OS#6951897 Only invalidate cached scopes for nested parents

lib/Runtime/Debug/TTSnapObjects.cpp

@@ -743,7 +743,7 @@ namespace TTD
 
             if(snapFuncInfo->CachedScopeObjId != TTD_INVALID_PTR_ID)
             {
-                fobj->SetCachedScope((Js::ActivationObjectEx*)inflator->LookupObject(snapFuncInfo->CachedScopeObjId));
+                fobj->SetCachedScope(Js::ActivationObjectEx::FromVar(inflator->LookupObject(snapFuncInfo->CachedScopeObjId)));
             }
 
             if(snapFuncInfo->HomeObjId != TTD_INVALID_PTR_ID)

lib/Runtime/Language/InterpreterStackFrame.cpp

@@ -5541,7 +5541,7 @@ namespace Js
 
     Var InterpreterStackFrame::OP_GetCachedFunc(Var instance, int32 index)
     {
-        ActivationObjectEx *obj = (ActivationObjectEx*)ActivationObjectEx::FromVar(instance);
+        ActivationObjectEx *obj = ActivationObjectEx::FromVar(instance);
 
         FuncCacheEntry *entry = obj->GetFuncCacheEntry((uint)index);
         return entry->func;
@@ -5555,7 +5555,7 @@ namespace Js
 
     void InterpreterStackFrame::OP_CommitScopeHelper(const PropertyIdArray *propIds)
     {
-        ActivationObjectEx *obj = (ActivationObjectEx*)ActivationObjectEx::FromVar(this->localClosure);
+        ActivationObjectEx *obj = ActivationObjectEx::FromVar(this->localClosure);
         ScriptFunction *func = obj->GetParentFunc();
 
         Assert(obj->GetParentFunc() == func);

lib/Runtime/Language/JavascriptOperators.cpp

@@ -5632,7 +5632,7 @@ CommonNumber:
 
     void JavascriptOperators::OP_InitCachedFuncs(Var varScope, FrameDisplay *pDisplay, const FuncInfoArray *info, ScriptContext *scriptContext)
     {
-        ActivationObjectEx *scopeObj = (ActivationObjectEx*)ActivationObjectEx::FromVar(varScope);
+        ActivationObjectEx *scopeObj = ActivationObjectEx::FromVar(varScope);
         Assert(scopeObj->GetTypeHandler()->GetInlineSlotCapacity() == 0);
 
         uint funcCount = info->count;

lib/Runtime/Library/JavascriptFunction.cpp

@@ -2726,16 +2726,17 @@ LABEL1:
                 // If this is the internal function of a generator function then return the original generator function
                 funcCaller = ScriptFunction::FromVar(funcCaller)->GetRealFunctionObject();
 
-                // This function is escaping, so make sure there isn't some caller that has a cached scope.
-                JavascriptFunction * func;
-                while (walker.GetCaller(&func))
+                // This function is escaping, so make sure there isn't some nested parent that has a cached scope.
+                if (ScriptFunction::Is(funcCaller))
                 {
-                    if (ScriptFunction::Is(func))
+                    FrameDisplay * pFrameDisplay = Js::ScriptFunction::FromVar(funcCaller)->GetEnvironment();
+                    uint length = (uint)pFrameDisplay->GetLength();
+                    for (uint i = 0; i < length; i++)
                     {
-                        ActivationObjectEx * obj = ScriptFunction::FromVar(func)->GetCachedScope();
-                        if (obj)
+                        void * scope = pFrameDisplay->GetItem(i);
+                        if (!Js::ScopeSlots::Is(scope) && Js::ActivationObjectEx::Is(scope))
                         {
-                            obj->InvalidateCachedScope();
+                            Js::ActivationObjectEx::FromVar(scope)->InvalidateCachedScope();
                         }
                     }
                 }

lib/Runtime/Types/ActivationObject.h

@@ -209,6 +209,12 @@ namespace Js
             return VirtualTableInfo<Js::ActivationObjectEx>::HasVirtualTable(instance);
         }
 
+        static ActivationObjectEx * FromVar(Var instance)
+        {
+            AssertOrFailFast(Is(instance));
+            return reinterpret_cast<ActivationObjectEx *>(instance);
+        }
+
     private:
         Field(ScriptFunction *) parentFunc;
         Field(uint) cachedFuncCount;