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 declarations are shared with other native JS files. 43 // They are all declared at this one spot to avoid redeclaration errors. 44 var $Object = global.Object; 45 var $Array = global.Array; 46 var $String = global.String; 47 var $Number = global.Number; 48 var $Function = global.Function; 49 var $Boolean = global.Boolean; 50 var $NaN = %GetRootNaN(); 51 var builtins = this; 52 53 // ECMA-262 Section 11.9.3. 54 function EQUALS(y) { 55 if (IS_STRING(this) && IS_STRING(y)) return %StringEquals(this, y); 56 var x = this; 57 58 while (true) { 59 if (IS_NUMBER(x)) { 60 while (true) { 61 if (IS_NUMBER(y)) return %NumberEquals(x, y); 62 if (IS_NULL_OR_UNDEFINED(y)) return 1; // not equal 63 if (!IS_SPEC_OBJECT(y)) { 64 // String or boolean. 65 return %NumberEquals(x, %ToNumber(y)); 66 } 67 y = %ToPrimitive(y, NO_HINT); 68 } 69 } else if (IS_STRING(x)) { 70 while (true) { 71 if (IS_STRING(y)) return %StringEquals(x, y); 72 if (IS_SYMBOL(y)) return 1; // not equal 73 if (IS_NUMBER(y)) return %NumberEquals(%ToNumber(x), y); 74 if (IS_BOOLEAN(y)) return %NumberEquals(%ToNumber(x), %ToNumber(y)); 75 if (IS_NULL_OR_UNDEFINED(y)) return 1; // not equal 76 y = %ToPrimitive(y, NO_HINT); 77 } 78 } else if (IS_SYMBOL(x)) { 79 while (true) { 80 if (IS_SYMBOL(y)) return %_ObjectEquals(x, y) ? 0 : 1; 81 if (!IS_SPEC_OBJECT(y)) return 1; // not equal 82 y = %ToPrimitive(y, NO_HINT); 83 } 84 } else if (IS_BOOLEAN(x)) { 85 if (IS_BOOLEAN(y)) return %_ObjectEquals(x, y) ? 0 : 1; 86 if (IS_NULL_OR_UNDEFINED(y)) return 1; 87 if (IS_NUMBER(y)) return %NumberEquals(%ToNumber(x), y); 88 if (IS_STRING(y)) return %NumberEquals(%ToNumber(x), %ToNumber(y)); 89 if (IS_SYMBOL(y)) return 1; // not equal 90 // y is object. 91 x = %ToNumber(x); 92 y = %ToPrimitive(y, NO_HINT); 93 } else if (IS_NULL_OR_UNDEFINED(x)) { 94 return IS_NULL_OR_UNDEFINED(y) ? 0 : 1; 95 } else { 96 // x is an object. 97 if (IS_SPEC_OBJECT(y)) { 98 return %_ObjectEquals(x, y) ? 0 : 1; 99 } 100 if (IS_NULL_OR_UNDEFINED(y)) return 1; // not equal 101 if (IS_BOOLEAN(y)) y = %ToNumber(y); 102 x = %ToPrimitive(x, NO_HINT); 103 } 104 } 105 } 106 107 // ECMA-262, section 11.9.4, page 56. 108 function STRICT_EQUALS(x) { 109 if (IS_STRING(this)) { 110 if (!IS_STRING(x)) return 1; // not equal 111 return %StringEquals(this, x); 112 } 113 114 if (IS_NUMBER(this)) { 115 if (!IS_NUMBER(x)) return 1; // not equal 116 return %NumberEquals(this, x); 117 } 118 119 // If anything else gets here, we just do simple identity check. 120 // Objects (including functions), null, undefined and booleans were 121 // checked in the CompareStub, so there should be nothing left. 122 return %_ObjectEquals(this, x) ? 0 : 1; 123 } 124 125 126 // ECMA-262, section 11.8.5, page 53. The 'ncr' parameter is used as 127 // the result when either (or both) the operands are NaN. 128 function COMPARE(x, ncr) { 129 var left; 130 var right; 131 // Fast cases for string, numbers and undefined compares. 132 if (IS_STRING(this)) { 133 if (IS_STRING(x)) return %_StringCompare(this, x); 134 if (IS_UNDEFINED(x)) return ncr; 135 left = this; 136 } else if (IS_NUMBER(this)) { 137 if (IS_NUMBER(x)) return %NumberCompare(this, x, ncr); 138 if (IS_UNDEFINED(x)) return ncr; 139 left = this; 140 } else if (IS_UNDEFINED(this)) { 141 if (!IS_UNDEFINED(x)) { 142 %ToPrimitive(x, NUMBER_HINT); 143 } 144 return ncr; 145 } else if (IS_UNDEFINED(x)) { 146 %ToPrimitive(this, NUMBER_HINT); 147 return ncr; 148 } else { 149 left = %ToPrimitive(this, NUMBER_HINT); 150 } 151 152 right = %ToPrimitive(x, NUMBER_HINT); 153 if (IS_STRING(left) && IS_STRING(right)) { 154 return %_StringCompare(left, right); 155 } else { 156 var left_number = %ToNumber(left); 157 var right_number = %ToNumber(right); 158 if (NUMBER_IS_NAN(left_number) || NUMBER_IS_NAN(right_number)) return ncr; 159 return %NumberCompare(left_number, right_number, ncr); 160 } 161 } 162 163 164 165 /* ----------------------------------- 166 - - - A r i t h m e t i c - - - 167 ----------------------------------- 168 */ 169 170 // ECMA-262, section 11.6.1, page 50. 171 function ADD(x) { 172 // Fast case: Check for number operands and do the addition. 173 if (IS_NUMBER(this) && IS_NUMBER(x)) return %NumberAdd(this, x); 174 if (IS_STRING(this) && IS_STRING(x)) return %_StringAdd(this, x); 175 176 // Default implementation. 177 var a = %ToPrimitive(this, NO_HINT); 178 var b = %ToPrimitive(x, NO_HINT); 179 180 if (IS_STRING(a)) { 181 return %_StringAdd(a, %ToString(b)); 182 } else if (IS_STRING(b)) { 183 return %_StringAdd(%NonStringToString(a), b); 184 } else { 185 return %NumberAdd(%ToNumber(a), %ToNumber(b)); 186 } 187 } 188 189 190 // Left operand (this) is already a string. 191 function STRING_ADD_LEFT(y) { 192 if (!IS_STRING(y)) { 193 if (IS_STRING_WRAPPER(y) && %_IsStringWrapperSafeForDefaultValueOf(y)) { 194 y = %_ValueOf(y); 195 } else { 196 y = IS_NUMBER(y) 197 ? %_NumberToString(y) 198 : %ToString(%ToPrimitive(y, NO_HINT)); 199 } 200 } 201 return %_StringAdd(this, y); 202 } 203 204 205 // Right operand (y) is already a string. 206 function STRING_ADD_RIGHT(y) { 207 var x = this; 208 if (!IS_STRING(x)) { 209 if (IS_STRING_WRAPPER(x) && %_IsStringWrapperSafeForDefaultValueOf(x)) { 210 x = %_ValueOf(x); 211 } else { 212 x = IS_NUMBER(x) 213 ? %_NumberToString(x) 214 : %ToString(%ToPrimitive(x, NO_HINT)); 215 } 216 } 217 return %_StringAdd(x, y); 218 } 219 220 221 // ECMA-262, section 11.6.2, page 50. 222 function SUB(y) { 223 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); 224 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 225 return %NumberSub(x, y); 226 } 227 228 229 // ECMA-262, section 11.5.1, page 48. 230 function MUL(y) { 231 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); 232 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 233 return %NumberMul(x, y); 234 } 235 236 237 // ECMA-262, section 11.5.2, page 49. 238 function DIV(y) { 239 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); 240 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 241 return %NumberDiv(x, y); 242 } 243 244 245 // ECMA-262, section 11.5.3, page 49. 246 function MOD(y) { 247 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); 248 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 249 return %NumberMod(x, y); 250 } 251 252 253 254 /* ------------------------------------------- 255 - - - B i t o p e r a t i o n s - - - 256 ------------------------------------------- 257 */ 258 259 // ECMA-262, section 11.10, page 57. 260 function BIT_OR(y) { 261 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); 262 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 263 return %NumberOr(x, y); 264 } 265 266 267 // ECMA-262, section 11.10, page 57. 268 function BIT_AND(y) { 269 var x; 270 if (IS_NUMBER(this)) { 271 x = this; 272 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 273 } else { 274 x = %NonNumberToNumber(this); 275 // Make sure to convert the right operand to a number before 276 // bailing out in the fast case, but after converting the 277 // left operand. This ensures that valueOf methods on the right 278 // operand are always executed. 279 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 280 // Optimize for the case where we end up AND'ing a value 281 // that doesn't convert to a number. This is common in 282 // certain benchmarks. 283 if (NUMBER_IS_NAN(x)) return 0; 284 } 285 return %NumberAnd(x, y); 286 } 287 288 289 // ECMA-262, section 11.10, page 57. 290 function BIT_XOR(y) { 291 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); 292 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 293 return %NumberXor(x, y); 294 } 295 296 297 // ECMA-262, section 11.7.1, page 51. 298 function SHL(y) { 299 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); 300 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 301 return %NumberShl(x, y); 302 } 303 304 305 // ECMA-262, section 11.7.2, page 51. 306 function SAR(y) { 307 var x; 308 if (IS_NUMBER(this)) { 309 x = this; 310 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 311 } else { 312 x = %NonNumberToNumber(this); 313 // Make sure to convert the right operand to a number before 314 // bailing out in the fast case, but after converting the 315 // left operand. This ensures that valueOf methods on the right 316 // operand are always executed. 317 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 318 // Optimize for the case where we end up shifting a value 319 // that doesn't convert to a number. This is common in 320 // certain benchmarks. 321 if (NUMBER_IS_NAN(x)) return 0; 322 } 323 return %NumberSar(x, y); 324 } 325 326 327 // ECMA-262, section 11.7.3, page 52. 328 function SHR(y) { 329 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); 330 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); 331 return %NumberShr(x, y); 332 } 333 334 335 336 /* ----------------------------- 337 - - - H e l p e r s - - - 338 ----------------------------- 339 */ 340 341 // ECMA-262, section 11.4.1, page 46. 342 function DELETE(key, strict) { 343 return %DeleteProperty(%ToObject(this), %ToName(key), strict); 344 } 345 346 347 // ECMA-262, section 11.8.7, page 54. 348 function IN(x) { 349 if (!IS_SPEC_OBJECT(x)) { 350 throw %MakeTypeError('invalid_in_operator_use', [this, x]); 351 } 352 return %_IsNonNegativeSmi(this) ? 353 %HasElement(x, this) : %HasProperty(x, %ToName(this)); 354 } 355 356 357 // ECMA-262, section 11.8.6, page 54. To make the implementation more 358 // efficient, the return value should be zero if the 'this' is an 359 // instance of F, and non-zero if not. This makes it possible to avoid 360 // an expensive ToBoolean conversion in the generated code. 361 function INSTANCE_OF(F) { 362 var V = this; 363 if (!IS_SPEC_FUNCTION(F)) { 364 throw %MakeTypeError('instanceof_function_expected', [F]); 365 } 366 367 // If V is not an object, return false. 368 if (!IS_SPEC_OBJECT(V)) { 369 return 1; 370 } 371 372 // Check if function is bound, if so, get [[BoundFunction]] from it 373 // and use that instead of F. 374 var bindings = %BoundFunctionGetBindings(F); 375 if (bindings) { 376 F = bindings[kBoundFunctionIndex]; // Always a non-bound function. 377 } 378 // Get the prototype of F; if it is not an object, throw an error. 379 var O = F.prototype; 380 if (!IS_SPEC_OBJECT(O)) { 381 throw %MakeTypeError('instanceof_nonobject_proto', [O]); 382 } 383 384 // Return whether or not O is in the prototype chain of V. 385 return %IsInPrototypeChain(O, V) ? 0 : 1; 386 } 387 388 389 // Filter a given key against an object by checking if the object 390 // has a property with the given key; return the key as a string if 391 // it has. Otherwise returns 0 (smi). Used in for-in statements. 392 function FILTER_KEY(key) { 393 var string = %ToName(key); 394 if (%HasProperty(this, string)) return string; 395 return 0; 396 } 397 398 399 function CALL_NON_FUNCTION() { 400 var delegate = %GetFunctionDelegate(this); 401 if (!IS_FUNCTION(delegate)) { 402 throw %MakeTypeError('called_non_callable', [typeof this]); 403 } 404 return %Apply(delegate, this, arguments, 0, %_ArgumentsLength()); 405 } 406 407 408 function CALL_NON_FUNCTION_AS_CONSTRUCTOR() { 409 var delegate = %GetConstructorDelegate(this); 410 if (!IS_FUNCTION(delegate)) { 411 throw %MakeTypeError('called_non_callable', [typeof this]); 412 } 413 return %Apply(delegate, this, arguments, 0, %_ArgumentsLength()); 414 } 415 416 417 function CALL_FUNCTION_PROXY() { 418 var arity = %_ArgumentsLength() - 1; 419 var proxy = %_Arguments(arity); // The proxy comes in as an additional arg. 420 var trap = %GetCallTrap(proxy); 421 return %Apply(trap, this, arguments, 0, arity); 422 } 423 424 425 function CALL_FUNCTION_PROXY_AS_CONSTRUCTOR() { 426 var proxy = this; 427 var trap = %GetConstructTrap(proxy); 428 return %Apply(trap, this, arguments, 0, %_ArgumentsLength()); 429 } 430 431 432 function APPLY_PREPARE(args) { 433 var length; 434 // First check whether length is a positive Smi and args is an 435 // array. This is the fast case. If this fails, we do the slow case 436 // that takes care of more eventualities. 437 if (IS_ARRAY(args)) { 438 length = args.length; 439 if (%_IsSmi(length) && length >= 0 && length < 0x800000 && 440 IS_SPEC_FUNCTION(this)) { 441 return length; 442 } 443 } 444 445 length = (args == null) ? 0 : %ToUint32(args.length); 446 447 // We can handle any number of apply arguments if the stack is 448 // big enough, but sanity check the value to avoid overflow when 449 // multiplying with pointer size. 450 if (length > 0x800000) { 451 throw %MakeRangeError('stack_overflow', []); 452 } 453 454 if (!IS_SPEC_FUNCTION(this)) { 455 throw %MakeTypeError('apply_non_function', 456 [ %ToString(this), typeof this ]); 457 } 458 459 // Make sure the arguments list has the right type. 460 if (args != null && !IS_SPEC_OBJECT(args)) { 461 throw %MakeTypeError('apply_wrong_args', []); 462 } 463 464 // Return the length which is the number of arguments to copy to the 465 // stack. It is guaranteed to be a small integer at this point. 466 return length; 467 } 468 469 470 function APPLY_OVERFLOW(length) { 471 throw %MakeRangeError('stack_overflow', []); 472 } 473 474 475 // Convert the receiver to an object - forward to ToObject. 476 function TO_OBJECT() { 477 return %ToObject(this); 478 } 479 480 481 // Convert the receiver to a number - forward to ToNumber. 482 function TO_NUMBER() { 483 return %ToNumber(this); 484 } 485 486 487 // Convert the receiver to a string - forward to ToString. 488 function TO_STRING() { 489 return %ToString(this); 490 } 491 492 493 /* ------------------------------------- 494 - - - C o n v e r s i o n s - - - 495 ------------------------------------- 496 */ 497 498 // ECMA-262, section 9.1, page 30. Use null/undefined for no hint, 499 // (1) for number hint, and (2) for string hint. 500 function ToPrimitive(x, hint) { 501 // Fast case check. 502 if (IS_STRING(x)) return x; 503 // Normal behavior. 504 if (!IS_SPEC_OBJECT(x)) return x; 505 if (IS_SYMBOL_WRAPPER(x)) return %_ValueOf(x); 506 if (hint == NO_HINT) hint = (IS_DATE(x)) ? STRING_HINT : NUMBER_HINT; 507 return (hint == NUMBER_HINT) ? %DefaultNumber(x) : %DefaultString(x); 508 } 509 510 511 // ECMA-262, section 9.2, page 30 512 function ToBoolean(x) { 513 if (IS_BOOLEAN(x)) return x; 514 if (IS_STRING(x)) return x.length != 0; 515 if (x == null) return false; 516 if (IS_NUMBER(x)) return !((x == 0) || NUMBER_IS_NAN(x)); 517 return true; 518 } 519 520 521 // ECMA-262, section 9.3, page 31. 522 function ToNumber(x) { 523 if (IS_NUMBER(x)) return x; 524 if (IS_STRING(x)) { 525 return %_HasCachedArrayIndex(x) ? %_GetCachedArrayIndex(x) 526 : %StringToNumber(x); 527 } 528 if (IS_BOOLEAN(x)) return x ? 1 : 0; 529 if (IS_UNDEFINED(x)) return NAN; 530 if (IS_SYMBOL(x)) return NAN; 531 return (IS_NULL(x)) ? 0 : ToNumber(%DefaultNumber(x)); 532 } 533 534 function NonNumberToNumber(x) { 535 if (IS_STRING(x)) { 536 return %_HasCachedArrayIndex(x) ? %_GetCachedArrayIndex(x) 537 : %StringToNumber(x); 538 } 539 if (IS_BOOLEAN(x)) return x ? 1 : 0; 540 if (IS_UNDEFINED(x)) return NAN; 541 if (IS_SYMBOL(x)) return NAN; 542 return (IS_NULL(x)) ? 0 : ToNumber(%DefaultNumber(x)); 543 } 544 545 546 // ECMA-262, section 9.8, page 35. 547 function ToString(x) { 548 if (IS_STRING(x)) return x; 549 if (IS_NUMBER(x)) return %_NumberToString(x); 550 if (IS_BOOLEAN(x)) return x ? 'true' : 'false'; 551 if (IS_UNDEFINED(x)) return 'undefined'; 552 return (IS_NULL(x)) ? 'null' : %ToString(%DefaultString(x)); 553 } 554 555 function NonStringToString(x) { 556 if (IS_NUMBER(x)) return %_NumberToString(x); 557 if (IS_BOOLEAN(x)) return x ? 'true' : 'false'; 558 if (IS_UNDEFINED(x)) return 'undefined'; 559 return (IS_NULL(x)) ? 'null' : %ToString(%DefaultString(x)); 560 } 561 562 563 // ES6 symbols 564 function ToName(x) { 565 return IS_SYMBOL(x) ? x : %ToString(x); 566 } 567 568 569 // ECMA-262, section 9.9, page 36. 570 function ToObject(x) { 571 if (IS_STRING(x)) return new $String(x); 572 if (IS_SYMBOL(x)) return new $Symbol(x); 573 if (IS_NUMBER(x)) return new $Number(x); 574 if (IS_BOOLEAN(x)) return new $Boolean(x); 575 if (IS_NULL_OR_UNDEFINED(x) && !IS_UNDETECTABLE(x)) { 576 throw %MakeTypeError('undefined_or_null_to_object', []); 577 } 578 return x; 579 } 580 581 582 // ECMA-262, section 9.4, page 34. 583 function ToInteger(x) { 584 if (%_IsSmi(x)) return x; 585 return %NumberToInteger(ToNumber(x)); 586 } 587 588 589 // ECMA-262, section 9.6, page 34. 590 function ToUint32(x) { 591 if (%_IsSmi(x) && x >= 0) return x; 592 return %NumberToJSUint32(ToNumber(x)); 593 } 594 595 596 // ECMA-262, section 9.5, page 34 597 function ToInt32(x) { 598 if (%_IsSmi(x)) return x; 599 return %NumberToJSInt32(ToNumber(x)); 600 } 601 602 603 // ES5, section 9.12 604 function SameValue(x, y) { 605 if (typeof x != typeof y) return false; 606 if (IS_NUMBER(x)) { 607 if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true; 608 // x is +0 and y is -0 or vice versa. 609 if (x === 0 && y === 0 && %_IsMinusZero(x) != %_IsMinusZero(y)) { 610 return false; 611 } 612 } 613 return x === y; 614 } 615 616 617 /* --------------------------------- 618 - - - U t i l i t i e s - - - 619 --------------------------------- 620 */ 621 622 // Returns if the given x is a primitive value - not an object or a 623 // function. 624 function IsPrimitive(x) { 625 // Even though the type of null is "object", null is still 626 // considered a primitive value. IS_SPEC_OBJECT handles this correctly 627 // (i.e., it will return false if x is null). 628 return !IS_SPEC_OBJECT(x); 629 } 630 631 632 // ECMA-262, section 8.6.2.6, page 28. 633 function DefaultNumber(x) { 634 var valueOf = x.valueOf; 635 if (IS_SPEC_FUNCTION(valueOf)) { 636 var v = %_CallFunction(x, valueOf); 637 if (%IsPrimitive(v)) return v; 638 } 639 640 var toString = x.toString; 641 if (IS_SPEC_FUNCTION(toString)) { 642 var s = %_CallFunction(x, toString); 643 if (%IsPrimitive(s)) return s; 644 } 645 646 throw %MakeTypeError('cannot_convert_to_primitive', []); 647 } 648 649 // ECMA-262, section 8.6.2.6, page 28. 650 function DefaultString(x) { 651 var toString = x.toString; 652 if (IS_SPEC_FUNCTION(toString)) { 653 var s = %_CallFunction(x, toString); 654 if (%IsPrimitive(s)) return s; 655 } 656 657 var valueOf = x.valueOf; 658 if (IS_SPEC_FUNCTION(valueOf)) { 659 var v = %_CallFunction(x, valueOf); 660 if (%IsPrimitive(v)) return v; 661 } 662 663 throw %MakeTypeError('cannot_convert_to_primitive', []); 664 } 665 666 function ToPositiveInteger(x, rangeErrorName) { 667 var i = TO_INTEGER(x); 668 if (i < 0) throw MakeRangeError(rangeErrorName); 669 return i; 670 } 671 672 673 // NOTE: Setting the prototype for Array must take place as early as 674 // possible due to code generation for array literals. When 675 // generating code for a array literal a boilerplate array is created 676 // that is cloned when running the code. It is essential that the 677 // boilerplate gets the right prototype. 678 %FunctionSetPrototype($Array, new $Array(0)); 679