mirror of
https://github.com/golang/go
synced 2024-11-22 09:44:40 -07:00
14305527f6
The Go spec requires that select case clauses be evaluated in order, which is stricter than normal ordering semantics. cmd/compile handled this correctly for send clauses, but was not correctly handling receive clauses that involved bare variable references. Discovered with @cuonglm. Fixes #43111. Change-Id: Iec93b6514dd771875b084ba49c15d7f4531b4a6f Reviewed-on: https://go-review.googlesource.com/c/go/+/277132 Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com> Reviewed-by: Keith Randall <khr@golang.org>
71 lines
896 B
Go
71 lines
896 B
Go
// run
|
|
|
|
// Copyright 2020 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
|
|
|
|
var ch chan int
|
|
var x int
|
|
|
|
func f() int {
|
|
close(ch)
|
|
ch = nil
|
|
return 0
|
|
}
|
|
|
|
func g() int {
|
|
ch = nil
|
|
x = 0
|
|
return 0
|
|
}
|
|
|
|
func main() {
|
|
var nilch chan int
|
|
var v int
|
|
var ok bool
|
|
_, _ = v, ok
|
|
|
|
ch = make(chan int)
|
|
select {
|
|
case <-ch:
|
|
case nilch <- f():
|
|
}
|
|
|
|
ch = make(chan int)
|
|
select {
|
|
case v = <-ch:
|
|
case nilch <- f():
|
|
}
|
|
|
|
ch = make(chan int)
|
|
select {
|
|
case v := <-ch: _ = v
|
|
case nilch <- f():
|
|
}
|
|
|
|
ch = make(chan int)
|
|
select {
|
|
case v, ok = <-ch:
|
|
case nilch <- f():
|
|
}
|
|
|
|
ch = make(chan int)
|
|
select {
|
|
case v, ok := <-ch: _, _ = v, ok
|
|
case nilch <- f():
|
|
}
|
|
|
|
ch1 := make(chan int, 1)
|
|
ch = ch1
|
|
x = 42
|
|
select {
|
|
case ch <- x:
|
|
case nilch <- g():
|
|
}
|
|
if got := <-ch1; got != 42 {
|
|
panic(got)
|
|
}
|
|
}
|