cmake_build.el

(require 'cl)
(require 'compile)

(defun upward-find-file (filename &optional startdir)
  (let
      ((dirname (expand-file-name
                 (if startdir startdir ".")))
       (found nil)
       (top nil))
    (while (not (or found top))
      (if (string= (expand-file-name dirname) "/")
          (setq top t))
      (if (file-exists-p (expand-file-name filename dirname))
          (setq found t)
        (setq dirname (expand-file-name ".." dirname))))
    (if found dirname nil)))

(defun cmake-compile ()
  (interactive)
  (setq builddir
        (expand-file-name "build"
                          (upward-find-file "build" ".")))
  (cd-absolute builddir)
  (message "moved %s" builddir)
  (compile (format "cmake .. -G Ninja && ninja"
               (upward-find-file "build" "."))))

(global-set-key "\C-cc" 'cmake-compile)