lisp/progmodes/cpp.el

   1 ;;; cpp.el --- Highlight or hide text according to cpp conditionals.
   2
   3 ;; Copyright (C) 1994 Free Software Foundation
   4
   5 ;; Author: Per Abrahamsen <abraham@iesd.auc.dk>
   6 ;; Keywords: c, faces, tools
   7
   8 ;; This file is part of GNU Emacs.
   9
  10 ;; GNU Emacs is free software; you can redistribute it and/or modify
  11 ;; it under the terms of the GNU General Public License as published by
  12 ;; the Free Software Foundation; either version 2, or (at your option)
  13 ;; any later version.
  14
  15 ;; GNU Emacs is distributed in the hope that it will be useful,
  16 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  17 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  18 ;; GNU General Public License for more details.
  19
  20 ;; You should have received a copy of the GNU General Public License
  21 ;; along with GNU Emacs; see the file COPYING.  If not, write to
  22 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
  23
  24 ;;; Commentary:
  25
  26 ;; Parse a text for C preprocessor conditionals, and highlight or hide
  27 ;; the text inside the conditionals as you wish.
  28
  29 ;; This package is inspired by Jim Coplien's delta editor for SCCS.
  30
  31 ;;; Todo:
  32
  33 ;; Should parse "#if" and "#elif" expressions and merge the faces
  34 ;; somehow.
  35
  36 ;; Somehow it is sometimes possible to make changes near a read only
  37 ;; area which you can't undo.  Their are other strange effects in that
  38 ;; area.
  39
  40 ;; The Edit buffer should -- optionally -- appear in its own frame.
  41
  42 ;; Conditionals seem to be rear-sticky.  They shouldn't be.
  43
  44 ;; Restore window configurations when exiting CPP Edit buffer.
  45
  46 ;;; Code:
  47
  48 ;;; Customization:
  49
  50 (defvar cpp-known-face 'invisible
  51   "*Face used for known cpp symbols.")
  52
  53 (defvar cpp-unknown-face 'highlight
  54   "*Face used for unknown cpp cymbols.")
  55
  56 (defvar cpp-face-type 'light
  57   "*Indicate what background face type you prefer.
  58 Can be either light or dark for color screens, mono for monochrome
  59 screens, and none if you don't use a window system.")
  60
  61 (defvar cpp-known-writable t
  62   "*Non-nil means you are allowed to modify the known conditionals.")
  63
  64 (defvar cpp-unknown-writable t
  65   "*Non-nil means you are allowed to modify the unknown conditionals.")
  66
  67 ;;; Parse Buffer:
  68
  69 (defvar cpp-parse-symbols nil
  70   "List of cpp macros used in the local buffer.")
  71 (make-variable-buffer-local 'cpp-parse-symbols)
  72
  73 (defconst cpp-parse-regexp
  74   ;; Regexp matching all tokens needed to find conditionals.
  75   (concat
  76    "'\\|\"\\|/\\*\\|//\\|"
  77    "\\(^[ \t]*#[ \t]*\\(ifdef\\|ifndef\\|if\\|"
  78    "elif\\|else\\|endif\\)\\b\\)"))
  79
  80 ;;;###autoload
  81 (defun cpp-highlight-buffer (arg)
  82   "Highlight C code according to preprocessor conditionals.
  83 This command pops up a buffer which you should edit to specify
  84 what kind of highlighting to use, and the criteria for highlighting.
  85 A prefix arg supresses display of that buffer."
  86   (interactive "P")
  87   (setq cpp-parse-symbols nil)
  88   (cpp-parse-reset)
  89   (if (null cpp-edit-list)
  90       (cpp-edit-load))
  91   (let (stack)
  92     (save-excursion
  93       (goto-char (point-min))
  94       (cpp-progress-message "Parsing...")
  95       (while (re-search-forward cpp-parse-regexp nil t)
  96         (cpp-progress-message "Parsing...%d%%"
  97                           (/ (* 100 (- (point) (point-min))) (buffer-size)))
  98         (let ((match (buffer-substring (match-beginning 0) (match-end 0))))
  99           (cond ((or (string-equal match "'")
 100                      (string-equal match "\""))
 101                  (goto-char (match-beginning 0))
 102                  (condition-case nil
 103                      (forward-sexp)
 104                    (error (cpp-parse-error
 105                            "Unterminated string or character"))))
 106                 ((string-equal match "/*")
 107                  (or (search-forward "*/" nil t)
 108                      (error "Unterminated comment")))
 109                 ((string-equal match "//")
 110                  (skip-chars-forward "^\n\r"))
 111                 (t
 112                  (end-of-line 1)
 113                  (let ((from (match-beginning 1))
 114                        (to (1+ (point)))
 115                        (type (buffer-substring (match-beginning 2)
 116                                                (match-end 2)))
 117                        (expr (buffer-substring (match-end 1) (point))))
 118                    (cond ((string-equal type "ifdef")
 119                           (cpp-parse-open t expr from to))
 120                          ((string-equal type "ifndef")
 121                           (cpp-parse-open nil expr from to))
 122                          ((string-equal type "if")
 123                           (cpp-parse-open t expr from to))
 124                          ((string-equal type "elif")
 125                           (let (cpp-known-face cpp-unknown-face)
 126                             (cpp-parse-close from to))
 127                           (cpp-parse-open t expr from to))
 128                          ((string-equal type "else")
 129                           (or stack (cpp-parse-error "Top level #else"))
 130                           (let ((entry (list (not (nth 0 (car stack)))
 131                                              (nth 1 (car stack))
 132                                              from to)))
 133                             (cpp-parse-close from to)
 134                             (setq stack (cons entry stack))))
 135                          ((string-equal type "endif")
 136                           (cpp-parse-close from to))
 137                          (t
 138                           (cpp-parse-error "Parser error"))))))))
 139       (message "Parsing...done"))
 140     (if stack
 141       (save-excursion
 142         (goto-char (nth 3 (car stack)))
 143         (cpp-parse-error "Unclosed conditional"))))
 144   (or arg
 145       (null cpp-parse-symbols)
 146       (cpp-parse-edit)))
 147
 148 (defun cpp-parse-open (branch expr begin end)
 149   ;; Push information about conditional to stack.
 150   (while (string-match "\\b[ \t]*/\\*.*\\*/[ \t]*\\b" expr)
 151     (setq expr (concat (substring expr 0 (match-beginning 0))
 152                        (substring expr (match-end 0)))))
 153   (if (string-match "\\b[ \t]*\\(//.*\\)?$" expr)
 154       (setq expr (substring expr 0 (match-beginning 0))))
 155   (while (string-match "[ \t]+" expr)
 156       (setq expr (concat (substring expr 0 (match-beginning 0))
 157                          (substring expr (match-end 0)))))
 158   (setq stack (cons (list branch expr begin end) stack))
 159   (or (member expr cpp-parse-symbols)
 160       (setq cpp-parse-symbols
 161             (cons expr cpp-parse-symbols)))
 162   (if (assoc expr cpp-edit-list)
 163       (cpp-make-known-overlay begin end)
 164     (cpp-make-unknown-overlay begin end)))
 165
 166 (defun cpp-parse-close (from to)
 167   ;; Pop top of stack and create overlay.
 168   (let ((entry (assoc (nth 1 (car stack)) cpp-edit-list))
 169         (branch (nth 0 (car stack)))
 170         (begin (nth 2 (car stack)))
 171         (end (nth 3 (car stack))))
 172     (setq stack (cdr stack))
 173     (if entry
 174         (let ((face (nth (if branch 1 2) entry))
 175               (read-only (eq (not branch) (nth 3 entry)))
 176               (priority (length stack))
 177               (overlay (make-overlay end from)))
 178           (cpp-make-known-overlay from to)
 179           (setq cpp-overlay-list (cons overlay cpp-overlay-list))
 180           (if priority (overlay-put overlay 'priority priority))
 181           (cond ((eq face 'invisible)
 182                  (cpp-make-overlay-hidden overlay))
 183                 ((eq face 'default))
 184                 (t
 185                  (overlay-put overlay 'face face)))
 186           (if read-only
 187               (cpp-make-overlay-read-only overlay)
 188             (cpp-make-overlay-sticky overlay)))
 189       (cpp-make-unknown-overlay from to))))
 190
 191 (defun cpp-parse-error (error)
 192   ;; Error message issued by the cpp parser.
 193   (error (concat error " at line %d") (count-lines (point-min) (point))))
 194
 195 (defun cpp-parse-reset ()
 196   "Reset display of cpp conditionals to normal."
 197   (interactive)
 198   (while cpp-overlay-list
 199     (delete-overlay (car cpp-overlay-list))
 200     (setq cpp-overlay-list (cdr cpp-overlay-list))))
 201
 202 ;;;###autoload
 203 (defun cpp-parse-edit ()
 204   "Edit display information for cpp conditionals."
 205   (interactive)
 206   (or cpp-parse-symbols
 207       (cpp-parse-buffer t))
 208   (let ((buffer (current-buffer)))
 209     (pop-to-buffer "*CPP Edit*")
 210     (cpp-edit-mode)
 211     (setq cpp-edit-buffer buffer)
 212     (cpp-edit-reset)))
 213
 214 ;;; Overlays:
 215
 216 (defvar cpp-overlay-list nil)
 217 ;; List of cpp overlays active in the current buffer.
 218 (make-variable-buffer-local 'cpp-overlay-list)
 219
 220 (defun cpp-make-known-overlay (start end)
 221   ;; Create an overlay for a known cpp command from START to END.
 222   (let ((overlay (make-overlay start end)))
 223     (if (eq cpp-known-face 'invisible)
 224         (cpp-make-overlay-hidden overlay)
 225       (or (eq cpp-known-face 'default)
 226           (overlay-put overlay 'face cpp-known-face))
 227       (if cpp-known-writable
 228           ()
 229         (overlay-put overlay 'modification-hooks '(cpp-signal-read-only))
 230         (overlay-put overlay 'insert-in-front-hooks '(cpp-signal-read-only))))
 231     (setq cpp-overlay-list (cons overlay cpp-overlay-list))))
 232
 233 (defun cpp-make-unknown-overlay (start end)
 234   ;; Create an overlay for an unknown cpp command from START to END.
 235   (let ((overlay (make-overlay start end)))
 236     (cond ((eq cpp-unknown-face 'invisible)
 237            (cpp-make-overlay-hidden overlay))
 238           ((eq cpp-unknown-face 'default))
 239           (t
 240            (overlay-put overlay 'face cpp-unknown-face)))
 241     (if cpp-unknown-writable
 242         ()
 243       (overlay-put overlay 'modification-hooks '(cpp-signal-read-only))
 244       (overlay-put overlay 'insert-in-front-hooks '(cpp-signal-read-only)))
 245     (setq cpp-overlay-list (cons overlay cpp-overlay-list))))
 246
 247 (defun cpp-make-overlay-hidden (overlay)
 248   ;; Make overlay hidden and intangible.
 249   (overlay-put overlay 'invisible t)
 250   (overlay-put overlay 'intangible t)
 251   ;; Unfortunately `intangible' is not implemented for overlays yet,
 252   ;; so we make is read-only instead.
 253   (overlay-put overlay 'modification-hooks '(cpp-signal-read-only)))
 254
 255 (defun cpp-make-overlay-read-only (overlay)
 256   ;; Make overlay read only.
 257   (overlay-put overlay 'modification-hooks '(cpp-signal-read-only))
 258   (overlay-put overlay 'insert-in-front-hooks '(cpp-signal-read-only))
 259   (overlay-put overlay 'insert-behind-hooks '(cpp-signal-read-only)))
 260
 261 (defun cpp-make-overlay-sticky (overlay)
 262   ;; Make OVERLAY grow when you insert text at either end.
 263   (overlay-put overlay 'insert-in-front-hooks '(cpp-grow-overlay))
 264   (overlay-put overlay 'insert-behind-hooks '(cpp-grow-overlay)))
 265
 266 (defun cpp-signal-read-only (overlay start end)
 267   ;; Only allow deleting the whole overlay.
 268   ;; Trying to change a read-only overlay.
 269   (if (or (< (overlay-start overlay) start)
 270           (> (overlay-end overlay) end))
 271       (error "This text is read only")))
 272
 273 (defun cpp-grow-overlay (overlay start end)
 274   ;; Make OVERLAY grow to contain range START to END.
 275   (move-overlay overlay
 276                 (min start (overlay-start overlay))
 277                 (max end (overlay-end overlay))))
 278
 279 ;;; Edit Buffer:
 280
 281 (defvar cpp-edit-list nil
 282   "Alist of cpp macros and information about how they should be displayed.
 283 Each entry is a list with the following elements:
 284 0. The name of the macro (a string).
 285 1. Face used for text that is `ifdef' the macro.
 286 2. Face used for text that is `ifndef' the macro.
 287 3. `t', `nil', or `both' depending on what text may be edited.")
 288
 289 (defvar cpp-edit-map nil)
 290 ;; Keymap for `cpp-edit-mode'.
 291
 292 (if cpp-edit-map
 293     ()
 294   (setq cpp-edit-map (make-keymap))
 295   (suppress-keymap cpp-edit-map)
 296   (define-key cpp-edit-map [ down-mouse-2 ] 'cpp-push-button)
 297   (define-key cpp-edit-map [ mouse-2 ] 'ignore)
 298   (define-key cpp-edit-map " " 'scroll-up)
 299   (define-key cpp-edit-map "\C-?" 'scroll-down)
 300   (define-key cpp-edit-map [ delete ] 'scroll-down)
 301   (define-key cpp-edit-map "\C-c\C-c" 'cpp-edit-apply)
 302   (define-key cpp-edit-map "a" 'cpp-edit-apply)
 303   (define-key cpp-edit-map "A" 'cpp-edit-apply)
 304   (define-key cpp-edit-map "r" 'cpp-edit-reset)
 305   (define-key cpp-edit-map "R" 'cpp-edit-reset)
 306   (define-key cpp-edit-map "s" 'cpp-edit-save)
 307   (define-key cpp-edit-map "S" 'cpp-edit-save)
 308   (define-key cpp-edit-map "l" 'cpp-edit-load)
 309   (define-key cpp-edit-map "L" 'cpp-edit-load)
 310   (define-key cpp-edit-map "h" 'cpp-edit-home)
 311   (define-key cpp-edit-map "H" 'cpp-edit-home)
 312   (define-key cpp-edit-map "b" 'cpp-edit-background)
 313   (define-key cpp-edit-map "B" 'cpp-edit-background)
 314   (define-key cpp-edit-map "k" 'cpp-edit-known)
 315   (define-key cpp-edit-map "K" 'cpp-edit-known)
 316   (define-key cpp-edit-map "u" 'cpp-edit-unknown)
 317   (define-key cpp-edit-map "u" 'cpp-edit-unknown)
 318   (define-key cpp-edit-map "t" 'cpp-edit-true)
 319   (define-key cpp-edit-map "T" 'cpp-edit-true)
 320   (define-key cpp-edit-map "f" 'cpp-edit-false)
 321   (define-key cpp-edit-map "F" 'cpp-edit-false)
 322   (define-key cpp-edit-map "w" 'cpp-edit-write)
 323   (define-key cpp-edit-map "W" 'cpp-edit-write)
 324   (define-key cpp-edit-map "X" 'cpp-edit-toggle-known)
 325   (define-key cpp-edit-map "x" 'cpp-edit-toggle-known)
 326   (define-key cpp-edit-map "Y" 'cpp-edit-toggle-unknown)
 327   (define-key cpp-edit-map "y" 'cpp-edit-toggle-unknown)
 328   (define-key cpp-edit-map "q" 'bury-buffer)
 329   (define-key cpp-edit-map "Q" 'bury-buffer))
 330
 331 (defvar cpp-edit-buffer nil)
 332 ;; Real buffer whose cpp display information we are editing.
 333 (make-variable-buffer-local 'cpp-edit-buffer)
 334
 335 (defvar cpp-edit-symbols nil)
 336 ;; Symbols defined in the edit buffer.
 337 (make-variable-buffer-local 'cpp-edit-symbols)
 338
 339 (defun cpp-edit-mode ()
 340   "Major mode for editing the criteria for highlighting cpp conditionals.
 341 Click on objects to change them.
 342 You can also use the keyboard accelerators indicated like this: [K]ey."
 343   (kill-all-local-variables)
 344   (buffer-disable-undo)
 345   (auto-save-mode -1)
 346   (setq buffer-read-only t)
 347   (setq major-mode 'cpp-edit-mode)
 348   (setq mode-name "CPP Edit")
 349   (use-local-map cpp-edit-map))
 350
 351 (defun cpp-edit-apply ()
 352   "Apply edited display information to original buffer."
 353   (interactive)
 354   (cpp-edit-home)
 355   (cpp-parse-buffer t))
 356
 357 (defun cpp-edit-reset ()
 358   "Reset display information from original buffer."
 359   (interactive)
 360   (let ((buffer (current-buffer))
 361         (buffer-read-only nil)
 362         (start (window-start))
 363         (pos (point))
 364         symbols)
 365     (set-buffer cpp-edit-buffer)
 366     (setq symbols cpp-parse-symbols)
 367     (set-buffer buffer)
 368     (setq cpp-edit-symbols symbols)
 369     (erase-buffer)
 370     (insert "CPP Display Information for `")
 371     (cpp-make-button (buffer-name cpp-edit-buffer) 'cpp-edit-home)
 372     (insert "' ")
 373     (cpp-make-button "[H]ome" 'cpp-edit-home)
 374     (insert " ")
 375     (cpp-make-button "[A]pply" 'cpp-edit-apply)
 376     (insert " ")
 377     (cpp-make-button "[S]ave" 'cpp-edit-save)
 378     (insert " ")
 379     (cpp-make-button "[L]oad" 'cpp-edit-load)
 380     (insert "\n\nClick mouse-2 on item you want to change or use\n"
 381             "keyboard equivalent indicated with brackets like [T]his.\n\n")
 382     (insert "[B]ackground: ")
 383     (cpp-make-button (car (rassq cpp-face-type cpp-face-type-list))
 384                      'cpp-edit-background)
 385     (insert "\n[K]nown conditionals: ")
 386     (cpp-make-button (cpp-face-name cpp-known-face)
 387                      'cpp-edit-known nil t)
 388     (insert " [X] ")
 389     (cpp-make-button (car (rassq cpp-known-writable cpp-writable-list))
 390                      'cpp-edit-toggle-known)
 391     (insert "\n[U]nknown conditionals: ")
 392     (cpp-make-button (cpp-face-name cpp-unknown-face)
 393                      'cpp-edit-unknown nil t)
 394     (insert " [Y] ")
 395     (cpp-make-button (car (rassq cpp-unknown-writable cpp-writable-list))
 396                      'cpp-edit-toggle-unknown)
 397     (insert (format "\n\n\n%39s: %14s %14s %7s\n\n" "Expression"
 398                     "[T]rue Face" "[F]alse Face" "[W]rite"))
 399     (while symbols
 400       (let*  ((symbol (car symbols))
 401               (entry (assoc symbol cpp-edit-list))
 402               (true (nth 1 entry))
 403               (false (nth 2 entry))
 404               (write (if entry (nth 3 entry) 'both)))
 405         (setq symbols (cdr symbols))
 406
 407         (if (and entry                  ; Make default entries unknown.
 408                  (or (null true) (eq true 'default))
 409                  (or (null false) (eq false 'default))
 410                  (eq write 'both))
 411             (setq cpp-edit-list (delq entry cpp-edit-list)
 412                   entry nil))
 413
 414         (if (> (length symbol) 29)
 415             (insert (substring symbol 0 39) ": ")
 416           (insert (format "%39s: " symbol)))
 417
 418         (cpp-make-button (cpp-face-name true)
 419                          'cpp-edit-true symbol t 14)
 420         (insert " ")
 421         (cpp-make-button (cpp-face-name false)
 422                          'cpp-edit-false symbol t 14)
 423         (insert " ")
 424         (cpp-make-button (car (rassq write cpp-branch-list))
 425                          'cpp-edit-write symbol nil 6)
 426         (insert "\n")))
 427     (insert "\n\n")
 428     (set-window-start nil start)
 429     (goto-char pos)))
 430
 431 (defun cpp-edit-load ()
 432   "Load cpp configuration."
 433   (interactive)
 434   (cond ((file-readable-p ".cpp.el")
 435          (load-file ".cpp.el"))
 436         ((file-readable-p "~/.cpp.el")
 437          (load-file ".cpp.el")))
 438   (if (eq major-mode 'cpp-edit-mode)
 439       (cpp-edit-reset)))
 440
 441 (defun cpp-edit-save ()
 442   "Load cpp configuration."
 443   (interactive)
 444   (require 'pp)
 445   (save-excursion
 446     (set-buffer cpp-edit-buffer)
 447     (let ((buffer (find-file-noselect ".cpp.el")))
 448       (set-buffer buffer)
 449       (erase-buffer)
 450       (pp (list 'setq 'cpp-known-face
 451                 (list 'quote cpp-known-face)) buffer)
 452       (pp (list 'setq 'cpp-unknown-face
 453                 (list 'quote cpp-unknown-face)) buffer)
 454       (pp (list 'setq 'cpp-face-type
 455                 (list 'quote cpp-face-type)) buffer)
 456       (pp (list 'setq 'cpp-known-writable
 457                 (list 'quote cpp-known-writable)) buffer)
 458       (pp (list 'setq 'cpp-unknown-writable
 459                 (list 'quote cpp-unknown-writable)) buffer)
 460       (pp (list 'setq 'cpp-edit-list
 461                 (list 'quote cpp-edit-list)) buffer)
 462       (write-file ".cpp.el"))))
 463
 464 (defun cpp-edit-home ()
 465   "Switch back to original buffer."
 466   (interactive)
 467   (if cpp-button-event
 468       (read-event))
 469   (pop-to-buffer cpp-edit-buffer))
 470
 471 (defun cpp-edit-background ()
 472   "Change default face collection."
 473   (interactive)
 474   (call-interactively 'cpp-choose-default-face)
 475   (cpp-edit-reset))
 476
 477 (defun cpp-edit-known ()
 478   "Select default for known conditionals."
 479   (interactive)
 480   (setq cpp-known-face (cpp-choose-face "Known face" cpp-known-face))
 481   (cpp-edit-reset))
 482
 483 (defun cpp-edit-unknown ()
 484   "Select default for unknown conditionals."
 485   (interactive)
 486   (setq cpp-unknown-face (cpp-choose-face "Unknown face" cpp-unknown-face))
 487   (cpp-edit-reset))
 488
 489 (defconst cpp-writable-list
 490   ;; Names used for the writable property.
 491   '(("writable" . t)
 492     ("read-only" . nil)))
 493
 494 (defun cpp-edit-toggle-known (arg)
 495   "Toggle writable status for known conditionals.
 496 With optional argument ARG, make them writable iff ARG is positive."
 497   (interactive "@P")
 498   (if (or (and (null arg) cpp-known-writable)
 499           (<= (prefix-numeric-value arg) 0))
 500       (setq cpp-known-writable nil)
 501     (setq cpp-known-writable t))
 502   (cpp-edit-reset))
 503
 504 (defun cpp-edit-toggle-unknown (arg)
 505   "Toggle writable status for unknown conditionals.
 506 With optional argument ARG, make them writable iff ARG is positive."
 507   (interactive "@P")
 508   (if (or (and (null arg) cpp-unknown-writable)
 509           (<= (prefix-numeric-value arg) 0))
 510       (setq cpp-unknown-writable nil)
 511     (setq cpp-unknown-writable t))
 512   (cpp-edit-reset))
 513
 514 (defun cpp-edit-true (symbol face)
 515   "Select SYMBOL's true FACE used for highlighting taken conditionals."
 516   (interactive
 517    (let ((symbol (cpp-choose-symbol)))
 518      (list symbol
 519            (cpp-choose-face "True face"
 520                             (nth 1 (assoc symbol cpp-edit-list))))))
 521   (setcar (nthcdr 1 (cpp-edit-list-entry-get-or-create symbol)) face)
 522   (cpp-edit-reset))
 523
 524 (defun cpp-edit-false (symbol face)
 525   "Select SYMBOL's false FACE used for highlighting untaken conditionals."
 526   (interactive
 527    (let ((symbol (cpp-choose-symbol)))
 528      (list symbol
 529            (cpp-choose-face "False face"
 530                             (nth 2 (assoc symbol cpp-edit-list))))))
 531   (setcar (nthcdr 2 (cpp-edit-list-entry-get-or-create symbol)) face)
 532   (cpp-edit-reset))
 533
 534 (defun cpp-edit-write (symbol branch)
 535   "Set which branches of SYMBOL should be writable to BRANCH.
 536 BRANCH should be either nil (false branch), t (true branch) or 'both."
 537   (interactive (list (cpp-choose-symbol) (cpp-choose-branch)))
 538   (setcar (nthcdr 3 (cpp-edit-list-entry-get-or-create symbol)) branch)
 539   (cpp-edit-reset))
 540
 541 (defun cpp-edit-list-entry-get-or-create (symbol)
 542   ;; Return the entry for SYMBOL in `cpp-edit-list'.
 543   ;; If it does not exist, create it.
 544   (let ((entry (assoc symbol cpp-edit-list)))
 545     (or entry
 546         (setq entry (list symbol nil nil 'both nil)
 547               cpp-edit-list (cons entry cpp-edit-list)))
 548     entry))
 549
 550 ;;; Prompts:
 551
 552 (defun cpp-choose-symbol ()
 553   ;; Choose a symbol if called from keyboard, otherwise use the one clicked on.
 554   (if cpp-button-event
 555       data
 556     (completing-read "Symbol: " (mapcar 'list cpp-edit-symbols) nil t)))
 557
 558 (defconst cpp-branch-list
 559   ;; Alist of branches.
 560   '(("false" . nil)
 561     ("true" . t)
 562     ("both" . both)))
 563
 564 (defun cpp-choose-branch ()
 565   ;; Choose a branch, either nil, t, or both.
 566   (if cpp-button-event
 567       (x-popup-menu cpp-button-event
 568                     (list "Branch" (cons "Branch" cpp-branch-list)))
 569     (cdr (assoc (completing-read "Branch: " cpp-branch-list nil t)
 570                 cpp-branch-list))))
 571
 572 (defun cpp-choose-face (prompt default)
 573   ;; Choose a face from cpp-face-defalt-list.
 574   ;; PROMPT is what to say to the user.
 575   ;; DEFAULT is the default face.
 576   (or (if cpp-button-event
 577           (x-popup-menu cpp-button-event
 578                         (list prompt (cons prompt cpp-face-default-list)))
 579         (let ((name (car (rassq default cpp-face-default-list))))
 580           (cdr (assoc (completing-read (if name
 581                                            (concat prompt
 582                                                    " (default " name "): ")
 583                                          (concat prompt ": "))
 584                                        cpp-face-default-list nil t)
 585                       cpp-face-all-list))))
 586       default))
 587
 588 (defconst cpp-face-type-list
 589   '(("light color background" . light)
 590     ("dark color background" . dark)
 591     ("monochrome" . mono)
 592     ("tty" . none))
 593   "Alist of strings and names of the defined face collections.")
 594
 595 (defun cpp-choose-default-face (type)
 596   ;; Choose default face list for screen of TYPE.
 597   ;; Type must be one of the types defined in `cpp-face-type-list'.
 598   (interactive (list (if cpp-button-event
 599                          (x-popup-menu cpp-button-event
 600                                        (list "Screen type"
 601                                              (cons "Screen type"
 602                                                    cpp-face-type-list)))
 603                        (cdr (assoc (completing-read "Screen type: "
 604                                                     cpp-face-type-list
 605                                                     nil t)
 606                                    cpp-face-type-list)))))
 607   (cond ((null type))
 608         ((eq type 'light)
 609          (if cpp-face-light-list
 610              ()
 611            (setq cpp-face-light-list
 612                  (mapcar 'cpp-create-bg-face cpp-face-light-name-list))
 613            (setq cpp-face-all-list
 614                  (append cpp-face-all-list cpp-face-light-list)))
 615          (setq cpp-face-type 'light)
 616          (setq cpp-face-default-list
 617                (append cpp-face-light-list cpp-face-none-list)))
 618         ((eq type 'dark)
 619          (if cpp-face-dark-list
 620              ()
 621            (setq cpp-face-dark-list
 622                  (mapcar 'cpp-create-bg-face cpp-face-dark-name-list))
 623            (setq cpp-face-all-list
 624                  (append cpp-face-all-list cpp-face-dark-list)))
 625          (setq cpp-face-type 'dark)
 626          (setq cpp-face-default-list
 627                (append cpp-face-dark-list cpp-face-none-list)))
 628         ((eq type 'mono)
 629          (setq cpp-face-type 'mono)
 630          (setq cpp-face-default-list
 631                (append cpp-face-mono-list cpp-face-none-list)))
 632         (t
 633          (setq cpp-face-type 'none)
 634          (setq cpp-face-default-list cpp-face-none-list))))
 635
 636 ;;; Buttons:
 637
 638 (defvar cpp-button-event nil)
 639 ;; This will be t in the callback for `cpp-make-button'.
 640
 641 (defun cpp-make-button (name callback &optional data face padding)
 642   ;; Create a button at point.
 643   ;; NAME is the name of the button.
 644   ;; CALLBACK is the function to call when the button is pushed.
 645   ;; DATA will be available to CALLBACK as a free variable.
 646   ;; FACE means that NAME is the name of a face in `cpp-face-all-list'.
 647   ;; PADDING means NAME will be right justified at that length.
 648   (let ((name (format "%s" name))
 649         from to)
 650     (cond ((null padding)
 651            (setq from (point))
 652            (insert name))
 653           ((> (length name) padding)
 654            (setq from (point))
 655            (insert (substring name 0 padding)))
 656           (t
 657            (insert (make-string (- padding (length name)) ? ))
 658            (setq from (point))
 659            (insert name)))
 660     (setq to (point))
 661     (setq face
 662           (if face
 663               (let ((check (cdr (assoc name cpp-face-all-list))))
 664                 (if (memq check '(default invisible))
 665                     'bold
 666                   check))
 667             'bold))
 668     (add-text-properties from to
 669                          (append (list 'face face)
 670                                  '(mouse-face highlight)
 671                                  (list 'cpp-callback callback)
 672                                  (if data (list 'cpp-data data))))))
 673
 674 (defun cpp-push-button (event)
 675   ;; Pushed a CPP button.
 676   (interactive "@e")
 677   (set-buffer (window-buffer (posn-window (event-start event))))
 678   (let ((pos (posn-point (event-start event))))
 679     (let ((data (get-text-property pos 'cpp-data))
 680           (fun (get-text-property pos 'cpp-callback))
 681           (cpp-button-event event))
 682       (cond (fun
 683              (call-interactively (get-text-property pos 'cpp-callback)))
 684             ((lookup-key global-map [ down-mouse-2])
 685              (call-interactively (lookup-key global-map [ down-mouse-2])))))))
 686
 687 ;;; Faces:
 688
 689 (defvar cpp-face-light-name-list
 690   '("light gray" "light blue" "light cyan" "light yellow" "light pink"
 691     "pale green" "beige" "orange" "magenta" "violet" "medium purple"
 692     "turquoise")
 693   "Background colours useful with dark foreground colors.")
 694
 695 (defvar cpp-face-dark-name-list
 696   '("dim gray" "blue" "cyan" "yellow" "red"
 697     "dark green" "brown" "dark orange" "dark khaki" "dark violet" "purple"
 698     "dark turquoise")
 699   "Background colours useful with light foreground colors.")
 700
 701 (defvar cpp-face-light-list nil
 702   "Alist of names and faces to be used for light backgrounds.")
 703
 704 (defvar cpp-face-dark-list nil
 705   "Alist of names and faces to be used for dark backgrounds.")
 706
 707 (defvar cpp-face-mono-list
 708   '(("bold" . 'bold)
 709     ("bold-italic" . 'bold-italic)
 710     ("italic" . 'italic)
 711     ("underline" . 'underline))
 712   "Alist of names and faces to be used for monocrome screens.")
 713
 714 (defvar cpp-face-none-list
 715    '(("default" . default)
 716      ("invisible" . invisible))
 717    "Alist of names and faces available even if you don't use a window system.")
 718
 719 (defvar cpp-face-all-list
 720   (append cpp-face-light-list
 721           cpp-face-dark-list
 722           cpp-face-mono-list
 723           cpp-face-none-list)
 724   "All faces used for highligting text inside cpp conditionals.")
 725
 726 (defvar cpp-face-default-list nil
 727   "List of faces you can choose from for cpp conditionals.")
 728
 729 (defun cpp-create-bg-face (color)
 730   ;; Create entry for face with background COLOR.
 731   (let ((name (intern (concat "cpp " color))))
 732     (make-face name)
 733     (set-face-background name color)
 734     (cons color name)))
 735
 736 (cpp-choose-default-face (if window-system cpp-face-type 'none))
 737
 738 (defun cpp-face-name (face)
 739   ;; Return the name of FACE from `cpp-face-all-list'.
 740   (let ((entry (rassq (if face face 'default) cpp-face-all-list)))
 741     (if entry
 742         (car entry)
 743       (format "<%s>" face))))
 744
 745 ;;; Utilities:
 746
 747 (defvar cpp-progress-time 0)
 748 ;; Last time we issued a progress message.
 749
 750 (defun cpp-progress-message (&rest args)
 751   ;; Report progress at most once a second.  Take same ARGS as `message'.
 752   (let ((time (nth 1 (current-time))))
 753     (if (= time cpp-progress-time)
 754         ()
 755       (setq cpp-progress-time time)
 756       (apply 'message args))))
 757
 758 (provide 'cpp)
 759
 760 ;;; cpp.el ends here