1 // run 2 3 // Copyright 2010 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 that structures pack densely, according to the alignment of the largest field. 8 9 package main 10 11 import ( 12 "fmt" 13 "os" 14 "strconv" 15 ) 16 17 type T1 struct { 18 x uint8 19 } 20 type T2 struct { 21 x uint16 22 } 23 type T4 struct { 24 x uint32 25 } 26 27 func main() { 28 report := len(os.Args) > 1 29 status := 0 30 var b1 [10]T1 31 a0, _ := strconv.ParseUint(fmt.Sprintf("%p", &b1[0])[2:], 16, 64) 32 a1, _ := strconv.ParseUint(fmt.Sprintf("%p", &b1[1])[2:], 16, 64) 33 if a1 != a0+1 { 34 fmt.Println("FAIL") 35 if report { 36 fmt.Println("alignment should be 1, is", a1-a0) 37 } 38 status = 1 39 } 40 var b2 [10]T2 41 a0, _ = strconv.ParseUint(fmt.Sprintf("%p", &b2[0])[2:], 16, 64) 42 a1, _ = strconv.ParseUint(fmt.Sprintf("%p", &b2[1])[2:], 16, 64) 43 if a1 != a0+2 { 44 if status == 0 { 45 fmt.Println("FAIL") 46 status = 1 47 } 48 if report { 49 fmt.Println("alignment should be 2, is", a1-a0) 50 } 51 } 52 var b4 [10]T4 53 a0, _ = strconv.ParseUint(fmt.Sprintf("%p", &b4[0])[2:], 16, 64) 54 a1, _ = strconv.ParseUint(fmt.Sprintf("%p", &b4[1])[2:], 16, 64) 55 if a1 != a0+4 { 56 if status == 0 { 57 fmt.Println("FAIL") 58 status = 1 59 } 60 if report { 61 fmt.Println("alignment should be 4, is", a1-a0) 62 } 63 } 64 os.Exit(status) 65 } 66
