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Diffstat (limited to 'js/src/vm/GlobalObject.cpp')
| -rw-r--r-- | js/src/vm/GlobalObject.cpp | 1052 |
1 files changed, 1052 insertions, 0 deletions
diff --git a/js/src/vm/GlobalObject.cpp b/js/src/vm/GlobalObject.cpp new file mode 100644 index 0000000000..6924cce0ad --- /dev/null +++ b/js/src/vm/GlobalObject.cpp @@ -0,0 +1,1052 @@ +/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*- + * vim: set ts=8 sts=2 et sw=2 tw=80: + * This Source Code Form is subject to the terms of the Mozilla Public + * License, v. 2.0. If a copy of the MPL was not distributed with this + * file, You can obtain one at http://mozilla.org/MPL/2.0/. */ + +#include "vm/GlobalObject.h" + +#include "jsapi.h" +#include "jsfriendapi.h" + +#include "builtin/AtomicsObject.h" +#include "builtin/BigInt.h" +#include "builtin/DataViewObject.h" +#ifdef JS_HAS_INTL_API +# include "builtin/intl/Collator.h" +# include "builtin/intl/DateTimeFormat.h" +# include "builtin/intl/DisplayNames.h" +# include "builtin/intl/ListFormat.h" +# include "builtin/intl/Locale.h" +# include "builtin/intl/NumberFormat.h" +# include "builtin/intl/PluralRules.h" +# include "builtin/intl/RelativeTimeFormat.h" +#endif +#include "builtin/FinalizationRegistryObject.h" +#include "builtin/MapObject.h" +#include "builtin/ShadowRealm.h" +#include "builtin/Symbol.h" +#include "builtin/WeakMapObject.h" +#include "builtin/WeakRefObject.h" +#include "builtin/WeakSetObject.h" +#include "debugger/DebugAPI.h" +#include "frontend/CompilationStencil.h" +#include "gc/FinalizationObservers.h" +#include "gc/GC.h" +#include "gc/GCContext.h" +#include "js/friend/ErrorMessages.h" // js::GetErrorMessage, JSMSG_* +#include "js/friend/WindowProxy.h" // js::ToWindowProxyIfWindow +#include "js/PropertyAndElement.h" // JS_DefineFunctions, JS_DefineProperties +#include "js/ProtoKey.h" +#include "vm/AsyncFunction.h" +#include "vm/AsyncIteration.h" +#include "vm/BooleanObject.h" +#include "vm/Compartment.h" +#include "vm/DateObject.h" +#include "vm/EnvironmentObject.h" +#include "vm/ErrorObject.h" +#include "vm/GeneratorObject.h" +#include "vm/JSContext.h" +#include "vm/NumberObject.h" +#include "vm/PIC.h" +#include "vm/PlainObject.h" +#include "vm/RegExpObject.h" +#include "vm/RegExpStatics.h" +#include "vm/SelfHosting.h" +#include "vm/StringObject.h" +#include "wasm/WasmJS.h" +#ifdef ENABLE_RECORD_TUPLE +# include "vm/RecordType.h" +# include "vm/TupleType.h" +#endif + +#include "gc/GCContext-inl.h" +#include "vm/JSObject-inl.h" +#include "vm/Realm-inl.h" + +using namespace js; + +namespace js { + +extern const JSClass IntlClass; +extern const JSClass JSONClass; +extern const JSClass MathClass; +extern const JSClass ReflectClass; + +} // namespace js + +static const JSClass* const protoTable[JSProto_LIMIT] = { +#define INIT_FUNC(name, clasp) clasp, +#define INIT_FUNC_DUMMY(name, clasp) nullptr, + JS_FOR_PROTOTYPES(INIT_FUNC, INIT_FUNC_DUMMY) +#undef INIT_FUNC_DUMMY +#undef INIT_FUNC +}; + +JS_PUBLIC_API const JSClass* js::ProtoKeyToClass(JSProtoKey key) { + MOZ_ASSERT(key < JSProto_LIMIT); + return protoTable[key]; +} + +/* static */ +bool GlobalObject::skipDeselectedConstructor(JSContext* cx, JSProtoKey key) { + switch (key) { + case JSProto_Null: + case JSProto_Object: + case JSProto_Function: + case JSProto_BoundFunction: + case JSProto_Array: + case JSProto_Boolean: + case JSProto_JSON: + case JSProto_Date: + case JSProto_Math: + case JSProto_Number: + case JSProto_String: + case JSProto_RegExp: + case JSProto_Error: + case JSProto_InternalError: + case JSProto_AggregateError: + case JSProto_EvalError: + case JSProto_RangeError: + case JSProto_ReferenceError: + case JSProto_SyntaxError: + case JSProto_TypeError: + case JSProto_URIError: + case JSProto_DebuggeeWouldRun: + case JSProto_CompileError: + case JSProto_LinkError: + case JSProto_RuntimeError: + case JSProto_ArrayBuffer: + case JSProto_Int8Array: + case JSProto_Uint8Array: + case JSProto_Int16Array: + case JSProto_Uint16Array: + case JSProto_Int32Array: + case JSProto_Uint32Array: + case JSProto_Float32Array: + case JSProto_Float64Array: + case JSProto_Uint8ClampedArray: + case JSProto_BigInt64Array: + case JSProto_BigUint64Array: + case JSProto_BigInt: + case JSProto_Proxy: + case JSProto_WeakMap: + case JSProto_Map: + case JSProto_Set: + case JSProto_DataView: + case JSProto_Symbol: + case JSProto_Reflect: + case JSProto_WeakSet: + case JSProto_TypedArray: + case JSProto_SavedFrame: + case JSProto_Promise: + case JSProto_AsyncFunction: + case JSProto_GeneratorFunction: + case JSProto_AsyncGeneratorFunction: +#ifdef ENABLE_RECORD_TUPLE + case JSProto_Record: + case JSProto_Tuple: +#endif + return false; + + case JSProto_WebAssembly: + return !wasm::HasSupport(cx); + + case JSProto_WasmModule: + case JSProto_WasmInstance: + case JSProto_WasmMemory: + case JSProto_WasmTable: + case JSProto_WasmGlobal: + case JSProto_WasmTag: +#ifdef ENABLE_WASM_TYPE_REFLECTIONS + case JSProto_WasmFunction: +#endif + case JSProto_WasmException: + return false; + +#ifdef JS_HAS_INTL_API + case JSProto_Intl: + case JSProto_Collator: + case JSProto_DateTimeFormat: + case JSProto_DisplayNames: + case JSProto_Locale: + case JSProto_ListFormat: + case JSProto_NumberFormat: + case JSProto_PluralRules: + case JSProto_RelativeTimeFormat: + return false; +#endif + + // Return true if the given constructor has been disabled at run-time. + case JSProto_Atomics: + case JSProto_SharedArrayBuffer: + return !cx->realm()->creationOptions().getSharedMemoryAndAtomicsEnabled(); + + case JSProto_WeakRef: + case JSProto_FinalizationRegistry: + return cx->realm()->creationOptions().getWeakRefsEnabled() == + JS::WeakRefSpecifier::Disabled; + + case JSProto_Iterator: + case JSProto_AsyncIterator: + return !cx->realm()->creationOptions().getIteratorHelpersEnabled(); + + case JSProto_ShadowRealm: + return !cx->realm()->creationOptions().getShadowRealmsEnabled(); + + default: + MOZ_CRASH("unexpected JSProtoKey"); + } +} + +static bool ShouldFreezeBuiltin(JSProtoKey key) { + switch (key) { + case JSProto_Object: + case JSProto_Array: + case JSProto_Function: + return true; + default: + return false; + } +} + +static unsigned GetAttrsForResolvedGlobal(GlobalObject* global, + JSProtoKey key) { + unsigned attrs = JSPROP_RESOLVING; + if (global->realm()->creationOptions().freezeBuiltins() && + ShouldFreezeBuiltin(key)) { + attrs |= JSPROP_PERMANENT | JSPROP_READONLY; + } + return attrs; +} + +/* static*/ +bool GlobalObject::resolveConstructor(JSContext* cx, + Handle<GlobalObject*> global, + JSProtoKey key, IfClassIsDisabled mode) { + MOZ_ASSERT(key != JSProto_Null); + MOZ_ASSERT(key != JSProto_BoundFunction, + "bound functions don't have their own proto object"); + MOZ_ASSERT(!global->isStandardClassResolved(key)); + MOZ_ASSERT(cx->compartment() == global->compartment()); + + // |global| must be same-compartment but make sure we're in its realm: the + // code below relies on this. + AutoRealm ar(cx, global); + + MOZ_ASSERT(!cx->isHelperThreadContext()); + + // Prohibit collection of allocation metadata. Metadata builders shouldn't + // need to observe lazily-constructed prototype objects coming into + // existence. And assertions start to fail when the builder itself attempts + // an allocation that re-entrantly tries to create the same prototype. + AutoSuppressAllocationMetadataBuilder suppressMetadata(cx); + + // Constructor resolution may execute self-hosted scripts. These + // self-hosted scripts do not call out to user code by construction. Allow + // all scripts to execute, even in debuggee compartments that are paused. + AutoSuppressDebuggeeNoExecuteChecks suppressNX(cx); + + // Some classes can be disabled at compile time, others at run time; + // if a feature is compile-time disabled, clasp is null. + const JSClass* clasp = ProtoKeyToClass(key); + if (!clasp || skipDeselectedConstructor(cx, key)) { + if (mode == IfClassIsDisabled::Throw) { + JS_ReportErrorNumberASCII(cx, GetErrorMessage, nullptr, + JSMSG_CONSTRUCTOR_DISABLED, + clasp ? clasp->name : "constructor"); + return false; + } + return true; + } + + // Class spec must have a constructor defined. + if (!clasp->specDefined()) { + return true; + } + + bool isObjectOrFunction = key == JSProto_Function || key == JSProto_Object; + + // We need to create the prototype first, and immediately stash it in the + // slot. This is so the following bootstrap ordering is possible: + // * Object.prototype + // * Function.prototype + // * Function + // * Object + // + // We get the above when Object is resolved before Function. If Function + // is resolved before Object, we'll end up re-entering resolveConstructor + // for Function, which is a problem. So if Function is being resolved + // before Object.prototype exists, we just resolve Object instead, since we + // know that Function will also be resolved before we return. + if (key == JSProto_Function && !global->hasPrototype(JSProto_Object)) { + return resolveConstructor(cx, global, JSProto_Object, + IfClassIsDisabled::DoNothing); + } + + // %IteratorPrototype%.map.[[Prototype]] is %Generator% and + // %Generator%.prototype.[[Prototype]] is %IteratorPrototype%. + // A workaround in initIteratorProto prevents runaway mutual recursion while + // setting these up. Ensure the workaround is triggered already: + if (key == JSProto_GeneratorFunction && + !global->hasBuiltinProto(ProtoKind::IteratorProto)) { + if (!getOrCreateIteratorPrototype(cx, global)) { + return false; + } + + // If iterator helpers are enabled, populating %IteratorPrototype% will + // have recursively gone through here. + if (global->isStandardClassResolved(key)) { + return true; + } + } + + // We don't always have a prototype (i.e. Math and JSON). If we don't, + // |createPrototype|, |prototypeFunctions|, and |prototypeProperties| + // should all be null. + RootedObject proto(cx); + if (ClassObjectCreationOp createPrototype = + clasp->specCreatePrototypeHook()) { + proto = createPrototype(cx, key); + if (!proto) { + return false; + } + + if (isObjectOrFunction) { + // Make sure that creating the prototype didn't recursively resolve + // our own constructor. We can't just assert that there's no + // prototype; OOMs can result in incomplete resolutions in which + // the prototype is saved but not the constructor. So use the same + // criteria that protects entry into this function. + MOZ_ASSERT(!global->isStandardClassResolved(key)); + + global->setPrototype(key, proto); + } + } + + // Create the constructor. + RootedObject ctor(cx, clasp->specCreateConstructorHook()(cx, key)); + if (!ctor) { + return false; + } + + RootedId id(cx, NameToId(ClassName(key, cx))); + if (isObjectOrFunction) { + if (clasp->specShouldDefineConstructor()) { + RootedValue ctorValue(cx, ObjectValue(*ctor)); + unsigned attrs = GetAttrsForResolvedGlobal(global, key); + if (!DefineDataProperty(cx, global, id, ctorValue, attrs)) { + return false; + } + } + + global->setConstructor(key, ctor); + } + + if (const JSFunctionSpec* funs = clasp->specPrototypeFunctions()) { + if (!JS_DefineFunctions(cx, proto, funs)) { + return false; + } + } + if (const JSPropertySpec* props = clasp->specPrototypeProperties()) { + if (!JS_DefineProperties(cx, proto, props)) { + return false; + } + } + if (const JSFunctionSpec* funs = clasp->specConstructorFunctions()) { + if (!JS_DefineFunctions(cx, ctor, funs)) { + return false; + } + } + if (const JSPropertySpec* props = clasp->specConstructorProperties()) { + if (!JS_DefineProperties(cx, ctor, props)) { + return false; + } + } + + // If the prototype exists, link it with the constructor. + if (proto && !LinkConstructorAndPrototype(cx, ctor, proto)) { + return false; + } + + // Call the post-initialization hook, if provided. + if (FinishClassInitOp finishInit = clasp->specFinishInitHook()) { + if (!finishInit(cx, ctor, proto)) { + return false; + } + } + + if (ShouldFreezeBuiltin(key)) { + if (!JS::MaybeFreezeCtorAndPrototype(cx, ctor, proto)) { + return false; + } + } + + if (!isObjectOrFunction) { + // Any operations that modifies the global object should be placed + // after any other fallible operations. + + // Fallible operation that modifies the global object. + if (clasp->specShouldDefineConstructor()) { + bool shouldReallyDefine = true; + + // On the web, it isn't presently possible to expose the global + // "SharedArrayBuffer" property unless the page is cross-site-isolated. + // Only define this constructor if an option on the realm indicates that + // it should be defined. + if (key == JSProto_SharedArrayBuffer) { + const JS::RealmCreationOptions& options = + global->realm()->creationOptions(); + + MOZ_ASSERT(options.getSharedMemoryAndAtomicsEnabled(), + "shouldn't be defining SharedArrayBuffer if shared memory " + "is disabled"); + + shouldReallyDefine = options.defineSharedArrayBufferConstructor(); + } + + if (shouldReallyDefine) { + RootedValue ctorValue(cx, ObjectValue(*ctor)); + unsigned attrs = GetAttrsForResolvedGlobal(global, key); + if (!DefineDataProperty(cx, global, id, ctorValue, attrs)) { + return false; + } + } + } + + // Infallible operations that modify the global object. + global->setConstructor(key, ctor); + if (proto) { + global->setPrototype(key, proto); + } + } + + return true; +} + +// Resolve a "globalThis" self-referential property if necessary, +// per a stage-3 proposal. https://github.com/tc39/ecma262/pull/702 +// +// We could also do this in |FinishObjectClassInit| to trim the global +// resolve hook. Unfortunately, |ToWindowProxyIfWindow| doesn't work then: +// the browser's |nsGlobalWindow::SetNewDocument| invokes Object init +// *before* it sets the global's WindowProxy using |js::SetWindowProxy|. +// +// Refactoring global object creation code to support this approach is a +// challenge for another day. +/* static */ +bool GlobalObject::maybeResolveGlobalThis(JSContext* cx, + Handle<GlobalObject*> global, + bool* resolved) { + if (!global->data().globalThisResolved) { + RootedValue v(cx, ObjectValue(*ToWindowProxyIfWindow(global))); + if (!DefineDataProperty(cx, global, cx->names().globalThis, v, + JSPROP_RESOLVING)) { + return false; + } + + *resolved = true; + global->data().globalThisResolved = true; + } + + return true; +} + +/* static */ +JSObject* GlobalObject::createBuiltinProto(JSContext* cx, + Handle<GlobalObject*> global, + ProtoKind kind, ObjectInitOp init) { + MOZ_ASSERT(!cx->isHelperThreadContext()); + if (!init(cx, global)) { + return nullptr; + } + + return &global->getBuiltinProto(kind); +} + +JSObject* GlobalObject::createBuiltinProto(JSContext* cx, + Handle<GlobalObject*> global, + ProtoKind kind, Handle<JSAtom*> tag, + ObjectInitWithTagOp init) { + MOZ_ASSERT(!cx->isHelperThreadContext()); + if (!init(cx, global, tag)) { + return nullptr; + } + + return &global->getBuiltinProto(kind); +} + +static bool ThrowTypeError(JSContext* cx, unsigned argc, Value* vp) { + ThrowTypeErrorBehavior(cx); + return false; +} + +/* static */ +JSObject* GlobalObject::getOrCreateThrowTypeError( + JSContext* cx, Handle<GlobalObject*> global) { + if (JSFunction* fun = global->data().throwTypeError) { + return fun; + } + + // Construct the unique [[%ThrowTypeError%]] function object, used only for + // "callee" and "caller" accessors on strict mode arguments objects. (The + // spec also uses this for "arguments" and "caller" on various functions, + // but we're experimenting with implementing them using accessors on + // |Function.prototype| right now.) + + RootedFunction throwTypeError( + cx, NewNativeFunction(cx, ThrowTypeError, 0, nullptr)); + if (!throwTypeError || !PreventExtensions(cx, throwTypeError)) { + return nullptr; + } + + // The "length" property of %ThrowTypeError% is non-configurable. + Rooted<PropertyDescriptor> nonConfigurableDesc(cx, + PropertyDescriptor::Empty()); + nonConfigurableDesc.setConfigurable(false); + + RootedId lengthId(cx, NameToId(cx->names().length)); + ObjectOpResult lengthResult; + if (!NativeDefineProperty(cx, throwTypeError, lengthId, nonConfigurableDesc, + lengthResult)) { + return nullptr; + } + MOZ_ASSERT(lengthResult); + + // The "name" property of %ThrowTypeError% is non-configurable, adjust + // the default property attributes accordingly. + RootedId nameId(cx, NameToId(cx->names().name)); + ObjectOpResult nameResult; + if (!NativeDefineProperty(cx, throwTypeError, nameId, nonConfigurableDesc, + nameResult)) { + return nullptr; + } + MOZ_ASSERT(nameResult); + + global->data().throwTypeError.init(throwTypeError); + return throwTypeError; +} + +GlobalObject* GlobalObject::createInternal(JSContext* cx, + const JSClass* clasp) { + MOZ_ASSERT(clasp->flags & JSCLASS_IS_GLOBAL); + MOZ_ASSERT(clasp->isTrace(JS_GlobalObjectTraceHook)); + + JSObject* obj = NewTenuredObjectWithGivenProto(cx, clasp, nullptr); + if (!obj) { + return nullptr; + } + + Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>()); + MOZ_ASSERT(global->isUnqualifiedVarObj()); + + { + auto data = cx->make_unique<GlobalObjectData>(cx->zone()); + if (!data) { + return nullptr; + } + // Note: it's important for the realm's global to be initialized at the + // same time as the global's GlobalObjectData, because we free the global's + // data when Realm::global_ is cleared. + cx->realm()->initGlobal(*global); + InitReservedSlot(global, GLOBAL_DATA_SLOT, data.release(), + MemoryUse::GlobalObjectData); + } + + Rooted<GlobalLexicalEnvironmentObject*> lexical( + cx, GlobalLexicalEnvironmentObject::create(cx, global)); + if (!lexical) { + return nullptr; + } + global->data().lexicalEnvironment.init(lexical); + + Rooted<GlobalScope*> emptyGlobalScope( + cx, GlobalScope::createEmpty(cx, ScopeKind::Global)); + if (!emptyGlobalScope) { + return nullptr; + } + global->data().emptyGlobalScope.init(emptyGlobalScope); + + if (!GlobalObject::createIntrinsicsHolder(cx, global)) { + return nullptr; + } + + if (!JSObject::setQualifiedVarObj(cx, global)) { + return nullptr; + } + if (!JSObject::setGenerationCountedGlobal(cx, global)) { + return nullptr; + } + + return global; +} + +/* static */ +GlobalObject* GlobalObject::new_(JSContext* cx, const JSClass* clasp, + JSPrincipals* principals, + JS::OnNewGlobalHookOption hookOption, + const JS::RealmOptions& options) { + MOZ_ASSERT(!cx->isExceptionPending()); + MOZ_ASSERT_IF(cx->zone(), !cx->zone()->isAtomsZone()); + + // If we are creating a new global in an existing compartment, make sure the + // compartment has a live global at all times (by rooting it here). + // See bug 1530364. + Rooted<GlobalObject*> existingGlobal(cx); + const JS::RealmCreationOptions& creationOptions = options.creationOptions(); + if (creationOptions.compartmentSpecifier() == + JS::CompartmentSpecifier::ExistingCompartment) { + Compartment* comp = creationOptions.compartment(); + existingGlobal = &comp->firstGlobal(); + } + + Realm* realm = NewRealm(cx, principals, options); + if (!realm) { + return nullptr; + } + + Rooted<GlobalObject*> global(cx); + { + AutoRealmUnchecked ar(cx, realm); + global = GlobalObject::createInternal(cx, clasp); + if (!global) { + return nullptr; + } + + // Make transactional initialization of these constructors by discarding the + // incompletely initialized global if an error occur. This also ensures the + // global's prototype chain is initialized (in FinishObjectClassInit). + if (!ensureConstructor(cx, global, JSProto_Object) || + !ensureConstructor(cx, global, JSProto_Function)) { + return nullptr; + } + + realm->clearInitializingGlobal(); + if (hookOption == JS::FireOnNewGlobalHook) { + JS_FireOnNewGlobalObject(cx, global); + } + } + + return global; +} + +GlobalScope& GlobalObject::emptyGlobalScope() const { + return *data().emptyGlobalScope; +} + +bool GlobalObject::valueIsEval(const Value& val) { + return val.isObject() && data().eval == &val.toObject(); +} + +/* static */ +bool GlobalObject::initStandardClasses(JSContext* cx, + Handle<GlobalObject*> global) { + /* Define a top-level property 'undefined' with the undefined value. */ + if (!DefineDataProperty( + cx, global, cx->names().undefined, UndefinedHandleValue, + JSPROP_PERMANENT | JSPROP_READONLY | JSPROP_RESOLVING)) { + return false; + } + + // Resolve a "globalThis" self-referential property if necessary. + bool resolved; + if (!GlobalObject::maybeResolveGlobalThis(cx, global, &resolved)) { + return false; + } + + for (size_t k = 0; k < JSProto_LIMIT; ++k) { + JSProtoKey key = static_cast<JSProtoKey>(k); + if (key != JSProto_Null && key != JSProto_BoundFunction && + !global->isStandardClassResolved(key)) { + if (!resolveConstructor(cx, global, static_cast<JSProtoKey>(k), + IfClassIsDisabled::DoNothing)) { + return false; + } + } + } + return true; +} + +/* static */ +JSFunction* GlobalObject::createConstructor(JSContext* cx, Native ctor, + JSAtom* nameArg, unsigned length, + gc::AllocKind kind, + const JSJitInfo* jitInfo) { + Rooted<JSAtom*> name(cx, nameArg); + JSFunction* fun = NewNativeConstructor(cx, ctor, length, name, kind); + if (!fun) { + return nullptr; + } + + if (jitInfo) { + fun->setJitInfo(jitInfo); + } + + return fun; +} + +static NativeObject* CreateBlankProto(JSContext* cx, const JSClass* clasp, + HandleObject proto) { + MOZ_ASSERT(!clasp->isJSFunction()); + + if (clasp == &PlainObject::class_) { + return NewPlainObjectWithProto(cx, proto, TenuredObject); + } + + return NewTenuredObjectWithGivenProto(cx, clasp, proto); +} + +/* static */ +NativeObject* GlobalObject::createBlankPrototype(JSContext* cx, + Handle<GlobalObject*> global, + const JSClass* clasp) { + RootedObject objectProto(cx, &global->getObjectPrototype()); + return CreateBlankProto(cx, clasp, objectProto); +} + +/* static */ +NativeObject* GlobalObject::createBlankPrototypeInheriting(JSContext* cx, + const JSClass* clasp, + HandleObject proto) { + return CreateBlankProto(cx, clasp, proto); +} + +bool js::LinkConstructorAndPrototype(JSContext* cx, JSObject* ctor_, + JSObject* proto_, unsigned prototypeAttrs, + unsigned constructorAttrs) { + RootedObject ctor(cx, ctor_), proto(cx, proto_); + + RootedValue protoVal(cx, ObjectValue(*proto)); + RootedValue ctorVal(cx, ObjectValue(*ctor)); + + return DefineDataProperty(cx, ctor, cx->names().prototype, protoVal, + prototypeAttrs) && + DefineDataProperty(cx, proto, cx->names().constructor, ctorVal, + constructorAttrs); +} + +bool js::DefinePropertiesAndFunctions(JSContext* cx, HandleObject obj, + const JSPropertySpec* ps, + const JSFunctionSpec* fs) { + if (ps && !JS_DefineProperties(cx, obj, ps)) { + return false; + } + if (fs && !JS_DefineFunctions(cx, obj, fs)) { + return false; + } + return true; +} + +bool js::DefineToStringTag(JSContext* cx, HandleObject obj, JSAtom* tag) { + RootedId toStringTagId( + cx, PropertyKey::Symbol(cx->wellKnownSymbols().toStringTag)); + RootedValue tagString(cx, StringValue(tag)); + return DefineDataProperty(cx, obj, toStringTagId, tagString, JSPROP_READONLY); +} + +/* static */ +NativeObject* GlobalObject::getOrCreateForOfPICObject( + JSContext* cx, Handle<GlobalObject*> global) { + cx->check(global); + NativeObject* forOfPIC = global->getForOfPICObject(); + if (forOfPIC) { + return forOfPIC; + } + + forOfPIC = ForOfPIC::createForOfPICObject(cx, global); + if (!forOfPIC) { + return nullptr; + } + global->data().forOfPICChain.init(forOfPIC); + return forOfPIC; +} + +/* static */ +JSObject* GlobalObject::getOrCreateRealmKeyObject( + JSContext* cx, Handle<GlobalObject*> global) { + cx->check(global); + if (PlainObject* key = global->data().realmKeyObject) { + return key; + } + + PlainObject* key = NewPlainObject(cx); + if (!key) { + return nullptr; + } + + global->data().realmKeyObject.init(key); + return key; +} + +/* static */ +RegExpStatics* GlobalObject::getRegExpStatics(JSContext* cx, + Handle<GlobalObject*> global) { + MOZ_ASSERT(cx); + + if (!global->data().regExpStatics) { + auto statics = RegExpStatics::create(cx); + if (!statics) { + return nullptr; + } + global->data().regExpStatics = std::move(statics); + } + + return global->data().regExpStatics.get(); +} + +gc::FinalizationRegistryGlobalData* +GlobalObject::getOrCreateFinalizationRegistryData() { + if (!data().finalizationRegistryData) { + data().finalizationRegistryData = + MakeUnique<gc::FinalizationRegistryGlobalData>(zone()); + } + + return maybeFinalizationRegistryData(); +} + +bool GlobalObject::addToVarNames(JSContext* cx, JS::Handle<JSAtom*> name) { + MOZ_ASSERT(name); + + if (!data().varNames.put(name)) { + ReportOutOfMemory(cx); + return false; + } + + return true; +} + +/* static */ +bool GlobalObject::createIntrinsicsHolder(JSContext* cx, + Handle<GlobalObject*> global) { + Rooted<NativeObject*> intrinsicsHolder( + cx, NewPlainObjectWithProto(cx, nullptr, TenuredObject)); + if (!intrinsicsHolder) { + return false; + } + + // Install the intrinsics holder on the global. + global->data().intrinsicsHolder.init(intrinsicsHolder); + return true; +} + +/* static */ +bool GlobalObject::getSelfHostedFunction(JSContext* cx, + Handle<GlobalObject*> global, + Handle<PropertyName*> selfHostedName, + Handle<JSAtom*> name, unsigned nargs, + MutableHandleValue funVal) { + if (global->maybeGetIntrinsicValue(selfHostedName, funVal.address(), cx)) { + RootedFunction fun(cx, &funVal.toObject().as<JSFunction>()); + if (fun->explicitName() == name) { + return true; + } + + if (fun->explicitName() == selfHostedName) { + // This function was initially cloned because it was called by + // other self-hosted code, so the clone kept its self-hosted name, + // instead of getting the name it's intended to have in content + // compartments. This can happen when a lazy builtin is initialized + // after self-hosted code for another builtin used the same + // function. In that case, we need to change the function's name, + // which is ok because it can't have been exposed to content + // before. + fun->setAtom(name); + return true; + } + + // The function might be installed multiple times on the same or + // different builtins, under different property names, so its name + // might be neither "selfHostedName" nor "name". In that case, its + // canonical name must've been set using the `_SetCanonicalName` + // intrinsic. + cx->runtime()->assertSelfHostedFunctionHasCanonicalName(selfHostedName); + return true; + } + + JSRuntime* runtime = cx->runtime(); + frontend::ScriptIndex index = + runtime->getSelfHostedScriptIndexRange(selfHostedName)->start; + JSFunction* fun = + runtime->selfHostStencil().instantiateSelfHostedLazyFunction( + cx, runtime->selfHostStencilInput().atomCache, index, name); + if (!fun) { + return false; + } + MOZ_ASSERT(fun->nargs() == nargs); + funVal.setObject(*fun); + + return GlobalObject::addIntrinsicValue(cx, global, selfHostedName, funVal); +} + +/* static */ +bool GlobalObject::getIntrinsicValueSlow(JSContext* cx, + Handle<GlobalObject*> global, + Handle<PropertyName*> name, + MutableHandleValue value) { + // If this is a C++ intrinsic, simply define the function on the intrinsics + // holder. + if (const JSFunctionSpec* spec = js::FindIntrinsicSpec(name)) { + RootedId id(cx, NameToId(name)); + RootedFunction fun(cx, JS::NewFunctionFromSpec(cx, spec, id)); + if (!fun) { + return false; + } + fun->setIsIntrinsic(); + + value.setObject(*fun); + return GlobalObject::addIntrinsicValue(cx, global, name, value); + } + + if (!cx->runtime()->getSelfHostedValue(cx, name, value)) { + return false; + } + + // It's possible in certain edge cases that cloning the value ended up + // defining the intrinsic. For instance, cloning can call NewArray, which + // resolves Array.prototype, which defines some self-hosted functions. If this + // happens we use the value already defined on the intrinsics holder. + if (global->maybeGetIntrinsicValue(name, value.address(), cx)) { + return true; + } + + return GlobalObject::addIntrinsicValue(cx, global, name, value); +} + +/* static */ +bool GlobalObject::addIntrinsicValue(JSContext* cx, + Handle<GlobalObject*> global, + Handle<PropertyName*> name, + HandleValue value) { + Rooted<NativeObject*> holder(cx, &global->getIntrinsicsHolder()); + + RootedId id(cx, NameToId(name)); + MOZ_ASSERT(!holder->containsPure(id)); + + constexpr PropertyFlags propFlags = {PropertyFlag::Configurable, + PropertyFlag::Writable}; + uint32_t slot; + if (!NativeObject::addProperty(cx, holder, id, propFlags, &slot)) { + return false; + } + holder->initSlot(slot, value); + return true; +} + +/* static */ +JSObject* GlobalObject::createIteratorPrototype(JSContext* cx, + Handle<GlobalObject*> global) { + if (!cx->realm()->creationOptions().getIteratorHelpersEnabled()) { + return getOrCreateBuiltinProto(cx, global, ProtoKind::IteratorProto, + initIteratorProto); + } + + if (!ensureConstructor(cx, global, JSProto_Iterator)) { + return nullptr; + } + JSObject* proto = &global->getPrototype(JSProto_Iterator); + global->initBuiltinProto(ProtoKind::IteratorProto, proto); + return proto; +} + +/* static */ +JSObject* GlobalObject::createAsyncIteratorPrototype( + JSContext* cx, Handle<GlobalObject*> global) { + if (!cx->realm()->creationOptions().getIteratorHelpersEnabled()) { + return getOrCreateBuiltinProto(cx, global, ProtoKind::AsyncIteratorProto, + initAsyncIteratorProto); + } + + if (!ensureConstructor(cx, global, JSProto_AsyncIterator)) { + return nullptr; + } + JSObject* proto = &global->getPrototype(JSProto_AsyncIterator); + global->initBuiltinProto(ProtoKind::AsyncIteratorProto, proto); + return proto; +} + +void GlobalObject::releaseData(JS::GCContext* gcx) { + GlobalObjectData* data = maybeData(); + setReservedSlot(GLOBAL_DATA_SLOT, PrivateValue(nullptr)); + gcx->delete_(this, data, MemoryUse::GlobalObjectData); +} + +GlobalObjectData::GlobalObjectData(Zone* zone) : varNames(zone) {} + +GlobalObjectData::~GlobalObjectData() = default; + +void GlobalObjectData::trace(JSTracer* trc, GlobalObject* global) { + // Atoms are always tenured so don't need to be traced during minor GC. + if (trc->runtime()->heapState() != JS::HeapState::MinorCollecting) { + varNames.trace(trc); + } + + for (auto& ctorWithProto : builtinConstructors) { + TraceNullableEdge(trc, &ctorWithProto.constructor, "global-builtin-ctor"); + TraceNullableEdge(trc, &ctorWithProto.prototype, + "global-builtin-ctor-proto"); + } + + for (auto& proto : builtinProtos) { + TraceNullableEdge(trc, &proto, "global-builtin-proto"); + } + + TraceNullableEdge(trc, &emptyGlobalScope, "global-empty-scope"); + + TraceNullableEdge(trc, &lexicalEnvironment, "global-lexical-env"); + TraceNullableEdge(trc, &windowProxy, "global-window-proxy"); + TraceNullableEdge(trc, &intrinsicsHolder, "global-intrinsics-holder"); + TraceNullableEdge(trc, &computedIntrinsicsHolder, + "global-computed-intrinsics-holder"); + TraceNullableEdge(trc, &forOfPICChain, "global-for-of-pic"); + TraceNullableEdge(trc, &sourceURLsHolder, "global-source-urls"); + TraceNullableEdge(trc, &realmKeyObject, "global-realm-key"); + TraceNullableEdge(trc, &throwTypeError, "global-throw-type-error"); + TraceNullableEdge(trc, &eval, "global-eval"); + TraceNullableEdge(trc, &emptyIterator, "global-empty-iterator"); + + TraceNullableEdge(trc, &arrayShapeWithDefaultProto, "global-array-shape"); + + for (auto& shape : plainObjectShapesWithDefaultProto) { + TraceNullableEdge(trc, &shape, "global-plain-shape"); + } + + TraceNullableEdge(trc, &functionShapeWithDefaultProto, + "global-function-shape"); + TraceNullableEdge(trc, &extendedFunctionShapeWithDefaultProto, + "global-ext-function-shape"); + + TraceNullableEdge(trc, &boundFunctionShapeWithDefaultProto, + "global-bound-function-shape"); + + if (regExpStatics) { + regExpStatics->trace(trc); + } + + TraceNullableEdge(trc, &mappedArgumentsTemplate, "mapped-arguments-template"); + TraceNullableEdge(trc, &unmappedArgumentsTemplate, + "unmapped-arguments-template"); + + TraceNullableEdge(trc, &iterResultTemplate, "iter-result-template_"); + TraceNullableEdge(trc, &iterResultWithoutPrototypeTemplate, + "iter-result-without-prototype-template"); + + TraceNullableEdge(trc, &selfHostingScriptSource, + "self-hosting-script-source"); + + if (finalizationRegistryData) { + finalizationRegistryData->trace(trc); + } +} + +void GlobalObjectData::addSizeOfIncludingThis( + mozilla::MallocSizeOf mallocSizeOf, JS::ClassInfo* info) const { + info->objectsMallocHeapGlobalData += mallocSizeOf(this); + + if (regExpStatics) { + info->objectsMallocHeapGlobalData += + regExpStatics->sizeOfIncludingThis(mallocSizeOf); + } + + info->objectsMallocHeapGlobalVarNamesSet += + varNames.shallowSizeOfExcludingThis(mallocSizeOf); +} |