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Diffstat (limited to 'deps/v8/src/json-parser.cc')
| -rw-r--r-- | deps/v8/src/json-parser.cc | 959 |
1 files changed, 0 insertions, 959 deletions
diff --git a/deps/v8/src/json-parser.cc b/deps/v8/src/json-parser.cc deleted file mode 100644 index a8a272ca4f..0000000000 --- a/deps/v8/src/json-parser.cc +++ /dev/null @@ -1,959 +0,0 @@ -// 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/hash-seed-inl.h" -#include "src/heap/heap-inl.h" // For string_table(). -#include "src/message-template.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" - -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 VectorOf(container_) + 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, - Just(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_); - allocation_ = (source_length_ >= kPretenureTreshold) ? AllocationType::kOld - : AllocationType::kYoung; - - // 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 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(no_gc); - if (content.IsOneByte()) { - DCHECK_EQ('"', c0_); - const uint8_t* input_chars = seq_source_->GetChars(no_gc) + 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(), allocation_); - 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, allocation_); - for (int i = 0; i < elements_size; i++) elems->set(i, *elements[i]); - json_array = factory()->NewJSArrayWithElements(elems, kind, allocation_); - break; - } - case PACKED_DOUBLE_ELEMENTS: { - Handle<FixedDoubleArray> elems = Handle<FixedDoubleArray>::cast( - factory()->NewFixedDoubleArray(elements_size, allocation_)); - for (int i = 0; i < elements_size; i++) { - elems->set(i, elements[i]->Number()); - } - json_array = factory()->NewJSArrayWithElements(elems, kind, allocation_); - 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 { - uint32_t i = 0; - int digits = 0; - if (c0_ < '1' || c0_ > '9') return ReportUnexpectedCharacter(); - do { - // This can overflow. That's OK, the "digits < 10" check below - // will discard overflown results. - 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 ? -static_cast<int>(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) { - DisallowHeapAllocation no_gc; - Vector<const uint8_t> chars(seq_source_->GetChars(no_gc) + beg_pos, length); - number = StringToDouble(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(result, - NO_FLAGS, // Hex, octal or trailing junk. - 0.0); - buffer.Dispose(); - } - SkipWhitespace(); - return factory()->NewNumber(number, allocation_); -} - -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, - AllocationType allocation); - -template <> -inline Handle<SeqTwoByteString> NewRawString(Factory* factory, int length, - AllocationType allocation) { - return factory->NewRawTwoByteString(length, allocation).ToHandleChecked(); -} - -template <> -inline Handle<SeqOneByteString> NewRawString(Factory* factory, int length, - AllocationType allocation) { - return factory->NewRawOneByteString(length, allocation).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, allocation_); - - { - DisallowHeapAllocation no_gc; - // Copy prefix into seq_str. - SinkChar* dest = seq_string->GetChars(no_gc); - 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>(HashSeed(isolate())); - 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); - } - 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())) { - DisallowHeapAllocation no_gc; - Vector<const uint8_t> string_vector( - seq_source_->GetChars(no_gc) + position_, length); - if (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, allocation_).ToHandleChecked(); - DisallowHeapAllocation no_gc; - uint8_t* dest = SeqOneByteString::cast(*result)->GetChars(no_gc); - 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 |