From af80af22b507ae23ae04372f30b98f7720c85f8a Mon Sep 17 00:00:00 2001 From: Robert Griesemer Date: Thu, 26 Aug 2021 12:27:06 -0700 Subject: cmd/compile/internal/types2: do not declare new methods on instantiated types Report an error if an alias is used to declare a method on an instantiated type. Also, when resolving the receiver type, don't use asNamed to avoid premature expansion of the type. Fixes #47968. Change-Id: Ie5acc4cfb1944deaaeeaee98707f31e256f8ef5e Reviewed-on: https://go-review.googlesource.com/c/go/+/345472 Trust: Robert Griesemer Reviewed-by: Matthew Dempsky --- .../types2/testdata/fixedbugs/issue47968.go2 | 21 +++++++++++++++++++++ 1 file changed, 21 insertions(+) create mode 100644 src/cmd/compile/internal/types2/testdata/fixedbugs/issue47968.go2 (limited to 'src/cmd/compile/internal/types2/testdata/fixedbugs/issue47968.go2') diff --git a/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47968.go2 b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47968.go2 new file mode 100644 index 0000000000..bbbe6805f2 --- /dev/null +++ b/src/cmd/compile/internal/types2/testdata/fixedbugs/issue47968.go2 @@ -0,0 +1,21 @@ +// 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. + +package p + +type T[P any] struct{} + +func (T[P]) m1() + +type A1 = T + +func (A1[P]) m2() {} + +type A2 = T[int] + +func (A2 /* ERROR cannot define methods on instantiated type T\[int\] */) m3() {} +func (_ /* ERROR cannot define methods on instantiated type T\[int\] */ A2) m4() {} + +func (T[int]) m5() {} // int is the type parameter name, not an instantiation +func (T[* /* ERROR must be an identifier */ int]) m6() {} // syntax error -- cgit v1.2.3-54-g00ecf