1// errorcheck -0 -m -l
2
3// Copyright 2015 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// Tests escape analysis for range of arrays.
8// Compiles but need not run.  Inlining is disabled.
9
10package main
11
12type A struct {
13	b [3]uint64
14}
15
16type B struct {
17	b [3]*uint64
18}
19
20func f(a A) int {
21	for i, x := range &a.b {
22		if x != 0 {
23			return 64*i + int(x)
24		}
25	}
26	return 0
27}
28
29func g(a *A) int { // ERROR "a does not escape"
30	for i, x := range &a.b {
31		if x != 0 {
32			return 64*i + int(x)
33		}
34	}
35	return 0
36}
37
38func h(a *B) *uint64 { // ERROR "leaking param: a to result ~r0 level=1"
39	for i, x := range &a.b {
40		if i == 0 {
41			return x
42		}
43	}
44	return nil
45}
46
47func h2(a *B) *uint64 { // ERROR "leaking param: a to result ~r0 level=1"
48	p := &a.b
49	for i, x := range p {
50		if i == 0 {
51			return x
52		}
53	}
54	return nil
55}
56
57// Seems like below should be level=1, not 0.
58func k(a B) *uint64 { // ERROR "leaking param: a to result ~r0 level=0"
59	for i, x := range &a.b {
60		if i == 0 {
61			return x
62		}
63	}
64	return nil
65}
66
67var sink *uint64
68
69func main() {
70	var a1, a2 A
71	var b1, b2, b3, b4 B
72	var x1, x2, x3, x4 uint64 // ERROR "moved to heap: x1" "moved to heap: x3"
73	b1.b[0] = &x1
74	b2.b[0] = &x2
75	b3.b[0] = &x3
76	b4.b[0] = &x4
77	f(a1)
78	g(&a2)
79	sink = h(&b1)
80	h(&b2)
81	sink = h2(&b1)
82	h2(&b4)
83	x1 = 17
84	println("*sink=", *sink) // Verify that sink addresses x1
85	x3 = 42
86	sink = k(b3)
87	println("*sink=", *sink) // Verify that sink addresses x3
88}
89