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关于Go的空指针检查

 1 year ago
source link: https://zhanggq.github.io/post/zgq-go-nil-pointer/
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最近开发过程中遇到挺多空指针引发的Coredump，想在CI过程中集成一下Go的代码检查工具，但实际发现这些工具的效果都不行……

一、测试代码

简单写了一些空指针代码，如下所示：

package main
import (
"fmt"
"reflect"
"testGolint/context" // 加载这个库时，就会调用其init()，所以其内部打印在main()之前
"time"
type Address struct {
Home string
Email string
type User struct {
Name string
Address *Address
func testCase0() {
fmt.Println("Test Case 0 Begin..")
var a = User{}
address := a.Address
if address == nil {
fmt.Println(*address) // nil dereference
fmt.Printf("Email Address = [%s] \n", address.Email) // 典型的空指针，查不出来
fmt.Println("Test Case 0 Finish..")
func testCase1() {
fmt.Println("Test Case 1 Begin..")
var a = &context.Context{}
var user = a.UserAllocate()
fmt.Printf("User Name %s \n", user.Name)
var company = user.WorkExps[0]
fmt.Printf("User Company Name %s \n", company.CompanyName) // 典型的空指针，查不出来
fmt.Println("Test Case 1 Finish..")
func testCase2() {
fmt.Println("Test Case 2 Begin..")
var a *context.Context
go func() {
fmt.Println("Before a.")
a = &context.Context{}
fmt.Println("After a")
//time.Sleep(1 * time.Second) // 加上这句就不会dump
go func() {
fmt.Println("Before UserInfo.")
a.UserInfo() // 这行很可能运行在a = &context.Context{}之前，会触发空指针dump
fmt.Println("After UserInfo.")
fmt.Println("Test Case 2 Finish..")
time.Sleep(3 * time.Second)
func IsNil(i interface{}) bool {
vi := reflect.ValueOf(i)
if vi.Kind() == reflect.Ptr {
return vi.IsNil()
return false
type Worker interface {
String() string
type Person struct {
Age uint8
Name string
Sex string
type Employee struct {
Person
type Employer struct {
Title string
Person
func (p *Person) String() string {
return fmt.Sprintf("Name: %s, Sex: %s, Age: %d", p.Name, p.Sex, p.Age)
func (er *Employer) String() string {
return fmt.Sprintf("%s, Title: %s", er.Person.String(), er.Title)
func testCase3() {
w Worker
emptyPoint *Employee
w = &Employer{
Title: "Title",
Person: Person{
Name: "Tom",
Age: 50,
Sex: "male",
if IsNil(w) {
fmt.Printf("interface w is nil")
return
// **bad** 是类型断言问题
e := w.(*Employee)
fmt.Println(e.String())
if e, ok := w.(*Employee); ok {
fmt.Printf("It's Employee, %s\n", e.String())
} else if e, ok := w.(*Employer); ok {
fmt.Printf("It's Employer, %s\n", e.String())
// **bad** 在嵌入式结构上定义方法时在nil指针上调用方法
fmt.Println(emptyPoint.String())
func main() {
fmt.Println("Test Begin..")
testCase0()
testCase1()
testCase2()
testCase3()
fmt.Println("Test Finish..")

二、Golangci-lint

名气最大的一个工具Golangci-lint。修改.golangci.yml，放开所有的限制，运行后发现核心的问题没查出来，只有一些格式问题：

golangci-lint.png

三、Nilness

Nilness是官方的一个专门检查空指针的工具，但运行后发现只能查几种简单的空指针场景：

nilness.png

四、Staticcheck

Staticcheck，依然不行：

staticcheck.png

五、Gocritic

Gocritic，不行：

gocritic1.png

gocritic2.png

report

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