1 ;;; company-clang.el --- company-mode completion backend for Clang -*- lexical-binding: t -*-
3 ;; Copyright (C) 2009, 2011, 2013-2015 Free Software Foundation, Inc.
5 ;; Author: Nikolaj Schumacher
7 ;; This file is part of GNU Emacs.
9 ;; GNU Emacs is free software: you can redistribute it and/or modify
10 ;; it under the terms of the GNU General Public License as published by
11 ;; the Free Software Foundation, either version 3 of the License, or
12 ;; (at your option) any later version.
14 ;; GNU Emacs is distributed in the hope that it will be useful,
15 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
16 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 ;; GNU General Public License for more details.
19 ;; You should have received a copy of the GNU General Public License
20 ;; along with GNU Emacs. If not, see <http://www.gnu.org/licenses/>.
29 (require 'company-template)
32 (defgroup company-clang nil
33 "Completion backend for Clang."
36 (defcustom company-clang-executable
37 (executable-find "clang")
38 "Location of clang executable."
41 (defcustom company-clang-begin-after-member-access t
42 "When non-nil, automatic completion will start whenever the current
43 symbol is preceded by \".\", \"->\" or \"::\", ignoring
44 `company-minimum-prefix-length'.
46 If `company-begin-commands' is a list, it should include `c-electric-lt-gt'
47 and `c-electric-colon', for automatic completion right after \">\" and
50 (defcustom company-clang-arguments nil
51 "Additional arguments to pass to clang when completing.
52 Prefix files (-include ...) can be selected with `company-clang-set-prefix'
53 or automatically through a custom `company-clang-prefix-guesser'."
54 :type '(repeat (string :tag "Argument")))
56 (defcustom company-clang-prefix-guesser 'company-clang-guess-prefix
57 "A function to determine the prefix file for the current buffer."
58 :type '(function :tag "Guesser function" nil))
60 (defvar company-clang-modes '(c-mode c++-mode objc-mode)
61 "Major modes which clang may complete.")
63 (defcustom company-clang-insert-arguments t
64 "When non-nil, insert function arguments as a template after completion."
66 :package-version '(company . "0.8.0"))
68 ;; prefix ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
70 (defvar company-clang--prefix nil)
72 (defsubst company-clang--guess-pch-file (file)
73 (let ((dir (directory-file-name (file-name-directory file))))
74 (when (equal (file-name-nondirectory dir) "Classes")
75 (setq dir (file-name-directory dir)))
76 (car (directory-files dir t "\\([^.]h\\|[^h]\\).pch\\'" t))))
78 (defsubst company-clang--file-substring (file beg end)
80 (insert-file-contents-literally file nil beg end)
83 (defun company-clang-guess-prefix ()
84 "Try to guess the prefix file for the current buffer."
85 ;; Prefixes seem to be called .pch. Pre-compiled headers do, too.
86 ;; So we look at the magic number to rule them out.
87 (let* ((file (company-clang--guess-pch-file buffer-file-name))
88 (magic-number (and file (company-clang--file-substring file 0 4))))
89 (unless (member magic-number '("CPCH" "gpch"))
92 (defun company-clang-set-prefix (&optional prefix)
93 "Use PREFIX as a prefix (-include ...) file for clang completion."
94 (interactive (let ((def (funcall company-clang-prefix-guesser)))
96 (setq def default-directory))
97 (list (read-file-name "Prefix file: "
98 (when def (file-name-directory def))
99 def t (when def (file-name-nondirectory def))))))
100 ;; TODO: pre-compile?
101 (setq company-clang--prefix (and (stringp prefix)
102 (file-regular-p prefix)
106 (add-hook 'kill-emacs-hook 'company-clang-set-prefix)
108 ;; parsing ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
110 ;; TODO: Handle Pattern (syntactic hints would be neat).
111 ;; Do we ever see OVERLOAD (or OVERRIDE)?
112 (defconst company-clang--completion-pattern
113 "^COMPLETION: \\_<\\(%s[a-zA-Z0-9_:]*\\)\\(?: : \\(.*\\)$\\)?$")
115 (defconst company-clang--error-buffer-name "*clang-error*")
117 (defun company-clang--lang-option ()
118 (if (eq major-mode 'objc-mode)
119 (if (string= "m" (file-name-extension buffer-file-name))
120 "objective-c" "objective-c++")
121 (substring (symbol-name major-mode) 0 -5)))
123 (defun company-clang--parse-output (prefix _objc)
124 (goto-char (point-min))
125 (let ((pattern (format company-clang--completion-pattern
126 (regexp-quote prefix)))
127 (case-fold-search nil)
129 (while (re-search-forward pattern nil t)
130 (setq match (match-string-no-properties 1))
131 (unless (equal match "Pattern")
133 (when (string-match ":" match)
134 (setq match (substring match 0 (match-beginning 0)))))
135 (let ((meta (match-string-no-properties 2)))
136 (when (and meta (not (string= match meta)))
137 (put-text-property 0 1 'meta
138 (company-clang--strip-formatting meta)
143 (defun company-clang--meta (candidate)
144 (get-text-property 0 'meta candidate))
146 (defun company-clang--annotation (candidate)
147 (let ((ann (company-clang--annotation-1 candidate)))
148 (if (not (and ann (string-prefix-p "(*)" ann)))
152 (search-backward ")")
153 (let ((pt (1+ (point))))
154 (re-search-forward ".\\_>" nil t)
155 (delete-region pt (point)))
158 (defun company-clang--annotation-1 (candidate)
159 (let ((meta (company-clang--meta candidate)))
162 ((string-match "[^:]:[^:]" meta)
163 (substring meta (1+ (match-beginning 0))))
164 ((string-match "\\((.*)[ a-z]*\\'\\)" meta)
165 (let ((paren (match-beginning 1)))
166 (if (not (eq (aref meta (1- paren)) ?>))
167 (match-string 1 meta)
171 (substring meta (1- (search-backward "<"))))))))))
173 (defun company-clang--strip-formatting (text)
174 (replace-regexp-in-string
176 (replace-regexp-in-string "[<{[]#\\|#[>}]" "" text t)
179 (defun company-clang--handle-error (res args)
180 (goto-char (point-min))
181 (let* ((buf (get-buffer-create company-clang--error-buffer-name))
182 (cmd (concat company-clang-executable " " (mapconcat 'identity args " ")))
183 (pattern (format company-clang--completion-pattern ""))
184 (err (if (re-search-forward pattern nil t)
185 (buffer-substring-no-properties (point-min)
186 (1- (match-beginning 0)))
187 ;; Warn the user more aggressively if no match was found.
188 (message "clang failed with error %d:\n%s" res cmd)
191 (with-current-buffer buf
192 (let ((inhibit-read-only t))
194 (insert (current-time-string)
195 (format "\nclang failed with error %d:\n" res)
198 (setq buffer-read-only t)
199 (goto-char (point-min))))))
201 (defun company-clang--start-process (prefix callback &rest args)
202 (let ((objc (derived-mode-p 'objc-mode))
203 (buf (get-buffer-create "*clang-output*"))
204 ;; Looks unnecessary in Emacs 25.1 and later.
205 (process-adaptive-read-buffering nil))
206 (if (get-buffer-process buf)
207 (funcall callback nil)
208 (with-current-buffer buf
210 (setq buffer-undo-list t))
211 (let ((process (apply #'start-process "company-clang" buf
212 company-clang-executable args)))
213 (set-process-sentinel
215 (lambda (proc status)
216 (unless (string-match-p "hangup" status)
219 (let ((res (process-exit-status proc)))
220 (with-current-buffer buf
222 (company-clang--handle-error res args))
223 ;; Still try to get any useful input.
224 (company-clang--parse-output prefix objc)))))))
225 (unless (company-clang--auto-save-p)
226 (send-region process (point-min) (point-max))
227 (send-string process "\n")
228 (process-send-eof process))))))
230 (defsubst company-clang--build-location (pos)
234 (if (company-clang--auto-save-p) buffer-file-name "-")
237 (encode-coding-region
238 (line-beginning-position)
243 (defsubst company-clang--build-complete-args (pos)
244 (append '("-fsyntax-only" "-Xclang" "-code-completion-macros")
245 (unless (company-clang--auto-save-p)
246 (list "-x" (company-clang--lang-option)))
247 company-clang-arguments
248 (when (stringp company-clang--prefix)
249 (list "-include" (expand-file-name company-clang--prefix)))
250 (list "-Xclang" (format "-code-completion-at=%s"
251 (company-clang--build-location pos)))
252 (list (if (company-clang--auto-save-p) buffer-file-name "-"))))
254 (defun company-clang--candidates (prefix callback)
255 (and (company-clang--auto-save-p)
258 (when (null company-clang--prefix)
259 (company-clang-set-prefix (or (funcall company-clang-prefix-guesser)
261 (apply 'company-clang--start-process
264 (company-clang--build-complete-args (- (point) (length prefix)))))
266 (defun company-clang--prefix ()
267 (if company-clang-begin-after-member-access
268 (company-grab-symbol-cons "\\.\\|->\\|::" 2)
269 (company-grab-symbol)))
271 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
273 (defconst company-clang-required-version 1.1)
275 (defvar company-clang--version nil)
277 (defun company-clang--auto-save-p ()
278 (< company-clang--version 2.9))
280 (defsubst company-clang-version ()
281 "Return the version of `company-clang-executable'."
283 (call-process company-clang-executable nil t nil "--version")
284 (goto-char (point-min))
285 (if (re-search-forward "clang\\(?: version \\|-\\)\\([0-9.]+\\)" nil t)
286 (let ((ver (string-to-number (match-string-no-properties 1))))
292 (defun company-clang (command &optional arg &rest ignored)
293 "`company-mode' completion backend for Clang.
294 Clang is a parser for C and ObjC. Clang version 1.1 or newer is required.
296 Additional command line arguments can be specified in
297 `company-clang-arguments'. Prefix files (-include ...) can be selected
298 with `company-clang-set-prefix' or automatically through a custom
299 `company-clang-prefix-guesser'.
301 With Clang versions before 2.9, we have to save the buffer before
302 performing completion. With Clang 2.9 and later, buffer contents are
303 passed via standard input."
304 (interactive (list 'interactive))
306 (interactive (company-begin-backend 'company-clang))
307 (init (when (memq major-mode company-clang-modes)
308 (unless company-clang-executable
309 (error "Company found no clang executable"))
310 (setq company-clang--version (company-clang-version))
311 (when (< company-clang--version company-clang-required-version)
312 (error "Company requires clang version 1.1"))))
313 (prefix (and (memq major-mode company-clang-modes)
315 company-clang-executable
316 (not (company-in-string-or-comment))
317 (or (company-clang--prefix) 'stop)))
318 (candidates (cons :async
319 (lambda (cb) (company-clang--candidates arg cb))))
320 (meta (company-clang--meta arg))
321 (annotation (company-clang--annotation arg))
322 (post-completion (let ((anno (company-clang--annotation arg)))
323 (when (and company-clang-insert-arguments anno)
325 (if (string-match "\\`:[^:]" anno)
326 (company-clang-objc-templatify anno)
327 (company-template-c-like-templatify
328 (concat arg anno))))))))
330 (provide 'company-clang)
331 ;;; company-clang.el ends here