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Diffstat (limited to 'Source/JavaScriptCore/runtime/JSCJSValue.cpp')
-rw-r--r-- | Source/JavaScriptCore/runtime/JSCJSValue.cpp | 326 |
1 files changed, 326 insertions, 0 deletions
diff --git a/Source/JavaScriptCore/runtime/JSCJSValue.cpp b/Source/JavaScriptCore/runtime/JSCJSValue.cpp new file mode 100644 index 000000000..627e9e077 --- /dev/null +++ b/Source/JavaScriptCore/runtime/JSCJSValue.cpp @@ -0,0 +1,326 @@ +/* + * Copyright (C) 1999-2001 Harri Porten (porten@kde.org) + * Copyright (C) 2001 Peter Kelly (pmk@post.com) + * Copyright (C) 2003, 2007, 2008, 2012 Apple Inc. All rights reserved. + * + * This library is free software; you can redistribute it and/or + * modify it under the terms of the GNU Library General Public + * License as published by the Free Software Foundation; either + * version 2 of the License, or (at your option) any later version. + * + * This library is distributed in the hope that it will be useful, + * but WITHOUT ANY WARRANTY; without even the implied warranty of + * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the GNU + * Library General Public License for more details. + * + * You should have received a copy of the GNU Library General Public License + * along with this library; see the file COPYING.LIB. If not, write to + * the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, + * Boston, MA 02110-1301, USA. + * + */ + +#include "config.h" +#include "JSCJSValue.h" + +#include "BooleanConstructor.h" +#include "BooleanPrototype.h" +#include "Error.h" +#include "ExceptionHelpers.h" +#include "GetterSetter.h" +#include "JSCJSValueInlines.h" +#include "JSFunction.h" +#include "JSGlobalObject.h" +#include "JSNotAnObject.h" +#include "NumberObject.h" +#include <wtf/MathExtras.h> +#include <wtf/StringExtras.h> + +namespace JSC { + +static const double D32 = 4294967296.0; + +// ECMA 9.4 +double JSValue::toInteger(ExecState* exec) const +{ + if (isInt32()) + return asInt32(); + double d = toNumber(exec); + return std::isnan(d) ? 0.0 : trunc(d); +} + +double JSValue::toIntegerPreserveNaN(ExecState* exec) const +{ + if (isInt32()) + return asInt32(); + return trunc(toNumber(exec)); +} + +double JSValue::toNumberSlowCase(ExecState* exec) const +{ + ASSERT(!isInt32() && !isDouble()); + if (isCell()) + return asCell()->toNumber(exec); + if (isTrue()) + return 1.0; + return isUndefined() ? QNaN : 0; // null and false both convert to 0. +} + +JSObject* JSValue::toObjectSlowCase(ExecState* exec, JSGlobalObject* globalObject) const +{ + ASSERT(!isCell()); + + if (isInt32() || isDouble()) + return constructNumber(exec, globalObject, asValue()); + if (isTrue() || isFalse()) + return constructBooleanFromImmediateBoolean(exec, globalObject, asValue()); + + ASSERT(isUndefinedOrNull()); + throwError(exec, createNotAnObjectError(exec, *this)); + return JSNotAnObject::create(exec); +} + +JSObject* JSValue::toThisObjectSlowCase(ExecState* exec) const +{ + ASSERT(!isCell()); + + if (isInt32() || isDouble()) + return constructNumber(exec, exec->lexicalGlobalObject(), asValue()); + if (isTrue() || isFalse()) + return constructBooleanFromImmediateBoolean(exec, exec->lexicalGlobalObject(), asValue()); + ASSERT(isUndefinedOrNull()); + return exec->globalThisValue(); +} + +JSObject* JSValue::synthesizePrototype(ExecState* exec) const +{ + if (isCell()) { + ASSERT(isString()); + return exec->lexicalGlobalObject()->stringPrototype(); + } + + if (isNumber()) + return exec->lexicalGlobalObject()->numberPrototype(); + if (isBoolean()) + return exec->lexicalGlobalObject()->booleanPrototype(); + + ASSERT(isUndefinedOrNull()); + throwError(exec, createNotAnObjectError(exec, *this)); + return JSNotAnObject::create(exec); +} + +// ECMA 8.7.2 +void JSValue::putToPrimitive(ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot) +{ + VM& vm = exec->vm(); + + unsigned index = propertyName.asIndex(); + if (index != PropertyName::NotAnIndex) { + putToPrimitiveByIndex(exec, index, value, slot.isStrictMode()); + return; + } + + // Check if there are any setters or getters in the prototype chain + JSObject* obj = synthesizePrototype(exec); + JSValue prototype; + if (propertyName != exec->propertyNames().underscoreProto) { + for (; !obj->structure()->hasReadOnlyOrGetterSetterPropertiesExcludingProto(); obj = asObject(prototype)) { + prototype = obj->prototype(); + if (prototype.isNull()) { + if (slot.isStrictMode()) + throwTypeError(exec, StrictModeReadonlyPropertyWriteError); + return; + } + } + } + + for (; ; obj = asObject(prototype)) { + unsigned attributes; + JSCell* specificValue; + PropertyOffset offset = obj->structure()->get(vm, propertyName, attributes, specificValue); + if (offset != invalidOffset) { + if (attributes & ReadOnly) { + if (slot.isStrictMode()) + throwError(exec, createTypeError(exec, StrictModeReadonlyPropertyWriteError)); + return; + } + + JSValue gs = obj->getDirect(offset); + if (gs.isGetterSetter()) { + JSObject* setterFunc = asGetterSetter(gs)->setter(); + if (!setterFunc) { + if (slot.isStrictMode()) + throwError(exec, createTypeError(exec, ASCIILiteral("setting a property that has only a getter"))); + return; + } + + CallData callData; + CallType callType = setterFunc->methodTable()->getCallData(setterFunc, callData); + MarkedArgumentBuffer args; + args.append(value); + + // If this is WebCore's global object then we need to substitute the shell. + call(exec, setterFunc, callType, callData, *this, args); + return; + } + + // If there's an existing property on the object or one of its + // prototypes it should be replaced, so break here. + break; + } + + prototype = obj->prototype(); + if (prototype.isNull()) + break; + } + + if (slot.isStrictMode()) + throwTypeError(exec, StrictModeReadonlyPropertyWriteError); + return; +} + +void JSValue::putToPrimitiveByIndex(ExecState* exec, unsigned propertyName, JSValue value, bool shouldThrow) +{ + if (propertyName > MAX_ARRAY_INDEX) { + PutPropertySlot slot(shouldThrow); + putToPrimitive(exec, Identifier::from(exec, propertyName), value, slot); + return; + } + + if (synthesizePrototype(exec)->attemptToInterceptPutByIndexOnHoleForPrototype(exec, *this, propertyName, value, shouldThrow)) + return; + + if (shouldThrow) + throwTypeError(exec, StrictModeReadonlyPropertyWriteError); +} + +void JSValue::dump(PrintStream& out) const +{ + if (!*this) + out.print("<JSValue()>"); + else if (isInt32()) + out.printf("Int32: %d", asInt32()); + else if (isDouble()) { +#if USE(JSVALUE64) + out.printf("Double: %lld, %lf", (long long)reinterpretDoubleToInt64(asDouble()), asDouble()); +#else + union { + double asDouble; + uint32_t asTwoInt32s[2]; + } u; + u.asDouble = asDouble(); + out.printf("Double: %08x:%08x, %lf", u.asTwoInt32s[1], u.asTwoInt32s[0], asDouble()); +#endif + } else if (isCell()) { + if (asCell()->inherits(&JSString::s_info)) { + JSString* string = jsCast<JSString*>(asCell()); + out.print("String: "); + if (string->isRope()) + out.print("(rope) "); + out.print(string->tryGetValue()); + } else if (asCell()->inherits(&Structure::s_info)) { + Structure* structure = jsCast<Structure*>(asCell()); + out.print( + "Structure: ", RawPointer(structure), ": ", structure->classInfo()->className, + ", ", IndexingTypeDump(structure->indexingTypeIncludingHistory())); + } else { + out.print("Cell: ", RawPointer(asCell())); + if (isObject() && asObject(*this)->butterfly()) + out.print("->", RawPointer(asObject(*this)->butterfly())); + out.print( + " (", RawPointer(asCell()->structure()), ": ", asCell()->structure()->classInfo()->className, + ", ", IndexingTypeDump(asCell()->structure()->indexingTypeIncludingHistory()), ")"); + } + } else if (isTrue()) + out.print("True"); + else if (isFalse()) + out.print("False"); + else if (isNull()) + out.print("Null"); + else if (isUndefined()) + out.print("Undefined"); + else + out.print("INVALID"); +} + +// This in the ToInt32 operation is defined in section 9.5 of the ECMA-262 spec. +// Note that this operation is identical to ToUInt32 other than to interpretation +// of the resulting bit-pattern (as such this metod is also called to implement +// ToUInt32). +// +// The operation can be descibed as round towards zero, then select the 32 least +// bits of the resulting value in 2s-complement representation. +int32_t toInt32(double number) +{ + int64_t bits = WTF::bitwise_cast<int64_t>(number); + int32_t exp = (static_cast<int32_t>(bits >> 52) & 0x7ff) - 0x3ff; + + // If exponent < 0 there will be no bits to the left of the decimal point + // after rounding; if the exponent is > 83 then no bits of precision can be + // left in the low 32-bit range of the result (IEEE-754 doubles have 52 bits + // of fractional precision). + // Note this case handles 0, -0, and all infinte, NaN, & denormal value. + if (exp < 0 || exp > 83) + return 0; + + // Select the appropriate 32-bits from the floating point mantissa. If the + // exponent is 52 then the bits we need to select are already aligned to the + // lowest bits of the 64-bit integer representation of tghe number, no need + // to shift. If the exponent is greater than 52 we need to shift the value + // left by (exp - 52), if the value is less than 52 we need to shift right + // accordingly. + int32_t result = (exp > 52) + ? static_cast<int32_t>(bits << (exp - 52)) + : static_cast<int32_t>(bits >> (52 - exp)); + + // IEEE-754 double precision values are stored omitting an implicit 1 before + // the decimal point; we need to reinsert this now. We may also the shifted + // invalid bits into the result that are not a part of the mantissa (the sign + // and exponent bits from the floatingpoint representation); mask these out. + if (exp < 32) { + int32_t missingOne = 1 << exp; + result &= missingOne - 1; + result += missingOne; + } + + // If the input value was negative (we could test either 'number' or 'bits', + // but testing 'bits' is likely faster) invert the result appropriately. + return bits < 0 ? -result : result; +} + +bool JSValue::isValidCallee() +{ + return asObject(asCell())->globalObject(); +} + +JSString* JSValue::toStringSlowCase(ExecState* exec) const +{ + VM& vm = exec->vm(); + ASSERT(!isString()); + if (isInt32()) + return jsString(&vm, vm.numericStrings.add(asInt32())); + if (isDouble()) + return jsString(&vm, vm.numericStrings.add(asDouble())); + if (isTrue()) + return vm.smallStrings.trueString(); + if (isFalse()) + return vm.smallStrings.falseString(); + if (isNull()) + return vm.smallStrings.nullString(); + if (isUndefined()) + return vm.smallStrings.undefinedString(); + + ASSERT(isCell()); + JSValue value = asCell()->toPrimitive(exec, PreferString); + if (exec->hadException()) + return jsEmptyString(exec); + ASSERT(!value.isObject()); + return value.toString(exec); +} + +String JSValue::toWTFStringSlowCase(ExecState* exec) const +{ + return inlineJSValueNotStringtoString(*this, exec); +} + +} // namespace JSC |