lisp/vc/ediff-merg.el

   1 ;;; ediff-merg.el --- merging utilities
   2
   3 ;; Copyright (C) 1994-2018 Free Software Foundation, Inc.
   4
   5 ;; Author: Michael Kifer <kifer@cs.stonybrook.edu>
   6 ;; Package: ediff
   7
   8 ;; This file is part of GNU Emacs.
   9
  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.
  14
  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.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs.  If not, see <https://www.gnu.org/licenses/>.
  22
  23 ;;; Commentary:
  24
  25 ;;; Code:
  26
  27
  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)
  34
  35 (require 'ediff-init)
  36 (require 'ediff-util)
  37
  38 (defcustom ediff-quit-merge-hook 'ediff-maybe-save-and-delete-merge
  39   "Hooks to run before quitting a merge job.
  40 The most common use is to save and delete the merge buffer."
  41   :type 'hook
  42   :group 'ediff-merge)
  43
  44
  45 (defcustom ediff-default-variant 'combined
  46   "The variant to be used as a default for buffer C in merging.
  47 Valid values are the symbols `default-A', `default-B', and `combined'."
  48   :type '(radio (const default-A) (const default-B) (const combined))
  49   :group 'ediff-merge)
  50
  51 (defcustom ediff-combination-pattern
  52   '("<<<<<<< variant A" A ">>>>>>> variant B" B  "####### Ancestor" Ancestor "======= end")
  53   "Pattern to be used for combining difference regions in buffers A and B.
  54 The value must be a list of the form
  55 \(STRING1 bufspec1  STRING2 bufspec2 STRING3 bufspec3 STRING4)
  56 where bufspec is the symbol A, B, or Ancestor. For instance, if the value is
  57 '(STRING1 A  STRING2 Ancestor STRING3 B STRING4) then the
  58 combined text will look like this:
  59
  60 STRING1
  61 diff region from variant A
  62 STRING2
  63 diff region from the ancestor
  64 STRING3
  65 diff region from variant B
  66 STRING4
  67 "
  68   :type '(choice (list string symbol string symbol string)
  69                  (list string symbol string symbol string symbol string))
  70   :group 'ediff-merge)
  71
  72 (defcustom ediff-show-clashes-only nil
  73   "If t, show only those diff regions where both buffers disagree with the ancestor.
  74 This means that regions that have status prefer-A or prefer-B will be
  75 skipped over.  A value of nil means show all regions."
  76   :type 'boolean
  77   :group 'ediff-merge
  78   )
  79 (make-variable-buffer-local 'ediff-show-clashes-only)
  80
  81 (defcustom ediff-skip-merge-regions-that-differ-from-default nil
  82   "If t, show only the regions that have not been changed by the user.
  83 A region is considered to have been changed if it is different from the current
  84 default (`default-A', `default-B', `combined') and it hasn't been marked as
  85 `prefer-A' or `prefer-B'.
  86 A region is considered to have been changed also when it is marked as
  87 `prefer-A', but is different from the corresponding difference region in
  88 Buffer A or if it is marked as `prefer-B' and is different from the region in
  89 Buffer B."
  90   :type 'boolean
  91   :group 'ediff-merge
  92   )
  93 (make-variable-buffer-local 'ediff-skip-merge-regions-that-differ-from-default)
  94
  95 (defvar state-of-merge)                 ; dynamic var
  96
  97 ;; check if there is no clash between the ancestor and one of the variants.
  98 ;; if it is not a merge job then return true
  99 (defun ediff-merge-region-is-non-clash (n)
 100   (if (ediff-merge-job)
 101       (string-match "prefer" (or (ediff-get-state-of-merge n) ""))
 102     t))
 103
 104 ;; If ediff-show-clashes-only, check if there is no clash between the ancestor
 105 ;; and one of the variants.
 106 (defun ediff-merge-region-is-non-clash-to-skip (n)
 107   (and (ediff-merge-job)
 108        ediff-show-clashes-only
 109        (ediff-merge-region-is-non-clash n)))
 110
 111 ;; If ediff-skip-changed-regions, check if the merge region differs from
 112 ;; the current default. If a region is different from the default, it means
 113 ;; that the user has made determination as to how to merge for this particular
 114 ;; region.
 115 (defun ediff-skip-merge-region-if-changed-from-default-p (n)
 116   (and (ediff-merge-job)
 117        ediff-skip-merge-regions-that-differ-from-default
 118        (ediff-merge-changed-from-default-p n 'prefers-too)))
 119
 120
 121 (defun ediff-get-combined-region (n)
 122   (let ((pattern-list ediff-combination-pattern)
 123         (combo-region "")
 124         (err-msg
 125          "ediff-combination-pattern: Invalid format. Please consult the documentation")
 126         region-delim region-spec)
 127
 128     (if (< (length pattern-list) 5)
 129         (error err-msg))
 130
 131     (while (> (length pattern-list) 2)
 132       (setq region-delim (nth 0 pattern-list)
 133             region-spec (nth 1 pattern-list))
 134       (or (and (stringp region-delim) (memq region-spec '(A B Ancestor)))
 135           (error err-msg))
 136
 137       (condition-case nil
 138           (setq combo-region
 139                 (concat combo-region
 140                         region-delim "\n"
 141                         (ediff-get-region-contents
 142                          n region-spec ediff-control-buffer)))
 143         (error ""))
 144       (setq pattern-list (cdr (cdr pattern-list)))
 145       )
 146
 147     (setq region-delim (nth 0 pattern-list))
 148     (or (stringp region-delim)
 149         (error err-msg))
 150     (setq combo-region (concat combo-region region-delim "\n"))
 151   ))
 152
 153 ;;(defsubst ediff-make-combined-diff (regA regB)
 154 ;;  (concat (nth 0 ediff-combination-pattern) "\n"
 155 ;;        regA
 156 ;;        (nth 1 ediff-combination-pattern) "\n"
 157 ;;        regB
 158 ;;        (nth 2 ediff-combination-pattern) "\n"))
 159
 160 (defsubst ediff-set-state-of-all-diffs-in-all-buffers (ctl-buf)
 161   (let ((n 0))
 162     (while (< n ediff-number-of-differences)
 163       (ediff-set-state-of-diff-in-all-buffers n ctl-buf)
 164       (setq n (1+ n)))))
 165
 166 (defun ediff-set-state-of-diff-in-all-buffers (n ctl-buf)
 167   (let ((regA (ediff-get-region-contents n 'A ctl-buf))
 168         (regB (ediff-get-region-contents n 'B ctl-buf))
 169         (regC (ediff-get-region-contents n 'C ctl-buf)))
 170     (cond ((and (string= regA regB) (string= regA  regC))
 171            (ediff-set-state-of-diff n 'A "=diff(B)")
 172            (ediff-set-state-of-diff n 'B "=diff(C)")
 173            (ediff-set-state-of-diff n 'C "=diff(A)"))
 174           ((string= regA regB)
 175            (ediff-set-state-of-diff n 'A "=diff(B)")
 176            (ediff-set-state-of-diff n 'B "=diff(A)")
 177            (ediff-set-state-of-diff n 'C nil))
 178           ((string= regA regC)
 179            (ediff-set-state-of-diff n 'A "=diff(C)")
 180            (ediff-set-state-of-diff n 'C "=diff(A)")
 181            (ediff-set-state-of-diff n 'B nil))
 182           ((string= regB regC)
 183            (ediff-set-state-of-diff n 'C "=diff(B)")
 184            (ediff-set-state-of-diff n 'B "=diff(C)")
 185            (ediff-set-state-of-diff n 'A nil))
 186           ((string= regC (ediff-get-combined-region n))
 187            (ediff-set-state-of-diff n 'A nil)
 188              (ediff-set-state-of-diff n 'B nil)
 189              (ediff-set-state-of-diff n 'C "=diff(A+B)"))
 190           (t (ediff-set-state-of-diff n 'A nil)
 191              (ediff-set-state-of-diff n 'B nil)
 192              (ediff-set-state-of-diff n 'C nil)))
 193     ))
 194
 195 (defun ediff-set-merge-mode ()
 196   (normal-mode t)
 197   (remove-hook 'write-file-functions 'ediff-set-merge-mode t))
 198
 199
 200 ;; Go over all diffs starting with DIFF-NUM and copy regions into buffer C
 201 ;; according to the state of the difference.
 202 ;; Since ediff-copy-diff refuses to copy identical diff regions, there is
 203 ;; no need to optimize ediff-do-merge any further.
 204 ;;
 205 ;; If re-merging, change state of merge in all diffs starting with
 206 ;; DIFF-NUM, except those where the state is prefer-* or where it is
 207 ;; `default-*' or `combined' but the buf C region appears to be modified
 208 ;; since last set by default.
 209 (defun ediff-do-merge (diff-num &optional remerging)
 210   (if (< diff-num 0) (setq diff-num 0))
 211   (let ((n diff-num)
 212         ;;(default-state-of-merge (format "%S" ediff-default-variant))
 213         do-not-copy state-of-merge)
 214     (while (< n ediff-number-of-differences)
 215       (setq do-not-copy nil) ; reset after each cycle
 216       (if (= (mod n 10) 0)
 217           (message "%s buffers A & B into C ... region %d of %d"
 218                    (if remerging "Re-merging" "Merging")
 219                    n
 220                    ediff-number-of-differences))
 221
 222       (setq state-of-merge (ediff-get-state-of-merge n))
 223
 224       (if remerging
 225           ;;(let ((reg-A (ediff-get-region-contents n 'A ediff-control-buffer))
 226           ;;    (reg-B (ediff-get-region-contents n 'B ediff-control-buffer))
 227           ;;    (reg-C (ediff-get-region-contents n 'C ediff-control-buffer)))
 228           (progn
 229
 230             ;; if region was edited since it was first set by default
 231             (if (or (ediff-merge-changed-from-default-p n)
 232                     ;; was preferred
 233                     (string-match "prefer" state-of-merge))
 234                 ;; then ignore
 235                 (setq do-not-copy t))
 236
 237             ;; change state of merge for this diff, if necessary
 238             (if (and (string-match "\\(default\\|combined\\)" state-of-merge)
 239                      (not do-not-copy))
 240                 (ediff-set-state-of-merge
 241                  n (format "%S" ediff-default-variant)))
 242             ))
 243
 244       ;; state-of-merge may have changed via ediff-set-state-of-merge, so
 245       ;; check it once again
 246       (setq state-of-merge (ediff-get-state-of-merge n))
 247
 248       (or do-not-copy
 249           (if (string= state-of-merge "combined")
 250               ;; use n+1 because ediff-combine-diffs works via user numbering
 251               ;; of diffs, which is 1+ to what ediff uses internally
 252               (ediff-combine-diffs (1+ n) 'batch)
 253             (ediff-copy-diff
 254              n (if (string-match "-A" state-of-merge) 'A 'B) 'C 'batch)))
 255       (setq n (1+ n)))
 256     (message "Merging buffers A & B into C ... Done")
 257     ))
 258
 259
 260 (defun ediff-re-merge ()
 261   "Remerge unmodified diff regions using a new default.  Start with the current region."
 262   (interactive)
 263   (let* ((default-variant-alist
 264            (list '("default-A") '("default-B") '("combined")))
 265          (actual-alist
 266           (delete (list (symbol-name ediff-default-variant))
 267                   default-variant-alist)))
 268     (setq ediff-default-variant
 269           (intern
 270            (completing-read
 271             (format-message "Current merge default is `%S'.  New default: "
 272                             ediff-default-variant)
 273             actual-alist nil 'must-match)))
 274     (ediff-do-merge ediff-current-difference 'remerge)
 275     (ediff-recenter)
 276   ))
 277
 278 (defun ediff-shrink-window-C (arg)
 279   "Shrink window C to just one line.
 280 With a prefix argument, returns window C to its normal size.
 281 Used only for merging jobs."
 282   (interactive "P")
 283   (if (not ediff-merge-job)
 284       (user-error "ediff-shrink-window-C can be used only for merging jobs"))
 285   (cond ((eq arg '-) (setq arg -1))
 286         ((not (numberp arg)) (setq arg nil)))
 287   (cond ((null arg)
 288          (let ((ediff-merge-window-share
 289                 (if (< (window-height ediff-window-C) 3)
 290                     ediff-merge-window-share 0)))
 291            (setq ediff-window-config-saved "") ; force redisplay
 292            (ediff-recenter 'no-rehighlight)))
 293         ((and (< arg 0) (> (window-height ediff-window-C) 2))
 294          (setq ediff-merge-window-share (* ediff-merge-window-share 0.9))
 295          (setq ediff-window-config-saved "") ; force redisplay
 296          (ediff-recenter 'no-rehighlight))
 297         ((and (> arg 0) (> (window-height ediff-window-A) 2))
 298          (setq ediff-merge-window-share (* ediff-merge-window-share 1.1))
 299          (setq ediff-window-config-saved "") ; force redisplay
 300          (ediff-recenter 'no-rehighlight))))
 301
 302
 303 ;; N here is the user's region number.  It is 1+ what Ediff uses internally.
 304 (defun ediff-combine-diffs (n &optional batch-invocation)
 305   "Combine Nth diff regions of buffers A and B and place the combination in C.
 306 N is a prefix argument.  If nil, combine the current difference regions.
 307 Combining is done according to the specifications in variable
 308 `ediff-combination-pattern'."
 309   (interactive "P")
 310   (setq n (if (numberp n) (1- n) ediff-current-difference))
 311
 312   (let (reg-combined)
 313     ;;(setq regA (ediff-get-region-contents n 'A ediff-control-buffer)
 314     ;;    regB (ediff-get-region-contents n 'B ediff-control-buffer))
 315     ;;(setq reg-combined (ediff-make-combined-diff regA regB))
 316     (setq reg-combined (ediff-get-combined-region n))
 317
 318     (ediff-copy-diff n nil 'C batch-invocation reg-combined))
 319     (or batch-invocation (ediff-jump-to-difference (1+ n))))
 320
 321
 322 ;; Checks if the region in buff C looks like a combination of the regions
 323 ;; in buffers A and B.  Return a list (reg-a-beg reg-a-end reg-b-beg reg-b-end)
 324 ;; These refer to where the delimiters for region A, B, Ancestor start and end
 325 ;; in buffer C
 326 (defun ediff-looks-like-combined-merge (region-num)
 327   (if ediff-merge-job
 328       (let ((combined (string-match (regexp-quote "(A+B)")
 329                                     (or (ediff-get-state-of-diff region-num 'C)
 330                                         "")))
 331             (mrgreg-beg (ediff-get-diff-posn 'C 'beg region-num))
 332             (mrgreg-end (ediff-get-diff-posn 'C 'end region-num))
 333             (pattern-list ediff-combination-pattern)
 334             delim reg-beg reg-end delim-regs-list)
 335
 336         (if combined
 337             (ediff-with-current-buffer ediff-buffer-C
 338               (while pattern-list
 339                 (goto-char mrgreg-beg)
 340                 (setq delim (nth 0 pattern-list))
 341                 (search-forward delim mrgreg-end 'noerror)
 342                 (setq reg-beg (match-beginning 0))
 343                 (setq reg-end (match-end 0))
 344                 (if (and reg-beg reg-end)
 345                     (setq delim-regs-list
 346                           ;; in reverse
 347                           (cons reg-end (cons reg-beg delim-regs-list))))
 348                 (if (> (length pattern-list) 1)
 349                     (setq pattern-list (cdr (cdr pattern-list)))
 350                   (setq pattern-list nil))
 351                 )))
 352
 353         (reverse delim-regs-list)
 354         )))
 355
 356 ;; Check if the non-preferred merge has been modified since originally set.
 357 ;; This affects only the regions that are marked as default-A/B or combined.
 358 ;; If PREFERS-TOO is non-nil, then look at the regions marked as prefers-A/B as
 359 ;; well.
 360 (defun ediff-merge-changed-from-default-p (diff-num &optional prefers-too)
 361   (let ((reg-A (ediff-get-region-contents diff-num 'A ediff-control-buffer))
 362         (reg-B (ediff-get-region-contents diff-num 'B ediff-control-buffer))
 363         (reg-C (ediff-get-region-contents diff-num 'C ediff-control-buffer)))
 364
 365     (setq state-of-merge (ediff-get-state-of-merge diff-num))
 366
 367     ;; if region was edited since it was first set by default
 368     (or (and (string= state-of-merge "default-A")
 369              (not (string= reg-A reg-C)))
 370         (and (string= state-of-merge "default-B")
 371              (not (string= reg-B reg-C)))
 372         (and (string= state-of-merge "combined")
 373              ;;(not (string= (ediff-make-combined-diff reg-A reg-B) reg-C)))
 374              (not (string= (ediff-get-combined-region diff-num) reg-C)))
 375         (and prefers-too
 376              (string= state-of-merge "prefer-A")
 377              (not (string= reg-A reg-C)))
 378         (and prefers-too
 379              (string= state-of-merge "prefer-B")
 380              (not (string= reg-B reg-C)))
 381         )))
 382
 383
 384 (provide 'ediff-merg)
 385
 386
 387 ;; Local Variables:
 388 ;; eval: (put 'ediff-defvar-local 'lisp-indent-hook 'defun)
 389 ;; eval: (put 'ediff-with-current-buffer 'lisp-indent-hook 1)
 390 ;; eval: (put 'ediff-with-current-buffer 'edebug-form-spec '(form body))
 391 ;; End:
 392
 393 ;;; ediff-merg.el ends here