Shorten menu description of "Other Display Specs" lispref node (Bug#7816).
[emacs.git] / lisp / ediff-merg.el
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1 ;;; ediff-merg.el --- merging utilities
3 ;; Copyright (C) 1994, 1995, 1996, 1997, 1998, 1999, 2000, 2001, 2002,
4 ;; 2003, 2004, 2005, 2006, 2007, 2008, 2009, 2010, 2011 Free Software Foundation, Inc.
6 ;; Author: Michael Kifer <kifer@cs.stonybrook.edu>
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 3 of the License, or
13 ;; (at your option) any later version.
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. If not, see <http://www.gnu.org/licenses/>.
23 ;;; Commentary:
25 ;;; Code:
28 ;; compiler pacifier
29 (defvar ediff-window-A)
30 (defvar ediff-window-B)
31 (defvar ediff-window-C)
32 (defvar ediff-merge-window-share)
33 (defvar ediff-window-config-saved)
35 (eval-when-compile
36 (require 'ediff-util))
37 ;; end pacifier
39 (require 'ediff-init)
41 (defcustom ediff-quit-merge-hook 'ediff-maybe-save-and-delete-merge
42 "Hooks to run before quitting a merge job.
43 The most common use is to save and delete the merge buffer."
44 :type 'hook
45 :group 'ediff-merge)
48 (defcustom ediff-default-variant 'combined
49 "The variant to be used as a default for buffer C in merging.
50 Valid values are the symbols `default-A', `default-B', and `combined'."
51 :type '(radio (const default-A) (const default-B) (const combined))
52 :group 'ediff-merge)
54 (defcustom ediff-combination-pattern
55 '("<<<<<<< variant A" A ">>>>>>> variant B" B "####### Ancestor" Ancestor "======= end")
56 "Pattern to be used for combining difference regions in buffers A and B.
57 The value must be a list of the form
58 \(STRING1 bufspec1 STRING2 bufspec2 STRING3 bufspec3 STRING4)
59 where bufspec is the symbol A, B, or Ancestor. For instance, if the value is
60 '(STRING1 A STRING2 Ancestor STRING3 B STRING4) then the
61 combined text will look like this:
63 STRING1
64 diff region from variant A
65 STRING2
66 diff region from the ancestor
67 STRING3
68 diff region from variant B
69 STRING4
71 :type '(choice (list string symbol string symbol string)
72 (list string symbol string symbol string symbol string))
73 :group 'ediff-merge)
75 (defcustom ediff-show-clashes-only nil
76 "If t, show only those diff regions where both buffers disagree with the ancestor.
77 This means that regions that have status prefer-A or prefer-B will be
78 skipped over. A value of nil means show all regions."
79 :type 'boolean
80 :group 'ediff-merge
82 (make-variable-buffer-local 'ediff-show-clashes-only)
84 (defcustom ediff-skip-merge-regions-that-differ-from-default nil
85 "If t, show only the regions that have not been changed by the user.
86 A region is considered to have been changed if it is different from the current
87 default (`default-A', `default-B', `combined') and it hasn't been marked as
88 `prefer-A' or `prefer-B'.
89 A region is considered to have been changed also when it is marked as
90 as `prefer-A', but is different from the corresponding difference region in
91 Buffer A or if it is marked as `prefer-B' and is different from the region in
92 Buffer B."
93 :type 'boolean
94 :group 'ediff-merge
96 (make-variable-buffer-local 'ediff-skip-merge-regions-that-differ-from-default)
98 ;; check if there is no clash between the ancestor and one of the variants.
99 ;; if it is not a merge job then return true
100 (defun ediff-merge-region-is-non-clash (n)
101 (if (ediff-merge-job)
102 (string-match "prefer" (or (ediff-get-state-of-merge n) ""))
105 ;; If ediff-show-clashes-only, check if there is no clash between the ancestor
106 ;; and one of the variants.
107 (defun ediff-merge-region-is-non-clash-to-skip (n)
108 (and (ediff-merge-job)
109 ediff-show-clashes-only
110 (ediff-merge-region-is-non-clash n)))
112 ;; If ediff-skip-changed-regions, check if the merge region differs from
113 ;; the current default. If a region is different from the default, it means
114 ;; that the user has made determination as to how to merge for this particular
115 ;; region.
116 (defun ediff-skip-merge-region-if-changed-from-default-p (n)
117 (and (ediff-merge-job)
118 ediff-skip-merge-regions-that-differ-from-default
119 (ediff-merge-changed-from-default-p n 'prefers-too)))
122 (defun ediff-get-combined-region (n)
123 (let ((pattern-list ediff-combination-pattern)
124 (combo-region "")
125 (err-msg
126 "ediff-combination-pattern: Invalid format. Please consult the documentation")
127 region-delim region-spec)
129 (if (< (length pattern-list) 5)
130 (error err-msg))
132 (while (> (length pattern-list) 2)
133 (setq region-delim (nth 0 pattern-list)
134 region-spec (nth 1 pattern-list))
135 (or (and (stringp region-delim) (memq region-spec '(A B Ancestor)))
136 (error err-msg))
138 (condition-case nil
139 (setq combo-region
140 (concat combo-region
141 region-delim "\n"
142 (ediff-get-region-contents
143 n region-spec ediff-control-buffer)))
144 (error ""))
145 (setq pattern-list (cdr (cdr pattern-list)))
148 (setq region-delim (nth 0 pattern-list))
149 (or (stringp region-delim)
150 (error err-msg))
151 (setq combo-region (concat combo-region region-delim "\n"))
154 ;;(defsubst ediff-make-combined-diff (regA regB)
155 ;; (concat (nth 0 ediff-combination-pattern) "\n"
156 ;; regA
157 ;; (nth 1 ediff-combination-pattern) "\n"
158 ;; regB
159 ;; (nth 2 ediff-combination-pattern) "\n"))
161 (defsubst ediff-set-state-of-all-diffs-in-all-buffers (ctl-buf)
162 (let ((n 0))
163 (while (< n ediff-number-of-differences)
164 (ediff-set-state-of-diff-in-all-buffers n ctl-buf)
165 (setq n (1+ n)))))
167 (defun ediff-set-state-of-diff-in-all-buffers (n ctl-buf)
168 (let ((regA (ediff-get-region-contents n 'A ctl-buf))
169 (regB (ediff-get-region-contents n 'B ctl-buf))
170 (regC (ediff-get-region-contents n 'C ctl-buf)))
171 (cond ((and (string= regA regB) (string= regA regC))
172 (ediff-set-state-of-diff n 'A "=diff(B)")
173 (ediff-set-state-of-diff n 'B "=diff(C)")
174 (ediff-set-state-of-diff n 'C "=diff(A)"))
175 ((string= regA regB)
176 (ediff-set-state-of-diff n 'A "=diff(B)")
177 (ediff-set-state-of-diff n 'B "=diff(A)")
178 (ediff-set-state-of-diff n 'C nil))
179 ((string= regA regC)
180 (ediff-set-state-of-diff n 'A "=diff(C)")
181 (ediff-set-state-of-diff n 'C "=diff(A)")
182 (ediff-set-state-of-diff n 'B nil))
183 ((string= regB regC)
184 (ediff-set-state-of-diff n 'C "=diff(B)")
185 (ediff-set-state-of-diff n 'B "=diff(C)")
186 (ediff-set-state-of-diff n 'A nil))
187 ((string= regC (ediff-get-combined-region n))
188 (ediff-set-state-of-diff n 'A nil)
189 (ediff-set-state-of-diff n 'B nil)
190 (ediff-set-state-of-diff n 'C "=diff(A+B)"))
191 (t (ediff-set-state-of-diff n 'A nil)
192 (ediff-set-state-of-diff n 'B nil)
193 (ediff-set-state-of-diff n 'C nil)))
196 (defun ediff-set-merge-mode ()
197 (normal-mode t)
198 (remove-hook 'local-write-file-hooks 'ediff-set-merge-mode))
201 ;; Go over all diffs starting with DIFF-NUM and copy regions into buffer C
202 ;; according to the state of the difference.
203 ;; Since ediff-copy-diff refuses to copy identical diff regions, there is
204 ;; no need to optimize ediff-do-merge any further.
206 ;; If re-merging, change state of merge in all diffs starting with
207 ;; DIFF-NUM, except those where the state is prefer-* or where it is
208 ;; `default-*' or `combined' but the buf C region appears to be modified
209 ;; since last set by default.
210 (defun ediff-do-merge (diff-num &optional remerging)
211 (if (< diff-num 0) (setq diff-num 0))
212 (let ((n diff-num)
213 ;;(default-state-of-merge (format "%S" ediff-default-variant))
214 do-not-copy state-of-merge)
215 (while (< n ediff-number-of-differences)
216 (setq do-not-copy nil) ; reset after each cycle
217 (if (= (mod n 10) 0)
218 (message "%s buffers A & B into C ... region %d of %d"
219 (if remerging "Re-merging" "Merging")
221 ediff-number-of-differences))
223 (setq state-of-merge (ediff-get-state-of-merge n))
225 (if remerging
226 ;;(let ((reg-A (ediff-get-region-contents n 'A ediff-control-buffer))
227 ;; (reg-B (ediff-get-region-contents n 'B ediff-control-buffer))
228 ;; (reg-C (ediff-get-region-contents n 'C ediff-control-buffer)))
229 (progn
231 ;; if region was edited since it was first set by default
232 (if (or (ediff-merge-changed-from-default-p n)
233 ;; was preferred
234 (string-match "prefer" state-of-merge))
235 ;; then ignore
236 (setq do-not-copy t))
238 ;; change state of merge for this diff, if necessary
239 (if (and (string-match "\\(default\\|combined\\)" state-of-merge)
240 (not do-not-copy))
241 (ediff-set-state-of-merge
242 n (format "%S" ediff-default-variant)))
245 ;; state-of-merge may have changed via ediff-set-state-of-merge, so
246 ;; check it once again
247 (setq state-of-merge (ediff-get-state-of-merge n))
249 (or do-not-copy
250 (if (string= state-of-merge "combined")
251 ;; use n+1 because ediff-combine-diffs works via user numbering
252 ;; of diffs, which is 1+ to what ediff uses internally
253 (ediff-combine-diffs (1+ n) 'batch)
254 (ediff-copy-diff
255 n (if (string-match "-A" state-of-merge) 'A 'B) 'C 'batch)))
256 (setq n (1+ n)))
257 (message "Merging buffers A & B into C ... Done")
261 (defun ediff-re-merge ()
262 "Remerge unmodified diff regions using a new default. Start with the current region."
263 (interactive)
264 (let* ((default-variant-alist
265 (list '("default-A") '("default-B") '("combined")))
266 (actual-alist
267 (delete (list (symbol-name ediff-default-variant))
268 default-variant-alist)))
269 (setq ediff-default-variant
270 (intern
271 (completing-read
272 (format "Current merge default is `%S'. New default: "
273 ediff-default-variant)
274 actual-alist nil 'must-match)))
275 (ediff-do-merge ediff-current-difference 'remerge)
276 (ediff-recenter)
279 (defun ediff-shrink-window-C (arg)
280 "Shrink window C to just one line.
281 With a prefix argument, returns window C to its normal size.
282 Used only for merging jobs."
283 (interactive "P")
284 (if (not ediff-merge-job)
285 (error "ediff-shrink-window-C can be used only for merging jobs"))
286 (cond ((eq arg '-) (setq arg -1))
287 ((not (numberp arg)) (setq arg nil)))
288 (cond ((null arg)
289 (let ((ediff-merge-window-share
290 (if (< (window-height ediff-window-C) 3)
291 ediff-merge-window-share 0)))
292 (setq ediff-window-config-saved "") ; force redisplay
293 (ediff-recenter 'no-rehighlight)))
294 ((and (< arg 0) (> (window-height ediff-window-C) 2))
295 (setq ediff-merge-window-share (* ediff-merge-window-share 0.9))
296 (setq ediff-window-config-saved "") ; force redisplay
297 (ediff-recenter 'no-rehighlight))
298 ((and (> arg 0) (> (window-height ediff-window-A) 2))
299 (setq ediff-merge-window-share (* ediff-merge-window-share 1.1))
300 (setq ediff-window-config-saved "") ; force redisplay
301 (ediff-recenter 'no-rehighlight))))
304 ;; N here is the user's region number. It is 1+ what Ediff uses internally.
305 (defun ediff-combine-diffs (n &optional batch-invocation)
306 "Combine Nth diff regions of buffers A and B and place the combination in C.
307 N is a prefix argument. If nil, combine the current difference regions.
308 Combining is done according to the specifications in variable
309 `ediff-combination-pattern'."
310 (interactive "P")
311 (setq n (if (numberp n) (1- n) ediff-current-difference))
313 (let (reg-combined)
314 ;;(setq regA (ediff-get-region-contents n 'A ediff-control-buffer)
315 ;; regB (ediff-get-region-contents n 'B ediff-control-buffer))
316 ;;(setq reg-combined (ediff-make-combined-diff regA regB))
317 (setq reg-combined (ediff-get-combined-region n))
319 (ediff-copy-diff n nil 'C batch-invocation reg-combined))
320 (or batch-invocation (ediff-jump-to-difference (1+ n))))
323 ;; Checks if the region in buff C looks like a combination of the regions
324 ;; in buffers A and B. Return a list (reg-a-beg reg-a-end reg-b-beg reg-b-end)
325 ;; These refer to where the delimiters for region A, B, Ancestor start and end
326 ;; in buffer C
327 (defun ediff-looks-like-combined-merge (region-num)
328 (if ediff-merge-job
329 (let ((combined (string-match (regexp-quote "(A+B)")
330 (or (ediff-get-state-of-diff region-num 'C)
331 "")))
332 (mrgreg-beg (ediff-get-diff-posn 'C 'beg region-num))
333 (mrgreg-end (ediff-get-diff-posn 'C 'end region-num))
334 (pattern-list ediff-combination-pattern)
335 delim reg-beg reg-end delim-regs-list)
337 (if combined
338 (ediff-with-current-buffer ediff-buffer-C
339 (while pattern-list
340 (goto-char mrgreg-beg)
341 (setq delim (nth 0 pattern-list))
342 (search-forward delim mrgreg-end 'noerror)
343 (setq reg-beg (match-beginning 0))
344 (setq reg-end (match-end 0))
345 (if (and reg-beg reg-end)
346 (setq delim-regs-list
347 ;; in reverse
348 (cons reg-end (cons reg-beg delim-regs-list))))
349 (if (> (length pattern-list) 1)
350 (setq pattern-list (cdr (cdr pattern-list)))
351 (setq pattern-list nil))
354 (reverse delim-regs-list)
357 (defvar state-of-merge) ; dynamic var
359 ;; Check if the non-preferred merge has been modified since originally set.
360 ;; This affects only the regions that are marked as default-A/B or combined.
361 ;; If PREFERS-TOO is non-nil, then look at the regions marked as prefers-A/B as
362 ;; well.
363 (defun ediff-merge-changed-from-default-p (diff-num &optional prefers-too)
364 (let ((reg-A (ediff-get-region-contents diff-num 'A ediff-control-buffer))
365 (reg-B (ediff-get-region-contents diff-num 'B ediff-control-buffer))
366 (reg-C (ediff-get-region-contents diff-num 'C ediff-control-buffer)))
368 (setq state-of-merge (ediff-get-state-of-merge diff-num))
370 ;; if region was edited since it was first set by default
371 (or (and (string= state-of-merge "default-A")
372 (not (string= reg-A reg-C)))
373 (and (string= state-of-merge "default-B")
374 (not (string= reg-B reg-C)))
375 (and (string= state-of-merge "combined")
376 ;;(not (string= (ediff-make-combined-diff reg-A reg-B) reg-C)))
377 (not (string= (ediff-get-combined-region diff-num) reg-C)))
378 (and prefers-too
379 (string= state-of-merge "prefer-A")
380 (not (string= reg-A reg-C)))
381 (and prefers-too
382 (string= state-of-merge "prefer-B")
383 (not (string= reg-B reg-C)))
387 (provide 'ediff-merg)
390 ;; Local Variables:
391 ;; eval: (put 'ediff-defvar-local 'lisp-indent-hook 'defun)
392 ;; eval: (put 'ediff-with-current-buffer 'lisp-indent-hook 1)
393 ;; eval: (put 'ediff-with-current-buffer 'edebug-form-spec '(form body))
394 ;; End:
396 ;; arch-tag: 9b798cf9-02ba-487f-a62e-b63aa823dbfb
397 ;;; ediff-merg.el ends here