Current File : //usr/local/go119/src/runtime/testdata/testprog/checkptr.go
// Copyright 2020 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 main
import (
"runtime"
"time"
"unsafe"
)
func init() {
register("CheckPtrAlignmentNoPtr", CheckPtrAlignmentNoPtr)
register("CheckPtrAlignmentPtr", CheckPtrAlignmentPtr)
register("CheckPtrAlignmentNilPtr", CheckPtrAlignmentNilPtr)
register("CheckPtrArithmetic", CheckPtrArithmetic)
register("CheckPtrArithmetic2", CheckPtrArithmetic2)
register("CheckPtrSize", CheckPtrSize)
register("CheckPtrSmall", CheckPtrSmall)
register("CheckPtrSliceOK", CheckPtrSliceOK)
register("CheckPtrSliceFail", CheckPtrSliceFail)
register("CheckPtrAlignmentNested", CheckPtrAlignmentNested)
}
func CheckPtrAlignmentNoPtr() {
var x [2]int64
p := unsafe.Pointer(&x[0])
sink2 = (*int64)(unsafe.Pointer(uintptr(p) + 1))
}
func CheckPtrAlignmentPtr() {
var x [2]int64
p := unsafe.Pointer(&x[0])
sink2 = (**int64)(unsafe.Pointer(uintptr(p) + 1))
}
// CheckPtrAlignmentNilPtr tests that checkptrAlignment doesn't crash
// on nil pointers (#47430).
func CheckPtrAlignmentNilPtr() {
var do func(int)
do = func(n int) {
// Inflate the stack so runtime.shrinkstack gets called during GC
if n > 0 {
do(n - 1)
}
var p unsafe.Pointer
_ = (*int)(p)
}
go func() {
for {
runtime.GC()
}
}()
go func() {
for i := 0; ; i++ {
do(i % 1024)
}
}()
time.Sleep(time.Second)
}
func CheckPtrArithmetic() {
var x int
i := uintptr(unsafe.Pointer(&x))
sink2 = (*int)(unsafe.Pointer(i))
}
func CheckPtrArithmetic2() {
var x [2]int64
p := unsafe.Pointer(&x[1])
var one uintptr = 1
sink2 = unsafe.Pointer(uintptr(p) & ^one)
}
func CheckPtrSize() {
p := new(int64)
sink2 = p
sink2 = (*[100]int64)(unsafe.Pointer(p))
}
func CheckPtrSmall() {
sink2 = unsafe.Pointer(uintptr(1))
}
func CheckPtrSliceOK() {
p := new([4]int64)
sink2 = unsafe.Slice(&p[1], 3)
}
func CheckPtrSliceFail() {
p := new(int64)
sink2 = p
sink2 = unsafe.Slice(p, 100)
}
func CheckPtrAlignmentNested() {
s := make([]int8, 100)
p := unsafe.Pointer(&s[0])
n := 9
_ = ((*[10]int8)(unsafe.Pointer((*[10]int64)(unsafe.Pointer(&p)))))[:n:n]
}
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