objects.h revision 592a9fc1d8ea420377a2e7efd0600e20b058be2b
1// Copyright 2011 the V8 project authors. All rights reserved. 2// Redistribution and use in source and binary forms, with or without 3// modification, are permitted provided that the following conditions are 4// met: 5// 6// * Redistributions of source code must retain the above copyright 7// notice, this list of conditions and the following disclaimer. 8// * Redistributions in binary form must reproduce the above 9// copyright notice, this list of conditions and the following 10// disclaimer in the documentation and/or other materials provided 11// with the distribution. 12// * Neither the name of Google Inc. nor the names of its 13// contributors may be used to endorse or promote products derived 14// from this software without specific prior written permission. 15// 16// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS 17// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT 18// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR 19// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT 20// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, 21// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT 22// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, 23// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY 24// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE 26// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 28#ifndef V8_OBJECTS_H_ 29#define V8_OBJECTS_H_ 30 31#include "allocation.h" 32#include "builtins.h" 33#include "list.h" 34#include "property-details.h" 35#include "smart-array-pointer.h" 36#include "unicode-inl.h" 37#if V8_TARGET_ARCH_ARM 38#include "arm/constants-arm.h" 39#elif V8_TARGET_ARCH_MIPS 40#include "mips/constants-mips.h" 41#endif 42#include "v8checks.h" 43 44 45// 46// Most object types in the V8 JavaScript are described in this file. 47// 48// Inheritance hierarchy: 49// - MaybeObject (an object or a failure) 50// - Failure (immediate for marking failed operation) 51// - Object 52// - Smi (immediate small integer) 53// - HeapObject (superclass for everything allocated in the heap) 54// - JSReceiver (suitable for property access) 55// - JSObject 56// - JSArray 57// - JSSet 58// - JSMap 59// - JSWeakMap 60// - JSRegExp 61// - JSFunction 62// - GlobalObject 63// - JSGlobalObject 64// - JSBuiltinsObject 65// - JSGlobalProxy 66// - JSValue 67// - JSMessageObject 68// - JSProxy 69// - JSFunctionProxy 70// - FixedArrayBase 71// - ByteArray 72// - FixedArray 73// - DescriptorArray 74// - HashTable 75// - Dictionary 76// - SymbolTable 77// - CompilationCacheTable 78// - CodeCacheHashTable 79// - MapCache 80// - Context 81// - JSFunctionResultCache 82// - ScopeInfo 83// - FixedDoubleArray 84// - ExternalArray 85// - ExternalPixelArray 86// - ExternalByteArray 87// - ExternalUnsignedByteArray 88// - ExternalShortArray 89// - ExternalUnsignedShortArray 90// - ExternalIntArray 91// - ExternalUnsignedIntArray 92// - ExternalFloatArray 93// - String 94// - SeqString 95// - SeqAsciiString 96// - SeqTwoByteString 97// - SlicedString 98// - ConsString 99// - ExternalString 100// - ExternalAsciiString 101// - ExternalTwoByteString 102// - HeapNumber 103// - Code 104// - Map 105// - Oddball 106// - Foreign 107// - SharedFunctionInfo 108// - Struct 109// - AccessorInfo 110// - AccessCheckInfo 111// - InterceptorInfo 112// - CallHandlerInfo 113// - TemplateInfo 114// - FunctionTemplateInfo 115// - ObjectTemplateInfo 116// - Script 117// - SignatureInfo 118// - TypeSwitchInfo 119// - DebugInfo 120// - BreakPointInfo 121// - CodeCache 122// 123// Formats of Object*: 124// Smi: [31 bit signed int] 0 125// HeapObject: [32 bit direct pointer] (4 byte aligned) | 01 126// Failure: [30 bit signed int] 11 127 128namespace v8 { 129namespace internal { 130 131enum ElementsKind { 132 // The "fast" kind for elements that only contain SMI values. Must be first 133 // to make it possible to efficiently check maps for this kind. 134 FAST_SMI_ONLY_ELEMENTS, 135 136 // The "fast" kind for tagged values. Must be second to make it possible to 137 // efficiently check maps for this and the FAST_SMI_ONLY_ELEMENTS kind 138 // together at once. 139 FAST_ELEMENTS, 140 141 // The "fast" kind for unwrapped, non-tagged double values. 142 FAST_DOUBLE_ELEMENTS, 143 144 // The "slow" kind. 145 DICTIONARY_ELEMENTS, 146 NON_STRICT_ARGUMENTS_ELEMENTS, 147 // The "fast" kind for external arrays 148 EXTERNAL_BYTE_ELEMENTS, 149 EXTERNAL_UNSIGNED_BYTE_ELEMENTS, 150 EXTERNAL_SHORT_ELEMENTS, 151 EXTERNAL_UNSIGNED_SHORT_ELEMENTS, 152 EXTERNAL_INT_ELEMENTS, 153 EXTERNAL_UNSIGNED_INT_ELEMENTS, 154 EXTERNAL_FLOAT_ELEMENTS, 155 EXTERNAL_DOUBLE_ELEMENTS, 156 EXTERNAL_PIXEL_ELEMENTS, 157 158 // Derived constants from ElementsKind 159 FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND = EXTERNAL_BYTE_ELEMENTS, 160 LAST_EXTERNAL_ARRAY_ELEMENTS_KIND = EXTERNAL_PIXEL_ELEMENTS, 161 FIRST_ELEMENTS_KIND = FAST_SMI_ONLY_ELEMENTS, 162 LAST_ELEMENTS_KIND = EXTERNAL_PIXEL_ELEMENTS 163}; 164 165const int kElementsKindCount = LAST_ELEMENTS_KIND - FIRST_ELEMENTS_KIND + 1; 166 167void PrintElementsKind(FILE* out, ElementsKind kind); 168 169inline bool IsMoreGeneralElementsKindTransition(ElementsKind from_kind, 170 ElementsKind to_kind); 171 172// Setter that skips the write barrier if mode is SKIP_WRITE_BARRIER. 173enum WriteBarrierMode { SKIP_WRITE_BARRIER, UPDATE_WRITE_BARRIER }; 174 175 176// PropertyNormalizationMode is used to specify whether to keep 177// inobject properties when normalizing properties of a JSObject. 178enum PropertyNormalizationMode { 179 CLEAR_INOBJECT_PROPERTIES, 180 KEEP_INOBJECT_PROPERTIES 181}; 182 183 184// NormalizedMapSharingMode is used to specify whether a map may be shared 185// by different objects with normalized properties. 186enum NormalizedMapSharingMode { 187 UNIQUE_NORMALIZED_MAP, 188 SHARED_NORMALIZED_MAP 189}; 190 191 192// Indicates whether a get method should implicitly create the object looked up. 193enum CreationFlag { 194 ALLOW_CREATION, 195 OMIT_CREATION 196}; 197 198 199// Instance size sentinel for objects of variable size. 200const int kVariableSizeSentinel = 0; 201 202 203// All Maps have a field instance_type containing a InstanceType. 204// It describes the type of the instances. 205// 206// As an example, a JavaScript object is a heap object and its map 207// instance_type is JS_OBJECT_TYPE. 208// 209// The names of the string instance types are intended to systematically 210// mirror their encoding in the instance_type field of the map. The default 211// encoding is considered TWO_BYTE. It is not mentioned in the name. ASCII 212// encoding is mentioned explicitly in the name. Likewise, the default 213// representation is considered sequential. It is not mentioned in the 214// name. The other representations (eg, CONS, EXTERNAL) are explicitly 215// mentioned. Finally, the string is either a SYMBOL_TYPE (if it is a 216// symbol) or a STRING_TYPE (if it is not a symbol). 217// 218// NOTE: The following things are some that depend on the string types having 219// instance_types that are less than those of all other types: 220// HeapObject::Size, HeapObject::IterateBody, the typeof operator, and 221// Object::IsString. 222// 223// NOTE: Everything following JS_VALUE_TYPE is considered a 224// JSObject for GC purposes. The first four entries here have typeof 225// 'object', whereas JS_FUNCTION_TYPE has typeof 'function'. 226#define INSTANCE_TYPE_LIST_ALL(V) \ 227 V(SYMBOL_TYPE) \ 228 V(ASCII_SYMBOL_TYPE) \ 229 V(CONS_SYMBOL_TYPE) \ 230 V(CONS_ASCII_SYMBOL_TYPE) \ 231 V(EXTERNAL_SYMBOL_TYPE) \ 232 V(EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE) \ 233 V(EXTERNAL_ASCII_SYMBOL_TYPE) \ 234 V(SHORT_EXTERNAL_SYMBOL_TYPE) \ 235 V(SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE) \ 236 V(SHORT_EXTERNAL_ASCII_SYMBOL_TYPE) \ 237 V(STRING_TYPE) \ 238 V(ASCII_STRING_TYPE) \ 239 V(CONS_STRING_TYPE) \ 240 V(CONS_ASCII_STRING_TYPE) \ 241 V(SLICED_STRING_TYPE) \ 242 V(EXTERNAL_STRING_TYPE) \ 243 V(EXTERNAL_STRING_WITH_ASCII_DATA_TYPE) \ 244 V(EXTERNAL_ASCII_STRING_TYPE) \ 245 V(SHORT_EXTERNAL_STRING_TYPE) \ 246 V(SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE) \ 247 V(SHORT_EXTERNAL_ASCII_STRING_TYPE) \ 248 V(PRIVATE_EXTERNAL_ASCII_STRING_TYPE) \ 249 \ 250 V(MAP_TYPE) \ 251 V(CODE_TYPE) \ 252 V(ODDBALL_TYPE) \ 253 V(JS_GLOBAL_PROPERTY_CELL_TYPE) \ 254 \ 255 V(HEAP_NUMBER_TYPE) \ 256 V(FOREIGN_TYPE) \ 257 V(BYTE_ARRAY_TYPE) \ 258 V(FREE_SPACE_TYPE) \ 259 /* Note: the order of these external array */ \ 260 /* types is relied upon in */ \ 261 /* Object::IsExternalArray(). */ \ 262 V(EXTERNAL_BYTE_ARRAY_TYPE) \ 263 V(EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE) \ 264 V(EXTERNAL_SHORT_ARRAY_TYPE) \ 265 V(EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE) \ 266 V(EXTERNAL_INT_ARRAY_TYPE) \ 267 V(EXTERNAL_UNSIGNED_INT_ARRAY_TYPE) \ 268 V(EXTERNAL_FLOAT_ARRAY_TYPE) \ 269 V(EXTERNAL_PIXEL_ARRAY_TYPE) \ 270 V(FILLER_TYPE) \ 271 \ 272 V(ACCESSOR_INFO_TYPE) \ 273 V(ACCESS_CHECK_INFO_TYPE) \ 274 V(INTERCEPTOR_INFO_TYPE) \ 275 V(CALL_HANDLER_INFO_TYPE) \ 276 V(FUNCTION_TEMPLATE_INFO_TYPE) \ 277 V(OBJECT_TEMPLATE_INFO_TYPE) \ 278 V(SIGNATURE_INFO_TYPE) \ 279 V(TYPE_SWITCH_INFO_TYPE) \ 280 V(SCRIPT_TYPE) \ 281 V(CODE_CACHE_TYPE) \ 282 V(POLYMORPHIC_CODE_CACHE_TYPE) \ 283 \ 284 V(FIXED_ARRAY_TYPE) \ 285 V(FIXED_DOUBLE_ARRAY_TYPE) \ 286 V(SHARED_FUNCTION_INFO_TYPE) \ 287 \ 288 V(JS_MESSAGE_OBJECT_TYPE) \ 289 \ 290 V(JS_VALUE_TYPE) \ 291 V(JS_OBJECT_TYPE) \ 292 V(JS_CONTEXT_EXTENSION_OBJECT_TYPE) \ 293 V(JS_GLOBAL_OBJECT_TYPE) \ 294 V(JS_BUILTINS_OBJECT_TYPE) \ 295 V(JS_GLOBAL_PROXY_TYPE) \ 296 V(JS_ARRAY_TYPE) \ 297 V(JS_PROXY_TYPE) \ 298 V(JS_WEAK_MAP_TYPE) \ 299 V(JS_REGEXP_TYPE) \ 300 \ 301 V(JS_FUNCTION_TYPE) \ 302 V(JS_FUNCTION_PROXY_TYPE) \ 303 304#ifdef ENABLE_DEBUGGER_SUPPORT 305#define INSTANCE_TYPE_LIST_DEBUGGER(V) \ 306 V(DEBUG_INFO_TYPE) \ 307 V(BREAK_POINT_INFO_TYPE) 308#else 309#define INSTANCE_TYPE_LIST_DEBUGGER(V) 310#endif 311 312#define INSTANCE_TYPE_LIST(V) \ 313 INSTANCE_TYPE_LIST_ALL(V) \ 314 INSTANCE_TYPE_LIST_DEBUGGER(V) 315 316 317// Since string types are not consecutive, this macro is used to 318// iterate over them. 319#define STRING_TYPE_LIST(V) \ 320 V(SYMBOL_TYPE, \ 321 kVariableSizeSentinel, \ 322 symbol, \ 323 Symbol) \ 324 V(ASCII_SYMBOL_TYPE, \ 325 kVariableSizeSentinel, \ 326 ascii_symbol, \ 327 AsciiSymbol) \ 328 V(CONS_SYMBOL_TYPE, \ 329 ConsString::kSize, \ 330 cons_symbol, \ 331 ConsSymbol) \ 332 V(CONS_ASCII_SYMBOL_TYPE, \ 333 ConsString::kSize, \ 334 cons_ascii_symbol, \ 335 ConsAsciiSymbol) \ 336 V(EXTERNAL_SYMBOL_TYPE, \ 337 ExternalTwoByteString::kSize, \ 338 external_symbol, \ 339 ExternalSymbol) \ 340 V(EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE, \ 341 ExternalTwoByteString::kSize, \ 342 external_symbol_with_ascii_data, \ 343 ExternalSymbolWithAsciiData) \ 344 V(EXTERNAL_ASCII_SYMBOL_TYPE, \ 345 ExternalAsciiString::kSize, \ 346 external_ascii_symbol, \ 347 ExternalAsciiSymbol) \ 348 V(SHORT_EXTERNAL_SYMBOL_TYPE, \ 349 ExternalTwoByteString::kShortSize, \ 350 short_external_symbol, \ 351 ShortExternalSymbol) \ 352 V(SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE, \ 353 ExternalTwoByteString::kShortSize, \ 354 short_external_symbol_with_ascii_data, \ 355 ShortExternalSymbolWithAsciiData) \ 356 V(SHORT_EXTERNAL_ASCII_SYMBOL_TYPE, \ 357 ExternalAsciiString::kShortSize, \ 358 short_external_ascii_symbol, \ 359 ShortExternalAsciiSymbol) \ 360 V(STRING_TYPE, \ 361 kVariableSizeSentinel, \ 362 string, \ 363 String) \ 364 V(ASCII_STRING_TYPE, \ 365 kVariableSizeSentinel, \ 366 ascii_string, \ 367 AsciiString) \ 368 V(CONS_STRING_TYPE, \ 369 ConsString::kSize, \ 370 cons_string, \ 371 ConsString) \ 372 V(CONS_ASCII_STRING_TYPE, \ 373 ConsString::kSize, \ 374 cons_ascii_string, \ 375 ConsAsciiString) \ 376 V(SLICED_STRING_TYPE, \ 377 SlicedString::kSize, \ 378 sliced_string, \ 379 SlicedString) \ 380 V(SLICED_ASCII_STRING_TYPE, \ 381 SlicedString::kSize, \ 382 sliced_ascii_string, \ 383 SlicedAsciiString) \ 384 V(EXTERNAL_STRING_TYPE, \ 385 ExternalTwoByteString::kSize, \ 386 external_string, \ 387 ExternalString) \ 388 V(EXTERNAL_STRING_WITH_ASCII_DATA_TYPE, \ 389 ExternalTwoByteString::kSize, \ 390 external_string_with_ascii_data, \ 391 ExternalStringWithAsciiData) \ 392 V(EXTERNAL_ASCII_STRING_TYPE, \ 393 ExternalAsciiString::kSize, \ 394 external_ascii_string, \ 395 ExternalAsciiString) \ 396 V(SHORT_EXTERNAL_STRING_TYPE, \ 397 ExternalTwoByteString::kShortSize, \ 398 short_external_string, \ 399 ShortExternalString) \ 400 V(SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE, \ 401 ExternalTwoByteString::kShortSize, \ 402 short_external_string_with_ascii_data, \ 403 ShortExternalStringWithAsciiData) \ 404 V(SHORT_EXTERNAL_ASCII_STRING_TYPE, \ 405 ExternalAsciiString::kShortSize, \ 406 short_external_ascii_string, \ 407 ShortExternalAsciiString) 408 409// A struct is a simple object a set of object-valued fields. Including an 410// object type in this causes the compiler to generate most of the boilerplate 411// code for the class including allocation and garbage collection routines, 412// casts and predicates. All you need to define is the class, methods and 413// object verification routines. Easy, no? 414// 415// Note that for subtle reasons related to the ordering or numerical values of 416// type tags, elements in this list have to be added to the INSTANCE_TYPE_LIST 417// manually. 418#define STRUCT_LIST_ALL(V) \ 419 V(ACCESSOR_INFO, AccessorInfo, accessor_info) \ 420 V(ACCESS_CHECK_INFO, AccessCheckInfo, access_check_info) \ 421 V(INTERCEPTOR_INFO, InterceptorInfo, interceptor_info) \ 422 V(CALL_HANDLER_INFO, CallHandlerInfo, call_handler_info) \ 423 V(FUNCTION_TEMPLATE_INFO, FunctionTemplateInfo, function_template_info) \ 424 V(OBJECT_TEMPLATE_INFO, ObjectTemplateInfo, object_template_info) \ 425 V(SIGNATURE_INFO, SignatureInfo, signature_info) \ 426 V(TYPE_SWITCH_INFO, TypeSwitchInfo, type_switch_info) \ 427 V(SCRIPT, Script, script) \ 428 V(CODE_CACHE, CodeCache, code_cache) \ 429 V(POLYMORPHIC_CODE_CACHE, PolymorphicCodeCache, polymorphic_code_cache) 430 431#ifdef ENABLE_DEBUGGER_SUPPORT 432#define STRUCT_LIST_DEBUGGER(V) \ 433 V(DEBUG_INFO, DebugInfo, debug_info) \ 434 V(BREAK_POINT_INFO, BreakPointInfo, break_point_info) 435#else 436#define STRUCT_LIST_DEBUGGER(V) 437#endif 438 439#define STRUCT_LIST(V) \ 440 STRUCT_LIST_ALL(V) \ 441 STRUCT_LIST_DEBUGGER(V) 442 443// We use the full 8 bits of the instance_type field to encode heap object 444// instance types. The high-order bit (bit 7) is set if the object is not a 445// string, and cleared if it is a string. 446const uint32_t kIsNotStringMask = 0x80; 447const uint32_t kStringTag = 0x0; 448const uint32_t kNotStringTag = 0x80; 449 450// Bit 6 indicates that the object is a symbol (if set) or not (if cleared). 451// There are not enough types that the non-string types (with bit 7 set) can 452// have bit 6 set too. 453const uint32_t kIsSymbolMask = 0x40; 454const uint32_t kNotSymbolTag = 0x0; 455const uint32_t kSymbolTag = 0x40; 456 457// If bit 7 is clear then bit 2 indicates whether the string consists of 458// two-byte characters or one-byte characters. 459const uint32_t kStringEncodingMask = 0x4; 460const uint32_t kTwoByteStringTag = 0x0; 461const uint32_t kAsciiStringTag = 0x4; 462 463// If bit 7 is clear, the low-order 2 bits indicate the representation 464// of the string. 465const uint32_t kStringRepresentationMask = 0x03; 466enum StringRepresentationTag { 467 kSeqStringTag = 0x0, 468 kConsStringTag = 0x1, 469 kExternalStringTag = 0x2, 470 kSlicedStringTag = 0x3 471}; 472const uint32_t kIsIndirectStringMask = 0x1; 473const uint32_t kIsIndirectStringTag = 0x1; 474STATIC_ASSERT((kSeqStringTag & kIsIndirectStringMask) == 0); 475STATIC_ASSERT((kExternalStringTag & kIsIndirectStringMask) == 0); 476STATIC_ASSERT( 477 (kConsStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); 478STATIC_ASSERT( 479 (kSlicedStringTag & kIsIndirectStringMask) == kIsIndirectStringTag); 480 481// Use this mask to distinguish between cons and slice only after making 482// sure that the string is one of the two (an indirect string). 483const uint32_t kSlicedNotConsMask = kSlicedStringTag & ~kConsStringTag; 484STATIC_ASSERT(IS_POWER_OF_TWO(kSlicedNotConsMask) && kSlicedNotConsMask != 0); 485 486// If bit 7 is clear, then bit 3 indicates whether this two-byte 487// string actually contains ascii data. 488const uint32_t kAsciiDataHintMask = 0x08; 489const uint32_t kAsciiDataHintTag = 0x08; 490 491// If bit 7 is clear and string representation indicates an external string, 492// then bit 4 indicates whether the data pointer is cached. 493const uint32_t kShortExternalStringMask = 0x10; 494const uint32_t kShortExternalStringTag = 0x10; 495 496 497// A ConsString with an empty string as the right side is a candidate 498// for being shortcut by the garbage collector unless it is a 499// symbol. It's not common to have non-flat symbols, so we do not 500// shortcut them thereby avoiding turning symbols into strings. See 501// heap.cc and mark-compact.cc. 502const uint32_t kShortcutTypeMask = 503 kIsNotStringMask | 504 kIsSymbolMask | 505 kStringRepresentationMask; 506const uint32_t kShortcutTypeTag = kConsStringTag; 507 508 509enum InstanceType { 510 // String types. 511 SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kSeqStringTag, 512 ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kSeqStringTag, 513 CONS_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kConsStringTag, 514 CONS_ASCII_SYMBOL_TYPE = kAsciiStringTag | kSymbolTag | kConsStringTag, 515 SHORT_EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | 516 kExternalStringTag | kShortExternalStringTag, 517 SHORT_EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE = 518 kTwoByteStringTag | kSymbolTag | kExternalStringTag | 519 kAsciiDataHintTag | kShortExternalStringTag, 520 SHORT_EXTERNAL_ASCII_SYMBOL_TYPE = kAsciiStringTag | kExternalStringTag | 521 kSymbolTag | kShortExternalStringTag, 522 EXTERNAL_SYMBOL_TYPE = kTwoByteStringTag | kSymbolTag | kExternalStringTag, 523 EXTERNAL_SYMBOL_WITH_ASCII_DATA_TYPE = 524 kTwoByteStringTag | kSymbolTag | kExternalStringTag | kAsciiDataHintTag, 525 EXTERNAL_ASCII_SYMBOL_TYPE = 526 kAsciiStringTag | kSymbolTag | kExternalStringTag, 527 STRING_TYPE = kTwoByteStringTag | kSeqStringTag, 528 ASCII_STRING_TYPE = kAsciiStringTag | kSeqStringTag, 529 CONS_STRING_TYPE = kTwoByteStringTag | kConsStringTag, 530 CONS_ASCII_STRING_TYPE = kAsciiStringTag | kConsStringTag, 531 SLICED_STRING_TYPE = kTwoByteStringTag | kSlicedStringTag, 532 SLICED_ASCII_STRING_TYPE = kAsciiStringTag | kSlicedStringTag, 533 SHORT_EXTERNAL_STRING_TYPE = 534 kTwoByteStringTag | kExternalStringTag | kShortExternalStringTag, 535 SHORT_EXTERNAL_STRING_WITH_ASCII_DATA_TYPE = 536 kTwoByteStringTag | kExternalStringTag | 537 kAsciiDataHintTag | kShortExternalStringTag, 538 SHORT_EXTERNAL_ASCII_STRING_TYPE = 539 kAsciiStringTag | kExternalStringTag | kShortExternalStringTag, 540 EXTERNAL_STRING_TYPE = kTwoByteStringTag | kExternalStringTag, 541 EXTERNAL_STRING_WITH_ASCII_DATA_TYPE = 542 kTwoByteStringTag | kExternalStringTag | kAsciiDataHintTag, 543 // LAST_STRING_TYPE 544 EXTERNAL_ASCII_STRING_TYPE = kAsciiStringTag | kExternalStringTag, 545 PRIVATE_EXTERNAL_ASCII_STRING_TYPE = EXTERNAL_ASCII_STRING_TYPE, 546 547 // Objects allocated in their own spaces (never in new space). 548 MAP_TYPE = kNotStringTag, // FIRST_NONSTRING_TYPE 549 CODE_TYPE, 550 ODDBALL_TYPE, 551 JS_GLOBAL_PROPERTY_CELL_TYPE, 552 553 // "Data", objects that cannot contain non-map-word pointers to heap 554 // objects. 555 HEAP_NUMBER_TYPE, 556 FOREIGN_TYPE, 557 BYTE_ARRAY_TYPE, 558 FREE_SPACE_TYPE, 559 EXTERNAL_BYTE_ARRAY_TYPE, // FIRST_EXTERNAL_ARRAY_TYPE 560 EXTERNAL_UNSIGNED_BYTE_ARRAY_TYPE, 561 EXTERNAL_SHORT_ARRAY_TYPE, 562 EXTERNAL_UNSIGNED_SHORT_ARRAY_TYPE, 563 EXTERNAL_INT_ARRAY_TYPE, 564 EXTERNAL_UNSIGNED_INT_ARRAY_TYPE, 565 EXTERNAL_FLOAT_ARRAY_TYPE, 566 EXTERNAL_DOUBLE_ARRAY_TYPE, 567 EXTERNAL_PIXEL_ARRAY_TYPE, // LAST_EXTERNAL_ARRAY_TYPE 568 FIXED_DOUBLE_ARRAY_TYPE, 569 FILLER_TYPE, // LAST_DATA_TYPE 570 571 // Structs. 572 ACCESSOR_INFO_TYPE, 573 ACCESS_CHECK_INFO_TYPE, 574 INTERCEPTOR_INFO_TYPE, 575 CALL_HANDLER_INFO_TYPE, 576 FUNCTION_TEMPLATE_INFO_TYPE, 577 OBJECT_TEMPLATE_INFO_TYPE, 578 SIGNATURE_INFO_TYPE, 579 TYPE_SWITCH_INFO_TYPE, 580 SCRIPT_TYPE, 581 CODE_CACHE_TYPE, 582 POLYMORPHIC_CODE_CACHE_TYPE, 583 // The following two instance types are only used when ENABLE_DEBUGGER_SUPPORT 584 // is defined. However as include/v8.h contain some of the instance type 585 // constants always having them avoids them getting different numbers 586 // depending on whether ENABLE_DEBUGGER_SUPPORT is defined or not. 587 DEBUG_INFO_TYPE, 588 BREAK_POINT_INFO_TYPE, 589 590 FIXED_ARRAY_TYPE, 591 SHARED_FUNCTION_INFO_TYPE, 592 593 JS_MESSAGE_OBJECT_TYPE, 594 595 // All the following types are subtypes of JSReceiver, which corresponds to 596 // objects in the JS sense. The first and the last type in this range are 597 // the two forms of function. This organization enables using the same 598 // compares for checking the JS_RECEIVER/SPEC_OBJECT range and the 599 // NONCALLABLE_JS_OBJECT range. 600 JS_FUNCTION_PROXY_TYPE, // FIRST_JS_RECEIVER_TYPE, FIRST_JS_PROXY_TYPE 601 JS_PROXY_TYPE, // LAST_JS_PROXY_TYPE 602 603 JS_VALUE_TYPE, // FIRST_JS_OBJECT_TYPE 604 JS_OBJECT_TYPE, 605 JS_CONTEXT_EXTENSION_OBJECT_TYPE, 606 JS_GLOBAL_OBJECT_TYPE, 607 JS_BUILTINS_OBJECT_TYPE, 608 JS_GLOBAL_PROXY_TYPE, 609 JS_ARRAY_TYPE, 610 JS_SET_TYPE, 611 JS_MAP_TYPE, 612 JS_WEAK_MAP_TYPE, 613 614 JS_REGEXP_TYPE, 615 616 JS_FUNCTION_TYPE, // LAST_JS_OBJECT_TYPE, LAST_JS_RECEIVER_TYPE 617 618 // Pseudo-types 619 FIRST_TYPE = 0x0, 620 LAST_TYPE = JS_FUNCTION_TYPE, 621 INVALID_TYPE = FIRST_TYPE - 1, 622 FIRST_NONSTRING_TYPE = MAP_TYPE, 623 // Boundaries for testing for an external array. 624 FIRST_EXTERNAL_ARRAY_TYPE = EXTERNAL_BYTE_ARRAY_TYPE, 625 LAST_EXTERNAL_ARRAY_TYPE = EXTERNAL_PIXEL_ARRAY_TYPE, 626 // Boundary for promotion to old data space/old pointer space. 627 LAST_DATA_TYPE = FILLER_TYPE, 628 // Boundary for objects represented as JSReceiver (i.e. JSObject or JSProxy). 629 // Note that there is no range for JSObject or JSProxy, since their subtypes 630 // are not continuous in this enum! The enum ranges instead reflect the 631 // external class names, where proxies are treated as either ordinary objects, 632 // or functions. 633 FIRST_JS_RECEIVER_TYPE = JS_FUNCTION_PROXY_TYPE, 634 LAST_JS_RECEIVER_TYPE = LAST_TYPE, 635 // Boundaries for testing the types represented as JSObject 636 FIRST_JS_OBJECT_TYPE = JS_VALUE_TYPE, 637 LAST_JS_OBJECT_TYPE = LAST_TYPE, 638 // Boundaries for testing the types represented as JSProxy 639 FIRST_JS_PROXY_TYPE = JS_FUNCTION_PROXY_TYPE, 640 LAST_JS_PROXY_TYPE = JS_PROXY_TYPE, 641 // Boundaries for testing whether the type is a JavaScript object. 642 FIRST_SPEC_OBJECT_TYPE = FIRST_JS_RECEIVER_TYPE, 643 LAST_SPEC_OBJECT_TYPE = LAST_JS_RECEIVER_TYPE, 644 // Boundaries for testing the types for which typeof is "object". 645 FIRST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_PROXY_TYPE, 646 LAST_NONCALLABLE_SPEC_OBJECT_TYPE = JS_REGEXP_TYPE, 647 // Note that the types for which typeof is "function" are not continuous. 648 // Define this so that we can put assertions on discrete checks. 649 NUM_OF_CALLABLE_SPEC_OBJECT_TYPES = 2 650}; 651 652const int kExternalArrayTypeCount = 653 LAST_EXTERNAL_ARRAY_TYPE - FIRST_EXTERNAL_ARRAY_TYPE + 1; 654 655STATIC_CHECK(JS_OBJECT_TYPE == Internals::kJSObjectType); 656STATIC_CHECK(FIRST_NONSTRING_TYPE == Internals::kFirstNonstringType); 657STATIC_CHECK(FOREIGN_TYPE == Internals::kForeignType); 658 659 660enum CompareResult { 661 LESS = -1, 662 EQUAL = 0, 663 GREATER = 1, 664 665 NOT_EQUAL = GREATER 666}; 667 668 669#define DECL_BOOLEAN_ACCESSORS(name) \ 670 inline bool name(); \ 671 inline void set_##name(bool value); \ 672 673 674#define DECL_ACCESSORS(name, type) \ 675 inline type* name(); \ 676 inline void set_##name(type* value, \ 677 WriteBarrierMode mode = UPDATE_WRITE_BARRIER); \ 678 679 680class DictionaryElementsAccessor; 681class ElementsAccessor; 682class FixedArrayBase; 683class ObjectVisitor; 684class StringStream; 685class Failure; 686 687struct ValueInfo : public Malloced { 688 ValueInfo() : type(FIRST_TYPE), ptr(NULL), str(NULL), number(0) { } 689 InstanceType type; 690 Object* ptr; 691 const char* str; 692 double number; 693}; 694 695 696// A template-ized version of the IsXXX functions. 697template <class C> static inline bool Is(Object* obj); 698 699 700class MaybeObject BASE_EMBEDDED { 701 public: 702 inline bool IsFailure(); 703 inline bool IsRetryAfterGC(); 704 inline bool IsOutOfMemory(); 705 inline bool IsException(); 706 INLINE(bool IsTheHole()); 707 inline bool ToObject(Object** obj) { 708 if (IsFailure()) return false; 709 *obj = reinterpret_cast<Object*>(this); 710 return true; 711 } 712 inline Failure* ToFailureUnchecked() { 713 ASSERT(IsFailure()); 714 return reinterpret_cast<Failure*>(this); 715 } 716 inline Object* ToObjectUnchecked() { 717 ASSERT(!IsFailure()); 718 return reinterpret_cast<Object*>(this); 719 } 720 inline Object* ToObjectChecked() { 721 CHECK(!IsFailure()); 722 return reinterpret_cast<Object*>(this); 723 } 724 725 template<typename T> 726 inline bool To(T** obj) { 727 if (IsFailure()) return false; 728 *obj = T::cast(reinterpret_cast<Object*>(this)); 729 return true; 730 } 731 732#ifdef OBJECT_PRINT 733 // Prints this object with details. 734 inline void Print() { 735 Print(stdout); 736 } 737 inline void PrintLn() { 738 PrintLn(stdout); 739 } 740 void Print(FILE* out); 741 void PrintLn(FILE* out); 742#endif 743#ifdef DEBUG 744 // Verifies the object. 745 void Verify(); 746#endif 747}; 748 749 750#define OBJECT_TYPE_LIST(V) \ 751 V(Smi) \ 752 V(HeapObject) \ 753 V(Number) \ 754 755#define HEAP_OBJECT_TYPE_LIST(V) \ 756 V(HeapNumber) \ 757 V(String) \ 758 V(Symbol) \ 759 V(SeqString) \ 760 V(ExternalString) \ 761 V(ConsString) \ 762 V(SlicedString) \ 763 V(ExternalTwoByteString) \ 764 V(ExternalAsciiString) \ 765 V(SeqTwoByteString) \ 766 V(SeqAsciiString) \ 767 \ 768 V(ExternalArray) \ 769 V(ExternalByteArray) \ 770 V(ExternalUnsignedByteArray) \ 771 V(ExternalShortArray) \ 772 V(ExternalUnsignedShortArray) \ 773 V(ExternalIntArray) \ 774 V(ExternalUnsignedIntArray) \ 775 V(ExternalFloatArray) \ 776 V(ExternalDoubleArray) \ 777 V(ExternalPixelArray) \ 778 V(ByteArray) \ 779 V(FreeSpace) \ 780 V(JSReceiver) \ 781 V(JSObject) \ 782 V(JSContextExtensionObject) \ 783 V(Map) \ 784 V(DescriptorArray) \ 785 V(DeoptimizationInputData) \ 786 V(DeoptimizationOutputData) \ 787 V(FixedArray) \ 788 V(FixedDoubleArray) \ 789 V(Context) \ 790 V(GlobalContext) \ 791 V(ScopeInfo) \ 792 V(JSFunction) \ 793 V(Code) \ 794 V(Oddball) \ 795 V(SharedFunctionInfo) \ 796 V(JSValue) \ 797 V(JSMessageObject) \ 798 V(StringWrapper) \ 799 V(Foreign) \ 800 V(Boolean) \ 801 V(JSArray) \ 802 V(JSProxy) \ 803 V(JSFunctionProxy) \ 804 V(JSSet) \ 805 V(JSMap) \ 806 V(JSWeakMap) \ 807 V(JSRegExp) \ 808 V(HashTable) \ 809 V(Dictionary) \ 810 V(SymbolTable) \ 811 V(JSFunctionResultCache) \ 812 V(NormalizedMapCache) \ 813 V(CompilationCacheTable) \ 814 V(CodeCacheHashTable) \ 815 V(PolymorphicCodeCacheHashTable) \ 816 V(MapCache) \ 817 V(Primitive) \ 818 V(GlobalObject) \ 819 V(JSGlobalObject) \ 820 V(JSBuiltinsObject) \ 821 V(JSGlobalProxy) \ 822 V(UndetectableObject) \ 823 V(AccessCheckNeeded) \ 824 V(JSGlobalPropertyCell) \ 825 826 827class JSReceiver; 828 829// Object is the abstract superclass for all classes in the 830// object hierarchy. 831// Object does not use any virtual functions to avoid the 832// allocation of the C++ vtable. 833// Since Smi and Failure are subclasses of Object no 834// data members can be present in Object. 835class Object : public MaybeObject { 836 public: 837 // Type testing. 838#define IS_TYPE_FUNCTION_DECL(type_) inline bool Is##type_(); 839 OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL) 840 HEAP_OBJECT_TYPE_LIST(IS_TYPE_FUNCTION_DECL) 841#undef IS_TYPE_FUNCTION_DECL 842 843 inline bool IsFixedArrayBase(); 844 845 // Returns true if this object is an instance of the specified 846 // function template. 847 inline bool IsInstanceOf(FunctionTemplateInfo* type); 848 849 inline bool IsStruct(); 850#define DECLARE_STRUCT_PREDICATE(NAME, Name, name) inline bool Is##Name(); 851 STRUCT_LIST(DECLARE_STRUCT_PREDICATE) 852#undef DECLARE_STRUCT_PREDICATE 853 854 INLINE(bool IsSpecObject()); 855 INLINE(bool IsSpecFunction()); 856 857 // Oddball testing. 858 INLINE(bool IsUndefined()); 859 INLINE(bool IsNull()); 860 INLINE(bool IsTheHole()); // Shadows MaybeObject's implementation. 861 INLINE(bool IsTrue()); 862 INLINE(bool IsFalse()); 863 inline bool IsArgumentsMarker(); 864 inline bool NonFailureIsHeapObject(); 865 866 // Filler objects (fillers and free space objects). 867 inline bool IsFiller(); 868 869 // Extract the number. 870 inline double Number(); 871 872 // Returns true if the object is of the correct type to be used as a 873 // implementation of a JSObject's elements. 874 inline bool HasValidElements(); 875 876 inline bool HasSpecificClassOf(String* name); 877 878 MUST_USE_RESULT MaybeObject* ToObject(); // ECMA-262 9.9. 879 Object* ToBoolean(); // ECMA-262 9.2. 880 881 // Convert to a JSObject if needed. 882 // global_context is used when creating wrapper object. 883 MUST_USE_RESULT MaybeObject* ToObject(Context* global_context); 884 885 // Converts this to a Smi if possible. 886 // Failure is returned otherwise. 887 MUST_USE_RESULT inline MaybeObject* ToSmi(); 888 889 void Lookup(String* name, LookupResult* result); 890 891 // Property access. 892 MUST_USE_RESULT inline MaybeObject* GetProperty(String* key); 893 MUST_USE_RESULT inline MaybeObject* GetProperty( 894 String* key, 895 PropertyAttributes* attributes); 896 MUST_USE_RESULT MaybeObject* GetPropertyWithReceiver( 897 Object* receiver, 898 String* key, 899 PropertyAttributes* attributes); 900 901 static Handle<Object> GetProperty(Handle<Object> object, 902 Handle<Object> receiver, 903 LookupResult* result, 904 Handle<String> key, 905 PropertyAttributes* attributes); 906 907 MUST_USE_RESULT MaybeObject* GetProperty(Object* receiver, 908 LookupResult* result, 909 String* key, 910 PropertyAttributes* attributes); 911 912 MUST_USE_RESULT MaybeObject* GetPropertyWithDefinedGetter(Object* receiver, 913 JSReceiver* getter); 914 915 static Handle<Object> GetElement(Handle<Object> object, uint32_t index); 916 inline MaybeObject* GetElement(uint32_t index); 917 // For use when we know that no exception can be thrown. 918 inline Object* GetElementNoExceptionThrown(uint32_t index); 919 MaybeObject* GetElementWithReceiver(Object* receiver, uint32_t index); 920 921 // Return the object's prototype (might be Heap::null_value()). 922 Object* GetPrototype(); 923 924 // Returns the permanent hash code associated with this object depending on 925 // the actual object type. Might return a failure in case no hash was 926 // created yet or GC was caused by creation. 927 MUST_USE_RESULT MaybeObject* GetHash(CreationFlag flag); 928 929 // Checks whether this object has the same value as the given one. This 930 // function is implemented according to ES5, section 9.12 and can be used 931 // to implement the Harmony "egal" function. 932 bool SameValue(Object* other); 933 934 // Tries to convert an object to an array index. Returns true and sets 935 // the output parameter if it succeeds. 936 inline bool ToArrayIndex(uint32_t* index); 937 938 // Returns true if this is a JSValue containing a string and the index is 939 // < the length of the string. Used to implement [] on strings. 940 inline bool IsStringObjectWithCharacterAt(uint32_t index); 941 942#ifdef DEBUG 943 // Verify a pointer is a valid object pointer. 944 static void VerifyPointer(Object* p); 945#endif 946 947 // Prints this object without details. 948 inline void ShortPrint() { 949 ShortPrint(stdout); 950 } 951 void ShortPrint(FILE* out); 952 953 // Prints this object without details to a message accumulator. 954 void ShortPrint(StringStream* accumulator); 955 956 // Casting: This cast is only needed to satisfy macros in objects-inl.h. 957 static Object* cast(Object* value) { return value; } 958 959 // Layout description. 960 static const int kHeaderSize = 0; // Object does not take up any space. 961 962 private: 963 DISALLOW_IMPLICIT_CONSTRUCTORS(Object); 964}; 965 966 967// Smi represents integer Numbers that can be stored in 31 bits. 968// Smis are immediate which means they are NOT allocated in the heap. 969// The this pointer has the following format: [31 bit signed int] 0 970// For long smis it has the following format: 971// [32 bit signed int] [31 bits zero padding] 0 972// Smi stands for small integer. 973class Smi: public Object { 974 public: 975 // Returns the integer value. 976 inline int value(); 977 978 // Convert a value to a Smi object. 979 static inline Smi* FromInt(int value); 980 981 static inline Smi* FromIntptr(intptr_t value); 982 983 // Returns whether value can be represented in a Smi. 984 static inline bool IsValid(intptr_t value); 985 986 // Casting. 987 static inline Smi* cast(Object* object); 988 989 // Dispatched behavior. 990 inline void SmiPrint() { 991 SmiPrint(stdout); 992 } 993 void SmiPrint(FILE* out); 994 void SmiPrint(StringStream* accumulator); 995#ifdef DEBUG 996 void SmiVerify(); 997#endif 998 999 static const int kMinValue = 1000 (static_cast<unsigned int>(-1)) << (kSmiValueSize - 1); 1001 static const int kMaxValue = -(kMinValue + 1); 1002 1003 private: 1004 DISALLOW_IMPLICIT_CONSTRUCTORS(Smi); 1005}; 1006 1007 1008// Failure is used for reporting out of memory situations and 1009// propagating exceptions through the runtime system. Failure objects 1010// are transient and cannot occur as part of the object graph. 1011// 1012// Failures are a single word, encoded as follows: 1013// +-------------------------+---+--+--+ 1014// |.........unused..........|sss|tt|11| 1015// +-------------------------+---+--+--+ 1016// 7 6 4 32 10 1017// 1018// 1019// The low two bits, 0-1, are the failure tag, 11. The next two bits, 1020// 2-3, are a failure type tag 'tt' with possible values: 1021// 00 RETRY_AFTER_GC 1022// 01 EXCEPTION 1023// 10 INTERNAL_ERROR 1024// 11 OUT_OF_MEMORY_EXCEPTION 1025// 1026// The next three bits, 4-6, are an allocation space tag 'sss'. The 1027// allocation space tag is 000 for all failure types except 1028// RETRY_AFTER_GC. For RETRY_AFTER_GC, the possible values are the 1029// allocation spaces (the encoding is found in globals.h). 1030 1031// Failure type tag info. 1032const int kFailureTypeTagSize = 2; 1033const int kFailureTypeTagMask = (1 << kFailureTypeTagSize) - 1; 1034 1035class Failure: public MaybeObject { 1036 public: 1037 // RuntimeStubs assumes EXCEPTION = 1 in the compiler-generated code. 1038 enum Type { 1039 RETRY_AFTER_GC = 0, 1040 EXCEPTION = 1, // Returning this marker tells the real exception 1041 // is in Isolate::pending_exception. 1042 INTERNAL_ERROR = 2, 1043 OUT_OF_MEMORY_EXCEPTION = 3 1044 }; 1045 1046 inline Type type() const; 1047 1048 // Returns the space that needs to be collected for RetryAfterGC failures. 1049 inline AllocationSpace allocation_space() const; 1050 1051 inline bool IsInternalError() const; 1052 inline bool IsOutOfMemoryException() const; 1053 1054 static inline Failure* RetryAfterGC(AllocationSpace space); 1055 static inline Failure* RetryAfterGC(); // NEW_SPACE 1056 static inline Failure* Exception(); 1057 static inline Failure* InternalError(); 1058 static inline Failure* OutOfMemoryException(); 1059 // Casting. 1060 static inline Failure* cast(MaybeObject* object); 1061 1062 // Dispatched behavior. 1063 inline void FailurePrint() { 1064 FailurePrint(stdout); 1065 } 1066 void FailurePrint(FILE* out); 1067 void FailurePrint(StringStream* accumulator); 1068#ifdef DEBUG 1069 void FailureVerify(); 1070#endif 1071 1072 private: 1073 inline intptr_t value() const; 1074 static inline Failure* Construct(Type type, intptr_t value = 0); 1075 1076 DISALLOW_IMPLICIT_CONSTRUCTORS(Failure); 1077}; 1078 1079 1080// Heap objects typically have a map pointer in their first word. However, 1081// during GC other data (eg, mark bits, forwarding addresses) is sometimes 1082// encoded in the first word. The class MapWord is an abstraction of the 1083// value in a heap object's first word. 1084class MapWord BASE_EMBEDDED { 1085 public: 1086 // Normal state: the map word contains a map pointer. 1087 1088 // Create a map word from a map pointer. 1089 static inline MapWord FromMap(Map* map); 1090 1091 // View this map word as a map pointer. 1092 inline Map* ToMap(); 1093 1094 1095 // Scavenge collection: the map word of live objects in the from space 1096 // contains a forwarding address (a heap object pointer in the to space). 1097 1098 // True if this map word is a forwarding address for a scavenge 1099 // collection. Only valid during a scavenge collection (specifically, 1100 // when all map words are heap object pointers, ie. not during a full GC). 1101 inline bool IsForwardingAddress(); 1102 1103 // Create a map word from a forwarding address. 1104 static inline MapWord FromForwardingAddress(HeapObject* object); 1105 1106 // View this map word as a forwarding address. 1107 inline HeapObject* ToForwardingAddress(); 1108 1109 static inline MapWord FromRawValue(uintptr_t value) { 1110 return MapWord(value); 1111 } 1112 1113 inline uintptr_t ToRawValue() { 1114 return value_; 1115 } 1116 1117 private: 1118 // HeapObject calls the private constructor and directly reads the value. 1119 friend class HeapObject; 1120 1121 explicit MapWord(uintptr_t value) : value_(value) {} 1122 1123 uintptr_t value_; 1124}; 1125 1126 1127// HeapObject is the superclass for all classes describing heap allocated 1128// objects. 1129class HeapObject: public Object { 1130 public: 1131 // [map]: Contains a map which contains the object's reflective 1132 // information. 1133 inline Map* map(); 1134 inline void set_map(Map* value); 1135 inline void set_map_unsafe(Map* value); 1136 1137 // During garbage collection, the map word of a heap object does not 1138 // necessarily contain a map pointer. 1139 inline MapWord map_word(); 1140 inline void set_map_word(MapWord map_word); 1141 1142 // The Heap the object was allocated in. Used also to access Isolate. 1143 inline Heap* GetHeap(); 1144 1145 // Convenience method to get current isolate. This method can be 1146 // accessed only when its result is the same as 1147 // Isolate::Current(), it ASSERTs this. See also comment for GetHeap. 1148 inline Isolate* GetIsolate(); 1149 1150 // Converts an address to a HeapObject pointer. 1151 static inline HeapObject* FromAddress(Address address); 1152 1153 // Returns the address of this HeapObject. 1154 inline Address address(); 1155 1156 // Iterates over pointers contained in the object (including the Map) 1157 void Iterate(ObjectVisitor* v); 1158 1159 // Iterates over all pointers contained in the object except the 1160 // first map pointer. The object type is given in the first 1161 // parameter. This function does not access the map pointer in the 1162 // object, and so is safe to call while the map pointer is modified. 1163 void IterateBody(InstanceType type, int object_size, ObjectVisitor* v); 1164 1165 // Returns the heap object's size in bytes 1166 inline int Size(); 1167 1168 // Given a heap object's map pointer, returns the heap size in bytes 1169 // Useful when the map pointer field is used for other purposes. 1170 // GC internal. 1171 inline int SizeFromMap(Map* map); 1172 1173 // Returns the field at offset in obj, as a read/write Object* reference. 1174 // Does no checking, and is safe to use during GC, while maps are invalid. 1175 // Does not invoke write barrier, so should only be assigned to 1176 // during marking GC. 1177 static inline Object** RawField(HeapObject* obj, int offset); 1178 1179 // Casting. 1180 static inline HeapObject* cast(Object* obj); 1181 1182 // Return the write barrier mode for this. Callers of this function 1183 // must be able to present a reference to an AssertNoAllocation 1184 // object as a sign that they are not going to use this function 1185 // from code that allocates and thus invalidates the returned write 1186 // barrier mode. 1187 inline WriteBarrierMode GetWriteBarrierMode(const AssertNoAllocation&); 1188 1189 // Dispatched behavior. 1190 void HeapObjectShortPrint(StringStream* accumulator); 1191#ifdef OBJECT_PRINT 1192 inline void HeapObjectPrint() { 1193 HeapObjectPrint(stdout); 1194 } 1195 void HeapObjectPrint(FILE* out); 1196 void PrintHeader(FILE* out, const char* id); 1197#endif 1198 1199#ifdef DEBUG 1200 void HeapObjectVerify(); 1201 inline void VerifyObjectField(int offset); 1202 inline void VerifySmiField(int offset); 1203 1204 // Verify a pointer is a valid HeapObject pointer that points to object 1205 // areas in the heap. 1206 static void VerifyHeapPointer(Object* p); 1207#endif 1208 1209 // Layout description. 1210 // First field in a heap object is map. 1211 static const int kMapOffset = Object::kHeaderSize; 1212 static const int kHeaderSize = kMapOffset + kPointerSize; 1213 1214 STATIC_CHECK(kMapOffset == Internals::kHeapObjectMapOffset); 1215 1216 protected: 1217 // helpers for calling an ObjectVisitor to iterate over pointers in the 1218 // half-open range [start, end) specified as integer offsets 1219 inline void IteratePointers(ObjectVisitor* v, int start, int end); 1220 // as above, for the single element at "offset" 1221 inline void IteratePointer(ObjectVisitor* v, int offset); 1222 1223 private: 1224 DISALLOW_IMPLICIT_CONSTRUCTORS(HeapObject); 1225}; 1226 1227 1228#define SLOT_ADDR(obj, offset) \ 1229 reinterpret_cast<Object**>((obj)->address() + offset) 1230 1231// This class describes a body of an object of a fixed size 1232// in which all pointer fields are located in the [start_offset, end_offset) 1233// interval. 1234template<int start_offset, int end_offset, int size> 1235class FixedBodyDescriptor { 1236 public: 1237 static const int kStartOffset = start_offset; 1238 static const int kEndOffset = end_offset; 1239 static const int kSize = size; 1240 1241 static inline void IterateBody(HeapObject* obj, ObjectVisitor* v); 1242 1243 template<typename StaticVisitor> 1244 static inline void IterateBody(HeapObject* obj) { 1245 StaticVisitor::VisitPointers(SLOT_ADDR(obj, start_offset), 1246 SLOT_ADDR(obj, end_offset)); 1247 } 1248}; 1249 1250 1251// This class describes a body of an object of a variable size 1252// in which all pointer fields are located in the [start_offset, object_size) 1253// interval. 1254template<int start_offset> 1255class FlexibleBodyDescriptor { 1256 public: 1257 static const int kStartOffset = start_offset; 1258 1259 static inline void IterateBody(HeapObject* obj, 1260 int object_size, 1261 ObjectVisitor* v); 1262 1263 template<typename StaticVisitor> 1264 static inline void IterateBody(HeapObject* obj, int object_size) { 1265 StaticVisitor::VisitPointers(SLOT_ADDR(obj, start_offset), 1266 SLOT_ADDR(obj, object_size)); 1267 } 1268}; 1269 1270#undef SLOT_ADDR 1271 1272 1273// The HeapNumber class describes heap allocated numbers that cannot be 1274// represented in a Smi (small integer) 1275class HeapNumber: public HeapObject { 1276 public: 1277 // [value]: number value. 1278 inline double value(); 1279 inline void set_value(double value); 1280 1281 // Casting. 1282 static inline HeapNumber* cast(Object* obj); 1283 1284 // Dispatched behavior. 1285 Object* HeapNumberToBoolean(); 1286 inline void HeapNumberPrint() { 1287 HeapNumberPrint(stdout); 1288 } 1289 void HeapNumberPrint(FILE* out); 1290 void HeapNumberPrint(StringStream* accumulator); 1291#ifdef DEBUG 1292 void HeapNumberVerify(); 1293#endif 1294 1295 inline int get_exponent(); 1296 inline int get_sign(); 1297 1298 // Layout description. 1299 static const int kValueOffset = HeapObject::kHeaderSize; 1300 // IEEE doubles are two 32 bit words. The first is just mantissa, the second 1301 // is a mixture of sign, exponent and mantissa. Our current platforms are all 1302 // little endian apart from non-EABI arm which is little endian with big 1303 // endian floating point word ordering! 1304 static const int kMantissaOffset = kValueOffset; 1305 static const int kExponentOffset = kValueOffset + 4; 1306 1307 static const int kSize = kValueOffset + kDoubleSize; 1308 static const uint32_t kSignMask = 0x80000000u; 1309 static const uint32_t kExponentMask = 0x7ff00000u; 1310 static const uint32_t kMantissaMask = 0xfffffu; 1311 static const int kMantissaBits = 52; 1312 static const int kExponentBits = 11; 1313 static const int kExponentBias = 1023; 1314 static const int kExponentShift = 20; 1315 static const int kMantissaBitsInTopWord = 20; 1316 static const int kNonMantissaBitsInTopWord = 12; 1317 1318 private: 1319 DISALLOW_IMPLICIT_CONSTRUCTORS(HeapNumber); 1320}; 1321 1322 1323// JSReceiver includes types on which properties can be defined, i.e., 1324// JSObject and JSProxy. 1325class JSReceiver: public HeapObject { 1326 public: 1327 enum DeleteMode { 1328 NORMAL_DELETION, 1329 STRICT_DELETION, 1330 FORCE_DELETION 1331 }; 1332 1333 // Casting. 1334 static inline JSReceiver* cast(Object* obj); 1335 1336 // Can cause GC. 1337 MUST_USE_RESULT MaybeObject* SetProperty(String* key, 1338 Object* value, 1339 PropertyAttributes attributes, 1340 StrictModeFlag strict_mode); 1341 MUST_USE_RESULT MaybeObject* SetProperty(LookupResult* result, 1342 String* key, 1343 Object* value, 1344 PropertyAttributes attributes, 1345 StrictModeFlag strict_mode); 1346 MUST_USE_RESULT MaybeObject* SetPropertyWithDefinedSetter(JSReceiver* setter, 1347 Object* value); 1348 1349 MUST_USE_RESULT MaybeObject* DeleteProperty(String* name, DeleteMode mode); 1350 MUST_USE_RESULT MaybeObject* DeleteElement(uint32_t index, DeleteMode mode); 1351 1352 // Set the index'th array element. 1353 // Can cause GC, or return failure if GC is required. 1354 MUST_USE_RESULT MaybeObject* SetElement(uint32_t index, 1355 Object* value, 1356 StrictModeFlag strict_mode, 1357 bool check_prototype); 1358 1359 // Tests for the fast common case for property enumeration. 1360 bool IsSimpleEnum(); 1361 1362 // Returns the class name ([[Class]] property in the specification). 1363 String* class_name(); 1364 1365 // Returns the constructor name (the name (possibly, inferred name) of the 1366 // function that was used to instantiate the object). 1367 String* constructor_name(); 1368 1369 inline PropertyAttributes GetPropertyAttribute(String* name); 1370 PropertyAttributes GetPropertyAttributeWithReceiver(JSReceiver* receiver, 1371 String* name); 1372 PropertyAttributes GetLocalPropertyAttribute(String* name); 1373 1374 // Can cause a GC. 1375 inline bool HasProperty(String* name); 1376 inline bool HasLocalProperty(String* name); 1377 inline bool HasElement(uint32_t index); 1378 1379 // Return the object's prototype (might be Heap::null_value()). 1380 inline Object* GetPrototype(); 1381 1382 // Set the object's prototype (only JSReceiver and null are allowed). 1383 MUST_USE_RESULT MaybeObject* SetPrototype(Object* value, 1384 bool skip_hidden_prototypes); 1385 1386 // Retrieves a permanent object identity hash code. The undefined value might 1387 // be returned in case no hash was created yet and OMIT_CREATION was used. 1388 inline MUST_USE_RESULT MaybeObject* GetIdentityHash(CreationFlag flag); 1389 1390 // Lookup a property. If found, the result is valid and has 1391 // detailed information. 1392 void LocalLookup(String* name, LookupResult* result); 1393 void Lookup(String* name, LookupResult* result); 1394 1395 protected: 1396 Smi* GenerateIdentityHash(); 1397 1398 private: 1399 PropertyAttributes GetPropertyAttribute(JSReceiver* receiver, 1400 LookupResult* result, 1401 String* name, 1402 bool continue_search); 1403 1404 DISALLOW_IMPLICIT_CONSTRUCTORS(JSReceiver); 1405}; 1406 1407// The JSObject describes real heap allocated JavaScript objects with 1408// properties. 1409// Note that the map of JSObject changes during execution to enable inline 1410// caching. 1411class JSObject: public JSReceiver { 1412 public: 1413 // [properties]: Backing storage for properties. 1414 // properties is a FixedArray in the fast case and a Dictionary in the 1415 // slow case. 1416 DECL_ACCESSORS(properties, FixedArray) // Get and set fast properties. 1417 inline void initialize_properties(); 1418 inline bool HasFastProperties(); 1419 inline StringDictionary* property_dictionary(); // Gets slow properties. 1420 1421 // [elements]: The elements (properties with names that are integers). 1422 // 1423 // Elements can be in two general modes: fast and slow. Each mode 1424 // corrensponds to a set of object representations of elements that 1425 // have something in common. 1426 // 1427 // In the fast mode elements is a FixedArray and so each element can 1428 // be quickly accessed. This fact is used in the generated code. The 1429 // elements array can have one of three maps in this mode: 1430 // fixed_array_map, non_strict_arguments_elements_map or 1431 // fixed_cow_array_map (for copy-on-write arrays). In the latter case 1432 // the elements array may be shared by a few objects and so before 1433 // writing to any element the array must be copied. Use 1434 // EnsureWritableFastElements in this case. 1435 // 1436 // In the slow mode the elements is either a NumberDictionary, an 1437 // ExternalArray, or a FixedArray parameter map for a (non-strict) 1438 // arguments object. 1439 DECL_ACCESSORS(elements, FixedArrayBase) 1440 inline void initialize_elements(); 1441 MUST_USE_RESULT inline MaybeObject* ResetElements(); 1442 inline ElementsKind GetElementsKind(); 1443 inline ElementsAccessor* GetElementsAccessor(); 1444 inline bool HasFastSmiOnlyElements(); 1445 inline bool HasFastElements(); 1446 // Returns if an object has either FAST_ELEMENT or FAST_SMI_ONLY_ELEMENT 1447 // elements. TODO(danno): Rename HasFastTypeElements to HasFastElements() and 1448 // HasFastElements to HasFastObjectElements. 1449 inline bool HasFastTypeElements(); 1450 inline bool HasFastDoubleElements(); 1451 inline bool HasNonStrictArgumentsElements(); 1452 inline bool HasDictionaryElements(); 1453 inline bool HasExternalPixelElements(); 1454 inline bool HasExternalArrayElements(); 1455 inline bool HasExternalByteElements(); 1456 inline bool HasExternalUnsignedByteElements(); 1457 inline bool HasExternalShortElements(); 1458 inline bool HasExternalUnsignedShortElements(); 1459 inline bool HasExternalIntElements(); 1460 inline bool HasExternalUnsignedIntElements(); 1461 inline bool HasExternalFloatElements(); 1462 inline bool HasExternalDoubleElements(); 1463 bool HasFastArgumentsElements(); 1464 bool HasDictionaryArgumentsElements(); 1465 inline bool AllowsSetElementsLength(); 1466 inline NumberDictionary* element_dictionary(); // Gets slow elements. 1467 1468 // Requires: HasFastElements(). 1469 MUST_USE_RESULT inline MaybeObject* EnsureWritableFastElements(); 1470 1471 // Collects elements starting at index 0. 1472 // Undefined values are placed after non-undefined values. 1473 // Returns the number of non-undefined values. 1474 MUST_USE_RESULT MaybeObject* PrepareElementsForSort(uint32_t limit); 1475 // As PrepareElementsForSort, but only on objects where elements is 1476 // a dictionary, and it will stay a dictionary. 1477 MUST_USE_RESULT MaybeObject* PrepareSlowElementsForSort(uint32_t limit); 1478 1479 MUST_USE_RESULT MaybeObject* GetPropertyWithCallback(Object* receiver, 1480 Object* structure, 1481 String* name); 1482 1483 // Can cause GC. 1484 MUST_USE_RESULT MaybeObject* SetPropertyForResult(LookupResult* result, 1485 String* key, 1486 Object* value, 1487 PropertyAttributes attributes, 1488 StrictModeFlag strict_mode); 1489 MUST_USE_RESULT MaybeObject* SetPropertyWithFailedAccessCheck( 1490 LookupResult* result, 1491 String* name, 1492 Object* value, 1493 bool check_prototype, 1494 StrictModeFlag strict_mode); 1495 MUST_USE_RESULT MaybeObject* SetPropertyWithCallback( 1496 Object* structure, 1497 String* name, 1498 Object* value, 1499 JSObject* holder, 1500 StrictModeFlag strict_mode); 1501 MUST_USE_RESULT MaybeObject* SetPropertyWithInterceptor( 1502 String* name, 1503 Object* value, 1504 PropertyAttributes attributes, 1505 StrictModeFlag strict_mode); 1506 MUST_USE_RESULT MaybeObject* SetPropertyPostInterceptor( 1507 String* name, 1508 Object* value, 1509 PropertyAttributes attributes, 1510 StrictModeFlag strict_mode); 1511 MUST_USE_RESULT MaybeObject* SetLocalPropertyIgnoreAttributes( 1512 String* key, 1513 Object* value, 1514 PropertyAttributes attributes); 1515 1516 // Retrieve a value in a normalized object given a lookup result. 1517 // Handles the special representation of JS global objects. 1518 Object* GetNormalizedProperty(LookupResult* result); 1519 1520 // Sets the property value in a normalized object given a lookup result. 1521 // Handles the special representation of JS global objects. 1522 Object* SetNormalizedProperty(LookupResult* result, Object* value); 1523 1524 // Sets the property value in a normalized object given (key, value, details). 1525 // Handles the special representation of JS global objects. 1526 MUST_USE_RESULT MaybeObject* SetNormalizedProperty(String* name, 1527 Object* value, 1528 PropertyDetails details); 1529 1530 // Deletes the named property in a normalized object. 1531 MUST_USE_RESULT MaybeObject* DeleteNormalizedProperty(String* name, 1532 DeleteMode mode); 1533 1534 // Retrieve interceptors. 1535 InterceptorInfo* GetNamedInterceptor(); 1536 InterceptorInfo* GetIndexedInterceptor(); 1537 1538 // Used from JSReceiver. 1539 PropertyAttributes GetPropertyAttributePostInterceptor(JSObject* receiver, 1540 String* name, 1541 bool continue_search); 1542 PropertyAttributes GetPropertyAttributeWithInterceptor(JSObject* receiver, 1543 String* name, 1544 bool continue_search); 1545 PropertyAttributes GetPropertyAttributeWithFailedAccessCheck( 1546 Object* receiver, 1547 LookupResult* result, 1548 String* name, 1549 bool continue_search); 1550 1551 MUST_USE_RESULT MaybeObject* DefineAccessor(String* name, 1552 bool is_getter, 1553 Object* fun, 1554 PropertyAttributes attributes); 1555 Object* LookupAccessor(String* name, bool is_getter); 1556 1557 MUST_USE_RESULT MaybeObject* DefineAccessor(AccessorInfo* info); 1558 1559 // Used from Object::GetProperty(). 1560 MaybeObject* GetPropertyWithFailedAccessCheck( 1561 Object* receiver, 1562 LookupResult* result, 1563 String* name, 1564 PropertyAttributes* attributes); 1565 MaybeObject* GetPropertyWithInterceptor( 1566 JSReceiver* receiver, 1567 String* name, 1568 PropertyAttributes* attributes); 1569 MaybeObject* GetPropertyPostInterceptor( 1570 JSReceiver* receiver, 1571 String* name, 1572 PropertyAttributes* attributes); 1573 MaybeObject* GetLocalPropertyPostInterceptor(JSReceiver* receiver, 1574 String* name, 1575 PropertyAttributes* attributes); 1576 1577 // Returns true if this is an instance of an api function and has 1578 // been modified since it was created. May give false positives. 1579 bool IsDirty(); 1580 1581 // If the receiver is a JSGlobalProxy this method will return its prototype, 1582 // otherwise the result is the receiver itself. 1583 inline Object* BypassGlobalProxy(); 1584 1585 // Accessors for hidden properties object. 1586 // 1587 // Hidden properties are not local properties of the object itself. 1588 // Instead they are stored in an auxiliary structure kept as a local 1589 // property with a special name Heap::hidden_symbol(). But if the 1590 // receiver is a JSGlobalProxy then the auxiliary object is a property 1591 // of its prototype, and if it's a detached proxy, then you can't have 1592 // hidden properties. 1593 1594 // Sets a hidden property on this object. Returns this object if successful, 1595 // undefined if called on a detached proxy, and a failure if a GC 1596 // is required 1597 MaybeObject* SetHiddenProperty(String* key, Object* value); 1598 // Gets the value of a hidden property with the given key. Returns undefined 1599 // if the property doesn't exist (or if called on a detached proxy), 1600 // otherwise returns the value set for the key. 1601 Object* GetHiddenProperty(String* key); 1602 // Deletes a hidden property. Deleting a non-existing property is 1603 // considered successful. 1604 void DeleteHiddenProperty(String* key); 1605 // Returns true if the object has a property with the hidden symbol as name. 1606 bool HasHiddenProperties(); 1607 1608 MUST_USE_RESULT MaybeObject* GetIdentityHash(CreationFlag flag); 1609 MUST_USE_RESULT MaybeObject* SetIdentityHash(Object* hash, CreationFlag flag); 1610 1611 MUST_USE_RESULT MaybeObject* DeleteProperty(String* name, DeleteMode mode); 1612 MUST_USE_RESULT MaybeObject* DeleteElement(uint32_t index, DeleteMode mode); 1613 1614 inline void ValidateSmiOnlyElements(); 1615 1616 // Makes sure that this object can contain non-smi Object as elements. 1617 inline MaybeObject* EnsureCanContainNonSmiElements(); 1618 1619 // Makes sure that this object can contain the specified elements. 1620 inline MaybeObject* EnsureCanContainElements(Object** elements, 1621 uint32_t count); 1622 inline MaybeObject* EnsureCanContainElements(FixedArray* elements); 1623 MaybeObject* EnsureCanContainElements(Arguments* arguments, 1624 uint32_t first_arg, 1625 uint32_t arg_count); 1626 1627 // Do we want to keep the elements in fast case when increasing the 1628 // capacity? 1629 bool ShouldConvertToSlowElements(int new_capacity); 1630 // Returns true if the backing storage for the slow-case elements of 1631 // this object takes up nearly as much space as a fast-case backing 1632 // storage would. In that case the JSObject should have fast 1633 // elements. 1634 bool ShouldConvertToFastElements(); 1635 // Returns true if the elements of JSObject contains only values that can be 1636 // represented in a FixedDoubleArray. 1637 bool CanConvertToFastDoubleElements(); 1638 1639 // Tells whether the index'th element is present. 1640 bool HasElementWithReceiver(JSReceiver* receiver, uint32_t index); 1641 1642 // Computes the new capacity when expanding the elements of a JSObject. 1643 static int NewElementsCapacity(int old_capacity) { 1644 // (old_capacity + 50%) + 16 1645 return old_capacity + (old_capacity >> 1) + 16; 1646 } 1647 1648 // Tells whether the index'th element is present and how it is stored. 1649 enum LocalElementType { 1650 // There is no element with given index. 1651 UNDEFINED_ELEMENT, 1652 1653 // Element with given index is handled by interceptor. 1654 INTERCEPTED_ELEMENT, 1655 1656 // Element with given index is character in string. 1657 STRING_CHARACTER_ELEMENT, 1658 1659 // Element with given index is stored in fast backing store. 1660 FAST_ELEMENT, 1661 1662 // Element with given index is stored in slow backing store. 1663 DICTIONARY_ELEMENT 1664 }; 1665 1666 LocalElementType HasLocalElement(uint32_t index); 1667 1668 bool HasElementWithInterceptor(JSReceiver* receiver, uint32_t index); 1669 bool HasElementPostInterceptor(JSReceiver* receiver, uint32_t index); 1670 1671 MUST_USE_RESULT MaybeObject* SetFastElement(uint32_t index, 1672 Object* value, 1673 StrictModeFlag strict_mode, 1674 bool check_prototype); 1675 1676 MUST_USE_RESULT MaybeObject* SetDictionaryElement(uint32_t index, 1677 Object* value, 1678 StrictModeFlag strict_mode, 1679 bool check_prototype); 1680 1681 MUST_USE_RESULT MaybeObject* SetFastDoubleElement( 1682 uint32_t index, 1683 Object* value, 1684 StrictModeFlag strict_mode, 1685 bool check_prototype = true); 1686 1687 // Set the index'th array element. 1688 // A Failure object is returned if GC is needed. 1689 MUST_USE_RESULT MaybeObject* SetElement(uint32_t index, 1690 Object* value, 1691 StrictModeFlag strict_mode, 1692 bool check_prototype); 1693 1694 // Returns the index'th element. 1695 // The undefined object if index is out of bounds. 1696 MaybeObject* GetElementWithInterceptor(Object* receiver, uint32_t index); 1697 1698 enum SetFastElementsCapacityMode { 1699 kAllowSmiOnlyElements, 1700 kDontAllowSmiOnlyElements 1701 }; 1702 1703 // Replace the elements' backing store with fast elements of the given 1704 // capacity. Update the length for JSArrays. Returns the new backing 1705 // store. 1706 MUST_USE_RESULT MaybeObject* SetFastElementsCapacityAndLength( 1707 int capacity, 1708 int length, 1709 SetFastElementsCapacityMode set_capacity_mode); 1710 MUST_USE_RESULT MaybeObject* SetFastDoubleElementsCapacityAndLength( 1711 int capacity, 1712 int length); 1713 1714 // Lookup interceptors are used for handling properties controlled by host 1715 // objects. 1716 inline bool HasNamedInterceptor(); 1717 inline bool HasIndexedInterceptor(); 1718 1719 // Support functions for v8 api (needed for correct interceptor behavior). 1720 bool HasRealNamedProperty(String* key); 1721 bool HasRealElementProperty(uint32_t index); 1722 bool HasRealNamedCallbackProperty(String* key); 1723 1724 // Initializes the array to a certain length 1725 MUST_USE_RESULT MaybeObject* SetElementsLength(Object* length); 1726 1727 // Get the header size for a JSObject. Used to compute the index of 1728 // internal fields as well as the number of internal fields. 1729 inline int GetHeaderSize(); 1730 1731 inline int GetInternalFieldCount(); 1732 inline int GetInternalFieldOffset(int index); 1733 inline Object* GetInternalField(int index); 1734 inline void SetInternalField(int index, Object* value); 1735 inline void SetInternalField(int index, Smi* value); 1736 1737 // The following lookup functions skip interceptors. 1738 void LocalLookupRealNamedProperty(String* name, LookupResult* result); 1739 void LookupRealNamedProperty(String* name, LookupResult* result); 1740 void LookupRealNamedPropertyInPrototypes(String* name, LookupResult* result); 1741 void LookupCallbackSetterInPrototypes(String* name, LookupResult* result); 1742 MUST_USE_RESULT MaybeObject* SetElementWithCallbackSetterInPrototypes( 1743 uint32_t index, Object* value, bool* found, StrictModeFlag strict_mode); 1744 void LookupCallback(String* name, LookupResult* result); 1745 1746 // Returns the number of properties on this object filtering out properties 1747 // with the specified attributes (ignoring interceptors). 1748 int NumberOfLocalProperties(PropertyAttributes filter); 1749 // Returns the number of enumerable properties (ignoring interceptors). 1750 int NumberOfEnumProperties(); 1751 // Fill in details for properties into storage starting at the specified 1752 // index. 1753 void GetLocalPropertyNames(FixedArray* storage, int index); 1754 1755 // Returns the number of properties on this object filtering out properties 1756 // with the specified attributes (ignoring interceptors). 1757 int NumberOfLocalElements(PropertyAttributes filter); 1758 // Returns the number of enumerable elements (ignoring interceptors). 1759 int NumberOfEnumElements(); 1760 // Returns the number of elements on this object filtering out elements 1761 // with the specified attributes (ignoring interceptors). 1762 int GetLocalElementKeys(FixedArray* storage, PropertyAttributes filter); 1763 // Count and fill in the enumerable elements into storage. 1764 // (storage->length() == NumberOfEnumElements()). 1765 // If storage is NULL, will count the elements without adding 1766 // them to any storage. 1767 // Returns the number of enumerable elements. 1768 int GetEnumElementKeys(FixedArray* storage); 1769 1770 // Add a property to a fast-case object using a map transition to 1771 // new_map. 1772 MUST_USE_RESULT MaybeObject* AddFastPropertyUsingMap(Map* new_map, 1773 String* name, 1774 Object* value); 1775 1776 // Add a constant function property to a fast-case object. 1777 // This leaves a CONSTANT_TRANSITION in the old map, and 1778 // if it is called on a second object with this map, a 1779 // normal property is added instead, with a map transition. 1780 // This avoids the creation of many maps with the same constant 1781 // function, all orphaned. 1782 MUST_USE_RESULT MaybeObject* AddConstantFunctionProperty( 1783 String* name, 1784 JSFunction* function, 1785 PropertyAttributes attributes); 1786 1787 MUST_USE_RESULT MaybeObject* ReplaceSlowProperty( 1788 String* name, 1789 Object* value, 1790 PropertyAttributes attributes); 1791 1792 // Returns a new map with all transitions dropped from the object's current 1793 // map and the ElementsKind set. 1794 static Handle<Map> GetElementsTransitionMap(Handle<JSObject> object, 1795 ElementsKind to_kind); 1796 MUST_USE_RESULT MaybeObject* GetElementsTransitionMap( 1797 ElementsKind elements_kind); 1798 1799 MUST_USE_RESULT MaybeObject* TransitionElementsKind(ElementsKind to_kind); 1800 1801 // Converts a descriptor of any other type to a real field, 1802 // backed by the properties array. Descriptors of visible 1803 // types, such as CONSTANT_FUNCTION, keep their enumeration order. 1804 // Converts the descriptor on the original object's map to a 1805 // map transition, and the the new field is on the object's new map. 1806 MUST_USE_RESULT MaybeObject* ConvertDescriptorToFieldAndMapTransition( 1807 String* name, 1808 Object* new_value, 1809 PropertyAttributes attributes); 1810 1811 // Converts a descriptor of any other type to a real field, 1812 // backed by the properties array. Descriptors of visible 1813 // types, such as CONSTANT_FUNCTION, keep their enumeration order. 1814 MUST_USE_RESULT MaybeObject* ConvertDescriptorToField( 1815 String* name, 1816 Object* new_value, 1817 PropertyAttributes attributes); 1818 1819 // Add a property to a fast-case object. 1820 MUST_USE_RESULT MaybeObject* AddFastProperty(String* name, 1821 Object* value, 1822 PropertyAttributes attributes); 1823 1824 // Add a property to a slow-case object. 1825 MUST_USE_RESULT MaybeObject* AddSlowProperty(String* name, 1826 Object* value, 1827 PropertyAttributes attributes); 1828 1829 // Add a property to an object. 1830 MUST_USE_RESULT MaybeObject* AddProperty(String* name, 1831 Object* value, 1832 PropertyAttributes attributes, 1833 StrictModeFlag strict_mode); 1834 1835 // Convert the object to use the canonical dictionary 1836 // representation. If the object is expected to have additional properties 1837 // added this number can be indicated to have the backing store allocated to 1838 // an initial capacity for holding these properties. 1839 MUST_USE_RESULT MaybeObject* NormalizeProperties( 1840 PropertyNormalizationMode mode, 1841 int expected_additional_properties); 1842 1843 // Convert and update the elements backing store to be a NumberDictionary 1844 // dictionary. Returns the backing after conversion. 1845 MUST_USE_RESULT MaybeObject* NormalizeElements(); 1846 1847 static void UpdateMapCodeCache(Handle<JSObject> object, 1848 Handle<String> name, 1849 Handle<Code> code); 1850 1851 MUST_USE_RESULT MaybeObject* UpdateMapCodeCache(String* name, Code* code); 1852 1853 // Transform slow named properties to fast variants. 1854 // Returns failure if allocation failed. 1855 MUST_USE_RESULT MaybeObject* TransformToFastProperties( 1856 int unused_property_fields); 1857 1858 // Access fast-case object properties at index. 1859 inline Object* FastPropertyAt(int index); 1860 inline Object* FastPropertyAtPut(int index, Object* value); 1861 1862 // Access to in object properties. 1863 inline int GetInObjectPropertyOffset(int index); 1864 inline Object* InObjectPropertyAt(int index); 1865 inline Object* InObjectPropertyAtPut(int index, 1866 Object* value, 1867 WriteBarrierMode mode 1868 = UPDATE_WRITE_BARRIER); 1869 1870 // Initializes the body after properties slot, properties slot is 1871 // initialized by set_properties. Fill the pre-allocated fields with 1872 // pre_allocated_value and the rest with filler_value. 1873 // Note: this call does not update write barrier, the caller is responsible 1874 // to ensure that |filler_value| can be collected without WB here. 1875 inline void InitializeBody(Map* map, 1876 Object* pre_allocated_value, 1877 Object* filler_value); 1878 1879 // Check whether this object references another object 1880 bool ReferencesObject(Object* obj); 1881 1882 // Casting. 1883 static inline JSObject* cast(Object* obj); 1884 1885 // Disalow further properties to be added to the object. 1886 MUST_USE_RESULT MaybeObject* PreventExtensions(); 1887 1888 1889 // Dispatched behavior. 1890 void JSObjectShortPrint(StringStream* accumulator); 1891#ifdef OBJECT_PRINT 1892 inline void JSObjectPrint() { 1893 JSObjectPrint(stdout); 1894 } 1895 void JSObjectPrint(FILE* out); 1896#endif 1897#ifdef DEBUG 1898 void JSObjectVerify(); 1899#endif 1900#ifdef OBJECT_PRINT 1901 inline void PrintProperties() { 1902 PrintProperties(stdout); 1903 } 1904 void PrintProperties(FILE* out); 1905 1906 inline void PrintElements() { 1907 PrintElements(stdout); 1908 } 1909 void PrintElements(FILE* out); 1910#endif 1911 1912 void PrintElementsTransition( 1913 FILE* file, ElementsKind from_kind, FixedArrayBase* from_elements, 1914 ElementsKind to_kind, FixedArrayBase* to_elements); 1915 1916#ifdef DEBUG 1917 // Structure for collecting spill information about JSObjects. 1918 class SpillInformation { 1919 public: 1920 void Clear(); 1921 void Print(); 1922 int number_of_objects_; 1923 int number_of_objects_with_fast_properties_; 1924 int number_of_objects_with_fast_elements_; 1925 int number_of_fast_used_fields_; 1926 int number_of_fast_unused_fields_; 1927 int number_of_slow_used_properties_; 1928 int number_of_slow_unused_properties_; 1929 int number_of_fast_used_elements_; 1930 int number_of_fast_unused_elements_; 1931 int number_of_slow_used_elements_; 1932 int number_of_slow_unused_elements_; 1933 }; 1934 1935 void IncrementSpillStatistics(SpillInformation* info); 1936#endif 1937 Object* SlowReverseLookup(Object* value); 1938 1939 // Getters and setters are stored in a fixed array property. 1940 // These are constants for their indices. 1941 static const int kGetterIndex = 0; 1942 static const int kSetterIndex = 1; 1943 1944 // Maximal number of fast properties for the JSObject. Used to 1945 // restrict the number of map transitions to avoid an explosion in 1946 // the number of maps for objects used as dictionaries. 1947 inline int MaxFastProperties(); 1948 1949 // Maximal number of elements (numbered 0 .. kMaxElementCount - 1). 1950 // Also maximal value of JSArray's length property. 1951 static const uint32_t kMaxElementCount = 0xffffffffu; 1952 1953 // Constants for heuristics controlling conversion of fast elements 1954 // to slow elements. 1955 1956 // Maximal gap that can be introduced by adding an element beyond 1957 // the current elements length. 1958 static const uint32_t kMaxGap = 1024; 1959 1960 // Maximal length of fast elements array that won't be checked for 1961 // being dense enough on expansion. 1962 static const int kMaxUncheckedFastElementsLength = 5000; 1963 1964 // Same as above but for old arrays. This limit is more strict. We 1965 // don't want to be wasteful with long lived objects. 1966 static const int kMaxUncheckedOldFastElementsLength = 500; 1967 1968 static const int kInitialMaxFastElementArray = 100000; 1969 static const int kMaxFastProperties = 12; 1970 static const int kMaxInstanceSize = 255 * kPointerSize; 1971 // When extending the backing storage for property values, we increase 1972 // its size by more than the 1 entry necessary, so sequentially adding fields 1973 // to the same object requires fewer allocations and copies. 1974 static const int kFieldsAdded = 3; 1975 1976 // Layout description. 1977 static const int kPropertiesOffset = HeapObject::kHeaderSize; 1978 static const int kElementsOffset = kPropertiesOffset + kPointerSize; 1979 static const int kHeaderSize = kElementsOffset + kPointerSize; 1980 1981 STATIC_CHECK(kHeaderSize == Internals::kJSObjectHeaderSize); 1982 1983 class BodyDescriptor : public FlexibleBodyDescriptor<kPropertiesOffset> { 1984 public: 1985 static inline int SizeOf(Map* map, HeapObject* object); 1986 }; 1987 1988 private: 1989 friend class DictionaryElementsAccessor; 1990 1991 MUST_USE_RESULT MaybeObject* GetElementWithCallback(Object* receiver, 1992 Object* structure, 1993 uint32_t index, 1994 Object* holder); 1995 MaybeObject* SetElementWithCallback(Object* structure, 1996 uint32_t index, 1997 Object* value, 1998 JSObject* holder, 1999 StrictModeFlag strict_mode); 2000 MUST_USE_RESULT MaybeObject* SetElementWithInterceptor( 2001 uint32_t index, 2002 Object* value, 2003 StrictModeFlag strict_mode, 2004 bool check_prototype); 2005 MUST_USE_RESULT MaybeObject* SetElementWithoutInterceptor( 2006 uint32_t index, 2007 Object* value, 2008 StrictModeFlag strict_mode, 2009 bool check_prototype); 2010 2011 // Searches the prototype chain for a callback setter and sets the property 2012 // with the setter if it finds one. The '*found' flag indicates whether 2013 // a setter was found or not. 2014 // This function can cause GC and can return a failure result with 2015 // '*found==true'. 2016 MUST_USE_RESULT MaybeObject* SetPropertyWithCallbackSetterInPrototypes( 2017 String* name, 2018 Object* value, 2019 PropertyAttributes attributes, 2020 bool* found, 2021 StrictModeFlag strict_mode); 2022 2023 MUST_USE_RESULT MaybeObject* DeletePropertyPostInterceptor(String* name, 2024 DeleteMode mode); 2025 MUST_USE_RESULT MaybeObject* DeletePropertyWithInterceptor(String* name); 2026 2027 MUST_USE_RESULT MaybeObject* DeleteElementWithInterceptor(uint32_t index); 2028 2029 MUST_USE_RESULT MaybeObject* DeleteFastElement(uint32_t index); 2030 MUST_USE_RESULT MaybeObject* DeleteDictionaryElement(uint32_t index, 2031 DeleteMode mode); 2032 2033 bool ReferencesObjectFromElements(FixedArray* elements, 2034 ElementsKind kind, 2035 Object* object); 2036 bool HasElementInElements(FixedArray* elements, 2037 ElementsKind kind, 2038 uint32_t index); 2039 2040 // Returns true if most of the elements backing storage is used. 2041 bool HasDenseElements(); 2042 2043 // Gets the current elements capacity and the number of used elements. 2044 void GetElementsCapacityAndUsage(int* capacity, int* used); 2045 2046 bool CanSetCallback(String* name); 2047 MUST_USE_RESULT MaybeObject* SetElementCallback( 2048 uint32_t index, 2049 Object* structure, 2050 PropertyAttributes attributes); 2051 MUST_USE_RESULT MaybeObject* SetPropertyCallback( 2052 String* name, 2053 Object* structure, 2054 PropertyAttributes attributes); 2055 MUST_USE_RESULT MaybeObject* DefineGetterSetter( 2056 String* name, 2057 PropertyAttributes attributes); 2058 2059 void LookupInDescriptor(String* name, LookupResult* result); 2060 2061 // Returns the hidden properties backing store object, currently 2062 // a StringDictionary, stored on this object. 2063 // If no hidden properties object has been put on this object, 2064 // return undefined, unless create_if_absent is true, in which case 2065 // a new dictionary is created, added to this object, and returned. 2066 MaybeObject* GetHiddenPropertiesDictionary(bool create_if_absent); 2067 // Updates the existing hidden properties dictionary. 2068 MaybeObject* SetHiddenPropertiesDictionary(StringDictionary* dictionary); 2069 2070 DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject); 2071}; 2072 2073 2074// Common superclass for FixedArrays that allow implementations to share 2075// common accessors and some code paths. 2076class FixedArrayBase: public HeapObject { 2077 public: 2078 // [length]: length of the array. 2079 inline int length(); 2080 inline void set_length(int value); 2081 2082 inline static FixedArrayBase* cast(Object* object); 2083 2084 // Layout description. 2085 // Length is smi tagged when it is stored. 2086 static const int kLengthOffset = HeapObject::kHeaderSize; 2087 static const int kHeaderSize = kLengthOffset + kPointerSize; 2088}; 2089 2090 2091class FixedDoubleArray; 2092 2093// FixedArray describes fixed-sized arrays with element type Object*. 2094class FixedArray: public FixedArrayBase { 2095 public: 2096 // Setter and getter for elements. 2097 inline Object* get(int index); 2098 // Setter that uses write barrier. 2099 inline void set(int index, Object* value); 2100 inline bool is_the_hole(int index); 2101 2102 // Setter that doesn't need write barrier). 2103 inline void set(int index, Smi* value); 2104 // Setter with explicit barrier mode. 2105 inline void set(int index, Object* value, WriteBarrierMode mode); 2106 2107 // Setters for frequently used oddballs located in old space. 2108 inline void set_undefined(int index); 2109 // TODO(isolates): duplicate. 2110 inline void set_undefined(Heap* heap, int index); 2111 inline void set_null(int index); 2112 // TODO(isolates): duplicate. 2113 inline void set_null(Heap* heap, int index); 2114 inline void set_the_hole(int index); 2115 2116 // Setters with less debug checks for the GC to use. 2117 inline void set_unchecked(int index, Smi* value); 2118 inline void set_null_unchecked(Heap* heap, int index); 2119 inline void set_unchecked(Heap* heap, int index, Object* value, 2120 WriteBarrierMode mode); 2121 2122 // Gives access to raw memory which stores the array's data. 2123 inline Object** data_start(); 2124 2125 // Copy operations. 2126 MUST_USE_RESULT inline MaybeObject* Copy(); 2127 MUST_USE_RESULT MaybeObject* CopySize(int new_length); 2128 2129 // Add the elements of a JSArray to this FixedArray. 2130 MUST_USE_RESULT MaybeObject* AddKeysFromJSArray(JSArray* array); 2131 2132 // Compute the union of this and other. 2133 MUST_USE_RESULT MaybeObject* UnionOfKeys(FixedArray* other); 2134 2135 // Copy a sub array from the receiver to dest. 2136 void CopyTo(int pos, FixedArray* dest, int dest_pos, int len); 2137 2138 // Garbage collection support. 2139 static int SizeFor(int length) { return kHeaderSize + length * kPointerSize; } 2140 2141 // Code Generation support. 2142 static int OffsetOfElementAt(int index) { return SizeFor(index); } 2143 2144 // Casting. 2145 static inline FixedArray* cast(Object* obj); 2146 2147 // Maximal allowed size, in bytes, of a single FixedArray. 2148 // Prevents overflowing size computations, as well as extreme memory 2149 // consumption. 2150 static const int kMaxSize = 128 * MB * kPointerSize; 2151 // Maximally allowed length of a FixedArray. 2152 static const int kMaxLength = (kMaxSize - kHeaderSize) / kPointerSize; 2153 2154 // Dispatched behavior. 2155#ifdef OBJECT_PRINT 2156 inline void FixedArrayPrint() { 2157 FixedArrayPrint(stdout); 2158 } 2159 void FixedArrayPrint(FILE* out); 2160#endif 2161#ifdef DEBUG 2162 void FixedArrayVerify(); 2163 // Checks if two FixedArrays have identical contents. 2164 bool IsEqualTo(FixedArray* other); 2165#endif 2166 2167 // Swap two elements in a pair of arrays. If this array and the 2168 // numbers array are the same object, the elements are only swapped 2169 // once. 2170 void SwapPairs(FixedArray* numbers, int i, int j); 2171 2172 // Sort prefix of this array and the numbers array as pairs wrt. the 2173 // numbers. If the numbers array and the this array are the same 2174 // object, the prefix of this array is sorted. 2175 void SortPairs(FixedArray* numbers, uint32_t len); 2176 2177 class BodyDescriptor : public FlexibleBodyDescriptor<kHeaderSize> { 2178 public: 2179 static inline int SizeOf(Map* map, HeapObject* object) { 2180 return SizeFor(reinterpret_cast<FixedArray*>(object)->length()); 2181 } 2182 }; 2183 2184 protected: 2185 // Set operation on FixedArray without using write barriers. Can 2186 // only be used for storing old space objects or smis. 2187 static inline void NoWriteBarrierSet(FixedArray* array, 2188 int index, 2189 Object* value); 2190 2191 private: 2192 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedArray); 2193}; 2194 2195 2196// FixedDoubleArray describes fixed-sized arrays with element type double. 2197class FixedDoubleArray: public FixedArrayBase { 2198 public: 2199 inline void Initialize(FixedArray* from); 2200 inline void Initialize(FixedDoubleArray* from); 2201 inline void Initialize(NumberDictionary* from); 2202 2203 // Setter and getter for elements. 2204 inline double get_scalar(int index); 2205 inline MaybeObject* get(int index); 2206 inline void set(int index, double value); 2207 inline void set_the_hole(int index); 2208 2209 // Checking for the hole. 2210 inline bool is_the_hole(int index); 2211 2212 // Copy operations 2213 MUST_USE_RESULT inline MaybeObject* Copy(); 2214 2215 // Garbage collection support. 2216 inline static int SizeFor(int length) { 2217 return kHeaderSize + length * kDoubleSize; 2218 } 2219 2220 // Code Generation support. 2221 static int OffsetOfElementAt(int index) { return SizeFor(index); } 2222 2223 inline static bool is_the_hole_nan(double value); 2224 inline static double hole_nan_as_double(); 2225 inline static double canonical_not_the_hole_nan_as_double(); 2226 2227 // Casting. 2228 static inline FixedDoubleArray* cast(Object* obj); 2229 2230 // Maximal allowed size, in bytes, of a single FixedDoubleArray. 2231 // Prevents overflowing size computations, as well as extreme memory 2232 // consumption. 2233 static const int kMaxSize = 512 * MB; 2234 // Maximally allowed length of a FixedArray. 2235 static const int kMaxLength = (kMaxSize - kHeaderSize) / kDoubleSize; 2236 2237 // Dispatched behavior. 2238#ifdef OBJECT_PRINT 2239 inline void FixedDoubleArrayPrint() { 2240 FixedDoubleArrayPrint(stdout); 2241 } 2242 void FixedDoubleArrayPrint(FILE* out); 2243#endif 2244 2245#ifdef DEBUG 2246 void FixedDoubleArrayVerify(); 2247#endif 2248 2249 private: 2250 DISALLOW_IMPLICIT_CONSTRUCTORS(FixedDoubleArray); 2251}; 2252 2253 2254class IncrementalMarking; 2255 2256 2257// DescriptorArrays are fixed arrays used to hold instance descriptors. 2258// The format of the these objects is: 2259// TODO(1399): It should be possible to make room for bit_field3 in the map 2260// without overloading the instance descriptors field in the map 2261// (and storing it in the DescriptorArray when the map has one). 2262// [0]: storage for bit_field3 for Map owning this object (Smi) 2263// [1]: point to a fixed array with (value, detail) pairs. 2264// [2]: next enumeration index (Smi), or pointer to small fixed array: 2265// [0]: next enumeration index (Smi) 2266// [1]: pointer to fixed array with enum cache 2267// [3]: first key 2268// [length() - 1]: last key 2269// 2270class DescriptorArray: public FixedArray { 2271 public: 2272 // Returns true for both shared empty_descriptor_array and for smis, which the 2273 // map uses to encode additional bit fields when the descriptor array is not 2274 // yet used. 2275 inline bool IsEmpty(); 2276 2277 // Returns the number of descriptors in the array. 2278 int number_of_descriptors() { 2279 ASSERT(length() > kFirstIndex || IsEmpty()); 2280 int len = length(); 2281 return len <= kFirstIndex ? 0 : len - kFirstIndex; 2282 } 2283 2284 int NextEnumerationIndex() { 2285 if (IsEmpty()) return PropertyDetails::kInitialIndex; 2286 Object* obj = get(kEnumerationIndexIndex); 2287 if (obj->IsSmi()) { 2288 return Smi::cast(obj)->value(); 2289 } else { 2290 Object* index = FixedArray::cast(obj)->get(kEnumCacheBridgeEnumIndex); 2291 return Smi::cast(index)->value(); 2292 } 2293 } 2294 2295 // Set next enumeration index and flush any enum cache. 2296 void SetNextEnumerationIndex(int value) { 2297 if (!IsEmpty()) { 2298 set(kEnumerationIndexIndex, Smi::FromInt(value)); 2299 } 2300 } 2301 bool HasEnumCache() { 2302 return !IsEmpty() && !get(kEnumerationIndexIndex)->IsSmi(); 2303 } 2304 2305 Object* GetEnumCache() { 2306 ASSERT(HasEnumCache()); 2307 FixedArray* bridge = FixedArray::cast(get(kEnumerationIndexIndex)); 2308 return bridge->get(kEnumCacheBridgeCacheIndex); 2309 } 2310 2311 // TODO(1399): It should be possible to make room for bit_field3 in the map 2312 // without overloading the instance descriptors field in the map 2313 // (and storing it in the DescriptorArray when the map has one). 2314 inline int bit_field3_storage(); 2315 inline void set_bit_field3_storage(int value); 2316 2317 // Initialize or change the enum cache, 2318 // using the supplied storage for the small "bridge". 2319 void SetEnumCache(FixedArray* bridge_storage, FixedArray* new_cache); 2320 2321 // Accessors for fetching instance descriptor at descriptor number. 2322 inline String* GetKey(int descriptor_number); 2323 inline Object* GetValue(int descriptor_number); 2324 inline Smi* GetDetails(int descriptor_number); 2325 inline PropertyType GetType(int descriptor_number); 2326 inline int GetFieldIndex(int descriptor_number); 2327 inline JSFunction* GetConstantFunction(int descriptor_number); 2328 inline Object* GetCallbacksObject(int descriptor_number); 2329 inline AccessorDescriptor* GetCallbacks(int descriptor_number); 2330 inline bool IsProperty(int descriptor_number); 2331 inline bool IsTransition(int descriptor_number); 2332 inline bool IsNullDescriptor(int descriptor_number); 2333 inline bool IsDontEnum(int descriptor_number); 2334 2335 class WhitenessWitness { 2336 public: 2337 inline explicit WhitenessWitness(DescriptorArray* array); 2338 inline ~WhitenessWitness(); 2339 2340 private: 2341 IncrementalMarking* marking_; 2342 }; 2343 2344 // Accessor for complete descriptor. 2345 inline void Get(int descriptor_number, Descriptor* desc); 2346 inline void Set(int descriptor_number, 2347 Descriptor* desc, 2348 const WhitenessWitness&); 2349 2350 // Transfer complete descriptor from another descriptor array to 2351 // this one. 2352 inline void CopyFrom(int index, 2353 DescriptorArray* src, 2354 int src_index, 2355 const WhitenessWitness&); 2356 2357 // Copy the descriptor array, insert a new descriptor and optionally 2358 // remove map transitions. If the descriptor is already present, it is 2359 // replaced. If a replaced descriptor is a real property (not a transition 2360 // or null), its enumeration index is kept as is. 2361 // If adding a real property, map transitions must be removed. If adding 2362 // a transition, they must not be removed. All null descriptors are removed. 2363 MUST_USE_RESULT MaybeObject* CopyInsert(Descriptor* descriptor, 2364 TransitionFlag transition_flag); 2365 2366 // Remove all transitions. Return a copy of the array with all transitions 2367 // removed, or a Failure object if the new array could not be allocated. 2368 MUST_USE_RESULT MaybeObject* RemoveTransitions(); 2369 2370 // Sort the instance descriptors by the hash codes of their keys. 2371 // Does not check for duplicates. 2372 void SortUnchecked(const WhitenessWitness&); 2373 2374 // Sort the instance descriptors by the hash codes of their keys. 2375 // Checks the result for duplicates. 2376 void Sort(const WhitenessWitness&); 2377 2378 // Search the instance descriptors for given name. 2379 inline int Search(String* name); 2380 2381 // As the above, but uses DescriptorLookupCache and updates it when 2382 // necessary. 2383 inline int SearchWithCache(String* name); 2384 2385 // Tells whether the name is present int the array. 2386 bool Contains(String* name) { return kNotFound != Search(name); } 2387 2388 // Perform a binary search in the instance descriptors represented 2389 // by this fixed array. low and high are descriptor indices. If there 2390 // are three instance descriptors in this array it should be called 2391 // with low=0 and high=2. 2392 int BinarySearch(String* name, int low, int high); 2393 2394 // Perform a linear search in the instance descriptors represented 2395 // by this fixed array. len is the number of descriptor indices that are 2396 // valid. Does not require the descriptors to be sorted. 2397 int LinearSearch(String* name, int len); 2398 2399 // Allocates a DescriptorArray, but returns the singleton 2400 // empty descriptor array object if number_of_descriptors is 0. 2401 MUST_USE_RESULT static MaybeObject* Allocate(int number_of_descriptors); 2402 2403 // Casting. 2404 static inline DescriptorArray* cast(Object* obj); 2405 2406 // Constant for denoting key was not found. 2407 static const int kNotFound = -1; 2408 2409 static const int kBitField3StorageIndex = 0; 2410 static const int kContentArrayIndex = 1; 2411 static const int kEnumerationIndexIndex = 2; 2412 static const int kFirstIndex = 3; 2413 2414 // The length of the "bridge" to the enum cache. 2415 static const int kEnumCacheBridgeLength = 2; 2416 static const int kEnumCacheBridgeEnumIndex = 0; 2417 static const int kEnumCacheBridgeCacheIndex = 1; 2418 2419 // Layout description. 2420 static const int kBitField3StorageOffset = FixedArray::kHeaderSize; 2421 static const int kContentArrayOffset = kBitField3StorageOffset + kPointerSize; 2422 static const int kEnumerationIndexOffset = kContentArrayOffset + kPointerSize; 2423 static const int kFirstOffset = kEnumerationIndexOffset + kPointerSize; 2424 2425 // Layout description for the bridge array. 2426 static const int kEnumCacheBridgeEnumOffset = FixedArray::kHeaderSize; 2427 static const int kEnumCacheBridgeCacheOffset = 2428 kEnumCacheBridgeEnumOffset + kPointerSize; 2429 2430#ifdef OBJECT_PRINT 2431 // Print all the descriptors. 2432 inline void PrintDescriptors() { 2433 PrintDescriptors(stdout); 2434 } 2435 void PrintDescriptors(FILE* out); 2436#endif 2437 2438#ifdef DEBUG 2439 // Is the descriptor array sorted and without duplicates? 2440 bool IsSortedNoDuplicates(); 2441 2442 // Are two DescriptorArrays equal? 2443 bool IsEqualTo(DescriptorArray* other); 2444#endif 2445 2446 // The maximum number of descriptors we want in a descriptor array (should 2447 // fit in a page). 2448 static const int kMaxNumberOfDescriptors = 1024 + 512; 2449 2450 private: 2451 // Conversion from descriptor number to array indices. 2452 static int ToKeyIndex(int descriptor_number) { 2453 return descriptor_number+kFirstIndex; 2454 } 2455 2456 static int ToDetailsIndex(int descriptor_number) { 2457 return (descriptor_number << 1) + 1; 2458 } 2459 2460 static int ToValueIndex(int descriptor_number) { 2461 return descriptor_number << 1; 2462 } 2463 2464 bool is_null_descriptor(int descriptor_number) { 2465 return PropertyDetails(GetDetails(descriptor_number)).type() == 2466 NULL_DESCRIPTOR; 2467 } 2468 // Swap operation on FixedArray without using write barriers. 2469 static inline void NoWriteBarrierSwap(FixedArray* array, 2470 int first, 2471 int second); 2472 2473 // Swap descriptor first and second. 2474 inline void NoWriteBarrierSwapDescriptors(int first, int second); 2475 2476 FixedArray* GetContentArray() { 2477 return FixedArray::cast(get(kContentArrayIndex)); 2478 } 2479 DISALLOW_IMPLICIT_CONSTRUCTORS(DescriptorArray); 2480}; 2481 2482 2483// HashTable is a subclass of FixedArray that implements a hash table 2484// that uses open addressing and quadratic probing. 2485// 2486// In order for the quadratic probing to work, elements that have not 2487// yet been used and elements that have been deleted are 2488// distinguished. Probing continues when deleted elements are 2489// encountered and stops when unused elements are encountered. 2490// 2491// - Elements with key == undefined have not been used yet. 2492// - Elements with key == the_hole have been deleted. 2493// 2494// The hash table class is parameterized with a Shape and a Key. 2495// Shape must be a class with the following interface: 2496// class ExampleShape { 2497// public: 2498// // Tells whether key matches other. 2499// static bool IsMatch(Key key, Object* other); 2500// // Returns the hash value for key. 2501// static uint32_t Hash(Key key); 2502// // Returns the hash value for object. 2503// static uint32_t HashForObject(Key key, Object* object); 2504// // Convert key to an object. 2505// static inline Object* AsObject(Key key); 2506// // The prefix size indicates number of elements in the beginning 2507// // of the backing storage. 2508// static const int kPrefixSize = ..; 2509// // The Element size indicates number of elements per entry. 2510// static const int kEntrySize = ..; 2511// }; 2512// The prefix size indicates an amount of memory in the 2513// beginning of the backing storage that can be used for non-element 2514// information by subclasses. 2515 2516template<typename Shape, typename Key> 2517class HashTable: public FixedArray { 2518 public: 2519 // Returns the number of elements in the hash table. 2520 int NumberOfElements() { 2521 return Smi::cast(get(kNumberOfElementsIndex))->value(); 2522 } 2523 2524 // Returns the number of deleted elements in the hash table. 2525 int NumberOfDeletedElements() { 2526 return Smi::cast(get(kNumberOfDeletedElementsIndex))->value(); 2527 } 2528 2529 // Returns the capacity of the hash table. 2530 int Capacity() { 2531 return Smi::cast(get(kCapacityIndex))->value(); 2532 } 2533 2534 // ElementAdded should be called whenever an element is added to a 2535 // hash table. 2536 void ElementAdded() { SetNumberOfElements(NumberOfElements() + 1); } 2537 2538 // ElementRemoved should be called whenever an element is removed from 2539 // a hash table. 2540 void ElementRemoved() { 2541 SetNumberOfElements(NumberOfElements() - 1); 2542 SetNumberOfDeletedElements(NumberOfDeletedElements() + 1); 2543 } 2544 void ElementsRemoved(int n) { 2545 SetNumberOfElements(NumberOfElements() - n); 2546 SetNumberOfDeletedElements(NumberOfDeletedElements() + n); 2547 } 2548 2549 // Returns a new HashTable object. Might return Failure. 2550 MUST_USE_RESULT static MaybeObject* Allocate( 2551 int at_least_space_for, 2552 PretenureFlag pretenure = NOT_TENURED); 2553 2554 // Computes the required capacity for a table holding the given 2555 // number of elements. May be more than HashTable::kMaxCapacity. 2556 static int ComputeCapacity(int at_least_space_for); 2557 2558 // Returns the key at entry. 2559 Object* KeyAt(int entry) { return get(EntryToIndex(entry)); } 2560 2561 // Tells whether k is a real key. The hole and undefined are not allowed 2562 // as keys and can be used to indicate missing or deleted elements. 2563 bool IsKey(Object* k) { 2564 return !k->IsTheHole() && !k->IsUndefined(); 2565 } 2566 2567 // Garbage collection support. 2568 void IteratePrefix(ObjectVisitor* visitor); 2569 void IterateElements(ObjectVisitor* visitor); 2570 2571 // Casting. 2572 static inline HashTable* cast(Object* obj); 2573 2574 // Compute the probe offset (quadratic probing). 2575 INLINE(static uint32_t GetProbeOffset(uint32_t n)) { 2576 return (n + n * n) >> 1; 2577 } 2578 2579 static const int kNumberOfElementsIndex = 0; 2580 static const int kNumberOfDeletedElementsIndex = 1; 2581 static const int kCapacityIndex = 2; 2582 static const int kPrefixStartIndex = 3; 2583 static const int kElementsStartIndex = 2584 kPrefixStartIndex + Shape::kPrefixSize; 2585 static const int kEntrySize = Shape::kEntrySize; 2586 static const int kElementsStartOffset = 2587 kHeaderSize + kElementsStartIndex * kPointerSize; 2588 static const int kCapacityOffset = 2589 kHeaderSize + kCapacityIndex * kPointerSize; 2590 2591 // Constant used for denoting a absent entry. 2592 static const int kNotFound = -1; 2593 2594 // Maximal capacity of HashTable. Based on maximal length of underlying 2595 // FixedArray. Staying below kMaxCapacity also ensures that EntryToIndex 2596 // cannot overflow. 2597 static const int kMaxCapacity = 2598 (FixedArray::kMaxLength - kElementsStartOffset) / kEntrySize; 2599 2600 // Find entry for key otherwise return kNotFound. 2601 inline int FindEntry(Key key); 2602 int FindEntry(Isolate* isolate, Key key); 2603 2604 protected: 2605 // Find the entry at which to insert element with the given key that 2606 // has the given hash value. 2607 uint32_t FindInsertionEntry(uint32_t hash); 2608 2609 // Returns the index for an entry (of the key) 2610 static inline int EntryToIndex(int entry) { 2611 return (entry * kEntrySize) + kElementsStartIndex; 2612 } 2613 2614 // Update the number of elements in the hash table. 2615 void SetNumberOfElements(int nof) { 2616 set(kNumberOfElementsIndex, Smi::FromInt(nof)); 2617 } 2618 2619 // Update the number of deleted elements in the hash table. 2620 void SetNumberOfDeletedElements(int nod) { 2621 set(kNumberOfDeletedElementsIndex, Smi::FromInt(nod)); 2622 } 2623 2624 // Sets the capacity of the hash table. 2625 void SetCapacity(int capacity) { 2626 // To scale a computed hash code to fit within the hash table, we 2627 // use bit-wise AND with a mask, so the capacity must be positive 2628 // and non-zero. 2629 ASSERT(capacity > 0); 2630 ASSERT(capacity <= kMaxCapacity); 2631 set(kCapacityIndex, Smi::FromInt(capacity)); 2632 } 2633 2634 2635 // Returns probe entry. 2636 static uint32_t GetProbe(uint32_t hash, uint32_t number, uint32_t size) { 2637 ASSERT(IsPowerOf2(size)); 2638 return (hash + GetProbeOffset(number)) & (size - 1); 2639 } 2640 2641 static uint32_t FirstProbe(uint32_t hash, uint32_t size) { 2642 return hash & (size - 1); 2643 } 2644 2645 static uint32_t NextProbe(uint32_t last, uint32_t number, uint32_t size) { 2646 return (last + number) & (size - 1); 2647 } 2648 2649 // Rehashes this hash-table into the new table. 2650 MUST_USE_RESULT MaybeObject* Rehash(HashTable* new_table, Key key); 2651 2652 // Attempt to shrink hash table after removal of key. 2653 MUST_USE_RESULT MaybeObject* Shrink(Key key); 2654 2655 // Ensure enough space for n additional elements. 2656 MUST_USE_RESULT MaybeObject* EnsureCapacity(int n, Key key); 2657}; 2658 2659 2660 2661// HashTableKey is an abstract superclass for virtual key behavior. 2662class HashTableKey { 2663 public: 2664 // Returns whether the other object matches this key. 2665 virtual bool IsMatch(Object* other) = 0; 2666 // Returns the hash value for this key. 2667 virtual uint32_t Hash() = 0; 2668 // Returns the hash value for object. 2669 virtual uint32_t HashForObject(Object* key) = 0; 2670 // Returns the key object for storing into the hash table. 2671 // If allocations fails a failure object is returned. 2672 MUST_USE_RESULT virtual MaybeObject* AsObject() = 0; 2673 // Required. 2674 virtual ~HashTableKey() {} 2675}; 2676 2677class SymbolTableShape { 2678 public: 2679 static inline bool IsMatch(HashTableKey* key, Object* value) { 2680 return key->IsMatch(value); 2681 } 2682 static inline uint32_t Hash(HashTableKey* key) { 2683 return key->Hash(); 2684 } 2685 static inline uint32_t HashForObject(HashTableKey* key, Object* object) { 2686 return key->HashForObject(object); 2687 } 2688 MUST_USE_RESULT static inline MaybeObject* AsObject(HashTableKey* key) { 2689 return key->AsObject(); 2690 } 2691 2692 static const int kPrefixSize = 0; 2693 static const int kEntrySize = 1; 2694}; 2695 2696class SeqAsciiString; 2697 2698// SymbolTable. 2699// 2700// No special elements in the prefix and the element size is 1 2701// because only the symbol itself (the key) needs to be stored. 2702class SymbolTable: public HashTable<SymbolTableShape, HashTableKey*> { 2703 public: 2704 // Find symbol in the symbol table. If it is not there yet, it is 2705 // added. The return value is the symbol table which might have 2706 // been enlarged. If the return value is not a failure, the symbol 2707 // pointer *s is set to the symbol found. 2708 MUST_USE_RESULT MaybeObject* LookupSymbol(Vector<const char> str, Object** s); 2709 MUST_USE_RESULT MaybeObject* LookupAsciiSymbol(Vector<const char> str, 2710 Object** s); 2711 MUST_USE_RESULT MaybeObject* LookupSubStringAsciiSymbol( 2712 Handle<SeqAsciiString> str, 2713 int from, 2714 int length, 2715 Object** s); 2716 MUST_USE_RESULT MaybeObject* LookupTwoByteSymbol(Vector<const uc16> str, 2717 Object** s); 2718 MUST_USE_RESULT MaybeObject* LookupString(String* key, Object** s); 2719 2720 // Looks up a symbol that is equal to the given string and returns 2721 // true if it is found, assigning the symbol to the given output 2722 // parameter. 2723 bool LookupSymbolIfExists(String* str, String** symbol); 2724 bool LookupTwoCharsSymbolIfExists(uint32_t c1, uint32_t c2, String** symbol); 2725 2726 // Casting. 2727 static inline SymbolTable* cast(Object* obj); 2728 2729 private: 2730 MUST_USE_RESULT MaybeObject* LookupKey(HashTableKey* key, Object** s); 2731 2732 DISALLOW_IMPLICIT_CONSTRUCTORS(SymbolTable); 2733}; 2734 2735 2736class MapCacheShape { 2737 public: 2738 static inline bool IsMatch(HashTableKey* key, Object* value) { 2739 return key->IsMatch(value); 2740 } 2741 static inline uint32_t Hash(HashTableKey* key) { 2742 return key->Hash(); 2743 } 2744 2745 static inline uint32_t HashForObject(HashTableKey* key, Object* object) { 2746 return key->HashForObject(object); 2747 } 2748 2749 MUST_USE_RESULT static inline MaybeObject* AsObject(HashTableKey* key) { 2750 return key->AsObject(); 2751 } 2752 2753 static const int kPrefixSize = 0; 2754 static const int kEntrySize = 2; 2755}; 2756 2757 2758// MapCache. 2759// 2760// Maps keys that are a fixed array of symbols to a map. 2761// Used for canonicalize maps for object literals. 2762class MapCache: public HashTable<MapCacheShape, HashTableKey*> { 2763 public: 2764 // Find cached value for a string key, otherwise return null. 2765 Object* Lookup(FixedArray* key); 2766 MUST_USE_RESULT MaybeObject* Put(FixedArray* key, Map* value); 2767 static inline MapCache* cast(Object* obj); 2768 2769 private: 2770 DISALLOW_IMPLICIT_CONSTRUCTORS(MapCache); 2771}; 2772 2773 2774template <typename Shape, typename Key> 2775class Dictionary: public HashTable<Shape, Key> { 2776 public: 2777 static inline Dictionary<Shape, Key>* cast(Object* obj) { 2778 return reinterpret_cast<Dictionary<Shape, Key>*>(obj); 2779 } 2780 2781 // Returns the value at entry. 2782 Object* ValueAt(int entry) { 2783 return this->get(HashTable<Shape, Key>::EntryToIndex(entry)+1); 2784 } 2785 2786 // Set the value for entry. 2787 // Returns false if the put wasn't performed due to property being read only. 2788 // Returns true on successful put. 2789 bool ValueAtPut(int entry, Object* value) { 2790 // Check that this value can actually be written. 2791 PropertyDetails details = DetailsAt(entry); 2792 // If a value has not been initilized we allow writing to it even if 2793 // it is read only (a declared const that has not been initialized). 2794 if (details.IsReadOnly() && !ValueAt(entry)->IsTheHole()) { 2795 return false; 2796 } 2797 this->set(HashTable<Shape, Key>::EntryToIndex(entry) + 1, value); 2798 return true; 2799 } 2800 2801 // Returns the property details for the property at entry. 2802 PropertyDetails DetailsAt(int entry) { 2803 ASSERT(entry >= 0); // Not found is -1, which is not caught by get(). 2804 return PropertyDetails( 2805 Smi::cast(this->get(HashTable<Shape, Key>::EntryToIndex(entry) + 2))); 2806 } 2807 2808 // Set the details for entry. 2809 void DetailsAtPut(int entry, PropertyDetails value) { 2810 this->set(HashTable<Shape, Key>::EntryToIndex(entry) + 2, value.AsSmi()); 2811 } 2812 2813 // Sorting support 2814 void CopyValuesTo(FixedArray* elements); 2815 2816 // Delete a property from the dictionary. 2817 Object* DeleteProperty(int entry, JSObject::DeleteMode mode); 2818 2819 // Attempt to shrink the dictionary after deletion of key. 2820 MUST_USE_RESULT MaybeObject* Shrink(Key key); 2821 2822 // Returns the number of elements in the dictionary filtering out properties 2823 // with the specified attributes. 2824 int NumberOfElementsFilterAttributes(PropertyAttributes filter); 2825 2826 // Returns the number of enumerable elements in the dictionary. 2827 int NumberOfEnumElements(); 2828 2829 enum SortMode { UNSORTED, SORTED }; 2830 // Copies keys to preallocated fixed array. 2831 void CopyKeysTo(FixedArray* storage, 2832 PropertyAttributes filter, 2833 SortMode sort_mode); 2834 // Fill in details for properties into storage. 2835 void CopyKeysTo(FixedArray* storage, int index, SortMode sort_mode); 2836 2837 // Accessors for next enumeration index. 2838 void SetNextEnumerationIndex(int index) { 2839 this->set(kNextEnumerationIndexIndex, Smi::FromInt(index)); 2840 } 2841 2842 int NextEnumerationIndex() { 2843 return Smi::cast(FixedArray::get(kNextEnumerationIndexIndex))->value(); 2844 } 2845 2846 // Returns a new array for dictionary usage. Might return Failure. 2847 MUST_USE_RESULT static MaybeObject* Allocate(int at_least_space_for); 2848 2849 // Ensure enough space for n additional elements. 2850 MUST_USE_RESULT MaybeObject* EnsureCapacity(int n, Key key); 2851 2852#ifdef OBJECT_PRINT 2853 inline void Print() { 2854 Print(stdout); 2855 } 2856 void Print(FILE* out); 2857#endif 2858 // Returns the key (slow). 2859 Object* SlowReverseLookup(Object* value); 2860 2861 // Sets the entry to (key, value) pair. 2862 inline void SetEntry(int entry, 2863 Object* key, 2864 Object* value); 2865 inline void SetEntry(int entry, 2866 Object* key, 2867 Object* value, 2868 PropertyDetails details); 2869 2870 MUST_USE_RESULT MaybeObject* Add(Key key, 2871 Object* value, 2872 PropertyDetails details); 2873 2874 protected: 2875 // Generic at put operation. 2876 MUST_USE_RESULT MaybeObject* AtPut(Key key, Object* value); 2877 2878 // Add entry to dictionary. 2879 MUST_USE_RESULT MaybeObject* AddEntry(Key key, 2880 Object* value, 2881 PropertyDetails details, 2882 uint32_t hash); 2883 2884 // Generate new enumeration indices to avoid enumeration index overflow. 2885 MUST_USE_RESULT MaybeObject* GenerateNewEnumerationIndices(); 2886 static const int kMaxNumberKeyIndex = 2887 HashTable<Shape, Key>::kPrefixStartIndex; 2888 static const int kNextEnumerationIndexIndex = kMaxNumberKeyIndex + 1; 2889}; 2890 2891 2892class StringDictionaryShape { 2893 public: 2894 static inline bool IsMatch(String* key, Object* other); 2895 static inline uint32_t Hash(String* key); 2896 static inline uint32_t HashForObject(String* key, Object* object); 2897 MUST_USE_RESULT static inline MaybeObject* AsObject(String* key); 2898 static const int kPrefixSize = 2; 2899 static const int kEntrySize = 3; 2900 static const bool kIsEnumerable = true; 2901}; 2902 2903 2904class StringDictionary: public Dictionary<StringDictionaryShape, String*> { 2905 public: 2906 static inline StringDictionary* cast(Object* obj) { 2907 ASSERT(obj->IsDictionary()); 2908 return reinterpret_cast<StringDictionary*>(obj); 2909 } 2910 2911 // Copies enumerable keys to preallocated fixed array. 2912 void CopyEnumKeysTo(FixedArray* storage, FixedArray* sort_array); 2913 2914 // For transforming properties of a JSObject. 2915 MUST_USE_RESULT MaybeObject* TransformPropertiesToFastFor( 2916 JSObject* obj, 2917 int unused_property_fields); 2918 2919 // Find entry for key, otherwise return kNotFound. Optimized version of 2920 // HashTable::FindEntry. 2921 int FindEntry(String* key); 2922}; 2923 2924 2925class NumberDictionaryShape { 2926 public: 2927 static inline bool IsMatch(uint32_t key, Object* other); 2928 static inline uint32_t Hash(uint32_t key); 2929 static inline uint32_t HashForObject(uint32_t key, Object* object); 2930 MUST_USE_RESULT static inline MaybeObject* AsObject(uint32_t key); 2931 static const int kPrefixSize = 2; 2932 static const int kEntrySize = 3; 2933 static const bool kIsEnumerable = false; 2934}; 2935 2936 2937class NumberDictionary: public Dictionary<NumberDictionaryShape, uint32_t> { 2938 public: 2939 static NumberDictionary* cast(Object* obj) { 2940 ASSERT(obj->IsDictionary()); 2941 return reinterpret_cast<NumberDictionary*>(obj); 2942 } 2943 2944 // Type specific at put (default NONE attributes is used when adding). 2945 MUST_USE_RESULT MaybeObject* AtNumberPut(uint32_t key, Object* value); 2946 MUST_USE_RESULT MaybeObject* AddNumberEntry(uint32_t key, 2947 Object* value, 2948 PropertyDetails details); 2949 2950 // Set an existing entry or add a new one if needed. 2951 MUST_USE_RESULT MaybeObject* Set(uint32_t key, 2952 Object* value, 2953 PropertyDetails details); 2954 2955 void UpdateMaxNumberKey(uint32_t key); 2956 2957 // If slow elements are required we will never go back to fast-case 2958 // for the elements kept in this dictionary. We require slow 2959 // elements if an element has been added at an index larger than 2960 // kRequiresSlowElementsLimit or set_requires_slow_elements() has been called 2961 // when defining a getter or setter with a number key. 2962 inline bool requires_slow_elements(); 2963 inline void set_requires_slow_elements(); 2964 2965 // Get the value of the max number key that has been added to this 2966 // dictionary. max_number_key can only be called if 2967 // requires_slow_elements returns false. 2968 inline uint32_t max_number_key(); 2969 2970 // Bit masks. 2971 static const int kRequiresSlowElementsMask = 1; 2972 static const int kRequiresSlowElementsTagSize = 1; 2973 static const uint32_t kRequiresSlowElementsLimit = (1 << 29) - 1; 2974}; 2975 2976 2977template <int entrysize> 2978class ObjectHashTableShape { 2979 public: 2980 static inline bool IsMatch(Object* key, Object* other); 2981 static inline uint32_t Hash(Object* key); 2982 static inline uint32_t HashForObject(Object* key, Object* object); 2983 MUST_USE_RESULT static inline MaybeObject* AsObject(Object* key); 2984 static const int kPrefixSize = 0; 2985 static const int kEntrySize = entrysize; 2986}; 2987 2988 2989// ObjectHashSet holds keys that are arbitrary objects by using the identity 2990// hash of the key for hashing purposes. 2991class ObjectHashSet: public HashTable<ObjectHashTableShape<1>, Object*> { 2992 public: 2993 static inline ObjectHashSet* cast(Object* obj) { 2994 ASSERT(obj->IsHashTable()); 2995 return reinterpret_cast<ObjectHashSet*>(obj); 2996 } 2997 2998 // Looks up whether the given key is part of this hash set. 2999 bool Contains(Object* key); 3000 3001 // Adds the given key to this hash set. 3002 MUST_USE_RESULT MaybeObject* Add(Object* key); 3003 3004 // Removes the given key from this hash set. 3005 MUST_USE_RESULT MaybeObject* Remove(Object* key); 3006}; 3007 3008 3009// ObjectHashTable maps keys that are arbitrary objects to object values by 3010// using the identity hash of the key for hashing purposes. 3011class ObjectHashTable: public HashTable<ObjectHashTableShape<2>, Object*> { 3012 public: 3013 static inline ObjectHashTable* cast(Object* obj) { 3014 ASSERT(obj->IsHashTable()); 3015 return reinterpret_cast<ObjectHashTable*>(obj); 3016 } 3017 3018 // Looks up the value associated with the given key. The undefined value is 3019 // returned in case the key is not present. 3020 Object* Lookup(Object* key); 3021 3022 // Adds (or overwrites) the value associated with the given key. Mapping a 3023 // key to the undefined value causes removal of the whole entry. 3024 MUST_USE_RESULT MaybeObject* Put(Object* key, Object* value); 3025 3026 private: 3027 friend class MarkCompactCollector; 3028 3029 void AddEntry(int entry, Object* key, Object* value); 3030 void RemoveEntry(int entry); 3031 3032 // Returns the index to the value of an entry. 3033 static inline int EntryToValueIndex(int entry) { 3034 return EntryToIndex(entry) + 1; 3035 } 3036}; 3037 3038 3039// JSFunctionResultCache caches results of some JSFunction invocation. 3040// It is a fixed array with fixed structure: 3041// [0]: factory function 3042// [1]: finger index 3043// [2]: current cache size 3044// [3]: dummy field. 3045// The rest of array are key/value pairs. 3046class JSFunctionResultCache: public FixedArray { 3047 public: 3048 static const int kFactoryIndex = 0; 3049 static const int kFingerIndex = kFactoryIndex + 1; 3050 static const int kCacheSizeIndex = kFingerIndex + 1; 3051 static const int kDummyIndex = kCacheSizeIndex + 1; 3052 static const int kEntriesIndex = kDummyIndex + 1; 3053 3054 static const int kEntrySize = 2; // key + value 3055 3056 static const int kFactoryOffset = kHeaderSize; 3057 static const int kFingerOffset = kFactoryOffset + kPointerSize; 3058 static const int kCacheSizeOffset = kFingerOffset + kPointerSize; 3059 3060 inline void MakeZeroSize(); 3061 inline void Clear(); 3062 3063 inline int size(); 3064 inline void set_size(int size); 3065 inline int finger_index(); 3066 inline void set_finger_index(int finger_index); 3067 3068 // Casting 3069 static inline JSFunctionResultCache* cast(Object* obj); 3070 3071#ifdef DEBUG 3072 void JSFunctionResultCacheVerify(); 3073#endif 3074}; 3075 3076 3077// ScopeInfo represents information about different scopes of a source 3078// program and the allocation of the scope's variables. Scope information 3079// is stored in a compressed form in ScopeInfo objects and is used 3080// at runtime (stack dumps, deoptimization, etc.). 3081 3082// This object provides quick access to scope info details for runtime 3083// routines. 3084class ScopeInfo : public FixedArray { 3085 public: 3086 static inline ScopeInfo* cast(Object* object); 3087 3088 // Return the type of this scope. 3089 ScopeType Type(); 3090 3091 // Does this scope call eval? 3092 bool CallsEval(); 3093 3094 // Return the language mode of this scope. 3095 LanguageMode language_mode(); 3096 3097 // Does this scope make a non-strict eval call? 3098 bool CallsNonStrictEval() { 3099 return CallsEval() && (language_mode() == CLASSIC_MODE); 3100 } 3101 3102 // Return the total number of locals allocated on the stack and in the 3103 // context. This includes the parameters that are allocated in the context. 3104 int LocalCount(); 3105 3106 // Return the number of stack slots for code. This number consists of two 3107 // parts: 3108 // 1. One stack slot per stack allocated local. 3109 // 2. One stack slot for the function name if it is stack allocated. 3110 int StackSlotCount(); 3111 3112 // Return the number of context slots for code if a context is allocated. This 3113 // number consists of three parts: 3114 // 1. Size of fixed header for every context: Context::MIN_CONTEXT_SLOTS 3115 // 2. One context slot per context allocated local. 3116 // 3. One context slot for the function name if it is context allocated. 3117 // Parameters allocated in the context count as context allocated locals. If 3118 // no contexts are allocated for this scope ContextLength returns 0. 3119 int ContextLength(); 3120 3121 // Is this scope the scope of a named function expression? 3122 bool HasFunctionName(); 3123 3124 // Return if this has context allocated locals. 3125 bool HasHeapAllocatedLocals(); 3126 3127 // Return if contexts are allocated for this scope. 3128 bool HasContext(); 3129 3130 // Return the function_name if present. 3131 String* FunctionName(); 3132 3133 // Return the name of the given parameter. 3134 String* ParameterName(int var); 3135 3136 // Return the name of the given local. 3137 String* LocalName(int var); 3138 3139 // Return the name of the given stack local. 3140 String* StackLocalName(int var); 3141 3142 // Return the name of the given context local. 3143 String* ContextLocalName(int var); 3144 3145 // Return the mode of the given context local. 3146 VariableMode ContextLocalMode(int var); 3147 3148 // Return the initialization flag of the given context local. 3149 InitializationFlag ContextLocalInitFlag(int var); 3150 3151 // Lookup support for serialized scope info. Returns the 3152 // the stack slot index for a given slot name if the slot is 3153 // present; otherwise returns a value < 0. The name must be a symbol 3154 // (canonicalized). 3155 int StackSlotIndex(String* name); 3156 3157 // Lookup support for serialized scope info. Returns the 3158 // context slot index for a given slot name if the slot is present; otherwise 3159 // returns a value < 0. The name must be a symbol (canonicalized). 3160 // If the slot is present and mode != NULL, sets *mode to the corresponding 3161 // mode for that variable. 3162 int ContextSlotIndex(String* name, 3163 VariableMode* mode, 3164 InitializationFlag* init_flag); 3165 3166 // Lookup support for serialized scope info. Returns the 3167 // parameter index for a given parameter name if the parameter is present; 3168 // otherwise returns a value < 0. The name must be a symbol (canonicalized). 3169 int ParameterIndex(String* name); 3170 3171 // Lookup support for serialized scope info. Returns the 3172 // function context slot index if the function name is present (named 3173 // function expressions, only), otherwise returns a value < 0. The name 3174 // must be a symbol (canonicalized). 3175 int FunctionContextSlotIndex(String* name, VariableMode* mode); 3176 3177 static Handle<ScopeInfo> Create(Scope* scope); 3178 3179 // Serializes empty scope info. 3180 static ScopeInfo* Empty(); 3181 3182#ifdef DEBUG 3183 void Print(); 3184#endif 3185 3186 // The layout of the static part of a ScopeInfo is as follows. Each entry is 3187 // numeric and occupies one array slot. 3188 // 1. A set of properties of the scope 3189 // 2. The number of parameters. This only applies to function scopes. For 3190 // non-function scopes this is 0. 3191 // 3. The number of non-parameter variables allocated on the stack. 3192 // 4. The number of non-parameter and parameter variables allocated in the 3193 // context. 3194#define FOR_EACH_NUMERIC_FIELD(V) \ 3195 V(Flags) \ 3196 V(ParameterCount) \ 3197 V(StackLocalCount) \ 3198 V(ContextLocalCount) 3199 3200#define FIELD_ACCESSORS(name) \ 3201 void Set##name(int value) { \ 3202 set(k##name, Smi::FromInt(value)); \ 3203 } \ 3204 int name() { \ 3205 if (length() > 0) { \ 3206 return Smi::cast(get(k##name))->value(); \ 3207 } else { \ 3208 return 0; \ 3209 } \ 3210 } 3211 FOR_EACH_NUMERIC_FIELD(FIELD_ACCESSORS) 3212#undef FIELD_ACCESSORS 3213 3214 private: 3215 enum { 3216#define DECL_INDEX(name) k##name, 3217 FOR_EACH_NUMERIC_FIELD(DECL_INDEX) 3218#undef DECL_INDEX 3219#undef FOR_EACH_NUMERIC_FIELD 3220 kVariablePartIndex 3221 }; 3222 3223 // The layout of the variable part of a ScopeInfo is as follows: 3224 // 1. ParameterEntries: 3225 // This part stores the names of the parameters for function scopes. One 3226 // slot is used per parameter, so in total this part occupies 3227 // ParameterCount() slots in the array. For other scopes than function 3228 // scopes ParameterCount() is 0. 3229 // 2. StackLocalEntries: 3230 // Contains the names of local variables that are allocated on the stack, 3231 // in increasing order of the stack slot index. One slot is used per stack 3232 // local, so in total this part occupies StackLocalCount() slots in the 3233 // array. 3234 // 3. ContextLocalNameEntries: 3235 // Contains the names of local variables and parameters that are allocated 3236 // in the context. They are stored in increasing order of the context slot 3237 // index starting with Context::MIN_CONTEXT_SLOTS. One slot is used per 3238 // context local, so in total this part occupies ContextLocalCount() slots 3239 // in the array. 3240 // 4. ContextLocalInfoEntries: 3241 // Contains the variable modes and initialization flags corresponding to 3242 // the context locals in ContextLocalNameEntries. One slot is used per 3243 // context local, so in total this part occupies ContextLocalCount() 3244 // slots in the array. 3245 // 5. FunctionNameEntryIndex: 3246 // If the scope belongs to a named function expression this part contains 3247 // information about the function variable. It always occupies two array 3248 // slots: a. The name of the function variable. 3249 // b. The context or stack slot index for the variable. 3250 int ParameterEntriesIndex(); 3251 int StackLocalEntriesIndex(); 3252 int ContextLocalNameEntriesIndex(); 3253 int ContextLocalInfoEntriesIndex(); 3254 int FunctionNameEntryIndex(); 3255 3256 // Location of the function variable for named function expressions. 3257 enum FunctionVariableInfo { 3258 NONE, // No function name present. 3259 STACK, // Function 3260 CONTEXT, 3261 UNUSED 3262 }; 3263 3264 // Properties of scopes. 3265 class TypeField: public BitField<ScopeType, 0, 3> {}; 3266 class CallsEvalField: public BitField<bool, 3, 1> {}; 3267 class LanguageModeField: public BitField<LanguageMode, 4, 2> {}; 3268 class FunctionVariableField: public BitField<FunctionVariableInfo, 6, 2> {}; 3269 class FunctionVariableMode: public BitField<VariableMode, 8, 3> {}; 3270 3271 // BitFields representing the encoded information for context locals in the 3272 // ContextLocalInfoEntries part. 3273 class ContextLocalMode: public BitField<VariableMode, 0, 3> {}; 3274 class ContextLocalInitFlag: public BitField<InitializationFlag, 3, 1> {}; 3275}; 3276 3277 3278// The cache for maps used by normalized (dictionary mode) objects. 3279// Such maps do not have property descriptors, so a typical program 3280// needs very limited number of distinct normalized maps. 3281class NormalizedMapCache: public FixedArray { 3282 public: 3283 static const int kEntries = 64; 3284 3285 MUST_USE_RESULT MaybeObject* Get(JSObject* object, 3286 PropertyNormalizationMode mode); 3287 3288 void Clear(); 3289 3290 // Casting 3291 static inline NormalizedMapCache* cast(Object* obj); 3292 3293#ifdef DEBUG 3294 void NormalizedMapCacheVerify(); 3295#endif 3296}; 3297 3298 3299// ByteArray represents fixed sized byte arrays. Used for the relocation info 3300// that is attached to code objects. 3301class ByteArray: public FixedArrayBase { 3302 public: 3303 inline int Size() { return RoundUp(length() + kHeaderSize, kPointerSize); } 3304 3305 // Setter and getter. 3306 inline byte get(int index); 3307 inline void set(int index, byte value); 3308 3309 // Treat contents as an int array. 3310 inline int get_int(int index); 3311 3312 static int SizeFor(int length) { 3313 return OBJECT_POINTER_ALIGN(kHeaderSize + length); 3314 } 3315 // We use byte arrays for free blocks in the heap. Given a desired size in 3316 // bytes that is a multiple of the word size and big enough to hold a byte 3317 // array, this function returns the number of elements a byte array should 3318 // have. 3319 static int LengthFor(int size_in_bytes) { 3320 ASSERT(IsAligned(size_in_bytes, kPointerSize)); 3321 ASSERT(size_in_bytes >= kHeaderSize); 3322 return size_in_bytes - kHeaderSize; 3323 } 3324 3325 // Returns data start address. 3326 inline Address GetDataStartAddress(); 3327 3328 // Returns a pointer to the ByteArray object for a given data start address. 3329 static inline ByteArray* FromDataStartAddress(Address address); 3330 3331 // Casting. 3332 static inline ByteArray* cast(Object* obj); 3333 3334 // Dispatched behavior. 3335 inline int ByteArraySize() { 3336 return SizeFor(this->length()); 3337 } 3338#ifdef OBJECT_PRINT 3339 inline void ByteArrayPrint() { 3340 ByteArrayPrint(stdout); 3341 } 3342 void ByteArrayPrint(FILE* out); 3343#endif 3344#ifdef DEBUG 3345 void ByteArrayVerify(); 3346#endif 3347 3348 // Layout description. 3349 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); 3350 3351 // Maximal memory consumption for a single ByteArray. 3352 static const int kMaxSize = 512 * MB; 3353 // Maximal length of a single ByteArray. 3354 static const int kMaxLength = kMaxSize - kHeaderSize; 3355 3356 private: 3357 DISALLOW_IMPLICIT_CONSTRUCTORS(ByteArray); 3358}; 3359 3360 3361// FreeSpace represents fixed sized areas of the heap that are not currently in 3362// use. Used by the heap and GC. 3363class FreeSpace: public HeapObject { 3364 public: 3365 // [size]: size of the free space including the header. 3366 inline int size(); 3367 inline void set_size(int value); 3368 3369 inline int Size() { return size(); } 3370 3371 // Casting. 3372 static inline FreeSpace* cast(Object* obj); 3373 3374#ifdef OBJECT_PRINT 3375 inline void FreeSpacePrint() { 3376 FreeSpacePrint(stdout); 3377 } 3378 void FreeSpacePrint(FILE* out); 3379#endif 3380#ifdef DEBUG 3381 void FreeSpaceVerify(); 3382#endif 3383 3384 // Layout description. 3385 // Size is smi tagged when it is stored. 3386 static const int kSizeOffset = HeapObject::kHeaderSize; 3387 static const int kHeaderSize = kSizeOffset + kPointerSize; 3388 3389 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); 3390 3391 private: 3392 DISALLOW_IMPLICIT_CONSTRUCTORS(FreeSpace); 3393}; 3394 3395 3396// An ExternalArray represents a fixed-size array of primitive values 3397// which live outside the JavaScript heap. Its subclasses are used to 3398// implement the CanvasArray types being defined in the WebGL 3399// specification. As of this writing the first public draft is not yet 3400// available, but Khronos members can access the draft at: 3401// https://cvs.khronos.org/svn/repos/3dweb/trunk/doc/spec/WebGL-spec.html 3402// 3403// The semantics of these arrays differ from CanvasPixelArray. 3404// Out-of-range values passed to the setter are converted via a C 3405// cast, not clamping. Out-of-range indices cause exceptions to be 3406// raised rather than being silently ignored. 3407class ExternalArray: public FixedArrayBase { 3408 public: 3409 inline bool is_the_hole(int index) { return false; } 3410 3411 // [external_pointer]: The pointer to the external memory area backing this 3412 // external array. 3413 DECL_ACCESSORS(external_pointer, void) // Pointer to the data store. 3414 3415 // Casting. 3416 static inline ExternalArray* cast(Object* obj); 3417 3418 // Maximal acceptable length for an external array. 3419 static const int kMaxLength = 0x3fffffff; 3420 3421 // ExternalArray headers are not quadword aligned. 3422 static const int kExternalPointerOffset = 3423 POINTER_SIZE_ALIGN(FixedArrayBase::kLengthOffset + kPointerSize); 3424 static const int kHeaderSize = kExternalPointerOffset + kPointerSize; 3425 static const int kAlignedSize = OBJECT_POINTER_ALIGN(kHeaderSize); 3426 3427 private: 3428 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalArray); 3429}; 3430 3431 3432// A ExternalPixelArray represents a fixed-size byte array with special 3433// semantics used for implementing the CanvasPixelArray object. Please see the 3434// specification at: 3435 3436// http://www.whatwg.org/specs/web-apps/current-work/ 3437// multipage/the-canvas-element.html#canvaspixelarray 3438// In particular, write access clamps the value written to 0 or 255 if the 3439// value written is outside this range. 3440class ExternalPixelArray: public ExternalArray { 3441 public: 3442 inline uint8_t* external_pixel_pointer(); 3443 3444 // Setter and getter. 3445 inline uint8_t get_scalar(int index); 3446 inline MaybeObject* get(int index); 3447 inline void set(int index, uint8_t value); 3448 3449 // This accessor applies the correct conversion from Smi, HeapNumber and 3450 // undefined and clamps the converted value between 0 and 255. 3451 Object* SetValue(uint32_t index, Object* value); 3452 3453 // Casting. 3454 static inline ExternalPixelArray* cast(Object* obj); 3455 3456#ifdef OBJECT_PRINT 3457 inline void ExternalPixelArrayPrint() { 3458 ExternalPixelArrayPrint(stdout); 3459 } 3460 void ExternalPixelArrayPrint(FILE* out); 3461#endif 3462#ifdef DEBUG 3463 void ExternalPixelArrayVerify(); 3464#endif // DEBUG 3465 3466 private: 3467 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalPixelArray); 3468}; 3469 3470 3471class ExternalByteArray: public ExternalArray { 3472 public: 3473 // Setter and getter. 3474 inline int8_t get_scalar(int index); 3475 inline MaybeObject* get(int index); 3476 inline void set(int index, int8_t value); 3477 3478 // This accessor applies the correct conversion from Smi, HeapNumber 3479 // and undefined. 3480 MaybeObject* SetValue(uint32_t index, Object* value); 3481 3482 // Casting. 3483 static inline ExternalByteArray* cast(Object* obj); 3484 3485#ifdef OBJECT_PRINT 3486 inline void ExternalByteArrayPrint() { 3487 ExternalByteArrayPrint(stdout); 3488 } 3489 void ExternalByteArrayPrint(FILE* out); 3490#endif 3491#ifdef DEBUG 3492 void ExternalByteArrayVerify(); 3493#endif // DEBUG 3494 3495 private: 3496 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalByteArray); 3497}; 3498 3499 3500class ExternalUnsignedByteArray: public ExternalArray { 3501 public: 3502 // Setter and getter. 3503 inline uint8_t get_scalar(int index); 3504 inline MaybeObject* get(int index); 3505 inline void set(int index, uint8_t value); 3506 3507 // This accessor applies the correct conversion from Smi, HeapNumber 3508 // and undefined. 3509 MaybeObject* SetValue(uint32_t index, Object* value); 3510 3511 // Casting. 3512 static inline ExternalUnsignedByteArray* cast(Object* obj); 3513 3514#ifdef OBJECT_PRINT 3515 inline void ExternalUnsignedByteArrayPrint() { 3516 ExternalUnsignedByteArrayPrint(stdout); 3517 } 3518 void ExternalUnsignedByteArrayPrint(FILE* out); 3519#endif 3520#ifdef DEBUG 3521 void ExternalUnsignedByteArrayVerify(); 3522#endif // DEBUG 3523 3524 private: 3525 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedByteArray); 3526}; 3527 3528 3529class ExternalShortArray: public ExternalArray { 3530 public: 3531 // Setter and getter. 3532 inline int16_t get_scalar(int index); 3533 inline MaybeObject* get(int index); 3534 inline void set(int index, int16_t value); 3535 3536 // This accessor applies the correct conversion from Smi, HeapNumber 3537 // and undefined. 3538 MaybeObject* SetValue(uint32_t index, Object* value); 3539 3540 // Casting. 3541 static inline ExternalShortArray* cast(Object* obj); 3542 3543#ifdef OBJECT_PRINT 3544 inline void ExternalShortArrayPrint() { 3545 ExternalShortArrayPrint(stdout); 3546 } 3547 void ExternalShortArrayPrint(FILE* out); 3548#endif 3549#ifdef DEBUG 3550 void ExternalShortArrayVerify(); 3551#endif // DEBUG 3552 3553 private: 3554 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalShortArray); 3555}; 3556 3557 3558class ExternalUnsignedShortArray: public ExternalArray { 3559 public: 3560 // Setter and getter. 3561 inline uint16_t get_scalar(int index); 3562 inline MaybeObject* get(int index); 3563 inline void set(int index, uint16_t value); 3564 3565 // This accessor applies the correct conversion from Smi, HeapNumber 3566 // and undefined. 3567 MaybeObject* SetValue(uint32_t index, Object* value); 3568 3569 // Casting. 3570 static inline ExternalUnsignedShortArray* cast(Object* obj); 3571 3572#ifdef OBJECT_PRINT 3573 inline void ExternalUnsignedShortArrayPrint() { 3574 ExternalUnsignedShortArrayPrint(stdout); 3575 } 3576 void ExternalUnsignedShortArrayPrint(FILE* out); 3577#endif 3578#ifdef DEBUG 3579 void ExternalUnsignedShortArrayVerify(); 3580#endif // DEBUG 3581 3582 private: 3583 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedShortArray); 3584}; 3585 3586 3587class ExternalIntArray: public ExternalArray { 3588 public: 3589 // Setter and getter. 3590 inline int32_t get_scalar(int index); 3591 inline MaybeObject* get(int index); 3592 inline void set(int index, int32_t value); 3593 3594 // This accessor applies the correct conversion from Smi, HeapNumber 3595 // and undefined. 3596 MaybeObject* SetValue(uint32_t index, Object* value); 3597 3598 // Casting. 3599 static inline ExternalIntArray* cast(Object* obj); 3600 3601#ifdef OBJECT_PRINT 3602 inline void ExternalIntArrayPrint() { 3603 ExternalIntArrayPrint(stdout); 3604 } 3605 void ExternalIntArrayPrint(FILE* out); 3606#endif 3607#ifdef DEBUG 3608 void ExternalIntArrayVerify(); 3609#endif // DEBUG 3610 3611 private: 3612 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalIntArray); 3613}; 3614 3615 3616class ExternalUnsignedIntArray: public ExternalArray { 3617 public: 3618 // Setter and getter. 3619 inline uint32_t get_scalar(int index); 3620 inline MaybeObject* get(int index); 3621 inline void set(int index, uint32_t value); 3622 3623 // This accessor applies the correct conversion from Smi, HeapNumber 3624 // and undefined. 3625 MaybeObject* SetValue(uint32_t index, Object* value); 3626 3627 // Casting. 3628 static inline ExternalUnsignedIntArray* cast(Object* obj); 3629 3630#ifdef OBJECT_PRINT 3631 inline void ExternalUnsignedIntArrayPrint() { 3632 ExternalUnsignedIntArrayPrint(stdout); 3633 } 3634 void ExternalUnsignedIntArrayPrint(FILE* out); 3635#endif 3636#ifdef DEBUG 3637 void ExternalUnsignedIntArrayVerify(); 3638#endif // DEBUG 3639 3640 private: 3641 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalUnsignedIntArray); 3642}; 3643 3644 3645class ExternalFloatArray: public ExternalArray { 3646 public: 3647 // Setter and getter. 3648 inline float get_scalar(int index); 3649 inline MaybeObject* get(int index); 3650 inline void set(int index, float value); 3651 3652 // This accessor applies the correct conversion from Smi, HeapNumber 3653 // and undefined. 3654 MaybeObject* SetValue(uint32_t index, Object* value); 3655 3656 // Casting. 3657 static inline ExternalFloatArray* cast(Object* obj); 3658 3659#ifdef OBJECT_PRINT 3660 inline void ExternalFloatArrayPrint() { 3661 ExternalFloatArrayPrint(stdout); 3662 } 3663 void ExternalFloatArrayPrint(FILE* out); 3664#endif 3665#ifdef DEBUG 3666 void ExternalFloatArrayVerify(); 3667#endif // DEBUG 3668 3669 private: 3670 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalFloatArray); 3671}; 3672 3673 3674class ExternalDoubleArray: public ExternalArray { 3675 public: 3676 // Setter and getter. 3677 inline double get_scalar(int index); 3678 inline MaybeObject* get(int index); 3679 inline void set(int index, double value); 3680 3681 // This accessor applies the correct conversion from Smi, HeapNumber 3682 // and undefined. 3683 MaybeObject* SetValue(uint32_t index, Object* value); 3684 3685 // Casting. 3686 static inline ExternalDoubleArray* cast(Object* obj); 3687 3688#ifdef OBJECT_PRINT 3689 inline void ExternalDoubleArrayPrint() { 3690 ExternalDoubleArrayPrint(stdout); 3691 } 3692 void ExternalDoubleArrayPrint(FILE* out); 3693#endif // OBJECT_PRINT 3694#ifdef DEBUG 3695 void ExternalDoubleArrayVerify(); 3696#endif // DEBUG 3697 3698 private: 3699 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalDoubleArray); 3700}; 3701 3702 3703// DeoptimizationInputData is a fixed array used to hold the deoptimization 3704// data for code generated by the Hydrogen/Lithium compiler. It also 3705// contains information about functions that were inlined. If N different 3706// functions were inlined then first N elements of the literal array will 3707// contain these functions. 3708// 3709// It can be empty. 3710class DeoptimizationInputData: public FixedArray { 3711 public: 3712 // Layout description. Indices in the array. 3713 static const int kTranslationByteArrayIndex = 0; 3714 static const int kInlinedFunctionCountIndex = 1; 3715 static const int kLiteralArrayIndex = 2; 3716 static const int kOsrAstIdIndex = 3; 3717 static const int kOsrPcOffsetIndex = 4; 3718 static const int kFirstDeoptEntryIndex = 5; 3719 3720 // Offsets of deopt entry elements relative to the start of the entry. 3721 static const int kAstIdOffset = 0; 3722 static const int kTranslationIndexOffset = 1; 3723 static const int kArgumentsStackHeightOffset = 2; 3724 static const int kPcOffset = 3; 3725 static const int kDeoptEntrySize = 4; 3726 3727 // Simple element accessors. 3728#define DEFINE_ELEMENT_ACCESSORS(name, type) \ 3729 type* name() { \ 3730 return type::cast(get(k##name##Index)); \ 3731 } \ 3732 void Set##name(type* value) { \ 3733 set(k##name##Index, value); \ 3734 } 3735 3736 DEFINE_ELEMENT_ACCESSORS(TranslationByteArray, ByteArray) 3737 DEFINE_ELEMENT_ACCESSORS(InlinedFunctionCount, Smi) 3738 DEFINE_ELEMENT_ACCESSORS(LiteralArray, FixedArray) 3739 DEFINE_ELEMENT_ACCESSORS(OsrAstId, Smi) 3740 DEFINE_ELEMENT_ACCESSORS(OsrPcOffset, Smi) 3741 3742#undef DEFINE_ELEMENT_ACCESSORS 3743 3744 // Accessors for elements of the ith deoptimization entry. 3745#define DEFINE_ENTRY_ACCESSORS(name, type) \ 3746 type* name(int i) { \ 3747 return type::cast(get(IndexForEntry(i) + k##name##Offset)); \ 3748 } \ 3749 void Set##name(int i, type* value) { \ 3750 set(IndexForEntry(i) + k##name##Offset, value); \ 3751 } 3752 3753 DEFINE_ENTRY_ACCESSORS(AstId, Smi) 3754 DEFINE_ENTRY_ACCESSORS(TranslationIndex, Smi) 3755 DEFINE_ENTRY_ACCESSORS(ArgumentsStackHeight, Smi) 3756 DEFINE_ENTRY_ACCESSORS(Pc, Smi) 3757 3758#undef DEFINE_ENTRY_ACCESSORS 3759 3760 int DeoptCount() { 3761 return (length() - kFirstDeoptEntryIndex) / kDeoptEntrySize; 3762 } 3763 3764 // Allocates a DeoptimizationInputData. 3765 MUST_USE_RESULT static MaybeObject* Allocate(int deopt_entry_count, 3766 PretenureFlag pretenure); 3767 3768 // Casting. 3769 static inline DeoptimizationInputData* cast(Object* obj); 3770 3771#ifdef ENABLE_DISASSEMBLER 3772 void DeoptimizationInputDataPrint(FILE* out); 3773#endif 3774 3775 private: 3776 static int IndexForEntry(int i) { 3777 return kFirstDeoptEntryIndex + (i * kDeoptEntrySize); 3778 } 3779 3780 static int LengthFor(int entry_count) { 3781 return IndexForEntry(entry_count); 3782 } 3783}; 3784 3785 3786// DeoptimizationOutputData is a fixed array used to hold the deoptimization 3787// data for code generated by the full compiler. 3788// The format of the these objects is 3789// [i * 2]: Ast ID for ith deoptimization. 3790// [i * 2 + 1]: PC and state of ith deoptimization 3791class DeoptimizationOutputData: public FixedArray { 3792 public: 3793 int DeoptPoints() { return length() / 2; } 3794 Smi* AstId(int index) { return Smi::cast(get(index * 2)); } 3795 void SetAstId(int index, Smi* id) { set(index * 2, id); } 3796 Smi* PcAndState(int index) { return Smi::cast(get(1 + index * 2)); } 3797 void SetPcAndState(int index, Smi* offset) { set(1 + index * 2, offset); } 3798 3799 static int LengthOfFixedArray(int deopt_points) { 3800 return deopt_points * 2; 3801 } 3802 3803 // Allocates a DeoptimizationOutputData. 3804 MUST_USE_RESULT static MaybeObject* Allocate(int number_of_deopt_points, 3805 PretenureFlag pretenure); 3806 3807 // Casting. 3808 static inline DeoptimizationOutputData* cast(Object* obj); 3809 3810#if defined(OBJECT_PRINT) || defined(ENABLE_DISASSEMBLER) 3811 void DeoptimizationOutputDataPrint(FILE* out); 3812#endif 3813}; 3814 3815 3816class SafepointEntry; 3817 3818 3819// Code describes objects with on-the-fly generated machine code. 3820class Code: public HeapObject { 3821 public: 3822 // Opaque data type for encapsulating code flags like kind, inline 3823 // cache state, and arguments count. 3824 // FLAGS_MIN_VALUE and FLAGS_MAX_VALUE are specified to ensure that 3825 // enumeration type has correct value range (see Issue 830 for more details). 3826 enum Flags { 3827 FLAGS_MIN_VALUE = kMinInt, 3828 FLAGS_MAX_VALUE = kMaxInt 3829 }; 3830 3831 enum Kind { 3832 FUNCTION, 3833 OPTIMIZED_FUNCTION, 3834 STUB, 3835 BUILTIN, 3836 LOAD_IC, 3837 KEYED_LOAD_IC, 3838 CALL_IC, 3839 KEYED_CALL_IC, 3840 STORE_IC, 3841 KEYED_STORE_IC, 3842 UNARY_OP_IC, 3843 BINARY_OP_IC, 3844 COMPARE_IC, 3845 TO_BOOLEAN_IC, 3846 // No more than 16 kinds. The value currently encoded in four bits in 3847 // Flags. 3848 3849 // Pseudo-kinds. 3850 REGEXP = BUILTIN, 3851 FIRST_IC_KIND = LOAD_IC, 3852 LAST_IC_KIND = TO_BOOLEAN_IC 3853 }; 3854 3855 enum { 3856 NUMBER_OF_KINDS = LAST_IC_KIND + 1 3857 }; 3858 3859 typedef int ExtraICState; 3860 3861 static const ExtraICState kNoExtraICState = 0; 3862 3863#ifdef ENABLE_DISASSEMBLER 3864 // Printing 3865 static const char* Kind2String(Kind kind); 3866 static const char* ICState2String(InlineCacheState state); 3867 static const char* PropertyType2String(PropertyType type); 3868 static void PrintExtraICState(FILE* out, Kind kind, ExtraICState extra); 3869 inline void Disassemble(const char* name) { 3870 Disassemble(name, stdout); 3871 } 3872 void Disassemble(const char* name, FILE* out); 3873#endif // ENABLE_DISASSEMBLER 3874 3875 // [instruction_size]: Size of the native instructions 3876 inline int instruction_size(); 3877 inline void set_instruction_size(int value); 3878 3879 // [relocation_info]: Code relocation information 3880 DECL_ACCESSORS(relocation_info, ByteArray) 3881 void InvalidateRelocation(); 3882 3883 // [handler_table]: Fixed array containing offsets of exception handlers. 3884 DECL_ACCESSORS(handler_table, FixedArray) 3885 3886 // [deoptimization_data]: Array containing data for deopt. 3887 DECL_ACCESSORS(deoptimization_data, FixedArray) 3888 3889 // [code_flushing_candidate]: Field only used during garbage 3890 // collection to hold code flushing candidates. The contents of this 3891 // field does not have to be traced during garbage collection since 3892 // it is only used by the garbage collector itself. 3893 DECL_ACCESSORS(next_code_flushing_candidate, Object) 3894 3895 // Unchecked accessors to be used during GC. 3896 inline ByteArray* unchecked_relocation_info(); 3897 inline FixedArray* unchecked_deoptimization_data(); 3898 3899 inline int relocation_size(); 3900 3901 // [flags]: Various code flags. 3902 inline Flags flags(); 3903 inline void set_flags(Flags flags); 3904 3905 // [flags]: Access to specific code flags. 3906 inline Kind kind(); 3907 inline InlineCacheState ic_state(); // Only valid for IC stubs. 3908 inline ExtraICState extra_ic_state(); // Only valid for IC stubs. 3909 inline PropertyType type(); // Only valid for monomorphic IC stubs. 3910 inline int arguments_count(); // Only valid for call IC stubs. 3911 3912 // Testers for IC stub kinds. 3913 inline bool is_inline_cache_stub(); 3914 inline bool is_load_stub() { return kind() == LOAD_IC; } 3915 inline bool is_keyed_load_stub() { return kind() == KEYED_LOAD_IC; } 3916 inline bool is_store_stub() { return kind() == STORE_IC; } 3917 inline bool is_keyed_store_stub() { return kind() == KEYED_STORE_IC; } 3918 inline bool is_call_stub() { return kind() == CALL_IC; } 3919 inline bool is_keyed_call_stub() { return kind() == KEYED_CALL_IC; } 3920 inline bool is_unary_op_stub() { return kind() == UNARY_OP_IC; } 3921 inline bool is_binary_op_stub() { return kind() == BINARY_OP_IC; } 3922 inline bool is_compare_ic_stub() { return kind() == COMPARE_IC; } 3923 inline bool is_to_boolean_ic_stub() { return kind() == TO_BOOLEAN_IC; } 3924 3925 // [major_key]: For kind STUB or BINARY_OP_IC, the major key. 3926 inline int major_key(); 3927 inline void set_major_key(int value); 3928 3929 // For stubs, tells whether they should always exist, so that they can be 3930 // called from other stubs. 3931 inline bool is_pregenerated(); 3932 inline void set_is_pregenerated(bool value); 3933 3934 // [optimizable]: For FUNCTION kind, tells if it is optimizable. 3935 inline bool optimizable(); 3936 inline void set_optimizable(bool value); 3937 3938 // [has_deoptimization_support]: For FUNCTION kind, tells if it has 3939 // deoptimization support. 3940 inline bool has_deoptimization_support(); 3941 inline void set_has_deoptimization_support(bool value); 3942 3943 // [has_debug_break_slots]: For FUNCTION kind, tells if it has 3944 // been compiled with debug break slots. 3945 inline bool has_debug_break_slots(); 3946 inline void set_has_debug_break_slots(bool value); 3947 3948 // [compiled_with_optimizing]: For FUNCTION kind, tells if it has 3949 // been compiled with IsOptimizing set to true. 3950 inline bool is_compiled_optimizable(); 3951 inline void set_compiled_optimizable(bool value); 3952 3953 // [allow_osr_at_loop_nesting_level]: For FUNCTION kind, tells for 3954 // how long the function has been marked for OSR and therefore which 3955 // level of loop nesting we are willing to do on-stack replacement 3956 // for. 3957 inline void set_allow_osr_at_loop_nesting_level(int level); 3958 inline int allow_osr_at_loop_nesting_level(); 3959 3960 // [stack_slots]: For kind OPTIMIZED_FUNCTION, the number of stack slots 3961 // reserved in the code prologue. 3962 inline unsigned stack_slots(); 3963 inline void set_stack_slots(unsigned slots); 3964 3965 // [safepoint_table_start]: For kind OPTIMIZED_CODE, the offset in 3966 // the instruction stream where the safepoint table starts. 3967 inline unsigned safepoint_table_offset(); 3968 inline void set_safepoint_table_offset(unsigned offset); 3969 3970 // [stack_check_table_start]: For kind FUNCTION, the offset in the 3971 // instruction stream where the stack check table starts. 3972 inline unsigned stack_check_table_offset(); 3973 inline void set_stack_check_table_offset(unsigned offset); 3974 3975 // [check type]: For kind CALL_IC, tells how to check if the 3976 // receiver is valid for the given call. 3977 inline CheckType check_type(); 3978 inline void set_check_type(CheckType value); 3979 3980 // [type-recording unary op type]: For kind UNARY_OP_IC. 3981 inline byte unary_op_type(); 3982 inline void set_unary_op_type(byte value); 3983 3984 // [type-recording binary op type]: For kind BINARY_OP_IC. 3985 inline byte binary_op_type(); 3986 inline void set_binary_op_type(byte value); 3987 inline byte binary_op_result_type(); 3988 inline void set_binary_op_result_type(byte value); 3989 3990 // [compare state]: For kind COMPARE_IC, tells what state the stub is in. 3991 inline byte compare_state(); 3992 inline void set_compare_state(byte value); 3993 3994 // [to_boolean_foo]: For kind TO_BOOLEAN_IC tells what state the stub is in. 3995 inline byte to_boolean_state(); 3996 inline void set_to_boolean_state(byte value); 3997 3998 // For kind STUB, major_key == CallFunction, tells whether there is 3999 // a function cache in the instruction stream. 4000 inline bool has_function_cache(); 4001 inline void set_has_function_cache(bool flag); 4002 4003 // Get the safepoint entry for the given pc. 4004 SafepointEntry GetSafepointEntry(Address pc); 4005 4006 // Mark this code object as not having a stack check table. Assumes kind 4007 // is FUNCTION. 4008 void SetNoStackCheckTable(); 4009 4010 // Find the first map in an IC stub. 4011 Map* FindFirstMap(); 4012 4013 // Flags operations. 4014 static inline Flags ComputeFlags( 4015 Kind kind, 4016 InlineCacheState ic_state = UNINITIALIZED, 4017 ExtraICState extra_ic_state = kNoExtraICState, 4018 PropertyType type = NORMAL, 4019 int argc = -1, 4020 InlineCacheHolderFlag holder = OWN_MAP); 4021 4022 static inline Flags ComputeMonomorphicFlags( 4023 Kind kind, 4024 PropertyType type, 4025 ExtraICState extra_ic_state = kNoExtraICState, 4026 InlineCacheHolderFlag holder = OWN_MAP, 4027 int argc = -1); 4028 4029 static inline InlineCacheState ExtractICStateFromFlags(Flags flags); 4030 static inline PropertyType ExtractTypeFromFlags(Flags flags); 4031 static inline Kind ExtractKindFromFlags(Flags flags); 4032 static inline InlineCacheHolderFlag ExtractCacheHolderFromFlags(Flags flags); 4033 static inline ExtraICState ExtractExtraICStateFromFlags(Flags flags); 4034 static inline int ExtractArgumentsCountFromFlags(Flags flags); 4035 4036 static inline Flags RemoveTypeFromFlags(Flags flags); 4037 4038 // Convert a target address into a code object. 4039 static inline Code* GetCodeFromTargetAddress(Address address); 4040 4041 // Convert an entry address into an object. 4042 static inline Object* GetObjectFromEntryAddress(Address location_of_address); 4043 4044 // Returns the address of the first instruction. 4045 inline byte* instruction_start(); 4046 4047 // Returns the address right after the last instruction. 4048 inline byte* instruction_end(); 4049 4050 // Returns the size of the instructions, padding, and relocation information. 4051 inline int body_size(); 4052 4053 // Returns the address of the first relocation info (read backwards!). 4054 inline byte* relocation_start(); 4055 4056 // Code entry point. 4057 inline byte* entry(); 4058 4059 // Returns true if pc is inside this object's instructions. 4060 inline bool contains(byte* pc); 4061 4062 // Relocate the code by delta bytes. Called to signal that this code 4063 // object has been moved by delta bytes. 4064 void Relocate(intptr_t delta); 4065 4066 // Migrate code described by desc. 4067 void CopyFrom(const CodeDesc& desc); 4068 4069 // Returns the object size for a given body (used for allocation). 4070 static int SizeFor(int body_size) { 4071 ASSERT_SIZE_TAG_ALIGNED(body_size); 4072 return RoundUp(kHeaderSize + body_size, kCodeAlignment); 4073 } 4074 4075 // Calculate the size of the code object to report for log events. This takes 4076 // the layout of the code object into account. 4077 int ExecutableSize() { 4078 // Check that the assumptions about the layout of the code object holds. 4079 ASSERT_EQ(static_cast<int>(instruction_start() - address()), 4080 Code::kHeaderSize); 4081 return instruction_size() + Code::kHeaderSize; 4082 } 4083 4084 // Locating source position. 4085 int SourcePosition(Address pc); 4086 int SourceStatementPosition(Address pc); 4087 4088 // Casting. 4089 static inline Code* cast(Object* obj); 4090 4091 // Dispatched behavior. 4092 int CodeSize() { return SizeFor(body_size()); } 4093 inline void CodeIterateBody(ObjectVisitor* v); 4094 4095 template<typename StaticVisitor> 4096 inline void CodeIterateBody(Heap* heap); 4097#ifdef OBJECT_PRINT 4098 inline void CodePrint() { 4099 CodePrint(stdout); 4100 } 4101 void CodePrint(FILE* out); 4102#endif 4103#ifdef DEBUG 4104 void CodeVerify(); 4105#endif 4106 4107 // Max loop nesting marker used to postpose OSR. We don't take loop 4108 // nesting that is deeper than 5 levels into account. 4109 static const int kMaxLoopNestingMarker = 6; 4110 4111 // Layout description. 4112 static const int kInstructionSizeOffset = HeapObject::kHeaderSize; 4113 static const int kRelocationInfoOffset = kInstructionSizeOffset + kIntSize; 4114 static const int kHandlerTableOffset = kRelocationInfoOffset + kPointerSize; 4115 static const int kDeoptimizationDataOffset = 4116 kHandlerTableOffset + kPointerSize; 4117 static const int kNextCodeFlushingCandidateOffset = 4118 kDeoptimizationDataOffset + kPointerSize; 4119 static const int kFlagsOffset = 4120 kNextCodeFlushingCandidateOffset + kPointerSize; 4121 4122 static const int kKindSpecificFlagsOffset = kFlagsOffset + kIntSize; 4123 static const int kKindSpecificFlagsSize = 2 * kIntSize; 4124 4125 static const int kHeaderPaddingStart = kKindSpecificFlagsOffset + 4126 kKindSpecificFlagsSize; 4127 4128 // Add padding to align the instruction start following right after 4129 // the Code object header. 4130 static const int kHeaderSize = 4131 (kHeaderPaddingStart + kCodeAlignmentMask) & ~kCodeAlignmentMask; 4132 4133 // Byte offsets within kKindSpecificFlagsOffset. 4134 static const int kStubMajorKeyOffset = kKindSpecificFlagsOffset; 4135 static const int kOptimizableOffset = kKindSpecificFlagsOffset; 4136 static const int kStackSlotsOffset = kKindSpecificFlagsOffset; 4137 static const int kCheckTypeOffset = kKindSpecificFlagsOffset; 4138 4139 static const int kUnaryOpTypeOffset = kStubMajorKeyOffset + 1; 4140 static const int kBinaryOpTypeOffset = kStubMajorKeyOffset + 1; 4141 static const int kCompareStateOffset = kStubMajorKeyOffset + 1; 4142 static const int kToBooleanTypeOffset = kStubMajorKeyOffset + 1; 4143 static const int kHasFunctionCacheOffset = kStubMajorKeyOffset + 1; 4144 4145 static const int kFullCodeFlags = kOptimizableOffset + 1; 4146 class FullCodeFlagsHasDeoptimizationSupportField: 4147 public BitField<bool, 0, 1> {}; // NOLINT 4148 class FullCodeFlagsHasDebugBreakSlotsField: public BitField<bool, 1, 1> {}; 4149 class FullCodeFlagsIsCompiledOptimizable: public BitField<bool, 2, 1> {}; 4150 4151 static const int kBinaryOpReturnTypeOffset = kBinaryOpTypeOffset + 1; 4152 4153 static const int kAllowOSRAtLoopNestingLevelOffset = kFullCodeFlags + 1; 4154 4155 static const int kSafepointTableOffsetOffset = kStackSlotsOffset + kIntSize; 4156 static const int kStackCheckTableOffsetOffset = kStackSlotsOffset + kIntSize; 4157 4158 // Flags layout. BitField<type, shift, size>. 4159 class ICStateField: public BitField<InlineCacheState, 0, 3> {}; 4160 class TypeField: public BitField<PropertyType, 3, 4> {}; 4161 class KindField: public BitField<Kind, 7, 4> {}; 4162 class CacheHolderField: public BitField<InlineCacheHolderFlag, 11, 1> {}; 4163 class ExtraICStateField: public BitField<ExtraICState, 12, 2> {}; 4164 class IsPregeneratedField: public BitField<bool, 14, 1> {}; 4165 4166 // Signed field cannot be encoded using the BitField class. 4167 static const int kArgumentsCountShift = 15; 4168 static const int kArgumentsCountMask = ~((1 << kArgumentsCountShift) - 1); 4169 4170 static const int kFlagsNotUsedInLookup = 4171 TypeField::kMask | CacheHolderField::kMask; 4172 4173 private: 4174 DISALLOW_IMPLICIT_CONSTRUCTORS(Code); 4175}; 4176 4177 4178// All heap objects have a Map that describes their structure. 4179// A Map contains information about: 4180// - Size information about the object 4181// - How to iterate over an object (for garbage collection) 4182class Map: public HeapObject { 4183 public: 4184 // Instance size. 4185 // Size in bytes or kVariableSizeSentinel if instances do not have 4186 // a fixed size. 4187 inline int instance_size(); 4188 inline void set_instance_size(int value); 4189 4190 // Count of properties allocated in the object. 4191 inline int inobject_properties(); 4192 inline void set_inobject_properties(int value); 4193 4194 // Count of property fields pre-allocated in the object when first allocated. 4195 inline int pre_allocated_property_fields(); 4196 inline void set_pre_allocated_property_fields(int value); 4197 4198 // Instance type. 4199 inline InstanceType instance_type(); 4200 inline void set_instance_type(InstanceType value); 4201 4202 // Tells how many unused property fields are available in the 4203 // instance (only used for JSObject in fast mode). 4204 inline int unused_property_fields(); 4205 inline void set_unused_property_fields(int value); 4206 4207 // Bit field. 4208 inline byte bit_field(); 4209 inline void set_bit_field(byte value); 4210 4211 // Bit field 2. 4212 inline byte bit_field2(); 4213 inline void set_bit_field2(byte value); 4214 4215 // Bit field 3. 4216 // TODO(1399): It should be possible to make room for bit_field3 in the map 4217 // without overloading the instance descriptors field (and storing it in the 4218 // DescriptorArray when the map has one). 4219 inline int bit_field3(); 4220 inline void set_bit_field3(int value); 4221 4222 // Tells whether the object in the prototype property will be used 4223 // for instances created from this function. If the prototype 4224 // property is set to a value that is not a JSObject, the prototype 4225 // property will not be used to create instances of the function. 4226 // See ECMA-262, 13.2.2. 4227 inline void set_non_instance_prototype(bool value); 4228 inline bool has_non_instance_prototype(); 4229 4230 // Tells whether function has special prototype property. If not, prototype 4231 // property will not be created when accessed (will return undefined), 4232 // and construction from this function will not be allowed. 4233 inline void set_function_with_prototype(bool value); 4234 inline bool function_with_prototype(); 4235 4236 // Tells whether the instance with this map should be ignored by the 4237 // __proto__ accessor. 4238 inline void set_is_hidden_prototype() { 4239 set_bit_field(bit_field() | (1 << kIsHiddenPrototype)); 4240 } 4241 4242 inline bool is_hidden_prototype() { 4243 return ((1 << kIsHiddenPrototype) & bit_field()) != 0; 4244 } 4245 4246 // Records and queries whether the instance has a named interceptor. 4247 inline void set_has_named_interceptor() { 4248 set_bit_field(bit_field() | (1 << kHasNamedInterceptor)); 4249 } 4250 4251 inline bool has_named_interceptor() { 4252 return ((1 << kHasNamedInterceptor) & bit_field()) != 0; 4253 } 4254 4255 // Records and queries whether the instance has an indexed interceptor. 4256 inline void set_has_indexed_interceptor() { 4257 set_bit_field(bit_field() | (1 << kHasIndexedInterceptor)); 4258 } 4259 4260 inline bool has_indexed_interceptor() { 4261 return ((1 << kHasIndexedInterceptor) & bit_field()) != 0; 4262 } 4263 4264 // Tells whether the instance is undetectable. 4265 // An undetectable object is a special class of JSObject: 'typeof' operator 4266 // returns undefined, ToBoolean returns false. Otherwise it behaves like 4267 // a normal JS object. It is useful for implementing undetectable 4268 // document.all in Firefox & Safari. 4269 // See https://bugzilla.mozilla.org/show_bug.cgi?id=248549. 4270 inline void set_is_undetectable() { 4271 set_bit_field(bit_field() | (1 << kIsUndetectable)); 4272 } 4273 4274 inline bool is_undetectable() { 4275 return ((1 << kIsUndetectable) & bit_field()) != 0; 4276 } 4277 4278 // Tells whether the instance has a call-as-function handler. 4279 inline void set_has_instance_call_handler() { 4280 set_bit_field(bit_field() | (1 << kHasInstanceCallHandler)); 4281 } 4282 4283 inline bool has_instance_call_handler() { 4284 return ((1 << kHasInstanceCallHandler) & bit_field()) != 0; 4285 } 4286 4287 inline void set_is_extensible(bool value); 4288 inline bool is_extensible(); 4289 4290 inline void set_elements_kind(ElementsKind elements_kind) { 4291 ASSERT(elements_kind < kElementsKindCount); 4292 ASSERT(kElementsKindCount <= (1 << kElementsKindBitCount)); 4293 set_bit_field2((bit_field2() & ~kElementsKindMask) | 4294 (elements_kind << kElementsKindShift)); 4295 ASSERT(this->elements_kind() == elements_kind); 4296 } 4297 4298 inline ElementsKind elements_kind() { 4299 return static_cast<ElementsKind>( 4300 (bit_field2() & kElementsKindMask) >> kElementsKindShift); 4301 } 4302 4303 // Tells whether the instance has fast elements that are only Smis. 4304 inline bool has_fast_smi_only_elements() { 4305 return elements_kind() == FAST_SMI_ONLY_ELEMENTS; 4306 } 4307 4308 // Tells whether the instance has fast elements. 4309 inline bool has_fast_elements() { 4310 return elements_kind() == FAST_ELEMENTS; 4311 } 4312 4313 inline bool has_fast_double_elements() { 4314 return elements_kind() == FAST_DOUBLE_ELEMENTS; 4315 } 4316 4317 inline bool has_non_strict_arguments_elements() { 4318 return elements_kind() == NON_STRICT_ARGUMENTS_ELEMENTS; 4319 } 4320 4321 inline bool has_external_array_elements() { 4322 ElementsKind kind(elements_kind()); 4323 return kind >= FIRST_EXTERNAL_ARRAY_ELEMENTS_KIND && 4324 kind <= LAST_EXTERNAL_ARRAY_ELEMENTS_KIND; 4325 } 4326 4327 inline bool has_dictionary_elements() { 4328 return elements_kind() == DICTIONARY_ELEMENTS; 4329 } 4330 4331 static bool IsValidElementsTransition(ElementsKind from_kind, 4332 ElementsKind to_kind); 4333 4334 // Tells whether the map is attached to SharedFunctionInfo 4335 // (for inobject slack tracking). 4336 inline void set_attached_to_shared_function_info(bool value); 4337 4338 inline bool attached_to_shared_function_info(); 4339 4340 // Tells whether the map is shared between objects that may have different 4341 // behavior. If true, the map should never be modified, instead a clone 4342 // should be created and modified. 4343 inline void set_is_shared(bool value); 4344 4345 inline bool is_shared(); 4346 4347 // Tells whether the instance needs security checks when accessing its 4348 // properties. 4349 inline void set_is_access_check_needed(bool access_check_needed); 4350 inline bool is_access_check_needed(); 4351 4352 // [prototype]: implicit prototype object. 4353 DECL_ACCESSORS(prototype, Object) 4354 4355 // [constructor]: points back to the function responsible for this map. 4356 DECL_ACCESSORS(constructor, Object) 4357 4358 inline JSFunction* unchecked_constructor(); 4359 4360 // Should only be called by the code that initializes map to set initial valid 4361 // value of the instance descriptor member. 4362 inline void init_instance_descriptors(); 4363 4364 // [instance descriptors]: describes the object. 4365 DECL_ACCESSORS(instance_descriptors, DescriptorArray) 4366 4367 // Sets the instance descriptor array for the map to be an empty descriptor 4368 // array. 4369 inline void clear_instance_descriptors(); 4370 4371 // [stub cache]: contains stubs compiled for this map. 4372 DECL_ACCESSORS(code_cache, Object) 4373 4374 // [prototype transitions]: cache of prototype transitions. 4375 // Prototype transition is a transition that happens 4376 // when we change object's prototype to a new one. 4377 // Cache format: 4378 // 0: finger - index of the first free cell in the cache 4379 // 1 + 2 * i: prototype 4380 // 2 + 2 * i: target map 4381 DECL_ACCESSORS(prototype_transitions, FixedArray) 4382 4383 inline FixedArray* unchecked_prototype_transitions(); 4384 4385 static const int kProtoTransitionHeaderSize = 1; 4386 static const int kProtoTransitionNumberOfEntriesOffset = 0; 4387 static const int kProtoTransitionElementsPerEntry = 2; 4388 static const int kProtoTransitionPrototypeOffset = 0; 4389 static const int kProtoTransitionMapOffset = 1; 4390 4391 inline int NumberOfProtoTransitions() { 4392 FixedArray* cache = prototype_transitions(); 4393 if (cache->length() == 0) return 0; 4394 return 4395 Smi::cast(cache->get(kProtoTransitionNumberOfEntriesOffset))->value(); 4396 } 4397 4398 inline void SetNumberOfProtoTransitions(int value) { 4399 FixedArray* cache = prototype_transitions(); 4400 ASSERT(cache->length() != 0); 4401 cache->set_unchecked(kProtoTransitionNumberOfEntriesOffset, 4402 Smi::FromInt(value)); 4403 } 4404 4405 // Lookup in the map's instance descriptors and fill out the result 4406 // with the given holder if the name is found. The holder may be 4407 // NULL when this function is used from the compiler. 4408 void LookupInDescriptors(JSObject* holder, 4409 String* name, 4410 LookupResult* result); 4411 4412 MUST_USE_RESULT MaybeObject* CopyDropDescriptors(); 4413 4414 MUST_USE_RESULT MaybeObject* CopyNormalized(PropertyNormalizationMode mode, 4415 NormalizedMapSharingMode sharing); 4416 4417 // Returns a copy of the map, with all transitions dropped from the 4418 // instance descriptors. 4419 MUST_USE_RESULT MaybeObject* CopyDropTransitions(); 4420 4421 // Returns the property index for name (only valid for FAST MODE). 4422 int PropertyIndexFor(String* name); 4423 4424 // Returns the next free property index (only valid for FAST MODE). 4425 int NextFreePropertyIndex(); 4426 4427 // Returns the number of properties described in instance_descriptors. 4428 int NumberOfDescribedProperties(); 4429 4430 // Casting. 4431 static inline Map* cast(Object* obj); 4432 4433 // Locate an accessor in the instance descriptor. 4434 AccessorDescriptor* FindAccessor(String* name); 4435 4436 // Code cache operations. 4437 4438 // Clears the code cache. 4439 inline void ClearCodeCache(Heap* heap); 4440 4441 // Update code cache. 4442 static void UpdateCodeCache(Handle<Map> map, 4443 Handle<String> name, 4444 Handle<Code> code); 4445 MUST_USE_RESULT MaybeObject* UpdateCodeCache(String* name, Code* code); 4446 4447 // Returns the found code or undefined if absent. 4448 Object* FindInCodeCache(String* name, Code::Flags flags); 4449 4450 // Returns the non-negative index of the code object if it is in the 4451 // cache and -1 otherwise. 4452 int IndexInCodeCache(Object* name, Code* code); 4453 4454 // Removes a code object from the code cache at the given index. 4455 void RemoveFromCodeCache(String* name, Code* code, int index); 4456 4457 // For every transition in this map, makes the transition's 4458 // target's prototype pointer point back to this map. 4459 // This is undone in MarkCompactCollector::ClearNonLiveTransitions(). 4460 void CreateBackPointers(); 4461 4462 void CreateOneBackPointer(Map* transition_target); 4463 4464 // Set all map transitions from this map to dead maps to null. 4465 // Also, restore the original prototype on the targets of these 4466 // transitions, so that we do not process this map again while 4467 // following back pointers. 4468 void ClearNonLiveTransitions(Heap* heap, Object* real_prototype); 4469 4470 // Computes a hash value for this map, to be used in HashTables and such. 4471 int Hash(); 4472 4473 // Compares this map to another to see if they describe equivalent objects. 4474 // If |mode| is set to CLEAR_INOBJECT_PROPERTIES, |other| is treated as if 4475 // it had exactly zero inobject properties. 4476 // The "shared" flags of both this map and |other| are ignored. 4477 bool EquivalentToForNormalization(Map* other, PropertyNormalizationMode mode); 4478 4479 // Returns true if this map and |other| describe equivalent objects. 4480 // The "shared" flags of both this map and |other| are ignored. 4481 bool EquivalentTo(Map* other) { 4482 return EquivalentToForNormalization(other, KEEP_INOBJECT_PROPERTIES); 4483 } 4484 4485 // Returns the contents of this map's descriptor array for the given string. 4486 // May return NULL. |safe_to_add_transition| is set to false and NULL 4487 // is returned if adding transitions is not allowed. 4488 Object* GetDescriptorContents(String* sentinel_name, 4489 bool* safe_to_add_transitions); 4490 4491 // Returns the map that this map transitions to if its elements_kind 4492 // is changed to |elements_kind|, or NULL if no such map is cached yet. 4493 // |safe_to_add_transitions| is set to false if adding transitions is not 4494 // allowed. 4495 Map* LookupElementsTransitionMap(ElementsKind elements_kind, 4496 bool* safe_to_add_transition); 4497 4498 // Adds an entry to this map's descriptor array for a transition to 4499 // |transitioned_map| when its elements_kind is changed to |elements_kind|. 4500 MaybeObject* AddElementsTransition(ElementsKind elements_kind, 4501 Map* transitioned_map); 4502 4503 // Returns the transitioned map for this map with the most generic 4504 // elements_kind that's found in |candidates|, or null handle if no match is 4505 // found at all. 4506 Handle<Map> FindTransitionedMap(MapHandleList* candidates); 4507 Map* FindTransitionedMap(MapList* candidates); 4508 4509 4510 // Dispatched behavior. 4511#ifdef OBJECT_PRINT 4512 inline void MapPrint() { 4513 MapPrint(stdout); 4514 } 4515 void MapPrint(FILE* out); 4516#endif 4517#ifdef DEBUG 4518 void MapVerify(); 4519 void SharedMapVerify(); 4520#endif 4521 4522 inline int visitor_id(); 4523 inline void set_visitor_id(int visitor_id); 4524 4525 typedef void (*TraverseCallback)(Map* map, void* data); 4526 4527 void TraverseTransitionTree(TraverseCallback callback, void* data); 4528 4529 static const int kMaxCachedPrototypeTransitions = 256; 4530 4531 Object* GetPrototypeTransition(Object* prototype); 4532 4533 MaybeObject* PutPrototypeTransition(Object* prototype, Map* map); 4534 4535 static const int kMaxPreAllocatedPropertyFields = 255; 4536 4537 // Layout description. 4538 static const int kInstanceSizesOffset = HeapObject::kHeaderSize; 4539 static const int kInstanceAttributesOffset = kInstanceSizesOffset + kIntSize; 4540 static const int kPrototypeOffset = kInstanceAttributesOffset + kIntSize; 4541 static const int kConstructorOffset = kPrototypeOffset + kPointerSize; 4542 // Storage for instance descriptors is overloaded to also contain additional 4543 // map flags when unused (bit_field3). When the map has instance descriptors, 4544 // the flags are transferred to the instance descriptor array and accessed 4545 // through an extra indirection. 4546 // TODO(1399): It should be possible to make room for bit_field3 in the map 4547 // without overloading the instance descriptors field, but the map is 4548 // currently perfectly aligned to 32 bytes and extending it at all would 4549 // double its size. After the increment GC work lands, this size restriction 4550 // could be loosened and bit_field3 moved directly back in the map. 4551 static const int kInstanceDescriptorsOrBitField3Offset = 4552 kConstructorOffset + kPointerSize; 4553 static const int kCodeCacheOffset = 4554 kInstanceDescriptorsOrBitField3Offset + kPointerSize; 4555 static const int kPrototypeTransitionsOffset = 4556 kCodeCacheOffset + kPointerSize; 4557 static const int kPadStart = kPrototypeTransitionsOffset + kPointerSize; 4558 static const int kSize = MAP_POINTER_ALIGN(kPadStart); 4559 4560 // Layout of pointer fields. Heap iteration code relies on them 4561 // being continuously allocated. 4562 static const int kPointerFieldsBeginOffset = Map::kPrototypeOffset; 4563 static const int kPointerFieldsEndOffset = 4564 Map::kPrototypeTransitionsOffset + kPointerSize; 4565 4566 // Byte offsets within kInstanceSizesOffset. 4567 static const int kInstanceSizeOffset = kInstanceSizesOffset + 0; 4568 static const int kInObjectPropertiesByte = 1; 4569 static const int kInObjectPropertiesOffset = 4570 kInstanceSizesOffset + kInObjectPropertiesByte; 4571 static const int kPreAllocatedPropertyFieldsByte = 2; 4572 static const int kPreAllocatedPropertyFieldsOffset = 4573 kInstanceSizesOffset + kPreAllocatedPropertyFieldsByte; 4574 static const int kVisitorIdByte = 3; 4575 static const int kVisitorIdOffset = kInstanceSizesOffset + kVisitorIdByte; 4576 4577 // Byte offsets within kInstanceAttributesOffset attributes. 4578 static const int kInstanceTypeOffset = kInstanceAttributesOffset + 0; 4579 static const int kUnusedPropertyFieldsOffset = kInstanceAttributesOffset + 1; 4580 static const int kBitFieldOffset = kInstanceAttributesOffset + 2; 4581 static const int kBitField2Offset = kInstanceAttributesOffset + 3; 4582 4583 STATIC_CHECK(kInstanceTypeOffset == Internals::kMapInstanceTypeOffset); 4584 4585 // Bit positions for bit field. 4586 static const int kUnused = 0; // To be used for marking recently used maps. 4587 static const int kHasNonInstancePrototype = 1; 4588 static const int kIsHiddenPrototype = 2; 4589 static const int kHasNamedInterceptor = 3; 4590 static const int kHasIndexedInterceptor = 4; 4591 static const int kIsUndetectable = 5; 4592 static const int kHasInstanceCallHandler = 6; 4593 static const int kIsAccessCheckNeeded = 7; 4594 4595 // Bit positions for bit field 2 4596 static const int kIsExtensible = 0; 4597 static const int kFunctionWithPrototype = 1; 4598 static const int kStringWrapperSafeForDefaultValueOf = 2; 4599 static const int kAttachedToSharedFunctionInfo = 3; 4600 // No bits can be used after kElementsKindFirstBit, they are all reserved for 4601 // storing ElementKind. 4602 static const int kElementsKindShift = 4; 4603 static const int kElementsKindBitCount = 4; 4604 4605 // Derived values from bit field 2 4606 static const int kElementsKindMask = (-1 << kElementsKindShift) & 4607 ((1 << (kElementsKindShift + kElementsKindBitCount)) - 1); 4608 static const int8_t kMaximumBitField2FastElementValue = static_cast<int8_t>( 4609 (FAST_ELEMENTS + 1) << Map::kElementsKindShift) - 1; 4610 static const int8_t kMaximumBitField2FastSmiOnlyElementValue = 4611 static_cast<int8_t>((FAST_SMI_ONLY_ELEMENTS + 1) << 4612 Map::kElementsKindShift) - 1; 4613 4614 // Bit positions for bit field 3 4615 static const int kIsShared = 0; 4616 4617 // Layout of the default cache. It holds alternating name and code objects. 4618 static const int kCodeCacheEntrySize = 2; 4619 static const int kCodeCacheEntryNameOffset = 0; 4620 static const int kCodeCacheEntryCodeOffset = 1; 4621 4622 typedef FixedBodyDescriptor<kPointerFieldsBeginOffset, 4623 kPointerFieldsEndOffset, 4624 kSize> BodyDescriptor; 4625 4626 private: 4627 String* elements_transition_sentinel_name(); 4628 DISALLOW_IMPLICIT_CONSTRUCTORS(Map); 4629}; 4630 4631 4632// An abstract superclass, a marker class really, for simple structure classes. 4633// It doesn't carry much functionality but allows struct classes to be 4634// identified in the type system. 4635class Struct: public HeapObject { 4636 public: 4637 inline void InitializeBody(int object_size); 4638 static inline Struct* cast(Object* that); 4639}; 4640 4641 4642// Script describes a script which has been added to the VM. 4643class Script: public Struct { 4644 public: 4645 // Script types. 4646 enum Type { 4647 TYPE_NATIVE = 0, 4648 TYPE_EXTENSION = 1, 4649 TYPE_NORMAL = 2 4650 }; 4651 4652 // Script compilation types. 4653 enum CompilationType { 4654 COMPILATION_TYPE_HOST = 0, 4655 COMPILATION_TYPE_EVAL = 1 4656 }; 4657 4658 // [source]: the script source. 4659 DECL_ACCESSORS(source, Object) 4660 4661 // [name]: the script name. 4662 DECL_ACCESSORS(name, Object) 4663 4664 // [id]: the script id. 4665 DECL_ACCESSORS(id, Object) 4666 4667 // [line_offset]: script line offset in resource from where it was extracted. 4668 DECL_ACCESSORS(line_offset, Smi) 4669 4670 // [column_offset]: script column offset in resource from where it was 4671 // extracted. 4672 DECL_ACCESSORS(column_offset, Smi) 4673 4674 // [data]: additional data associated with this script. 4675 DECL_ACCESSORS(data, Object) 4676 4677 // [context_data]: context data for the context this script was compiled in. 4678 DECL_ACCESSORS(context_data, Object) 4679 4680 // [wrapper]: the wrapper cache. 4681 DECL_ACCESSORS(wrapper, Foreign) 4682 4683 // [type]: the script type. 4684 DECL_ACCESSORS(type, Smi) 4685 4686 // [compilation]: how the the script was compiled. 4687 DECL_ACCESSORS(compilation_type, Smi) 4688 4689 // [line_ends]: FixedArray of line ends positions. 4690 DECL_ACCESSORS(line_ends, Object) 4691 4692 // [eval_from_shared]: for eval scripts the shared funcion info for the 4693 // function from which eval was called. 4694 DECL_ACCESSORS(eval_from_shared, Object) 4695 4696 // [eval_from_instructions_offset]: the instruction offset in the code for the 4697 // function from which eval was called where eval was called. 4698 DECL_ACCESSORS(eval_from_instructions_offset, Smi) 4699 4700 static inline Script* cast(Object* obj); 4701 4702 // If script source is an external string, check that the underlying 4703 // resource is accessible. Otherwise, always return true. 4704 inline bool HasValidSource(); 4705 4706#ifdef OBJECT_PRINT 4707 inline void ScriptPrint() { 4708 ScriptPrint(stdout); 4709 } 4710 void ScriptPrint(FILE* out); 4711#endif 4712#ifdef DEBUG 4713 void ScriptVerify(); 4714#endif 4715 4716 static const int kSourceOffset = HeapObject::kHeaderSize; 4717 static const int kNameOffset = kSourceOffset + kPointerSize; 4718 static const int kLineOffsetOffset = kNameOffset + kPointerSize; 4719 static const int kColumnOffsetOffset = kLineOffsetOffset + kPointerSize; 4720 static const int kDataOffset = kColumnOffsetOffset + kPointerSize; 4721 static const int kContextOffset = kDataOffset + kPointerSize; 4722 static const int kWrapperOffset = kContextOffset + kPointerSize; 4723 static const int kTypeOffset = kWrapperOffset + kPointerSize; 4724 static const int kCompilationTypeOffset = kTypeOffset + kPointerSize; 4725 static const int kLineEndsOffset = kCompilationTypeOffset + kPointerSize; 4726 static const int kIdOffset = kLineEndsOffset + kPointerSize; 4727 static const int kEvalFromSharedOffset = kIdOffset + kPointerSize; 4728 static const int kEvalFrominstructionsOffsetOffset = 4729 kEvalFromSharedOffset + kPointerSize; 4730 static const int kSize = kEvalFrominstructionsOffsetOffset + kPointerSize; 4731 4732 private: 4733 DISALLOW_IMPLICIT_CONSTRUCTORS(Script); 4734}; 4735 4736 4737// List of builtin functions we want to identify to improve code 4738// generation. 4739// 4740// Each entry has a name of a global object property holding an object 4741// optionally followed by ".prototype", a name of a builtin function 4742// on the object (the one the id is set for), and a label. 4743// 4744// Installation of ids for the selected builtin functions is handled 4745// by the bootstrapper. 4746// 4747// NOTE: Order is important: math functions should be at the end of 4748// the list and MathFloor should be the first math function. 4749#define FUNCTIONS_WITH_ID_LIST(V) \ 4750 V(Array.prototype, push, ArrayPush) \ 4751 V(Array.prototype, pop, ArrayPop) \ 4752 V(Function.prototype, apply, FunctionApply) \ 4753 V(String.prototype, charCodeAt, StringCharCodeAt) \ 4754 V(String.prototype, charAt, StringCharAt) \ 4755 V(String, fromCharCode, StringFromCharCode) \ 4756 V(Math, floor, MathFloor) \ 4757 V(Math, round, MathRound) \ 4758 V(Math, ceil, MathCeil) \ 4759 V(Math, abs, MathAbs) \ 4760 V(Math, log, MathLog) \ 4761 V(Math, sin, MathSin) \ 4762 V(Math, cos, MathCos) \ 4763 V(Math, tan, MathTan) \ 4764 V(Math, asin, MathASin) \ 4765 V(Math, acos, MathACos) \ 4766 V(Math, atan, MathATan) \ 4767 V(Math, exp, MathExp) \ 4768 V(Math, sqrt, MathSqrt) \ 4769 V(Math, pow, MathPow) 4770 4771 4772enum BuiltinFunctionId { 4773#define DECLARE_FUNCTION_ID(ignored1, ignore2, name) \ 4774 k##name, 4775 FUNCTIONS_WITH_ID_LIST(DECLARE_FUNCTION_ID) 4776#undef DECLARE_FUNCTION_ID 4777 // Fake id for a special case of Math.pow. Note, it continues the 4778 // list of math functions. 4779 kMathPowHalf, 4780 kFirstMathFunctionId = kMathFloor 4781}; 4782 4783 4784// SharedFunctionInfo describes the JSFunction information that can be 4785// shared by multiple instances of the function. 4786class SharedFunctionInfo: public HeapObject { 4787 public: 4788 // [name]: Function name. 4789 DECL_ACCESSORS(name, Object) 4790 4791 // [code]: Function code. 4792 DECL_ACCESSORS(code, Code) 4793 4794 // [scope_info]: Scope info. 4795 DECL_ACCESSORS(scope_info, ScopeInfo) 4796 4797 // [construct stub]: Code stub for constructing instances of this function. 4798 DECL_ACCESSORS(construct_stub, Code) 4799 4800 inline Code* unchecked_code(); 4801 4802 // Returns if this function has been compiled to native code yet. 4803 inline bool is_compiled(); 4804 4805 // [length]: The function length - usually the number of declared parameters. 4806 // Use up to 2^30 parameters. 4807 inline int length(); 4808 inline void set_length(int value); 4809 4810 // [formal parameter count]: The declared number of parameters. 4811 inline int formal_parameter_count(); 4812 inline void set_formal_parameter_count(int value); 4813 4814 // Set the formal parameter count so the function code will be 4815 // called without using argument adaptor frames. 4816 inline void DontAdaptArguments(); 4817 4818 // [expected_nof_properties]: Expected number of properties for the function. 4819 inline int expected_nof_properties(); 4820 inline void set_expected_nof_properties(int value); 4821 4822 // Inobject slack tracking is the way to reclaim unused inobject space. 4823 // 4824 // The instance size is initially determined by adding some slack to 4825 // expected_nof_properties (to allow for a few extra properties added 4826 // after the constructor). There is no guarantee that the extra space 4827 // will not be wasted. 4828 // 4829 // Here is the algorithm to reclaim the unused inobject space: 4830 // - Detect the first constructor call for this SharedFunctionInfo. 4831 // When it happens enter the "in progress" state: remember the 4832 // constructor's initial_map and install a special construct stub that 4833 // counts constructor calls. 4834 // - While the tracking is in progress create objects filled with 4835 // one_pointer_filler_map instead of undefined_value. This way they can be 4836 // resized quickly and safely. 4837 // - Once enough (kGenerousAllocationCount) objects have been created 4838 // compute the 'slack' (traverse the map transition tree starting from the 4839 // initial_map and find the lowest value of unused_property_fields). 4840 // - Traverse the transition tree again and decrease the instance size 4841 // of every map. Existing objects will resize automatically (they are 4842 // filled with one_pointer_filler_map). All further allocations will 4843 // use the adjusted instance size. 4844 // - Decrease expected_nof_properties so that an allocations made from 4845 // another context will use the adjusted instance size too. 4846 // - Exit "in progress" state by clearing the reference to the initial_map 4847 // and setting the regular construct stub (generic or inline). 4848 // 4849 // The above is the main event sequence. Some special cases are possible 4850 // while the tracking is in progress: 4851 // 4852 // - GC occurs. 4853 // Check if the initial_map is referenced by any live objects (except this 4854 // SharedFunctionInfo). If it is, continue tracking as usual. 4855 // If it is not, clear the reference and reset the tracking state. The 4856 // tracking will be initiated again on the next constructor call. 4857 // 4858 // - The constructor is called from another context. 4859 // Immediately complete the tracking, perform all the necessary changes 4860 // to maps. This is necessary because there is no efficient way to track 4861 // multiple initial_maps. 4862 // Proceed to create an object in the current context (with the adjusted 4863 // size). 4864 // 4865 // - A different constructor function sharing the same SharedFunctionInfo is 4866 // called in the same context. This could be another closure in the same 4867 // context, or the first function could have been disposed. 4868 // This is handled the same way as the previous case. 4869 // 4870 // Important: inobject slack tracking is not attempted during the snapshot 4871 // creation. 4872 4873 static const int kGenerousAllocationCount = 8; 4874 4875 // [construction_count]: Counter for constructor calls made during 4876 // the tracking phase. 4877 inline int construction_count(); 4878 inline void set_construction_count(int value); 4879 4880 // [initial_map]: initial map of the first function called as a constructor. 4881 // Saved for the duration of the tracking phase. 4882 // This is a weak link (GC resets it to undefined_value if no other live 4883 // object reference this map). 4884 DECL_ACCESSORS(initial_map, Object) 4885 4886 // True if the initial_map is not undefined and the countdown stub is 4887 // installed. 4888 inline bool IsInobjectSlackTrackingInProgress(); 4889 4890 // Starts the tracking. 4891 // Stores the initial map and installs the countdown stub. 4892 // IsInobjectSlackTrackingInProgress is normally true after this call, 4893 // except when tracking have not been started (e.g. the map has no unused 4894 // properties or the snapshot is being built). 4895 void StartInobjectSlackTracking(Map* map); 4896 4897 // Completes the tracking. 4898 // IsInobjectSlackTrackingInProgress is false after this call. 4899 void CompleteInobjectSlackTracking(); 4900 4901 // Clears the initial_map before the GC marking phase to ensure the reference 4902 // is weak. IsInobjectSlackTrackingInProgress is false after this call. 4903 void DetachInitialMap(); 4904 4905 // Restores the link to the initial map after the GC marking phase. 4906 // IsInobjectSlackTrackingInProgress is true after this call. 4907 void AttachInitialMap(Map* map); 4908 4909 // False if there are definitely no live objects created from this function. 4910 // True if live objects _may_ exist (existence not guaranteed). 4911 // May go back from true to false after GC. 4912 DECL_BOOLEAN_ACCESSORS(live_objects_may_exist) 4913 4914 // [instance class name]: class name for instances. 4915 DECL_ACCESSORS(instance_class_name, Object) 4916 4917 // [function data]: This field holds some additional data for function. 4918 // Currently it either has FunctionTemplateInfo to make benefit the API 4919 // or Smi identifying a builtin function. 4920 // In the long run we don't want all functions to have this field but 4921 // we can fix that when we have a better model for storing hidden data 4922 // on objects. 4923 DECL_ACCESSORS(function_data, Object) 4924 4925 inline bool IsApiFunction(); 4926 inline FunctionTemplateInfo* get_api_func_data(); 4927 inline bool HasBuiltinFunctionId(); 4928 inline BuiltinFunctionId builtin_function_id(); 4929 4930 // [script info]: Script from which the function originates. 4931 DECL_ACCESSORS(script, Object) 4932 4933 // [num_literals]: Number of literals used by this function. 4934 inline int num_literals(); 4935 inline void set_num_literals(int value); 4936 4937 // [start_position_and_type]: Field used to store both the source code 4938 // position, whether or not the function is a function expression, 4939 // and whether or not the function is a toplevel function. The two 4940 // least significants bit indicates whether the function is an 4941 // expression and the rest contains the source code position. 4942 inline int start_position_and_type(); 4943 inline void set_start_position_and_type(int value); 4944 4945 // [debug info]: Debug information. 4946 DECL_ACCESSORS(debug_info, Object) 4947 4948 // [inferred name]: Name inferred from variable or property 4949 // assignment of this function. Used to facilitate debugging and 4950 // profiling of JavaScript code written in OO style, where almost 4951 // all functions are anonymous but are assigned to object 4952 // properties. 4953 DECL_ACCESSORS(inferred_name, String) 4954 4955 // The function's name if it is non-empty, otherwise the inferred name. 4956 String* DebugName(); 4957 4958 // Position of the 'function' token in the script source. 4959 inline int function_token_position(); 4960 inline void set_function_token_position(int function_token_position); 4961 4962 // Position of this function in the script source. 4963 inline int start_position(); 4964 inline void set_start_position(int start_position); 4965 4966 // End position of this function in the script source. 4967 inline int end_position(); 4968 inline void set_end_position(int end_position); 4969 4970 // Is this function a function expression in the source code. 4971 DECL_BOOLEAN_ACCESSORS(is_expression) 4972 4973 // Is this function a top-level function (scripts, evals). 4974 DECL_BOOLEAN_ACCESSORS(is_toplevel) 4975 4976 // Bit field containing various information collected by the compiler to 4977 // drive optimization. 4978 inline int compiler_hints(); 4979 inline void set_compiler_hints(int value); 4980 4981 // A counter used to determine when to stress the deoptimizer with a 4982 // deopt. 4983 inline Smi* deopt_counter(); 4984 inline void set_deopt_counter(Smi* counter); 4985 4986 // Add information on assignments of the form this.x = ...; 4987 void SetThisPropertyAssignmentsInfo( 4988 bool has_only_simple_this_property_assignments, 4989 FixedArray* this_property_assignments); 4990 4991 // Clear information on assignments of the form this.x = ...; 4992 void ClearThisPropertyAssignmentsInfo(); 4993 4994 // Indicate that this function only consists of assignments of the form 4995 // this.x = y; where y is either a constant or refers to an argument. 4996 inline bool has_only_simple_this_property_assignments(); 4997 4998 // Indicates if this function can be lazy compiled. 4999 // This is used to determine if we can safely flush code from a function 5000 // when doing GC if we expect that the function will no longer be used. 5001 DECL_BOOLEAN_ACCESSORS(allows_lazy_compilation) 5002 5003 // Indicates how many full GCs this function has survived with assigned 5004 // code object. Used to determine when it is relatively safe to flush 5005 // this code object and replace it with lazy compilation stub. 5006 // Age is reset when GC notices that the code object is referenced 5007 // from the stack or compilation cache. 5008 inline int code_age(); 5009 inline void set_code_age(int age); 5010 5011 // Indicates whether optimizations have been disabled for this 5012 // shared function info. If a function is repeatedly optimized or if 5013 // we cannot optimize the function we disable optimization to avoid 5014 // spending time attempting to optimize it again. 5015 DECL_BOOLEAN_ACCESSORS(optimization_disabled) 5016 5017 // Indicates the language mode of the function's code as defined by the 5018 // current harmony drafts for the next ES language standard. Possible 5019 // values are: 5020 // 1. CLASSIC_MODE - Unrestricted syntax and semantics, same as in ES5. 5021 // 2. STRICT_MODE - Restricted syntax and semantics, same as in ES5. 5022 // 3. EXTENDED_MODE - Only available under the harmony flag, not part of ES5. 5023 inline LanguageMode language_mode(); 5024 inline void set_language_mode(LanguageMode language_mode); 5025 5026 // Indicates whether the language mode of this function is CLASSIC_MODE. 5027 inline bool is_classic_mode(); 5028 5029 // Indicates whether the language mode of this function is EXTENDED_MODE. 5030 inline bool is_extended_mode(); 5031 5032 // False if the function definitely does not allocate an arguments object. 5033 DECL_BOOLEAN_ACCESSORS(uses_arguments) 5034 5035 // True if the function has any duplicated parameter names. 5036 DECL_BOOLEAN_ACCESSORS(has_duplicate_parameters) 5037 5038 // Indicates whether the function is a native function. 5039 // These needs special treatment in .call and .apply since 5040 // null passed as the receiver should not be translated to the 5041 // global object. 5042 DECL_BOOLEAN_ACCESSORS(native) 5043 5044 // Indicates that the function was created by the Function function. 5045 // Though it's anonymous, toString should treat it as if it had the name 5046 // "anonymous". We don't set the name itself so that the system does not 5047 // see a binding for it. 5048 DECL_BOOLEAN_ACCESSORS(name_should_print_as_anonymous) 5049 5050 // Indicates whether the function is a bound function created using 5051 // the bind function. 5052 DECL_BOOLEAN_ACCESSORS(bound) 5053 5054 // Indicates that the function is anonymous (the name field can be set 5055 // through the API, which does not change this flag). 5056 DECL_BOOLEAN_ACCESSORS(is_anonymous) 5057 5058 // Indicates whether or not the code in the shared function support 5059 // deoptimization. 5060 inline bool has_deoptimization_support(); 5061 5062 // Enable deoptimization support through recompiled code. 5063 void EnableDeoptimizationSupport(Code* recompiled); 5064 5065 // Disable (further) attempted optimization of all functions sharing this 5066 // shared function info. The function is the one we actually tried to 5067 // optimize. 5068 void DisableOptimization(JSFunction* function); 5069 5070 // Lookup the bailout ID and ASSERT that it exists in the non-optimized 5071 // code, returns whether it asserted (i.e., always true if assertions are 5072 // disabled). 5073 bool VerifyBailoutId(int id); 5074 5075 // Check whether a inlined constructor can be generated with the given 5076 // prototype. 5077 bool CanGenerateInlineConstructor(Object* prototype); 5078 5079 // Prevents further attempts to generate inline constructors. 5080 // To be called if generation failed for any reason. 5081 void ForbidInlineConstructor(); 5082 5083 // For functions which only contains this property assignments this provides 5084 // access to the names for the properties assigned. 5085 DECL_ACCESSORS(this_property_assignments, Object) 5086 inline int this_property_assignments_count(); 5087 inline void set_this_property_assignments_count(int value); 5088 String* GetThisPropertyAssignmentName(int index); 5089 bool IsThisPropertyAssignmentArgument(int index); 5090 int GetThisPropertyAssignmentArgument(int index); 5091 Object* GetThisPropertyAssignmentConstant(int index); 5092 5093 // [source code]: Source code for the function. 5094 bool HasSourceCode(); 5095 Object* GetSourceCode(); 5096 5097 inline int opt_count(); 5098 inline void set_opt_count(int opt_count); 5099 5100 // Source size of this function. 5101 int SourceSize(); 5102 5103 // Calculate the instance size. 5104 int CalculateInstanceSize(); 5105 5106 // Calculate the number of in-object properties. 5107 int CalculateInObjectProperties(); 5108 5109 // Dispatched behavior. 5110 // Set max_length to -1 for unlimited length. 5111 void SourceCodePrint(StringStream* accumulator, int max_length); 5112#ifdef OBJECT_PRINT 5113 inline void SharedFunctionInfoPrint() { 5114 SharedFunctionInfoPrint(stdout); 5115 } 5116 void SharedFunctionInfoPrint(FILE* out); 5117#endif 5118#ifdef DEBUG 5119 void SharedFunctionInfoVerify(); 5120#endif 5121 5122 // Helpers to compile the shared code. Returns true on success, false on 5123 // failure (e.g., stack overflow during compilation). 5124 static bool EnsureCompiled(Handle<SharedFunctionInfo> shared, 5125 ClearExceptionFlag flag); 5126 static bool CompileLazy(Handle<SharedFunctionInfo> shared, 5127 ClearExceptionFlag flag); 5128 5129 // Casting. 5130 static inline SharedFunctionInfo* cast(Object* obj); 5131 5132 // Constants. 5133 static const int kDontAdaptArgumentsSentinel = -1; 5134 5135 // Layout description. 5136 // Pointer fields. 5137 static const int kNameOffset = HeapObject::kHeaderSize; 5138 static const int kCodeOffset = kNameOffset + kPointerSize; 5139 static const int kScopeInfoOffset = kCodeOffset + kPointerSize; 5140 static const int kConstructStubOffset = kScopeInfoOffset + kPointerSize; 5141 static const int kInstanceClassNameOffset = 5142 kConstructStubOffset + kPointerSize; 5143 static const int kFunctionDataOffset = 5144 kInstanceClassNameOffset + kPointerSize; 5145 static const int kScriptOffset = kFunctionDataOffset + kPointerSize; 5146 static const int kDebugInfoOffset = kScriptOffset + kPointerSize; 5147 static const int kInferredNameOffset = kDebugInfoOffset + kPointerSize; 5148 static const int kInitialMapOffset = 5149 kInferredNameOffset + kPointerSize; 5150 static const int kThisPropertyAssignmentsOffset = 5151 kInitialMapOffset + kPointerSize; 5152 static const int kDeoptCounterOffset = 5153 kThisPropertyAssignmentsOffset + kPointerSize; 5154#if V8_HOST_ARCH_32_BIT 5155 // Smi fields. 5156 static const int kLengthOffset = 5157 kDeoptCounterOffset + kPointerSize; 5158 static const int kFormalParameterCountOffset = kLengthOffset + kPointerSize; 5159 static const int kExpectedNofPropertiesOffset = 5160 kFormalParameterCountOffset + kPointerSize; 5161 static const int kNumLiteralsOffset = 5162 kExpectedNofPropertiesOffset + kPointerSize; 5163 static const int kStartPositionAndTypeOffset = 5164 kNumLiteralsOffset + kPointerSize; 5165 static const int kEndPositionOffset = 5166 kStartPositionAndTypeOffset + kPointerSize; 5167 static const int kFunctionTokenPositionOffset = 5168 kEndPositionOffset + kPointerSize; 5169 static const int kCompilerHintsOffset = 5170 kFunctionTokenPositionOffset + kPointerSize; 5171 static const int kThisPropertyAssignmentsCountOffset = 5172 kCompilerHintsOffset + kPointerSize; 5173 static const int kOptCountOffset = 5174 kThisPropertyAssignmentsCountOffset + kPointerSize; 5175 // Total size. 5176 static const int kSize = kOptCountOffset + kPointerSize; 5177#else 5178 // The only reason to use smi fields instead of int fields 5179 // is to allow iteration without maps decoding during 5180 // garbage collections. 5181 // To avoid wasting space on 64-bit architectures we use 5182 // the following trick: we group integer fields into pairs 5183 // First integer in each pair is shifted left by 1. 5184 // By doing this we guarantee that LSB of each kPointerSize aligned 5185 // word is not set and thus this word cannot be treated as pointer 5186 // to HeapObject during old space traversal. 5187 static const int kLengthOffset = 5188 kDeoptCounterOffset + kPointerSize; 5189 static const int kFormalParameterCountOffset = 5190 kLengthOffset + kIntSize; 5191 5192 static const int kExpectedNofPropertiesOffset = 5193 kFormalParameterCountOffset + kIntSize; 5194 static const int kNumLiteralsOffset = 5195 kExpectedNofPropertiesOffset + kIntSize; 5196 5197 static const int kEndPositionOffset = 5198 kNumLiteralsOffset + kIntSize; 5199 static const int kStartPositionAndTypeOffset = 5200 kEndPositionOffset + kIntSize; 5201 5202 static const int kFunctionTokenPositionOffset = 5203 kStartPositionAndTypeOffset + kIntSize; 5204 static const int kCompilerHintsOffset = 5205 kFunctionTokenPositionOffset + kIntSize; 5206 5207 static const int kThisPropertyAssignmentsCountOffset = 5208 kCompilerHintsOffset + kIntSize; 5209 static const int kOptCountOffset = 5210 kThisPropertyAssignmentsCountOffset + kIntSize; 5211 5212 // Total size. 5213 static const int kSize = kOptCountOffset + kIntSize; 5214 5215#endif 5216 5217 // The construction counter for inobject slack tracking is stored in the 5218 // most significant byte of compiler_hints which is otherwise unused. 5219 // Its offset depends on the endian-ness of the architecture. 5220#if __BYTE_ORDER == __LITTLE_ENDIAN 5221 static const int kConstructionCountOffset = kCompilerHintsOffset + 3; 5222#elif __BYTE_ORDER == __BIG_ENDIAN 5223 static const int kConstructionCountOffset = kCompilerHintsOffset + 0; 5224#else 5225#error Unknown byte ordering 5226#endif 5227 5228 static const int kAlignedSize = POINTER_SIZE_ALIGN(kSize); 5229 5230 typedef FixedBodyDescriptor<kNameOffset, 5231 kThisPropertyAssignmentsOffset + kPointerSize, 5232 kSize> BodyDescriptor; 5233 5234 // Bit positions in start_position_and_type. 5235 // The source code start position is in the 30 most significant bits of 5236 // the start_position_and_type field. 5237 static const int kIsExpressionBit = 0; 5238 static const int kIsTopLevelBit = 1; 5239 static const int kStartPositionShift = 2; 5240 static const int kStartPositionMask = ~((1 << kStartPositionShift) - 1); 5241 5242 // Bit positions in compiler_hints. 5243 static const int kCodeAgeSize = 3; 5244 static const int kCodeAgeMask = (1 << kCodeAgeSize) - 1; 5245 5246 enum CompilerHints { 5247 kHasOnlySimpleThisPropertyAssignments, 5248 kAllowLazyCompilation, 5249 kLiveObjectsMayExist, 5250 kCodeAgeShift, 5251 kOptimizationDisabled = kCodeAgeShift + kCodeAgeSize, 5252 kStrictModeFunction, 5253 kExtendedModeFunction, 5254 kUsesArguments, 5255 kHasDuplicateParameters, 5256 kNative, 5257 kBoundFunction, 5258 kIsAnonymous, 5259 kNameShouldPrintAsAnonymous, 5260 kCompilerHintsCount // Pseudo entry 5261 }; 5262 5263 private: 5264#if V8_HOST_ARCH_32_BIT 5265 // On 32 bit platforms, compiler hints is a smi. 5266 static const int kCompilerHintsSmiTagSize = kSmiTagSize; 5267 static const int kCompilerHintsSize = kPointerSize; 5268#else 5269 // On 64 bit platforms, compiler hints is not a smi, see comment above. 5270 static const int kCompilerHintsSmiTagSize = 0; 5271 static const int kCompilerHintsSize = kIntSize; 5272#endif 5273 5274 STATIC_ASSERT(SharedFunctionInfo::kCompilerHintsCount <= 5275 SharedFunctionInfo::kCompilerHintsSize * kBitsPerByte); 5276 5277 public: 5278 // Constants for optimizing codegen for strict mode function and 5279 // native tests. 5280 // Allows to use byte-width instructions. 5281 static const int kStrictModeBitWithinByte = 5282 (kStrictModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte; 5283 5284 static const int kExtendedModeBitWithinByte = 5285 (kExtendedModeFunction + kCompilerHintsSmiTagSize) % kBitsPerByte; 5286 5287 static const int kNativeBitWithinByte = 5288 (kNative + kCompilerHintsSmiTagSize) % kBitsPerByte; 5289 5290#if __BYTE_ORDER == __LITTLE_ENDIAN 5291 static const int kStrictModeByteOffset = kCompilerHintsOffset + 5292 (kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte; 5293 static const int kExtendedModeByteOffset = kCompilerHintsOffset + 5294 (kExtendedModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte; 5295 static const int kNativeByteOffset = kCompilerHintsOffset + 5296 (kNative + kCompilerHintsSmiTagSize) / kBitsPerByte; 5297#elif __BYTE_ORDER == __BIG_ENDIAN 5298 static const int kStrictModeByteOffset = kCompilerHintsOffset + 5299 (kCompilerHintsSize - 1) - 5300 ((kStrictModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte); 5301 static const int kExtendedModeByteOffset = kCompilerHintsOffset + 5302 (kCompilerHintsSize - 1) - 5303 ((kExtendedModeFunction + kCompilerHintsSmiTagSize) / kBitsPerByte); 5304 static const int kNativeByteOffset = kCompilerHintsOffset + 5305 (kCompilerHintsSize - 1) - 5306 ((kNative + kCompilerHintsSmiTagSize) / kBitsPerByte); 5307#else 5308#error Unknown byte ordering 5309#endif 5310 5311 private: 5312 DISALLOW_IMPLICIT_CONSTRUCTORS(SharedFunctionInfo); 5313}; 5314 5315 5316// JSFunction describes JavaScript functions. 5317class JSFunction: public JSObject { 5318 public: 5319 // [prototype_or_initial_map]: 5320 DECL_ACCESSORS(prototype_or_initial_map, Object) 5321 5322 // [shared]: The information about the function that 5323 // can be shared by instances. 5324 DECL_ACCESSORS(shared, SharedFunctionInfo) 5325 5326 inline SharedFunctionInfo* unchecked_shared(); 5327 5328 // [context]: The context for this function. 5329 inline Context* context(); 5330 inline Object* unchecked_context(); 5331 inline void set_context(Object* context); 5332 5333 // [code]: The generated code object for this function. Executed 5334 // when the function is invoked, e.g. foo() or new foo(). See 5335 // [[Call]] and [[Construct]] description in ECMA-262, section 5336 // 8.6.2, page 27. 5337 inline Code* code(); 5338 inline void set_code(Code* code); 5339 inline void ReplaceCode(Code* code); 5340 5341 inline Code* unchecked_code(); 5342 5343 // Tells whether this function is builtin. 5344 inline bool IsBuiltin(); 5345 5346 // Tells whether or not the function needs arguments adaption. 5347 inline bool NeedsArgumentsAdaption(); 5348 5349 // Tells whether or not this function has been optimized. 5350 inline bool IsOptimized(); 5351 5352 // Tells whether or not this function can be optimized. 5353 inline bool IsOptimizable(); 5354 5355 // Mark this function for lazy recompilation. The function will be 5356 // recompiled the next time it is executed. 5357 void MarkForLazyRecompilation(); 5358 5359 // Helpers to compile this function. Returns true on success, false on 5360 // failure (e.g., stack overflow during compilation). 5361 static bool CompileLazy(Handle<JSFunction> function, 5362 ClearExceptionFlag flag); 5363 static bool CompileOptimized(Handle<JSFunction> function, 5364 int osr_ast_id, 5365 ClearExceptionFlag flag); 5366 5367 // Tells whether or not the function is already marked for lazy 5368 // recompilation. 5369 inline bool IsMarkedForLazyRecompilation(); 5370 5371 // Check whether or not this function is inlineable. 5372 bool IsInlineable(); 5373 5374 // [literals_or_bindings]: Fixed array holding either 5375 // the materialized literals or the bindings of a bound function. 5376 // 5377 // If the function contains object, regexp or array literals, the 5378 // literals array prefix contains the object, regexp, and array 5379 // function to be used when creating these literals. This is 5380 // necessary so that we do not dynamically lookup the object, regexp 5381 // or array functions. Performing a dynamic lookup, we might end up 5382 // using the functions from a new context that we should not have 5383 // access to. 5384 // 5385 // On bound functions, the array is a (copy-on-write) fixed-array containing 5386 // the function that was bound, bound this-value and any bound 5387 // arguments. Bound functions never contain literals. 5388 DECL_ACCESSORS(literals_or_bindings, FixedArray) 5389 5390 inline FixedArray* literals(); 5391 inline void set_literals(FixedArray* literals); 5392 5393 inline FixedArray* function_bindings(); 5394 inline void set_function_bindings(FixedArray* bindings); 5395 5396 // The initial map for an object created by this constructor. 5397 inline Map* initial_map(); 5398 inline void set_initial_map(Map* value); 5399 inline bool has_initial_map(); 5400 5401 // Get and set the prototype property on a JSFunction. If the 5402 // function has an initial map the prototype is set on the initial 5403 // map. Otherwise, the prototype is put in the initial map field 5404 // until an initial map is needed. 5405 inline bool has_prototype(); 5406 inline bool has_instance_prototype(); 5407 inline Object* prototype(); 5408 inline Object* instance_prototype(); 5409 Object* SetInstancePrototype(Object* value); 5410 MUST_USE_RESULT MaybeObject* SetPrototype(Object* value); 5411 5412 // After prototype is removed, it will not be created when accessed, and 5413 // [[Construct]] from this function will not be allowed. 5414 Object* RemovePrototype(); 5415 inline bool should_have_prototype(); 5416 5417 // Accessor for this function's initial map's [[class]] 5418 // property. This is primarily used by ECMA native functions. This 5419 // method sets the class_name field of this function's initial map 5420 // to a given value. It creates an initial map if this function does 5421 // not have one. Note that this method does not copy the initial map 5422 // if it has one already, but simply replaces it with the new value. 5423 // Instances created afterwards will have a map whose [[class]] is 5424 // set to 'value', but there is no guarantees on instances created 5425 // before. 5426 Object* SetInstanceClassName(String* name); 5427 5428 // Returns if this function has been compiled to native code yet. 5429 inline bool is_compiled(); 5430 5431 // [next_function_link]: Field for linking functions. This list is treated as 5432 // a weak list by the GC. 5433 DECL_ACCESSORS(next_function_link, Object) 5434 5435 // Prints the name of the function using PrintF. 5436 inline void PrintName() { 5437 PrintName(stdout); 5438 } 5439 void PrintName(FILE* out); 5440 5441 // Casting. 5442 static inline JSFunction* cast(Object* obj); 5443 5444 // Iterates the objects, including code objects indirectly referenced 5445 // through pointers to the first instruction in the code object. 5446 void JSFunctionIterateBody(int object_size, ObjectVisitor* v); 5447 5448 // Dispatched behavior. 5449#ifdef OBJECT_PRINT 5450 inline void JSFunctionPrint() { 5451 JSFunctionPrint(stdout); 5452 } 5453 void JSFunctionPrint(FILE* out); 5454#endif 5455#ifdef DEBUG 5456 void JSFunctionVerify(); 5457#endif 5458 5459 // Returns the number of allocated literals. 5460 inline int NumberOfLiterals(); 5461 5462 // Retrieve the global context from a function's literal array. 5463 static Context* GlobalContextFromLiterals(FixedArray* literals); 5464 5465 // Layout descriptors. The last property (from kNonWeakFieldsEndOffset to 5466 // kSize) is weak and has special handling during garbage collection. 5467 static const int kCodeEntryOffset = JSObject::kHeaderSize; 5468 static const int kPrototypeOrInitialMapOffset = 5469 kCodeEntryOffset + kPointerSize; 5470 static const int kSharedFunctionInfoOffset = 5471 kPrototypeOrInitialMapOffset + kPointerSize; 5472 static const int kContextOffset = kSharedFunctionInfoOffset + kPointerSize; 5473 static const int kLiteralsOffset = kContextOffset + kPointerSize; 5474 static const int kNonWeakFieldsEndOffset = kLiteralsOffset + kPointerSize; 5475 static const int kNextFunctionLinkOffset = kNonWeakFieldsEndOffset; 5476 static const int kSize = kNextFunctionLinkOffset + kPointerSize; 5477 5478 // Layout of the literals array. 5479 static const int kLiteralsPrefixSize = 1; 5480 static const int kLiteralGlobalContextIndex = 0; 5481 5482 // Layout of the bound-function binding array. 5483 static const int kBoundFunctionIndex = 0; 5484 static const int kBoundThisIndex = 1; 5485 static const int kBoundArgumentsStartIndex = 2; 5486 5487 private: 5488 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunction); 5489}; 5490 5491 5492// JSGlobalProxy's prototype must be a JSGlobalObject or null, 5493// and the prototype is hidden. JSGlobalProxy always delegates 5494// property accesses to its prototype if the prototype is not null. 5495// 5496// A JSGlobalProxy can be reinitialized which will preserve its identity. 5497// 5498// Accessing a JSGlobalProxy requires security check. 5499 5500class JSGlobalProxy : public JSObject { 5501 public: 5502 // [context]: the owner global context of this global proxy object. 5503 // It is null value if this object is not used by any context. 5504 DECL_ACCESSORS(context, Object) 5505 5506 // Casting. 5507 static inline JSGlobalProxy* cast(Object* obj); 5508 5509 // Dispatched behavior. 5510#ifdef OBJECT_PRINT 5511 inline void JSGlobalProxyPrint() { 5512 JSGlobalProxyPrint(stdout); 5513 } 5514 void JSGlobalProxyPrint(FILE* out); 5515#endif 5516#ifdef DEBUG 5517 void JSGlobalProxyVerify(); 5518#endif 5519 5520 // Layout description. 5521 static const int kContextOffset = JSObject::kHeaderSize; 5522 static const int kSize = kContextOffset + kPointerSize; 5523 5524 private: 5525 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalProxy); 5526}; 5527 5528 5529// Forward declaration. 5530class JSBuiltinsObject; 5531class JSGlobalPropertyCell; 5532 5533// Common super class for JavaScript global objects and the special 5534// builtins global objects. 5535class GlobalObject: public JSObject { 5536 public: 5537 // [builtins]: the object holding the runtime routines written in JS. 5538 DECL_ACCESSORS(builtins, JSBuiltinsObject) 5539 5540 // [global context]: the global context corresponding to this global object. 5541 DECL_ACCESSORS(global_context, Context) 5542 5543 // [global receiver]: the global receiver object of the context 5544 DECL_ACCESSORS(global_receiver, JSObject) 5545 5546 // Retrieve the property cell used to store a property. 5547 JSGlobalPropertyCell* GetPropertyCell(LookupResult* result); 5548 5549 // This is like GetProperty, but is used when you know the lookup won't fail 5550 // by throwing an exception. This is for the debug and builtins global 5551 // objects, where it is known which properties can be expected to be present 5552 // on the object. 5553 Object* GetPropertyNoExceptionThrown(String* key) { 5554 Object* answer = GetProperty(key)->ToObjectUnchecked(); 5555 return answer; 5556 } 5557 5558 // Ensure that the global object has a cell for the given property name. 5559 static Handle<JSGlobalPropertyCell> EnsurePropertyCell( 5560 Handle<GlobalObject> global, 5561 Handle<String> name); 5562 // TODO(kmillikin): This function can be eliminated once the stub cache is 5563 // full handlified (and the static helper can be written directly). 5564 MUST_USE_RESULT MaybeObject* EnsurePropertyCell(String* name); 5565 5566 // Casting. 5567 static inline GlobalObject* cast(Object* obj); 5568 5569 // Layout description. 5570 static const int kBuiltinsOffset = JSObject::kHeaderSize; 5571 static const int kGlobalContextOffset = kBuiltinsOffset + kPointerSize; 5572 static const int kGlobalReceiverOffset = kGlobalContextOffset + kPointerSize; 5573 static const int kHeaderSize = kGlobalReceiverOffset + kPointerSize; 5574 5575 private: 5576 DISALLOW_IMPLICIT_CONSTRUCTORS(GlobalObject); 5577}; 5578 5579 5580// JavaScript global object. 5581class JSGlobalObject: public GlobalObject { 5582 public: 5583 // Casting. 5584 static inline JSGlobalObject* cast(Object* obj); 5585 5586 // Dispatched behavior. 5587#ifdef OBJECT_PRINT 5588 inline void JSGlobalObjectPrint() { 5589 JSGlobalObjectPrint(stdout); 5590 } 5591 void JSGlobalObjectPrint(FILE* out); 5592#endif 5593#ifdef DEBUG 5594 void JSGlobalObjectVerify(); 5595#endif 5596 5597 // Layout description. 5598 static const int kSize = GlobalObject::kHeaderSize; 5599 5600 private: 5601 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalObject); 5602}; 5603 5604 5605// Builtins global object which holds the runtime routines written in 5606// JavaScript. 5607class JSBuiltinsObject: public GlobalObject { 5608 public: 5609 // Accessors for the runtime routines written in JavaScript. 5610 inline Object* javascript_builtin(Builtins::JavaScript id); 5611 inline void set_javascript_builtin(Builtins::JavaScript id, Object* value); 5612 5613 // Accessors for code of the runtime routines written in JavaScript. 5614 inline Code* javascript_builtin_code(Builtins::JavaScript id); 5615 inline void set_javascript_builtin_code(Builtins::JavaScript id, Code* value); 5616 5617 // Casting. 5618 static inline JSBuiltinsObject* cast(Object* obj); 5619 5620 // Dispatched behavior. 5621#ifdef OBJECT_PRINT 5622 inline void JSBuiltinsObjectPrint() { 5623 JSBuiltinsObjectPrint(stdout); 5624 } 5625 void JSBuiltinsObjectPrint(FILE* out); 5626#endif 5627#ifdef DEBUG 5628 void JSBuiltinsObjectVerify(); 5629#endif 5630 5631 // Layout description. The size of the builtins object includes 5632 // room for two pointers per runtime routine written in javascript 5633 // (function and code object). 5634 static const int kJSBuiltinsCount = Builtins::id_count; 5635 static const int kJSBuiltinsOffset = GlobalObject::kHeaderSize; 5636 static const int kJSBuiltinsCodeOffset = 5637 GlobalObject::kHeaderSize + (kJSBuiltinsCount * kPointerSize); 5638 static const int kSize = 5639 kJSBuiltinsCodeOffset + (kJSBuiltinsCount * kPointerSize); 5640 5641 static int OffsetOfFunctionWithId(Builtins::JavaScript id) { 5642 return kJSBuiltinsOffset + id * kPointerSize; 5643 } 5644 5645 static int OffsetOfCodeWithId(Builtins::JavaScript id) { 5646 return kJSBuiltinsCodeOffset + id * kPointerSize; 5647 } 5648 5649 private: 5650 DISALLOW_IMPLICIT_CONSTRUCTORS(JSBuiltinsObject); 5651}; 5652 5653 5654// Representation for JS Wrapper objects, String, Number, Boolean, Date, etc. 5655class JSValue: public JSObject { 5656 public: 5657 // [value]: the object being wrapped. 5658 DECL_ACCESSORS(value, Object) 5659 5660 // Casting. 5661 static inline JSValue* cast(Object* obj); 5662 5663 // Dispatched behavior. 5664#ifdef OBJECT_PRINT 5665 inline void JSValuePrint() { 5666 JSValuePrint(stdout); 5667 } 5668 void JSValuePrint(FILE* out); 5669#endif 5670#ifdef DEBUG 5671 void JSValueVerify(); 5672#endif 5673 5674 // Layout description. 5675 static const int kValueOffset = JSObject::kHeaderSize; 5676 static const int kSize = kValueOffset + kPointerSize; 5677 5678 private: 5679 DISALLOW_IMPLICIT_CONSTRUCTORS(JSValue); 5680}; 5681 5682 5683// Representation of message objects used for error reporting through 5684// the API. The messages are formatted in JavaScript so this object is 5685// a real JavaScript object. The information used for formatting the 5686// error messages are not directly accessible from JavaScript to 5687// prevent leaking information to user code called during error 5688// formatting. 5689class JSMessageObject: public JSObject { 5690 public: 5691 // [type]: the type of error message. 5692 DECL_ACCESSORS(type, String) 5693 5694 // [arguments]: the arguments for formatting the error message. 5695 DECL_ACCESSORS(arguments, JSArray) 5696 5697 // [script]: the script from which the error message originated. 5698 DECL_ACCESSORS(script, Object) 5699 5700 // [stack_trace]: the stack trace for this error message. 5701 DECL_ACCESSORS(stack_trace, Object) 5702 5703 // [stack_frames]: an array of stack frames for this error object. 5704 DECL_ACCESSORS(stack_frames, Object) 5705 5706 // [start_position]: the start position in the script for the error message. 5707 inline int start_position(); 5708 inline void set_start_position(int value); 5709 5710 // [end_position]: the end position in the script for the error message. 5711 inline int end_position(); 5712 inline void set_end_position(int value); 5713 5714 // Casting. 5715 static inline JSMessageObject* cast(Object* obj); 5716 5717 // Dispatched behavior. 5718#ifdef OBJECT_PRINT 5719 inline void JSMessageObjectPrint() { 5720 JSMessageObjectPrint(stdout); 5721 } 5722 void JSMessageObjectPrint(FILE* out); 5723#endif 5724#ifdef DEBUG 5725 void JSMessageObjectVerify(); 5726#endif 5727 5728 // Layout description. 5729 static const int kTypeOffset = JSObject::kHeaderSize; 5730 static const int kArgumentsOffset = kTypeOffset + kPointerSize; 5731 static const int kScriptOffset = kArgumentsOffset + kPointerSize; 5732 static const int kStackTraceOffset = kScriptOffset + kPointerSize; 5733 static const int kStackFramesOffset = kStackTraceOffset + kPointerSize; 5734 static const int kStartPositionOffset = kStackFramesOffset + kPointerSize; 5735 static const int kEndPositionOffset = kStartPositionOffset + kPointerSize; 5736 static const int kSize = kEndPositionOffset + kPointerSize; 5737 5738 typedef FixedBodyDescriptor<HeapObject::kMapOffset, 5739 kStackFramesOffset + kPointerSize, 5740 kSize> BodyDescriptor; 5741}; 5742 5743 5744// Regular expressions 5745// The regular expression holds a single reference to a FixedArray in 5746// the kDataOffset field. 5747// The FixedArray contains the following data: 5748// - tag : type of regexp implementation (not compiled yet, atom or irregexp) 5749// - reference to the original source string 5750// - reference to the original flag string 5751// If it is an atom regexp 5752// - a reference to a literal string to search for 5753// If it is an irregexp regexp: 5754// - a reference to code for ASCII inputs (bytecode or compiled), or a smi 5755// used for tracking the last usage (used for code flushing). 5756// - a reference to code for UC16 inputs (bytecode or compiled), or a smi 5757// used for tracking the last usage (used for code flushing).. 5758// - max number of registers used by irregexp implementations. 5759// - number of capture registers (output values) of the regexp. 5760class JSRegExp: public JSObject { 5761 public: 5762 // Meaning of Type: 5763 // NOT_COMPILED: Initial value. No data has been stored in the JSRegExp yet. 5764 // ATOM: A simple string to match against using an indexOf operation. 5765 // IRREGEXP: Compiled with Irregexp. 5766 // IRREGEXP_NATIVE: Compiled to native code with Irregexp. 5767 enum Type { NOT_COMPILED, ATOM, IRREGEXP }; 5768 enum Flag { NONE = 0, GLOBAL = 1, IGNORE_CASE = 2, MULTILINE = 4 }; 5769 5770 class Flags { 5771 public: 5772 explicit Flags(uint32_t value) : value_(value) { } 5773 bool is_global() { return (value_ & GLOBAL) != 0; } 5774 bool is_ignore_case() { return (value_ & IGNORE_CASE) != 0; } 5775 bool is_multiline() { return (value_ & MULTILINE) != 0; } 5776 uint32_t value() { return value_; } 5777 private: 5778 uint32_t value_; 5779 }; 5780 5781 DECL_ACCESSORS(data, Object) 5782 5783 inline Type TypeTag(); 5784 inline int CaptureCount(); 5785 inline Flags GetFlags(); 5786 inline String* Pattern(); 5787 inline Object* DataAt(int index); 5788 // Set implementation data after the object has been prepared. 5789 inline void SetDataAt(int index, Object* value); 5790 5791 // Used during GC when flushing code or setting age. 5792 inline Object* DataAtUnchecked(int index); 5793 inline void SetDataAtUnchecked(int index, Object* value, Heap* heap); 5794 inline Type TypeTagUnchecked(); 5795 5796 static int code_index(bool is_ascii) { 5797 if (is_ascii) { 5798 return kIrregexpASCIICodeIndex; 5799 } else { 5800 return kIrregexpUC16CodeIndex; 5801 } 5802 } 5803 5804 static int saved_code_index(bool is_ascii) { 5805 if (is_ascii) { 5806 return kIrregexpASCIICodeSavedIndex; 5807 } else { 5808 return kIrregexpUC16CodeSavedIndex; 5809 } 5810 } 5811 5812 static inline JSRegExp* cast(Object* obj); 5813 5814 // Dispatched behavior. 5815#ifdef DEBUG 5816 void JSRegExpVerify(); 5817#endif 5818 5819 static const int kDataOffset = JSObject::kHeaderSize; 5820 static const int kSize = kDataOffset + kPointerSize; 5821 5822 // Indices in the data array. 5823 static const int kTagIndex = 0; 5824 static const int kSourceIndex = kTagIndex + 1; 5825 static const int kFlagsIndex = kSourceIndex + 1; 5826 static const int kDataIndex = kFlagsIndex + 1; 5827 // The data fields are used in different ways depending on the 5828 // value of the tag. 5829 // Atom regexps (literal strings). 5830 static const int kAtomPatternIndex = kDataIndex; 5831 5832 static const int kAtomDataSize = kAtomPatternIndex + 1; 5833 5834 // Irregexp compiled code or bytecode for ASCII. If compilation 5835 // fails, this fields hold an exception object that should be 5836 // thrown if the regexp is used again. 5837 static const int kIrregexpASCIICodeIndex = kDataIndex; 5838 // Irregexp compiled code or bytecode for UC16. If compilation 5839 // fails, this fields hold an exception object that should be 5840 // thrown if the regexp is used again. 5841 static const int kIrregexpUC16CodeIndex = kDataIndex + 1; 5842 5843 // Saved instance of Irregexp compiled code or bytecode for ASCII that 5844 // is a potential candidate for flushing. 5845 static const int kIrregexpASCIICodeSavedIndex = kDataIndex + 2; 5846 // Saved instance of Irregexp compiled code or bytecode for UC16 that is 5847 // a potential candidate for flushing. 5848 static const int kIrregexpUC16CodeSavedIndex = kDataIndex + 3; 5849 5850 // Maximal number of registers used by either ASCII or UC16. 5851 // Only used to check that there is enough stack space 5852 static const int kIrregexpMaxRegisterCountIndex = kDataIndex + 4; 5853 // Number of captures in the compiled regexp. 5854 static const int kIrregexpCaptureCountIndex = kDataIndex + 5; 5855 5856 static const int kIrregexpDataSize = kIrregexpCaptureCountIndex + 1; 5857 5858 // Offsets directly into the data fixed array. 5859 static const int kDataTagOffset = 5860 FixedArray::kHeaderSize + kTagIndex * kPointerSize; 5861 static const int kDataAsciiCodeOffset = 5862 FixedArray::kHeaderSize + kIrregexpASCIICodeIndex * kPointerSize; 5863 static const int kDataUC16CodeOffset = 5864 FixedArray::kHeaderSize + kIrregexpUC16CodeIndex * kPointerSize; 5865 static const int kIrregexpCaptureCountOffset = 5866 FixedArray::kHeaderSize + kIrregexpCaptureCountIndex * kPointerSize; 5867 5868 // In-object fields. 5869 static const int kSourceFieldIndex = 0; 5870 static const int kGlobalFieldIndex = 1; 5871 static const int kIgnoreCaseFieldIndex = 2; 5872 static const int kMultilineFieldIndex = 3; 5873 static const int kLastIndexFieldIndex = 4; 5874 static const int kInObjectFieldCount = 5; 5875 5876 // The uninitialized value for a regexp code object. 5877 static const int kUninitializedValue = -1; 5878 5879 // The compilation error value for the regexp code object. The real error 5880 // object is in the saved code field. 5881 static const int kCompilationErrorValue = -2; 5882 5883 // When we store the sweep generation at which we moved the code from the 5884 // code index to the saved code index we mask it of to be in the [0:255] 5885 // range. 5886 static const int kCodeAgeMask = 0xff; 5887}; 5888 5889 5890class CompilationCacheShape { 5891 public: 5892 static inline bool IsMatch(HashTableKey* key, Object* value) { 5893 return key->IsMatch(value); 5894 } 5895 5896 static inline uint32_t Hash(HashTableKey* key) { 5897 return key->Hash(); 5898 } 5899 5900 static inline uint32_t HashForObject(HashTableKey* key, Object* object) { 5901 return key->HashForObject(object); 5902 } 5903 5904 MUST_USE_RESULT static MaybeObject* AsObject(HashTableKey* key) { 5905 return key->AsObject(); 5906 } 5907 5908 static const int kPrefixSize = 0; 5909 static const int kEntrySize = 2; 5910}; 5911 5912 5913class CompilationCacheTable: public HashTable<CompilationCacheShape, 5914 HashTableKey*> { 5915 public: 5916 // Find cached value for a string key, otherwise return null. 5917 Object* Lookup(String* src); 5918 Object* LookupEval(String* src, 5919 Context* context, 5920 LanguageMode language_mode, 5921 int scope_position); 5922 Object* LookupRegExp(String* source, JSRegExp::Flags flags); 5923 MaybeObject* Put(String* src, Object* value); 5924 MaybeObject* PutEval(String* src, 5925 Context* context, 5926 SharedFunctionInfo* value, 5927 int scope_position); 5928 MaybeObject* PutRegExp(String* src, JSRegExp::Flags flags, FixedArray* value); 5929 5930 // Remove given value from cache. 5931 void Remove(Object* value); 5932 5933 static inline CompilationCacheTable* cast(Object* obj); 5934 5935 private: 5936 DISALLOW_IMPLICIT_CONSTRUCTORS(CompilationCacheTable); 5937}; 5938 5939 5940class CodeCache: public Struct { 5941 public: 5942 DECL_ACCESSORS(default_cache, FixedArray) 5943 DECL_ACCESSORS(normal_type_cache, Object) 5944 5945 // Add the code object to the cache. 5946 MUST_USE_RESULT MaybeObject* Update(String* name, Code* code); 5947 5948 // Lookup code object in the cache. Returns code object if found and undefined 5949 // if not. 5950 Object* Lookup(String* name, Code::Flags flags); 5951 5952 // Get the internal index of a code object in the cache. Returns -1 if the 5953 // code object is not in that cache. This index can be used to later call 5954 // RemoveByIndex. The cache cannot be modified between a call to GetIndex and 5955 // RemoveByIndex. 5956 int GetIndex(Object* name, Code* code); 5957 5958 // Remove an object from the cache with the provided internal index. 5959 void RemoveByIndex(Object* name, Code* code, int index); 5960 5961 static inline CodeCache* cast(Object* obj); 5962 5963#ifdef OBJECT_PRINT 5964 inline void CodeCachePrint() { 5965 CodeCachePrint(stdout); 5966 } 5967 void CodeCachePrint(FILE* out); 5968#endif 5969#ifdef DEBUG 5970 void CodeCacheVerify(); 5971#endif 5972 5973 static const int kDefaultCacheOffset = HeapObject::kHeaderSize; 5974 static const int kNormalTypeCacheOffset = 5975 kDefaultCacheOffset + kPointerSize; 5976 static const int kSize = kNormalTypeCacheOffset + kPointerSize; 5977 5978 private: 5979 MUST_USE_RESULT MaybeObject* UpdateDefaultCache(String* name, Code* code); 5980 MUST_USE_RESULT MaybeObject* UpdateNormalTypeCache(String* name, Code* code); 5981 Object* LookupDefaultCache(String* name, Code::Flags flags); 5982 Object* LookupNormalTypeCache(String* name, Code::Flags flags); 5983 5984 // Code cache layout of the default cache. Elements are alternating name and 5985 // code objects for non normal load/store/call IC's. 5986 static const int kCodeCacheEntrySize = 2; 5987 static const int kCodeCacheEntryNameOffset = 0; 5988 static const int kCodeCacheEntryCodeOffset = 1; 5989 5990 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCache); 5991}; 5992 5993 5994class CodeCacheHashTableShape { 5995 public: 5996 static inline bool IsMatch(HashTableKey* key, Object* value) { 5997 return key->IsMatch(value); 5998 } 5999 6000 static inline uint32_t Hash(HashTableKey* key) { 6001 return key->Hash(); 6002 } 6003 6004 static inline uint32_t HashForObject(HashTableKey* key, Object* object) { 6005 return key->HashForObject(object); 6006 } 6007 6008 MUST_USE_RESULT static MaybeObject* AsObject(HashTableKey* key) { 6009 return key->AsObject(); 6010 } 6011 6012 static const int kPrefixSize = 0; 6013 static const int kEntrySize = 2; 6014}; 6015 6016 6017class CodeCacheHashTable: public HashTable<CodeCacheHashTableShape, 6018 HashTableKey*> { 6019 public: 6020 Object* Lookup(String* name, Code::Flags flags); 6021 MUST_USE_RESULT MaybeObject* Put(String* name, Code* code); 6022 6023 int GetIndex(String* name, Code::Flags flags); 6024 void RemoveByIndex(int index); 6025 6026 static inline CodeCacheHashTable* cast(Object* obj); 6027 6028 // Initial size of the fixed array backing the hash table. 6029 static const int kInitialSize = 64; 6030 6031 private: 6032 DISALLOW_IMPLICIT_CONSTRUCTORS(CodeCacheHashTable); 6033}; 6034 6035 6036class PolymorphicCodeCache: public Struct { 6037 public: 6038 DECL_ACCESSORS(cache, Object) 6039 6040 static void Update(Handle<PolymorphicCodeCache> cache, 6041 MapHandleList* maps, 6042 Code::Flags flags, 6043 Handle<Code> code); 6044 6045 MUST_USE_RESULT MaybeObject* Update(MapHandleList* maps, 6046 Code::Flags flags, 6047 Code* code); 6048 6049 // Returns an undefined value if the entry is not found. 6050 Handle<Object> Lookup(MapHandleList* maps, Code::Flags flags); 6051 6052 static inline PolymorphicCodeCache* cast(Object* obj); 6053 6054#ifdef OBJECT_PRINT 6055 inline void PolymorphicCodeCachePrint() { 6056 PolymorphicCodeCachePrint(stdout); 6057 } 6058 void PolymorphicCodeCachePrint(FILE* out); 6059#endif 6060#ifdef DEBUG 6061 void PolymorphicCodeCacheVerify(); 6062#endif 6063 6064 static const int kCacheOffset = HeapObject::kHeaderSize; 6065 static const int kSize = kCacheOffset + kPointerSize; 6066 6067 private: 6068 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCache); 6069}; 6070 6071 6072class PolymorphicCodeCacheHashTable 6073 : public HashTable<CodeCacheHashTableShape, HashTableKey*> { 6074 public: 6075 Object* Lookup(MapHandleList* maps, int code_kind); 6076 6077 MUST_USE_RESULT MaybeObject* Put(MapHandleList* maps, 6078 int code_kind, 6079 Code* code); 6080 6081 static inline PolymorphicCodeCacheHashTable* cast(Object* obj); 6082 6083 static const int kInitialSize = 64; 6084 private: 6085 DISALLOW_IMPLICIT_CONSTRUCTORS(PolymorphicCodeCacheHashTable); 6086}; 6087 6088 6089enum AllowNullsFlag {ALLOW_NULLS, DISALLOW_NULLS}; 6090enum RobustnessFlag {ROBUST_STRING_TRAVERSAL, FAST_STRING_TRAVERSAL}; 6091 6092 6093class StringHasher { 6094 public: 6095 explicit inline StringHasher(int length); 6096 6097 // Returns true if the hash of this string can be computed without 6098 // looking at the contents. 6099 inline bool has_trivial_hash(); 6100 6101 // Add a character to the hash and update the array index calculation. 6102 inline void AddCharacter(uc32 c); 6103 6104 // Adds a character to the hash but does not update the array index 6105 // calculation. This can only be called when it has been verified 6106 // that the input is not an array index. 6107 inline void AddCharacterNoIndex(uc32 c); 6108 6109 // Returns the value to store in the hash field of a string with 6110 // the given length and contents. 6111 uint32_t GetHashField(); 6112 6113 // Returns true if the characters seen so far make up a legal array 6114 // index. 6115 bool is_array_index() { return is_array_index_; } 6116 6117 bool is_valid() { return is_valid_; } 6118 6119 void invalidate() { is_valid_ = false; } 6120 6121 // Calculated hash value for a string consisting of 1 to 6122 // String::kMaxArrayIndexSize digits with no leading zeros (except "0"). 6123 // value is represented decimal value. 6124 static uint32_t MakeArrayIndexHash(uint32_t value, int length); 6125 6126 private: 6127 uint32_t array_index() { 6128 ASSERT(is_array_index()); 6129 return array_index_; 6130 } 6131 6132 inline uint32_t GetHash(); 6133 6134 int length_; 6135 uint32_t raw_running_hash_; 6136 uint32_t array_index_; 6137 bool is_array_index_; 6138 bool is_first_char_; 6139 bool is_valid_; 6140 friend class TwoCharHashTableKey; 6141}; 6142 6143 6144// Calculates string hash. 6145template <typename schar> 6146inline uint32_t HashSequentialString(const schar* chars, int length); 6147 6148 6149// The characteristics of a string are stored in its map. Retrieving these 6150// few bits of information is moderately expensive, involving two memory 6151// loads where the second is dependent on the first. To improve efficiency 6152// the shape of the string is given its own class so that it can be retrieved 6153// once and used for several string operations. A StringShape is small enough 6154// to be passed by value and is immutable, but be aware that flattening a 6155// string can potentially alter its shape. Also be aware that a GC caused by 6156// something else can alter the shape of a string due to ConsString 6157// shortcutting. Keeping these restrictions in mind has proven to be error- 6158// prone and so we no longer put StringShapes in variables unless there is a 6159// concrete performance benefit at that particular point in the code. 6160class StringShape BASE_EMBEDDED { 6161 public: 6162 inline explicit StringShape(String* s); 6163 inline explicit StringShape(Map* s); 6164 inline explicit StringShape(InstanceType t); 6165 inline bool IsSequential(); 6166 inline bool IsExternal(); 6167 inline bool IsCons(); 6168 inline bool IsSliced(); 6169 inline bool IsIndirect(); 6170 inline bool IsExternalAscii(); 6171 inline bool IsExternalTwoByte(); 6172 inline bool IsSequentialAscii(); 6173 inline bool IsSequentialTwoByte(); 6174 inline bool IsSymbol(); 6175 inline StringRepresentationTag representation_tag(); 6176 inline uint32_t encoding_tag(); 6177 inline uint32_t full_representation_tag(); 6178 inline uint32_t size_tag(); 6179#ifdef DEBUG 6180 inline uint32_t type() { return type_; } 6181 inline void invalidate() { valid_ = false; } 6182 inline bool valid() { return valid_; } 6183#else 6184 inline void invalidate() { } 6185#endif 6186 6187 private: 6188 uint32_t type_; 6189#ifdef DEBUG 6190 inline void set_valid() { valid_ = true; } 6191 bool valid_; 6192#else 6193 inline void set_valid() { } 6194#endif 6195}; 6196 6197 6198// The String abstract class captures JavaScript string values: 6199// 6200// Ecma-262: 6201// 4.3.16 String Value 6202// A string value is a member of the type String and is a finite 6203// ordered sequence of zero or more 16-bit unsigned integer values. 6204// 6205// All string values have a length field. 6206class String: public HeapObject { 6207 public: 6208 // Representation of the flat content of a String. 6209 // A non-flat string doesn't have flat content. 6210 // A flat string has content that's encoded as a sequence of either 6211 // ASCII chars or two-byte UC16. 6212 // Returned by String::GetFlatContent(). 6213 class FlatContent { 6214 public: 6215 // Returns true if the string is flat and this structure contains content. 6216 bool IsFlat() { return state_ != NON_FLAT; } 6217 // Returns true if the structure contains ASCII content. 6218 bool IsAscii() { return state_ == ASCII; } 6219 // Returns true if the structure contains two-byte content. 6220 bool IsTwoByte() { return state_ == TWO_BYTE; } 6221 6222 // Return the ASCII content of the string. Only use if IsAscii() returns 6223 // true. 6224 Vector<const char> ToAsciiVector() { 6225 ASSERT_EQ(ASCII, state_); 6226 return Vector<const char>::cast(buffer_); 6227 } 6228 // Return the two-byte content of the string. Only use if IsTwoByte() 6229 // returns true. 6230 Vector<const uc16> ToUC16Vector() { 6231 ASSERT_EQ(TWO_BYTE, state_); 6232 return Vector<const uc16>::cast(buffer_); 6233 } 6234 6235 private: 6236 enum State { NON_FLAT, ASCII, TWO_BYTE }; 6237 6238 // Constructors only used by String::GetFlatContent(). 6239 explicit FlatContent(Vector<const char> chars) 6240 : buffer_(Vector<const byte>::cast(chars)), 6241 state_(ASCII) { } 6242 explicit FlatContent(Vector<const uc16> chars) 6243 : buffer_(Vector<const byte>::cast(chars)), 6244 state_(TWO_BYTE) { } 6245 FlatContent() : buffer_(), state_(NON_FLAT) { } 6246 6247 Vector<const byte> buffer_; 6248 State state_; 6249 6250 friend class String; 6251 }; 6252 6253 // Get and set the length of the string. 6254 inline int length(); 6255 inline void set_length(int value); 6256 6257 // Get and set the hash field of the string. 6258 inline uint32_t hash_field(); 6259 inline void set_hash_field(uint32_t value); 6260 6261 // Returns whether this string has only ASCII chars, i.e. all of them can 6262 // be ASCII encoded. This might be the case even if the string is 6263 // two-byte. Such strings may appear when the embedder prefers 6264 // two-byte external representations even for ASCII data. 6265 inline bool IsAsciiRepresentation(); 6266 inline bool IsTwoByteRepresentation(); 6267 6268 // Cons and slices have an encoding flag that may not represent the actual 6269 // encoding of the underlying string. This is taken into account here. 6270 // Requires: this->IsFlat() 6271 inline bool IsAsciiRepresentationUnderneath(); 6272 inline bool IsTwoByteRepresentationUnderneath(); 6273 6274 // NOTE: this should be considered only a hint. False negatives are 6275 // possible. 6276 inline bool HasOnlyAsciiChars(); 6277 6278 // Get and set individual two byte chars in the string. 6279 inline void Set(int index, uint16_t value); 6280 // Get individual two byte char in the string. Repeated calls 6281 // to this method are not efficient unless the string is flat. 6282 inline uint16_t Get(int index); 6283 6284 // Try to flatten the string. Checks first inline to see if it is 6285 // necessary. Does nothing if the string is not a cons string. 6286 // Flattening allocates a sequential string with the same data as 6287 // the given string and mutates the cons string to a degenerate 6288 // form, where the first component is the new sequential string and 6289 // the second component is the empty string. If allocation fails, 6290 // this function returns a failure. If flattening succeeds, this 6291 // function returns the sequential string that is now the first 6292 // component of the cons string. 6293 // 6294 // Degenerate cons strings are handled specially by the garbage 6295 // collector (see IsShortcutCandidate). 6296 // 6297 // Use FlattenString from Handles.cc to flatten even in case an 6298 // allocation failure happens. 6299 inline MaybeObject* TryFlatten(PretenureFlag pretenure = NOT_TENURED); 6300 6301 // Convenience function. Has exactly the same behavior as 6302 // TryFlatten(), except in the case of failure returns the original 6303 // string. 6304 inline String* TryFlattenGetString(PretenureFlag pretenure = NOT_TENURED); 6305 6306 // Tries to return the content of a flat string as a structure holding either 6307 // a flat vector of char or of uc16. 6308 // If the string isn't flat, and therefore doesn't have flat content, the 6309 // returned structure will report so, and can't provide a vector of either 6310 // kind. 6311 FlatContent GetFlatContent(); 6312 6313 // Returns the parent of a sliced string or first part of a flat cons string. 6314 // Requires: StringShape(this).IsIndirect() && this->IsFlat() 6315 inline String* GetUnderlying(); 6316 6317 // Mark the string as an undetectable object. It only applies to 6318 // ascii and two byte string types. 6319 bool MarkAsUndetectable(); 6320 6321 // Return a substring. 6322 MUST_USE_RESULT MaybeObject* SubString(int from, 6323 int to, 6324 PretenureFlag pretenure = NOT_TENURED); 6325 6326 // String equality operations. 6327 inline bool Equals(String* other); 6328 bool IsEqualTo(Vector<const char> str); 6329 bool IsAsciiEqualTo(Vector<const char> str); 6330 bool IsTwoByteEqualTo(Vector<const uc16> str); 6331 6332 // Return a UTF8 representation of the string. The string is null 6333 // terminated but may optionally contain nulls. Length is returned 6334 // in length_output if length_output is not a null pointer The string 6335 // should be nearly flat, otherwise the performance of this method may 6336 // be very slow (quadratic in the length). Setting robustness_flag to 6337 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it 6338 // handles unexpected data without causing assert failures and it does not 6339 // do any heap allocations. This is useful when printing stack traces. 6340 SmartArrayPointer<char> ToCString(AllowNullsFlag allow_nulls, 6341 RobustnessFlag robustness_flag, 6342 int offset, 6343 int length, 6344 int* length_output = 0); 6345 SmartArrayPointer<char> ToCString( 6346 AllowNullsFlag allow_nulls = DISALLOW_NULLS, 6347 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL, 6348 int* length_output = 0); 6349 6350 inline int Utf8Length() { return Utf8Length(this, 0, length()); } 6351 static int Utf8Length(String* input, int from, int to); 6352 6353 // Return a 16 bit Unicode representation of the string. 6354 // The string should be nearly flat, otherwise the performance of 6355 // of this method may be very bad. Setting robustness_flag to 6356 // ROBUST_STRING_TRAVERSAL invokes behaviour that is robust This means it 6357 // handles unexpected data without causing assert failures and it does not 6358 // do any heap allocations. This is useful when printing stack traces. 6359 SmartArrayPointer<uc16> ToWideCString( 6360 RobustnessFlag robustness_flag = FAST_STRING_TRAVERSAL); 6361 6362 // Tells whether the hash code has been computed. 6363 inline bool HasHashCode(); 6364 6365 // Returns a hash value used for the property table 6366 inline uint32_t Hash(); 6367 6368 static uint32_t ComputeHashField(unibrow::CharacterStream* buffer, 6369 int length); 6370 6371 static bool ComputeArrayIndex(unibrow::CharacterStream* buffer, 6372 uint32_t* index, 6373 int length); 6374 6375 // Externalization. 6376 bool MakeExternal(v8::String::ExternalStringResource* resource); 6377 bool MakeExternal(v8::String::ExternalAsciiStringResource* resource); 6378 6379 // Conversion. 6380 inline bool AsArrayIndex(uint32_t* index); 6381 6382 // Casting. 6383 static inline String* cast(Object* obj); 6384 6385 void PrintOn(FILE* out); 6386 6387 // For use during stack traces. Performs rudimentary sanity check. 6388 bool LooksValid(); 6389 6390 // Dispatched behavior. 6391 void StringShortPrint(StringStream* accumulator); 6392#ifdef OBJECT_PRINT 6393 inline void StringPrint() { 6394 StringPrint(stdout); 6395 } 6396 void StringPrint(FILE* out); 6397 6398 char* ToAsciiArray(); 6399#endif 6400#ifdef DEBUG 6401 void StringVerify(); 6402#endif 6403 inline bool IsFlat(); 6404 6405 // Layout description. 6406 static const int kLengthOffset = HeapObject::kHeaderSize; 6407 static const int kHashFieldOffset = kLengthOffset + kPointerSize; 6408 static const int kSize = kHashFieldOffset + kPointerSize; 6409 6410 // Maximum number of characters to consider when trying to convert a string 6411 // value into an array index. 6412 static const int kMaxArrayIndexSize = 10; 6413 6414 // Max ascii char code. 6415 static const int kMaxAsciiCharCode = unibrow::Utf8::kMaxOneByteChar; 6416 static const unsigned kMaxAsciiCharCodeU = unibrow::Utf8::kMaxOneByteChar; 6417 static const int kMaxUC16CharCode = 0xffff; 6418 6419 // Minimum length for a cons string. 6420 static const int kMinNonFlatLength = 13; 6421 6422 // Mask constant for checking if a string has a computed hash code 6423 // and if it is an array index. The least significant bit indicates 6424 // whether a hash code has been computed. If the hash code has been 6425 // computed the 2nd bit tells whether the string can be used as an 6426 // array index. 6427 static const int kHashNotComputedMask = 1; 6428 static const int kIsNotArrayIndexMask = 1 << 1; 6429 static const int kNofHashBitFields = 2; 6430 6431 // Shift constant retrieving hash code from hash field. 6432 static const int kHashShift = kNofHashBitFields; 6433 6434 // Array index strings this short can keep their index in the hash 6435 // field. 6436 static const int kMaxCachedArrayIndexLength = 7; 6437 6438 // For strings which are array indexes the hash value has the string length 6439 // mixed into the hash, mainly to avoid a hash value of zero which would be 6440 // the case for the string '0'. 24 bits are used for the array index value. 6441 static const int kArrayIndexValueBits = 24; 6442 static const int kArrayIndexLengthBits = 6443 kBitsPerInt - kArrayIndexValueBits - kNofHashBitFields; 6444 6445 STATIC_CHECK((kArrayIndexLengthBits > 0)); 6446 STATIC_CHECK(kMaxArrayIndexSize < (1 << kArrayIndexLengthBits)); 6447 6448 static const int kArrayIndexHashLengthShift = 6449 kArrayIndexValueBits + kNofHashBitFields; 6450 6451 static const int kArrayIndexHashMask = (1 << kArrayIndexHashLengthShift) - 1; 6452 6453 static const int kArrayIndexValueMask = 6454 ((1 << kArrayIndexValueBits) - 1) << kHashShift; 6455 6456 // Check that kMaxCachedArrayIndexLength + 1 is a power of two so we 6457 // could use a mask to test if the length of string is less than or equal to 6458 // kMaxCachedArrayIndexLength. 6459 STATIC_CHECK(IS_POWER_OF_TWO(kMaxCachedArrayIndexLength + 1)); 6460 6461 static const int kContainsCachedArrayIndexMask = 6462 (~kMaxCachedArrayIndexLength << kArrayIndexHashLengthShift) | 6463 kIsNotArrayIndexMask; 6464 6465 // Value of empty hash field indicating that the hash is not computed. 6466 static const int kEmptyHashField = 6467 kIsNotArrayIndexMask | kHashNotComputedMask; 6468 6469 // Value of hash field containing computed hash equal to zero. 6470 static const int kZeroHash = kIsNotArrayIndexMask; 6471 6472 // Maximal string length. 6473 static const int kMaxLength = (1 << (32 - 2)) - 1; 6474 6475 // Max length for computing hash. For strings longer than this limit the 6476 // string length is used as the hash value. 6477 static const int kMaxHashCalcLength = 16383; 6478 6479 // Limit for truncation in short printing. 6480 static const int kMaxShortPrintLength = 1024; 6481 6482 // Support for regular expressions. 6483 const uc16* GetTwoByteData(); 6484 const uc16* GetTwoByteData(unsigned start); 6485 6486 // Support for StringInputBuffer 6487 static const unibrow::byte* ReadBlock(String* input, 6488 unibrow::byte* util_buffer, 6489 unsigned capacity, 6490 unsigned* remaining, 6491 unsigned* offset); 6492 static const unibrow::byte* ReadBlock(String** input, 6493 unibrow::byte* util_buffer, 6494 unsigned capacity, 6495 unsigned* remaining, 6496 unsigned* offset); 6497 6498 // Helper function for flattening strings. 6499 template <typename sinkchar> 6500 static void WriteToFlat(String* source, 6501 sinkchar* sink, 6502 int from, 6503 int to); 6504 6505 static inline bool IsAscii(const char* chars, int length) { 6506 const char* limit = chars + length; 6507#ifdef V8_HOST_CAN_READ_UNALIGNED 6508 ASSERT(kMaxAsciiCharCode == 0x7F); 6509 const uintptr_t non_ascii_mask = kUintptrAllBitsSet / 0xFF * 0x80; 6510 while (chars <= limit - sizeof(uintptr_t)) { 6511 if (*reinterpret_cast<const uintptr_t*>(chars) & non_ascii_mask) { 6512 return false; 6513 } 6514 chars += sizeof(uintptr_t); 6515 } 6516#endif 6517 while (chars < limit) { 6518 if (static_cast<uint8_t>(*chars) > kMaxAsciiCharCodeU) return false; 6519 ++chars; 6520 } 6521 return true; 6522 } 6523 6524 static inline bool IsAscii(const uc16* chars, int length) { 6525 const uc16* limit = chars + length; 6526 while (chars < limit) { 6527 if (*chars > kMaxAsciiCharCodeU) return false; 6528 ++chars; 6529 } 6530 return true; 6531 } 6532 6533 protected: 6534 class ReadBlockBuffer { 6535 public: 6536 ReadBlockBuffer(unibrow::byte* util_buffer_, 6537 unsigned cursor_, 6538 unsigned capacity_, 6539 unsigned remaining_) : 6540 util_buffer(util_buffer_), 6541 cursor(cursor_), 6542 capacity(capacity_), 6543 remaining(remaining_) { 6544 } 6545 unibrow::byte* util_buffer; 6546 unsigned cursor; 6547 unsigned capacity; 6548 unsigned remaining; 6549 }; 6550 6551 static inline const unibrow::byte* ReadBlock(String* input, 6552 ReadBlockBuffer* buffer, 6553 unsigned* offset, 6554 unsigned max_chars); 6555 static void ReadBlockIntoBuffer(String* input, 6556 ReadBlockBuffer* buffer, 6557 unsigned* offset_ptr, 6558 unsigned max_chars); 6559 6560 private: 6561 // Try to flatten the top level ConsString that is hiding behind this 6562 // string. This is a no-op unless the string is a ConsString. Flatten 6563 // mutates the ConsString and might return a failure. 6564 MUST_USE_RESULT MaybeObject* SlowTryFlatten(PretenureFlag pretenure); 6565 6566 static inline bool IsHashFieldComputed(uint32_t field); 6567 6568 // Slow case of String::Equals. This implementation works on any strings 6569 // but it is most efficient on strings that are almost flat. 6570 bool SlowEquals(String* other); 6571 6572 // Slow case of AsArrayIndex. 6573 bool SlowAsArrayIndex(uint32_t* index); 6574 6575 // Compute and set the hash code. 6576 uint32_t ComputeAndSetHash(); 6577 6578 DISALLOW_IMPLICIT_CONSTRUCTORS(String); 6579}; 6580 6581 6582// The SeqString abstract class captures sequential string values. 6583class SeqString: public String { 6584 public: 6585 // Casting. 6586 static inline SeqString* cast(Object* obj); 6587 6588 // Layout description. 6589 static const int kHeaderSize = String::kSize; 6590 6591 private: 6592 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqString); 6593}; 6594 6595 6596// The AsciiString class captures sequential ascii string objects. 6597// Each character in the AsciiString is an ascii character. 6598class SeqAsciiString: public SeqString { 6599 public: 6600 static const bool kHasAsciiEncoding = true; 6601 6602 // Dispatched behavior. 6603 inline uint16_t SeqAsciiStringGet(int index); 6604 inline void SeqAsciiStringSet(int index, uint16_t value); 6605 6606 // Get the address of the characters in this string. 6607 inline Address GetCharsAddress(); 6608 6609 inline char* GetChars(); 6610 6611 // Casting 6612 static inline SeqAsciiString* cast(Object* obj); 6613 6614 // Garbage collection support. This method is called by the 6615 // garbage collector to compute the actual size of an AsciiString 6616 // instance. 6617 inline int SeqAsciiStringSize(InstanceType instance_type); 6618 6619 // Computes the size for an AsciiString instance of a given length. 6620 static int SizeFor(int length) { 6621 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kCharSize); 6622 } 6623 6624 // Maximal memory usage for a single sequential ASCII string. 6625 static const int kMaxSize = 512 * MB - 1; 6626 // Maximal length of a single sequential ASCII string. 6627 // Q.v. String::kMaxLength which is the maximal size of concatenated strings. 6628 static const int kMaxLength = (kMaxSize - kHeaderSize); 6629 6630 // Support for StringInputBuffer. 6631 inline void SeqAsciiStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, 6632 unsigned* offset, 6633 unsigned chars); 6634 inline const unibrow::byte* SeqAsciiStringReadBlock(unsigned* remaining, 6635 unsigned* offset, 6636 unsigned chars); 6637 6638 private: 6639 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqAsciiString); 6640}; 6641 6642 6643// The TwoByteString class captures sequential unicode string objects. 6644// Each character in the TwoByteString is a two-byte uint16_t. 6645class SeqTwoByteString: public SeqString { 6646 public: 6647 static const bool kHasAsciiEncoding = false; 6648 6649 // Dispatched behavior. 6650 inline uint16_t SeqTwoByteStringGet(int index); 6651 inline void SeqTwoByteStringSet(int index, uint16_t value); 6652 6653 // Get the address of the characters in this string. 6654 inline Address GetCharsAddress(); 6655 6656 inline uc16* GetChars(); 6657 6658 // For regexp code. 6659 const uint16_t* SeqTwoByteStringGetData(unsigned start); 6660 6661 // Casting 6662 static inline SeqTwoByteString* cast(Object* obj); 6663 6664 // Garbage collection support. This method is called by the 6665 // garbage collector to compute the actual size of a TwoByteString 6666 // instance. 6667 inline int SeqTwoByteStringSize(InstanceType instance_type); 6668 6669 // Computes the size for a TwoByteString instance of a given length. 6670 static int SizeFor(int length) { 6671 return OBJECT_POINTER_ALIGN(kHeaderSize + length * kShortSize); 6672 } 6673 6674 // Maximal memory usage for a single sequential two-byte string. 6675 static const int kMaxSize = 512 * MB - 1; 6676 // Maximal length of a single sequential two-byte string. 6677 // Q.v. String::kMaxLength which is the maximal size of concatenated strings. 6678 static const int kMaxLength = (kMaxSize - kHeaderSize) / sizeof(uint16_t); 6679 6680 // Support for StringInputBuffer. 6681 inline void SeqTwoByteStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, 6682 unsigned* offset_ptr, 6683 unsigned chars); 6684 6685 private: 6686 DISALLOW_IMPLICIT_CONSTRUCTORS(SeqTwoByteString); 6687}; 6688 6689 6690// The ConsString class describes string values built by using the 6691// addition operator on strings. A ConsString is a pair where the 6692// first and second components are pointers to other string values. 6693// One or both components of a ConsString can be pointers to other 6694// ConsStrings, creating a binary tree of ConsStrings where the leaves 6695// are non-ConsString string values. The string value represented by 6696// a ConsString can be obtained by concatenating the leaf string 6697// values in a left-to-right depth-first traversal of the tree. 6698class ConsString: public String { 6699 public: 6700 // First string of the cons cell. 6701 inline String* first(); 6702 // Doesn't check that the result is a string, even in debug mode. This is 6703 // useful during GC where the mark bits confuse the checks. 6704 inline Object* unchecked_first(); 6705 inline void set_first(String* first, 6706 WriteBarrierMode mode = UPDATE_WRITE_BARRIER); 6707 6708 // Second string of the cons cell. 6709 inline String* second(); 6710 // Doesn't check that the result is a string, even in debug mode. This is 6711 // useful during GC where the mark bits confuse the checks. 6712 inline Object* unchecked_second(); 6713 inline void set_second(String* second, 6714 WriteBarrierMode mode = UPDATE_WRITE_BARRIER); 6715 6716 // Dispatched behavior. 6717 uint16_t ConsStringGet(int index); 6718 6719 // Casting. 6720 static inline ConsString* cast(Object* obj); 6721 6722 // Layout description. 6723 static const int kFirstOffset = POINTER_SIZE_ALIGN(String::kSize); 6724 static const int kSecondOffset = kFirstOffset + kPointerSize; 6725 static const int kSize = kSecondOffset + kPointerSize; 6726 6727 // Support for StringInputBuffer. 6728 inline const unibrow::byte* ConsStringReadBlock(ReadBlockBuffer* buffer, 6729 unsigned* offset_ptr, 6730 unsigned chars); 6731 inline void ConsStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, 6732 unsigned* offset_ptr, 6733 unsigned chars); 6734 6735 // Minimum length for a cons string. 6736 static const int kMinLength = 13; 6737 6738 typedef FixedBodyDescriptor<kFirstOffset, kSecondOffset + kPointerSize, kSize> 6739 BodyDescriptor; 6740 6741#ifdef DEBUG 6742 void ConsStringVerify(); 6743#endif 6744 6745 private: 6746 DISALLOW_IMPLICIT_CONSTRUCTORS(ConsString); 6747}; 6748 6749 6750// The Sliced String class describes strings that are substrings of another 6751// sequential string. The motivation is to save time and memory when creating 6752// a substring. A Sliced String is described as a pointer to the parent, 6753// the offset from the start of the parent string and the length. Using 6754// a Sliced String therefore requires unpacking of the parent string and 6755// adding the offset to the start address. A substring of a Sliced String 6756// are not nested since the double indirection is simplified when creating 6757// such a substring. 6758// Currently missing features are: 6759// - handling externalized parent strings 6760// - external strings as parent 6761// - truncating sliced string to enable otherwise unneeded parent to be GC'ed. 6762class SlicedString: public String { 6763 public: 6764 inline String* parent(); 6765 inline void set_parent(String* parent); 6766 inline int offset(); 6767 inline void set_offset(int offset); 6768 6769 // Dispatched behavior. 6770 uint16_t SlicedStringGet(int index); 6771 6772 // Casting. 6773 static inline SlicedString* cast(Object* obj); 6774 6775 // Layout description. 6776 static const int kParentOffset = POINTER_SIZE_ALIGN(String::kSize); 6777 static const int kOffsetOffset = kParentOffset + kPointerSize; 6778 static const int kSize = kOffsetOffset + kPointerSize; 6779 6780 // Support for StringInputBuffer 6781 inline const unibrow::byte* SlicedStringReadBlock(ReadBlockBuffer* buffer, 6782 unsigned* offset_ptr, 6783 unsigned chars); 6784 inline void SlicedStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, 6785 unsigned* offset_ptr, 6786 unsigned chars); 6787 // Minimum length for a sliced string. 6788 static const int kMinLength = 13; 6789 6790 typedef FixedBodyDescriptor<kParentOffset, 6791 kOffsetOffset + kPointerSize, kSize> 6792 BodyDescriptor; 6793 6794#ifdef DEBUG 6795 void SlicedStringVerify(); 6796#endif 6797 6798 private: 6799 DISALLOW_IMPLICIT_CONSTRUCTORS(SlicedString); 6800}; 6801 6802 6803// The ExternalString class describes string values that are backed by 6804// a string resource that lies outside the V8 heap. ExternalStrings 6805// consist of the length field common to all strings, a pointer to the 6806// external resource. It is important to ensure (externally) that the 6807// resource is not deallocated while the ExternalString is live in the 6808// V8 heap. 6809// 6810// The API expects that all ExternalStrings are created through the 6811// API. Therefore, ExternalStrings should not be used internally. 6812class ExternalString: public String { 6813 public: 6814 // Casting 6815 static inline ExternalString* cast(Object* obj); 6816 6817 // Layout description. 6818 static const int kResourceOffset = POINTER_SIZE_ALIGN(String::kSize); 6819 static const int kShortSize = kResourceOffset + kPointerSize; 6820 static const int kResourceDataOffset = kResourceOffset + kPointerSize; 6821 static const int kSize = kResourceDataOffset + kPointerSize; 6822 6823 // Return whether external string is short (data pointer is not cached). 6824 inline bool is_short(); 6825 6826 STATIC_CHECK(kResourceOffset == Internals::kStringResourceOffset); 6827 6828 private: 6829 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalString); 6830}; 6831 6832 6833// The ExternalAsciiString class is an external string backed by an 6834// ASCII string. 6835class ExternalAsciiString: public ExternalString { 6836 public: 6837 static const bool kHasAsciiEncoding = true; 6838 6839 typedef v8::String::ExternalAsciiStringResource Resource; 6840 6841 // The underlying resource. 6842 inline const Resource* resource(); 6843 inline void set_resource(const Resource* buffer); 6844 6845 // Update the pointer cache to the external character array. 6846 // The cached pointer is always valid, as the external character array does = 6847 // not move during lifetime. Deserialization is the only exception, after 6848 // which the pointer cache has to be refreshed. 6849 inline void update_data_cache(); 6850 6851 inline const char* GetChars(); 6852 6853 // Dispatched behavior. 6854 inline uint16_t ExternalAsciiStringGet(int index); 6855 6856 // Casting. 6857 static inline ExternalAsciiString* cast(Object* obj); 6858 6859 // Garbage collection support. 6860 inline void ExternalAsciiStringIterateBody(ObjectVisitor* v); 6861 6862 template<typename StaticVisitor> 6863 inline void ExternalAsciiStringIterateBody(); 6864 6865 // Support for StringInputBuffer. 6866 const unibrow::byte* ExternalAsciiStringReadBlock(unsigned* remaining, 6867 unsigned* offset, 6868 unsigned chars); 6869 inline void ExternalAsciiStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, 6870 unsigned* offset, 6871 unsigned chars); 6872 6873 private: 6874 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalAsciiString); 6875}; 6876 6877 6878// The ExternalTwoByteString class is an external string backed by a UTF-16 6879// encoded string. 6880class ExternalTwoByteString: public ExternalString { 6881 public: 6882 static const bool kHasAsciiEncoding = false; 6883 6884 typedef v8::String::ExternalStringResource Resource; 6885 6886 // The underlying string resource. 6887 inline const Resource* resource(); 6888 inline void set_resource(const Resource* buffer); 6889 6890 // Update the pointer cache to the external character array. 6891 // The cached pointer is always valid, as the external character array does = 6892 // not move during lifetime. Deserialization is the only exception, after 6893 // which the pointer cache has to be refreshed. 6894 inline void update_data_cache(); 6895 6896 inline const uint16_t* GetChars(); 6897 6898 // Dispatched behavior. 6899 inline uint16_t ExternalTwoByteStringGet(int index); 6900 6901 // For regexp code. 6902 inline const uint16_t* ExternalTwoByteStringGetData(unsigned start); 6903 6904 // Casting. 6905 static inline ExternalTwoByteString* cast(Object* obj); 6906 6907 // Garbage collection support. 6908 inline void ExternalTwoByteStringIterateBody(ObjectVisitor* v); 6909 6910 template<typename StaticVisitor> 6911 inline void ExternalTwoByteStringIterateBody(); 6912 6913 6914 // Support for StringInputBuffer. 6915 void ExternalTwoByteStringReadBlockIntoBuffer(ReadBlockBuffer* buffer, 6916 unsigned* offset_ptr, 6917 unsigned chars); 6918 6919 private: 6920 DISALLOW_IMPLICIT_CONSTRUCTORS(ExternalTwoByteString); 6921}; 6922 6923 6924// Utility superclass for stack-allocated objects that must be updated 6925// on gc. It provides two ways for the gc to update instances, either 6926// iterating or updating after gc. 6927class Relocatable BASE_EMBEDDED { 6928 public: 6929 explicit inline Relocatable(Isolate* isolate); 6930 inline virtual ~Relocatable(); 6931 virtual void IterateInstance(ObjectVisitor* v) { } 6932 virtual void PostGarbageCollection() { } 6933 6934 static void PostGarbageCollectionProcessing(); 6935 static int ArchiveSpacePerThread(); 6936 static char* ArchiveState(Isolate* isolate, char* to); 6937 static char* RestoreState(Isolate* isolate, char* from); 6938 static void Iterate(ObjectVisitor* v); 6939 static void Iterate(ObjectVisitor* v, Relocatable* top); 6940 static char* Iterate(ObjectVisitor* v, char* t); 6941 private: 6942 Isolate* isolate_; 6943 Relocatable* prev_; 6944}; 6945 6946 6947// A flat string reader provides random access to the contents of a 6948// string independent of the character width of the string. The handle 6949// must be valid as long as the reader is being used. 6950class FlatStringReader : public Relocatable { 6951 public: 6952 FlatStringReader(Isolate* isolate, Handle<String> str); 6953 FlatStringReader(Isolate* isolate, Vector<const char> input); 6954 void PostGarbageCollection(); 6955 inline uc32 Get(int index); 6956 int length() { return length_; } 6957 private: 6958 String** str_; 6959 bool is_ascii_; 6960 int length_; 6961 const void* start_; 6962}; 6963 6964 6965// Note that StringInputBuffers are not valid across a GC! To fix this 6966// it would have to store a String Handle instead of a String* and 6967// AsciiStringReadBlock would have to be modified to use memcpy. 6968// 6969// StringInputBuffer is able to traverse any string regardless of how 6970// deeply nested a sequence of ConsStrings it is made of. However, 6971// performance will be better if deep strings are flattened before they 6972// are traversed. Since flattening requires memory allocation this is 6973// not always desirable, however (esp. in debugging situations). 6974class StringInputBuffer: public unibrow::InputBuffer<String, String*, 1024> { 6975 public: 6976 virtual void Seek(unsigned pos); 6977 inline StringInputBuffer(): unibrow::InputBuffer<String, String*, 1024>() {} 6978 explicit inline StringInputBuffer(String* backing): 6979 unibrow::InputBuffer<String, String*, 1024>(backing) {} 6980}; 6981 6982 6983class SafeStringInputBuffer 6984 : public unibrow::InputBuffer<String, String**, 256> { 6985 public: 6986 virtual void Seek(unsigned pos); 6987 inline SafeStringInputBuffer() 6988 : unibrow::InputBuffer<String, String**, 256>() {} 6989 explicit inline SafeStringInputBuffer(String** backing) 6990 : unibrow::InputBuffer<String, String**, 256>(backing) {} 6991}; 6992 6993 6994template <typename T> 6995class VectorIterator { 6996 public: 6997 VectorIterator(T* d, int l) : data_(Vector<const T>(d, l)), index_(0) { } 6998 explicit VectorIterator(Vector<const T> data) : data_(data), index_(0) { } 6999 T GetNext() { return data_[index_++]; } 7000 bool has_more() { return index_ < data_.length(); } 7001 private: 7002 Vector<const T> data_; 7003 int index_; 7004}; 7005 7006 7007// The Oddball describes objects null, undefined, true, and false. 7008class Oddball: public HeapObject { 7009 public: 7010 // [to_string]: Cached to_string computed at startup. 7011 DECL_ACCESSORS(to_string, String) 7012 7013 // [to_number]: Cached to_number computed at startup. 7014 DECL_ACCESSORS(to_number, Object) 7015 7016 inline byte kind(); 7017 inline void set_kind(byte kind); 7018 7019 // Casting. 7020 static inline Oddball* cast(Object* obj); 7021 7022 // Dispatched behavior. 7023#ifdef DEBUG 7024 void OddballVerify(); 7025#endif 7026 7027 // Initialize the fields. 7028 MUST_USE_RESULT MaybeObject* Initialize(const char* to_string, 7029 Object* to_number, 7030 byte kind); 7031 7032 // Layout description. 7033 static const int kToStringOffset = HeapObject::kHeaderSize; 7034 static const int kToNumberOffset = kToStringOffset + kPointerSize; 7035 static const int kKindOffset = kToNumberOffset + kPointerSize; 7036 static const int kSize = kKindOffset + kPointerSize; 7037 7038 static const byte kFalse = 0; 7039 static const byte kTrue = 1; 7040 static const byte kNotBooleanMask = ~1; 7041 static const byte kTheHole = 2; 7042 static const byte kNull = 3; 7043 static const byte kArgumentMarker = 4; 7044 static const byte kUndefined = 5; 7045 static const byte kOther = 6; 7046 7047 // The ToNumber value of a hidden oddball is a negative smi. 7048 static const int kLeastHiddenOddballNumber = -5; 7049 7050 typedef FixedBodyDescriptor<kToStringOffset, 7051 kToNumberOffset + kPointerSize, 7052 kSize> BodyDescriptor; 7053 7054 private: 7055 DISALLOW_IMPLICIT_CONSTRUCTORS(Oddball); 7056}; 7057 7058 7059class JSGlobalPropertyCell: public HeapObject { 7060 public: 7061 // [value]: value of the global property. 7062 DECL_ACCESSORS(value, Object) 7063 7064 // Casting. 7065 static inline JSGlobalPropertyCell* cast(Object* obj); 7066 7067#ifdef DEBUG 7068 void JSGlobalPropertyCellVerify(); 7069#endif 7070#ifdef OBJECT_PRINT 7071 inline void JSGlobalPropertyCellPrint() { 7072 JSGlobalPropertyCellPrint(stdout); 7073 } 7074 void JSGlobalPropertyCellPrint(FILE* out); 7075#endif 7076 7077 // Layout description. 7078 static const int kValueOffset = HeapObject::kHeaderSize; 7079 static const int kSize = kValueOffset + kPointerSize; 7080 7081 typedef FixedBodyDescriptor<kValueOffset, 7082 kValueOffset + kPointerSize, 7083 kSize> BodyDescriptor; 7084 7085 private: 7086 DISALLOW_IMPLICIT_CONSTRUCTORS(JSGlobalPropertyCell); 7087}; 7088 7089 7090// The JSProxy describes EcmaScript Harmony proxies 7091class JSProxy: public JSReceiver { 7092 public: 7093 // [handler]: The handler property. 7094 DECL_ACCESSORS(handler, Object) 7095 7096 // [hash]: The hash code property (undefined if not initialized yet). 7097 DECL_ACCESSORS(hash, Object) 7098 7099 // Casting. 7100 static inline JSProxy* cast(Object* obj); 7101 7102 bool HasPropertyWithHandler(String* name); 7103 bool HasElementWithHandler(uint32_t index); 7104 7105 MUST_USE_RESULT MaybeObject* GetPropertyWithHandler( 7106 Object* receiver, 7107 String* name); 7108 MUST_USE_RESULT MaybeObject* GetElementWithHandler( 7109 Object* receiver, 7110 uint32_t index); 7111 7112 MUST_USE_RESULT MaybeObject* SetPropertyWithHandler( 7113 String* name, 7114 Object* value, 7115 PropertyAttributes attributes, 7116 StrictModeFlag strict_mode); 7117 MUST_USE_RESULT MaybeObject* SetElementWithHandler( 7118 uint32_t index, 7119 Object* value, 7120 StrictModeFlag strict_mode); 7121 7122 // If the handler defines an accessor property, invoke its setter 7123 // (or throw if only a getter exists) and set *found to true. Otherwise false. 7124 MUST_USE_RESULT MaybeObject* SetPropertyWithHandlerIfDefiningSetter( 7125 String* name, 7126 Object* value, 7127 PropertyAttributes attributes, 7128 StrictModeFlag strict_mode, 7129 bool* found); 7130 7131 MUST_USE_RESULT MaybeObject* DeletePropertyWithHandler( 7132 String* name, 7133 DeleteMode mode); 7134 MUST_USE_RESULT MaybeObject* DeleteElementWithHandler( 7135 uint32_t index, 7136 DeleteMode mode); 7137 7138 MUST_USE_RESULT PropertyAttributes GetPropertyAttributeWithHandler( 7139 JSReceiver* receiver, 7140 String* name); 7141 MUST_USE_RESULT PropertyAttributes GetElementAttributeWithHandler( 7142 JSReceiver* receiver, 7143 uint32_t index); 7144 7145 MUST_USE_RESULT MaybeObject* GetIdentityHash(CreationFlag flag); 7146 7147 // Turn this into an (empty) JSObject. 7148 void Fix(); 7149 7150 // Initializes the body after the handler slot. 7151 inline void InitializeBody(int object_size, Object* value); 7152 7153 // Invoke a trap by name. If the trap does not exist on this's handler, 7154 // but derived_trap is non-NULL, invoke that instead. May cause GC. 7155 Handle<Object> CallTrap(const char* name, 7156 Handle<Object> derived_trap, 7157 int argc, 7158 Handle<Object> args[]); 7159 7160 // Dispatched behavior. 7161#ifdef OBJECT_PRINT 7162 inline void JSProxyPrint() { 7163 JSProxyPrint(stdout); 7164 } 7165 void JSProxyPrint(FILE* out); 7166#endif 7167#ifdef DEBUG 7168 void JSProxyVerify(); 7169#endif 7170 7171 // Layout description. We add padding so that a proxy has the same 7172 // size as a virgin JSObject. This is essential for becoming a JSObject 7173 // upon freeze. 7174 static const int kHandlerOffset = HeapObject::kHeaderSize; 7175 static const int kHashOffset = kHandlerOffset + kPointerSize; 7176 static const int kPaddingOffset = kHashOffset + kPointerSize; 7177 static const int kSize = JSObject::kHeaderSize; 7178 static const int kHeaderSize = kPaddingOffset; 7179 static const int kPaddingSize = kSize - kPaddingOffset; 7180 7181 STATIC_CHECK(kPaddingSize >= 0); 7182 7183 typedef FixedBodyDescriptor<kHandlerOffset, 7184 kPaddingOffset, 7185 kSize> BodyDescriptor; 7186 7187 private: 7188 DISALLOW_IMPLICIT_CONSTRUCTORS(JSProxy); 7189}; 7190 7191 7192class JSFunctionProxy: public JSProxy { 7193 public: 7194 // [call_trap]: The call trap. 7195 DECL_ACCESSORS(call_trap, Object) 7196 7197 // [construct_trap]: The construct trap. 7198 DECL_ACCESSORS(construct_trap, Object) 7199 7200 // Casting. 7201 static inline JSFunctionProxy* cast(Object* obj); 7202 7203 // Dispatched behavior. 7204#ifdef OBJECT_PRINT 7205 inline void JSFunctionProxyPrint() { 7206 JSFunctionProxyPrint(stdout); 7207 } 7208 void JSFunctionProxyPrint(FILE* out); 7209#endif 7210#ifdef DEBUG 7211 void JSFunctionProxyVerify(); 7212#endif 7213 7214 // Layout description. 7215 static const int kCallTrapOffset = JSProxy::kPaddingOffset; 7216 static const int kConstructTrapOffset = kCallTrapOffset + kPointerSize; 7217 static const int kPaddingOffset = kConstructTrapOffset + kPointerSize; 7218 static const int kSize = JSFunction::kSize; 7219 static const int kPaddingSize = kSize - kPaddingOffset; 7220 7221 STATIC_CHECK(kPaddingSize >= 0); 7222 7223 typedef FixedBodyDescriptor<kHandlerOffset, 7224 kConstructTrapOffset + kPointerSize, 7225 kSize> BodyDescriptor; 7226 7227 private: 7228 DISALLOW_IMPLICIT_CONSTRUCTORS(JSFunctionProxy); 7229}; 7230 7231 7232// The JSSet describes EcmaScript Harmony sets 7233class JSSet: public JSObject { 7234 public: 7235 // [set]: the backing hash set containing keys. 7236 DECL_ACCESSORS(table, Object) 7237 7238 // Casting. 7239 static inline JSSet* cast(Object* obj); 7240 7241#ifdef OBJECT_PRINT 7242 inline void JSSetPrint() { 7243 JSSetPrint(stdout); 7244 } 7245 void JSSetPrint(FILE* out); 7246#endif 7247#ifdef DEBUG 7248 void JSSetVerify(); 7249#endif 7250 7251 static const int kTableOffset = JSObject::kHeaderSize; 7252 static const int kSize = kTableOffset + kPointerSize; 7253 7254 private: 7255 DISALLOW_IMPLICIT_CONSTRUCTORS(JSSet); 7256}; 7257 7258 7259// The JSMap describes EcmaScript Harmony maps 7260class JSMap: public JSObject { 7261 public: 7262 // [table]: the backing hash table mapping keys to values. 7263 DECL_ACCESSORS(table, Object) 7264 7265 // Casting. 7266 static inline JSMap* cast(Object* obj); 7267 7268#ifdef OBJECT_PRINT 7269 inline void JSMapPrint() { 7270 JSMapPrint(stdout); 7271 } 7272 void JSMapPrint(FILE* out); 7273#endif 7274#ifdef DEBUG 7275 void JSMapVerify(); 7276#endif 7277 7278 static const int kTableOffset = JSObject::kHeaderSize; 7279 static const int kSize = kTableOffset + kPointerSize; 7280 7281 private: 7282 DISALLOW_IMPLICIT_CONSTRUCTORS(JSMap); 7283}; 7284 7285 7286// The JSWeakMap describes EcmaScript Harmony weak maps 7287class JSWeakMap: public JSObject { 7288 public: 7289 // [table]: the backing hash table mapping keys to values. 7290 DECL_ACCESSORS(table, Object) 7291 7292 // [next]: linked list of encountered weak maps during GC. 7293 DECL_ACCESSORS(next, Object) 7294 7295 // Casting. 7296 static inline JSWeakMap* cast(Object* obj); 7297 7298#ifdef OBJECT_PRINT 7299 inline void JSWeakMapPrint() { 7300 JSWeakMapPrint(stdout); 7301 } 7302 void JSWeakMapPrint(FILE* out); 7303#endif 7304#ifdef DEBUG 7305 void JSWeakMapVerify(); 7306#endif 7307 7308 static const int kTableOffset = JSObject::kHeaderSize; 7309 static const int kNextOffset = kTableOffset + kPointerSize; 7310 static const int kSize = kNextOffset + kPointerSize; 7311 7312 private: 7313 DISALLOW_IMPLICIT_CONSTRUCTORS(JSWeakMap); 7314}; 7315 7316 7317// Foreign describes objects pointing from JavaScript to C structures. 7318// Since they cannot contain references to JS HeapObjects they can be 7319// placed in old_data_space. 7320class Foreign: public HeapObject { 7321 public: 7322 // [address]: field containing the address. 7323 inline Address foreign_address(); 7324 inline void set_foreign_address(Address value); 7325 7326 // Casting. 7327 static inline Foreign* cast(Object* obj); 7328 7329 // Dispatched behavior. 7330 inline void ForeignIterateBody(ObjectVisitor* v); 7331 7332 template<typename StaticVisitor> 7333 inline void ForeignIterateBody(); 7334 7335#ifdef OBJECT_PRINT 7336 inline void ForeignPrint() { 7337 ForeignPrint(stdout); 7338 } 7339 void ForeignPrint(FILE* out); 7340#endif 7341#ifdef DEBUG 7342 void ForeignVerify(); 7343#endif 7344 7345 // Layout description. 7346 7347 static const int kForeignAddressOffset = HeapObject::kHeaderSize; 7348 static const int kSize = kForeignAddressOffset + kPointerSize; 7349 7350 STATIC_CHECK(kForeignAddressOffset == Internals::kForeignAddressOffset); 7351 7352 private: 7353 DISALLOW_IMPLICIT_CONSTRUCTORS(Foreign); 7354}; 7355 7356 7357// The JSArray describes JavaScript Arrays 7358// Such an array can be in one of two modes: 7359// - fast, backing storage is a FixedArray and length <= elements.length(); 7360// Please note: push and pop can be used to grow and shrink the array. 7361// - slow, backing storage is a HashTable with numbers as keys. 7362class JSArray: public JSObject { 7363 public: 7364 // [length]: The length property. 7365 DECL_ACCESSORS(length, Object) 7366 7367 // Overload the length setter to skip write barrier when the length 7368 // is set to a smi. This matches the set function on FixedArray. 7369 inline void set_length(Smi* length); 7370 7371 MUST_USE_RESULT MaybeObject* JSArrayUpdateLengthFromIndex(uint32_t index, 7372 Object* value); 7373 7374 // Initialize the array with the given capacity. The function may 7375 // fail due to out-of-memory situations, but only if the requested 7376 // capacity is non-zero. 7377 MUST_USE_RESULT MaybeObject* Initialize(int capacity); 7378 7379 // Set the content of the array to the content of storage. 7380 inline MaybeObject* SetContent(FixedArray* storage); 7381 7382 // Casting. 7383 static inline JSArray* cast(Object* obj); 7384 7385 // Uses handles. Ensures that the fixed array backing the JSArray has at 7386 // least the stated size. 7387 inline void EnsureSize(int minimum_size_of_backing_fixed_array); 7388 7389 // Dispatched behavior. 7390#ifdef OBJECT_PRINT 7391 inline void JSArrayPrint() { 7392 JSArrayPrint(stdout); 7393 } 7394 void JSArrayPrint(FILE* out); 7395#endif 7396#ifdef DEBUG 7397 void JSArrayVerify(); 7398#endif 7399 7400 // Number of element slots to pre-allocate for an empty array. 7401 static const int kPreallocatedArrayElements = 4; 7402 7403 // Layout description. 7404 static const int kLengthOffset = JSObject::kHeaderSize; 7405 static const int kSize = kLengthOffset + kPointerSize; 7406 7407 private: 7408 // Expand the fixed array backing of a fast-case JSArray to at least 7409 // the requested size. 7410 void Expand(int minimum_size_of_backing_fixed_array); 7411 7412 DISALLOW_IMPLICIT_CONSTRUCTORS(JSArray); 7413}; 7414 7415 7416// JSRegExpResult is just a JSArray with a specific initial map. 7417// This initial map adds in-object properties for "index" and "input" 7418// properties, as assigned by RegExp.prototype.exec, which allows 7419// faster creation of RegExp exec results. 7420// This class just holds constants used when creating the result. 7421// After creation the result must be treated as a JSArray in all regards. 7422class JSRegExpResult: public JSArray { 7423 public: 7424 // Offsets of object fields. 7425 static const int kIndexOffset = JSArray::kSize; 7426 static const int kInputOffset = kIndexOffset + kPointerSize; 7427 static const int kSize = kInputOffset + kPointerSize; 7428 // Indices of in-object properties. 7429 static const int kIndexIndex = 0; 7430 static const int kInputIndex = 1; 7431 private: 7432 DISALLOW_IMPLICIT_CONSTRUCTORS(JSRegExpResult); 7433}; 7434 7435 7436// An accessor must have a getter, but can have no setter. 7437// 7438// When setting a property, V8 searches accessors in prototypes. 7439// If an accessor was found and it does not have a setter, 7440// the request is ignored. 7441// 7442// If the accessor in the prototype has the READ_ONLY property attribute, then 7443// a new value is added to the local object when the property is set. 7444// This shadows the accessor in the prototype. 7445class AccessorInfo: public Struct { 7446 public: 7447 DECL_ACCESSORS(getter, Object) 7448 DECL_ACCESSORS(setter, Object) 7449 DECL_ACCESSORS(data, Object) 7450 DECL_ACCESSORS(name, Object) 7451 DECL_ACCESSORS(flag, Smi) 7452 7453 inline bool all_can_read(); 7454 inline void set_all_can_read(bool value); 7455 7456 inline bool all_can_write(); 7457 inline void set_all_can_write(bool value); 7458 7459 inline bool prohibits_overwriting(); 7460 inline void set_prohibits_overwriting(bool value); 7461 7462 inline PropertyAttributes property_attributes(); 7463 inline void set_property_attributes(PropertyAttributes attributes); 7464 7465 static inline AccessorInfo* cast(Object* obj); 7466 7467#ifdef OBJECT_PRINT 7468 inline void AccessorInfoPrint() { 7469 AccessorInfoPrint(stdout); 7470 } 7471 void AccessorInfoPrint(FILE* out); 7472#endif 7473#ifdef DEBUG 7474 void AccessorInfoVerify(); 7475#endif 7476 7477 static const int kGetterOffset = HeapObject::kHeaderSize; 7478 static const int kSetterOffset = kGetterOffset + kPointerSize; 7479 static const int kDataOffset = kSetterOffset + kPointerSize; 7480 static const int kNameOffset = kDataOffset + kPointerSize; 7481 static const int kFlagOffset = kNameOffset + kPointerSize; 7482 static const int kSize = kFlagOffset + kPointerSize; 7483 7484 private: 7485 // Bit positions in flag. 7486 static const int kAllCanReadBit = 0; 7487 static const int kAllCanWriteBit = 1; 7488 static const int kProhibitsOverwritingBit = 2; 7489 class AttributesField: public BitField<PropertyAttributes, 3, 3> {}; 7490 7491 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessorInfo); 7492}; 7493 7494 7495class AccessCheckInfo: public Struct { 7496 public: 7497 DECL_ACCESSORS(named_callback, Object) 7498 DECL_ACCESSORS(indexed_callback, Object) 7499 DECL_ACCESSORS(data, Object) 7500 7501 static inline AccessCheckInfo* cast(Object* obj); 7502 7503#ifdef OBJECT_PRINT 7504 inline void AccessCheckInfoPrint() { 7505 AccessCheckInfoPrint(stdout); 7506 } 7507 void AccessCheckInfoPrint(FILE* out); 7508#endif 7509#ifdef DEBUG 7510 void AccessCheckInfoVerify(); 7511#endif 7512 7513 static const int kNamedCallbackOffset = HeapObject::kHeaderSize; 7514 static const int kIndexedCallbackOffset = kNamedCallbackOffset + kPointerSize; 7515 static const int kDataOffset = kIndexedCallbackOffset + kPointerSize; 7516 static const int kSize = kDataOffset + kPointerSize; 7517 7518 private: 7519 DISALLOW_IMPLICIT_CONSTRUCTORS(AccessCheckInfo); 7520}; 7521 7522 7523class InterceptorInfo: public Struct { 7524 public: 7525 DECL_ACCESSORS(getter, Object) 7526 DECL_ACCESSORS(setter, Object) 7527 DECL_ACCESSORS(query, Object) 7528 DECL_ACCESSORS(deleter, Object) 7529 DECL_ACCESSORS(enumerator, Object) 7530 DECL_ACCESSORS(data, Object) 7531 7532 static inline InterceptorInfo* cast(Object* obj); 7533 7534#ifdef OBJECT_PRINT 7535 inline void InterceptorInfoPrint() { 7536 InterceptorInfoPrint(stdout); 7537 } 7538 void InterceptorInfoPrint(FILE* out); 7539#endif 7540#ifdef DEBUG 7541 void InterceptorInfoVerify(); 7542#endif 7543 7544 static const int kGetterOffset = HeapObject::kHeaderSize; 7545 static const int kSetterOffset = kGetterOffset + kPointerSize; 7546 static const int kQueryOffset = kSetterOffset + kPointerSize; 7547 static const int kDeleterOffset = kQueryOffset + kPointerSize; 7548 static const int kEnumeratorOffset = kDeleterOffset + kPointerSize; 7549 static const int kDataOffset = kEnumeratorOffset + kPointerSize; 7550 static const int kSize = kDataOffset + kPointerSize; 7551 7552 private: 7553 DISALLOW_IMPLICIT_CONSTRUCTORS(InterceptorInfo); 7554}; 7555 7556 7557class CallHandlerInfo: public Struct { 7558 public: 7559 DECL_ACCESSORS(callback, Object) 7560 DECL_ACCESSORS(data, Object) 7561 7562 static inline CallHandlerInfo* cast(Object* obj); 7563 7564#ifdef OBJECT_PRINT 7565 inline void CallHandlerInfoPrint() { 7566 CallHandlerInfoPrint(stdout); 7567 } 7568 void CallHandlerInfoPrint(FILE* out); 7569#endif 7570#ifdef DEBUG 7571 void CallHandlerInfoVerify(); 7572#endif 7573 7574 static const int kCallbackOffset = HeapObject::kHeaderSize; 7575 static const int kDataOffset = kCallbackOffset + kPointerSize; 7576 static const int kSize = kDataOffset + kPointerSize; 7577 7578 private: 7579 DISALLOW_IMPLICIT_CONSTRUCTORS(CallHandlerInfo); 7580}; 7581 7582 7583class TemplateInfo: public Struct { 7584 public: 7585 DECL_ACCESSORS(tag, Object) 7586 DECL_ACCESSORS(property_list, Object) 7587 7588#ifdef DEBUG 7589 void TemplateInfoVerify(); 7590#endif 7591 7592 static const int kTagOffset = HeapObject::kHeaderSize; 7593 static const int kPropertyListOffset = kTagOffset + kPointerSize; 7594 static const int kHeaderSize = kPropertyListOffset + kPointerSize; 7595 protected: 7596 DISALLOW_IMPLICIT_CONSTRUCTORS(TemplateInfo); 7597}; 7598 7599 7600class FunctionTemplateInfo: public TemplateInfo { 7601 public: 7602 DECL_ACCESSORS(serial_number, Object) 7603 DECL_ACCESSORS(call_code, Object) 7604 DECL_ACCESSORS(property_accessors, Object) 7605 DECL_ACCESSORS(prototype_template, Object) 7606 DECL_ACCESSORS(parent_template, Object) 7607 DECL_ACCESSORS(named_property_handler, Object) 7608 DECL_ACCESSORS(indexed_property_handler, Object) 7609 DECL_ACCESSORS(instance_template, Object) 7610 DECL_ACCESSORS(class_name, Object) 7611 DECL_ACCESSORS(signature, Object) 7612 DECL_ACCESSORS(instance_call_handler, Object) 7613 DECL_ACCESSORS(access_check_info, Object) 7614 DECL_ACCESSORS(flag, Smi) 7615 7616 // Following properties use flag bits. 7617 DECL_BOOLEAN_ACCESSORS(hidden_prototype) 7618 DECL_BOOLEAN_ACCESSORS(undetectable) 7619 // If the bit is set, object instances created by this function 7620 // requires access check. 7621 DECL_BOOLEAN_ACCESSORS(needs_access_check) 7622 DECL_BOOLEAN_ACCESSORS(read_only_prototype) 7623 7624 static inline FunctionTemplateInfo* cast(Object* obj); 7625 7626#ifdef OBJECT_PRINT 7627 inline void FunctionTemplateInfoPrint() { 7628 FunctionTemplateInfoPrint(stdout); 7629 } 7630 void FunctionTemplateInfoPrint(FILE* out); 7631#endif 7632#ifdef DEBUG 7633 void FunctionTemplateInfoVerify(); 7634#endif 7635 7636 static const int kSerialNumberOffset = TemplateInfo::kHeaderSize; 7637 static const int kCallCodeOffset = kSerialNumberOffset + kPointerSize; 7638 static const int kPropertyAccessorsOffset = kCallCodeOffset + kPointerSize; 7639 static const int kPrototypeTemplateOffset = 7640 kPropertyAccessorsOffset + kPointerSize; 7641 static const int kParentTemplateOffset = 7642 kPrototypeTemplateOffset + kPointerSize; 7643 static const int kNamedPropertyHandlerOffset = 7644 kParentTemplateOffset + kPointerSize; 7645 static const int kIndexedPropertyHandlerOffset = 7646 kNamedPropertyHandlerOffset + kPointerSize; 7647 static const int kInstanceTemplateOffset = 7648 kIndexedPropertyHandlerOffset + kPointerSize; 7649 static const int kClassNameOffset = kInstanceTemplateOffset + kPointerSize; 7650 static const int kSignatureOffset = kClassNameOffset + kPointerSize; 7651 static const int kInstanceCallHandlerOffset = kSignatureOffset + kPointerSize; 7652 static const int kAccessCheckInfoOffset = 7653 kInstanceCallHandlerOffset + kPointerSize; 7654 static const int kFlagOffset = kAccessCheckInfoOffset + kPointerSize; 7655 static const int kSize = kFlagOffset + kPointerSize; 7656 7657 private: 7658 // Bit position in the flag, from least significant bit position. 7659 static const int kHiddenPrototypeBit = 0; 7660 static const int kUndetectableBit = 1; 7661 static const int kNeedsAccessCheckBit = 2; 7662 static const int kReadOnlyPrototypeBit = 3; 7663 7664 DISALLOW_IMPLICIT_CONSTRUCTORS(FunctionTemplateInfo); 7665}; 7666 7667 7668class ObjectTemplateInfo: public TemplateInfo { 7669 public: 7670 DECL_ACCESSORS(constructor, Object) 7671 DECL_ACCESSORS(internal_field_count, Object) 7672 7673 static inline ObjectTemplateInfo* cast(Object* obj); 7674 7675#ifdef OBJECT_PRINT 7676 inline void ObjectTemplateInfoPrint() { 7677 ObjectTemplateInfoPrint(stdout); 7678 } 7679 void ObjectTemplateInfoPrint(FILE* out); 7680#endif 7681#ifdef DEBUG 7682 void ObjectTemplateInfoVerify(); 7683#endif 7684 7685 static const int kConstructorOffset = TemplateInfo::kHeaderSize; 7686 static const int kInternalFieldCountOffset = 7687 kConstructorOffset + kPointerSize; 7688 static const int kSize = kInternalFieldCountOffset + kPointerSize; 7689}; 7690 7691 7692class SignatureInfo: public Struct { 7693 public: 7694 DECL_ACCESSORS(receiver, Object) 7695 DECL_ACCESSORS(args, Object) 7696 7697 static inline SignatureInfo* cast(Object* obj); 7698 7699#ifdef OBJECT_PRINT 7700 inline void SignatureInfoPrint() { 7701 SignatureInfoPrint(stdout); 7702 } 7703 void SignatureInfoPrint(FILE* out); 7704#endif 7705#ifdef DEBUG 7706 void SignatureInfoVerify(); 7707#endif 7708 7709 static const int kReceiverOffset = Struct::kHeaderSize; 7710 static const int kArgsOffset = kReceiverOffset + kPointerSize; 7711 static const int kSize = kArgsOffset + kPointerSize; 7712 7713 private: 7714 DISALLOW_IMPLICIT_CONSTRUCTORS(SignatureInfo); 7715}; 7716 7717 7718class TypeSwitchInfo: public Struct { 7719 public: 7720 DECL_ACCESSORS(types, Object) 7721 7722 static inline TypeSwitchInfo* cast(Object* obj); 7723 7724#ifdef OBJECT_PRINT 7725 inline void TypeSwitchInfoPrint() { 7726 TypeSwitchInfoPrint(stdout); 7727 } 7728 void TypeSwitchInfoPrint(FILE* out); 7729#endif 7730#ifdef DEBUG 7731 void TypeSwitchInfoVerify(); 7732#endif 7733 7734 static const int kTypesOffset = Struct::kHeaderSize; 7735 static const int kSize = kTypesOffset + kPointerSize; 7736}; 7737 7738 7739#ifdef ENABLE_DEBUGGER_SUPPORT 7740// The DebugInfo class holds additional information for a function being 7741// debugged. 7742class DebugInfo: public Struct { 7743 public: 7744 // The shared function info for the source being debugged. 7745 DECL_ACCESSORS(shared, SharedFunctionInfo) 7746 // Code object for the original code. 7747 DECL_ACCESSORS(original_code, Code) 7748 // Code object for the patched code. This code object is the code object 7749 // currently active for the function. 7750 DECL_ACCESSORS(code, Code) 7751 // Fixed array holding status information for each active break point. 7752 DECL_ACCESSORS(break_points, FixedArray) 7753 7754 // Check if there is a break point at a code position. 7755 bool HasBreakPoint(int code_position); 7756 // Get the break point info object for a code position. 7757 Object* GetBreakPointInfo(int code_position); 7758 // Clear a break point. 7759 static void ClearBreakPoint(Handle<DebugInfo> debug_info, 7760 int code_position, 7761 Handle<Object> break_point_object); 7762 // Set a break point. 7763 static void SetBreakPoint(Handle<DebugInfo> debug_info, int code_position, 7764 int source_position, int statement_position, 7765 Handle<Object> break_point_object); 7766 // Get the break point objects for a code position. 7767 Object* GetBreakPointObjects(int code_position); 7768 // Find the break point info holding this break point object. 7769 static Object* FindBreakPointInfo(Handle<DebugInfo> debug_info, 7770 Handle<Object> break_point_object); 7771 // Get the number of break points for this function. 7772 int GetBreakPointCount(); 7773 7774 static inline DebugInfo* cast(Object* obj); 7775 7776#ifdef OBJECT_PRINT 7777 inline void DebugInfoPrint() { 7778 DebugInfoPrint(stdout); 7779 } 7780 void DebugInfoPrint(FILE* out); 7781#endif 7782#ifdef DEBUG 7783 void DebugInfoVerify(); 7784#endif 7785 7786 static const int kSharedFunctionInfoIndex = Struct::kHeaderSize; 7787 static const int kOriginalCodeIndex = kSharedFunctionInfoIndex + kPointerSize; 7788 static const int kPatchedCodeIndex = kOriginalCodeIndex + kPointerSize; 7789 static const int kActiveBreakPointsCountIndex = 7790 kPatchedCodeIndex + kPointerSize; 7791 static const int kBreakPointsStateIndex = 7792 kActiveBreakPointsCountIndex + kPointerSize; 7793 static const int kSize = kBreakPointsStateIndex + kPointerSize; 7794 7795 private: 7796 static const int kNoBreakPointInfo = -1; 7797 7798 // Lookup the index in the break_points array for a code position. 7799 int GetBreakPointInfoIndex(int code_position); 7800 7801 DISALLOW_IMPLICIT_CONSTRUCTORS(DebugInfo); 7802}; 7803 7804 7805// The BreakPointInfo class holds information for break points set in a 7806// function. The DebugInfo object holds a BreakPointInfo object for each code 7807// position with one or more break points. 7808class BreakPointInfo: public Struct { 7809 public: 7810 // The position in the code for the break point. 7811 DECL_ACCESSORS(code_position, Smi) 7812 // The position in the source for the break position. 7813 DECL_ACCESSORS(source_position, Smi) 7814 // The position in the source for the last statement before this break 7815 // position. 7816 DECL_ACCESSORS(statement_position, Smi) 7817 // List of related JavaScript break points. 7818 DECL_ACCESSORS(break_point_objects, Object) 7819 7820 // Removes a break point. 7821 static void ClearBreakPoint(Handle<BreakPointInfo> info, 7822 Handle<Object> break_point_object); 7823 // Set a break point. 7824 static void SetBreakPoint(Handle<BreakPointInfo> info, 7825 Handle<Object> break_point_object); 7826 // Check if break point info has this break point object. 7827 static bool HasBreakPointObject(Handle<BreakPointInfo> info, 7828 Handle<Object> break_point_object); 7829 // Get the number of break points for this code position. 7830 int GetBreakPointCount(); 7831 7832 static inline BreakPointInfo* cast(Object* obj); 7833 7834#ifdef OBJECT_PRINT 7835 inline void BreakPointInfoPrint() { 7836 BreakPointInfoPrint(stdout); 7837 } 7838 void BreakPointInfoPrint(FILE* out); 7839#endif 7840#ifdef DEBUG 7841 void BreakPointInfoVerify(); 7842#endif 7843 7844 static const int kCodePositionIndex = Struct::kHeaderSize; 7845 static const int kSourcePositionIndex = kCodePositionIndex + kPointerSize; 7846 static const int kStatementPositionIndex = 7847 kSourcePositionIndex + kPointerSize; 7848 static const int kBreakPointObjectsIndex = 7849 kStatementPositionIndex + kPointerSize; 7850 static const int kSize = kBreakPointObjectsIndex + kPointerSize; 7851 7852 private: 7853 DISALLOW_IMPLICIT_CONSTRUCTORS(BreakPointInfo); 7854}; 7855#endif // ENABLE_DEBUGGER_SUPPORT 7856 7857 7858#undef DECL_BOOLEAN_ACCESSORS 7859#undef DECL_ACCESSORS 7860 7861 7862// Abstract base class for visiting, and optionally modifying, the 7863// pointers contained in Objects. Used in GC and serialization/deserialization. 7864class ObjectVisitor BASE_EMBEDDED { 7865 public: 7866 virtual ~ObjectVisitor() {} 7867 7868 // Visits a contiguous arrays of pointers in the half-open range 7869 // [start, end). Any or all of the values may be modified on return. 7870 virtual void VisitPointers(Object** start, Object** end) = 0; 7871 7872 // To allow lazy clearing of inline caches the visitor has 7873 // a rich interface for iterating over Code objects.. 7874 7875 // Visits a code target in the instruction stream. 7876 virtual void VisitCodeTarget(RelocInfo* rinfo); 7877 7878 // Visits a code entry in a JS function. 7879 virtual void VisitCodeEntry(Address entry_address); 7880 7881 // Visits a global property cell reference in the instruction stream. 7882 virtual void VisitGlobalPropertyCell(RelocInfo* rinfo); 7883 7884 // Visits a runtime entry in the instruction stream. 7885 virtual void VisitRuntimeEntry(RelocInfo* rinfo) {} 7886 7887 // Visits the resource of an ASCII or two-byte string. 7888 virtual void VisitExternalAsciiString( 7889 v8::String::ExternalAsciiStringResource** resource) {} 7890 virtual void VisitExternalTwoByteString( 7891 v8::String::ExternalStringResource** resource) {} 7892 7893 // Visits a debug call target in the instruction stream. 7894 virtual void VisitDebugTarget(RelocInfo* rinfo); 7895 7896 // Handy shorthand for visiting a single pointer. 7897 virtual void VisitPointer(Object** p) { VisitPointers(p, p + 1); } 7898 7899 // Visit pointer embedded into a code object. 7900 virtual void VisitEmbeddedPointer(RelocInfo* rinfo); 7901 7902 // Visits a contiguous arrays of external references (references to the C++ 7903 // heap) in the half-open range [start, end). Any or all of the values 7904 // may be modified on return. 7905 virtual void VisitExternalReferences(Address* start, Address* end) {} 7906 7907 virtual void VisitExternalReference(RelocInfo* rinfo); 7908 7909 inline void VisitExternalReference(Address* p) { 7910 VisitExternalReferences(p, p + 1); 7911 } 7912 7913 // Visits a handle that has an embedder-assigned class ID. 7914 virtual void VisitEmbedderReference(Object** p, uint16_t class_id) {} 7915 7916#ifdef DEBUG 7917 // Intended for serialization/deserialization checking: insert, or 7918 // check for the presence of, a tag at this position in the stream. 7919 virtual void Synchronize(const char* tag) {} 7920#else 7921 inline void Synchronize(const char* tag) {} 7922#endif 7923}; 7924 7925 7926class StructBodyDescriptor : public 7927 FlexibleBodyDescriptor<HeapObject::kHeaderSize> { 7928 public: 7929 static inline int SizeOf(Map* map, HeapObject* object) { 7930 return map->instance_size(); 7931 } 7932}; 7933 7934 7935// BooleanBit is a helper class for setting and getting a bit in an 7936// integer or Smi. 7937class BooleanBit : public AllStatic { 7938 public: 7939 static inline bool get(Smi* smi, int bit_position) { 7940 return get(smi->value(), bit_position); 7941 } 7942 7943 static inline bool get(int value, int bit_position) { 7944 return (value & (1 << bit_position)) != 0; 7945 } 7946 7947 static inline Smi* set(Smi* smi, int bit_position, bool v) { 7948 return Smi::FromInt(set(smi->value(), bit_position, v)); 7949 } 7950 7951 static inline int set(int value, int bit_position, bool v) { 7952 if (v) { 7953 value |= (1 << bit_position); 7954 } else { 7955 value &= ~(1 << bit_position); 7956 } 7957 return value; 7958 } 7959}; 7960 7961} } // namespace v8::internal 7962 7963#endif // V8_OBJECTS_H_ 7964