From: Cuong Manh Le Date: Fri, 10 Sep 2021 00:44:02 +0000 (+0700) Subject: cmd/compile: prevent importReader reading type parameter twice X-Git-Tag: go1.18beta1~1362 X-Git-Url: http://www.git.cypherpunks.su/?a=commitdiff_plain;h=b8c802b1161528fcf8ba78b1dff5720dd5b4eb9f;p=gostls13.git cmd/compile: prevent importReader reading type parameter twice The importReader always reads type parameter before declaring type stub declaration. Thus, for recursive type, the type parameter is going to be read twice, cause the bound more than once error. To fix this, only read the type parameter after declaring stub obj, thus r.doDecl can see the type was already inserted and terminate the recursive call earlier. Fixes #48280 Change-Id: I272e2f214f739fb8ec71a8628ba297477e1b7755 Reviewed-on: https://go-review.googlesource.com/c/go/+/349009 Trust: Cuong Manh Le Trust: Dan Scales Run-TryBot: Cuong Manh Le TryBot-Result: Go Bot Reviewed-by: Dan Scales --- diff --git a/src/cmd/compile/internal/importer/iimport.go b/src/cmd/compile/internal/importer/iimport.go index b61b1e97fb..7f7143dcfe 100644 --- a/src/cmd/compile/internal/importer/iimport.go +++ b/src/cmd/compile/internal/importer/iimport.go @@ -318,17 +318,17 @@ func (r *importReader) obj(name string) { r.declare(types2.NewFunc(pos, r.currPkg, name, sig)) case 'T', 'U': - var tparams []*types2.TypeParam - if tag == 'U' { - tparams = r.tparamList() - } - // Types can be recursive. We need to setup a stub // declaration before recursing. obj := types2.NewTypeName(pos, r.currPkg, name, nil) named := types2.NewNamed(obj, nil, nil) - named.SetTypeParams(tparams) + // Declare obj before calling r.tparamList, so the new type name is recognized + // if used in the constraint of one of its own typeparams (see #48280). r.declare(obj) + if tag == 'U' { + tparams := r.tparamList() + named.SetTypeParams(tparams) + } underlying := r.p.typAt(r.uint64(), named).Underlying() named.SetUnderlying(underlying) diff --git a/test/typeparam/issue48280.dir/a.go b/test/typeparam/issue48280.dir/a.go new file mode 100644 index 0000000000..17859e6aa9 --- /dev/null +++ b/test/typeparam/issue48280.dir/a.go @@ -0,0 +1,11 @@ +// 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 a + +type I[T I[T]] interface { + F() T +} + +type S struct{} diff --git a/test/typeparam/issue48280.dir/main.go b/test/typeparam/issue48280.dir/main.go new file mode 100644 index 0000000000..b9981c6f61 --- /dev/null +++ b/test/typeparam/issue48280.dir/main.go @@ -0,0 +1,11 @@ +// 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 main + +import "a" + +func main() { + _ = a.S{} +} diff --git a/test/typeparam/issue48280.go b/test/typeparam/issue48280.go new file mode 100644 index 0000000000..76930e5e4f --- /dev/null +++ b/test/typeparam/issue48280.go @@ -0,0 +1,7 @@ +// rundir -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. + +package ignored