/* -*- 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/. */ #ifndef jsobj_h #define jsobj_h /* * JS object definitions. * * A JS object consists of a possibly-shared object descriptor containing * ordered property names, called the map; and a dense vector of property * values, called slots. The map/slot pointer pair is GC'ed, while the map * is reference counted and the slot vector is malloc'ed. */ #include "mozilla/MemoryReporting.h" #include "gc/Barrier.h" #include "gc/Marking.h" #include "js/Conversions.h" #include "js/GCAPI.h" #include "js/GCVector.h" #include "js/HeapAPI.h" #include "vm/Shape.h" #include "vm/String.h" #include "vm/Xdr.h" namespace JS { struct ClassInfo; } // namespace JS namespace js { using PropertyDescriptorVector = JS::GCVector; class GCMarker; class Nursery; namespace gc { class RelocationOverlay; } // namespace gc inline JSObject* CastAsObject(GetterOp op) { return JS_FUNC_TO_DATA_PTR(JSObject*, op); } inline JSObject* CastAsObject(SetterOp op) { return JS_FUNC_TO_DATA_PTR(JSObject*, op); } inline Value CastAsObjectJsval(GetterOp op) { return ObjectOrNullValue(CastAsObject(op)); } inline Value CastAsObjectJsval(SetterOp op) { return ObjectOrNullValue(CastAsObject(op)); } /******************************************************************************/ extern const Class IntlClass; extern const Class JSONClass; extern const Class MathClass; class GlobalObject; class NewObjectCache; enum class IntegrityLevel { Sealed, Frozen }; // Forward declarations, required for later friend declarations. bool PreventExtensions(JSContext* cx, JS::HandleObject obj, JS::ObjectOpResult& result, IntegrityLevel level = IntegrityLevel::Sealed); bool SetImmutablePrototype(js::ExclusiveContext* cx, JS::HandleObject obj, bool* succeeded); } /* namespace js */ /* * A JavaScript object. The members common to all objects are as follows: * * - The |group_| member stores the group of the object, which contains its * prototype object, its class and the possible types of its properties. * * Subclasses of JSObject --- mainly NativeObject and JSFunction --- add more * members. Notable among these is the object's shape, which stores flags and * some other state, and, for native objects, the layout of all its properties. * The second word of a JSObject generally stores its shape; if the second word * stores anything else, the value stored cannot be a valid Shape* pointer, so * that shape guards can be performed on objects without regard to the specific * layout in use. */ class JSObject : public js::gc::Cell { protected: js::GCPtrObjectGroup group_; private: friend class js::Shape; friend class js::GCMarker; friend class js::NewObjectCache; friend class js::Nursery; friend class js::gc::RelocationOverlay; friend bool js::PreventExtensions(JSContext* cx, JS::HandleObject obj, JS::ObjectOpResult& result, js::IntegrityLevel level); friend bool js::SetImmutablePrototype(js::ExclusiveContext* cx, JS::HandleObject obj, bool* succeeded); // Make a new group to use for a singleton object. static js::ObjectGroup* makeLazyGroup(JSContext* cx, js::HandleObject obj); public: bool isNative() const { return getClass()->isNative(); } const js::Class* getClass() const { return group_->clasp(); } const JSClass* getJSClass() const { return Jsvalify(getClass()); } bool hasClass(const js::Class* c) const { return getClass() == c; } js::LookupPropertyOp getOpsLookupProperty() const { return getClass()->getOpsLookupProperty(); } js::DefinePropertyOp getOpsDefineProperty() const { return getClass()->getOpsDefineProperty(); } js::HasPropertyOp getOpsHasProperty() const { return getClass()->getOpsHasProperty(); } js::GetPropertyOp getOpsGetProperty() const { return getClass()->getOpsGetProperty(); } js::SetPropertyOp getOpsSetProperty() const { return getClass()->getOpsSetProperty(); } js::GetOwnPropertyOp getOpsGetOwnPropertyDescriptor() const { return getClass()->getOpsGetOwnPropertyDescriptor(); } js::DeletePropertyOp getOpsDeleteProperty() const { return getClass()->getOpsDeleteProperty(); } js::GetElementsOp getOpsGetElements() const { return getClass()->getOpsGetElements(); } JSNewEnumerateOp getOpsEnumerate() const { return getClass()->getOpsEnumerate(); } JSFunToStringOp getOpsFunToString() const { return getClass()->getOpsFunToString(); } js::ObjectGroup* group() const { MOZ_ASSERT(!hasLazyGroup()); return groupRaw(); } js::ObjectGroup* groupRaw() const { return group_; } /* * Whether this is the only object which has its specified group. This * object will have its group constructed lazily as needed by analysis. */ bool isSingleton() const { return group_->singleton(); } /* * Whether the object's group has not been constructed yet. If an object * might have a lazy group, use getGroup() below, otherwise group(). */ bool hasLazyGroup() const { return group_->lazy(); } JSCompartment* compartment() const { return group_->compartment(); } JSCompartment* maybeCompartment() const { return compartment(); } inline js::Shape* maybeShape() const; inline js::Shape* ensureShape(js::ExclusiveContext* cx); /* * Make a non-array object with the specified initial state. This method * takes ownership of any extantSlots it is passed. */ static inline JSObject* create(js::ExclusiveContext* cx, js::gc::AllocKind kind, js::gc::InitialHeap heap, js::HandleShape shape, js::HandleObjectGroup group); // Set the initial slots and elements of an object. These pointers are only // valid for native objects, but during initialization are set for all // objects. For non-native objects, these must not be dynamically allocated // pointers which leak when the non-native object finishes initialization. inline void setInitialSlotsMaybeNonNative(js::HeapSlot* slots); inline void setInitialElementsMaybeNonNative(js::HeapSlot* elements); enum GenerateShape { GENERATE_NONE, GENERATE_SHAPE }; static bool setFlags(js::ExclusiveContext* cx, JS::HandleObject obj, js::BaseShape::Flag flags, GenerateShape generateShape = GENERATE_NONE); inline bool hasAllFlags(js::BaseShape::Flag flags) const; /* * An object is a delegate if it is on another object's prototype or scope * chain, and therefore the delegate might be asked implicitly to get or * set a property on behalf of another object. Delegates may be accessed * directly too, as may any object, but only those objects linked after the * head of any prototype or scope chain are flagged as delegates. This * definition helps to optimize shape-based property cache invalidation * (see Purge{Scope,Proto}Chain in jsobj.cpp). */ inline bool isDelegate() const; static bool setDelegate(js::ExclusiveContext* cx, JS::HandleObject obj) { return setFlags(cx, obj, js::BaseShape::DELEGATE, GENERATE_SHAPE); } inline bool isBoundFunction() const; inline bool hasSpecialEquality() const; // A "qualified" varobj is the object on which "qualified" variable // declarations (i.e., those defined with "var") are kept. // // Conceptually, when a var binding is defined, it is defined on the // innermost qualified varobj on the scope chain. // // Function scopes (CallObjects) are qualified varobjs, and there can be // no other qualified varobj that is more inner for var bindings in that // function. As such, all references to local var bindings in a function // may be statically bound to the function scope. This is subject to // further optimization. Unaliased bindings inside functions reside // entirely on the frame, not in CallObjects. // // Global scopes are also qualified varobjs. It is possible to statically // know, for a given script, that are no more inner qualified varobjs, so // free variable references can be statically bound to the global. // // Finally, there are non-syntactic qualified varobjs used by embedders // (e.g., Gecko and XPConnect), as they often wish to run scripts under a // scope that captures var bindings. inline bool isQualifiedVarObj() const; static bool setQualifiedVarObj(js::ExclusiveContext* cx, JS::HandleObject obj) { return setFlags(cx, obj, js::BaseShape::QUALIFIED_VAROBJ); } // An "unqualified" varobj is the object on which "unqualified" // assignments (i.e., bareword assignments for which the LHS does not // exist on the scope chain) are kept. inline bool isUnqualifiedVarObj() const; // Objects with an uncacheable proto can have their prototype mutated // without inducing a shape change on the object. JIT inline caches should // do an explicit group guard to guard against this. Singletons always // generate a new shape when their prototype changes, regardless of this // hasUncacheableProto flag. inline bool hasUncacheableProto() const; static bool setUncacheableProto(js::ExclusiveContext* cx, JS::HandleObject obj) { MOZ_ASSERT(obj->hasStaticPrototype(), "uncacheability as a concept is only applicable to static " "(not dynamically-computed) prototypes"); return setFlags(cx, obj, js::BaseShape::UNCACHEABLE_PROTO, GENERATE_SHAPE); } /* * Whether SETLELEM was used to access this object. See also the comment near * PropertyTree::MAX_HEIGHT. */ inline bool hadElementsAccess() const; static bool setHadElementsAccess(js::ExclusiveContext* cx, JS::HandleObject obj) { return setFlags(cx, obj, js::BaseShape::HAD_ELEMENTS_ACCESS); } /* * Whether there may be indexed properties on this object, excluding any in * the object's elements. */ inline bool isIndexed() const; /* * If this object was instantiated with `new Ctor`, return the constructor's * display atom. Otherwise, return nullptr. */ static bool constructorDisplayAtom(JSContext* cx, js::HandleObject obj, js::MutableHandleAtom name); /* * The same as constructorDisplayAtom above, however if this object has a * lazy group, nullptr is returned. This allows for use in situations that * cannot GC and where having some information, even if it is inconsistently * available, is better than no information. */ JSAtom* maybeConstructorDisplayAtom() const; /* GC support. */ void traceChildren(JSTracer* trc); void fixupAfterMovingGC(); static const JS::TraceKind TraceKind = JS::TraceKind::Object; static const size_t MaxTagBits = 3; static bool isNullLike(const JSObject* obj) { return uintptr_t(obj) < (1 << MaxTagBits); } MOZ_ALWAYS_INLINE JS::Zone* zone() const { return group_->zone(); } MOZ_ALWAYS_INLINE JS::shadow::Zone* shadowZone() const { return JS::shadow::Zone::asShadowZone(zone()); } MOZ_ALWAYS_INLINE JS::Zone* zoneFromAnyThread() const { return group_->zoneFromAnyThread(); } MOZ_ALWAYS_INLINE JS::shadow::Zone* shadowZoneFromAnyThread() const { return JS::shadow::Zone::asShadowZone(zoneFromAnyThread()); } static MOZ_ALWAYS_INLINE void readBarrier(JSObject* obj); static MOZ_ALWAYS_INLINE void writeBarrierPre(JSObject* obj); static MOZ_ALWAYS_INLINE void writeBarrierPost(void* cellp, JSObject* prev, JSObject* next); /* Return the allocKind we would use if we were to tenure this object. */ js::gc::AllocKind allocKindForTenure(const js::Nursery& nursery) const; size_t tenuredSizeOfThis() const { MOZ_ASSERT(isTenured()); return js::gc::Arena::thingSize(asTenured().getAllocKind()); } void addSizeOfExcludingThis(mozilla::MallocSizeOf mallocSizeOf, JS::ClassInfo* info); // We can only use addSizeOfExcludingThis on tenured objects: it assumes it // can apply mallocSizeOf to bits and pieces of the object, whereas objects // in the nursery may have those bits and pieces allocated in the nursery // along with them, and are not each their own malloc blocks. size_t sizeOfIncludingThisInNursery() const; // Marks this object as having a singleton group, and leave the group lazy. // Constructs a new, unique shape for the object. This should only be // called for an object that was just created. static inline bool setSingleton(js::ExclusiveContext* cx, js::HandleObject obj); // Change an existing object to have a singleton group. static bool changeToSingleton(JSContext* cx, js::HandleObject obj); static inline js::ObjectGroup* getGroup(JSContext* cx, js::HandleObject obj); const js::GCPtrObjectGroup& groupFromGC() const { /* Direct field access for use by GC. */ return group_; } /* * We permit proxies to dynamically compute their prototype if desired. * (Not all proxies will so desire: in particular, most DOM proxies can * track their prototype with a single, nullable JSObject*.) If a proxy * so desires, we store (JSObject*)0x1 in the proto field of the object's * group. * * We offer three ways to get an object's prototype: * * 1. obj->staticPrototype() returns the prototype, but it asserts if obj * is a proxy, and the proxy has opted to dynamically compute its * prototype using a getPrototype() handler. * 2. obj->taggedProto() returns a TaggedProto, which can be tested to * check if the proto is an object, nullptr, or lazily computed. * 3. js::GetPrototype(cx, obj, &proto) computes the proto of an object. * If obj is a proxy with dynamically-computed prototype, this code may * perform arbitrary behavior (allocation, GC, run JS) while computing * the proto. */ js::TaggedProto taggedProto() const { return group_->proto(); } bool hasTenuredProto() const; bool uninlinedIsProxy() const; JSObject* staticPrototype() const { MOZ_ASSERT(hasStaticPrototype()); return taggedProto().toObjectOrNull(); } // Normal objects and a subset of proxies have an uninteresting, static // (albeit perhaps mutable) [[Prototype]]. For such objects the // [[Prototype]] is just a value returned when needed for accesses, or // modified in response to requests. These objects store the // [[Prototype]] directly within |obj->group_|. bool hasStaticPrototype() const { return !hasDynamicPrototype(); } // The remaining proxies have a [[Prototype]] requiring dynamic computation // for every access, going through the proxy handler {get,set}Prototype and // setImmutablePrototype methods. (Wrappers particularly use this to keep // the wrapper/wrappee [[Prototype]]s consistent.) bool hasDynamicPrototype() const { bool dynamic = taggedProto().isDynamic(); MOZ_ASSERT_IF(dynamic, uninlinedIsProxy()); MOZ_ASSERT_IF(dynamic, !isNative()); return dynamic; } // True iff this object's [[Prototype]] is immutable. Must be called only // on objects with a static [[Prototype]]! inline bool staticPrototypeIsImmutable() const; inline void setGroup(js::ObjectGroup* group); /* * Mark an object that has been iterated over and is a singleton. We need * to recover this information in the object's type information after it * is purged on GC. */ inline bool isIteratedSingleton() const; static bool setIteratedSingleton(js::ExclusiveContext* cx, JS::HandleObject obj) { return setFlags(cx, obj, js::BaseShape::ITERATED_SINGLETON); } /* * Mark an object as requiring its default 'new' type to have unknown * properties. */ inline bool isNewGroupUnknown() const; static bool setNewGroupUnknown(JSContext* cx, const js::Class* clasp, JS::HandleObject obj); // Mark an object as having its 'new' script information cleared. inline bool wasNewScriptCleared() const; static bool setNewScriptCleared(js::ExclusiveContext* cx, JS::HandleObject obj) { return setFlags(cx, obj, js::BaseShape::NEW_SCRIPT_CLEARED); } /* Set a new prototype for an object with a singleton type. */ static bool splicePrototype(JSContext* cx, js::HandleObject obj, const js::Class* clasp, js::Handle proto); /* * For bootstrapping, whether to splice a prototype for Function.prototype * or the global object. */ bool shouldSplicePrototype(); /* * Environment chains. * * The environment chain of an object is the link in the search path when * a script does a name lookup on an environment object. For JS internal * environment objects --- Call, LexicalEnvironment, and WithEnvironment * --- the chain is stored in the first fixed slot of the object. For * other environment objects, the chain goes directly to the global. * * In code which is not marked hasNonSyntacticScope, environment chains * can contain only syntactic environment objects (see * IsSyntacticEnvironment) with a global object at the root as the * environment of the outermost non-function script. In * hasNonSyntacticScope code, the environment of the outermost * non-function script might not be a global object, and can have a mix of * other objects above it before the global object is reached. */ /* * Get the enclosing environment of an object. When called on a * non-EnvironmentObject, this will just be the global (the name * "enclosing environment" still applies in this situation because * non-EnvironmentObjects can be on the environment chain). */ inline JSObject* enclosingEnvironment() const; inline js::GlobalObject& global() const; // In some rare cases the global object's compartment's global may not be // the same global object. For this reason, we need to take extra care when // tracing. // // These cases are: // 1) The off-thread parsing task uses a dummy global since it cannot // share with the actual global being used concurrently on the main // thread. // 2) A GC may occur when creating the GlobalObject, in which case the // compartment global pointer may not yet be set. In this case there is // nothing interesting to trace in the compartment. inline bool isOwnGlobal(JSTracer*) const; inline js::GlobalObject* globalForTracing(JSTracer*) const; /* * ES5 meta-object properties and operations. */ public: // Indicates whether a non-proxy is extensible. Don't call on proxies! // This method really shouldn't exist -- but there are a few internal // places that want it (JITs and the like), and it'd be a pain to mark them // all as friends. inline bool nonProxyIsExtensible() const; public: /* * Iterator-specific getters and setters. */ static const uint32_t ITER_CLASS_NFIXED_SLOTS = 1; /* * Back to generic stuff. */ bool isCallable() const; bool isConstructor() const; JSNative callHook() const; JSNative constructHook() const; MOZ_ALWAYS_INLINE void finalize(js::FreeOp* fop); public: static bool reportReadOnly(JSContext* cx, jsid id, unsigned report = JSREPORT_ERROR); static bool reportNotConfigurable(JSContext* cx, jsid id, unsigned report = JSREPORT_ERROR); static bool reportNotExtensible(JSContext* cx, js::HandleObject obj, unsigned report = JSREPORT_ERROR); static bool nonNativeSetProperty(JSContext* cx, js::HandleObject obj, js::HandleId id, js::HandleValue v, js::HandleValue receiver, JS::ObjectOpResult& result); static bool nonNativeSetElement(JSContext* cx, js::HandleObject obj, uint32_t index, js::HandleValue v, js::HandleValue receiver, JS::ObjectOpResult& result); static bool swap(JSContext* cx, JS::HandleObject a, JS::HandleObject b); private: void fixDictionaryShapeAfterSwap(); public: inline void initArrayClass(); /* * In addition to the generic object interface provided by JSObject, * specific types of objects may provide additional operations. To access, * these addition operations, callers should use the pattern: * * if (obj.is()) { * XObject& x = obj.as(); * x.foo(); * } * * These XObject classes form a hierarchy. For example, for a cloned block * object, the following predicates are true: is, * is and is. Each of these has a * respective class that derives and adds operations. * * A class XObject is defined in a vm/XObject{.h, .cpp, -inl.h} file * triplet (along with any class YObject that derives XObject). * * Note that X represents a low-level representation and does not query the * [[Class]] property of object defined by the spec (for this, see * js::GetBuiltinClass). */ template inline bool is() const { return getClass() == &T::class_; } template T& as() { MOZ_ASSERT(this->is()); return *static_cast(this); } template const T& as() const { MOZ_ASSERT(this->is()); return *static_cast(this); } #ifdef DEBUG void dump(FILE* fp) const; void dump() const; #endif /* JIT Accessors */ static size_t offsetOfGroup() { return offsetof(JSObject, group_); } // Maximum size in bytes of a JSObject. static const size_t MAX_BYTE_SIZE = 4 * sizeof(void*) + 16 * sizeof(JS::Value); private: JSObject() = delete; JSObject(const JSObject& other) = delete; void operator=(const JSObject& other) = delete; }; template MOZ_ALWAYS_INLINE JS::Handle js::RootedBase::as() const { const JS::Rooted& self = *static_cast*>(this); MOZ_ASSERT(self->is()); return Handle::fromMarkedLocation(reinterpret_cast(self.address())); } template MOZ_ALWAYS_INLINE JS::Handle js::HandleBase::as() const { const JS::Handle& self = *static_cast*>(this); MOZ_ASSERT(self->is()); return Handle::fromMarkedLocation(reinterpret_cast(self.address())); } /* * The only sensible way to compare JSObject with == is by identity. We use * const& instead of * as a syntactic way to assert non-null. This leads to an * abundance of address-of operators to identity. Hence this overload. */ static MOZ_ALWAYS_INLINE bool operator==(const JSObject& lhs, const JSObject& rhs) { return &lhs == &rhs; } static MOZ_ALWAYS_INLINE bool operator!=(const JSObject& lhs, const JSObject& rhs) { return &lhs != &rhs; } // Size of the various GC thing allocation sizes used for objects. struct JSObject_Slots0 : JSObject { void* data[3]; }; struct JSObject_Slots2 : JSObject { void* data[3]; js::Value fslots[2]; }; struct JSObject_Slots4 : JSObject { void* data[3]; js::Value fslots[4]; }; struct JSObject_Slots8 : JSObject { void* data[3]; js::Value fslots[8]; }; struct JSObject_Slots12 : JSObject { void* data[3]; js::Value fslots[12]; }; struct JSObject_Slots16 : JSObject { void* data[3]; js::Value fslots[16]; }; /* static */ MOZ_ALWAYS_INLINE void JSObject::readBarrier(JSObject* obj) { MOZ_ASSERT_IF(obj, !isNullLike(obj)); if (obj && obj->isTenured()) obj->asTenured().readBarrier(&obj->asTenured()); } /* static */ MOZ_ALWAYS_INLINE void JSObject::writeBarrierPre(JSObject* obj) { MOZ_ASSERT_IF(obj, !isNullLike(obj)); if (obj && obj->isTenured()) obj->asTenured().writeBarrierPre(&obj->asTenured()); } /* static */ MOZ_ALWAYS_INLINE void JSObject::writeBarrierPost(void* cellp, JSObject* prev, JSObject* next) { MOZ_ASSERT(cellp); MOZ_ASSERT_IF(next, !IsNullTaggedPointer(next)); MOZ_ASSERT_IF(prev, !IsNullTaggedPointer(prev)); // If the target needs an entry, add it. js::gc::StoreBuffer* buffer; if (next && (buffer = next->storeBuffer())) { // If we know that the prev has already inserted an entry, we can skip // doing the lookup to add the new entry. Note that we cannot safely // assert the presence of the entry because it may have been added // via a different store buffer. if (prev && prev->storeBuffer()) return; buffer->putCell(static_cast(cellp)); return; } // Remove the prev entry if the new value does not need it. if (prev && (buffer = prev->storeBuffer())) buffer->unputCell(static_cast(cellp)); } namespace js { inline bool IsCallable(const Value& v) { return v.isObject() && v.toObject().isCallable(); } // ES6 rev 24 (2014 April 27) 7.2.5 IsConstructor inline bool IsConstructor(const Value& v) { return v.isObject() && v.toObject().isConstructor(); } } /* namespace js */ class JSValueArray { public: const js::Value* array; size_t length; JSValueArray(const js::Value* v, size_t c) : array(v), length(c) {} }; class ValueArray { public: js::Value* array; size_t length; ValueArray(js::Value* v, size_t c) : array(v), length(c) {} }; namespace js { /*** Standard internal methods ******************************************************************** * * The functions below are the fundamental operations on objects. See the * comment about "Standard internal methods" in jsapi.h. */ /* * ES6 [[GetPrototypeOf]]. Get obj's prototype, storing it in protop. * * If obj is definitely not a proxy, the infallible obj->getProto() can be used * instead. See the comment on JSObject::getTaggedProto(). */ inline bool GetPrototype(JSContext* cx, HandleObject obj, MutableHandleObject protop); /* * ES6 [[SetPrototypeOf]]. Change obj's prototype to proto. * * Returns false on error, success of operation in *result. For example, if * obj is not extensible, its prototype is fixed. js::SetPrototype will return * true, because no exception is thrown for this; but *result will be false. */ extern bool SetPrototype(JSContext* cx, HandleObject obj, HandleObject proto, ObjectOpResult& result); /* Convenience function: like the above, but throw on failure. */ extern bool SetPrototype(JSContext* cx, HandleObject obj, HandleObject proto); /* * ES6 [[IsExtensible]]. Extensible objects can have new properties defined on * them. Inextensible objects can't, and their [[Prototype]] slot is fixed as * well. */ inline bool IsExtensible(ExclusiveContext* cx, HandleObject obj, bool* extensible); /* * ES6 [[PreventExtensions]]. Attempt to change the [[Extensible]] bit on |obj| * to false. Indicate success or failure through the |result| outparam, or * actual error through the return value. * * The `level` argument is SM-specific. `obj` should have an integrity level of * at least `level`. */ extern bool PreventExtensions(JSContext* cx, HandleObject obj, ObjectOpResult& result, IntegrityLevel level); /* Convenience function. As above, but throw on failure. */ extern bool PreventExtensions(JSContext* cx, HandleObject obj, IntegrityLevel level = IntegrityLevel::Sealed); /* * ES6 [[GetOwnProperty]]. Get a description of one of obj's own properties. * * If no such property exists on obj, return true with desc.object() set to * null. */ extern bool GetOwnPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id, MutableHandle desc); /* ES6 [[DefineOwnProperty]]. Define a property on obj. */ extern bool DefineProperty(JSContext* cx, HandleObject obj, HandleId id, Handle desc, ObjectOpResult& result); extern bool DefineProperty(ExclusiveContext* cx, HandleObject obj, HandleId id, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs, ObjectOpResult& result); extern bool DefineProperty(ExclusiveContext* cx, HandleObject obj, PropertyName* name, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs, ObjectOpResult& result); extern bool DefineElement(ExclusiveContext* cx, HandleObject obj, uint32_t index, HandleValue value, JSGetterOp getter, JSSetterOp setter, unsigned attrs, ObjectOpResult& result); /* * When the 'result' out-param is omitted, the behavior is the same as above, except * that any failure results in a TypeError. */ extern bool DefineProperty(JSContext* cx, HandleObject obj, HandleId id, Handle desc); extern bool DefineProperty(ExclusiveContext* cx, HandleObject obj, HandleId id, HandleValue value, JSGetterOp getter = nullptr, JSSetterOp setter = nullptr, unsigned attrs = JSPROP_ENUMERATE); extern bool DefineProperty(ExclusiveContext* cx, HandleObject obj, PropertyName* name, HandleValue value, JSGetterOp getter = nullptr, JSSetterOp setter = nullptr, unsigned attrs = JSPROP_ENUMERATE); extern bool DefineElement(ExclusiveContext* cx, HandleObject obj, uint32_t index, HandleValue value, JSGetterOp getter = nullptr, JSSetterOp setter = nullptr, unsigned attrs = JSPROP_ENUMERATE); /* * ES6 [[Has]]. Set *foundp to true if `id in obj` (that is, if obj has an own * or inherited property obj[id]), false otherwise. */ inline bool HasProperty(JSContext* cx, HandleObject obj, HandleId id, bool* foundp); inline bool HasProperty(JSContext* cx, HandleObject obj, PropertyName* name, bool* foundp); /* * ES6 [[Get]]. Get the value of the property `obj[id]`, or undefined if no * such property exists. * * Typically obj == receiver; if obj != receiver then the caller is most likely * a proxy using GetProperty to finish a property get that started out as * `receiver[id]`, and we've already searched the prototype chain up to `obj`. */ inline bool GetProperty(JSContext* cx, HandleObject obj, HandleValue receiver, HandleId id, MutableHandleValue vp); inline bool GetProperty(JSContext* cx, HandleObject obj, HandleValue receiver, PropertyName* name, MutableHandleValue vp) { RootedId id(cx, NameToId(name)); return GetProperty(cx, obj, receiver, id, vp); } inline bool GetProperty(JSContext* cx, HandleObject obj, HandleObject receiver, HandleId id, MutableHandleValue vp) { RootedValue receiverValue(cx, ObjectValue(*receiver)); return GetProperty(cx, obj, receiverValue, id, vp); } inline bool GetProperty(JSContext* cx, HandleObject obj, HandleObject receiver, PropertyName* name, MutableHandleValue vp) { RootedValue receiverValue(cx, ObjectValue(*receiver)); return GetProperty(cx, obj, receiverValue, name, vp); } inline bool GetElement(JSContext* cx, HandleObject obj, HandleValue receiver, uint32_t index, MutableHandleValue vp); inline bool GetElement(JSContext* cx, HandleObject obj, HandleObject receiver, uint32_t index, MutableHandleValue vp); inline bool GetPropertyNoGC(JSContext* cx, JSObject* obj, const Value& receiver, jsid id, Value* vp); inline bool GetPropertyNoGC(JSContext* cx, JSObject* obj, JSObject* receiver, jsid id, Value* vp) { return GetPropertyNoGC(cx, obj, ObjectValue(*receiver), id, vp); } inline bool GetPropertyNoGC(JSContext* cx, JSObject* obj, const Value& receiver, PropertyName* name, Value* vp) { return GetPropertyNoGC(cx, obj, receiver, NameToId(name), vp); } inline bool GetPropertyNoGC(JSContext* cx, JSObject* obj, JSObject* receiver, PropertyName* name, Value* vp) { return GetPropertyNoGC(cx, obj, ObjectValue(*receiver), name, vp); } inline bool GetElementNoGC(JSContext* cx, JSObject* obj, const Value& receiver, uint32_t index, Value* vp); inline bool GetElementNoGC(JSContext* cx, JSObject* obj, JSObject* receiver, uint32_t index, Value* vp); /* * ES6 [[Set]]. Carry out the assignment `obj[id] = v`. * * The `receiver` argument has to do with how [[Set]] interacts with the * prototype chain and proxies. It's hard to explain and ES6 doesn't really * try. Long story short, if you just want bog-standard assignment, pass * `ObjectValue(*obj)` as receiver. Or better, use one of the signatures that * doesn't have a receiver parameter. * * Callers pass obj != receiver e.g. when a proxy is involved, obj is the * proxy's target, and the proxy is using SetProperty to finish an assignment * that started out as `receiver[id] = v`, by delegating it to obj. */ inline bool SetProperty(JSContext* cx, HandleObject obj, HandleId id, HandleValue v, HandleValue receiver, ObjectOpResult& result); inline bool SetProperty(JSContext* cx, HandleObject obj, HandleId id, HandleValue v) { RootedValue receiver(cx, ObjectValue(*obj)); ObjectOpResult result; return SetProperty(cx, obj, id, v, receiver, result) && result.checkStrict(cx, obj, id); } inline bool SetProperty(JSContext* cx, HandleObject obj, PropertyName* name, HandleValue v, HandleValue receiver, ObjectOpResult& result) { RootedId id(cx, NameToId(name)); return SetProperty(cx, obj, id, v, receiver, result); } inline bool SetProperty(JSContext* cx, HandleObject obj, PropertyName* name, HandleValue v) { RootedId id(cx, NameToId(name)); RootedValue receiver(cx, ObjectValue(*obj)); ObjectOpResult result; return SetProperty(cx, obj, id, v, receiver, result) && result.checkStrict(cx, obj, id); } inline bool SetElement(JSContext* cx, HandleObject obj, uint32_t index, HandleValue v, HandleValue receiver, ObjectOpResult& result); /* * ES6 draft rev 31 (15 Jan 2015) 7.3.3 Put (O, P, V, Throw), except that on * success, the spec says this is supposed to return a boolean value, which we * don't bother doing. */ inline bool PutProperty(JSContext* cx, HandleObject obj, HandleId id, HandleValue v, bool strict) { RootedValue receiver(cx, ObjectValue(*obj)); ObjectOpResult result; return SetProperty(cx, obj, id, v, receiver, result) && result.checkStrictErrorOrWarning(cx, obj, id, strict); } /* * ES6 [[Delete]]. Equivalent to the JS code `delete obj[id]`. */ inline bool DeleteProperty(JSContext* cx, HandleObject obj, HandleId id, ObjectOpResult& result); inline bool DeleteElement(JSContext* cx, HandleObject obj, uint32_t index, ObjectOpResult& result); /*** SpiderMonkey nonstandard internal methods ***************************************************/ /** * If |obj| (underneath any functionally-transparent wrapper proxies) has as * its [[GetPrototypeOf]] trap the ordinary [[GetPrototypeOf]] behavior defined * for ordinary objects, set |*isOrdinary = true| and store |obj|'s prototype * in |result|. Otherwise set |*isOrdinary = false|. In case of error, both * outparams have unspecified value. */ extern bool GetPrototypeIfOrdinary(JSContext* cx, HandleObject obj, bool* isOrdinary, MutableHandleObject protop); /* * Attempt to make |obj|'s [[Prototype]] immutable, such that subsequently * trying to change it will not work. If an internal error occurred, * returns false. Otherwise, |*succeeded| is set to true iff |obj|'s * [[Prototype]] is now immutable. */ extern bool SetImmutablePrototype(js::ExclusiveContext* cx, JS::HandleObject obj, bool* succeeded); extern bool GetPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id, MutableHandle desc); /* * Deprecated. A version of HasProperty that also returns the object on which * the property was found (but that information is unreliable for proxies), and * the Shape of the property, if native. */ extern bool LookupProperty(JSContext* cx, HandleObject obj, HandleId id, MutableHandleObject objp, MutableHandleShape propp); inline bool LookupProperty(JSContext* cx, HandleObject obj, PropertyName* name, MutableHandleObject objp, MutableHandleShape propp) { RootedId id(cx, NameToId(name)); return LookupProperty(cx, obj, id, objp, propp); } /* Set *result to tell whether obj has an own property with the given id. */ extern bool HasOwnProperty(JSContext* cx, HandleObject obj, HandleId id, bool* result); /** * This enum is used to select whether the defined functions should be marked as * builtin native instrinsics for self-hosted code. */ enum DefineAsIntrinsic { NotIntrinsic, AsIntrinsic }; extern bool DefineFunctions(JSContext* cx, HandleObject obj, const JSFunctionSpec* fs, DefineAsIntrinsic intrinsic); /* ES6 draft rev 36 (2015 March 17) 7.1.1 ToPrimitive(vp[, preferredType]) */ extern bool ToPrimitiveSlow(JSContext* cx, JSType hint, MutableHandleValue vp); inline bool ToPrimitive(JSContext* cx, MutableHandleValue vp) { if (vp.isPrimitive()) return true; return ToPrimitiveSlow(cx, JSTYPE_VOID, vp); } inline bool ToPrimitive(JSContext* cx, JSType preferredType, MutableHandleValue vp) { if (vp.isPrimitive()) return true; return ToPrimitiveSlow(cx, preferredType, vp); } /* * toString support. (This isn't called GetClassName because there's a macro in * with that name.) */ extern const char* GetObjectClassName(JSContext* cx, HandleObject obj); /* * Return an object that may be used as `this` in place of obj. For most * objects this just returns obj. * * Some JSObjects shouldn't be exposed directly to script. This includes (at * least) WithEnvironmentObjects and Window objects. However, since both of * those can be on scope chains, we sometimes would expose those as `this` if * we were not so vigilant about calling GetThisValue where appropriate. * * See comments at ComputeImplicitThis. */ Value GetThisValue(JSObject* obj); /* * */ typedef JSObject* (*ClassInitializerOp)(JSContext* cx, JS::HandleObject obj); /* Fast access to builtin constructors and prototypes. */ bool GetBuiltinConstructor(ExclusiveContext* cx, JSProtoKey key, MutableHandleObject objp); bool GetBuiltinPrototype(ExclusiveContext* cx, JSProtoKey key, MutableHandleObject objp); JSObject* GetBuiltinPrototypePure(GlobalObject* global, JSProtoKey protoKey); extern bool SetClassAndProto(JSContext* cx, HandleObject obj, const Class* clasp, Handle proto); extern bool IsStandardPrototype(JSObject* obj, JSProtoKey key); } /* namespace js */ /* * Select Object.prototype method names shared between jsapi.cpp and jsobj.cpp. */ extern const char js_watch_str[]; extern const char js_unwatch_str[]; extern const char js_hasOwnProperty_str[]; extern const char js_isPrototypeOf_str[]; extern const char js_propertyIsEnumerable_str[]; #ifdef JS_OLD_GETTER_SETTER_METHODS extern const char js_defineGetter_str[]; extern const char js_defineSetter_str[]; extern const char js_lookupGetter_str[]; extern const char js_lookupSetter_str[]; #endif namespace js { inline gc::InitialHeap GetInitialHeap(NewObjectKind newKind, const Class* clasp) { if (newKind == NurseryAllocatedProxy) { MOZ_ASSERT(clasp->isProxy()); MOZ_ASSERT(clasp->hasFinalize()); MOZ_ASSERT(!CanNurseryAllocateFinalizedClass(clasp)); return gc::DefaultHeap; } if (newKind != GenericObject) return gc::TenuredHeap; if (clasp->hasFinalize() && !CanNurseryAllocateFinalizedClass(clasp)) return gc::TenuredHeap; return gc::DefaultHeap; } bool NewObjectWithTaggedProtoIsCachable(ExclusiveContext* cxArg, Handle proto, NewObjectKind newKind, const Class* clasp); // ES6 9.1.15 GetPrototypeFromConstructor. extern bool GetPrototypeFromConstructor(JSContext* cx, js::HandleObject newTarget, js::MutableHandleObject proto); extern bool GetPrototypeFromCallableConstructor(JSContext* cx, const CallArgs& args, js::MutableHandleObject proto); // Specialized call for constructing |this| with a known function callee, // and a known prototype. extern JSObject* CreateThisForFunctionWithProto(JSContext* cx, js::HandleObject callee, HandleObject newTarget, HandleObject proto, NewObjectKind newKind = GenericObject); // Specialized call for constructing |this| with a known function callee. extern JSObject* CreateThisForFunction(JSContext* cx, js::HandleObject callee, js::HandleObject newTarget, NewObjectKind newKind); // Generic call for constructing |this|. extern JSObject* CreateThis(JSContext* cx, const js::Class* clasp, js::HandleObject callee); extern JSObject* CloneObject(JSContext* cx, HandleObject obj, Handle proto); extern JSObject* DeepCloneObjectLiteral(JSContext* cx, HandleObject obj, NewObjectKind newKind = GenericObject); inline JSGetterOp CastAsGetterOp(JSObject* object) { return JS_DATA_TO_FUNC_PTR(JSGetterOp, object); } inline JSSetterOp CastAsSetterOp(JSObject* object) { return JS_DATA_TO_FUNC_PTR(JSSetterOp, object); } /* ES6 draft rev 32 (2015 Feb 2) 6.2.4.5 ToPropertyDescriptor(Obj) */ bool ToPropertyDescriptor(JSContext* cx, HandleValue descval, bool checkAccessors, MutableHandle desc); /* * Throw a TypeError if desc.getterObject() or setterObject() is not * callable. This performs exactly the checks omitted by ToPropertyDescriptor * when checkAccessors is false. */ bool CheckPropertyDescriptorAccessors(JSContext* cx, Handle desc); void CompletePropertyDescriptor(MutableHandle desc); /* * Read property descriptors from props, as for Object.defineProperties. See * ES5 15.2.3.7 steps 3-5. */ extern bool ReadPropertyDescriptors(JSContext* cx, HandleObject props, bool checkAccessors, AutoIdVector* ids, MutableHandle descs); /* Read the name using a dynamic lookup on the scopeChain. */ extern bool LookupName(JSContext* cx, HandlePropertyName name, HandleObject scopeChain, MutableHandleObject objp, MutableHandleObject pobjp, MutableHandleShape propp); extern bool LookupNameNoGC(JSContext* cx, PropertyName* name, JSObject* scopeChain, JSObject** objp, JSObject** pobjp, Shape** propp); /* * Like LookupName except returns the global object if 'name' is not found in * any preceding scope. * * Additionally, pobjp and propp are not needed by callers so they are not * returned. */ extern bool LookupNameWithGlobalDefault(JSContext* cx, HandlePropertyName name, HandleObject scopeChain, MutableHandleObject objp); /* * Like LookupName except returns the unqualified var object if 'name' is not * found in any preceding scope. Normally the unqualified var object is the * global. If the value for the name in the looked-up scope is an * uninitialized lexical, an UninitializedLexicalObject is returned. * * Additionally, pobjp is not needed by callers so it is not returned. */ extern bool LookupNameUnqualified(JSContext* cx, HandlePropertyName name, HandleObject scopeChain, MutableHandleObject objp); } // namespace js namespace js { extern JSObject* FindVariableScope(JSContext* cx, JSFunction** funp); bool LookupPropertyPure(ExclusiveContext* cx, JSObject* obj, jsid id, JSObject** objp, Shape** propp); bool LookupOwnPropertyPure(ExclusiveContext* cx, JSObject* obj, jsid id, Shape** propp, bool* isTypedArrayOutOfRange = nullptr); bool GetPropertyPure(ExclusiveContext* cx, JSObject* obj, jsid id, Value* vp); bool GetGetterPure(ExclusiveContext* cx, JSObject* obj, jsid id, JSFunction** fp); bool GetOwnGetterPure(ExclusiveContext* cx, JSObject* obj, jsid id, JSFunction** fp); bool GetOwnNativeGetterPure(JSContext* cx, JSObject* obj, jsid id, JSNative* native); bool HasOwnDataPropertyPure(JSContext* cx, JSObject* obj, jsid id, bool* result); bool GetOwnPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id, MutableHandle desc); bool GetOwnPropertyDescriptor(JSContext* cx, HandleObject obj, HandleId id, MutableHandleValue vp); /* * Like JS::FromPropertyDescriptor, but ignore desc.object() and always set vp * to an object on success. * * Use JS::FromPropertyDescriptor for getOwnPropertyDescriptor, since desc.object() * is used to indicate whether a result was found or not. Use this instead for * defineProperty: it would be senseless to define a "missing" property. */ extern bool FromPropertyDescriptorToObject(JSContext* cx, Handle desc, MutableHandleValue vp); extern bool IsDelegate(JSContext* cx, HandleObject obj, const Value& v, bool* result); // obj is a JSObject*, but we root it immediately up front. We do it // that way because we need a Rooted temporary in this method anyway. extern bool IsDelegateOfObject(JSContext* cx, HandleObject protoObj, JSObject* obj, bool* result); /* Wrap boolean, number or string as Boolean, Number or String object. */ extern JSObject* PrimitiveToObject(JSContext* cx, const Value& v); } /* namespace js */ namespace js { /* For converting stack values to objects. */ MOZ_ALWAYS_INLINE JSObject* ToObjectFromStack(JSContext* cx, HandleValue vp) { if (vp.isObject()) return &vp.toObject(); return js::ToObjectSlow(cx, vp, true); } template bool XDRObjectLiteral(XDRState* xdr, MutableHandleObject obj); /* * Report a TypeError: "so-and-so is not an object". * Using NotNullObject is usually less code. */ extern void ReportNotObject(JSContext* cx, const Value& v); inline JSObject* NonNullObject(JSContext* cx, const Value& v) { if (v.isObject()) return &v.toObject(); ReportNotObject(cx, v); return nullptr; } extern bool GetFirstArgumentAsObject(JSContext* cx, const CallArgs& args, const char* method, MutableHandleObject objp); /* Helpers for throwing. These always return false. */ extern bool Throw(JSContext* cx, jsid id, unsigned errorNumber); extern bool Throw(JSContext* cx, JSObject* obj, unsigned errorNumber); /* * ES6 rev 29 (6 Dec 2014) 7.3.13. Mark obj as non-extensible, and adjust each * of obj's own properties' attributes appropriately: each property becomes * non-configurable, and if level == Frozen, data properties become * non-writable as well. */ extern bool SetIntegrityLevel(JSContext* cx, HandleObject obj, IntegrityLevel level); inline bool FreezeObject(JSContext* cx, HandleObject obj) { return SetIntegrityLevel(cx, obj, IntegrityLevel::Frozen); } /* * ES6 rev 29 (6 Dec 2014) 7.3.14. Code shared by Object.isSealed and * Object.isFrozen. */ extern bool TestIntegrityLevel(JSContext* cx, HandleObject obj, IntegrityLevel level, bool* resultp); extern bool SpeciesConstructor(JSContext* cx, HandleObject obj, HandleValue defaultCtor, MutableHandleValue pctor); extern bool SpeciesConstructor(JSContext* cx, HandleObject obj, JSProtoKey ctorKey, MutableHandleValue pctor); extern bool GetObjectFromIncumbentGlobal(JSContext* cx, MutableHandleObject obj); } /* namespace js */ #endif /* jsobj_h */