From 16c2b3615ae7b565947ff7d0cff06d4809236c2e Mon Sep 17 00:00:00 2001 From: Cuong Manh Le Date: Sat, 23 Jul 2022 22:31:35 +0700 Subject: [PATCH] [release-branch.go1.19] cmd/compile: fix wrong typeparams for selector expr with embedded generic type For selector expression "x.M" where "M" is a promoted method, irgen is using the type of receiver "x" for determining the typeparams for instantiation. However, because M is a promoted method, so its associated receiver is not "x", but "x.T" where "T" is the embedded field of "x". That casues a mismatch when converting non-shape types arguments. Fixing it by using the actual receiver which has the method, instead of using the base receiver. Fixes #54243 Change-Id: I1836fc422d734df14e9e6664d4bd014503960bfc Reviewed-on: https://go-review.googlesource.com/c/go/+/419294 TryBot-Result: Gopher Robot Run-TryBot: Cuong Manh Le Reviewed-by: Matthew Dempsky Reviewed-by: Keith Randall Reviewed-by: Keith Randall Reviewed-on: https://go-review.googlesource.com/c/go/+/423114 Reviewed-by: Carlos Amedee --- src/cmd/compile/internal/noder/stencil.go | 7 ++----- test/fixedbugs/issue53982.go | 25 +++++++++++++++++++++++ 2 files changed, 27 insertions(+), 5 deletions(-) create mode 100644 test/fixedbugs/issue53982.go diff --git a/src/cmd/compile/internal/noder/stencil.go b/src/cmd/compile/internal/noder/stencil.go index d3f51e00cd..6fcb31b472 100644 --- a/src/cmd/compile/internal/noder/stencil.go +++ b/src/cmd/compile/internal/noder/stencil.go @@ -334,10 +334,6 @@ func (g *genInst) buildClosure(outer *ir.Func, x ir.Node) ir.Node { } else { // ir.OMETHEXPR or ir.METHVALUE // Method expression T.M where T is a generic type. se := x.(*ir.SelectorExpr) - targs := deref(se.X.Type()).RParams() - if len(targs) == 0 { - panic("bad") - } if x.Op() == ir.OMETHVALUE { rcvrValue = se.X } @@ -348,7 +344,8 @@ func (g *genInst) buildClosure(outer *ir.Func, x ir.Node) ir.Node { // of se.Selection, since that will be the type that actually has // the method. recv := deref(se.Selection.Type.Recv().Type) - if len(recv.RParams()) == 0 { + targs := recv.RParams() + if len(targs) == 0 { // The embedded type that actually has the method is not // actually generic, so no need to build a closure. return x diff --git a/test/fixedbugs/issue53982.go b/test/fixedbugs/issue53982.go new file mode 100644 index 0000000000..512b1af2bc --- /dev/null +++ b/test/fixedbugs/issue53982.go @@ -0,0 +1,25 @@ +// build + +// 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 main + +type S[K, V any] struct { + E[V] +} + +type E[K any] struct{} + +func (e E[K]) M() E[K] { + return e +} + +func G[K, V any](V) { + _ = (*S[K, V]).M +} + +func main() { + G[*int](new(int)) +} -- 2.48.1