From 26a029d407be480d791972afb5975cf62c9360a6 Mon Sep 17 00:00:00 2001 From: Daniel Baumann Date: Fri, 19 Apr 2024 02:47:55 +0200 Subject: Adding upstream version 124.0.1. Signed-off-by: Daniel Baumann --- js/src/vm/JSObject.cpp | 3526 ++++++++++++++++++++++++++++++++++++++++++++++++ 1 file changed, 3526 insertions(+) create mode 100644 js/src/vm/JSObject.cpp (limited to 'js/src/vm/JSObject.cpp') diff --git a/js/src/vm/JSObject.cpp b/js/src/vm/JSObject.cpp new file mode 100644 index 0000000000..bafc7a4437 --- /dev/null +++ b/js/src/vm/JSObject.cpp @@ -0,0 +1,3526 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +/* + * JS object implementation. + */ + +#include "vm/JSObject-inl.h" + +#include "mozilla/MemoryReporting.h" +#include "mozilla/Try.h" + +#include + +#include "jsapi.h" +#include "jsexn.h" +#include "jsfriendapi.h" +#include "jsnum.h" +#include "jstypes.h" + +#include "builtin/BigInt.h" +#include "builtin/MapObject.h" +#include "builtin/Object.h" +#include "builtin/String.h" +#include "builtin/Symbol.h" +#include "builtin/WeakSetObject.h" +#include "gc/AllocKind.h" +#include "gc/GC.h" +#include "js/CharacterEncoding.h" +#include "js/friend/DumpFunctions.h" // js::DumpObject +#include "js/friend/ErrorMessages.h" // JSErrNum, js::GetErrorMessage, JSMSG_* +#include "js/friend/WindowProxy.h" // js::IsWindow, js::ToWindowProxyIfWindow +#include "js/MemoryMetrics.h" +#include "js/Prefs.h" // JS::Prefs +#include "js/Printer.h" // js::GenericPrinter, js::Fprinter +#include "js/PropertyDescriptor.h" // JS::FromPropertyDescriptor +#include "js/PropertySpec.h" // JSPropertySpec +#include "js/Proxy.h" +#include "js/Result.h" +#include "js/UbiNode.h" +#include "js/Wrapper.h" +#include "proxy/DeadObjectProxy.h" +#include "util/Memory.h" +#include "util/Text.h" +#include "util/WindowsWrapper.h" +#include "vm/ArgumentsObject.h" +#include "vm/ArrayBufferObject.h" +#include "vm/ArrayBufferViewObject.h" +#include "vm/BytecodeUtil.h" +#include "vm/Compartment.h" +#include "vm/DateObject.h" +#include "vm/Interpreter.h" +#include "vm/Iteration.h" +#include "vm/JSAtomUtils.h" // Atomize +#include "vm/JSContext.h" +#include "vm/JSFunction.h" +#include "vm/JSONPrinter.h" // js::JSONPrinter +#include "vm/JSScript.h" +#include "vm/PromiseObject.h" +#include "vm/ProxyObject.h" +#include "vm/RegExpObject.h" +#include "vm/Shape.h" +#include "vm/TypedArrayObject.h" +#include "vm/Watchtower.h" +#include "vm/WrapperObject.h" +#ifdef ENABLE_RECORD_TUPLE +# include "builtin/RecordObject.h" +# include "builtin/TupleObject.h" +# include "vm/RecordType.h" +# include "vm/TupleType.h" +#endif + +#include "gc/StableCellHasher-inl.h" +#include "vm/BooleanObject-inl.h" +#include "vm/EnvironmentObject-inl.h" +#include "vm/Interpreter-inl.h" +#include "vm/JSAtomUtils-inl.h" // AtomToId, PrimitiveValueToId, IndexToId +#include "vm/JSContext-inl.h" +#include "vm/NativeObject-inl.h" +#include "vm/NumberObject-inl.h" +#include "vm/ObjectFlags-inl.h" +#include "vm/Realm-inl.h" +#include "vm/StringObject-inl.h" +#include "vm/TypedArrayObject-inl.h" +#include "wasm/WasmGcObject-inl.h" + +using namespace js; + +using mozilla::Maybe; + +void js::ReportNotObject(JSContext* cx, JSErrNum err, int spindex, + HandleValue v) { + MOZ_ASSERT(!v.isObject()); + ReportValueError(cx, err, spindex, v, nullptr); +} + +void js::ReportNotObject(JSContext* cx, JSErrNum err, HandleValue v) { + ReportNotObject(cx, err, JSDVG_SEARCH_STACK, v); +} + +void js::ReportNotObject(JSContext* cx, const Value& v) { + RootedValue value(cx, v); + ReportNotObject(cx, JSMSG_OBJECT_REQUIRED, value); +} + +void js::ReportNotObjectArg(JSContext* cx, const char* nth, const char* fun, + HandleValue v) { + MOZ_ASSERT(!v.isObject()); + + UniqueChars bytes; + if (const char* chars = ValueToSourceForError(cx, v, bytes)) { + JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, + JSMSG_OBJECT_REQUIRED_ARG, nth, fun, chars); + } +} + +JS_PUBLIC_API const char* JS::InformalValueTypeName(const Value& v) { + switch (v.type()) { + case ValueType::Double: + case ValueType::Int32: + return "number"; + case ValueType::Boolean: + return "boolean"; + case ValueType::Undefined: + return "undefined"; + case ValueType::Null: + return "null"; + case ValueType::String: + return "string"; + case ValueType::Symbol: + return "symbol"; + case ValueType::BigInt: + return "bigint"; + case ValueType::Object: +#ifdef ENABLE_RECORD_TUPLE + case ValueType::ExtendedPrimitive: +#endif + return v.getObjectPayload().getClass()->name; + case ValueType::Magic: + return "magic"; + case ValueType::PrivateGCThing: + break; + } + + MOZ_CRASH("unexpected type"); +} + +// ES6 draft rev37 6.2.4.4 FromPropertyDescriptor +JS_PUBLIC_API bool JS::FromPropertyDescriptor( + JSContext* cx, Handle> desc_, + MutableHandleValue vp) { + AssertHeapIsIdle(); + CHECK_THREAD(cx); + cx->check(desc_); + + // Step 1. + if (desc_.isNothing()) { + vp.setUndefined(); + return true; + } + + Rooted desc(cx, *desc_); + return FromPropertyDescriptorToObject(cx, desc, vp); +} + +bool js::FromPropertyDescriptorToObject(JSContext* cx, + Handle desc, + MutableHandleValue vp) { + // Step 2-3. + RootedObject obj(cx, NewPlainObject(cx)); + if (!obj) { + return false; + } + + const JSAtomState& names = cx->names(); + + // Step 4. + if (desc.hasValue()) { + if (!DefineDataProperty(cx, obj, names.value, desc.value())) { + return false; + } + } + + // Step 5. + RootedValue v(cx); + if (desc.hasWritable()) { + v.setBoolean(desc.writable()); + if (!DefineDataProperty(cx, obj, names.writable, v)) { + return false; + } + } + + // Step 6. + if (desc.hasGetter()) { + if (JSObject* get = desc.getter()) { + v.setObject(*get); + } else { + v.setUndefined(); + } + if (!DefineDataProperty(cx, obj, names.get, v)) { + return false; + } + } + + // Step 7. + if (desc.hasSetter()) { + if (JSObject* set = desc.setter()) { + v.setObject(*set); + } else { + v.setUndefined(); + } + if (!DefineDataProperty(cx, obj, names.set, v)) { + return false; + } + } + + // Step 8. + if (desc.hasEnumerable()) { + v.setBoolean(desc.enumerable()); + if (!DefineDataProperty(cx, obj, names.enumerable, v)) { + return false; + } + } + + // Step 9. + if (desc.hasConfigurable()) { + v.setBoolean(desc.configurable()); + if (!DefineDataProperty(cx, obj, names.configurable, v)) { + return false; + } + } + + vp.setObject(*obj); + return true; +} + +bool js::GetFirstArgumentAsObject(JSContext* cx, const CallArgs& args, + const char* method, + MutableHandleObject objp) { + if (!args.requireAtLeast(cx, method, 1)) { + return false; + } + + HandleValue v = args[0]; + if (!v.isObject()) { + UniqueChars bytes = + DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, v, nullptr); + if (!bytes) { + return false; + } + JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr, + JSMSG_UNEXPECTED_TYPE, bytes.get(), + "not an object"); + return false; + } + + objp.set(&v.toObject()); + return true; +} + +static bool GetPropertyIfPresent(JSContext* cx, HandleObject obj, HandleId id, + MutableHandleValue vp, bool* foundp) { + if (!HasProperty(cx, obj, id, foundp)) { + return false; + } + if (!*foundp) { + vp.setUndefined(); + return true; + } + + return GetProperty(cx, obj, obj, id, vp); +} + +bool js::Throw(JSContext* cx, HandleId id, unsigned errorNumber, + const char* details) { + MOZ_ASSERT(js_ErrorFormatString[errorNumber].argCount == (details ? 2 : 1)); + MOZ_ASSERT_IF(details, JS::StringIsASCII(details)); + + UniqueChars bytes = + IdToPrintableUTF8(cx, id, IdToPrintableBehavior::IdIsPropertyKey); + if (!bytes) { + return false; + } + + if (details) { + JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr, errorNumber, + bytes.get(), details); + } else { + JS_ReportErrorNumberUTF8(cx, GetErrorMessage, nullptr, errorNumber, + bytes.get()); + } + + return false; +} + +/*** PropertyDescriptor operations and DefineProperties *********************/ + +static Result<> CheckCallable(JSContext* cx, JSObject* obj, + const char* fieldName) { + if (obj && !obj->isCallable()) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_BAD_GET_SET_FIELD, fieldName); + return cx->alreadyReportedError(); + } + return Ok(); +} + +// 6.2.5.5 ToPropertyDescriptor(Obj) +bool js::ToPropertyDescriptor(JSContext* cx, HandleValue descval, + bool checkAccessors, + MutableHandle desc_) { + // Step 1. + RootedObject obj(cx, + RequireObject(cx, JSMSG_OBJECT_REQUIRED_PROP_DESC, descval)); + if (!obj) { + return false; + } + + // Step 2. + Rooted desc(cx, PropertyDescriptor::Empty()); + + RootedId id(cx); + RootedValue v(cx); + + // Steps 3-4. + id = NameToId(cx->names().enumerable); + bool hasEnumerable = false; + if (!GetPropertyIfPresent(cx, obj, id, &v, &hasEnumerable)) { + return false; + } + if (hasEnumerable) { + desc.setEnumerable(ToBoolean(v)); + } + + // Steps 5-6. + id = NameToId(cx->names().configurable); + bool hasConfigurable = false; + if (!GetPropertyIfPresent(cx, obj, id, &v, &hasConfigurable)) { + return false; + } + if (hasConfigurable) { + desc.setConfigurable(ToBoolean(v)); + } + + // Steps 7-8. + id = NameToId(cx->names().value); + bool hasValue = false; + if (!GetPropertyIfPresent(cx, obj, id, &v, &hasValue)) { + return false; + } + if (hasValue) { + desc.setValue(v); + } + + // Steps 9-10. + id = NameToId(cx->names().writable); + bool hasWritable = false; + if (!GetPropertyIfPresent(cx, obj, id, &v, &hasWritable)) { + return false; + } + if (hasWritable) { + desc.setWritable(ToBoolean(v)); + } + + // Steps 11-12. + id = NameToId(cx->names().get); + bool hasGet = false; + if (!GetPropertyIfPresent(cx, obj, id, &v, &hasGet)) { + return false; + } + RootedObject getter(cx); + if (hasGet) { + if (v.isObject()) { + if (checkAccessors) { + JS_TRY_OR_RETURN_FALSE(cx, CheckCallable(cx, &v.toObject(), "getter")); + } + getter = &v.toObject(); + } else if (v.isUndefined()) { + getter = nullptr; + } else { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_BAD_GET_SET_FIELD, "getter"); + return false; + } + } + + // Steps 13-14. + id = NameToId(cx->names().set); + bool hasSet = false; + if (!GetPropertyIfPresent(cx, obj, id, &v, &hasSet)) { + return false; + } + RootedObject setter(cx); + if (hasSet) { + if (v.isObject()) { + if (checkAccessors) { + JS_TRY_OR_RETURN_FALSE(cx, CheckCallable(cx, &v.toObject(), "setter")); + } + setter = &v.toObject(); + } else if (v.isUndefined()) { + setter = nullptr; + } else { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_BAD_GET_SET_FIELD, "setter"); + return false; + } + } + + // Step 15. + if (hasGet || hasSet) { + if (hasValue || hasWritable) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_INVALID_DESCRIPTOR); + return false; + } + + // We delay setGetter/setSetter after the previous check, + // because otherwise we would assert. + if (hasGet) { + desc.setGetter(getter); + } + if (hasSet) { + desc.setSetter(setter); + } + } + + desc.assertValid(); + desc_.set(desc); + return true; +} + +Result<> js::CheckPropertyDescriptorAccessors(JSContext* cx, + Handle desc) { + if (desc.hasGetter()) { + MOZ_TRY(CheckCallable(cx, desc.getter(), "getter")); + } + + if (desc.hasSetter()) { + MOZ_TRY(CheckCallable(cx, desc.setter(), "setter")); + } + + return Ok(); +} + +// 6.2.5.6 CompletePropertyDescriptor(Desc) +void js::CompletePropertyDescriptor(MutableHandle desc) { + // Step 1. + desc.assertValid(); + + // Step 2. + // Let like be the Record { [[Value]]: undefined, [[Writable]]: false, + // [[Get]]: undefined, [[Set]]: undefined, + // [[Enumerable]]: false, [[Configurable]]: false }. + + // Step 3. + if (desc.isGenericDescriptor() || desc.isDataDescriptor()) { + // Step 3.a. + if (!desc.hasValue()) { + desc.setValue(UndefinedHandleValue); + } + // Step 3.b. + if (!desc.hasWritable()) { + desc.setWritable(false); + } + } else { + // Step 4.a. + if (!desc.hasGetter()) { + desc.setGetter(nullptr); + } + // Step 4.b. + if (!desc.hasSetter()) { + desc.setSetter(nullptr); + } + } + + // Step 5. + if (!desc.hasEnumerable()) { + desc.setEnumerable(false); + } + + // Step 6. + if (!desc.hasConfigurable()) { + desc.setConfigurable(false); + } + + desc.assertComplete(); +} + +bool js::ReadPropertyDescriptors( + JSContext* cx, HandleObject props, bool checkAccessors, + MutableHandleIdVector ids, MutableHandle descs) { + if (!GetPropertyKeys(cx, props, JSITER_OWNONLY | JSITER_SYMBOLS, ids)) { + return false; + } + + RootedId id(cx); + for (size_t i = 0, len = ids.length(); i < len; i++) { + id = ids[i]; + Rooted desc(cx); + RootedValue v(cx); + if (!GetProperty(cx, props, props, id, &v) || + !ToPropertyDescriptor(cx, v, checkAccessors, &desc) || + !descs.append(desc)) { + return false; + } + } + return true; +} + +/*** Seal and freeze ********************************************************/ + +/* ES6 draft rev 29 (6 Dec 2014) 7.3.13. */ +bool js::SetIntegrityLevel(JSContext* cx, HandleObject obj, + IntegrityLevel level) { + cx->check(obj); + + // Steps 3-5. (Steps 1-2 are redundant assertions.) + if (!PreventExtensions(cx, obj)) { + return false; + } + + // Steps 6-9, loosely interpreted. + if (obj->is() && !obj->is() && + !obj->is()) { + Handle nobj = obj.as(); + + // Use a fast path to seal/freeze properties. This has the benefit of + // creating shared property maps if possible, whereas the slower/generic + // implementation below ends up converting non-empty objects to dictionary + // mode. + if (nobj->shape()->propMapLength() > 0) { + if (!NativeObject::freezeOrSealProperties(cx, nobj, level)) { + return false; + } + } + + // Ordinarily ArraySetLength handles this, but we're going behind its back + // right now, so we must do this manually. + if (level == IntegrityLevel::Frozen && obj->is()) { + obj->as().setNonWritableLength(cx); + } + } else { + // Steps 6-7. + RootedIdVector keys(cx); + if (!GetPropertyKeys( + cx, obj, JSITER_HIDDEN | JSITER_OWNONLY | JSITER_SYMBOLS, &keys)) { + return false; + } + + RootedId id(cx); + Rooted desc(cx, PropertyDescriptor::Empty()); + + // 8.a/9.a. The two different loops are merged here. + for (size_t i = 0; i < keys.length(); i++) { + id = keys[i]; + + if (level == IntegrityLevel::Sealed) { + // 8.a.i. + desc.setConfigurable(false); + } else { + // 9.a.i-ii. + Rooted> currentDesc(cx); + if (!GetOwnPropertyDescriptor(cx, obj, id, ¤tDesc)) { + return false; + } + + // 9.a.iii. + if (currentDesc.isNothing()) { + continue; + } + + // 9.a.iii.1-2 + desc = PropertyDescriptor::Empty(); + if (currentDesc->isAccessorDescriptor()) { + desc.setConfigurable(false); + } else { + desc.setConfigurable(false); + desc.setWritable(false); + } + } + + // 8.a.i-ii. / 9.a.iii.3-4 + if (!DefineProperty(cx, obj, id, desc)) { + return false; + } + } + } + + // Finally, freeze or seal the dense elements. + if (obj->is()) { + if (!ObjectElements::FreezeOrSeal(cx, obj.as(), level)) { + return false; + } + } + + return true; +} + +static bool ResolveLazyProperties(JSContext* cx, Handle obj) { + const JSClass* clasp = obj->getClass(); + if (JSEnumerateOp enumerate = clasp->getEnumerate()) { + if (!enumerate(cx, obj)) { + return false; + } + } + if (clasp->getNewEnumerate() && clasp->getResolve()) { + RootedIdVector properties(cx); + if (!clasp->getNewEnumerate()(cx, obj, &properties, + /* enumerableOnly = */ false)) { + return false; + } + + RootedId id(cx); + for (size_t i = 0; i < properties.length(); i++) { + id = properties[i]; + bool found; + if (!HasOwnProperty(cx, obj, id, &found)) { + return false; + } + } + } + return true; +} + +// ES6 draft rev33 (12 Feb 2015) 7.3.15 +bool js::TestIntegrityLevel(JSContext* cx, HandleObject obj, + IntegrityLevel level, bool* result) { + // Steps 3-6. (Steps 1-2 are redundant assertions.) + bool status; + if (!IsExtensible(cx, obj, &status)) { + return false; + } + if (status) { + *result = false; + return true; + } + + // Fast path for native objects. + if (obj->is()) { + Handle nobj = obj.as(); + + // Force lazy properties to be resolved. + if (!ResolveLazyProperties(cx, nobj)) { + return false; + } + + // Typed array elements are configurable, writable properties, so if any + // elements are present, the typed array can neither be sealed nor frozen. + if (nobj->is() && + nobj->as().length().valueOr(0) > 0) { + *result = false; + return true; + } + + bool hasDenseElements = false; + for (size_t i = 0; i < nobj->getDenseInitializedLength(); i++) { + if (nobj->containsDenseElement(i)) { + hasDenseElements = true; + break; + } + } + + if (hasDenseElements) { + // Unless the sealed flag is set, dense elements are configurable. + if (!nobj->denseElementsAreSealed()) { + *result = false; + return true; + } + + // Unless the frozen flag is set, dense elements are writable. + if (level == IntegrityLevel::Frozen && !nobj->denseElementsAreFrozen()) { + *result = false; + return true; + } + } + + // Steps 7-9. + for (ShapePropertyIter iter(nobj->shape()); !iter.done(); iter++) { + // Steps 9.c.i-ii. + if (iter->configurable() || + (level == IntegrityLevel::Frozen && iter->isDataDescriptor() && + iter->writable())) { + // Private fields on objects don't participate in the frozen state, and + // so should be elided from checking for frozen state. + if (iter->key().isPrivateName()) { + continue; + } + + *result = false; + return true; + } + } + } else { + // Steps 7-8. + RootedIdVector props(cx); + if (!GetPropertyKeys( + cx, obj, JSITER_HIDDEN | JSITER_OWNONLY | JSITER_SYMBOLS, &props)) { + return false; + } + + // Step 9. + RootedId id(cx); + Rooted> desc(cx); + for (size_t i = 0, len = props.length(); i < len; i++) { + id = props[i]; + + // Steps 9.a-b. + if (!GetOwnPropertyDescriptor(cx, obj, id, &desc)) { + return false; + } + + // Step 9.c. + if (desc.isNothing()) { + continue; + } + + // Steps 9.c.i-ii. + if (desc->configurable() || + (level == IntegrityLevel::Frozen && desc->isDataDescriptor() && + desc->writable())) { + // Since we don't request JSITER_PRIVATE in GetPropertyKeys above, we + // should never see a private name here. + MOZ_ASSERT(!id.isPrivateName()); + *result = false; + return true; + } + } + } + + // Step 10. + *result = true; + return true; +} + +/* * */ + +static MOZ_ALWAYS_INLINE NativeObject* NewObject( + JSContext* cx, const JSClass* clasp, Handle proto, + gc::AllocKind kind, NewObjectKind newKind, ObjectFlags objFlags) { + MOZ_ASSERT(clasp->isNativeObject()); + + // Some classes have specialized allocation functions and shouldn't end up + // here. + MOZ_ASSERT(clasp != &ArrayObject::class_); + MOZ_ASSERT(clasp != &PlainObject::class_); + MOZ_ASSERT(!clasp->isJSFunction()); + + // Computing nfixed based on the AllocKind isn't right for objects which can + // store fixed data inline (TypedArrays and ArrayBuffers) so for simplicity + // and performance reasons we don't support such objects here. + MOZ_ASSERT(!ClassCanHaveFixedData(clasp)); + size_t nfixed = GetGCKindSlots(kind); + + if (CanChangeToBackgroundAllocKind(kind, clasp)) { + kind = ForegroundToBackgroundAllocKind(kind); + } + + Rooted shape( + cx, SharedShape::getInitialShape(cx, clasp, cx->realm(), proto, nfixed, + objFlags)); + if (!shape) { + return nullptr; + } + + gc::Heap heap = GetInitialHeap(newKind, clasp); + NativeObject* obj = NativeObject::create(cx, kind, heap, shape); + if (!obj) { + return nullptr; + } + + probes::CreateObject(cx, obj); + return obj; +} + +NativeObject* js::NewObjectWithGivenTaggedProto( + JSContext* cx, const JSClass* clasp, Handle proto, + gc::AllocKind allocKind, NewObjectKind newKind, ObjectFlags objFlags) { + return NewObject(cx, clasp, proto, allocKind, newKind, objFlags); +} + +NativeObject* js::NewObjectWithClassProto(JSContext* cx, const JSClass* clasp, + HandleObject protoArg, + gc::AllocKind allocKind, + NewObjectKind newKind, + ObjectFlags objFlags) { + if (protoArg) { + return NewObjectWithGivenTaggedProto(cx, clasp, AsTaggedProto(protoArg), + allocKind, newKind, objFlags); + } + + // Find the appropriate proto for clasp. Built-in classes have a cached + // proto on cx->global(); all others get %ObjectPrototype%. + JSProtoKey protoKey = JSCLASS_CACHED_PROTO_KEY(clasp); + if (protoKey == JSProto_Null) { + protoKey = JSProto_Object; + } + + JSObject* proto = GlobalObject::getOrCreatePrototype(cx, protoKey); + if (!proto) { + return nullptr; + } + + Rooted taggedProto(cx, TaggedProto(proto)); + return NewObject(cx, clasp, taggedProto, allocKind, newKind, objFlags); +} + +bool js::GetPrototypeFromConstructor(JSContext* cx, HandleObject newTarget, + JSProtoKey intrinsicDefaultProto, + MutableHandleObject proto) { + RootedValue protov(cx); + if (!GetProperty(cx, newTarget, newTarget, cx->names().prototype, &protov)) { + return false; + } + if (protov.isObject()) { + proto.set(&protov.toObject()); + } else if (newTarget->is() && + newTarget->as().realm() == cx->realm()) { + // Steps 4.a-b fetch the builtin prototype of the current realm, which we + // represent as nullptr. + proto.set(nullptr); + } else if (intrinsicDefaultProto == JSProto_Null) { + // Bug 1317416. The caller did not pass a reasonable JSProtoKey, so let the + // caller select a prototype object. Most likely they will choose one from + // the wrong realm. + proto.set(nullptr); + } else { + // Step 4.a: Let realm be ? GetFunctionRealm(constructor); + Realm* realm = JS::GetFunctionRealm(cx, newTarget); + if (!realm) { + return false; + } + + // Step 4.b: Set proto to realm's intrinsic object named + // intrinsicDefaultProto. + { + Maybe ar; + if (cx->realm() != realm) { + ar.emplace(cx, realm->maybeGlobal()); + } + proto.set(GlobalObject::getOrCreatePrototype(cx, intrinsicDefaultProto)); + } + if (!proto) { + return false; + } + if (!cx->compartment()->wrap(cx, proto)) { + return false; + } + } + return true; +} + +/* static */ +bool JSObject::nonNativeSetProperty(JSContext* cx, HandleObject obj, + HandleId id, HandleValue v, + HandleValue receiver, + ObjectOpResult& result) { + return obj->getOpsSetProperty()(cx, obj, id, v, receiver, result); +} + +/* static */ +bool JSObject::nonNativeSetElement(JSContext* cx, HandleObject obj, + uint32_t index, HandleValue v, + HandleValue receiver, + ObjectOpResult& result) { + RootedId id(cx); + if (!IndexToId(cx, index, &id)) { + return false; + } + return nonNativeSetProperty(cx, obj, id, v, receiver, result); +} + +static bool CopyPropertyFrom(JSContext* cx, HandleId id, HandleObject target, + HandleObject obj) { + // |target| must not be a CCW because we need to enter its realm below and + // CCWs are not associated with a single realm. + MOZ_ASSERT(!IsCrossCompartmentWrapper(target)); + + // |obj| and |cx| are generally not same-compartment with |target| here. + cx->check(obj, id); + Rooted> desc(cx); + + if (!GetOwnPropertyDescriptor(cx, obj, id, &desc)) { + return false; + } + MOZ_ASSERT(desc.isSome()); + + JSAutoRealm ar(cx, target); + cx->markId(id); + RootedId wrappedId(cx, id); + if (!cx->compartment()->wrap(cx, &desc)) { + return false; + } + + Rooted desc_(cx, *desc); + return DefineProperty(cx, target, wrappedId, desc_); +} + +JS_PUBLIC_API bool JS_CopyOwnPropertiesAndPrivateFields(JSContext* cx, + HandleObject target, + HandleObject obj) { + // Both |obj| and |target| must not be CCWs because we need to enter their + // realms below and CCWs are not associated with a single realm. + MOZ_ASSERT(!IsCrossCompartmentWrapper(obj)); + MOZ_ASSERT(!IsCrossCompartmentWrapper(target)); + + JSAutoRealm ar(cx, obj); + + RootedIdVector props(cx); + if (!GetPropertyKeys( + cx, obj, + JSITER_PRIVATE | JSITER_OWNONLY | JSITER_HIDDEN | JSITER_SYMBOLS, + &props)) { + return false; + } + + for (size_t i = 0; i < props.length(); ++i) { + if (!CopyPropertyFrom(cx, props[i], target, obj)) { + return false; + } + } + + return true; +} + +static bool InitializePropertiesFromCompatibleNativeObject( + JSContext* cx, Handle dst, Handle src) { + cx->check(src, dst); + MOZ_ASSERT(src->getClass() == dst->getClass()); + MOZ_ASSERT(dst->shape()->objectFlags().isEmpty()); + MOZ_ASSERT(src->numFixedSlots() == dst->numFixedSlots()); + MOZ_ASSERT(!src->inDictionaryMode()); + MOZ_ASSERT(!dst->inDictionaryMode()); + + if (!dst->ensureElements(cx, src->getDenseInitializedLength())) { + return false; + } + + uint32_t initialized = src->getDenseInitializedLength(); + for (uint32_t i = 0; i < initialized; ++i) { + dst->setDenseInitializedLength(i + 1); + dst->initDenseElement(i, src->getDenseElement(i)); + } + + // If there are no properties to copy, we're done. + if (!src->sharedShape()->propMap()) { + return true; + } + + Rooted shape(cx); + if (src->staticPrototype() == dst->staticPrototype()) { + shape = src->sharedShape(); + } else { + // We need to generate a new shape for dst that has dst's proto but all + // the property information from src. Note that we asserted above that + // dst's object flags are empty. + SharedShape* srcShape = src->sharedShape(); + ObjectFlags objFlags; + objFlags = CopyPropMapObjectFlags(objFlags, srcShape->objectFlags()); + Rooted map(cx, srcShape->propMap()); + uint32_t mapLength = srcShape->propMapLength(); + shape = SharedShape::getPropMapShape(cx, dst->shape()->base(), + dst->numFixedSlots(), map, mapLength, + objFlags); + if (!shape) { + return false; + } + } + + uint32_t oldSpan = dst->sharedShape()->slotSpan(); + uint32_t newSpan = shape->slotSpan(); + if (!dst->setShapeAndAddNewSlots(cx, shape, oldSpan, newSpan)) { + return false; + } + for (size_t i = JSCLASS_RESERVED_SLOTS(src->getClass()); i < newSpan; i++) { + dst->setSlot(i, src->getSlot(i)); + } + + return true; +} + +JS_PUBLIC_API bool JS_InitializePropertiesFromCompatibleNativeObject( + JSContext* cx, HandleObject dst, HandleObject src) { + return InitializePropertiesFromCompatibleNativeObject( + cx, dst.as(), src.as()); +} + +bool js::ObjectMayBeSwapped(const JSObject* obj) { + const JSClass* clasp = obj->getClass(); + + // We want to optimize Window/globals and Gecko doesn't require transplanting + // them (only the WindowProxy around them). A Window may be a DOMClass, so we + // explicitly check if this is a global. + if (clasp->isGlobal()) { + return false; + } + + // WindowProxy, Wrapper, DeadProxyObject, DOMProxy, and DOMClass (non-global) + // types may be swapped. It is hard to detect DOMProxy from shell, so target + // proxies in general. + return clasp->isProxyObject() || clasp->isDOMClass(); +} + +bool NativeObject::prepareForSwap(JSContext* cx, + MutableHandleValueVector slotValuesOut) { + MOZ_ASSERT(slotValuesOut.empty()); + + for (size_t i = 0; i < slotSpan(); i++) { + if (!slotValuesOut.append(getSlot(i))) { + return false; + } + } + + if (hasDynamicSlots()) { + ObjectSlots* slotsHeader = getSlotsHeader(); + size_t size = ObjectSlots::allocSize(slotsHeader->capacity()); + RemoveCellMemory(this, size, MemoryUse::ObjectSlots); + if (!cx->nursery().isInside(slotsHeader)) { + if (!isTenured()) { + cx->nursery().removeMallocedBuffer(slotsHeader, size); + } + js_free(slotsHeader); + } + setEmptyDynamicSlots(0); + } + + if (hasDynamicElements()) { + ObjectElements* elements = getElementsHeader(); + void* allocatedElements = getUnshiftedElementsHeader(); + size_t count = elements->numAllocatedElements(); + size_t size = count * sizeof(HeapSlot); + + if (isTenured()) { + RemoveCellMemory(this, size, MemoryUse::ObjectElements); + } else if (cx->nursery().isInside(allocatedElements)) { + // Move nursery allocated elements in case they end up in a tenured + // object. + ObjectElements* newElements = + reinterpret_cast(js_pod_malloc(count)); + if (!newElements) { + return false; + } + + memmove(newElements, elements, size); + elements_ = newElements->elements(); + } else { + cx->nursery().removeMallocedBuffer(allocatedElements, size); + } + MOZ_ASSERT(hasDynamicElements()); + } + + return true; +} + +/* static */ +bool NativeObject::fixupAfterSwap(JSContext* cx, Handle obj, + gc::AllocKind kind, + HandleValueVector slotValues) { + // This object has just been swapped with some other object, and its shape + // no longer reflects its allocated size. Correct this information and + // fill the slots in with the specified values. + MOZ_ASSERT_IF(!obj->inDictionaryMode(), + obj->slotSpan() == slotValues.length()); + + // Make sure the shape's numFixedSlots() is correct. + size_t nfixed = gc::GetGCKindSlots(kind); + if (nfixed != obj->shape()->numFixedSlots()) { + if (!NativeObject::changeNumFixedSlotsAfterSwap(cx, obj, nfixed)) { + return false; + } + MOZ_ASSERT(obj->shape()->numFixedSlots() == nfixed); + } + + uint32_t oldDictionarySlotSpan = + obj->inDictionaryMode() ? slotValues.length() : 0; + + MOZ_ASSERT(!obj->hasUniqueId()); + size_t ndynamic = + calculateDynamicSlots(nfixed, slotValues.length(), obj->getClass()); + size_t currentSlots = obj->getSlotsHeader()->capacity(); + MOZ_ASSERT(ndynamic >= currentSlots); + if (ndynamic > currentSlots) { + if (!obj->growSlots(cx, currentSlots, ndynamic)) { + return false; + } + } + + if (obj->inDictionaryMode()) { + obj->setDictionaryModeSlotSpan(oldDictionarySlotSpan); + } + + for (size_t i = 0, len = slotValues.length(); i < len; i++) { + obj->initSlotUnchecked(i, slotValues[i]); + } + + if (obj->hasDynamicElements()) { + ObjectElements* elements = obj->getElementsHeader(); + void* allocatedElements = obj->getUnshiftedElementsHeader(); + MOZ_ASSERT(!cx->nursery().isInside(allocatedElements)); + size_t size = elements->numAllocatedElements() * sizeof(HeapSlot); + if (obj->isTenured()) { + AddCellMemory(obj, size, MemoryUse::ObjectElements); + } else if (!cx->nursery().registerMallocedBuffer(allocatedElements, size)) { + return false; + } + } + + return true; +} + +[[nodiscard]] bool ProxyObject::prepareForSwap( + JSContext* cx, MutableHandleValueVector valuesOut) { + MOZ_ASSERT(valuesOut.empty()); + + // Remove the GCPtrs we're about to swap from the store buffer, to + // ensure we don't trace bogus values. + gc::StoreBuffer& sb = cx->runtime()->gc.storeBuffer(); + + // Reserve space for the expando, private slot and the reserved slots. + if (!valuesOut.reserve(2 + numReservedSlots())) { + return false; + } + + js::detail::ProxyValueArray* valArray = data.values(); + sb.unputValue(&valArray->expandoSlot); + sb.unputValue(&valArray->privateSlot); + valuesOut.infallibleAppend(valArray->expandoSlot); + valuesOut.infallibleAppend(valArray->privateSlot); + + for (size_t i = 0; i < numReservedSlots(); i++) { + sb.unputValue(&valArray->reservedSlots.slots[i]); + valuesOut.infallibleAppend(valArray->reservedSlots.slots[i]); + } + + if (isTenured() && !usingInlineValueArray()) { + size_t count = detail::ProxyValueArray::allocCount(numReservedSlots()); + RemoveCellMemory(this, count * sizeof(Value), + MemoryUse::ProxyExternalValueArray); + js_free(valArray); + data.reservedSlots = nullptr; + } + + return true; +} + +bool ProxyObject::fixupAfterSwap(JSContext* cx, + const HandleValueVector values) { + MOZ_ASSERT(getClass()->isProxyObject()); + + size_t nreserved = numReservedSlots(); + + // |values| contains the expando slot, private slot and the reserved slots. + MOZ_ASSERT(values.length() == 2 + nreserved); + + // Allocate the external value array in malloc memory, even for nursery + // proxies. + size_t count = detail::ProxyValueArray::allocCount(nreserved); + auto* allocation = js_pod_malloc(count); + if (!allocation) { + return false; + } + + size_t size = count * sizeof(Value); + if (isTenured()) { + AddCellMemory(&asTenured(), size, MemoryUse::ProxyExternalValueArray); + } else if (!cx->nursery().registerMallocedBuffer(allocation, size)) { + js_free(allocation); + return false; + } + + auto* valArray = reinterpret_cast(allocation); + + valArray->expandoSlot = values[0]; + valArray->privateSlot = values[1]; + + for (size_t i = 0; i < nreserved; i++) { + valArray->reservedSlots.slots[i] = values[i + 2]; + } + + data.reservedSlots = &valArray->reservedSlots; + MOZ_ASSERT(!usingInlineValueArray()); + return true; +} + +static gc::AllocKind SwappableObjectAllocKind(JSObject* obj) { + MOZ_ASSERT(ObjectMayBeSwapped(obj)); + + if (obj->isTenured()) { + return obj->asTenured().getAllocKind(); + } + + if (obj->is()) { + return obj->as().allocKindForTenure(); + } + + return obj->as().allocKindForTenure(); +} + +/* Use this method with extreme caution. It trades the guts of two objects. */ +void JSObject::swap(JSContext* cx, HandleObject a, HandleObject b, + AutoEnterOOMUnsafeRegion& oomUnsafe) { + // Ensure swap doesn't cause a finalizer to be run at the wrong time. + MOZ_ASSERT(a->isBackgroundFinalized() == b->isBackgroundFinalized()); + + MOZ_ASSERT(a->compartment() == b->compartment()); + + // You must have entered the objects' compartment before calling this. + MOZ_ASSERT(cx->compartment() == a->compartment()); + + // Only certain types of objects are allowed to be swapped. This allows the + // JITs to better optimize objects that can never swap and rules out most + // builtin objects that have special behaviour. + MOZ_RELEASE_ASSERT(js::ObjectMayBeSwapped(a)); + MOZ_RELEASE_ASSERT(js::ObjectMayBeSwapped(b)); + + if (!Watchtower::watchObjectSwap(cx, a, b)) { + oomUnsafe.crash("watchObjectSwap"); + } + + // Ensure we update any embedded nursery pointers in either object. + gc::StoreBuffer& storeBuffer = cx->runtime()->gc.storeBuffer(); + if (a->isTenured()) { + storeBuffer.putWholeCell(a); + } + if (b->isTenured()) { + storeBuffer.putWholeCell(b); + } + if (a->isTenured() || b->isTenured()) { + if (a->zone()->wasGCStarted()) { + storeBuffer.setMayHavePointersToDeadCells(); + } + } + + unsigned r = NotifyGCPreSwap(a, b); + + ProxyObject* pa = a->is() ? &a->as() : nullptr; + ProxyObject* pb = b->is() ? &b->as() : nullptr; + bool aIsProxyWithInlineValues = pa && pa->usingInlineValueArray(); + bool bIsProxyWithInlineValues = pb && pb->usingInlineValueArray(); + + bool aIsUsedAsPrototype = a->isUsedAsPrototype(); + bool bIsUsedAsPrototype = b->isUsedAsPrototype(); + + // Swap element associations. + Zone* zone = a->zone(); + + // Record any associated unique IDs and prepare for swap. + // + // Note that unique IDs are NOT swapped but remain associated with the + // original address. + uint64_t aid = 0; + uint64_t bid = 0; + (void)gc::MaybeGetUniqueId(a, &aid); + (void)gc::MaybeGetUniqueId(b, &bid); + NativeObject* na = a->is() ? &a->as() : nullptr; + NativeObject* nb = b->is() ? &b->as() : nullptr; + if ((aid || bid) && (na || nb)) { + // We can't remove unique IDs from native objects when they are swapped with + // objects without an ID. Instead ensure they both have IDs so we always + // have something to overwrite the old ID with. + if (!gc::GetOrCreateUniqueId(a, &aid) || + !gc::GetOrCreateUniqueId(b, &bid)) { + oomUnsafe.crash("Failed to create unique ID during swap"); + } + + // IDs stored in NativeObjects could shadow those stored in the zone + // table. Remove any zone table IDs first. + if (pa && aid) { + gc::RemoveUniqueId(a); + } + if (pb && bid) { + gc::RemoveUniqueId(b); + } + } + + gc::AllocKind ka = SwappableObjectAllocKind(a); + gc::AllocKind kb = SwappableObjectAllocKind(b); + + size_t sa = gc::Arena::thingSize(ka); + size_t sb = gc::Arena::thingSize(kb); + if (sa == sb && a->isTenured() == b->isTenured()) { + // When both objects are the same size and in the same heap, just do a plain + // swap of their contents. + + // Swap slot associations. + zone->swapCellMemory(a, b, MemoryUse::ObjectSlots); + + size_t size = sa; + char tmp[sizeof(JSObject_Slots16)]; + MOZ_ASSERT(size <= sizeof(tmp)); + + js_memcpy(tmp, a, size); + js_memcpy(a, b, size); + js_memcpy(b, tmp, size); + + zone->swapCellMemory(a, b, MemoryUse::ObjectElements); + zone->swapCellMemory(a, b, MemoryUse::ProxyExternalValueArray); + + if (aIsProxyWithInlineValues) { + b->as().setInlineValueArray(); + } + if (bIsProxyWithInlineValues) { + a->as().setInlineValueArray(); + } + } else { + // Avoid GC in here to avoid confusing the tracing code with our + // intermediate state. + gc::AutoSuppressGC suppress(cx); + + // When the objects have different sizes, they will have different numbers + // of fixed slots before and after the swap, so the slots for native objects + // will need to be rearranged. Remember the original values from the + // objects. + RootedValueVector avals(cx); + RootedValueVector bvals(cx); + if (na && !na->prepareForSwap(cx, &avals)) { + oomUnsafe.crash("NativeObject::prepareForSwap"); + } + if (nb && !nb->prepareForSwap(cx, &bvals)) { + oomUnsafe.crash("NativeObject::prepareForSwap"); + } + + // Do the same for proxy value arrays. + if (pa && !pa->prepareForSwap(cx, &avals)) { + oomUnsafe.crash("ProxyObject::prepareForSwap"); + } + if (pb && !pb->prepareForSwap(cx, &bvals)) { + oomUnsafe.crash("ProxyObject::prepareForSwap"); + } + + // Swap the main fields of the objects, whether they are native objects or + // proxies. + char tmp[sizeof(JSObject_Slots0)]; + js_memcpy(&tmp, a, sizeof tmp); + js_memcpy(a, b, sizeof tmp); + js_memcpy(b, &tmp, sizeof tmp); + + if (na && + !NativeObject::fixupAfterSwap(cx, b.as(), kb, avals)) { + oomUnsafe.crash("NativeObject::fixupAfterSwap"); + } + if (nb && + !NativeObject::fixupAfterSwap(cx, a.as(), ka, bvals)) { + oomUnsafe.crash("NativeObject::fixupAfterSwap"); + } + + if (pa && !b->as().fixupAfterSwap(cx, avals)) { + oomUnsafe.crash("ProxyObject::fixupAfterSwap"); + } + if (pb && !a->as().fixupAfterSwap(cx, bvals)) { + oomUnsafe.crash("ProxyObject::fixupAfterSwap"); + } + } + + // Restore original unique IDs. + if ((aid || bid) && (na || nb)) { + if ((aid && !gc::SetOrUpdateUniqueId(cx, a, aid)) || + (bid && !gc::SetOrUpdateUniqueId(cx, b, bid))) { + oomUnsafe.crash("Failed to set unique ID after swap"); + } + } + MOZ_ASSERT_IF(aid, gc::GetUniqueIdInfallible(a) == aid); + MOZ_ASSERT_IF(bid, gc::GetUniqueIdInfallible(b) == bid); + + // Preserve the IsUsedAsPrototype flag on the objects. + if (aIsUsedAsPrototype) { + if (!JSObject::setIsUsedAsPrototype(cx, a)) { + oomUnsafe.crash("setIsUsedAsPrototype"); + } + } + if (bIsUsedAsPrototype) { + if (!JSObject::setIsUsedAsPrototype(cx, b)) { + oomUnsafe.crash("setIsUsedAsPrototype"); + } + } + + /* + * We need a write barrier here. If |a| was marked and |b| was not, then + * after the swap, |b|'s guts would never be marked. The write barrier + * solves this. + * + * Normally write barriers happen before the write. However, that's not + * necessary here because nothing is being destroyed. We're just swapping. + */ + PreWriteBarrier(zone, a.get(), [](JSTracer* trc, JSObject* obj) { + obj->traceChildren(trc); + }); + PreWriteBarrier(zone, b.get(), [](JSTracer* trc, JSObject* obj) { + obj->traceChildren(trc); + }); + + NotifyGCPostSwap(a, b, r); +} + +static NativeObject* DefineConstructorAndPrototype( + JSContext* cx, HandleObject obj, Handle atom, + HandleObject protoProto, const JSClass* clasp, Native constructor, + unsigned nargs, const JSPropertySpec* ps, const JSFunctionSpec* fs, + const JSPropertySpec* static_ps, const JSFunctionSpec* static_fs, + NativeObject** ctorp) { + // Create the prototype object. + Rooted proto( + cx, GlobalObject::createBlankPrototypeInheriting(cx, clasp, protoProto)); + if (!proto) { + return nullptr; + } + + Rooted ctor(cx); + if (!constructor) { + ctor = proto; + } else { + ctor = NewNativeConstructor(cx, constructor, nargs, atom); + if (!ctor) { + return nullptr; + } + + if (!LinkConstructorAndPrototype(cx, ctor, proto)) { + return nullptr; + } + } + + if (!DefinePropertiesAndFunctions(cx, proto, ps, fs) || + (ctor != proto && + !DefinePropertiesAndFunctions(cx, ctor, static_ps, static_fs))) { + return nullptr; + } + + RootedId id(cx, AtomToId(atom)); + RootedValue value(cx, ObjectValue(*ctor)); + if (!DefineDataProperty(cx, obj, id, value, 0)) { + return nullptr; + } + + if (ctorp) { + *ctorp = ctor; + } + return proto; +} + +NativeObject* js::InitClass(JSContext* cx, HandleObject obj, + const JSClass* protoClass, HandleObject protoProto_, + const char* name, Native constructor, + unsigned nargs, const JSPropertySpec* ps, + const JSFunctionSpec* fs, + const JSPropertySpec* static_ps, + const JSFunctionSpec* static_fs, + NativeObject** ctorp) { + Rooted atom(cx, Atomize(cx, name, strlen(name))); + if (!atom) { + return nullptr; + } + + /* + * All instances of the class will inherit properties from the prototype + * object we are about to create (in DefineConstructorAndPrototype), which + * in turn will inherit from protoProto. + * + * If protoProto is nullptr, default to Object.prototype. + * If protoClass is nullptr, default to PlainObject. + */ + RootedObject protoProto(cx, protoProto_); + if (!protoProto) { + protoProto = &cx->global()->getObjectPrototype(); + } + if (!protoClass) { + protoClass = &PlainObject::class_; + } + + return DefineConstructorAndPrototype(cx, obj, atom, protoProto, protoClass, + constructor, nargs, ps, fs, static_ps, + static_fs, ctorp); +} + +/** + * Returns the original Object.prototype from the embedding-provided incumbent + * global. + * + * Really, we want the incumbent global itself so we can pass it to other + * embedding hooks which need it. Specifically, the enqueue promise hook + * takes an incumbent global so it can set that on the PromiseCallbackJob + * it creates. + * + * The reason for not just returning the global itself is that we'd need to + * wrap it into the current compartment, and later unwrap it. Unwrapping + * globals is tricky, though: we might accidentally unwrap through an inner + * to its outer window and end up with the wrong global. Plain objects don't + * have this problem, so we use the global's Object.prototype. The code using + * it - e.g. EnqueuePromiseReactionJob - can then unwrap the object and get + * its global without fear of unwrapping too far. + */ +bool js::GetObjectFromIncumbentGlobal(JSContext* cx, MutableHandleObject obj) { + Rooted globalObj(cx, cx->runtime()->getIncumbentGlobal(cx)); + if (!globalObj) { + obj.set(nullptr); + return true; + } + + obj.set(&globalObj->getObjectPrototype()); + + // The object might be from a different compartment, so wrap it. + if (obj && !cx->compartment()->wrap(cx, obj)) { + return false; + } + + return true; +} + +static bool IsStandardPrototype(JSObject* obj, JSProtoKey key) { + return obj->nonCCWGlobal().maybeGetPrototype(key) == obj; +} + +JSProtoKey JS::IdentifyStandardInstance(JSObject* obj) { + // Note: The prototype shares its JSClass with instances. + MOZ_ASSERT(!obj->is()); + JSProtoKey key = StandardProtoKeyOrNull(obj); + if (key != JSProto_Null && !IsStandardPrototype(obj, key)) { + return key; + } + return JSProto_Null; +} + +JSProtoKey JS::IdentifyStandardPrototype(JSObject* obj) { + // Note: The prototype shares its JSClass with instances. + MOZ_ASSERT(!obj->is()); + JSProtoKey key = StandardProtoKeyOrNull(obj); + if (key != JSProto_Null && IsStandardPrototype(obj, key)) { + return key; + } + return JSProto_Null; +} + +JSProtoKey JS::IdentifyStandardInstanceOrPrototype(JSObject* obj) { + return StandardProtoKeyOrNull(obj); +} + +JSProtoKey JS::IdentifyStandardConstructor(JSObject* obj) { + // Note that isNativeConstructor does not imply that we are a standard + // constructor, but the converse is true (at least until we start having + // self-hosted constructors for standard classes). This lets us avoid a costly + // loop for many functions (which, depending on the call site, may be the + // common case). + if (!obj->is() || + !(obj->as().flags().isNativeConstructor())) { + return JSProto_Null; + } + + static_assert(JSProto_Null == 0, + "Loop below can start at 1 to skip JSProto_Null"); + + GlobalObject& global = obj->as().global(); + for (size_t k = 1; k < JSProto_LIMIT; ++k) { + JSProtoKey key = static_cast(k); + if (global.maybeGetConstructor(key) == obj) { + return key; + } + } + + return JSProto_Null; +} + +bool js::LookupProperty(JSContext* cx, HandleObject obj, js::HandleId id, + MutableHandleObject objp, PropertyResult* propp) { + if (LookupPropertyOp op = obj->getOpsLookupProperty()) { + return op(cx, obj, id, objp, propp); + } + return NativeLookupPropertyInline(cx, obj.as(), id, objp, + propp); +} + +bool js::LookupName(JSContext* cx, Handle name, + HandleObject envChain, MutableHandleObject objp, + MutableHandleObject pobjp, PropertyResult* propp) { + RootedId id(cx, NameToId(name)); + + for (RootedObject env(cx, envChain); env; env = env->enclosingEnvironment()) { + if (!LookupProperty(cx, env, id, pobjp, propp)) { + return false; + } + if (propp->isFound()) { + objp.set(env); + return true; + } + } + + objp.set(nullptr); + pobjp.set(nullptr); + propp->setNotFound(); + return true; +} + +bool js::LookupNameNoGC(JSContext* cx, PropertyName* name, JSObject* envChain, + JSObject** objp, NativeObject** pobjp, + PropertyResult* propp) { + AutoAssertNoPendingException nogc(cx); + + MOZ_ASSERT(!*objp && !*pobjp && propp->isNotFound()); + + for (JSObject* env = envChain; env; env = env->enclosingEnvironment()) { + if (env->getOpsLookupProperty()) { + return false; + } + if (!NativeLookupPropertyInline(cx, &env->as(), + NameToId(name), pobjp, propp)) { + return false; + } + if (propp->isFound()) { + *objp = env; + return true; + } + } + + return true; +} + +bool js::LookupNameWithGlobalDefault(JSContext* cx, Handle name, + HandleObject envChain, + MutableHandleObject objp) { + RootedId id(cx, NameToId(name)); + + RootedObject pobj(cx); + PropertyResult prop; + + RootedObject env(cx, envChain); + for (; !env->is(); env = env->enclosingEnvironment()) { + if (!LookupProperty(cx, env, id, &pobj, &prop)) { + return false; + } + if (prop.isFound()) { + break; + } + } + + objp.set(env); + return true; +} + +bool js::LookupNameUnqualified(JSContext* cx, Handle name, + HandleObject envChain, + MutableHandleObject objp) { + RootedId id(cx, NameToId(name)); + + RootedObject pobj(cx); + PropertyResult prop; + + RootedObject env(cx, envChain); + for (; !env->isUnqualifiedVarObj(); env = env->enclosingEnvironment()) { + if (!LookupProperty(cx, env, id, &pobj, &prop)) { + return false; + } + if (prop.isFound()) { + break; + } + } + + // See note above RuntimeLexicalErrorObject. + if (pobj == env) { + bool isTDZ = false; + if (prop.isFound() && name != cx->names().dot_this_) { + // Treat Debugger environments specially for TDZ checks, as they + // look like non-native environments but in fact wrap native + // environments. + if (env->is()) { + RootedValue v(cx); + Rooted envProxy( + cx, &env->as()); + if (!DebugEnvironmentProxy::getMaybeSentinelValue(cx, envProxy, id, + &v)) { + return false; + } + isTDZ = IsUninitializedLexical(v); + } else { + isTDZ = IsUninitializedLexicalSlot(env, prop); + } + } + + if (isTDZ) { + env = RuntimeLexicalErrorObject::create(cx, env, + JSMSG_UNINITIALIZED_LEXICAL); + if (!env) { + return false; + } + } else if (env->is() && + !prop.propertyInfo().writable()) { + // Assigning to a named lambda callee name is a no-op in sloppy mode. + if (!(env->is() && + env->as().scope().kind() == + ScopeKind::NamedLambda)) { + MOZ_ASSERT(name != cx->names().dot_this_); + env = + RuntimeLexicalErrorObject::create(cx, env, JSMSG_BAD_CONST_ASSIGN); + if (!env) { + return false; + } + } + } + } + + objp.set(env); + return true; +} + +bool js::HasOwnProperty(JSContext* cx, HandleObject obj, HandleId id, + bool* result) { + if (obj->is()) { + return Proxy::hasOwn(cx, obj, id, result); + } + + if (GetOwnPropertyOp op = obj->getOpsGetOwnPropertyDescriptor()) { + Rooted> desc(cx); + if (!op(cx, obj, id, &desc)) { + return false; + } + *result = desc.isSome(); + return true; + } + + PropertyResult prop; + if (!NativeLookupOwnProperty(cx, obj.as(), id, &prop)) { + return false; + } + *result = prop.isFound(); + return true; +} + +bool js::LookupPropertyPure(JSContext* cx, JSObject* obj, jsid id, + NativeObject** objp, PropertyResult* propp) { + if (obj->getOpsLookupProperty()) { + return false; + } + return NativeLookupPropertyInline( + cx, &obj->as(), id, objp, propp); +} + +bool js::LookupOwnPropertyPure(JSContext* cx, JSObject* obj, jsid id, + PropertyResult* propp) { + if (obj->getOpsLookupProperty()) { + return false; + } + return NativeLookupOwnPropertyInline( + cx, &obj->as(), id, propp); +} + +static inline bool NativeGetPureInline(NativeObject* pobj, jsid id, + PropertyResult prop, Value* vp, + JSContext* cx) { + if (prop.isDenseElement()) { + *vp = pobj->getDenseElement(prop.denseElementIndex()); + return true; + } + if (prop.isTypedArrayElement()) { + size_t idx = prop.typedArrayElementIndex(); + return pobj->as().getElement(cx, idx, vp); + } + + // Fail if we have a custom getter. + PropertyInfo propInfo = prop.propertyInfo(); + if (!propInfo.isDataProperty()) { + return false; + } + + *vp = pobj->getSlot(propInfo.slot()); + MOZ_ASSERT(!vp->isMagic()); + return true; +} + +bool js::GetPropertyPure(JSContext* cx, JSObject* obj, jsid id, Value* vp) { + NativeObject* pobj; + PropertyResult prop; + if (!LookupPropertyPure(cx, obj, id, &pobj, &prop)) { + return false; + } + + if (prop.isNotFound()) { + vp->setUndefined(); + return true; + } + + return NativeGetPureInline(pobj, id, prop, vp, cx); +} + +bool js::GetOwnPropertyPure(JSContext* cx, JSObject* obj, jsid id, Value* vp, + bool* found) { + PropertyResult prop; + if (!LookupOwnPropertyPure(cx, obj, id, &prop)) { + return false; + } + + if (prop.isNotFound()) { + *found = false; + vp->setUndefined(); + return true; + } + + *found = true; + return obj->is() && + NativeGetPureInline(&obj->as(), id, prop, vp, cx); +} + +static inline bool NativeGetGetterPureInline(NativeObject* holder, + PropertyResult prop, + JSFunction** fp) { + MOZ_ASSERT(prop.isNativeProperty()); + + PropertyInfo propInfo = prop.propertyInfo(); + if (holder->hasGetter(propInfo)) { + JSObject* getter = holder->getGetter(propInfo); + if (getter->is()) { + *fp = &getter->as(); + return true; + } + } + + *fp = nullptr; + return true; +} + +bool js::GetGetterPure(JSContext* cx, JSObject* obj, jsid id, JSFunction** fp) { + /* Just like GetPropertyPure, but get getter function, without invoking + * it. */ + NativeObject* pobj; + PropertyResult prop; + if (!LookupPropertyPure(cx, obj, id, &pobj, &prop)) { + return false; + } + + if (prop.isNotFound()) { + *fp = nullptr; + return true; + } + + return prop.isNativeProperty() && NativeGetGetterPureInline(pobj, prop, fp); +} + +bool js::GetOwnGetterPure(JSContext* cx, JSObject* obj, jsid id, + JSFunction** fp) { + JS::AutoCheckCannotGC nogc; + PropertyResult prop; + if (!LookupOwnPropertyPure(cx, obj, id, &prop)) { + return false; + } + + if (prop.isNotFound()) { + *fp = nullptr; + return true; + } + + return prop.isNativeProperty() && + NativeGetGetterPureInline(&obj->as(), prop, fp); +} + +bool js::GetOwnNativeGetterPure(JSContext* cx, JSObject* obj, jsid id, + JSNative* native) { + JS::AutoCheckCannotGC nogc; + *native = nullptr; + PropertyResult prop; + if (!LookupOwnPropertyPure(cx, obj, id, &prop)) { + return false; + } + + if (!prop.isNativeProperty()) { + return true; + } + + PropertyInfo propInfo = prop.propertyInfo(); + + NativeObject* nobj = &obj->as(); + if (!nobj->hasGetter(propInfo)) { + return true; + } + + JSObject* getterObj = nobj->getGetter(propInfo); + if (!getterObj->is()) { + return true; + } + + JSFunction* getter = &getterObj->as(); + if (!getter->isNativeFun()) { + return true; + } + + *native = getter->native(); + return true; +} + +bool js::HasOwnDataPropertyPure(JSContext* cx, JSObject* obj, jsid id, + bool* result) { + PropertyResult prop; + if (!LookupOwnPropertyPure(cx, obj, id, &prop)) { + return false; + } + + *result = prop.isNativeProperty() && prop.propertyInfo().isDataProperty(); + return true; +} + +bool js::GetPrototypeIfOrdinary(JSContext* cx, HandleObject obj, + bool* isOrdinary, MutableHandleObject protop) { + if (obj->is()) { + return js::Proxy::getPrototypeIfOrdinary(cx, obj, isOrdinary, protop); + } + + *isOrdinary = true; + protop.set(obj->staticPrototype()); + return true; +} + +/*** ES6 standard internal methods ******************************************/ + +bool js::SetPrototype(JSContext* cx, HandleObject obj, HandleObject proto, + JS::ObjectOpResult& result) { + // The proxy trap subsystem fully handles prototype-setting for proxies + // with dynamic [[Prototype]]s. + if (obj->hasDynamicPrototype()) { + MOZ_ASSERT(obj->is()); + return Proxy::setPrototype(cx, obj, proto, result); + } + + /* + * ES6 9.1.2 step 3-4 if |obj.[[Prototype]]| has SameValue as |proto| return + * true. Since the values in question are objects, we can just compare + * pointers. + */ + if (proto == obj->staticPrototype()) { + return result.succeed(); + } + + /* Disallow mutation of immutable [[Prototype]]s. */ + if (obj->staticPrototypeIsImmutable()) { + return result.fail(JSMSG_CANT_SET_PROTO); + } + + /* + * Disallow mutating the [[Prototype]] on WebAssembly GC objects. + */ + if (obj->is()) { + return result.fail(JSMSG_CANT_SET_PROTO); + } + + /* ES6 9.1.2 step 5 forbids changing [[Prototype]] if not [[Extensible]]. */ + bool extensible; + if (!IsExtensible(cx, obj, &extensible)) { + return false; + } + if (!extensible) { + return result.fail(JSMSG_CANT_SET_PROTO); + } + + /* + * ES6 9.1.2 step 6 forbids generating cyclical prototype chains. But we + * have to do this comparison on the observable WindowProxy, not on the + * possibly-Window object we're setting the proto on. + */ + RootedObject objMaybeWindowProxy(cx, ToWindowProxyIfWindow(obj)); + RootedObject obj2(cx, proto); + while (obj2) { + MOZ_ASSERT(!IsWindow(obj2)); + if (obj2 == objMaybeWindowProxy) { + return result.fail(JSMSG_CANT_SET_PROTO_CYCLE); + } + + bool isOrdinary; + if (!GetPrototypeIfOrdinary(cx, obj2, &isOrdinary, &obj2)) { + return false; + } + if (!isOrdinary) { + break; + } + } + + Rooted taggedProto(cx, TaggedProto(proto)); + if (!JSObject::setProtoUnchecked(cx, obj, taggedProto)) { + return false; + } + + return result.succeed(); +} + +bool js::SetPrototype(JSContext* cx, HandleObject obj, HandleObject proto) { + ObjectOpResult result; + return SetPrototype(cx, obj, proto, result) && result.checkStrict(cx, obj); +} + +bool js::PreventExtensions(JSContext* cx, HandleObject obj, + ObjectOpResult& result) { + if (obj->is()) { + return js::Proxy::preventExtensions(cx, obj, result); + } + + if (obj->is()) { + return result.failCantPreventExtensions(); + } + + if (!obj->nonProxyIsExtensible()) { + // If the following assertion fails, there's somewhere else a missing + // call to shrinkCapacityToInitializedLength() which needs to be found + // and fixed. + MOZ_ASSERT_IF(obj->is(), + obj->as().getDenseInitializedLength() == + obj->as().getDenseCapacity()); + + return result.succeed(); + } + + if (obj->is()) { + // Force lazy properties to be resolved. + Handle nobj = obj.as(); + if (!ResolveLazyProperties(cx, nobj)) { + return false; + } + + // Prepare the elements. We have to do this before we mark the object + // non-extensible; that's fine because these changes are not observable. + ObjectElements::PrepareForPreventExtensions(cx, nobj); + } + + // Finally, set the NotExtensible flag on the Shape and ObjectElements. + if (!JSObject::setFlag(cx, obj, ObjectFlag::NotExtensible)) { + return false; + } + if (obj->is()) { + ObjectElements::PreventExtensions(&obj->as()); + } + + return result.succeed(); +} + +bool js::PreventExtensions(JSContext* cx, HandleObject obj) { + ObjectOpResult result; + return PreventExtensions(cx, obj, result) && result.checkStrict(cx, obj); +} + +bool js::GetOwnPropertyDescriptor( + JSContext* cx, HandleObject obj, HandleId id, + MutableHandle> desc) { + if (GetOwnPropertyOp op = obj->getOpsGetOwnPropertyDescriptor()) { + bool ok = op(cx, obj, id, desc); + if (ok && desc.isSome()) { + desc->assertComplete(); + } + return ok; + } + + return NativeGetOwnPropertyDescriptor(cx, obj.as(), id, desc); +} + +bool js::DefineProperty(JSContext* cx, HandleObject obj, HandleId id, + Handle desc) { + ObjectOpResult result; + return DefineProperty(cx, obj, id, desc, result) && + result.checkStrict(cx, obj, id); +} + +bool js::DefineProperty(JSContext* cx, HandleObject obj, HandleId id, + Handle desc, + ObjectOpResult& result) { + desc.assertValid(); + if (DefinePropertyOp op = obj->getOpsDefineProperty()) { + return op(cx, obj, id, desc, result); + } + return NativeDefineProperty(cx, obj.as(), id, desc, result); +} + +bool js::DefineAccessorProperty(JSContext* cx, HandleObject obj, HandleId id, + HandleObject getter, HandleObject setter, + unsigned attrs, ObjectOpResult& result) { + Rooted desc( + cx, PropertyDescriptor::Accessor( + getter ? mozilla::Some(getter) : mozilla::Nothing(), + setter ? mozilla::Some(setter) : mozilla::Nothing(), attrs)); + + if (DefinePropertyOp op = obj->getOpsDefineProperty()) { + return op(cx, obj, id, desc, result); + } + return NativeDefineProperty(cx, obj.as(), id, desc, result); +} + +bool js::DefineDataProperty(JSContext* cx, HandleObject obj, HandleId id, + HandleValue value, unsigned attrs, + ObjectOpResult& result) { + Rooted desc(cx, PropertyDescriptor::Data(value, attrs)); + if (DefinePropertyOp op = obj->getOpsDefineProperty()) { + return op(cx, obj, id, desc, result); + } + return NativeDefineProperty(cx, obj.as(), id, desc, result); +} + +bool js::DefineAccessorProperty(JSContext* cx, HandleObject obj, HandleId id, + HandleObject getter, HandleObject setter, + unsigned attrs) { + ObjectOpResult result; + if (!DefineAccessorProperty(cx, obj, id, getter, setter, attrs, result)) { + return false; + } + if (!result) { + result.reportError(cx, obj, id); + return false; + } + return true; +} + +bool js::DefineDataProperty(JSContext* cx, HandleObject obj, HandleId id, + HandleValue value, unsigned attrs) { + ObjectOpResult result; + if (!DefineDataProperty(cx, obj, id, value, attrs, result)) { + return false; + } + if (!result) { + result.reportError(cx, obj, id); + return false; + } + return true; +} + +bool js::DefineDataProperty(JSContext* cx, HandleObject obj, PropertyName* name, + HandleValue value, unsigned attrs) { + RootedId id(cx, NameToId(name)); + return DefineDataProperty(cx, obj, id, value, attrs); +} + +bool js::DefineDataElement(JSContext* cx, HandleObject obj, uint32_t index, + HandleValue value, unsigned attrs) { + RootedId id(cx); + if (!IndexToId(cx, index, &id)) { + return false; + } + return DefineDataProperty(cx, obj, id, value, attrs); +} + +/*** SpiderMonkey nonstandard internal methods ******************************/ + +// Mark an object as having an immutable prototype +// +// NOTE: This does not correspond to the SetImmutablePrototype ECMAScript +// method. +bool js::SetImmutablePrototype(JSContext* cx, HandleObject obj, + bool* succeeded) { + if (obj->hasDynamicPrototype()) { + return Proxy::setImmutablePrototype(cx, obj, succeeded); + } + + if (!JSObject::setFlag(cx, obj, ObjectFlag::ImmutablePrototype)) { + return false; + } + *succeeded = true; + return true; +} + +bool js::GetPropertyDescriptor( + JSContext* cx, HandleObject obj, HandleId id, + MutableHandle> desc, + MutableHandleObject holder) { + RootedObject pobj(cx); + for (pobj = obj; pobj;) { + if (!GetOwnPropertyDescriptor(cx, pobj, id, desc)) { + return false; + } + + if (desc.isSome()) { + holder.set(pobj); + return true; + } + + if (!GetPrototype(cx, pobj, &pobj)) { + return false; + } + } + + MOZ_ASSERT(desc.isNothing()); + holder.set(nullptr); + return true; +} + +/* * */ + +extern bool PropertySpecNameToId(JSContext* cx, JSPropertySpec::Name name, + MutableHandleId id); + +// If a property or method is part of an experimental feature that can be +// disabled at run-time by a preference, we keep it in the JSFunctionSpec / +// JSPropertySpec list, but omit the definition if the preference is off. +JS_PUBLIC_API bool js::ShouldIgnorePropertyDefinition(JSContext* cx, + JSProtoKey key, jsid id) { + if (!cx->realm()->creationOptions().getToSourceEnabled() && + (id == NameToId(cx->names().toSource) || + id == NameToId(cx->names().uneval))) { + return true; + } + + if (key == JSProto_FinalizationRegistry && + JS::GetWeakRefsEnabled() == + JS::WeakRefSpecifier::EnabledWithoutCleanupSome && + id == NameToId(cx->names().cleanupSome)) { + return true; + } + + // It's gently surprising that this is JSProto_Function, but the trick + // to realize is that this is a -constructor function-, not a function + // on the prototype; and the proto of the constructor is JSProto_Function. + if (key == JSProto_Function && !JS::Prefs::array_grouping() && + (id == NameToId(cx->names().groupBy))) { + return true; + } + +#ifdef NIGHTLY_BUILD + if (key == JSProto_Set && !JS::Prefs::experimental_new_set_methods() && + (id == NameToId(cx->names().union_) || + id == NameToId(cx->names().difference) || + id == NameToId(cx->names().intersection) || + id == NameToId(cx->names().isSubsetOf) || + id == NameToId(cx->names().isSupersetOf) || + id == NameToId(cx->names().isDisjointFrom) || + id == NameToId(cx->names().symmetricDifference))) { + return true; + } +#endif + +#ifdef NIGHTLY_BUILD + if (key == JSProto_ArrayBuffer && !JS::Prefs::arraybuffer_transfer() && + (id == NameToId(cx->names().transfer) || + id == NameToId(cx->names().transferToFixedLength) || + id == NameToId(cx->names().detached))) { + return true; + } + + if (key == JSProto_ArrayBuffer && + !JS::Prefs::experimental_arraybuffer_resizable() && + (id == NameToId(cx->names().maxByteLength) || + id == NameToId(cx->names().resizable) || + id == NameToId(cx->names().resize))) { + return true; + } + + if (key == JSProto_SharedArrayBuffer && + !JS::Prefs::experimental_sharedarraybuffer_growable() && + (id == NameToId(cx->names().maxByteLength) || + id == NameToId(cx->names().growable) || + id == NameToId(cx->names().grow))) { + return true; + } +#endif + + return false; +} + +static bool DefineFunctionFromSpec(JSContext* cx, HandleObject obj, + const JSFunctionSpec* fs) { + RootedId id(cx); + if (!PropertySpecNameToId(cx, fs->name, &id)) { + return false; + } + + if (ShouldIgnorePropertyDefinition(cx, StandardProtoKeyOrNull(obj), id)) { + return true; + } + + JSFunction* fun = NewFunctionFromSpec(cx, fs, id); + if (!fun) { + return false; + } + + RootedValue funVal(cx, ObjectValue(*fun)); + return DefineDataProperty(cx, obj, id, funVal, fs->flags & ~JSFUN_FLAGS_MASK); +} + +bool js::DefineFunctions(JSContext* cx, HandleObject obj, + const JSFunctionSpec* fs) { + for (; fs->name; fs++) { + if (!DefineFunctionFromSpec(cx, obj, fs)) { + return false; + } + } + return true; +} + +/*** ToPrimitive ************************************************************/ + +/* + * Gets |obj[id]|. If that value's not callable, returns true and stores an + * object value in *vp. If it's callable, calls it with no arguments and |obj| + * as |this|, returning the result in *vp. + * + * This is a mini-abstraction for ES6 draft rev 36 (2015 Mar 17), + * 7.1.1, second algorithm (OrdinaryToPrimitive), steps 5.a-c. + */ +static bool MaybeCallMethod(JSContext* cx, HandleObject obj, HandleId id, + MutableHandleValue vp) { + if (!GetProperty(cx, obj, obj, id, vp)) { + return false; + } + if (!IsCallable(vp)) { + vp.setObject(*obj); + return true; + } + + return js::Call(cx, vp, obj, vp); +} + +static bool ReportCantConvert(JSContext* cx, unsigned errorNumber, + HandleObject obj, JSType hint) { + const JSClass* clasp = obj->getClass(); + + // Avoid recursive death when decompiling in ReportValueError. + RootedString str(cx); + if (hint == JSTYPE_STRING) { + str = JS_AtomizeString(cx, clasp->name); + if (!str) { + return false; + } + } else { + str = nullptr; + } + + RootedValue val(cx, ObjectValue(*obj)); + ReportValueError(cx, errorNumber, JSDVG_SEARCH_STACK, val, str, + hint == JSTYPE_UNDEFINED ? "primitive type" + : hint == JSTYPE_STRING ? "string" + : "number"); + return false; +} + +bool JS::OrdinaryToPrimitive(JSContext* cx, HandleObject obj, JSType hint, + MutableHandleValue vp) { + MOZ_ASSERT(hint == JSTYPE_NUMBER || hint == JSTYPE_STRING || + hint == JSTYPE_UNDEFINED); + + Rooted id(cx); + + const JSClass* clasp = obj->getClass(); + if (hint == JSTYPE_STRING) { + id = NameToId(cx->names().toString); + + bool calledToString = false; + if (clasp == &StringObject::class_) { + // Optimize (new String(...)).toString(). + StringObject* nobj = &obj->as(); + if (HasNativeMethodPure(nobj, cx->names().toString, str_toString, cx)) { + vp.setString(nobj->unbox()); + return true; + } + } else if (clasp == &PlainObject::class_) { + JSFunction* fun; + if (GetPropertyPure(cx, obj, id, vp.address()) && + IsFunctionObject(vp, &fun)) { + // Common case: we have a toString function. Try to short-circuit if + // it's Object.prototype.toString and there's no @@toStringTag. + if (fun->maybeNative() == obj_toString && + !MaybeHasInterestingSymbolProperty( + cx, obj, cx->wellKnownSymbols().toStringTag)) { + vp.setString(cx->names().object_Object_); + return true; + } + if (!js::Call(cx, vp, obj, vp)) { + return false; + } + calledToString = true; + } + } + + if (!calledToString) { + if (!MaybeCallMethod(cx, obj, id, vp)) { + return false; + } + } + if (vp.isPrimitive()) { + return true; + } + + id = NameToId(cx->names().valueOf); + if (!MaybeCallMethod(cx, obj, id, vp)) { + return false; + } + if (vp.isPrimitive()) { + return true; + } + } else { + id = NameToId(cx->names().valueOf); + + if (clasp == &StringObject::class_) { + // Optimize new String(...).valueOf(). + StringObject* nobj = &obj->as(); + if (HasNativeMethodPure(nobj, cx->names().valueOf, str_toString, cx)) { + vp.setString(nobj->unbox()); + return true; + } + } else if (clasp == &NumberObject::class_) { + // Optimize new Number(...).valueOf(). + NumberObject* nobj = &obj->as(); + if (HasNativeMethodPure(nobj, cx->names().valueOf, num_valueOf, cx)) { + vp.setNumber(nobj->unbox()); + return true; + } + } + + if (!MaybeCallMethod(cx, obj, id, vp)) { + return false; + } + if (vp.isPrimitive()) { + return true; + } + + id = NameToId(cx->names().toString); + if (!MaybeCallMethod(cx, obj, id, vp)) { + return false; + } + if (vp.isPrimitive()) { + return true; + } + } + + return ReportCantConvert(cx, JSMSG_CANT_CONVERT_TO, obj, hint); +} + +bool js::ToPrimitiveSlow(JSContext* cx, JSType preferredType, + MutableHandleValue vp) { + // Step numbers refer to the first algorithm listed in ES6 draft rev 36 + // (2015 Mar 17) 7.1.1 ToPrimitive. + MOZ_ASSERT(preferredType == JSTYPE_UNDEFINED || + preferredType == JSTYPE_STRING || preferredType == JSTYPE_NUMBER); + RootedObject obj(cx, &vp.toObject()); + + // Steps 4-5. + RootedValue method(cx); + if (!GetInterestingSymbolProperty(cx, obj, cx->wellKnownSymbols().toPrimitive, + &method)) { + return false; + } + + // Step 6. + if (!method.isNullOrUndefined()) { + // Step 6 of GetMethod. js::Call() below would do this check and throw a + // TypeError anyway, but this produces a better error message. + if (!IsCallable(method)) { + return ReportCantConvert(cx, JSMSG_TOPRIMITIVE_NOT_CALLABLE, obj, + preferredType); + } + + // Steps 1-3, 6.a-b. + RootedValue arg0( + cx, + StringValue(preferredType == JSTYPE_STRING ? cx->names().string + : preferredType == JSTYPE_NUMBER ? cx->names().number + : cx->names().default_)); + + if (!js::Call(cx, method, vp, arg0, vp)) { + return false; + } + + // Steps 6.c-d. + if (vp.isObject()) { + return ReportCantConvert(cx, JSMSG_TOPRIMITIVE_RETURNED_OBJECT, obj, + preferredType); + } + return true; + } + + return OrdinaryToPrimitive(cx, obj, preferredType, vp); +} + +/* ES6 draft rev 28 (2014 Oct 14) 7.1.14 */ +bool js::ToPropertyKeySlow(JSContext* cx, HandleValue argument, + MutableHandleId result) { + MOZ_ASSERT(argument.isObject()); + + // Steps 1-2. + RootedValue key(cx, argument); + if (!ToPrimitiveSlow(cx, JSTYPE_STRING, &key)) { + return false; + } + + // Steps 3-4. + return PrimitiveValueToId(cx, key, result); +} + +/* * */ + +bool js::IsPrototypeOf(JSContext* cx, HandleObject protoObj, JSObject* obj, + bool* result) { + RootedObject obj2(cx, obj); + for (;;) { + // The [[Prototype]] chain might be cyclic. + if (!CheckForInterrupt(cx)) { + return false; + } + if (!GetPrototype(cx, obj2, &obj2)) { + return false; + } + if (!obj2) { + *result = false; + return true; + } + if (obj2 == protoObj) { + *result = true; + return true; + } + } +} + +JSObject* js::PrimitiveToObject(JSContext* cx, const Value& v) { + MOZ_ASSERT(v.isPrimitive()); + + switch (v.type()) { + case ValueType::String: { + Rooted str(cx, v.toString()); + return StringObject::create(cx, str); + } + case ValueType::Double: + case ValueType::Int32: + return NumberObject::create(cx, v.toNumber()); + case ValueType::Boolean: + return BooleanObject::create(cx, v.toBoolean()); + case ValueType::Symbol: { + RootedSymbol symbol(cx, v.toSymbol()); + return SymbolObject::create(cx, symbol); + } + case ValueType::BigInt: { + RootedBigInt bigInt(cx, v.toBigInt()); + return BigIntObject::create(cx, bigInt); + } +#ifdef ENABLE_RECORD_TUPLE + case ValueType::ExtendedPrimitive: { + JSObject& obj = v.toExtendedPrimitive(); + + if (obj.is()) { + Rooted rec(cx, &obj.as()); + return RecordObject::create(cx, rec); + } + if (obj.is()) { + Rooted tuple(cx, &obj.as()); + return TupleObject::create(cx, tuple); + } + + MOZ_CRASH("Unexpected ExtendedPrimitive type."); + } +#endif + case ValueType::Undefined: + case ValueType::Null: + case ValueType::Magic: + case ValueType::PrivateGCThing: + case ValueType::Object: + break; + } + + MOZ_CRASH("unexpected type"); +} + +// Like PrimitiveToObject, but returns the JSProtoKey of the prototype that +// would be used without actually creating the object. +JSProtoKey js::PrimitiveToProtoKey(JSContext* cx, const Value& v) { + MOZ_ASSERT(v.isPrimitive()); + + switch (v.type()) { + case ValueType::String: + return JSProto_String; + case ValueType::Double: + case ValueType::Int32: + return JSProto_Number; + case ValueType::Boolean: + return JSProto_Boolean; + case ValueType::Symbol: + return JSProto_Symbol; + case ValueType::BigInt: + return JSProto_BigInt; +#ifdef ENABLE_RECORD_TUPLE + case ValueType::ExtendedPrimitive: + if (v.toExtendedPrimitive().is()) { + return JSProto_Tuple; + } + if (v.toExtendedPrimitive().is()) { + return JSProto_Null; + } + MOZ_CRASH("Unsupported ExtendedPrimitive"); +#endif + case ValueType::Undefined: + case ValueType::Null: + case ValueType::Magic: + case ValueType::PrivateGCThing: + case ValueType::Object: + break; + } + + MOZ_CRASH("unexpected type"); +} + +/* + * Invokes the ES5 ToObject algorithm on vp, returning the result. If vp might + * already be an object, use ToObject. reportScanStack controls how null and + * undefined errors are reported. + * + * Callers must handle the already-object case. + */ +JSObject* js::ToObjectSlow(JSContext* cx, JS::HandleValue val, + bool reportScanStack) { + MOZ_ASSERT(!val.isMagic()); + MOZ_ASSERT(!val.isObject()); + + if (val.isNullOrUndefined()) { + ReportIsNullOrUndefinedForPropertyAccess( + cx, val, reportScanStack ? JSDVG_SEARCH_STACK : JSDVG_IGNORE_STACK); + return nullptr; + } + + return PrimitiveToObject(cx, val); +} + +JSObject* js::ToObjectSlowForPropertyAccess(JSContext* cx, JS::HandleValue val, + int valIndex, HandleId key) { + MOZ_ASSERT(!val.isMagic()); + MOZ_ASSERT(!val.isObject()); + + if (val.isNullOrUndefined()) { + ReportIsNullOrUndefinedForPropertyAccess(cx, val, valIndex, key); + return nullptr; + } + + return PrimitiveToObject(cx, val); +} + +JSObject* js::ToObjectSlowForPropertyAccess(JSContext* cx, JS::HandleValue val, + int valIndex, + Handle key) { + MOZ_ASSERT(!val.isMagic()); + MOZ_ASSERT(!val.isObject()); + + if (val.isNullOrUndefined()) { + RootedId keyId(cx, NameToId(key)); + ReportIsNullOrUndefinedForPropertyAccess(cx, val, valIndex, keyId); + return nullptr; + } + + return PrimitiveToObject(cx, val); +} + +JSObject* js::ToObjectSlowForPropertyAccess(JSContext* cx, JS::HandleValue val, + int valIndex, + HandleValue keyValue) { + MOZ_ASSERT(!val.isMagic()); + MOZ_ASSERT(!val.isObject()); + + if (val.isNullOrUndefined()) { + RootedId key(cx); + if (keyValue.isPrimitive()) { + if (!PrimitiveValueToId(cx, keyValue, &key)) { + return nullptr; + } + ReportIsNullOrUndefinedForPropertyAccess(cx, val, valIndex, key); + } else { + ReportIsNullOrUndefinedForPropertyAccess(cx, val, valIndex); + } + return nullptr; + } + + return PrimitiveToObject(cx, val); +} + +JSObject* js::GetThisObject(JSObject* obj) { + // Use the WindowProxy if the global is a Window, as Window must never be + // exposed to script. + if (obj->is()) { + return ToWindowProxyIfWindow(obj); + } + + // We should not expose any environments except NSVOs to script. The NSVO is + // pretending to be the global object in this case. + MOZ_ASSERT(obj->is() || + !obj->is()); + + return obj; +} + +JSObject* js::GetThisObjectOfLexical(JSObject* env) { + return env->as().thisObject(); +} + +JSObject* js::GetThisObjectOfWith(JSObject* env) { + MOZ_ASSERT(env->is()); + return GetThisObject(env->as().withThis()); +} + +class GetObjectSlotNameFunctor : public JS::TracingContext::Functor { + JSObject* obj; + + public: + explicit GetObjectSlotNameFunctor(JSObject* ctx) : obj(ctx) {} + virtual void operator()(JS::TracingContext* trc, char* buf, + size_t bufsize) override; +}; + +void GetObjectSlotNameFunctor::operator()(JS::TracingContext* tcx, char* buf, + size_t bufsize) { + MOZ_ASSERT(tcx->index() != JS::TracingContext::InvalidIndex); + + uint32_t slot = uint32_t(tcx->index()); + + Maybe key; + if (obj->is()) { + NativeShape* shape = obj->as().shape(); + for (ShapePropertyIter iter(shape); !iter.done(); iter++) { + if (iter->hasSlot() && iter->slot() == slot) { + key.emplace(iter->key()); + break; + } + } + } + + if (key.isNothing()) { + do { + const char* slotname = nullptr; + const char* pattern = nullptr; + if (obj->is()) { + pattern = "CLASS_OBJECT(%s)"; + if (false) { + ; + } +#define TEST_SLOT_MATCHES_PROTOTYPE(name, clasp) \ + else if ((JSProto_##name) == slot) { \ + slotname = #name; \ + } + JS_FOR_EACH_PROTOTYPE(TEST_SLOT_MATCHES_PROTOTYPE) +#undef TEST_SLOT_MATCHES_PROTOTYPE + } else { + pattern = "%s"; + if (obj->is()) { + if (slot == EnvironmentObject::enclosingEnvironmentSlot()) { + slotname = "enclosing_environment"; + } else if (obj->is()) { + if (slot == CallObject::calleeSlot()) { + slotname = "callee_slot"; + } + } else if (obj->is()) { + if (slot == WithEnvironmentObject::objectSlot()) { + slotname = "with_object"; + } else if (slot == WithEnvironmentObject::thisSlot()) { + slotname = "with_this"; + } + } + } + } + + if (slotname) { + snprintf(buf, bufsize, pattern, slotname); + } else { + snprintf(buf, bufsize, "**UNKNOWN SLOT %" PRIu32 "**", slot); + } + } while (false); + } else { + if (key->isInt()) { + snprintf(buf, bufsize, "%" PRId32, key->toInt()); + } else if (key->isAtom()) { + PutEscapedString(buf, bufsize, key->toAtom(), 0); + } else if (key->isSymbol()) { + snprintf(buf, bufsize, "**SYMBOL KEY**"); + } else { + snprintf(buf, bufsize, "**FINALIZED ATOM KEY**"); + } + } +} + +/*** Debugging routines *****************************************************/ + +#if defined(DEBUG) || defined(JS_JITSPEW) + +/* + * Routines to print out values during debugging. These are JS_PUBLIC_API to + * help the debugger find them and to support temporarily hacking js::Dump* + * calls into other code. + */ + +namespace js { + +// We don't want jsfriendapi.h to depend on GenericPrinter, +// so these functions are declared directly in the cpp. + +JS_PUBLIC_API void DumpValue(const JS::Value& val, js::GenericPrinter& out); + +JS_PUBLIC_API void DumpId(jsid id, js::GenericPrinter& out); + +JS_PUBLIC_API void DumpInterpreterFrame(JSContext* cx, js::GenericPrinter& out, + InterpreterFrame* start = nullptr); + +} // namespace js + +JS_PUBLIC_API void js::DumpValue(const Value& val, js::GenericPrinter& out) { + val.dump(out); +} + +JS_PUBLIC_API void js::DumpId(jsid id, js::GenericPrinter& out) { + out.printf("jsid %p = ", (void*)id.asRawBits()); + id.dump(out); +} + +bool JSObject::hasSameRealmAs(JSContext* cx) const { + return nonCCWRealm() == cx->realm(); +} + +bool JSObject::uninlinedIsProxyObject() const { return is(); } + +bool JSObject::uninlinedNonProxyIsExtensible() const { + return nonProxyIsExtensible(); +} + +void JSObject::dump() const { + js::Fprinter out(stderr); + dump(out); +} + +void JSObject::dump(js::GenericPrinter& out) const { + js::JSONPrinter json(out); + dump(json); + out.put("\n"); +} + +void JSObject::dump(js::JSONPrinter& json) const { + json.beginObject(); + dumpFields(json); + json.endObject(); +} + +# define FOR_EACH_CLASS(M) \ + M(ArrayBufferViewObject) \ + M(ArrayBufferObject) \ + M(JSFunction) \ + M(PromiseObject) \ + M(RegExpObject) + +static void DumpOwnFields(const JSObject* obj, js::JSONPrinter& json) { +# define CALL(CLASS) \ + if (obj->is()) { \ + obj->as().dumpOwnFields(json); \ + return; \ + } + FOR_EACH_CLASS(CALL) +# undef CALL +} + +static void DumpOwnStringContent(const JSObject* obj, js::GenericPrinter& out) { +# define CALL(CLASS) \ + if (obj->is()) { \ + out.put(" "); \ + obj->as().dumpOwnStringContent(out); \ + return; \ + } + FOR_EACH_CLASS(CALL) +# undef CALL +} + +# undef FOR_EACH_CLASS + +void JSObject::dumpFields(js::JSONPrinter& json) const { + json.formatProperty("address", "(JSObject*)0x%p", this); + + if (IsCrossCompartmentWrapper(this)) { + json.formatProperty("compartment", "(JS::Compartment*)0x%p", compartment()); + } else { + JSObject* globalObj = &nonCCWGlobal(); + js::GenericPrinter& out = json.beginStringProperty("nonCCWGlobal"); + globalObj->dumpStringContent(out); + json.endStringProperty(); + } + + const JSClass* clasp = getClass(); + json.formatProperty("clasp", "<%s @ (JSClass*)0x%p>", clasp->name, clasp); + + js::GenericPrinter& out = json.beginStringProperty("shape"); + shape()->dumpStringContent(out); + json.endStringProperty(); + + json.beginObjectProperty("shape.base"); + shape()->base()->dumpFields(json); + json.endObject(); + + if (IsProxy(this)) { + const js::BaseProxyHandler* handler = GetProxyHandler(this); + if (IsDeadProxyObject(this)) { + json.formatProperty("handler", "(js::DeadObjectProxy*)0x%p", handler); + } else if (IsCrossCompartmentWrapper(this)) { + json.formatProperty("handler", "(js::CrossCompartmentWrapper*)0x%p", + handler); + } else { + json.formatProperty("handler", "(js::BaseProxyHandler*)0x%p", handler); + } + + Value priv = GetProxyPrivate(this); + if (!priv.isUndefined()) { + js::GenericPrinter& out = json.beginStringProperty("private"); + priv.dumpStringContent(out); + json.endStringProperty(); + } + + Value expando = GetProxyExpando(this); + if (!expando.isNull()) { + js::GenericPrinter& out = json.beginStringProperty("expando"); + expando.dumpStringContent(out); + json.endStringProperty(); + } + + if (is()) { + json.boolProperty("isQualifiedVarObj", isQualifiedVarObj()); + json.boolProperty("isUnqualifiedVarObj", isUnqualifiedVarObj()); + } + } + + DumpOwnFields(this, json); + + if (is()) { + const auto* nobj = &as(); + + js::GenericPrinter& out = json.beginStringProperty("elementsHeader"); + nobj->getElementsHeader()->dumpStringContent(out); + json.endStringProperty(); + + uint32_t reserved = JSCLASS_RESERVED_SLOTS(clasp); + if (reserved) { + char name[256]; + json.beginObjectProperty("reservedSlots"); + for (uint32_t i = 0; i < reserved; i++) { + SprintfLiteral(name, "%u", i); + js::GenericPrinter& out = json.beginStringProperty(name); + nobj->getSlot(i).dumpStringContent(out); + json.endStringProperty(); + } + json.endObject(); + } + + json.beginObjectProperty("properties"); + if (PropMap* map = nobj->shape()->propMap()) { + Vector maps; + while (true) { + if (!maps.append(map)) { + json.property("error", "*oom in JSObject::dumpFields*"); + break; + } + if (!map->hasPrevious()) { + break; + } + map = map->asLinked()->previous(); + } + + for (size_t i = maps.length(); i > 0; i--) { + size_t index = i - 1; + PropMap* map = maps[index]; + uint32_t len = (index == 0) ? shape()->asNative().propMapLength() + : PropMap::Capacity; + for (uint32_t j = 0; j < len; j++) { + if (!map->hasKey(j)) { + MOZ_ASSERT(map->isDictionary()); + continue; + } + + JS::UniqueChars propChars = map->getPropertyNameAt(j); + if (!propChars) { + json.property("error", "*oom in PropMap::getPropertyNameAt*"); + continue; + } + + js::GenericPrinter& out = json.beginStringProperty(propChars.get()); + + PropertyInfoWithKey prop = map->getPropertyInfoWithKey(j); + if (prop.isDataProperty()) { + nobj->getSlot(prop.slot()).dumpStringContent(out); + out.put(" "); + } else if (prop.isAccessorProperty()) { + out.printf("getter=0x%p, setter=0x%p", nobj->getGetter(prop), + nobj->getSetter(prop)); + out.put(" "); + } + + out.put("("); + map->dumpDescriptorStringContentAt(out, j); + out.put(")"); + + json.endStringProperty(); + } + } + } + json.endObject(); + + uint32_t slots = nobj->getDenseInitializedLength(); + if (slots) { + char name[64]; + json.beginObjectProperty("elements"); + for (uint32_t i = 0; i < slots; i++) { + SprintfLiteral(name, "%u", i); + js::GenericPrinter& out = json.beginStringProperty(name); + nobj->getDenseElement(i).dumpStringContent(out); + json.endStringProperty(); + } + json.endObject(); + } + } +} + +void JSObject::dumpStringContent(js::GenericPrinter& out) const { + out.printf("<%s", getClass()->name); + + DumpOwnStringContent(this, out); + + out.printf(" @ (JSObject*)0x%p>", this); +} + +static void MaybeDumpScope(Scope* scope, js::GenericPrinter& out) { + if (scope) { + out.printf(" scope: %s\n", ScopeKindString(scope->kind())); + for (BindingIter bi(scope); bi; bi++) { + out.put(" "); + StringValue(bi.name()).dump(out); + } + } +} + +static void MaybeDumpValue(const char* name, const Value& v, + js::GenericPrinter& out) { + if (!v.isNull()) { + out.printf(" %s: ", name); + v.dump(out); + } +} + +JS_PUBLIC_API void js::DumpInterpreterFrame(JSContext* cx, + js::GenericPrinter& out, + InterpreterFrame* start) { + /* This should only called during live debugging. */ + ScriptFrameIter i(cx); + if (!start) { + if (i.done()) { + out.printf("no stack for cx = %p\n", (void*)cx); + return; + } + } else { + while (!i.done() && !i.isJSJit() && i.interpFrame() != start) { + ++i; + } + + if (i.done()) { + out.printf("fp = %p not found in cx = %p\n", (void*)start, (void*)cx); + return; + } + } + + for (; !i.done(); ++i) { + if (i.isJSJit()) { + out.put("JIT frame\n"); + } else { + out.printf("InterpreterFrame at %p\n", (void*)i.interpFrame()); + } + + if (i.isFunctionFrame()) { + out.put("callee fun: "); + RootedValue v(cx); + JSObject* fun = i.callee(cx); + v.setObject(*fun); + v.get().dump(out); + } else { + out.put("global or eval frame, no callee\n"); + } + + out.printf("file %s line %u\n", i.script()->filename(), + i.script()->lineno()); + + if (jsbytecode* pc = i.pc()) { + out.printf(" pc = %p\n", pc); + out.printf(" current op: %s\n", CodeName(JSOp(*pc))); + MaybeDumpScope(i.script()->lookupScope(pc), out); + } + if (i.isFunctionFrame()) { + MaybeDumpValue("this", i.thisArgument(cx), out); + } + if (!i.isJSJit()) { + out.put(" rval: "); + i.interpFrame()->returnValue().get().dump(out); + } + + out.put(" flags:"); + if (i.isConstructing()) { + out.put(" constructing"); + } + if (!i.isJSJit() && i.interpFrame()->isDebuggerEvalFrame()) { + out.put(" debugger eval"); + } + if (i.isEvalFrame()) { + out.put(" eval"); + } + out.putChar('\n'); + + out.printf(" envChain: (JSObject*) %p\n", (void*)i.environmentChain(cx)); + + out.putChar('\n'); + } +} + +#endif /* defined(DEBUG) || defined(JS_JITSPEW) */ + +JS_PUBLIC_API void js::DumpBacktrace(JSContext* cx, FILE* fp) { + Fprinter out(fp); + js::DumpBacktrace(cx, out); +} + +JS_PUBLIC_API void js::DumpBacktrace(JSContext* cx, js::GenericPrinter& out) { + size_t depth = 0; + for (AllFramesIter i(cx); !i.done(); ++i, ++depth) { + const char* filename; + unsigned line; + if (i.hasScript()) { + filename = JS_GetScriptFilename(i.script()); + line = PCToLineNumber(i.script(), i.pc()); + } else { + filename = i.filename(); + line = i.computeLine(); + } + char frameType = i.isInterp() ? 'i' + : i.isBaseline() ? 'b' + : i.isIon() ? 'I' + : i.isWasm() ? 'W' + : '?'; + + out.printf("#%zu %14p %c %s:%u", depth, i.rawFramePtr(), frameType, + filename, line); + + if (i.hasScript()) { + out.printf(" (%p @ %zu)\n", i.script(), i.script()->pcToOffset(i.pc())); + } else { + out.printf(" (%p)\n", i.pc()); + } + } +} + +JS_PUBLIC_API void js::DumpBacktrace(JSContext* cx) { + DumpBacktrace(cx, stdout); +} + +/* * */ + +bool JSObject::isBackgroundFinalized() const { + if (isTenured()) { + return js::gc::IsBackgroundFinalized(asTenured().getAllocKind()); + } + + js::Nursery& nursery = runtimeFromMainThread()->gc.nursery(); + return js::gc::IsBackgroundFinalized(allocKindForTenure(nursery)); +} + +js::gc::AllocKind JSObject::allocKindForTenure( + const js::Nursery& nursery) const { + using namespace js::gc; + + MOZ_ASSERT(IsInsideNursery(this)); + + if (canHaveFixedElements()) { + const NativeObject& nobj = as(); + MOZ_ASSERT(nobj.numFixedSlots() == 0); + + /* Use minimal size object if we are just going to copy the pointer. */ + if (!nursery.isInside(nobj.getUnshiftedElementsHeader())) { + return gc::AllocKind::OBJECT0_BACKGROUND; + } + + size_t nelements = nobj.getDenseCapacity(); + return ForegroundToBackgroundAllocKind(GetGCArrayKind(nelements)); + } + + if (is()) { + return as().getAllocKind(); + } + + // Fixed length typed arrays in the nursery may have a lazily allocated + // buffer, make sure there is room for the array's fixed data when moving the + // array. + if (is() && + !as().hasBuffer()) { + gc::AllocKind allocKind; + if (as().hasInlineElements()) { + size_t nbytes = as().byteLength(); + allocKind = FixedLengthTypedArrayObject::AllocKindForLazyBuffer(nbytes); + } else { + allocKind = GetGCObjectKind(getClass()); + } + return ForegroundToBackgroundAllocKind(allocKind); + } + + // Proxies that are CrossCompartmentWrappers may be nursery allocated. + if (is()) { + return as().allocKindForTenure(); + } + + // WasmStructObjects have a variable-length tail which contains the first + // few data fields, so make sure we copy it all over to the new object. + if (is()) { + // Figure out the size of this object, from the object's TypeDef. + const wasm::TypeDef* typeDef = &as().typeDef(); + return WasmStructObject::allocKindForTypeDef(typeDef); + } + + // WasmArrayObjects sometimes have a variable-length tail which contains the + // data for small arrays. Make sure we copy it all over to the new object. + if (is()) { + gc::AllocKind allocKind = as().allocKind(); + return allocKind; + } + + // All nursery allocatable non-native objects are handled above. + return as().allocKindForTenure(); +} + +void JSObject::addSizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf, + JS::ClassInfo* info, + JS::RuntimeSizes* runtimeSizes) { + if (is() && as().hasDynamicSlots()) { + info->objectsMallocHeapSlots += + mallocSizeOf(as().getSlotsHeader()); + } + + if (is() && as().hasDynamicElements()) { + void* allocatedElements = as().getUnshiftedElementsHeader(); + info->objectsMallocHeapElementsNormal += mallocSizeOf(allocatedElements); + } + + // Other things may be measured in the future if DMD indicates it is + // worthwhile. + if (is() || is() || is() || + is() || is() || is()) { + // Do nothing. But this function is hot, and we win by getting the + // common cases out of the way early. Some stats on the most common + // classes, as measured during a vanilla browser session: + // - (53.7%, 53.7%): Function + // - (18.0%, 71.7%): Object + // - (16.9%, 88.6%): Array + // - ( 3.9%, 92.5%): Call + // - ( 2.8%, 95.3%): RegExp + // - ( 1.0%, 96.4%): Proxy + + // Note that any JSClass that is special cased below likely needs to + // specify the JSCLASS_DELAY_METADATA_BUILDER flag, or else we will + // probably crash if the object metadata callback attempts to get the + // size of the new object (which Debugger code does) before private + // slots are initialized. + } else if (is()) { + info->objectsMallocHeapMisc += + as().sizeOfMisc(mallocSizeOf); + } else if (is()) { + info->objectsMallocHeapMisc += as().sizeOfData(mallocSizeOf); + } else if (is()) { + info->objectsMallocHeapMisc += as().sizeOfData(mallocSizeOf); + } else if (is()) { + info->objectsMallocHeapMisc += + as().sizeOfMisc(mallocSizeOf); + } else if (is()) { + ArrayBufferObject::addSizeOfExcludingThis(this, mallocSizeOf, info, + runtimeSizes); + } else if (is()) { + SharedArrayBufferObject::addSizeOfExcludingThis(this, mallocSizeOf, info, + runtimeSizes); + } else if (is()) { + as().addSizeOfData(mallocSizeOf, info); + } else if (is()) { + info->objectsMallocHeapMisc += + as().sizeOfExcludingThis(mallocSizeOf); + } +#ifdef JS_HAS_CTYPES + else { + // This must be the last case. + info->objectsMallocHeapMisc += ctypes::SizeOfDataIfCDataObject( + mallocSizeOf, const_cast(this)); + } +#endif +} + +size_t JSObject::sizeOfIncludingThisInNursery() const { + // This function doesn't concern itself yet with typed objects (bug 1133593). + + MOZ_ASSERT(!isTenured()); + + const Nursery& nursery = runtimeFromMainThread()->gc.nursery(); + size_t size = gc::Arena::thingSize(allocKindForTenure(nursery)); + + if (is()) { + const NativeObject& native = as(); + + size += native.numDynamicSlots() * sizeof(Value); + + if (native.hasDynamicElements()) { + js::ObjectElements& elements = *native.getElementsHeader(); + size += (elements.capacity + elements.numShiftedElements()) * + sizeof(HeapSlot); + } + + if (is()) { + size += as().sizeOfData(); + } + } + + return size; +} + +JS::ubi::Node::Size JS::ubi::Concrete::size( + mozilla::MallocSizeOf mallocSizeOf) const { + JSObject& obj = get(); + + if (!obj.isTenured()) { + return obj.sizeOfIncludingThisInNursery(); + } + + JS::ClassInfo info; + obj.addSizeOfExcludingThis(mallocSizeOf, &info, nullptr); + return obj.tenuredSizeOfThis() + info.sizeOfAllThings(); +} + +const char16_t JS::ubi::Concrete::concreteTypeName[] = u"JSObject"; + +void JSObject::traceChildren(JSTracer* trc) { + TraceCellHeaderEdge(trc, this, "shape"); + + Shape* objShape = shape(); + if (objShape->isNative()) { + NativeObject* nobj = &as(); + + { + GetObjectSlotNameFunctor func(nobj); + JS::AutoTracingDetails ctx(trc, func); + JS::AutoTracingIndex index(trc); + // Tracing can mutate the target but cannot change the slot count, + // but the compiler has no way of knowing this. + const uint32_t nslots = nobj->slotSpan(); + for (uint32_t i = 0; i < nslots; ++i) { + TraceEdge(trc, &nobj->getSlotRef(i), "object slot"); + ++index; + } + MOZ_ASSERT(nslots == nobj->slotSpan()); + } + + TraceRange(trc, nobj->getDenseInitializedLength(), + static_cast(nobj->getDenseElements()), + "objectElements"); + } + + // Call the trace hook at the end so that during a moving GC the trace hook + // will see updated fields and slots. + const JSClass* clasp = objShape->getObjectClass(); + if (clasp->hasTrace()) { + clasp->doTrace(trc, this); + } +} + +// ES 2016 7.3.20. +[[nodiscard]] JSObject* js::SpeciesConstructor( + JSContext* cx, HandleObject obj, HandleObject defaultCtor, + bool (*isDefaultSpecies)(JSContext*, JSFunction*)) { + // Step 1 (implicit). + + // Fast-path for steps 2 - 8. Applies if all of the following conditions + // are met: + // - obj.constructor can be retrieved without side-effects. + // - obj.constructor[[@@species]] can be retrieved without side-effects. + // - obj.constructor[[@@species]] is the builtin's original @@species + // getter. + RootedValue ctor(cx); + bool ctorGetSucceeded = GetPropertyPure( + cx, obj, NameToId(cx->names().constructor), ctor.address()); + if (ctorGetSucceeded && ctor.isObject() && &ctor.toObject() == defaultCtor) { + jsid speciesId = PropertyKey::Symbol(cx->wellKnownSymbols().species); + JSFunction* getter; + if (GetGetterPure(cx, defaultCtor, speciesId, &getter) && getter && + isDefaultSpecies(cx, getter)) { + return defaultCtor; + } + } + + // Step 2. + if (!ctorGetSucceeded && + !GetProperty(cx, obj, obj, cx->names().constructor, &ctor)) { + return nullptr; + } + + // Step 3. + if (ctor.isUndefined()) { + return defaultCtor; + } + + // Step 4. + if (!ctor.isObject()) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_OBJECT_REQUIRED, + "object's 'constructor' property"); + return nullptr; + } + + // Step 5. + RootedObject ctorObj(cx, &ctor.toObject()); + RootedValue s(cx); + RootedId speciesId(cx, PropertyKey::Symbol(cx->wellKnownSymbols().species)); + if (!GetProperty(cx, ctorObj, ctor, speciesId, &s)) { + return nullptr; + } + + // Step 6. + if (s.isNullOrUndefined()) { + return defaultCtor; + } + + // Step 7. + if (IsConstructor(s)) { + return &s.toObject(); + } + + // Step 8. + JS_ReportErrorNumberASCII( + cx, GetErrorMessage, nullptr, JSMSG_NOT_CONSTRUCTOR, + "[Symbol.species] property of object's constructor"); + return nullptr; +} + +[[nodiscard]] JSObject* js::SpeciesConstructor( + JSContext* cx, HandleObject obj, JSProtoKey ctorKey, + bool (*isDefaultSpecies)(JSContext*, JSFunction*)) { + RootedObject defaultCtor(cx, + GlobalObject::getOrCreateConstructor(cx, ctorKey)); + if (!defaultCtor) { + return nullptr; + } + return SpeciesConstructor(cx, obj, defaultCtor, isDefaultSpecies); +} + +bool js::Unbox(JSContext* cx, HandleObject obj, MutableHandleValue vp) { + if (MOZ_UNLIKELY(obj->is())) { + return Proxy::boxedValue_unbox(cx, obj, vp); + } + + if (obj->is()) { + vp.setBoolean(obj->as().unbox()); + } else if (obj->is()) { + vp.setNumber(obj->as().unbox()); + } else if (obj->is()) { + vp.setString(obj->as().unbox()); + } else if (obj->is()) { + vp.set(obj->as().UTCTime()); + } else if (obj->is()) { + vp.setSymbol(obj->as().unbox()); + } else if (obj->is()) { + vp.setBigInt(obj->as().unbox()); +#ifdef ENABLE_RECORD_TUPLE + } else if (obj->is()) { + vp.setExtendedPrimitive(*obj->as().unbox()); + } else if (obj->is()) { + vp.setExtendedPrimitive(obj->as().unbox()); +#endif + } else { + vp.setUndefined(); + } + + return true; +} + +#ifdef DEBUG +void js::AssertJSClassInvariants(const JSClass* clasp) { + MOZ_ASSERT(JS::StringIsASCII(clasp->name)); + + // Native objects shouldn't use the property operation hooks in ObjectOps. + // Doing so could violate JIT invariants. + // + // Environment objects unfortunately use these hooks, but environment objects + // are not exposed directly to script so they're generally less of an issue. + if (clasp->isNativeObject() && clasp != &WithEnvironmentObject::class_ && + clasp != &ModuleEnvironmentObject::class_ && + clasp != &RuntimeLexicalErrorObject::class_) { + MOZ_ASSERT(!clasp->getOpsLookupProperty()); + MOZ_ASSERT_IF(clasp != &MappedArgumentsObject::class_, + !clasp->getOpsDefineProperty()); + MOZ_ASSERT(!clasp->getOpsHasProperty()); + MOZ_ASSERT(!clasp->getOpsGetProperty()); + MOZ_ASSERT(!clasp->getOpsSetProperty()); + MOZ_ASSERT(!clasp->getOpsGetOwnPropertyDescriptor()); + MOZ_ASSERT(!clasp->getOpsDeleteProperty()); + } +} + +/* static */ +void JSObject::debugCheckNewObject(Shape* shape, js::gc::AllocKind allocKind, + js::gc::Heap heap) { + const JSClass* clasp = shape->getObjectClass(); + + if (!ClassCanHaveFixedData(clasp)) { + NativeShape* nshape = &shape->asNative(); + if (clasp == &ArrayObject::class_) { + // Arrays can store the ObjectElements header inline. + MOZ_ASSERT(nshape->numFixedSlots() == 0); + } else { + MOZ_ASSERT(gc::GetGCKindSlots(allocKind) == nshape->numFixedSlots()); + } + } + + // Assert background finalization is used when possible. + MOZ_ASSERT(!CanChangeToBackgroundAllocKind(allocKind, clasp)); + + // Classes with a finalizer must specify whether instances will be finalized + // on the main thread or in the background, except proxies whose behaviour + // depends on the target object. + static const uint32_t FinalizeMask = + JSCLASS_FOREGROUND_FINALIZE | JSCLASS_BACKGROUND_FINALIZE; + uint32_t flags = clasp->flags; + uint32_t finalizeFlags = flags & FinalizeMask; + if (clasp->hasFinalize() && !clasp->isProxyObject()) { + MOZ_ASSERT(finalizeFlags == JSCLASS_FOREGROUND_FINALIZE || + finalizeFlags == JSCLASS_BACKGROUND_FINALIZE); + MOZ_ASSERT((finalizeFlags == JSCLASS_BACKGROUND_FINALIZE) == + IsBackgroundFinalized(allocKind)); + } else { + MOZ_ASSERT(finalizeFlags == 0); + } + + MOZ_ASSERT_IF(clasp->hasFinalize(), + heap == gc::Heap::Tenured || + CanNurseryAllocateFinalizedClass(clasp) || + clasp->isProxyObject()); + + MOZ_ASSERT(!shape->isDictionary()); + MOZ_ASSERT(!shape->realm()->hasObjectPendingMetadata()); + + // Non-native classes manage their own data and slots, so numFixedSlots is + // always 0. Note that proxy classes can have reserved slots but they're not + // included in numFixedSlots. + if (!clasp->isNativeObject()) { + MOZ_ASSERT_IF(!clasp->isProxyObject(), JSCLASS_RESERVED_SLOTS(clasp) == 0); + } +} +#endif -- cgit v1.2.3