Vscode-cpptools: The option -enable-pretty-printing doesn't work for remote debugging with gdbserver

[slawmilcz]

Type: Debugger

The pretty-printers don't work for remote debugging with gdbserver,
whilst they do work for local debugging with gdb only.

target machine with Ubuntu 18.04:
gdbserver :10000 ./test_app

host machine with Ubuntu 18.04:
Visual Studio Code - debugging

Describe the bug

• OS and Version: Ubuntu 18.04
• VS Code Version: 1.39.2
• C/C++ Extension Version: 0.26.1

To Reproduce

The launch.json configuration:

    {
        "name": "C++ Remote Debug - local",
        "type": "cppdbg",
        "request": "launch",
        "miDebuggerPath":"/usr/bin/gdb",
        "miDebuggerServerAddress": "x.x.x.x:10000",
        "program": "/home/slawek/test_app",
        "cwd": "/home/slawek",
        "externalConsole": true,
        "linux": {
            "MIMode": "gdb",
            "setupCommands": [
                {
                    "description": "Enable pretty-printing for gdb",
                    "text": "-enable-pretty-printing",
                    "ignoreFailures": true
                },
                {
                    "description": "Auto load symbols when loading an .so file",
                     "text": "set auto-solib-add",
                     "ignoreFailures": false
                }
            ]
        },
    },

Additional context

Here is the launch.json configuration for local debugging with gdb:

    {
        "name": "(gdb) Launch",
        "type": "cppdbg",
        "request": "launch",
        "program": "${workspaceFolder}/test_app",
        "args": [],
        "stopAtEntry": false,
        "cwd": "${workspaceFolder}",
        "environment": [],
        "externalConsole": false,
        "MIMode": "gdb",
        "setupCommands": [
            {
                "description": "Enable pretty-printing for gdb",
                "text": "-enable-pretty-printing",
                "ignoreFailures": true
            }
        ]
    },

[pieandcakes]

@slawmilcz When you say they don't work, are you saying that gdb <-> gdbserver doesn't support pretty printing or that our extension is doing something wrong?

[slawmilcz]

Hi, I don't know if the problem is in your extension or somewhere between gdb and gdbserver.
I see that your extension does provide an option to enable pretty-printers also for the configuration with gdbserver, so I assumed that gdb <-> gdbserver should support it. However I failed to run it successfully on my side and I found no special instructions on your website to apply. So please advice if you managed to get it up and running when validating this option. Thanks in advance.

[pieandcakes]

The default json adds that flag if you use gdb. It doesn't necessarily mean it works with gdb <-> gdbserver.

[slawmilcz]

OK, I understand that you don't have any evidence for this feature to work with gdbserver.
Do you have any other extensions with debugging helpers for libstdc++ that could be used successfully for remote debugging with gdbserver? Thank you for your support.

[pieandcakes]

@slawmilcz This article seems to solve the gdbserver problem. It looks like a problem with where the pretty printers are located in that they need to be in the same spot on both machines.

Let me know if that helps.

[slawmilcz]

Yes, this article was very helpful for me to understand how to set up pretty-printers for remote debugging with gdbserver. For the configuration with both local and remote machines running on Ubuntu 18 all I had to do was create on the local machine in its home directory the .gdbinit file with correct path to the libstdc++ pretty-printer. Many, many thanks for your help!

[dianjuar]

@slawmilcz did you fix your problem? I'm following the instructions and my pretty print still without working

[dianjuar]

Never mind, I just looked again step by step and adapting the locations of the files mentioned there into my context and I was able to achieve it.

I just want to warn the next persons that face this problem, that the files referenced on the post may not be in the exact paths mentioned but in a totally different path, that depends on your SO or distro.

[Ecordonnier]

I managed to configure it on Debian 9 using this config in ~/.gdbinit:

python
import sys
sys.path.insert(0, '/usr/share/gcc-6/python/')
from libstdcxx.v6.printers import register_libstdcxx_printers
register_libstdcxx_printers (None)
end

[liuyatao]

@Ecordonnier This works for me. It's great!

[github-actions[bot]]

This issue has been closed automatically because it's labeled as 'external'.