golang/test/escape_mutations.go

78 lines
1.8 KiB
Go

// errorcheck -0 -m -d=escapemutationscalls,zerocopy -l
// Copyright 2023 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 p
import "fmt"
type B struct {
x int
px *int
pb *B
}
func F1(b *B) { // ERROR "mutates param: b derefs=0"
b.x = 1
}
func F2(b *B) { // ERROR "mutates param: b derefs=1"
*b.px = 1
}
func F2a(b *B) { // ERROR "mutates param: b derefs=0"
b.px = nil
}
func F3(b *B) { // ERROR "leaking param: b"
fmt.Println(b) // ERROR "\.\.\. argument does not escape"
}
func F4(b *B) { // ERROR "leaking param content: b"
fmt.Println(*b) // ERROR "\.\.\. argument does not escape" "\*b escapes to heap"
}
func F4a(b *B) { // ERROR "leaking param content: b" "mutates param: b derefs=0"
b.x = 2
fmt.Println(*b) // ERROR "\.\.\. argument does not escape" "\*b escapes to heap"
}
func F5(b *B) { // ERROR "leaking param: b"
sink = b
}
func F6(b *B) int { // ERROR "b does not escape, mutate, or call"
return b.x
}
var sink any
func M() {
var b B // ERROR "moved to heap: b"
F1(&b)
F2(&b)
F2a(&b)
F3(&b)
F4(&b)
}
func g(s string) { // ERROR "s does not escape, mutate, or call"
sink = &([]byte(s))[10] // ERROR "\(\[\]byte\)\(s\) escapes to heap"
}
func h(out []byte, s string) { // ERROR "mutates param: out derefs=0" "s does not escape, mutate, or call"
copy(out, []byte(s)) // ERROR "zero-copy string->\[\]byte conversion" "\(\[\]byte\)\(s\) does not escape"
}
func i(s string) byte { // ERROR "s does not escape, mutate, or call"
p := []byte(s) // ERROR "zero-copy string->\[\]byte conversion" "\(\[\]byte\)\(s\) does not escape"
return p[20]
}
func j(s string, x byte) { // ERROR "s does not escape, mutate, or call"
p := []byte(s) // ERROR "\(\[\]byte\)\(s\) does not escape"
p[20] = x
}