Bug 947448 - Define and use nsXPCWrappedJS::IsRootWrapper. r=bholley

js/xpconnect/src/XPCJSRuntime.cpp

@@ -674,7 +674,7 @@ CanSkipWrappedJS(nsXPCWrappedJS *wrappedJS)
     // If traversing wrappedJS wouldn't release it, nor
     // cause any other objects to be added to the graph, no
     // need to add it to the graph at all.
-    bool isRootWrappedJS = wrappedJS->GetRootWrapper() == wrappedJS;
+    bool isRootWrappedJS = wrappedJS->IsRootWrapper();
     if (nsCCUncollectableMarker::sGeneration &&
         (!obj || !xpc_IsGrayGCThing(obj)) &&
         !wrappedJS->IsSubjectToFinalization() &&

js/xpconnect/src/XPCWrappedJS.cpp

@@ -51,15 +51,12 @@ NS_CYCLE_COLLECTION_CLASSNAME(nsXPCWrappedJS)::Traverse
         cb.NoteJSChild(tmp->GetJSObjectPreserveColor());
     }
 
-    nsXPCWrappedJS* root = tmp->GetRootWrapper();
-    if (root == tmp) {
-        // The root wrapper keeps the aggregated native object alive.
+    if (tmp->IsRootWrapper()) {
         NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "aggregated native");
         cb.NoteXPCOMChild(tmp->GetAggregatedNativeObject());
     } else {
-        // Non-root wrappers keep their root alive.
         NS_CYCLE_COLLECTION_NOTE_EDGE_NAME(cb, "root");
-        cb.NoteXPCOMChild(static_cast<nsIXPConnectWrappedJS*>(root));
+        cb.NoteXPCOMChild(static_cast<nsIXPConnectWrappedJS*>(tmp->GetRootWrapper()));
     }
 
     return NS_OK;
@@ -219,7 +216,7 @@ nsXPCWrappedJS::GetTraceName(JSTracer* trc, char *buf, size_t bufsize)
 NS_IMETHODIMP
 nsXPCWrappedJS::GetWeakReference(nsIWeakReference** aInstancePtr)
 {
-    if (mRoot != this)
+    if (!IsRootWrapper())
         return mRoot->GetWeakReference(aInstancePtr);
 
     return nsSupportsWeakReference::GetWeakReference(aInstancePtr);
@@ -356,7 +353,7 @@ nsXPCWrappedJS::nsXPCWrappedJS(JSContext* cx,
     NS_ADDREF(aClass);
     NS_IF_ADDREF(mOuter);
 
-    if (mRoot != this)
+    if (!IsRootWrapper())
         NS_ADDREF(mRoot);
 
 }
@@ -365,8 +362,7 @@ nsXPCWrappedJS::~nsXPCWrappedJS()
 {
     NS_PRECONDITION(0 == mRefCnt, "refcounting error");
 
-    if (mRoot == this) {
-        // Remove this root wrapper from the map
+    if (IsRootWrapper()) {
         XPCJSRuntime* rt = nsXPConnect::GetRuntimeInstance();
         JSObject2WrappedJSMap* map = rt->GetWrappedJSMap();
         if (map)
@@ -381,8 +377,7 @@ nsXPCWrappedJS::Unlink()
     if (IsValid()) {
         XPCJSRuntime* rt = nsXPConnect::GetRuntimeInstance();
         if (rt) {
-            if (mRoot == this) {
-                // remove this root wrapper from the map
+            if (IsRootWrapper()) {
                 JSObject2WrappedJSMap* map = rt->GetWrappedJSMap();
                 if (map)
                     map->Remove(this);
@@ -395,7 +390,7 @@ nsXPCWrappedJS::Unlink()
         mJSObj = nullptr;
     }
 
-    if (mRoot == this) {
+    if (IsRootWrapper()) {
         ClearWeakReferences();
     } else if (mRoot) {
         // unlink this wrapper
@@ -551,9 +546,8 @@ nsXPCWrappedJS::DebugDump(int16_t depth)
     XPC_LOG_ALWAYS(("nsXPCWrappedJS @ %x with mRefCnt = %d", this, mRefCnt.get()));
         XPC_LOG_INDENT();
 
-        bool isRoot = mRoot == this;
         XPC_LOG_ALWAYS(("%s wrapper around JSObject @ %x", \
-                        isRoot ? "ROOT":"non-root", mJSObj.get()));
+                        IsRootWrapper() ? "ROOT":"non-root", mJSObj.get()));
         char* name;
         GetClass()->GetInterfaceInfo()->GetName(&name);
         XPC_LOG_ALWAYS(("interface name is %s", name));
@@ -565,18 +559,18 @@ nsXPCWrappedJS::DebugDump(int16_t depth)
             NS_Free(iid);
         XPC_LOG_ALWAYS(("nsXPCWrappedJSClass @ %x", mClass));
 
-        if (!isRoot)
+        if (!IsRootWrapper())
             XPC_LOG_OUTDENT();
         if (mNext) {
-            if (isRoot) {
+            if (IsRootWrapper()) {
                 XPC_LOG_ALWAYS(("Additional wrappers for this object..."));
                 XPC_LOG_INDENT();
             }
             mNext->DebugDump(depth);
-            if (isRoot)
+            if (IsRootWrapper())
                 XPC_LOG_OUTDENT();
         }
-        if (isRoot)
+        if (IsRootWrapper())
             XPC_LOG_OUTDENT();
 #endif
     return NS_OK;

js/xpconnect/src/xpcprivate.h

@@ -2502,6 +2502,7 @@ public:
     nsXPCWrappedJS* Find(REFNSIID aIID);
     nsXPCWrappedJS* FindInherited(REFNSIID aIID);
 
+    bool IsRootWrapper() const {return mRoot == this;}
     bool IsValid() const {return mJSObj != nullptr;}
     void SystemIsBeingShutDown();