// Copyright 2011 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.
#ifndef V8_JSON_PARSER_H_
#define V8_JSON_PARSER_H_
#include "src/v8.h"
#include "src/char-predicates-inl.h"
#include "src/conversions.h"
#include "src/heap/spaces-inl.h"
#include "src/messages.h"
#include "src/token.h"
namespace v8 {
namespace internal {
// A simple json parser.
template <bool seq_one_byte>
class JsonParser BASE_EMBEDDED {
public:
MUST_USE_RESULT static MaybeHandle<Object> Parse(Handle<String> source) {
return JsonParser(source).ParseJson();
}
static const int kEndOfString = -1;
private:
explicit JsonParser(Handle<String> source)
: source_(source),
source_length_(source->length()),
isolate_(source->map()->GetHeap()->isolate()),
factory_(isolate_->factory()),
zone_(isolate_),
object_constructor_(isolate_->native_context()->object_function(),
isolate_),
position_(-1) {
source_ = String::Flatten(source_);
pretenure_ = (source_length_ >= kPretenureTreshold) ? TENURED : NOT_TENURED;
// Optimized fast case where we only have Latin1 characters.
if (seq_one_byte) {
seq_source_ = Handle<SeqOneByteString>::cast(source_);
}
}
// Parse a string containing a single JSON value.
MaybeHandle<Object> ParseJson();
inline void Advance() {
position_++;
if (position_ >= source_length_) {
c0_ = kEndOfString;
} else if (seq_one_byte) {
c0_ = seq_source_->SeqOneByteStringGet(position_);
} else {
c0_ = source_->Get(position_);
}
}
// The JSON lexical grammar is specified in the ECMAScript 5 standard,
// section 15.12.1.1. The only allowed whitespace characters between tokens
// are tab, carriage-return, newline and space.
inline void AdvanceSkipWhitespace() {
do {
Advance();
} while (c0_ == ' ' || c0_ == '\t' || c0_ == '\n' || c0_ == '\r');
}
inline void SkipWhitespace() {
while (c0_ == ' ' || c0_ == '\t' || c0_ == '\n' || c0_ == '\r') {
Advance();
}
}
inline uc32 AdvanceGetChar() {
Advance();
return c0_;
}
// Checks that current charater is c.
// If so, then consume c and skip whitespace.
inline bool MatchSkipWhiteSpace(uc32 c) {
if (c0_ == c) {
AdvanceSkipWhitespace();
return true;
}
return false;
}
// A JSON string (production JSONString) is subset of valid JavaScript string
// literals. The string must only be double-quoted (not single-quoted), and
// the only allowed backslash-escapes are ", /, \, b, f, n, r, t and
// four-digit hex escapes (uXXXX). Any other use of backslashes is invalid.
Handle<String> ParseJsonString() {
return ScanJsonString<false>();
}
bool ParseJsonString(Handle<String> expected) {
int length = expected->length();
if (source_->length() - position_ - 1 > length) {
DisallowHeapAllocation no_gc;
String::FlatContent content = expected->GetFlatContent();
if (content.IsOneByte()) {
DCHECK_EQ('"', c0_);
const uint8_t* input_chars = seq_source_->GetChars() + position_ + 1;
const uint8_t* expected_chars = content.ToOneByteVector().start();
for (int i = 0; i < length; i++) {
uint8_t c0 = input_chars[i];
if (c0 != expected_chars[i] ||
c0 == '"' || c0 < 0x20 || c0 == '\\') {
return false;
}
}
if (input_chars[length] == '"') {
position_ = position_ + length + 1;
AdvanceSkipWhitespace();
return true;
}
}
}
return false;
}
Handle<String> ParseJsonInternalizedString() {
return ScanJsonString<true>();
}
template <bool is_internalized>
Handle<String> ScanJsonString();
// Creates a new string and copies prefix[start..end] into the beginning
// of it. Then scans the rest of the string, adding characters after the
// prefix. Called by ScanJsonString when reaching a '\' or non-Latin1 char.
template <typename StringType, typename SinkChar>
Handle<String> SlowScanJsonString(Handle<String> prefix, int start, int end);
// A JSON number (production JSONNumber) is a subset of the valid JavaScript
// decimal number literals.
// It includes an optional minus sign, must have at least one
// digit before and after a decimal point, may not have prefixed zeros (unless
// the integer part is zero), and may include an exponent part (e.g., "e-10").
// Hexadecimal and octal numbers are not allowed.
Handle<Object> ParseJsonNumber();
// Parse a single JSON value from input (grammar production JSONValue).
// A JSON value is either a (double-quoted) string literal, a number literal,
// one of "true", "false", or "null", or an object or array literal.
Handle<Object> ParseJsonValue();
// Parse a JSON object literal (grammar production JSONObject).
// An object literal is a squiggly-braced and comma separated sequence
// (possibly empty) of key/value pairs, where the key is a JSON string
// literal, the value is a JSON value, and the two are separated by a colon.
// A JSON array doesn't allow numbers and identifiers as keys, like a
// JavaScript array.
Handle<Object> ParseJsonObject();
// Parses a JSON array literal (grammar production JSONArray). An array
// literal is a square-bracketed and comma separated sequence (possibly empty)
// of JSON values.
// A JSON array doesn't allow leaving out values from the sequence, nor does
// it allow a terminal comma, like a JavaScript array does.
Handle<Object> ParseJsonArray();
// Mark that a parsing error has happened at the current token, and
// return a null handle. Primarily for readability.
inline Handle<Object> ReportUnexpectedCharacter() {
return Handle<Object>::null();
}
inline Isolate* isolate() { return isolate_; }
inline Factory* factory() { return factory_; }
inline Handle<JSFunction> object_constructor() { return object_constructor_; }
static const int kInitialSpecialStringLength = 1024;
static const int kPretenureTreshold = 100 * 1024;
private:
Zone* zone() { return &zone_; }
void CommitStateToJsonObject(Handle<JSObject> json_object, Handle<Map> map,
ZoneList<Handle<Object> >* properties);
Handle<String> source_;
int source_length_;
Handle<SeqOneByteString> seq_source_;
PretenureFlag pretenure_;
Isolate* isolate_;
Factory* factory_;
Zone zone_;
Handle<JSFunction> object_constructor_;
uc32 c0_;
int position_;
};
template <bool seq_one_byte>
MaybeHandle<Object> JsonParser<seq_one_byte>::ParseJson() {
// Advance to the first character (possibly EOS)
AdvanceSkipWhitespace();
Handle<Object> result = ParseJsonValue();
if (result.is_null() || c0_ != kEndOfString) {
// Some exception (for example stack overflow) is already pending.
if (isolate_->has_pending_exception()) return Handle<Object>::null();
// Parse failed. Current character is the unexpected token.
const char* message;
Factory* factory = this->factory();
Handle<JSArray> array;
switch (c0_) {
case kEndOfString:
message = "unexpected_eos";
array = factory->NewJSArray(0);
break;
case '-':
case '0':
case '1':
case '2':
case '3':
case '4':
case '5':
case '6':
case '7':
case '8':
case '9':
message = "unexpected_token_number";
array = factory->NewJSArray(0);
break;
case '"':
message = "unexpected_token_string";
array = factory->NewJSArray(0);
break;
default:
message = "unexpected_token";
Handle<Object> name = factory->LookupSingleCharacterStringFromCode(c0_);
Handle<FixedArray> element = factory->NewFixedArray(1);
element->set(0, *name);
array = factory->NewJSArrayWithElements(element);
break;
}
MessageLocation location(factory->NewScript(source_),
position_,
position_ + 1);
Handle<Object> error;
ASSIGN_RETURN_ON_EXCEPTION(isolate(), error,
factory->NewSyntaxError(message, array), Object);
return isolate()->template Throw<Object>(error, &location);
}
return result;
}
// Parse any JSON value.
template <bool seq_one_byte>
Handle<Object> JsonParser<seq_one_byte>::ParseJsonValue() {
StackLimitCheck stack_check(isolate_);
if (stack_check.HasOverflowed()) {
isolate_->StackOverflow();
return Handle<Object>::null();
}
if (c0_ == '"') return ParseJsonString();
if ((c0_ >= '0' && c0_ <= '9') || c0_ == '-') return ParseJsonNumber();
if (c0_ == '{') return ParseJsonObject();
if (c0_ == '[') return ParseJsonArray();
if (c0_ == 'f') {
if (AdvanceGetChar() == 'a' && AdvanceGetChar() == 'l' &&
AdvanceGetChar() == 's' && AdvanceGetChar() == 'e') {
AdvanceSkipWhitespace();
return factory()->false_value();
}
return ReportUnexpectedCharacter();
}
if (c0_ == 't') {
if (AdvanceGetChar() == 'r' && AdvanceGetChar() == 'u' &&
AdvanceGetChar() == 'e') {
AdvanceSkipWhitespace();
return factory()->true_value();
}
return ReportUnexpectedCharacter();
}
if (c0_ == 'n') {
if (AdvanceGetChar() == 'u' && AdvanceGetChar() == 'l' &&
AdvanceGetChar() == 'l') {
AdvanceSkipWhitespace();
return factory()->null_value();
}
return ReportUnexpectedCharacter();
}
return ReportUnexpectedCharacter();
}
// Parse a JSON object. Position must be right at '{'.
template <bool seq_one_byte>
Handle<Object> JsonParser<seq_one_byte>::ParseJsonObject() {
HandleScope scope(isolate());
Handle<JSObject> json_object =
factory()->NewJSObject(object_constructor(), pretenure_);
Handle<Map> map(json_object->map());
ZoneList<Handle<Object> > properties(8, zone());
DCHECK_EQ(c0_, '{');
bool transitioning = true;
AdvanceSkipWhitespace();
if (c0_ != '}') {
do {
if (c0_ != '"') return ReportUnexpectedCharacter();
int start_position = position_;
Advance();
uint32_t index = 0;
if (c0_ >= '0' && c0_ <= '9') {
// Maybe an array index, try to parse it.
if (c0_ == '0') {
// With a leading zero, the string has to be "0" only to be an index.
Advance();
} else {
do {
int d = c0_ - '0';
if (index > 429496729U - ((d > 5) ? 1 : 0)) break;
index = (index * 10) + d;
Advance();
} while (c0_ >= '0' && c0_ <= '9');
}
if (c0_ == '"') {
// Successfully parsed index, parse and store element.
AdvanceSkipWhitespace();
if (c0_ != ':') return ReportUnexpectedCharacter();
AdvanceSkipWhitespace();
Handle<Object> value = ParseJsonValue();
if (value.is_null()) return ReportUnexpectedCharacter();
JSObject::SetOwnElement(json_object, index, value, SLOPPY).Assert();
continue;
}
// Not an index, fallback to the slow path.
}
position_ = start_position;
#ifdef DEBUG
c0_ = '"';
#endif
Handle<String> key;
Handle<Object> value;
// Try to follow existing transitions as long as possible. Once we stop
// transitioning, no transition can be found anymore.
if (transitioning) {
// First check whether there is a single expected transition. If so, try
// to parse it first.
bool follow_expected = false;
Handle<Map> target;
if (seq_one_byte) {
key = Map::ExpectedTransitionKey(map);
follow_expected = !key.is_null() && ParseJsonString(key);
}
// If the expected transition hits, follow it.
if (follow_expected) {
target = Map::ExpectedTransitionTarget(map);
} else {
// If the expected transition failed, parse an internalized string and
// try to find a matching transition.
key = ParseJsonInternalizedString();
if (key.is_null()) return ReportUnexpectedCharacter();
target = Map::FindTransitionToField(map, key);
// If a transition was found, follow it and continue.
transitioning = !target.is_null();
}
if (c0_ != ':') return ReportUnexpectedCharacter();
AdvanceSkipWhitespace();
value = ParseJsonValue();
if (value.is_null()) return ReportUnexpectedCharacter();
if (transitioning) {
int descriptor = map->NumberOfOwnDescriptors();
PropertyDetails details =
target->instance_descriptors()->GetDetails(descriptor);
Representation expected_representation = details.representation();
if (value->FitsRepresentation(expected_representation)) {
if (expected_representation.IsDouble()) {
value = Object::NewStorageFor(isolate(), value,
expected_representation);
} else if (expected_representation.IsHeapObject() &&
!target->instance_descriptors()->GetFieldType(
descriptor)->NowContains(value)) {
Handle<HeapType> value_type(value->OptimalType(
isolate(), expected_representation));
Map::GeneralizeFieldType(target, descriptor, value_type);
}
DCHECK(target->instance_descriptors()->GetFieldType(
descriptor)->NowContains(value));
properties.Add(value, zone());
map = target;
continue;
} else {
transitioning = false;
}
}
// Commit the intermediate state to the object and stop transitioning.
CommitStateToJsonObject(json_object, map, &properties);
} else {
key = ParseJsonInternalizedString();
if (key.is_null() || c0_ != ':') return ReportUnexpectedCharacter();
AdvanceSkipWhitespace();
value = ParseJsonValue();
if (value.is_null()) return ReportUnexpectedCharacter();
}
Runtime::DefineObjectProperty(json_object, key, value, NONE).Check();
} while (MatchSkipWhiteSpace(','));
if (c0_ != '}') {
return ReportUnexpectedCharacter();
}
// If we transitioned until the very end, transition the map now.
if (transitioning) {
CommitStateToJsonObject(json_object, map, &properties);
}
}
AdvanceSkipWhitespace();
return scope.CloseAndEscape(json_object);
}
template <bool seq_one_byte>
void JsonParser<seq_one_byte>::CommitStateToJsonObject(
Handle<JSObject> json_object, Handle<Map> map,
ZoneList<Handle<Object> >* properties) {
JSObject::AllocateStorageForMap(json_object, map);
DCHECK(!json_object->map()->is_dictionary_map());
DisallowHeapAllocation no_gc;
Factory* factory = isolate()->factory();
// If the |json_object|'s map is exactly the same as |map| then the
// |properties| values correspond to the |map| and nothing more has to be
// done. But if the |json_object|'s map is different then we have to
// iterate descriptors to ensure that properties still correspond to the
// map.
bool slow_case = json_object->map() != *map;
DescriptorArray* descriptors = NULL;
int length = properties->length();
if (slow_case) {
descriptors = json_object->map()->instance_descriptors();
DCHECK(json_object->map()->NumberOfOwnDescriptors() == length);
}
for (int i = 0; i < length; i++) {
Handle<Object> value = (*properties)[i];
if (slow_case && value->IsMutableHeapNumber() &&
!descriptors->GetDetails(i).representation().IsDouble()) {
// Turn mutable heap numbers into immutable if the field representation
// is not double.
HeapNumber::cast(*value)->set_map(*factory->heap_number_map());
}
FieldIndex index = FieldIndex::ForPropertyIndex(*map, i);
json_object->FastPropertyAtPut(index, *value);
}
}
// Parse a JSON array. Position must be right at '['.
template <bool seq_one_byte>
Handle<Object> JsonParser<seq_one_byte>::ParseJsonArray() {
HandleScope scope(isolate());
ZoneList<Handle<Object> > elements(4, zone());
DCHECK_EQ(c0_, '[');
AdvanceSkipWhitespace();
if (c0_ != ']') {
do {
Handle<Object> element = ParseJsonValue();
if (element.is_null()) return ReportUnexpectedCharacter();
elements.Add(element, zone());
} while (MatchSkipWhiteSpace(','));
if (c0_ != ']') {
return ReportUnexpectedCharacter();
}
}
AdvanceSkipWhitespace();
// Allocate a fixed array with all the elements.
Handle<FixedArray> fast_elements =
factory()->NewFixedArray(elements.length(), pretenure_);
for (int i = 0, n = elements.length(); i < n; i++) {
fast_elements->set(i, *elements[i]);
}
Handle<Object> json_array = factory()->NewJSArrayWithElements(
fast_elements, FAST_ELEMENTS, pretenure_);
return scope.CloseAndEscape(json_array);
}
template <bool seq_one_byte>
Handle<Object> JsonParser<seq_one_byte>::ParseJsonNumber() {
bool negative = false;
int beg_pos = position_;
if (c0_ == '-') {
Advance();
negative = true;
}
if (c0_ == '0') {
Advance();
// Prefix zero is only allowed if it's the only digit before
// a decimal point or exponent.
if ('0' <= c0_ && c0_ <= '9') return ReportUnexpectedCharacter();
} else {
int i = 0;
int digits = 0;
if (c0_ < '1' || c0_ > '9') return ReportUnexpectedCharacter();
do {
i = i * 10 + c0_ - '0';
digits++;
Advance();
} while (c0_ >= '0' && c0_ <= '9');
if (c0_ != '.' && c0_ != 'e' && c0_ != 'E' && digits < 10) {
SkipWhitespace();
return Handle<Smi>(Smi::FromInt((negative ? -i : i)), isolate());
}
}
if (c0_ == '.') {
Advance();
if (c0_ < '0' || c0_ > '9') return ReportUnexpectedCharacter();
do {
Advance();
} while (c0_ >= '0' && c0_ <= '9');
}
if (AsciiAlphaToLower(c0_) == 'e') {
Advance();
if (c0_ == '-' || c0_ == '+') Advance();
if (c0_ < '0' || c0_ > '9') return ReportUnexpectedCharacter();
do {
Advance();
} while (c0_ >= '0' && c0_ <= '9');
}
int length = position_ - beg_pos;
double number;
if (seq_one_byte) {
Vector<const uint8_t> chars(seq_source_->GetChars() + beg_pos, length);
number = StringToDouble(isolate()->unicode_cache(),
chars,
NO_FLAGS, // Hex, octal or trailing junk.
base::OS::nan_value());
} else {
Vector<uint8_t> buffer = Vector<uint8_t>::New(length);
String::WriteToFlat(*source_, buffer.start(), beg_pos, position_);
Vector<const uint8_t> result =
Vector<const uint8_t>(buffer.start(), length);
number = StringToDouble(isolate()->unicode_cache(),
result,
NO_FLAGS, // Hex, octal or trailing junk.
0.0);
buffer.Dispose();
}
SkipWhitespace();
return factory()->NewNumber(number, pretenure_);
}
template <typename StringType>
inline void SeqStringSet(Handle<StringType> seq_str, int i, uc32 c);
template <>
inline void SeqStringSet(Handle<SeqTwoByteString> seq_str, int i, uc32 c) {
seq_str->SeqTwoByteStringSet(i, c);
}
template <>
inline void SeqStringSet(Handle<SeqOneByteString> seq_str, int i, uc32 c) {
seq_str->SeqOneByteStringSet(i, c);
}
template <typename StringType>
inline Handle<StringType> NewRawString(Factory* factory,
int length,
PretenureFlag pretenure);
template <>
inline Handle<SeqTwoByteString> NewRawString(Factory* factory,
int length,
PretenureFlag pretenure) {
return factory->NewRawTwoByteString(length, pretenure).ToHandleChecked();
}
template <>
inline Handle<SeqOneByteString> NewRawString(Factory* factory,
int length,
PretenureFlag pretenure) {
return factory->NewRawOneByteString(length, pretenure).ToHandleChecked();
}
// Scans the rest of a JSON string starting from position_ and writes
// prefix[start..end] along with the scanned characters into a
// sequential string of type StringType.
template <bool seq_one_byte>
template <typename StringType, typename SinkChar>
Handle<String> JsonParser<seq_one_byte>::SlowScanJsonString(
Handle<String> prefix, int start, int end) {
int count = end - start;
int max_length = count + source_length_ - position_;
int length = Min(max_length, Max(kInitialSpecialStringLength, 2 * count));
Handle<StringType> seq_string =
NewRawString<StringType>(factory(), length, pretenure_);
// Copy prefix into seq_str.
SinkChar* dest = seq_string->GetChars();
String::WriteToFlat(*prefix, dest, start, end);
while (c0_ != '"') {
// Check for control character (0x00-0x1f) or unterminated string (<0).
if (c0_ < 0x20) return Handle<String>::null();
if (count >= length) {
// We need to create a longer sequential string for the result.
return SlowScanJsonString<StringType, SinkChar>(seq_string, 0, count);
}
if (c0_ != '\\') {
// If the sink can contain UC16 characters, or source_ contains only
// Latin1 characters, there's no need to test whether we can store the
// character. Otherwise check whether the UC16 source character can fit
// in the Latin1 sink.
if (sizeof(SinkChar) == kUC16Size || seq_one_byte ||
c0_ <= String::kMaxOneByteCharCode) {
SeqStringSet(seq_string, count++, c0_);
Advance();
} else {
// StringType is SeqOneByteString and we just read a non-Latin1 char.
return SlowScanJsonString<SeqTwoByteString, uc16>(seq_string, 0, count);
}
} else {
Advance(); // Advance past the \.
switch (c0_) {
case '"':
case '\\':
case '/':
SeqStringSet(seq_string, count++, c0_);
break;
case 'b':
SeqStringSet(seq_string, count++, '\x08');
break;
case 'f':
SeqStringSet(seq_string, count++, '\x0c');
break;
case 'n':
SeqStringSet(seq_string, count++, '\x0a');
break;
case 'r':
SeqStringSet(seq_string, count++, '\x0d');
break;
case 't':
SeqStringSet(seq_string, count++, '\x09');
break;
case 'u': {
uc32 value = 0;
for (int i = 0; i < 4; i++) {
Advance();
int digit = HexValue(c0_);
if (digit < 0) {
return Handle<String>::null();
}
value = value * 16 + digit;
}
if (sizeof(SinkChar) == kUC16Size ||
value <= String::kMaxOneByteCharCode) {
SeqStringSet(seq_string, count++, value);
break;
} else {
// StringType is SeqOneByteString and we just read a non-Latin1
// char.
position_ -= 6; // Rewind position_ to \ in \uxxxx.
Advance();
return SlowScanJsonString<SeqTwoByteString, uc16>(seq_string,
0,
count);
}
}
default:
return Handle<String>::null();
}
Advance();
}
}
DCHECK_EQ('"', c0_);
// Advance past the last '"'.
AdvanceSkipWhitespace();
// Shrink seq_string length to count and return.
return SeqString::Truncate(seq_string, count);
}
template <bool seq_one_byte>
template <bool is_internalized>
Handle<String> JsonParser<seq_one_byte>::ScanJsonString() {
DCHECK_EQ('"', c0_);
Advance();
if (c0_ == '"') {
AdvanceSkipWhitespace();
return factory()->empty_string();
}
if (seq_one_byte && is_internalized) {
// Fast path for existing internalized strings. If the the string being
// parsed is not a known internalized string, contains backslashes or
// unexpectedly reaches the end of string, return with an empty handle.
uint32_t running_hash = isolate()->heap()->HashSeed();
int position = position_;
uc32 c0 = c0_;
do {
if (c0 == '\\') {
c0_ = c0;
int beg_pos = position_;
position_ = position;
return SlowScanJsonString<SeqOneByteString, uint8_t>(source_,
beg_pos,
position_);
}
if (c0 < 0x20) return Handle<String>::null();
if (static_cast<uint32_t>(c0) >
unibrow::Utf16::kMaxNonSurrogateCharCode) {
running_hash =
StringHasher::AddCharacterCore(running_hash,
unibrow::Utf16::LeadSurrogate(c0));
running_hash =
StringHasher::AddCharacterCore(running_hash,
unibrow::Utf16::TrailSurrogate(c0));
} else {
running_hash = StringHasher::AddCharacterCore(running_hash, c0);
}
position++;
if (position >= source_length_) return Handle<String>::null();
c0 = seq_source_->SeqOneByteStringGet(position);
} while (c0 != '"');
int length = position - position_;
uint32_t hash = (length <= String::kMaxHashCalcLength)
? StringHasher::GetHashCore(running_hash)
: static_cast<uint32_t>(length);
Vector<const uint8_t> string_vector(
seq_source_->GetChars() + position_, length);
StringTable* string_table = isolate()->heap()->string_table();
uint32_t capacity = string_table->Capacity();
uint32_t entry = StringTable::FirstProbe(hash, capacity);
uint32_t count = 1;
Handle<String> result;
while (true) {
Object* element = string_table->KeyAt(entry);
if (element == isolate()->heap()->undefined_value()) {
// Lookup failure.
result = factory()->InternalizeOneByteString(
seq_source_, position_, length);
break;
}
if (element != isolate()->heap()->the_hole_value() &&
String::cast(element)->IsOneByteEqualTo(string_vector)) {
result = Handle<String>(String::cast(element), isolate());
#ifdef DEBUG
uint32_t hash_field =
(hash << String::kHashShift) | String::kIsNotArrayIndexMask;
DCHECK_EQ(static_cast<int>(result->Hash()),
static_cast<int>(hash_field >> String::kHashShift));
#endif
break;
}
entry = StringTable::NextProbe(entry, count++, capacity);
}
position_ = position;
// Advance past the last '"'.
AdvanceSkipWhitespace();
return result;
}
int beg_pos = position_;
// Fast case for Latin1 only without escape characters.
do {
// Check for control character (0x00-0x1f) or unterminated string (<0).
if (c0_ < 0x20) return Handle<String>::null();
if (c0_ != '\\') {
if (seq_one_byte || c0_ <= String::kMaxOneByteCharCode) {
Advance();
} else {
return SlowScanJsonString<SeqTwoByteString, uc16>(source_,
beg_pos,
position_);
}
} else {
return SlowScanJsonString<SeqOneByteString, uint8_t>(source_,
beg_pos,
position_);
}
} while (c0_ != '"');
int length = position_ - beg_pos;
Handle<String> result =
factory()->NewRawOneByteString(length, pretenure_).ToHandleChecked();
uint8_t* dest = SeqOneByteString::cast(*result)->GetChars();
String::WriteToFlat(*source_, dest, beg_pos, position_);
DCHECK_EQ('"', c0_);
// Advance past the last '"'.
AdvanceSkipWhitespace();
return result;
}
} } // namespace v8::internal
#endif // V8_JSON_PARSER_H_