feat: add compile_commands.json output to make debug build

[virchau13]

Describe your PR, what does it fix/add?

This makes all the include resolution and diagnostic information work properly (with the clangd language server on NixOS, at least.) Probably makes this line unnecessary:

Hyprland/src/includes.hpp

Line 6 in 2e76376

#pragma diag_suppress 1696

Is there anything you want to mention? (unchecked code, possible bugs, found problems, breaking compatibility, etc.)

• As far as I can tell, the xwayland dependency provides literally nothing.

/nix/store/i3yspjhpqz8n25phd91p5cyrh2jl1xvh-xwayland-23.2.6
├── bin
│  └── Xwayland
├── lib
│  ├── pkgconfig
│  │  └── xwayland.pc
│  └── xorg
│     └── protocol.txt
└── share
   ├── applications
   │  └── org.freedesktop.Xwayland.desktop
   └── man
      └── man1
         ├── Xserver.1.gz
         └── Xwayland.1.gz

I'm not sure why it's even in CMakeLists.txt in the first place.

• This shouldn't conflict with Install files using CMake, use CMake for Nix #5667.

• If you add -DCMAKE_LINKER_TYPE=MOLD and install the Mold linker, the debug builds become significantly faster, but I don't know if I should add that to this PR.

Is it ready for merging, or does it need work?

Ready for merge.

[fufexan]

Probably makes this line unnecessary:

If it's the case, can you also remove it in this PR?

[virchau13]

I don't have VSCode, so someone else should test if this actually fixes it in VSCode (I tested it in Neovim).

[BvngeeCord]

Can confirm, this fixes all include errors for me in Neovim with Clangd. Note: by default, clangd shouldn't need compile_commands.json to be symlinked to the project root, as looks upwards naturally starting from where the source file is. Though it might still be good to be safe.

Alternatively, set(CMAKE_EXPORT_COMPILE_COMMANDS TRUE) can be set inside of CMakeLists.txt instead of the env var if that is preffered (which is what I've been doing).