Home | History | Annotate | Download | only in test 
      1 // run
      2 
      3 // Copyright 2011 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 package main
      8 
      9 import "unsafe"
     10 
     11 type T struct {
     12 	X int
     13 }
     14 
     15 var t T
     16 
     17 func isUintptr(uintptr) {}
     18 
     19 type T2 struct {
     20 	A int32
     21 	U2
     22 }
     23 
     24 type U2 struct {
     25 	B int32
     26 	C int32
     27 }
     28 
     29 var t2 T2
     30 var p2 *T2
     31 
     32 func main() {
     33 	// Test unsafe.Sizeof, unsafe.Alignof, and unsafe.Offsetof all return uintptr.
     34 	isUintptr(unsafe.Sizeof(t))
     35 	isUintptr(unsafe.Alignof(t))
     36 	isUintptr(unsafe.Offsetof(t.X))
     37 
     38 	// Test correctness of Offsetof with respect to embedded fields (issue 4909).
     39 	if unsafe.Offsetof(t2.C) != 8 {
     40 		println(unsafe.Offsetof(t2.C), "!= 8")
     41 		panic("unsafe.Offsetof(t2.C) != 8")
     42 	}
     43 	if unsafe.Offsetof(p2.C) != 8 {
     44 		println(unsafe.Offsetof(p2.C), "!= 8")
     45 		panic("unsafe.Offsetof(p2.C) != 8")
     46 	}
     47 	if unsafe.Offsetof(t2.U2.C) != 4 {
     48 		println(unsafe.Offsetof(t2.U2.C), "!= 4")
     49 		panic("unsafe.Offsetof(t2.U2.C) != 4")
     50 	}
     51 	if unsafe.Offsetof(p2.U2.C) != 4 {
     52 		println(unsafe.Offsetof(p2.U2.C), "!= 4")
     53 		panic("unsafe.Offsetof(p2.U2.C) != 4")
     54 	}
     55 	testDeep()
     56 	testNotEmbedded()
     57 }
     58 
     59 type (
     60 	S1 struct {
     61 		A int64
     62 		S2
     63 	}
     64 	S2 struct {
     65 		B int64
     66 		S3
     67 	}
     68 	S3 struct {
     69 		C int64
     70 		S4
     71 	}
     72 	S4 struct {
     73 		D int64
     74 		S5
     75 	}
     76 	S5 struct {
     77 		E int64
     78 		S6
     79 	}
     80 	S6 struct {
     81 		F int64
     82 		S7
     83 	}
     84 	S7 struct {
     85 		G int64
     86 		S8
     87 	}
     88 	S8 struct {
     89 		H int64
     90 		*S1
     91 	}
     92 )
     93 
     94 func testDeep() {
     95 	var s1 S1
     96 	switch {
     97 	case unsafe.Offsetof(s1.A) != 0:
     98 		panic("unsafe.Offsetof(s1.A) != 0")
     99 	case unsafe.Offsetof(s1.B) != 8:
    100 		panic("unsafe.Offsetof(s1.B) != 8")
    101 	case unsafe.Offsetof(s1.C) != 16:
    102 		panic("unsafe.Offsetof(s1.C) != 16")
    103 	case unsafe.Offsetof(s1.D) != 24:
    104 		panic("unsafe.Offsetof(s1.D) != 24")
    105 	case unsafe.Offsetof(s1.E) != 32:
    106 		panic("unsafe.Offsetof(s1.E) != 32")
    107 	case unsafe.Offsetof(s1.F) != 40:
    108 		panic("unsafe.Offsetof(s1.F) != 40")
    109 	case unsafe.Offsetof(s1.G) != 48:
    110 		panic("unsafe.Offsetof(s1.G) != 48")
    111 	case unsafe.Offsetof(s1.H) != 56:
    112 		panic("unsafe.Offsetof(s1.H) != 56")
    113 	case unsafe.Offsetof(s1.S1) != 64:
    114 		panic("unsafe.Offsetof(s1.S1) != 64")
    115 	case unsafe.Offsetof(s1.S1.S2.S3.S4.S5.S6.S7.S8.S1.S2) != 8:
    116 		panic("unsafe.Offsetof(s1.S1.S2.S3.S4.S5.S6.S7.S8.S1.S2) != 8")
    117 	}
    118 }
    119 
    120 func testNotEmbedded() {
    121 	type T2 struct {
    122 		B int32
    123 		C int32
    124 	}
    125 	type T1 struct {
    126 		A int32
    127 		T2
    128 	}
    129 	type T struct {
    130 		Dummy int32
    131 		F     T1
    132 		P     *T1
    133 	}
    134 
    135 	var t T
    136 	var p *T
    137 	switch {
    138 	case unsafe.Offsetof(t.F.B) != 4:
    139 		panic("unsafe.Offsetof(t.F.B) != 4")
    140 	case unsafe.Offsetof(t.F.C) != 8:
    141 		panic("unsafe.Offsetof(t.F.C) != 8")
    142 
    143 	case unsafe.Offsetof(t.P.B) != 4:
    144 		panic("unsafe.Offsetof(t.P.B) != 4")
    145 	case unsafe.Offsetof(t.P.C) != 8:
    146 		panic("unsafe.Offsetof(t.P.C) != 8")
    147 
    148 	case unsafe.Offsetof(p.F.B) != 4:
    149 		panic("unsafe.Offsetof(p.F.B) != 4")
    150 	case unsafe.Offsetof(p.F.C) != 8:
    151 		panic("unsafe.Offsetof(p.F.C) != 8")
    152 
    153 	case unsafe.Offsetof(p.P.B) != 4:
    154 		panic("unsafe.Offsetof(p.P.B) != 4")
    155 	case unsafe.Offsetof(p.P.C) != 8:
    156 		panic("unsafe.Offsetof(p.P.C) != 8")
    157 	}
    158 }
    159