diff --git a/src/cmd/compile/internal/gc/esc.go b/src/cmd/compile/internal/gc/esc.go index 7ef07961dea..03c0adafd51 100644 --- a/src/cmd/compile/internal/gc/esc.go +++ b/src/cmd/compile/internal/gc/esc.go @@ -680,7 +680,18 @@ func (e *EscState) esc(n *Node, parent *Node) { } e.esc(n.Left, n) + + if n.Op == ORANGE { + // ORANGE node's Right is evaluated before the loop + e.loopdepth-- + } + e.esc(n.Right, n) + + if n.Op == ORANGE { + e.loopdepth++ + } + e.esclist(n.Nbody, n) e.esclist(n.List, n) e.esclist(n.Rlist, n) diff --git a/test/fixedbugs/issue21709.go b/test/fixedbugs/issue21709.go new file mode 100644 index 00000000000..bf5d9d23f18 --- /dev/null +++ b/test/fixedbugs/issue21709.go @@ -0,0 +1,37 @@ +// errorcheck -0 -l -m + +// Copyright 2017 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. + +// Issue 21709: range expression overly escapes. + +package p + +type S struct{} + +func (s *S) Inc() {} // ERROR "\(\*S\).Inc s does not escape" +var N int + +func F1() { + var s S // ERROR "moved to heap: s" + for i := 0; i < N; i++ { + fs := []func(){ // ERROR "F1 \[\]func\(\) literal does not escape" + s.Inc, // ERROR "F1 s.Inc does not escape" "s escapes to heap" + } + for _, f := range fs { + f() + } + } +} + +func F2() { + var s S // ERROR "moved to heap: s" + for i := 0; i < N; i++ { + for _, f := range []func(){ // ERROR "F2 \[\]func\(\) literal does not escape" + s.Inc, // ERROR "F2 s.Inc does not escape" "s escapes to heap" + } { + f() + } + } +}