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 10 package main 11 12 type A struct { 13 b [3]uint64 14 } 15 16 type B struct { 17 b [3]*uint64 18 } 19 20 func f(a A) int { 21 for i, x := range &a.b { // ERROR "f &a.b does not escape" 22 if x != 0 { 23 return 64*i + int(x) 24 } 25 } 26 return 0 27 } 28 29 func g(a *A) int { // ERROR "g a does not escape" 30 for i, x := range &a.b { // ERROR "g &a.b does not escape" 31 if x != 0 { 32 return 64*i + int(x) 33 } 34 } 35 return 0 36 } 37 38 func h(a *B) *uint64 { // ERROR "leaking param: a to result ~r1 level=1" 39 for i, x := range &a.b { // ERROR "h &a.b does not escape" 40 if i == 0 { 41 return x 42 } 43 } 44 return nil 45 } 46 47 func h2(a *B) *uint64 { // ERROR "leaking param: a to result ~r1 level=1" 48 p := &a.b // ERROR "h2 &a.b does not escape" 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. 58 func k(a B) *uint64 { // ERROR "leaking param: a to result ~r1 level=0" 59 for i, x := range &a.b { // ERROR "k &a.b does not escape" 60 if i == 0 { 61 return x 62 } 63 } 64 return nil 65 } 66 67 var sink *uint64 68 69 func 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 // ERROR "&x1 escapes to heap" 74 b2.b[0] = &x2 // ERROR "main &x2 does not escape" 75 b3.b[0] = &x3 // ERROR "&x3 escapes to heap" 76 b4.b[0] = &x4 // ERROR "main &x4 does not escape" 77 f(a1) 78 g(&a2) // ERROR "main &a2 does not escape" 79 sink = h(&b1) // ERROR "main &b1 does not escape" 80 h(&b2) // ERROR "main &b2 does not escape" 81 sink = h2(&b1) // ERROR "main &b1 does not escape" 82 h2(&b4) // ERROR "main &b4 does not escape" 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
