1 ;;; hide-ifdef-mode.el --- hides selected code within ifdef.
3 ;;; Copyright (C) 1988, 1994 Free Software Foundation, Inc.
5 ;; Author: Dan LaLiberte <liberte@a.cs.uiuc.edu>
7 ;; Keywords: c, outlines
9 ;; This file is part of GNU Emacs.
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)
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.
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
23 ;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA.
27 ;;; To initialize, toggle the hide-ifdef minor mode with
29 ;;; M-x hide-ifdef-mode
31 ;;; This will set up key bindings and call hide-ifdef-mode-hook if it
32 ;;; has a value. To explicitly hide ifdefs using a buffer-local
33 ;;; define list (default empty), type
35 ;;; M-x hide-ifdefs or C-c @ h
37 ;;; Hide-ifdef suppresses the display of code that the preprocessor wouldn't
38 ;;; pass through. The support of constant expressions in #if lines is
39 ;;; limited to identifiers, parens, and the operators: &&, ||, !, and
40 ;;; "defined". Please extend this.
42 ;;; The hidden code is marked by ellipses (...). Be
43 ;;; cautious when editing near ellipses, since the hidden text is
44 ;;; still in the buffer, and you can move the point into it and modify
45 ;;; text unawares. If you don't want to see the ellipses, set
46 ;;; selective-display-ellipses to nil. But this can be dangerous.
47 ;;; You can make your buffer read-only while hide-ifdef-hiding by setting
48 ;;; hide-ifdef-read-only to a non-nil value. You can toggle this
49 ;;; variable with hide-ifdef-toggle-read-only (C-c @ C-q).
51 ;;; You can undo the effect of hide-ifdefs by typing
53 ;;; M-x show-ifdefs or C-c @ s
55 ;;; Use M-x hide-ifdef-define (C-c @ d) to define a symbol.
56 ;;; Use M-x hide-ifdef-undef (C-c @ u) to undefine a symbol.
58 ;;; If you define or undefine a symbol while hide-ifdef-mode is in effect,
59 ;;; the display will be updated. Only the define list for the current
60 ;;; buffer will be affected. You can save changes to the local define
61 ;;; list with hide-ifdef-set-define-alist. This adds entries
62 ;;; to hide-ifdef-define-alist.
64 ;;; If you have defined a hide-ifdef-mode-hook, you can set
65 ;;; up a list of symbols that may be used by hide-ifdefs as in the
66 ;;; following example:
68 ;;; (setq hide-ifdef-mode-hook
70 ;;; (if (not hide-ifdef-define-alist)
71 ;;; (setq hide-ifdef-define-alist
75 ;;; (hide-ifdef-use-define-alist 'list2) ; use list2 by default
78 ;;; You can call hide-ifdef-use-define-alist (C-c @ u) at any time to specify
79 ;;; another list to use.
81 ;;; To cause ifdefs to be hidden as soon as hide-ifdef-mode is called,
82 ;;; set hide-ifdef-initially to non-nil.
84 ;;; If you set hide-ifdef-lines to t, hide-ifdefs hides all the #ifdef lines.
85 ;;; In the absence of highlighting, that might be a bad idea. If you set
86 ;;; hide-ifdef-lines to nil (the default), the surrounding preprocessor
87 ;;; lines will be displayed. That can be confusing in its own
88 ;;; right. Other variations on display are possible, but not much
91 ;;; You can explicitly hide or show individual ifdef blocks irrespective
92 ;;; of the define list by using hide-ifdef-block and show-ifdef-block.
94 ;;; You can move the point between ifdefs with forward-ifdef, backward-ifdef,
95 ;;; up-ifdef, down-ifdef, next-ifdef, and previous-ifdef.
97 ;;; If you have minor-mode-alist in your mode line (the default) two labels
98 ;;; may appear. "Ifdef" will appear when hide-ifdef-mode is active. "Hiding"
99 ;;; will appear when text may be hidden ("hide-ifdef-hiding" is non-nil).
101 ;;; Written by Brian Marick, at Gould, Computer Systems Division, Urbana IL.
102 ;;; Extensively modified by Daniel LaLiberte (while at Gould).
104 ;;; You may freely modify and distribute this, but keep a record
105 ;;; of modifications and send comments to:
106 ;;; liberte@a.cs.uiuc.edu or ihnp4!uiucdcs!liberte
107 ;;; I will continue to upgrade hide-ifdef-mode
108 ;;; with your contributions.
114 (defvar hide-ifdef-mode-submap nil
115 "Keymap used with Hide-Ifdef mode.")
117 (defvar hide-ifdef-mode-map nil
118 "Keymap used with Hide-Ifdef mode.")
120 (defconst hide-ifdef-mode-prefix-key "\C-c@"
121 "Prefix key for all Hide-Ifdef mode commands.")
123 ;; Set up the submap that goes after the prefix key.
124 (if hide-ifdef-mode-submap
125 () ; dont redefine it.
126 (setq hide-ifdef-mode-submap (make-sparse-keymap))
127 (define-key hide-ifdef-mode-submap "d" 'hide-ifdef-define)
128 (define-key hide-ifdef-mode-submap "u" 'hide-ifdef-undef)
129 (define-key hide-ifdef-mode-submap "D" 'hide-ifdef-set-define-alist)
130 (define-key hide-ifdef-mode-submap "U" 'hide-ifdef-use-define-alist)
132 (define-key hide-ifdef-mode-submap "h" 'hide-ifdefs)
133 (define-key hide-ifdef-mode-submap "s" 'show-ifdefs)
134 (define-key hide-ifdef-mode-submap "\C-d" 'hide-ifdef-block)
135 (define-key hide-ifdef-mode-submap "\C-s" 'show-ifdef-block)
137 (define-key hide-ifdef-mode-submap "\C-q" 'hide-ifdef-toggle-read-only)
138 (let ((where (where-is-internal 'toggle-read-only '(keymap) t)))
140 (define-key hide-ifdef-mode-submap
142 'hide-ifdef-toggle-outside-read-only)))
145 ;; Set up the mode's main map, which leads via the prefix key to the submap.
146 (if hide-ifdef-mode-map
148 (setq hide-ifdef-mode-map (make-sparse-keymap))
149 (define-key hide-ifdef-mode-map hide-ifdef-mode-prefix-key
150 hide-ifdef-mode-submap))
152 (defvar hide-ifdef-mode nil
153 "Non-nil when hide-ifdef-mode is activated.")
155 (defvar hide-ifdef-hiding nil
156 "Non-nil when text may be hidden.")
158 ;; Arrange to use the mode's map when the mode is enabled.
159 (or (assq 'hide-ifdef-mode minor-mode-map-alist)
160 (setq minor-mode-map-alist
161 (cons (cons 'hide-ifdef-mode hide-ifdef-mode-map)
162 minor-mode-map-alist)))
164 (or (assq 'hide-ifdef-hiding minor-mode-alist)
165 (setq minor-mode-alist
166 (cons '(hide-ifdef-hiding " Hiding")
169 (or (assq 'hide-ifdef-mode minor-mode-alist)
170 (setq minor-mode-alist
171 (cons '(hide-ifdef-mode " Ifdef")
174 ;; fix c-mode syntax table so we can recognize whole symbols.
175 (defvar hide-ifdef-syntax-table
176 (copy-syntax-table c-mode-syntax-table)
177 "Syntax table used for tokenizing #if expressions.")
179 (modify-syntax-entry ?_ "w" hide-ifdef-syntax-table)
180 (modify-syntax-entry ?& "." hide-ifdef-syntax-table)
181 (modify-syntax-entry ?\| "." hide-ifdef-syntax-table)
184 (defun hide-ifdef-mode (arg)
185 "Toggle Hide-Ifdef mode. This is a minor mode, albeit a large one.
186 With ARG, turn Hide-Ifdef mode on iff arg is positive.
187 In Hide-Ifdef mode, code within #ifdef constructs that the C preprocessor
188 would eliminate may be hidden from view. Several variables affect
189 how the hiding is done:
192 An association list of defined and undefined symbols for the
193 current buffer. Initially, the global value of `hide-ifdef-env'
196 hide-ifdef-define-alist
197 An association list of defined symbol lists.
198 Use `hide-ifdef-set-define-alist' to save the current `hide-ifdef-env'
199 and `hide-ifdef-use-define-alist' to set the current `hide-ifdef-env'
200 from one of the lists in `hide-ifdef-define-alist'.
203 Set to non-nil to not show #if, #ifdef, #ifndef, #else, and
204 #endif lines when hiding.
207 Indicates whether `hide-ifdefs' should be called when Hide-Ifdef mode
211 Set to non-nil if you want to make buffers read only while hiding.
212 After `show-ifdefs', read-only status is restored to previous value.
214 \\{hide-ifdef-mode-map}"
217 (make-local-variable 'hide-ifdef-mode)
218 (setq hide-ifdef-mode
220 (not hide-ifdef-mode)
221 (> (prefix-numeric-value arg) 0)))
223 (force-mode-line-update)
227 ; inherit global values
228 (make-local-variable 'hide-ifdef-env)
229 (setq hide-ifdef-env (default-value 'hide-ifdef-env))
231 (make-local-variable 'hide-ifdef-hiding)
232 (setq hide-ifdef-hiding (default-value 'hide-ifdef-hiding))
234 (make-local-variable 'hif-outside-read-only)
235 (setq hif-outside-read-only buffer-read-only)
237 (run-hooks 'hide-ifdef-mode-hook)
239 (if hide-ifdef-initially
242 (message "Enter Hide-Ifdef mode")
244 ; else end hide-ifdef-mode
245 (if hide-ifdef-hiding
247 (message "Exit Hide-Ifdef mode")
251 ;; from outline.el with docstring fixed.
252 (defun hif-outline-flag-region (from to flag)
253 "Hides or shows lines from FROM to TO, according to FLAG.
254 If FLAG is \\n (newline character) then text is shown, while if FLAG is \\^M
255 \(control-M) the text is hidden."
256 (let ((modp (buffer-modified-p)))
257 (unwind-protect (progn
258 (subst-char-in-region from to
259 (if (= flag ?\n) ?\^M ?\n)
261 (set-buffer-modified-p modp))
264 (defun hif-show-all ()
265 "Show all of the text in the current buffer."
267 (hif-outline-flag-region (point-min) (point-max) ?\n))
269 ;; By putting this on after-revert-hook, we arrange that it only
270 ;; does anything when revert-buffer avoids turning off the mode.
271 ;; (That can happen in VC.)
272 (defun hif-before-revert-function ()
273 (and hide-ifdef-mode hide-ifdef-hiding
275 (add-hook 'after-revert-hook 'hif-before-revert-function)
277 (defun hide-ifdef-region (start end)
278 "START is the start of a #if or #else form. END is the ending part.
279 Everything including these lines is made invisible."
280 (hif-outline-flag-region start end ?\^M)
283 (defun hif-show-ifdef-region (start end)
284 "Everything between START and END is made visible."
285 (hif-outline-flag-region start end ?\n)
290 ;===%%SF%% evaluation (Start) ===
292 ;; It is not useful to set this to anything but `eval'.
293 ;; In fact, the variable might as well be eliminated.
294 (defvar hide-ifdef-evaluator 'eval
295 "The function to use to evaluate a form.
296 The evaluator is given a canonical form and returns t if text under
297 that form should be displayed.")
299 (defvar hif-undefined-symbol nil
300 "...is by default considered to be false.")
302 (defvar hide-ifdef-env nil
303 "An alist of defined symbols and their values.")
306 (defun hif-set-var (var value)
307 "Prepend (var value) pair to hide-ifdef-env."
308 (setq hide-ifdef-env (cons (cons var value) hide-ifdef-env)))
311 (defun hif-lookup (var)
312 ; (message "hif-lookup %s" var)
313 (let ((val (assoc var hide-ifdef-env)))
316 hif-undefined-symbol)))
318 (defun hif-defined (var)
320 ; when #if expressions are fully supported, defined result should be 1
321 ; (if (assoc var hide-ifdef-env)
327 ;===%%SF%% evaluation (End) ===
331 ;===%%SF%% parsing (Start) ===
332 ;;; The code that understands what ifs and ifdef in files look like.
334 (defconst hif-cpp-prefix "\\(^\\|\r\\)[ \t]*#[ \t]*")
335 (defconst hif-ifndef-regexp (concat hif-cpp-prefix "ifndef"))
336 (defconst hif-ifx-regexp (concat hif-cpp-prefix "if\\(n?def\\)?[ \t]+"))
337 (defconst hif-else-regexp (concat hif-cpp-prefix "else"))
338 (defconst hif-endif-regexp (concat hif-cpp-prefix "endif"))
339 (defconst hif-ifx-else-endif-regexp
340 (concat hif-ifx-regexp "\\|" hif-else-regexp "\\|" hif-endif-regexp))
343 (defun hif-infix-to-prefix (token-list)
344 "Convert list of tokens in infix into prefix list"
345 ; (message "hif-infix-to-prefix: %s" token-list)
346 (if (= 1 (length token-list))
347 (` (hif-lookup (quote (, (car token-list)))))
348 (hif-parse-if-exp token-list))
351 ; pattern to match initial identifier, !, &&, ||, (, or ).
352 ; Added ==, + and -: garyo@avs.com 8/9/94
353 (defconst hif-token-regexp "^\\(!\\|&&\\|||\\|[!=]=\\|[()+-]\\|\\w+\\)")
354 (defconst hif-end-of-comment "\\*/")
357 (defun hif-tokenize (expr-string)
358 "Separate string into a list of tokens"
359 (let ((token-list nil)
361 (expr-length (length expr-string))
362 (current-syntax-table (syntax-table)))
365 (set-syntax-table hide-ifdef-syntax-table)
366 (while (< expr-start expr-length)
367 ; (message "expr-start = %d" expr-start) (sit-for 1)
369 ((string-match "^[ \t]+" expr-string expr-start)
371 (setq expr-start (match-end 0))
372 ;; stick newline in string so ^ matches on the next string-match
373 (aset expr-string (1- expr-start) ?\n))
375 ((string-match "^/\\*" expr-string expr-start)
376 (setq expr-start (match-end 0))
377 (aset expr-string (1- expr-start) ?\n)
379 (string-match hif-end-of-comment
380 expr-string expr-start) ; eat comment
381 (string-match "$" expr-string expr-start)) ; multi-line comment
382 (setq expr-start (match-end 0))
383 (aset expr-string (1- expr-start) ?\n))
385 ((string-match "^//" expr-string expr-start)
386 (string-match "$" expr-string expr-start)
387 (setq expr-start (match-end 0)))
389 ((string-match hif-token-regexp expr-string expr-start)
390 (let ((token (substring expr-string expr-start (match-end 0))))
391 (setq expr-start (match-end 0))
392 (aset expr-string (1- expr-start) ?\n)
393 ; (message "token: %s" token) (sit-for 1)
397 ((string-equal token "||") 'or)
398 ((string-equal token "&&") 'and)
399 ((string-equal token "==") 'equal)
400 ((string-equal token "!=") 'hif-notequal)
401 ((string-equal token "!") 'not)
402 ((string-equal token "defined") 'hif-defined)
403 ((string-equal token "(") 'lparen)
404 ((string-equal token ")") 'rparen)
405 ((string-equal token "+") 'hif-plus)
406 ((string-equal token "-") 'hif-minus)
409 (t (error "Bad #if expression: %s" expr-string)))))
410 (set-syntax-table current-syntax-table))
411 (nreverse token-list)))
413 ;;;-----------------------------------------------------------------
414 ;;; Translate C preprocessor #if expressions using recursive descent.
415 ;;; This parser is limited to the operators &&, ||, !, and "defined".
416 ;;; Added ==, !=, +, and -. Gary Oberbrunner, garyo@avs.com, 8/9/94
418 (defun hif-parse-if-exp (token-list)
419 "Parse the TOKEN-LIST. Return translated list in prefix form."
423 (if token ; is there still a token?
424 (error "Error: unexpected token: %s" token))))
426 (defun hif-nexttoken ()
427 "Pop the next token from token-list into the let variable \"token\"."
428 (setq token (car token-list))
429 (setq token-list (cdr token-list))
433 "Parse an expression as found in #if.
434 expr : term | expr '||' term."
435 (let ((result (hif-term)))
436 (while (eq token 'or)
438 (setq result (list 'or result (hif-term))))
442 "Parse a term : eq-expr | term '&&' eq-expr."
443 (let ((result (hif-eq-expr)))
444 (while (eq token 'and)
446 (setq result (list 'and result (hif-eq-expr))))
449 (defun hif-eq-expr ()
450 "Parse an eq-expr : math | eq-expr '=='|'!=' math."
451 (let ((result (hif-math))
453 (while (or (eq token 'equal) (eq token 'hif-notequal))
454 (setq eq-token token)
456 (setq result (list eq-token result (hif-math))))
460 "Parse an expression with + or - and simpler things.
461 math : factor | math '+|-' factor."
462 (let ((result (hif-factor))
464 (while (or (eq token 'hif-plus) (eq token 'hif-minus))
467 (setq result (list math-op result (hif-factor))))
471 "Parse a factor: '!' factor | '(' expr ')' | 'defined(' id ')' | id."
475 (list 'not (hif-factor)))
479 (let ((result (hif-expr)))
480 (if (not (eq token 'rparen))
481 (error "Bad token in parenthesized expression: %s" token)
485 ((eq token 'hif-defined)
487 (if (not (eq token 'lparen))
488 (error "Error: expected \"(\" after \"defined\""))
491 (if (memq token '(or and not hif-defined lparen rparen))
492 (error "Error: unexpected token: %s" token))
494 (if (not (eq token 'rparen))
495 (error "Error: expected \")\" after identifier"))
497 (` (hif-defined (quote (, ident))))
502 (if (memq ident '(or and))
503 (error "Error: missing identifier"))
505 (` (hif-lookup (quote (, ident))))
509 (defun hif-mathify (val)
510 "Treat VAL as a number: if it's t or nil, use 1 or 0."
517 (defun hif-plus (a b)
518 "Like ordinary plus but treat t and nil as 1 and 0."
519 (+ (hif-mathify a) (hif-mathify b)))
520 (defun hif-minus (a b)
521 "Like ordinary minus but treat t and nil as 1 and 0."
522 (- (hif-mathify a) (hif-mathify b)))
523 (defun hif-notequal (a b)
524 "Like (not (equal A B)) but as one symbol."
527 ;;;----------- end of parser -----------------------
530 (defun hif-canonicalize ()
531 "When at beginning of #ifX, returns a Lisp expression for its condition."
533 (let ((negate (looking-at hif-ifndef-regexp)))
534 (re-search-forward hif-ifx-regexp)
536 (buffer-substring (point)
537 (progn (skip-chars-forward "^\n\r") (point))))
538 (expr (hif-infix-to-prefix (hif-tokenize expr-string))))
539 ; (message "hif-canonicalized: %s" expr)
545 (defun hif-find-any-ifX ()
546 "Move to next #if..., or #ifndef, at point or after."
547 ; (message "find ifX at %d" (point))
549 (re-search-forward hif-ifx-regexp (point-max) t)
550 (beginning-of-line)))
553 (defun hif-find-next-relevant ()
554 "Move to next #if..., #else, or #endif, after the current line."
555 ; (message "hif-find-next-relevant at %d" (point))
557 ; avoid infinite recursion by only going to beginning of line if match found
558 (if (re-search-forward hif-ifx-else-endif-regexp (point-max) t)
559 (beginning-of-line)))
561 (defun hif-find-previous-relevant ()
562 "Move to previous #if..., #else, or #endif, before the current line."
563 ; (message "hif-find-previous-relevant at %d" (point))
565 ; avoid infinite recursion by only going to beginning of line if match found
566 (if (re-search-backward hif-ifx-else-endif-regexp (point-min) t)
567 (beginning-of-line)))
570 (defun hif-looking-at-ifX () ;; Should eventually see #if
571 (looking-at hif-ifx-regexp))
572 (defun hif-looking-at-endif ()
573 (looking-at hif-endif-regexp))
574 (defun hif-looking-at-else ()
575 (looking-at hif-else-regexp))
579 (defun hif-ifdef-to-endif ()
580 "If positioned at #ifX or #else form, skip to corresponding #endif."
581 ; (message "hif-ifdef-to-endif at %d" (point)) (sit-for 1)
582 (hif-find-next-relevant)
583 (cond ((hif-looking-at-ifX)
584 (hif-ifdef-to-endif) ; find endif of nested if
585 (hif-ifdef-to-endif)) ; find outer endif or else
586 ((hif-looking-at-else)
587 (hif-ifdef-to-endif)) ; find endif following else
588 ((hif-looking-at-endif)
591 (error "Mismatched #ifdef #endif pair"))))
594 (defun hif-endif-to-ifdef ()
595 "If positioned at #endif form, skip backward to corresponding #ifX."
596 ; (message "hif-endif-to-ifdef at %d" (point))
597 (let ((start (point)))
598 (hif-find-previous-relevant)
599 (if (= start (point))
600 (error "Mismatched #ifdef #endif pair")))
601 (cond ((hif-looking-at-endif)
602 (hif-endif-to-ifdef) ; find beginning of nested if
603 (hif-endif-to-ifdef)) ; find beginning of outer if or else
604 ((hif-looking-at-else)
605 (hif-endif-to-ifdef))
606 ((hif-looking-at-ifX)
608 (t))) ; never gets here
611 (defun forward-ifdef (&optional arg)
612 "Move point to beginning of line of the next ifdef-endif.
613 With argument, do this that many times."
615 (or arg (setq arg 1))
617 (backward-ifdef (- arg)))
620 (let ((start (point)))
621 (if (not (hif-looking-at-ifX))
622 (hif-find-next-relevant))
623 (if (hif-looking-at-ifX)
626 (error "No following #ifdef")
630 (defun backward-ifdef (&optional arg)
631 "Move point to beginning of the previous ifdef-endif.
632 With argument, do this that many times."
634 (or arg (setq arg 1))
636 (forward-ifdef (- arg)))
640 (let ((start (point)))
641 (if (not (hif-looking-at-endif))
642 (hif-find-previous-relevant))
643 (if (hif-looking-at-endif)
646 (error "No previous #ifdef")))))
650 "Move point to beginning of nested ifdef or else-part."
652 (let ((start (point)))
653 (hif-find-next-relevant)
654 (if (or (hif-looking-at-ifX) (hif-looking-at-else))
657 (error "No following #ifdef"))))
661 "Move point to beginning of enclosing ifdef or else-part."
664 (let ((start (point)))
665 (if (not (hif-looking-at-endif))
666 (hif-find-previous-relevant))
667 (if (hif-looking-at-endif)
668 (hif-endif-to-ifdef))
669 (if (= start (point))
670 (error "No previous #ifdef"))))
672 (defun next-ifdef (&optional arg)
673 "Move to the beginning of the next #ifX, #else, or #endif.
674 With argument, do this that many times."
676 (or arg (setq arg 1))
678 (previous-ifdef (- arg)))
681 (hif-find-next-relevant)
685 (error "No following #ifdefs, #elses, or #endifs")))))
687 (defun previous-ifdef (&optional arg)
688 "Move to the beginning of the previous #ifX, #else, or #endif.
689 With argument, do this that many times."
691 (or arg (setq arg 1))
693 (next-ifdef (- arg)))
696 (let ((start (point)))
697 (hif-find-previous-relevant)
698 (if (= start (point))
699 (error "No previous #ifdefs, #elses, or #endifs")
703 ;===%%SF%% parsing (End) ===
706 ;===%%SF%% hide-ifdef-hiding (Start) ===
709 ;;; A range is a structure with four components:
710 ;;; ELSE-P True if there was an else clause for the ifdef.
711 ;;; START The start of the range. (beginning of line)
712 ;;; ELSE The else marker (beginning of line)
713 ;;; Only valid if ELSE-P is true.
714 ;;; END The end of the range. (beginning of line)
716 (defun hif-make-range (else-p start end &optional else)
717 (list else-p start else end))
719 (defun hif-range-else-p (range) (elt range 0))
720 (defun hif-range-start (range) (elt range 1))
721 (defun hif-range-else (range) (elt range 2))
722 (defun hif-range-end (range) (elt range 3))
727 ;;; The workhorse, it delimits the #if region. Reasonably simple:
728 ;;; Skip until an #else or #endif is found, remembering positions. If
729 ;;; an #else was found, skip some more, looking for the true #endif.
731 (defun hif-find-range ()
732 "Returns a Range structure describing the current #if region.
733 Point is left unchanged."
734 ; (message "hif-find-range at %d" (point))
737 (let ((start (point))
741 ;; Part one. Look for either #endif or #else.
742 ;; This loop-and-a-half dedicated to E. Dijkstra.
743 (hif-find-next-relevant)
744 (while (hif-looking-at-ifX) ; Skip nested ifdef
746 (hif-find-next-relevant))
747 ;; Found either a #else or an #endif.
748 (cond ((hif-looking-at-else)
752 (setq end (point)) ; (save-excursion (end-of-line) (point))
754 ;; If found #else, look for #endif.
757 (hif-find-next-relevant)
758 (while (hif-looking-at-ifX) ; Skip nested ifdef
760 (hif-find-next-relevant))
761 (if (hif-looking-at-else)
762 (error "Found two elses in a row? Broken!"))
763 (setq end (point)) ; (save-excursion (end-of-line) (point))
765 (hif-make-range else-p start end else))))
769 ;;; NOTE: If there's an #ifdef at the beginning of the file, we can't
770 ;;; hide it. There's no previous newline to replace. If we added
771 ;;; one, we'd throw off all the counts. Feh.
773 (defun hif-hide-line (point)
774 "Hide the line containing point. Does nothing if `hide-ifdef-lines' is nil."
778 (let ((modp (buffer-modified-p)))
782 (if (not (= (point) 1))
783 (hide-ifdef-region (1- (point)) (point))))
784 (set-buffer-modified-p modp))
789 ;;; Hif-Possibly-Hide
790 ;;; There are four cases. The #ifX expression is "taken" if it
791 ;;; the hide-ifdef-evaluator returns T. Presumably, this means the code
792 ;;; inside the #ifdef would be included when the program was
795 ;;; Case 1: #ifX taken, and there's an #else.
796 ;;; The #else part must be hidden. The #if (then) part must be
797 ;;; processed for nested #ifX's.
798 ;;; Case 2: #ifX taken, and there's no #else.
799 ;;; The #if part must be processed for nested #ifX's.
800 ;;; Case 3: #ifX not taken, and there's an #else.
801 ;;; The #if part must be hidden. The #else part must be processed
803 ;;; Case 4: #ifX not taken, and there's no #else.
804 ;;; The #ifX part must be hidden.
806 ;;; Further processing is done by narrowing to the relevant region
807 ;;; and just recursively calling hide-ifdef-guts.
809 ;;; When hif-possibly-hide returns, point is at the end of the
810 ;;; possibly-hidden range.
812 (defun hif-recurse-on (start end)
813 "Call `hide-ifdef-guts' after narrowing to end of START line and END line."
818 (narrow-to-region (point) end)
821 (defun hif-possibly-hide ()
822 "Called at #ifX expression, this hides those parts that should be hidden.
823 It uses the judgement of `hide-ifdef-evaluator'."
824 ; (message "hif-possibly-hide") (sit-for 1)
825 (let ((test (hif-canonicalize))
826 (range (hif-find-range)))
827 ; (message "test = %s" test) (sit-for 1)
829 (hif-hide-line (hif-range-end range))
830 (if (funcall hide-ifdef-evaluator test)
831 (cond ((hif-range-else-p range) ; case 1
832 (hif-hide-line (hif-range-else range))
833 (hide-ifdef-region (hif-range-else range)
834 (1- (hif-range-end range)))
835 (hif-recurse-on (hif-range-start range)
836 (hif-range-else range)))
838 (hif-recurse-on (hif-range-start range)
839 (hif-range-end range))))
840 (cond ((hif-range-else-p range) ; case 3
841 (hif-hide-line (hif-range-else range))
842 (hide-ifdef-region (hif-range-start range)
843 (1- (hif-range-else range)))
844 (hif-recurse-on (hif-range-else range)
845 (hif-range-end range)))
847 (hide-ifdef-region (point)
848 (1- (hif-range-end range))))
850 (hif-hide-line (hif-range-start range)) ; Always hide start.
851 (goto-char (hif-range-end range))
857 (defun hide-ifdef-guts ()
858 "Does most of the work of `hide-ifdefs'.
859 It does not do the work that's pointless to redo on a recursive entry."
860 ; (message "hide-ifdef-guts")
862 (goto-char (point-min))
863 (while (hif-find-any-ifX)
864 (hif-possibly-hide))))
866 ;===%%SF%% hide-ifdef-hiding (End) ===
869 ;===%%SF%% exports (Start) ===
872 (defvar hide-ifdef-initially nil
873 "*Non-nil means call `hide-ifdefs' when Hide-Ifdef mode is first activated.")
876 (defvar hide-ifdef-read-only nil
877 "*Set to non-nil if you want buffer to be read-only while hiding text.")
879 (defvar hif-outside-read-only nil
880 "Internal variable. Saves the value of `buffer-read-only' while hiding.")
883 (defvar hide-ifdef-lines nil
884 "*Non-nil means hide the #ifX, #else, and #endif lines.")
886 (defun hide-ifdef-toggle-read-only ()
887 "Toggle hide-ifdef-read-only."
889 (setq hide-ifdef-read-only (not hide-ifdef-read-only))
890 (message "Hide-Read-Only %s"
891 (if hide-ifdef-read-only "ON" "OFF"))
892 (if hide-ifdef-hiding
893 (setq buffer-read-only (or hide-ifdef-read-only hif-outside-read-only)))
894 (force-mode-line-update))
896 (defun hide-ifdef-toggle-outside-read-only ()
897 "Replacement for `toggle-read-only' within Hide-Ifdef mode."
899 (setq hif-outside-read-only (not hif-outside-read-only))
900 (message "Read only %s"
901 (if hif-outside-read-only "ON" "OFF"))
902 (setq buffer-read-only
903 (or (and hide-ifdef-hiding hide-ifdef-read-only)
904 hif-outside-read-only)
906 (force-mode-line-update))
909 (defun hide-ifdef-define (var)
910 "Define a VAR so that #ifdef VAR would be included."
911 (interactive "SDefine what? ")
913 (if hide-ifdef-hiding (hide-ifdefs)))
915 (defun hide-ifdef-undef (var)
916 "Undefine a VAR so that #ifdef VAR would not be included."
917 (interactive "SUndefine what? ")
918 (hif-set-var var nil)
919 (if hide-ifdef-hiding (hide-ifdefs)))
922 (defun hide-ifdefs (&optional nomsg)
923 "Hide the contents of some #ifdefs.
924 Assume that defined symbols have been added to `hide-ifdef-env'.
925 The text hidden is the text that would not be included by the C
926 preprocessor if it were given the file with those symbols defined.
928 Turn off hiding by calling `show-ifdefs'."
931 (message "Hiding...")
932 (setq hif-outside-read-only buffer-read-only)
933 (if (not hide-ifdef-mode)
934 (hide-ifdef-mode 1)) ; turn on hide-ifdef-mode
935 (if hide-ifdef-hiding
936 (show-ifdefs)) ; Otherwise, deep confusion.
937 (let ((inhibit-read-only t))
938 (setq selective-display t)
939 (setq hide-ifdef-hiding t)
941 (setq buffer-read-only (or hide-ifdef-read-only hif-outside-read-only))
943 (message "Hiding done")))
946 (defun show-ifdefs ()
947 "Cancel the effects of `hide-ifdef': show the contents of all #ifdefs."
949 (setq buffer-read-only hif-outside-read-only)
950 (setq selective-display nil) ; defaults
951 (let ((inhibit-read-only t))
953 (setq hide-ifdef-hiding nil))
956 (defun hif-find-ifdef-block ()
957 "Utility for hide and show `ifdef-block'.
958 Set top and bottom of ifdef block."
962 (if (not (or (hif-looking-at-else) (hif-looking-at-ifX)))
966 (setq max-bottom (1- (point))))
969 (if (not (hif-looking-at-endif))
970 (hif-find-next-relevant))
971 (while (hif-looking-at-ifX)
973 (hif-find-next-relevant))
974 (setq bottom (min max-bottom (1- (point))))))
978 (defun hide-ifdef-block ()
979 "Hide the ifdef block (true or false part) enclosing or before the cursor."
981 (if (not hide-ifdef-mode)
983 (setq selective-display t)
984 (let (top bottom (inhibit-read-only t))
985 (hif-find-ifdef-block) ; set top and bottom - dynamic scoping
986 (hide-ifdef-region top bottom)
990 (hif-hide-line (1+ bottom))))
991 (setq hide-ifdef-hiding t))
992 (setq buffer-read-only (or hide-ifdef-read-only hif-outside-read-only)))
995 (defun show-ifdef-block ()
996 "Show the ifdef block (true or false part) enclosing or before the cursor."
998 (let ((inhibit-read-only t))
1002 (hif-show-ifdef-region (1- (point)) (progn (end-of-line) (point))))
1005 (hif-find-ifdef-block)
1006 (hif-show-ifdef-region (1- top) bottom)))))
1009 ;;; definition alist support
1011 (defvar hide-ifdef-define-alist nil
1012 "A global assoc list of pre-defined symbol lists")
1014 (defun hif-compress-define-list (env)
1015 "Compress the define list ENV into a list of defined symbols only."
1016 (let ((defs (mapcar '(lambda (arg)
1017 (if (hif-lookup (car arg)) (car arg)))
1022 (setq new-defs (cons (car defs) new-defs)))
1023 (setq defs (cdr defs)))
1026 (defun hide-ifdef-set-define-alist (name)
1027 "Set the association for NAME to `hide-ifdef-env'."
1028 (interactive "SSet define list: ")
1029 (setq hide-ifdef-define-alist
1030 (cons (cons name (hif-compress-define-list hide-ifdef-env))
1031 hide-ifdef-define-alist)))
1033 (defun hide-ifdef-use-define-alist (name)
1034 "Set `hide-ifdef-env' to the define list specified by NAME."
1035 (interactive "SUse define list: ")
1036 (let ((define-list (assoc name hide-ifdef-define-alist)))
1038 (setq hide-ifdef-env
1039 (mapcar '(lambda (arg) (cons arg t))
1041 (error "No define list for %s" name))
1042 (if hide-ifdef-hiding (hide-ifdefs))))
1046 ;;; hideif.el ends here