Undo defer parse mode issue with formals

aneeshdk · aneeshdk · commit 36ce60b11983 · 2016-04-21T01:04:08.000-07:00
In undo defer parse mode we reconstruct the pid ref stack for the formals.
With my last change to insert a new reference for each param symbol in the
body I missed making change in the undo defer parse mode. This change adds
the code to do that for both split scope and non-split scope.
diff --git a/lib/Parser/Parse.cpp b/lib/Parser/Parse.cpp
@@ -5032,9 +5032,8 @@ bool Parser::ParseFncDeclHelper(ParseNodePtr pnodeFnc, ParseNodePtr pnodeFncPare
         {
             paramScope->ForEachSymbol([this](Symbol* paramSym)
             {
-                Symbol* sym = paramSym->GetPid()->GetTopRef()->GetSym();
                 PidRefStack* ref = PushPidRef(paramSym->GetPid());
-                ref->SetSym(sym);
+                ref->SetSym(paramSym);
             });
         }
 
@@ -10470,6 +10469,29 @@ void Parser::FinishDeferredFunction(ParseNodePtr pnodeScopeList)
             pnodeFnc->sxFnc.pnodeVars = nullptr;
             m_ppnodeVar = &pnodeFnc->sxFnc.pnodeVars;
 
+            if (scope != nullptr && !pnodeFnc->sxFnc.IsAsync())
+            {
+                if (scope->GetCanMergeWithBodyScope())
+                {
+                    scope->ForEachSymbol([this](Symbol* paramSym)
+                    {
+                        PidRefStack* ref = PushPidRef(paramSym->GetPid());
+                        ref->SetSym(paramSym);
+                    });
+                }
+                else
+                {
+                    OUTPUT_TRACE_DEBUGONLY(Js::ParsePhase, _u("The param and body scope of the function %s cannot be merged\n"), pnodeFnc->sxFnc.pnodeName ? pnodeFnc->sxFnc.pnodeName->sxVar.pid->Psz() : _u("Anonymous function"));
+                    // Add a new symbol reference for each formal in the param scope to the body scope.
+                    scope->ForEachSymbol([this](Symbol* param) {
+                        OUTPUT_TRACE_DEBUGONLY(Js::ParsePhase, _u("Creating a duplicate symbol for the parameter %s in the body scope\n"), param->GetPid()->Psz());
+                        ParseNodePtr paramNode = this->CreateVarDeclNode(param->GetPid(), STVariable, false, nullptr, false);
+                        Assert(paramNode && paramNode->sxVar.sym->GetScope()->GetScopeType() == ScopeType_FunctionBody);
+                        paramNode->sxVar.sym->SetHasInit(true);
+                    });
+                }
+            }
+
             Assert(m_currentNodeNonLambdaFunc == nullptr);
             m_currentNodeNonLambdaFunc = pnodeFnc;
 
diff --git a/test/es6/default-splitscope-undodeferparse.js b/test/es6/default-splitscope-undodeferparse.js
@@ -0,0 +1,64 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+function foo1(a, b) {
+    if (b != 10) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+    if (eval('b') != 10) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+    var b = 1;
+    if (b != 1) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+}
+foo1(undefined, 10);
+
+function foo2(a, b = 10) {
+    if (b != 10) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+    if (eval('b') != 10) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+    var b = 1;
+    if (b != 1) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+}
+foo2();
+
+function foo3(a = 10, b = function () { return a; }) {
+    if (b() != 10) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+    if (eval('b()') != 10) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+    var a = 1;
+    if (b() != 10) {
+        print("FAILED")
+    } else {
+        print("PASSED");
+    }
+}
+foo3();
diff --git a/test/es6/rlexe.xml b/test/es6/rlexe.xml
@@ -730,6 +730,12 @@
       <compile-flags>-force:deferparse -ES6DefaultArgsSplitScope -ES6Generators -args summary -endargs</compile-flags>
     </default>
   </test>
+  <test>
+    <default>
+      <files>default-splitscope-undodeferparse.js</files>
+      <compile-flags>-forceundodefer -ES6DefaultArgsSplitScope</compile-flags>
+    </default>
+  </test>
   <test>
     <default>
       <files>rest.js</files>
