1 ;;; diff.el --- Run `diff' in compilation-mode.
3 ;; Copyright (C) 1992 Free Software Foundation, Inc.
5 ;; Keyword: unix, tools
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 2, or (at your option)
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; see the file COPYING. If not, write to
21 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
27 (defvar diff-switches "-c"
28 "*A string or list of strings specifying switches to be be passed to diff.")
30 (defvar diff-regexp-alist
32 ;; -u format: @@ -OLDSTART,OLDEND +NEWSTART,NEWEND @@
33 ("^@@ -\\([0-9]+\\),[0-9]+ \\+\\([0-9]+\\),[0-9]+ @@$" 1 2)
35 ;; -c format: *** OLDSTART,OLDEND ****
36 ("^\\*\\*\\* \\([0-9]+\\),[0-9]+ \\*\\*\\*\\*$" 1 nil)
37 ;; --- NEWSTART,NEWEND ----
38 ("^--- \\([0-9]+\\),[0-9]+ ----$" nil 1)
40 ;; plain diff format: OLDSTART[,OLDEND]{a,d,c}NEWSTART[,NEWEND]
41 ("^\\([0-9]+\\)\\(,[0-9]+\\)?[adc]\\([0-9]+\\)\\(,[0-9]+\\)?$" 1 3)
43 ;; -e (ed) format: OLDSTART[,OLDEND]{a,d,c}
44 ("^\\([0-9]+\\)\\(,[0-9]+\\)?[adc]$" 1)
46 ;; -f format: {a,d,c}OLDSTART[ OLDEND]
47 ;; -n format: {a,d,c}OLDSTART LINES-CHANGED
48 ("^[adc]\\([0-9]+\\)\\( [0-9]+\\)?$" 1)
50 "Alist (REGEXP OLD-IDX NEW-IDX) of regular expressions to match difference
51 sections in \\[diff] output. If REGEXP matches, the OLD-IDX'th
52 subexpression gives the line number in the old file, and NEW-IDX'th
53 subexpression gives the line number in the new file. If OLD-IDX or NEW-IDX
54 is nil, REGEXP matches only half a section.")
56 (defvar diff-old-file nil
57 "This is the old file name in the comparison in this buffer.")
58 (defvar diff-new-file nil
59 "This is the new file name in the comparison in this buffer.")
60 (defvar diff-old-temp-file nil
61 "This is the name of a temp file to be deleted after diff finishes.")
62 (defvar diff-new-temp-file nil
63 "This is the name of a temp file to be deleted after diff finishes.")
65 ;; See compilation-parse-errors-function (compile.el).
66 (defun diff-parse-differences (limit-search find-at-least)
67 (setq compilation-error-list nil)
68 (message "Parsing differences...")
70 ;; Don't reparse diffs already seen at last parse.
71 (goto-char compilation-parsing-end)
73 ;; Construct in REGEXP a regexp composed of all those in dired-regexp-alist.
74 (let ((regexp (mapconcat (lambda (elt)
75 (concat "\\(" (car elt) "\\)"))
78 ;; (GROUP-IDX OLD-IDX NEW-IDX)
79 (groups (let ((subexpr 1))
87 (setq subexpr (+ subexpr 1
88 (count-regexp-groupings
93 (function (lambda (file subexpr)
94 (setq compilation-error-list
97 ;; Report location of message
98 ;; at beginning of line.
100 (match-beginning subexpr))
103 ;; Report location of corresponding text.
104 (let ((line (string-to-int
106 (match-beginning subexpr)
107 (match-end subexpr)))))
109 (set-buffer (find-file-noselect file))
113 compilation-error-list)))))
119 (while (and (not found-desired)
120 ;; We don't just pass LIMIT-SEARCH to re-search-forward
121 ;; because we want to find matches containing LIMIT-SEARCH
122 ;; but which extend past it.
123 (re-search-forward regexp nil t))
125 ;; Find which individual regexp matched.
127 (while (and g (null (match-beginning (car (car g)))))
131 (if (nth 1 g) ;OLD-IDX
132 (funcall new-error diff-old-file (nth 1 g)))
133 (if (nth 2 g) ;NEW-IDX
134 (funcall new-error diff-new-file (nth 2 g)))
136 (setq num-loci-found (1+ num-loci-found))
137 (if (or (and find-at-least
138 (>= num-loci-found find-at-least))
139 (and limit-search (>= (point) limit-search)))
140 ;; We have found as many new loci as the user wants,
141 ;; or the user wanted a specific diff, and we're past it.
142 (setq found-desired t)))
144 (setq compilation-parsing-end (point))
145 ;; Set to point-max, not point, so we don't perpetually
146 ;; parse the last bit of text when it isn't a diff header.
147 (setq compilation-parsing-end (point-max)))
148 (message "Parsing differences...done"))
149 (setq compilation-error-list (nreverse compilation-error-list)))
152 (defun diff (old new &optional switches)
153 "Find and display the differences between OLD and NEW files.
154 Interactively the current buffer's file name is the default for for NEW
155 and a backup file for NEW is the default for OLD.
156 With prefix arg, prompt for diff switches."
162 (setq newf (buffer-file-name)
163 newf (if (and newf (file-exists-p newf))
165 (concat "Diff new file: ("
166 (file-name-nondirectory newf) ") ")
168 (read-file-name "Diff new file: " nil nil t)))
169 (setq oldf (file-newest-backup newf)
170 oldf (if (and oldf (file-exists-p oldf))
172 (concat "Diff original file: ("
173 (file-name-nondirectory oldf) ") ")
174 (file-name-directory oldf) oldf t)
175 (read-file-name "Diff original file: "
176 (file-name-directory newf) nil t))))))
177 (if current-prefix-arg
178 (list (read-string "Diff switches: "
179 (if (stringp diff-switches)
181 (mapconcat 'identity diff-switches " "))))
183 (setq new (expand-file-name new)
184 old (expand-file-name old))
185 (let ((old-alt (file-local-copy old))
186 (new-alt (file-local-copy new))
192 (if (consp diff-switches)
194 (list diff-switches))
195 (if (or old-alt new-alt)
196 (list "-L" old "-L" new))
197 (list (or old-alt old))
198 (list (or new-alt new)))
201 (compile-internal command
202 "No more differences" "Diff"
203 'diff-parse-differences))
206 (set (make-local-variable 'diff-old-file) old)
207 (set (make-local-variable 'diff-new-file) new)
208 (set (make-local-variable 'diff-old-temp-file) old-alt)
209 (set (make-local-variable 'diff-new-temp-file) new-alt)
210 (set (make-local-variable 'compilation-finish-function)
211 (function (lambda (buff msg)
212 (if diff-old-temp-file
213 (delete-file diff-old-temp-file))
214 (if diff-new-temp-file
215 (delete-file diff-new-temp-file))))))
219 (defun diff-backup (file &optional switches)
220 "Diff this file with its backup file or vice versa.
221 Uses the latest backup, if there are several numerical backups.
222 If this file is a backup, diff it with its original.
223 The backup file is the first file given to `diff'."
224 (interactive (list (read-file-name "Diff (file with backup): ")
225 (if current-prefix-arg
226 (read-string "Diff switches: "
227 (if (stringp diff-switches)
233 (if (backup-file-name-p file)
235 ori (file-name-sans-versions file))
236 (setq bak (or (diff-latest-backup-file file)
237 (error "No backup found for %s" file))
239 (diff bak ori switches)))
241 (defun diff-latest-backup-file (fn) ; actually belongs into files.el
242 "Return the latest existing backup of FILE, or nil."
243 ;; First try simple backup, then the highest numbered of the
245 ;; Ignore the value of version-control because we look for existing
246 ;; backups, which maybe were made earlier or by another user with
247 ;; a different value of version-control.
248 (setq fn (expand-file-name fn))
250 (let ((bak (make-backup-file-name fn)))
251 (if (file-exists-p bak) bak))
252 (let* ((dir (file-name-directory fn))
253 (base-versions (concat (file-name-nondirectory fn) ".~"))
254 (bv-length (length base-versions)))
257 (file-name-all-completions base-versions dir)
258 ;; bv-length is a fluid var for backup-extract-version:
261 (> (backup-extract-version fn1)
262 (backup-extract-version fn2))))))))))
264 ;;; diff.el ends here