1// buildrun -t 45
2
3//go:build !js && !wasip1
4
5// Copyright 2021 The Go Authors. All rights reserved.
6// Use of this source code is governed by a BSD-style
7// license that can be found in the LICENSE file.
8
9// Ensure that runtime traceback does not infinite loop for
10// the testcase below.
11
12package main
13
14import (
15	"bytes"
16	"io/ioutil"
17	"log"
18	"os"
19	"os/exec"
20	"path/filepath"
21)
22
23const prog = `
24
25package main
26
27import "context"
28
29var gpi *int
30
31type nAO struct {
32	eE bool
33}
34
35type NAO func(*nAO)
36
37func WEA() NAO {
38	return func(o *nAO) { o.eE = true }
39}
40
41type R struct {
42	cM *CM
43}
44
45type CM int
46
47type A string
48
49func (m *CM) NewA(ctx context.Context, cN string, nn *nAO, opts ...NAO) (*A, error) {
50	for _, o := range opts {
51		o(nn)
52	}
53	s := A("foo")
54	return &s, nil
55}
56
57func (r *R) CA(ctx context.Context, cN string, nn *nAO) (*int, error) {
58	cA, err := r.cM.NewA(ctx, cN, nn, WEA(), WEA())
59	if err == nil {
60		return nil, err
61	}
62	println(cA)
63	x := int(42)
64	return &x, nil
65}
66
67func main() {
68	c := CM(1)
69	r := R{cM: &c}
70	var ctx context.Context
71	nnr := nAO{}
72	pi, err := r.CA(ctx, "foo", nil)
73	if err != nil {
74		panic("bad")
75	}
76	println(nnr.eE)
77	gpi = pi
78}
79`
80
81func main() {
82	dir, err := ioutil.TempDir("", "46234")
83	if err != nil {
84		log.Fatal(err)
85	}
86	defer os.RemoveAll(dir)
87
88	file := filepath.Join(dir, "main.go")
89	if err := ioutil.WriteFile(file, []byte(prog), 0655); err != nil {
90		log.Fatalf("Write error %v", err)
91	}
92
93	cmd := exec.Command("go", "run", file)
94	output, err := cmd.CombinedOutput()
95	if err == nil {
96		log.Fatalf("Passed, expected an error")
97	}
98
99	want := []byte("nil pointer dereference")
100	if !bytes.Contains(output, want) {
101		log.Fatalf("Unmatched error message %q:\nin\n%s\nError: %v", want, output, err)
102	}
103}
104