ObjectPrototype.cpp   [plain text]

/*
 *  Copyright (C) 1999-2000 Harri Porten (porten@kde.org)
 *  Copyright (C) 2008-2020 Apple Inc. All rights reserved.
 *
 *  This library is free software; you can redistribute it and/or
 *  modify it under the terms of the GNU Lesser 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
 *  Lesser General Public License for more details.
 *
 *  You should have received a copy of the GNU Lesser General Public
 *  License along with this library; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 */

#include "config.h"
#include "ObjectPrototype.h"

#include "GetterSetter.h"
#include "HasOwnPropertyCache.h"
#include "IntegrityInlines.h"
#include "JSCInlines.h"
#include "PropertySlot.h"

namespace JSC {

static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncValueOf);
static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncHasOwnProperty);
static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncIsPrototypeOf);
static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncDefineGetter);
static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncDefineSetter);
static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncLookupGetter);
static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncLookupSetter);
static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncPropertyIsEnumerable);
static JSC_DECLARE_HOST_FUNCTION(objectProtoFuncToLocaleString);

STATIC_ASSERT_IS_TRIVIALLY_DESTRUCTIBLE(ObjectPrototype);

const ClassInfo ObjectPrototype::s_info = { "Object", &JSNonFinalObject::s_info, nullptr, nullptr, CREATE_METHOD_TABLE(ObjectPrototype) };

ObjectPrototype::ObjectPrototype(VM& vm, Structure* stucture)
    : JSNonFinalObject(vm, stucture)
{
}

void ObjectPrototype::finishCreation(VM& vm, JSGlobalObject* globalObject)
{
    Base::finishCreation(vm);
    ASSERT(inherits(vm, info()));
    
    putDirectWithoutTransition(vm, vm.propertyNames->toString, globalObject->objectProtoToStringFunction(), static_cast<unsigned>(PropertyAttribute::DontEnum));
    JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->toLocaleString, objectProtoFuncToLocaleString, static_cast<unsigned>(PropertyAttribute::DontEnum), 0);
    JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->valueOf, objectProtoFuncValueOf, static_cast<unsigned>(PropertyAttribute::DontEnum), 0);
    JSC_NATIVE_INTRINSIC_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->hasOwnProperty, objectProtoFuncHasOwnProperty, static_cast<unsigned>(PropertyAttribute::DontEnum), 1, HasOwnPropertyIntrinsic);
    JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->propertyIsEnumerable, objectProtoFuncPropertyIsEnumerable, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
    JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->isPrototypeOf, objectProtoFuncIsPrototypeOf, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
    JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineGetter__, objectProtoFuncDefineGetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 2);
    JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__defineSetter__, objectProtoFuncDefineSetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 2);
    JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupGetter__, objectProtoFuncLookupGetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
    JSC_NATIVE_FUNCTION_WITHOUT_TRANSITION(vm.propertyNames->__lookupSetter__, objectProtoFuncLookupSetter, static_cast<unsigned>(PropertyAttribute::DontEnum), 1);
}

ObjectPrototype* ObjectPrototype::create(VM& vm, JSGlobalObject* globalObject, Structure* structure)
{
    ObjectPrototype* prototype = new (NotNull, allocateCell<ObjectPrototype>(vm.heap)) ObjectPrototype(vm, structure);
    prototype->finishCreation(vm, globalObject);
    return prototype;
}

// ------------------------------ Functions --------------------------------

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncValueOf, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    JSValue thisValue = callFrame->thisValue().toThis(globalObject, ECMAMode::strict());
    JSObject* valueObj = thisValue.toObject(globalObject);
    if (UNLIKELY(!valueObj))
        return encodedJSValue();
    Integrity::auditStructureID(globalObject->vm(), valueObj->structureID());
    return JSValue::encode(valueObj);
}

bool objectPrototypeHasOwnProperty(JSGlobalObject* globalObject, JSValue base, const Identifier& propertyName)
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);
    JSValue thisValue = base.toThis(globalObject, ECMAMode::strict());
    JSObject* thisObject = thisValue.toObject(globalObject);
    EXCEPTION_ASSERT(!!scope.exception() == !thisObject);
    if (UNLIKELY(!thisObject))
        return false;

    Structure* structure = thisObject->structure(vm);
    HasOwnPropertyCache* hasOwnPropertyCache = vm.ensureHasOwnPropertyCache();
    if (Optional<bool> result = hasOwnPropertyCache->get(structure, propertyName)) {
        ASSERT(*result == thisObject->hasOwnProperty(globalObject, propertyName));
        scope.assertNoException();
        return *result;
    }

    PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
    bool result = thisObject->hasOwnProperty(globalObject, propertyName, slot);
    RETURN_IF_EXCEPTION(scope, false);

    hasOwnPropertyCache->tryAdd(vm, slot, thisObject, propertyName, result);
    return result;
}

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncHasOwnProperty, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    JSValue base = callFrame->thisValue();
    auto propertyName = callFrame->argument(0).toPropertyKey(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());
    scope.release();
    return JSValue::encode(jsBoolean(objectPrototypeHasOwnProperty(globalObject, base, propertyName)));
}

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncIsPrototypeOf, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    if (!callFrame->argument(0).isObject())
        return JSValue::encode(jsBoolean(false));

    JSValue thisValue = callFrame->thisValue().toThis(globalObject, ECMAMode::strict());
    JSObject* thisObj = thisValue.toObject(globalObject);
    EXCEPTION_ASSERT(!!scope.exception() == !thisObj);
    if (UNLIKELY(!thisObj))
        return encodedJSValue();

    JSValue v = asObject(callFrame->argument(0))->getPrototype(vm, globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    while (true) {
        if (!v.isObject())
            return JSValue::encode(jsBoolean(false));
        if (v == thisObj)
            return JSValue::encode(jsBoolean(true));
        v = asObject(v)->getPrototype(vm, globalObject);
        RETURN_IF_EXCEPTION(scope, encodedJSValue());
    }
}

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncDefineGetter, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    JSObject* thisObject = callFrame->thisValue().toThis(globalObject, ECMAMode::strict()).toObject(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    JSValue get = callFrame->argument(1);
    if (!get.isCallable(vm))
        return throwVMTypeError(globalObject, scope, "invalid getter usage"_s);

    auto propertyName = callFrame->argument(0).toPropertyKey(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    PropertyDescriptor descriptor;
    descriptor.setGetter(get);
    descriptor.setEnumerable(true);
    descriptor.setConfigurable(true);

    bool shouldThrow = true;
    scope.release();
    thisObject->methodTable(vm)->defineOwnProperty(thisObject, globalObject, propertyName, descriptor, shouldThrow);

    return JSValue::encode(jsUndefined());
}

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncDefineSetter, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    JSObject* thisObject = callFrame->thisValue().toThis(globalObject, ECMAMode::strict()).toObject(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    JSValue set = callFrame->argument(1);
    if (!set.isCallable(vm))
        return throwVMTypeError(globalObject, scope, "invalid setter usage"_s);

    auto propertyName = callFrame->argument(0).toPropertyKey(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    PropertyDescriptor descriptor;
    descriptor.setSetter(set);
    descriptor.setEnumerable(true);
    descriptor.setConfigurable(true);

    bool shouldThrow = true;
    scope.release();
    thisObject->methodTable(vm)->defineOwnProperty(thisObject, globalObject, propertyName, descriptor, shouldThrow);

    return JSValue::encode(jsUndefined());
}

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncLookupGetter, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    JSObject* thisObject = callFrame->thisValue().toThis(globalObject, ECMAMode::strict()).toObject(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    auto propertyName = callFrame->argument(0).toPropertyKey(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
    bool hasProperty = thisObject->getPropertySlot(globalObject, propertyName, slot);
    EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
    if (hasProperty) {
        if (slot.isAccessor()) {
            GetterSetter* getterSetter = slot.getterSetter();
            return getterSetter->isGetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->getter());
        }
        if (slot.attributes() & PropertyAttribute::CustomAccessor) {
            PropertyDescriptor descriptor;
            ASSERT(slot.slotBase());
            if (slot.slotBase()->getOwnPropertyDescriptor(globalObject, propertyName, descriptor))
                return descriptor.getterPresent() ? JSValue::encode(descriptor.getter()) : JSValue::encode(jsUndefined());
        }
    }

    return JSValue::encode(jsUndefined());
}

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncLookupSetter, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    JSObject* thisObject = callFrame->thisValue().toThis(globalObject, ECMAMode::strict()).toObject(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    auto propertyName = callFrame->argument(0).toPropertyKey(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    PropertySlot slot(thisObject, PropertySlot::InternalMethodType::GetOwnProperty);
    bool hasProperty = thisObject->getPropertySlot(globalObject, propertyName, slot);
    EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
    if (hasProperty) {
        if (slot.isAccessor()) {
            GetterSetter* getterSetter = slot.getterSetter();
            return getterSetter->isSetterNull() ? JSValue::encode(jsUndefined()) : JSValue::encode(getterSetter->setter());
        }
        if (slot.attributes() & PropertyAttribute::CustomAccessor) {
            PropertyDescriptor descriptor;
            ASSERT(slot.slotBase());
            if (slot.slotBase()->getOwnPropertyDescriptor(globalObject, propertyName, descriptor))
                return descriptor.setterPresent() ? JSValue::encode(descriptor.setter()) : JSValue::encode(jsUndefined());
        }
    }

    return JSValue::encode(jsUndefined());
}

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncPropertyIsEnumerable, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    auto propertyName = callFrame->argument(0).toPropertyKey(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    JSObject* thisObject = callFrame->thisValue().toThis(globalObject, ECMAMode::strict()).toObject(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    scope.release();
    PropertyDescriptor descriptor;
    bool enumerable = thisObject->getOwnPropertyDescriptor(globalObject, propertyName, descriptor) && descriptor.enumerable();
    return JSValue::encode(jsBoolean(enumerable));
}

// 15.2.4.3 Object.prototype.toLocaleString()
JSC_DEFINE_HOST_FUNCTION(objectProtoFuncToLocaleString, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    // 1. Let V be the this value.
    JSValue thisValue = callFrame->thisValue();

    // 2. Invoke(V, "toString")

    // Let O be the result of calling ToObject passing the this value as the argument.
    JSObject* object = thisValue.toThis(globalObject, ECMAMode::strict()).toObject(globalObject);
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    // Let toString be the O.[[Get]]("toString", V)
    PropertySlot slot(thisValue, PropertySlot::InternalMethodType::Get);
    bool hasProperty = object->getPropertySlot(globalObject, vm.propertyNames->toString, slot);
    EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
    JSValue toString = hasProperty ? slot.getValue(globalObject, vm.propertyNames->toString) : jsUndefined();
    RETURN_IF_EXCEPTION(scope, encodedJSValue());

    // If IsCallable(toString) is false, throw a TypeError exception.
    auto callData = getCallData(vm, toString);
    if (callData.type == CallData::Type::None)
        return throwVMTypeError(globalObject, scope);

    // Return the result of calling the [[Call]] internal method of toString passing the this value and no arguments.
    RELEASE_AND_RETURN(scope, JSValue::encode(call(globalObject, toString, callData, thisValue, *vm.emptyList)));
}

JSC_DEFINE_HOST_FUNCTION(objectProtoFuncToString, (JSGlobalObject* globalObject, CallFrame* callFrame))
{
    VM& vm = globalObject->vm();
    auto scope = DECLARE_THROW_SCOPE(vm);

    JSValue thisValue = callFrame->thisValue().toThis(globalObject, ECMAMode::strict());
    if (thisValue.isUndefinedOrNull())
        return JSValue::encode(thisValue.isUndefined() ? vm.smallStrings.undefinedObjectString() : vm.smallStrings.nullObjectString());
    JSObject* thisObject = thisValue.toObject(globalObject);
    EXCEPTION_ASSERT(!!scope.exception() == !thisObject);
    if (!thisObject)
        return JSValue::encode(jsUndefined());

    Integrity::auditStructureID(vm, thisObject->structureID());
    auto result = thisObject->structure(vm)->cachedSpecialProperty(CachedSpecialPropertyKey::ToStringTag);
    if (result)
        return JSValue::encode(result);

    String tag = thisObject->methodTable(vm)->toStringName(thisObject, globalObject);
    RETURN_IF_EXCEPTION(scope, { });
    JSString* jsTag = nullptr;

    PropertySlot slot(thisObject, PropertySlot::InternalMethodType::Get);
    bool hasProperty = thisObject->getPropertySlot(globalObject, vm.propertyNames->toStringTagSymbol, slot);
    EXCEPTION_ASSERT(!scope.exception() || !hasProperty);
    if (hasProperty) {
        JSValue tagValue = slot.getValue(globalObject, vm.propertyNames->toStringTagSymbol);
        RETURN_IF_EXCEPTION(scope, { });
        if (tagValue.isString())
            jsTag = asString(tagValue);
    }

    if (!jsTag) {
        ASSERT_WITH_MESSAGE(tag.length() > 1, "toStringName() should return strings two or more characters long.");
        jsTag = jsNontrivialString(vm, WTFMove(tag));
    }

    JSString* jsResult = jsString(globalObject, vm.smallStrings.objectStringStart(), jsTag, vm.smallStrings.singleCharacterString(']'));
    RETURN_IF_EXCEPTION(scope, { });
    thisObject->structure(vm)->cacheSpecialProperty(globalObject, vm, jsResult, CachedSpecialPropertyKey::ToStringTag, slot);
    return JSValue::encode(jsResult);
}

} // namespace JSC