dap_adapters: add gdb

[jansol]

Nothing special here, just launching gdb with -i=dap. Nicer to have it as a builtin type instead of a custom DAP though.

[RemcoSmitsDev]

Hey, yeah totally agree, thanks for adding this!
Do you have a task example that we can share inside a specific Zed channel for GDB?

[Anthony-Eid]

Thank you for implementing this!

[Anthony-Eid]

Hey, yeah totally agree, thanks for adding this! Do you have a task example that we can share inside a specific Zed channel for GDB?

I think it would be similar to lldb

{
  "label": "LLDB Debug Zed",
  "program": "$ZED_WORKTREE_ROOT/target/debug/zed",
  "adapter": "gdb",
  "request": "launch"
  "initialize_args": {
      "stopAtBeginningOfMainSubprogram": true
   }
}

[RemcoSmitsDev]

Would it be similar to LLDB? I would like to add a default config for debugging Zed with GDB inside the /.zed/debug.json and inside the initial-debug-tasks.json.

  {
    "label": "Debug Zed with LLDB",
    "adapter": "lldb",
    "program": "$ZED_WORKTREE_ROOT/target/debug/zed",
    "request": "launch",
    "cwd": "$ZED_WORKTREE_ROOT"
  }

GDB debug task example??

  {
    "label": "Debug Zed with GDB",
    "adapter": "gdb",
    "program": "$ZED_WORKTREE_ROOT/target/debug/zed",
    "request": "launch",
    "cwd": "$ZED_WORKTREE_ROOT"
  }

[jansol]

I have this left over in the project where I tested last time:

  {
    "label": "Launch in GDB",
    "adapter": "gdb",
    "session_type": "launch",
    "program": "$ZED_WORKTREE_ROOT/build/main-binary",
    "initialize_args": {
      "args": [],
      "cwd": "$ZED_WORKTREE_ROOT",
      "env": {},
      "stopAtBeginningOfMainSubprogram": true
    }
  }

But it seems the format has changed since then?

Also the stopAtBeginningOfMainSubprogram should really not be needed. It's just the only way I've gotten the debugger to actually open instead of exiting immediately.

[RemcoSmitsDev]

Could you also add this to the .zed/debug.json? I wanted to push this change, but I cannot to your fork.

  {
    "label": "Debug Zed with GDB",
    "adapter": "gdb",
    "program": "$ZED_WORKTREE_ROOT/target/debug/zed",
    "request": "launch",
    "cwd": "$ZED_WORKTREE_ROOT",
    "initialize_args": {
      "stopAtBeginningOfMainSubprogram": true
    }
  }

[RemcoSmitsDev]

I also saw that GDB support attach, we might want to implement that as well. Happy to help to make that work, but cannot get GDB to work on my MacBook.

[jansol]

Attaching to a process with GDB is indeed possible, but requires special permissions (SYS_PTRACE capability or root) so that should probably wait until we have some form of polkit integration for escalating privileges.

[RemcoSmitsDev]

Alright, thanks for the clarification and your contribution!

[Anthony-Eid]

We should add a cfg flag to disable gfb on m series macs because there’s no arm port available.

That way people can’t select it when it’s bot possible to use

[jansol]

GDB is apparently perfectly fine on aarch64, just not on macOS.