1// errorcheck
2
3// Copyright 2016 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7// Test basic restrictions on type aliases.
8
9package p
10
11import (
12	"reflect"
13	. "reflect"
14)
15
16type T0 struct{}
17
18// Valid type alias declarations.
19
20type _ = T0
21type _ = int
22type _ = struct{}
23type _ = reflect.Value
24type _ = Value
25
26type (
27	A0 = T0
28	A1 = int
29	A2 = struct{}
30	A3 = reflect.Value
31	A4 = Value
32	A5 = Value
33
34	N0 A0
35)
36
37// Methods can be declared on the original named type and the alias.
38func (T0) m1()  {} // GCCGO_ERROR "previous"
39func (*T0) m1() {} // ERROR "method redeclared: T0\.m1|T0\.m1 already declared|redefinition of .m1."
40func (A0) m1()  {} // ERROR "T0\.m1 already declared|redefinition of .m1."
41func (A0) m1()  {} // ERROR "T0\.m1 already declared|redefinition of .m1."
42func (A0) m2()  {}
43
44// Type aliases and the original type name can be used interchangeably.
45var _ A0 = T0{}
46var _ T0 = A0{}
47
48// But aliases and original types cannot be used with new types based on them.
49var _ N0 = T0{} // ERROR "cannot use T0{} \(value of type T0\) as N0 value in variable declaration"
50var _ N0 = A0{} // ERROR "cannot use A0{} \(value of type A0\) as N0 value in variable declaration"
51
52var _ A5 = Value{}
53
54var _ interface {
55	m1()
56	m2()
57} = T0{}
58
59var _ interface {
60	m1()
61	m2()
62} = A0{}
63
64func _() {
65	type _ = T0
66	type _ = int
67	type _ = struct{}
68	type _ = reflect.Value
69	type _ = Value
70
71	type (
72		A0 = T0
73		A1 = int
74		A2 = struct{}
75		A3 = reflect.Value
76		A4 = Value
77		A5 Value
78
79		N0 A0
80	)
81
82	var _ A0 = T0{}
83	var _ T0 = A0{}
84
85	var _ N0 = T0{} // ERROR "cannot use T0{} \(value of type T0\) as N0 value in variable declaration"
86	var _ N0 = A0{} // ERROR "cannot use A0{} \(value of type A0\) as N0 value in variable declaration"
87
88	var _ A5 = Value{} // ERROR "cannot use Value{} \(value of type reflect\.Value\) as A5 value in variable declaration"
89}
90
91// Invalid type alias declarations.
92
93type _ = reflect.ValueOf // ERROR "reflect.ValueOf .*is not a type|expected type"
94
95func (A1) m() {} // ERROR "cannot define new methods on non-local type|may not define methods on non-local type"
96func (A2) m() {} // ERROR "invalid receiver type"
97func (A3) m() {} // ERROR "cannot define new methods on non-local type|may not define methods on non-local type"
98func (A4) m() {} // ERROR "cannot define new methods on non-local type|may not define methods on non-local type"
99
100type B1 = struct{}
101
102func (B1) m() {} // ERROR "invalid receiver type"
103
104// TODO(gri) expand
105