cpp.el 25.6 KB
Newer Older
Richard M. Stallman's avatar
Richard M. Stallman committed
1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43 44 45 46 47 48 49 50 51 52 53 54 55 56 57 58 59 60 61 62 63 64 65 66 67 68 69 70 71 72 73 74 75 76 77 78 79 80 81 82 83 84 85 86 87 88 89 90 91 92 93 94 95 96 97 98 99 100 101 102 103 104 105 106 107 108 109 110 111 112 113 114 115 116 117 118 119 120 121 122 123 124 125 126 127 128 129 130 131 132 133 134 135 136 137 138 139 140 141 142 143 144 145 146 147 148 149 150 151 152 153 154 155 156 157 158 159 160 161 162 163 164 165 166 167 168 169 170 171 172 173 174 175 176 177 178 179 180 181 182 183 184 185 186 187 188 189 190 191 192 193 194 195 196 197 198 199 200 201 202 203 204 205 206 207 208 209 210 211 212 213 214 215 216 217 218 219 220 221 222 223 224 225 226 227 228 229 230 231 232 233 234 235 236 237 238 239 240 241 242 243 244 245 246 247 248 249 250 251 252 253 254 255 256 257 258 259 260 261 262 263 264 265 266 267 268 269 270 271 272 273 274 275 276 277 278 279 280 281 282 283 284 285 286 287 288 289 290 291 292 293 294 295 296 297 298 299 300 301 302 303 304 305 306 307 308 309 310 311 312 313 314 315 316 317 318 319 320 321 322 323 324 325 326 327 328 329 330 331 332 333 334 335 336 337 338 339 340 341 342 343 344 345 346 347 348 349 350 351 352 353 354 355 356 357 358 359 360 361 362 363 364 365 366 367 368 369 370 371 372 373 374 375 376 377 378 379 380 381 382 383 384 385 386 387 388 389 390 391 392 393 394 395 396 397 398 399 400 401 402 403 404 405 406 407 408 409 410 411 412 413 414 415 416 417 418 419 420 421 422 423 424 425 426 427 428 429 430 431 432 433 434 435 436 437 438 439 440 441 442 443 444 445 446 447 448 449 450 451 452 453 454 455 456 457 458 459 460 461 462 463 464 465 466 467 468 469 470 471 472 473 474 475 476 477 478 479 480 481 482 483 484 485 486 487 488 489 490 491 492 493 494 495 496 497 498 499 500 501 502 503 504 505 506 507 508 509 510 511 512 513 514 515 516 517 518 519 520 521 522 523 524 525 526 527 528 529 530 531 532 533 534 535 536 537 538 539 540 541 542 543 544 545 546 547 548 549 550 551 552 553 554 555 556 557 558 559 560 561 562 563 564 565 566 567 568 569 570 571 572 573 574 575 576 577 578 579 580 581 582 583 584 585 586 587 588 589 590 591 592 593 594 595 596 597 598 599 600 601 602 603 604 605 606 607 608 609 610 611 612 613 614 615 616 617 618 619 620 621 622 623 624 625 626 627 628 629 630 631 632 633 634 635 636 637 638 639 640 641 642 643 644 645 646 647 648 649 650 651 652 653 654 655 656 657 658 659 660 661 662 663 664 665 666 667 668 669 670 671 672 673 674 675 676 677 678 679 680 681 682 683 684 685 686 687 688 689 690 691 692 693 694 695 696 697 698 699 700 701 702 703 704 705 706 707 708 709 710 711 712 713 714 715 716 717 718 719 720 721 722 723 724 725 726 727 728 729 730 731 732 733 734 735 736 737 738 739 740 741 742 743 744 745 746 747 748 749 750 751 752 753 754 755 756 757 758 759 760 761 762 763 764 765 766 767 768 769 770 771 772 773
;;; cpp.el --- Highlight or hide text according to cpp conditionals.

;; Copyright (C) 1994 Free Software Foundation

;; Author: Per Abrahamsen <abraham@iesd.auc.dk>
;; Version: $Id: 0.2 ALPHA RELEASE WITH BUGS $
;; Keywords: c, faces, tools

;; LCD Archive Entry:
;; cpp|Per Abrahamsen|abraham@iesd.auc.dk|
;; Highlight or hide text according to cpp conditionals|
;; $Date: 1994-07-20 $|$Revision: 0.2 $|~/misc/cpp.Z|

;; This program is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 2, or (at your option)
;; any later version.
;; 
;; This program is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.
;; 
;; You should have received a copy of the GNU General Public License
;; along with this program; if not, write to the Free Software
;; Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.

;;; Comments:

;; Parse a text for C preprocessor conditionals, and highlight or hide
;; the text inside the conditionals as you wish.

;; Insert the following in your `emacs' to activate it.  This assumes
;; you use BAW's superior cc-mode instead of Boring Old C-Mode.

;; (autoload 'cpp-parse-buffer "cpp" "Parse and display cpp conditionals." t)
  
;; (eval-after-load "cc-mode"
;;   '(progn
;;      (define-key c-mode-map "\C-c\C-x" 'cpp-parse-buffer)
;;      (define-key-after (bar (lookup-key c-mode-map [ menu-bar c ]))
;;        [ cpp-parse ] '("Parse Conditionals" . cpp-parse-buffer) 'up))))

;; Requires GNU Emacs 19.

;;; Todo:

;; Should parse "#if" and "#elif" expressions and merge the faces
;; somehow. 

;; Somehow it is sometimes possible to make changes near a read only
;; area which you can't undo.  Their are other strange effects in that
;; area.

;; The Edit buffer should -- optionally -- appear in its own frame.

;; Conditionals seem to be rear-sticky.  They shouldn't be.

;; Restore window configurations when exiting CPP Edit buffer.

;;; Code:

;;; Customization:

(defvar cpp-known-face 'invisible
  "*Face used for known cpp symbols.")

(defvar cpp-unknown-face 'highlight
  "*Face used for unknown cpp cymbols.")

(defvar cpp-face-type 'light 
  "*Indicate what background face type you prefer.
Can be either light or dark for color screens, mono for monochrome
screens, and none if you don't use a window system.")

(defvar cpp-known-writable t
  "*Non-nil means you are allowed to modify the known conditionals.")

(defvar cpp-unknown-writable t
  "*Non-nil means you are allowed to modify the unknown conditionals.")

;;; Parse Buffer:

(defvar cpp-parse-symbols nil
  "List of cpp macros used in the local buffer.")
(make-variable-buffer-local 'cpp-parse-symbols)

(defconst cpp-parse-regexp
  ;; Regexp matching all tokens needed to find conditionals.
  (concat
   "'\\|\"\\|/\\*\\|//\\|"
   "\\(^[ \t]*#[ \t]*\\(ifdef\\|ifndef\\|if\\|"
   "elif\\|else\\|endif\\)\\b\\)"))

;;;###autoload
(defun cpp-parse-buffer (arg)
  "Parse all conditionals in the current buffer end edit symbols.
A prefix arg supress editing the symbols."
  (interactive "P")
  (setq cpp-parse-symbols nil)
  (cpp-parse-reset)
  (if (null cpp-edit-list)
      (cpp-edit-load))
  (let (stack)
    (save-excursion
      (goto-char (point-min))
      (cpp-progress-message "Parsing...")
      (while (re-search-forward cpp-parse-regexp nil t)
	(cpp-progress-message "Parsing...%d%%"
			  (/ (* 100 (- (point) (point-min))) (buffer-size)))
	(let ((match (buffer-substring (match-beginning 0) (match-end 0))))
	  (cond ((or (string-equal match "'")
		     (string-equal match "\""))
		 (goto-char (match-beginning 0))
		 (condition-case nil
		     (forward-sexp)
		   (error (cpp-parse-error
			   "Unterminated string or character"))))
		((string-equal match "/*")
		 (or (search-forward "*/" nil t)
		     (error "Unterminated comment")))
		((string-equal match "//")
		 (skip-chars-forward "^\n\r"))
		(t
		 (end-of-line 1)
		 (let ((from (match-beginning 1))
		       (to (1+ (point)))
		       (type (buffer-substring (match-beginning 2)
					       (match-end 2)))
		       (expr (buffer-substring (match-end 1) (point))))
		   (cond ((string-equal type "ifdef")
			  (cpp-parse-open t expr from to))
			 ((string-equal type "ifndef")
			  (cpp-parse-open nil expr from to))
			 ((string-equal type "if")
			  (cpp-parse-open t expr from to))
			 ((string-equal type "elif")
			  (let (cpp-known-face cpp-unknown-face)
			    (cpp-parse-close from to))
			  (cpp-parse-open t expr from to))
			 ((string-equal type "else")
			  (or stack (cpp-parse-error "Top level #else"))
			  (let ((entry (list (not (nth 0 (car stack)))
					     (nth 1 (car stack))
					     from to)))
			    (cpp-parse-close from to)
			    (setq stack (cons entry stack))))
			 ((string-equal type "endif")
			  (cpp-parse-close from to))
			 (t
			  (cpp-parse-error "Parser error"))))))))
      (message "Parsing...done"))
    (if stack
      (save-excursion
	(goto-char (nth 3 (car stack)))
	(cpp-parse-error "Unclosed conditional"))))
  (or arg
      (null cpp-parse-symbols)
      (cpp-parse-edit)))

(defun cpp-parse-open (branch expr begin end)
  ;; Push information about conditional to stack.
  (while (string-match "\\b[ \t]*/\\*.*\\*/[ \t]*\\b" expr)
    (setq expr (concat (substring expr 0 (match-beginning 0))
		       (substring expr (match-end 0)))))
  (if (string-match "\\b[ \t]*\\(//.*\\)?$" expr)
      (setq expr (substring expr 0 (match-beginning 0))))
  (while (string-match "[ \t]+" expr)
      (setq expr (concat (substring expr 0 (match-beginning 0))
			 (substring expr (match-end 0)))))
  (setq stack (cons (list branch expr begin end) stack))
  (or (member expr cpp-parse-symbols)
      (setq cpp-parse-symbols
	    (cons expr cpp-parse-symbols)))
  (if (assoc expr cpp-edit-list)
      (cpp-make-known-overlay begin end)
    (cpp-make-unknown-overlay begin end)))

(defun cpp-parse-close (from to)
  ;; Pop top of stack and create overlay.
  (let ((entry (assoc (nth 1 (car stack)) cpp-edit-list))
	(branch (nth 0 (car stack)))
	(begin (nth 2 (car stack)))
	(end (nth 3 (car stack))))
    (setq stack (cdr stack))
    (if entry
	(let ((face (nth (if branch 1 2) entry))
	      (read-only (eq (not branch) (nth 3 entry)))
	      (priority (length stack))
	      (overlay (make-overlay end from)))
	  (cpp-make-known-overlay from to)
	  (setq cpp-overlay-list (cons overlay cpp-overlay-list))
	  (if priority (overlay-put overlay 'priority priority))
	  (cond ((eq face 'invisible)
		 (cpp-make-overlay-hidden overlay))
		((eq face 'default))
		(t
		 (overlay-put overlay 'face face)))
	  (if read-only
	      (cpp-make-overlay-read-only overlay)
	    (cpp-make-overlay-sticky overlay)))
      (cpp-make-unknown-overlay from to))))

(defun cpp-parse-error (error)
  ;; Error message issued by the cpp parser.
  (error (concat error " at line %d") (count-lines (point-min) (point))))

(defun cpp-parse-reset ()
  "Reset display of cpp conditionals to normal."
  (interactive)
  (while cpp-overlay-list
    (delete-overlay (car cpp-overlay-list))
    (setq cpp-overlay-list (cdr cpp-overlay-list))))

;;;###autoload
(defun cpp-parse-edit ()
  "Edit display information for cpp conditionals."
  (interactive)
  (or cpp-parse-symbols
      (cpp-parse-buffer t))
  (let ((buffer (current-buffer)))
    (pop-to-buffer "*CPP Edit*")
    (cpp-edit-mode)
    (setq cpp-edit-buffer buffer)
    (cpp-edit-reset)))

;;; Overlays:

(defvar cpp-overlay-list nil)
;; List of cpp overlays active in the current buffer.
(make-variable-buffer-local 'cpp-overlay-list)

(defun cpp-make-known-overlay (start end)
  ;; Create an overlay for a known cpp command from START to END.
  (let ((overlay (make-overlay start end)))
    (if (eq cpp-known-face 'invisible)
	(cpp-make-overlay-hidden overlay)
      (or (eq cpp-known-face 'default)
	  (overlay-put overlay 'face cpp-known-face))
      (if cpp-known-writable
	  ()
	(overlay-put overlay 'modification-hooks '(cpp-signal-read-only))
	(overlay-put overlay 'insert-in-front-hooks '(cpp-signal-read-only))))
    (setq cpp-overlay-list (cons overlay cpp-overlay-list))))

(defun cpp-make-unknown-overlay (start end)
  ;; Create an overlay for an unknown cpp command from START to END.
  (let ((overlay (make-overlay start end)))
    (cond ((eq cpp-unknown-face 'invisible)
	   (cpp-make-overlay-hidden overlay))
	  ((eq cpp-unknown-face 'default))
	  (t 
	   (overlay-put overlay 'face cpp-unknown-face)))
    (if cpp-unknown-writable
	()
      (overlay-put overlay 'modification-hooks '(cpp-signal-read-only))
      (overlay-put overlay 'insert-in-front-hooks '(cpp-signal-read-only)))
    (setq cpp-overlay-list (cons overlay cpp-overlay-list))))

(defun cpp-make-overlay-hidden (overlay)
  ;; Make overlay hidden and intangible.
  (overlay-put overlay 'invisible t)
  (overlay-put overlay 'intangible t)
  ;; Unfortunately `intangible' is not implemented for overlays yet,
  ;; so we make is read-only instead.
  (overlay-put overlay 'modification-hooks '(cpp-signal-read-only)))

(defun cpp-make-overlay-read-only (overlay)
  ;; Make overlay read only.
  (overlay-put overlay 'modification-hooks '(cpp-signal-read-only))
  (overlay-put overlay 'insert-in-front-hooks '(cpp-signal-read-only))
  (overlay-put overlay 'insert-behind-hooks '(cpp-signal-read-only)))

(defun cpp-make-overlay-sticky (overlay)
  ;; Make OVERLAY grow when you insert text at either end.
  (overlay-put overlay 'insert-in-front-hooks '(cpp-grow-overlay))
  (overlay-put overlay 'insert-behind-hooks '(cpp-grow-overlay)))

(defun cpp-signal-read-only (overlay start end)
  ;; Only allow deleting the whole overlay.
  ;; Trying to change a read-only overlay.
  (if (or (< (overlay-start overlay) start)
	  (> (overlay-end overlay) end))
      (error "This text is read only")))

(defun cpp-grow-overlay (overlay start end)
  ;; Make OVERLAY grow to contain range START to END.
  (move-overlay overlay
		(min start (overlay-start overlay))
		(max end (overlay-end overlay))))

;;; Edit Buffer:

(defvar cpp-edit-list nil
  "Alist of cpp macros and information about how they should be displayed.
Each entry is a list with the following elements:
0. The name of the macro (a string).
1. Face used for text that is `ifdef' the macro.
2. Face used for text that is `ifndef' the macro.
3. `t', `nil', or `both' depending on what text may be edited.")

(defvar cpp-edit-map nil)
;; Keymap for `cpp-edit-mode'.

(if cpp-edit-map
    ()
  (setq cpp-edit-map (make-keymap))
  (suppress-keymap cpp-edit-map)
  (define-key cpp-edit-map [ down-mouse-2 ] 'cpp-push-button)
  (define-key cpp-edit-map [ mouse-2 ] 'ignore)
  (define-key cpp-edit-map " " 'scroll-up)
  (define-key cpp-edit-map "\C-?" 'scroll-down)
  (define-key cpp-edit-map [ delete ] 'scroll-down)
  (define-key cpp-edit-map "\C-c\C-c" 'cpp-edit-apply)
  (define-key cpp-edit-map "a" 'cpp-edit-apply)
  (define-key cpp-edit-map "A" 'cpp-edit-apply)
  (define-key cpp-edit-map "r" 'cpp-edit-reset)
  (define-key cpp-edit-map "R" 'cpp-edit-reset)
  (define-key cpp-edit-map "s" 'cpp-edit-save)
  (define-key cpp-edit-map "S" 'cpp-edit-save)
  (define-key cpp-edit-map "l" 'cpp-edit-load)
  (define-key cpp-edit-map "L" 'cpp-edit-load)
  (define-key cpp-edit-map "h" 'cpp-edit-home)
  (define-key cpp-edit-map "H" 'cpp-edit-home)
  (define-key cpp-edit-map "b" 'cpp-edit-background)
  (define-key cpp-edit-map "B" 'cpp-edit-background)
  (define-key cpp-edit-map "k" 'cpp-edit-known)
  (define-key cpp-edit-map "K" 'cpp-edit-known)
  (define-key cpp-edit-map "u" 'cpp-edit-unknown)
  (define-key cpp-edit-map "u" 'cpp-edit-unknown)
  (define-key cpp-edit-map "t" 'cpp-edit-true)
  (define-key cpp-edit-map "T" 'cpp-edit-true)
  (define-key cpp-edit-map "f" 'cpp-edit-false)
  (define-key cpp-edit-map "F" 'cpp-edit-false)
  (define-key cpp-edit-map "w" 'cpp-edit-write)
  (define-key cpp-edit-map "W" 'cpp-edit-write)
  (define-key cpp-edit-map "X" 'cpp-edit-toggle-known)
  (define-key cpp-edit-map "x" 'cpp-edit-toggle-known)
  (define-key cpp-edit-map "Y" 'cpp-edit-toggle-unknown)
  (define-key cpp-edit-map "y" 'cpp-edit-toggle-unknown)
  (define-key cpp-edit-map "q" 'bury-buffer)
  (define-key cpp-edit-map "Q" 'bury-buffer))

(defvar cpp-edit-buffer nil)
;; Real buffer whose cpp display information we are editing.
(make-variable-buffer-local 'cpp-edit-buffer)

(defvar cpp-edit-symbols nil)
;; Symbols defined in the edit buffer.
(make-variable-buffer-local 'cpp-edit-symbols)

(defun cpp-edit-mode ()
  "Major mode for editing cpp display information.
Click on objects to change them.  
You can also use the keyboard accelerators indicated like this: [K]ey."
  (kill-all-local-variables)
  (buffer-disable-undo)
  (auto-save-mode -1)
  (setq buffer-read-only t)
  (setq major-mode 'cpp-edit-mode)
  (setq mode-name "CPP Edit")
  (use-local-map cpp-edit-map))

(defun cpp-edit-apply ()
  "Apply edited display information to original buffer."
  (interactive)
  (cpp-edit-home)
  (cpp-parse-buffer t))

(defun cpp-edit-reset ()
  "Reset display information from original buffer."
  (interactive)
  (let ((buffer (current-buffer))
	(buffer-read-only nil)
	(start (window-start))
	(pos (point))
	symbols)
    (set-buffer cpp-edit-buffer)
    (setq symbols cpp-parse-symbols)
    (set-buffer buffer)
    (setq cpp-edit-symbols symbols)
    (erase-buffer)
    (insert "CPP Display Information for `")
    (cpp-make-button (buffer-name cpp-edit-buffer) 'cpp-edit-home)
    (insert "' ")
    (cpp-make-button "[H]ome" 'cpp-edit-home)
    (insert " ")
    (cpp-make-button "[A]pply" 'cpp-edit-apply)
    (insert " ")
    (cpp-make-button "[S]ave" 'cpp-edit-save)
    (insert " ")
    (cpp-make-button "[L]oad" 'cpp-edit-load)
    (insert "\n\nClick mouse-2 on item you want to change or use\n"
	    "keyboard equivalent indicated with brackets like [T]his.\n\n")
    (insert "[B]ackground: ")
    (cpp-make-button (car (rassq cpp-face-type cpp-face-type-list))
		     'cpp-edit-background)
    (insert "\n[K]nown conditionals: ")
    (cpp-make-button (cpp-face-name cpp-known-face)
		     'cpp-edit-known nil t)
    (insert " [X] ")
    (cpp-make-button (car (rassq cpp-known-writable cpp-writable-list))
		     'cpp-edit-toggle-known)
    (insert "\n[U]nknown conditionals: ")
    (cpp-make-button (cpp-face-name cpp-unknown-face)
		     'cpp-edit-unknown nil t)
    (insert " [Y] ")
    (cpp-make-button (car (rassq cpp-unknown-writable cpp-writable-list))
		     'cpp-edit-toggle-unknown)
    (insert (format "\n\n\n%39s: %14s %14s %7s\n\n" "Expression"
		    "[T]rue Face" "[F]alse Face" "[W]rite"))
    (while symbols
      (let*  ((symbol (car symbols))
	      (entry (assoc symbol cpp-edit-list))
	      (true (nth 1 entry))
	      (false (nth 2 entry))
	      (write (if entry (nth 3 entry) 'both)))
	(setq symbols (cdr symbols))

	(if (and entry			; Make default entries unknown.
		 (or (null true) (eq true 'default))
		 (or (null false) (eq false 'default))
		 (eq write 'both))
	    (setq cpp-edit-list (delq entry cpp-edit-list)
		  entry nil))
	
	(if (> (length symbol) 29)
	    (insert (substring symbol 0 39) ": ")
	  (insert (format "%39s: " symbol)))

	(cpp-make-button (cpp-face-name true)
			 'cpp-edit-true symbol t 14)
	(insert " ")
	(cpp-make-button (cpp-face-name false)
			 'cpp-edit-false symbol t 14)
	(insert " ")
	(cpp-make-button (car (rassq write cpp-branch-list))
			 'cpp-edit-write symbol nil 6)
	(insert "\n")))
    (insert "\n\n")
    (set-window-start nil start)
    (goto-char pos)))

(defun cpp-edit-load ()
  "Load cpp configuration."
  (interactive)
  (cond ((file-readable-p ".cpp.el")
	 (load-file ".cpp.el"))
	((file-readable-p "~/.cpp.el")
	 (load-file ".cpp.el")))
  (cpp-edit-reset))

(defun cpp-edit-save ()
  "Load cpp configuration."
  (interactive)
  (require 'pp)
  (save-excursion
    (set-buffer cpp-edit-buffer)
    (let ((buffer (find-file-noselect ".cpp.el")))
      (set-buffer buffer)
      (erase-buffer)
      (pp (list 'setq 'cpp-known-face
		(list 'quote cpp-known-face)) buffer)
      (pp (list 'setq 'cpp-unknown-face
		(list 'quote cpp-unknown-face)) buffer)
      (pp (list 'setq 'cpp-face-type
		(list 'quote cpp-face-type)) buffer)
      (pp (list 'setq 'cpp-known-writable
		(list 'quote cpp-known-writable)) buffer)
      (pp (list 'setq 'cpp-unknown-writable
		(list 'quote cpp-unknown-writable)) buffer)
      (pp (list 'setq 'cpp-edit-list
		(list 'quote cpp-edit-list)) buffer)
      (write-file ".cpp.el"))))

(defun cpp-edit-home ()
  "Switch back to original buffer."
  (interactive)
  (if cpp-button-event
      (read-event))
  (pop-to-buffer cpp-edit-buffer))

(defun cpp-edit-background ()
  "Change default face collection."
  (interactive)
  (call-interactively 'cpp-choose-default-face)
  (cpp-edit-reset))

(defun cpp-edit-known ()
  "Select default for known conditionals."
  (interactive)
  (setq cpp-known-face (cpp-choose-face "Known face" cpp-known-face))
  (cpp-edit-reset))

(defun cpp-edit-unknown ()
  "Select default for unknown conditionals."
  (interactive)
  (setq cpp-unknown-face (cpp-choose-face "Unknown face" cpp-unknown-face))
  (cpp-edit-reset))

(defconst cpp-writable-list
  ;; Names used for the writable property.
  '(("writable" . t)
    ("read-only" . nil)))

(defun cpp-edit-toggle-known (arg)
  "Toggle writable status for known conditionals.
With optional argument ARG, make them writable iff ARG is positive."
  (interactive "@P")
  (if (or (and (null arg) cpp-known-writable)
	  (<= (prefix-numeric-value arg) 0))
      (setq cpp-known-writable nil)
    (setq cpp-known-writable t))
  (cpp-edit-reset))

(defun cpp-edit-toggle-unknown (arg)
  "Toggle writable status for unknown conditionals.
With optional argument ARG, make them writable iff ARG is positive."
  (interactive "@P")
  (if (or (and (null arg) cpp-unknown-writable)
	  (<= (prefix-numeric-value arg) 0))
      (setq cpp-unknown-writable nil)
    (setq cpp-unknown-writable t))
  (cpp-edit-reset))

(defun cpp-edit-true (symbol face)
  "Select SYMBOL's true FACE used for highlighting taken conditionals."
  (interactive
   (let ((symbol (cpp-choose-symbol)))
     (list symbol
	   (cpp-choose-face "True face"
			    (nth 1 (assoc symbol cpp-edit-list))))))
  (setcar (nthcdr 1 (cpp-edit-list-entry-get-or-create symbol)) face)
  (cpp-edit-reset))

(defun cpp-edit-false (symbol face)
  "Select SYMBOL's false FACE used for highlighting untaken conditionals."
  (interactive
   (let ((symbol (cpp-choose-symbol)))
     (list symbol
	   (cpp-choose-face "False face" 
			    (nth 2 (assoc symbol cpp-edit-list))))))
  (setcar (nthcdr 2 (cpp-edit-list-entry-get-or-create symbol)) face)
  (cpp-edit-reset))

(defun cpp-edit-write (symbol branch)
  "Set which branches of SYMBOL should be writable to BRANCH.
BRANCH should be either nil (false branch), t (true branch) or 'both."
  (interactive (list (cpp-choose-symbol) (cpp-choose-branch)))
  (setcar (nthcdr 3 (cpp-edit-list-entry-get-or-create symbol)) branch)
  (cpp-edit-reset))

(defun cpp-edit-list-entry-get-or-create (symbol)
  ;; Return the entry for SYMBOL in `cpp-edit-list'.
  ;; If it does not exist, create it.
  (let ((entry (assoc symbol cpp-edit-list)))
    (or entry
	(setq entry (list symbol nil nil 'both nil)
	      cpp-edit-list (cons entry cpp-edit-list)))
    entry))

;;; Prompts:

(defun cpp-choose-symbol ()
  ;; Choose a symbol if called from keyboard, otherwise use the one clicked on.
  (if cpp-button-event
      data
    (completing-read "Symbol: " (mapcar 'list cpp-edit-symbols) nil t)))

(defconst cpp-branch-list
  ;; Alist of branches.
  '(("false" . nil)
    ("true" . t)
    ("both" . both)))

(defun cpp-choose-branch ()
  ;; Choose a branch, either nil, t, or both.
  (if cpp-button-event
      (x-popup-menu cpp-button-event
		    (list "Branch" (cons "Branch" cpp-branch-list)))
    (cdr (assoc	(completing-read "Branch: " cpp-branch-list nil t)
		cpp-branch-list))))

(defun cpp-choose-face (prompt default)
  ;; Choose a face from cpp-face-defalt-list.
  ;; PROMPT is what to say to the user.
  ;; DEFAULT is the default face.
  (or (if cpp-button-event
	  (x-popup-menu cpp-button-event
			(list prompt (cons prompt cpp-face-default-list)))
	(let ((name (car (rassq default cpp-face-default-list))))
	  (cdr (assoc (completing-read (if name
					   (concat prompt
						   " (default " name "): ")
					 (concat prompt ": "))
				       cpp-face-default-list nil t)
		      cpp-face-all-list))))
      default))

(defconst cpp-face-type-list
  '(("light color background" . light)
    ("dark color background" . dark)
    ("monochrome" . mono)
    ("tty" . none))
  "Alist of strings and names of the defined face collections.")

(defun cpp-choose-default-face (type)
  ;; Choose default face list for screen of TYPE.
  ;; Type must be one of the types defined in `cpp-face-type-list'.
  (interactive (list (if cpp-button-event
			 (x-popup-menu cpp-button-event
				       (list "Screen type"
					     (cons "Screen type"
						   cpp-face-type-list)))
		       (cdr (assoc (completing-read "Screen type: "
						    cpp-face-type-list
						    nil t)
				   cpp-face-type-list)))))
  (cond ((null type))
	((eq type 'light)
	 (if cpp-face-light-list
	     ()
	   (setq cpp-face-light-list
		 (mapcar 'cpp-create-bg-face cpp-face-light-name-list))
	   (setq cpp-face-all-list
		 (append cpp-face-all-list cpp-face-light-list)))
	 (setq cpp-face-type 'light)
	 (setq cpp-face-default-list
	       (append cpp-face-light-list cpp-face-none-list)))
	((eq type 'dark)
	 (if cpp-face-dark-list
	     ()
	   (setq cpp-face-dark-list
		 (mapcar 'cpp-create-bg-face cpp-face-dark-name-list))
	   (setq cpp-face-all-list
		 (append cpp-face-all-list cpp-face-dark-list)))
	 (setq cpp-face-type 'dark)
	 (setq cpp-face-default-list
	       (append cpp-face-dark-list cpp-face-none-list)))
	((eq type 'mono)
	 (setq cpp-face-type 'mono)
	 (setq cpp-face-default-list
	       (append cpp-face-mono-list cpp-face-none-list)))
	(t
	 (setq cpp-face-type 'none)
	 (setq cpp-face-default-list cpp-face-none-list))))

;;; Buttons:

(defvar cpp-button-event nil)
;; This will be t in the callback for `cpp-make-button'.

(defun cpp-make-button (name callback &optional data face padding)
  ;; Create a button at point.
  ;; NAME is the name of the button.
  ;; CALLBACK is the function to call when the button is pushed.
  ;; DATA will be available to CALLBACK as a free variable.
  ;; FACE means that NAME is the name of a face in `cpp-face-all-list'.
  ;; PADDING means NAME will be right justified at that length.
  (let ((name (format "%s" name))
	from to)
    (cond ((null padding)
	   (setq from (point))
	   (insert name))
	  ((> (length name) padding)
	   (setq from (point))
	   (insert (substring name 0 padding)))
	  (t
	   (insert (make-string (- padding (length name)) ? ))
	   (setq from (point))
	   (insert name)))
    (setq to (point))
    (setq face
	  (if face
	      (let ((check (cdr (assoc name cpp-face-all-list))))
		(if (memq check '(default invisible))
		    'bold
		  check))
	    'bold))
    (add-text-properties from to
			 (append (list 'face face)
				 '(mouse-face highlight)
				 (list 'cpp-callback callback)
				 (if data (list 'cpp-data data))))))

(defun cpp-push-button (event)
  ;; Pushed a CPP button.
  (interactive "@e")
  (set-buffer (window-buffer (posn-window (event-start event))))
  (let ((pos (posn-point (event-start event))))
    (let ((data (get-text-property pos 'cpp-data))
	  (fun (get-text-property pos 'cpp-callback))
	  (cpp-button-event event))
      (cond (fun
	     (call-interactively (get-text-property pos 'cpp-callback)))
	    ((lookup-key global-map [ down-mouse-2])
	     (call-interactively (lookup-key global-map [ down-mouse-2])))))))

;;; Faces:

(defvar cpp-face-light-name-list
  '("light gray" "light blue" "light cyan" "light yellow" "light pink"
    "pale green" "beige" "orange" "magenta" "violet" "medium purple"
    "turquoise")
  "Background colours useful with dark foreground colors.")

(defvar cpp-face-dark-name-list
  '("dim gray" "blue" "cyan" "yellow" "red"
    "dark green" "brown" "dark orange" "dark khaki" "dark violet" "purple"
    "dark turquoise")
  "Background colours useful with light foreground colors.")

(defvar cpp-face-light-list nil
  "Alist of names and faces to be used for light backgrounds.")

(defvar cpp-face-dark-list nil
  "Alist of names and faces to be used for dark backgrounds.")

(defvar cpp-face-mono-list
  '(("bold" . 'bold)
    ("bold-italic" . 'bold-italic)
    ("italic" . 'italic)
    ("underline" . 'underline))
  "Alist of names and faces to be used for monocrome screens.")

(defvar cpp-face-none-list
   '(("default" . default)
     ("invisible" . invisible))
   "Alist of names and faces available even if you don't use a window system.")

(defvar cpp-face-all-list
  (append cpp-face-light-list
	  cpp-face-dark-list
	  cpp-face-mono-list
	  cpp-face-none-list)
  "All faces used for highligting text inside cpp conditionals.")

(defvar cpp-face-default-list nil
  "List of faces you can choose from for cpp conditionals.")

(defun cpp-create-bg-face (color)
  ;; Create entry for face with background COLOR.
  (let ((name (intern (concat "cpp " color))))
    (make-face name)
    (set-face-background name color)
    (cons color name)))

(cpp-choose-default-face (if window-system cpp-face-type 'none))

(defun cpp-face-name (face)
  ;; Return the name of FACE from `cpp-face-all-list'.
  (let ((entry (rassq (if face face 'default) cpp-face-all-list)))
    (if entry
	(car entry)
      (format "<%s>" face))))

;;; Utilities:

(defvar cpp-progress-time 0)
;; Last time we issued a progress message.

(defun cpp-progress-message (&rest args)
  ;; Report progress at most once a second.  Take same ARGS as `message'.
  (let ((time (nth 1 (current-time))))
    (if (= time cpp-progress-time)
	()
      (setq cpp-progress-time time)
      (apply 'message args))))

(provide 'cpp)

;;; cpp.el ends here