Ben Murdoch | 61f157c | 2016-09-16 13:49:30 +0100 | [diff] [blame] | 1 | // Copyright 2016 the V8 project authors. All rights reserved. |
| 2 | // Use of this source code is governed by a BSD-style license that can be |
| 3 | // found in the LICENSE file. |
| 4 | |
| 5 | #include "src/json-parser.h" |
| 6 | |
| 7 | #include "src/char-predicates-inl.h" |
| 8 | #include "src/conversions.h" |
| 9 | #include "src/debug/debug.h" |
| 10 | #include "src/factory.h" |
| 11 | #include "src/field-type.h" |
| 12 | #include "src/messages.h" |
| 13 | #include "src/objects-inl.h" |
| 14 | #include "src/parsing/scanner.h" |
| 15 | #include "src/parsing/token.h" |
| 16 | #include "src/property-descriptor.h" |
| 17 | #include "src/transitions.h" |
| 18 | |
| 19 | namespace v8 { |
| 20 | namespace internal { |
| 21 | |
| 22 | MaybeHandle<Object> JsonParseInternalizer::Internalize(Isolate* isolate, |
| 23 | Handle<Object> object, |
| 24 | Handle<Object> reviver) { |
| 25 | DCHECK(reviver->IsCallable()); |
| 26 | JsonParseInternalizer internalizer(isolate, |
| 27 | Handle<JSReceiver>::cast(reviver)); |
| 28 | Handle<JSObject> holder = |
| 29 | isolate->factory()->NewJSObject(isolate->object_function()); |
| 30 | Handle<String> name = isolate->factory()->empty_string(); |
| 31 | JSObject::AddProperty(holder, name, object, NONE); |
| 32 | return internalizer.InternalizeJsonProperty(holder, name); |
| 33 | } |
| 34 | |
| 35 | MaybeHandle<Object> JsonParseInternalizer::InternalizeJsonProperty( |
| 36 | Handle<JSReceiver> holder, Handle<String> name) { |
| 37 | HandleScope outer_scope(isolate_); |
| 38 | Handle<Object> value; |
| 39 | ASSIGN_RETURN_ON_EXCEPTION( |
| 40 | isolate_, value, Object::GetPropertyOrElement(holder, name), Object); |
| 41 | if (value->IsJSReceiver()) { |
| 42 | Handle<JSReceiver> object = Handle<JSReceiver>::cast(value); |
| 43 | Maybe<bool> is_array = Object::IsArray(object); |
| 44 | if (is_array.IsNothing()) return MaybeHandle<Object>(); |
| 45 | if (is_array.FromJust()) { |
| 46 | Handle<Object> length_object; |
| 47 | ASSIGN_RETURN_ON_EXCEPTION( |
| 48 | isolate_, length_object, |
| 49 | Object::GetLengthFromArrayLike(isolate_, object), Object); |
| 50 | double length = length_object->Number(); |
| 51 | for (double i = 0; i < length; i++) { |
| 52 | HandleScope inner_scope(isolate_); |
| 53 | Handle<Object> index = isolate_->factory()->NewNumber(i); |
| 54 | Handle<String> name = isolate_->factory()->NumberToString(index); |
| 55 | if (!RecurseAndApply(object, name)) return MaybeHandle<Object>(); |
| 56 | } |
| 57 | } else { |
| 58 | Handle<FixedArray> contents; |
| 59 | ASSIGN_RETURN_ON_EXCEPTION( |
| 60 | isolate_, contents, |
| 61 | KeyAccumulator::GetKeys(object, KeyCollectionMode::kOwnOnly, |
| 62 | ENUMERABLE_STRINGS, |
| 63 | GetKeysConversion::kConvertToString), |
| 64 | Object); |
| 65 | for (int i = 0; i < contents->length(); i++) { |
| 66 | HandleScope inner_scope(isolate_); |
| 67 | Handle<String> name(String::cast(contents->get(i)), isolate_); |
| 68 | if (!RecurseAndApply(object, name)) return MaybeHandle<Object>(); |
| 69 | } |
| 70 | } |
| 71 | } |
| 72 | Handle<Object> argv[] = {name, value}; |
| 73 | Handle<Object> result; |
| 74 | ASSIGN_RETURN_ON_EXCEPTION( |
| 75 | isolate_, result, Execution::Call(isolate_, reviver_, holder, 2, argv), |
| 76 | Object); |
| 77 | return outer_scope.CloseAndEscape(result); |
| 78 | } |
| 79 | |
| 80 | bool JsonParseInternalizer::RecurseAndApply(Handle<JSReceiver> holder, |
| 81 | Handle<String> name) { |
| 82 | Handle<Object> result; |
| 83 | ASSIGN_RETURN_ON_EXCEPTION_VALUE( |
| 84 | isolate_, result, InternalizeJsonProperty(holder, name), false); |
| 85 | Maybe<bool> change_result = Nothing<bool>(); |
| 86 | if (result->IsUndefined(isolate_)) { |
| 87 | change_result = JSReceiver::DeletePropertyOrElement(holder, name, SLOPPY); |
| 88 | } else { |
| 89 | PropertyDescriptor desc; |
| 90 | desc.set_value(result); |
| 91 | desc.set_configurable(true); |
| 92 | desc.set_enumerable(true); |
| 93 | desc.set_writable(true); |
| 94 | change_result = JSReceiver::DefineOwnProperty(isolate_, holder, name, &desc, |
| 95 | Object::DONT_THROW); |
| 96 | } |
| 97 | MAYBE_RETURN(change_result, false); |
| 98 | return true; |
| 99 | } |
| 100 | |
| 101 | template <bool seq_one_byte> |
| 102 | JsonParser<seq_one_byte>::JsonParser(Isolate* isolate, Handle<String> source) |
| 103 | : source_(source), |
| 104 | source_length_(source->length()), |
| 105 | isolate_(isolate), |
| 106 | factory_(isolate_->factory()), |
| 107 | zone_(isolate_->allocator()), |
| 108 | object_constructor_(isolate_->native_context()->object_function(), |
| 109 | isolate_), |
| 110 | position_(-1) { |
| 111 | source_ = String::Flatten(source_); |
| 112 | pretenure_ = (source_length_ >= kPretenureTreshold) ? TENURED : NOT_TENURED; |
| 113 | |
| 114 | // Optimized fast case where we only have Latin1 characters. |
| 115 | if (seq_one_byte) { |
| 116 | seq_source_ = Handle<SeqOneByteString>::cast(source_); |
| 117 | } |
| 118 | } |
| 119 | |
| 120 | template <bool seq_one_byte> |
| 121 | MaybeHandle<Object> JsonParser<seq_one_byte>::ParseJson() { |
| 122 | // Advance to the first character (possibly EOS) |
| 123 | AdvanceSkipWhitespace(); |
| 124 | Handle<Object> result = ParseJsonValue(); |
| 125 | if (result.is_null() || c0_ != kEndOfString) { |
| 126 | // Some exception (for example stack overflow) is already pending. |
| 127 | if (isolate_->has_pending_exception()) return Handle<Object>::null(); |
| 128 | |
| 129 | // Parse failed. Current character is the unexpected token. |
| 130 | Factory* factory = this->factory(); |
| 131 | MessageTemplate::Template message; |
| 132 | Handle<Object> arg1 = Handle<Smi>(Smi::FromInt(position_), isolate()); |
| 133 | Handle<Object> arg2; |
| 134 | |
| 135 | switch (c0_) { |
| 136 | case kEndOfString: |
| 137 | message = MessageTemplate::kJsonParseUnexpectedEOS; |
| 138 | break; |
| 139 | case '-': |
| 140 | case '0': |
| 141 | case '1': |
| 142 | case '2': |
| 143 | case '3': |
| 144 | case '4': |
| 145 | case '5': |
| 146 | case '6': |
| 147 | case '7': |
| 148 | case '8': |
| 149 | case '9': |
| 150 | message = MessageTemplate::kJsonParseUnexpectedTokenNumber; |
| 151 | break; |
| 152 | case '"': |
| 153 | message = MessageTemplate::kJsonParseUnexpectedTokenString; |
| 154 | break; |
| 155 | default: |
| 156 | message = MessageTemplate::kJsonParseUnexpectedToken; |
| 157 | arg2 = arg1; |
| 158 | arg1 = factory->LookupSingleCharacterStringFromCode(c0_); |
| 159 | break; |
| 160 | } |
| 161 | |
| 162 | Handle<Script> script(factory->NewScript(source_)); |
| 163 | // We should sent compile error event because we compile JSON object in |
| 164 | // separated source file. |
| 165 | isolate()->debug()->OnCompileError(script); |
| 166 | MessageLocation location(script, position_, position_ + 1); |
| 167 | Handle<Object> error = factory->NewSyntaxError(message, arg1, arg2); |
| 168 | return isolate()->template Throw<Object>(error, &location); |
| 169 | } |
| 170 | return result; |
| 171 | } |
| 172 | |
| 173 | MaybeHandle<Object> InternalizeJsonProperty(Handle<JSObject> holder, |
| 174 | Handle<String> key); |
| 175 | |
| 176 | template <bool seq_one_byte> |
| 177 | void JsonParser<seq_one_byte>::Advance() { |
| 178 | position_++; |
| 179 | if (position_ >= source_length_) { |
| 180 | c0_ = kEndOfString; |
| 181 | } else if (seq_one_byte) { |
| 182 | c0_ = seq_source_->SeqOneByteStringGet(position_); |
| 183 | } else { |
| 184 | c0_ = source_->Get(position_); |
| 185 | } |
| 186 | } |
| 187 | |
| 188 | template <bool seq_one_byte> |
| 189 | void JsonParser<seq_one_byte>::AdvanceSkipWhitespace() { |
| 190 | do { |
| 191 | Advance(); |
| 192 | } while (c0_ == ' ' || c0_ == '\t' || c0_ == '\n' || c0_ == '\r'); |
| 193 | } |
| 194 | |
| 195 | template <bool seq_one_byte> |
| 196 | void JsonParser<seq_one_byte>::SkipWhitespace() { |
| 197 | while (c0_ == ' ' || c0_ == '\t' || c0_ == '\n' || c0_ == '\r') { |
| 198 | Advance(); |
| 199 | } |
| 200 | } |
| 201 | |
| 202 | template <bool seq_one_byte> |
| 203 | uc32 JsonParser<seq_one_byte>::AdvanceGetChar() { |
| 204 | Advance(); |
| 205 | return c0_; |
| 206 | } |
| 207 | |
| 208 | template <bool seq_one_byte> |
| 209 | bool JsonParser<seq_one_byte>::MatchSkipWhiteSpace(uc32 c) { |
| 210 | if (c0_ == c) { |
| 211 | AdvanceSkipWhitespace(); |
| 212 | return true; |
| 213 | } |
| 214 | return false; |
| 215 | } |
| 216 | |
| 217 | template <bool seq_one_byte> |
| 218 | bool JsonParser<seq_one_byte>::ParseJsonString(Handle<String> expected) { |
| 219 | int length = expected->length(); |
| 220 | if (source_->length() - position_ - 1 > length) { |
| 221 | DisallowHeapAllocation no_gc; |
| 222 | String::FlatContent content = expected->GetFlatContent(); |
| 223 | if (content.IsOneByte()) { |
| 224 | DCHECK_EQ('"', c0_); |
| 225 | const uint8_t* input_chars = seq_source_->GetChars() + position_ + 1; |
| 226 | const uint8_t* expected_chars = content.ToOneByteVector().start(); |
| 227 | for (int i = 0; i < length; i++) { |
| 228 | uint8_t c0 = input_chars[i]; |
| 229 | if (c0 != expected_chars[i] || c0 == '"' || c0 < 0x20 || c0 == '\\') { |
| 230 | return false; |
| 231 | } |
| 232 | } |
| 233 | if (input_chars[length] == '"') { |
| 234 | position_ = position_ + length + 1; |
| 235 | AdvanceSkipWhitespace(); |
| 236 | return true; |
| 237 | } |
| 238 | } |
| 239 | } |
| 240 | return false; |
| 241 | } |
| 242 | |
| 243 | // Parse any JSON value. |
| 244 | template <bool seq_one_byte> |
| 245 | Handle<Object> JsonParser<seq_one_byte>::ParseJsonValue() { |
| 246 | StackLimitCheck stack_check(isolate_); |
| 247 | if (stack_check.HasOverflowed()) { |
| 248 | isolate_->StackOverflow(); |
| 249 | return Handle<Object>::null(); |
| 250 | } |
| 251 | |
| 252 | if (stack_check.InterruptRequested() && |
| 253 | isolate_->stack_guard()->HandleInterrupts()->IsException(isolate_)) { |
| 254 | return Handle<Object>::null(); |
| 255 | } |
| 256 | |
| 257 | if (c0_ == '"') return ParseJsonString(); |
| 258 | if ((c0_ >= '0' && c0_ <= '9') || c0_ == '-') return ParseJsonNumber(); |
| 259 | if (c0_ == '{') return ParseJsonObject(); |
| 260 | if (c0_ == '[') return ParseJsonArray(); |
| 261 | if (c0_ == 'f') { |
| 262 | if (AdvanceGetChar() == 'a' && AdvanceGetChar() == 'l' && |
| 263 | AdvanceGetChar() == 's' && AdvanceGetChar() == 'e') { |
| 264 | AdvanceSkipWhitespace(); |
| 265 | return factory()->false_value(); |
| 266 | } |
| 267 | return ReportUnexpectedCharacter(); |
| 268 | } |
| 269 | if (c0_ == 't') { |
| 270 | if (AdvanceGetChar() == 'r' && AdvanceGetChar() == 'u' && |
| 271 | AdvanceGetChar() == 'e') { |
| 272 | AdvanceSkipWhitespace(); |
| 273 | return factory()->true_value(); |
| 274 | } |
| 275 | return ReportUnexpectedCharacter(); |
| 276 | } |
| 277 | if (c0_ == 'n') { |
| 278 | if (AdvanceGetChar() == 'u' && AdvanceGetChar() == 'l' && |
| 279 | AdvanceGetChar() == 'l') { |
| 280 | AdvanceSkipWhitespace(); |
| 281 | return factory()->null_value(); |
| 282 | } |
| 283 | return ReportUnexpectedCharacter(); |
| 284 | } |
| 285 | return ReportUnexpectedCharacter(); |
| 286 | } |
| 287 | |
| 288 | template <bool seq_one_byte> |
| 289 | ParseElementResult JsonParser<seq_one_byte>::ParseElement( |
| 290 | Handle<JSObject> json_object) { |
| 291 | uint32_t index = 0; |
| 292 | // Maybe an array index, try to parse it. |
| 293 | if (c0_ == '0') { |
| 294 | // With a leading zero, the string has to be "0" only to be an index. |
| 295 | Advance(); |
| 296 | } else { |
| 297 | do { |
| 298 | int d = c0_ - '0'; |
| 299 | if (index > 429496729U - ((d + 3) >> 3)) break; |
| 300 | index = (index * 10) + d; |
| 301 | Advance(); |
| 302 | } while (IsDecimalDigit(c0_)); |
| 303 | } |
| 304 | |
| 305 | if (c0_ == '"') { |
| 306 | // Successfully parsed index, parse and store element. |
| 307 | AdvanceSkipWhitespace(); |
| 308 | |
| 309 | if (c0_ == ':') { |
| 310 | AdvanceSkipWhitespace(); |
| 311 | Handle<Object> value = ParseJsonValue(); |
| 312 | if (!value.is_null()) { |
| 313 | JSObject::SetOwnElementIgnoreAttributes(json_object, index, value, NONE) |
| 314 | .Assert(); |
| 315 | return kElementFound; |
| 316 | } else { |
| 317 | return kNullHandle; |
| 318 | } |
| 319 | } |
| 320 | } |
| 321 | return kElementNotFound; |
| 322 | } |
| 323 | |
| 324 | // Parse a JSON object. Position must be right at '{'. |
| 325 | template <bool seq_one_byte> |
| 326 | Handle<Object> JsonParser<seq_one_byte>::ParseJsonObject() { |
| 327 | HandleScope scope(isolate()); |
| 328 | Handle<JSObject> json_object = |
| 329 | factory()->NewJSObject(object_constructor(), pretenure_); |
| 330 | Handle<Map> map(json_object->map()); |
| 331 | int descriptor = 0; |
| 332 | ZoneList<Handle<Object> > properties(8, zone()); |
| 333 | DCHECK_EQ(c0_, '{'); |
| 334 | |
| 335 | bool transitioning = true; |
| 336 | |
| 337 | AdvanceSkipWhitespace(); |
| 338 | if (c0_ != '}') { |
| 339 | do { |
| 340 | if (c0_ != '"') return ReportUnexpectedCharacter(); |
| 341 | |
| 342 | int start_position = position_; |
| 343 | Advance(); |
| 344 | |
| 345 | if (IsDecimalDigit(c0_)) { |
| 346 | ParseElementResult element_result = ParseElement(json_object); |
| 347 | if (element_result == kNullHandle) return Handle<Object>::null(); |
| 348 | if (element_result == kElementFound) continue; |
| 349 | } |
| 350 | // Not an index, fallback to the slow path. |
| 351 | |
| 352 | position_ = start_position; |
| 353 | #ifdef DEBUG |
| 354 | c0_ = '"'; |
| 355 | #endif |
| 356 | |
| 357 | Handle<String> key; |
| 358 | Handle<Object> value; |
| 359 | |
| 360 | // Try to follow existing transitions as long as possible. Once we stop |
| 361 | // transitioning, no transition can be found anymore. |
| 362 | DCHECK(transitioning); |
| 363 | // First check whether there is a single expected transition. If so, try |
| 364 | // to parse it first. |
| 365 | bool follow_expected = false; |
| 366 | Handle<Map> target; |
| 367 | if (seq_one_byte) { |
| 368 | key = TransitionArray::ExpectedTransitionKey(map); |
| 369 | follow_expected = !key.is_null() && ParseJsonString(key); |
| 370 | } |
| 371 | // If the expected transition hits, follow it. |
| 372 | if (follow_expected) { |
| 373 | target = TransitionArray::ExpectedTransitionTarget(map); |
| 374 | } else { |
| 375 | // If the expected transition failed, parse an internalized string and |
| 376 | // try to find a matching transition. |
| 377 | key = ParseJsonInternalizedString(); |
| 378 | if (key.is_null()) return ReportUnexpectedCharacter(); |
| 379 | |
| 380 | target = TransitionArray::FindTransitionToField(map, key); |
| 381 | // If a transition was found, follow it and continue. |
| 382 | transitioning = !target.is_null(); |
| 383 | } |
| 384 | if (c0_ != ':') return ReportUnexpectedCharacter(); |
| 385 | |
| 386 | AdvanceSkipWhitespace(); |
| 387 | value = ParseJsonValue(); |
| 388 | if (value.is_null()) return ReportUnexpectedCharacter(); |
| 389 | |
| 390 | if (transitioning) { |
| 391 | PropertyDetails details = |
| 392 | target->instance_descriptors()->GetDetails(descriptor); |
| 393 | Representation expected_representation = details.representation(); |
| 394 | |
| 395 | if (value->FitsRepresentation(expected_representation)) { |
| 396 | if (expected_representation.IsHeapObject() && |
| 397 | !target->instance_descriptors() |
| 398 | ->GetFieldType(descriptor) |
| 399 | ->NowContains(value)) { |
| 400 | Handle<FieldType> value_type( |
| 401 | value->OptimalType(isolate(), expected_representation)); |
| 402 | Map::GeneralizeFieldType(target, descriptor, |
| 403 | expected_representation, value_type); |
| 404 | } |
| 405 | DCHECK(target->instance_descriptors() |
| 406 | ->GetFieldType(descriptor) |
| 407 | ->NowContains(value)); |
| 408 | properties.Add(value, zone()); |
| 409 | map = target; |
| 410 | descriptor++; |
| 411 | continue; |
| 412 | } else { |
| 413 | transitioning = false; |
| 414 | } |
| 415 | } |
| 416 | |
| 417 | DCHECK(!transitioning); |
| 418 | |
| 419 | // Commit the intermediate state to the object and stop transitioning. |
| 420 | CommitStateToJsonObject(json_object, map, &properties); |
| 421 | |
| 422 | JSObject::DefinePropertyOrElementIgnoreAttributes(json_object, key, value) |
| 423 | .Check(); |
| 424 | } while (transitioning && MatchSkipWhiteSpace(',')); |
| 425 | |
| 426 | // If we transitioned until the very end, transition the map now. |
| 427 | if (transitioning) { |
| 428 | CommitStateToJsonObject(json_object, map, &properties); |
| 429 | } else { |
| 430 | while (MatchSkipWhiteSpace(',')) { |
| 431 | HandleScope local_scope(isolate()); |
| 432 | if (c0_ != '"') return ReportUnexpectedCharacter(); |
| 433 | |
| 434 | int start_position = position_; |
| 435 | Advance(); |
| 436 | |
| 437 | if (IsDecimalDigit(c0_)) { |
| 438 | ParseElementResult element_result = ParseElement(json_object); |
| 439 | if (element_result == kNullHandle) return Handle<Object>::null(); |
| 440 | if (element_result == kElementFound) continue; |
| 441 | } |
| 442 | // Not an index, fallback to the slow path. |
| 443 | |
| 444 | position_ = start_position; |
| 445 | #ifdef DEBUG |
| 446 | c0_ = '"'; |
| 447 | #endif |
| 448 | |
| 449 | Handle<String> key; |
| 450 | Handle<Object> value; |
| 451 | |
| 452 | key = ParseJsonInternalizedString(); |
| 453 | if (key.is_null() || c0_ != ':') return ReportUnexpectedCharacter(); |
| 454 | |
| 455 | AdvanceSkipWhitespace(); |
| 456 | value = ParseJsonValue(); |
| 457 | if (value.is_null()) return ReportUnexpectedCharacter(); |
| 458 | |
| 459 | JSObject::DefinePropertyOrElementIgnoreAttributes(json_object, key, |
| 460 | value) |
| 461 | .Check(); |
| 462 | } |
| 463 | } |
| 464 | |
| 465 | if (c0_ != '}') { |
| 466 | return ReportUnexpectedCharacter(); |
| 467 | } |
| 468 | } |
| 469 | AdvanceSkipWhitespace(); |
| 470 | return scope.CloseAndEscape(json_object); |
| 471 | } |
| 472 | |
| 473 | template <bool seq_one_byte> |
| 474 | void JsonParser<seq_one_byte>::CommitStateToJsonObject( |
| 475 | Handle<JSObject> json_object, Handle<Map> map, |
| 476 | ZoneList<Handle<Object> >* properties) { |
| 477 | JSObject::AllocateStorageForMap(json_object, map); |
| 478 | DCHECK(!json_object->map()->is_dictionary_map()); |
| 479 | |
| 480 | DisallowHeapAllocation no_gc; |
| 481 | |
| 482 | int length = properties->length(); |
| 483 | for (int i = 0; i < length; i++) { |
| 484 | Handle<Object> value = (*properties)[i]; |
| 485 | json_object->WriteToField(i, *value); |
| 486 | } |
| 487 | } |
| 488 | |
| 489 | // Parse a JSON array. Position must be right at '['. |
| 490 | template <bool seq_one_byte> |
| 491 | Handle<Object> JsonParser<seq_one_byte>::ParseJsonArray() { |
| 492 | HandleScope scope(isolate()); |
| 493 | ZoneList<Handle<Object> > elements(4, zone()); |
| 494 | DCHECK_EQ(c0_, '['); |
| 495 | |
| 496 | AdvanceSkipWhitespace(); |
| 497 | if (c0_ != ']') { |
| 498 | do { |
| 499 | Handle<Object> element = ParseJsonValue(); |
| 500 | if (element.is_null()) return ReportUnexpectedCharacter(); |
| 501 | elements.Add(element, zone()); |
| 502 | } while (MatchSkipWhiteSpace(',')); |
| 503 | if (c0_ != ']') { |
| 504 | return ReportUnexpectedCharacter(); |
| 505 | } |
| 506 | } |
| 507 | AdvanceSkipWhitespace(); |
| 508 | // Allocate a fixed array with all the elements. |
| 509 | Handle<FixedArray> fast_elements = |
| 510 | factory()->NewFixedArray(elements.length(), pretenure_); |
| 511 | for (int i = 0, n = elements.length(); i < n; i++) { |
| 512 | fast_elements->set(i, *elements[i]); |
| 513 | } |
| 514 | Handle<Object> json_array = factory()->NewJSArrayWithElements( |
| 515 | fast_elements, FAST_ELEMENTS, pretenure_); |
| 516 | return scope.CloseAndEscape(json_array); |
| 517 | } |
| 518 | |
| 519 | template <bool seq_one_byte> |
| 520 | Handle<Object> JsonParser<seq_one_byte>::ParseJsonNumber() { |
| 521 | bool negative = false; |
| 522 | int beg_pos = position_; |
| 523 | if (c0_ == '-') { |
| 524 | Advance(); |
| 525 | negative = true; |
| 526 | } |
| 527 | if (c0_ == '0') { |
| 528 | Advance(); |
| 529 | // Prefix zero is only allowed if it's the only digit before |
| 530 | // a decimal point or exponent. |
| 531 | if (IsDecimalDigit(c0_)) return ReportUnexpectedCharacter(); |
| 532 | } else { |
| 533 | int i = 0; |
| 534 | int digits = 0; |
| 535 | if (c0_ < '1' || c0_ > '9') return ReportUnexpectedCharacter(); |
| 536 | do { |
| 537 | i = i * 10 + c0_ - '0'; |
| 538 | digits++; |
| 539 | Advance(); |
| 540 | } while (IsDecimalDigit(c0_)); |
| 541 | if (c0_ != '.' && c0_ != 'e' && c0_ != 'E' && digits < 10) { |
| 542 | SkipWhitespace(); |
| 543 | return Handle<Smi>(Smi::FromInt((negative ? -i : i)), isolate()); |
| 544 | } |
| 545 | } |
| 546 | if (c0_ == '.') { |
| 547 | Advance(); |
| 548 | if (!IsDecimalDigit(c0_)) return ReportUnexpectedCharacter(); |
| 549 | do { |
| 550 | Advance(); |
| 551 | } while (IsDecimalDigit(c0_)); |
| 552 | } |
| 553 | if (AsciiAlphaToLower(c0_) == 'e') { |
| 554 | Advance(); |
| 555 | if (c0_ == '-' || c0_ == '+') Advance(); |
| 556 | if (!IsDecimalDigit(c0_)) return ReportUnexpectedCharacter(); |
| 557 | do { |
| 558 | Advance(); |
| 559 | } while (IsDecimalDigit(c0_)); |
| 560 | } |
| 561 | int length = position_ - beg_pos; |
| 562 | double number; |
| 563 | if (seq_one_byte) { |
| 564 | Vector<const uint8_t> chars(seq_source_->GetChars() + beg_pos, length); |
| 565 | number = StringToDouble(isolate()->unicode_cache(), chars, |
| 566 | NO_FLAGS, // Hex, octal or trailing junk. |
| 567 | std::numeric_limits<double>::quiet_NaN()); |
| 568 | } else { |
| 569 | Vector<uint8_t> buffer = Vector<uint8_t>::New(length); |
| 570 | String::WriteToFlat(*source_, buffer.start(), beg_pos, position_); |
| 571 | Vector<const uint8_t> result = |
| 572 | Vector<const uint8_t>(buffer.start(), length); |
| 573 | number = StringToDouble(isolate()->unicode_cache(), result, |
| 574 | NO_FLAGS, // Hex, octal or trailing junk. |
| 575 | 0.0); |
| 576 | buffer.Dispose(); |
| 577 | } |
| 578 | SkipWhitespace(); |
| 579 | return factory()->NewNumber(number, pretenure_); |
| 580 | } |
| 581 | |
| 582 | template <typename StringType> |
| 583 | inline void SeqStringSet(Handle<StringType> seq_str, int i, uc32 c); |
| 584 | |
| 585 | template <> |
| 586 | inline void SeqStringSet(Handle<SeqTwoByteString> seq_str, int i, uc32 c) { |
| 587 | seq_str->SeqTwoByteStringSet(i, c); |
| 588 | } |
| 589 | |
| 590 | template <> |
| 591 | inline void SeqStringSet(Handle<SeqOneByteString> seq_str, int i, uc32 c) { |
| 592 | seq_str->SeqOneByteStringSet(i, c); |
| 593 | } |
| 594 | |
| 595 | template <typename StringType> |
| 596 | inline Handle<StringType> NewRawString(Factory* factory, int length, |
| 597 | PretenureFlag pretenure); |
| 598 | |
| 599 | template <> |
| 600 | inline Handle<SeqTwoByteString> NewRawString(Factory* factory, int length, |
| 601 | PretenureFlag pretenure) { |
| 602 | return factory->NewRawTwoByteString(length, pretenure).ToHandleChecked(); |
| 603 | } |
| 604 | |
| 605 | template <> |
| 606 | inline Handle<SeqOneByteString> NewRawString(Factory* factory, int length, |
| 607 | PretenureFlag pretenure) { |
| 608 | return factory->NewRawOneByteString(length, pretenure).ToHandleChecked(); |
| 609 | } |
| 610 | |
| 611 | // Scans the rest of a JSON string starting from position_ and writes |
| 612 | // prefix[start..end] along with the scanned characters into a |
| 613 | // sequential string of type StringType. |
| 614 | template <bool seq_one_byte> |
| 615 | template <typename StringType, typename SinkChar> |
| 616 | Handle<String> JsonParser<seq_one_byte>::SlowScanJsonString( |
| 617 | Handle<String> prefix, int start, int end) { |
| 618 | int count = end - start; |
| 619 | int max_length = count + source_length_ - position_; |
| 620 | int length = Min(max_length, Max(kInitialSpecialStringLength, 2 * count)); |
| 621 | Handle<StringType> seq_string = |
| 622 | NewRawString<StringType>(factory(), length, pretenure_); |
| 623 | // Copy prefix into seq_str. |
| 624 | SinkChar* dest = seq_string->GetChars(); |
| 625 | String::WriteToFlat(*prefix, dest, start, end); |
| 626 | |
| 627 | while (c0_ != '"') { |
| 628 | // Check for control character (0x00-0x1f) or unterminated string (<0). |
| 629 | if (c0_ < 0x20) return Handle<String>::null(); |
| 630 | if (count >= length) { |
| 631 | // We need to create a longer sequential string for the result. |
| 632 | return SlowScanJsonString<StringType, SinkChar>(seq_string, 0, count); |
| 633 | } |
| 634 | if (c0_ != '\\') { |
| 635 | // If the sink can contain UC16 characters, or source_ contains only |
| 636 | // Latin1 characters, there's no need to test whether we can store the |
| 637 | // character. Otherwise check whether the UC16 source character can fit |
| 638 | // in the Latin1 sink. |
| 639 | if (sizeof(SinkChar) == kUC16Size || seq_one_byte || |
| 640 | c0_ <= String::kMaxOneByteCharCode) { |
| 641 | SeqStringSet(seq_string, count++, c0_); |
| 642 | Advance(); |
| 643 | } else { |
| 644 | // StringType is SeqOneByteString and we just read a non-Latin1 char. |
| 645 | return SlowScanJsonString<SeqTwoByteString, uc16>(seq_string, 0, count); |
| 646 | } |
| 647 | } else { |
| 648 | Advance(); // Advance past the \. |
| 649 | switch (c0_) { |
| 650 | case '"': |
| 651 | case '\\': |
| 652 | case '/': |
| 653 | SeqStringSet(seq_string, count++, c0_); |
| 654 | break; |
| 655 | case 'b': |
| 656 | SeqStringSet(seq_string, count++, '\x08'); |
| 657 | break; |
| 658 | case 'f': |
| 659 | SeqStringSet(seq_string, count++, '\x0c'); |
| 660 | break; |
| 661 | case 'n': |
| 662 | SeqStringSet(seq_string, count++, '\x0a'); |
| 663 | break; |
| 664 | case 'r': |
| 665 | SeqStringSet(seq_string, count++, '\x0d'); |
| 666 | break; |
| 667 | case 't': |
| 668 | SeqStringSet(seq_string, count++, '\x09'); |
| 669 | break; |
| 670 | case 'u': { |
| 671 | uc32 value = 0; |
| 672 | for (int i = 0; i < 4; i++) { |
| 673 | Advance(); |
| 674 | int digit = HexValue(c0_); |
| 675 | if (digit < 0) { |
| 676 | return Handle<String>::null(); |
| 677 | } |
| 678 | value = value * 16 + digit; |
| 679 | } |
| 680 | if (sizeof(SinkChar) == kUC16Size || |
| 681 | value <= String::kMaxOneByteCharCode) { |
| 682 | SeqStringSet(seq_string, count++, value); |
| 683 | break; |
| 684 | } else { |
| 685 | // StringType is SeqOneByteString and we just read a non-Latin1 |
| 686 | // char. |
| 687 | position_ -= 6; // Rewind position_ to \ in \uxxxx. |
| 688 | Advance(); |
| 689 | return SlowScanJsonString<SeqTwoByteString, uc16>(seq_string, 0, |
| 690 | count); |
| 691 | } |
| 692 | } |
| 693 | default: |
| 694 | return Handle<String>::null(); |
| 695 | } |
| 696 | Advance(); |
| 697 | } |
| 698 | } |
| 699 | |
| 700 | DCHECK_EQ('"', c0_); |
| 701 | // Advance past the last '"'. |
| 702 | AdvanceSkipWhitespace(); |
| 703 | |
| 704 | // Shrink seq_string length to count and return. |
| 705 | return SeqString::Truncate(seq_string, count); |
| 706 | } |
| 707 | |
| 708 | template <bool seq_one_byte> |
| 709 | template <bool is_internalized> |
| 710 | Handle<String> JsonParser<seq_one_byte>::ScanJsonString() { |
| 711 | DCHECK_EQ('"', c0_); |
| 712 | Advance(); |
| 713 | if (c0_ == '"') { |
| 714 | AdvanceSkipWhitespace(); |
| 715 | return factory()->empty_string(); |
| 716 | } |
| 717 | |
| 718 | if (seq_one_byte && is_internalized) { |
| 719 | // Fast path for existing internalized strings. If the the string being |
| 720 | // parsed is not a known internalized string, contains backslashes or |
| 721 | // unexpectedly reaches the end of string, return with an empty handle. |
| 722 | uint32_t running_hash = isolate()->heap()->HashSeed(); |
| 723 | int position = position_; |
| 724 | uc32 c0 = c0_; |
| 725 | do { |
| 726 | if (c0 == '\\') { |
| 727 | c0_ = c0; |
| 728 | int beg_pos = position_; |
| 729 | position_ = position; |
| 730 | return SlowScanJsonString<SeqOneByteString, uint8_t>(source_, beg_pos, |
| 731 | position_); |
| 732 | } |
| 733 | if (c0 < 0x20) return Handle<String>::null(); |
| 734 | running_hash = StringHasher::AddCharacterCore(running_hash, |
| 735 | static_cast<uint16_t>(c0)); |
| 736 | position++; |
| 737 | if (position >= source_length_) return Handle<String>::null(); |
| 738 | c0 = seq_source_->SeqOneByteStringGet(position); |
| 739 | } while (c0 != '"'); |
| 740 | int length = position - position_; |
| 741 | uint32_t hash = (length <= String::kMaxHashCalcLength) |
| 742 | ? StringHasher::GetHashCore(running_hash) |
| 743 | : static_cast<uint32_t>(length); |
| 744 | Vector<const uint8_t> string_vector(seq_source_->GetChars() + position_, |
| 745 | length); |
| 746 | StringTable* string_table = isolate()->heap()->string_table(); |
| 747 | uint32_t capacity = string_table->Capacity(); |
| 748 | uint32_t entry = StringTable::FirstProbe(hash, capacity); |
| 749 | uint32_t count = 1; |
| 750 | Handle<String> result; |
| 751 | while (true) { |
| 752 | Object* element = string_table->KeyAt(entry); |
| 753 | if (element->IsUndefined(isolate())) { |
| 754 | // Lookup failure. |
| 755 | result = |
| 756 | factory()->InternalizeOneByteString(seq_source_, position_, length); |
| 757 | break; |
| 758 | } |
| 759 | if (!element->IsTheHole(isolate()) && |
| 760 | String::cast(element)->IsOneByteEqualTo(string_vector)) { |
| 761 | result = Handle<String>(String::cast(element), isolate()); |
| 762 | #ifdef DEBUG |
| 763 | uint32_t hash_field = |
| 764 | (hash << String::kHashShift) | String::kIsNotArrayIndexMask; |
| 765 | DCHECK_EQ(static_cast<int>(result->Hash()), |
| 766 | static_cast<int>(hash_field >> String::kHashShift)); |
| 767 | #endif |
| 768 | break; |
| 769 | } |
| 770 | entry = StringTable::NextProbe(entry, count++, capacity); |
| 771 | } |
| 772 | position_ = position; |
| 773 | // Advance past the last '"'. |
| 774 | AdvanceSkipWhitespace(); |
| 775 | return result; |
| 776 | } |
| 777 | |
| 778 | int beg_pos = position_; |
| 779 | // Fast case for Latin1 only without escape characters. |
| 780 | do { |
| 781 | // Check for control character (0x00-0x1f) or unterminated string (<0). |
| 782 | if (c0_ < 0x20) return Handle<String>::null(); |
| 783 | if (c0_ != '\\') { |
| 784 | if (seq_one_byte || c0_ <= String::kMaxOneByteCharCode) { |
| 785 | Advance(); |
| 786 | } else { |
| 787 | return SlowScanJsonString<SeqTwoByteString, uc16>(source_, beg_pos, |
| 788 | position_); |
| 789 | } |
| 790 | } else { |
| 791 | return SlowScanJsonString<SeqOneByteString, uint8_t>(source_, beg_pos, |
| 792 | position_); |
| 793 | } |
| 794 | } while (c0_ != '"'); |
| 795 | int length = position_ - beg_pos; |
| 796 | Handle<String> result = |
| 797 | factory()->NewRawOneByteString(length, pretenure_).ToHandleChecked(); |
| 798 | uint8_t* dest = SeqOneByteString::cast(*result)->GetChars(); |
| 799 | String::WriteToFlat(*source_, dest, beg_pos, position_); |
| 800 | |
| 801 | DCHECK_EQ('"', c0_); |
| 802 | // Advance past the last '"'. |
| 803 | AdvanceSkipWhitespace(); |
| 804 | return result; |
| 805 | } |
| 806 | |
| 807 | // Explicit instantiation. |
| 808 | template class JsonParser<true>; |
| 809 | template class JsonParser<false>; |
| 810 | |
| 811 | } // namespace internal |
| 812 | } // namespace v8 |