|  | // run | 
|  |  | 
|  | // Copyright 2013 The Go Authors.  All rights reserved. | 
|  | // Use of this source code is governed by a BSD-style | 
|  | // license that can be found in the LICENSE file. | 
|  |  | 
|  | package main | 
|  |  | 
|  | // Concrete types implementing M method. | 
|  | // Smaller than a word, word-sized, larger than a word. | 
|  | // Value and pointer receivers. | 
|  |  | 
|  | type Tinter interface { | 
|  | M(int, byte) (byte, int) | 
|  | } | 
|  |  | 
|  | type Tsmallv byte | 
|  |  | 
|  | func (v Tsmallv) M(x int, b byte) (byte, int) { return b, x+int(v) } | 
|  |  | 
|  | type Tsmallp byte | 
|  |  | 
|  | func (p *Tsmallp) M(x int, b byte) (byte, int) { return b, x+int(*p) } | 
|  |  | 
|  | type Twordv uintptr | 
|  |  | 
|  | func (v Twordv) M(x int, b byte) (byte, int) { return b, x+int(v) } | 
|  |  | 
|  | type Twordp uintptr | 
|  |  | 
|  | func (p *Twordp) M(x int, b byte) (byte, int) { return b, x+int(*p) } | 
|  |  | 
|  | type Tbigv [2]uintptr | 
|  |  | 
|  | func (v Tbigv) M(x int, b byte) (byte, int) { return b, x+int(v[0])+int(v[1]) } | 
|  |  | 
|  | type Tbigp [2]uintptr | 
|  |  | 
|  | func (p *Tbigp) M(x int, b byte) (byte, int) { return b, x+int(p[0])+int(p[1]) } | 
|  |  | 
|  | // Again, with an unexported method. | 
|  |  | 
|  | type tsmallv byte | 
|  |  | 
|  | func (v tsmallv) m(x int, b byte) (byte, int) { return b, x+int(v) } | 
|  |  | 
|  | type tsmallp byte | 
|  |  | 
|  | func (p *tsmallp) m(x int, b byte) (byte, int) { return b, x+int(*p) } | 
|  |  | 
|  | type twordv uintptr | 
|  |  | 
|  | func (v twordv) m(x int, b byte) (byte, int) { return b, x+int(v) } | 
|  |  | 
|  | type twordp uintptr | 
|  |  | 
|  | func (p *twordp) m(x int, b byte) (byte, int) { return b, x+int(*p) } | 
|  |  | 
|  | type tbigv [2]uintptr | 
|  |  | 
|  | func (v tbigv) m(x int, b byte) (byte, int) { return b, x+int(v[0])+int(v[1]) } | 
|  |  | 
|  | type tbigp [2]uintptr | 
|  |  | 
|  | func (p *tbigp) m(x int, b byte) (byte, int) { return b, x+int(p[0])+int(p[1]) } | 
|  |  | 
|  | type tinter interface { | 
|  | m(int, byte) (byte, int) | 
|  | } | 
|  |  | 
|  | // Embedding via pointer. | 
|  |  | 
|  | type T1 struct { | 
|  | T2 | 
|  | } | 
|  |  | 
|  | type T2 struct { | 
|  | *T3 | 
|  | } | 
|  |  | 
|  | type T3 struct { | 
|  | *T4 | 
|  | } | 
|  |  | 
|  | type T4 struct { | 
|  | } | 
|  |  | 
|  | func (t4 T4) M(x int, b byte) (byte, int) { return b, x+40 } | 
|  |  | 
|  | var failed = false | 
|  |  | 
|  | func CheckI(name string, i Tinter, inc int) { | 
|  | b, x := i.M(1000, 99) | 
|  | if b != 99 || x != 1000+inc { | 
|  | failed = true | 
|  | print(name, ".M(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n") | 
|  | } | 
|  |  | 
|  | CheckF("(i="+name+")", i.M, inc) | 
|  | } | 
|  |  | 
|  | func CheckF(name string, f func(int, byte) (byte, int), inc int) { | 
|  | b, x := f(1000, 99) | 
|  | if b != 99 || x != 1000+inc { | 
|  | failed = true | 
|  | print(name, "(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n") | 
|  | } | 
|  | } | 
|  |  | 
|  | func checkI(name string, i tinter, inc int) { | 
|  | b, x := i.m(1000, 99) | 
|  | if b != 99 || x != 1000+inc { | 
|  | failed = true | 
|  | print(name, ".m(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n") | 
|  | } | 
|  |  | 
|  | checkF("(i="+name+")", i.m, inc) | 
|  | } | 
|  |  | 
|  | func checkF(name string, f func(int, byte) (byte, int), inc int) { | 
|  | b, x := f(1000, 99) | 
|  | if b != 99 || x != 1000+inc { | 
|  | failed = true | 
|  | print(name, "(1000, 99) = ", b, ", ", x, " want 99, ", 1000+inc, "\n") | 
|  | } | 
|  | } | 
|  |  | 
|  | func shouldPanic(f func()) { | 
|  | defer func() { | 
|  | if recover() == nil { | 
|  | panic("not panicking") | 
|  | } | 
|  | }() | 
|  | f() | 
|  | } | 
|  |  | 
|  | func shouldNotPanic(f func()) { | 
|  | f() | 
|  | } | 
|  |  | 
|  | func main() { | 
|  | sv := Tsmallv(1) | 
|  | CheckI("sv", sv, 1) | 
|  | CheckF("sv.M", sv.M, 1) | 
|  | CheckF("(&sv).M", (&sv).M, 1) | 
|  | psv := &sv | 
|  | CheckI("psv", psv, 1) | 
|  | CheckF("psv.M", psv.M, 1) | 
|  | CheckF("(*psv).M", (*psv).M, 1) | 
|  |  | 
|  | sp := Tsmallp(2) | 
|  | CheckI("&sp", &sp, 2) | 
|  | CheckF("sp.M", sp.M, 2) | 
|  | CheckF("(&sp).M", (&sp).M, 2) | 
|  | psp := &sp | 
|  | CheckI("psp", psp, 2) | 
|  | CheckF("psp.M", psp.M, 2) | 
|  | CheckF("(*psp).M", (*psp).M, 2) | 
|  |  | 
|  | wv := Twordv(3) | 
|  | CheckI("wv", wv, 3) | 
|  | CheckF("wv.M", wv.M, 3) | 
|  | CheckF("(&wv).M", (&wv).M, 3) | 
|  | pwv := &wv | 
|  | CheckI("pwv", pwv, 3) | 
|  | CheckF("pwv.M", pwv.M, 3) | 
|  | CheckF("(*pwv).M", (*pwv).M, 3) | 
|  |  | 
|  | wp := Twordp(4) | 
|  | CheckI("&wp", &wp, 4) | 
|  | CheckF("wp.M", wp.M, 4) | 
|  | CheckF("(&wp).M", (&wp).M, 4) | 
|  | pwp := &wp | 
|  | CheckI("pwp", pwp, 4) | 
|  | CheckF("pwp.M", pwp.M, 4) | 
|  | CheckF("(*pwp).M", (*pwp).M, 4) | 
|  |  | 
|  | bv := Tbigv([2]uintptr{5, 6}) | 
|  | pbv := &bv | 
|  | CheckI("bv", bv, 11) | 
|  | CheckF("bv.M", bv.M, 11) | 
|  | CheckF("(&bv).M", (&bv).M, 11) | 
|  | CheckI("pbv", pbv, 11) | 
|  | CheckF("pbv.M", pbv.M, 11) | 
|  | CheckF("(*pbv).M", (*pbv).M, 11) | 
|  |  | 
|  | bp := Tbigp([2]uintptr{7,8}) | 
|  | CheckI("&bp", &bp, 15) | 
|  | CheckF("bp.M", bp.M, 15) | 
|  | CheckF("(&bp).M", (&bp).M, 15) | 
|  | pbp := &bp | 
|  | CheckI("pbp", pbp, 15) | 
|  | CheckF("pbp.M", pbp.M, 15) | 
|  | CheckF("(*pbp).M", (*pbp).M, 15) | 
|  |  | 
|  | _sv := tsmallv(1) | 
|  | checkI("_sv", _sv, 1) | 
|  | checkF("_sv.m", _sv.m, 1) | 
|  | checkF("(&_sv).m", (&_sv).m, 1) | 
|  | _psv := &_sv | 
|  | checkI("_psv", _psv, 1) | 
|  | checkF("_psv.m", _psv.m, 1) | 
|  | checkF("(*_psv).m", (*_psv).m, 1) | 
|  |  | 
|  | _sp := tsmallp(2) | 
|  | checkI("&_sp", &_sp, 2) | 
|  | checkF("_sp.m", _sp.m, 2) | 
|  | checkF("(&_sp).m", (&_sp).m, 2) | 
|  | _psp := &_sp | 
|  | checkI("_psp", _psp, 2) | 
|  | checkF("_psp.m", _psp.m, 2) | 
|  | checkF("(*_psp).m", (*_psp).m, 2) | 
|  |  | 
|  | _wv := twordv(3) | 
|  | checkI("_wv", _wv, 3) | 
|  | checkF("_wv.m", _wv.m, 3) | 
|  | checkF("(&_wv).m", (&_wv).m, 3) | 
|  | _pwv := &_wv | 
|  | checkI("_pwv", _pwv, 3) | 
|  | checkF("_pwv.m", _pwv.m, 3) | 
|  | checkF("(*_pwv).m", (*_pwv).m, 3) | 
|  |  | 
|  | _wp := twordp(4) | 
|  | checkI("&_wp", &_wp, 4) | 
|  | checkF("_wp.m", _wp.m, 4) | 
|  | checkF("(&_wp).m", (&_wp).m, 4) | 
|  | _pwp := &_wp | 
|  | checkI("_pwp", _pwp, 4) | 
|  | checkF("_pwp.m", _pwp.m, 4) | 
|  | checkF("(*_pwp).m", (*_pwp).m, 4) | 
|  |  | 
|  | _bv := tbigv([2]uintptr{5, 6}) | 
|  | _pbv := &_bv | 
|  | checkI("_bv", _bv, 11) | 
|  | checkF("_bv.m", _bv.m, 11) | 
|  | checkF("(&_bv).m", (&_bv).m, 11) | 
|  | checkI("_pbv", _pbv, 11) | 
|  | checkF("_pbv.m", _pbv.m, 11) | 
|  | checkF("(*_pbv).m", (*_pbv).m, 11) | 
|  |  | 
|  | _bp := tbigp([2]uintptr{7,8}) | 
|  | checkI("&_bp", &_bp, 15) | 
|  | checkF("_bp.m", _bp.m, 15) | 
|  | checkF("(&_bp).m", (&_bp).m, 15) | 
|  | _pbp := &_bp | 
|  | checkI("_pbp", _pbp, 15) | 
|  | checkF("_pbp.m", _pbp.m, 15) | 
|  | checkF("(*_pbp).m", (*_pbp).m, 15) | 
|  |  | 
|  | t4 := T4{} | 
|  | t3 := T3{&t4} | 
|  | t2 := T2{&t3} | 
|  | t1 := T1{t2} | 
|  | CheckI("t4", t4, 40) | 
|  | CheckI("&t4", &t4, 40) | 
|  | CheckI("t3", t3, 40) | 
|  | CheckI("&t3", &t3, 40) | 
|  | CheckI("t2", t2, 40) | 
|  | CheckI("&t2", &t2, 40) | 
|  | CheckI("t1", t1, 40) | 
|  | CheckI("&t1", &t1, 40) | 
|  |  | 
|  | // x.M panics if x is an interface type and is nil, | 
|  | // or if x.M expands to (*x).M where x is nil, | 
|  | // or if x.M expands to x.y.z.w.M where something | 
|  | // along the evaluation of x.y.z.w is nil. | 
|  | var f func(int, byte) (byte, int) | 
|  | shouldPanic(func() { psv = nil; f = psv.M }) | 
|  | shouldPanic(func() { pwv = nil; f = pwv.M }) | 
|  | shouldPanic(func() { pbv = nil; f = pbv.M }) | 
|  | shouldPanic(func() { var i Tinter; f = i.M }) | 
|  | shouldPanic(func() { _psv = nil; f = _psv.m }) | 
|  | shouldPanic(func() { _pwv = nil; f = _pwv.m }) | 
|  | shouldPanic(func() { _pbv = nil; f = _pbv.m }) | 
|  | shouldPanic(func() { var _i tinter; f = _i.m }) | 
|  | shouldPanic(func() { var t1 T1; f = t1.M }) | 
|  | shouldPanic(func() { var t2 T2; f = t2.M }) | 
|  | shouldPanic(func() { var t3 *T3; f = t3.M }) | 
|  | shouldPanic(func() { var t3 T3; f = t3.M }) | 
|  |  | 
|  | if f != nil { | 
|  | panic("something set f") | 
|  | } | 
|  |  | 
|  | // x.M does not panic if x is a nil pointer and | 
|  | // M is a method with a pointer receiver. | 
|  | shouldNotPanic(func() { psp = nil; f = psp.M }) | 
|  | shouldNotPanic(func() { pwp = nil; f = pwp.M }) | 
|  | shouldNotPanic(func() { pbp = nil; f = pbp.M }) | 
|  | shouldNotPanic(func() { _psp = nil; f = _psp.m }) | 
|  | shouldNotPanic(func() { _pwp = nil; f = _pwp.m }) | 
|  | shouldNotPanic(func() { _pbp = nil; f = _pbp.m }) | 
|  | shouldNotPanic(func() { var t4 T4; f = t4.M }) | 
|  | if f == nil { | 
|  | panic("nothing set f") | 
|  | } | 
|  | } |