// errorcheck -0 -live -d=eagerwb // Copyright 2016 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 15747: liveness analysis was marking heap-escaped params live too much, // and worse was using the wrong bitmap bits to do so. // TODO(austin): This expects function calls to the write barrier, so // we enable the legacy eager write barrier. Fix this once the // buffered write barrier works on all arches. package p var global *[]byte type Q struct{} type T struct{ M string } var b bool func f1(q *Q, xx []byte) interface{} { // ERROR "live at call to newobject: xx$" "live at call to writebarrierptr: &xx$" "live at entry to f1: xx$" // xx was copied from the stack to the heap on the previous line: // xx was live for the first two prints but then it switched to &xx // being live. We should not see plain xx again. if b { global = &xx // ERROR "live at call to writebarrierptr: &xx$" } xx, _, err := f2(xx, 5) // ERROR "live at call to f2: &xx$" "live at call to writebarrierptr: err.data err.type$" if err != nil { return err } return nil } //go:noinline func f2(d []byte, n int) (odata, res []byte, e interface{}) { // ERROR "live at entry to f2: d$" if n > len(d) { return d, nil, &T{M: "hello"} // ERROR "live at call to newobject: d" "live at call to writebarrierptr: d" } res = d[:n] odata = d[n:] return }