Emacs – C/C++ Programming

This page is written to summarize my configuration for C/C++ programming with Emacs.

Besides Emacs, following extensions are also needed. The installation can be finished by the built-in package manager, elpa. Before the installation, following configuration in ~/.emacs for elpa is necessary.

(setq package-archives '(("gnu" . "http://elpa.gnu.org/packages/")
             ("melpa" . "http://melpa.milkbox.net/packages/")))
(package-initialize)

Through elpa, install following extensions.

company

It represents complete anything. Just as its name implies, it is used for completion. It is similar to auto-complete, but I prefer company. In order to enable automatical completion in C/C++ programming, I use clang ¹ as backend in lieu of semantic, since semantic-based completion is too slow. However, as long as company is installed, semantic is already built-in, a.k.a. company-semantic. Moreover, it precedes clang-based backend. To deal with the problem, we remove semantic from the list of backend for company.

(global-company-mode t)
(setq company-idle-delay 0)
(setq company-backends (delete 'company-semantic company-backends))
(add-to-list 'company-backends 'company-c-headers)

BTW, for sake of completion based on other third-party libraries, we can create an elisp file .dir-locals.el in the project root. E.g. ITPP library installed in /opt/itpp.

((nil . ((company-clang-arguments . ("-I/opt/itpp/include")))))

yasnippet

It stands for yet another snippet and can be directly installed via elpa. As its name indicates, it provides a large number of useful snippets and templates.

(require 'yasnippet)
(yas-global-mode t)

doxymacs²

This extension aims to integrate doxygen into emacs. The related functionalities are bound to keys with prefix C-c C-d.

(require 'doxymacs)
(add-hook 'c-mode-common-hook 'doxymacs-mode)
(defun my-doxymacs-font-lock-hook ()
  (if (or (eq major-mode 'c-mode) (eq major-mode 'c++-mode))
      (doxymacs-font-lock)))
(add-hook 'font-lock-mode-hook 'my-doxymacs-font-lock-hook)

cscope³

Index the source codes and enable freely jumping between definitions, declarations and provokings of variables or functions. The related functionalities are bound to keys with prefix C-c s.

(add-hook 'c-mode-common-hook '(lambda() (require 'xcscope) (cscope-setup)))

What deserves notice, not only programming but also debugging can be finished in the Emacs. We can run M-x gdb to enter debug mode. Optionally, we can also start many window mode by M-x gdb-many-windows. In the debugging, many useful functions are bound to keys with prefix C-x C-a.