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
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.
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.
28 // This files contains runtime support implemented in JavaScript.
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.
37 /* -----------------------------------
38 - - - C o m p a r i s o n - - -
39 -----------------------------------
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();
53 // ECMA-262 Section 11.9.3.
55 if (IS_STRING(this) && IS_STRING(y)) return %StringEquals(this, y);
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)) {
65 return %NumberEquals(x, %ToNumber(y));
67 y = %ToPrimitive(y, NO_HINT);
69 } else if (IS_STRING(x)) {
71 if (IS_STRING(y)) return %StringEquals(x, y);
72 if (IS_NUMBER(y)) return %NumberEquals(%ToNumber(x), y);
73 if (IS_BOOLEAN(y)) return %NumberEquals(%ToNumber(x), %ToNumber(y));
74 if (IS_NULL_OR_UNDEFINED(y)) return 1; // not equal
75 y = %ToPrimitive(y, NO_HINT);
77 } else if (IS_BOOLEAN(x)) {
78 if (IS_BOOLEAN(y)) return %_ObjectEquals(x, y) ? 0 : 1;
79 if (IS_NULL_OR_UNDEFINED(y)) return 1;
80 if (IS_NUMBER(y)) return %NumberEquals(%ToNumber(x), y);
81 if (IS_STRING(y)) return %NumberEquals(%ToNumber(x), %ToNumber(y));
84 y = %ToPrimitive(y, NO_HINT);
85 } else if (IS_NULL_OR_UNDEFINED(x)) {
86 return IS_NULL_OR_UNDEFINED(y) ? 0 : 1;
89 if (IS_SPEC_OBJECT(y)) {
90 return %_ObjectEquals(x, y) ? 0 : 1;
92 if (IS_NULL_OR_UNDEFINED(y)) return 1; // not equal
93 if (IS_BOOLEAN(y)) y = %ToNumber(y);
94 x = %ToPrimitive(x, NO_HINT);
99 // ECMA-262, section 11.9.4, page 56.
100 function STRICT_EQUALS(x) {
101 if (IS_STRING(this)) {
102 if (!IS_STRING(x)) return 1; // not equal
103 return %StringEquals(this, x);
106 if (IS_NUMBER(this)) {
107 if (!IS_NUMBER(x)) return 1; // not equal
108 return %NumberEquals(this, x);
111 // If anything else gets here, we just do simple identity check.
112 // Objects (including functions), null, undefined and booleans were
113 // checked in the CompareStub, so there should be nothing left.
114 return %_ObjectEquals(this, x) ? 0 : 1;
118 // ECMA-262, section 11.8.5, page 53. The 'ncr' parameter is used as
119 // the result when either (or both) the operands are NaN.
120 function COMPARE(x, ncr) {
123 // Fast cases for string, numbers and undefined compares.
124 if (IS_STRING(this)) {
125 if (IS_STRING(x)) return %_StringCompare(this, x);
126 if (IS_UNDEFINED(x)) return ncr;
128 } else if (IS_NUMBER(this)) {
129 if (IS_NUMBER(x)) return %NumberCompare(this, x, ncr);
130 if (IS_UNDEFINED(x)) return ncr;
132 } else if (IS_UNDEFINED(this)) {
133 if (!IS_UNDEFINED(x)) {
134 %ToPrimitive(x, NUMBER_HINT);
137 } else if (IS_UNDEFINED(x)) {
138 %ToPrimitive(this, NUMBER_HINT);
141 left = %ToPrimitive(this, NUMBER_HINT);
144 right = %ToPrimitive(x, NUMBER_HINT);
145 if (IS_STRING(left) && IS_STRING(right)) {
146 return %_StringCompare(left, right);
148 var left_number = %ToNumber(left);
149 var right_number = %ToNumber(right);
150 if (NUMBER_IS_NAN(left_number) || NUMBER_IS_NAN(right_number)) return ncr;
151 return %NumberCompare(left_number, right_number, ncr);
157 /* -----------------------------------
158 - - - A r i t h m e t i c - - -
159 -----------------------------------
162 // ECMA-262, section 11.6.1, page 50.
164 // Fast case: Check for number operands and do the addition.
165 if (IS_NUMBER(this) && IS_NUMBER(x)) return %NumberAdd(this, x);
166 if (IS_STRING(this) && IS_STRING(x)) return %_StringAdd(this, x);
168 // Default implementation.
169 var a = %ToPrimitive(this, NO_HINT);
170 var b = %ToPrimitive(x, NO_HINT);
173 return %_StringAdd(a, %ToString(b));
174 } else if (IS_STRING(b)) {
175 return %_StringAdd(%NonStringToString(a), b);
177 return %NumberAdd(%ToNumber(a), %ToNumber(b));
182 // Left operand (this) is already a string.
183 function STRING_ADD_LEFT(y) {
185 if (IS_STRING_WRAPPER(y) && %_IsStringWrapperSafeForDefaultValueOf(y)) {
189 ? %_NumberToString(y)
190 : %ToString(%ToPrimitive(y, NO_HINT));
193 return %_StringAdd(this, y);
197 // Right operand (y) is already a string.
198 function STRING_ADD_RIGHT(y) {
201 if (IS_STRING_WRAPPER(x) && %_IsStringWrapperSafeForDefaultValueOf(x)) {
205 ? %_NumberToString(x)
206 : %ToString(%ToPrimitive(x, NO_HINT));
209 return %_StringAdd(x, y);
213 // ECMA-262, section 11.6.2, page 50.
215 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
216 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
217 return %NumberSub(x, y);
221 // ECMA-262, section 11.5.1, page 48.
223 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
224 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
225 return %NumberMul(x, y);
229 // ECMA-262, section 11.5.2, page 49.
231 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
232 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
233 return %NumberDiv(x, y);
237 // ECMA-262, section 11.5.3, page 49.
239 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
240 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
241 return %NumberMod(x, y);
246 /* -------------------------------------------
247 - - - B i t o p e r a t i o n s - - -
248 -------------------------------------------
251 // ECMA-262, section 11.10, page 57.
253 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
254 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
255 return %NumberOr(x, y);
259 // ECMA-262, section 11.10, page 57.
260 function BIT_AND(y) {
262 if (IS_NUMBER(this)) {
264 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
266 x = %NonNumberToNumber(this);
267 // Make sure to convert the right operand to a number before
268 // bailing out in the fast case, but after converting the
269 // left operand. This ensures that valueOf methods on the right
270 // operand are always executed.
271 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
272 // Optimize for the case where we end up AND'ing a value
273 // that doesn't convert to a number. This is common in
274 // certain benchmarks.
275 if (NUMBER_IS_NAN(x)) return 0;
277 return %NumberAnd(x, y);
281 // ECMA-262, section 11.10, page 57.
282 function BIT_XOR(y) {
283 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
284 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
285 return %NumberXor(x, y);
289 // ECMA-262, section 11.4.7, page 47.
290 function UNARY_MINUS() {
291 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
292 return %NumberUnaryMinus(x);
296 // ECMA-262, section 11.4.8, page 48.
298 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
299 return %NumberNot(x);
303 // ECMA-262, section 11.7.1, page 51.
305 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
306 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
307 return %NumberShl(x, y);
311 // ECMA-262, section 11.7.2, page 51.
314 if (IS_NUMBER(this)) {
316 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
318 x = %NonNumberToNumber(this);
319 // Make sure to convert the right operand to a number before
320 // bailing out in the fast case, but after converting the
321 // left operand. This ensures that valueOf methods on the right
322 // operand are always executed.
323 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
324 // Optimize for the case where we end up shifting a value
325 // that doesn't convert to a number. This is common in
326 // certain benchmarks.
327 if (NUMBER_IS_NAN(x)) return 0;
329 return %NumberSar(x, y);
333 // ECMA-262, section 11.7.3, page 52.
335 var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this);
336 if (!IS_NUMBER(y)) y = %NonNumberToNumber(y);
337 return %NumberShr(x, y);
342 /* -----------------------------
343 - - - H e l p e r s - - -
344 -----------------------------
347 // ECMA-262, section 11.4.1, page 46.
348 function DELETE(key, strict) {
349 return %DeleteProperty(%ToObject(this), %ToString(key), strict);
353 // ECMA-262, section 11.8.7, page 54.
355 if (!IS_SPEC_OBJECT(x)) {
356 throw %MakeTypeError('invalid_in_operator_use', [this, x]);
358 return %_IsNonNegativeSmi(this) ?
359 %HasElement(x, this) : %HasProperty(x, %ToString(this));
363 // ECMA-262, section 11.8.6, page 54. To make the implementation more
364 // efficient, the return value should be zero if the 'this' is an
365 // instance of F, and non-zero if not. This makes it possible to avoid
366 // an expensive ToBoolean conversion in the generated code.
367 function INSTANCE_OF(F) {
369 if (!IS_SPEC_FUNCTION(F)) {
370 throw %MakeTypeError('instanceof_function_expected', [V]);
373 // If V is not an object, return false.
374 if (!IS_SPEC_OBJECT(V)) {
378 // Check if function is bound, if so, get [[BoundFunction]] from it
379 // and use that instead of F.
380 var bindings = %BoundFunctionGetBindings(F);
382 F = bindings[kBoundFunctionIndex]; // Always a non-bound function.
384 // Get the prototype of F; if it is not an object, throw an error.
386 if (!IS_SPEC_OBJECT(O)) {
387 throw %MakeTypeError('instanceof_nonobject_proto', [O]);
390 // Return whether or not O is in the prototype chain of V.
391 return %IsInPrototypeChain(O, V) ? 0 : 1;
395 // Filter a given key against an object by checking if the object
396 // has a property with the given key; return the key as a string if
397 // it has. Otherwise returns 0 (smi). Used in for-in statements.
398 function FILTER_KEY(key) {
399 var string = %ToString(key);
400 if (%HasProperty(this, string)) return string;
405 function CALL_NON_FUNCTION() {
406 var delegate = %GetFunctionDelegate(this);
407 if (!IS_FUNCTION(delegate)) {
408 throw %MakeTypeError('called_non_callable', [typeof this]);
410 return %Apply(delegate, this, arguments, 0, %_ArgumentsLength());
414 function CALL_NON_FUNCTION_AS_CONSTRUCTOR() {
415 var delegate = %GetConstructorDelegate(this);
416 if (!IS_FUNCTION(delegate)) {
417 throw %MakeTypeError('called_non_callable', [typeof this]);
419 return %Apply(delegate, this, arguments, 0, %_ArgumentsLength());
423 function CALL_FUNCTION_PROXY() {
424 var arity = %_ArgumentsLength() - 1;
425 var proxy = %_Arguments(arity); // The proxy comes in as an additional arg.
426 var trap = %GetCallTrap(proxy);
427 return %Apply(trap, this, arguments, 0, arity);
431 function CALL_FUNCTION_PROXY_AS_CONSTRUCTOR() {
433 var trap = %GetConstructTrap(proxy);
434 return %Apply(trap, this, arguments, 0, %_ArgumentsLength());
438 function APPLY_PREPARE(args) {
440 // First check whether length is a positive Smi and args is an
441 // array. This is the fast case. If this fails, we do the slow case
442 // that takes care of more eventualities.
443 if (IS_ARRAY(args)) {
444 length = args.length;
445 if (%_IsSmi(length) && length >= 0 && length < 0x800000 &&
446 IS_SPEC_FUNCTION(this)) {
451 length = (args == null) ? 0 : %ToUint32(args.length);
453 // We can handle any number of apply arguments if the stack is
454 // big enough, but sanity check the value to avoid overflow when
455 // multiplying with pointer size.
456 if (length > 0x800000) {
457 throw %MakeRangeError('stack_overflow', []);
460 if (!IS_SPEC_FUNCTION(this)) {
461 throw %MakeTypeError('apply_non_function',
462 [ %ToString(this), typeof this ]);
465 // Make sure the arguments list has the right type.
466 if (args != null && !IS_SPEC_OBJECT(args)) {
467 throw %MakeTypeError('apply_wrong_args', []);
470 // Return the length which is the number of arguments to copy to the
471 // stack. It is guaranteed to be a small integer at this point.
476 function APPLY_OVERFLOW(length) {
477 throw %MakeRangeError('stack_overflow', []);
481 // Convert the receiver to an object - forward to ToObject.
482 function TO_OBJECT() {
483 return %ToObject(this);
487 // Convert the receiver to a number - forward to ToNumber.
488 function TO_NUMBER() {
489 return %ToNumber(this);
493 // Convert the receiver to a string - forward to ToString.
494 function TO_STRING() {
495 return %ToString(this);
499 /* -------------------------------------
500 - - - C o n v e r s i o n s - - -
501 -------------------------------------
504 // ECMA-262, section 9.1, page 30. Use null/undefined for no hint,
505 // (1) for number hint, and (2) for string hint.
506 function ToPrimitive(x, hint) {
508 if (IS_STRING(x)) return x;
510 if (!IS_SPEC_OBJECT(x)) return x;
511 if (hint == NO_HINT) hint = (IS_DATE(x)) ? STRING_HINT : NUMBER_HINT;
512 return (hint == NUMBER_HINT) ? %DefaultNumber(x) : %DefaultString(x);
516 // ECMA-262, section 9.2, page 30
517 function ToBoolean(x) {
518 if (IS_BOOLEAN(x)) return x;
519 if (IS_STRING(x)) return x.length != 0;
520 if (x == null) return false;
521 if (IS_NUMBER(x)) return !((x == 0) || NUMBER_IS_NAN(x));
526 // ECMA-262, section 9.3, page 31.
527 function ToNumber(x) {
528 if (IS_NUMBER(x)) return x;
530 return %_HasCachedArrayIndex(x) ? %_GetCachedArrayIndex(x)
531 : %StringToNumber(x);
533 if (IS_BOOLEAN(x)) return x ? 1 : 0;
534 if (IS_UNDEFINED(x)) return $NaN;
535 return (IS_NULL(x)) ? 0 : ToNumber(%DefaultNumber(x));
538 function NonNumberToNumber(x) {
540 return %_HasCachedArrayIndex(x) ? %_GetCachedArrayIndex(x)
541 : %StringToNumber(x);
543 if (IS_BOOLEAN(x)) return x ? 1 : 0;
544 if (IS_UNDEFINED(x)) return $NaN;
545 return (IS_NULL(x)) ? 0 : ToNumber(%DefaultNumber(x));
549 // ECMA-262, section 9.8, page 35.
550 function ToString(x) {
551 if (IS_STRING(x)) return x;
552 if (IS_NUMBER(x)) return %_NumberToString(x);
553 if (IS_BOOLEAN(x)) return x ? 'true' : 'false';
554 if (IS_UNDEFINED(x)) return 'undefined';
555 return (IS_NULL(x)) ? 'null' : %ToString(%DefaultString(x));
558 function NonStringToString(x) {
559 if (IS_NUMBER(x)) return %_NumberToString(x);
560 if (IS_BOOLEAN(x)) return x ? 'true' : 'false';
561 if (IS_UNDEFINED(x)) return 'undefined';
562 return (IS_NULL(x)) ? 'null' : %ToString(%DefaultString(x));
566 // ECMA-262, section 9.9, page 36.
567 function ToObject(x) {
568 if (IS_STRING(x)) return new $String(x);
569 if (IS_NUMBER(x)) return new $Number(x);
570 if (IS_BOOLEAN(x)) return new $Boolean(x);
571 if (IS_NULL_OR_UNDEFINED(x) && !IS_UNDETECTABLE(x)) {
572 throw %MakeTypeError('null_to_object', []);
578 // ECMA-262, section 9.4, page 34.
579 function ToInteger(x) {
580 if (%_IsSmi(x)) return x;
581 return %NumberToInteger(ToNumber(x));
585 // ECMA-262, section 9.6, page 34.
586 function ToUint32(x) {
587 if (%_IsSmi(x) && x >= 0) return x;
588 return %NumberToJSUint32(ToNumber(x));
592 // ECMA-262, section 9.5, page 34
593 function ToInt32(x) {
594 if (%_IsSmi(x)) return x;
595 return %NumberToJSInt32(ToNumber(x));
600 function SameValue(x, y) {
601 if (typeof x != typeof y) return false;
603 if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true;
604 // x is +0 and y is -0 or vice versa.
605 if (x === 0 && y === 0 && (1 / x) != (1 / y)) return false;
611 /* ---------------------------------
612 - - - U t i l i t i e s - - -
613 ---------------------------------
616 // Returns if the given x is a primitive value - not an object or a
618 function IsPrimitive(x) {
619 // Even though the type of null is "object", null is still
620 // considered a primitive value. IS_SPEC_OBJECT handles this correctly
621 // (i.e., it will return false if x is null).
622 return !IS_SPEC_OBJECT(x);
626 // ECMA-262, section 8.6.2.6, page 28.
627 function DefaultNumber(x) {
628 var valueOf = x.valueOf;
629 if (IS_SPEC_FUNCTION(valueOf)) {
630 var v = %_CallFunction(x, valueOf);
631 if (%IsPrimitive(v)) return v;
634 var toString = x.toString;
635 if (IS_SPEC_FUNCTION(toString)) {
636 var s = %_CallFunction(x, toString);
637 if (%IsPrimitive(s)) return s;
640 throw %MakeTypeError('cannot_convert_to_primitive', []);
644 // ECMA-262, section 8.6.2.6, page 28.
645 function DefaultString(x) {
646 var toString = x.toString;
647 if (IS_SPEC_FUNCTION(toString)) {
648 var s = %_CallFunction(x, toString);
649 if (%IsPrimitive(s)) return s;
652 var valueOf = x.valueOf;
653 if (IS_SPEC_FUNCTION(valueOf)) {
654 var v = %_CallFunction(x, valueOf);
655 if (%IsPrimitive(v)) return v;
658 throw %MakeTypeError('cannot_convert_to_primitive', []);
662 // NOTE: Setting the prototype for Array must take place as early as
663 // possible due to code generation for array literals. When
664 // generating code for a array literal a boilerplate array is created
665 // that is cloned when running the code. It is essential that the
666 // boilerplate gets the right prototype.
667 %FunctionSetPrototype($Array, new $Array(0));