// +build ignore package main import "reflect" // Test of channels with reflection. var a, b int func chanreflect1() { ch := make(chan *int, 0) // @line cr1make crv := reflect.ValueOf(ch) crv.Send(reflect.ValueOf(&a)) print(crv.Interface()) // @types chan *int print(crv.Interface().(chan *int)) // @pointsto makechan@cr1make:12 print(<-ch) // @pointsto main.a } func chanreflect1i() { // Exercises reflect.Value conversions to/from interfaces: // a different code path than for concrete types. ch := make(chan interface{}, 0) reflect.ValueOf(ch).Send(reflect.ValueOf(&a)) v := <-ch print(v) // @types *int print(v.(*int)) // @pointsto main.a } func chanreflect2() { ch := make(chan *int, 0) ch <- &b crv := reflect.ValueOf(ch) r, _ := crv.Recv() print(r.Interface()) // @types *int print(r.Interface().(*int)) // @pointsto main.b } func chanOfRecv() { // MakeChan(<-chan) is a no-op. t := reflect.ChanOf(reflect.RecvDir, reflect.TypeOf(&a)) print(reflect.Zero(t).Interface()) // @types <-chan *int print(reflect.MakeChan(t, 0).Interface().(<-chan *int)) // @pointsto print(reflect.MakeChan(t, 0).Interface().(chan *int)) // @pointsto } func chanOfSend() { // MakeChan(chan<-) is a no-op. t := reflect.ChanOf(reflect.SendDir, reflect.TypeOf(&a)) print(reflect.Zero(t).Interface()) // @types chan<- *int print(reflect.MakeChan(t, 0).Interface().(chan<- *int)) // @pointsto print(reflect.MakeChan(t, 0).Interface().(chan *int)) // @pointsto } func chanOfBoth() { t := reflect.ChanOf(reflect.BothDir, reflect.TypeOf(&a)) print(reflect.Zero(t).Interface()) // @types chan *int ch := reflect.MakeChan(t, 0) print(ch.Interface().(chan *int)) // @pointsto ch.Send(reflect.ValueOf(&b)) ch.Interface().(chan *int) <- &a r, _ := ch.Recv() print(r.Interface().(*int)) // @pointsto main.a | main.b print(<-ch.Interface().(chan *int)) // @pointsto main.a | main.b } var unknownDir reflect.ChanDir // not a constant func chanOfUnknown() { // Unknown channel direction: assume all three. // MakeChan only works on the bi-di channel type. t := reflect.ChanOf(unknownDir, reflect.TypeOf(&a)) print(reflect.Zero(t).Interface()) // @types <-chan *int | chan<- *int | chan *int print(reflect.MakeChan(t, 0).Interface()) // @types chan *int } func main() { chanreflect1() chanreflect1i() chanreflect2() chanOfRecv() chanOfSend() chanOfBoth() chanOfUnknown() }