| // Copyright 2016 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/json-parser.h" |
| |
| #include "src/char-predicates-inl.h" |
| #include "src/conversions.h" |
| #include "src/debug/debug.h" |
| #include "src/field-type.h" |
| #include "src/messages.h" |
| #include "src/objects-inl.h" |
| #include "src/objects/hash-table-inl.h" |
| #include "src/property-descriptor.h" |
| #include "src/string-hasher.h" |
| #include "src/transitions.h" |
| #include "src/unicode-cache.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| namespace { |
| |
| // A vector-like data structure that uses a larger vector for allocation, and |
| // provides limited utility access. The original vector must not be used for the |
| // duration, and it may even be reallocated. This allows vector storage to be |
| // reused for the properties of sibling objects. |
| template <typename Container> |
| class VectorSegment { |
| public: |
| using value_type = typename Container::value_type; |
| |
| explicit VectorSegment(Container* container) |
| : container_(*container), begin_(container->size()) {} |
| ~VectorSegment() { container_.resize(begin_); } |
| |
| Vector<const value_type> GetVector() const { |
| return Vector<const value_type>(container_.data() + begin_, |
| container_.size() - begin_); |
| } |
| |
| template <typename T> |
| void push_back(T&& value) { |
| container_.push_back(std::forward<T>(value)); |
| } |
| |
| private: |
| Container& container_; |
| const typename Container::size_type begin_; |
| }; |
| |
| } // namespace |
| |
| MaybeHandle<Object> JsonParseInternalizer::Internalize(Isolate* isolate, |
| Handle<Object> object, |
| Handle<Object> reviver) { |
| DCHECK(reviver->IsCallable()); |
| JsonParseInternalizer internalizer(isolate, |
| Handle<JSReceiver>::cast(reviver)); |
| Handle<JSObject> holder = |
| isolate->factory()->NewJSObject(isolate->object_function()); |
| Handle<String> name = isolate->factory()->empty_string(); |
| JSObject::AddProperty(isolate, holder, name, object, NONE); |
| return internalizer.InternalizeJsonProperty(holder, name); |
| } |
| |
| MaybeHandle<Object> JsonParseInternalizer::InternalizeJsonProperty( |
| Handle<JSReceiver> holder, Handle<String> name) { |
| HandleScope outer_scope(isolate_); |
| Handle<Object> value; |
| ASSIGN_RETURN_ON_EXCEPTION( |
| isolate_, value, Object::GetPropertyOrElement(isolate_, holder, name), |
| Object); |
| if (value->IsJSReceiver()) { |
| Handle<JSReceiver> object = Handle<JSReceiver>::cast(value); |
| Maybe<bool> is_array = Object::IsArray(object); |
| if (is_array.IsNothing()) return MaybeHandle<Object>(); |
| if (is_array.FromJust()) { |
| Handle<Object> length_object; |
| ASSIGN_RETURN_ON_EXCEPTION( |
| isolate_, length_object, |
| Object::GetLengthFromArrayLike(isolate_, object), Object); |
| double length = length_object->Number(); |
| for (double i = 0; i < length; i++) { |
| HandleScope inner_scope(isolate_); |
| Handle<Object> index = isolate_->factory()->NewNumber(i); |
| Handle<String> name = isolate_->factory()->NumberToString(index); |
| if (!RecurseAndApply(object, name)) return MaybeHandle<Object>(); |
| } |
| } else { |
| Handle<FixedArray> contents; |
| ASSIGN_RETURN_ON_EXCEPTION( |
| isolate_, contents, |
| KeyAccumulator::GetKeys(object, KeyCollectionMode::kOwnOnly, |
| ENUMERABLE_STRINGS, |
| GetKeysConversion::kConvertToString), |
| Object); |
| for (int i = 0; i < contents->length(); i++) { |
| HandleScope inner_scope(isolate_); |
| Handle<String> name(String::cast(contents->get(i)), isolate_); |
| if (!RecurseAndApply(object, name)) return MaybeHandle<Object>(); |
| } |
| } |
| } |
| Handle<Object> argv[] = {name, value}; |
| Handle<Object> result; |
| ASSIGN_RETURN_ON_EXCEPTION( |
| isolate_, result, Execution::Call(isolate_, reviver_, holder, 2, argv), |
| Object); |
| return outer_scope.CloseAndEscape(result); |
| } |
| |
| bool JsonParseInternalizer::RecurseAndApply(Handle<JSReceiver> holder, |
| Handle<String> name) { |
| STACK_CHECK(isolate_, false); |
| |
| Handle<Object> result; |
| ASSIGN_RETURN_ON_EXCEPTION_VALUE( |
| isolate_, result, InternalizeJsonProperty(holder, name), false); |
| Maybe<bool> change_result = Nothing<bool>(); |
| if (result->IsUndefined(isolate_)) { |
| change_result = JSReceiver::DeletePropertyOrElement(holder, name, |
| LanguageMode::kSloppy); |
| } else { |
| PropertyDescriptor desc; |
| desc.set_value(result); |
| desc.set_configurable(true); |
| desc.set_enumerable(true); |
| desc.set_writable(true); |
| change_result = JSReceiver::DefineOwnProperty(isolate_, holder, name, &desc, |
| kDontThrow); |
| } |
| MAYBE_RETURN(change_result, false); |
| return true; |
| } |
| |
| template <bool seq_one_byte> |
| JsonParser<seq_one_byte>::JsonParser(Isolate* isolate, Handle<String> source) |
| : source_(source), |
| source_length_(source->length()), |
| isolate_(isolate), |
| zone_(isolate_->allocator(), ZONE_NAME), |
| object_constructor_(isolate_->native_context()->object_function(), |
| isolate_), |
| position_(-1), |
| properties_(&zone_) { |
| source_ = String::Flatten(isolate, 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_); |
| } |
| } |
| |
| 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. |
| Factory* factory = this->factory(); |
| MessageTemplate::Template message; |
| Handle<Object> arg1 = Handle<Smi>(Smi::FromInt(position_), isolate()); |
| Handle<Object> arg2; |
| |
| switch (c0_) { |
| case kEndOfString: |
| message = MessageTemplate::kJsonParseUnexpectedEOS; |
| break; |
| case '-': |
| case '0': |
| case '1': |
| case '2': |
| case '3': |
| case '4': |
| case '5': |
| case '6': |
| case '7': |
| case '8': |
| case '9': |
| message = MessageTemplate::kJsonParseUnexpectedTokenNumber; |
| break; |
| case '"': |
| message = MessageTemplate::kJsonParseUnexpectedTokenString; |
| break; |
| default: |
| message = MessageTemplate::kJsonParseUnexpectedToken; |
| arg2 = arg1; |
| arg1 = factory->LookupSingleCharacterStringFromCode(c0_); |
| break; |
| } |
| |
| Handle<Script> script(factory->NewScript(source_)); |
| if (isolate()->NeedsSourcePositionsForProfiling()) { |
| Script::InitLineEnds(script); |
| } |
| // We should sent compile error event because we compile JSON object in |
| // separated source file. |
| isolate()->debug()->OnCompileError(script); |
| MessageLocation location(script, position_, position_ + 1); |
| Handle<Object> error = factory->NewSyntaxError(message, arg1, arg2); |
| return isolate()->template Throw<Object>(error, &location); |
| } |
| return result; |
| } |
| |
| MaybeHandle<Object> InternalizeJsonProperty(Handle<JSObject> holder, |
| Handle<String> key); |
| |
| template <bool seq_one_byte> |
| void JsonParser<seq_one_byte>::Advance() { |
| position_++; |
| if (position_ >= source_length_) { |
| c0_ = kEndOfString; |
| } else if (seq_one_byte) { |
| c0_ = seq_source_->SeqOneByteStringGet(position_); |
| } else { |
| c0_ = source_->Get(position_); |
| } |
| } |
| |
| template <bool seq_one_byte> |
| void JsonParser<seq_one_byte>::AdvanceSkipWhitespace() { |
| do { |
| Advance(); |
| } while (c0_ == ' ' || c0_ == '\t' || c0_ == '\n' || c0_ == '\r'); |
| } |
| |
| template <bool seq_one_byte> |
| void JsonParser<seq_one_byte>::SkipWhitespace() { |
| while (c0_ == ' ' || c0_ == '\t' || c0_ == '\n' || c0_ == '\r') { |
| Advance(); |
| } |
| } |
| |
| template <bool seq_one_byte> |
| uc32 JsonParser<seq_one_byte>::AdvanceGetChar() { |
| Advance(); |
| return c0_; |
| } |
| |
| template <bool seq_one_byte> |
| bool JsonParser<seq_one_byte>::MatchSkipWhiteSpace(uc32 c) { |
| if (c0_ == c) { |
| AdvanceSkipWhitespace(); |
| return true; |
| } |
| return false; |
| } |
| |
| template <bool seq_one_byte> |
| bool JsonParser<seq_one_byte>::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; |
| } |
| |
| // 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 (stack_check.InterruptRequested() && |
| isolate_->stack_guard()->HandleInterrupts()->IsException(isolate_)) { |
| 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(); |
| } |
| |
| template <bool seq_one_byte> |
| ParseElementResult JsonParser<seq_one_byte>::ParseElement( |
| Handle<JSObject> json_object) { |
| uint32_t index = 0; |
| // 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 + 3) >> 3)) break; |
| index = (index * 10) + d; |
| Advance(); |
| } while (IsDecimalDigit(c0_)); |
| } |
| |
| if (c0_ == '"') { |
| // Successfully parsed index, parse and store element. |
| AdvanceSkipWhitespace(); |
| |
| if (c0_ == ':') { |
| AdvanceSkipWhitespace(); |
| Handle<Object> value = ParseJsonValue(); |
| if (!value.is_null()) { |
| JSObject::SetOwnElementIgnoreAttributes(json_object, index, value, NONE) |
| .Assert(); |
| return kElementFound; |
| } else { |
| return kNullHandle; |
| } |
| } |
| } |
| return kElementNotFound; |
| } |
| |
| // 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(), isolate()); |
| int descriptor = 0; |
| VectorSegment<ZoneVector<Handle<Object>>> properties(&properties_); |
| DCHECK_EQ(c0_, '{'); |
| |
| bool transitioning = true; |
| |
| AdvanceSkipWhitespace(); |
| if (c0_ != '}') { |
| do { |
| if (c0_ != '"') return ReportUnexpectedCharacter(); |
| |
| int start_position = position_; |
| Advance(); |
| |
| if (IsDecimalDigit(c0_)) { |
| ParseElementResult element_result = ParseElement(json_object); |
| if (element_result == kNullHandle) return Handle<Object>::null(); |
| if (element_result == kElementFound) 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. |
| DCHECK(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) { |
| DisallowHeapAllocation no_gc; |
| TransitionsAccessor transitions(isolate(), *map, &no_gc); |
| key = transitions.ExpectedTransitionKey(); |
| follow_expected = !key.is_null() && ParseJsonString(key); |
| // If the expected transition hits, follow it. |
| if (follow_expected) { |
| target = transitions.ExpectedTransitionTarget(); |
| } |
| } |
| if (!follow_expected) { |
| // If the expected transition failed, parse an internalized string and |
| // try to find a matching transition. |
| key = ParseJsonString(); |
| if (key.is_null()) return ReportUnexpectedCharacter(); |
| |
| // If a transition was found, follow it and continue. |
| transitioning = TransitionsAccessor(isolate(), map) |
| .FindTransitionToField(key) |
| .ToHandle(&target); |
| } |
| if (c0_ != ':') return ReportUnexpectedCharacter(); |
| |
| AdvanceSkipWhitespace(); |
| value = ParseJsonValue(); |
| if (value.is_null()) return ReportUnexpectedCharacter(); |
| |
| if (transitioning) { |
| PropertyDetails details = |
| target->instance_descriptors()->GetDetails(descriptor); |
| Representation expected_representation = details.representation(); |
| |
| if (value->FitsRepresentation(expected_representation)) { |
| if (expected_representation.IsHeapObject() && |
| !target->instance_descriptors() |
| ->GetFieldType(descriptor) |
| ->NowContains(value)) { |
| Handle<FieldType> value_type( |
| value->OptimalType(isolate(), expected_representation)); |
| Map::GeneralizeField(isolate(), target, descriptor, |
| details.constness(), expected_representation, |
| value_type); |
| } |
| DCHECK(target->instance_descriptors() |
| ->GetFieldType(descriptor) |
| ->NowContains(value)); |
| properties.push_back(value); |
| map = target; |
| descriptor++; |
| continue; |
| } else { |
| transitioning = false; |
| } |
| } |
| |
| DCHECK(!transitioning); |
| |
| // Commit the intermediate state to the object and stop transitioning. |
| CommitStateToJsonObject(json_object, map, properties.GetVector()); |
| |
| JSObject::DefinePropertyOrElementIgnoreAttributes(json_object, key, value) |
| .Check(); |
| } while (transitioning && MatchSkipWhiteSpace(',')); |
| |
| // If we transitioned until the very end, transition the map now. |
| if (transitioning) { |
| CommitStateToJsonObject(json_object, map, properties.GetVector()); |
| } else { |
| while (MatchSkipWhiteSpace(',')) { |
| HandleScope local_scope(isolate()); |
| if (c0_ != '"') return ReportUnexpectedCharacter(); |
| |
| int start_position = position_; |
| Advance(); |
| |
| if (IsDecimalDigit(c0_)) { |
| ParseElementResult element_result = ParseElement(json_object); |
| if (element_result == kNullHandle) return Handle<Object>::null(); |
| if (element_result == kElementFound) continue; |
| } |
| // Not an index, fallback to the slow path. |
| |
| position_ = start_position; |
| #ifdef DEBUG |
| c0_ = '"'; |
| #endif |
| |
| Handle<String> key; |
| Handle<Object> value; |
| |
| key = ParseJsonString(); |
| if (key.is_null() || c0_ != ':') return ReportUnexpectedCharacter(); |
| |
| AdvanceSkipWhitespace(); |
| value = ParseJsonValue(); |
| if (value.is_null()) return ReportUnexpectedCharacter(); |
| |
| JSObject::DefinePropertyOrElementIgnoreAttributes(json_object, key, |
| value) |
| .Check(); |
| } |
| } |
| |
| if (c0_ != '}') { |
| return ReportUnexpectedCharacter(); |
| } |
| } |
| AdvanceSkipWhitespace(); |
| return scope.CloseAndEscape(json_object); |
| } |
| |
| template <bool seq_one_byte> |
| void JsonParser<seq_one_byte>::CommitStateToJsonObject( |
| Handle<JSObject> json_object, Handle<Map> map, |
| Vector<const Handle<Object>> properties) { |
| JSObject::AllocateStorageForMap(json_object, map); |
| DCHECK(!json_object->map()->is_dictionary_map()); |
| |
| DisallowHeapAllocation no_gc; |
| DescriptorArray* descriptors = json_object->map()->instance_descriptors(); |
| for (int i = 0; i < properties.length(); i++) { |
| Handle<Object> value = properties[i]; |
| // Initializing store. |
| json_object->WriteToField(i, descriptors->GetDetails(i), *value); |
| } |
| } |
| |
| class ElementKindLattice { |
| private: |
| enum { |
| SMI_ELEMENTS, |
| NUMBER_ELEMENTS, |
| OBJECT_ELEMENTS, |
| }; |
| |
| public: |
| ElementKindLattice() : value_(SMI_ELEMENTS) {} |
| |
| void Update(Handle<Object> o) { |
| if (o->IsSmi()) { |
| return; |
| } else if (o->IsHeapNumber()) { |
| if (value_ < NUMBER_ELEMENTS) value_ = NUMBER_ELEMENTS; |
| } else { |
| DCHECK(!o->IsNumber()); |
| value_ = OBJECT_ELEMENTS; |
| } |
| } |
| |
| ElementsKind GetElementsKind() const { |
| switch (value_) { |
| case SMI_ELEMENTS: |
| return PACKED_SMI_ELEMENTS; |
| case NUMBER_ELEMENTS: |
| return PACKED_DOUBLE_ELEMENTS; |
| case OBJECT_ELEMENTS: |
| return PACKED_ELEMENTS; |
| default: |
| UNREACHABLE(); |
| return PACKED_ELEMENTS; |
| } |
| } |
| |
| private: |
| int 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()); |
| ZoneVector<Handle<Object>> elements(zone()); |
| DCHECK_EQ(c0_, '['); |
| |
| ElementKindLattice lattice; |
| |
| AdvanceSkipWhitespace(); |
| if (c0_ != ']') { |
| do { |
| Handle<Object> element = ParseJsonValue(); |
| if (element.is_null()) return ReportUnexpectedCharacter(); |
| elements.push_back(element); |
| lattice.Update(element); |
| } while (MatchSkipWhiteSpace(',')); |
| if (c0_ != ']') { |
| return ReportUnexpectedCharacter(); |
| } |
| } |
| AdvanceSkipWhitespace(); |
| |
| // Allocate a fixed array with all the elements. |
| |
| Handle<Object> json_array; |
| const ElementsKind kind = lattice.GetElementsKind(); |
| int elements_size = static_cast<int>(elements.size()); |
| |
| switch (kind) { |
| case PACKED_ELEMENTS: |
| case PACKED_SMI_ELEMENTS: { |
| Handle<FixedArray> elems = |
| factory()->NewFixedArray(elements_size, pretenure_); |
| for (int i = 0; i < elements_size; i++) elems->set(i, *elements[i]); |
| json_array = factory()->NewJSArrayWithElements(elems, kind, pretenure_); |
| break; |
| } |
| case PACKED_DOUBLE_ELEMENTS: { |
| Handle<FixedDoubleArray> elems = Handle<FixedDoubleArray>::cast( |
| factory()->NewFixedDoubleArray(elements_size, pretenure_)); |
| for (int i = 0; i < elements_size; i++) { |
| elems->set(i, elements[i]->Number()); |
| } |
| json_array = factory()->NewJSArrayWithElements(elems, kind, pretenure_); |
| break; |
| } |
| default: |
| UNREACHABLE(); |
| } |
| |
| 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 (IsDecimalDigit(c0_)) 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 (IsDecimalDigit(c0_)); |
| if (c0_ != '.' && c0_ != 'e' && c0_ != 'E' && digits < 10) { |
| SkipWhitespace(); |
| return Handle<Smi>(Smi::FromInt((negative ? -i : i)), isolate()); |
| } |
| } |
| if (c0_ == '.') { |
| Advance(); |
| if (!IsDecimalDigit(c0_)) return ReportUnexpectedCharacter(); |
| do { |
| Advance(); |
| } while (IsDecimalDigit(c0_)); |
| } |
| if (AsciiAlphaToLower(c0_) == 'e') { |
| Advance(); |
| if (c0_ == '-' || c0_ == '+') Advance(); |
| if (!IsDecimalDigit(c0_)) return ReportUnexpectedCharacter(); |
| do { |
| Advance(); |
| } while (IsDecimalDigit(c0_)); |
| } |
| 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. |
| std::numeric_limits<double>::quiet_NaN()); |
| } 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> |
| Handle<String> JsonParser<seq_one_byte>::ScanJsonString() { |
| DCHECK_EQ('"', c0_); |
| Advance(); |
| if (c0_ == '"') { |
| AdvanceSkipWhitespace(); |
| return factory()->empty_string(); |
| } |
| |
| if (seq_one_byte) { |
| // 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. |
| |
| // We intentionally use local variables instead of fields, compute hash |
| // while we are iterating a string and manually inline StringTable lookup |
| // here. |
| |
| int position = position_; |
| uc32 c0 = c0_; |
| uint32_t running_hash = |
| static_cast<uint32_t>(isolate()->heap()->HashSeed()); |
| uint32_t index = 0; |
| bool is_array_index = true; |
| |
| do { |
| if (c0 == '\\') { |
| c0_ = c0; |
| int beg_pos = position_; |
| position_ = position; |
| return SlowScanJsonString<SeqOneByteString, uint8_t>(source_, beg_pos, |
| position_); |
| } |
| if (c0 < 0x20) { |
| c0_ = c0; |
| position_ = position; |
| return Handle<String>::null(); |
| } |
| if (is_array_index) { |
| // With leading zero, the string has to be "0" to be a valid index. |
| if (!IsDecimalDigit(c0) || (position > position_ && index == 0)) { |
| is_array_index = false; |
| } else { |
| int d = c0 - '0'; |
| is_array_index = index <= 429496729U - ((d + 3) >> 3); |
| index = (index * 10) + d; |
| } |
| } |
| running_hash = StringHasher::AddCharacterCore(running_hash, |
| static_cast<uint16_t>(c0)); |
| position++; |
| if (position >= source_length_) { |
| c0_ = kEndOfString; |
| position_ = position; |
| return Handle<String>::null(); |
| } |
| c0 = seq_source_->SeqOneByteStringGet(position); |
| } while (c0 != '"'); |
| int length = position - position_; |
| uint32_t hash; |
| if (is_array_index) { |
| hash = |
| StringHasher::MakeArrayIndexHash(index, length) >> String::kHashShift; |
| } else if (length <= String::kMaxHashCalcLength) { |
| hash = StringHasher::GetHashCore(running_hash); |
| } else { |
| 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->IsUndefined(isolate())) { |
| // Lookup failure. |
| result = |
| factory()->InternalizeOneByteString(seq_source_, position_, length); |
| break; |
| } |
| if (!element->IsTheHole(isolate()) && |
| String::cast(element)->IsOneByteEqualTo(string_vector)) { |
| result = Handle<String>(String::cast(element), isolate()); |
| DCHECK_EQ(result->Hash(), |
| (hash << String::kHashShift) >> String::kHashShift); |
| 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; |
| } |
| |
| // Explicit instantiation. |
| template class JsonParser<true>; |
| template class JsonParser<false>; |
| |
| } // namespace internal |
| } // namespace v8 |
