1 ;;; diff.el --- Run `diff' in compilation-mode.
3 ;; Copyright (C) 1992 Free Software Foundation, Inc.
5 ;; Keywords: 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.
25 ;; This package helps you explore differences between files, using the
26 ;; UNIX command diff(1). The commands are `diff' and `diff-backup'.
27 ;; You can specify options with `diff-switches'.
33 ;;; This is duplicated in vc.el.
34 (defvar diff-switches
"-c"
35 "*A string or list of strings specifying switches to be be passed to diff.")
37 (defvar diff-regexp-alist
39 ;; -u format: @@ -OLDSTART,OLDEND +NEWSTART,NEWEND @@
40 ("^@@ -\\([0-9]+\\),[0-9]+ \\+\\([0-9]+\\),[0-9]+ @@$" 1 2)
42 ;; -c format: *** OLDSTART,OLDEND ****
43 ("^\\*\\*\\* \\([0-9]+\\),[0-9]+ \\*\\*\\*\\*$" 1 nil
)
44 ;; --- NEWSTART,NEWEND ----
45 ("^--- \\([0-9]+\\),[0-9]+ ----$" nil
1)
47 ;; plain diff format: OLDSTART[,OLDEND]{a,d,c}NEWSTART[,NEWEND]
48 ("^\\([0-9]+\\)\\(,[0-9]+\\)?[adc]\\([0-9]+\\)\\(,[0-9]+\\)?$" 1 3)
50 ;; -e (ed) format: OLDSTART[,OLDEND]{a,d,c}
51 ("^\\([0-9]+\\)\\(,[0-9]+\\)?[adc]$" 1)
53 ;; -f format: {a,d,c}OLDSTART[ OLDEND]
54 ;; -n format: {a,d,c}OLDSTART LINES-CHANGED
55 ("^[adc]\\([0-9]+\\)\\( [0-9]+\\)?$" 1)
57 "Alist (REGEXP OLD-IDX NEW-IDX) of regular expressions to match difference
58 sections in \\[diff] output. If REGEXP matches, the OLD-IDX'th
59 subexpression gives the line number in the old file, and NEW-IDX'th
60 subexpression gives the line number in the new file. If OLD-IDX or NEW-IDX
61 is nil, REGEXP matches only half a section.")
63 (defvar diff-old-file nil
64 "This is the old file name in the comparison in this buffer.")
65 (defvar diff-new-file nil
66 "This is the new file name in the comparison in this buffer.")
67 (defvar diff-old-temp-file nil
68 "This is the name of a temp file to be deleted after diff finishes.")
69 (defvar diff-new-temp-file nil
70 "This is the name of a temp file to be deleted after diff finishes.")
72 ;; See compilation-parse-errors-function (compile.el).
73 (defun diff-parse-differences (limit-search find-at-least
)
74 (setq compilation-error-list nil
)
75 (message "Parsing differences...")
77 ;; Don't reparse diffs already seen at last parse.
78 (if compilation-parsing-end
(goto-char compilation-parsing-end
))
80 ;; Construct in REGEXP a regexp composed of all those in dired-regexp-alist.
81 (let ((regexp (mapconcat (lambda (elt)
82 (concat "\\(" (car elt
) "\\)"))
85 ;; (GROUP-IDX OLD-IDX NEW-IDX)
86 (groups (let ((subexpr 1))
94 (setq subexpr
(+ subexpr
1
95 (count-regexp-groupings
100 (function (lambda (file subexpr
)
101 (setq compilation-error-list
103 (cons (save-excursion
104 ;; Report location of message
105 ;; at beginning of line.
107 (match-beginning subexpr
))
110 ;; Report location of corresponding text.
111 (let ((line (string-to-int
113 (match-beginning subexpr
)
114 (match-end subexpr
)))))
116 (set-buffer (find-file-noselect file
))
120 compilation-error-list
)))))
126 (while (and (not found-desired
)
127 ;; We don't just pass LIMIT-SEARCH to re-search-forward
128 ;; because we want to find matches containing LIMIT-SEARCH
129 ;; but which extend past it.
130 (re-search-forward regexp nil t
))
132 ;; Find which individual regexp matched.
134 (while (and g
(null (match-beginning (car (car g
)))))
138 (if (nth 1 g
) ;OLD-IDX
139 (funcall new-error diff-old-file
(nth 1 g
)))
140 (if (nth 2 g
) ;NEW-IDX
141 (funcall new-error diff-new-file
(nth 2 g
)))
143 (setq num-loci-found
(1+ num-loci-found
))
144 (if (or (and find-at-least
145 (>= num-loci-found find-at-least
))
146 (and limit-search
(>= (point) limit-search
)))
147 ;; We have found as many new loci as the user wants,
148 ;; or the user wanted a specific diff, and we're past it.
149 (setq found-desired t
)))
151 (setq compilation-parsing-end
(point))
152 ;; Set to point-max, not point, so we don't perpetually
153 ;; parse the last bit of text when it isn't a diff header.
154 (setq compilation-parsing-end
(point-max)))
155 (message "Parsing differences...done"))
156 (setq compilation-error-list
(nreverse compilation-error-list
)))
159 (defun diff (old new
&optional switches
)
160 "Find and display the differences between OLD and NEW files.
161 Interactively the current buffer's file name is the default for for NEW
162 and a backup file for NEW is the default for OLD.
163 With prefix arg, prompt for diff switches."
169 (setq newf
(buffer-file-name)
170 newf
(if (and newf
(file-exists-p newf
))
172 (concat "Diff new file: ("
173 (file-name-nondirectory newf
) ") ")
175 (read-file-name "Diff new file: " nil nil t
)))
176 (setq oldf
(file-newest-backup newf
)
177 oldf
(if (and oldf
(file-exists-p oldf
))
179 (concat "Diff original file: ("
180 (file-name-nondirectory oldf
) ") ")
181 (file-name-directory oldf
) oldf t
)
182 (read-file-name "Diff original file: "
183 (file-name-directory newf
) nil t
))))))
184 (if current-prefix-arg
185 (list (read-string "Diff switches: "
186 (if (stringp diff-switches
)
188 (mapconcat 'identity diff-switches
" "))))
190 (setq new
(expand-file-name new
)
191 old
(expand-file-name old
))
192 (let ((old-alt (file-local-copy old
))
193 (new-alt (file-local-copy new
))
199 (if (consp diff-switches
)
201 (list diff-switches
))
202 (if (or old-alt new-alt
)
203 (list "-L" old
"-L" new
))
204 (list (or old-alt old
))
205 (list (or new-alt new
)))
208 (compile-internal command
209 "No more differences" "Diff"
210 'diff-parse-differences
))
213 (set (make-local-variable 'diff-old-file
) old
)
214 (set (make-local-variable 'diff-new-file
) new
)
215 (set (make-local-variable 'diff-old-temp-file
) old-alt
)
216 (set (make-local-variable 'diff-new-temp-file
) new-alt
)
217 (set (make-local-variable 'compilation-finish-function
)
218 (function (lambda (buff msg
)
219 (if diff-old-temp-file
220 (delete-file diff-old-temp-file
))
221 (if diff-new-temp-file
222 (delete-file diff-new-temp-file
))))))
226 (defun diff-backup (file &optional switches
)
227 "Diff this file with its backup file or vice versa.
228 Uses the latest backup, if there are several numerical backups.
229 If this file is a backup, diff it with its original.
230 The backup file is the first file given to `diff'."
231 (interactive (list (read-file-name "Diff (file with backup): ")
232 (if current-prefix-arg
233 (read-string "Diff switches: "
234 (if (stringp diff-switches
)
240 (if (backup-file-name-p file
)
242 ori
(file-name-sans-versions file
))
243 (setq bak
(or (diff-latest-backup-file file
)
244 (error "No backup found for %s" file
))
246 (diff bak ori switches
)))
248 (defun diff-latest-backup-file (fn) ; actually belongs into files.el
249 "Return the latest existing backup of FILE, or nil."
250 ;; First try simple backup, then the highest numbered of the
252 ;; Ignore the value of version-control because we look for existing
253 ;; backups, which maybe were made earlier or by another user with
254 ;; a different value of version-control.
255 (setq fn
(expand-file-name fn
))
257 (let ((bak (make-backup-file-name fn
)))
258 (if (file-exists-p bak
) bak
))
259 (let* ((dir (file-name-directory fn
))
260 (base-versions (concat (file-name-nondirectory fn
) ".~"))
261 (bv-length (length base-versions
)))
264 (file-name-all-completions base-versions dir
)
265 ;; bv-length is a fluid var for backup-extract-version:
268 (> (backup-extract-version fn1
)
269 (backup-extract-version fn2
))))))))))
273 ;;; diff.el ends here