1 files changed, 189 insertions, 0 deletions
diff --git a/test/blank.go b/test/blank.go
new file mode 100644
index 0000000..0539deb
--- /dev/null
+++ b/test/blank.go
@@ -0,0 +1,189 @@
+// run
+
+// 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.
+
+// Test behavior of the blank identifier (_).
+
+package main
+
+import (
+	"os"
+	"unsafe"
+)
+
+import _ "fmt"
+
+var call string
+
+type T struct {
+	_, _, _ int
+}
+
+func (T) _() {
+}
+
+func (T) _() {
+}
+
+type U struct {
+	_ struct{ a, b, c int }
+}
+
+const (
+	c0 = iota
+	_
+	_
+	_
+	c4
+)
+
+var ints = []string{
+	"1",
+	"2",
+	"3",
+}
+
+func f() (int, int) {
+	call += "f"
+	return 1, 2
+}
+
+func g() (float64, float64) {
+	call += "g"
+	return 3, 4
+}
+
+func h(_ int, _ float64) {
+}
+
+func i() int {
+	call += "i"
+	return 23
+}
+
+var _ = i()
+
+func main() {
+	if call != "i" {
+		panic("init did not run")
+	}
+	call = ""
+	_, _ = 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)
+	}
+
+	// go.tools/ssa/interp cannot support unsafe.Pointer.
+	if os.Getenv("GOSSAINTERP") == "" {
+		type T1 struct{ x, y, z int }
+		t1 := *(*T)(unsafe.Pointer(&T1{1, 2, 3}))
+		t2 := *(*T)(unsafe.Pointer(&T1{4, 5, 6}))
+		if t1 != t2 {
+			panic("T{} != T{}")
+		}
+
+		var u1, u2 interface{}
+		u1 = *(*U)(unsafe.Pointer(&T1{1, 2, 3}))
+		u2 = *(*U)(unsafe.Pointer(&T1{4, 5, 6}))
+		if u1 != u2 {
+			panic("U{} != U{}")
+		}
+	}
+
+	h(a, b)
+
+	m()
+}
+
+type I interface {
+	M(_ int, y int)
+}
+
+type TI struct{}
+
+func (_ TI) M(x int, y int) {
+	if x != y {
+		println("invalid M call:", x, y)
+		panic("bad M")
+	}
+}
+
+var fp = func(_ int, y int) {}
+
+func init() {
+	fp = fp1
+}
+
+func fp1(x, y int) {
+	if x != y {
+		println("invalid fp1 call:", x, y)
+		panic("bad fp1")
+	}
+}
+
+func m() {
+	var i I
+
+	i = TI{}
+	i.M(1, 1)
+	i.M(2, 2)
+
+	fp(1, 1)
+	fp(2, 2)
+}
+
+// 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
+}