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Diffstat (limited to 'emacs.d/lisp/dir-locals.el')
| -rw-r--r-- | emacs.d/lisp/dir-locals.el | 183 |
1 files changed, 183 insertions, 0 deletions
diff --git a/emacs.d/lisp/dir-locals.el b/emacs.d/lisp/dir-locals.el new file mode 100644 index 0000000..f88457b --- /dev/null +++ b/emacs.d/lisp/dir-locals.el @@ -0,0 +1,183 @@ +;;; dir-locals.el --- Local variables for a directory tree + +;; Copyright (C) 2005, 2006 Free Software Foundation, Inc. + +;; Author: Dave Love <fx@gnu.org> +;; Keywords: files +;; $Revision: 1.7 $ +;; URL: http://www.loveshack.ukfsn.org/emacs + +;; This file is free software; you can redistribute it and/or modify +;; it under the terms of the GNU General Public License as published by +;; the Free Software Foundation; either version 2, or (at your option) +;; any later version. + +;; This file is distributed in the hope that it will be useful, +;; but WITHOUT ANY WARRANTY; without even the implied warranty of +;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +;; GNU General Public License for more details. + +;; You should have received a copy of the GNU General Public License +;; along with GNU Emacs; see the file COPYING. If not, write to +;; the Free Software Foundation, Inc., 59 Temple Place - Suite 330, +;; Boston, MA 02111-1307, USA. + +;;; Commentary: + +;; It can be useful to specify local variables directory-wide, e.g. to +;; define CC mode styles consistently. This library implements such a +;; scheme, controlled by the global minor mode `dir-locals-mode'. + +;; Place a file named `.emacs-locals' (or the value of +;; `dir-locals-file-name') in the directory root. This should specify +;; local variables in the usual way. The values it sets are inherited +;; when a file in the directory tree is found. Local variables +;; specified in the found file override the directory-wide ones. + +;; However, `eval' pseudo-variables specified in the file are +;; evaluated (assuming `enable-local-eval' is true) _before_ any +;; directory-wide processing, and they are evaluated in a scratch +;; buffer, so that they are only useful for side effects on local +;; variables. `mode' pseudo-variables which specify minor modes +;; toggle those modes for files within the directory. If +;; .emacs-locals specifies a major mode, it doesn't propagate, but any +;; local variables and minor modes its hook sets will; thus it should +;; normally not specify a major mode. The `coding' pseudo-variable +;; will not propagate from .emacs-locals. + +;; For example, with dir-locals mode on, placing this in .emacs-locals +;; at the top-level of the Linux source tree would set the C +;; indentation style appropriately for files within the tree: +;; +;; Local variables: +;; c-file-style: "linux" +;; End: +;; +;; (and ignore the stupid remarks in Documentation/CodingStyle). + +;; Another possible use is, say, setting change-log parameters in +;; different trees for which the Emacs 22 development source broke use +;; of change-log-mode-hook. + +;; NB: This doesn't work with some versions of the Emacs 22 codebase +;; which changed the way hack-local-variables-hook is run, but the +;; change has been reverted. + +;; Another, less clean, implementation of this sort of thing was +;; posted to gnu-emacs-sources as dirvals.el by Benjamin Rutt +;; <rutt.4@osu.edu>, June 2006, based on work by Matt Armstrong +;; <matt@lickey.com>. It uses a different format for the equivalent +;; of .emacs-locals. + +;;; Code: + +(defgroup dir-locals () + "Directory-wide file-local variables" + :link '(emacs-commentary-link "dir-locals") + :group 'files) + +(defcustom dir-locals-file-name ".emacs-locals" + "File name used by Dir-Locals mode to specify local variables. +This should specify local variables in the normal way. When Dir-Locals +minor mode is active, these will be inherited by files found in a +directory tree containing such a file at its root. + +This may also be a function of no arguments which returns the name to +use, allowing arbitrary per-directory customization of the +per-directory customization file on the basis of `default-directory'." + :group 'dir-locals + :type '(choice file function)) + +;; Adapted from dirvals.el. +(defcustom dir-locals-chase-remote nil + "Non-nil means search upwards for `dir-locals-file-name' in remote filesystem." + :group 'dir-locals + :type 'boolean) + +(define-minor-mode dir-locals-mode + "Toggle use of directory-wide file-local variables. +See `dir-locals-file-name'." + :global t + (if dir-locals-mode + (add-hook 'hack-local-variables-hook 'dir-locals-hack-local-variables) + (remove-hook 'hack-local-variables-hook + 'dir-locals-hack-local-variables))) + +;; Following find-change-log. Fixme: Should be abstracted from there. +(defun dir-locals-tree-find (file) + "Find FILE in the current directory or one of its parents. +If one is found, return its fully-qualified name, otherwise return +nil. + +FILE may be a string or a nullary function returning one on the basis +of `default-directory'." + (unless (and (not dir-locals-chase-remote) + (fboundp 'file-remote-p) ; not in Emacs 21 + (file-remote-p default-directory)) + (let* ((dir-name + ;; Chase links in the source file and start searching in + ;; the dir where it resides. + (or (if buffer-file-name + (file-name-directory (file-chase-links buffer-file-name))) + default-directory)) + (file (if (functionp file) + (funcall file) + file)) + (file1 (if (file-directory-p dir-name) + (expand-file-name file dir-name)))) + ;; Chase links before visiting the file. This makes it easier + ;; to use a file for several related directories. + (setq file1 (expand-file-name (file-chase-links file1))) + ;; Move up in the dir hierarchy till we find a suitable file. + (while (and (not (file-exists-p file1)) + (setq dir-name (file-name-directory + (directory-file-name + (file-name-directory file1)))) + ;; Give up if we are already at the root dir. + (not (string= (file-name-directory file1) dir-name))) + ;; Move up to the parent dir and try again. + (setq file1 (expand-file-name (file-name-nondirectory file) dir-name))) + (if (file-exists-p file1) + file1)))) + +(defun dir-locals-hack-local-variables () + "Set local variables from directory-wide values. +Inherit the local variables set in `dir-locals-file-name' if that is +found by `dir-locals-tree-find'. Ignore everything ignored by +`hack-local-variables'." + (let* ((file (dir-locals-tree-find dir-locals-file-name)) + (hack-local-variables-hook nil) + (buffer-file + (if buffer-file-name + (expand-file-name (file-chase-links buffer-file-name)))) + ;; Fixme: Probably condition-case this and ensure any error + ;; messages indicate the directory file. + (vars (when (and file + ;; Don't do it twice, so as to avoid + ;; repeating possible interactive queries. + (not (equal file buffer-file))) + (with-temp-buffer + ;; Make queries from `hack-local-variables' clearer. + (rename-buffer (file-name-nondirectory file) t) + (insert-file-contents file) + (let* ((locals (buffer-local-variables)) + (_ (hack-local-variables)) + (new-locals (buffer-local-variables))) + ;; Derive the list of new pairs. + (dolist (l locals) + (setq new-locals (delete l new-locals))) + ;; And some internals which get updated. + (dolist (l '(buffer-display-time buffer-display-count)) + (setq new-locals (assq-delete-all l new-locals))) + new-locals))))) + (dolist (v vars) + (let ((sym (car v))) + (unless (local-variable-p sym) ; file-locals take precedence + (if (and (string-match "-mode\\'" (symbol-name sym)) + (fboundp sym)) + (funcall sym) + (set (make-local-variable sym) (cdr v)))))))) + +(provide 'dir-locals) + +;;; dir-locals.el ends here |