How to Debug C/C++ with VSCode and Remote LLDB

TL;DR

  1. Install VSCode plugin Remote Development (be it container or SSH), and install LLDB DAP in the remote environment
  2. Install lldb in source code environment
  3. Build the project with debug symbols
  4. Configure .vscode/launch.json 
    {
	"version": "0.2.0",
	"configurations": [
		{
			"type": "lldb-dap",
			"request": "launch",
			"name": "Launch",
			"program": "${workspaceRoot}/<your program>",
			"args": [],
			"env": [],
			"cwd": "${workspaceRoot}"
		}
	]
}

Explained

Modern debuggers employ client/server architecture to provide debugging features. The architecture is shown below, using lldb as an example.

lldb debugger architecture

The debugger client (e.g. VSCode) sends commands to the debugger server (e.g. lldb) and receives the results. The debugger server interacts with the target program and provides the results back to the client. Then the debugger client displays the results to the user.

lldb is a debugger for C/C++, based on the LLVM project. To debug a program with lldb, you need to build the program with debug symbols.