Bug 1363200 - JSAPI for realms: JS::Get/SetRealmPrivate(). r=sfink

The existing CompartmentPrivate struct will be split into two parts,
one part containing per-realm (i.e. per web page) data and one
containing per-compartment (i.e. per trust realm) data.

--HG--
extra : rebase_source : 8b5693d05b618cc7d7299f725b26d5535ee847f9

js/public/Realm.h

@@ -59,6 +59,16 @@ GetRealmForCompartment(JSCompartment* compartment) {
     return reinterpret_cast<Realm*>(compartment);
 }
 
+// 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);
+
 extern JS_PUBLIC_API(JSObject*)
 GetRealmObjectPrototype(JSContext* cx);
 

js/src/jscompartment.cpp

@@ -67,6 +67,7 @@ JSCompartment::JSCompartment(Zone* zone, const JS::CompartmentOptions& options =
     enterCompartmentDepth(0),
     performanceMonitoring(runtime_),
     data(nullptr),
+    realmData(nullptr),
     allocationMetadataBuilder(nullptr),
     lastAnimationTime(0),
     regExps(zone),

js/src/jscompartment.h

@@ -691,6 +691,7 @@ struct JSCompartment
 
   public:
     void*                        data;
+    void*                        realmData;
 
   private:
     const js::AllocationMetadataBuilder *allocationMetadataBuilder;

js/src/vm/Realm.cpp

@@ -34,6 +34,17 @@ gc::RealmNeedsSweep(JS::Realm* realm)
     return JS::GetCompartmentForRealm(realm)->globalIsAboutToBeFinalized();
 }
 
+JS_PUBLIC_API(void*)
+JS::GetRealmPrivate(JS::Realm* realm)
+{
+    return GetCompartmentForRealm(realm)->realmData;
+}
+
+JS_PUBLIC_API(void)
+JS::SetRealmPrivate(JS::Realm* realm, void* data)
+{
+    GetCompartmentForRealm(realm)->realmData = data;
+}
 
 JS_PUBLIC_API(JSObject*)
 JS::GetRealmObjectPrototype(JSContext* cx)