c-eldoc.el

Display description of the function under the cursor.

Original version: http://www.emacswiki.org/emacs/c-eldoc.el

This forked version uses deferred.el to support asynchronous processing.

Installation

First, download and compile c-eldoc.el

wget http://github.com/mooz/c-eldoc/raw/master/c-eldoc.el

If you havn't installed deferred.el,

wget http://github.com/kiwanami/emacs-deferred/raw/master/deferred.el

Then, place c-eldoc.el (and deferred.el) into your site-lisp directory.

Finally, add following lines to your emacs config file (e.g. .emacs).

(add-hook 'c-mode-hook 'c-turn-on-eldoc-mode)
(add-hook 'c++-mode-hook 'c-turn-on-eldoc-mode)

Customization

Cache

c-eldoc.el uses cache to reduce the times of compilation. This cache has expiration time (default 120 seconds) and you can customize this value.

(setq c-eldoc-buffer-regenerate-time 60)

You can explicitly force update the cache and get latest result by calling c-eldoc-force-cache-update.

The following settings this update command to the Ctrl-c + d key.

(defun c-eldoc-define-keybindings (map)
  (define-key map (kbd "C-c d") 'c-eldoc-force-cache-update))

(add-hook 'c-mode-hook
          (lambda ()
            (c-eldoc-define-keybindings c-mode-map)))

(add-hook 'c++-mode-hook
          (lambda ()
            (c-eldoc-define-keybindings c++-mode-map)))

Compile options

You can customize the compiler and the compile options.

Here are the default values.

(defvar c-eldoc-cpp-command "/lib/cpp ") ;; compiler
(defvar c-eldoc-cpp-macro-arguments "-dD -w -P")
(defvar c-eldoc-cpp-normal-arguments "-w -P")
(defvar c-eldoc-includes "`pkg-config gtk+-2.0 --cflags` -I./ -I../ ") ;; include flags

To customize them, use setq.

(setq c-eldoc-cpp-command "/usr/local/bin/clang")

Styles

You can customize style of current argument.

Press M-x and type customize-face and specify c-eldoc-current-argument-face.