fix: diagnose not implement when assign value to closure variable (#2750)

Fixes: #2749

Author: HerrCai0907

src/compiler.ts

@@ -5596,13 +5596,21 @@ export class Compiler extends DiagnosticEmitter {
     // to compile just the value, we need to know the target's type
     let targetType: Type;
     switch (target.kind) {
-      case ElementKind.Global: {
-        if (!this.compileGlobalLazy(<Global>target, expression)) {
+      case ElementKind.Global:
+      case ElementKind.Local: {
+        if (target.kind == ElementKind.Global) {
+          if (!this.compileGlobalLazy(<Global>target, expression)) {
+            return this.module.unreachable();
+          }
+        } else if (!(<Local>target).declaredByFlow(flow)) {
+          // TODO: closures
+          this.error(
+            DiagnosticCode.Not_implemented_0,
+            expression.range,
+            "Closures"
+          );
           return this.module.unreachable();
         }
-        // fall-through
-      }
-      case ElementKind.Local: {
         if (this.pendingElements.has(target)) {
           this.error(
             DiagnosticCode.Variable_0_used_before_its_declaration,
@@ -7371,7 +7379,7 @@ export class Compiler extends DiagnosticEmitter {
           this.currentType = localType;
         }
 
-        if (target.parent != flow.targetFunction) {
+        if (!local.declaredByFlow(flow)) {
           // TODO: closures
           this.error(
             DiagnosticCode.Not_implemented_0,

src/program.ts

@@ -3639,6 +3639,10 @@ export class Local extends VariableLikeElement {
     assert(type != Type.void);
     this.setType(type);
   }
+
+  declaredByFlow(flow: Flow): bool {
+    return this.parent == flow.targetFunction;
+  }
 }
 
 /** A yet unresolved function prototype. */

tests/compiler/closure.json

@@ -10,6 +10,8 @@
     "$local0; // closure 3",
     "AS100: Not implemented: Closures",
     "$local0(123); // closure 4",
+    "AS100: Not implemented: Closures",
+    "$local0 = 10; // closure 5",
     "EOF"
   ]
 }

tests/compiler/closure.ts

@@ -28,4 +28,12 @@ function testFuncParam($local0: (x: i32) => void): () => void {
 }
 testFuncParam((x: i32) => {});
 
+function testAssign(): (value: i32) => void {
+  let $local0 = 0;
+  return function inner(value: i32): void {
+    $local0 = 10; // closure 5
+  };
+}
+testAssign();
+
 ERROR("EOF");