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925d2fb36c
This CL implements the remainder of the zero-copy string->[]byte conversion optimization initially attempted in go.dev/cl/520395, but fixes the tracking of mutations due to ODEREF/ODOTPTR assignments, and adds more comprehensive tests that I should have included originally. However, this CL also keeps it behind the -d=zerocopy flag. The next CL will enable it by default (for easier rollback). Updates #2205. Change-Id: Ic330260099ead27fc00e2680a59c6ff23cb63c2b Reviewed-on: https://go-review.googlesource.com/c/go/+/520599 Auto-Submit: Matthew Dempsky <mdempsky@google.com> TryBot-Result: Gopher Robot <gobot@golang.org> Reviewed-by: Than McIntosh <thanm@google.com> Run-TryBot: Matthew Dempsky <mdempsky@google.com> Reviewed-by: Cuong Manh Le <cuong.manhle.vn@gmail.com>
78 lines
1.8 KiB
Go
78 lines
1.8 KiB
Go
// errorcheck -0 -m -d=escapemutationscalls,zerocopy -l
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// Copyright 2023 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 p
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import "fmt"
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type B struct {
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x int
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px *int
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pb *B
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}
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func F1(b *B) { // ERROR "mutates param: b derefs=0"
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b.x = 1
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}
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func F2(b *B) { // ERROR "mutates param: b derefs=1"
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*b.px = 1
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}
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func F2a(b *B) { // ERROR "mutates param: b derefs=0"
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b.px = nil
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}
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func F3(b *B) { // ERROR "leaking param: b"
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fmt.Println(b) // ERROR "\.\.\. argument does not escape"
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}
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func F4(b *B) { // ERROR "leaking param content: b"
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fmt.Println(*b) // ERROR "\.\.\. argument does not escape" "\*b escapes to heap"
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}
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func F4a(b *B) { // ERROR "leaking param content: b" "mutates param: b derefs=0"
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b.x = 2
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fmt.Println(*b) // ERROR "\.\.\. argument does not escape" "\*b escapes to heap"
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}
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func F5(b *B) { // ERROR "leaking param: b"
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sink = b
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}
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func F6(b *B) int { // ERROR "b does not escape, mutate, or call"
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return b.x
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}
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var sink any
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func M() {
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var b B // ERROR "moved to heap: b"
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F1(&b)
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F2(&b)
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F2a(&b)
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F3(&b)
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F4(&b)
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}
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func g(s string) { // ERROR "s does not escape, mutate, or call"
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sink = &([]byte(s))[10] // ERROR "\(\[\]byte\)\(s\) escapes to heap"
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}
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func h(out []byte, s string) { // ERROR "mutates param: out derefs=0" "s does not escape, mutate, or call"
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copy(out, []byte(s)) // ERROR "zero-copy string->\[\]byte conversion" "\(\[\]byte\)\(s\) does not escape"
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}
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func i(s string) byte { // ERROR "s does not escape, mutate, or call"
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p := []byte(s) // ERROR "zero-copy string->\[\]byte conversion" "\(\[\]byte\)\(s\) does not escape"
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return p[20]
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}
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func j(s string, x byte) { // ERROR "s does not escape, mutate, or call"
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p := []byte(s) // ERROR "\(\[\]byte\)\(s\) does not escape"
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p[20] = x
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}
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