gc: less aggressive name binding, for better line numbers in errors

Cleans up a few other corner cases too.

R=ken2
CC=golang-dev
https://golang.org/cl/1592045

1 files changed, 44 insertions, 0 deletions

diff --git a/test/undef.go b/test/undef.go
new file mode 100644
index 0000000000..70785675ab
--- /dev/null
+++ b/test/undef.go
@@ -0,0 +1,44 @@
+// errchk $G -e $D/$F.go
+
+// Copyright 2010 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.
+
+// Check line numbers in error messages.
+
+package main
+
+var (
+	_ = x	// ERROR "undefined: x"
+	_ = x	// ERROR "undefined: x"
+	_ = x	// ERROR "undefined: x"
+)
+
+type T struct {
+	y int
+}
+
+func foo() *T { return &T{y: 99} }
+func bar() int { return y }	// ERROR "undefined: y"
+
+type T1 struct {
+	y1 int
+}
+
+func foo1() *T1 { return &T1{y1: 99} }
+var y1 = 2
+func bar1() int { return y1 }
+
+func f1(val interface{}) {
+	switch v := val.(type) {
+	default:
+		println(v)
+	}
+}
+
+func f2(val interface{}) {
+	switch val.(type) {
+	default:
+		println(v)	// ERROR "undefined: v"
+	}
+}