go/test/label1.go
Daniel Martí 2923b14a7b cmd/compile/internal/gc: don't panic on continue in switch
Continues outside of a loop are not allowed. Most of these possibilities
were tested in label1.go, but one was missing - a plain continue in a
switch/select but no enclosing loop.

This used to error with a "continue not in loop" in 1.8, but recently
was broken by c03e75e5. In particular, innerloop does not only account
for loops, but also for switches and selects. Swap it by bools that
track whether breaks and continues should be allowed.

While at it, improve the wording of errors for breaks that are not where
they should be. Change "loop" by "loop, switch, or select" since they
can be used in any of those.

And add tests to make sure this isn't broken again. Use a separate func
since I couldn't get the compiler to crash on f() itself, possibly due
to the recursive call on itself.

Fixes #19934.

Change-Id: I8f09c6c2107fd95cac50efc2a8cb03cbc128c35e
Reviewed-on: https://go-review.googlesource.com/40357
Run-TryBot: Daniel Martí <mvdan@mvdan.cc>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Josh Bleecher Snyder <josharian@gmail.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
2017-04-12 14:27:45 +00:00

123 lines
1.9 KiB
Go

// errorcheck
// Copyright 2011 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.
// Verify that erroneous labels are caught by the compiler.
// This set is caught by pass 2. That's why this file is label1.go.
// Does not compile.
package main
var x int
func f1() {
switch x {
case 1:
continue // ERROR "continue is not in a loop$"
}
select {
default:
continue // ERROR "continue is not in a loop$"
}
}
func f2() {
L1:
for {
if x == 0 {
break L1
}
if x == 1 {
continue L1
}
goto L1
}
L2:
select {
default:
if x == 0 {
break L2
}
if x == 1 {
continue L2 // ERROR "invalid continue label .*L2|continue is not in a loop$"
}
goto L2
}
for {
if x == 1 {
continue L2 // ERROR "invalid continue label .*L2"
}
}
L3:
switch {
case x > 10:
if x == 11 {
break L3
}
if x == 12 {
continue L3 // ERROR "invalid continue label .*L3|continue is not in a loop$"
}
goto L3
}
L4:
if true {
if x == 13 {
break L4 // ERROR "invalid break label .*L4"
}
if x == 14 {
continue L4 // ERROR "invalid continue label .*L4|continue is not in a loop$"
}
if x == 15 {
goto L4
}
}
L5:
f2()
if x == 16 {
break L5 // ERROR "invalid break label .*L5"
}
if x == 17 {
continue L5 // ERROR "invalid continue label .*L5|continue is not in a loop$"
}
if x == 18 {
goto L5
}
for {
if x == 19 {
break L1 // ERROR "invalid break label .*L1"
}
if x == 20 {
continue L1 // ERROR "invalid continue label .*L1"
}
if x == 21 {
goto L1
}
}
continue // ERROR "continue is not in a loop$"
for {
continue on // ERROR "continue label not defined: on"
}
break // ERROR "break is not in a loop, switch, or select"
for {
break dance // ERROR "break label not defined: dance"
}
for {
switch x {
case 1:
continue
}
}
}