Commit cee5cd5a authored by Todd Neal's avatar Todd Neal

cmd/compile: fix error when typeswitching on untyped

Fixes #20185
Fixes #19977

Change-Id: I8434713d20616ff0c0bc8f33f017e2548a5cccfa
Reviewed-on: https://go-review.googlesource.com/42210
Run-TryBot: Todd Neal <todd@tneal.org>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: default avatarJosh Bleecher Snyder <josharian@gmail.com>
parent 5e157db3
......@@ -177,7 +177,14 @@ func typecheckswitch(n *Node) {
}
}
if top == Etype && n.Type != nil {
if n.Type == nil || n.Type.IsUntyped() {
// if the value we're switching on has no type or is untyped,
// we've already printed an error and don't need to continue
// typechecking the body
return
}
if top == Etype {
ll := ncase.List
if ncase.Rlist.Len() != 0 {
nvar := ncase.Rlist.First()
......
// errorcheck
// Copyright 2017 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.
// Issue 19977: multiple error messages when type switching on an undefined
package foo
func Foo() {
switch x := a.(type) { // ERROR "undefined: a"
default:
_ = x
}
}
// errorcheck
// Copyright 2017 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.
// Issue 20185: type switching on untyped values (e.g. nil or consts)
// caused an internal compiler error.
package p
func F() {
switch t := nil.(type) { // ERROR "cannot type switch on non-interface value nil"
default:
_ = t
}
}
const x = 1
func G() {
switch t := x.(type) { // ERROR "cannot type switch on non-interface value x \(type untyped number\)"
default:
}
}
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