1// run
2
3// Copyright 2020 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
7// Check to make sure that we compare fields in order. See issue 8606.
8
9package main
10
11import "fmt"
12
13func main() {
14	type A [2]interface{}
15	type A2 [6]interface{}
16	type S struct{ x, y interface{} }
17	type S2 struct{ x, y, z, a, b, c interface{} }
18	type T1 struct {
19		i interface{}
20		a int64
21		j interface{}
22	}
23	type T2 struct {
24		i       interface{}
25		a, b, c int64
26		j       interface{}
27	}
28	type T3 struct {
29		i interface{}
30		s string
31		j interface{}
32	}
33	type S3 struct {
34		f any
35		i int
36	}
37	type S4 struct {
38		a [1000]byte
39		b any
40	}
41	b := []byte{1}
42	s1 := S3{func() {}, 0}
43	s2 := S3{func() {}, 1}
44
45	for _, test := range []struct {
46		panic bool
47		a, b  interface{}
48	}{
49		{false, A{1, b}, A{2, b}},
50		{true, A{b, 1}, A{b, 2}},
51		{false, A{1, b}, A{"2", b}},
52		{true, A{b, 1}, A{b, "2"}},
53
54		{false, A2{1, b}, A2{2, b}},
55		{true, A2{b, 1}, A2{b, 2}},
56		{false, A2{1, b}, A2{"2", b}},
57		{true, A2{b, 1}, A2{b, "2"}},
58
59		{false, S{1, b}, S{2, b}},
60		{true, S{b, 1}, S{b, 2}},
61		{false, S{1, b}, S{"2", b}},
62		{true, S{b, 1}, S{b, "2"}},
63
64		{false, S2{x: 1, y: b}, S2{x: 2, y: b}},
65		{true, S2{x: b, y: 1}, S2{x: b, y: 2}},
66		{false, S2{x: 1, y: b}, S2{x: "2", y: b}},
67		{true, S2{x: b, y: 1}, S2{x: b, y: "2"}},
68
69		{true, T1{i: b, a: 1}, T1{i: b, a: 2}},
70		{false, T1{a: 1, j: b}, T1{a: 2, j: b}},
71		{true, T2{i: b, a: 1}, T2{i: b, a: 2}},
72		{false, T2{a: 1, j: b}, T2{a: 2, j: b}},
73		{true, T3{i: b, s: "foo"}, T3{i: b, s: "bar"}},
74		{false, T3{s: "foo", j: b}, T3{s: "bar", j: b}},
75		{true, T3{i: b, s: "fooz"}, T3{i: b, s: "bar"}},
76		{false, T3{s: "fooz", j: b}, T3{s: "bar", j: b}},
77		{true, A{s1, s2}, A{s2, s1}},
78		{true, s1, s2},
79		{false, S4{[1000]byte{0}, func() {}}, S4{[1000]byte{1}, func() {}}},
80	} {
81		f := func() {
82			defer func() {
83				if recover() != nil {
84					panic(fmt.Sprintf("comparing %#v and %#v panicked", test.a, test.b))
85				}
86			}()
87			if test.a == test.b {
88				panic(fmt.Sprintf("values %#v and %#v should not be equal", test.a, test.b))
89			}
90		}
91		if test.panic {
92			shouldPanic(fmt.Sprintf("comparing %#v and %#v did not panic", test.a, test.b), f)
93		} else {
94			f() // should not panic
95		}
96	}
97}
98
99func shouldPanic(name string, f func()) {
100	defer func() {
101		if recover() == nil {
102			panic(name)
103		}
104	}()
105	f()
106}
107