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https://github.com/golang/go
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62 lines
1.8 KiB
Go
62 lines
1.8 KiB
Go
// Copyright 2014 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 testdata
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import (
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"reflect"
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"unsafe"
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)
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func f() {
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var x unsafe.Pointer
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var y uintptr
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x = unsafe.Pointer(y) // ERROR "possible misuse of unsafe.Pointer"
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y = uintptr(x)
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// only allowed pointer arithmetic is ptr +/- num.
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// num+ptr is technically okay but still flagged: write ptr+num instead.
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x = unsafe.Pointer(uintptr(x) + 1)
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x = unsafe.Pointer(1 + uintptr(x)) // ERROR "possible misuse of unsafe.Pointer"
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x = unsafe.Pointer(uintptr(x) + uintptr(x)) // ERROR "possible misuse of unsafe.Pointer"
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x = unsafe.Pointer(uintptr(x) - 1)
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x = unsafe.Pointer(1 - uintptr(x)) // ERROR "possible misuse of unsafe.Pointer"
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// certain uses of reflect are okay
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var v reflect.Value
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x = unsafe.Pointer(v.Pointer())
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x = unsafe.Pointer(v.UnsafeAddr())
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var s1 *reflect.StringHeader
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x = unsafe.Pointer(s1.Data)
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var s2 *reflect.SliceHeader
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x = unsafe.Pointer(s2.Data)
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var s3 reflect.StringHeader
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x = unsafe.Pointer(s3.Data) // ERROR "possible misuse of unsafe.Pointer"
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var s4 reflect.SliceHeader
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x = unsafe.Pointer(s4.Data) // ERROR "possible misuse of unsafe.Pointer"
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// but only in reflect
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var vv V
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x = unsafe.Pointer(vv.Pointer()) // ERROR "possible misuse of unsafe.Pointer"
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x = unsafe.Pointer(vv.UnsafeAddr()) // ERROR "possible misuse of unsafe.Pointer"
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var ss1 *StringHeader
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x = unsafe.Pointer(ss1.Data) // ERROR "possible misuse of unsafe.Pointer"
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var ss2 *SliceHeader
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x = unsafe.Pointer(ss2.Data) // ERROR "possible misuse of unsafe.Pointer"
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}
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type V interface {
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Pointer() uintptr
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UnsafeAddr() uintptr
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}
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type StringHeader struct {
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Data uintptr
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}
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type SliceHeader struct {
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Data uintptr
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}
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