mirror of
https://github.com/golang/go
synced 2024-09-04 23:44:16 +00:00
cmd/compile: fix parameterized interfaces
type I[T any] interface{} This is an interface, but it has a type parameter. We need to distinguish that from an interface that is not parameterized. That means when doing type substitution on an interface with parameters, we need to make a new one. Same for non-empty interfaces. Even if the type parameter is not used in any method, we sill need to make a new type. Similar case to tstruct, above. Change-Id: I23ad9f21d2c4ef675bf3f7d84899d9e4919d05e7 Reviewed-on: https://go-review.googlesource.com/c/go/+/344578 Trust: Keith Randall <khr@golang.org> Trust: Dan Scales <danscales@google.com> Run-TryBot: Keith Randall <khr@golang.org> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Dan Scales <danscales@google.com>
This commit is contained in:
parent
39eb1cc3f4
commit
4f0dedca71
|
@ -1163,8 +1163,8 @@ func (ts *Tsubster) typ1(t *types.Type) *types.Type {
|
|||
}
|
||||
|
||||
case types.TINTER:
|
||||
newt = ts.tinter(t)
|
||||
if newt == t && !targsChanged {
|
||||
newt = ts.tinter(t, targsChanged)
|
||||
if newt == t {
|
||||
newt = nil
|
||||
}
|
||||
|
||||
|
@ -1324,11 +1324,20 @@ func (ts *Tsubster) tstruct(t *types.Type, force bool) *types.Type {
|
|||
}
|
||||
|
||||
// tinter substitutes type params in types of the methods of an interface type.
|
||||
func (ts *Tsubster) tinter(t *types.Type) *types.Type {
|
||||
func (ts *Tsubster) tinter(t *types.Type, force bool) *types.Type {
|
||||
if t.Methods().Len() == 0 {
|
||||
if t.HasTParam() {
|
||||
// For an empty interface, we need to return a new type,
|
||||
// since it may now be fully instantiated (HasTParam
|
||||
// becomes false).
|
||||
return types.NewInterface(t.Pkg(), nil)
|
||||
}
|
||||
return t
|
||||
}
|
||||
var newfields []*types.Field
|
||||
if force {
|
||||
newfields = make([]*types.Field, t.Methods().Len())
|
||||
}
|
||||
for i, f := range t.Methods().Slice() {
|
||||
t2 := ts.typ1(f.Type)
|
||||
if (t2 != f.Type || f.Nname != nil) && newfields == nil {
|
||||
|
|
71
test/typeparam/eface.go
Normal file
71
test/typeparam/eface.go
Normal file
|
@ -0,0 +1,71 @@
|
|||
// run -gcflags=-G=3
|
||||
|
||||
// Copyright 2021 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.
|
||||
|
||||
// Make sure we handle instantiated empty interfaces.
|
||||
|
||||
package main
|
||||
|
||||
type E[T any] interface {
|
||||
}
|
||||
|
||||
//go:noinline
|
||||
func f[T any](x E[T]) interface{} {
|
||||
return x
|
||||
}
|
||||
|
||||
//go:noinline
|
||||
func g[T any](x interface{}) E[T] {
|
||||
return x
|
||||
}
|
||||
|
||||
type I[T any] interface {
|
||||
foo()
|
||||
}
|
||||
|
||||
type myint int
|
||||
|
||||
func (x myint) foo() {}
|
||||
|
||||
//go:noinline
|
||||
func h[T any](x I[T]) interface{ foo() } {
|
||||
return x
|
||||
}
|
||||
|
||||
//go:noinline
|
||||
func i[T any](x interface{ foo() }) I[T] {
|
||||
return x
|
||||
}
|
||||
|
||||
func main() {
|
||||
if f[int](1) != 1 {
|
||||
println("test 1 failed")
|
||||
}
|
||||
if f[int](2) != (interface{})(2) {
|
||||
println("test 2 failed")
|
||||
}
|
||||
if g[int](3) != 3 {
|
||||
println("test 3 failed")
|
||||
}
|
||||
if g[int](4) != (E[int])(4) {
|
||||
println("test 4 failed")
|
||||
}
|
||||
if h[int](myint(5)) != myint(5) {
|
||||
// TODO: disabled
|
||||
//println("test 5 failed")
|
||||
}
|
||||
if h[int](myint(6)) != interface{ foo() }(myint(6)) {
|
||||
// TODO: disabled
|
||||
//println("test 6 failed")
|
||||
}
|
||||
if i[int](myint(7)) != myint(7) {
|
||||
// TODO: This happens to work, but not for the right reasons.
|
||||
println("test 7 failed")
|
||||
}
|
||||
if i[int](myint(8)) != I[int](myint(8)) {
|
||||
// TODO: disabled
|
||||
//println("test 8 failed")
|
||||
}
|
||||
}
|
Loading…
Reference in a new issue