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-rw-r--r--js/src/vm/JSObject.cpp3526
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diff --git a/js/src/vm/JSObject.cpp b/js/src/vm/JSObject.cpp
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+++ b/js/src/vm/JSObject.cpp
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+/* -*- 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 <string.h>
+
+#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<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, &currentDesc)) {
+ 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, so if any
+ // elements are present, the typed array can neither be sealed nor frozen.
+ if (nobj->is<TypedArrayObject>() &&
+ 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) {
+ 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<SharedShape*> 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<TaggedProto> 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> 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 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<mozilla::Maybe<PropertyDescriptor>> 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<PropertyDescriptor> 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<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) {
+ 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<ObjectElements*>(js_pod_malloc<HeapSlot>(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<NativeObject*> 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 GCPtr<Value>s 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<JS::Value>(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<js::detail::ProxyValueArray*>(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<NativeObject>()) {
+ return obj->as<NativeObject>().allocKindForTenure();
+ }
+
+ return obj->as<ProxyObject>().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<ProxyObject>() ? &a->as<ProxyObject>() : nullptr;
+ ProxyObject* pb = b->is<ProxyObject>() ? &b->as<ProxyObject>() : 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<NativeObject>() ? &a->as<NativeObject>() : nullptr;
+ NativeObject* nb = b->is<NativeObject>() ? &b->as<NativeObject>() : 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<ProxyObject>().setInlineValueArray();
+ }
+ if (bIsProxyWithInlineValues) {
+ a->as<ProxyObject>().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<NativeObject>(), kb, avals)) {
+ oomUnsafe.crash("NativeObject::fixupAfterSwap");
+ }
+ if (nb &&
+ !NativeObject::fixupAfterSwap(cx, a.as<NativeObject>(), ka, bvals)) {
+ oomUnsafe.crash("NativeObject::fixupAfterSwap");
+ }
+
+ if (pa && !b->as<ProxyObject>().fixupAfterSwap(cx, avals)) {
+ oomUnsafe.crash("ProxyObject::fixupAfterSwap");
+ }
+ if (pb && !a->as<ProxyObject>().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<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;
+ }
+
+ 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::GetObjectFromIncumbentGlobal(JSContext* cx, MutableHandleObject obj) {
+ Rooted<GlobalObject*> 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<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,
+ 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<NoGC>(cx, &env->as<NativeObject>(),
+ NameToId(name), pobjp, propp)) {
+ return false;
+ }
+ if (propp->isFound()) {
+ *objp = env;
+ return true;
+ }
+ }
+
+ return true;
+}
+
+bool js::LookupNameWithGlobalDefault(JSContext* cx, Handle<PropertyName*> name,
+ HandleObject envChain,
+ MutableHandleObject objp) {
+ 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 false;
+ }
+ if (prop.isFound()) {
+ break;
+ }
+ }
+
+ objp.set(env);
+ return true;
+}
+
+bool js::LookupNameUnqualified(JSContext* cx, Handle<PropertyName*> 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<DebugEnvironmentProxy>()) {
+ RootedValue v(cx);
+ Rooted<DebugEnvironmentProxy*> envProxy(
+ cx, &env->as<DebugEnvironmentProxy>());
+ 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<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_);
+ 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<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::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<NativeObject>(), 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<NativeObject>();
+ if (!nobj->hasGetter(propInfo)) {
+ return true;
+ }
+
+ JSObject* getterObj = nobj->getGetter(propInfo);
+ if (!getterObj->is<JSFunction>()) {
+ return true;
+ }
+
+ JSFunction* getter = &getterObj->as<JSFunction>();
+ 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<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);
+}
+
+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->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::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<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;
+ }
+ }
+
+ 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<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);
+ }
+#ifdef ENABLE_RECORD_TUPLE
+ case ValueType::ExtendedPrimitive: {
+ JSObject& obj = v.toExtendedPrimitive();
+
+ if (obj.is<RecordType>()) {
+ Rooted<RecordType*> rec(cx, &obj.as<RecordType>());
+ return RecordObject::create(cx, rec);
+ }
+ if (obj.is<TupleType>()) {
+ Rooted<TupleType*> tuple(cx, &obj.as<TupleType>());
+ 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<TupleType>()) {
+ return JSProto_Tuple;
+ }
+ if (v.toExtendedPrimitive().is<RecordType>()) {
+ 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<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);
+}
+
+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<GlobalObject>()) {
+ 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<NonSyntacticVariablesObject>() ||
+ !obj->is<EnvironmentObject>());
+
+ return obj;
+}
+
+JSObject* js::GetThisObjectOfLexical(JSObject* env) {
+ return env->as<ExtensibleLexicalEnvironmentObject>().thisObject();
+}
+
+JSObject* js::GetThisObjectOfWith(JSObject* env) {
+ MOZ_ASSERT(env->is<WithEnvironmentObject>());
+ return GetThisObject(env->as<WithEnvironmentObject>().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<PropertyKey> key;
+ if (obj->is<NativeObject>()) {
+ 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 {
+ 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<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();
+ }
+
+ Value expando = GetProxyExpando(this);
+ if (!expando.isNull()) {
+ js::GenericPrinter& out = json.beginStringProperty("expando");
+ 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::allocKindForTenure(
+ const js::Nursery& nursery) const {
+ using namespace js::gc;
+
+ MOZ_ASSERT(IsInsideNursery(this));
+
+ if (canHaveFixedElements()) {
+ 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_BACKGROUND;
+ }
+
+ size_t nelements = nobj.getDenseCapacity();
+ return ForegroundToBackgroundAllocKind(GetGCArrayKind(nelements));
+ }
+
+ if (is<JSFunction>()) {
+ return as<JSFunction>().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<FixedLengthTypedArrayObject>() &&
+ !as<FixedLengthTypedArrayObject>().hasBuffer()) {
+ gc::AllocKind allocKind;
+ if (as<FixedLengthTypedArrayObject>().hasInlineElements()) {
+ size_t nbytes = as<FixedLengthTypedArrayObject>().byteLength();
+ allocKind = FixedLengthTypedArrayObject::AllocKindForLazyBuffer(nbytes);
+ } else {
+ allocKind = GetGCObjectKind(getClass());
+ }
+ return ForegroundToBackgroundAllocKind(allocKind);
+ }
+
+ // 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();
+ 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<WasmArrayObject>()) {
+ gc::AllocKind allocKind = as<WasmArrayObject>().allocKind();
+ return allocKind;
+ }
+
+ // All nursery allocatable non-native objects are handled above.
+ return as<NativeObject>().allocKindForTenure();
+}
+
+void JSObject::addSizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf,
+ JS::ClassInfo* info,
+ JS::RuntimeSizes* runtimeSizes) {
+ if (is<NativeObject>() && as<NativeObject>().hasDynamicSlots()) {
+ info->objectsMallocHeapSlots +=
+ mallocSizeOf(as<NativeObject>().getSlotsHeader());
+ }
+
+ if (is<NativeObject>() && as<NativeObject>().hasDynamicElements()) {
+ void* allocatedElements = as<NativeObject>().getUnshiftedElementsHeader();
+ info->objectsMallocHeapElementsNormal += mallocSizeOf(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->objectsMallocHeapMisc +=
+ as<ArgumentsObject>().sizeOfMisc(mallocSizeOf);
+ } else if (is<MapObject>()) {
+ info->objectsMallocHeapMisc += as<MapObject>().sizeOfData(mallocSizeOf);
+ } else if (is<SetObject>()) {
+ info->objectsMallocHeapMisc += as<SetObject>().sizeOfData(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->objectsMallocHeapMisc +=
+ as<WeakCollectionObject>().sizeOfExcludingThis(mallocSizeOf);
+ }
+#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() 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<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();
+ }
+ }
+
+ return size;
+}
+
+JS::ubi::Node::Size JS::ubi::Concrete<JSObject>::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<JSObject>::concreteTypeName[] = u"JSObject";
+
+void JSObject::traceChildren(JSTracer* trc) {
+ TraceCellHeaderEdge(trc, this, "shape");
+
+ Shape* objShape = shape();
+ if (objShape->isNative()) {
+ NativeObject* nobj = &as<NativeObject>();
+
+ {
+ 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<HeapSlot*>(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<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());
+#ifdef ENABLE_RECORD_TUPLE
+ } else if (obj->is<RecordObject>()) {
+ vp.setExtendedPrimitive(*obj->as<RecordObject>().unbox());
+ } else if (obj->is<TupleObject>()) {
+ vp.setExtendedPrimitive(obj->as<TupleObject>().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
generated by cgit v1.2.3 (git 2.39.1) at 2024-11-18 23:13:57 +0000