Go每日一库之174：delve (Go 调试工具)

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

# 安装完成后查看版本
$ dlv verison

Delve Debugger
Version: 1.20.1
Build: $Id: 96e65b6c615845d42e0e31d903f6475b0e4ece6e 

// main.go

package main

func main() {
    println("hello world")
}

$ dlv debug main.go

# Type 'help' for list of commands.
(dlv) 

# 输入 help 查看参数说明
(dlv) help
The following commands are available:

Running the program:
call ------------------------ Resumes process
...
...
types ---------------------- Print list of types

Type help followed by a command for full documentation.

# 运行程序
(dlv) continue
hello world
Process 3637 has exited with status 0

# 编译源文件
$ go build -o main main.go

$ dlv exec ./main

Type 'help' for list of commands.
(dlv) 

# 接下来的步骤和调试源文件的一样，这里不再赘述

package main

import "time"

func main() {
    time.Sleep(time.Minute)
    println("hello world")
}

$ go run main.go

# 查看进程 ID
$ ps -ef | grep "go run main.go"

7602 27666  0 21:30 pts/6    00:00:00 go run main.go

# 调试进程
$ dlv attach 7602

Type 'help' for list of commands.
(dlv) 

...

# 1 分钟之后，main.go 并未正常退出，因为当前正在调试
# 输入 continue 继续运行

(dlv) continue 
Process 7602 has exited with status 0

// main.go

package main

var (
    x = 1024
)

func main() {
    for i := 0; i < 5; i++ {
        println(i)
    }
}

# 开始调试
$ dlv debug main.go

Type 'help' for list of commands.
(dlv)

# 增加断点
(dlv) b main.main
Breakpoint 1 set at 0x45f0c6 for main.main() ./main.go:7

# 查看断点
(dlv) bp
...
Breakpoint 2 (enabled) at 0x45f0c6 for main.main() ./main.go:7 (0)

# 运行程序
(dlv) continue
> main.main() ./main.go:7 (hits goroutine(1):1 total:1) (PC: 0x45f0c6)
2:
3: var (
4:         x = 1024
5: )
6:
=>   7: func main() {
8:         for i := 0; i < 5; i++ {
9:                 println(i)
10:         }
11: }
12:
# 可以看到，程序停在了设置的断点上

# 打印包变量
(dlv) vars vars main.x
...
main.x = 1024
...

# 单步调试
(dlv) next
> main.main() ./main.go:8 (PC: 0x45f0d4)
3: var (
4:         x = 1024
5: )
6:
7: func main() {
=>   8:         x = 0
9:         for i := 0; i < 5; i++ {
10:                 println(i)
11:         }
12: }
13:

# 再次单步调试
(dlv) next
> main.main() ./main.go:9 (PC: 0x45f0df)
4:         x = 1024
5: )
6:
7: func main() {
8:         x = 0
=>   9:         for i := 0; i < 5; i++ {
10:                 println(i)
11:         }
12: }
13:
14: //timeout := time.After(time.Minute)

# 可以看到，程序停在了循环语句

# 打印包变量
(dlv) vars main.x
main.x = 0

# 再次单步调试
(dlv) next
> main.main() ./main.go:10 (PC: 0x45f0f4)
5: )
6:
7: func main() {
8:         x = 0
9:         for i := 0; i < 5; i++ {
=>  10:                 println(i)
11:         }
12: }
13:
14: //timeout := time.After(time.Minute)
15: //


# 打印本地变量
(dlv) locals
i = 0

# 查看堆栈信息
(dlv) stack
0  0x000000000045f0f4 in main.main
at ./main.go:10
1  0x00000000004358b8 in runtime.main
at /usr/local/go/src/runtime/proc.go:250
2  0x000000000045c0c1 in runtime.goexit
at /usr/local/go/src/runtime/asm_amd64.s:1594


# 打印 goroutine 信息
(dlv) goroutine
Thread 27873 at ./main.go:10
Goroutine 1:
...

# 删除所有断点
(dlv) clearall
Breakpoint 1 cleared at 0x45f0c6 for main.main() ./main.go:7

# 继续执行
(dlv) continue
1
2
3
4
Process 27873 has exited with status 0

# 退出调试
(dlv) exit

# 禁用内联和优化 (细节可以阅读引用文章列表)
go run -gcflags "-N -l" main.go