {

MemsetPointer(elements->data_start(), isolate->heap()->undefined_value(),

length);

}

} else {

elements = isolate->factory()->NewFixedArray(length);

}

for (int i = position; i < length; ++i) {

Handle<Object> str =

isolate->factory()->LookupSingleCharacterStringFromCode(s->Get(i));

elements->set(i, *str);

}

#ifdef DEBUG

for (int i = 0; i < length; ++i) {

DCHECK(String::cast(elements->get(i))->length() == 1);

}

#endif

return *isolate->factory()->NewJSArrayWithElements(elements);

}

RUNTIME_FUNCTION(Runtime_StringLessThan) {

HandleScope handle_scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, x, 0);

CONVERT_ARG_HANDLE_CHECKED(String, y, 1);

switch (String::Compare(x, y)) {

case ComparisonResult::kLessThan:

return isolate->heap()->true_value();

case ComparisonResult::kEqual:

case ComparisonResult::kGreaterThan:

return isolate->heap()->false_value();

case ComparisonResult::kUndefined:

break;

}

UNREACHABLE();

}

RUNTIME_FUNCTION(Runtime_StringLessThanOrEqual) {

HandleScope handle_scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, x, 0);

CONVERT_ARG_HANDLE_CHECKED(String, y, 1);

switch (String::Compare(x, y)) {

case ComparisonResult::kEqual:

case ComparisonResult::kLessThan:

return isolate->heap()->true_value();

case ComparisonResult::kGreaterThan:

return isolate->heap()->false_value();

case ComparisonResult::kUndefined:

break;

}

UNREACHABLE();

}

RUNTIME_FUNCTION(Runtime_StringGreaterThan) {

HandleScope handle_scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, x, 0);

CONVERT_ARG_HANDLE_CHECKED(String, y, 1);

switch (String::Compare(x, y)) {

case ComparisonResult::kGreaterThan:

return isolate->heap()->true_value();

case ComparisonResult::kEqual:

case ComparisonResult::kLessThan:

return isolate->heap()->false_value();

case ComparisonResult::kUndefined:

break;

}

UNREACHABLE();

}

RUNTIME_FUNCTION(Runtime_StringGreaterThanOrEqual) {

HandleScope handle_scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, x, 0);

CONVERT_ARG_HANDLE_CHECKED(String, y, 1);

switch (String::Compare(x, y)) {

case ComparisonResult::kEqual:

case ComparisonResult::kGreaterThan:

return isolate->heap()->true_value();

case ComparisonResult::kLessThan:

return isolate->heap()->false_value();

case ComparisonResult::kUndefined:

break;

}

UNREACHABLE();

}

RUNTIME_FUNCTION(Runtime_StringEqual) {

HandleScope handle_scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, x, 0);

CONVERT_ARG_HANDLE_CHECKED(String, y, 1);

return isolate->heap()->ToBoolean(String::Equals(x, y));

}

RUNTIME_FUNCTION(Runtime_StringNotEqual) {

HandleScope handle_scope(isolate);

DCHECK_EQ(2, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, x, 0);

CONVERT_ARG_HANDLE_CHECKED(String, y, 1);

return isolate->heap()->ToBoolean(!String::Equals(x, y));

}

RUNTIME_FUNCTION(Runtime_FlattenString) {

HandleScope scope(isolate);

DCHECK_EQ(1, args.length());

CONVERT_ARG_HANDLE_CHECKED(String, str, 0);

return *String::Flatten(str);

}

RUNTIME_FUNCTION(Runtime_StringCharFromCode) {

HandleScope handlescope(isolate);

DCHECK_EQ(1, args.length());

if (args[0]->IsNumber()) {

CONVERT_NUMBER_CHECKED(uint32_t, code, Uint32, args[0]);

code &= 0xffff;

return *isolate->factory()->LookupSingleCharacterStringFromCode(code);

}

return isolate->heap()->empty_string();

}

RUNTIME_FUNCTION(Runtime_StringMaxLength) {

SealHandleScope shs(isolate);

return Smi::FromInt(String::kMaxLength);

}

} // namespace internal

} // namespace v8