code.delx.au - gnu-emacs-elpa/blob - company-clang.el

   1 ;;; company-clang.el --- company-mode completion back-end for Clang
   2
   3 ;; Copyright (C) 2009, 2011, 2013  Free Software Foundation, Inc.
   4
   5 ;; Author: Nikolaj Schumacher
   6
   7 ;; This file is part of GNU Emacs.
   8
   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.
  13
  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.
  18
  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/>.
  21
  22
  23 ;;; Commentary:
  24 ;;
  25
  26 ;;; Code:
  27
  28 (require 'company)
  29 (require 'company-template)
  30 (eval-when-compile (require 'cl))
  31
  32 (defgroup company-clang nil
  33   "Completion back-end for Clang."
  34   :group 'company)
  35
  36 (defcustom company-clang-executable
  37   (executable-find "clang")
  38   "Location of clang executable."
  39   :type 'file)
  40
  41 (defcustom company-clang-begin-after-member-access t
  42   "When non-nil, automatic completion will start whenever the current symbol
  43 is preceded by \".\" or \"->\", ignoring `company-minimum-prefix-length'.
  44
  45 If `company-begin-commands' is a list, it should include `c-electric-lt-gt'.")
  46
  47 (defcustom company-clang-arguments nil
  48   "Additional arguments to pass to clang when completing.
  49 Prefix files (-include ...) can be selected with
  50 `company-clang-set-prefix' or automatically through a custom
  51 `company-clang-prefix-guesser'."
  52   :type '(repeat (string :tag "Argument" nil)))
  53
  54 (defcustom company-clang-prefix-guesser 'company-clang-guess-prefix
  55   "A function to determine the prefix file for the current buffer."
  56   :type '(function :tag "Guesser function" nil))
  57
  58 (defvar company-clang-modes '(c-mode c++-mode objc-mode)
  59   "Major modes which clang may complete.")
  60
  61 ;; prefix ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
  62
  63 (defvar company-clang--prefix nil)
  64
  65 (defsubst company-clang--guess-pch-file (file)
  66   (let ((dir (directory-file-name (file-name-directory file))))
  67     (when (equal (file-name-nondirectory dir) "Classes")
  68       (setq dir (file-name-directory dir)))
  69     (car (directory-files dir t "\\([^.]h\\|[^h]\\).pch\\'" t))))
  70
  71 (defsubst company-clang--file-substring (file beg end)
  72   (with-temp-buffer
  73     (insert-file-contents-literally file nil beg end)
  74     (buffer-string)))
  75
  76 (defun company-clang-guess-prefix ()
  77   "Try to guess the prefix file for the current buffer."
  78   ;; Prefixes seem to be called .pch.  Pre-compiled headers do, too.
  79   ;; So we look at the magic number to rule them out.
  80   (let* ((file (company-clang--guess-pch-file buffer-file-name))
  81          (magic-number (and file (company-clang--file-substring file 0 4))))
  82     (unless (member magic-number '("CPCH" "gpch"))
  83       file)))
  84
  85 (defun company-clang-set-prefix (&optional prefix)
  86   "Use PREFIX as a prefix (-include ...) file for clang completion."
  87   (interactive (let ((def (funcall company-clang-prefix-guesser)))
  88      (unless (stringp def)
  89        (setq def default-directory))
  90      (list (read-file-name "Prefix file: "
  91                            (when def (file-name-directory def))
  92                            def t (when def (file-name-nondirectory def))))))
  93   ;; TODO: pre-compile?
  94   (setq company-clang--prefix (and (stringp prefix)
  95                                    (file-regular-p prefix)
  96                                    prefix)))
  97
  98 ;; Clean-up on exit.
  99 (add-hook 'kill-emacs-hook 'company-clang-set-prefix)
 100
 101 ;; parsing ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 102
 103 ;; TODO: Handle Pattern (syntactic hints would be neat).
 104 ;; Do we ever see OVERLOAD (or OVERRIDE)?
 105 (defconst company-clang--completion-pattern
 106   "^COMPLETION: \\_<\\(%s[a-zA-Z0-9_:]*\\)\\(?: : \\(.*\\)$\\)?$")
 107
 108 (defconst company-clang--error-buffer-name "*clang error*")
 109
 110 (defvar company-clang--meta-cache nil)
 111
 112 (defun company-clang--lang-option ()
 113      (if (eq major-mode 'objc-mode)
 114          (if (string= "m" (file-name-extension buffer-file-name))
 115              "objective-c" "objective-c++")
 116        (substring (symbol-name major-mode) 0 -5)))
 117
 118 (defun company-clang--parse-output (prefix objc)
 119   (goto-char (point-min))
 120   (let ((pattern (format company-clang--completion-pattern
 121                          (regexp-quote prefix)))
 122         (case-fold-search nil)
 123         lines match)
 124     (setq company-clang--meta-cache (make-hash-table :test 'equal))
 125     (while (re-search-forward pattern nil t)
 126       (setq match (match-string-no-properties 1))
 127       (unless (equal match "Pattern")
 128         (let ((meta (match-string-no-properties 2)))
 129           (when (and meta (not (string= match meta)))
 130             (setq meta (company-clang--strip-formatting meta))
 131             (when (and (not objc) (string-match "\\((.*)\\)" meta))
 132               (setq match (concat match (match-string 1 meta))))
 133             (puthash match meta company-clang--meta-cache)))
 134         (push match lines)))
 135     lines))
 136
 137 (defun company-clang--strip-formatting (text)
 138   (replace-regexp-in-string
 139    "#]" " "
 140    (replace-regexp-in-string "[<{[]#\\|#[>}]" "" text t)
 141    t))
 142
 143 (defun company-clang--handle-error (res args)
 144   (goto-char (point-min))
 145   (let* ((buf (get-buffer-create company-clang--error-buffer-name))
 146          (cmd (concat company-clang-executable (mapconcat 'identity args " ")))
 147          (pattern (format company-clang--completion-pattern ""))
 148          (err (if (re-search-forward pattern nil t)
 149                   (buffer-substring-no-properties (point-min)
 150                                                   (1- (match-beginning 0)))
 151                 ;; Warn the user more aggressively if no match was found.
 152                 (message "clang failed with error %d:\n%s" res cmd)
 153                 (buffer-string))))
 154
 155     (with-current-buffer buf
 156       (let ((inhibit-read-only t))
 157         (erase-buffer)
 158         (insert (current-time-string)
 159                 (format "\nclang failed with error %d:\n" res)
 160                 cmd "\n\n")
 161         (insert err)
 162         (setq buffer-read-only t)
 163         (goto-char (point-min))))))
 164
 165 (defun company-clang--call-process (prefix &rest args)
 166   (let ((objc (derived-mode-p 'objc-mode))
 167         (buf (get-buffer-create "*clang-output*"))
 168         res)
 169     (with-current-buffer buf (erase-buffer))
 170     (setq res (if (company-clang--auto-save-p)
 171                   (apply 'call-process company-clang-executable nil buf nil args)
 172                 (apply 'call-process-region (point-min) (point-max)
 173                        company-clang-executable nil buf nil args)))
 174     (with-current-buffer buf
 175       (unless (eq 0 res)
 176         (company-clang--handle-error res args))
 177       ;; Still try to get any useful input.
 178       (company-clang--parse-output prefix objc))))
 179
 180 (defsubst company-clang--build-location (pos)
 181   (save-excursion
 182     (goto-char pos)
 183     (format "%s:%d:%d"
 184             (if (company-clang--auto-save-p) buffer-file-name "-")
 185             (line-number-at-pos)
 186             (1+ (current-column)))))
 187
 188 (defsubst company-clang--build-complete-args (pos)
 189   (append '("-cc1" "-fsyntax-only" "-code-completion-macros")
 190           (unless (company-clang--auto-save-p)
 191             (list "-x" (company-clang--lang-option)))
 192           company-clang-arguments
 193           (when (stringp company-clang--prefix)
 194             (list "-include" (expand-file-name company-clang--prefix)))
 195           '("-code-completion-at")
 196           (list (company-clang--build-location pos))
 197           (list (if (company-clang--auto-save-p) buffer-file-name "-"))))
 198
 199 (defun company-clang--candidates (prefix)
 200   (and (company-clang--auto-save-p)
 201        (buffer-modified-p)
 202        (basic-save-buffer))
 203   (when (null company-clang--prefix)
 204     (company-clang-set-prefix (or (funcall company-clang-prefix-guesser)
 205                                   'none)))
 206   (apply 'company-clang--call-process
 207          prefix
 208          (company-clang--build-complete-args (- (point) (length prefix)))))
 209
 210 (defun company-clang--prefix ()
 211   (let ((symbol (company-grab-symbol)))
 212     (if symbol
 213         (if (and company-clang-begin-after-member-access
 214                  (save-excursion
 215                    (forward-char (- (length symbol)))
 216                    (looking-back "\\.\\|->" (- (point) 3))))
 217             (cons symbol t)
 218           symbol)
 219       'stop)))
 220
 221 ;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;;
 222
 223 (defconst company-clang-required-version 1.1)
 224
 225 (defvar company-clang--version nil)
 226
 227 (defun company-clang--auto-save-p ()
 228   (< company-clang--version 2.9))
 229
 230 (defsubst company-clang-version ()
 231   "Return the version of `company-clang-executable'."
 232   (with-temp-buffer
 233     (call-process company-clang-executable nil t nil "--version")
 234     (goto-char (point-min))
 235     (if (re-search-forward "clang\\(?: version \\|-\\)\\([0-9.]+\\)" nil t)
 236         (let ((ver (string-to-number (match-string-no-properties 1))))
 237           (if (> ver 100)
 238               (/ ver 100)
 239             ver))
 240       0)))
 241
 242 (defun company-clang-objc-templatify (selector)
 243   (let* ((end (point-marker))
 244          (beg (- (point) (length selector)))
 245          (templ (company-template-declare-template beg end))
 246          (cnt 0))
 247     (save-excursion
 248       (goto-char beg)
 249       (catch 'stop
 250         (while (search-forward ":" end t)
 251           (company-template-add-field templ (point) (format "arg%d" cnt))
 252           (if (< (point) end)
 253               (insert " ")
 254             (throw 'stop t))
 255           (incf cnt))))
 256     (company-template-move-to-first templ)))
 257
 258 (defun company-clang (command &optional arg &rest ignored)
 259   "`company-mode' completion back-end for Clang.
 260 Clang is a parser for C and ObjC.  Clang version 1.1 or newer is required.
 261
 262 Additional command line arguments can be specified in
 263 `company-clang-arguments'.  Prefix files (-include ...) can be selected
 264 with `company-clang-set-prefix' or automatically through a custom
 265 `company-clang-prefix-guesser'.
 266
 267 With Clang versions before 2.9, we have to save the buffer before performing
 268 completion.  With Clang 2.9 and later, buffer contents are passed via stardard
 269 input."
 270   (interactive (list 'interactive))
 271   (case command
 272     (interactive (company-begin-backend 'company-clang))
 273     (init (when (memq major-mode company-clang-modes)
 274             (unless company-clang-executable
 275               (error "Company found no clang executable"))
 276             (setq company-clang--version (company-clang-version))
 277             (when (< company-clang--version company-clang-required-version)
 278               (error "Company requires clang version 1.1"))))
 279     (prefix (and (memq major-mode company-clang-modes)
 280                  buffer-file-name
 281                  company-clang-executable
 282                  (not (company-in-string-or-comment))
 283                  (company-clang--prefix)))
 284     (candidates (company-clang--candidates arg))
 285     (meta (gethash arg company-clang--meta-cache))
 286     (crop (and (string-match ":\\|(" arg)
 287                (substring arg 0 (match-beginning 0))))
 288     (post-completion (cond
 289                       ((not (derived-mode-p 'objc-mode))
 290                        (company-template-c-like-templatify arg))
 291                       ((string-match ":" arg)
 292                        (company-clang-objc-templatify arg))))))
 293
 294 (provide 'company-clang)
 295 ;;; company-clang.el ends here