Auto-complete C/C++ functions

Question

I want code completion for C/C++ functions and variables from headers. I tried to install Auto-complete and Company, but C/C ++ functions/variables aren't complemented.

Here is the relevant portion of my .emacs file:

;; Auto-complete (AC)
(require 'auto-complete)

(require 'auto-complete-config)
(ac-config-default)

Answer 1

A vanilla company install wont quite get you where you want; you'll need to use use something like the company-c-headers package. Tuhdo has written an excellent document on using Emacs as a C/C++ IDE, which has instructions on setting up company-c-headers, along with a lot of other stuff.

I don't know what Emacs version you're using, but in 24.5 with Company, you'd do something like this:

1. Install the company-c-headers package from MELPA -- M-x package-install company-c-headers

2. Add this to your emacs config file (init.el / .emacs.d / whathaveyou)

   (require 'company)
   (add-hook 'global-init-hook 'global-company-mode)
   (add-to-list 'company-backends 'company-c-headers)
   

Note that company-c-headers by default only searches two paths for headers. If you want it to search others, you'll need to add them yourself. (For more on that, see Tuhdo)