runtime.js revision d91b9f7d46489a9ee00f9cb415630299c76a502b
1// Copyright 2006-2008 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// This files contains runtime support implemented in JavaScript. 29 30// CAUTION: Some of the functions specified in this file are called 31// directly from compiled code. These are the functions with names in 32// ALL CAPS. The compiled code passes the first argument in 'this' and 33// it does not push the function onto the stack. This means that you 34// cannot use contexts in all these functions. 35 36 37/* ----------------------------------- 38 - - - C o m p a r i s o n - - - 39 ----------------------------------- 40*/ 41 42// The following const declarations are shared with other native JS files. 43// They are all declared at this one spot to avoid const redeclaration errors. 44const $Object = global.Object; 45const $Array = global.Array; 46const $String = global.String; 47const $Number = global.Number; 48const $Function = global.Function; 49const $Boolean = global.Boolean; 50const $NaN = 0/0; 51 52 53// ECMA-262, section 11.9.1, page 55. 54function EQUALS(y) { 55 if (IS_STRING(this) && IS_STRING(y)) return %StringEquals(this, y); 56 var x = this; 57 58 // NOTE: We use iteration instead of recursion, because it is 59 // difficult to call EQUALS with the correct setting of 'this' in 60 // an efficient way. 61 while (true) { 62 if (IS_NUMBER(x)) { 63 if (y == null) return 1; // not equal 64 return %NumberEquals(x, %ToNumber(y)); 65 } else if (IS_STRING(x)) { 66 if (IS_STRING(y)) return %StringEquals(x, y); 67 if (IS_NUMBER(y)) return %NumberEquals(%ToNumber(x), y); 68 if (IS_BOOLEAN(y)) return %NumberEquals(%ToNumber(x), %ToNumber(y)); 69 if (y == null) return 1; // not equal 70 y = %ToPrimitive(y, NO_HINT); 71 } else if (IS_BOOLEAN(x)) { 72 if (IS_BOOLEAN(y)) { 73 return %_ObjectEquals(x, y) ? 0 : 1; 74 } 75 if (y == null) return 1; // not equal 76 return %NumberEquals(%ToNumber(x), %ToNumber(y)); 77 } else if (x == null) { 78 // NOTE: This checks for both null and undefined. 79 return (y == null) ? 0 : 1; 80 } else { 81 // x is not a number, boolean, null or undefined. 82 if (y == null) return 1; // not equal 83 if (IS_OBJECT(y)) { 84 return %_ObjectEquals(x, y) ? 0 : 1; 85 } 86 if (IS_FUNCTION(y)) { 87 return %_ObjectEquals(x, y) ? 0 : 1; 88 } 89 90 x = %ToPrimitive(x, NO_HINT); 91 } 92 } 93} 94 95// ECMA-262, section 11.9.4, page 56. 96function STRICT_EQUALS(x) { 97 if (IS_STRING(this)) { 98 if (!IS_STRING(x)) return 1; // not equal 99 return %StringEquals(this, x); 100 } 101 102 if (IS_NUMBER(this)) { 103 if (!IS_NUMBER(x)) return 1; // not equal 104 return %NumberEquals(this, x); 105 } 106 107 // If anything else gets here, we just do simple identity check. 108 // Objects (including functions), null, undefined and booleans were 109 // checked in the CompareStub, so there should be nothing left. 110 return %_ObjectEquals(this, x) ? 0 : 1; 111} 112 113 114// ECMA-262, section 11.8.5, page 53. The 'ncr' parameter is used as 115// the result when either (or both) the operands are NaN. 116function COMPARE(x, ncr) { 117 var left; 118 119 // Fast cases for string, numbers and undefined compares. 120 if (IS_STRING(this)) { 121 if (IS_STRING(x)) return %_StringCompare(this, x); 122 if (IS_UNDEFINED(x)) return ncr; 123 left = this; 124 } else if (IS_NUMBER(this)) { 125 if (IS_NUMBER(x)) return %NumberCompare(this, x, ncr); 126 if (IS_UNDEFINED(x)) return ncr; 127 left = this; 128 } else if (IS_UNDEFINED(this)) { 129 return ncr; 130 } else { 131 if (IS_UNDEFINED(x)) return ncr; 132 left = %ToPrimitive(this, NUMBER_HINT); 133 } 134 135 // Default implementation. 136 var right = %ToPrimitive(x, NUMBER_HINT); 137 if (IS_STRING(left) && IS_STRING(right)) { 138 return %_StringCompare(left, right); 139 } else { 140 var left_number = %ToNumber(left); 141 var right_number = %ToNumber(right); 142 if (NUMBER_IS_NAN(left_number) || NUMBER_IS_NAN(right_number)) return ncr; 143 return %NumberCompare(left_number, right_number, ncr); 144 } 145} 146 147 148 149/* ----------------------------------- 150 - - - A r i t h m e t i c - - - 151 ----------------------------------- 152*/ 153 154// ECMA-262, section 11.6.1, page 50. 155function ADD(x) { 156 // Fast case: Check for number operands and do the addition. 157 if (IS_NUMBER(this) && IS_NUMBER(x)) return %NumberAdd(this, x); 158 if (IS_STRING(this) && IS_STRING(x)) return %_StringAdd(this, x); 159 160 // Default implementation. 161 var a = %ToPrimitive(this, NO_HINT); 162 var b = %ToPrimitive(x, NO_HINT); 163 164 if (IS_STRING(a)) { 165 return %_StringAdd(a, %ToString(b)); 166 } else if (IS_STRING(b)) { 167 return %_StringAdd(%ToString(a), b); 168 } else { 169 return %NumberAdd(%ToNumber(a), %ToNumber(b)); 170 } 171} 172 173 174// Left operand (this) is already a string. 175function STRING_ADD_LEFT(y) { 176 if (!IS_STRING(y)) { 177 if (IS_STRING_WRAPPER(y)) { 178 y = %_ValueOf(y); 179 } else { 180 y = IS_NUMBER(y) 181 ? %NumberToString(y) 182 : %ToString(%ToPrimitive(y, NO_HINT)); 183 } 184 } 185 return %_StringAdd(this, y); 186} 187 188 189// Right operand (y) is already a string. 190function STRING_ADD_RIGHT(y) { 191 var x = this; 192 if (!IS_STRING(x)) { 193 if (IS_STRING_WRAPPER(x)) { 194 x = %_ValueOf(x); 195 } else { 196 x = IS_NUMBER(x) 197 ? %NumberToString(x) 198 : %ToString(%ToPrimitive(x, NO_HINT)); 199 } 200 } 201 return %_StringAdd(x, y); 202} 203 204 205// ECMA-262, section 11.6.2, page 50. 206function SUB(y) { 207 var x = IS_NUMBER(this) ? this : %ToNumber(this); 208 if (!IS_NUMBER(y)) y = %ToNumber(y); 209 return %NumberSub(x, y); 210} 211 212 213// ECMA-262, section 11.5.1, page 48. 214function MUL(y) { 215 var x = IS_NUMBER(this) ? this : %ToNumber(this); 216 if (!IS_NUMBER(y)) y = %ToNumber(y); 217 return %NumberMul(x, y); 218} 219 220 221// ECMA-262, section 11.5.2, page 49. 222function DIV(y) { 223 var x = IS_NUMBER(this) ? this : %ToNumber(this); 224 if (!IS_NUMBER(y)) y = %ToNumber(y); 225 return %NumberDiv(x, y); 226} 227 228 229// ECMA-262, section 11.5.3, page 49. 230function MOD(y) { 231 var x = IS_NUMBER(this) ? this : %ToNumber(this); 232 if (!IS_NUMBER(y)) y = %ToNumber(y); 233 return %NumberMod(x, y); 234} 235 236 237 238/* ------------------------------------------- 239 - - - B i t o p e r a t i o n s - - - 240 ------------------------------------------- 241*/ 242 243// ECMA-262, section 11.10, page 57. 244function BIT_OR(y) { 245 var x = IS_NUMBER(this) ? this : %ToNumber(this); 246 if (!IS_NUMBER(y)) y = %ToNumber(y); 247 return %NumberOr(x, y); 248} 249 250 251// ECMA-262, section 11.10, page 57. 252function BIT_AND(y) { 253 var x; 254 if (IS_NUMBER(this)) { 255 x = this; 256 if (!IS_NUMBER(y)) y = %ToNumber(y); 257 } else { 258 x = %ToNumber(this); 259 // Make sure to convert the right operand to a number before 260 // bailing out in the fast case, but after converting the 261 // left operand. This ensures that valueOf methods on the right 262 // operand are always executed. 263 if (!IS_NUMBER(y)) y = %ToNumber(y); 264 // Optimize for the case where we end up AND'ing a value 265 // that doesn't convert to a number. This is common in 266 // certain benchmarks. 267 if (NUMBER_IS_NAN(x)) return 0; 268 } 269 return %NumberAnd(x, y); 270} 271 272 273// ECMA-262, section 11.10, page 57. 274function BIT_XOR(y) { 275 var x = IS_NUMBER(this) ? this : %ToNumber(this); 276 if (!IS_NUMBER(y)) y = %ToNumber(y); 277 return %NumberXor(x, y); 278} 279 280 281// ECMA-262, section 11.4.7, page 47. 282function UNARY_MINUS() { 283 var x = IS_NUMBER(this) ? this : %ToNumber(this); 284 return %NumberUnaryMinus(x); 285} 286 287 288// ECMA-262, section 11.4.8, page 48. 289function BIT_NOT() { 290 var x = IS_NUMBER(this) ? this : %ToNumber(this); 291 return %NumberNot(x); 292} 293 294 295// ECMA-262, section 11.7.1, page 51. 296function SHL(y) { 297 var x = IS_NUMBER(this) ? this : %ToNumber(this); 298 if (!IS_NUMBER(y)) y = %ToNumber(y); 299 return %NumberShl(x, y); 300} 301 302 303// ECMA-262, section 11.7.2, page 51. 304function SAR(y) { 305 var x; 306 if (IS_NUMBER(this)) { 307 x = this; 308 if (!IS_NUMBER(y)) y = %ToNumber(y); 309 } else { 310 x = %ToNumber(this); 311 // Make sure to convert the right operand to a number before 312 // bailing out in the fast case, but after converting the 313 // left operand. This ensures that valueOf methods on the right 314 // operand are always executed. 315 if (!IS_NUMBER(y)) y = %ToNumber(y); 316 // Optimize for the case where we end up shifting a value 317 // that doesn't convert to a number. This is common in 318 // certain benchmarks. 319 if (NUMBER_IS_NAN(x)) return 0; 320 } 321 return %NumberSar(x, y); 322} 323 324 325// ECMA-262, section 11.7.3, page 52. 326function SHR(y) { 327 var x = IS_NUMBER(this) ? this : %ToNumber(this); 328 if (!IS_NUMBER(y)) y = %ToNumber(y); 329 return %NumberShr(x, y); 330} 331 332 333 334/* ----------------------------- 335 - - - H e l p e r s - - - 336 ----------------------------- 337*/ 338 339// ECMA-262, section 11.4.1, page 46. 340function DELETE(key) { 341 return %DeleteProperty(%ToObject(this), %ToString(key)); 342} 343 344 345// ECMA-262, section 11.8.7, page 54. 346function IN(x) { 347 if (x == null || (!IS_OBJECT(x) && !IS_FUNCTION(x))) { 348 throw %MakeTypeError('invalid_in_operator_use', [this, x]); 349 } 350 return %_IsNonNegativeSmi(this) ? %HasElement(x, this) : %HasProperty(x, %ToString(this)); 351} 352 353 354// ECMA-262, section 11.8.6, page 54. To make the implementation more 355// efficient, the return value should be zero if the 'this' is an 356// instance of F, and non-zero if not. This makes it possible to avoid 357// an expensive ToBoolean conversion in the generated code. 358function INSTANCE_OF(F) { 359 var V = this; 360 if (!IS_FUNCTION(F)) { 361 throw %MakeTypeError('instanceof_function_expected', [V]); 362 } 363 364 // If V is not an object, return false. 365 if (IS_NULL(V) || (!IS_OBJECT(V) && !IS_FUNCTION(V))) { 366 return 1; 367 } 368 369 // Get the prototype of F; if it is not an object, throw an error. 370 var O = F.prototype; 371 if (IS_NULL(O) || (!IS_OBJECT(O) && !IS_FUNCTION(O))) { 372 throw %MakeTypeError('instanceof_nonobject_proto', [O]); 373 } 374 375 // Return whether or not O is in the prototype chain of V. 376 return %IsInPrototypeChain(O, V) ? 0 : 1; 377} 378 379 380// Get an array of property keys for the given object. Used in 381// for-in statements. 382function GET_KEYS() { 383 return %GetPropertyNames(this); 384} 385 386 387// Filter a given key against an object by checking if the object 388// has a property with the given key; return the key as a string if 389// it has. Otherwise returns null. Used in for-in statements. 390function FILTER_KEY(key) { 391 var string = %ToString(key); 392 if (%HasProperty(this, string)) return string; 393 return null; 394} 395 396 397function CALL_NON_FUNCTION() { 398 var callee = %GetCalledFunction(); 399 var delegate = %GetFunctionDelegate(callee); 400 if (!IS_FUNCTION(delegate)) { 401 throw %MakeTypeError('called_non_callable', [typeof callee]); 402 } 403 404 var parameters = %NewArguments(delegate); 405 return delegate.apply(callee, parameters); 406} 407 408 409function CALL_NON_FUNCTION_AS_CONSTRUCTOR() { 410 var callee = %GetCalledFunction(); 411 var delegate = %GetConstructorDelegate(callee); 412 if (!IS_FUNCTION(delegate)) { 413 throw %MakeTypeError('called_non_callable', [typeof callee]); 414 } 415 416 var parameters = %NewArguments(delegate); 417 return delegate.apply(callee, parameters); 418} 419 420 421function APPLY_PREPARE(args) { 422 var length; 423 // First check whether length is a positive Smi and args is an 424 // array. This is the fast case. If this fails, we do the slow case 425 // that takes care of more eventualities. 426 if (IS_ARRAY(args)) { 427 length = args.length; 428 if (%_IsSmi(length) && length >= 0 && length < 0x800000 && IS_FUNCTION(this)) { 429 return length; 430 } 431 } 432 433 length = (args == null) ? 0 : %ToUint32(args.length); 434 435 // We can handle any number of apply arguments if the stack is 436 // big enough, but sanity check the value to avoid overflow when 437 // multiplying with pointer size. 438 if (length > 0x800000) { 439 throw %MakeRangeError('apply_overflow', [length]); 440 } 441 442 if (!IS_FUNCTION(this)) { 443 throw %MakeTypeError('apply_non_function', [ %ToString(this), typeof this ]); 444 } 445 446 // Make sure the arguments list has the right type. 447 if (args != null && !IS_ARRAY(args) && !IS_ARGUMENTS(args)) { 448 throw %MakeTypeError('apply_wrong_args', []); 449 } 450 451 // Return the length which is the number of arguments to copy to the 452 // stack. It is guaranteed to be a small integer at this point. 453 return length; 454} 455 456 457function APPLY_OVERFLOW(length) { 458 throw %MakeRangeError('apply_overflow', [length]); 459} 460 461 462// Convert the receiver to an object - forward to ToObject. 463function TO_OBJECT() { 464 return %ToObject(this); 465} 466 467 468// Convert the receiver to a number - forward to ToNumber. 469function TO_NUMBER() { 470 return %ToNumber(this); 471} 472 473 474// Convert the receiver to a string - forward to ToString. 475function TO_STRING() { 476 return %ToString(this); 477} 478 479 480// Specialized version of String.charAt. It assumes string as 481// the receiver type and that the index is a number. 482function STRING_CHAR_AT(pos) { 483 var char_code = %_FastCharCodeAt(this, pos); 484 if (!%_IsSmi(char_code)) { 485 return %StringCharAt(this, pos); 486 } 487 return %CharFromCode(char_code); 488} 489 490 491/* ------------------------------------- 492 - - - C o n v e r s i o n s - - - 493 ------------------------------------- 494*/ 495 496// ECMA-262, section 9.1, page 30. Use null/undefined for no hint, 497// (1) for number hint, and (2) for string hint. 498function ToPrimitive(x, hint) { 499 // Fast case check. 500 if (IS_STRING(x)) return x; 501 // Normal behavior. 502 if (!IS_OBJECT(x) && !IS_FUNCTION(x)) return x; 503 if (x == null) return x; // check for null, undefined 504 if (hint == NO_HINT) hint = (IS_DATE(x)) ? STRING_HINT : NUMBER_HINT; 505 return (hint == NUMBER_HINT) ? %DefaultNumber(x) : %DefaultString(x); 506} 507 508 509// ECMA-262, section 9.3, page 31. 510function ToNumber(x) { 511 if (IS_NUMBER(x)) return x; 512 if (IS_STRING(x)) return %StringToNumber(x); 513 if (IS_BOOLEAN(x)) return x ? 1 : 0; 514 if (IS_UNDEFINED(x)) return $NaN; 515 return (IS_NULL(x)) ? 0 : ToNumber(%DefaultNumber(x)); 516} 517 518 519// ECMA-262, section 9.8, page 35. 520function ToString(x) { 521 if (IS_STRING(x)) return x; 522 if (IS_NUMBER(x)) return %NumberToString(x); 523 if (IS_BOOLEAN(x)) return x ? 'true' : 'false'; 524 if (IS_UNDEFINED(x)) return 'undefined'; 525 return (IS_NULL(x)) ? 'null' : %ToString(%DefaultString(x)); 526} 527 528 529// ... where did this come from? 530function ToBoolean(x) { 531 if (IS_BOOLEAN(x)) return x; 532 if (IS_STRING(x)) return x.length != 0; 533 if (x == null) return false; 534 if (IS_NUMBER(x)) return !((x == 0) || NUMBER_IS_NAN(x)); 535 return true; 536} 537 538 539// ECMA-262, section 9.9, page 36. 540function ToObject(x) { 541 if (IS_STRING(x)) return new $String(x); 542 if (IS_NUMBER(x)) return new $Number(x); 543 if (IS_BOOLEAN(x)) return new $Boolean(x); 544 if (IS_NULL_OR_UNDEFINED(x) && !IS_UNDETECTABLE(x)) { 545 throw %MakeTypeError('null_to_object', []); 546 } 547 return x; 548} 549 550 551// ECMA-262, section 9.4, page 34. 552function ToInteger(x) { 553 if (%_IsSmi(x)) return x; 554 return %NumberToInteger(ToNumber(x)); 555} 556 557 558// ECMA-262, section 9.6, page 34. 559function ToUint32(x) { 560 if (%_IsSmi(x) && x >= 0) return x; 561 return %NumberToJSUint32(ToNumber(x)); 562} 563 564 565// ECMA-262, section 9.5, page 34 566function ToInt32(x) { 567 if (%_IsSmi(x)) return x; 568 return %NumberToJSInt32(ToNumber(x)); 569} 570 571 572 573/* --------------------------------- 574 - - - U t i l i t i e s - - - 575 --------------------------------- 576*/ 577 578// Returns if the given x is a primitive value - not an object or a 579// function. 580function IsPrimitive(x) { 581 if (!IS_OBJECT(x) && !IS_FUNCTION(x)) { 582 return true; 583 } else { 584 // Even though the type of null is "object", null is still 585 // considered a primitive value. 586 return IS_NULL(x); 587 } 588} 589 590 591// ECMA-262, section 8.6.2.6, page 28. 592function DefaultNumber(x) { 593 if (IS_FUNCTION(x.valueOf)) { 594 var v = x.valueOf(); 595 if (%IsPrimitive(v)) return v; 596 } 597 598 if (IS_FUNCTION(x.toString)) { 599 var s = x.toString(); 600 if (%IsPrimitive(s)) return s; 601 } 602 603 throw %MakeTypeError('cannot_convert_to_primitive', []); 604} 605 606 607// ECMA-262, section 8.6.2.6, page 28. 608function DefaultString(x) { 609 if (IS_FUNCTION(x.toString)) { 610 var s = x.toString(); 611 if (%IsPrimitive(s)) return s; 612 } 613 614 if (IS_FUNCTION(x.valueOf)) { 615 var v = x.valueOf(); 616 if (%IsPrimitive(v)) return v; 617 } 618 619 throw %MakeTypeError('cannot_convert_to_primitive', []); 620} 621 622 623// NOTE: Setting the prototype for Array must take place as early as 624// possible due to code generation for array literals. When 625// generating code for a array literal a boilerplate array is created 626// that is cloned when running the code. It is essiential that the 627// boilerplate gets the right prototype. 628%FunctionSetPrototype($Array, new $Array(0)); 629