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;;; google-c-style.el --- Google's C/C++ style for c-mode
;; Keywords: c, tools
;; google-c-style.el is Copyright (C) 2008 Google Inc. All Rights Reserved.
;; It is free software; you can redistribute it and/or modify it under the
;; terms of either:
;; a) the GNU General Public License as published by the Free Software
;; Foundation; either version 1, or (at your option) any later version, or
;; b) the "Artistic License".
;;; Commentary:
;; Provides the google C/C++ coding style. You may wish to add
;; `google-set-c-style' to your `c-mode-common-hook' after requiring this
;; file. For example:
;; (add-hook 'c-mode-common-hook 'google-set-c-style)
;; If you want the RETURN key to go to the next line and space over
;; to the right place, add this to your .emacs right after the load-file:
;; (add-hook 'c-mode-common-hook 'google-make-newline-indent)
;;; Code:
;; For some reason 1) c-backward-syntactic-ws is a macro and 2) under Emacs 22
;; bytecode cannot call (unexpanded) macros at run time:
(eval-when-compile (require 'cc-defs))
;; Wrapper function needed for Emacs 21 and XEmacs (Emacs 22 offers the more
;; elegant solution of composing a list of lineup functions or quantities with
;; operators such as "add")
(defun google-c-lineup-expression-plus-4 (langelem)
"Indents to the beginning of the current C expression plus 4 spaces.
This implements title \"Function Declarations and Definitions\"
of the Google C++ Style Guide for the case where the previous
line ends with an open parenthese.
\"Current C expression\", as per the Google Style Guide and as
clarified by subsequent discussions, means the whole expression
regardless of the number of nested parentheses, but excluding
non-expression material such as \"if(\" and \"for(\" control
Suitable for inclusion in `c-offsets-alist'."
;; Go to beginning of *previous* line:
;; We are making a reasonable assumption that if there is a control
;; structure to indent past, it has to be at the beginning of the line.
((looking-at "\\(\\(if\\|for\\|while\\)\\s *(\\)")
(goto-char (match-end 1)))
;; For constructor initializer lists, the reference point for line-up is
;; the token after the initial colon.
((looking-at ":\\s *")
(goto-char (match-end 0))))
(vector (+ 4 (current-column)))))
(defconst google-c-style
`((c-recognize-knr-p . nil)
(c-enable-xemacs-performance-kludge-p . t) ; speed up indentation in XEmacs
(c-basic-offset . 2)
(indent-tabs-mode . nil)
(c-comment-only-line-offset . 0)
(c-hanging-braces-alist . ((defun-open after)
(defun-close before after)
(class-open after)
(class-close before after)
(inexpr-class-open after)
(inexpr-class-close before)
(namespace-open after)
(inline-open after)
(inline-close before after)
(block-open after)
(block-close . c-snug-do-while)
(extern-lang-open after)
(extern-lang-close after)
(statement-case-open after)
(substatement-open after)))
(c-hanging-colons-alist . ((case-label)
(label after)
(access-label after)
(member-init-intro before)
. (c-semi&comma-no-newlines-for-oneline-inliners
(c-indent-comments-syntactically-p . t)
(comment-column . 40)
(c-indent-comment-alist . ((other . (space . 2))))
(c-cleanup-list . (brace-else-brace
(c-offsets-alist . ((arglist-intro google-c-lineup-expression-plus-4)
(func-decl-cont . ++)
(member-init-intro . ++)
(inher-intro . ++)
(comment-intro . 0)
(arglist-close . c-lineup-arglist)
(topmost-intro . 0)
(block-open . 0)
(inline-open . 0)
(substatement-open . 0)
(,(when (fboundp 'c-no-indent-after-java-annotations)
,(when (fboundp 'c-lineup-assignments)
(label . /)
(case-label . +)
(statement-case-open . +)
(statement-case-intro . +) ; case w/o {
(access-label . /)
(innamespace . 0))))
"Google C/C++ Programming Style.")
(defun google-set-c-style ()
"Set the current buffer's c-style to Google C/C++ Programming
Style. Meant to be added to `c-mode-common-hook'."
(make-local-variable 'c-tab-always-indent)
(setq c-tab-always-indent t)
(c-add-style "Google" google-c-style t))
(defun google-make-newline-indent ()
"Sets up preferred newline behavior. Not set by default. Meant
to be added to `c-mode-common-hook'."
(define-key c-mode-base-map "\C-m" 'newline-and-indent)
(define-key c-mode-base-map [ret] 'newline-and-indent))
(provide 'google-c-style)
;;; google-c-style.el ends here