gracefully handle recursive engine invocations

sebastienros · Feb 4, 2021 · e2404d8 · e2404d8
1 parent 7e44891
commit e2404d8
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Showing 4 changed files with 39 additions and 22 deletions.
diff --git a/Jint.Tests.Test262/Test262Test.cs b/Jint.Tests.Test262/Test262Test.cs
@@ -100,7 +100,7 @@ protected void RunTestCode(string code, bool strict)
                 var parser = new JavaScriptParser(args.At(0).AsString(), options);
                 var script = parser.ParseScript(strict);
 
-                var value = engine.Execute(script, false).GetCompletionValue();
+                var value = engine.Execute(script).GetCompletionValue();
                 
                 return value;
             }), true, true, true));

diff --git a/Jint.Tests/Runtime/EngineTests.cs b/Jint.Tests/Runtime/EngineTests.cs
@@ -2934,6 +2934,19 @@ public void ShouldReuseOptions()
             Assert.Equal(1, Convert.ToInt32(engine2.GetValue("x").ToObject()));
         }
 
+        [Fact]
+        public void RecursiveCallStack()
+        {
+            var engine = new Engine();
+            Func<string, object> evaluateCode = code => engine.Execute(code).GetCompletionValue();
+            var evaluateCodeValue = JsValue.FromObject(engine, evaluateCode);
+
+            engine.SetValue("evaluateCode", evaluateCodeValue);
+            var result = (int) engine.Execute(@"evaluateCode('678 + 711')").GetCompletionValue().AsNumber();
+
+            Assert.Equal(1389, result);
+        }
+
         private class Wrapper
         {
             public Testificate Test { get; set; }

diff --git a/Jint/Engine.cs b/Jint/Engine.cs
@@ -349,16 +349,12 @@ public Engine Execute(string source, ParserOptions parserOptions)
 
         public Engine Execute(Script script)
         {
-            return Execute(script, true);
-        }
-
-        internal Engine Execute(Script script, bool resetState)
-        {
-            if (resetState)
+            // only if we are not in a recursive call, we can reset constraints and last statement
+            // we assume that call stack will be empty only when exited on top level of call chain
+            if (CallStack.Count == 0)
             {
                 ResetConstraints();
                 ResetLastStatement();
-                ResetCallStack();
             }
 
             using (new StrictModeScope(_isStrict || script.Strict))
@@ -1254,16 +1250,19 @@ internal JsValue Construct(IConstructor constructor, JsValue[] arguments, JsValu
                 DebugHandler.AddToDebugCallStack(functionInstance);
             }
 
-            var result = functionInstance.Call(thisObject, arguments);
-
-            if (_isDebugMode)
+            try
             {
-                DebugHandler.PopDebugCallStack();
+                return functionInstance.Call(thisObject, arguments);
             }
+            finally
+            {
+                if (_isDebugMode)
+                {
+                    DebugHandler.PopDebugCallStack();
+                }
 
-            CallStack.Pop();
-
-            return result;
+                CallStack.Pop();
+            }
         }
 
         internal JsValue Construct(
@@ -1287,16 +1286,19 @@ internal JsValue Construct(IConstructor constructor, JsValue[] arguments, JsValu
                 DebugHandler.AddToDebugCallStack(functionInstance);
             }
 
-            var result = ((IConstructor) functionInstance).Construct(arguments, newTarget);
-
-            if (_isDebugMode)
+            try
             {
-                DebugHandler.PopDebugCallStack();
+                return ((IConstructor) functionInstance).Construct(arguments, newTarget);
             }
+            finally
+            {
+                if (_isDebugMode)
+                {
+                    DebugHandler.PopDebugCallStack();
+                }
 
-            CallStack.Pop();
-
-            return result;
+                CallStack.Pop();
+            }
         }
     }
 }
diff --git a/Jint/Runtime/CallStack/JintCallStack.cs b/Jint/Runtime/CallStack/JintCallStack.cs
@@ -60,6 +60,8 @@ public CallStackElement Pop()
             return item;
         }
 
+        public int Count => _stack._size;
+
         public void Clear()
         {
             _stack.Clear();