launch.json

{
    // Use IntelliSense to learn about possible attributes.
    // Hover to view descriptions of existing attributes.
    // For more information, visit: https://go.microsoft.com/fwlink/?linkid=830387
    "version": "0.2.0",
    "configurations": [
    {
        "name": "(lldb) Attach",
        "type": "cppdbg",
        "request": "attach",
        "program": "enter program name, for example ${workspaceFolder}/a.out",
        "processId": "${command:pickProcess}",
        "MIMode": "lldb"
    },
        {
            "name": "g++ - Build and debug active file",
            "type": "cppdbg",
            "request": "launch",
            "program": "${fileDirname}/${fileBasenameNoExtension}",
            "args": [],
            "stopAtEntry": false,
            "cwd": "${workspaceFolder}",
            "environment": [],
            "externalConsole": false,
            "MIMode": "lldb",
            "preLaunchTask": "C/C++: g++ build active file"
        }
    ]
}