defer: enable loop lowering

test/defer_test.go

@@ -0,0 +1,60 @@
+//go:build llgo
+
+/*
+ * Copyright (c) 2025 The GoPlus Authors (goplus.org). All rights reserved.
+ *
+ * Licensed under the Apache License, Version 2.0 (the "License");
+ * you may not use this file except in compliance with the License.
+ * You may obtain a copy of the License at
+ *
+ *     http://www.apache.org/licenses/LICENSE-2.0
+ *
+ * Unless required by applicable law or agreed to in writing, software
+ * distributed under the License is distributed on an "AS IS" BASIS,
+ * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+ * See the License for the specific language governing permissions and
+ * limitations under the License.
+ */
+
+package test
+
+import (
+	"reflect"
+	"testing"
+)
+
+// runLoopDefers exercises a defer statement inside a loop and relies on
+// defers executing after the loop but before the function returns.
+func runLoopDefers() (result []int) {
+	for i := 0; i < 3; i++ {
+		v := i
+		defer func() {
+			result = append(result, v)
+		}()
+	}
+	return
+}
+
+func runLoopDeferCount(n int) (count int) {
+	for i := 0; i < n; i++ {
+		defer func() {
+			count++
+		}()
+	}
+	return
+}
+
+func TestDeferInLoopOrder(t *testing.T) {
+	got := runLoopDefers()
+	want := []int{2, 1, 0}
+	if !reflect.DeepEqual(got, want) {
+		t.Fatalf("unexpected defer order: got %v, want %v", got, want)
+	}
+}
+
+func TestDeferLoopStress(t *testing.T) {
+	const n = 1_000_000
+	if got := runLoopDeferCount(n); got != n {
+		t.Fatalf("unexpected count: got %d, want %d", got, n)
+	}
+}