write-only variable _

R=ken
OCL=34465
CL=34470

3 files changed, 103 insertions, 1 deletions

diff --git a/test/blank.go b/test/blank.go
new file mode 100644
index 000000000..4919841a4
--- /dev/null
+++ b/test/blank.go
@@ -0,0 +1,90 @@
+// $G $D/$F.go && $L $F.$A && ./$A.out
+
+// Copyright 2009 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 call string
+
+type T struct {
+	_, _, _ int;
+}
+
+const (
+	c0 = iota;
+	_;
+	_;
+	_;
+	c4;
+)
+
+var ints = []string {
+	"1",
+	"2",
+	"3"
+}
+
+func f() (int, int) {
+	call += "f";
+	return 1,2
+}
+
+func g() (float, float) {
+	call += "g";
+	return 3,4
+}
+
+func h(_ int, _ float) {
+}
+
+func i() int {
+	call += "i";
+	return 23;
+}
+
+func main()
+{
+	_, _ = f();
+	a, _ := f();
+	if a != 1 {panic(a)}
+	b, _ := g();
+	if b != 3 {panic(b)}
+	_, a = f();
+	if a != 2 {panic(a)}
+	_, b = g();
+	if b != 4 {panic(b)}
+	_ = i();
+	if call != "ffgfgi" {panic(call)}
+	if c4 != 4 {panic(c4)}
+
+	out := "";
+	for _, s := range ints {
+		out += s;
+	}
+	if out != "123" {panic(out)}
+
+	sum := 0;
+	for s, _ := range ints {
+		sum += s;
+	}
+	if sum != 3 {panic(sum)}
+
+	h(a,b);
+}
+
+// useless but legal
+var _ int = 1;
+var _ = 2;
+var _, _ = 3, 4;
+const _ = 3;
+const _, _ = 4, 5;
+type _ int;
+func _() {
+	panic("oops")
+}
+
+func ff() {
+	var _ int = 1;
+}
diff --git a/test/blank1.go b/test/blank1.go
new file mode 100644
index 000000000..2fa6e9f8f
--- /dev/null
+++ b/test/blank1.go
@@ -0,0 +1,12 @@
+// errchk $G -e $D/$F.go
+
+// Copyright 2009 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 _	// ERROR "invalid package name _"
+
+func main() {
+	_();	// ERROR "cannot use _ as value"
+	x := _+1;	// ERROR "cannot use _ as value"
+}
diff --git a/test/fixedbugs/bug154.go b/test/fixedbugs/bug154.go
index 60bcb8e50..66f7212b5 100644
--- a/test/fixedbugs/bug154.go
+++ b/test/fixedbugs/bug154.go
@@ -16,7 +16,7 @@ func f0() string {
 
 func f1() string {
 	const f = 3.141592;
-	_ := float64(float32(f));  // appears to change the precision of f
+	x := float64(float32(f));  // appears to change the precision of f
 	return fmt.Sprintf("%v", float64(f));
 }