From: David R. Jenni <david.r.jenni@gmail.com>
Date: Fri, 10 Feb 2017 18:25:58 +0000 (+0100)
Subject: cmd/compile: silence superfluous assignment error message
X-Git-Tag: go1.9beta1~1454
X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=d55f52882656122869b6b409be783bfb5a2fd2fb;p=gostls13.git

cmd/compile: silence superfluous assignment error message

Avoid printing a second error message when a field of an undefined
variable is accessed.

Fixes #8440.

Change-Id: I3fe0b11fa3423cec3871cb01b5951efa8ea7451a
Reviewed-on: https://go-review.googlesource.com/36751
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
Run-TryBot: Matthew Dempsky <mdempsky@google.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
---

diff --git a/src/cmd/compile/internal/gc/typecheck.go b/src/cmd/compile/internal/gc/typecheck.go
index d131825688..5807f1929e 100644
--- a/src/cmd/compile/internal/gc/typecheck.go
+++ b/src/cmd/compile/internal/gc/typecheck.go
@@ -3213,8 +3213,8 @@ func checkassign(stmt *Node, n *Node) {
 		return
 	}
 
-	// have already complained about n being undefined
-	if n.Op == ONONAME {
+	// have already complained about n being invalid
+	if n.Type == nil {
 		return
 	}
 
diff --git a/test/fixedbugs/issue14010.go b/test/fixedbugs/issue14010.go
index f5cab41a0d..2786e107e8 100644
--- a/test/fixedbugs/issue14010.go
+++ b/test/fixedbugs/issue14010.go
@@ -11,5 +11,5 @@ package main
 
 func main() {
 	true = false // ERROR "cannot assign to true"
-	byte = 0     // ERROR "not an expression" "cannot assign to byte"
+	byte = 0     // ERROR "not an expression"
 }
diff --git a/test/fixedbugs/issue8440.go b/test/fixedbugs/issue8440.go
new file mode 100644
index 0000000000..f9b1dea3eb
--- /dev/null
+++ b/test/fixedbugs/issue8440.go
@@ -0,0 +1,11 @@
+// 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.
+
+package main
+
+func main() {
+	n.foo = 6 // ERROR "undefined: n in n.foo"
+}