1 // run 2 3 // Copyright 2016 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 ( 10 "fmt" 11 "io" 12 "os" 13 "reflect" 14 "unsafe" 15 ) 16 17 type RWS struct{} 18 19 func (x *RWS) Read(p []byte) (n int, err error) { return } 20 func (x *RWS) Write(p []byte) (n int, err error) { return } 21 func (x *RWS) Seek(offset int64, whence int) (n int64, err error) { return } 22 func (x *RWS) String() string { return "rws" } 23 24 func makeRWS() io.ReadWriteSeeker { return &RWS{} } 25 func makeStringer() fmt.Stringer { return &RWS{} } 26 27 // Test correct construction of static empty interface values 28 var efaces = [...]struct { 29 x interface{} 30 s string 31 }{ 32 {nil, "<nil> <nil>"}, 33 {1, "int 1"}, 34 {int(1), "int 1"}, 35 {Int(int(2)), "main.Int Int=2"}, 36 {int(Int(3)), "int 3"}, 37 {[1]int{2}, "[1]int [2]"}, 38 {io.Reader(io.ReadWriter(io.ReadWriteSeeker(nil))), "<nil> <nil>"}, 39 {io.Reader(io.ReadWriter(io.ReadWriteSeeker(&RWS{}))), "*main.RWS rws"}, 40 {makeRWS(), "*main.RWS rws"}, 41 {map[string]string{"here": "there"}, "map[string]string map[here:there]"}, 42 {chan bool(nil), "chan bool <nil>"}, 43 {unsafe.Pointer(uintptr(0)), "unsafe.Pointer <nil>"}, 44 {(*byte)(nil), "*uint8 <nil>"}, 45 {io.Writer((*os.File)(nil)), "*os.File <nil>"}, 46 {(interface{})(io.Writer((*os.File)(nil))), "*os.File <nil>"}, 47 {fmt.Stringer(Strunger(((*Int)(nil)))), "*main.Int <nil>"}, 48 } 49 50 type Int int 51 52 func (i Int) String() string { return fmt.Sprintf("Int=%d", i) } 53 func (i Int) Strung() {} 54 55 type Strunger interface { 56 fmt.Stringer 57 Strung() 58 } 59 60 // Test correct construction of static non-empty interface values 61 var ifaces = [...]struct { 62 x fmt.Stringer 63 s string 64 }{ 65 {nil, "<nil> <nil> %!s(<nil>)"}, 66 {Int(3), "main.Int 3 Int=3"}, 67 {Int(int(Int(4))), "main.Int 4 Int=4"}, 68 {Strunger(Int(5)), "main.Int 5 Int=5"}, 69 {makeStringer(), "*main.RWS &main.RWS{} rws"}, 70 {fmt.Stringer(nil), "<nil> <nil> %!s(<nil>)"}, 71 {(*RWS)(nil), "*main.RWS (*main.RWS)(nil) rws"}, 72 } 73 74 // Test correct handling of direct interface values 75 var ( 76 one int = 1 77 iptr interface{} = &one 78 clos int 79 f interface{} = func() { clos++ } 80 deep interface{} = [1]struct{ a *[2]byte }{{a: &[2]byte{'z', 'w'}}} 81 ch interface{} = make(chan bool, 1) 82 ) 83 84 func main() { 85 var fail bool 86 for i, test := range efaces { 87 s := fmt.Sprintf("%[1]T %[1]v", test.x) 88 if s != test.s { 89 fmt.Printf("eface(%d)=%q want %q\n", i, s, test.s) 90 fail = true 91 } 92 } 93 94 for i, test := range ifaces { 95 s := fmt.Sprintf("%[1]T %#[1]v %[1]s", test.x) 96 if s != test.s { 97 fmt.Printf("iface(%d)=%q want %q\n", i, s, test.s) 98 fail = true 99 } 100 } 101 102 if got := *(iptr.(*int)); got != 1 { 103 fmt.Printf("bad int ptr %d\n", got) 104 fail = true 105 } 106 107 f.(func())() 108 f.(func())() 109 f.(func())() 110 if clos != 3 { 111 fmt.Printf("bad closure exec %d\n", clos) 112 fail = true 113 } 114 115 if !reflect.DeepEqual(*(deep.([1]struct{ a *[2]byte })[0].a), [2]byte{'z', 'w'}) { 116 fmt.Printf("bad deep directiface\n") 117 fail = true 118 } 119 120 cc := ch.(chan bool) 121 cc <- true 122 if got := <-cc; !got { 123 fmt.Printf("bad chan\n") 124 fail = true 125 } 126 127 if fail { 128 fmt.Println("BUG") 129 os.Exit(1) 130 } 131 } 132
