Initial commit: Go 1.23 release state

test/typeparam/issue48962.dir/a.go

@@ -0,0 +1,12 @@
+// Copyright 2022 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 a
+
+type (
+	A[P any]               [10]P
+	S[P any]               struct{ f P }
+	P[P any]               *P
+	M[K comparable, V any] map[K]V
+)

test/typeparam/issue48962.dir/b.go

@@ -0,0 +1,51 @@
+// Copyright 2022 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 b
+
+import "./a"
+
+type (
+	lA[P any]               [10]P
+	lS[P any]               struct{ f P }
+	lP[P any]               *P
+	lM[K comparable, V any] map[K]V
+)
+
+// local cycles
+type (
+	A  lA[A]            // ERROR "invalid recursive type"
+	S  lS[S]            // ERROR "invalid recursive type"
+	P  lP[P]            // ok (indirection through lP)
+	M1 lM[int, M1]      // ok (indirection through lM)
+	M2 lM[lA[byte], M2] // ok (indirection through lM)
+
+	A2 lA[lS[lP[A2]]] // ok (indirection through lP)
+	A3 lA[lS[lS[A3]]] // ERROR "invalid recursive type"
+)
+
+// cycles through imported types
+type (
+	Ai  a.A[Ai]             // ERROR "invalid recursive type"
+	Si  a.S[Si]             // ERROR "invalid recursive type"
+	Pi  a.P[Pi]             // ok (indirection through a.P)
+	M1i a.M[int, M1i]       // ok (indirection through a.M)
+	M2i a.M[a.A[byte], M2i] // ok (indirection through a.M)
+
+	A2i a.A[a.S[a.P[A2i]]] // ok (indirection through a.P)
+	A3i a.A[a.S[a.S[A3i]]] // ERROR "invalid recursive type"
+
+	T2 a.S[T0[T2]] // ERROR "invalid recursive type"
+	T3 T0[Ai]      // no follow-on error here
+)
+
+// test case from issue
+
+type T0[P any] struct {
+	f P
+}
+
+type T1 struct { // ERROR "invalid recursive type"
+	_ T0[T1]
+}