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| -rw-r--r-- | js/src/vm/ObjectOperations.h | 301 |
1 files changed, 301 insertions, 0 deletions
diff --git a/js/src/vm/ObjectOperations.h b/js/src/vm/ObjectOperations.h new file mode 100644 index 0000000000..ef8c3575de --- /dev/null +++ b/js/src/vm/ObjectOperations.h @@ -0,0 +1,301 @@ +/* -*- 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/. */ + +/* Fundamental operations on objects. */ + +#ifndef vm_ObjectOperations_h +#define vm_ObjectOperations_h + +#include "mozilla/Attributes.h" // MOZ_ALWAYS_INLINE +#include "mozilla/Maybe.h" + +#include <stdint.h> // uint32_t + +#include "js/Id.h" // INT_TO_JSID, jsid, JSID_INT_MAX, SYMBOL_TO_JSID +#include "js/PropertyDescriptor.h" // JSPROP_ENUMERATE, JS::PropertyDescriptor +#include "js/RootingAPI.h" // JS::Handle, JS::MutableHandle, JS::Rooted +#include "js/TypeDecls.h" // fwd-decl: JSContext, Symbol, Value +#include "vm/StringType.h" // js::NameToId + +namespace JS { +class ObjectOpResult; +} + +namespace js { + +class PropertyResult; + +// 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, JS::Handle<JSObject*> obj, + JS::MutableHandle<JSObject*> 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, JS::Handle<JSObject*> obj, + JS::Handle<JSObject*> proto, + JS::ObjectOpResult& result); + +/* Convenience function: like the above, but throw on failure. */ +extern bool SetPrototype(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<JSObject*> 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(JSContext* cx, JS::Handle<JSObject*> 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. + */ +extern bool PreventExtensions(JSContext* cx, JS::Handle<JSObject*> obj, + JS::ObjectOpResult& result); + +/* Convenience function. As above, but throw on failure. */ +extern bool PreventExtensions(JSContext* cx, JS::Handle<JSObject*> obj); + +/* + * ES6 [[GetOwnProperty]]. Get a description of one of obj's own properties. + * + * If no such property exists on obj, desc will be Nothing(). + */ +extern bool GetOwnPropertyDescriptor( + JSContext* cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id, + JS::MutableHandle<mozilla::Maybe<JS::PropertyDescriptor>> desc); + +/* ES6 [[DefineOwnProperty]]. Define a property on obj. */ +extern bool DefineProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, + Handle<JS::PropertyDescriptor> desc, + JS::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, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, + JS::Handle<JS::PropertyDescriptor> desc); + +extern bool DefineAccessorProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, + JS::Handle<JSObject*> getter, + JS::Handle<JSObject*> setter, unsigned attrs, + JS::ObjectOpResult& result); + +extern bool DefineDataProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, JS::Handle<JS::Value> value, + unsigned attrs, JS::ObjectOpResult& result); + +extern bool DefineAccessorProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, + JS::Handle<JSObject*> getter, + JS::Handle<JSObject*> setter, + unsigned attrs = JSPROP_ENUMERATE); + +extern bool DefineDataProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, JS::Handle<JS::Value> value, + unsigned attrs = JSPROP_ENUMERATE); + +extern bool DefineDataProperty(JSContext* cx, JS::Handle<JSObject*> obj, + PropertyName* name, JS::Handle<JS::Value> value, + unsigned attrs = JSPROP_ENUMERATE); + +extern bool DefineDataElement(JSContext* cx, JS::Handle<JSObject*> obj, + uint32_t index, JS::Handle<JS::Value> value, + 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, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, bool* foundp); + +inline bool HasProperty(JSContext* cx, JS::Handle<JSObject*> 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, JS::Handle<JSObject*> obj, + JS::Handle<JS::Value> receiver, JS::Handle<jsid> id, + JS::MutableHandle<JS::Value> vp); + +inline bool GetProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<JS::Value> receiver, PropertyName* name, + JS::MutableHandle<JS::Value> vp); + +inline bool GetProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<JSObject*> receiver, JS::Handle<jsid> id, + JS::MutableHandle<JS::Value> vp); + +inline bool GetProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<JSObject*> receiver, PropertyName* name, + JS::MutableHandle<JS::Value> vp); + +inline bool GetElement(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<JS::Value> receiver, uint32_t index, + JS::MutableHandle<JS::Value> vp); + +inline bool GetElement(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<JSObject*> receiver, uint32_t index, + JS::MutableHandle<JS::Value> vp); + +inline bool GetPropertyNoGC(JSContext* cx, JSObject* obj, + const JS::Value& receiver, jsid id, JS::Value* vp); + +inline bool GetPropertyNoGC(JSContext* cx, JSObject* obj, + const JS::Value& receiver, PropertyName* name, + JS::Value* vp); + +inline bool GetElementNoGC(JSContext* cx, JSObject* obj, + const JS::Value& receiver, uint32_t index, + JS::Value* vp); + +// Returns whether |obj| or an object on its proto chain may have an interesting +// symbol property (see JSObject::hasInterestingSymbolProperty). If it returns +// true, *holder is set to the object that may have this property. +MOZ_ALWAYS_INLINE bool MaybeHasInterestingSymbolProperty( + JSContext* cx, JSObject* obj, JS::Symbol* symbol, + JSObject** holder = nullptr); + +// Like GetProperty but optimized for interesting symbol properties like +// @@toStringTag. +MOZ_ALWAYS_INLINE bool GetInterestingSymbolProperty( + JSContext* cx, JS::Handle<JSObject*> obj, JS::Symbol* sym, + JS::MutableHandle<JS::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, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, JS::Handle<JS::Value> v, + JS::Handle<JS::Value> receiver, + JS::ObjectOpResult& result); + +inline bool SetProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, JS::Handle<JS::Value> v); + +inline bool SetProperty(JSContext* cx, JS::Handle<JSObject*> obj, + PropertyName* name, JS::Handle<JS::Value> v, + JS::Handle<JS::Value> receiver, + JS::ObjectOpResult& result); + +inline bool SetProperty(JSContext* cx, JS::Handle<JSObject*> obj, + PropertyName* name, JS::Handle<JS::Value> v); + +inline bool SetElement(JSContext* cx, JS::Handle<JSObject*> obj, uint32_t index, + JS::Handle<JS::Value> v, JS::Handle<JS::Value> receiver, + JS::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, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, JS::Handle<JS::Value> v, + bool strict); + +/* + * ES6 [[Delete]]. Equivalent to the JS code `delete obj[id]`. + */ +inline bool DeleteProperty(JSContext* cx, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, JS::ObjectOpResult& result); + +inline bool DeleteElement(JSContext* cx, JS::Handle<JSObject*> obj, + uint32_t index, JS::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, JS::Handle<JSObject*> obj, + bool* isOrdinary, + JS::MutableHandle<JSObject*> 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(JSContext* cx, JS::Handle<JSObject*> obj, + bool* succeeded); + +/* + * Deprecated. Finds a PropertyDescriptor somewhere along the prototype chain, + * similar to GetOwnPropertyDescriptor. |holder| indicates on which object the + * property was found. + */ +extern bool GetPropertyDescriptor( + JSContext* cx, JS::Handle<JSObject*> obj, JS::Handle<jsid> id, + MutableHandle<mozilla::Maybe<JS::PropertyDescriptor>> desc, + JS::MutableHandle<JSObject*> holder); + +/* + * 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, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, + JS::MutableHandle<JSObject*> objp, + PropertyResult* propp); + +inline bool LookupProperty(JSContext* cx, JS::Handle<JSObject*> obj, + PropertyName* name, + JS::MutableHandle<JSObject*> objp, + PropertyResult* propp) { + JS::Rooted<jsid> 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, JS::Handle<JSObject*> obj, + JS::Handle<jsid> id, bool* result); + +} /* namespace js */ + +#endif /* vm_ObjectOperations_h */ |