fix this in closure error (#141)

Signed-off-by: Su Yihan <[email protected]>

src/scope.ts

@@ -436,16 +436,18 @@ export class Scope {
 
     getRootFunctionScope(): FunctionScope | null {
         let currentScope: Scope | null = this;
+        const flattenScopes: FunctionScope[] = [];
         while (currentScope !== null) {
-            if (
-                currentScope instanceof FunctionScope &&
-                currentScope.parent instanceof GlobalScope
-            ) {
-                return currentScope;
+            if (currentScope instanceof FunctionScope) {
+                flattenScopes.push(currentScope);
             }
             currentScope = currentScope.parent;
         }
-        return null;
+        if (flattenScopes.length === 0) {
+            return null;
+        } else {
+            return flattenScopes[flattenScopes.length - 1];
+        }
     }
 
     public addDeclareName(name: string) {

src/semantics/builder_context.ts

@@ -333,20 +333,21 @@ export class BuildContext {
         const var_decl = value.ref as VarDeclareNode;
         var_decl.setUsedByClosureFunction();
 
-        /* The found varDeclareNode needs a deep copy, since the arribute is different between various scopes */
-        const new_var_decl = var_decl.copy();
-        new_var_decl.setUsedByClosureFunction();
-
-        new_var_decl.curCtx = curFunc.varList![0];
-        const newValue = value.copy();
-        newValue.ref = new_var_decl;
+        let new_var_decl = var_decl;
+        let newValue = value;
 
         ownScope = ownScope.getRootFunctionScope()!;
         for (let i = env_idx + 1; i < this.stackEnv.length; i++) {
             const env = this.stackEnv[i];
             if (env.function) {
                 /* Closure variables can only be used within the same rootFunction */
                 if (env.scope.getRootFunctionScope()! === ownScope) {
+                    /* The found varDeclareNode needs a deep copy, since the arribute is different between various scopes */
+                    new_var_decl = var_decl.copy();
+                    new_var_decl.setUsedByClosureFunction();
+                    new_var_decl.curCtx = env.function.varList![0];
+                    newValue = value.copy();
+                    newValue.ref = new_var_decl;
                     env.function.pushClosureVarDeclare(new_var_decl);
                     if (!env.closures)
                         env.closures = new Map<SymbolKey, VarValue>();

tests/samples/this_in_closure.ts

@@ -0,0 +1,29 @@
+/*
+ * Copyright (C) 2023 Intel Corporation.  All rights reserved.
+ * SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
+ */
+
+class Home {
+    printTag(str:string){
+        console.log(str);
+    }
+    element(id: number) {
+        console.log(id);
+    }
+    render() {
+        const arr: string[] = ['start', 'stop', 'pause', 'resume']
+        arr.forEach((val, index, arr) => {
+            const node_event = {
+                event: (text: string, hh: number) => {
+                    this.element(hh);
+                }
+            }
+            this.printTag(val);
+        });
+    }
+}
+
+export function useThisInClosure() {
+    let home = new Home();
+    home.render();
+}

tools/validate/wamr/validation.json

@@ -3799,6 +3799,16 @@
             }
         ]
     },
+    {
+        "module": "this_in_closure",
+        "entries": [
+            {
+                "name": "useThisInClosure",
+                "args": [],
+                "result": "start\nstop\npause\nresume"
+            }
+        ]
+    },
     {
         "module": "this_in_method",
         "entries": [