lisp/smerge-mode.el

   1 ;;; smerge-mode.el --- Minor mode to resolve diff3 conflicts
   2
   3 ;; Copyright (C) 1999, 2000, 2001, 2002, 2003,
   4 ;;   2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.
   5
   6 ;; Author: Stefan Monnier <monnier@iro.umontreal.ca>
   7 ;; Keywords: tools revision-control merge diff3 cvs conflict
   8
   9 ;; This file is part of GNU Emacs.
  10
  11 ;; GNU Emacs is free software; you can redistribute it and/or modify
  12 ;; it under the terms of the GNU General Public License as published by
  13 ;; the Free Software Foundation; either version 3, or (at your option)
  14 ;; any later version.
  15
  16 ;; GNU Emacs is distributed in the hope that it will be useful,
  17 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  18 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  19 ;; GNU General Public License for more details.
  20
  21 ;; You should have received a copy of the GNU General Public License
  22 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  23 ;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
  24 ;; Boston, MA 02110-1301, USA.
  25
  26 ;;; Commentary:
  27
  28 ;; Provides a lightweight alternative to emerge/ediff.
  29 ;; To use it, simply add to your .emacs the following lines:
  30 ;;
  31 ;;   (autoload 'smerge-mode "smerge-mode" nil t)
  32 ;;
  33 ;; you can even have it turned on automatically with the following
  34 ;; piece of code in your .emacs:
  35 ;;
  36 ;;   (defun sm-try-smerge ()
  37 ;;     (save-excursion
  38 ;;       (goto-char (point-min))
  39 ;;       (when (re-search-forward "^<<<<<<< " nil t)
  40 ;;         (smerge-mode 1))))
  41 ;;   (add-hook 'find-file-hook 'sm-try-smerge t)
  42
  43 ;;; Todo:
  44
  45 ;; - if requested, ask the user whether he wants to call ediff right away
  46
  47 ;;; Code:
  48
  49 (eval-when-compile (require 'cl))
  50
  51
  52 ;;; The real definition comes later.
  53 (defvar smerge-mode)
  54
  55 (defgroup smerge ()
  56   "Minor mode to highlight and resolve diff3 conflicts."
  57   :group 'tools
  58   :prefix "smerge-")
  59
  60 (defcustom smerge-diff-buffer-name "*vc-diff*"
  61   "Buffer name to use for displaying diffs."
  62   :group 'smerge
  63   :type '(choice
  64           (const "*vc-diff*")
  65           (const "*cvs-diff*")
  66           (const "*smerge-diff*")
  67           string))
  68
  69 (defcustom smerge-diff-switches
  70   (append '("-d" "-b")
  71           (if (listp diff-switches) diff-switches (list diff-switches)))
  72   "A list of strings specifying switches to be passed to diff.
  73 Used in `smerge-diff-base-mine' and related functions."
  74   :group 'smerge
  75   :type '(repeat string))
  76
  77 (defcustom smerge-auto-leave t
  78   "Non-nil means to leave `smerge-mode' when the last conflict is resolved."
  79   :group 'smerge
  80   :type 'boolean)
  81
  82 (defcustom smerge-auto-refine t
  83   "Automatically highlight changes in detail as the user visits conflicts."
  84   :group 'smerge
  85   :type 'boolean)
  86
  87 (defface smerge-mine
  88   '((((min-colors 88) (background light))
  89      (:foreground "blue1"))
  90     (((background light))
  91      (:foreground "blue"))
  92     (((min-colors 88) (background dark))
  93      (:foreground "cyan1"))
  94     (((background dark))
  95      (:foreground "cyan")))
  96   "Face for your code."
  97   :group 'smerge)
  98 ;; backward-compatibility alias
  99 (put 'smerge-mine-face 'face-alias 'smerge-mine)
 100 (defvar smerge-mine-face 'smerge-mine)
 101
 102 (defface smerge-other
 103   '((((background light))
 104      (:foreground "darkgreen"))
 105     (((background dark))
 106      (:foreground "lightgreen")))
 107   "Face for the other code."
 108   :group 'smerge)
 109 ;; backward-compatibility alias
 110 (put 'smerge-other-face 'face-alias 'smerge-other)
 111 (defvar smerge-other-face 'smerge-other)
 112
 113 (defface smerge-base
 114   '((((min-colors 88) (background light))
 115      (:foreground "red1"))
 116     (((background light))
 117      (:foreground "red"))
 118     (((background dark))
 119      (:foreground "orange")))
 120   "Face for the base code."
 121   :group 'smerge)
 122 ;; backward-compatibility alias
 123 (put 'smerge-base-face 'face-alias 'smerge-base)
 124 (defvar smerge-base-face 'smerge-base)
 125
 126 (defface smerge-markers
 127   '((((background light))
 128      (:background "grey85"))
 129     (((background dark))
 130      (:background "grey30")))
 131   "Face for the conflict markers."
 132   :group 'smerge)
 133 ;; backward-compatibility alias
 134 (put 'smerge-markers-face 'face-alias 'smerge-markers)
 135 (defvar smerge-markers-face 'smerge-markers)
 136
 137 (defface smerge-refined-change
 138   '((t :background "yellow"))
 139   "Face used for char-based changes shown by `smerge-refine'."
 140   :group 'smerge)
 141
 142 (easy-mmode-defmap smerge-basic-map
 143   `(("n" . smerge-next)
 144     ("p" . smerge-prev)
 145     ("r" . smerge-resolve)
 146     ("a" . smerge-keep-all)
 147     ("b" . smerge-keep-base)
 148     ("o" . smerge-keep-other)
 149     ("m" . smerge-keep-mine)
 150     ("E" . smerge-ediff)
 151     ("C" . smerge-combine-with-next)
 152     ("R" . smerge-refine)
 153     ("\C-m" . smerge-keep-current)
 154     ("=" . ,(make-sparse-keymap "Diff"))
 155     ("=<" "base-mine" . smerge-diff-base-mine)
 156     ("=>" "base-other" . smerge-diff-base-other)
 157     ("==" "mine-other" . smerge-diff-mine-other))
 158   "The base keymap for `smerge-mode'.")
 159
 160 (defcustom smerge-command-prefix "\C-c^"
 161   "Prefix for `smerge-mode' commands."
 162   :group 'smerge
 163   :type '(choice (string "\e") (string "\C-c^") (string "") string))
 164
 165 (easy-mmode-defmap smerge-mode-map
 166   `((,smerge-command-prefix . ,smerge-basic-map))
 167   "Keymap for `smerge-mode'.")
 168
 169 (defvar smerge-check-cache nil)
 170 (make-variable-buffer-local 'smerge-check-cache)
 171 (defun smerge-check (n)
 172   (condition-case nil
 173       (let ((state (cons (point) (buffer-modified-tick))))
 174         (unless (equal (cdr smerge-check-cache) state)
 175           (smerge-match-conflict)
 176           (setq smerge-check-cache (cons (match-data) state)))
 177         (nth (* 2 n) (car smerge-check-cache)))
 178     (error nil)))
 179
 180 (easy-menu-define smerge-mode-menu smerge-mode-map
 181   "Menu for `smerge-mode'."
 182   '("SMerge"
 183     ["Next" smerge-next :help "Go to next conflict"]
 184     ["Previous" smerge-prev :help "Go to previous conflict"]
 185     "--"
 186     ["Keep All" smerge-keep-all :help "Keep all three versions"
 187      :active (smerge-check 1)]
 188     ["Keep Current" smerge-keep-current :help "Use current (at point) version"
 189      :active (and (smerge-check 1) (> (smerge-get-current) 0))]
 190     "--"
 191     ["Revert to Base" smerge-keep-base :help "Revert to base version"
 192      :active (smerge-check 2)]
 193     ["Keep Other" smerge-keep-other :help "Keep `other' version"
 194      :active (smerge-check 3)]
 195     ["Keep Yours" smerge-keep-mine :help "Keep your version"
 196      :active (smerge-check 1)]
 197     "--"
 198     ["Diff Base/Mine" smerge-diff-base-mine
 199      :help "Diff `base' and `mine' for current conflict"
 200      :active (smerge-check 2)]
 201     ["Diff Base/Other" smerge-diff-base-other
 202      :help "Diff `base' and `other' for current conflict"
 203      :active (smerge-check 2)]
 204     ["Diff Mine/Other" smerge-diff-mine-other
 205      :help "Diff `mine' and `other' for current conflict"
 206      :active (smerge-check 1)]
 207     "--"
 208     ["Invoke Ediff" smerge-ediff
 209      :help "Use Ediff to resolve the conflicts"
 210      :active (smerge-check 1)]
 211     ["Auto Resolve" smerge-resolve
 212      :help "Try auto-resolution heuristics"
 213      :active (smerge-check 1)]
 214     ["Combine" smerge-combine-with-next
 215      :help "Combine current conflict with next"
 216      :active (smerge-check 1)]
 217     ))
 218
 219 (easy-menu-define smerge-context-menu nil
 220   "Context menu for mine area in `smerge-mode'."
 221   '(nil
 222     ["Keep Current" smerge-keep-current :help "Use current (at point) version"]
 223     ["Kill Current" smerge-kill-current :help "Remove current (at point) version"]
 224     ["Keep All" smerge-keep-all :help "Keep all three versions"]
 225     "---"
 226     ["More..." (popup-menu smerge-mode-menu) :help "Show full SMerge mode menu"]
 227     ))
 228
 229 (defconst smerge-font-lock-keywords
 230   '((smerge-find-conflict
 231      (1 smerge-mine-face prepend t)
 232      (2 smerge-base-face prepend t)
 233      (3 smerge-other-face prepend t)
 234      ;; FIXME: `keep' doesn't work right with syntactic fontification.
 235      (0 smerge-markers-face keep)
 236      (4 nil t t)
 237      (5 nil t t)))
 238   "Font lock patterns for `smerge-mode'.")
 239
 240 (defconst smerge-begin-re "^<<<<<<< \\(.*\\)\n")
 241 (defconst smerge-end-re "^>>>>>>> .*\n")
 242 (defconst smerge-base-re "^||||||| .*\n")
 243 (defconst smerge-other-re "^=======\n")
 244
 245 (defvar smerge-conflict-style nil
 246   "Keep track of which style of conflict is in use.
 247 Can be nil if the style is undecided, or else:
 248 - `diff3-E'
 249 - `diff3-A'")
 250
 251 ;; Compiler pacifiers
 252 (defvar font-lock-mode)
 253 (defvar font-lock-keywords)
 254
 255 ;;;;
 256 ;;;; Actual code
 257 ;;;;
 258
 259 ;; Define smerge-next and smerge-prev
 260 (easy-mmode-define-navigation smerge smerge-begin-re "conflict" nil nil
 261   (if smerge-auto-refine
 262       (condition-case nil (smerge-refine) (error nil))))
 263
 264 (defconst smerge-match-names ["conflict" "mine" "base" "other"])
 265
 266 (defun smerge-ensure-match (n)
 267   (unless (match-end n)
 268     (error "No `%s'" (aref smerge-match-names n))))
 269
 270 (defun smerge-auto-leave ()
 271   (when (and smerge-auto-leave
 272              (save-excursion (goto-char (point-min))
 273                              (not (re-search-forward smerge-begin-re nil t))))
 274     (when (and (listp buffer-undo-list) smerge-mode)
 275       (push (list 'apply 'smerge-mode 1) buffer-undo-list))
 276     (smerge-mode -1)))
 277
 278
 279 (defun smerge-keep-all ()
 280   "Concatenate all versions."
 281   (interactive)
 282   (smerge-match-conflict)
 283   (let ((mb2 (or (match-beginning 2) (point-max)))
 284         (me2 (or (match-end 2) (point-min))))
 285     (delete-region (match-end 3) (match-end 0))
 286     (delete-region (max me2 (match-end 1)) (match-beginning 3))
 287     (if (and (match-end 2) (/= (match-end 1) (match-end 3)))
 288         (delete-region (match-end 1) (match-beginning 2)))
 289     (delete-region (match-beginning 0) (min (match-beginning 1) mb2))
 290     (smerge-auto-leave)))
 291
 292 (defun smerge-keep-n (n)
 293   (smerge-remove-props (match-beginning 0) (match-end 0))
 294   ;; We used to use replace-match, but that did not preserve markers so well.
 295   (delete-region (match-end n) (match-end 0))
 296   (delete-region (match-beginning 0) (match-beginning n)))
 297
 298 (defun smerge-combine-with-next ()
 299   "Combine the current conflict with the next one."
 300   ;; `smerge-auto-combine' relies on the finish position (at the beginning
 301   ;; of the closing marker).
 302   (interactive)
 303   (smerge-match-conflict)
 304   (let ((ends nil))
 305     (dolist (i '(3 2 1 0))
 306       (push (if (match-end i) (copy-marker (match-end i) t)) ends))
 307     (setq ends (apply 'vector ends))
 308     (goto-char (aref ends 0))
 309     (if (not (re-search-forward smerge-begin-re nil t))
 310         (error "No next conflict")
 311       (smerge-match-conflict)
 312       (let ((match-data (mapcar (lambda (m) (if m (copy-marker m)))
 313                                 (match-data))))
 314         ;; First copy the in-between text in each alternative.
 315         (dolist (i '(1 2 3))
 316           (when (aref ends i)
 317             (goto-char (aref ends i))
 318             (insert-buffer-substring (current-buffer)
 319                                      (aref ends 0) (car match-data))))
 320         (delete-region (aref ends 0) (car match-data))
 321         ;; Then move the second conflict's alternatives into the first.
 322         (dolist (i '(1 2 3))
 323           (set-match-data match-data)
 324           (when (and (aref ends i) (match-end i))
 325             (goto-char (aref ends i))
 326             (insert-buffer-substring (current-buffer)
 327                                      (match-beginning i) (match-end i))))
 328         (delete-region (car match-data) (cadr match-data))
 329         ;; Free the markers.
 330         (dolist (m match-data) (if m (move-marker m nil)))
 331         (mapc (lambda (m) (if m (move-marker m nil))) ends)))))
 332
 333 (defvar smerge-auto-combine-max-separation 2
 334   "Max number of lines between conflicts that should be combined.")
 335
 336 (defun smerge-auto-combine ()
 337   "Automatically combine conflicts that are near each other."
 338   (interactive)
 339   (save-excursion
 340     (goto-char (point-min))
 341     (while (smerge-find-conflict)
 342       ;; 2 is 1 (default) + 1 (the begin markers).
 343       (while (save-excursion
 344                (smerge-find-conflict
 345                 (line-beginning-position
 346                  (+ 2 smerge-auto-combine-max-separation))))
 347         (forward-line -1)               ;Go back inside the conflict.
 348         (smerge-combine-with-next)
 349         (forward-line 1)                ;Move past the end of the conflict.
 350         ))))
 351
 352 (defvar smerge-resolve-function
 353   (lambda () (error "Don't know how to resolve"))
 354   "Mode-specific merge function.
 355 The function is called with zero or one argument (non-nil if the resolution
 356 function should only apply safe heuristics) and with the match data set
 357 according to `smerge-match-conflict'.")
 358 (add-to-list 'debug-ignored-errors "Don't know how to resolve")
 359
 360 (defvar smerge-text-properties
 361   `(help-echo "merge conflict: mouse-3 shows a menu"
 362     ;; mouse-face highlight
 363     keymap (keymap (down-mouse-3 . smerge-popup-context-menu))))
 364
 365 (defun smerge-remove-props (beg end)
 366   (remove-overlays beg end 'smerge 'refine)
 367   (remove-overlays beg end 'smerge 'conflict)
 368   ;; Now that we use overlays rather than text-properties, this function
 369   ;; does not cause refontification any more.  It can be seen very clearly
 370   ;; in buffers where jit-lock-contextually is not t, in which case deleting
 371   ;; the "<<<<<<< foobar" leading line leaves the rest of the conflict
 372   ;; highlighted as if it were still a valid conflict.  Note that in many
 373   ;; important cases (such as the previous example) we're actually called
 374   ;; during font-locking so inhibit-modification-hooks is non-nil, so we
 375   ;; can't just modify the buffer and expect font-lock to be triggered as in:
 376   ;; (put-text-property beg end 'smerge-force-highlighting nil)
 377   (let ((modified (buffer-modified-p)))
 378     (remove-text-properties beg end '(fontified nil))
 379     (restore-buffer-modified-p modified)))
 380
 381 (defun smerge-popup-context-menu (event)
 382   "Pop up the Smerge mode context menu under mouse."
 383   (interactive "e")
 384   (if (and smerge-mode
 385            (save-excursion (posn-set-point (event-end event)) (smerge-check 1)))
 386       (progn
 387         (posn-set-point (event-end event))
 388         (smerge-match-conflict)
 389         (let ((i (smerge-get-current))
 390               o)
 391           (if (<= i 0)
 392               ;; Out of range
 393               (popup-menu smerge-mode-menu)
 394             ;; Install overlay.
 395             (setq o (make-overlay (match-beginning i) (match-end i)))
 396             (unwind-protect
 397                 (progn
 398                   (overlay-put o 'face 'highlight)
 399                   (sit-for 0)           ;Display the new highlighting.
 400                   (popup-menu smerge-context-menu))
 401               ;; Delete overlay.
 402               (delete-overlay o)))))
 403     ;; There's no conflict at point, the text-props are just obsolete.
 404     (save-excursion
 405       (let ((beg (re-search-backward smerge-end-re nil t))
 406             (end (re-search-forward smerge-begin-re nil t)))
 407         (smerge-remove-props (or beg (point-min)) (or end (point-max)))
 408         (push event unread-command-events)))))
 409
 410 (defun smerge-resolve (&optional safe)
 411   "Resolve the conflict at point intelligently.
 412 This relies on mode-specific knowledge and thus only works in
 413 some major modes.  Uses `smerge-resolve-function' to do the actual work."
 414   (interactive)
 415   (smerge-match-conflict)
 416   (smerge-remove-props (match-beginning 0) (match-end 0))
 417   (cond
 418    ;; Trivial diff3 -A non-conflicts.
 419    ((and (eq (match-end 1) (match-end 3))
 420          (eq (match-beginning 1) (match-beginning 3)))
 421     (smerge-keep-n 3))
 422    ;; Mode-specific conflict resolution.
 423    ((condition-case nil
 424         (atomic-change-group
 425           (if safe
 426               (funcall smerge-resolve-function safe)
 427             (funcall smerge-resolve-function))
 428           t)
 429       (error nil))
 430     ;; Nothing to do: the resolution function has done it already.
 431     nil)
 432    ;; FIXME: Add "if [ diff -b MINE OTHER ]; then select OTHER; fi"
 433    ((and (match-end 2)
 434          ;; FIXME: Add "diff -b BASE MINE | patch OTHER".
 435          ;; FIXME: Add "diff -b BASE OTHER | patch MINE".
 436          nil)
 437     )
 438    ((and (not (match-end 2))
 439          ;; FIXME: Add "diff -b"-based refinement.
 440          nil)
 441     )
 442    (t
 443     (error "Don't know how to resolve")))
 444   (smerge-auto-leave))
 445
 446 (defun smerge-resolve-all ()
 447   "Perform automatic resolution on all conflicts."
 448   (interactive)
 449   (save-excursion
 450     (goto-char (point-min))
 451     (while (re-search-forward smerge-begin-re nil t)
 452       (condition-case nil
 453           (progn
 454             (smerge-match-conflict)
 455             (smerge-resolve 'safe))
 456         (error nil)))))
 457
 458 (defun smerge-batch-resolve ()
 459   ;; command-line-args-left is what is left of the command line.
 460   (if (not noninteractive)
 461       (error "`smerge-batch-resolve' is to be used only with -batch"))
 462   (while command-line-args-left
 463     (let ((file (pop command-line-args-left)))
 464       (if (string-match "\\.rej\\'" file)
 465           ;; .rej files should never contain diff3 markers, on the other hand,
 466           ;; in Arch, .rej files are sometimes used to indicate that the
 467           ;; main file has diff3 markers.  So you can pass **/*.rej and
 468           ;; it will DTRT.
 469           (setq file (substring file 0 (match-beginning 0))))
 470       (message "Resolving conflicts in %s..." file)
 471       (when (file-readable-p file)
 472         (with-current-buffer (find-file-noselect file)
 473           (smerge-resolve-all)
 474           (save-buffer)
 475           (kill-buffer (current-buffer)))))))
 476
 477 (defun smerge-keep-base ()
 478   "Revert to the base version."
 479   (interactive)
 480   (smerge-match-conflict)
 481   (smerge-ensure-match 2)
 482   (smerge-keep-n 2)
 483   (smerge-auto-leave))
 484
 485 (defun smerge-keep-other ()
 486   "Use \"other\" version."
 487   (interactive)
 488   (smerge-match-conflict)
 489   ;;(smerge-ensure-match 3)
 490   (smerge-keep-n 3)
 491   (smerge-auto-leave))
 492
 493 (defun smerge-keep-mine ()
 494   "Keep your version."
 495   (interactive)
 496   (smerge-match-conflict)
 497   ;;(smerge-ensure-match 1)
 498   (smerge-keep-n 1)
 499   (smerge-auto-leave))
 500
 501 (defun smerge-get-current ()
 502   (let ((i 3))
 503     (while (or (not (match-end i))
 504                (< (point) (match-beginning i))
 505                (>= (point) (match-end i)))
 506       (decf i))
 507     i))
 508
 509 (defun smerge-keep-current ()
 510   "Use the current (under the cursor) version."
 511   (interactive)
 512   (smerge-match-conflict)
 513   (let ((i (smerge-get-current)))
 514     (if (<= i 0) (error "Not inside a version")
 515       (smerge-keep-n i)
 516       (smerge-auto-leave))))
 517
 518 (defun smerge-kill-current ()
 519   "Remove the current (under the cursor) version."
 520   (interactive)
 521   (smerge-match-conflict)
 522   (let ((i (smerge-get-current)))
 523     (if (<= i 0) (error "Not inside a version")
 524       (let ((left nil))
 525         (dolist (n '(3 2 1))
 526           (if (and (match-end n) (/= (match-end n) (match-end i)))
 527               (push n left)))
 528         (if (and (cdr left)
 529                  (/= (match-end (car left)) (match-end (cadr left))))
 530             (ding)                      ;We don't know how to do that.
 531           (smerge-keep-n (car left))
 532           (smerge-auto-leave))))))
 533
 534 (defun smerge-diff-base-mine ()
 535   "Diff 'base' and 'mine' version in current conflict region."
 536   (interactive)
 537   (smerge-diff 2 1))
 538
 539 (defun smerge-diff-base-other ()
 540   "Diff 'base' and 'other' version in current conflict region."
 541   (interactive)
 542   (smerge-diff 2 3))
 543
 544 (defun smerge-diff-mine-other ()
 545   "Diff 'mine' and 'other' version in current conflict region."
 546   (interactive)
 547   (smerge-diff 1 3))
 548
 549 (defun smerge-match-conflict ()
 550   "Get info about the conflict.  Puts the info in the `match-data'.
 551 The submatches contain:
 552  0:  the whole conflict.
 553  1:  your code.
 554  2:  the base code.
 555  3:  other code.
 556 An error is raised if not inside a conflict."
 557   (save-excursion
 558     (condition-case nil
 559         (let* ((orig-point (point))
 560
 561                (_ (forward-line 1))
 562                (_ (re-search-backward smerge-begin-re))
 563
 564                (start (match-beginning 0))
 565                (mine-start (match-end 0))
 566                (filename (or (match-string 1) ""))
 567
 568                (_ (re-search-forward smerge-end-re))
 569                (_ (assert (< orig-point (match-end 0))))
 570
 571                (other-end (match-beginning 0))
 572                (end (match-end 0))
 573
 574                (_ (re-search-backward smerge-other-re start))
 575
 576                (mine-end (match-beginning 0))
 577                (other-start (match-end 0))
 578
 579                base-start base-end)
 580
 581           ;; handle the various conflict styles
 582           (cond
 583            ((save-excursion
 584               (goto-char mine-start)
 585               (re-search-forward smerge-begin-re end t))
 586             ;; There's a nested conflict and we're after the the beginning
 587             ;; of the outer one but before the beginning of the inner one.
 588             ;; Of course, maybe this is not a nested conflict but in that
 589             ;; case it can only be something nastier that we don't know how
 590             ;; to handle, so may as well arbitrarily decide to treat it as
 591             ;; a nested conflict.  --Stef
 592             (error "There is a nested conflict"))
 593
 594            ((re-search-backward smerge-base-re start t)
 595             ;; a 3-parts conflict
 596             (set (make-local-variable 'smerge-conflict-style) 'diff3-A)
 597             (setq base-end mine-end)
 598             (setq mine-end (match-beginning 0))
 599             (setq base-start (match-end 0)))
 600
 601            ((string= filename (file-name-nondirectory
 602                                (or buffer-file-name "")))
 603             ;; a 2-parts conflict
 604             (set (make-local-variable 'smerge-conflict-style) 'diff3-E))
 605
 606            ((and (not base-start)
 607                  (or (eq smerge-conflict-style 'diff3-A)
 608                      (equal filename "ANCESTOR")
 609                      (string-match "\\`[.0-9]+\\'" filename)))
 610             ;; a same-diff conflict
 611             (setq base-start mine-start)
 612             (setq base-end   mine-end)
 613             (setq mine-start other-start)
 614             (setq mine-end   other-end)))
 615
 616           (store-match-data (list start end
 617                                   mine-start mine-end
 618                                   base-start base-end
 619                                   other-start other-end
 620                                   (when base-start (1- base-start)) base-start
 621                                   (1- other-start) other-start))
 622           t)
 623       (search-failed (error "Point not in conflict region")))))
 624
 625 (add-to-list 'debug-ignored-errors "Point not in conflict region")
 626
 627 (defun smerge-conflict-overlay (pos)
 628   "Return the conflict overlay at POS if any."
 629   (let ((ols (overlays-at pos))
 630         conflict)
 631     (dolist (ol ols)
 632       (if (and (eq (overlay-get ol 'smerge) 'conflict)
 633                (> (overlay-end ol) pos))
 634           (setq conflict ol)))
 635     conflict))
 636
 637 (defun smerge-find-conflict (&optional limit)
 638   "Find and match a conflict region.  Intended as a font-lock MATCHER.
 639 The submatches are the same as in `smerge-match-conflict'.
 640 Returns non-nil if a match is found between point and LIMIT.
 641 Point is moved to the end of the conflict."
 642   (let ((found nil)
 643         (pos (point))
 644         conflict)
 645     ;; First check to see if point is already inside a conflict, using
 646     ;; the conflict overlays.
 647     (while (and (not found) (setq conflict (smerge-conflict-overlay pos)))
 648       ;; Check the overlay's validity and kill it if it's out of date.
 649       (condition-case nil
 650           (progn
 651             (goto-char (overlay-start conflict))
 652             (smerge-match-conflict)
 653             (goto-char (match-end 0))
 654             (if (<= (point) pos)
 655                 (error "Matching backward!")
 656               (setq found t)))
 657         (error (smerge-remove-props
 658                 (overlay-start conflict) (overlay-end conflict))
 659                (goto-char pos))))
 660     ;; If we're not already inside a conflict, look for the next conflict
 661     ;; and add/update its overlay.
 662     (while (and (not found) (re-search-forward smerge-begin-re limit t))
 663       (condition-case nil
 664           (progn
 665             (smerge-match-conflict)
 666             (goto-char (match-end 0))
 667             (let ((conflict (smerge-conflict-overlay (1- (point)))))
 668               (if conflict
 669                   ;; Update its location, just in case it got messed up.
 670                   (move-overlay conflict (match-beginning 0) (match-end 0))
 671                 (setq conflict (make-overlay (match-beginning 0) (match-end 0)
 672                                              nil 'front-advance nil))
 673                 (overlay-put conflict 'evaporate t)
 674                 (overlay-put conflict 'smerge 'conflict)
 675                 (let ((props smerge-text-properties))
 676                   (while props
 677                     (overlay-put conflict (pop props) (pop props))))))
 678             (setq found t))
 679         (error nil)))
 680     found))
 681
 682 ;;; Refined change highlighting
 683
 684 (defvar smerge-refine-forward-function 'smerge-refine-forward
 685   "Function used to determine an \"atomic\" element.
 686 You can set it to `forward-char' to get char-level granularity.
 687 Its behavior has mainly two restrictions:
 688 - if this function encounters a newline, it's important that it stops right
 689   after the newline.
 690   This only matters if `smerge-refine-ignore-whitespace' is nil.
 691 - it needs to be unaffected by changes performed by the `preproc' argument
 692   to `smerge-refine-subst'.
 693   This only matters if `smerge-refine-weight-hack' is nil.")
 694
 695 (defvar smerge-refine-ignore-whitespace t
 696   "If non-nil,Indicate that smerge-refine should try to ignore change in whitespace.")
 697
 698 (defvar smerge-refine-weight-hack t
 699   "If non-nil, pass to diff as many lines as there are chars in the region.
 700 I.e. each atomic element (e.g. word) will be copied as many times (on different
 701 lines) as it has chars.  This has 2 advantages:
 702 - if `diff' tries to minimize the number *lines* (rather than chars)
 703   added/removed, this adjust the weights so that adding/removing long
 704   symbols is considered correspondingly more costly.
 705 - `smerge-refine-forward-function' only needs to be called when chopping up
 706   the regions, and `forward-char' can be used afterwards.
 707 It has the following disadvantages:
 708 - cannot use `diff -w' because the weighting causes added spaces in a line
 709   to be represented as added copies of some line, so `diff -w' can't do the
 710   right thing any more.
 711 - may in degenerate cases take a 1KB input region and turn it into a 1MB
 712   file to pass to diff.")
 713
 714 (defun smerge-refine-forward (n)
 715   (let ((case-fold-search nil)
 716         (re "[[:upper:]]?[[:lower:]]+\\|[[:upper:]]+\\|[[:digit:]]+\\|.\\|\n"))
 717     (when (and smerge-refine-ignore-whitespace
 718                ;; smerge-refine-weight-hack causes additional spaces to
 719                ;; appear as additional lines as well, so even if diff ignore
 720                ;; whitespace changes, it'll report added/removed lines :-(
 721                (not smerge-refine-weight-hack))
 722       (setq re (concat "[ \t]*\\(?:" re "\\)")))
 723     (dotimes (i n)
 724       (unless (looking-at re) (error "Smerge refine internal error"))
 725       (goto-char (match-end 0)))))
 726
 727 (defun smerge-refine-chopup-region (beg end file &optional preproc)
 728   "Chopup the region into small elements, one per line.
 729 Save the result into FILE.
 730 If non-nil, PREPROC is called with no argument in a buffer that contains
 731 a copy of the text, just before chopping it up.  It can be used to replace
 732 chars to try and eliminate some spurious differences."
 733   ;; We used to chop up char-by-char rather than word-by-word like ediff
 734   ;; does.  It had the benefit of simplicity and very fine results, but it
 735   ;; often suffered from problem that diff would find correlations where
 736   ;; there aren't any, so the resulting "change" didn't make much sense.
 737   ;; You can still get this behavior by setting
 738   ;; `smerge-refine-forward-function' to `forward-char'.
 739   (let ((buf (current-buffer)))
 740     (with-temp-buffer
 741       (insert-buffer-substring buf beg end)
 742       (when preproc (goto-char (point-min)) (funcall preproc))
 743       (when smerge-refine-ignore-whitespace
 744         ;; It doesn't make much of a difference for diff-fine-highlight
 745         ;; because we still have the _/+/</>/! prefix anyway.  Can still be
 746         ;; useful in other circumstances.
 747         (subst-char-in-region (point-min) (point-max) ?\n ?\s))
 748       (goto-char (point-min))
 749       (while (not (eobp))
 750         (funcall smerge-refine-forward-function 1)
 751         (let ((s (if (prog2 (forward-char -1) (bolp) (forward-char 1))
 752                      nil
 753                    (buffer-substring (line-beginning-position) (point)))))
 754           ;; We add \n after each char except after \n, so we get
 755           ;; one line per text char, where each line contains
 756           ;; just one char, except for \n chars which are
 757           ;; represented by the empty line.
 758           (unless (eq (char-before) ?\n) (insert ?\n))
 759           ;; HACK ALERT!!
 760           (if smerge-refine-weight-hack
 761               (dotimes (i (1- (length s))) (insert s "\n")))))
 762       (unless (bolp) (error "Smerge refine internal error"))
 763       (let ((coding-system-for-write 'emacs-mule))
 764         (write-region (point-min) (point-max) file nil 'nomessage)))))
 765
 766 (defun smerge-refine-highlight-change (buf beg match-num1 match-num2 props)
 767   (with-current-buffer buf
 768     (goto-char beg)
 769     (let* ((startline (- (string-to-number match-num1) 1))
 770            (beg (progn (funcall (if smerge-refine-weight-hack
 771                                     'forward-char
 772                                   smerge-refine-forward-function)
 773                                 startline)
 774                        (point)))
 775            (end (progn (funcall (if smerge-refine-weight-hack
 776                                     'forward-char
 777                                   smerge-refine-forward-function)
 778                           (if match-num2
 779                               (- (string-to-number match-num2)
 780                                  startline)
 781                             1))
 782                        (point))))
 783       (when smerge-refine-ignore-whitespace
 784         (skip-chars-backward " \t\n" beg) (setq end (point))
 785         (goto-char beg)
 786         (skip-chars-forward " \t\n" end)  (setq beg (point)))
 787       (when (> end beg)
 788         (let ((ol (make-overlay
 789                    beg end nil
 790                    ;; Make them tend to shrink rather than spread when editing.
 791                    'front-advance nil)))
 792           (overlay-put ol 'evaporate t)
 793           (dolist (x props) (overlay-put ol (car x) (cdr x)))
 794           ol)))))
 795
 796 (defun smerge-refine-subst (beg1 end1 beg2 end2 props &optional preproc)
 797   "Show fine differences in the two regions BEG1..END1 and BEG2..END2.
 798 PROPS is an alist of properties to put (via overlays) on the changes.
 799 If non-nil, PREPROC is called with no argument in a buffer that contains
 800 a copy of a region, just before preparing it to for `diff'.  It can be used to
 801 replace chars to try and eliminate some spurious differences."
 802   (let* ((buf (current-buffer))
 803          (pos (point))
 804          (file1 (make-temp-file "diff1"))
 805          (file2 (make-temp-file "diff2")))
 806     ;; Chop up regions into smaller elements and save into files.
 807     (smerge-refine-chopup-region beg1 end1 file1 preproc)
 808     (smerge-refine-chopup-region beg2 end2 file2 preproc)
 809
 810     ;; Call diff on those files.
 811     (unwind-protect
 812         (with-temp-buffer
 813           (let ((coding-system-for-read 'emacs-mule))
 814             (call-process diff-command nil t nil
 815                           (if (and smerge-refine-ignore-whitespace
 816                                    (not smerge-refine-weight-hack))
 817                               ;; Pass -a so diff treats it as a text file even
 818                               ;; if it contains \0 and such.
 819                               ;; Pass -d so as to get the smallest change, but
 820                               ;; also and more importantly because otherwise it
 821                               ;; may happen that diff doesn't behave like
 822                               ;; smerge-refine-weight-hack expects it to.
 823                               ;; See http://thread.gmane.org/gmane.emacs.devel/82685.
 824                               "-awd" "-ad")
 825                           file1 file2))
 826           ;; Process diff's output.
 827           (goto-char (point-min))
 828           (let ((last1 nil)
 829                 (last2 nil))
 830             (while (not (eobp))
 831               (if (not (looking-at "\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)?\\([acd]\\)\\([0-9]+\\)\\(?:,\\([0-9]+\\)\\)?$"))
 832                   (error "Unexpected patch hunk header: %s"
 833                          (buffer-substring (point) (line-end-position))))
 834               (let ((op (char-after (match-beginning 3)))
 835                     (m1 (match-string 1))
 836                     (m2 (match-string 2))
 837                     (m4 (match-string 4))
 838                     (m5 (match-string 5)))
 839                 (when (memq op '(?d ?c))
 840                   (setq last1
 841                         (smerge-refine-highlight-change buf beg1 m1 m2 props)))
 842                 (when (memq op '(?a ?c))
 843                   (setq last2
 844                         (smerge-refine-highlight-change buf beg2 m4 m5 props))))
 845               (forward-line 1)                            ;Skip hunk header.
 846               (and (re-search-forward "^[0-9]" nil 'move) ;Skip hunk body.
 847                    (goto-char (match-beginning 0))))
 848             ;; (assert (or (null last1) (< (overlay-start last1) end1)))
 849             ;; (assert (or (null last2) (< (overlay-start last2) end2)))
 850             (if smerge-refine-weight-hack
 851                 (progn
 852                   ;; (assert (or (null last1) (<= (overlay-end last1) end1)))
 853                   ;; (assert (or (null last2) (<= (overlay-end last2) end2)))
 854                   )
 855               ;; smerge-refine-forward-function when calling in chopup may
 856               ;; have stopped because it bumped into EOB whereas in
 857               ;; smerge-refine-weight-hack it may go a bit further.
 858               (if (and last1 (> (overlay-end last1) end1))
 859                   (move-overlay last1 (overlay-start last1) end1))
 860               (if (and last2 (> (overlay-end last2) end2))
 861                   (move-overlay last2 (overlay-start last2) end2))
 862               )))
 863       (goto-char pos)
 864       (delete-file file1)
 865       (delete-file file2))))
 866
 867 (defun smerge-refine ()
 868   "Highlight the parts of the conflict that are different."
 869   (interactive)
 870   ;; FIXME: make it work with 3-way conflicts.
 871   (smerge-match-conflict)
 872   (remove-overlays (match-beginning 0) (match-end 0) 'smerge 'refine)
 873   (smerge-ensure-match 1)
 874   (smerge-ensure-match 3)
 875   ;; Match 1 and 3 may be one and the same in case of trivial diff3 -A conflict.
 876   (let ((n1 (if (eq (match-end 1) (match-end 3)) 2 1)))
 877     (smerge-refine-subst (match-beginning n1) (match-end n1)
 878                          (match-beginning 3)  (match-end 3)
 879                          '((smerge . refine)
 880                            (face . smerge-refined-change)))))
 881
 882 (defun smerge-diff (n1 n2)
 883   (smerge-match-conflict)
 884   (smerge-ensure-match n1)
 885   (smerge-ensure-match n2)
 886   (let ((name1 (aref smerge-match-names n1))
 887         (name2 (aref smerge-match-names n2))
 888         ;; Read them before the match-data gets clobbered.
 889         (beg1 (match-beginning n1))
 890         (end1 (match-end n1))
 891         (beg2 (match-beginning n2))
 892         (end2 (match-end n2))
 893         (file1 (make-temp-file "smerge1"))
 894         (file2 (make-temp-file "smerge2"))
 895         (dir default-directory)
 896         (file (if buffer-file-name (file-relative-name buffer-file-name)))
 897         ;; We would want to use `emacs-mule-unix' for read&write, but we
 898         ;; bump into problems with the coding-system used by diff to write
 899         ;; the file names and the time stamps in the header.
 900         ;; `buffer-file-coding-system' is not always correct either, but if
 901         ;; the OS/user uses only one coding-system, then it works.
 902         (coding-system-for-read buffer-file-coding-system))
 903     (write-region beg1 end1 file1 nil 'nomessage)
 904     (write-region beg2 end2 file2 nil 'nomessage)
 905     (unwind-protect
 906         (with-current-buffer (get-buffer-create smerge-diff-buffer-name)
 907           (setq default-directory dir)
 908           (let ((inhibit-read-only t))
 909             (erase-buffer)
 910             (let ((status
 911                    (apply 'call-process diff-command nil t nil
 912                           (append smerge-diff-switches
 913                                   (list "-L" (concat name1 "/" file)
 914                                         "-L" (concat name2 "/" file)
 915                                         file1 file2)))))
 916               (if (eq status 0) (insert "No differences found.\n"))))
 917           (goto-char (point-min))
 918           (diff-mode)
 919           (display-buffer (current-buffer) t))
 920       (delete-file file1)
 921       (delete-file file2))))
 922
 923 ;; compiler pacifiers
 924 (defvar smerge-ediff-windows)
 925 (defvar smerge-ediff-buf)
 926 (defvar ediff-buffer-A)
 927 (defvar ediff-buffer-B)
 928 (defvar ediff-buffer-C)
 929 (defvar ediff-ancestor-buffer)
 930 (defvar ediff-quit-hook)
 931 (declare-function ediff-cleanup-mess "ediff-util" nil)
 932
 933 ;;;###autoload
 934 (defun smerge-ediff (&optional name-mine name-other name-base)
 935   "Invoke ediff to resolve the conflicts.
 936 NAME-MINE, NAME-OTHER, and NAME-BASE, if non-nil, are used for the
 937 buffer names."
 938   (interactive)
 939   (let* ((buf (current-buffer))
 940          (mode major-mode)
 941          ;;(ediff-default-variant 'default-B)
 942          (config (current-window-configuration))
 943          (filename (file-name-nondirectory buffer-file-name))
 944          (mine (generate-new-buffer
 945                 (or name-mine (concat "*" filename " MINE*"))))
 946          (other (generate-new-buffer
 947                  (or name-other (concat "*" filename " OTHER*"))))
 948          base)
 949     (with-current-buffer mine
 950       (buffer-disable-undo)
 951       (insert-buffer-substring buf)
 952       (goto-char (point-min))
 953       (while (smerge-find-conflict)
 954         (when (match-beginning 2) (setq base t))
 955         (smerge-keep-n 1))
 956       (buffer-enable-undo)
 957       (set-buffer-modified-p nil)
 958       (funcall mode))
 959
 960     (with-current-buffer other
 961       (buffer-disable-undo)
 962       (insert-buffer-substring buf)
 963       (goto-char (point-min))
 964       (while (smerge-find-conflict)
 965         (smerge-keep-n 3))
 966       (buffer-enable-undo)
 967       (set-buffer-modified-p nil)
 968       (funcall mode))
 969
 970     (when base
 971       (setq base (generate-new-buffer
 972                   (or name-base (concat "*" filename " BASE*"))))
 973       (with-current-buffer base
 974         (buffer-disable-undo)
 975         (insert-buffer-substring buf)
 976         (goto-char (point-min))
 977         (while (smerge-find-conflict)
 978           (if (match-end 2)
 979               (smerge-keep-n 2)
 980             (delete-region (match-beginning 0) (match-end 0))))
 981         (buffer-enable-undo)
 982         (set-buffer-modified-p nil)
 983         (funcall mode)))
 984
 985     ;; the rest of the code is inspired from vc.el
 986     ;; Fire up ediff.
 987     (set-buffer
 988      (if base
 989          (ediff-merge-buffers-with-ancestor mine other base)
 990           ;; nil 'ediff-merge-revisions-with-ancestor buffer-file-name)
 991        (ediff-merge-buffers mine other)))
 992         ;; nil 'ediff-merge-revisions buffer-file-name)))
 993
 994     ;; Ediff is now set up, and we are in the control buffer.
 995     ;; Do a few further adjustments and take precautions for exit.
 996     (set (make-local-variable 'smerge-ediff-windows) config)
 997     (set (make-local-variable 'smerge-ediff-buf) buf)
 998     (set (make-local-variable 'ediff-quit-hook)
 999          (lambda ()
1000            (let ((buffer-A ediff-buffer-A)
1001                  (buffer-B ediff-buffer-B)
1002                  (buffer-C ediff-buffer-C)
1003                  (buffer-Ancestor ediff-ancestor-buffer)
1004                  (buf smerge-ediff-buf)
1005                  (windows smerge-ediff-windows))
1006              (ediff-cleanup-mess)
1007              (with-current-buffer buf
1008                (erase-buffer)
1009                (insert-buffer-substring buffer-C)
1010                (kill-buffer buffer-A)
1011                (kill-buffer buffer-B)
1012                (kill-buffer buffer-C)
1013                (when (bufferp buffer-Ancestor) (kill-buffer buffer-Ancestor))
1014                (set-window-configuration windows)
1015                (message "Conflict resolution finished; you may save the buffer")))))
1016     (message "Please resolve conflicts now; exit ediff when done")))
1017
1018 (defun smerge-makeup-conflict (pt1 pt2 pt3 &optional pt4)
1019   "Insert diff3 markers to make a new conflict.
1020 Uses point and mark for 2 of the relevant positions and previous marks
1021 for the other ones.
1022 By default, makes up a 2-way conflict,
1023 with a \\[universal-argument] prefix, makes up a 3-way conflict."
1024   (interactive
1025    (list (point)
1026          (mark)
1027          (progn (pop-mark) (mark))
1028          (when current-prefix-arg (pop-mark) (mark))))
1029   ;; Start from the end so as to avoid problems with pos-changes.
1030   (destructuring-bind (pt1 pt2 pt3 &optional pt4)
1031       (sort (list* pt1 pt2 pt3 (if pt4 (list pt4))) '>=)
1032     (goto-char pt1) (beginning-of-line)
1033     (insert ">>>>>>> OTHER\n")
1034     (goto-char pt2) (beginning-of-line)
1035     (insert "=======\n")
1036     (goto-char pt3) (beginning-of-line)
1037     (when pt4
1038       (insert "||||||| BASE\n")
1039       (goto-char pt4) (beginning-of-line))
1040     (insert "<<<<<<< MINE\n"))
1041   (if smerge-mode nil (smerge-mode 1))
1042   (smerge-refine))
1043
1044
1045 (defconst smerge-parsep-re
1046   (concat smerge-begin-re "\\|" smerge-end-re "\\|"
1047           smerge-base-re "\\|" smerge-other-re "\\|"))
1048
1049 ;;;###autoload
1050 (define-minor-mode smerge-mode
1051   "Minor mode to simplify editing output from the diff3 program.
1052 \\{smerge-mode-map}"
1053   :group 'smerge :lighter " SMerge"
1054   (when (and (boundp 'font-lock-mode) font-lock-mode)
1055     (save-excursion
1056       (if smerge-mode
1057           (font-lock-add-keywords nil smerge-font-lock-keywords 'append)
1058         (font-lock-remove-keywords nil smerge-font-lock-keywords))
1059       (goto-char (point-min))
1060       (while (smerge-find-conflict)
1061         (save-excursion
1062           (font-lock-fontify-region (match-beginning 0) (match-end 0) nil)))))
1063   (if (string-match (regexp-quote smerge-parsep-re) paragraph-separate)
1064       (unless smerge-mode
1065         (set (make-local-variable 'paragraph-separate)
1066              (replace-match "" t t paragraph-separate)))
1067     (when smerge-mode
1068         (set (make-local-variable 'paragraph-separate)
1069              (concat smerge-parsep-re paragraph-separate))))
1070   (unless smerge-mode
1071     (smerge-remove-props (point-min) (point-max))))
1072
1073 ;;;###autoload
1074 (defun smerge-start-session ()
1075   "Turn on `smerge-mode' and move point to first conflict marker.
1076 If no conflict maker is found, turn off `smerge-mode'."
1077   (smerge-mode 1)
1078   (condition-case nil
1079       (smerge-next)
1080     (error (smerge-auto-leave))))
1081
1082 (provide 'smerge-mode)
1083
1084 ;; arch-tag: 605c8d1e-e43d-4943-a6f3-1bcc4333e690
1085 ;;; smerge-mode.el ends here