emacs rtags configuration

init.el

(menu-bar-mode -1)

(global-set-key "\M-g" 'goto-line)
(global-set-key "\M-." 'rtags-find-symbol-at-point)
(global-set-key "\M-," 'rtags-location-stack-back)
(global-set-key (kbd "M-]") 'next-error)         ; Go to next error (or msg)                                                                                                                               
(global-set-key (kbd "M-[") 'previous-error)     ; Go to previous error or msg                                                                                                                             
(global-set-key (kbd "M-m") 'rtags-find-references-at-point)

(require 'package)
(setq package-enable-at-startup nil)
(add-to-list 'package-archives
             '("melpa" . "https://melpa.org/packages/"))

(package-initialize)

;; Bootstrap `use-package'                                                                                                                                                                                 
(unless (package-installed-p 'use-package)
  (package-refresh-contents)
    (package-install 'use-package))

;; compile rtags according to https://github.com/Andersbakken/rtags                                                                                                                                        
;; and put https://github.com/Andersbakken/rtags/src/rtags.el into ~/.emacs.d/cpp/                                                                                                                         
(add-to-list 'load-path "~/.emacs.d/misc/")

(use-package company
             :ensure t)

(require 'popwin)
(popwin-mode 1)
(global-set-key (kbd "C-z") popwin:keymap)

(require 'rtags)

(setq rtags-autostart-diagnostics t)
(rtags-diagnostics)
(setq rtags-completions-enabled t)
(push 'company-rtags company-backends)
(global-company-mode)
(define-key c-mode-base-map (kbd "<C-tab>") (function company-complete))

;; eldoc mode for rtags: https://github.com/Andersbakken/rtags/issues/987                                                                                                                                  
(require 'subr-x)
(defun fontify-string (str mode)
  "Return STR fontified according to MODE."
  (with-temp-buffer
    (insert str)
    (delay-mode-hooks (funcall mode))
    (font-lock-default-function mode)
    (font-lock-default-fontify-region
     (point-min) (point-max) nil)
    (buffer-string)))

(defun rtags-eldoc-function ()
  (let ((summary (rtags-get-summary-text)))
    (and summary
         (fontify-string
          (replace-regexp-in-string
           "{[^}]*$" ""
           (mapconcat
            (lambda (str) (if (= 0 (length str)) "//" (string-trim str)))
            (split-string summary "\r?\n")
            " "))
          major-mode))))

(defun rtags-eldoc-mode ()
  (interactive)
  (setq-local eldoc-documentation-function #'rtags-eldoc-function)
  (eldoc-mode 1))

;; add hooks                                                                                                                                                                                               
(add-hook 'c-mode-hook 'rtags-start-process-unless-running)
(add-hook 'c++-mode-hook 'rtags-start-process-unless-running)
(add-hook 'c++-mode-hook 'rtags-start-process-unless-running)
(add-hook 'objc-mode-hook 'rtags-start-process-unless-running)

(add-hook 'c-mode-hook 'rtags-eldoc-mode)
(add-hook 'c++-mode-hook 'rtags-eldoc-mode)
(add-hook 'objc-mode-hook 'rtags-eldoc-mode)