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// +build !gcflags_noopt
// errorcheck -0 -m
// Copyright 2018 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 foo
import "bytes"
// In order to get desired results, we need a combination of
// both escape analysis and inlining.
func bufferNotEscape() string {
// b itself does not escape, only its buf field will be
// copied during String() call, but object "handle" itself
// can be stack-allocated.
var b bytes.Buffer
b.WriteString("123")
b.Write([]byte{'4'}) // ERROR "\[\]byte{...} does not escape$"
return b.String() // ERROR "inlining call to bytes.\(\*Buffer\).String$" "string\(bytes.b.buf\[bytes.b.off:\]\) escapes to heap$"
}
func bufferNoEscape2(xs []string) int { // ERROR "xs does not escape$"
b := bytes.NewBuffer(make([]byte, 0, 64)) // ERROR "&bytes.Buffer{...} does not escape$" "make\(\[\]byte, 0, 64\) does not escape$" "inlining call to bytes.NewBuffer$"
for _, x := range xs {
b.WriteString(x)
}
return b.Len() // ERROR "inlining call to bytes.\(\*Buffer\).Len$"
}
func bufferNoEscape3(xs []string) string { // ERROR "xs does not escape$"
b := bytes.NewBuffer(make([]byte, 0, 64)) // ERROR "&bytes.Buffer{...} does not escape$" "make\(\[\]byte, 0, 64\) does not escape$" "inlining call to bytes.NewBuffer$"
for _, x := range xs {
b.WriteString(x)
b.WriteByte(',')
}
return b.String() // ERROR "inlining call to bytes.\(\*Buffer\).String$" "string\(bytes.b.buf\[bytes.b.off:\]\) escapes to heap$"
}
func bufferNoEscape4() []byte {
var b bytes.Buffer
b.Grow(64) // ERROR "bufferNoEscape4 ignoring self-assignment in bytes.b.buf = bytes.b.buf\[:bytes.m·3\]$" "inlining call to bytes.\(\*Buffer\).Grow$"
useBuffer(&b)
return b.Bytes() // ERROR "inlining call to bytes.\(\*Buffer\).Bytes$"
}
func bufferNoEscape5() { // ERROR "can inline bufferNoEscape5$"
b := bytes.NewBuffer(make([]byte, 0, 128)) // ERROR "&bytes.Buffer{...} does not escape$" "make\(\[\]byte, 0, 128\) does not escape$" "inlining call to bytes.NewBuffer$"
useBuffer(b)
}
//go:noinline
func useBuffer(b *bytes.Buffer) { // ERROR "b does not escape$"
b.WriteString("1234")
}
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