test: add a test for parameterized embedded field
Make sure that an embedded field like "MyStruct[T]" works and can be
referenced via the name MyStruct.
Change-Id: I8be1f1184dd42c4e54e4144aff2fd85e30af722f
Reviewed-on: https://go-review.googlesource.com/c/go/+/356312
Trust: Dan Scales <danscales@google.com>
Reviewed-by: Robert Griesemer <gri@golang.org>
diff --git a/src/cmd/compile/internal/typecheck/subr.go b/src/cmd/compile/internal/typecheck/subr.go
index b3fc745..b4d5302 100644
--- a/src/cmd/compile/internal/typecheck/subr.go
+++ b/src/cmd/compile/internal/typecheck/subr.go
@@ -1324,9 +1324,6 @@
}
}
if newfields != nil {
- // TODO(danscales): make sure this works for the field
- // names of embedded types (which should keep the name of
- // the type param, not the instantiated type).
newfields[i] = types.NewField(f.Pos, f.Sym, t2)
newfields[i].Embedded = f.Embedded
newfields[i].Note = f.Note
diff --git a/test/typeparam/genembed2.go b/test/typeparam/genembed2.go
new file mode 100644
index 0000000..6effd2e
--- /dev/null
+++ b/test/typeparam/genembed2.go
@@ -0,0 +1,46 @@
+// 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.
+
+// Test for declaration and use of a parameterized embedded field.
+
+package main
+
+import (
+ "fmt"
+ "sync"
+)
+
+type MyStruct[T any] struct {
+ val T
+}
+
+type Lockable[T any] struct {
+ MyStruct[T]
+ mu sync.Mutex
+}
+
+// Get returns the value stored in a Lockable.
+func (l *Lockable[T]) Get() T {
+ l.mu.Lock()
+ defer l.mu.Unlock()
+ return l.MyStruct.val
+}
+
+// Set sets the value in a Lockable.
+func (l *Lockable[T]) Set(v T) {
+ l.mu.Lock()
+ defer l.mu.Unlock()
+ l.MyStruct = MyStruct[T]{v}
+}
+
+func main() {
+ var li Lockable[int]
+
+ li.Set(5)
+ if got, want := li.Get(), 5; got != want {
+ panic(fmt.Sprintf("got %d, want %d", got, want))
+ }
+}
