// Copyright 2006-2008 the V8 project authors. All rights reserved. // Redistribution and use in source and binary forms, with or without // modification, are permitted provided that the following conditions are // met: // // * Redistributions of source code must retain the above copyright // notice, this list of conditions and the following disclaimer. // * Redistributions in binary form must reproduce the above // copyright notice, this list of conditions and the following // disclaimer in the documentation and/or other materials provided // with the distribution. // * Neither the name of Google Inc. nor the names of its // contributors may be used to endorse or promote products derived // from this software without specific prior written permission. // // THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS // "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT // LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR // A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT // OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, // SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. // This files contains runtime support implemented in JavaScript. // CAUTION: Some of the functions specified in this file are called // directly from compiled code. These are the functions with names in // ALL CAPS. The compiled code passes the first argument in 'this' and // it does not push the function onto the stack. This means that you // cannot use contexts in all these functions. /* ----------------------------------- - - - C o m p a r i s o n - - - ----------------------------------- */ // The following const declarations are shared with other native JS files. // They are all declared at this one spot to avoid const redeclaration errors. const $Object = global.Object; const $Array = global.Array; const $String = global.String; const $Number = global.Number; const $Function = global.Function; const $Boolean = global.Boolean; const $NaN = 0/0; const builtins = this; // ECMA-262 Section 11.9.3. function EQUALS(y) { if (IS_STRING(this) && IS_STRING(y)) return %StringEquals(this, y); var x = this; while (true) { if (IS_NUMBER(x)) { while (true) { if (IS_NUMBER(y)) return %NumberEquals(x, y); if (IS_NULL_OR_UNDEFINED(y)) return 1; // not equal if (!IS_SPEC_OBJECT(y)) { // String or boolean. return %NumberEquals(x, %ToNumber(y)); } y = %ToPrimitive(y, NO_HINT); } } else if (IS_STRING(x)) { while (true) { if (IS_STRING(y)) return %StringEquals(x, y); if (IS_NUMBER(y)) return %NumberEquals(%ToNumber(x), y); if (IS_BOOLEAN(y)) return %NumberEquals(%ToNumber(x), %ToNumber(y)); if (IS_NULL_OR_UNDEFINED(y)) return 1; // not equal y = %ToPrimitive(y, NO_HINT); } } else if (IS_BOOLEAN(x)) { if (IS_BOOLEAN(y)) return %_ObjectEquals(x, y) ? 0 : 1; if (IS_NULL_OR_UNDEFINED(y)) return 1; if (IS_NUMBER(y)) return %NumberEquals(%ToNumber(x), y); if (IS_STRING(y)) return %NumberEquals(%ToNumber(x), %ToNumber(y)); // y is object. x = %ToNumber(x); y = %ToPrimitive(y, NO_HINT); } else if (IS_NULL_OR_UNDEFINED(x)) { return IS_NULL_OR_UNDEFINED(y) ? 0 : 1; } else { // x is an object. if (IS_SPEC_OBJECT(y)) { return %_ObjectEquals(x, y) ? 0 : 1; } if (IS_NULL_OR_UNDEFINED(y)) return 1; // not equal if (IS_BOOLEAN(y)) y = %ToNumber(y); x = %ToPrimitive(x, NO_HINT); } } } // ECMA-262, section 11.9.4, page 56. function STRICT_EQUALS(x) { if (IS_STRING(this)) { if (!IS_STRING(x)) return 1; // not equal return %StringEquals(this, x); } if (IS_NUMBER(this)) { if (!IS_NUMBER(x)) return 1; // not equal return %NumberEquals(this, x); } // If anything else gets here, we just do simple identity check. // Objects (including functions), null, undefined and booleans were // checked in the CompareStub, so there should be nothing left. return %_ObjectEquals(this, x) ? 0 : 1; } // ECMA-262, section 11.8.5, page 53. The 'ncr' parameter is used as // the result when either (or both) the operands are NaN. function COMPARE(x, ncr) { var left; var right; // Fast cases for string, numbers and undefined compares. if (IS_STRING(this)) { if (IS_STRING(x)) return %_StringCompare(this, x); if (IS_UNDEFINED(x)) return ncr; left = this; } else if (IS_NUMBER(this)) { if (IS_NUMBER(x)) return %NumberCompare(this, x, ncr); if (IS_UNDEFINED(x)) return ncr; left = this; } else if (IS_UNDEFINED(this)) { if (!IS_UNDEFINED(x)) { %ToPrimitive(x, NUMBER_HINT); } return ncr; } else if (IS_UNDEFINED(x)) { %ToPrimitive(this, NUMBER_HINT); return ncr; } else { left = %ToPrimitive(this, NUMBER_HINT); } right = %ToPrimitive(x, NUMBER_HINT); if (IS_STRING(left) && IS_STRING(right)) { return %_StringCompare(left, right); } else { var left_number = %ToNumber(left); var right_number = %ToNumber(right); if (NUMBER_IS_NAN(left_number) || NUMBER_IS_NAN(right_number)) return ncr; return %NumberCompare(left_number, right_number, ncr); } } /* ----------------------------------- - - - A r i t h m e t i c - - - ----------------------------------- */ // ECMA-262, section 11.6.1, page 50. function ADD(x) { // Fast case: Check for number operands and do the addition. if (IS_NUMBER(this) && IS_NUMBER(x)) return %NumberAdd(this, x); if (IS_STRING(this) && IS_STRING(x)) return %_StringAdd(this, x); // Default implementation. var a = %ToPrimitive(this, NO_HINT); var b = %ToPrimitive(x, NO_HINT); if (IS_STRING(a)) { return %_StringAdd(a, %ToString(b)); } else if (IS_STRING(b)) { return %_StringAdd(%NonStringToString(a), b); } else { return %NumberAdd(%ToNumber(a), %ToNumber(b)); } } // Left operand (this) is already a string. function STRING_ADD_LEFT(y) { if (!IS_STRING(y)) { if (IS_STRING_WRAPPER(y) && %_IsStringWrapperSafeForDefaultValueOf(y)) { y = %_ValueOf(y); } else { y = IS_NUMBER(y) ? %_NumberToString(y) : %ToString(%ToPrimitive(y, NO_HINT)); } } return %_StringAdd(this, y); } // Right operand (y) is already a string. function STRING_ADD_RIGHT(y) { var x = this; if (!IS_STRING(x)) { if (IS_STRING_WRAPPER(x) && %_IsStringWrapperSafeForDefaultValueOf(x)) { x = %_ValueOf(x); } else { x = IS_NUMBER(x) ? %_NumberToString(x) : %ToString(%ToPrimitive(x, NO_HINT)); } } return %_StringAdd(x, y); } // ECMA-262, section 11.6.2, page 50. function SUB(y) { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); return %NumberSub(x, y); } // ECMA-262, section 11.5.1, page 48. function MUL(y) { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); return %NumberMul(x, y); } // ECMA-262, section 11.5.2, page 49. function DIV(y) { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); return %NumberDiv(x, y); } // ECMA-262, section 11.5.3, page 49. function MOD(y) { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); return %NumberMod(x, y); } /* ------------------------------------------- - - - B i t o p e r a t i o n s - - - ------------------------------------------- */ // ECMA-262, section 11.10, page 57. function BIT_OR(y) { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); return %NumberOr(x, y); } // ECMA-262, section 11.10, page 57. function BIT_AND(y) { var x; if (IS_NUMBER(this)) { x = this; if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); } else { x = %NonNumberToNumber(this); // Make sure to convert the right operand to a number before // bailing out in the fast case, but after converting the // left operand. This ensures that valueOf methods on the right // operand are always executed. if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); // Optimize for the case where we end up AND'ing a value // that doesn't convert to a number. This is common in // certain benchmarks. if (NUMBER_IS_NAN(x)) return 0; } return %NumberAnd(x, y); } // ECMA-262, section 11.10, page 57. function BIT_XOR(y) { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); return %NumberXor(x, y); } // ECMA-262, section 11.4.7, page 47. function UNARY_MINUS() { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); return %NumberUnaryMinus(x); } // ECMA-262, section 11.4.8, page 48. function BIT_NOT() { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); return %NumberNot(x); } // ECMA-262, section 11.7.1, page 51. function SHL(y) { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); return %NumberShl(x, y); } // ECMA-262, section 11.7.2, page 51. function SAR(y) { var x; if (IS_NUMBER(this)) { x = this; if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); } else { x = %NonNumberToNumber(this); // Make sure to convert the right operand to a number before // bailing out in the fast case, but after converting the // left operand. This ensures that valueOf methods on the right // operand are always executed. if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); // Optimize for the case where we end up shifting a value // that doesn't convert to a number. This is common in // certain benchmarks. if (NUMBER_IS_NAN(x)) return 0; } return %NumberSar(x, y); } // ECMA-262, section 11.7.3, page 52. function SHR(y) { var x = IS_NUMBER(this) ? this : %NonNumberToNumber(this); if (!IS_NUMBER(y)) y = %NonNumberToNumber(y); return %NumberShr(x, y); } /* ----------------------------- - - - H e l p e r s - - - ----------------------------- */ // ECMA-262, section 11.4.1, page 46. function DELETE(key, strict) { return %DeleteProperty(%ToObject(this), %ToString(key), strict); } // ECMA-262, section 11.8.7, page 54. function IN(x) { if (!IS_SPEC_OBJECT(x)) { throw %MakeTypeError('invalid_in_operator_use', [this, x]); } return %_IsNonNegativeSmi(this) ? %HasElement(x, this) : %HasProperty(x, %ToString(this)); } // ECMA-262, section 11.8.6, page 54. To make the implementation more // efficient, the return value should be zero if the 'this' is an // instance of F, and non-zero if not. This makes it possible to avoid // an expensive ToBoolean conversion in the generated code. function INSTANCE_OF(F) { var V = this; if (!IS_SPEC_FUNCTION(F)) { throw %MakeTypeError('instanceof_function_expected', [V]); } // If V is not an object, return false. if (!IS_SPEC_OBJECT(V)) { return 1; } // Get the prototype of F; if it is not an object, throw an error. var O = F.prototype; if (!IS_SPEC_OBJECT(O)) { throw %MakeTypeError('instanceof_nonobject_proto', [O]); } // Return whether or not O is in the prototype chain of V. return %IsInPrototypeChain(O, V) ? 0 : 1; } // Get an array of property keys for the given object. Used in // for-in statements. function GET_KEYS() { return %GetPropertyNames(this); } // Filter a given key against an object by checking if the object // has a property with the given key; return the key as a string if // it has. Otherwise returns 0 (smi). Used in for-in statements. function FILTER_KEY(key) { var string = %ToString(key); if (%HasProperty(this, string)) return string; return 0; } function CALL_NON_FUNCTION() { var delegate = %GetFunctionDelegate(this); if (!IS_FUNCTION(delegate)) { throw %MakeTypeError('called_non_callable', [typeof this]); } return %Apply(delegate, this, arguments, 0, %_ArgumentsLength()); } function CALL_NON_FUNCTION_AS_CONSTRUCTOR() { var delegate = %GetConstructorDelegate(this); if (!IS_FUNCTION(delegate)) { throw %MakeTypeError('called_non_callable', [typeof this]); } return %Apply(delegate, this, arguments, 0, %_ArgumentsLength()); } function CALL_FUNCTION_PROXY() { var arity = %_ArgumentsLength() - 1; var proxy = %_Arguments(arity); // The proxy comes in as an additional arg. var trap = %GetCallTrap(proxy); return %Apply(trap, this, arguments, 0, arity); } function CALL_FUNCTION_PROXY_AS_CONSTRUCTOR() { var proxy = this; var trap = %GetConstructTrap(proxy); return %Apply(trap, this, arguments, 0, %_ArgumentsLength()); } function APPLY_PREPARE(args) { var length; // First check whether length is a positive Smi and args is an // array. This is the fast case. If this fails, we do the slow case // that takes care of more eventualities. if (IS_ARRAY(args)) { length = args.length; if (%_IsSmi(length) && length >= 0 && length < 0x800000 && IS_SPEC_FUNCTION(this)) { return length; } } length = (args == null) ? 0 : %ToUint32(args.length); // We can handle any number of apply arguments if the stack is // big enough, but sanity check the value to avoid overflow when // multiplying with pointer size. if (length > 0x800000) { throw %MakeRangeError('stack_overflow', []); } if (!IS_SPEC_FUNCTION(this)) { throw %MakeTypeError('apply_non_function', [ %ToString(this), typeof this ]); } // Make sure the arguments list has the right type. if (args != null && !IS_ARRAY(args) && !IS_ARGUMENTS(args)) { throw %MakeTypeError('apply_wrong_args', []); } // Return the length which is the number of arguments to copy to the // stack. It is guaranteed to be a small integer at this point. return length; } function APPLY_OVERFLOW(length) { throw %MakeRangeError('stack_overflow', []); } // Convert the receiver to an object - forward to ToObject. function TO_OBJECT() { return %ToObject(this); } // Convert the receiver to a number - forward to ToNumber. function TO_NUMBER() { return %ToNumber(this); } // Convert the receiver to a string - forward to ToString. function TO_STRING() { return %ToString(this); } /* ------------------------------------- - - - C o n v e r s i o n s - - - ------------------------------------- */ // ECMA-262, section 9.1, page 30. Use null/undefined for no hint, // (1) for number hint, and (2) for string hint. function ToPrimitive(x, hint) { // Fast case check. if (IS_STRING(x)) return x; // Normal behavior. if (!IS_SPEC_OBJECT(x)) return x; if (hint == NO_HINT) hint = (IS_DATE(x)) ? STRING_HINT : NUMBER_HINT; return (hint == NUMBER_HINT) ? %DefaultNumber(x) : %DefaultString(x); } // ECMA-262, section 9.2, page 30 function ToBoolean(x) { if (IS_BOOLEAN(x)) return x; if (IS_STRING(x)) return x.length != 0; if (x == null) return false; if (IS_NUMBER(x)) return !((x == 0) || NUMBER_IS_NAN(x)); return true; } // ECMA-262, section 9.3, page 31. function ToNumber(x) { if (IS_NUMBER(x)) return x; if (IS_STRING(x)) { return %_HasCachedArrayIndex(x) ? %_GetCachedArrayIndex(x) : %StringToNumber(x); } if (IS_BOOLEAN(x)) return x ? 1 : 0; if (IS_UNDEFINED(x)) return $NaN; return (IS_NULL(x)) ? 0 : ToNumber(%DefaultNumber(x)); } function NonNumberToNumber(x) { if (IS_STRING(x)) { return %_HasCachedArrayIndex(x) ? %_GetCachedArrayIndex(x) : %StringToNumber(x); } if (IS_BOOLEAN(x)) return x ? 1 : 0; if (IS_UNDEFINED(x)) return $NaN; return (IS_NULL(x)) ? 0 : ToNumber(%DefaultNumber(x)); } // ECMA-262, section 9.8, page 35. function ToString(x) { if (IS_STRING(x)) return x; if (IS_NUMBER(x)) return %_NumberToString(x); if (IS_BOOLEAN(x)) return x ? 'true' : 'false'; if (IS_UNDEFINED(x)) return 'undefined'; return (IS_NULL(x)) ? 'null' : %ToString(%DefaultString(x)); } function NonStringToString(x) { if (IS_NUMBER(x)) return %_NumberToString(x); if (IS_BOOLEAN(x)) return x ? 'true' : 'false'; if (IS_UNDEFINED(x)) return 'undefined'; return (IS_NULL(x)) ? 'null' : %ToString(%DefaultString(x)); } // ECMA-262, section 9.9, page 36. function ToObject(x) { if (IS_STRING(x)) return new $String(x); if (IS_NUMBER(x)) return new $Number(x); if (IS_BOOLEAN(x)) return new $Boolean(x); if (IS_NULL_OR_UNDEFINED(x) && !IS_UNDETECTABLE(x)) { throw %MakeTypeError('null_to_object', []); } return x; } // ECMA-262, section 9.4, page 34. function ToInteger(x) { if (%_IsSmi(x)) return x; return %NumberToInteger(ToNumber(x)); } // ECMA-262, section 9.6, page 34. function ToUint32(x) { if (%_IsSmi(x) && x >= 0) return x; return %NumberToJSUint32(ToNumber(x)); } // ECMA-262, section 9.5, page 34 function ToInt32(x) { if (%_IsSmi(x)) return x; return %NumberToJSInt32(ToNumber(x)); } // ES5, section 9.12 function SameValue(x, y) { if (typeof x != typeof y) return false; if (IS_NUMBER(x)) { if (NUMBER_IS_NAN(x) && NUMBER_IS_NAN(y)) return true; // x is +0 and y is -0 or vice versa. if (x === 0 && y === 0 && (1 / x) != (1 / y)) return false; } return x === y; } /* --------------------------------- - - - U t i l i t i e s - - - --------------------------------- */ // Returns if the given x is a primitive value - not an object or a // function. function IsPrimitive(x) { // Even though the type of null is "object", null is still // considered a primitive value. IS_SPEC_OBJECT handles this correctly // (i.e., it will return false if x is null). return !IS_SPEC_OBJECT(x); } // ECMA-262, section 8.6.2.6, page 28. function DefaultNumber(x) { var valueOf = x.valueOf; if (IS_SPEC_FUNCTION(valueOf)) { var v = %_CallFunction(x, valueOf); if (%IsPrimitive(v)) return v; } var toString = x.toString; if (IS_SPEC_FUNCTION(toString)) { var s = %_CallFunction(x, toString); if (%IsPrimitive(s)) return s; } throw %MakeTypeError('cannot_convert_to_primitive', []); } // ECMA-262, section 8.6.2.6, page 28. function DefaultString(x) { var toString = x.toString; if (IS_SPEC_FUNCTION(toString)) { var s = %_CallFunction(x, toString); if (%IsPrimitive(s)) return s; } var valueOf = x.valueOf; if (IS_SPEC_FUNCTION(valueOf)) { var v = %_CallFunction(x, valueOf); if (%IsPrimitive(v)) return v; } throw %MakeTypeError('cannot_convert_to_primitive', []); } // NOTE: Setting the prototype for Array must take place as early as // possible due to code generation for array literals. When // generating code for a array literal a boilerplate array is created // that is cloned when running the code. It is essential that the // boilerplate gets the right prototype. %FunctionSetPrototype($Array, new $Array(0));