What the heck is this?

When I first started doing C++ programming this Summer with Grail, I wanted to use Emacs as my primary editor. I quickly found out that ccls exists, and was well integrated into Doom Emacs. The primary issue with this setup was that ccls couldn't tell where different imports were, and kept giving an error. The way that Clang based language servers (like clangd) work is they require a compile_commands.json file which contains the commands that run on each file in the project when compiled. Without one of these, the language server doesn't know how to index the project, and starts throwing out false errors.

How do I get one?

The easy way

If your project uses CMake, set the variable CMAKE_EXPORT_COMPILE_COMMANDS to ON and a compile_commands.json will generate in the build folder. Symlink that thing to the root directory of the project and you're good to go.

The slightly more painful way

If your project doesn't use CMake (Grail used a bizarre and confusing system using make before this Summer), the best way to generate one of these files is going to be with bear. As per the README, generating the file is as easy as:

bear -- <your-build-command>