1 // errorcheck -0 -N -m -l 2 3 // Copyright 2016 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 // The escape analyzer needs to run till its root set settles 8 // (this is not that often, it turns out). 9 // This test is likely to become stale because the leak depends 10 // on a spurious-escape bug -- return an interface as a named 11 // output parameter appears to cause the called closure to escape, 12 // where returning it as a regular type does not. 13 14 package main 15 16 import ( 17 "fmt" 18 ) 19 20 type closure func(i, j int) ent 21 22 type ent int 23 24 func (e ent) String() string { 25 return fmt.Sprintf("%d", int(e)) // ERROR "ent.String ... argument does not escape$" "int\(e\) escapes to heap$" 26 } 27 28 //go:noinline 29 func foo(ops closure, j int) (err fmt.Stringer) { // ERROR "leaking param: ops$" "leaking param: ops to result err level=0$" 30 enqueue := func(i int) fmt.Stringer { // ERROR "func literal escapes to heap$" 31 return ops(i, j) // ERROR "ops\(i, j\) escapes to heap$" 32 } 33 err = enqueue(4) 34 if err != nil { 35 return err 36 } 37 return // return result of enqueue, a fmt.Stringer 38 } 39 40 func main() { 41 // 3 identical functions, to get different escape behavior. 42 f := func(i, j int) ent { // ERROR "func literal escapes to heap$" 43 return ent(i + j) 44 } 45 i := foo(f, 3).(ent) 46 fmt.Printf("foo(f,3)=%d\n", int(i)) // ERROR "int\(i\) escapes to heap$" "main ... argument does not escape$" 47 } 48
