dlv调试工具

Go 语言调试工具 —dlv

本文记录下dlv 安装和使用记录。

安装

下载 和编译delve 分支

$ git clone https://github.com/go-delve/delve
$ cd delve
$ go install github.com/go-delve/delve/cmd/dlv

Go versin 1.16版本和之后的版本 可以直接使用

$ go install github.com/go-delve/delve/cmd/dlv@latest

dlv 安装到$GOPATH/bin目录下，可以执行执行dlv命令查看是否安装成功.

[lituanjie@localhost src]$ dlv help
Delve is a source level debugger for Go programs.
Delve enables you to interact with your program by controlling the execution of the process,
evaluating variables, and providing information of thread / goroutine state, CPU register state and more.
......

如何调试的程序

dlv attach

dlv 使用attach 命令调试运行的程序，先使用ps -aux | grep pid-name 找到程序的pid号，在执行dlv attach pid-num

[lituanjie@localhost ~]$ ps -aux | grep dlv_test
lituanj+ 30992  0.0  0.0 702960  6956 pts/3    Sl+  16:17   0:00 ./dlv_test
lituanj+ 31282  0.0  0.0 112812   976 pts/1    S+   16:19   0:00 grep --color=auto dlv_test
[lituanjie@localhost ~]$ 
[lituanjie@localhost ~]$ dlv attach 30992
Type 'help' for list of commands.
(dlv) 
(dlv)

dlv debug

使用dlv debug 会编译并调试当前目录下的程序，也可以指定package的位置

[lituanjie@localhost dlv_test]$ dlv  debug
Type 'help' for list of commands.
(dlv) break main.main
Breakpoint 1 (enabled) set at 0x4b8918 for main.main() ./main.go:8
(dlv) c
> main.main() ./main.go:8 (hits goroutine(1):1 total:1) (PC: 0x4b8918)
     3:    import (
     4:        "fmt"
     5:        "time"
     6:    )
     7:    
=>   8:    func main() {
     9:        fmt.Println("dlv test")
    10:        for {
    11:            time.Sleep(2 * time.Second)
    12:            fmt.Println("dlv test")
    13:        }
(dlv) n

也可制定package

[lituanjie@localhost src]$ dlv debug github.com/dlv_test/

dlv exec

dlv exec 是调试已经编译好的程序

[lituanjie@localhost dlv_test]$ go build main.go
[lituanjie@localhost dlv_test]$ ls
main  main.go
[lituanjie@localhost dlv_test]$ dlv exec ./main
Type 'help' for list of commands.
(dlv) b main.main
Breakpoint 1 (enabled) set at 0x4992f3 for main.main() ./main.go:8
(dlv) n
> main.main() ./main.go:8 (hits goroutine(1):1 total:1) (PC: 0x4992f3)
Warning: debugging optimized function
     3:    import (
     4:        "fmt"
     5:        "time"
     6:    )
     7:    
=>   8:    func main() {
     9:        fmt.Println("dlv test")
    10:        for {
    11:            time.Sleep(2 * time.Second)
    12:            fmt.Println("dlv test")
    13:        }
(dlv)

dlv core

使用dlv core 可以core文件

远程调试

go 语言支持远程调试，在程序运行的机器上开启dlv server, 在代码编译机上开启dlv client，可以方便调试。

--headless                         Run debug server only, in headless mode.

这个命令适合 attach, debug, test …等调试，在调试的时候加上—headless选项就可以。

dlv [exec | attach | debug | test ...] --headless --listen  ip:portnum  进程

dlv server

ubuntu@ubuntu:~$ dlv exec --headless --listen  :3000 ./main  
API server listening at: [::]:3000

dlv client

#172.16.0.22 是server的IP地址
[lituanjie@localhost ~]$ dlv connect 172.16.0.22:3000
Type 'help' for list of commands.
(dlv) b main.main
Breakpoint 1 (enabled) set at 0x4992f3 for main.main() ./workspace/newgitlab/gowork/src/github.com/dlv_test/main.go:8
(dlv) c
> main.main() ./workspace/newgitlab/gowork/src/github.com/dlv_test/main.go:8 (hits goroutine(1):1 total:1) (PC: 0x4992f3)
Warning: debugging optimized function
     3:    import (
     4:        "fmt"
     5:        "time"
     6:    )
     7:    
=>   8:    func main() {
     9:        fmt.Println("dlv test")
    10:        for {
    11:            time.Sleep(2 * time.Second)
    12:            fmt.Println("dlv test")
    13:        }
(dlv)

go 编译的程序是优化之后的程序，在调试中会出现信息不全的情况，最好在编译时加上gcflags='all=-N -l'

go build -gcflags='all=-N -l' main.go

常用的命令

常用指定断点方式

• *<address> Specifies the location of memory address address. address can be specified as a decimal, hexadecimal or octal number
• <filename>:<line> Specifies the line line in filename. filename can be the partial path to a file or even just the base name as long as the expression remains unambiguous.
• <line> Specifies the line line in the current file
• +<offset> Specifies the line offset lines after the current one
• -<offset> Specifies the line offset lines before the current one
• <function>[:<line>] Specifies the line line inside function. The full syntax for function is <package>.(*<receiver type>).<function name> however the only required element is the function name, everything else can be omitted as long as the expression remains unambiguous. For setting a breakpoint on an init function (ex: main.init), the <filename>:<line> syntax should be used to break in the correct init function at the correct location.
• /<regex>/ Specifies the location of all the functions matching regex