[MERGE #5999 @MikeHolman] remove stale entry from sourceinfo after asm.js parse failure

Merge pull request #5999 from MikeHolman:stalesource

Fixes #5942

Author: MikeHolman

lib/Runtime/Base/ScriptContext.cpp

@@ -2550,7 +2550,7 @@ namespace Js
         SRCINFO const * pSrcInfo, CompileScriptException * pse, Utf8SourceInfo** ppSourceInfo,
         const char16 *rootDisplayName, LoadScriptFlag loadScriptFlag, Js::Var scriptSource)
     {
-        uint sourceIndex;
+        uint sourceIndex = Constants::InvalidSourceIndex;
         JavascriptFunction * pFunction = nullptr;
 
         ParseNodeProg * parseTree = ParseScript(parser, script, cb, pSrcInfo,
@@ -2567,7 +2567,11 @@ namespace Js
             Assert((loadScriptFlag & LoadScriptFlag_disableAsmJs) != LoadScriptFlag_disableAsmJs);
 
             pse->Free();
-
+            if (sourceIndex != Constants::InvalidSourceIndex)
+            {
+                // If we registered source, we should remove it or we will register another source info
+                this->RemoveSource(sourceIndex);
+            }
             loadScriptFlag = (LoadScriptFlag)(loadScriptFlag | LoadScriptFlag_disableAsmJs);
             return LoadScript(script, cb, pSrcInfo, pse, ppSourceInfo,
                 rootDisplayName, loadScriptFlag, scriptSource);
@@ -2806,6 +2810,12 @@ namespace Js
         return info;
     }
 
+    void ScriptContext::RemoveSource(uint index)
+    {
+        Assert(this->sourceList->IsItemValid(index)); // This assert should be a subset of info != null- if info was null, in the last collect, we'd have invalidated the item
+        this->sourceList->RemoveAt(index);
+    }
+
     bool ScriptContext::IsItemValidInSourceList(int index)
     {
         return (index < this->sourceList->Count()) && this->sourceList->IsItemValid(index);

lib/Runtime/Base/ScriptContext.h

@@ -1464,6 +1464,7 @@ namespace Js
         uint SaveSourceNoCopy(Utf8SourceInfo* sourceInfo, int cchLength, bool isCesu8);
 
         Utf8SourceInfo* GetSource(uint sourceIndex);
+        void RemoveSource(uint sourceIndex);
 
         uint SourceCount() const { return (uint)sourceList->Count(); }
         void CleanSourceList() { CleanSourceListInternal(false); }

lib/Runtime/Library/GlobalObject.cpp

@@ -866,7 +866,7 @@ using namespace Js;
         HRESULT hrCodeGen = S_OK;
         CompileScriptException se;
         Js::ParseableFunctionInfo * funcBody = NULL;
-
+        uint sourceIndex = Constants::InvalidSourceIndex;
         BEGIN_LEAVE_SCRIPT_INTERNAL(scriptContext);
         BEGIN_TRANSLATE_EXCEPTION_TO_HRESULT
         {
@@ -914,7 +914,7 @@ using namespace Js;
                 Js::AutoDynamicCodeReference dynamicFunctionReference(scriptContext);
 
                 Assert(cchSource < MAXLONG);
-                uint sourceIndex = scriptContext->SaveSourceNoCopy(sourceInfo, cchSource, true);
+                sourceIndex = scriptContext->SaveSourceNoCopy(sourceInfo, cchSource, true);
 
                 // Tell byte code gen not to attempt to interact with the caller's context if this is indirect eval.
                 // TODO: Handle strict mode.
@@ -958,8 +958,13 @@ using namespace Js;
             }
             else if (hrCodeGen == JSERR_AsmJsCompileError)
             {
-                // if asm.js compilation succeeded, retry with asm.js disabled
+                // if asm.js compilation failed, retry with asm.js disabled
                 grfscr |= fscrNoAsmJs;
+                if (sourceIndex != Constants::InvalidSourceIndex)
+                {
+                    // If we registered source, we should remove it or we will register another source info
+                    scriptContext->RemoveSource(sourceIndex);
+                }
                 return DefaultEvalHelper(scriptContext, source, sourceLength, moduleID, grfscr, pszTitle, registerDocument, isIndirect, strictMode);
             }
             JavascriptError::MapAndThrowError(scriptContext, hrCodeGen);

test/DebuggerCommon/failedasm.js

@@ -0,0 +1,11 @@
+//-------------------------------------------------------------------------------------------------------
+// Copyright (C) Microsoft. All rights reserved.
+// Licensed under the MIT license. See LICENSE.txt file in the project root for full license information.
+//-------------------------------------------------------------------------------------------------------
+
+function func_0() {                                                                
+    'use asm';                                                                     
+}                                                                                  
+WScript.Attach(func_0);
+
+print("Pass")

test/DebuggerCommon/rlexe.xml

@@ -359,6 +359,12 @@
       <compile-flags>-debuglaunch -dbgbaseline:level_1.js.dbg.baseline</compile-flags>
     </default>
   </test>
+  <test>
+    <default>
+      <files>failedasm.js</files>
+      <compile-flags>-dbgbaseline:emptyJson.dbg.baseline</compile-flags>
+    </default>
+  </test>
   <test>
     <default>
       <files>ES6_spread.js</files>