lisp/smerge-mode.el

   1 ;;; smerge-mode.el --- Minor mode to resolve diff3 conflicts
   2
   3 ;; Copyright (C) 1999, 2000, 2001  Free Software Foundation, Inc.
   4
   5 ;; Author: Stefan Monnier <monnier@cs.yale.edu>
   6 ;; Keywords: merge diff3 cvs conflict
   7 ;; Revision: $Id: smerge-mode.el,v 1.19 2002/10/10 13:01:14 monnier Exp $
   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 2, 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., 59 Temple Place - Suite 330,
  24 ;; Boston, MA 02111-1307, 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 (defgroup smerge ()
  53   "Minor mode to resolve diff3 conflicts."
  54   :group 'tools
  55   :prefix "smerge-")
  56
  57 (defcustom smerge-diff-buffer-name "*vc-diff*"
  58   "Buffer name to use for displaying diffs."
  59   :group 'smerge
  60   :type '(choice
  61           (const "*vc-diff*")
  62           (const "*cvs-diff*")
  63           (const "*smerge-diff*")
  64           string))
  65
  66 (defcustom smerge-diff-switches
  67   (append '("-d" "-b")
  68           (if (listp diff-switches) diff-switches (list diff-switches)))
  69   "*A list of strings specifying switches to be be passed to diff.
  70 Used in `smerge-diff-base-mine' and related functions."
  71   :group 'smerge
  72   :type '(repeat string))
  73
  74 (defcustom smerge-auto-leave t
  75   "*Non-nil means to leave `smerge-mode' when the last conflict is resolved."
  76   :group 'smerge
  77   :type 'boolean)
  78
  79 (defface smerge-mine-face
  80   '((((background light))
  81      (:foreground "blue"))
  82     (((background dark))
  83      (:foreground "cyan")))
  84   "Face for your code."
  85   :group 'smerge)
  86 (defvar smerge-mine-face 'smerge-mine-face)
  87
  88 (defface smerge-other-face
  89   '((((background light))
  90      (:foreground "darkgreen"))
  91     (((background dark))
  92      (:foreground "lightgreen")))
  93   "Face for the other code."
  94   :group 'smerge)
  95 (defvar smerge-other-face 'smerge-other-face)
  96
  97 (defface smerge-base-face
  98   '((((background light))
  99      (:foreground "red"))
 100     (((background dark))
 101      (:foreground "orange")))
 102   "Face for the base code."
 103   :group 'smerge)
 104 (defvar smerge-base-face 'smerge-base-face)
 105
 106 (defface smerge-markers-face
 107   '((((background light))
 108      (:background "grey85"))
 109     (((background dark))
 110      (:background "grey30")))
 111   "Face for the conflict markers."
 112   :group 'smerge)
 113 (defvar smerge-markers-face 'smerge-markers-face)
 114
 115 (easy-mmode-defmap smerge-basic-map
 116   `(("n" . smerge-next)
 117     ("p" . smerge-prev)
 118     ("r" . smerge-resolve)
 119     ("a" . smerge-keep-all)
 120     ("b" . smerge-keep-base)
 121     ("o" . smerge-keep-other)
 122     ("m" . smerge-keep-mine)
 123     ("E" . smerge-ediff)
 124     ("\C-m" . smerge-keep-current)
 125     ("=" . ,(make-sparse-keymap "Diff"))
 126     ("=<" "base-mine" . smerge-diff-base-mine)
 127     ("=>" "base-other" . smerge-diff-base-other)
 128     ("==" "mine-other" . smerge-diff-mine-other))
 129   "The base keymap for `smerge-mode'.")
 130
 131 (defcustom smerge-command-prefix "\C-c^"
 132   "Prefix for `smerge-mode' commands."
 133   :group 'smerge
 134   :type '(choice (string "\e") (string "\C-c^") (string "") string))
 135
 136 (easy-mmode-defmap smerge-mode-map
 137   `((,smerge-command-prefix . ,smerge-basic-map))
 138   "Keymap for `smerge-mode'.")
 139
 140 (easy-menu-define smerge-mode-menu smerge-mode-map
 141   "Menu for `smerge-mode'."
 142   '("SMerge"
 143     ["Next" smerge-next :help "Go to next conflict"]
 144     ["Previous" smerge-prev :help "Go to previous conflict"]
 145     ["Keep All" smerge-keep-all :help "Keep all three versions"]
 146     ["Revert to Base" smerge-keep-base :help "Revert to base version"]
 147     ["Keep Other" smerge-keep-other :help "Keep `other' version"]
 148     ["Keep Yours" smerge-keep-mine :help "Keep your version"]
 149     ["Keep Current" smerge-keep-current :help "Use current (at point) version"]
 150     "--"
 151     ["Diff Base/Mine" smerge-diff-base-mine
 152      :help "Diff `base' and `mine' for current conflict"]
 153     ["Diff Base/Other" smerge-diff-base-other
 154      :help "Diff `base' and `other' for current conflict"]
 155     ["Diff Mine/Other" smerge-diff-mine-other
 156      :help "Diff `mine' and `other' for current conflict"]
 157     "--"
 158     ["Invoke Ediff" smerge-ediff
 159      :help "Use Ediff to resolve the conflicts"]
 160     ))
 161
 162 (defconst smerge-font-lock-keywords
 163   '((smerge-find-conflict
 164      (1 smerge-mine-face prepend t)
 165      (2 smerge-base-face prepend t)
 166      (3 smerge-other-face prepend t)
 167      ;; FIXME: `keep' doesn't work right with syntactic fontification.
 168      (0 smerge-markers-face keep)
 169      (4 nil t t)
 170      (5 nil t t)))
 171   "Font lock patterns for `smerge-mode'.")
 172
 173 (defconst smerge-begin-re "^<<<<<<< \\(.*\\)\n")
 174 (defconst smerge-end-re "^>>>>>>> .*\n")
 175 (defconst smerge-base-re "^||||||| .*\n")
 176 (defconst smerge-other-re "^=======\n")
 177
 178 (defvar smerge-conflict-style nil
 179   "Keep track of which style of conflict is in use.
 180 Can be nil if the style is undecided, or else:
 181 - `diff3-E'
 182 - `diff3-A'")
 183
 184 ;; Compiler pacifiers
 185 (defvar font-lock-mode)
 186 (defvar font-lock-keywords)
 187
 188 ;;;;
 189 ;;;; Actual code
 190 ;;;;
 191
 192 ;; Define smerge-next and smerge-prev
 193 (easy-mmode-define-navigation smerge smerge-begin-re "conflict")
 194
 195 (defconst smerge-match-names ["conflict" "mine" "base" "other"])
 196
 197 (defun smerge-ensure-match (n)
 198   (unless (match-end n)
 199     (error (format "No `%s'" (aref smerge-match-names n)))))
 200
 201 (defun smerge-auto-leave ()
 202   (when (and smerge-auto-leave
 203              (save-excursion (goto-char (point-min))
 204                              (not (re-search-forward smerge-begin-re nil t))))
 205     (smerge-mode -1)))
 206
 207
 208 (defun smerge-keep-all ()
 209   "Keep all three versions.
 210 Convenient for the kind of conflicts that can arise in ChangeLog files."
 211   (interactive)
 212   (smerge-match-conflict)
 213   (replace-match (concat (or (match-string 1) "")
 214                          (or (match-string 2) "")
 215                          (or (match-string 3) ""))
 216                  t t)
 217   (smerge-auto-leave))
 218
 219 (defun smerge-combine-with-next ()
 220   "Combine the current conflict with the next one."
 221   (interactive)
 222   (smerge-match-conflict)
 223   (let ((ends nil))
 224     (dolist (i '(3 2 1 0))
 225       (push (if (match-end i) (copy-marker (match-end i) t)) ends))
 226     (setq ends (apply 'vector ends))
 227     (goto-char (aref ends 0))
 228     (if (not (re-search-forward smerge-begin-re nil t))
 229         (error "No next conflict")
 230       (smerge-match-conflict)
 231       (let ((match-data (mapcar (lambda (m) (if m (copy-marker m)))
 232                                 (match-data))))
 233         ;; First copy the in-between text in each alternative.
 234         (dolist (i '(1 2 3))
 235           (when (aref ends i)
 236             (goto-char (aref ends i))
 237             (insert-buffer-substring (current-buffer)
 238                                      (aref ends 0) (car match-data))))
 239         (delete-region (aref ends 0) (car match-data))
 240         ;; Then move the second conflict's alternatives into the first.
 241         (dolist (i '(1 2 3))
 242           (set-match-data match-data)
 243           (when (and (aref ends i) (match-end i))
 244             (goto-char (aref ends i))
 245             (insert-buffer-substring (current-buffer)
 246                                      (match-beginning i) (match-end i))))
 247         (delete-region (car match-data) (cadr match-data))
 248         ;; Free the markers.
 249         (dolist (m match-data) (if m (move-marker m nil)))
 250         (mapc (lambda (m) (if m (move-marker m nil))) ends)))))
 251
 252 (defvar smerge-resolve-function
 253   (lambda () (error "Don't know how to resolve"))
 254   "Mode-specific merge function.
 255 The function is called with no argument and with the match data set
 256 according to `smerge-match-conflict'.")
 257
 258 (defun smerge-resolve ()
 259   "Resolve the conflict at point intelligently.
 260 This relies on mode-specific knowledge and thus only works in
 261 some major modes.  Uses `smerge-resolve-function' to do the actual work."
 262   (interactive)
 263   (smerge-match-conflict)
 264   (funcall smerge-resolve-function)
 265   (smerge-auto-leave))
 266
 267 (defun smerge-keep-base ()
 268   "Revert to the base version."
 269   (interactive)
 270   (smerge-match-conflict)
 271   (smerge-ensure-match 2)
 272   (replace-match (match-string 2) t t)
 273   (smerge-auto-leave))
 274
 275 (defun smerge-keep-other ()
 276   "Use \"other\" version."
 277   (interactive)
 278   (smerge-match-conflict)
 279   ;;(smerge-ensure-match 3)
 280   (replace-match (match-string 3) t t)
 281   (smerge-auto-leave))
 282
 283 (defun smerge-keep-mine ()
 284   "Keep your version."
 285   (interactive)
 286   (smerge-match-conflict)
 287   ;;(smerge-ensure-match 1)
 288   (replace-match (match-string 1) t t)
 289   (smerge-auto-leave))
 290
 291 (defun smerge-keep-current ()
 292   "Use the current (under the cursor) version."
 293   (interactive)
 294   (smerge-match-conflict)
 295   (let ((i 3))
 296     (while (or (not (match-end i))
 297                (< (point) (match-beginning i))
 298                (>= (point) (match-end i)))
 299       (decf i))
 300     (if (<= i 0) (error "Not inside a version")
 301       (replace-match (match-string i) t t)
 302       (smerge-auto-leave))))
 303
 304 (defun smerge-diff-base-mine ()
 305   "Diff 'base' and 'mine' version in current conflict region."
 306   (interactive)
 307   (smerge-diff 2 1))
 308
 309 (defun smerge-diff-base-other ()
 310   "Diff 'base' and 'other' version in current conflict region."
 311   (interactive)
 312   (smerge-diff 2 3))
 313
 314 (defun smerge-diff-mine-other ()
 315   "Diff 'mine' and 'other' version in current conflict region."
 316   (interactive)
 317   (smerge-diff 1 3))
 318
 319 (defun smerge-match-conflict ()
 320   "Get info about the conflict.  Puts the info in the `match-data'.
 321 The submatches contain:
 322  0:  the whole conflict.
 323  1:  your code.
 324  2:  the base code.
 325  3:  other code.
 326 An error is raised if not inside a conflict."
 327   (save-excursion
 328     (condition-case nil
 329         (let* ((orig-point (point))
 330
 331                (_ (forward-line 1))
 332                (_ (re-search-backward smerge-begin-re))
 333
 334                (start (match-beginning 0))
 335                (mine-start (match-end 0))
 336                (filename (or (match-string 1) ""))
 337
 338                (_ (re-search-forward smerge-end-re))
 339                (_ (assert (< orig-point (match-end 0))))
 340
 341                (other-end (match-beginning 0))
 342                (end (match-end 0))
 343
 344                (_ (re-search-backward smerge-other-re start))
 345
 346                (mine-end (match-beginning 0))
 347                (other-start (match-end 0))
 348
 349                base-start base-end)
 350
 351           ;; handle the various conflict styles
 352           (cond
 353            ((re-search-backward smerge-base-re start t)
 354             ;; a 3-parts conflict
 355             (set (make-local-variable 'smerge-conflict-style) 'diff3-A)
 356             (setq base-end mine-end)
 357             (setq mine-end (match-beginning 0))
 358             (setq base-start (match-end 0)))
 359
 360           ((string= filename (file-name-nondirectory
 361                               (or buffer-file-name "")))
 362            ;; a 2-parts conflict
 363            (set (make-local-variable 'smerge-conflict-style) 'diff3-E))
 364
 365           ((and (not base-start)
 366                 (or (eq smerge-conflict-style 'diff3-A)
 367                     (string-match "^[.0-9]+\\'" filename)))
 368            ;; a same-diff conflict
 369            (setq base-start mine-start)
 370            (setq base-end   mine-end)
 371            (setq mine-start other-start)
 372            (setq mine-end   other-end)))
 373
 374           (store-match-data (list start end
 375                                   mine-start mine-end
 376                                   base-start base-end
 377                                   other-start other-end
 378                                   (when base-start (1- base-start)) base-start
 379                                   (1- other-start) other-start))
 380           t)
 381       (search-failed (error "Point not in conflict region")))))
 382
 383 (defun smerge-find-conflict (&optional limit)
 384   "Find and match a conflict region.  Intended as a font-lock MATCHER.
 385 The submatches are the same as in `smerge-match-conflict'.
 386 Returns non-nil if a match is found between the point and LIMIT.
 387 The point is moved to the end of the conflict."
 388   (when (re-search-forward smerge-begin-re limit t)
 389     (ignore-errors
 390       (smerge-match-conflict)
 391       (goto-char (match-end 0)))))
 392
 393 (defun smerge-diff (n1 n2)
 394   (smerge-match-conflict)
 395   (smerge-ensure-match n1)
 396   (smerge-ensure-match n2)
 397   (let ((name1 (aref smerge-match-names n1))
 398         (name2 (aref smerge-match-names n2))
 399         ;; Read them before the match-data gets clobbered.
 400         (beg1 (match-beginning n1))
 401         (end1 (match-end n1))
 402         (beg2 (match-beginning n2))
 403         (end2 (match-end n2))
 404         (file1 (make-temp-file "smerge1"))
 405         (file2 (make-temp-file "smerge2"))
 406         (dir default-directory)
 407         (file (file-relative-name buffer-file-name))
 408         (coding-system-for-read buffer-file-coding-system))
 409     (write-region beg1 end1 file1 nil 'nomessage)
 410     (write-region beg2 end2 file2 nil 'nomessage)
 411     (unwind-protect
 412         (with-current-buffer (get-buffer-create smerge-diff-buffer-name)
 413           (setq default-directory dir)
 414           (let ((inhibit-read-only t))
 415             (erase-buffer)
 416             (let ((status
 417                    (apply 'call-process diff-command nil t nil
 418                           (append smerge-diff-switches
 419                                   (list "-L" (concat name1 "/" file)
 420                                         "-L" (concat name2 "/" file)
 421                                         file1 file2)))))
 422               (if (eq status 0) (insert "No differences found.\n"))))
 423           (goto-char (point-min))
 424           (diff-mode)
 425           (display-buffer (current-buffer) t))
 426       (delete-file file1)
 427       (delete-file file2))))
 428
 429 ;; compiler pacifiers
 430 (defvar smerge-ediff-windows)
 431 (defvar smerge-ediff-buf)
 432 (defvar ediff-buffer-A)
 433 (defvar ediff-buffer-B)
 434 (defvar ediff-buffer-C)
 435
 436 ;;;###autoload
 437 (defun smerge-ediff (&optional name-mine name-other name-base)
 438   "Invoke ediff to resolve the conflicts.
 439 NAME-MINE, NAME-OTHER, and NAME-BASE, if non-nil, are used for the
 440 buffer names."
 441   (interactive)
 442   (let* ((buf (current-buffer))
 443          (mode major-mode)
 444          ;;(ediff-default-variant 'default-B)
 445          (config (current-window-configuration))
 446          (filename (file-name-nondirectory buffer-file-name))
 447          (mine (generate-new-buffer
 448                 (or name-mine (concat "*" filename " MINE*"))))
 449          (other (generate-new-buffer
 450                  (or name-other (concat "*" filename " OTHER*"))))
 451          base)
 452     (with-current-buffer mine
 453       (buffer-disable-undo)
 454       (insert-buffer-substring buf)
 455       (goto-char (point-min))
 456       (while (smerge-find-conflict)
 457         (when (match-beginning 2) (setq base t))
 458         (replace-match (match-string 1) t t))
 459       (buffer-enable-undo)
 460       (set-buffer-modified-p nil)
 461       (funcall mode))
 462
 463     (with-current-buffer other
 464       (buffer-disable-undo)
 465       (insert-buffer-substring buf)
 466       (goto-char (point-min))
 467       (while (smerge-find-conflict)
 468         (replace-match (match-string 3) t t))
 469       (buffer-enable-undo)
 470       (set-buffer-modified-p nil)
 471       (funcall mode))
 472
 473     (when base
 474       (setq base (generate-new-buffer
 475                   (or name-base (concat "*" filename " BASE*"))))
 476       (with-current-buffer base
 477         (buffer-disable-undo)
 478         (insert-buffer-substring buf)
 479         (goto-char (point-min))
 480         (while (smerge-find-conflict)
 481           (replace-match (or (match-string 2) "") t t))
 482         (buffer-enable-undo)
 483         (set-buffer-modified-p nil)
 484         (funcall mode)))
 485
 486     ;; the rest of the code is inspired from vc.el
 487     ;; Fire up ediff.
 488     (set-buffer
 489      (if base
 490          (ediff-merge-buffers-with-ancestor mine other base)
 491           ;; nil 'ediff-merge-revisions-with-ancestor buffer-file-name)
 492        (ediff-merge-buffers mine other)))
 493         ;; nil 'ediff-merge-revisions buffer-file-name)))
 494
 495     ;; Ediff is now set up, and we are in the control buffer.
 496     ;; Do a few further adjustments and take precautions for exit.
 497     (set (make-local-variable 'smerge-ediff-windows) config)
 498     (set (make-local-variable 'smerge-ediff-buf) buf)
 499     (set (make-local-variable 'ediff-quit-hook)
 500          (lambda ()
 501            (let ((buffer-A ediff-buffer-A)
 502                  (buffer-B ediff-buffer-B)
 503                  (buffer-C ediff-buffer-C)
 504                  (buffer-Ancestor ediff-ancestor-buffer)
 505                  (buf smerge-ediff-buf)
 506                  (windows smerge-ediff-windows))
 507              (ediff-cleanup-mess)
 508              (with-current-buffer buf
 509                (erase-buffer)
 510                (insert-buffer buffer-C)
 511                (kill-buffer buffer-A)
 512                (kill-buffer buffer-B)
 513                (kill-buffer buffer-C)
 514                (when (bufferp buffer-Ancestor) (kill-buffer buffer-Ancestor))
 515                (set-window-configuration windows)
 516                (message "Conflict resolution finished; you may save the buffer")))))
 517     (message "Please resolve conflicts now; exit ediff when done")))
 518
 519
 520 ;;;###autoload
 521 (define-minor-mode smerge-mode
 522   "Minor mode to simplify editing output from the diff3 program.
 523 \\{smerge-mode-map}"
 524   nil " SMerge" nil
 525   (when (and (boundp 'font-lock-mode) font-lock-mode)
 526     (set (make-local-variable 'font-lock-multiline) t)
 527     (save-excursion
 528       (if smerge-mode
 529           (font-lock-add-keywords nil smerge-font-lock-keywords 'append)
 530         (font-lock-remove-keywords nil smerge-font-lock-keywords))
 531       (goto-char (point-min))
 532       (while (smerge-find-conflict)
 533         (save-excursion
 534           (font-lock-fontify-region (match-beginning 0) (match-end 0) nil))))))
 535
 536
 537 (provide 'smerge-mode)
 538 ;;; smerge-mode.el ends here