1// run
2
3// Copyright 2014 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7package main
8
9import (
10	"reflect"
11	"runtime"
12	"unsafe"
13)
14
15func main() {
16	test1()
17	test2()
18}
19
20func test1() {
21	var all []interface{}
22	for i := 0; i < 100; i++ {
23		p := new([]int)
24		*p = append(*p, 1, 2, 3, 4)
25		h := (*reflect.SliceHeader)(unsafe.Pointer(p))
26		all = append(all, h, p)
27	}
28	runtime.GC()
29	for i := 0; i < 100; i++ {
30		p := *all[2*i+1].(*[]int)
31		if p[0] != 1 || p[1] != 2 || p[2] != 3 || p[3] != 4 {
32			println("BUG test1: bad slice at index", i, p[0], p[1], p[2], p[3])
33			return
34		}
35	}
36}
37
38type T struct {
39	H *reflect.SliceHeader
40	P *[]int
41}
42
43func test2() {
44	var all []T
45	for i := 0; i < 100; i++ {
46		p := new([]int)
47		*p = append(*p, 1, 2, 3, 4)
48		h := (*reflect.SliceHeader)(unsafe.Pointer(p))
49		all = append(all, T{H: h}, T{P: p})
50	}
51	runtime.GC()
52	for i := 0; i < 100; i++ {
53		p := *all[2*i+1].P
54		if p[0] != 1 || p[1] != 2 || p[2] != 3 || p[3] != 4 {
55			println("BUG test2: bad slice at index", i, p[0], p[1], p[2], p[3])
56			return
57		}
58	}
59}
60