Golevka / emacs-clang-complete-async

An emacs plugin to complete C and C++ code using libclang
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emacs-clang-complete-async is an emacs extension to complete C and C++ code, it uses libclang to parse the source code on the fly and provides completion candidates to auto-complete (http://cx4a.org/software/auto-complete).

[[https://github.com/Golevka/emacs-clang-complete-async/raw/master/screenshots/showcase.png]]

This extension is not implemented in pure elisp, it is made up of a client part (auto-complete-clang-async.el, written in elisp) and a server part (clang-complete binary, written in C), they work cooperately in asynchonous client-server fashion.

An experimental feature is added to this branch --- running =ac-clang-syntax-check= to highlight errornous lines in your souce code.

[[https://github.com/Golevka/emacs-clang-complete-async/raw/master/screenshots/syntax_check.png]]

Compile the server part (clang-complete binary) first, by executing =make=. The build process uses =llvm-config= to determine the location of libclang and the appropriate compile flags to use. If =llvm-config= is not in your path or has a different name, you can pass =make= an =LLVM_CONFIG= argument, e.g. =make LLVM_CONFIG=llvm-config-3.4=.

Copy auto-complete-clang-async.el and the previously compiled clang-complete executable to ~/.emacs.d/, and add the following code to your .emacs file.

+BEGIN_SRC elisp

(require 'auto-complete-clang-async)

(defun ac-cc-mode-setup () (setq ac-clang-complete-executable "~/.emacs.d/clang-complete") (setq ac-sources '(ac-source-clang-async)) (ac-clang-launch-completion-process) )

(defun my-ac-config () (add-hook 'c-mode-common-hook 'ac-cc-mode-setup) (add-hook 'auto-complete-mode-hook 'ac-common-setup) (global-auto-complete-mode t))

(my-ac-config)

+END_SRC

Now emacs-clang-complete-async will show completion candidates automatically when you type as usual in C or C++ mode.

This extension fades in emacs C/C++ mode and provides candidates automatically while you typing code, if you want to add parameters to clang (libclang, actually), such as -Ipath, just call ac-clang-set-cflags interactively or set the value of ac-clang-flags in .emacs or .dir-locals.el, maybe you need an explicit call to ac-clang-update-cmdlineargs to make changes to cflags take effect, which is a niggling part of it T T

Most code of auto-complete-clang-async.el is taken from brainjcj's auto-complete-clang.el, The only difference between this one and bj's ac-clang-complete is: This one interacts with a process geared with libclang to retrieve completion candidates instead of calling clang process, which is way slower, and the asynchonous nature of our C-S based working model won't block the editor while parsing source code and resolving completion candidates, which provides a "smooth" coding experience.