blob: 9e0aab1774de17a03ca6de12c9e98f9d7236360b [file] [log] [blame]
/*
* 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 "CustomGetterSetter.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 "StructureInlines.h"
#include <wtf/MathExtras.h>
#include <wtf/StringExtras.h>
namespace JSC {
// 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() ? PNaN : 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());
VM& vm = exec->vm();
vm.throwException(exec, createNotAnObjectError(exec, *this));
return JSNotAnObject::create(vm);
}
JSValue JSValue::toThisSlowCase(ExecState* exec, ECMAMode ecmaMode) const
{
ASSERT(!isCell());
if (ecmaMode == StrictMode)
return *this;
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()) {
if (isString())
return exec->lexicalGlobalObject()->stringPrototype();
ASSERT(isSymbol());
return exec->lexicalGlobalObject()->symbolPrototype();
}
if (isNumber())
return exec->lexicalGlobalObject()->numberPrototype();
if (isBoolean())
return exec->lexicalGlobalObject()->booleanPrototype();
ASSERT(isUndefinedOrNull());
VM& vm = exec->vm();
vm.throwException(exec, createNotAnObjectError(exec, *this));
return JSNotAnObject::create(vm);
}
// ECMA 8.7.2
void JSValue::putToPrimitive(ExecState* exec, PropertyName propertyName, JSValue value, PutPropertySlot& slot)
{
VM& vm = exec->vm();
if (Optional<uint32_t> index = parseIndex(propertyName)) {
putToPrimitiveByIndex(exec, index.value(), 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;
PropertyOffset offset = obj->structure()->get(vm, propertyName, attributes);
if (offset != invalidOffset) {
if (attributes & ReadOnly) {
if (slot.isStrictMode())
exec->vm().throwException(exec, createTypeError(exec, StrictModeReadonlyPropertyWriteError));
return;
}
JSValue gs = obj->getDirect(offset);
if (gs.isGetterSetter()) {
callSetter(exec, *this, gs, value, slot.isStrictMode() ? StrictMode : NotStrictMode);
return;
}
if (gs.isCustomGetterSetter()) {
callCustomSetter(exec, gs, obj, slot.thisValue(), value);
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(*this, 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
{
dumpInContext(out, 0);
}
void JSValue::dumpInContext(PrintStream& out, DumpContext* context) const
{
dumpInContextAssumingStructure(
out, context, (!!*this && isCell()) ? asCell()->structure() : nullptr);
}
void JSValue::dumpInContextAssumingStructure(
PrintStream& out, DumpContext* context, Structure* structure) 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 (structure->classInfo()->isSubClassOf(JSString::info())) {
JSString* string = jsCast<JSString*>(asCell());
out.print("String");
if (string->isRope())
out.print(" (rope)");
const StringImpl* impl = string->tryGetValueImpl();
if (impl) {
if (impl->isAtomic())
out.print(" (atomic)");
if (impl->isAtomic())
out.print(" (identifier)");
if (impl->isSymbol())
out.print(" (symbol)");
} else
out.print(" (unresolved)");
out.print(": ", impl);
} else if (structure->classInfo()->isSubClassOf(Structure::info()))
out.print("Structure: ", inContext(*jsCast<Structure*>(asCell()), context));
else {
out.print("Cell: ", RawPointer(asCell()));
out.print(" (", inContext(*structure, context), ")");
}
#if USE(JSVALUE64)
out.print(", ID: ", asCell()->structureID());
#endif
} 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");
}
void JSValue::dumpForBacktrace(PrintStream& out) const
{
if (!*this)
out.print("<JSValue()>");
else if (isInt32())
out.printf("%d", asInt32());
else if (isDouble())
out.printf("%lf", asDouble());
else if (isCell()) {
if (asCell()->inherits(JSString::info())) {
JSString* string = jsCast<JSString*>(asCell());
const StringImpl* impl = string->tryGetValueImpl();
if (impl)
out.print("\"", impl, "\"");
else
out.print("(unresolved string)");
} else if (asCell()->inherits(Structure::info())) {
out.print("Structure[ ", asCell()->structure()->classInfo()->className);
#if USE(JSVALUE64)
out.print(" ID: ", asCell()->structureID());
#endif
out.print("]: ", RawPointer(asCell()));
} else {
out.print("Cell[", asCell()->structure()->classInfo()->className);
#if USE(JSVALUE64)
out.print(" ID: ", asCell()->structureID());
#endif
out.print("]: ", RawPointer(asCell()));
}
} 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()) {
auto integer = asInt32();
if (static_cast<unsigned>(integer) <= 9)
return vm.smallStrings.singleCharacterString(integer + '0');
return jsNontrivialString(&vm, vm.numericStrings.add(integer));
}
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();
if (isSymbol()) {
throwTypeError(exec);
return jsEmptyString(exec);
}
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
{
VM& vm = exec->vm();
if (isInt32())
return vm.numericStrings.add(asInt32());
if (isDouble())
return vm.numericStrings.add(asDouble());
if (isTrue())
return vm.propertyNames->trueKeyword.string();
if (isFalse())
return vm.propertyNames->falseKeyword.string();
if (isNull())
return vm.propertyNames->nullKeyword.string();
if (isUndefined())
return vm.propertyNames->undefinedKeyword.string();
return toString(exec)->value(exec);
}
} // namespace JSC