+#+END_SRC
+
+** C & C++
+C/C++ ide tools
+1. completion (file name, function name, variable name)
+2. template yasnippet (keywords, if, function)
+3. tags jump
+*** c/c++ style
+#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ ;; (setq c-default-style "stroustrup"
+ ;; c-basic-offset 4)
+
+ ;; ;; "C-M-j" is my global binding for avy goto line below
+ ;; ;; disable it in c mode
+ ;; (mapcar #'(lambda (map)
+ ;; (define-key map (kbd "C-M-j") nil))
+ ;; (list c-mode-map
+ ;; c++-mode-map
+ ;; objc-mode-map))
+
+ ;; objective c
+ (add-to-list 'auto-mode-alist '("\\.mm\\'" . objc-mode))
+
+ (setq-default c-hungry-delete-key t)
+
+
+ ;; Looks `c-hanging-braces-alist' doesn't work as expected when `electric-pair-mode' is enabled.
+ (electric-pair-mode 1)
+
+ (defconst sd/c-style
+ '("stroustrup"
+ (c-tab-always-indent . t)
+ (c-basic-offset . 4)
+ (c-hanging-braces-alist . ((substatement-open before)
+ (statement-block-intro before)))
+ (c-hanging-colons-alist . ())
+ (c-echo-syntactic-information-p . nil)
+ (c-hanging-semi&comma-criteria . ()))
+ "My C programming style")
+
+ (c-add-style "sd-c-style" sd/c-style)
+
+ (setq c-default-style "sd-c-style")
+
+ (add-hook 'c-mode-hook '(lambda ()
+ (c-toggle-auto-newline 1)
+ (c-set-style "sd-c-style")))
+
+ ;; (advice-add 'c-electric-brace :after (lambda (arg) "Add new line after insert {}" (newline-and-indent)))
+#+END_SRC
+*** irony
+**** install irony server
+Install clang, on mac, it has =libclang.dylib=, but no develop headers. Install by =brew=
+#+BEGIN_SRC sh
+ brew install llvm --with-clang
+#+END_SRC
+
+then install irony searver, and =LIBCLANG_LIBRARY= and =LIBCLANG_INCLUDE_DIR= accordingly
+#+BEGIN_SRC emacs-lisp :tangle no :results silent
+ (irony-install-server)
+#+END_SRC
+
+#+BEGIN_SRC sh
+ cmake -DLIBCLANG_LIBRARY\=/usr/local/Cellar/llvm/4.0.1/lib/libclang.dylib \
+ -DLIBCLANG_INCLUDE_DIR=/usr/local/Cellar/llvm/4.0.1/include \
+ -DCMAKE_INSTALL_PREFIX\=/Users/peng/.emacs.d/irony/ \
+ /Users/peng/.emacs.d/elpa/irony-20160713.1245/server && cmake --build . --use-stderr --config Release --target install
+#+END_SRC
+
+**** irony config
+irony-mode-hook, copied from [[https://github.com/Sarcasm/irony-mode][irony-mode]] github
+#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ ;; (use-package irony
+ ;; :ensure t
+ ;; :init
+ ;; (add-hook 'c++-mode-hook 'irony-mode)
+ ;; (add-hook 'c-mode-hook 'irony-mode)
+ ;; (add-hook 'objc-mode-hook 'irony-mode))
+
+ ;; replace the `completion-at-point' and `complete-symbol' bindings in
+ ;; irony-mode's buffers by irony-mode's function
+
+ (defun my-irony-mode-hook ()
+ (define-key irony-mode-map [remap completion-at-point]
+ 'irony-completion-at-point-async)
+ (define-key irony-mode-map [remap complete-symbol]
+ 'irony-completion-at-point-async))
+
+ ;; (add-hook 'irony-mode-hook 'my-irony-mode-hook)
+ ;; (add-hook 'irony-mode-hook 'irony-cdb-autosetup-compile-options)
+
+ ;; (add-hook 'c++-mode-local-vars-hook #'sd/c++-mode-local-vars)
+
+ ;; add C++ completions, because by default c++ file can not complete
+ ;; c++ std functions, another method is create .dir-local.el file, for p
+ ;; for project see irony
+ (defun sd/c++-mode-local-vars ()
+ (setq irony--compile-options
+ '("-std=c++11"
+ "-stdlib=libc++"
+ "-I/usr/include/c++/4.2.1")))
+#+END_SRC
+
+irony-company
+#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ ;; (use-package company-irony
+ ;; :ensure t)
+
+ ;; (use-package flycheck-irony
+ ;; :ensure t)
+
+ ;; (use-package company-c-headers
+ ;; :ensure t
+ ;; :config
+ ;; (add-to-list 'company-c-headers-path-system "/usr/include/c++/4.2.1/")
+ ;; (add-to-list 'company-c-headers-path-system "/usr/local/include/"))
+
+ ;; (with-eval-after-load 'company
+ ;; (add-to-list 'company-backends 'company-irony)
+ ;; (add-to-list 'company-backends 'company-c-headers))
+
+ ;; (with-eval-after-load 'company
+ ;; (push '(company-irony :with company-yasnippet) company-backends)
+ ;; (push '(company-c-headers :with company-yasnippet) company-backends))
+
+ ;; (with-eval-after-load 'flycheck
+ ;; (add-hook 'flycheck-mode-hook #'flycheck-irony-setup))
+#+END_SRC
+
+*** flycheck
+#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ (use-package flycheck
+ :ensure t)
+#+END_SRC
+
+*** gtags
+#+BEGIN_SRC emacs-lisp :tangle yes :results silent
+ (use-package ggtags
+ :ensure t
+ :config
+ (define-key ggtags-mode-map (kbd "M-g d") 'ggtags-find-definition)
+ (define-key ggtags-mode-map (kbd "M-g r") 'ggtags-find-reference)
+ (define-key ggtags-mode-map (kbd "M-g r") 'ggtags-find-reference)
+ (define-key ggtags-mode-map (kbd "C-c g s") 'ggtags-find-other-symbol)
+ (define-key ggtags-mode-map (kbd "C-c g h") 'ggtags-view-tag-history)
+ (define-key ggtags-mode-map (kbd "C-c g r") 'ggtags-find-reference)
+ (define-key ggtags-mode-map (kbd "C-c g f") 'ggtags-find-file)
+ (define-key ggtags-mode-map (kbd "C-c g c") 'ggtags-create-tags)
+ (define-key ggtags-mode-map (kbd "C-c g u") 'ggtags-update-tags))
+
+ (add-hook 'c-mode-common-hook
+ (lambda ()
+ (when (derived-mode-p 'c-mode 'c++-mode 'java-mode)
+ (ggtags-mode 1))))