/* 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 <string.h>
#include "jsapi.h"
#include "jsfriendapi.h"
#include "jstypes.h"
#include "builtin/BigInt.h"
#include "builtin/Date.h"
#include "builtin/MapObject.h"
#include "builtin/Number.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/ErrorObject.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/SelfHosting.h"
#include "vm/Shape.h"
#include "vm/TypedArrayObject.h"
#include "vm/Watchtower.h"
#include "vm/WrapperObject.h"
#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;
const char* chars = ValueToSourceForError(cx, v, bytes);
MOZ_ASSERT(chars);
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:
return v.toObject().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<Maybe<PropertyDescriptor>> desc_,
MutableHandleValue vp) {
AssertHeapIsIdle();
CHECK_THREAD(cx);
cx->check(desc_);
// Step 1.
if (desc_.isNothing()) {
vp.setUndefined();
return true;
}
Rooted<PropertyDescriptor> desc(cx, *desc_);
return FromPropertyDescriptorToObject(cx, desc, vp);
}
bool js::FromPropertyDescriptorToObject(JSContext* cx,
Handle<PropertyDescriptor> 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<PropertyDescriptor> desc_) {
// Step 1.
RootedObject obj(cx,
RequireObject(cx, JSMSG_OBJECT_REQUIRED_PROP_DESC, descval));
if (!obj) {
return false;
}
// Step 2.
Rooted<PropertyDescriptor> 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<PropertyDescriptor> 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<PropertyDescriptor> 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<PropertyDescriptorVector> 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<PropertyDescriptor> 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<NativeObject>() && !obj->is<TypedArrayObject>() &&
!obj->is<MappedArgumentsObject>()) {
Handle<NativeObject*> nobj = obj.as<NativeObject>();
// 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<ArrayObject>()) {
obj->as<ArrayObject>().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<PropertyDescriptor> 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<Maybe<PropertyDescriptor>> 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<NativeObject>()) {
if (!ObjectElements::FreezeOrSeal(cx, obj.as<NativeObject>(), level)) {
return false;
}
}
return true;
}
static bool ResolveLazyProperties(JSContext* cx, Handle<NativeObject*> 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<NativeObject>()) {
Handle<NativeObject*> nobj = obj.as<NativeObject>();
// Force lazy properties to be resolved.
if (!ResolveLazyProperties(cx, nobj)) {
return false;
}
// Typed array elements are configurable, writable properties if the backing
// buffer is mutable, so if any elements are present, the typed array can
// neither be sealed nor frozen.
if (nobj->is<TypedArrayObject>() &&
!nobj->is<ImmutableTypedArrayObject>() &&
nobj->as<TypedArrayObject>().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<NoGC> 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<Maybe<PropertyDescriptor>> 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<TaggedProto> proto,
gc::AllocKind kind, NewObjectKind newKind, ObjectFlags objFlags,
gc::AllocSite* allocSite = nullptr) {
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());
MOZ_ASSERT_IF(allocSite, allocSite->zone() == cx->zone());
// 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);
kind = gc::GetFinalizedAllocKindForClass(kind, clasp);
Rooted<SharedShape*> shape(
cx, SharedShape::getInitialShape(cx, clasp, cx->realm(), proto, nfixed,
objFlags));
if (!shape) {
return nullptr;
}
gc::Heap heap = GetInitialHeap(newKind, clasp, allocSite);
NativeObject* obj = NativeObject::create(cx, kind, heap, shape, allocSite);
if (!obj) {
return nullptr;
}
probes::CreateObject(cx, obj);
return obj;
}
NativeObject* js::NewObjectWithGivenTaggedProto(
JSContext* cx,
const JSClass* clasp, Handle<TaggedProto> proto,
gc::AllocKind allocKind, NewObjectKind newKind, ObjectFlags objFlags) {
return NewObject(cx, clasp, proto, allocKind, newKind, objFlags);
}
NativeObject* js::NewObjectWithGivenTaggedProtoAndAllocSite(
JSContext* cx,
const JSClass* clasp, Handle<TaggedProto> proto,
gc::AllocKind allocKind, NewObjectKind newKind, ObjectFlags objFlags,
gc::AllocSite* site) {
return NewObject(cx, clasp, proto, allocKind, newKind, objFlags, site);
}
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> 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<JSFunction>() &&
newTarget->as<JSFunction>().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<AutoRealm> 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 InitializePropertiesFromCompatibleNativeObject(
JSContext* cx, Handle<NativeObject*> dst, Handle<NativeObject*> 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<SharedShape*> 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<SharedPropMap*> 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<NativeObject>(), src.as<NativeObject>());
}
bool js::ObjectMayBeSwapped(
const JSObject* obj) {
// Only proxies may be swapped: WindowProxy, Wrapper, DeadProxyObject,
// RemoteObjectProxy. We don't want to support a native object becoming a
// proxy object or vice versa.
if (!obj->is<ProxyObject>()) {
return false;
}
const auto* handler = obj->as<ProxyObject>().handler();
MOZ_ASSERT_IF(handler->isScripted(), !handler->mayBeSwapped());
return handler->mayBeSwapped();
}
static NativeObject* DefineConstructorAndPrototype(
JSContext* cx, HandleObject obj, Handle<JSAtom*> 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<NativeObject*> proto(
cx, GlobalObject::createBlankPrototypeInheriting(cx, clasp, protoProto));
if (!proto) {
return nullptr;
}
Rooted<NativeObject*> 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;
}
if (clasp->specShouldDefineConstructor()) {
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<JSAtom*> 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::GetObjectFromHostDefinedData(
JSContext* cx, MutableHandleObject incumbentGlobalRepresentative,
MutableHandleObject optionalHostDefinedData) {
// Note! To avoid re-rooting we're using the variable
// incumbentGlobalRepresentative, however, it is not 'the representative'
// until the getObjectPrototypeBelow
//
// Slightly confusing but intentional as this path can be quite hot.
if (!cx->runtime()->getHostDefinedData(cx, incumbentGlobalRepresentative,
optionalHostDefinedData)) {
return false;
}
if (!incumbentGlobalRepresentative) {
MOZ_ASSERT(!optionalHostDefinedData);
return true;
}
MOZ_ASSERT(incumbentGlobalRepresentative->is<GlobalObject>());
// After this line it's now actually the representative.
incumbentGlobalRepresentative.set(
&incumbentGlobalRepresentative->as<GlobalObject>().getObjectPrototype());
return cx->compartment()->wrap(cx, incumbentGlobalRepresentative);
}
/* See above GetObjectFromHostDefinedData comment */
bool js::GetIncumbentGlobalRepresentative(
JSContext* cx, MutableHandleObject incumbentGlobalRepresentative) {
if (!cx->jobQueue->getHostDefinedGlobal(cx, incumbentGlobalRepresentative)) {
return false;
}
if (incumbentGlobalRepresentative) {
MOZ_ASSERT(incumbentGlobalRepresentative->is<GlobalObject>());
incumbentGlobalRepresentative.set(
&incumbentGlobalRepresentative->as<GlobalObject>()
.getObjectPrototype());
if (!cx->compartment()->wrap(cx, incumbentGlobalRepresentative)) {
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<CrossCompartmentWrapperObject>());
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<CrossCompartmentWrapperObject>());
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<JSFunction>() ||
!(obj->as<JSFunction>().flags().isNativeConstructor())) {
return JSProto_Null;
}
static_assert(JSProto_Null ==
0,
"Loop below can start at 1 to skip JSProto_Null");
GlobalObject& global = obj->as<JSFunction>().global();
for (size_t k =
1; k < JSProto_LIMIT; ++k) {
JSProtoKey key = static_cast<JSProtoKey>(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<CanGC>(cx, obj.as<NativeObject>(), id, objp,
propp);
}
bool js::LookupName(JSContext* cx, Handle<PropertyName*> 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,
NativeObject** pobjp, PropertyResult* propp) {
AutoAssertNoPendingException nogc(cx);
MOZ_ASSERT(!*pobjp && propp->isNotFound());
for (JSObject* env = envChain; env; env = env->enclosingEnvironment()) {
if (env->getOpsLookupProperty()) {
return false;
}
if (!NativeLookupPropertyInline<NoGC>(cx, &env->as<NativeObject>(),
NameToId(name), pobjp, propp)) {
return false;
}
if (propp->isFound()) {
return true;
}
}
return true;
}
static bool IsTemporalDeadZone(JSContext* cx, HandleObject env, HandleId id,
const PropertyResult& prop,
bool* isTDZ) {
MOZ_ASSERT(prop.isFound());
// We do our own explicit checking for |this|
if (id.isAtom(cx->names().dot_this_)) {
*isTDZ =
false;
return true;
}
// Treat Debugger environments specially for TDZ checks, as they
// look like non-native environments but in fact wrap native
// environments.
if (env->is<DebugEnvironmentProxy>()) {
RootedValue v(cx);
auto envProxy = env.as<DebugEnvironmentProxy>();
if (!DebugEnvironmentProxy::getMaybeSentinelValue(cx, envProxy, id, &v)) {
return false;
}
*isTDZ = IsUninitializedLexical(v);
return true;
}
*isTDZ = IsUninitializedLexicalSlot(env, prop);
return true;
}
JSObject* js::LookupNameWithGlobalDefault(JSContext* cx,
Handle<PropertyName*> name,
HandleObject envChain) {
RootedId id(cx, NameToId(name));
RootedObject pobj(cx);
PropertyResult prop;
RootedObject env(cx, envChain);
for (; !env->is<GlobalObject>(); env = env->enclosingEnvironment()) {
if (!LookupProperty(cx, env, id, &pobj, &prop)) {
return nullptr;
}
if (prop.isFound()) {
break;
}
}
// Uninitialized lexicals can't appear on the prototype chain, so only check
// for TDZ when |pobj == env|.
//
// JSOp::BindName is always directly followed by JSOp::GetBoundName, so don't
// bother to create a RuntimeLexicalErrorObject.
if (pobj == env) {
MOZ_ASSERT(prop.isFound());
bool isTDZ;
if (!IsTemporalDeadZone(cx, env, id, prop, &isTDZ)) {
return nullptr;
}
if (isTDZ) {
ReportRuntimeLexicalError(cx, JSMSG_UNINITIALIZED_LEXICAL, name);
return nullptr;
}
}
return env;
}
JSObject* js::LookupNameUnqualified(JSContext* cx, Handle<PropertyName*> name,
HandleObject envChain) {
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 nullptr;
}
if (prop.isFound()) {
break;
}
}
// Uninitialized lexicals can't appear on the prototype chain, so only check
// for TDZ and `const` bindings when |pobj == env|.
//
// See note above RuntimeLexicalErrorObject.
if (pobj == env) {
MOZ_ASSERT(prop.isFound());
bool isTDZ;
if (!IsTemporalDeadZone(cx, env, id, prop, &isTDZ)) {
return nullptr;
}
if (isTDZ) {
return RuntimeLexicalErrorObject::create(cx, env,
JSMSG_UNINITIALIZED_LEXICAL);
}
if (env->is<LexicalEnvironmentObject>() &&
!prop.propertyInfo().writable()) {
// Assigning to a named lambda callee name is a no-op in sloppy mode.
if (!(env->is<BlockLexicalEnvironmentObject>() &&
env->as<BlockLexicalEnvironmentObject>().scope().kind() ==
ScopeKind::NamedLambda)) {
MOZ_ASSERT(name != cx->names().dot_this_);
return RuntimeLexicalErrorObject::create(cx, env,
JSMSG_BAD_CONST_ASSIGN);
}
}
}
return env;
}
bool js::HasOwnProperty(JSContext* cx, HandleObject obj, HandleId id,
bool* result) {
if (obj->is<ProxyObject>()) {
return Proxy::hasOwn(cx, obj, id, result);
}
if (GetOwnPropertyOp op = obj->getOpsGetOwnPropertyDescriptor()) {
Rooted<mozilla::Maybe<PropertyDescriptor>> desc(cx);
if (!op(cx, obj, id, &desc)) {
return false;
}
*result = desc.isSome();
return true;
}
PropertyResult prop;
if (!NativeLookupOwnProperty<CanGC>(cx, obj.as<NativeObject>(), 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<NoGC, LookupResolveMode::CheckMayResolve>(
cx, &obj->as<NativeObject>(), id, objp, propp);
}
bool js::LookupOwnPropertyPure(JSContext* cx, JSObject* obj, jsid id,
PropertyResult* propp) {
if (obj->getOpsLookupProperty()) {
return false;
}
return NativeLookupOwnPropertyInline<NoGC,
LookupResolveMode::CheckMayResolve>(
cx, &obj->as<NativeObject>(), 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<TypedArrayObject>().getElement<NoGC>(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<NativeObject>() &&
NativeGetPureInline(&obj->as<NativeObject>(), 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<JSFunction>()) {
*fp = &getter->as<JSFunction>();
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::GetPrototypeIfOrdinary(JSContext* cx, HandleObject obj,
bool* isOrdinary, MutableHandleObject protop) {
if (obj->is<js::ProxyObject>()) {
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<ProxyObject>());
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<WasmGcObject>()) {
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> 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);
}
/**
* IsTypedArrayFixedLength ( O )
*
* ES2025 draft rev 3e6f71c9402f91344ef9560425cc1e8fc45abf86
*/
static bool IsTypedArrayFixedLength(ResizableTypedArrayObject* obj) {
MOZ_ASSERT(obj->hasResizableBuffer());
// Step 1.
if (obj->isAutoLength()) {
return false;
}
// Steps 2-4.
return obj->isSharedMemory();
}
bool js::PreventExtensions(JSContext* cx, HandleObject obj,
ObjectOpResult& result) {
if (obj->is<ProxyObject>()) {
return js::Proxy::preventExtensions(cx, obj, result);
}
if (obj->is<WasmGcObject>()) {
return result.failCantPreventExtensions();
}
if (obj->is<ResizableTypedArrayObject>() &&
!IsTypedArrayFixedLength(&obj->as<ResizableTypedArrayObject>())) {
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<NativeObject>(),
obj->as<NativeObject>().getDenseInitializedLength() ==
obj->as<NativeObject>().getDenseCapacity());
return result.succeed();
}
if (obj->is<NativeObject>()) {
// Force lazy properties to be resolved.
Handle<NativeObject*> nobj = obj.as<NativeObject>();
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<NativeObject>()) {
ObjectElements::PreventExtensions(&obj->as<NativeObject>());
}
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<Maybe<PropertyDescriptor>> 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<NativeObject>(), id, desc);
}
bool js::DefineProperty(JSContext* cx, HandleObject obj, HandleId id,
Handle<PropertyDescriptor> 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<PropertyDescriptor> desc,
ObjectOpResult& result) {
desc.assertValid();
if (DefinePropertyOp op = obj->getOpsDefineProperty()) {
return op(cx, obj, id, desc, result);
}
return NativeDefineProperty(cx, obj.as<NativeObject>(), id, desc, result);
}
bool js::DefineAccessorProperty(JSContext* cx, HandleObject obj, HandleId id,
HandleObject getter, HandleObject setter,
unsigned attrs, ObjectOpResult& result) {
Rooted<PropertyDescriptor> 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<NativeObject>(), id, desc, result);
}
bool js::DefineDataProperty(JSContext* cx, HandleObject obj, HandleId id,
HandleValue value,
unsigned attrs,
ObjectOpResult& result) {
Rooted<PropertyDescriptor> desc(cx, PropertyDescriptor::Data(value, attrs));
if (DefinePropertyOp op = obj->getOpsDefineProperty()) {
return op(cx, obj, id, desc, result);
}
return NativeDefineProperty(cx, obj.as<NativeObject>(), 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<mozilla::Maybe<PropertyDescriptor>> 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::Prefs::experimental_weakrefs_expose_cleanupSome() &&
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) {
if (!JS::Prefs::experimental_error_iserror() &&
id == NameToId(cx->names().isError)) {
return true;
}
if (!JS::Prefs::experimental_iterator_sequencing() &&
id == NameToId(cx->names().concat)) {
return true;
}
if (!JS::Prefs::experimental_joint_iteration() &&
(id == NameToId(cx->names().zip) ||
id == NameToId(cx->names().zipKeyed))) {
return true;
}
}
#ifdef JS_HAS_INTL_API
if (key == JSProto_Date && !JS::Prefs::experimental_temporal() &&
id == NameToId(cx->names().toTemporalInstant)) {
return true;
}
if (key == JSProto_Locale && !JS::Prefs::experimental_intl_locale_info()) {
if (id == NameToId(cx->names().firstDayOfWeek) ||
id == NameToId(cx->names().getTextInfo) ||
id == NameToId(cx->names().getNumberingSystems) ||
id == NameToId(cx->names().getCollations) ||
id == NameToId(cx->names().getCalendars) ||
id == NameToId(cx->names().getHourCycles) ||
id == NameToId(cx->names().getWeekInfo) ||
id == NameToId(cx->names().getTimeZones)) {
return true;
}
}
#endif
#ifdef NIGHTLY_BUILD
// 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) {
if (!JS::Prefs::experimental_iterator_range() &&
(id == NameToId(cx->names().range))) {
return true;
}
if (!JS::Prefs::experimental_promise_allkeyed() &&
(id == NameToId(cx->names().allKeyed) ||
id == NameToId(cx->names().allSettledKeyed))) {
return true;
}
}
if (key == JSProto_ArrayBuffer &&
!JS::Prefs::experimental_arraybuffer_immutable()) {
if (id == NameToId(cx->names().immutable) ||
id == NameToId(cx->names().sliceToImmutable) ||
id == NameToId(cx->names().transferToImmutable)) {
return true;
}
}
if (key == JSProto_Iterator) {
if (!JS::Prefs::experimental_iterator_chunking() &&
(id == NameToId(cx->names().chunks) ||
id == NameToId(cx->names().windows))) {
return true;
}
if (!JS::Prefs::experimental_iterator_join() &&
id == NameToId(cx->names().join)) {
return true;
}
if (!JS::Prefs::experimental_iterator_includes() &&
id == NameToId(cx->names().includes)) {
return true;
}
}
#endif
if (key == JSProto_Function &&
!JS::Prefs::experimental_error_capture_stack_trace() &&
id == NameToId(cx->names().captureStackTrace)) {
return true;
}
if (key == JSProto_Function &&
!JS::Prefs::experimental_error_stack_trace_limit() &&
id == NameToId(cx->names().stackTraceLimit)) {
return true;
}
if (key == JSProto_Atomics && !JS::Prefs::experimental_atomics_pause() &&
id == NameToId(cx->names().pause)) {
return true;
}
if (key == JSProto_Atomics && !JS::Prefs::atomics_wait_async() &&
id == NameToId(cx->names().waitAsync)) {
return true;
}
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<jsid> 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<StringObject>();
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<StringObject>();
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<NumberObject>();
if (HasNativeMethodPure(nobj, cx->names().valueOf, num_valueOf, cx)) {
vp.setNumber(nobj->unbox());
return true;
}
}
else if (clasp == &DateObject::class_) {
DateObject* dateObj = &obj->as<DateObject>();
if (HasNativeMethodPure(dateObj, cx->names().valueOf, date_valueOf, cx)) {
vp.set(dateObj->UTCTime());
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);
RootedTuple<JSObject*, Value, Value> roots(cx);
RootedField<JSObject*,
0> obj(roots, &vp.toObject());
// Steps 4-5.
RootedField<Value,
1> method(roots);
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.
RootedField<Value,
2> arg0(
roots,
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<CanGC>(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<JSString*> 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);
}
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;
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<PropertyName*> 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<CanGC>(cx, keyValue, &key)) {
return nullptr;
}
ReportIsNullOrUndefinedForPropertyAccess(cx, val, valIndex, key);
}
else {
ReportIsNullOrUndefinedForPropertyAccess(cx, val, valIndex);
}
return nullptr;
}
return PrimitiveToObject(cx, val);
}
enum class SlotsKind { Fixed, Dynamic };
class GetObjectSlotNameFunctor : public JS::TracingContext::Functor {
NativeObject* obj;
SlotsKind kind;
public:
explicit GetObjectSlotNameFunctor(NativeObject* obj, SlotsKind kind)
: obj(obj), kind(kind) {}
virtual
void operator()(JS::TracingContext* trc,
const char* name,
char* buf,
size_t bufsize) override;
};
void GetObjectSlotNameFunctor::
operator()(JS::TracingContext* tcx,
const char* name,
char* buf,
size_t bufsize) {
MOZ_ASSERT(tcx->index() != JS::TracingContext::InvalidIndex);
uint32_t slot = uint32_t(tcx->index());
if (kind == SlotsKind::Dynamic) {
slot += obj->numFixedSlots();
}
Maybe<PropertyKey> key;
NativeShape* shape = obj->as<NativeObject>().shape();
for (ShapePropertyIter<NoGC> 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<GlobalObject>()) {
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<EnvironmentObject>()) {
if (slot == EnvironmentObject::enclosingEnvironmentSlot()) {
slotname =
"enclosing_environment";
}
else if (obj->is<CallObject>()) {
if (slot == CallObject::calleeSlot()) {
slotname =
"callee_slot";
}
}
else if (obj->is<WithEnvironmentObject>()) {
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 {
MOZ_CRASH(
"Unexpected key kind");
}
}
}
/*** 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<ProxyObject>(); }
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<
CLASS>()) { \
obj->as<
CLASS>().dumpOwnFields(json); \
return; \
}
FOR_EACH_CLASS(CALL)
# undef CALL
}
static void DumpOwnStringContent(
const JSObject* obj, js::GenericPrinter& out) {
# define CALL(
CLASS) \
if (obj->is<
CLASS>()) { \
out.put(
" "); \
obj->as<
CLASS>().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();
}
if (JSObject* expando = GetProxyExpando(this)) {
js::GenericPrinter& out = json.beginStringProperty(
"expando");
JS::ObjectValue(*expando).dumpStringContent(out);
json.endStringProperty();
}
if (is<DebugEnvironmentProxy>()) {
json.boolProperty(
"isQualifiedVarObj", isQualifiedVarObj());
json.boolProperty(
"isUnqualifiedVarObj", isUnqualifiedVarObj());
}
}
DumpOwnFields(this, json);
if (is<NativeObject>()) {
const auto* nobj = &as<NativeObject>();
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<PropMap*,
8, SystemAllocPolicy> 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::allocKind()
const {
if (isTenured()) {
return asTenured().getAllocKind();
}
Nursery& nursery = runtimeFromMainThread()->gc.nursery();
return allocKindForTenure(nursery);
}
js::gc::AllocKind JSObject::allocKindForTenure(
const js::Nursery& nursery)
const {
using
namespace js::gc;
MOZ_ASSERT(IsInsideNursery(this));
if (is<NativeObject>()) {
if (is<ArrayObject>()) {
const NativeObject& nobj = as<NativeObject>();
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;
}
size_t nelements = nobj.getDenseCapacity();
AllocKind kind = GetGCArrayKind(nelements);
MOZ_ASSERT(GetObjectFinalizeKind(getClass()) == gc::FinalizeKind::None);
MOZ_ASSERT(!IsFinalizedKind(kind));
return kind;
}
if (is<JSFunction>()) {
return as<JSFunction>().getAllocKind();
}
if (is<FixedLengthTypedArrayObject>()) {
return as<FixedLengthTypedArrayObject>().allocKindForTenure();
}
return as<NativeObject>().allocKindForTenure();
}
// Handle all non-native objects.
// Proxies that are CrossCompartmentWrappers may be nursery allocated.
if (is<ProxyObject>()) {
return as<ProxyObject>().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<WasmStructObject>()) {
// Figure out the size of this object, from the object's TypeDef.
const wasm::
TypeDef*
typeDef = &as<WasmStructObject>().
typeDef();
AllocKind kind =
typeDef->structType().allocKind_;
return GetFinalizedAllocKindForClass(kind, getClass());
}
// 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.
MOZ_ASSERT(is<WasmArrayObject>());
gc::AllocKind allocKind = as<WasmArrayObject>().allocKind();
return allocKind;
}
void JSObject::addSizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf,
JS::ClassInfo* info,
JS::RuntimeSizes* runtimeSizes) {
if (is<NativeObject>() && as<NativeObject>().hasDynamicSlots()) {
info->objectsGCBufferSlots +=
gc::GetAllocSize(zone(), as<NativeObject>().getSlotsHeader());
}
if (is<NativeObject>() && as<NativeObject>().hasDynamicElements()) {
void* allocatedElements = as<NativeObject>().getUnshiftedElementsHeader();
info->objectsGCBufferElementsNormal +=
gc::GetAllocSize(zone(), allocatedElements);
}
// Other things may be measured in the future if DMD indicates it is
// worthwhile.
if (is<JSFunction>() || is<PlainObject>() || is<ArrayObject>() ||
is<CallObject>() || is<RegExpObject>() || is<ProxyObject>()) {
// 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<ArgumentsObject>()) {
info->objectsGCBufferMisc += as<ArgumentsObject>().sizeOfMisc();
}
else if (is<MapObject>()) {
info->objectsGCBufferMisc += as<MapObject>().sizeOfBufferData();
info->objectsMallocHeapMisc +=
as<MapObject>().sizeOfMallocData(mallocSizeOf);
}
else if (is<SetObject>()) {
info->objectsGCBufferMisc += as<SetObject>().sizeOfBufferData();
info->objectsMallocHeapMisc +=
as<SetObject>().sizeOfMallocData(mallocSizeOf);
}
else if (is<PropertyIteratorObject>()) {
info->objectsMallocHeapMisc +=
as<PropertyIteratorObject>().sizeOfMisc(mallocSizeOf);
}
else if (is<ArrayBufferObject>()) {
ArrayBufferObject::addSizeOfExcludingThis(this, mallocSizeOf, info,
runtimeSizes);
}
else if (is<SharedArrayBufferObject>()) {
SharedArrayBufferObject::addSizeOfExcludingThis(this, mallocSizeOf, info,
runtimeSizes);
}
else if (is<GlobalObject>()) {
as<GlobalObject>().addSizeOfData(mallocSizeOf, info);
}
else if (is<WeakCollectionObject>()) {
info->objectsGCBufferMisc +=
as<WeakCollectionObject>().sizeOfExcludingThis(mallocSizeOf);
}
else if (is<WasmStructObject>()) {
const WasmStructObject& s = as<WasmStructObject>();
info->objectsGCBufferSlots += s.sizeOfExcludingThis();
}
else if (is<WasmArrayObject>()) {
const WasmArrayObject& a = as<WasmArrayObject>();
info->objectsGCBufferElementsNormal += a.sizeOfExcludingThis();
}
#ifdef JS_HAS_CTYPES
else {
// This must be the last case.
info->objectsMallocHeapMisc += ctypes::SizeOfDataIfCDataObject(
mallocSizeOf,
const_cast<JSObject*>(this));
}
#endif
}
size_t JSObject::sizeOfIncludingThisInNursery(
mozilla::MallocSizeOf mallocSizeOf)
const {
MOZ_ASSERT(!isTenured());
const Nursery& nursery = runtimeFromMainThread()->gc.nursery();
size_t size = gc::Arena::thingSize(allocKindForTenure(nursery));
if (is<NativeObject>()) {
const NativeObject& native = as<NativeObject>();
size += native.numDynamicSlots() *
sizeof(Value);
if (native.hasDynamicElements()) {
js::ObjectElements& elements = *native.getElementsHeader();
size += (elements.capacity + elements.numShiftedElements()) *
sizeof(HeapSlot);
}
if (is<ArgumentsObject>()) {
size += as<ArgumentsObject>().sizeOfData();
}
}
else if (is<WasmStructObject>()) {
const WasmStructObject& s = as<WasmStructObject>();
size += s.sizeOfExcludingThis();
}
else if (is<WasmArrayObject>()) {
const WasmArrayObject& a = as<WasmArrayObject>();
size += a.sizeOfExcludingThis();
}
return size;
}
JS::ubi::Node::Size JS::ubi::Concrete<JSObject>::size(
mozilla::MallocSizeOf mallocSizeOf)
const {
JSObject& obj = get();
if (!obj.isTenured()) {
return obj.sizeOfIncludingThisInNursery(mallocSizeOf);
}
JS::ClassInfo info;
obj.addSizeOfExcludingThis(mallocSizeOf, &info, nullptr);
return obj.tenuredSizeOfThis() + info.sizeOfAllThings();
}
const char16_t JS::ubi::Concrete<JSObject>::concreteTypeName[] = u
"JSObject";
void JSObject::traceChildren(JSTracer* trc) {
TraceCellHeaderEdge(trc, this,
"shape");
Shape* objShape = shape();
if (objShape->isNative()) {
NativeObject* nobj = &as<NativeObject>();
if (nobj->hasDynamicSlots()) {
ObjectSlots* slots = nobj->getSlotsHeader();
MOZ_ASSERT(nobj->slots_ == slots->slots());
TraceBufferEdge(trc, &slots,
"objectDynamicSlots buffer");
if (slots != nobj->getSlotsHeader()) {
nobj->slots_ = slots->slots();
}
}
if (nobj->hasDynamicElements()) {
void* buffer = nobj->getUnshiftedElementsHeader();
uint32_t numShifted = nobj->getElementsHeader()->numShiftedElements();
TraceBufferEdge(trc, &buffer,
"objectDynamicElements buffer");
if (buffer != nobj->getUnshiftedElementsHeader()) {
nobj->elements_ =
reinterpret_cast<ObjectElements*>(buffer)->elements() + numShifted;
}
}
const uint32_t nslots = nobj->slotSpan();
const uint32_t nfixed = nobj->numFixedSlots();
{
GetObjectSlotNameFunctor func(nobj, SlotsKind::Fixed);
JS::AutoTracingDetails ctx(trc, func);
TraceRange(trc, std::min(nslots, nfixed), nobj->fixedSlots(),
"objectFixedSlots");
}
if (nslots > nfixed) {
MOZ_ASSERT(nobj->hasDynamicSlots());
GetObjectSlotNameFunctor func(nobj, SlotsKind::Dynamic);
JS::AutoTracingDetails ctx(trc, func);
TraceRange(trc, nslots - nfixed, nobj->slots_.get(),
"objectDynamicSlots");
#if defined(JS_GC_CONCURRENT_MARKING) &&
defined(DEBUG)
// Any unused dynamic slots that should be undefined.
if (nobj->hasDynamicSlots()) {
uint32_t nfixed = nobj->numFixedSlots();
uint32_t start = nslots;
uint32_t end = nfixed + nobj->numDynamicSlots();
MOZ_ASSERT(start >= nobj->numFixedSlots());
HeapSlot* dynamicSlots = nobj->getSlotAddressUnchecked(start);
for (uint32_t i =
0; i < end - start; i++) {
MOZ_ASSERT(dynamicSlots[i].isUndefined());
}
}
#endif
}
TraceRange(trc, nobj->getDenseInitializedLength(),
nobj->getDenseElements().begin(),
"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<ProxyObject>())) {
return Proxy::boxedValue_unbox(cx, obj, vp);
}
if (obj->is<BooleanObject>()) {
vp.setBoolean(obj->as<BooleanObject>().unbox());
}
else if (obj->is<NumberObject>()) {
vp.setNumber(obj->as<NumberObject>().unbox());
}
else if (obj->is<StringObject>()) {
vp.setString(obj->as<StringObject>().unbox());
}
else if (obj->is<DateObject>()) {
vp.set(obj->as<DateObject>().UTCTime());
}
else if (obj->is<SymbolObject>()) {
vp.setSymbol(obj->as<SymbolObject>().unbox());
}
else if (obj->is<BigIntObject>()) {
vp.setBigInt(obj->as<BigIntObject>().unbox());
}
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());
}
}
using
namespace gc;
if (!clasp->isProxyObject()) {
// Check |allocKind| has the correct finalization kind for the class.
gc::FinalizeKind finalizeKind = GetObjectFinalizeKind(clasp);
MOZ_ASSERT_IF(finalizeKind == gc::FinalizeKind::None,
!IsFinalizedKind(allocKind));
MOZ_ASSERT_IF(finalizeKind == gc::FinalizeKind::Background,
IsBackgroundFinalized(allocKind));
MOZ_ASSERT_IF(finalizeKind == gc::FinalizeKind::Foreground,
IsForegroundFinalized(allocKind));
}
// 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);
}
else {
MOZ_ASSERT(finalizeFlags ==
0);
}
MOZ_ASSERT_IF(clasp->hasFinalize(),
heap == gc::Heap::Tenured ||
CanNurseryAllocateFinalizedClass(clasp) ||
clasp->isProxyObject());
MOZ_ASSERT(!shape->isDictionary());
// If the class has the JSCLASS_DELAY_METADATA_BUILDER flag, the caller must
// use AutoSetNewObjectMetadata.
MOZ_ASSERT_IF(clasp->shouldDelayMetadataBuilder(),
shape->realm()->hasActiveAutoSetNewObjectMetadata());
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
