Debugging VSCode plugin and the language server

August 27, 2023 ยท View on GitHub

Prerequisites

  • You can successfully build this project from source.
  • Install LLDB and the LLDB Extension.
  • Open the root folder in VSCode. Press CtrlShiftD and here you can access the preconfigured debug setups.

Common knowledge

  • All debug configurations open a new [Extension Development Host] VSCode instance where only the Zeek extension being debugged is enabled.
  • To activate the extension you need to open any Zeek script file (.zeek/.bro) in [Extension Development Host].

Debug TypeScript VSCode extension

  • Run Extension (Debug Build) - runs extension with the locally built LSP server (target/debug/zeek-language-server).

TypeScript debugging is configured to watch your source edits and recompile. To apply changes to an already running debug process, press CtrlShiftP and run the following command in your [Extension Development Host]

> Developer: Reload Window

Debug LSP server

  • When attaching a debugger to an already running zeek-language-server server on Linux you might need to enable ptrace for unrelated processes by running:

    echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope

  • By default, the LSP server is built without debug information. To enable it, you'll need to change Cargo.toml:

    [profile.dev]
debug = 2

  • Select Run Extension (Debug Build) to run your locally built target/debug/zeek-language-server.

  • In the original VSCode window once again select the Attach To Server debug configuration.

  • A list of running processes should appear. Select the zeek-language-server from this repo.

  • Navigate to src/lsp.rs and add a breakpoint to the hover function.

  • Go back to the [Extension Development Host] instance and hover over a Zeek variable and your breakpoint should hit.

Troubleshooting

Can't find the zeek-language-server process

It could be a case of just jumping the gun.

The zeek-language-server is only started once the onLanguage:zeek activation.

Make sure you open a Zeek script file in the [Extension Development Host] and try again.

Can't connect to zeek-language-server

Make sure you have run echo 0 | sudo tee /proc/sys/kernel/yama/ptrace_scope.

By default this should reset back to 1 every time you log in.

Breakpoints are never being hit

Check your version of lldb. If it's version 6 and lower, use the classic adapter type. It's lldb.adapterType in settings file.

If you're running lldb version 7, change the lldb adapter type to bundled or native.