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58 lines
2.2 KiB
58 lines
2.2 KiB
4 months ago
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// +build !gcflags_noopt
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// errorcheck -0 -m
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// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package foo
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import "bytes"
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// In order to get desired results, we need a combination of
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// both escape analysis and inlining.
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func bufferNotEscape() string {
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// b itself does not escape, only its buf field will be
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// copied during String() call, but object "handle" itself
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// can be stack-allocated.
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var b bytes.Buffer
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b.WriteString("123")
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b.Write([]byte{'4'}) // ERROR "\[\]byte literal does not escape$"
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return b.String() // ERROR "inlining call to bytes.\(\*Buffer\).String$" "string\(bytes.b.buf\[bytes.b.off:\]\) escapes to heap$"
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}
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func bufferNoEscape2(xs []string) int { // ERROR "xs does not escape$"
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b := bytes.NewBuffer(make([]byte, 0, 64)) // ERROR "&bytes.Buffer literal does not escape$" "make\(\[\]byte, 0, 64\) does not escape$" "inlining call to bytes.NewBuffer$"
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for _, x := range xs {
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b.WriteString(x)
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}
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return b.Len() // ERROR "inlining call to bytes.\(\*Buffer\).Len$"
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}
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func bufferNoEscape3(xs []string) string { // ERROR "xs does not escape$"
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b := bytes.NewBuffer(make([]byte, 0, 64)) // ERROR "&bytes.Buffer literal does not escape$" "make\(\[\]byte, 0, 64\) does not escape$" "inlining call to bytes.NewBuffer$"
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for _, x := range xs {
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b.WriteString(x)
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b.WriteByte(',')
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}
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return b.String() // ERROR "inlining call to bytes.\(\*Buffer\).String$" "string\(bytes.b.buf\[bytes.b.off:\]\) escapes to heap$"
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}
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func bufferNoEscape4() []byte {
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var b bytes.Buffer
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b.Grow(64) // ERROR "bufferNoEscape4 ignoring self-assignment in bytes.b.buf = bytes.b.buf\[:bytes.m·3\]$" "inlining call to bytes.\(\*Buffer\).Grow$"
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useBuffer(&b)
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return b.Bytes() // ERROR "inlining call to bytes.\(\*Buffer\).Bytes$"
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}
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func bufferNoEscape5() { // ERROR "can inline bufferNoEscape5$"
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b := bytes.NewBuffer(make([]byte, 0, 128)) // ERROR "&bytes.Buffer literal does not escape$" "make\(\[\]byte, 0, 128\) does not escape$" "inlining call to bytes.NewBuffer$"
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useBuffer(b)
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}
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//go:noinline
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func useBuffer(b *bytes.Buffer) { // ERROR "b does not escape$"
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b.WriteString("1234")
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}
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