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/* -*- Mode: C++; tab-width: 8; indent-tabs-mode: nil; c-basic-offset: 2 -*-
* vim: set ts=8 sts=2 et sw=2 tw=80:
* This Source Code Form is subject to the terms of the Mozilla Public
* License, v. 2.0. If a copy of the MPL was not distributed with this
* file, You can obtain one at http://mozilla.org/MPL/2.0/. */
#ifndef js_public_Object_h
#define js_public_Object_h
#include "js/shadow/Object.h" // JS::shadow::Object
#include "mozilla/Assertions.h" // MOZ_ASSERT
#include <stddef.h> // size_t
#include <stdint.h> // uint32_t
#include "jstypes.h" // JS_PUBLIC_API
#include "js/Class.h" // js::ESClass, JSCLASS_RESERVED_SLOTS, JSCLASS_HAS_PRIVATE
#include "js/Realm.h" // JS::GetCompartmentForRealm
#include "js/RootingAPI.h" // JS::{,Mutable}Handle
#include "js/shadow/ObjectGroup.h" // JS::shadow::ObjectGroup
#include "js/Value.h" // JS::Value
struct JS_PUBLIC_API JSContext;
class JS_PUBLIC_API JSObject;
namespace JS {
class JS_PUBLIC_API Compartment;
/**
* Determine the ECMAScript "class" -- Date, String, RegExp, and all the other
* builtin object types (described in ECMAScript in terms of an objecting having
* "an [[ArrayBufferData]] internal slot" or similar language for other kinds of
* object -- of the provided object.
*
* If this function is passed a wrapper that can be unwrapped, the determination
* is performed on that object. If the wrapper can't be unwrapped, and it's not
* a wrapper that prefers to treat this operation as a failure, this function
* will indicate that the object is |js::ESClass::Other|.
*/
extern JS_PUBLIC_API bool GetBuiltinClass(JSContext* cx, Handle<JSObject*> obj,
js::ESClass* cls);
/** Get the |JSClass| of an object. */
inline const JSClass* GetClass(const JSObject* obj) {
return reinterpret_cast<const shadow::Object*>(obj)->group->clasp;
}
/**
* Get the |JS::Compartment*| of an object.
*
* Note that the compartment of an object in this realm, that is a
* cross-compartment wrapper around an object from another realm, is the
* compartment of this realm.
*/
static MOZ_ALWAYS_INLINE Compartment* GetCompartment(JSObject* obj) {
Realm* realm = reinterpret_cast<shadow::Object*>(obj)->group->realm;
return GetCompartmentForRealm(realm);
}
/**
* Get the private value stored for an object whose class has a private.
*
* It is safe to call this function within |obj|'s finalize hook.
*/
inline void* GetPrivate(JSObject* obj) {
MOZ_ASSERT(GetClass(obj)->flags & JSCLASS_HAS_PRIVATE);
const auto* nobj = reinterpret_cast<const shadow::Object*>(obj);
return nobj->fixedSlots()[nobj->numFixedSlots()].toPrivate();
}
/**
* Set the private value for |obj|.
*
* This function may called during the finalization of |obj|.
*/
extern JS_PUBLIC_API void SetPrivate(JSObject* obj, void* data);
/**
* Get the value stored in a reserved slot in an object.
*
* If |obj| is known to be a proxy and you're willing to use friend APIs,
* |js::GetProxyReservedSlot| in "js/Proxy.h" is very slightly more efficient.
*/
inline const Value& GetReservedSlot(JSObject* obj, size_t slot) {
MOZ_ASSERT(slot < JSCLASS_RESERVED_SLOTS(GetClass(obj)));
return reinterpret_cast<const shadow::Object*>(obj)->slotRef(slot);
}
namespace detail {
extern JS_FRIEND_API void SetReservedSlotWithBarrier(JSObject* obj, size_t slot,
const Value& value);
} // namespace detail
/**
* Store a value in an object's reserved slot.
*
* This can be used with both native objects and proxies. However, if |obj| is
* known to be a proxy, |js::SetProxyReservedSlot| in "js/Proxy.h" is very
* slightly more efficient.
*/
inline void SetReservedSlot(JSObject* obj, size_t slot, const Value& value) {
MOZ_ASSERT(slot < JSCLASS_RESERVED_SLOTS(GetClass(obj)));
auto* sobj = reinterpret_cast<shadow::Object*>(obj);
if (sobj->slotRef(slot).isGCThing() || value.isGCThing()) {
detail::SetReservedSlotWithBarrier(obj, slot, value);
} else {
sobj->slotRef(slot) = value;
}
}
} // namespace JS
#endif // js_public_Object_h
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