Andy Garfield andygarfield

How to use clangd C/C++ LSP in any project

tl;dr: If you want to just know the method, skip to How to section

Clangd is a state-of-the-art C/C++ LSP that can be used in every popular text editors like Neovim, Emacs or VS Code. Even CLion uses clangd under the hood. Unfortunately, clangd requires compile_commands.json to work, and the easiest way to painlessly generate it is to use CMake.

For simple projects you can try to use Bear - it will capture compile commands and generate compile_commands.json. Although I could never make it work in big projects with custom or complicated build systems.

But what if I tell you you can quickly hack your way around that, and generate compile_commands.json for any project, no matter how compilcated? I have used that way at work for years, originaly because I used CLion which supported only CMake projects - but now I use that method succesfully with clangd and Neovim.

	# Copyright 2020 Ben Kehoe
	#
	# Permission is hereby granted, free of charge, to any person obtaining a copy of this
	# software and associated documentation files (the "Software"), to deal in the Software
	# without restriction, including without limitation the rights to use, copy, modify,
	# merge, publish, distribute, sublicense, and/or sell copies of the Software, and to
	# permit persons to whom the Software is furnished to do so.
	#
	# THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR IMPLIED,
	# INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY, FITNESS FOR A

	// Compile with clang or MSVC (WINDOWS ONLY RN)
	//
	// Implementing a POC green threads system using safepoints to show how cheap and simple it can
	// be done, all you need to do is call SAFEPOINT_POLL in your own language at the top of every
	// loop and function body (you can loosen up on this depending on the latency of pausing you're
	// willing to pay). Safepoint polling is made cheap because it's a load without a use site
	// which means it doesn't introduce a stall and pays a sub-cycle cost because of it (wastes resources
	// sure but doesn't block up the rest of execution).
	//
	// # safepoint poll