1 // Copyright 2014 The Go Authors. All rights reserved. 2 // Use of this source code is governed by a BSD-style 3 // license that can be found in the LICENSE file. 4 5 package testdata 6 7 import ( 8 "reflect" 9 "unsafe" 10 ) 11 12 func f() { 13 var x unsafe.Pointer 14 var y uintptr 15 x = unsafe.Pointer(y) // ERROR "possible misuse of unsafe.Pointer" 16 y = uintptr(x) 17 18 // only allowed pointer arithmetic is ptr +/-/&^ num. 19 // num+ptr is technically okay but still flagged: write ptr+num instead. 20 x = unsafe.Pointer(uintptr(x) + 1) 21 x = unsafe.Pointer(1 + uintptr(x)) // ERROR "possible misuse of unsafe.Pointer" 22 x = unsafe.Pointer(uintptr(x) + uintptr(x)) // ERROR "possible misuse of unsafe.Pointer" 23 x = unsafe.Pointer(uintptr(x) - 1) 24 x = unsafe.Pointer(1 - uintptr(x)) // ERROR "possible misuse of unsafe.Pointer" 25 x = unsafe.Pointer(uintptr(x) &^ 3) 26 x = unsafe.Pointer(1 &^ uintptr(x)) // ERROR "possible misuse of unsafe.Pointer" 27 28 // certain uses of reflect are okay 29 var v reflect.Value 30 x = unsafe.Pointer(v.Pointer()) 31 x = unsafe.Pointer(v.UnsafeAddr()) 32 var s1 *reflect.StringHeader 33 x = unsafe.Pointer(s1.Data) 34 var s2 *reflect.SliceHeader 35 x = unsafe.Pointer(s2.Data) 36 var s3 reflect.StringHeader 37 x = unsafe.Pointer(s3.Data) // ERROR "possible misuse of unsafe.Pointer" 38 var s4 reflect.SliceHeader 39 x = unsafe.Pointer(s4.Data) // ERROR "possible misuse of unsafe.Pointer" 40 41 // but only in reflect 42 var vv V 43 x = unsafe.Pointer(vv.Pointer()) // ERROR "possible misuse of unsafe.Pointer" 44 x = unsafe.Pointer(vv.UnsafeAddr()) // ERROR "possible misuse of unsafe.Pointer" 45 var ss1 *StringHeader 46 x = unsafe.Pointer(ss1.Data) // ERROR "possible misuse of unsafe.Pointer" 47 var ss2 *SliceHeader 48 x = unsafe.Pointer(ss2.Data) // ERROR "possible misuse of unsafe.Pointer" 49 50 } 51 52 type V interface { 53 Pointer() uintptr 54 UnsafeAddr() uintptr 55 } 56 57 type StringHeader struct { 58 Data uintptr 59 } 60 61 type SliceHeader struct { 62 Data uintptr 63 } 64
