// run
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// Copyright 2011 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package main
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import "unsafe"
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type T struct {
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X int
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}
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var t T
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func isUintptr(uintptr) {}
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type T2 struct {
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A int32
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U2
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}
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type U2 struct {
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B int32
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C int32
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}
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var t2 T2
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var p2 *T2
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func main() {
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// Test unsafe.Sizeof, unsafe.Alignof, and unsafe.Offsetof all return uintptr.
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isUintptr(unsafe.Sizeof(t))
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isUintptr(unsafe.Alignof(t))
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isUintptr(unsafe.Offsetof(t.X))
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// Test correctness of Offsetof with respect to embedded fields (issue 4909).
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if unsafe.Offsetof(t2.C) != 8 {
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println(unsafe.Offsetof(t2.C), "!= 8")
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panic("unsafe.Offsetof(t2.C) != 8")
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}
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if unsafe.Offsetof(p2.C) != 8 {
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println(unsafe.Offsetof(p2.C), "!= 8")
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panic("unsafe.Offsetof(p2.C) != 8")
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}
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if unsafe.Offsetof(t2.U2.C) != 4 {
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println(unsafe.Offsetof(t2.U2.C), "!= 4")
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panic("unsafe.Offsetof(t2.U2.C) != 4")
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}
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if unsafe.Offsetof(p2.U2.C) != 4 {
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println(unsafe.Offsetof(p2.U2.C), "!= 4")
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panic("unsafe.Offsetof(p2.U2.C) != 4")
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}
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testDeep()
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testNotEmbedded()
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}
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type (
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S1 struct {
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A int64
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S2
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}
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S2 struct {
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B int64
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S3
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}
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S3 struct {
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C int64
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S4
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}
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S4 struct {
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D int64
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S5
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}
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S5 struct {
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E int64
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S6
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}
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S6 struct {
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F int64
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S7
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}
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S7 struct {
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G int64
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S8
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}
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S8 struct {
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H int64
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*S1
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}
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)
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func testDeep() {
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var s1 S1
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switch {
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case unsafe.Offsetof(s1.A) != 0:
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panic("unsafe.Offsetof(s1.A) != 0")
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case unsafe.Offsetof(s1.B) != 8:
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panic("unsafe.Offsetof(s1.B) != 8")
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case unsafe.Offsetof(s1.C) != 16:
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panic("unsafe.Offsetof(s1.C) != 16")
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case unsafe.Offsetof(s1.D) != 24:
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panic("unsafe.Offsetof(s1.D) != 24")
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case unsafe.Offsetof(s1.E) != 32:
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panic("unsafe.Offsetof(s1.E) != 32")
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case unsafe.Offsetof(s1.F) != 40:
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panic("unsafe.Offsetof(s1.F) != 40")
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case unsafe.Offsetof(s1.G) != 48:
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panic("unsafe.Offsetof(s1.G) != 48")
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case unsafe.Offsetof(s1.H) != 56:
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panic("unsafe.Offsetof(s1.H) != 56")
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case unsafe.Offsetof(s1.S1) != 64:
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panic("unsafe.Offsetof(s1.S1) != 64")
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case unsafe.Offsetof(s1.S1.S2.S3.S4.S5.S6.S7.S8.S1.S2) != 8:
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panic("unsafe.Offsetof(s1.S1.S2.S3.S4.S5.S6.S7.S8.S1.S2) != 8")
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}
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}
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func testNotEmbedded() {
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type T2 struct {
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B int32
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C int32
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}
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type T1 struct {
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A int32
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T2
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}
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type T struct {
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Dummy int32
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F T1
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P *T1
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}
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var t T
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var p *T
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switch {
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case unsafe.Offsetof(t.F.B) != 4:
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panic("unsafe.Offsetof(t.F.B) != 4")
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case unsafe.Offsetof(t.F.C) != 8:
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panic("unsafe.Offsetof(t.F.C) != 8")
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case unsafe.Offsetof(t.P.B) != 4:
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panic("unsafe.Offsetof(t.P.B) != 4")
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case unsafe.Offsetof(t.P.C) != 8:
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panic("unsafe.Offsetof(t.P.C) != 8")
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case unsafe.Offsetof(p.F.B) != 4:
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panic("unsafe.Offsetof(p.F.B) != 4")
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case unsafe.Offsetof(p.F.C) != 8:
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panic("unsafe.Offsetof(p.F.C) != 8")
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case unsafe.Offsetof(p.P.B) != 4:
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panic("unsafe.Offsetof(p.P.B) != 4")
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case unsafe.Offsetof(p.P.C) != 8:
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panic("unsafe.Offsetof(p.P.C) != 8")
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}
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}
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