1 ;;; diff.el --- run `diff' in compilation-mode
3 ;; Copyright (C) 1992, 1994, 1996, 2001 Free Software Foundation, Inc.
6 ;; Keywords: unix, tools
8 ;; This file is part of GNU Emacs.
10 ;; GNU Emacs is free software; you can redistribute it and/or modify
11 ;; it under the terms of the GNU General Public License as published by
12 ;; the Free Software Foundation; either version 2, or (at your option)
15 ;; GNU Emacs is distributed in the hope that it will be useful,
16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
18 ;; GNU General Public License for more details.
20 ;; You should have received a copy of the GNU General Public License
21 ;; along with GNU Emacs; see the file COPYING. If not, write to the
22 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
23 ;; Boston, MA 02111-1307, USA.
27 ;; This package helps you explore differences between files, using the
28 ;; UNIX command diff(1). The commands are `diff' and `diff-backup'.
29 ;; You can specify options with `diff-switches'.
36 "Comparing files with `diff'."
40 (defcustom diff-switches
"-c"
41 "*A string or list of strings specifying switches to be be passed to diff."
42 :type
'(choice string
(repeat string
))
46 (defcustom diff-command
"diff"
47 "*The command to use to run diff."
51 (defvar diff-regexp-alist
53 ;; -u format: @@ -OLDSTART,OLDEND +NEWSTART,NEWEND @@
54 ("^@@ -\\([0-9]+\\),[0-9]+ \\+\\([0-9]+\\),[0-9]+ @@$" 1 2)
56 ;; -c format: *** OLDSTART,OLDEND ****
57 ("^\\*\\*\\* \\([0-9]+\\),[0-9]+ \\*\\*\\*\\*$" 1 nil
)
58 ;; --- NEWSTART,NEWEND ----
59 ("^--- \\([0-9]+\\),[0-9]+ ----$" nil
1)
61 ;; plain diff format: OLDSTART[,OLDEND]{a,d,c}NEWSTART[,NEWEND]
62 ("^\\([0-9]+\\)\\(,[0-9]+\\)?[adc]\\([0-9]+\\)\\(,[0-9]+\\)?$" 1 3)
64 ;; -e (ed) format: OLDSTART[,OLDEND]{a,d,c}
65 ("^\\([0-9]+\\)\\(,[0-9]+\\)?[adc]$" 1)
67 ;; -f format: {a,d,c}OLDSTART[ OLDEND]
68 ;; -n format: {a,d,c}OLDSTART LINES-CHANGED
69 ("^[adc]\\([0-9]+\\)\\( [0-9]+\\)?$" 1)
71 "Alist of regular expressions to match difference sections in \\[diff] output.
72 Each element has the form (REGEXP OLD-IDX NEW-IDX).
73 Any text that REGEXP matches identifies one difference hunk
74 or the header of a hunk.
76 The OLD-IDX'th subexpression of REGEXP gives the line number
77 in the old file, and NEW-IDX'th subexpression gives the line number
78 in the new file. If OLD-IDX or NEW-IDX
79 is nil, REGEXP matches only half a hunk.")
81 (defvar diff-old-file nil
82 "This is the old file name in the comparison in this buffer.")
83 (defvar diff-new-file nil
84 "This is the new file name in the comparison in this buffer.")
85 (defvar diff-old-temp-file nil
86 "This is the name of a temp file to be deleted after diff finishes.")
87 (defvar diff-new-temp-file nil
88 "This is the name of a temp file to be deleted after diff finishes.")
90 ;; See compilation-parse-errors-function (compile.el).
91 (defun diff-parse-differences (limit-search find-at-least
)
92 (setq compilation-error-list nil
)
93 (message "Parsing differences...")
95 ;; Don't reparse diffs already seen at last parse.
96 (if compilation-parsing-end
(goto-char compilation-parsing-end
))
98 ;; Construct in REGEXP a regexp composed of all those in dired-regexp-alist.
99 (let ((regexp (mapconcat (lambda (elt)
100 (concat "\\(" (car elt
) "\\)"))
103 ;; (GROUP-IDX OLD-IDX NEW-IDX)
104 (groups (let ((subexpr 1))
105 (mapcar (lambda (elt)
112 (setq subexpr
(+ subexpr
1
113 (count-regexp-groupings
118 (function (lambda (file subexpr
)
119 (setq compilation-error-list
121 (list (save-excursion
122 ;; Report location of message
123 ;; at beginning of line.
125 (match-beginning subexpr
))
128 ;; Report location of corresponding text.
132 (match-beginning subexpr
)
133 (match-end subexpr
)))
135 compilation-error-list
)))))
141 (while (and (not found-desired
)
142 ;; We don't just pass LIMIT-SEARCH to re-search-forward
143 ;; because we want to find matches containing LIMIT-SEARCH
144 ;; but which extend past it.
145 (re-search-forward regexp nil t
))
147 ;; Find which individual regexp matched.
149 (while (and g
(null (match-beginning (car (car g
)))))
153 (if (nth 1 g
) ;OLD-IDX
154 (funcall new-error diff-old-file
(nth 1 g
)))
155 (if (nth 2 g
) ;NEW-IDX
156 (funcall new-error diff-new-file
(nth 2 g
)))
158 (setq num-loci-found
(1+ num-loci-found
))
159 (if (or (and find-at-least
160 (>= num-loci-found find-at-least
))
161 (and limit-search
(>= (point) limit-search
)))
162 ;; We have found as many new loci as the user wants,
163 ;; or the user wanted a specific diff, and we're past it.
164 (setq found-desired t
)))
165 (set-marker compilation-parsing-end
166 (if found-desired
(point)
167 ;; Set to point-max, not point, so we don't perpetually
168 ;; parse the last bit of text when it isn't a diff header.
170 (message "Parsing differences...done"))
171 (setq compilation-error-list
(nreverse compilation-error-list
)))
173 (defun diff-process-setup ()
174 "Set up \`compilation-exit-message-function' for \`diff'."
175 ;; Avoid frightening people with "abnormally terminated"
176 ;; if diff finds differences.
177 (set (make-local-variable 'compilation-exit-message-function
)
178 (lambda (status code msg
)
179 (cond ((not (eq status
'exit
))
182 '("finished (no differences)\n" .
"no differences"))
184 '("finished\n" .
"differences found"))
189 (defun diff (old new
&optional switches no-async
)
190 "Find and display the differences between OLD and NEW files.
191 Interactively the current buffer's file name is the default for NEW
192 and a backup file for NEW is the default for OLD.
193 With prefix arg, prompt for diff switches.
194 If NO-ASYNC is non-nil, call diff synchronously."
200 (setq newf
(buffer-file-name)
201 newf
(if (and newf
(file-exists-p newf
))
203 (concat "Diff new file: (default "
204 (file-name-nondirectory newf
) ") ")
206 (read-file-name "Diff new file: " nil nil t
)))
207 (setq oldf
(file-newest-backup newf
)
208 oldf
(if (and oldf
(file-exists-p oldf
))
210 (concat "Diff original file: (default "
211 (file-name-nondirectory oldf
) ") ")
212 (file-name-directory oldf
) oldf t
)
213 (read-file-name "Diff original file: "
214 (file-name-directory newf
) nil t
))))))
215 (if current-prefix-arg
216 (list (read-string "Diff switches: "
217 (if (stringp diff-switches
)
219 (mapconcat 'identity diff-switches
" "))))
221 (setq new
(expand-file-name new
)
222 old
(expand-file-name old
))
223 (let ((old-alt (file-local-copy old
))
224 (new-alt (file-local-copy new
))
227 (let ((compilation-process-setup-function 'diff-process-setup
)
230 (append (list diff-command
)
231 ;; Use explicitly specified switches
234 switches
(list switches
))
235 ;; If not specified, use default.
236 (if (consp diff-switches
)
238 (list diff-switches
)))
239 (if (or old-alt new-alt
)
240 (list "-L" old
"-L" new
))
242 (shell-quote-argument (or old-alt old
)))
244 (shell-quote-argument (or new-alt new
))))
247 (compile-internal command
248 "No more differences" "Diff"
249 'diff-parse-differences
250 nil nil nil nil nil nil no-async
))
252 (set (make-local-variable 'diff-old-file
) old
)
253 (set (make-local-variable 'diff-new-file
) new
)
254 (set (make-local-variable 'diff-old-temp-file
) old-alt
)
255 (set (make-local-variable 'diff-new-temp-file
) new-alt
)
256 (set (make-local-variable 'compilation-finish-function
)
257 (function (lambda (buff msg
)
258 (if diff-old-temp-file
259 (delete-file diff-old-temp-file
))
260 (if diff-new-temp-file
261 (delete-file diff-new-temp-file
)))))
262 ;; When async processes aren't available, the compilation finish
263 ;; function doesn't get chance to run. Invoke it by hand.
264 (or (fboundp 'start-process
)
265 (funcall compilation-finish-function nil nil
))
269 (defun diff-backup (file &optional switches
)
270 "Diff this file with its backup file or vice versa.
271 Uses the latest backup, if there are several numerical backups.
272 If this file is a backup, diff it with its original.
273 The backup file is the first file given to `diff'."
274 (interactive (list (read-file-name "Diff (file with backup): ")
275 (if current-prefix-arg
276 (read-string "Diff switches: "
277 (if (stringp diff-switches
)
283 (if (backup-file-name-p file
)
285 ori
(file-name-sans-versions file
))
286 (setq bak
(or (diff-latest-backup-file file
)
287 (error "No backup found for %s" file
))
289 (diff bak ori switches
)))
291 (defun diff-latest-backup-file (fn) ; actually belongs into files.el
292 "Return the latest existing backup of FILE, or nil."
293 (let ((handler (find-file-name-handler fn
'diff-latest-backup-file
)))
295 (funcall handler
'diff-latest-backup-file fn
)
296 (file-newest-backup fn
))))
300 ;;; arch-tag: 7de2c29b-7ea5-4b85-9b9d-72dd860de2bd
301 ;;; diff.el ends here