Bug 860085 - Rename xpc::{Push,Pop}JSContext and make them assert against DOM JSContexts. r=gabor

js/xpconnect/src/XPCJSRuntime.cpp

@@ -1106,10 +1106,10 @@ void
 XPCJSRuntime::CTypesActivityCallback(JSContext *cx, js::CTypesActivityType type)
 {
   if (type == js::CTYPES_CALLBACK_BEGIN) {
-    if (!Get()->GetJSContextStack()->Push(cx))
+    if (!xpc::PushJSContextNoScriptContext(cx))
       MOZ_CRASH();
   } else if (type == js::CTYPES_CALLBACK_END) {
-    Get()->GetJSContextStack()->Pop();
+    xpc::PopJSContextNoScriptContext();
   }
 }
 

js/xpconnect/src/nsCxPusher.cpp

@@ -113,15 +113,15 @@ AutoCxPusher::AutoCxPusher(JSContext* cx, bool allowNull) : mScriptIsRunning(fal
     mScx = GetScriptContextFromJSContext(cx);
 
   // NB: The GetDynamicScriptContext is historical and might not be sane.
-  if (cx && nsJSUtils::GetDynamicScriptContext(cx) &&
-      xpc::IsJSContextOnStack(cx))
+  XPCJSContextStack *stack = XPCJSRuntime::Get()->GetJSContextStack();
+  if (cx && nsJSUtils::GetDynamicScriptContext(cx) && stack->HasJSContext(cx))
   {
     // If the context is on the stack, that means that a script
     // is running at the moment in the context.
     mScriptIsRunning = true;
   }
 
-  if (!xpc::PushJSContext(cx)) {
+  if (!stack->Push(cx)) {
     MOZ_CRASH();
   }
 
@@ -154,7 +154,7 @@ AutoCxPusher::~AutoCxPusher()
                                 js::GetEnterCompartmentDepth(mPushedContext));
   DebugOnly<JSContext*> stackTop;
   MOZ_ASSERT(mPushedContext == nsXPConnect::XPConnect()->GetCurrentJSContext());
-  xpc::PopJSContext();
+  XPCJSRuntime::Get()->GetJSContextStack()->Pop();
 
   if (!mScriptIsRunning && mScx) {
     // No JS is running in the context, but executing the event handler might have

js/xpconnect/src/nsXPConnect.cpp

@@ -1129,7 +1129,7 @@ nsXPConnect::OnProcessNextEvent(nsIThreadInternal *aThread, bool aMayWait,
     // Push a null JSContext so that we don't see any script during
     // event processing.
     MOZ_ASSERT(NS_IsMainThread());
-    bool ok = PushJSContext(nullptr);
+    bool ok = PushJSContextNoScriptContext(nullptr);
     NS_ENSURE_TRUE(ok, NS_ERROR_FAILURE);
     return NS_OK;
 }
@@ -1148,7 +1148,7 @@ nsXPConnect::AfterProcessNextEvent(nsIThreadInternal *aThread,
     nsJSContext::MaybePokeCC();
     nsDOMMutationObserver::HandleMutations();
 
-    PopJSContext();
+    PopJSContextNoScriptContext();
 
     // If the cx stack is empty, that means we're at the an un-nested event
     // loop. This is a good time to make changes to debug mode.
@@ -1284,13 +1284,14 @@ nsXPConnect::GetSafeJSContext()
 namespace xpc {
 
 bool
-PushJSContext(JSContext *aCx)
+PushJSContextNoScriptContext(JSContext *aCx)
 {
+    MOZ_ASSERT_IF(aCx, !GetScriptContextFromJSContext(aCx));
     return XPCJSRuntime::Get()->GetJSContextStack()->Push(aCx);
 }
 
 void
-PopJSContext()
+PopJSContextNoScriptContext()
 {
     XPCJSRuntime::Get()->GetJSContextStack()->Pop();
 }

js/xpconnect/src/xpcprivate.h

@@ -3225,6 +3225,18 @@ struct XPCJSContextInfo {
     bool savedFrameChain;
 };
 
+namespace xpc {
+
+// These functions are used in a few places where a callback model makes it
+// impossible to push a JSContext using one of our stack-scoped classes. We
+// depend on those stack-scoped classes to maintain nsIScriptContext
+// invariants, so these functions may only be used of the context is not
+// associated with an nsJSContext/nsIScriptContext.
+bool PushJSContextNoScriptContext(JSContext *aCx);
+void PopJSContextNoScriptContext();
+
+} /* namespace xpc */
+
 class XPCJSContextStack
 {
 public:
@@ -3870,11 +3882,6 @@ bool IsOutObject(JSContext* cx, JSObject* obj);
 
 nsresult HasInstance(JSContext *cx, JS::HandleObject objArg, const nsID *iid, bool *bp);
 
-// Internal use only.
-bool PushJSContext(JSContext *aCx);
-void PopJSContext();
-bool IsJSContextOnStack(JSContext *aCx);
-
 } // namespace xpc
 
 /***************************************************************************/