feat(csharp,debug): add C# debugger support

[filipdutescu]

Add C# debugger support in the languages.toml file. This includes "launch" and "attach" configurations that employ netcoredbg.

In order to make it work with the aforementioned debugger, the Initialized DAP event response is changed to include an optional DebuggerCapabilities response, as per the specification.

Closes: #4212
Signed-off-by: Filip Dutescu filip.dutescu@gmail.com

[filipdutescu]

I do not know what the proper procedure for addressing comments is, but I pushed one specifically with your change and if approved, I can rebase and squash my PR prior to merger, if it help or you are ok with this flow.

[CptPotato]

So, I tried to give this a spin but didn't have much luck.

I created a simple console application, set a breakpoint and launched the dll in the debugger. However the breakpoint didn't trigger.
Trying to communicate with the debugger after that (using commands such as pause/continue) result in a channel closed error. Trying to launch the debug target again produces an error, too: Debugger is already running (netcoredbg is not running at this point).

I am aware that helix' debug functionality is still very experimental, but is there something I'm missing to run this debugger?

[filipdutescu]

What does helix.log say? I ran debug without problem on a small CLI C# project and all worked well 🤔 where did you set the breakpoint? That could also play a part in your issue.

[CptPotato]

Thanks for the quick reply! This is the test program:

using System;

namespace Test;

static class Program
{
    public static void Main()
    {
        var x = "asdf";
        Console.WriteLine(x); // < breakpoint on this line
    }
}

You're right, the helix log reports an error for an unhandled event. Unless I messed something up my build should include the code changes from this PR. I'll double check again just to be sure.

helix.log

2022-10-12T11:41:35.057 helix_view::handlers::dap [WARN] Unhandled event Capabilities(Capabilities {
    capabilities: DebuggerCapabilities {
        supports_configuration_done_request: Some(true),
        supports_function_breakpoints: Some(true),
        supports_conditional_breakpoints: Some(true),
        supports_hit_conditional_breakpoints: None,
        supports_evaluate_for_hovers: None,
        supports_step_back: None,
        supports_set_variable: Some(true),
        supports_restart_frame: None,
        supports_goto_targets_request: None,
        supports_step_in_targets_request: None,
        supports_completions_request: None,
        supports_modules_request: None,
        supports_restart_request: None,
        supports_exception_options: Some(false),
        supports_value_formatting_options: None,
        supports_exception_info_request: Some(true),
        support_terminate_debuggee: Some(true),
        support_suspend_debuggee: None,
        supports_delayed_stack_trace_loading: None,
        supports_loaded_sources_request: None,
        supports_log_points: None,
        supports_terminate_threads_request: None,
        supports_set_expression: Some(true),
        supports_terminate_request: Some(true),
        supports_data_breakpoints: None,
        supports_read_memory_request: None,
        supports_write_memory_request: None,
        supports_disassemble_request: None,
        supports_cancel_request: Some(true),
        supports_breakpoint_locations_request: None,
        supports_clipboard_context: None,
        supports_stepping_granularity: None,
        supports_instruction_breakpoints: None,
        supports_exception_filter_options: Some(true),
        exception_breakpoint_filters: Some([ExceptionBreakpointsFilter {
            filter: "all",
            label: "all",
            description: None,
            default: None,
            supports_condition: None,
            condition_description: None
        }, ExceptionBreakpointsFilter {
            filter: "user-unhandled",
            label: "user-unhandled",
            description: None,
            default: None,
            supports_condition: None,
            condition_description: None
        }]),
        completion_trigger_characters: None,
        additional_module_columns: None,
        supported_checksum_algorithms: None
    }
})
2022-10-12T11:41:35.093 helix_dap::transport [ERROR] err: <- IO(Os {
    code: 10054,
    kind: ConnectionReset,
    message: "An existing connection was forcibly closed by the remote host."
})

[filipdutescu]

Try running helix with the -v param to get more verbose logs. Also, I forgot to ask but could you tell me what your environment looks like (OS, netcoredbg version etc)? I have no problems on ArchLinux, netcoredbg 2.0.0-78.

[filipdutescu]

Here is also my test program which worked:

namespace TestHx
{
    public class Program
    {
        public static void Main(string[] args)
        {
            Console.WriteLine("Enter text:");
            var a = 123;
            // Thread.Sleep(10000);
            // var a = Console.ReadLine();
            Console.WriteLine("Hello, World!"); // breakpoint here
            Console.WriteLine($"{a}");
        }
    }
}

Make sure you also built the project right before launching the debugger, in order to have the latest version available, otherwise breakpoints could be skipped since the source code and DLL fail to match

[CptPotato]

So I did a cargo clean & rebuild but get the same behavior.

Also, here's my env:

• Windows 10 x64 (maybe that's the problem 🙃)
• helix built from master (with changes from this PR applied)
• netcoredbg 2.2.0-7 (1c7c1f5, Release)

This is the verbose log (only including helix_dap and helix_view::handlers::dap).
The suspicious part is that the DAP connection is closed (towards the end of the log) so it might have exited early or crashed.

helix.log

helix_dap::transport[INFO] -> DAP {
    "type": "request",
    "seq": 0,
    "command": "initialize",
    "arguments": {
        "adapterID": "netcoredbg",
        "clientID": "hx",
        "clientName": "helix",
        "columnsStartAt1": true,
        "linesStartAt1": true,
        "locale": "en-us",
        "pathFormat": "path",
        "supportsInvalidatedEvent": false,
        "supportsMemoryReferences": false,
        "supportsProgressReporting": false,
        "supportsRunInTerminalRequest": true,
        "supportsVariablePaging": false,
        "supportsVariableType": true
    }
}
helix_dap::transport[INFO] <- DAP {
    "body": {
        "capabilities": {
            "exceptionBreakpointFilters": [{
                "filter": "all",
                "label": "all"
            }, {
                "filter": "user-unhandled",
                "label": "user-unhandled"
            }],
            "supportTerminateDebuggee": true,
            "supportsCancelRequest": true,
            "supportsConditionalBreakpoints": true,
            "supportsConfigurationDoneRequest": true,
            "supportsExceptionFilterOptions": true,
            "supportsExceptionInfoRequest": true,
            "supportsExceptionOptions": false,
            "supportsFunctionBreakpoints": true,
            "supportsSetExpression": true,
            "supportsSetVariable": true,
            "supportsTerminateRequest": true
        }
    },
    "event": "capabilities",
    "seq": "1",
    "type": "event"
}
helix_dap::transport[INFO] <- DAP event Capabilities(Capabilities {
    capabilities: DebuggerCapabilities {
        supports_configuration_done_request: Some(true),
        supports_function_breakpoints: Some(true),
        supports_conditional_breakpoints: Some(true),
        supports_hit_conditional_breakpoints: None,
        supports_evaluate_for_hovers: None,
        supports_step_back: None,
        supports_set_variable: Some(true),
        supports_restart_frame: None,
        supports_goto_targets_request: None,
        supports_step_in_targets_request: None,
        supports_completions_request: None,
        supports_modules_request: None,
        supports_restart_request: None,
        supports_exception_options: Some(false),
        supports_value_formatting_options: None,
        supports_exception_info_request: Some(true),
        support_terminate_debuggee: Some(true),
        support_suspend_debuggee: None,
        supports_delayed_stack_trace_loading: None,
        supports_loaded_sources_request: None,
        supports_log_points: None,
        supports_terminate_threads_request: None,
        supports_set_expression: Some(true),
        supports_terminate_request: Some(true),
        supports_data_breakpoints: None,
        supports_read_memory_request: None,
        supports_write_memory_request: None,
        supports_disassemble_request: None,
        supports_cancel_request: Some(true),
        supports_breakpoint_locations_request: None,
        supports_clipboard_context: None,
        supports_stepping_granularity: None,
        supports_instruction_breakpoints: None,
        supports_exception_filter_options: Some(true),
        exception_breakpoint_filters: Some([ExceptionBreakpointsFilter {
            filter: "all",
            label: "all",
            description: None,
            default: None,
            supports_condition: None,
            condition_description: None
        }, ExceptionBreakpointsFilter {
            filter: "user-unhandled",
            label: "user-unhandled",
            description: None,
            default: None,
            supports_condition: None,
            condition_description: None
        }]),
        completion_trigger_characters: None,
        additional_module_columns: None,
        supported_checksum_algorithms: None
    }
})
helix_dap::transport[INFO] <- DAP {
    "body": {},
    "event": "initialized",
    "seq": "2",
    "type": "event"
}
helix_dap::transport[INFO] <- DAP event Initialized(Some(DebuggerCapabilities {
    supports_configuration_done_request: None,
    supports_function_breakpoints: None,
    supports_conditional_breakpoints: None,
    supports_hit_conditional_breakpoints: None,
    supports_evaluate_for_hovers: None,
    supports_step_back: None,
    supports_set_variable: None,
    supports_restart_frame: None,
    supports_goto_targets_request: None,
    supports_step_in_targets_request: None,
    supports_completions_request: None,
    supports_modules_request: None,
    supports_restart_request: None,
    supports_exception_options: None,
    supports_value_formatting_options: None,
    supports_exception_info_request: None,
    support_terminate_debuggee: None,
    support_suspend_debuggee: None,
    supports_delayed_stack_trace_loading: None,
    supports_loaded_sources_request: None,
    supports_log_points: None,
    supports_terminate_threads_request: None,
    supports_set_expression: None,
    supports_terminate_request: None,
    supports_data_breakpoints: None,
    supports_read_memory_request: None,
    supports_write_memory_request: None,
    supports_disassemble_request: None,
    supports_cancel_request: None,
    supports_breakpoint_locations_request: None,
    supports_clipboard_context: None,
    supports_stepping_granularity: None,
    supports_instruction_breakpoints: None,
    supports_exception_filter_options: None,
    exception_breakpoint_filters: None,
    completion_trigger_characters: None,
    additional_module_columns: None,
    supported_checksum_algorithms: None
}))
helix_dap::transport[INFO] <- DAP {
    "body": {
        "exceptionBreakpointFilters": [{
            "filter": "all",
            "label": "all"
        }, {
            "filter": "user-unhandled",
            "label": "user-unhandled"
        }],
        "supportTerminateDebuggee": true,
        "supportsCancelRequest": true,
        "supportsConditionalBreakpoints": true,
        "supportsConfigurationDoneRequest": true,
        "supportsExceptionFilterOptions": true,
        "supportsExceptionInfoRequest": true,
        "supportsExceptionOptions": false,
        "supportsFunctionBreakpoints": true,
        "supportsSetExpression": true,
        "supportsSetVariable": true,
        "supportsTerminateRequest": true
    },
    "command": "initialize",
    "request_seq": 0,
    "seq": "3",
    "success": true,
    "type": "response"
}
helix_dap::transport[INFO] <- DAP success in response to 0
helix_view::handlers::dap[WARN] Unhandled event Capabilities(Capabilities {
    capabilities: DebuggerCapabilities {
        supports_configuration_done_request: Some(true),
        supports_function_breakpoints: Some(true),
        supports_conditional_breakpoints: Some(true),
        supports_hit_conditional_breakpoints: None,
        supports_evaluate_for_hovers: None,
        supports_step_back: None,
        supports_set_variable: Some(true),
        supports_restart_frame: None,
        supports_goto_targets_request: None,
        supports_step_in_targets_request: None,
        supports_completions_request: None,
        supports_modules_request: None,
        supports_restart_request: None,
        supports_exception_options: Some(false),
        supports_value_formatting_options: None,
        supports_exception_info_request: Some(true),
        support_terminate_debuggee: Some(true),
        support_suspend_debuggee: None,
        supports_delayed_stack_trace_loading: None,
        supports_loaded_sources_request: None,
        supports_log_points: None,
        supports_terminate_threads_request: None,
        supports_set_expression: Some(true),
        supports_terminate_request: Some(true),
        supports_data_breakpoints: None,
        supports_read_memory_request: None,
        supports_write_memory_request: None,
        supports_disassemble_request: None,
        supports_cancel_request: Some(true),
        supports_breakpoint_locations_request: None,
        supports_clipboard_context: None,
        supports_stepping_granularity: None,
        supports_instruction_breakpoints: None,
        supports_exception_filter_options: Some(true),
        exception_breakpoint_filters: Some([ExceptionBreakpointsFilter {
            filter: "all",
            label: "all",
            description: None,
            default: None,
            supports_condition: None,
            condition_description: None
        }, ExceptionBreakpointsFilter {
            filter: "user-unhandled",
            label: "user-unhandled",
            description: None,
            default: None,
            supports_condition: None,
            condition_description: None
        }]),
        completion_trigger_characters: None,
        additional_module_columns: None,
        supported_checksum_algorithms: None
    }
})
helix_dap::transport[INFO] -> DAP {
    "type": "request",
    "seq": 2,
    "command": "setBreakpoints",
    "arguments": {
        "breakpoints": [{
            "line": 10
        }],
        "source": {
            "path": "[...]\\test\\Program.cs"
        },
        "sourceModified": false
    }
}
helix_dap::transport[ERROR] err: <- IO(Os {
    code: 10054,
    kind: ConnectionReset,
    message: "An existing connection was forcibly closed by the remote host."
})
helix_dap::transport[INFO] -> DAP {
    "type": "request",
    "seq": 3,
    "command": "configurationDone",
    "arguments": null
}

---

Using the netcoredbg command line directly seems to work, though:

netcorecbg

ncdb> file dotnet
ncdb> set args test.dll
ncdb> break test.dll!Program.cs:10
 Breakpoint 1 at Program.cs:10 --pending, warning: No executable code of the debugger's target code type is associated with this line.
ncdb> run
^running

library loaded: [...]\dotnet\shared\Microsoft.NETCore.App\6.0.9\System.Private.CoreLib.dll
no symbols loaded, base address: 0x7ffc616b0000, size: 10629120(0xa23000)

thread created, id: 16156

library loaded: [...]\test\bin\Debug\net6.0\test.dll
symbols loaded, base address: 0x1a9dc7c0000, size: 32768(0x8000)
breakpoint modified,  Breakpoint 1 at [..]\test\Program.cs:10

library loaded: [...]\dotnet\shared\Microsoft.NETCore.App\6.0.9\System.Runtime.dll
no symbols loaded, base address: 0x1a9dc7d0000, size: 57344(0xe000)

library loaded: [...]\dotnet\shared\Microsoft.NETCore.App\6.0.9\System.Console.dll
no symbols loaded, base address: 0x7ffca3480000, size: 155648(0x26000)

stopped, reason: breakpoint 1 hit, thread id: 16156, stopped threads: all, times= 1, frame={Test.Program.Main() at [..]\test\Program.cs:10
}
ncdb> print x
x = "asdf"
ncdb> detach

stopped, reason: exited, exit-code: 0
^exit

[filipdutescu]

At a first glance, it seems to be a netcoredbg issue, rather than a Helix one 🤔 I don't have access to a Windows machine right now, but later on today I could try and setup one. It also seems to have been caused by netcoredbg not liking the SetBreakpoints request and crashed.

Are you able to debug Helix on your environment? I'd be really curious if we could get any more info from it, besides what's logged. Also, by any chance, would you happen to have a Linux/MacOS machine on which you could test it as well?

[filipdutescu]

I think the path is wrong:

helix_dap::transport[INFO] -> DAP {
    "type": "request",
    "seq": 2,
    "command": "setBreakpoints",
    "arguments": {
        "breakpoints": [{
            "line": 10
        }],
        "source": {
            "path": "[...]\\test\\Program.cs"
        },
        "sourceModified": false
    }
}

For me it actually puts the absolute path there. @the-mikedavis any idea why that might happen on Win?

[CptPotato]

Thanks a lot for looking into this.

Are you able to debug Helix on your environment? I'd be really curious if we could get any more info from it, besides what's logged. Also, by any chance, would you happen to have a Linux/MacOS machine on which you could test it as well?

I didn't look much into setting up rust debugging yet to be honest. I could try to get it working or otherwise add a few additional logs to narrow it down.
I also have a Linux machine but I never compiled C# on it, though I might give it a shot if I can set it up. Would be interesting to see if the problem is platform specific.

In the meantime, I don't mean to block this PR in case it works on Linux/MacOS. There's probably people other than me that have been looking forward to C# debugging in helix.

---

I think the path is wrong

Ah my bad.. I didn't mention that I truncated all file paths in the logs I have posted. It is indeed the full path to the source file.

[filipdutescu]

How did you get netcoredbg? Could you try using the instructions from https://aur.archlinux.org/cgit/aur.git/tree/PKGBUILD?h=netcoredbg (Win equivalent to the build() section)?

[the-mikedavis]

This works for me locally on linux 👍

[the-mikedavis]

👍 Looks like Initialized extends Event which has an optional body field https://microsoft.github.io/debug-adapter-protocol/specification#Base_Protocol_Event