зеркало из https://github.com/mozilla/gecko-dev.git
203 строки
7.2 KiB
C++
203 строки
7.2 KiB
C++
/* -*- 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_Realm_h
|
|
#define js_Realm_h
|
|
|
|
#include "js/shadow/Realm.h" // JS::shadow::Realm
|
|
|
|
#include "js/GCPolicyAPI.h"
|
|
#include "js/TypeDecls.h" // forward-declaration of JS::Realm
|
|
|
|
/************************************************************************/
|
|
|
|
// [SMDOC] Realms
|
|
//
|
|
// Data associated with a global object. In the browser each frame has its
|
|
// own global/realm.
|
|
|
|
namespace js {
|
|
namespace gc {
|
|
JS_PUBLIC_API void TraceRealm(JSTracer* trc, JS::Realm* realm,
|
|
const char* name);
|
|
} // namespace gc
|
|
} // namespace js
|
|
|
|
namespace JS {
|
|
class JS_PUBLIC_API AutoRequireNoGC;
|
|
|
|
// Each Realm holds a weak reference to its GlobalObject.
|
|
template <>
|
|
struct GCPolicy<Realm*> : public NonGCPointerPolicy<Realm*> {
|
|
static void trace(JSTracer* trc, Realm** vp, const char* name) {
|
|
if (*vp) {
|
|
::js::gc::TraceRealm(trc, *vp, name);
|
|
}
|
|
}
|
|
};
|
|
|
|
// Get the current realm, if any. The ECMAScript spec calls this "the current
|
|
// Realm Record".
|
|
extern JS_PUBLIC_API Realm* GetCurrentRealmOrNull(JSContext* cx);
|
|
|
|
// Return the compartment that contains a given realm.
|
|
inline JS::Compartment* GetCompartmentForRealm(Realm* realm) {
|
|
return shadow::Realm::get(realm)->compartment();
|
|
}
|
|
|
|
// Return an object's realm. All objects except cross-compartment wrappers are
|
|
// created in a particular realm, which never changes. Returns null if obj is
|
|
// a cross-compartment wrapper.
|
|
extern JS_PUBLIC_API Realm* GetObjectRealmOrNull(JSObject* obj);
|
|
|
|
// Get the value of the "private data" internal field of the given Realm.
|
|
// This field is initially null and is set using SetRealmPrivate.
|
|
// It's a pointer to embeddding-specific data that SpiderMonkey never uses.
|
|
extern JS_PUBLIC_API void* GetRealmPrivate(Realm* realm);
|
|
|
|
// Set the "private data" internal field of the given Realm.
|
|
extern JS_PUBLIC_API void SetRealmPrivate(Realm* realm, void* data);
|
|
|
|
typedef void (*DestroyRealmCallback)(JS::GCContext* gcx, Realm* realm);
|
|
|
|
// Set the callback SpiderMonkey calls just before garbage-collecting a realm.
|
|
// Embeddings can use this callback to free private data associated with the
|
|
// realm via SetRealmPrivate.
|
|
//
|
|
// By the time this is called, the global object for the realm has already been
|
|
// collected.
|
|
extern JS_PUBLIC_API void SetDestroyRealmCallback(
|
|
JSContext* cx, DestroyRealmCallback callback);
|
|
|
|
using RealmNameCallback = void (*)(JSContext* cx, Realm* realm, char* buf,
|
|
size_t bufsize,
|
|
const JS::AutoRequireNoGC& nogc);
|
|
|
|
// Set the callback SpiderMonkey calls to get the name of a realm, for
|
|
// diagnostic output.
|
|
extern JS_PUBLIC_API void SetRealmNameCallback(JSContext* cx,
|
|
RealmNameCallback callback);
|
|
|
|
// Get the global object for the given realm. This only returns nullptr during
|
|
// GC, between collecting the global object and destroying the Realm.
|
|
extern JS_PUBLIC_API JSObject* GetRealmGlobalOrNull(Realm* realm);
|
|
|
|
// Initialize standard JS class constructors, prototypes, and any top-level
|
|
// functions and constants associated with the standard classes (e.g. isNaN
|
|
// for Number).
|
|
extern JS_PUBLIC_API bool InitRealmStandardClasses(JSContext* cx);
|
|
|
|
// If the current realm has the non-standard freezeBuiltins option set to true,
|
|
// freeze the constructor object and seal the prototype.
|
|
extern JS_PUBLIC_API bool MaybeFreezeCtorAndPrototype(JSContext* cx,
|
|
HandleObject ctor,
|
|
HandleObject maybeProto);
|
|
|
|
/*
|
|
* Ways to get various per-Realm objects. All the getters declared below operate
|
|
* on the JSContext's current Realm.
|
|
*/
|
|
|
|
extern JS_PUBLIC_API JSObject* GetRealmObjectPrototype(JSContext* cx);
|
|
extern JS_PUBLIC_API JS::Handle<JSObject*> GetRealmObjectPrototypeHandle(
|
|
JSContext* cx);
|
|
|
|
extern JS_PUBLIC_API JSObject* GetRealmFunctionPrototype(JSContext* cx);
|
|
|
|
extern JS_PUBLIC_API JSObject* GetRealmArrayPrototype(JSContext* cx);
|
|
|
|
extern JS_PUBLIC_API JSObject* GetRealmErrorPrototype(JSContext* cx);
|
|
|
|
extern JS_PUBLIC_API JSObject* GetRealmIteratorPrototype(JSContext* cx);
|
|
|
|
extern JS_PUBLIC_API JSObject* GetRealmAsyncIteratorPrototype(JSContext* cx);
|
|
|
|
// Returns an object that represents the realm, that can be referred from
|
|
// other realm/compartment.
|
|
// See the consumer in `MaybeCrossOriginObjectMixins::EnsureHolder` for details.
|
|
extern JS_PUBLIC_API JSObject* GetRealmKeyObject(JSContext* cx);
|
|
|
|
// Implements https://tc39.github.io/ecma262/#sec-getfunctionrealm
|
|
// 7.3.22 GetFunctionRealm ( obj )
|
|
//
|
|
// WARNING: may return a realm in a different compartment!
|
|
//
|
|
// Will throw an exception and return nullptr when a security wrapper or revoked
|
|
// proxy is encountered.
|
|
extern JS_PUBLIC_API Realm* GetFunctionRealm(JSContext* cx,
|
|
HandleObject objArg);
|
|
|
|
/** NB: This API is infallible; a nullptr return value does not indicate error.
|
|
*
|
|
* |target| must not be a cross-compartment wrapper because CCWs are not
|
|
* associated with a single realm.
|
|
*
|
|
* Entering a realm roots the realm and its global object until the matching
|
|
* JS::LeaveRealm() call.
|
|
*/
|
|
extern JS_PUBLIC_API JS::Realm* EnterRealm(JSContext* cx, JSObject* target);
|
|
|
|
extern JS_PUBLIC_API void LeaveRealm(JSContext* cx, JS::Realm* oldRealm);
|
|
|
|
} // namespace JS
|
|
|
|
/*
|
|
* At any time, a JSContext has a current (possibly-nullptr) realm. The
|
|
* preferred way to change the current realm is with JSAutoRealm:
|
|
*
|
|
* void foo(JSContext* cx, JSObject* obj) {
|
|
* // in some realm 'r'
|
|
* {
|
|
* JSAutoRealm ar(cx, obj); // constructor enters
|
|
* // in the realm of 'obj'
|
|
* } // destructor leaves
|
|
* // back in realm 'r'
|
|
* }
|
|
*
|
|
* The object passed to JSAutoRealm must *not* be a cross-compartment wrapper,
|
|
* because CCWs are not associated with a single realm.
|
|
*
|
|
* For more complicated uses that don't neatly fit in a C++ stack frame, the
|
|
* realm can be entered and left using separate function calls:
|
|
*
|
|
* void foo(JSContext* cx, JSObject* obj) {
|
|
* // in 'oldRealm'
|
|
* JS::Realm* oldRealm = JS::EnterRealm(cx, obj);
|
|
* // in the realm of 'obj'
|
|
* JS::LeaveRealm(cx, oldRealm);
|
|
* // back in 'oldRealm'
|
|
* }
|
|
*
|
|
* Note: these calls must still execute in a LIFO manner w.r.t all other
|
|
* enter/leave calls on the context. Furthermore, only the return value of a
|
|
* JS::EnterRealm call may be passed as the 'oldRealm' argument of
|
|
* the corresponding JS::LeaveRealm call.
|
|
*
|
|
* Entering a realm roots the realm and its global object for the lifetime of
|
|
* the JSAutoRealm.
|
|
*/
|
|
|
|
class MOZ_RAII JS_PUBLIC_API JSAutoRealm {
|
|
JSContext* cx_;
|
|
JS::Realm* oldRealm_;
|
|
|
|
public:
|
|
JSAutoRealm(JSContext* cx, JSObject* target);
|
|
JSAutoRealm(JSContext* cx, JSScript* target);
|
|
~JSAutoRealm();
|
|
};
|
|
|
|
class MOZ_RAII JS_PUBLIC_API JSAutoNullableRealm {
|
|
JSContext* cx_;
|
|
JS::Realm* oldRealm_;
|
|
|
|
public:
|
|
explicit JSAutoNullableRealm(JSContext* cx, JSObject* targetOrNull);
|
|
~JSAutoNullableRealm();
|
|
};
|
|
|
|
#endif // js_Realm_h
|