Add cmake support to emacs.

nix/configuration/roles/emacs/default.nix

@@ -127,6 +127,8 @@ in
                     final.nixfmt-rfc-style # auto-formatting nix files through nixd
                     final.clang # To compile tree-sitter grammars
                     final.shellcheck
+                    final.cmake-language-server
+                    final.cmake # Used by cmake-language-server
                   ]
                 }
               '';

nix/configuration/roles/emacs/files/emacs/elisp/lang-cmake.el

@@ -0,0 +1,18 @@
+(require 'common-lsp)
+
+(use-package cmake-mode
+  :commands cmake-mode
+  :hook (
+         (cmake-mode . (lambda ()
+                         (eglot-ensure)
+                         (defclass my/eglot-cmake (eglot-lsp-server) ()
+                           :documentation
+                           "Own eglot server class.")
+
+                         (add-to-list 'eglot-server-programs
+                                      '(cmake-mode . (my/eglot-cmake "cmake-language-server")))
+                         ))
+         )
+  )
+
+(provide 'lang-cmake)

nix/configuration/roles/emacs/files/emacs/init.el

@@ -38,4 +38,6 @@
 
 (require 'lang-nix)
 
+(require 'lang-cmake)
+
 (load-directory autoload-directory)