1 // errorcheck -+ -0 -l -d=wb 2 3 // Copyright 2016 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 write barrier elimination for notinheap. 8 9 package p 10 11 type t1 struct { 12 x *nih 13 s []nih 14 y [1024]byte // Prevent write decomposition 15 } 16 17 type t2 struct { 18 x *ih 19 s []ih 20 y [1024]byte 21 } 22 23 //go:notinheap 24 type nih struct { 25 x uintptr 26 } 27 28 type ih struct { // In-heap type 29 x uintptr 30 } 31 32 var ( 33 v1 t1 34 v2 t2 35 36 v1s []t1 37 v2s []t2 38 ) 39 40 func f() { 41 // Test direct writes 42 v1.x = nil // no barrier 43 v2.x = nil // ERROR "write barrier" 44 v1.s = []nih(nil) // no barrier 45 v2.s = []ih(nil) // ERROR "write barrier" 46 } 47 48 func g() { 49 // Test aggregate writes 50 v1 = t1{x: nil} // no barrier 51 v2 = t2{x: nil} // ERROR "write barrier" 52 } 53 54 func h() { 55 // Test copies and appends. 56 copy(v1s, v1s[1:]) // no barrier 57 copy(v2s, v2s[1:]) // ERROR "write barrier" 58 _ = append(v1s, v1s...) // no barrier 59 _ = append(v2s, v2s...) // ERROR "write barrier" 60 } 61
