go/test/alias2.go
Cuong Manh Le 2c95e3a6a8 cmd/compile: use clearer error message for stuct literal
This CL changes "T literal.M" error message to "T{...}.M". It's clearer
expression and focusing user on actual issue.

Updates #38745

Change-Id: I84b455a86742f37e0bde5bf390aa02984eecc3c9
Reviewed-on: https://go-review.googlesource.com/c/go/+/253677
Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com>
TryBot-Result: Gobot Gobot <gobot@golang.org>
Reviewed-by: Matthew Dempsky <mdempsky@google.com>
2020-09-12 08:31:49 +00:00

105 lines
2.5 KiB
Go

// errorcheck
// Copyright 2016 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 basic restrictions on type aliases.
package p
import (
"reflect"
. "reflect"
)
type T0 struct{}
// Valid type alias declarations.
type _ = T0
type _ = int
type _ = struct{}
type _ = reflect.Value
type _ = Value
type (
A0 = T0
A1 = int
A2 = struct{}
A3 = reflect.Value
A4 = Value
A5 = Value
N0 A0
)
// Methods can be declared on the original named type and the alias.
func (T0) m1() {} // GCCGO_ERROR "previous"
func (*T0) m1() {} // ERROR "method redeclared: T0\.m1|redefinition of .m1."
func (A0) m1() {} // ERROR "T0\.m1 redeclared in this block|redefinition of .m1."
func (A0) m1() {} // ERROR "T0\.m1 redeclared in this block|redefinition of .m1."
func (A0) m2() {}
// Type aliases and the original type name can be used interchangeably.
var _ A0 = T0{}
var _ T0 = A0{}
// But aliases and original types cannot be used with new types based on them.
var _ N0 = T0{} // ERROR "cannot use T0{} \(type T0\) as type N0 in assignment|incompatible type"
var _ N0 = A0{} // ERROR "cannot use T0{} \(type T0\) as type N0 in assignment|incompatible type"
var _ A5 = Value{}
var _ interface {
m1()
m2()
} = T0{}
var _ interface {
m1()
m2()
} = A0{}
func _() {
type _ = T0
type _ = int
type _ = struct{}
type _ = reflect.Value
type _ = Value
type (
A0 = T0
A1 = int
A2 = struct{}
A3 = reflect.Value
A4 = Value
A5 Value
N0 A0
)
var _ A0 = T0{}
var _ T0 = A0{}
var _ N0 = T0{} // ERROR "cannot use T0{} \(type T0\) as type N0 in assignment|incompatible type"
var _ N0 = A0{} // ERROR "cannot use T0{} \(type T0\) as type N0 in assignment|incompatible type"
var _ A5 = Value{} // ERROR "cannot use reflect\.Value{} \(type reflect.Value\) as type A5 in assignment|incompatible type"
}
// Invalid type alias declarations.
type _ = reflect.ValueOf // ERROR "reflect.ValueOf is not a type|expected type"
func (A1) m() {} // ERROR "cannot define new methods on non-local type int|may not define methods on non-local type"
func (A2) m() {} // ERROR "invalid receiver type"
func (A3) m() {} // ERROR "cannot define new methods on non-local type reflect.Value|may not define methods on non-local type"
func (A4) m() {} // ERROR "cannot define new methods on non-local type reflect.Value|may not define methods on non-local type"
type B1 = struct{}
func (B1) m() {} // ERROR "invalid receiver type"
// TODO(gri) expand