/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 4 -*- * 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 "jsobjinlines.h" #include "mozilla/ArrayUtils.h" #include "mozilla/MathAlgorithms.h" #include "mozilla/MemoryReporting.h" #include "mozilla/SizePrintfMacros.h" #include "mozilla/TemplateLib.h" #include #include "jsapi.h" #include "jsarray.h" #include "jsatom.h" #include "jscntxt.h" #include "jsfriendapi.h" #include "jsfun.h" #include "jsgc.h" #include "jsiter.h" #include "jsnum.h" #include "jsopcode.h" #include "jsprf.h" #include "jsscript.h" #include "jsstr.h" #include "jstypes.h" #include "jsutil.h" #include "jswin.h" #include "jswrapper.h" #include "builtin/BigInt.h" #include "builtin/Eval.h" #include "builtin/Object.h" #include "builtin/SymbolObject.h" #include "frontend/BytecodeCompiler.h" #include "gc/Marking.h" #include "gc/Policy.h" #include "jit/BaselineJIT.h" #include "js/MemoryMetrics.h" #include "js/Proxy.h" #include "js/UbiNode.h" #include "js/UniquePtr.h" #include "vm/ArgumentsObject.h" #include "vm/Interpreter.h" #include "vm/ProxyObject.h" #include "vm/RegExpStaticsObject.h" #include "vm/Shape.h" #include "vm/TypedArrayCommon.h" #include "jsatominlines.h" #include "jsboolinlines.h" #include "jscntxtinlines.h" #include "jscompartmentinlines.h" #include "vm/ArrayObject-inl.h" #include "vm/BooleanObject-inl.h" #include "vm/Caches-inl.h" #include "vm/Interpreter-inl.h" #include "vm/NativeObject-inl.h" #include "vm/NumberObject-inl.h" #include "vm/Shape-inl.h" #include "vm/StringObject-inl.h" using namespace js; using namespace js::gc; using mozilla::DebugOnly; using mozilla::Maybe; void js::ReportNotObject(JSContext* cx, const Value& v) { MOZ_ASSERT(!v.isObject()); RootedValue value(cx, v); UniqueChars bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, value, nullptr); if (bytes) JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, JSMSG_NOT_NONNULL_OBJECT, bytes.get()); } JS_PUBLIC_API(const char*) JS::InformalValueTypeName(const Value& v) { if (v.isObject()) return v.toObject().getClass()->name; if (v.isString()) return "string"; if (v.isSymbol()) return "symbol"; if (v.isNumber()) return "number"; if (v.isBoolean()) return "boolean"; if (v.isNull()) return "null"; if (v.isUndefined()) return "undefined"; return "value"; } // ES6 draft rev37 6.2.4.4 FromPropertyDescriptor JS_PUBLIC_API(bool) JS::FromPropertyDescriptor(JSContext* cx, Handle desc, MutableHandleValue vp) { AssertHeapIsIdle(cx); CHECK_REQUEST(cx); assertSameCompartment(cx, desc); // Step 1. if (!desc.object()) { vp.setUndefined(); return true; } return FromPropertyDescriptorToObject(cx, desc, vp); } bool js::FromPropertyDescriptorToObject(JSContext* cx, Handle desc, MutableHandleValue vp) { // Step 2-3. RootedObject obj(cx, NewBuiltinClassInstance(cx)); if (!obj) return false; const JSAtomState& names = cx->names(); // Step 4. if (desc.hasValue()) { if (!DefineProperty(cx, obj, names.value, desc.value())) return false; } // Step 5. RootedValue v(cx); if (desc.hasWritable()) { v.setBoolean(desc.writable()); if (!DefineProperty(cx, obj, names.writable, v)) return false; } // Step 6. if (desc.hasGetterObject()) { if (JSObject* get = desc.getterObject()) v.setObject(*get); else v.setUndefined(); if (!DefineProperty(cx, obj, names.get, v)) return false; } // Step 7. if (desc.hasSetterObject()) { if (JSObject* set = desc.setterObject()) v.setObject(*set); else v.setUndefined(); if (!DefineProperty(cx, obj, names.set, v)) return false; } // Step 8. if (desc.hasEnumerable()) { v.setBoolean(desc.enumerable()); if (!DefineProperty(cx, obj, names.enumerable, v)) return false; } // Step 9. if (desc.hasConfigurable()) { v.setBoolean(desc.configurable()); if (!DefineProperty(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.length() == 0) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_MORE_ARGS_NEEDED, method, "0", "s"); return false; } HandleValue v = args[0]; if (!v.isObject()) { UniqueChars bytes = DecompileValueGenerator(cx, JSDVG_SEARCH_STACK, v, nullptr); if (!bytes) return false; JS_ReportErrorNumberLatin1(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, jsid id, unsigned errorNumber) { MOZ_ASSERT(js_ErrorFormatString[errorNumber].argCount == 1); RootedValue idVal(cx, IdToValue(id)); JSString* idstr = ValueToSource(cx, idVal); if (!idstr) return false; JSAutoByteString bytes(cx, idstr); if (!bytes) return false; JS_ReportErrorNumberLatin1(cx, GetErrorMessage, nullptr, errorNumber, bytes.ptr()); return false; } bool js::Throw(JSContext* cx, JSObject* obj, unsigned errorNumber) { if (js_ErrorFormatString[errorNumber].argCount == 1) { RootedValue val(cx, ObjectValue(*obj)); ReportValueErrorFlags(cx, JSREPORT_ERROR, errorNumber, JSDVG_IGNORE_STACK, val, nullptr, nullptr, nullptr); } else { MOZ_ASSERT(js_ErrorFormatString[errorNumber].argCount == 0); JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, errorNumber); } 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(); } bool js::ToPropertyDescriptor(JSContext* cx, HandleValue descval, bool checkAccessors, MutableHandle desc) { // step 2 RootedObject obj(cx, NonNullObject(cx, descval)); if (!obj) return false; // step 3 desc.clear(); bool found = false; RootedId id(cx); RootedValue v(cx); unsigned attrs = 0; // step 4 id = NameToId(cx->names().enumerable); if (!GetPropertyIfPresent(cx, obj, id, &v, &found)) return false; if (found) { if (ToBoolean(v)) attrs |= JSPROP_ENUMERATE; } else { attrs |= JSPROP_IGNORE_ENUMERATE; } // step 5 id = NameToId(cx->names().configurable); if (!GetPropertyIfPresent(cx, obj, id, &v, &found)) return false; if (found) { if (!ToBoolean(v)) attrs |= JSPROP_PERMANENT; } else { attrs |= JSPROP_IGNORE_PERMANENT; } // step 6 id = NameToId(cx->names().value); if (!GetPropertyIfPresent(cx, obj, id, &v, &found)) return false; if (found) desc.value().set(v); else attrs |= JSPROP_IGNORE_VALUE; // step 7 id = NameToId(cx->names().writable); if (!GetPropertyIfPresent(cx, obj, id, &v, &found)) return false; if (found) { if (!ToBoolean(v)) attrs |= JSPROP_READONLY; } else { attrs |= JSPROP_IGNORE_READONLY; } // step 8 bool hasGetOrSet; id = NameToId(cx->names().get); if (!GetPropertyIfPresent(cx, obj, id, &v, &found)) return false; hasGetOrSet = found; if (found) { if (v.isObject()) { if (checkAccessors) JS_TRY_OR_RETURN_FALSE(cx, CheckCallable(cx, &v.toObject(), js_getter_str)); desc.setGetterObject(&v.toObject()); } else if (!v.isUndefined()) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_GET_SET_FIELD, js_getter_str); return false; } attrs |= JSPROP_GETTER | JSPROP_SHARED; } // step 9 id = NameToId(cx->names().set); if (!GetPropertyIfPresent(cx, obj, id, &v, &found)) return false; hasGetOrSet |= found; if (found) { if (v.isObject()) { if (checkAccessors) JS_TRY_OR_RETURN_FALSE(cx, CheckCallable(cx, &v.toObject(), js_setter_str)); desc.setSetterObject(&v.toObject()); } else if (!v.isUndefined()) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_BAD_GET_SET_FIELD, js_setter_str); return false; } attrs |= JSPROP_SETTER | JSPROP_SHARED; } // step 10 if (hasGetOrSet) { if (!(attrs & JSPROP_IGNORE_READONLY) || !(attrs & JSPROP_IGNORE_VALUE)) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_INVALID_DESCRIPTOR); return false; } // By convention, these bits are not used on accessor descriptors. attrs &= ~(JSPROP_IGNORE_READONLY | JSPROP_IGNORE_VALUE); } desc.setAttributes(attrs); MOZ_ASSERT_IF(attrs & JSPROP_READONLY, !(attrs & (JSPROP_GETTER | JSPROP_SETTER))); MOZ_ASSERT_IF(attrs & (JSPROP_GETTER | JSPROP_SETTER), attrs & JSPROP_SHARED); return true; } Result<> js::CheckPropertyDescriptorAccessors(JSContext* cx, Handle desc) { if (desc.hasGetterObject()) MOZ_TRY(CheckCallable(cx, desc.getterObject(), js_getter_str)); if (desc.hasSetterObject()) MOZ_TRY(CheckCallable(cx, desc.setterObject(), js_setter_str)); return Ok(); } void js::CompletePropertyDescriptor(MutableHandle desc) { desc.assertValid(); if (desc.isGenericDescriptor() || desc.isDataDescriptor()) { if (!desc.hasWritable()) desc.attributesRef() |= JSPROP_READONLY; desc.attributesRef() &= ~(JSPROP_IGNORE_READONLY | JSPROP_IGNORE_VALUE); } else { if (!desc.hasGetterObject()) desc.setGetterObject(nullptr); if (!desc.hasSetterObject()) desc.setSetterObject(nullptr); desc.attributesRef() |= JSPROP_GETTER | JSPROP_SETTER | JSPROP_SHARED; } if (!desc.hasConfigurable()) desc.attributesRef() |= JSPROP_PERMANENT; desc.attributesRef() &= ~(JSPROP_IGNORE_PERMANENT | JSPROP_IGNORE_ENUMERATE); desc.assertComplete(); } bool js::ReadPropertyDescriptors(JSContext* cx, HandleObject props, bool checkAccessors, AutoIdVector* ids, MutableHandle descs) { if (!GetPropertyKeys(cx, props, JSITER_OWNONLY | JSITER_SYMBOLS, ids)) return false; RootedId id(cx); for (size_t i = 0, len = ids->length(); i < len; i++) { id = (*ids)[i]; Rooted desc(cx); RootedValue v(cx); if (!GetProperty(cx, props, props, id, &v) || !ToPropertyDescriptor(cx, v, checkAccessors, &desc) || !descs.append(desc)) { return false; } } return true; } /*** Seal and freeze *****************************************************************************/ static unsigned GetSealedOrFrozenAttributes(unsigned attrs, IntegrityLevel level) { /* Make all attributes permanent; if freezing, make data attributes read-only. */ if (level == IntegrityLevel::Frozen && !(attrs & (JSPROP_GETTER | JSPROP_SETTER))) return JSPROP_PERMANENT | JSPROP_READONLY; return JSPROP_PERMANENT; } /* ES6 draft rev 29 (6 Dec 2014) 7.3.13. */ bool js::SetIntegrityLevel(JSContext* cx, HandleObject obj, IntegrityLevel level) { assertSameCompartment(cx, obj); // Steps 3-5. (Steps 1-2 are redundant assertions.) if (!PreventExtensions(cx, obj, level)) return false; // Steps 6-7. AutoIdVector keys(cx); if (!GetPropertyKeys(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY | JSITER_SYMBOLS, &keys)) return false; // Steps 8-9, loosely interpreted. if (obj->isNative() && !obj->as().inDictionaryMode() && !obj->is() && !obj->is()) { HandleNativeObject nobj = obj.as(); // Seal/freeze non-dictionary objects by constructing a new shape // hierarchy mirroring the original one, which can be shared if many // objects with the same structure are sealed/frozen. If we use the // generic path below then any non-empty object will be converted to // dictionary mode. RootedShape last(cx, EmptyShape::getInitialShape(cx, nobj->getClass(), nobj->taggedProto(), nobj->numFixedSlots(), nobj->lastProperty()->getObjectFlags())); if (!last) return false; // Get an in-order list of the shapes in this object. Rooted shapes(cx, ShapeVector(cx)); for (Shape::Range r(nobj->lastProperty()); !r.empty(); r.popFront()) { if (!shapes.append(&r.front())) return false; } Reverse(shapes.begin(), shapes.end()); for (Shape* shape : shapes) { Rooted child(cx, StackShape(shape)); child.setAttrs(child.attrs() | GetSealedOrFrozenAttributes(child.attrs(), level)); if (!JSID_IS_EMPTY(child.get().propid) && level == IntegrityLevel::Frozen) MarkTypePropertyNonWritable(cx, nobj, child.get().propid); last = cx->zone()->propertyTree.getChild(cx, last, child); if (!last) return false; } MOZ_ASSERT(nobj->lastProperty()->slotSpan() == last->slotSpan()); JS_ALWAYS_TRUE(nobj->setLastProperty(cx, last)); // Ordinarily ArraySetLength handles this, but we're going behind its back // right now, so we must do this manually. // // ArraySetLength also implements the capacity <= length invariant for // arrays with non-writable length. We don't need to do anything special // for that, because capacity was zeroed out by preventExtensions. (See // the assertion about getDenseCapacity above.) if (level == IntegrityLevel::Frozen && obj->is()) { if (!obj->as().maybeCopyElementsForWrite(cx)) return false; obj->as().getElementsHeader()->setNonwritableArrayLength(); } } else { RootedId id(cx); Rooted desc(cx); const unsigned AllowConfigure = JSPROP_IGNORE_ENUMERATE | JSPROP_IGNORE_READONLY | JSPROP_IGNORE_VALUE; const unsigned AllowConfigureAndWritable = AllowConfigure & ~JSPROP_IGNORE_READONLY; // 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.setAttributes(AllowConfigure | JSPROP_PERMANENT); } else { // 9.a.i-ii. Rooted currentDesc(cx); if (!GetOwnPropertyDescriptor(cx, obj, id, ¤tDesc)) return false; // 9.a.iii. if (!currentDesc.object()) continue; // 9.a.iii.1-2 if (currentDesc.isAccessorDescriptor()) desc.setAttributes(AllowConfigure | JSPROP_PERMANENT); else desc.setAttributes(AllowConfigureAndWritable | JSPROP_PERMANENT | JSPROP_READONLY); } // 8.a.i-ii. / 9.a.iii.3-4 if (!DefineProperty(cx, obj, id, desc)) 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; } // Steps 7-8. AutoIdVector props(cx); if (!GetPropertyKeys(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY | JSITER_SYMBOLS, &props)) return false; // Step 9. RootedId id(cx); Rooted desc(cx); for (size_t i = 0, len = props.length(); i < len; i++) { id = props[i]; // Steps 9.a-b. if (!GetOwnPropertyDescriptor(cx, obj, id, &desc)) return false; // Step 9.c. if (!desc.object()) continue; // Steps 9.c.i-ii. if (desc.configurable() || (level == IntegrityLevel::Frozen && desc.isDataDescriptor() && desc.writable())) { *result = false; return true; } } // Step 10. *result = true; return true; } /* * */ /* * Get the GC kind to use for scripted 'new' on the given class. * FIXME bug 547327: estimate the size from the allocation site. */ static inline gc::AllocKind NewObjectGCKind(const js::Class* clasp) { if (clasp == &ArrayObject::class_) return gc::AllocKind::OBJECT8; if (clasp == &JSFunction::class_) return gc::AllocKind::OBJECT2; return gc::AllocKind::OBJECT4; } static inline JSObject* NewObject(ExclusiveContext* cx, HandleObjectGroup group, gc::AllocKind kind, NewObjectKind newKind, uint32_t initialShapeFlags = 0) { const Class* clasp = group->clasp(); MOZ_ASSERT(clasp != &ArrayObject::class_); MOZ_ASSERT_IF(clasp == &JSFunction::class_, kind == AllocKind::FUNCTION || kind == AllocKind::FUNCTION_EXTENDED); // For objects which can have fixed data following the object, only use // enough fixed slots to cover the number of reserved slots in the object, // regardless of the allocation kind specified. size_t nfixed = ClassCanHaveFixedData(clasp) ? GetGCKindSlots(gc::GetGCObjectKind(clasp), clasp) : GetGCKindSlots(kind, clasp); RootedShape shape(cx, EmptyShape::getInitialShape(cx, clasp, group->proto(), nfixed, initialShapeFlags)); if (!shape) return nullptr; gc::InitialHeap heap = GetInitialHeap(newKind, clasp); JSObject* obj; JS_TRY_VAR_OR_RETURN_NULL(cx, obj, JSObject::create(cx, kind, heap, shape, group)); if (newKind == SingletonObject) { RootedObject nobj(cx, obj); if (!JSObject::setSingleton(cx, nobj)) return nullptr; obj = nobj; } probes::CreateObject(cx, obj); return obj; } void NewObjectCache::fillProto(EntryIndex entry, const Class* clasp, js::TaggedProto proto, gc::AllocKind kind, NativeObject* obj) { MOZ_ASSERT_IF(proto.isObject(), !proto.toObject()->is()); MOZ_ASSERT(obj->taggedProto() == proto); return fill(entry, clasp, proto.raw(), kind, obj); } bool js::NewObjectWithTaggedProtoIsCachable(ExclusiveContext* cxArg, Handle proto, NewObjectKind newKind, const Class* clasp) { return cxArg->isJSContext() && proto.isObject() && newKind == GenericObject && clasp->isNative() && !proto.toObject()->is(); } JSObject* js::NewObjectWithGivenTaggedProto(ExclusiveContext* cxArg, const Class* clasp, Handle proto, gc::AllocKind allocKind, NewObjectKind newKind, uint32_t initialShapeFlags) { if (CanBeFinalizedInBackground(allocKind, clasp)) allocKind = GetBackgroundAllocKind(allocKind); bool isCachable = NewObjectWithTaggedProtoIsCachable(cxArg, proto, newKind, clasp); if (isCachable) { JSContext* cx = cxArg->asJSContext(); NewObjectCache& cache = cx->caches.newObjectCache; NewObjectCache::EntryIndex entry = -1; if (cache.lookupProto(clasp, proto.toObject(), allocKind, &entry)) { JSObject* obj = cache.newObjectFromHit(cx, entry, GetInitialHeap(newKind, clasp)); if (obj) return obj; } } RootedObjectGroup group(cxArg, ObjectGroup::defaultNewGroup(cxArg, clasp, proto, nullptr)); if (!group) return nullptr; RootedObject obj(cxArg, NewObject(cxArg, group, allocKind, newKind, initialShapeFlags)); if (!obj) return nullptr; if (isCachable && !obj->as().hasDynamicSlots()) { NewObjectCache& cache = cxArg->asJSContext()->caches.newObjectCache; NewObjectCache::EntryIndex entry = -1; cache.lookupProto(clasp, proto.toObject(), allocKind, &entry); cache.fillProto(entry, clasp, proto, allocKind, &obj->as()); } return obj; } static bool NewObjectIsCachable(ExclusiveContext* cxArg, NewObjectKind newKind, const Class* clasp) { return cxArg->isJSContext() && newKind == GenericObject && clasp->isNative(); } JSObject* js::NewObjectWithClassProtoCommon(ExclusiveContext* cx, const Class* clasp, HandleObject protoArg, gc::AllocKind allocKind, NewObjectKind newKind) { if (protoArg) return NewObjectWithGivenTaggedProto(cx, clasp, AsTaggedProto(protoArg), allocKind, newKind); if (CanBeFinalizedInBackground(allocKind, clasp)) allocKind = GetBackgroundAllocKind(allocKind); Handle global = cx->global(); bool isCachable = NewObjectIsCachable(cx, newKind, clasp); if (isCachable) { NewObjectCache& cache = cx->asJSContext()->caches.newObjectCache; NewObjectCache::EntryIndex entry = -1; if (cache.lookupGlobal(clasp, global, allocKind, &entry)) { gc::InitialHeap heap = GetInitialHeap(newKind, clasp); JSObject* obj = cache.newObjectFromHit(cx->asJSContext(), entry, heap); if (obj) return obj; } } // 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; RootedObject proto(cx); if (!GetBuiltinPrototype(cx, protoKey, &proto)) return nullptr; RootedObjectGroup group(cx, ObjectGroup::defaultNewGroup(cx, clasp, AsTaggedProto(proto))); if (!group) return nullptr; JSObject* obj = NewObject(cx, group, allocKind, newKind); if (!obj) return nullptr; if (isCachable && !obj->as().hasDynamicSlots()) { NewObjectCache& cache = cx->asJSContext()->caches.newObjectCache; NewObjectCache::EntryIndex entry = -1; cache.lookupGlobal(clasp, global, allocKind, &entry); cache.fillGlobal(entry, clasp, global, allocKind, &obj->as()); } return obj; } static bool NewObjectWithGroupIsCachable(ExclusiveContext* cx, HandleObjectGroup group, NewObjectKind newKind) { return group->proto().isObject() && newKind == GenericObject && group->clasp()->isNative() && (!group->newScript() || group->newScript()->analyzed()) && cx->isJSContext(); } /* * Create a plain object with the specified group. This bypasses getNewGroup to * avoid losing creation site information for objects made by scripted 'new'. */ JSObject* js::NewObjectWithGroupCommon(ExclusiveContext* cx, HandleObjectGroup group, gc::AllocKind allocKind, NewObjectKind newKind) { MOZ_ASSERT(gc::IsObjectAllocKind(allocKind)); if (CanBeFinalizedInBackground(allocKind, group->clasp())) allocKind = GetBackgroundAllocKind(allocKind); bool isCachable = NewObjectWithGroupIsCachable(cx, group, newKind); if (isCachable) { NewObjectCache& cache = cx->asJSContext()->caches.newObjectCache; NewObjectCache::EntryIndex entry = -1; if (cache.lookupGroup(group, allocKind, &entry)) { JSObject* obj = cache.newObjectFromHit(cx->asJSContext(), entry, GetInitialHeap(newKind, group->clasp())); if (obj) return obj; } } JSObject* obj = NewObject(cx, group, allocKind, newKind); if (!obj) return nullptr; if (isCachable && !obj->as().hasDynamicSlots()) { NewObjectCache& cache = cx->asJSContext()->caches.newObjectCache; NewObjectCache::EntryIndex entry = -1; cache.lookupGroup(group, allocKind, &entry); cache.fillGroup(entry, group, allocKind, &obj->as()); } return obj; } bool js::NewObjectScriptedCall(JSContext* cx, MutableHandleObject pobj) { jsbytecode* pc; RootedScript script(cx, cx->currentScript(&pc)); gc::AllocKind allocKind = NewObjectGCKind(&PlainObject::class_); NewObjectKind newKind = GenericObject; if (script && ObjectGroup::useSingletonForAllocationSite(script, pc, &PlainObject::class_)) newKind = SingletonObject; RootedObject obj(cx, NewBuiltinClassInstance(cx, allocKind, newKind)); if (!obj) return false; if (script) { /* Try to specialize the group of the object to the scripted call site. */ if (!ObjectGroup::setAllocationSiteObjectGroup(cx, script, pc, obj, newKind == SingletonObject)) return false; } pobj.set(obj); return true; } JSObject* js::CreateThis(JSContext* cx, const Class* newclasp, HandleObject callee) { RootedObject proto(cx); if (!GetPrototypeFromConstructor(cx, callee, &proto)) return nullptr; gc::AllocKind kind = NewObjectGCKind(newclasp); return NewObjectWithClassProto(cx, newclasp, proto, kind); } static inline JSObject* CreateThisForFunctionWithGroup(JSContext* cx, HandleObjectGroup group, NewObjectKind newKind) { if (group->maybeUnboxedLayout() && newKind != SingletonObject) return UnboxedPlainObject::create(cx, group, newKind); if (TypeNewScript* newScript = group->newScript()) { if (newScript->analyzed()) { // The definite properties analysis has been performed for this // group, so get the shape and alloc kind to use from the // TypeNewScript's template. RootedPlainObject templateObject(cx, newScript->templateObject()); MOZ_ASSERT(templateObject->group() == group); RootedPlainObject res(cx, CopyInitializerObject(cx, templateObject, newKind)); if (!res) return nullptr; if (newKind == SingletonObject) { Rooted proto(cx, TaggedProto(templateObject->staticPrototype())); if (!JSObject::splicePrototype(cx, res, &PlainObject::class_, proto)) return nullptr; } else { res->setGroup(group); } return res; } // The initial objects registered with a TypeNewScript can't be in the // nursery. if (newKind == GenericObject) newKind = TenuredObject; // Not enough objects with this group have been created yet, so make a // plain object and register it with the group. Use the maximum number // of fixed slots, as is also required by the TypeNewScript. gc::AllocKind allocKind = GuessObjectGCKind(NativeObject::MAX_FIXED_SLOTS); PlainObject* res = NewObjectWithGroup(cx, group, allocKind, newKind); if (!res) return nullptr; // Make sure group->newScript is still there. if (newKind != SingletonObject && group->newScript()) group->newScript()->registerNewObject(res); return res; } gc::AllocKind allocKind = NewObjectGCKind(&PlainObject::class_); if (newKind == SingletonObject) { Rooted protoRoot(cx, group->proto()); return NewObjectWithGivenTaggedProto(cx, &PlainObject::class_, protoRoot, allocKind, newKind); } return NewObjectWithGroup(cx, group, allocKind, newKind); } JSObject* js::CreateThisForFunctionWithProto(JSContext* cx, HandleObject callee, HandleObject newTarget, HandleObject proto, NewObjectKind newKind /* = GenericObject */) { RootedObject res(cx); if (proto) { RootedObjectGroup group(cx, ObjectGroup::defaultNewGroup(cx, nullptr, TaggedProto(proto), newTarget)); if (!group) return nullptr; if (group->newScript() && !group->newScript()->analyzed()) { bool regenerate; if (!group->newScript()->maybeAnalyze(cx, group, ®enerate)) return nullptr; if (regenerate) { // The script was analyzed successfully and may have changed // the new type table, so refetch the group. group = ObjectGroup::defaultNewGroup(cx, nullptr, TaggedProto(proto), newTarget); MOZ_ASSERT(group && group->newScript()); } } res = CreateThisForFunctionWithGroup(cx, group, newKind); } else { res = NewBuiltinClassInstance(cx, newKind); } if (res) { JSScript* script = JSFunction::getOrCreateScript(cx, callee.as()); if (!script) return nullptr; TypeScript::SetThis(cx, script, TypeSet::ObjectType(res)); } return res; } bool js::GetPrototypeFromConstructor(JSContext* cx, HandleObject newTarget, MutableHandleObject proto) { RootedValue protov(cx); if (!GetProperty(cx, newTarget, newTarget, cx->names().prototype, &protov)) return false; proto.set(protov.isObject() ? &protov.toObject() : nullptr); return true; } bool js::GetPrototypeFromCallableConstructor(JSContext* cx, const CallArgs& args, MutableHandleObject proto) { RootedObject newTarget(cx); if (args.isConstructing()) newTarget = &args.newTarget().toObject(); else newTarget = &args.callee(); return GetPrototypeFromConstructor(cx, newTarget, proto); } JSObject* js::CreateThisForFunction(JSContext* cx, HandleObject callee, HandleObject newTarget, NewObjectKind newKind) { RootedObject proto(cx); if (!GetPrototypeFromConstructor(cx, newTarget, &proto)) return nullptr; JSObject* obj = CreateThisForFunctionWithProto(cx, callee, newTarget, proto, newKind); if (obj && newKind == SingletonObject) { RootedPlainObject nobj(cx, &obj->as()); /* Reshape the singleton before passing it as the 'this' value. */ NativeObject::clear(cx, nobj); JSScript* calleeScript = callee->as().nonLazyScript(); TypeScript::SetThis(cx, calleeScript, TypeSet::ObjectType(nobj)); return nobj; } return obj; } /* 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); } JS_FRIEND_API(bool) JS_CopyPropertyFrom(JSContext* cx, HandleId id, HandleObject target, HandleObject obj, PropertyCopyBehavior copyBehavior) { // |obj| and |cx| are generally not same-compartment with |target| here. assertSameCompartment(cx, obj, id); Rooted desc(cx); if (!GetOwnPropertyDescriptor(cx, obj, id, &desc)) return false; MOZ_ASSERT(desc.object()); // Silently skip JSGetterOp/JSSetterOp-implemented accessors. if (desc.getter() && !desc.hasGetterObject()) return true; if (desc.setter() && !desc.hasSetterObject()) return true; if (copyBehavior == MakeNonConfigurableIntoConfigurable) { // Mask off the JSPROP_PERMANENT bit. desc.attributesRef() &= ~JSPROP_PERMANENT; } JSAutoCompartment ac(cx, target); RootedId wrappedId(cx, id); if (!cx->compartment()->wrap(cx, &desc)) return false; return DefineProperty(cx, target, wrappedId, desc); } JS_FRIEND_API(bool) JS_CopyPropertiesFrom(JSContext* cx, HandleObject target, HandleObject obj) { JSAutoCompartment ac(cx, obj); AutoIdVector props(cx); if (!GetPropertyKeys(cx, obj, JSITER_OWNONLY | JSITER_HIDDEN | JSITER_SYMBOLS, &props)) return false; for (size_t i = 0; i < props.length(); ++i) { if (!JS_CopyPropertyFrom(cx, props[i], target, obj)) return false; } return true; } static bool CopyProxyObject(JSContext* cx, Handle from, Handle to) { MOZ_ASSERT(from->getClass() == to->getClass()); if (from->is() && (Wrapper::wrapperHandler(from)->flags() & Wrapper::CROSS_COMPARTMENT)) { to->setCrossCompartmentPrivate(GetProxyPrivate(from)); } else { RootedValue v(cx, GetProxyPrivate(from)); if (!cx->compartment()->wrap(cx, &v)) return false; to->setSameCompartmentPrivate(v); } RootedValue v(cx); for (size_t n = 0; n < js::detail::PROXY_EXTRA_SLOTS; n++) { v = GetProxyExtra(from, n); if (!cx->compartment()->wrap(cx, &v)) return false; SetProxyExtra(to, n, v); } return true; } JSObject* js::CloneObject(JSContext* cx, HandleObject obj, Handle proto) { if (!obj->isNative() && !obj->is()) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_CANT_CLONE_OBJECT); return nullptr; } RootedObject clone(cx); if (obj->isNative()) { clone = NewObjectWithGivenTaggedProto(cx, obj->getClass(), proto); if (!clone) return nullptr; if (clone->is() && (obj->compartment() != clone->compartment())) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_CANT_CLONE_OBJECT); return nullptr; } if (obj->as().hasPrivate()) clone->as().setPrivate(obj->as().getPrivate()); } else { ProxyOptions options; options.setClass(obj->getClass()); clone = ProxyObject::New(cx, GetProxyHandler(obj), JS::NullHandleValue, proto, options); if (!clone) return nullptr; if (!CopyProxyObject(cx, obj.as(), clone.as())) return nullptr; } return clone; } static bool GetScriptArrayObjectElements(ExclusiveContext* cx, HandleObject obj, MutableHandle> values) { MOZ_ASSERT(!obj->isSingleton()); MOZ_ASSERT(obj->is() || obj->is()); MOZ_ASSERT(!obj->isIndexed()); size_t length = GetAnyBoxedOrUnboxedArrayLength(obj); if (!values.appendN(MagicValue(JS_ELEMENTS_HOLE), length)) return false; size_t initlen = GetAnyBoxedOrUnboxedInitializedLength(obj); for (size_t i = 0; i < initlen; i++) values[i].set(GetAnyBoxedOrUnboxedDenseElement(obj, i)); return true; } static bool GetScriptPlainObjectProperties(ExclusiveContext* cx, HandleObject obj, MutableHandle properties) { if (obj->is()) { PlainObject* nobj = &obj->as(); if (!properties.appendN(IdValuePair(), nobj->slotSpan())) return false; for (Shape::Range r(nobj->lastProperty()); !r.empty(); r.popFront()) { Shape& shape = r.front(); MOZ_ASSERT(shape.isDataDescriptor()); uint32_t slot = shape.slot(); properties[slot].get().id = shape.propid(); properties[slot].get().value = nobj->getSlot(slot); } for (size_t i = 0; i < nobj->getDenseInitializedLength(); i++) { Value v = nobj->getDenseElement(i); if (!v.isMagic(JS_ELEMENTS_HOLE) && !properties.append(IdValuePair(INT_TO_JSID(i), v))) return false; } return true; } if (obj->is()) { UnboxedPlainObject* nobj = &obj->as(); const UnboxedLayout& layout = nobj->layout(); if (!properties.appendN(IdValuePair(), layout.properties().length())) return false; for (size_t i = 0; i < layout.properties().length(); i++) { const UnboxedLayout::Property& property = layout.properties()[i]; properties[i].get().id = NameToId(property.name); properties[i].get().value = nobj->getValue(property); } return true; } MOZ_CRASH("Bad object kind"); } static bool DeepCloneValue(JSContext* cx, Value* vp, NewObjectKind newKind) { if (vp->isObject()) { RootedObject obj(cx, &vp->toObject()); obj = DeepCloneObjectLiteral(cx, obj, newKind); if (!obj) return false; vp->setObject(*obj); } return true; } JSObject* js::DeepCloneObjectLiteral(JSContext* cx, HandleObject obj, NewObjectKind newKind) { /* NB: Keep this in sync with XDRObjectLiteral. */ MOZ_ASSERT_IF(obj->isSingleton(), cx->compartment()->behaviors().getSingletonsAsTemplates()); MOZ_ASSERT(obj->is() || obj->is() || obj->is() || obj->is()); MOZ_ASSERT(newKind != SingletonObject); if (obj->is() || obj->is()) { Rooted> values(cx, GCVector(cx)); if (!GetScriptArrayObjectElements(cx, obj, &values)) return nullptr; // Deep clone any elements. for (uint32_t i = 0; i < values.length(); ++i) { if (!DeepCloneValue(cx, values[i].address(), newKind)) return nullptr; } ObjectGroup::NewArrayKind arrayKind = ObjectGroup::NewArrayKind::Normal; if (obj->is() && obj->as().denseElementsAreCopyOnWrite()) arrayKind = ObjectGroup::NewArrayKind::CopyOnWrite; return ObjectGroup::newArrayObject(cx, values.begin(), values.length(), newKind, arrayKind); } Rooted properties(cx, IdValueVector(cx)); if (!GetScriptPlainObjectProperties(cx, obj, &properties)) return nullptr; for (size_t i = 0; i < properties.length(); i++) { if (!DeepCloneValue(cx, &properties[i].get().value, newKind)) return nullptr; } if (obj->isSingleton()) newKind = SingletonObject; return ObjectGroup::newPlainObject(cx, properties.begin(), properties.length(), newKind); } static bool InitializePropertiesFromCompatibleNativeObject(JSContext* cx, HandleNativeObject dst, HandleNativeObject src) { assertSameCompartment(cx, src, dst); MOZ_ASSERT(src->getClass() == dst->getClass()); MOZ_ASSERT(dst->lastProperty()->getObjectFlags() == 0); MOZ_ASSERT(!src->isSingleton()); MOZ_ASSERT(src->numFixedSlots() == dst->numFixedSlots()); 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)); } MOZ_ASSERT(!src->hasPrivate()); RootedShape shape(cx); if (src->staticPrototype() == dst->staticPrototype()) { shape = src->lastProperty(); } 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 0. shape = EmptyShape::getInitialShape(cx, dst->getClass(), dst->taggedProto(), dst->numFixedSlots(), 0); if (!shape) return false; // Get an in-order list of the shapes in the src object. Rooted shapes(cx, ShapeVector(cx)); for (Shape::Range r(src->lastProperty()); !r.empty(); r.popFront()) { if (!shapes.append(&r.front())) return false; } Reverse(shapes.begin(), shapes.end()); for (Shape* shape : shapes) { Rooted child(cx, StackShape(shape)); shape = cx->zone()->propertyTree.getChild(cx, shape, child); if (!shape) return false; } } size_t span = shape->slotSpan(); if (!dst->setLastProperty(cx, shape)) return false; for (size_t i = JSCLASS_RESERVED_SLOTS(src->getClass()); i < span; i++) dst->setSlot(i, src->getSlot(i)); return true; } JS_FRIEND_API(bool) JS_InitializePropertiesFromCompatibleNativeObject(JSContext* cx, HandleObject dst, HandleObject src) { return InitializePropertiesFromCompatibleNativeObject(cx, dst.as(), src.as()); } template bool js::XDRObjectLiteral(XDRState* xdr, MutableHandleObject obj) { /* NB: Keep this in sync with DeepCloneObjectLiteral. */ ExclusiveContext* cx = xdr->cx(); assertSameCompartment(cx, obj); // Distinguish between objects and array classes. uint32_t isArray = 0; { if (mode == XDR_ENCODE) { MOZ_ASSERT(obj->is() || obj->is() || obj->is() || obj->is()); isArray = (obj->is() || obj->is()) ? 1 : 0; } if (!xdr->codeUint32(&isArray)) return false; } RootedValue tmpValue(cx), tmpIdValue(cx); RootedId tmpId(cx); if (isArray) { Rooted> values(cx, GCVector(cx)); if (mode == XDR_ENCODE && !GetScriptArrayObjectElements(cx, obj, &values)) return false; uint32_t initialized; if (mode == XDR_ENCODE) initialized = values.length(); if (!xdr->codeUint32(&initialized)) return false; if (mode == XDR_DECODE && !values.appendN(MagicValue(JS_ELEMENTS_HOLE), initialized)) return false; // Recursively copy dense elements. for (unsigned i = 0; i < initialized; i++) { if (!xdr->codeConstValue(values[i])) return false; } uint32_t copyOnWrite; if (mode == XDR_ENCODE) copyOnWrite = obj->is() && obj->as().denseElementsAreCopyOnWrite(); if (!xdr->codeUint32(©OnWrite)) return false; if (mode == XDR_DECODE) { ObjectGroup::NewArrayKind arrayKind = copyOnWrite ? ObjectGroup::NewArrayKind::CopyOnWrite : ObjectGroup::NewArrayKind::Normal; obj.set(ObjectGroup::newArrayObject(cx, values.begin(), values.length(), TenuredObject, arrayKind)); if (!obj) return false; } return true; } // Code the properties in the object. Rooted properties(cx, IdValueVector(cx)); if (mode == XDR_ENCODE && !GetScriptPlainObjectProperties(cx, obj, &properties)) return false; uint32_t nproperties = properties.length(); if (!xdr->codeUint32(&nproperties)) return false; if (mode == XDR_DECODE && !properties.appendN(IdValuePair(), nproperties)) return false; for (size_t i = 0; i < nproperties; i++) { if (mode == XDR_ENCODE) { tmpIdValue = IdToValue(properties[i].get().id); tmpValue = properties[i].get().value; } if (!xdr->codeConstValue(&tmpIdValue) || !xdr->codeConstValue(&tmpValue)) return false; if (mode == XDR_DECODE) { if (!ValueToId(cx, tmpIdValue, &tmpId)) return false; properties[i].get().id = tmpId; properties[i].get().value = tmpValue; } } // Code whether the object is a singleton. uint32_t isSingleton; if (mode == XDR_ENCODE) isSingleton = obj->isSingleton() ? 1 : 0; if (!xdr->codeUint32(&isSingleton)) return false; if (mode == XDR_DECODE) { NewObjectKind newKind = isSingleton ? SingletonObject : TenuredObject; obj.set(ObjectGroup::newPlainObject(cx, properties.begin(), properties.length(), newKind)); if (!obj) return false; } return true; } template bool js::XDRObjectLiteral(XDRState* xdr, MutableHandleObject obj); template bool js::XDRObjectLiteral(XDRState* xdr, MutableHandleObject obj); /* static */ bool NativeObject::fillInAfterSwap(JSContext* cx, HandleNativeObject obj, const Vector& values, void* priv) { // 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(obj->slotSpan() == values.length()); // Make sure the shape's numFixedSlots() is correct. size_t nfixed = gc::GetGCKindSlots(obj->asTenured().getAllocKind(), obj->getClass()); if (nfixed != obj->shape_->numFixedSlots()) { if (!NativeObject::generateOwnShape(cx, obj)) return false; obj->shape_->setNumFixedSlots(nfixed); } if (obj->hasPrivate()) obj->setPrivate(priv); else MOZ_ASSERT(!priv); if (obj->slots_) { js_free(obj->slots_); obj->slots_ = nullptr; } if (size_t ndynamic = dynamicSlotsCount(nfixed, values.length(), obj->getClass())) { obj->slots_ = cx->zone()->pod_malloc(ndynamic); if (!obj->slots_) return false; Debug_SetSlotRangeToCrashOnTouch(obj->slots_, ndynamic); } obj->initSlotRange(0, values.begin(), values.length()); return true; } void JSObject::fixDictionaryShapeAfterSwap() { // Dictionary shapes can point back to their containing objects, so after // swapping the guts of those objects fix the pointers up. if (isNative() && as().inDictionaryMode()) as().shape_->listp = &as().shape_; } /* Use this method with extreme caution. It trades the guts of two objects. */ bool JSObject::swap(JSContext* cx, HandleObject a, HandleObject b) { // Ensure swap doesn't cause a finalizer to not be run. MOZ_ASSERT(IsBackgroundFinalized(a->asTenured().getAllocKind()) == IsBackgroundFinalized(b->asTenured().getAllocKind())); MOZ_ASSERT(a->compartment() == b->compartment()); AutoEnterOOMUnsafeRegion oomUnsafe; AutoCompartment ac(cx, a); if (!JSObject::getGroup(cx, a)) oomUnsafe.crash("JSObject::swap"); if (!JSObject::getGroup(cx, b)) oomUnsafe.crash("JSObject::swap"); /* * Neither object may be in the nursery, but ensure we update any embedded * nursery pointers in either object. */ MOZ_ASSERT(!IsInsideNursery(a) && !IsInsideNursery(b)); cx->runtime()->gc.storeBuffer.putWholeCell(a); cx->runtime()->gc.storeBuffer.putWholeCell(b); unsigned r = NotifyGCPreSwap(a, b); // Do the fundamental swapping of the contents of two objects. MOZ_ASSERT(a->compartment() == b->compartment()); MOZ_ASSERT(a->is() == b->is()); // Don't try to swap functions with different sizes. MOZ_ASSERT_IF(a->is(), a->tenuredSizeOfThis() == b->tenuredSizeOfThis()); // Watch for oddball objects that have special organizational issues and // can't be swapped. MOZ_ASSERT(!a->is() && !b->is()); MOZ_ASSERT(!a->is() && !b->is()); MOZ_ASSERT(!a->is() && !b->is()); MOZ_ASSERT(!a->is() && !b->is()); MOZ_ASSERT(!a->is() && !b->is()); if (a->tenuredSizeOfThis() == b->tenuredSizeOfThis()) { // When both objects are the same size, just do a plain swap of their // contents. size_t size = a->tenuredSizeOfThis(); char tmp[mozilla::tl::Max::value]; MOZ_ASSERT(size <= sizeof(tmp)); js_memcpy(tmp, a, size); js_memcpy(a, b, size); js_memcpy(b, tmp, size); a->fixDictionaryShapeAfterSwap(); b->fixDictionaryShapeAfterSwap(); } else { // Avoid GC in here to avoid confusing the tracing code with our // intermediate state. 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. NativeObject* na = a->isNative() ? &a->as() : nullptr; NativeObject* nb = b->isNative() ? &b->as() : nullptr; // Remember the original values from the objects. Vector avals(cx); void* apriv = nullptr; if (na) { apriv = na->hasPrivate() ? na->getPrivate() : nullptr; for (size_t i = 0; i < na->slotSpan(); i++) { if (!avals.append(na->getSlot(i))) oomUnsafe.crash("JSObject::swap"); } } Vector bvals(cx); void* bpriv = nullptr; if (nb) { bpriv = nb->hasPrivate() ? nb->getPrivate() : nullptr; for (size_t i = 0; i < nb->slotSpan(); i++) { if (!bvals.append(nb->getSlot(i))) oomUnsafe.crash("JSObject::swap"); } } // 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); a->fixDictionaryShapeAfterSwap(); b->fixDictionaryShapeAfterSwap(); if (na) { if (!NativeObject::fillInAfterSwap(cx, b.as(), avals, apriv)) oomUnsafe.crash("fillInAfterSwap"); } if (nb) { if (!NativeObject::fillInAfterSwap(cx, a.as(), bvals, bpriv)) oomUnsafe.crash("fillInAfterSwap"); } } // Swapping the contents of two objects invalidates type sets which contain // either of the objects, so mark all such sets as unknown. MarkObjectGroupUnknownProperties(cx, a->group()); MarkObjectGroupUnknownProperties(cx, b->group()); /* * 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. */ JS::Zone* zone = a->zone(); if (zone->needsIncrementalBarrier()) { a->traceChildren(zone->barrierTracer()); b->traceChildren(zone->barrierTracer()); } NotifyGCPostSwap(a, b, r); return true; } static bool DefineStandardSlot(JSContext* cx, HandleObject obj, JSProtoKey key, JSAtom* atom, HandleValue v, uint32_t attrs, bool& named) { RootedId id(cx, AtomToId(atom)); named = DefineProperty(cx, obj, id, v, nullptr, nullptr, attrs); return named; } static void SetClassObject(JSObject* obj, JSProtoKey key, JSObject* cobj, JSObject* proto) { if (!obj->is()) return; obj->as().setConstructor(key, ObjectOrNullValue(cobj)); obj->as().setPrototype(key, ObjectOrNullValue(proto)); } static void ClearClassObject(JSObject* obj, JSProtoKey key) { if (!obj->is()) return; obj->as().setConstructor(key, UndefinedValue()); obj->as().setPrototype(key, UndefinedValue()); } static NativeObject* DefineConstructorAndPrototype(JSContext* cx, HandleObject obj, JSProtoKey key, HandleAtom atom, HandleObject protoProto, const Class* clasp, Native constructor, unsigned nargs, const JSPropertySpec* ps, const JSFunctionSpec* fs, const JSPropertySpec* static_ps, const JSFunctionSpec* static_fs, NativeObject** ctorp, AllocKind ctorKind) { /* * Create a prototype object for this class. * * FIXME: lazy standard (built-in) class initialization and even older * eager boostrapping code rely on all of these properties: * * 1. NewObject attempting to compute a default prototype object when * passed null for proto; and * * 2. NewObject tolerating no default prototype (null proto slot value) * due to this js::InitClass call coming from js::InitFunctionClass on an * otherwise-uninitialized global. * * 3. NewObject allocating a JSFunction-sized GC-thing when clasp is * &JSFunction::class_, not a JSObject-sized (smaller) GC-thing. * * The JS_NewObjectForGivenProto and JS_NewObject APIs also allow clasp to * be &JSFunction::class_ (we could break compatibility easily). But * fixing (3) is not enough without addressing the bootstrapping dependency * on (1) and (2). */ /* * Create the prototype object. (GlobalObject::createBlankPrototype isn't * used because it won't let us use protoProto as the proto. */ RootedNativeObject proto(cx, NewNativeObjectWithClassProto(cx, clasp, protoProto, SingletonObject)); if (!proto) return nullptr; /* After this point, control must exit via label bad or out. */ RootedNativeObject ctor(cx); bool named = false; bool cached = false; if (!constructor) { /* * Lacking a constructor, name the prototype (e.g., Math) unless this * class (a) is anonymous, i.e. for internal use only; (b) the class * of obj (the global object) is has a reserved slot indexed by key; * and (c) key is not the null key. */ if (!(clasp->flags & JSCLASS_IS_ANONYMOUS) || !obj->is() || key == JSProto_Null) { uint32_t attrs = (clasp->flags & JSCLASS_IS_ANONYMOUS) ? JSPROP_READONLY | JSPROP_PERMANENT : 0; RootedValue value(cx, ObjectValue(*proto)); if (!DefineStandardSlot(cx, obj, key, atom, value, attrs, named)) goto bad; } ctor = proto; } else { RootedFunction fun(cx, NewNativeConstructor(cx, constructor, nargs, atom, ctorKind)); if (!fun) goto bad; /* * Set the class object early for standard class constructors. Type * inference may need to access these, and js::GetBuiltinPrototype will * fail if it tries to do a reentrant reconstruction of the class. */ if (key != JSProto_Null) { SetClassObject(obj, key, fun, proto); cached = true; } RootedValue value(cx, ObjectValue(*fun)); if (!DefineStandardSlot(cx, obj, key, atom, value, 0, named)) goto bad; /* * Optionally construct the prototype object, before the class has * been fully initialized. Allow the ctor to replace proto with a * different object, as is done for operator new. */ ctor = fun; if (!LinkConstructorAndPrototype(cx, ctor, proto)) goto bad; /* Bootstrap Function.prototype (see also JS_InitStandardClasses). */ Rooted tagged(cx, TaggedProto(proto)); if (ctor->getClass() == clasp && !JSObject::splicePrototype(cx, ctor, clasp, tagged)) goto bad; } if (!DefinePropertiesAndFunctions(cx, proto, ps, fs) || (ctor != proto && !DefinePropertiesAndFunctions(cx, ctor, static_ps, static_fs))) { goto bad; } /* If this is a standard class, cache its prototype. */ if (!cached && key != JSProto_Null) SetClassObject(obj, key, ctor, proto); if (ctorp) *ctorp = ctor; return proto; bad: if (named) { ObjectOpResult ignored; RootedId id(cx, AtomToId(atom)); // XXX FIXME - absurd to call this here; instead define the property last. DeleteProperty(cx, obj, id, ignored); } if (cached) ClearClassObject(obj, key); return nullptr; } NativeObject* js::InitClass(JSContext* cx, HandleObject obj, HandleObject protoProto_, const Class* clasp, Native constructor, unsigned nargs, const JSPropertySpec* ps, const JSFunctionSpec* fs, const JSPropertySpec* static_ps, const JSFunctionSpec* static_fs, NativeObject** ctorp, AllocKind ctorKind) { RootedObject protoProto(cx, protoProto_); /* Check function pointer members. */ MOZ_ASSERT(clasp->getGetProperty() != JS_PropertyStub); MOZ_ASSERT(clasp->getSetProperty() != JS_StrictPropertyStub); RootedAtom atom(cx, Atomize(cx, clasp->name, strlen(clasp->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. * * When initializing a standard class (other than Object), if protoProto is * null, default to Object.prototype. The engine's internal uses of * js::InitClass depend on this nicety. */ JSProtoKey key = JSCLASS_CACHED_PROTO_KEY(clasp); if (key != JSProto_Null && !protoProto && !GetBuiltinPrototype(cx, JSProto_Object, &protoProto)) { return nullptr; } return DefineConstructorAndPrototype(cx, obj, key, atom, protoProto, clasp, constructor, nargs, ps, fs, static_ps, static_fs, ctorp, ctorKind); } void JSObject::fixupAfterMovingGC() { // For copy-on-write objects that don't own their elements, fix up the // elements pointer if it points to inline elements in the owning object. if (is()) { NativeObject& obj = as(); if (obj.denseElementsAreCopyOnWrite()) { NativeObject* owner = obj.getElementsHeader()->ownerObject(); // Get the new owner pointer but don't call MaybeForwarded as we // don't need to access the object's shape. if (IsForwarded(owner)) owner = Forwarded(owner); if (owner != &obj && owner->hasFixedElements()) obj.elements_ = owner->getElementsHeader()->elements(); MOZ_ASSERT(!IsForwarded(obj.getElementsHeader()->ownerObject().get())); } } } bool js::SetClassAndProto(JSContext* cx, HandleObject obj, const Class* clasp, Handle proto) { // Regenerate the object's shape. If the object is a proto (isDelegate()), // we also need to regenerate shapes for all of the objects along the old // prototype chain, in case any entries were filled by looking up through // obj. Stop when a non-native object is found, prototype lookups will not // be cached across these. // // How this shape change is done is very delicate; the change can be made // either by marking the object's prototype as uncacheable (such that the // JIT'ed ICs cannot assume the shape determines the prototype) or by just // generating a new shape for the object. Choosing the former is bad if the // object is on the prototype chain of other objects, as the uncacheable // prototype can inhibit iterator caches on those objects and slow down // prototype accesses. Choosing the latter is bad if there are many similar // objects to this one which will have their prototype mutated, as the // generateOwnShape forces the object into dictionary mode and similar // property lineages will be repeatedly cloned. // // :XXX: bug 707717 make this code less brittle. RootedObject oldproto(cx, obj); while (oldproto && oldproto->isNative()) { if (oldproto->isSingleton()) { // We always generate a new shape if the object is a singleton, // regardless of the uncacheable-proto flag. ICs may rely on // this. if (!NativeObject::generateOwnShape(cx, oldproto.as())) return false; } else { if (!JSObject::setUncacheableProto(cx, oldproto)) return false; } if (!obj->isDelegate()) { // If |obj| is not a proto of another object, we don't need to // reshape the whole proto chain. MOZ_ASSERT(obj == oldproto); break; } oldproto = oldproto->staticPrototype(); } if (proto.isObject()) { RootedObject protoObj(cx, proto.toObject()); if (!JSObject::setDelegate(cx, protoObj)) return false; } if (obj->isSingleton()) { /* * Just splice the prototype, but mark the properties as unknown for * consistent behavior. */ if (!JSObject::splicePrototype(cx, obj, clasp, proto)) return false; MarkObjectGroupUnknownProperties(cx, obj->group()); return true; } if (proto.isObject()) { RootedObject protoObj(cx, proto.toObject()); if (!JSObject::setNewGroupUnknown(cx, clasp, protoObj)) return false; } ObjectGroup* group = ObjectGroup::defaultNewGroup(cx, clasp, proto); if (!group) return false; /* * Setting __proto__ on an object that has escaped and may be referenced by * other heap objects can only be done if the properties of both objects * are unknown. Type sets containing this object will contain the original * type but not the new type of the object, so we need to treat all such * type sets as unknown. */ MarkObjectGroupUnknownProperties(cx, obj->group()); MarkObjectGroupUnknownProperties(cx, group); obj->setGroup(group); return true; } /* static */ bool JSObject::changeToSingleton(JSContext* cx, HandleObject obj) { MOZ_ASSERT(!obj->isSingleton()); MarkObjectGroupUnknownProperties(cx, obj->group()); ObjectGroup* group = ObjectGroup::lazySingletonGroup(cx, obj->getClass(), obj->taggedProto()); if (!group) return false; obj->group_ = group; return true; } static bool MaybeResolveConstructor(ExclusiveContext* cxArg, Handle global, JSProtoKey key) { if (global->isStandardClassResolved(key)) return true; if (!cxArg->shouldBeJSContext()) return false; JSContext* cx = cxArg->asJSContext(); return GlobalObject::resolveConstructor(cx, global, key); } bool js::GetBuiltinConstructor(ExclusiveContext* cx, JSProtoKey key, MutableHandleObject objp) { MOZ_ASSERT(key != JSProto_Null); Rooted global(cx, cx->global()); if (!MaybeResolveConstructor(cx, global, key)) return false; objp.set(&global->getConstructor(key).toObject()); return true; } bool js::GetBuiltinPrototype(ExclusiveContext* cx, JSProtoKey key, MutableHandleObject protop) { MOZ_ASSERT(key != JSProto_Null); Rooted global(cx, cx->global()); if (!MaybeResolveConstructor(cx, global, key)) return false; protop.set(&global->getPrototype(key).toObject()); return true; } bool js::IsStandardPrototype(JSObject* obj, JSProtoKey key) { GlobalObject& global = obj->global(); Value v = global.getPrototype(key); return v.isObject() && obj == &v.toObject(); } /** * 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) { RootedObject globalObj(cx, cx->runtime()->getIncumbentGlobal(cx)); if (!globalObj) { obj.set(nullptr); return true; } { AutoCompartment ac(cx, globalObj); Handle global = globalObj.as(); obj.set(GlobalObject::getOrCreateObjectPrototype(cx, global)); if (!obj) return false; } // The object might be from a different compartment, so wrap it. if (obj && !cx->compartment()->wrap(cx, obj)) return false; return true; } JSProtoKey JS::IdentifyStandardInstance(JSObject* obj) { // Note: The prototype shares its JSClass with instances. MOZ_ASSERT(!obj->is()); JSProtoKey key = StandardProtoKeyOrNull(obj); if (key != JSProto_Null && !IsStandardPrototype(obj, key)) return key; return JSProto_Null; } JSProtoKey JS::IdentifyStandardPrototype(JSObject* obj) { // Note: The prototype shares its JSClass with instances. MOZ_ASSERT(!obj->is()); JSProtoKey key = StandardProtoKeyOrNull(obj); if (key != JSProto_Null && IsStandardPrototype(obj, key)) return key; return JSProto_Null; } JSProtoKey JS::IdentifyStandardInstanceOrPrototype(JSObject* obj) { return StandardProtoKeyOrNull(obj); } JSProtoKey JS::IdentifyStandardConstructor(JSObject* obj) { // Note that NATIVE_CTOR does not imply that we are a standard constructor, // but the converse is true (at least until we start having self-hosted // constructors for standard classes). This lets us avoid a costly loop for // many functions (which, depending on the call site, may be the common case). if (!obj->is() || !(obj->as().flags() & JSFunction::NATIVE_CTOR)) return JSProto_Null; GlobalObject& global = obj->global(); for (size_t k = 0; k < JSProto_LIMIT; ++k) { JSProtoKey key = static_cast(k); if (global.getConstructor(key) == ObjectValue(*obj)) return key; } return JSProto_Null; } bool JSObject::isCallable() const { if (is()) return true; return callHook() != nullptr; } bool JSObject::isConstructor() const { if (is()) { const JSFunction& fun = as(); return fun.isConstructor(); } return constructHook() != nullptr; } JSNative JSObject::callHook() const { const js::Class* clasp = getClass(); if (JSNative call = clasp->getCall()) return call; if (is()) { const js::ProxyObject& p = as(); if (p.handler()->isCallable(const_cast(this))) return js::proxy_Call; } return nullptr; } JSNative JSObject::constructHook() const { const js::Class* clasp = getClass(); if (JSNative construct = clasp->getConstruct()) return construct; if (is()) { const js::ProxyObject& p = as(); if (p.handler()->isConstructor(const_cast(this))) return js::proxy_Construct; } return nullptr; } bool js::LookupProperty(JSContext* cx, HandleObject obj, js::HandleId id, MutableHandleObject objp, MutableHandle propp) { /* NB: The logic of lookupProperty is implicitly reflected in * BaselineIC.cpp's |EffectlesslyLookupProperty| logic. * If this changes, please remember to update the logic there as well. */ if (LookupPropertyOp op = obj->getOpsLookupProperty()) return op(cx, obj, id, objp, propp); return LookupPropertyInline(cx, obj.as(), id, objp, propp); } bool js::LookupName(JSContext* cx, HandlePropertyName name, HandleObject envChain, MutableHandleObject objp, MutableHandleObject pobjp, MutableHandle 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) { 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, JSObject** pobjp, PropertyResult* propp) { AutoAssertNoException nogc(cx); MOZ_ASSERT(!*objp && !*pobjp && !*propp); for (JSObject* env = envChain; env; env = env->enclosingEnvironment()) { if (env->getOpsLookupProperty()) return false; if (!LookupPropertyInline(cx, &env->as(), NameToId(name), pobjp, propp)) return false; if (*propp) { *objp = env; return true; } } return true; } bool js::LookupNameWithGlobalDefault(JSContext* cx, HandlePropertyName name, HandleObject envChain, MutableHandleObject objp) { RootedId id(cx, NameToId(name)); RootedObject pobj(cx); Rooted prop(cx); RootedObject env(cx, envChain); for (; !env->is(); env = env->enclosingEnvironment()) { if (!LookupProperty(cx, env, id, &pobj, &prop)) return false; if (prop) break; } objp.set(env); return true; } bool js::LookupNameUnqualified(JSContext* cx, HandlePropertyName name, HandleObject envChain, MutableHandleObject objp) { RootedId id(cx, NameToId(name)); RootedObject pobj(cx); Rooted prop(cx); RootedObject env(cx, envChain); for (; !env->isUnqualifiedVarObj(); env = env->enclosingEnvironment()) { if (!LookupProperty(cx, env, id, &pobj, &prop)) return false; if (prop) break; } // See note above RuntimeLexicalErrorObject. if (pobj == env) { bool isTDZ = false; if (prop && name != cx->names().dotThis) { // Treat Debugger environments specially for TDZ checks, as they // look like non-native environments but in fact wrap native // environments. if (env->is()) { RootedValue v(cx); Rooted envProxy(cx, &env->as()); if (!DebugEnvironmentProxy::getMaybeSentinelValue(cx, envProxy, id, &v)) return false; isTDZ = IsUninitializedLexical(v); } else { isTDZ = IsUninitializedLexicalSlot(env, prop); } } if (isTDZ) { env = RuntimeLexicalErrorObject::create(cx, env, JSMSG_UNINITIALIZED_LEXICAL); if (!env) return false; } else if (env->is() && !prop.shape()->writable()) { // Assigning to a named lambda callee name is a no-op in sloppy mode. Rooted lexicalEnv(cx, &env->as()); if (lexicalEnv->isExtensible() || lexicalEnv->scope().kind() != ScopeKind::NamedLambda) { MOZ_ASSERT(name != cx->names().dotThis); env = RuntimeLexicalErrorObject::create(cx, env, JSMSG_BAD_CONST_ASSIGN); if (!env) return false; } } } objp.set(env); return true; } bool js::HasOwnProperty(JSContext* cx, HandleObject obj, HandleId id, bool* result) { if (obj->is()) return Proxy::hasOwn(cx, obj, id, result); if (GetOwnPropertyOp op = obj->getOpsGetOwnPropertyDescriptor()) { Rooted desc(cx); if (!op(cx, obj, id, &desc)) return false; *result = !!desc.object(); return true; } Rooted prop(cx); if (!NativeLookupOwnProperty(cx, obj.as(), id, &prop)) return false; *result = prop.isFound(); return true; } bool js::LookupPropertyPure(ExclusiveContext* cx, JSObject* obj, jsid id, JSObject** objp, PropertyResult* propp) { bool isTypedArrayOutOfRange = false; do { if (!LookupOwnPropertyPure(cx, obj, id, propp, &isTypedArrayOutOfRange)) return false; if (*propp) { *objp = obj; return true; } if (isTypedArrayOutOfRange) { *objp = nullptr; return true; } obj = obj->staticPrototype(); } while (obj); *objp = nullptr; propp->setNotFound(); return true; } bool js::LookupOwnPropertyPure(ExclusiveContext* cx, JSObject* obj, jsid id, PropertyResult* propp, bool* isTypedArrayOutOfRange /* = nullptr */) { JS::AutoCheckCannotGC nogc; if (isTypedArrayOutOfRange) *isTypedArrayOutOfRange = false; if (obj->isNative()) { // Search for a native dense element, typed array element, or property. if (JSID_IS_INT(id) && obj->as().containsDenseElement(JSID_TO_INT(id))) { propp->setDenseOrTypedArrayElement(); return true; } if (obj->is()) { uint64_t index; if (IsTypedArrayIndex(id, &index)) { if (index < obj->as().length()) { propp->setDenseOrTypedArrayElement(); } else { propp->setNotFound(); if (isTypedArrayOutOfRange) *isTypedArrayOutOfRange = true; } return true; } } if (Shape* shape = obj->as().lookupPure(id)) { propp->setNativeProperty(shape); return true; } // Fail if there's a resolve hook, unless the mayResolve hook tells // us the resolve hook won't define a property with this id. if (ClassMayResolveId(cx->names(), obj->getClass(), id, obj)) return false; } else if (obj->is()) { if (obj->as().containsUnboxedOrExpandoProperty(cx, id)) { propp->setNonNativeProperty(); return true; } } else if (obj->is()) { if (obj->as().containsProperty(cx, id)) { propp->setNonNativeProperty(); return true; } } else if (obj->is()) { if (obj->as().typeDescr().hasProperty(cx->names(), id)) { propp->setNonNativeProperty(); return true; } } else { return false; } propp->setNotFound(); return true; } static inline bool NativeGetPureInline(NativeObject* pobj, jsid id, PropertyResult prop, Value* vp, ExclusiveContext* cx) { if (prop.isDenseOrTypedArrayElement()) { // For simplicity we ignore the TypedArray with string index case. if (!JSID_IS_INT(id)) return false; return pobj->getDenseOrTypedArrayElement(cx, JSID_TO_INT(id), vp); } // Fail if we have a custom getter. Shape* shape = prop.shape(); if (!shape->hasDefaultGetter()) return false; if (shape->hasSlot()) { *vp = pobj->getSlot(shape->slot()); MOZ_ASSERT(!vp->isMagic()); } else { vp->setUndefined(); } return true; } bool js::GetPropertyPure(ExclusiveContext* cx, JSObject* obj, jsid id, Value* vp) { JSObject* pobj; PropertyResult prop; if (!LookupPropertyPure(cx, obj, id, &pobj, &prop)) return false; if (!prop) { vp->setUndefined(); return true; } return pobj->isNative() && NativeGetPureInline(&pobj->as(), id, prop, vp, cx); } static inline bool NativeGetGetterPureInline(PropertyResult prop, JSFunction** fp) { if (!prop.isDenseOrTypedArrayElement() && prop.shape()->hasGetterObject()) { Shape* shape = prop.shape(); if (shape->getterObject()->is()) { *fp = &shape->getterObject()->as(); return true; } } *fp = nullptr; return true; } bool js::GetGetterPure(ExclusiveContext* cx, JSObject* obj, jsid id, JSFunction** fp) { /* Just like GetPropertyPure, but get getter function, without invoking * it. */ JSObject* pobj; PropertyResult prop; if (!LookupPropertyPure(cx, obj, id, &pobj, &prop)) return false; if (!prop) { *fp = nullptr; return true; } return prop.isNativeProperty() && NativeGetGetterPureInline(prop, fp); } bool js::GetOwnGetterPure(ExclusiveContext* cx, JSObject* obj, jsid id, JSFunction** fp) { JS::AutoCheckCannotGC nogc; PropertyResult prop; if (!LookupOwnPropertyPure(cx, obj, id, &prop)) return false; if (!prop) { *fp = nullptr; return true; } return prop.isNativeProperty() && NativeGetGetterPureInline(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 || prop.isDenseOrTypedArrayElement() || !prop.shape()->hasGetterObject()) return true; JSObject* getterObj = prop.shape()->getterObject(); if (!getterObj->is()) return true; JSFunction* getter = &getterObj->as(); if (!getter->isNative()) 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 && !prop.isDenseOrTypedArrayElement() && prop.shape()->hasDefaultGetter() && prop.shape()->hasSlot(); return true; } /* static */ bool JSObject::reportReadOnly(JSContext* cx, jsid id, unsigned report) { RootedValue val(cx, IdToValue(id)); return ReportValueErrorFlags(cx, report, JSMSG_READ_ONLY, JSDVG_IGNORE_STACK, val, nullptr, nullptr, nullptr); } /* static */ bool JSObject::reportNotConfigurable(JSContext* cx, jsid id, unsigned report) { RootedValue val(cx, IdToValue(id)); return ReportValueErrorFlags(cx, report, JSMSG_CANT_DELETE, JSDVG_IGNORE_STACK, val, nullptr, nullptr, nullptr); } /* static */ bool JSObject::reportNotExtensible(JSContext* cx, HandleObject obj, unsigned report) { RootedValue val(cx, ObjectValue(*obj)); return ReportValueErrorFlags(cx, report, JSMSG_OBJECT_NOT_EXTENSIBLE, JSDVG_IGNORE_STACK, val, nullptr, nullptr, nullptr); } bool js::GetPrototypeIfOrdinary(JSContext* cx, HandleObject obj, bool* isOrdinary, MutableHandleObject protop) { if (obj->is()) return js::Proxy::getPrototypeIfOrdinary(cx, obj, isOrdinary, protop); *isOrdinary = true; protop.set(obj->staticPrototype()); return true; } /*** ES6 standard internal methods ***************************************************************/ bool js::SetPrototype(JSContext* cx, HandleObject obj, HandleObject proto, JS::ObjectOpResult& result) { // The proxy trap subsystem fully handles prototype-setting for proxies // with dynamic [[Prototype]]s. if (obj->hasDynamicPrototype()) { MOZ_ASSERT(obj->is()); return Proxy::setPrototype(cx, obj, proto, result); } /* * ES6 9.1.2 step 3-4 if |obj.[[Prototype]]| has SameValue as |proto| return true. * Since the values in question are objects, we can just compare pointers. */ if (proto == obj->staticPrototype()) return result.succeed(); /* Disallow mutation of immutable [[Prototype]]s. */ if (obj->staticPrototypeIsImmutable()) return result.fail(JSMSG_CANT_SET_PROTO); /* * Disallow mutating the [[Prototype]] on ArrayBuffer objects, which * due to their complicated delegate-object shenanigans can't easily * have a mutable [[Prototype]]. */ if (obj->is()) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_CANT_SET_PROTO_OF, "incompatible ArrayBuffer"); return false; } /* * Disallow mutating the [[Prototype]] on Typed Objects, per the spec. */ if (obj->is()) { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_CANT_SET_PROTO_OF, "incompatible TypedObject"); return false; } /* 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); // If this is a global object, resolve the Object class so that its // [[Prototype]] chain is always properly immutable, even in the presence // of lazy standard classes. if (obj->is()) { Handle global = obj.as(); if (!GlobalObject::ensureConstructor(cx, global, JSProto_Object)) return false; } /* * 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; } // Convert unboxed objects to their native representations before changing // their prototype/group, as they depend on the group for their layout. if (!MaybeConvertUnboxedObjectToNative(cx, obj)) return false; Rooted taggedProto(cx, TaggedProto(proto)); if (!SetClassAndProto(cx, obj, obj->getClass(), 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, IntegrityLevel level) { if (obj->is()) return js::Proxy::preventExtensions(cx, obj, result); if (!obj->nonProxyIsExtensible()) return result.succeed(); if (!MaybeConvertUnboxedObjectToNative(cx, obj)) return false; // Force lazy properties to be resolved. AutoIdVector props(cx); if (!js::GetPropertyKeys(cx, obj, JSITER_HIDDEN | JSITER_OWNONLY, &props)) return false; // Actually prevent extension. If the object is being frozen, do it by // setting the frozen flag on both the object and the object group. // Otherwise, fallback to sparsifying the object, which makes sure no // element can be added without a call to isExtensible, at the cost of // performance. if (obj->isNative()) { if (level == IntegrityLevel::Frozen) { MarkObjectGroupFlags(cx, obj, OBJECT_FLAG_FROZEN); if (!ObjectElements::FreezeElements(cx, obj.as())) return false; } else if (!NativeObject::sparsifyDenseElements(cx, obj.as())) { return false; } } if (!JSObject::setFlags(cx, obj, BaseShape::NOT_EXTENSIBLE, JSObject::GENERATE_SHAPE)) { // We failed to mark the object non-extensible, so reset the frozen // flag on the elements. MOZ_ASSERT(obj->nonProxyIsExtensible()); if (obj->isNative() && obj->as().getElementsHeader()->isFrozen()) obj->as().getElementsHeader()->markNotFrozen(); return false; } return result.succeed(); } bool js::PreventExtensions(JSContext* cx, HandleObject obj, IntegrityLevel level) { ObjectOpResult result; return PreventExtensions(cx, obj, result, level) && result.checkStrict(cx, obj); } bool js::GetOwnPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id, MutableHandle desc) { if (GetOwnPropertyOp op = obj->getOpsGetOwnPropertyDescriptor()) { bool ok = op(cx, obj, id, desc); if (ok) desc.assertCompleteIfFound(); return ok; } return NativeGetOwnPropertyDescriptor(cx, obj.as(), id, desc); } bool js::DefineProperty(JSContext* cx, HandleObject obj, HandleId id, Handle desc) { ObjectOpResult result; return DefineProperty(cx, obj, id, desc, result) && result.checkStrict(cx, obj, id); } bool js::DefineProperty(JSContext* cx, HandleObject obj, HandleId id, Handle desc, ObjectOpResult& result) { desc.assertValid(); if (DefinePropertyOp op = obj->getOpsDefineProperty()) return op(cx, obj, id, desc, result); return NativeDefineProperty(cx, obj.as(), id, desc, result); } bool js::DefineProperty(ExclusiveContext* cx, HandleObject obj, HandleId id, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs, ObjectOpResult& result) { MOZ_ASSERT(!(attrs & JSPROP_PROPOP_ACCESSORS)); Rooted desc(cx); desc.initFields(nullptr, value, attrs, getter, setter); if (DefinePropertyOp op = obj->getOpsDefineProperty()) { if (!cx->shouldBeJSContext()) return false; return op(cx->asJSContext(), obj, id, desc, result); } return NativeDefineProperty(cx, obj.as(), id, desc, result); } bool js::DefineProperty(ExclusiveContext* cx, HandleObject obj, PropertyName* name, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs, ObjectOpResult& result) { RootedId id(cx, NameToId(name)); return DefineProperty(cx, obj, id, value, getter, setter, attrs, result); } bool js::DefineElement(ExclusiveContext* cx, HandleObject obj, uint32_t index, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs, ObjectOpResult& result) { MOZ_ASSERT(getter != JS_PropertyStub); MOZ_ASSERT(setter != JS_StrictPropertyStub); RootedId id(cx); if (!IndexToId(cx, index, &id)) return false; return DefineProperty(cx, obj, id, value, getter, setter, attrs, result); } bool js::DefineProperty(ExclusiveContext* cx, HandleObject obj, HandleId id, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs) { ObjectOpResult result; if (!DefineProperty(cx, obj, id, value, getter, setter, attrs, result)) return false; if (!result) { if (!cx->shouldBeJSContext()) return false; result.reportError(cx->asJSContext(), obj, id); return false; } return true; } bool js::DefineProperty(ExclusiveContext* cx, HandleObject obj, PropertyName* name, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs) { RootedId id(cx, NameToId(name)); return DefineProperty(cx, obj, id, value, getter, setter, attrs); } bool js::DefineElement(ExclusiveContext* cx, HandleObject obj, uint32_t index, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs) { MOZ_ASSERT(getter != JS_PropertyStub); MOZ_ASSERT(setter != JS_StrictPropertyStub); RootedId id(cx); if (!IndexToId(cx, index, &id)) return false; return DefineProperty(cx, obj, id, value, getter, setter, attrs); } /*** SpiderMonkey nonstandard internal methods ***************************************************/ bool js::SetImmutablePrototype(ExclusiveContext* cx, HandleObject obj, bool* succeeded) { if (obj->hasDynamicPrototype()) { if (!cx->shouldBeJSContext()) return false; return Proxy::setImmutablePrototype(cx->asJSContext(), obj, succeeded); } if (!JSObject::setFlags(cx, obj, BaseShape::IMMUTABLE_PROTOTYPE)) return false; *succeeded = true; return true; } bool js::GetPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id, MutableHandle desc) { RootedObject pobj(cx); for (pobj = obj; pobj;) { if (pobj->is()) { bool ok = Proxy::getPropertyDescriptor(cx, pobj, id, desc); if (ok) desc.assertCompleteIfFound(); return ok; } if (!GetOwnPropertyDescriptor(cx, pobj, id, desc)) return false; if (desc.object()) return true; if (!GetPrototype(cx, pobj, &pobj)) return false; } MOZ_ASSERT(!desc.object()); return true; } const char* js::GetObjectClassName(JSContext* cx, HandleObject obj) { assertSameCompartment(cx, obj); if (obj->is()) return Proxy::className(cx, obj); return obj->getClass()->name; } /* * */ extern bool PropertySpecNameToId(JSContext* cx, const char* name, MutableHandleId id, js::PinningBehavior pin = js::DoNotPinAtom); static bool DefineFunctionFromSpec(JSContext* cx, HandleObject obj, const JSFunctionSpec* fs, unsigned flags, DefineAsIntrinsic intrinsic) { GetterOp gop; SetterOp sop; if (flags & JSFUN_STUB_GSOPS) { // JSFUN_STUB_GSOPS is a request flag only, not stored in fun->flags or // the defined property's attributes. flags &= ~JSFUN_STUB_GSOPS; gop = nullptr; sop = nullptr; } else { gop = obj->getClass()->getGetProperty(); sop = obj->getClass()->getSetProperty(); MOZ_ASSERT(gop != JS_PropertyStub); MOZ_ASSERT(sop != JS_StrictPropertyStub); } RootedId id(cx); if (!PropertySpecNameToId(cx, fs->name, &id)) return false; if (StandardProtoKeyOrNull(obj) == JSProto_Array && id == NameToId(cx->names().values)) { if (!cx->options().arrayProtoValues()) return true; } JSFunction* fun = NewFunctionFromSpec(cx, fs, id); if (!fun) return false; if (intrinsic == AsIntrinsic) fun->setIsIntrinsic(); RootedValue funVal(cx, ObjectValue(*fun)); return DefineProperty(cx, obj, id, funVal, gop, sop, flags & ~JSFUN_FLAGS_MASK); } bool js::DefineFunctions(JSContext* cx, HandleObject obj, const JSFunctionSpec* fs, DefineAsIntrinsic intrinsic) { for (; fs->name; fs++) { if (!DefineFunctionFromSpec(cx, obj, fs, fs->flags, intrinsic)) 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 Class* clasp = obj->getClass(); // Avoid recursive death when decompiling in ReportValueError. RootedString str(cx); if (hint == JSTYPE_STRING) { str = JS_AtomizeAndPinString(cx, clasp->name); if (!str) return false; } else { str = nullptr; } RootedValue val(cx, ObjectValue(*obj)); ReportValueError2(cx, errorNumber, JSDVG_SEARCH_STACK, val, str, hint == JSTYPE_VOID ? "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_VOID); Rooted id(cx); const Class* clasp = obj->getClass(); if (hint == JSTYPE_STRING) { id = NameToId(cx->names().toString); /* Optimize (new String(...)).toString(). */ if (clasp == &StringObject::class_) { StringObject* nobj = &obj->as(); if (HasNativeMethodPure(nobj, cx->names().toString, str_toString, cx)) { vp.setString(nobj->unbox()); return true; } } 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); /* Optimize new String(...).valueOf(). */ if (clasp == &StringObject::class_) { StringObject* nobj = &obj->as(); if (HasNativeMethodPure(nobj, cx->names().valueOf, str_toString, cx)) { vp.setString(nobj->unbox()); return true; } } /* Optimize new Number(...).valueOf(). */ if (clasp == &NumberObject::class_) { NumberObject* nobj = &obj->as(); if (HasNativeMethodPure(nobj, cx->names().valueOf, num_valueOf, cx)) { vp.setNumber(nobj->unbox()); return true; } } if (!MaybeCallMethod(cx, obj, id, vp)) return false; if (vp.isPrimitive()) return true; id = NameToId(cx->names().toString); if (!MaybeCallMethod(cx, obj, id, vp)) return false; if (vp.isPrimitive()) return true; } return ReportCantConvert(cx, JSMSG_CANT_CONVERT_TO, obj, hint); } bool js::ToPrimitiveSlow(JSContext* cx, JSType preferredType, MutableHandleValue vp) { // Step numbers refer to the first algorithm listed in ES6 draft rev 36 // (2015 Mar 17) 7.1.1 ToPrimitive. MOZ_ASSERT(preferredType == JSTYPE_VOID || preferredType == JSTYPE_STRING || preferredType == JSTYPE_NUMBER); RootedObject obj(cx, &vp.toObject()); // Steps 4-5. RootedId id(cx, SYMBOL_TO_JSID(cx->wellKnownSymbols().toPrimitive)); RootedValue method(cx); if (!GetProperty(cx, obj, obj, id, &method)) return false; // Step 6. if (!method.isUndefined()) { // 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); } /* * */ bool js::IsDelegate(JSContext* cx, HandleObject obj, const js::Value& v, bool* result) { if (v.isPrimitive()) { *result = false; return true; } return IsDelegateOfObject(cx, obj, &v.toObject(), result); } bool js::IsDelegateOfObject(JSContext* cx, HandleObject protoObj, JSObject* obj, bool* result) { RootedObject obj2(cx, obj); for (;;) { if (!GetPrototype(cx, obj2, &obj2)) return false; if (!obj2) { *result = false; return true; } if (obj2 == protoObj) { *result = true; return true; } } } JSObject* js::GetBuiltinPrototypePure(GlobalObject* global, JSProtoKey protoKey) { MOZ_ASSERT(JSProto_Null <= protoKey); MOZ_ASSERT(protoKey < JSProto_LIMIT); if (protoKey != JSProto_Null) { const Value& v = global->getPrototype(protoKey); if (v.isObject()) return &v.toObject(); } return nullptr; } JSObject* js::PrimitiveToObject(JSContext* cx, const Value& v) { if (v.isString()) { Rooted str(cx, v.toString()); return StringObject::create(cx, str); } if (v.isNumber()) return NumberObject::create(cx, v.toNumber()); if (v.isBoolean()) return BooleanObject::create(cx, v.toBoolean()); if (v.isSymbol()) { RootedSymbol symbol(cx, v.toSymbol()); return SymbolObject::create(cx, symbol); } MOZ_ASSERT(v.isBigInt()); RootedBigInt bigInt(cx, v.toBigInt()); return BigIntObject::create(cx, bigInt); } /* * Invokes the ES5 ToObject algorithm on vp, returning the result. If vp might * already be an object, use ToObject. reportCantConvert 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()) { if (reportScanStack) { ReportIsNullOrUndefined(cx, JSDVG_SEARCH_STACK, val, nullptr); } else { JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, JSMSG_CANT_CONVERT_TO, val.isNull() ? "null" : "undefined", "object"); } return nullptr; } return PrimitiveToObject(cx, val); } Value js::GetThisValue(JSObject* obj) { if (obj->is()) return ObjectValue(*ToWindowProxyIfWindow(obj)); if (obj->is()) { if (!obj->as().isExtensible()) return UndefinedValue(); return obj->as().thisValue(); } if (obj->is()) return UndefinedValue(); if (obj->is()) return ObjectValue(*obj->as().withThis()); if (obj->is()) return GetThisValue(obj->enclosingEnvironment()); return ObjectValue(*obj); } class GetObjectSlotNameFunctor : public JS::CallbackTracer::ContextFunctor { JSObject* obj; public: explicit GetObjectSlotNameFunctor(JSObject* ctx) : obj(ctx) {} virtual void operator()(JS::CallbackTracer* trc, char* buf, size_t bufsize) override; }; void GetObjectSlotNameFunctor::operator()(JS::CallbackTracer* trc, char* buf, size_t bufsize) { MOZ_ASSERT(trc->contextIndex() != JS::CallbackTracer::InvalidIndex); uint32_t slot = uint32_t(trc->contextIndex()); Shape* shape; if (obj->isNative()) { shape = obj->as().lastProperty(); while (shape && (!shape->hasSlot() || shape->slot() != slot)) shape = shape->previous(); } else { shape = nullptr; } if (!shape) { do { const char* slotname = nullptr; const char* pattern = nullptr; if (obj->is()) { pattern = "CLASS_OBJECT(%s)"; if (false) ; #define TEST_SLOT_MATCHES_PROTOTYPE(name,init,clasp) \ else if ((JSProto_##name) == slot) { slotname = js_##name##_str; } JS_FOR_EACH_PROTOTYPE(TEST_SLOT_MATCHES_PROTOTYPE) #undef TEST_SLOT_MATCHES_PROTOTYPE } else { pattern = "%s"; if (obj->is()) { if (slot == EnvironmentObject::enclosingEnvironmentSlot()) { slotname = "enclosing_environment"; } else if (obj->is()) { if (slot == CallObject::calleeSlot()) slotname = "callee_slot"; } else if (obj->is()) { if (slot == WithEnvironmentObject::objectSlot()) slotname = "with_object"; else if (slot == WithEnvironmentObject::thisSlot()) slotname = "with_this"; } } } if (slotname) snprintf(buf, bufsize, pattern, slotname); else snprintf(buf, bufsize, "**UNKNOWN SLOT %" PRIu32 "**", slot); } while (false); } else { jsid propid = shape->propid(); if (JSID_IS_INT(propid)) { snprintf(buf, bufsize, "%" PRId32, JSID_TO_INT(propid)); } else if (JSID_IS_ATOM(propid)) { PutEscapedString(buf, bufsize, JSID_TO_ATOM(propid), 0); } else if (JSID_IS_SYMBOL(propid)) { snprintf(buf, bufsize, "**SYMBOL KEY**"); } else { snprintf(buf, bufsize, "**FINALIZED ATOM KEY**"); } } } /*** Debugging routines **************************************************************************/ #ifdef DEBUG /* * Routines to print out values during debugging. These are FRIEND_API to help * the debugger find them and to support temporarily hacking js::Dump* calls * into other code. */ static void dumpValue(const Value& v, FILE* fp) { if (v.isNull()) fprintf(fp, "null"); else if (v.isUndefined()) fprintf(fp, "undefined"); else if (v.isInt32()) fprintf(fp, "%d", v.toInt32()); else if (v.isDouble()) fprintf(fp, "%g", v.toDouble()); else if (v.isString()) v.toString()->dump(fp); else if (v.isSymbol()) v.toSymbol()->dump(fp); else if (v.isObject() && v.toObject().is()) { JSFunction* fun = &v.toObject().as(); if (fun->displayAtom()) { fputs("displayAtom(), 0); } else { fputs("hasScript()) { JSScript* script = fun->nonLazyScript(); fprintf(fp, " (%s:%" PRIuSIZE ")", script->filename() ? script->filename() : "", script->lineno()); } fprintf(fp, " at %p>", (void*) fun); } else if (v.isObject()) { JSObject* obj = &v.toObject(); const Class* clasp = obj->getClass(); fprintf(fp, "<%s%s at %p>", clasp->name, (clasp == &PlainObject::class_) ? "" : " object", (void*) obj); } else if (v.isBoolean()) { if (v.toBoolean()) fprintf(fp, "true"); else fprintf(fp, "false"); } else if (v.isMagic()) { fprintf(fp, ""); } else { fprintf(fp, "unexpected value"); } } JS_FRIEND_API(void) js::DumpValue(const Value& val, FILE* fp) { dumpValue(val, fp); fputc('\n', fp); } JS_FRIEND_API(void) js::DumpId(jsid id, FILE* fp) { fprintf(fp, "jsid %p = ", (void*) JSID_BITS(id)); dumpValue(IdToValue(id), fp); fputc('\n', fp); } static void DumpProperty(const NativeObject* obj, Shape& shape, FILE* fp) { jsid id = shape.propid(); uint8_t attrs = shape.attributes(); fprintf(fp, " ((js::Shape*) %p) ", (void*) &shape); if (attrs & JSPROP_ENUMERATE) fprintf(fp, "enumerate "); if (attrs & JSPROP_READONLY) fprintf(fp, "readonly "); if (attrs & JSPROP_PERMANENT) fprintf(fp, "permanent "); if (attrs & JSPROP_SHARED) fprintf(fp, "shared "); if (shape.hasGetterValue()) fprintf(fp, "getterValue=%p ", (void*) shape.getterObject()); else if (!shape.hasDefaultGetter()) fprintf(fp, "getterOp=%p ", JS_FUNC_TO_DATA_PTR(void*, shape.getterOp())); if (shape.hasSetterValue()) fprintf(fp, "setterValue=%p ", (void*) shape.setterObject()); else if (!shape.hasDefaultSetter()) fprintf(fp, "setterOp=%p ", JS_FUNC_TO_DATA_PTR(void*, shape.setterOp())); if (JSID_IS_ATOM(id) || JSID_IS_INT(id) || JSID_IS_SYMBOL(id)) dumpValue(js::IdToValue(id), fp); else fprintf(fp, "unknown jsid %p", (void*) JSID_BITS(id)); uint32_t slot = shape.hasSlot() ? shape.maybeSlot() : SHAPE_INVALID_SLOT; fprintf(fp, ": slot %d", slot); if (shape.hasSlot()) { fprintf(fp, " = "); dumpValue(obj->getSlot(slot), fp); } else if (slot != SHAPE_INVALID_SLOT) { fprintf(fp, " (INVALID!)"); } fprintf(fp, "\n"); } bool JSObject::uninlinedIsProxy() const { return is(); } void JSObject::dump(FILE* fp) const { const JSObject* obj = this; JSObject* globalObj = &global(); fprintf(fp, "object %p from global %p [%s]\n", (void*) obj, (void*) globalObj, globalObj->getClass()->name); const Class* clasp = obj->getClass(); fprintf(fp, "class %p %s\n", (const void*)clasp, clasp->name); if (obj->hasLazyGroup()) { fprintf(fp, "lazy group\n"); } else { const ObjectGroup* group = obj->group(); fprintf(fp, "group %p\n", (const void*)group); } fprintf(fp, "flags:"); if (obj->isDelegate()) fprintf(fp, " delegate"); if (!obj->is() && !obj->nonProxyIsExtensible()) fprintf(fp, " not_extensible"); if (obj->isIndexed()) fprintf(fp, " indexed"); if (obj->isBoundFunction()) fprintf(fp, " bound_function"); if (obj->isQualifiedVarObj()) fprintf(fp, " varobj"); if (obj->isUnqualifiedVarObj()) fprintf(fp, " unqualified_varobj"); if (obj->isIteratedSingleton()) fprintf(fp, " iterated_singleton"); if (obj->isNewGroupUnknown()) fprintf(fp, " new_type_unknown"); if (obj->hasUncacheableProto()) fprintf(fp, " has_uncacheable_proto"); if (obj->hadElementsAccess()) fprintf(fp, " had_elements_access"); if (obj->wasNewScriptCleared()) fprintf(fp, " new_script_cleared"); if (obj->hasStaticPrototype() && obj->staticPrototypeIsImmutable()) fprintf(fp, " immutable_prototype"); if (obj->isNative()) { const NativeObject* nobj = &obj->as(); if (nobj->inDictionaryMode()) fprintf(fp, " inDictionaryMode"); if (nobj->hasShapeTable()) fprintf(fp, " hasShapeTable"); } fprintf(fp, "\n"); if (obj->isNative()) { const NativeObject* nobj = &obj->as(); uint32_t slots = nobj->getDenseInitializedLength(); if (slots) { fprintf(fp, "elements\n"); for (uint32_t i = 0; i < slots; i++) { fprintf(fp, " %3d: ", i); dumpValue(nobj->getDenseElement(i), fp); fprintf(fp, "\n"); fflush(fp); } } } fprintf(fp, "proto "); TaggedProto proto = obj->taggedProto(); if (proto.isDynamic()) fprintf(fp, ""); else dumpValue(ObjectOrNullValue(proto.toObjectOrNull()), fp); fputc('\n', fp); if (clasp->flags & JSCLASS_HAS_PRIVATE) fprintf(fp, "private %p\n", obj->as().getPrivate()); if (!obj->isNative()) fprintf(fp, "not native\n"); uint32_t reservedEnd = JSCLASS_RESERVED_SLOTS(clasp); uint32_t slots = obj->isNative() ? obj->as().slotSpan() : 0; uint32_t stop = obj->isNative() ? reservedEnd : slots; if (stop > 0) fprintf(fp, obj->isNative() ? "reserved slots:\n" : "slots:\n"); for (uint32_t i = 0; i < stop; i++) { fprintf(fp, " %3d ", i); if (i < reservedEnd) fprintf(fp, "(reserved) "); fprintf(fp, "= "); dumpValue(obj->as().getSlot(i), fp); fputc('\n', fp); } if (obj->isNative()) { fprintf(fp, "properties:\n"); Vector props; for (Shape::Range r(obj->as().lastProperty()); !r.empty(); r.popFront()) { if (!props.append(&r.front())) { fprintf(fp, "(OOM while appending properties)\n"); break; } } for (size_t i = props.length(); i-- != 0;) DumpProperty(&obj->as(), *props[i], fp); } fputc('\n', fp); } // For debuggers. void JSObject::dump() const { dump(stderr); } static void MaybeDumpScope(Scope* scope, FILE* fp) { if (scope) { fprintf(fp, " scope: %s\n", ScopeKindString(scope->kind())); for (BindingIter bi(scope); bi; bi++) { fprintf(fp, " "); dumpValue(StringValue(bi.name()), fp); fputc('\n', fp); } } } static void MaybeDumpValue(const char* name, const Value& v, FILE* fp) { if (!v.isNull()) { fprintf(fp, " %s: ", name); dumpValue(v, fp); fputc('\n', fp); } } JS_FRIEND_API(void) js::DumpInterpreterFrame(JSContext* cx, FILE* fp, InterpreterFrame* start) { /* This should only called during live debugging. */ ScriptFrameIter i(cx); if (!start) { if (i.done()) { fprintf(fp, "no stack for cx = %p\n", (void*) cx); return; } } else { while (!i.done() && !i.isJit() && i.interpFrame() != start) ++i; if (i.done()) { fprintf(fp, "fp = %p not found in cx = %p\n", (void*)start, (void*)cx); return; } } for (; !i.done(); ++i) { if (i.isJit()) fprintf(fp, "JIT frame\n"); else fprintf(fp, "InterpreterFrame at %p\n", (void*) i.interpFrame()); if (i.isFunctionFrame()) { fprintf(fp, "callee fun: "); RootedValue v(cx); JSObject* fun = i.callee(cx); v.setObject(*fun); dumpValue(v, fp); } else { fprintf(fp, "global or eval frame, no callee"); } fputc('\n', fp); fprintf(fp, "file %s line %" PRIuSIZE "\n", i.script()->filename(), i.script()->lineno()); if (jsbytecode* pc = i.pc()) { fprintf(fp, " pc = %p\n", pc); fprintf(fp, " current op: %s\n", CodeName[*pc]); MaybeDumpScope(i.script()->lookupScope(pc), fp); } if (i.isFunctionFrame()) MaybeDumpValue("this", i.thisArgument(cx), fp); if (!i.isJit()) { fprintf(fp, " rval: "); dumpValue(i.interpFrame()->returnValue(), fp); fputc('\n', fp); } fprintf(fp, " flags:"); if (i.isConstructing()) fprintf(fp, " constructing"); if (!i.isJit() && i.interpFrame()->isDebuggerEvalFrame()) fprintf(fp, " debugger eval"); if (i.isEvalFrame()) fprintf(fp, " eval"); fputc('\n', fp); fprintf(fp, " envChain: (JSObject*) %p\n", (void*) i.environmentChain(cx)); fputc('\n', fp); } } #endif /* DEBUG */ JS_FRIEND_API(void) js::DumpBacktrace(JSContext* cx, FILE* fp) { Sprinter sprinter(cx, false); if (!sprinter.init()) { fprintf(fp, "js::DumpBacktrace: OOM\n"); return; } 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' : '?'; sprinter.printf("#%" PRIuSIZE " %14p %c %s:%d", depth, i.rawFramePtr(), frameType, filename, line); if (i.hasScript()) { sprinter.printf(" (%p @ %" PRIuSIZE ")\n", i.script(), i.script()->pcToOffset(i.pc())); } else { sprinter.printf(" (%p)\n", i.pc()); } } fprintf(fp, "%s", sprinter.string()); #ifdef XP_WIN32 if (IsDebuggerPresent()) OutputDebugStringA(sprinter.string()); #endif } JS_FRIEND_API(void) js::DumpBacktrace(JSContext* cx) { DumpBacktrace(cx, stdout); } /* * */ js::gc::AllocKind JSObject::allocKindForTenure(const js::Nursery& nursery) const { if (is()) { const ArrayObject& aobj = as(); MOZ_ASSERT(aobj.numFixedSlots() == 0); /* Use minimal size object if we are just going to copy the pointer. */ if (!nursery.isInside(aobj.getElementsHeader())) return AllocKind::OBJECT0_BACKGROUND; size_t nelements = aobj.getDenseCapacity(); return GetBackgroundAllocKind(GetGCArrayKind(nelements)); } if (is()) return as().getAllocKind(); /* * Typed arrays in the nursery may have a lazily allocated buffer, make * sure there is room for the array's fixed data when moving the array. */ if (is() && !as().hasBuffer()) { size_t nbytes = as().byteLength(); if (as().hasInlineElements()) return GetBackgroundAllocKind(TypedArrayObject::AllocKindForLazyBuffer(nbytes)); return GetGCObjectKind(getClass()); } // Proxies that are CrossCompartmentWrappers may be nursery allocated. if (IsProxy(this)) return as().allocKindForTenure(); // Unboxed plain objects are sized according to the data they store. if (is()) { size_t nbytes = as().layoutDontCheckGeneration().size(); return GetGCObjectKindForBytes(UnboxedPlainObject::offsetOfData() + nbytes); } // Unboxed arrays use inline data if their size is small enough. if (is()) { const UnboxedArrayObject* nobj = &as(); size_t nbytes = UnboxedArrayObject::offsetOfInlineElements() + nobj->capacity() * nobj->elementSize(); if (nbytes <= JSObject::MAX_BYTE_SIZE) return GetGCObjectKindForBytes(nbytes); return AllocKind::OBJECT0; } // Inlined typed objects are followed by their data, so make sure we copy // it all over to the new object. if (is()) { // Figure out the size of this object, from the prototype's TypeDescr. // The objects we are traversing here are all tenured, so we don't need // to check forwarding pointers. TypeDescr& descr = as().typeDescr(); MOZ_ASSERT(!IsInsideNursery(&descr)); return InlineTypedObject::allocKindForTypeDescriptor(&descr); } // Outline typed objects use the minimum allocation kind. if (is()) return AllocKind::OBJECT0; // All nursery allocatable non-native objects are handled above. MOZ_ASSERT(isNative()); AllocKind kind = GetGCObjectFixedSlotsKind(as().numFixedSlots()); MOZ_ASSERT(!IsBackgroundFinalized(kind)); if (!CanBeFinalizedInBackground(kind, getClass())) return kind; return GetBackgroundAllocKind(kind); } void JSObject::addSizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf, JS::ClassInfo* info) { if (is() && as().hasDynamicSlots()) info->objectsMallocHeapSlots += mallocSizeOf(as().slots_); if (is() && as().hasDynamicElements()) { js::ObjectElements* elements = as().getElementsHeader(); if (!elements->isCopyOnWrite() || elements->ownerObject() == this) info->objectsMallocHeapElementsNormal += mallocSizeOf(elements); } // Other things may be measured in the future if DMD indicates it is worthwhile. if (is() || is() || is() || is() || is() || is()) { // Do nothing. But this function is hot, and we win by getting the // common cases out of the way early. Some stats on the most common // classes, as measured during a vanilla browser session: // - (53.7%, 53.7%): Function // - (18.0%, 71.7%): Object // - (16.9%, 88.6%): Array // - ( 3.9%, 92.5%): Call // - ( 2.8%, 95.3%): RegExp // - ( 1.0%, 96.4%): Proxy // Note that any JSClass that is special cased below likely needs to // specify the JSCLASS_DELAY_METADATA_CALLBACK flag, or else we will // probably crash if the object metadata callback attempts to get the // size of the new object (which Debugger code does) before private // slots are initialized. } else if (is()) { info->objectsMallocHeapMisc += as().sizeOfMisc(mallocSizeOf); } else if (is()) { info->objectsMallocHeapMisc += as().sizeOfData(mallocSizeOf); } else if (is()) { info->objectsMallocHeapMisc += as().sizeOfMisc(mallocSizeOf); } else if (is()) { ArrayBufferObject::addSizeOfExcludingThis(this, mallocSizeOf, info); } else if (is()) { SharedArrayBufferObject::addSizeOfExcludingThis(this, mallocSizeOf, info); #ifdef JS_HAS_CTYPES } else { // This must be the last case. info->objectsMallocHeapMisc += js::SizeOfDataIfCDataObject(mallocSizeOf, const_cast(this)); #endif } } size_t JSObject::sizeOfIncludingThisInNursery() const { // This function doesn't concern itself yet with typed objects (bug 1133593) // nor unboxed objects (bug 1133592). MOZ_ASSERT(!isTenured()); const Nursery& nursery = compartment()->runtimeFromAnyThread()->gc.nursery; size_t size = Arena::thingSize(allocKindForTenure(nursery)); if (is()) { const NativeObject& native = as(); size += native.numFixedSlots() * sizeof(Value); size += native.numDynamicSlots() * sizeof(Value); if (native.hasDynamicElements()) { js::ObjectElements& elements = *native.getElementsHeader(); if (!elements.isCopyOnWrite() || elements.ownerObject() == this) size += elements.capacity * sizeof(HeapSlot); } if (is()) size += as().sizeOfData(); } return size; } JS::ubi::Node::Size JS::ubi::Concrete::size(mozilla::MallocSizeOf mallocSizeOf) const { JSObject& obj = get(); if (!obj.isTenured()) return obj.sizeOfIncludingThisInNursery(); JS::ClassInfo info; obj.addSizeOfExcludingThis(mallocSizeOf, &info); return obj.tenuredSizeOfThis() + info.sizeOfAllThings(); } const char16_t JS::ubi::Concrete::concreteTypeName[] = u"JSObject"; void JSObject::traceChildren(JSTracer* trc) { TraceEdge(trc, &group_, "group"); if (is()) as().traceShape(trc); const Class* clasp = group_->clasp(); if (clasp->isNative()) { NativeObject* nobj = &as(); { GetObjectSlotNameFunctor func(nobj); JS::AutoTracingDetails ctx(trc, func); JS::AutoTracingIndex index(trc); // Tracing can mutate the target but cannot change the slot count, // but the compiler has no way of knowing this. const uint32_t nslots = nobj->slotSpan(); for (uint32_t i = 0; i < nslots; ++i) { TraceManuallyBarrieredEdge(trc, nobj->getSlotRef(i).unsafeUnbarrieredForTracing(), "object slot"); ++index; } MOZ_ASSERT(nslots == nobj->slotSpan()); } do { if (nobj->denseElementsAreCopyOnWrite()) { GCPtrNativeObject& owner = nobj->getElementsHeader()->ownerObject(); if (owner != nobj) { TraceEdge(trc, &owner, "objectElementsOwner"); break; } } TraceRange(trc, nobj->getDenseInitializedLength(), static_cast(nobj->getDenseElementsAllowCopyOnWrite()), "objectElements"); } while (false); } // Call the trace hook at the end so that during a moving GC the trace hook // will see updated fields and slots. if (clasp->hasTrace()) clasp->doTrace(trc, this); } static JSAtom* displayAtomFromObjectGroup(ObjectGroup& group) { TypeNewScript* script = group.newScript(); if (!script) return nullptr; return script->function()->displayAtom(); } /* static */ bool JSObject::constructorDisplayAtom(JSContext* cx, js::HandleObject obj, js::MutableHandleAtom name) { ObjectGroup *g = JSObject::getGroup(cx, obj); if (!g) return false; name.set(displayAtomFromObjectGroup(*g)); return true; } JSAtom* JSObject::maybeConstructorDisplayAtom() const { if (hasLazyGroup()) return nullptr; return displayAtomFromObjectGroup(*group()); } // ES 2016 7.3.20. MOZ_MUST_USE 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) { RootedObject ctorObj(cx, &ctor.toObject()); RootedId speciesId(cx, SYMBOL_TO_JSID(cx->wellKnownSymbols().species)); JSFunction* getter; if (GetGetterPure(cx, ctorObj, 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_NOT_NONNULL_OBJECT, "object's 'constructor' property"); return nullptr; } // Step 5. RootedObject ctorObj(cx, &ctor.toObject()); RootedValue s(cx); RootedId speciesId(cx, SYMBOL_TO_JSID(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; } MOZ_MUST_USE JSObject* js::SpeciesConstructor(JSContext* cx, HandleObject obj, JSProtoKey ctorKey, bool (*isDefaultSpecies)(JSContext*, JSFunction*)) { if (!GlobalObject::ensureConstructor(cx, cx->global(), ctorKey)) return nullptr; RootedObject defaultCtor(cx, &cx->global()->getConstructor(ctorKey).toObject()); return SpeciesConstructor(cx, obj, defaultCtor, isDefaultSpecies); } bool js::Unbox(JSContext* cx, HandleObject obj, MutableHandleValue vp) { if (MOZ_UNLIKELY(obj->is())) return Proxy::boxedValue_unbox(cx, obj, vp); if (obj->is()) vp.setBoolean(obj->as().unbox()); else if (obj->is()) vp.setNumber(obj->as().unbox()); else if (obj->is()) vp.setString(obj->as().unbox()); else if (obj->is()) vp.set(obj->as().UTCTime()); else vp.setUndefined(); return true; }