Complete the support for Microsoft Debugger Adapter Protocol in Theia

[slemeur]

Goals

Provides debugger support for the next generation Che's IDE.

Description

Theia will be used for the foundation of the new IDE provided with the next gen Che (#8266). This new IDE does not provide Debugger capabilities for the time being. There are some plans to implement the Debug Adapter Protocol (https://github.com/Microsoft/vscode-debugadapter-node), but we'll need to study how this will impact the next generation Che.

https://code.visualstudio.com/docs/extensions/example-debuggers

Tasks

Establish Debug Sessions

• Connect/Disconnect remote target Connect to Debug Target #8929
• Start/Stop debug targets

Threads

• Show threads of debug targets Show Threads of Debug Target #9421
• Show Stack of Suspended Threads Display Thread Stack #9423
• Show Source for Suspended Threads Theia DAP: Show Source for Suspended Threads #10048

Suspend/Resume Actions

• Suspend/Resume Actions Suspend/Resume Actions #9424

Stack Frame Variables

• Display Theia DAP: Display stack frame variables #9819
• Modify Theia DAP: Modify stack frame variables #9820

Watch expressions

• add/remove/edit watch expressions, evaluate them automatically in selected frame.

Step actions

• In/out/over DAP: Step in, out, over #10076
• Into selection
  This is not possible with DAP only, as we do not know the structure of the text at the selection
• Run to Line Run to line eclipse-theia/theia#3424

Breakpoints

• Show List of Breakpoints #9809 Show list of Breakpoints
• Enable/Disable
• Remove Breakpoint

Line Breakpoint

• DAP Create Line Breakpoint DAP Create Line Breakpoint #10077
• display in editor

Function Breakpoint eclipse-theia/theia#3312 (Typefox)

• create
• display in editor

[tolusha]

@tsmaeder
I've added a list of tasks without clarification to know if we go in right direction.

[tsmaeder]

Here are a couple of thoughts about self hosting:

• We need to be able to debug sidecars.
  • How do we connect to them.
  • How is che-in-che launched?
  • How do we launch debug adapters (if necessary)?
  • How do we connect to the debug network addresses?
• Minimal Feature list
  • Multiple debug targets at the same time (minimum: Theia, Che server, jdt.ls sidecar)
  • Connect to che in che debug targets
  • Line breakpoints
  • List of threads Show Threads of Debug Target #9421 Show Threads of Debug Target
  • Source lookup & display line
  • Display Call stack of stopped thread Display Thread Stack #9423 Display Thread Stack
  • Display stack frame variables
  • Thread Stop/Resume action Suspend/Resume Actions #9424 Suspend/Resume Actions
  • Step over/into(/out)

[mkwork]

Hello.
I've reviewed debug adapter protocol in case of it's integration with vim or emacs and have found out some vendor lock in.
While in the LSP all capabilities and possible outputs are defined in the protocol itself, vscode debugging api is split into two parts:

• D(ebug)A(adapter)P(protocol) server
• Extension part with full support of vscode api

While DAP part implementation strategy is clear, Extension part can potentially call any of vscode api. So there is no way to reuse vscode extensions without support of vscode api in general.

Please be aware of this.

I think, that DAP protocol part could get some kick start part of a really open specification. Humble individual like me can't support and promote such a great thing. I can only contribute only. But I believe a project like yours is able to implement such great effort.

[slemeur]

Cross linking to: eclipse-theia/theia#1573

[tsmaeder]

@mkwork I don't think straight up reuse of VSCode is a target here, AFAIK, the plugin model is quite different. We would like to reuse the debug adapter executables, though.

[mkwork]

@tsmaeder Yep. I talk about reusing debug adapters. Them can be rely on vscode extension part. Imho, thats a reason why there are tons of open LSP extensions, and few open extensions for DAP. And no more frontends for DAP as I know.

[tsmaeder]

Implementation task & epics

#8929 Connect to Debug Target
#9421 Show Threads
#9423 Display Stack Frames
#9424 Suspend/Resume Action

[benoitf]

@tolusha @tsmaeder should we close this issue ?

[tsmaeder]

I guess that would be up to @slemeur