| `mips64`                    | `big`                   | `mips64`            |

## Compilation environments

Nix can be compiled using multiple environments:

- `stdenv`: default;
- `gccStdenv`: force the use of `gcc` compiler;
- `clangStdenv`: force the use of `clang` compiler;
- `ccacheStdenv`: enable [ccache], a compiler cache to speed up compilation.

To build with one of those environments, you can use

```console
$ nix build .#nix-cli-ccacheStdenv
```

for flake-enabled Nix, or

```console
$ nix-build --attr nix-cli-ccacheStdenv
```

for classic Nix.

You can use any of the other supported environments in place of `nix-cli-ccacheStdenv`.

## Editor integration

The `clangd` LSP server is installed by default on the `clang`-based `devShell`s.
See [supported compilation environments](#compilation-environments) and instructions how to set up a shell [with flakes](#nix-with-flakes) or in [classic Nix](#classic-nix).

To use the LSP with your editor, you will want a `compile_commands.json` file telling `clangd` how we are compiling the code.
Meson's configure always produces this inside the build directory.

Configure your editor to use the `clangd` from the `.#native-clangStdenv` shell.
You can do that either by running it inside the development shell, or by using [nix-direnv](https://github.com/nix-community/nix-direnv) and [the appropriate editor plugin](https://github.com/direnv/direnv/wiki#editor-integration).

> **Note**
>
> For some editors (e.g. Visual Studio Code), you may need to install a [special extension](https://open-vsx.org/extension/llvm-vs-code-extensions/vscode-clangd) for the editor to interact with `clangd`.
> Some other editors (e.g. Emacs, Vim) need a plugin to support LSP servers in general (e.g. [lsp-mode](https://github.com/emacs-lsp/lsp-mode) for Emacs and [vim-lsp](https://github.com/prabirshrestha/vim-lsp) for vim).
> Editor-specific setup is typically opinionated, so we will not cover it here in more detail.

## Formatting and pre-commit hooks

You may run the formatters as a one-off using:

```console
./maintainers/format.sh
```

### Pre-commit hooks

If you'd like to run the formatters before every commit, install the hooks:

```
pre-commit-hooks-install
```

This installs [pre-commit](https://pre-commit.com) using [cachix/git-hooks.nix](https://github.com/cachix/git-hooks.nix).

When making a commit, pay attention to the console output.
If it fails, run `git add --patch` to approve the suggestions _and commit again_.

To refresh pre-commit hook's config file, do the following:
1. Exit the development shell and start it again by running `nix develop`.
2. If you also use the pre-commit hook, also run `pre-commit-hooks-install` again.

### VSCode

Insert the following json into your `.vscode/settings.json` file to configure `nixfmt`.
This will be picked up by the _Format Document_ command, `"editor.formatOnSave"`, etc.

```json
{
  "nix.formatterPath": "nixfmt",
  "nix.serverSettings": {
    "nixd": {
      "formatting": {
        "command": [
          "nixfmt"
        ],
      },
    },
    "nil": {
      "formatting": {
        "command": [
          "nixfmt"
        ],
      },
    },
  },
}
```