1// run
2
3// Copyright 2015 The Go Authors. All rights reserved.
4// Use of this source code is governed by a BSD-style
5// license that can be found in the LICENSE file.
6
7// issue 10253: cmd/gc: incorrect escape analysis of closures
8// Partial call x.foo was not promoted to heap.
9
10package main
11
12func main() {
13	c := make(chan bool)
14	// Create a new goroutine to get a default-size stack segment.
15	go func() {
16		x := new(X)
17		clos(x.foo)()
18		c <- true
19	}()
20	<-c
21}
22
23type X int
24
25func (x *X) foo() {
26}
27
28func clos(x func()) func() {
29	f := func() {
30		print("")
31		x() // This statement crashed, because the partial call was allocated on the old stack.
32	}
33	// Grow stack so that partial call x becomes invalid if allocated on stack.
34	growstack(10000)
35	c := make(chan bool)
36	// Spoil the previous stack segment.
37	go func() {
38		c <- true
39	}()
40	<-c
41	return f
42}
43
44func growstack(x int) {
45	if x == 0 {
46		return
47	}
48	growstack(x - 1)
49}
50