Source file test/escape_map.go
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 // Test escape analysis for maps. 8 9 package escape 10 11 var sink interface{} 12 13 func map0() { 14 m := make(map[*int]*int) // ERROR "make\(map\[\*int\]\*int\) does not escape" 15 // BAD: i should not escape 16 i := 0 // ERROR "moved to heap: i" 17 // BAD: j should not escape 18 j := 0 // ERROR "moved to heap: j" 19 m[&i] = &j 20 _ = m 21 } 22 23 func map1() *int { 24 m := make(map[*int]*int) // ERROR "make\(map\[\*int\]\*int\) does not escape" 25 // BAD: i should not escape 26 i := 0 // ERROR "moved to heap: i" 27 j := 0 // ERROR "moved to heap: j" 28 m[&i] = &j 29 return m[&i] 30 } 31 32 func map2() map[*int]*int { 33 m := make(map[*int]*int) // ERROR "make\(map\[\*int\]\*int\) escapes to heap" 34 i := 0 // ERROR "moved to heap: i" 35 j := 0 // ERROR "moved to heap: j" 36 m[&i] = &j 37 return m 38 } 39 40 func map3() []*int { 41 m := make(map[*int]*int) // ERROR "make\(map\[\*int\]\*int\) does not escape" 42 i := 0 // ERROR "moved to heap: i" 43 // BAD: j should not escape 44 j := 0 // ERROR "moved to heap: j" 45 m[&i] = &j 46 var r []*int 47 for k := range m { 48 r = append(r, k) 49 } 50 return r 51 } 52 53 func map4() []*int { 54 m := make(map[*int]*int) // ERROR "make\(map\[\*int\]\*int\) does not escape" 55 // BAD: i should not escape 56 i := 0 // ERROR "moved to heap: i" 57 j := 0 // ERROR "moved to heap: j" 58 m[&i] = &j 59 var r []*int 60 for k, v := range m { 61 // We want to test exactly "for k, v := range m" rather than "for _, v := range m". 62 // The following if is merely to use (but not leak) k. 63 if k != nil { 64 r = append(r, v) 65 } 66 } 67 return r 68 } 69 70 func map5(m map[*int]*int) { // ERROR "m does not escape" 71 i := 0 // ERROR "moved to heap: i" 72 j := 0 // ERROR "moved to heap: j" 73 m[&i] = &j 74 } 75 76 func map6(m map[*int]*int) { // ERROR "m does not escape" 77 if m != nil { 78 m = make(map[*int]*int) // ERROR "make\(map\[\*int\]\*int\) does not escape" 79 } 80 i := 0 // ERROR "moved to heap: i" 81 j := 0 // ERROR "moved to heap: j" 82 m[&i] = &j 83 } 84 85 func map7() { 86 // BAD: i should not escape 87 i := 0 // ERROR "moved to heap: i" 88 // BAD: j should not escape 89 j := 0 // ERROR "moved to heap: j" 90 m := map[*int]*int{&i: &j} // ERROR "map\[\*int\]\*int{...} does not escape" 91 _ = m 92 } 93 94 func map8() { 95 i := 0 // ERROR "moved to heap: i" 96 j := 0 // ERROR "moved to heap: j" 97 m := map[*int]*int{&i: &j} // ERROR "map\[\*int\]\*int{...} escapes to heap" 98 sink = m 99 } 100 101 func map9() *int { 102 // BAD: i should not escape 103 i := 0 // ERROR "moved to heap: i" 104 j := 0 // ERROR "moved to heap: j" 105 m := map[*int]*int{&i: &j} // ERROR "map\[\*int\]\*int{...} does not escape" 106 return m[nil] 107 } 108