Initial commit: Go 1.23 release state

test/interface/assertinline.go

@@ -0,0 +1,74 @@
+// errorcheck -0 -d=typeassert
+
+// Copyright 2015 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 p
+
+func assertptr(x interface{}) *int {
+	return x.(*int) // ERROR "type assertion inlined"
+}
+
+func assertptr2(x interface{}) (*int, bool) {
+	z, ok := x.(*int) // ERROR "type assertion inlined"
+	return z, ok
+}
+
+func assertfunc(x interface{}) func() {
+	return x.(func()) // ERROR "type assertion inlined"
+}
+
+func assertfunc2(x interface{}) (func(), bool) {
+	z, ok := x.(func()) // ERROR "type assertion inlined"
+	return z, ok
+}
+
+func assertstruct(x interface{}) struct{ *int } {
+	return x.(struct{ *int }) // ERROR "type assertion inlined"
+}
+
+func assertstruct2(x interface{}) (struct{ *int }, bool) {
+	z, ok := x.(struct{ *int }) // ERROR "type assertion inlined"
+	return z, ok
+}
+
+func assertbig(x interface{}) complex128 {
+	return x.(complex128) // ERROR "type assertion inlined"
+}
+
+func assertbig2(x interface{}) (complex128, bool) {
+	z, ok := x.(complex128) // ERROR "type assertion inlined"
+	return z, ok
+}
+
+func assertbig2ok(x interface{}) (complex128, bool) {
+	_, ok := x.(complex128) // ERROR "type assertion inlined"
+	return 0, ok
+}
+
+func assertslice(x interface{}) []int {
+	return x.([]int) // ERROR "type assertion inlined"
+}
+
+func assertslice2(x interface{}) ([]int, bool) {
+	z, ok := x.([]int) // ERROR "type assertion inlined"
+	return z, ok
+}
+
+func assertslice2ok(x interface{}) ([]int, bool) {
+	_, ok := x.([]int) // ERROR "type assertion inlined"
+	return nil, ok
+}
+
+type I interface {
+	foo()
+}
+
+func assertInter(x interface{}) I {
+	return x.(I) // ERROR "type assertion not inlined"
+}
+func assertInter2(x interface{}) (I, bool) {
+	z, ok := x.(I) // ERROR "type assertion not inlined"
+	return z, ok
+}

test/interface/bigdata.go

@@ -0,0 +1,74 @@
+// 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 big vs. small, pointer vs. value interface methods.
+
+package main
+
+type I interface { M() int64 }
+
+type BigPtr struct { a, b, c, d int64 }
+func (z *BigPtr) M() int64 { return z.a+z.b+z.c+z.d }
+
+type SmallPtr struct { a int32 }
+func (z *SmallPtr) M() int64 { return int64(z.a) }
+
+type IntPtr int32
+func (z *IntPtr) M() int64 { return int64(*z) }
+
+var bad bool
+
+func test(name string, i I) {
+	m := i.M()
+	if m != 12345 {
+		println(name, m)
+		bad = true
+	}
+}
+
+func ptrs() {
+	var bigptr BigPtr = BigPtr{ 10000, 2000, 300, 45 }
+	var smallptr SmallPtr = SmallPtr{ 12345 }
+	var intptr IntPtr = 12345
+
+//	test("bigptr", bigptr)
+	test("&bigptr", &bigptr)
+//	test("smallptr", smallptr)
+	test("&smallptr", &smallptr)
+//	test("intptr", intptr)
+	test("&intptr", &intptr)
+}
+
+type Big struct { a, b, c, d int64 }
+func (z Big) M() int64 { return z.a+z.b+z.c+z.d }
+
+type Small struct { a int32 }
+func (z Small) M() int64 { return int64(z.a) }
+
+type Int int32
+func (z Int) M() int64 { return int64(z) }
+
+func nonptrs() {
+	var big Big = Big{ 10000, 2000, 300, 45 }
+	var small Small = Small{ 12345 }
+	var int Int = 12345
+
+	test("big", big)
+	test("&big", &big)
+	test("small", small)
+	test("&small", &small)
+	test("int", int)
+	test("&int", &int)
+}
+
+func main() {
+	ptrs()
+	nonptrs()
+
+	if bad {
+		println("BUG: interface4")
+	}
+}

test/interface/convert.go

@@ -0,0 +1,146 @@
+// 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 all the different interface conversion runtime functions.
+
+package main
+
+type Stringer interface {
+	String() string
+}
+type StringLengther interface {
+	String() string
+	Length() int
+}
+type Empty interface{}
+
+type T string
+
+func (t T) String() string {
+	return string(t)
+}
+func (t T) Length() int {
+	return len(t)
+}
+
+type U string
+
+func (u U) String() string {
+	return string(u)
+}
+
+var t = T("hello")
+var u = U("goodbye")
+var e Empty
+var s Stringer = t
+var sl StringLengther = t
+var i int
+var ok bool
+
+func hello(s string) {
+	if s != "hello" {
+		println("not hello: ", s)
+		panic("fail")
+	}
+}
+
+func five(i int) {
+	if i != 5 {
+		println("not 5: ", i)
+		panic("fail")
+	}
+}
+
+func true(ok bool) {
+	if !ok {
+		panic("not true")
+	}
+}
+
+func false(ok bool) {
+	if ok {
+		panic("not false")
+	}
+}
+
+func main() {
+	// T2I
+	s = t
+	hello(s.String())
+
+	// I2T
+	t = s.(T)
+	hello(t.String())
+
+	// T2E
+	e = t
+
+	// E2T
+	t = e.(T)
+	hello(t.String())
+
+	// T2I again
+	sl = t
+	hello(sl.String())
+	five(sl.Length())
+
+	// I2I static
+	s = sl
+	hello(s.String())
+
+	// I2I dynamic
+	sl = s.(StringLengther)
+	hello(sl.String())
+	five(sl.Length())
+
+	// I2E (and E2T)
+	e = s
+	hello(e.(T).String())
+
+	// E2I
+	s = e.(Stringer)
+	hello(s.String())
+
+	// I2T2 true
+	t, ok = s.(T)
+	true(ok)
+	hello(t.String())
+
+	// I2T2 false
+	_, ok = s.(U)
+	false(ok)
+
+	// I2I2 true
+	sl, ok = s.(StringLengther)
+	true(ok)
+	hello(sl.String())
+	five(sl.Length())
+
+	// I2I2 false (and T2I)
+	s = u
+	sl, ok = s.(StringLengther)
+	false(ok)
+
+	// E2T2 true
+	t, ok = e.(T)
+	true(ok)
+	hello(t.String())
+
+	// E2T2 false
+	i, ok = e.(int)
+	false(ok)
+
+	// E2I2 true
+	sl, ok = e.(StringLengther)
+	true(ok)
+	hello(sl.String())
+	five(sl.Length())
+
+	// E2I2 false (and T2E)
+	e = u
+	sl, ok = e.(StringLengther)
+	false(ok)
+}

test/interface/convert1.go

@@ -0,0 +1,24 @@
+// 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 static interface conversion of interface value nil.
+
+package main
+
+type R interface { R() }
+type RW interface { R(); W() }
+
+var e interface {}
+var r R
+var rw RW
+
+func main() {
+	r = r
+	r = rw
+	e = r
+	e = rw
+	rw = rw
+}

test/interface/convert2.go

@@ -0,0 +1,24 @@
+// 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 static interface conversion of interface value nil.
+
+package main
+
+type R interface { R() }
+type RW interface { R(); W() }
+
+var e interface {}
+var r R
+var rw RW
+
+func main() {
+	r = r
+	r = rw
+	e = r
+	e = rw
+	rw = rw
+}

test/interface/embed.go

@@ -0,0 +1,61 @@
+// 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 methods derived from embedded interface values.
+
+package main
+
+import "os"
+
+const Value = 1e12
+
+type Inter interface { M() int64 }
+
+type T int64
+func (t T) M() int64 { return int64(t) }
+var t = T(Value)
+var pt = &t
+var ti Inter = t
+
+type S struct { Inter }
+var s = S{ ti }
+var ps = &s
+
+var i Inter
+
+var ok = true
+
+func check(s string, v int64) {
+	if v != Value {
+		println(s, v)
+		ok = false
+	}
+}
+
+func main() {
+	check("t.M()", t.M())
+	check("pt.M()", pt.M())
+	check("ti.M()", ti.M())
+	check("s.M()", s.M())
+	check("ps.M()", ps.M())
+
+	i = t
+	check("i = t; i.M()", i.M())
+
+	i = pt
+	check("i = pt; i.M()", i.M())
+
+	i = s
+	check("i = s; i.M()", i.M())
+
+	i = ps
+	check("i = ps; i.M()", i.M())
+
+	if !ok {
+		println("BUG: interface10")
+		os.Exit(1)
+	}
+}

test/interface/embed1.dir/embed0.go

@@ -0,0 +1,28 @@
+// 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 that embedded interface types can have local methods.
+
+package p
+
+type T int
+
+func (t T) m() {}
+
+type I interface{ m() }
+type J interface{ I }
+
+func main() {
+	var i I
+	var j J
+	var t T
+	i = t
+	j = t
+	_ = i
+	_ = j
+	i = j
+	_ = i
+	j = i
+	_ = j
+}

test/interface/embed1.dir/embed1.go

@@ -0,0 +1,43 @@
+// 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 that embedded interface types can have local methods.
+
+package main
+
+import "./embed0"
+
+type T int
+func (t T) m() {}
+
+type I interface { m() }
+type J interface { I }
+
+type PI interface { p.I }
+type PJ interface { p.J }
+
+func main() {
+	var i I
+	var j J
+	var t T
+	i = t
+	j = t
+	_ = i
+	_ = j
+	i = j
+	_ = i
+	j = i
+	_ = j
+	var pi PI
+	var pj PJ
+	var pt p.T
+	pi = pt
+	pj = pt
+	_ = pi
+	_ = pj
+	pi = pj
+	_ = pi
+	pj = pi
+	_ = pj
+}

test/interface/embed1.go

@@ -0,0 +1,9 @@
+// rundir
+
+// 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 that embedded interface types can have local methods.
+
+package ignored

test/interface/embed2.go

@@ -0,0 +1,75 @@
+// errorcheck
+
+// 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 methods derived from embedded interface and *interface values.
+
+package main
+
+import "os"
+
+const Value = 1e12
+
+type Inter interface {
+	M() int64
+}
+
+type T int64
+
+func (t T) M() int64 { return int64(t) }
+
+var t = T(Value)
+var pt = &t
+var ti Inter = t
+var pti = &ti
+
+type S struct{ Inter }
+
+var s = S{ti}
+var ps = &s
+
+type SP struct{ *Inter } // ERROR "interface"
+
+var i Inter
+var pi = &i
+
+var ok = true
+
+func check(s string, v int64) {
+	if v != Value {
+		println(s, v)
+		ok = false
+	}
+}
+
+func main() {
+	check("t.M()", t.M())
+	check("pt.M()", pt.M())
+	check("ti.M()", ti.M())
+	check("pti.M()", pti.M()) // ERROR "pointer to interface, not interface|no field or method M"
+	check("s.M()", s.M())
+	check("ps.M()", ps.M())
+
+	i = t
+	check("i = t; i.M()", i.M())
+	check("i = t; pi.M()", pi.M()) // ERROR "pointer to interface, not interface|no field or method M"
+
+	i = pt
+	check("i = pt; i.M()", i.M())
+	check("i = pt; pi.M()", pi.M()) // ERROR "pointer to interface, not interface|no field or method M"
+
+	i = s
+	check("i = s; i.M()", i.M())
+	check("i = s; pi.M()", pi.M()) // ERROR "pointer to interface, not interface|no field or method M"
+
+	i = ps
+	check("i = ps; i.M()", i.M())
+	check("i = ps; pi.M()", pi.M()) // ERROR "pointer to interface, not interface|no field or method M"
+
+	if !ok {
+		println("BUG: interface10")
+		os.Exit(1)
+	}
+}

test/interface/embed3.dir/embed0.go

@@ -0,0 +1,21 @@
+// Copyright 2019 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 p
+
+type I1 interface {
+	Foo(int)
+}
+
+type I2 interface {
+	foo(int)
+}
+
+type M1 int
+
+func (M1) foo() {}
+
+type M2 int
+
+func (M2) foo(int) {}

test/interface/embed3.dir/embed1.go

@@ -0,0 +1,78 @@
+// Copyright 2019 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
+
+import "./embed0"
+
+type X1 struct{}
+
+func (X1) Foo() {}
+
+type X2 struct{}
+
+func (X2) foo() {}
+
+type X3 struct{}
+
+func (X3) foo(int) {}
+
+type X4 struct{ p.M1 }
+
+type X5 struct{ p.M1 }
+
+func (X5) foo(int) {}
+
+type X6 struct{ p.M2 }
+
+type X7 struct{ p.M2 }
+
+func (X7) foo() {}
+
+type X8 struct{ p.M2 }
+
+func (X8) foo(int) {}
+
+func main() {
+	var i1 interface{} = X1{}
+	check(func() { _ = i1.(p.I1) }, "interface conversion: main.X1 is not p.I1: missing method Foo")
+
+	var i2 interface{} = X2{}
+	check(func() { _ = i2.(p.I2) }, "interface conversion: main.X2 is not p.I2: missing method foo")
+
+	var i3 interface{} = X3{}
+	check(func() { _ = i3.(p.I2) }, "interface conversion: main.X3 is not p.I2: missing method foo")
+
+	var i4 interface{} = X4{}
+	check(func() { _ = i4.(p.I2) }, "interface conversion: main.X4 is not p.I2: missing method foo")
+
+	var i5 interface{} = X5{}
+	check(func() { _ = i5.(p.I2) }, "interface conversion: main.X5 is not p.I2: missing method foo")
+
+	var i6 interface{} = X6{}
+	check(func() { _ = i6.(p.I2) }, "")
+
+	var i7 interface{} = X7{}
+	check(func() { _ = i7.(p.I2) }, "")
+
+	var i8 interface{} = X8{}
+	check(func() { _ = i8.(p.I2) }, "")
+}
+
+func check(f func(), msg string) {
+	defer func() {
+		v := recover()
+		if v == nil {
+			if msg == "" {
+				return
+			}
+			panic("did not panic")
+		}
+		got := v.(error).Error()
+		if msg != got {
+			panic("want '" + msg + "', got '" + got + "'")
+		}
+	}()
+	f()
+}

test/interface/embed3.go

@@ -0,0 +1,7 @@
+// rundir
+
+// Copyright 2019 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 ignored

test/interface/explicit.go

@@ -0,0 +1,106 @@
+// errorcheck
+
+// 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.
+
+// Verify compiler messages about erroneous static interface conversions.
+// Does not compile.
+
+package main
+
+type T struct {
+	a int
+}
+
+var t *T
+
+type X int
+
+func (x *X) M() {}
+
+type I interface {
+	M()
+}
+
+var i I
+
+type I2 interface {
+	M()
+	N()
+}
+
+var i2 I2
+
+type E interface{}
+
+var e E
+
+func main() {
+	e = t // ok
+	t = e // ERROR "need explicit|need type assertion"
+
+	// neither of these can work,
+	// because i has an extra method
+	// that t does not, so i cannot contain a t.
+	i = t // ERROR "incompatible|missing method M"
+	t = i // ERROR "incompatible|assignment$"
+
+	i = i2 // ok
+	i2 = i // ERROR "incompatible|missing method N"
+
+	i = I(i2)  // ok
+	i2 = I2(i) // ERROR "invalid|missing N method|cannot convert"
+
+	e = E(t) // ok
+	t = T(e) // ERROR "need explicit|need type assertion|incompatible|cannot convert"
+
+	// cannot type-assert non-interfaces
+	f := 2.0
+	_ = f.(int) // ERROR "non-interface type|only valid for interface types|not an interface"
+
+}
+
+type M interface {
+	M()
+}
+
+var m M
+
+var _ = m.(int) // ERROR "impossible type assertion"
+
+type Int int
+
+func (Int) M(float64) {}
+
+var _ = m.(Int) // ERROR "impossible type assertion"
+
+var _ = m.(X) // ERROR "pointer receiver"
+
+var ii int
+var jj Int
+
+var m1 M = ii // ERROR "incompatible|missing"
+var m2 M = jj // ERROR "incompatible|wrong type for method M"
+
+var m3 = M(ii) // ERROR "invalid|missing|cannot convert"
+var m4 = M(jj) // ERROR "invalid|wrong type for M method|cannot convert"
+
+type B1 interface {
+	_() // ERROR "methods must have a unique non-blank name"
+}
+
+type B2 interface {
+	M()
+	_() // ERROR "methods must have a unique non-blank name"
+}
+
+type T2 struct{}
+
+func (t *T2) M() {}
+func (t *T2) _() {}
+
+// Already reported about the invalid blank interface method above;
+// no need to report about not implementing it.
+var b1 B1 = &T2{}
+var b2 B2 = &T2{}

test/interface/fail.go

@@ -0,0 +1,39 @@
+// 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 that interface conversion fails when method is missing.
+
+package main
+
+type I interface {
+	Foo()
+}
+
+func main() {
+	shouldPanic(p1)
+}
+
+func p1() {
+	var s *S
+	var i I
+	var e interface{}
+	e = s
+	i = e.(I)
+	_ = i
+}
+
+type S struct{}
+
+func (s *S) _() {}
+
+func shouldPanic(f func()) {
+	defer func() {
+		if recover() == nil {
+			panic("function should panic")
+		}
+	}()
+	f()
+}

test/interface/fake.go

@@ -0,0 +1,97 @@
+// 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 interface comparisons using types hidden
+// inside reflected-on structs.
+
+package main
+
+import "reflect"
+
+type T struct {
+	F float32
+	G float32
+
+	S string
+	T string
+
+	U uint32
+	V uint32
+
+	W uint32
+	X uint32
+
+	Y uint32
+	Z uint32
+}
+
+func add(s, t string) string {
+	return s + t
+}
+
+func assert(b bool) {
+	if !b {
+		panic("assert")
+	}
+}
+
+func main() {
+	var x T
+	x.F = 1.0
+	x.G = x.F
+	x.S = add("abc", "def")
+	x.T = add("abc", "def")
+	x.U = 1
+	x.V = 2
+	x.W = 1 << 28
+	x.X = 2 << 28
+	x.Y = 0x12345678
+	x.Z = x.Y
+
+	// check mem and string
+	v := reflect.ValueOf(x)
+	i := v.Field(0)
+	j := v.Field(1)
+	assert(i.Interface() == j.Interface())
+
+	s := v.Field(2)
+	t := v.Field(3)
+	assert(s.Interface() == t.Interface())
+
+	// make sure different values are different.
+	// make sure whole word is being compared,
+	// not just a single byte.
+	i = v.Field(4)
+	j = v.Field(5)
+	assert(i.Interface() != j.Interface())
+
+	i = v.Field(6)
+	j = v.Field(7)
+	assert(i.Interface() != j.Interface())
+
+	i = v.Field(8)
+	j = v.Field(9)
+	assert(i.Interface() == j.Interface())
+}
+
+/*
+comparing uncomparable type float32
+throw: interface compare
+
+panic PC=0x28ceb8 [1]
+throw+0x41 /Users/rsc/goX/src/runtime/runtime.c:54
+	throw(0x3014a, 0x0)
+ifaceeq+0x15c /Users/rsc/goX/src/runtime/iface.c:501
+	ifaceeq(0x2aa7c0, 0x0, 0x0, 0x0, 0x2aa7c0, ...)
+sys·ifaceeq+0x48 /Users/rsc/goX/src/runtime/iface.c:527
+	sys·ifaceeq(0x2aa7c0, 0x0, 0x0, 0x0, 0x2aa7c0, ...)
+main·main+0x190 /Users/rsc/goX/src/cmd/gc/x.go:10
+	main·main()
+mainstart+0xf /Users/rsc/goX/src/runtime/amd64/asm.s:53
+	mainstart()
+sys·Goexit /Users/rsc/goX/src/runtime/proc.c:124
+	sys·Goexit()
+*/

test/interface/noeq.go

@@ -0,0 +1,40 @@
+// run
+
+// Copyright 2011 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 run-time error detection for interface values containing types
+// that cannot be compared for equality.
+
+package main
+
+func main() {
+	cmp(1)
+
+	var (
+		m map[int]int
+		s struct{ x []int }
+		f func()
+	)
+	noCmp(m)
+	noCmp(s)
+	noCmp(f)
+}
+
+func cmp(x interface{}) bool {
+	return x == x
+}
+
+func noCmp(x interface{}) {
+	shouldPanic(func() { cmp(x) })
+}
+
+func shouldPanic(f func()) {
+	defer func() {
+		if recover() == nil {
+			panic("function should panic")
+		}
+	}()
+	f()
+}

test/interface/pointer.go

@@ -0,0 +1,37 @@
+// errorcheck
+
+// 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 that interface{M()} = *interface{M()} produces a compiler error.
+// Does not compile.
+
+package main
+
+type Inst interface {
+	Next() *Inst
+}
+
+type Regexp struct {
+	code  []Inst
+	start Inst
+}
+
+type Start struct {
+	foo *Inst
+}
+
+func (start *Start) Next() *Inst { return nil }
+
+func AddInst(Inst) *Inst {
+	print("ok in addinst\n")
+	return nil
+}
+
+func main() {
+	print("call addinst\n")
+	var _ Inst = AddInst(new(Start)) // ERROR "pointer to interface|incompatible type"
+	print("return from  addinst\n")
+	var _ *Inst = new(Start) // ERROR "pointer to interface|incompatible type"
+}

test/interface/private.dir/private1.go

@@ -0,0 +1,18 @@
+// Copyright 2011 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.
+
+// Imported by private.go, which should not be able to see the private method.
+
+package p
+
+type Exported interface {
+	private()
+}
+
+type Implementation struct{}
+
+func (p *Implementation) private() {}
+
+var X = new(Implementation)
+

test/interface/private.dir/prog.go

@@ -0,0 +1,33 @@
+// Copyright 2011 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 that unexported methods are not visible outside the package.
+// Does not compile.
+
+package main
+
+import "./private1"
+
+type Exported interface {
+	private()
+}
+
+type Implementation struct{}
+
+func (p *Implementation) private() {}
+
+func main() {
+	var x Exported
+	x = new(Implementation)
+	x.private()
+
+	var px p.Exported
+	px = p.X
+
+	px.private()			// ERROR "private"
+
+	px = new(Implementation)	// ERROR "private"
+
+	x = px				// ERROR "private"
+}

test/interface/private.go

@@ -0,0 +1,10 @@
+// errorcheckdir
+
+// Copyright 2011 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 that unexported methods are not visible outside the package.
+// Does not compile.
+
+package ignored

test/interface/receiver.go

@@ -0,0 +1,121 @@
+// 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 Implicit methods for embedded types and
+// mixed pointer and non-pointer receivers.
+
+package main
+
+type T int
+
+var nv, np int
+
+func (t T) V() {
+	if t != 42 {
+		panic(t)
+	}
+	nv++
+}
+
+func (t *T) P() {
+	if *t != 42 {
+		println(t, *t)
+		panic("fail")
+	}
+	np++
+}
+
+type V interface {
+	V()
+}
+type P interface {
+	P()
+	V()
+}
+
+type S struct {
+	T
+}
+
+type SP struct {
+	*T
+}
+
+func main() {
+	var t T
+	var v V
+	var p P
+
+	t = 42
+
+	t.P()
+	t.V()
+
+	v = t
+	v.V()
+
+	p = &t
+	p.P()
+	p.V()
+
+	v = &t
+	v.V()
+
+	//	p = t	// ERROR
+	var i interface{} = t
+	if _, ok := i.(P); ok {
+		println("dynamic i.(P) succeeded incorrectly")
+		panic("fail")
+	}
+
+	//	println("--struct--");
+	var s S
+	s.T = 42
+	s.P()
+	s.V()
+
+	v = s
+	s.V()
+
+	p = &s
+	p.P()
+	p.V()
+
+	v = &s
+	v.V()
+
+	//	p = s	// ERROR
+	var j interface{} = s
+	if _, ok := j.(P); ok {
+		println("dynamic j.(P) succeeded incorrectly")
+		panic("fail")
+	}
+
+	//	println("--struct pointer--");
+	var sp SP
+	sp.T = &t
+	sp.P()
+	sp.V()
+
+	v = sp
+	sp.V()
+
+	p = &sp
+	p.P()
+	p.V()
+
+	v = &sp
+	v.V()
+
+	p = sp // not error
+	p.P()
+	p.V()
+
+	if nv != 13 || np != 7 {
+		println("bad count", nv, np)
+		panic("fail")
+	}
+}

test/interface/receiver1.go

@@ -0,0 +1,59 @@
+// errorcheck
+
+// 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.
+
+// Verify compiler complains about missing implicit methods.
+// Does not compile.
+
+package main
+
+type T int
+
+func (t T) V()
+func (t *T) P()
+
+type V interface {
+	V()
+}
+type P interface {
+	P()
+	V()
+}
+
+type S struct {
+	T
+}
+type SP struct {
+	*T
+}
+
+func main() {
+	var t T
+	var v V
+	var p P
+	var s S
+	var sp SP
+
+	v = t
+	p = t // ERROR "does not implement|requires a pointer|cannot use"
+	_, _ = v, p
+	v = &t
+	p = &t
+	_, _ = v, p
+
+	v = s
+	p = s // ERROR "does not implement|requires a pointer|cannot use"
+	_, _ = v, p
+	v = &s
+	p = &s
+	_, _ = v, p
+
+	v = sp
+	p = sp // no error!
+	_, _ = v, p
+	v = &sp
+	p = &sp
+	_, _ = v, p
+}

test/interface/recursive.go

@@ -0,0 +1,21 @@
+// compile
+
+// 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.
+
+// Check mutually recursive interfaces
+
+package recursive
+
+type I1 interface {
+	foo() I2
+}
+
+type I2 interface {
+	bar() I1
+}
+
+type T int
+func (t T) foo() I2 { return t }
+func (t T) bar() I1 { return t }

test/interface/recursive1.dir/recursive1.go

@@ -0,0 +1,15 @@
+// Copyright 2012 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.
+
+// Mutually recursive type definitions imported and used by recursive1.go.
+
+package p
+
+type I1 interface {
+	F() I2
+}
+
+type I2 interface {
+	I1
+}

test/interface/recursive1.dir/recursive2.go

@@ -0,0 +1,20 @@
+// Copyright 2012 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 that the mutually recursive types in recursive1.go made it
+// intact and with the same meaning, by assigning to or using them.
+
+package main
+
+import "./recursive1"
+
+func main() {
+	var i1 p.I1
+	var i2 p.I2
+	i1 = i2
+	i2 = i1
+	i1 = i2.F()
+	i2 = i1.F()
+	_, _ = i1, i2
+}

test/interface/recursive1.go

@@ -0,0 +1,9 @@
+// compiledir
+
+// Copyright 2012 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.
+
+// Mutually recursive type definitions imported and used by recursive1.go.
+
+package ignored

test/interface/returntype.go

@@ -0,0 +1,38 @@
+// 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 interface methods with different return types are distinct.
+
+package main
+
+type S struct { a int }
+type T struct { b string }
+
+func (s *S) Name() int8 { return 1 }
+func (t *T) Name() int64 { return 64 }
+
+type I1 interface { Name() int8 }
+type I2 interface { Name() int64 }
+
+func main() {
+	shouldPanic(p1)
+}
+
+func p1() {
+	var i1 I1
+	var s *S
+	i1 = s
+	print(i1.(I2).Name())
+}
+
+func shouldPanic(f func()) {
+	defer func() {
+		if recover() == nil {
+			panic("function should panic")
+		}
+	}()
+	f()
+}

test/interface/struct.go

@@ -0,0 +1,156 @@
+// 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 interface values containing structures.
+
+package main
+
+import "os"
+
+var fail int
+
+func check(b bool, msg string) {
+	if (!b) {
+		println("failure in", msg)
+		fail++
+	}
+}
+
+type I1 interface { Get() int; Put(int) }
+
+type S1 struct { i int }
+func (p S1) Get() int { return p.i }
+func (p S1) Put(i int) { p.i = i }
+
+func f1() {
+	s := S1{1}
+	var i I1 = s
+	i.Put(2)
+	check(i.Get() == 1, "f1 i")
+	check(s.i == 1, "f1 s")
+}
+
+func f2() {
+	s := S1{1}
+	var i I1 = &s
+	i.Put(2)
+	check(i.Get() == 1, "f2 i")
+	check(s.i == 1, "f2 s")
+}
+
+func f3() {
+	s := &S1{1}
+	var i I1 = s
+	i.Put(2)
+	check(i.Get() == 1, "f3 i")
+	check(s.i == 1, "f3 s")
+}
+
+type S2 struct { i int }
+func (p *S2) Get() int { return p.i }
+func (p *S2) Put(i int) { p.i = i }
+
+// Disallowed by restriction of values going to pointer receivers
+// func f4() {
+//	 s := S2{1}
+//	 var i I1 = s
+//	 i.Put(2)
+//	 check(i.Get() == 2, "f4 i")
+//	 check(s.i == 1, "f4 s")
+// }
+
+func f5() {
+	s := S2{1}
+	var i I1 = &s
+	i.Put(2)
+	check(i.Get() == 2, "f5 i")
+	check(s.i == 2, "f5 s")
+}
+
+func f6() {
+	s := &S2{1}
+	var i I1 = s
+	i.Put(2)
+	check(i.Get() == 2, "f6 i")
+	check(s.i == 2, "f6 s")
+}
+
+type I2 interface { Get() int64; Put(int64) }
+
+type S3 struct { i, j, k, l int64 }
+func (p S3) Get() int64 { return p.l }
+func (p S3) Put(i int64) { p.l = i }
+
+func f7() {
+	s := S3{1, 2, 3, 4}
+	var i I2 = s
+	i.Put(5)
+	check(i.Get() == 4, "f7 i")
+	check(s.l == 4, "f7 s")
+}
+
+func f8() {
+	s := S3{1, 2, 3, 4}
+	var i I2 = &s
+	i.Put(5)
+	check(i.Get() == 4, "f8 i")
+	check(s.l == 4, "f8 s")
+}
+
+func f9() {
+	s := &S3{1, 2, 3, 4}
+	var i I2 = s
+	i.Put(5)
+	check(i.Get() == 4, "f9 i")
+	check(s.l == 4, "f9 s")
+}
+
+type S4 struct { i, j, k, l int64 }
+func (p *S4) Get() int64 { return p.l }
+func (p *S4) Put(i int64) { p.l = i }
+
+// Disallowed by restriction of values going to pointer receivers
+// func f10() {
+//	 s := S4{1, 2, 3, 4}
+//	 var i I2 = s
+//	 i.Put(5)
+//	 check(i.Get() == 5, "f10 i")
+//	 check(s.l == 4, "f10 s")
+// }
+
+func f11() {
+	s := S4{1, 2, 3, 4}
+	var i I2 = &s
+	i.Put(5)
+	check(i.Get() == 5, "f11 i")
+	check(s.l == 5, "f11 s")
+}
+
+func f12() {
+	s := &S4{1, 2, 3, 4}
+	var i I2 = s
+	i.Put(5)
+	check(i.Get() == 5, "f12 i")
+	check(s.l == 5, "f12 s")
+}
+
+func main() {
+	f1()
+	f2()
+	f3()
+//	f4()
+	f5()
+	f6()
+	f7()
+	f8()
+	f9()
+//	f10()
+	f11()
+	f12()
+	if fail > 0 {
+		os.Exit(1)
+	}
+}