henriquelalves

 henriquelalves

setting up emacs for godot engine development

2023-07-13
#emacs#godot

This is a quick blog post, in case any developer wonders how to configure their favourite OS to use with Godot development (the Engine code itself, not individual projects).

I previously had a tough time configuring Emacs for C/C++ projects, probably because I had no idea what I was doing, but I like to think that the problem was the LSP support on Emacs. Nowadays it's pretty much straightforward. The main requisite is following this guide:

https://emacs-lsp.github.io/lsp-mode/tutorials/CPP-guide/

To install the corresponding LSP packages on your Emacs. The main packages are lsp-mode (main LSP mode), lsp-ui (LSP UI support), dap-mode (for debugging), company (autocomplete) and flycheck (syntax checking). Remember to set up clangd first.

Ignore their Project Setup section for the Godot project. Instead, what you want to do is run scons compiledb=yes compile_commands.json on the Godot project root folder, so it generates the stuff LSP needs.

After setting up clangd, LSP and generating compile_commands.json, Emacs should behave just like any other IDE a normal sensible person would use if they don't like the THRILL of breaking their IDE configuration every now and then.

To be able to use the debug commands (M-x dap-debug) the tutorial points you to, you have to create a launch.json file in the Godot project root, the Debug launch command configuration. Mine looks like this:

{
		"name": "Launch Project",
		"type": "cppdbg",
		"request": "launch",
		// Change to godot.linuxbsd.tools.64.llvm for llvm-based builds.
		"program": "${workspaceFolder}/bin/godot.linuxbsd.editor.dev.x86_64",
		// Change the arguments below for the project you want to test with.
		// To run the project instead of editing it, remove the "--editor" argument.
		"args": [ "--editor, "--path", "path-to-your-godot-project-folder" ],
		"stopAtEntry": false,
		"cwd": "${workspaceFolder}",
		"environment": [],
		"externalConsole": false,
}

That's the VSCode .json from the Godot documentation guide, but replacing lldb with cppdbg, and removing the preLaunchTask property (you'll have to create a "build" task .json if you want a preLaunchTask). After that, you should be able to add breakpoints with M-x dap-breakpoint-add and run M-x dap-debug successfully.

Why Emacs, though? Isn't VSCode much easier to configure and use for C++ development?

Yes.