Initial commit: Go 1.23 release state

test/fixedbugs/issue27518b.go

@@ -0,0 +1,72 @@
+// run
+
+// Copyright 2018 The Go Authors. All rights reserved.
+// Use of this source code is governed by a BSD-style
+// license that can be found in the LICENSE file.
+
+package main
+
+import "runtime"
+
+var finalized bool
+var err string
+
+type HeapObj [8]int64
+
+const filler int64 = 0x123456789abcdef0
+
+func (h *HeapObj) init() {
+	for i := 0; i < len(*h); i++ {
+		h[i] = filler
+	}
+}
+func (h *HeapObj) check() {
+	for i := 0; i < len(*h); i++ {
+		if h[i] != filler {
+			err = "filler overwritten"
+		}
+	}
+}
+
+type StackObj struct {
+	h *HeapObj
+}
+
+func gc(shouldFinalize bool) {
+	runtime.GC()
+	runtime.GC()
+	runtime.GC()
+	if shouldFinalize != finalized {
+		err = "heap object finalized at the wrong time"
+	}
+}
+
+func main() {
+	var s StackObj
+	s.h = new(HeapObj)
+	s.h.init()
+	runtime.SetFinalizer(s.h, func(h *HeapObj) {
+		finalized = true
+	})
+	gc(false)
+	h := g(&s)
+	gc(false)
+	h.check()
+	gc(true) // finalize here, after return value's last use. (Go1.11 never runs the finalizer.)
+	if err != "" {
+		panic(err)
+	}
+}
+
+func g(p *StackObj) (v *HeapObj) {
+	gc(false)
+	v = p.h // last use of the stack object. the only reference to the heap object is in the return slot.
+	gc(false)
+	defer func() {
+		gc(false)
+		recover()
+		gc(false)
+	}()
+	*(*int)(nil) = 0
+	return
+}