Bug 1723715 part 16 - Move WindowProxy to GlobalObjectData. r=jonco

This is done last because it requires reordering the initialization code, and we
can finally do this now.

Differential Revision: https://phabricator.services.mozilla.com/D121996

js/public/Class.h

@@ -572,7 +572,7 @@ static const uint32_t JSCLASS_FOREGROUND_FINALIZE =
 // application.
 static const uint32_t JSCLASS_GLOBAL_APPLICATION_SLOTS = 5;
 static const uint32_t JSCLASS_GLOBAL_SLOT_COUNT =
-    JSCLASS_GLOBAL_APPLICATION_SLOTS + 2;
+    JSCLASS_GLOBAL_APPLICATION_SLOTS + 1;
 
 static constexpr uint32_t JSCLASS_GLOBAL_FLAGS_WITH_SLOTS(uint32_t n) {
   return JSCLASS_IS_GLOBAL |

js/src/vm/GlobalObject.cpp

@@ -661,26 +661,11 @@ GlobalObject* GlobalObject::createInternal(JSContext* cx,
   Rooted<GlobalObject*> global(cx, &obj->as<GlobalObject>());
   MOZ_ASSERT(global->isUnqualifiedVarObj());
 
-  Rooted<GlobalLexicalEnvironmentObject*> lexical(
-      cx, GlobalLexicalEnvironmentObject::create(cx, global));
-  if (!lexical) {
-    return nullptr;
-  }
-
-  Rooted<GlobalScope*> emptyGlobalScope(
-      cx, GlobalScope::createEmpty(cx, ScopeKind::Global));
-  if (!emptyGlobalScope) {
-    return nullptr;
-  }
-
   {
     auto data = cx->make_unique<GlobalObjectData>();
     if (!data) {
       return nullptr;
     }
-    data->emptyGlobalScope.init(emptyGlobalScope);
-    data->lexicalEnvironment.init(lexical);
-
     // Note: it's important for the realm's global to be initialized at the
     // same time as the global's GlobalObjectData, because we free the global's
     // data when Realm::global_ is cleared.
@@ -689,6 +674,20 @@ GlobalObject* GlobalObject::createInternal(JSContext* cx,
                      MemoryUse::GlobalObjectData);
   }
 
+  Rooted<GlobalLexicalEnvironmentObject*> lexical(
+      cx, GlobalLexicalEnvironmentObject::create(cx, global));
+  if (!lexical) {
+    return nullptr;
+  }
+  global->data().lexicalEnvironment.init(lexical);
+
+  Rooted<GlobalScope*> emptyGlobalScope(
+      cx, GlobalScope::createEmpty(cx, ScopeKind::Global));
+  if (!emptyGlobalScope) {
+    return nullptr;
+  }
+  global->data().emptyGlobalScope.init(emptyGlobalScope);
+
   if (!JSObject::setQualifiedVarObj(cx, global)) {
     return nullptr;
   }
@@ -1162,9 +1161,10 @@ void GlobalObjectData::trace(JSTracer* trc) {
     TraceNullableEdge(trc, &proto, "global-builtin-proto");
   }
 
-  TraceEdge(trc, &emptyGlobalScope, "global-empty-scope");
+  TraceNullableEdge(trc, &emptyGlobalScope, "global-empty-scope");
 
   TraceNullableEdge(trc, &lexicalEnvironment, "global-lexical-env");
+  TraceNullableEdge(trc, &windowProxy, "global-window-proxy");
   TraceNullableEdge(trc, &regExpStatics, "global-regexp-statics");
   TraceNullableEdge(trc, &intrinsicsHolder, "global-intrinsics-holder");
   TraceNullableEdge(trc, &forOfPICChain, "global-for-of-pic");

js/src/vm/GlobalObject.h

@@ -116,6 +116,9 @@ class GlobalObjectData {
   // The lexical environment for global let/const/class bindings.
   HeapPtr<GlobalLexicalEnvironmentObject*> lexicalEnvironment;
 
+  // The WindowProxy associated with this global.
+  HeapPtr<JSObject*> windowProxy;
+
   // Global state for regular expressions.
   HeapPtr<RegExpStaticsObject*> regExpStatics;
 
@@ -155,7 +158,6 @@ class GlobalObjectData {
 class GlobalObject : public NativeObject {
   enum : unsigned {
     GLOBAL_DATA_SLOT = JSCLASS_GLOBAL_APPLICATION_SLOTS,
-    WINDOW_PROXY,
 
     // Total reserved-slot count for global objects.
     RESERVED_SLOTS
@@ -922,16 +924,10 @@ class GlobalObject : public NativeObject {
   static NativeObject* getOrCreateForOfPICObject(JSContext* cx,
                                                  Handle<GlobalObject*> global);
 
-  JSObject* windowProxy() const {
-    return &getReservedSlot(WINDOW_PROXY).toObject();
-  }
-  JSObject* maybeWindowProxy() const {
-    Value v = getReservedSlot(WINDOW_PROXY);
-    MOZ_ASSERT(v.isObject() || v.isUndefined());
-    return v.isObject() ? &v.toObject() : nullptr;
-  }
+  JSObject* maybeWindowProxy() const { return data().windowProxy; }
+
   void setWindowProxy(JSObject* windowProxy) {
-    setReservedSlot(WINDOW_PROXY, ObjectValue(*windowProxy));
+    data().windowProxy = windowProxy;
   }
 
   ArrayObject* getSourceURLsHolder() const { return data().sourceURLsHolder; }