Bug 797304 - Replace MoveWrapper nonsense with orphan fixup. r=peterv (889232fd) · Commits · Tommy Webb / Tor Browser

content/base/public/nsContentUtils.h

+0 −8

Original line number	Diff line number	Diff line
		@@ -200,14 +200,6 @@ public:
		*/
		static JSContext* GetContextFromDocument(nsIDocument *aDocument);

		/**
		* When a document's scope changes (e.g., from document.open(), call this
		* function to move all content wrappers from the old scope to the new one.
		*/
		static nsresult ReparentContentWrappersInScope(JSContext *cx,
		nsIScriptGlobalObject *aOldScope,
		nsIScriptGlobalObject *aNewScope);

		static bool IsCallerChrome();

		static bool IsCallerTrustedForRead();

content/base/src/nsContentUtils.cpp

+0 −17

Original line number	Diff line number	Diff line
		@@ -1721,23 +1721,6 @@ nsContentUtils::TraceSafeJSContext(JSTracer* aTrc)
		}
		}

		nsresult
		nsContentUtils::ReparentContentWrappersInScope(JSContext *cx,
		nsIScriptGlobalObject *aOldScope,
		nsIScriptGlobalObject *aNewScope)
		{
		JSObject *oldScopeObj = aOldScope->GetGlobalJSObject();
		JSObject *newScopeObj = aNewScope->GetGlobalJSObject();

		if (!newScopeObj \|\| !oldScopeObj) {
		// We can't really do anything without the JSObjects.

		return NS_ERROR_NOT_AVAILABLE;
		}

		return sXPConnect->MoveWrappers(cx, oldScopeObj, newScopeObj);
		}

		nsPIDOMWindow *
		nsContentUtils::GetWindowFromCaller()
		{

content/html/document/src/nsHTMLDocument.cpp

+1 −1

Original line number	Diff line number	Diff line
		@@ -1499,7 +1499,7 @@ nsHTMLDocument::Open(const nsAString& aContentTypeOrUrl,
		static_cast<nsINode*>(this),
		getter_AddRefs(ignored));
		NS_ENSURE_SUCCESS(rv, rv);
		rv = nsContentUtils::ReparentContentWrappersInScope(cx, oldScope, newScope);
		rv = xpc->RescueOrphansInScope(cx, oldScope->GetGlobalJSObject());
		NS_ENSURE_SUCCESS(rv, rv);
		}
		}

js/xpconnect/idl/nsIXPConnect.idl

+2 −4

Original line number	Diff line number	Diff line
		@@ -288,7 +288,7 @@ interface nsIXPCFunctionThisTranslator : nsISupports
		{ 0xbd, 0xd6, 0x0, 0x0, 0x64, 0x65, 0x73, 0x74 } }
		%}

		[uuid(d94c13ae-7585-4e7b-b7ad-482976bc6f1b)]
		[uuid(e28a33ce-dfe9-4816-ae20-0f1dc8077230)]
		interface nsIXPConnect : nsISupports
		{
		%{ C++
		@@ -524,9 +524,7 @@ interface nsIXPConnect : nsISupports
		in JSObjectPtr aNewParent,
		in nsISupports aCOMObj);
		void
		moveWrappers(in JSContextPtr aJSContext,
		in JSObjectPtr aOldScope,
		in JSObjectPtr aNewScope);
		rescueOrphansInScope(in JSContextPtr aJSContext, in JSObjectPtr aScope);

		void clearAllWrappedNativeSecurityPolicies();

js/xpconnect/src/nsXPConnect.cpp

+9 −126

Original line number	Diff line number	Diff line
		@@ -1551,150 +1551,33 @@ MoveableWrapperFinder(JSDHashTable table, JSDHashEntryHdr hdr,
		return JS_DHASH_NEXT;
		}

		static nsresult
		MoveWrapper(XPCCallContext& ccx, XPCWrappedNative *wrapper,
		XPCWrappedNativeScope newScope, XPCWrappedNativeScope oldScope)
		{
		// First, check to see if this wrapper really needs to be
		// reparented.

		if (wrapper->GetScope() == newScope) {
		// The wrapper already got moved, nothing to do here.
		return NS_OK;
		}

		// For performance reasons, we wait to fix up orphaned wrappers (wrappers
		// whose parents have moved to another scope) until right before they
		// threaten to confuse us.
		//
		// If this wrapper is an orphan, reunite it with its parent. If, following
		// that, the wrapper is no longer in the old scope, then we don't need to
		// reparent it.
		MOZ_ASSERT(wrapper->GetScope() == oldScope);
		nsresult rv = wrapper->RescueOrphans(ccx);
		NS_ENSURE_SUCCESS(rv, rv);
		if (wrapper->GetScope() != oldScope)
		return NS_OK;

		nsISupports *identity = wrapper->GetIdentityObject();
		nsCOMPtr<nsIClassInfo> info(do_QueryInterface(identity));

		// ClassInfo is implemented as singleton objects. If the identity
		// object here is the same object as returned by the QI, then it
		// is the singleton classinfo, so we don't need to reparent it.
		if (SameCOMIdentity(identity, info))
		info = nullptr;

		if (!info)
		return NS_OK;

		XPCNativeScriptableCreateInfo sciProto;
		XPCNativeScriptableCreateInfo sci;
		const XPCNativeScriptableCreateInfo& sciWrapper =
		XPCWrappedNative::GatherScriptableCreateInfo(identity, info,
		sciProto, sci);

		// If the wrapper doesn't want precreate, then we don't need to
		// worry about reparenting it.
		if (!sciWrapper.GetFlags().WantPreCreate())
		return NS_OK;

		JSObject *newParent = oldScope->GetGlobalJSObject();
		rv = sciWrapper.GetCallback()->PreCreate(identity, ccx,
		newParent,
		&newParent);
		if (NS_FAILED(rv))
		return rv;

		if (newParent == oldScope->GetGlobalJSObject()) {
		// The old scope still works for this wrapper. We have to
		// assume that the wrapper will continue to return the old
		// scope from PreCreate, so don't move it.
		return NS_OK;
		}

		// These are pretty special circumstances. Make sure that the parent here
		// is a bonafide WN with a proper parent chain.
		MOZ_ASSERT(!js::IsCrossCompartmentWrapper(newParent));
		MOZ_ASSERT(IS_WRAPPER_CLASS(js::GetObjectClass(newParent)));
		if (!IS_WN_WRAPPER_OBJECT(newParent))
		NS_ENSURE_STATE(MorphSlimWrapper(ccx, newParent));
		XPCWrappedNative *parentWrapper =
		static_cast<XPCWrappedNative*>(js::GetObjectPrivate(newParent));
		rv = parentWrapper->RescueOrphans(ccx);
		NS_ENSURE_SUCCESS(rv, rv);

		// The wrapper returned a new parent. If the new parent is in a
		// different scope, then we need to reparent it, otherwise, the
		// old scope is fine.

		XPCWrappedNativeScope *betterScope = parentWrapper->GetScope();
		if (betterScope == oldScope) {
		// The wrapper asked for a different object, but that object
		// was in the same scope. This means that the new parent
		// simply hasn't been reparented yet, so reparent it first,
		// and then continue reparenting the wrapper itself.

		rv = MoveWrapper(ccx, parentWrapper, newScope, oldScope);
		NS_ENSURE_SUCCESS(rv, rv);

		// If the parent wanted to stay in the old scope, we have to stay with
		// it. This can happen when doing document.write when the old detached
		// about:blank document is still floating around in the scope. Leave it
		// behind to die.
		if (parentWrapper->GetScope() == oldScope)
		return NS_OK;
		NS_ASSERTION(parentWrapper->GetScope() == newScope,
		"A _third_ scope? Oh dear...");

		} else
		NS_ASSERTION(betterScope == newScope, "Weird scope returned");

		// Now, reparent the wrapper, since we know that it wants to be
		// reparented.

		nsRefPtr<XPCWrappedNative> junk;
		rv = XPCWrappedNative::ReparentWrapperIfFound(ccx, oldScope,
		newScope, parentWrapper->GetFlatJSObject(),
		wrapper->GetIdentityObject(),
		getter_AddRefs(junk));
		return rv;
		}

		/* void moveWrappers(in JSContextPtr aJSContext, in JSObjectPtr aOldScope, in JSObjectPtr aNewScope); */
		/* void rescueOrphansInScope(in JSContextPtr aJSContext, in JSObjectPtr aScope); */
		NS_IMETHODIMP
		nsXPConnect::MoveWrappers(JSContext *aJSContext,
		JSObject *aOldScope,
		JSObject *aNewScope)
		nsXPConnect::RescueOrphansInScope(JSContext aJSContext, JSObject aScope)
		{
		XPCCallContext ccx(NATIVE_CALLER, aJSContext);
		if (!ccx.IsValid())
		return UnexpectedFailure(NS_ERROR_FAILURE);

		XPCWrappedNativeScope *oldScope =
		XPCWrappedNativeScope::FindInJSObjectScope(ccx, aOldScope);
		if (!oldScope)
		return UnexpectedFailure(NS_ERROR_FAILURE);

		XPCWrappedNativeScope *newScope =
		XPCWrappedNativeScope::FindInJSObjectScope(ccx, aNewScope);
		if (!newScope)
		XPCWrappedNativeScope *scope =
		XPCWrappedNativeScope::FindInJSObjectScope(ccx, aScope);
		if (!scope)
		return UnexpectedFailure(NS_ERROR_FAILURE);

		// First, look through the old scope and find all of the wrappers that
		// we're going to move.
		// First, look through the old scope and find all of the wrappers that we
		// might need to rescue.
		nsTArray<nsRefPtr<XPCWrappedNative> > wrappersToMove;

		{ // scoped lock
		XPCAutoLock lock(GetRuntime()->GetMapLock());
		Native2WrappedNativeMap *map = oldScope->GetWrappedNativeMap();
		Native2WrappedNativeMap *map = scope->GetWrappedNativeMap();
		wrappersToMove.SetCapacity(map->Count());
		map->Enumerate(MoveableWrapperFinder, &wrappersToMove);
		}

		// Now that we have the wrappers, reparent them to the new scope.
		for (uint32_t i = 0, stop = wrappersToMove.Length(); i < stop; ++i) {
		nsresult rv = MoveWrapper(ccx, wrappersToMove[i], newScope, oldScope);
		nsresult rv = wrappersToMove[i]->RescueOrphans(ccx);
		NS_ENSURE_SUCCESS(rv, rv);
		}