调试Golang可执行文件时,无法在vscode中获取局部变量

时间:2019-06-02 10:53:30

标签: go visual-studio-code vscode-debugger

我在Golang中创建了一个示例项目:

sampleapp/
sampleapp/main.go

具有以下代码:

package main

import (
    "flag"
    "fmt"
)

func main() {
    var name = flag.String("name", "user1", "user name")
    var age = flag.Int("age", 20, "user age")
    fmt.Println(*name)
    fmt.Println(*age)
}

我关注了https://code.visualstudio.com/docs/editor/debugging,并创建了以下launch.json

 {
    "version": "0.2.0",
    "configurations": [
        {
            "name": "Launch file",
            "type": "go",
            "request": "launch",
            "mode": "auto",
            "program": "${workspaceFolder}/main.go",
            "env": {},
            "args": []
        },
        {
            "name": "Launch exec",
            "type": "go",
            "request": "launch",
            "mode": "exec",
            "program": "${workspaceFolder}/sampleapp",
            "env": {},
            "args": []
        }
    ]
}

当我在主机上使用启动文件调试模式设置断点时-我能够单步执行程序,并且可以看到用户名 age的值如下:

enter image description here

但是当我像这样构建应用程序后使用启动exec 调试模式时:

go build

我可以单步执行代码,但是 Local 部分由于微调器持续运行而挂起,并且没有显示以下任何局部变量:

enter image description here

我必须做一个重新加载窗口,以摆脱悬挂的Local vars微调框。我检查了vscode问题,看到了https://github.com/microsoft/vscode-go/issues/2444,但在这种情况下,当出现紧急情况时不会显示变量。但就我而言,我只是打印两个变量。

我认为这可能与我的 dlv 安装有关,但是当我对可执行文件使用 dlv 进行调试时,我能够获取这些值(从中删除不必要的行 dlv 输出):

dlv exec sampleapp
Type 'help' for list of commands.
(dlv) break main.main
Breakpoint 1 set at 0x109e1f3 for main.main() ./main.go:8
(dlv) s
> main.main() ./main.go:8 (hits goroutine(1):1 total:1) (PC: 0x109e1f3)
Warning: debugging optimized function
     3: import (
     4:         "flag"
     5:         "fmt"
     6: )
     7:
=>   8: func main() {
     9:         var name = flag.String("name", "user1", "user name")
    10:         var age = flag.Int("age", 20, "user age")
    11:         fmt.Println(*name)
    12:         fmt.Println(*age)
    13: }
(dlv) s
> main.main() ./main.go:9 (PC: 0x109e202)
Warning: debugging optimized function
     4:         "flag"
     5:         "fmt"
     6: )
     7:
     8: func main() {
=>   9:         var name = flag.String("name", "user1", "user name")
    10:         var age = flag.Int("age", 20, "user age")
    11:         fmt.Println(*name)
    12:         fmt.Println(*age)
    13: }
(dlv) s
> main.main() ./main.go:11 (PC: 0x109e29f)
Warning: debugging optimized function
     6: )
     7:
     8: func main() {
     9:         var name = flag.String("name", "user1", "user name")
    10:         var age = flag.Int("age", 20, "user age")
=>  11:         fmt.Println(*name)
    12:         fmt.Println(*age)
    13: }
(dlv) stepout
user1
> main.main() ./main.go:12 (PC: 0x109e31a)
Warning: debugging optimized function
     7:
     8: func main() {
     9:         var name = flag.String("name", "user1", "user name")
    10:         var age = flag.Int("age", 20, "user age")
    11:         fmt.Println(*name)
=>  12:         fmt.Println(*age)
    13: }
(dlv) p name
*"user1"
(dlv) p age
*20

在这里我缺少一些非常基本的东西吗?

1 个答案:

答案 0 :(得分:1)

我最初可以重现您的问题,但是在升级到VSCode 1.35.1版(我在MacOSX上)之后,该问题消失了。我可以在调试过程中使用“启动exec”看到变量值

我认为编译器优化使它成为问题。对于使用生成的可执行文件应该可以正常工作 go build -gcflags="-N -l"

-N: disable optimization -l: disable inlining

Golang也正式提出了建议:https://golang.org/doc/gdb