Neovim C++ debugger setup using nvim-dap and mason

Download codelldb binary §

To obtain codelldb binary, either install vscode extension lldb or download it using mason plugin. The path will be differs based on the method used to downloaded. Use google to figure out path/to/codelldb.

Setting up adapter config §

The generic way codelldb work with nvim dap in a conceptuall level would be , have a debugging server running on a port like this mannually codelldb --port 1337 . and have nvim-dap connect to it. But a better way is to launch the server automatically by the adapter and then connect to it. This was quite a headache until i came across a chinese dev forum.

Tip

Depending on your system, you may need to compile your app with debugger symbols See How to compile c/c++ with debugging symbols.

 
 dap.adapters.codelldb = function(on_adapter)
   -- This asks the system for a free port
   local tcp = vim.loop.new_tcp()
   tcp:bind('127.0.0.1', 0)
   local port = tcp:getsockname().port
   tcp:shutdown()
   tcp:close()
 
   -- Start codelldb with the port
   local stdout = vim.loop.new_pipe(false)
   local stderr = vim.loop.new_pipe(false)
   local opts = {
     stdio = {nil, stdout, stderr},
     args = {'--port', tostring(port)},
   }
   local handle
   local pid_or_err
   handle, pid_or_err = vim.loop.spawn('/path/to/lldb', opts, function(code)
     stdout:close()
     stderr:close()
     handle:close()
     if code ~= 0 then
       print("codelldb exited with code", code)
     end
   end)
   if not handle then
     vim.notify("Error running codelldb: " .. tostring(pid_or_err), vim.log.levels.ERROR)
     stdout:close()
     stderr:close()
     return
   end
   vim.notify('codelldb started. pid=' .. pid_or_err)
   stderr:read_start(function(err, chunk)
     assert(not err, err)
     if chunk then
       vim.schedule(function()
         require("dap.repl").append(chunk)
       end)
     end
   end)
   local adapter = {
     type = 'server',
     host = '127.0.0.1',
     port = port
   }
   -- 💀
   -- Wait for codelldb to get ready and start listening before telling nvim-dap to connect
   -- If you get connect errors, try to increase 500 to a higher value, or check the stderr (Open the REPL)
   vim.defer_fn(function() on_adapter(adapter) end, 1000)
 end
 
 -- don't forget to compile/build with debug symbols, otherwise it won't work.
 dap.configurations.cpp = {
   {
     name = "runit",
     type = "codelldb",
     request = "launch",
 
     program = function()
       return vim.fn.input('', vim.fn.getcwd() , 'file')
     end,
 
     args = {"--log_level=all"},
     cwd = "${workspaceFolder}",
     stopOnEntry = false,
     terminal = 'integrated',
 
     pid = function()
             local handle = io.popen('pgrep hw$')
             local result = handle:read()
             handle:close()
             return result
     end
   },
 }
 
 dap.configurations.c = dap.configurations.cpp
 dap.configurations.h = dap.configurations.cpp
 dap.configurations.rust = dap.configurations.cpp