go/test/fixedbugs/issue45258.go

// compile

// 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

type Fooer interface {
	Foo() Barer
}

type Barer interface {
	Bar()
}

type impl struct{}

func (r *impl) Foo() Barer {
	return r
}

func (r *impl) Bar() {}

func f1() {
	var r Fooer = &impl{}
	r.Foo().Bar()
}
cmd/compile: skip "_" function in reflectdata.MarkUsedIfaceMethod CL 256798 added compiler ability to retain only used interface methods, by generating a mark relocation whenever an interface method is used. To do that, the compiler needs the current function linker object. However, for unnamed function "func _()", its linker object is nil, causes the compiler crashes for code in #45258. CL 283313 fixed the code in #45258 unintentionally, since when the compiler now does not walk unnamed functions anymore. This CL fixes the root issue, by making reflectdata.MarkUsedIfaceMethod skips unnamed functions, and also adding regression test. Fixes #45258 Change-Id: I4cbefb0a89d9928f70c00dc8a271cb61cd20a49c Reviewed-on: https://go-review.googlesource.com/c/go/+/311130 Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org> 2021-04-18 19:39:50 +00:00			`// compile`

			`// 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`

			`type Fooer interface {`
			`Foo() Barer`
			`}`

			`type Barer interface {`
			`Bar()`
			`}`

			`type impl struct{}`

			`func (r *impl) Foo() Barer {`
			`return r`
			`}`

			`func (r *impl) Bar() {}`

[dev.typeparams] test: rename blank functions This CL renames blank functions in the test/ directory so that they don't rely on the compiler doing anything more than typechecking them. In particular, I ran this search to find files that used blank functions and methods: $ git grep -l '^func.\b_(' \| xargs grep -n '^' \| grep '\.go:1:' \| grep -v '// errorcheck$' I then skipped updating a few files: blank.go * fixedbugs/issue11699.go * fixedbugs/issue29870.go These tests specifically check that blank functions/methods work. * interface/fail.go Not sure the motivation for the blank method here, but it's empty anyway. * typeparam/tparam1.go Type-checking test, but uses "-G" (to use types2 instead of typecheck). Updates #47446. Change-Id: I9ec1714f499808768bd0dcd7ae6016fb2b078e5e Reviewed-on: https://go-review.googlesource.com/c/go/+/338094 Trust: Matthew Dempsky <mdempsky@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Robert Griesemer <gri@golang.org> 2021-07-28 19:59:14 +00:00			`func f1() {`
cmd/compile: skip "_" function in reflectdata.MarkUsedIfaceMethod CL 256798 added compiler ability to retain only used interface methods, by generating a mark relocation whenever an interface method is used. To do that, the compiler needs the current function linker object. However, for unnamed function "func _()", its linker object is nil, causes the compiler crashes for code in #45258. CL 283313 fixed the code in #45258 unintentionally, since when the compiler now does not walk unnamed functions anymore. This CL fixes the root issue, by making reflectdata.MarkUsedIfaceMethod skips unnamed functions, and also adding regression test. Fixes #45258 Change-Id: I4cbefb0a89d9928f70c00dc8a271cb61cd20a49c Reviewed-on: https://go-review.googlesource.com/c/go/+/311130 Trust: Cuong Manh Le <cuong.manhle.vn@gmail.com> Run-TryBot: Cuong Manh Le <cuong.manhle.vn@gmail.com> TryBot-Result: Go Bot <gobot@golang.org> Reviewed-by: Keith Randall <khr@golang.org> 2021-04-18 19:39:50 +00:00			`var r Fooer = &impl{}`
			`r.Foo().Bar()`
			`}`