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emacs/lisp/progmodes/hideif.el
Glenn Morris d7a0267c8d Add 2007 to copyright years.
2007-01-21 03:53:13 +00:00

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;;; hideif.el --- hides selected code within ifdef
;; Copyright (C) 1988, 1994, 2001, 2002, 2003, 2004, 2005, 2006, 2007
;; Free Software Foundation, Inc.
;; Author: Daniel LaLiberte <liberte@holonexus.org>
;; Maintainer: FSF
;; Keywords: c, outlines
;; This file is part of GNU Emacs.
;; GNU Emacs 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.
;; GNU Emacs 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 GNU Emacs; see the file COPYING. If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.
;;; Commentary:
;; To initialize, toggle the hide-ifdef minor mode with
;;
;; M-x hide-ifdef-mode
;;
;; This will set up key bindings and call hide-ifdef-mode-hook if it
;; has a value. To explicitly hide ifdefs using a buffer-local
;; define list (default empty), type
;;
;; M-x hide-ifdefs or C-c @ h
;;
;; Hide-ifdef suppresses the display of code that the preprocessor wouldn't
;; pass through. The support of constant expressions in #if lines is
;; limited to identifiers, parens, and the operators: &&, ||, !, and
;; "defined". Please extend this.
;;
;; The hidden code is marked by ellipses (...). Be
;; cautious when editing near ellipses, since the hidden text is
;; still in the buffer, and you can move the point into it and modify
;; text unawares.
;; You can make your buffer read-only while hide-ifdef-hiding by setting
;; hide-ifdef-read-only to a non-nil value. You can toggle this
;; variable with hide-ifdef-toggle-read-only (C-c @ C-q).
;;
;; You can undo the effect of hide-ifdefs by typing
;;
;; M-x show-ifdefs or C-c @ s
;;
;; Use M-x hide-ifdef-define (C-c @ d) to define a symbol.
;; Use M-x hide-ifdef-undef (C-c @ u) to undefine a symbol.
;;
;; If you define or undefine a symbol while hide-ifdef-mode is in effect,
;; the display will be updated. Only the define list for the current
;; buffer will be affected. You can save changes to the local define
;; list with hide-ifdef-set-define-alist. This adds entries
;; to hide-ifdef-define-alist.
;;
;; If you have defined a hide-ifdef-mode-hook, you can set
;; up a list of symbols that may be used by hide-ifdefs as in the
;; following example:
;;
;; (add-hook 'hide-ifdef-mode-hook
;; (lambda ()
;; (unless hide-ifdef-define-alist
;; (setq hide-ifdef-define-alist
;; '((list1 ONE TWO)
;; (list2 TWO THREE))))
;; (hide-ifdef-use-define-alist 'list2))) ; use list2 by default
;;
;; You can call hide-ifdef-use-define-alist (C-c @ U) at any time to specify
;; another list to use.
;;
;; To cause ifdefs to be hidden as soon as hide-ifdef-mode is called,
;; set hide-ifdef-initially to non-nil.
;;
;; If you set hide-ifdef-lines to t, hide-ifdefs hides all the #ifdef lines.
;; In the absence of highlighting, that might be a bad idea. If you set
;; hide-ifdef-lines to nil (the default), the surrounding preprocessor
;; lines will be displayed. That can be confusing in its own
;; right. Other variations on display are possible, but not much
;; better.
;;
;; You can explicitly hide or show individual ifdef blocks irrespective
;; of the define list by using hide-ifdef-block and show-ifdef-block.
;;
;; You can move the point between ifdefs with forward-ifdef, backward-ifdef,
;; up-ifdef, down-ifdef, next-ifdef, and previous-ifdef.
;;
;; If you have minor-mode-alist in your mode line (the default) two labels
;; may appear. "Ifdef" will appear when hide-ifdef-mode is active. "Hiding"
;; will appear when text may be hidden ("hide-ifdef-hiding" is non-nil).
;;
;; Written by Brian Marick, at Gould, Computer Systems Division, Urbana IL.
;; Extensively modified by Daniel LaLiberte (while at Gould).
;;
;; You may freely modify and distribute this, but keep a record
;; of modifications and send comments to:
;; liberte@a.cs.uiuc.edu or ihnp4!uiucdcs!liberte
;; I will continue to upgrade hide-ifdef-mode
;; with your contributions.
;;; Code:
(require 'cc-mode)
(defgroup hide-ifdef nil
"Hide selected code within `ifdef'."
:group 'c)
(defvar hide-ifdef-mode-submap
;; Set up the submap that goes after the prefix key.
(let ((map (make-sparse-keymap)))
(define-key map "d" 'hide-ifdef-define)
(define-key map "u" 'hide-ifdef-undef)
(define-key map "D" 'hide-ifdef-set-define-alist)
(define-key map "U" 'hide-ifdef-use-define-alist)
(define-key map "h" 'hide-ifdefs)
(define-key map "s" 'show-ifdefs)
(define-key map "\C-d" 'hide-ifdef-block)
(define-key map "\C-s" 'show-ifdef-block)
(define-key map "\C-q" 'hide-ifdef-toggle-read-only)
(substitute-key-definition
'toggle-read-only 'hide-ifdef-toggle-outside-read-only map)
map)
"Keymap used by `hide-ifdef-mode' under `hide-ifdef-mode-prefix-key'.")
(defconst hide-ifdef-mode-prefix-key "\C-c@"
"Prefix key for all Hide-Ifdef mode commands.")
(defvar hide-ifdef-mode-map
;; Set up the mode's main map, which leads via the prefix key to the submap.
(let ((map (make-sparse-keymap)))
(define-key map hide-ifdef-mode-prefix-key hide-ifdef-mode-submap)
map)
"Keymap used with `hide-ifdef-mode'.")
(defvar hide-ifdef-hiding nil
"Non-nil when text may be hidden.")
(or (assq 'hide-ifdef-hiding minor-mode-alist)
(setq minor-mode-alist
(cons '(hide-ifdef-hiding " Hiding")
minor-mode-alist)))
;; fix c-mode syntax table so we can recognize whole symbols.
(defvar hide-ifdef-syntax-table
(let ((st (copy-syntax-table c-mode-syntax-table)))
(modify-syntax-entry ?_ "w" st)
(modify-syntax-entry ?& "." st)
(modify-syntax-entry ?\| "." st)
st)
"Syntax table used for tokenizing #if expressions.")
(defvar hide-ifdef-env nil
"An alist of defined symbols and their values.")
(defvar hif-outside-read-only nil
"Internal variable. Saves the value of `buffer-read-only' while hiding.")
;;;###autoload
(define-minor-mode hide-ifdef-mode
"Toggle Hide-Ifdef mode. This is a minor mode, albeit a large one.
With ARG, turn Hide-Ifdef mode on if arg is positive, off otherwise.
In Hide-Ifdef mode, code within #ifdef constructs that the C preprocessor
would eliminate may be hidden from view. Several variables affect
how the hiding is done:
`hide-ifdef-env'
An association list of defined and undefined symbols for the
current buffer. Initially, the global value of `hide-ifdef-env'
is used.
`hide-ifdef-define-alist'
An association list of defined symbol lists.
Use `hide-ifdef-set-define-alist' to save the current `hide-ifdef-env'
and `hide-ifdef-use-define-alist' to set the current `hide-ifdef-env'
from one of the lists in `hide-ifdef-define-alist'.
`hide-ifdef-lines'
Set to non-nil to not show #if, #ifdef, #ifndef, #else, and
#endif lines when hiding.
`hide-ifdef-initially'
Indicates whether `hide-ifdefs' should be called when Hide-Ifdef mode
is activated.
`hide-ifdef-read-only'
Set to non-nil if you want to make buffers read only while hiding.
After `show-ifdefs', read-only status is restored to previous value.
\\{hide-ifdef-mode-map}"
:group 'hide-ifdef :lighter " Ifdef"
(if hide-ifdef-mode
(progn
;; inherit global values
(set (make-local-variable 'hide-ifdef-env)
(default-value 'hide-ifdef-env))
(set (make-local-variable 'hide-ifdef-hiding)
(default-value 'hide-ifdef-hiding))
(set (make-local-variable 'hif-outside-read-only) buffer-read-only)
(set (make-local-variable 'line-move-ignore-invisible) t)
(add-hook 'change-major-mode-hook
(lambda () (hide-ifdef-mode -1)) nil t)
(add-to-invisibility-spec '(hide-ifdef . t))
(if hide-ifdef-initially
(hide-ifdefs)
(show-ifdefs)))
;; else end hide-ifdef-mode
(kill-local-variable 'line-move-ignore-invisible)
(remove-from-invisibility-spec '(hide-ifdef . t))
(if hide-ifdef-hiding
(show-ifdefs))))
(defun hif-show-all ()
"Show all of the text in the current buffer."
(interactive)
(hif-show-ifdef-region (point-min) (point-max)))
;; By putting this on after-revert-hook, we arrange that it only
;; does anything when revert-buffer avoids turning off the mode.
;; (That can happen in VC.)
(defun hif-after-revert-function ()
(and hide-ifdef-mode hide-ifdef-hiding
(hide-ifdefs t)))
(add-hook 'after-revert-hook 'hif-after-revert-function)
(defun hif-end-of-line ()
(end-of-line)
(while (= (logand 1 (skip-chars-backward "\\\\")) 1)
(end-of-line 2)))
(defun hide-ifdef-region-internal (start end)
(remove-overlays start end 'invisible 'hide-ifdef)
(let ((o (make-overlay start end)))
(overlay-put o 'invisible 'hide-ifdef)))
(defun hide-ifdef-region (start end)
"START is the start of a #if or #else form. END is the ending part.
Everything including these lines is made invisible."
(save-excursion
(goto-char start) (hif-end-of-line) (setq start (point))
(goto-char end) (hif-end-of-line) (setq end (point))
(hide-ifdef-region-internal start end)))
(defun hif-show-ifdef-region (start end)
"Everything between START and END is made visible."
(remove-overlays start end 'invisible 'hide-ifdef))
;;===%%SF%% evaluation (Start) ===
;; It is not useful to set this to anything but `eval'.
;; In fact, the variable might as well be eliminated.
(defvar hide-ifdef-evaluator 'eval
"The function to use to evaluate a form.
The evaluator is given a canonical form and returns t if text under
that form should be displayed.")
(defvar hif-undefined-symbol nil
"...is by default considered to be false.")
(defun hif-set-var (var value)
"Prepend (var value) pair to hide-ifdef-env."
(setq hide-ifdef-env (cons (cons var value) hide-ifdef-env)))
(defun hif-lookup (var)
;; (message "hif-lookup %s" var)
(let ((val (assoc var hide-ifdef-env)))
(if val
(cdr val)
hif-undefined-symbol)))
(defun hif-defined (var)
(if (assoc var hide-ifdef-env) 1 0))
;;===%%SF%% evaluation (End) ===
;;===%%SF%% parsing (Start) ===
;;; The code that understands what ifs and ifdef in files look like.
(defconst hif-cpp-prefix "\\(^\\|\r\\)[ \t]*#[ \t]*")
(defconst hif-ifndef-regexp (concat hif-cpp-prefix "ifndef"))
(defconst hif-ifx-regexp (concat hif-cpp-prefix "if\\(n?def\\)?[ \t]+"))
(defconst hif-else-regexp (concat hif-cpp-prefix "else"))
(defconst hif-endif-regexp (concat hif-cpp-prefix "endif"))
(defconst hif-ifx-else-endif-regexp
(concat hif-ifx-regexp "\\|" hif-else-regexp "\\|" hif-endif-regexp))
;; Used to store the current token and the whole token list during parsing.
;; Only bound dynamically.
(defvar hif-token)
(defvar hif-token-list)
;; pattern to match initial identifier, !, &&, ||, (, or ).
;; Added ==, + and -: garyo@avs.com 8/9/94
(defconst hif-token-regexp
"\\(&&\\|||\\|[!=]=\\|!\\|[()+?:-]\\|[<>]=?\\|\\w+\\)")
(defun hif-tokenize (start end)
"Separate string between START and END into a list of tokens."
(let ((token-list nil))
(with-syntax-table hide-ifdef-syntax-table
(save-excursion
(goto-char start)
(while (progn (forward-comment (point-max)) (< (point) end))
;; (message "expr-start = %d" expr-start) (sit-for 1)
(cond
((looking-at "\\\\\n")
(forward-char 2))
((looking-at hif-token-regexp)
(let ((token (buffer-substring (point) (match-end 0))))
(goto-char (match-end 0))
;; (message "token: %s" token) (sit-for 1)
(push (cond
((string-equal token "||") 'or)
((string-equal token "&&") 'and)
((string-equal token "==") 'equal)
((string-equal token "!=") 'hif-notequal)
((string-equal token "!") 'not)
((string-equal token "defined") 'hif-defined)
((string-equal token "(") 'lparen)
((string-equal token ")") 'rparen)
((string-equal token ">") 'hif-greater)
((string-equal token "<") 'hif-less)
((string-equal token ">=") 'hif-greater-equal)
((string-equal token "<=") 'hif-less-equal)
((string-equal token "+") 'hif-plus)
((string-equal token "-") 'hif-minus)
((string-equal token "?") 'hif-conditional)
((string-equal token ":") 'hif-colon)
((string-match "\\`[0-9]*\\'" token)
(string-to-number token))
(t (intern token)))
token-list)))
(t (error "Bad #if expression: %s" (buffer-string)))))))
(nreverse token-list)))
;;;-----------------------------------------------------------------
;;; Translate C preprocessor #if expressions using recursive descent.
;;; This parser is limited to the operators &&, ||, !, and "defined".
;;; Added ==, !=, +, and -. Gary Oberbrunner, garyo@avs.com, 8/9/94
(defsubst hif-nexttoken ()
"Pop the next token from token-list into the let variable \"hif-token\"."
(setq hif-token (pop hif-token-list)))
(defun hif-parse-if-exp (hif-token-list)
"Parse the TOKEN-LIST. Return translated list in prefix form."
(hif-nexttoken)
(prog1
(hif-expr)
(if hif-token ; is there still a token?
(error "Error: unexpected token: %s" hif-token))))
(defun hif-expr ()
"Parse an expression as found in #if.
expr : or-expr | or-expr '?' expr ':' expr."
(let ((result (hif-or-expr))
middle)
(while (eq hif-token 'hif-conditional)
(hif-nexttoken)
(setq middle (hif-expr))
(if (eq hif-token 'hif-colon)
(progn
(hif-nexttoken)
(setq result (list 'hif-conditional result middle (hif-expr))))
(error "Error: unexpected token: %s" hif-token)))
result))
(defun hif-or-expr ()
"Parse n or-expr : and-expr | or-expr '||' and-expr."
(let ((result (hif-and-expr)))
(while (eq hif-token 'or)
(hif-nexttoken)
(setq result (list 'hif-or result (hif-and-expr))))
result))
(defun hif-and-expr ()
"Parse an and-expr : eq-expr | and-expr '&&' eq-expr."
(let ((result (hif-eq-expr)))
(while (eq hif-token 'and)
(hif-nexttoken)
(setq result (list 'hif-and result (hif-eq-expr))))
result))
(defun hif-eq-expr ()
"Parse an eq-expr : math | eq-expr `=='|`!='|`<'|`>'|`>='|`<=' math."
(let ((result (hif-math))
(eq-token nil))
(while (memq hif-token '(equal hif-notequal hif-greater hif-less
hif-greater-equal hif-less-equal))
(setq eq-token hif-token)
(hif-nexttoken)
(setq result (list eq-token result (hif-math))))
result))
(defun hif-math ()
"Parse an expression with + or - and simpler things.
math : factor | math '+|-' factor."
(let ((result (hif-factor))
(math-op nil))
(while (memq hif-token '(hif-plus hif-minus))
(setq math-op hif-token)
(hif-nexttoken)
(setq result (list math-op result (hif-factor))))
result))
(defun hif-factor ()
"Parse a factor: '!' factor | '(' expr ')' | 'defined(' id ')' | id."
(cond
((eq hif-token 'not)
(hif-nexttoken)
(list 'hif-not (hif-factor)))
((eq hif-token 'lparen)
(hif-nexttoken)
(let ((result (hif-expr)))
(if (not (eq hif-token 'rparen))
(error "Bad token in parenthesized expression: %s" hif-token)
(hif-nexttoken)
result)))
((eq hif-token 'hif-defined)
(hif-nexttoken)
(let ((paren (when (eq hif-token 'lparen) (hif-nexttoken) t))
(ident hif-token))
(if (memq hif-token '(or and not hif-defined lparen rparen))
(error "Error: unexpected token: %s" hif-token))
(when paren
(hif-nexttoken)
(unless (eq hif-token 'rparen)
(error "Error: expected \")\" after identifier")))
(hif-nexttoken)
`(hif-defined (quote ,ident))))
((numberp hif-token)
(prog1 hif-token (hif-nexttoken)))
(t ; identifier
(let ((ident hif-token))
(if (memq ident '(or and))
(error "Error: missing identifier"))
(hif-nexttoken)
`(hif-lookup (quote ,ident))))))
(defun hif-mathify (val)
"Treat VAL as a number: if it's t or nil, use 1 or 0."
(cond ((eq val t) 1)
((null val) 0)
(t val)))
(defun hif-conditional (a b c)
(if (not (zerop (hif-mathify a))) (hif-mathify b) (hif-mathify c)))
(defun hif-and (a b)
(and (not (zerop (hif-mathify a))) (not (zerop (hif-mathify b)))))
(defun hif-or (a b)
(or (not (zerop (hif-mathify a))) (not (zerop (hif-mathify b)))))
(defun hif-not (a)
(zerop (hif-mathify a)))
(defun hif-plus (a b)
"Like ordinary plus but treat t and nil as 1 and 0."
(+ (hif-mathify a) (hif-mathify b)))
(defun hif-minus (a b)
"Like ordinary minus but treat t and nil as 1 and 0."
(- (hif-mathify a) (hif-mathify b)))
(defun hif-notequal (a b)
"Like (not (equal A B)) but as one symbol."
(not (equal a b)))
(defun hif-greater (a b)
"Simple comparison."
(> (hif-mathify a) (hif-mathify b)))
(defun hif-less (a b)
"Simple comparison."
(< (hif-mathify a) (hif-mathify b)))
(defun hif-greater-equal (a b)
"Simple comparison."
(>= (hif-mathify a) (hif-mathify b)))
(defun hif-less-equal (a b)
"Simple comparison."
(<= (hif-mathify a) (hif-mathify b)))
;;;----------- end of parser -----------------------
(defun hif-canonicalize ()
"When at beginning of #ifX, return a Lisp expression for its condition."
(save-excursion
(let ((negate (looking-at hif-ifndef-regexp)))
(re-search-forward hif-ifx-regexp)
(let* ((tokens (hif-tokenize (point)
(progn (hif-end-of-line) (point))))
(expr (hif-parse-if-exp tokens)))
;; (message "hif-canonicalized: %s" expr)
(if negate
(list 'hif-not expr)
expr)))))
(defun hif-find-any-ifX ()
"Move to next #if..., or #ifndef, at point or after."
;; (message "find ifX at %d" (point))
(prog1
(re-search-forward hif-ifx-regexp (point-max) t)
(beginning-of-line)))
(defun hif-find-next-relevant ()
"Move to next #if..., #else, or #endif, after the current line."
;; (message "hif-find-next-relevant at %d" (point))
(end-of-line)
;; avoid infinite recursion by only going to beginning of line if match found
(if (re-search-forward hif-ifx-else-endif-regexp (point-max) t)
(beginning-of-line)))
(defun hif-find-previous-relevant ()
"Move to previous #if..., #else, or #endif, before the current line."
;; (message "hif-find-previous-relevant at %d" (point))
(beginning-of-line)
;; avoid infinite recursion by only going to beginning of line if match found
(if (re-search-backward hif-ifx-else-endif-regexp (point-min) t)
(beginning-of-line)))
(defun hif-looking-at-ifX () ;; Should eventually see #if
(looking-at hif-ifx-regexp))
(defun hif-looking-at-endif ()
(looking-at hif-endif-regexp))
(defun hif-looking-at-else ()
(looking-at hif-else-regexp))
(defun hif-ifdef-to-endif ()
"If positioned at #ifX or #else form, skip to corresponding #endif."
;; (message "hif-ifdef-to-endif at %d" (point)) (sit-for 1)
(hif-find-next-relevant)
(cond ((hif-looking-at-ifX)
(hif-ifdef-to-endif) ; find endif of nested if
(hif-ifdef-to-endif)) ; find outer endif or else
((hif-looking-at-else)
(hif-ifdef-to-endif)) ; find endif following else
((hif-looking-at-endif)
'done)
(t
(error "Mismatched #ifdef #endif pair"))))
(defun hif-endif-to-ifdef ()
"If positioned at #endif form, skip backward to corresponding #ifX."
;; (message "hif-endif-to-ifdef at %d" (point))
(let ((start (point)))
(hif-find-previous-relevant)
(if (= start (point))
(error "Mismatched #ifdef #endif pair")))
(cond ((hif-looking-at-endif)
(hif-endif-to-ifdef) ; find beginning of nested if
(hif-endif-to-ifdef)) ; find beginning of outer if or else
((hif-looking-at-else)
(hif-endif-to-ifdef))
((hif-looking-at-ifX)
'done)
(t))) ; never gets here
(defun forward-ifdef (&optional arg)
"Move point to beginning of line of the next ifdef-endif.
With argument, do this that many times."
(interactive "p")
(or arg (setq arg 1))
(if (< arg 0) (backward-ifdef (- arg))
(while (< 0 arg)
(setq arg (- arg))
(let ((start (point)))
(unless (hif-looking-at-ifX)
(hif-find-next-relevant))
(if (hif-looking-at-ifX)
(hif-ifdef-to-endif)
(goto-char start)
(error "No following #ifdef"))))))
(defun backward-ifdef (&optional arg)
"Move point to beginning of the previous ifdef-endif.
With argument, do this that many times."
(interactive "p")
(or arg (setq arg 1))
(if (< arg 0) (forward-ifdef (- arg))
(while (< 0 arg)
(setq arg (1- arg))
(beginning-of-line)
(let ((start (point)))
(unless (hif-looking-at-endif)
(hif-find-previous-relevant))
(if (hif-looking-at-endif)
(hif-endif-to-ifdef)
(goto-char start)
(error "No previous #ifdef"))))))
(defun down-ifdef ()
"Move point to beginning of nested ifdef or else-part."
(interactive)
(let ((start (point)))
(hif-find-next-relevant)
(if (or (hif-looking-at-ifX) (hif-looking-at-else))
()
(goto-char start)
(error "No following #ifdef"))))
(defun up-ifdef ()
"Move point to beginning of enclosing ifdef or else-part."
(interactive)
(beginning-of-line)
(let ((start (point)))
(unless (hif-looking-at-endif)
(hif-find-previous-relevant))
(if (hif-looking-at-endif)
(hif-endif-to-ifdef))
(if (= start (point))
(error "No previous #ifdef"))))
(defun next-ifdef (&optional arg)
"Move to the beginning of the next #ifX, #else, or #endif.
With argument, do this that many times."
(interactive "p")
(or arg (setq arg 1))
(if (< arg 0) (previous-ifdef (- arg))
(while (< 0 arg)
(setq arg (1- arg))
(hif-find-next-relevant)
(when (eolp)
(beginning-of-line)
(error "No following #ifdefs, #elses, or #endifs")))))
(defun previous-ifdef (&optional arg)
"Move to the beginning of the previous #ifX, #else, or #endif.
With argument, do this that many times."
(interactive "p")
(or arg (setq arg 1))
(if (< arg 0) (next-ifdef (- arg))
(while (< 0 arg)
(setq arg (1- arg))
(let ((start (point)))
(hif-find-previous-relevant)
(if (= start (point))
(error "No previous #ifdefs, #elses, or #endifs"))))))
;;===%%SF%% parsing (End) ===
;;===%%SF%% hide-ifdef-hiding (Start) ===
;;; A range is a structure with four components:
;;; ELSE-P True if there was an else clause for the ifdef.
;;; START The start of the range. (beginning of line)
;;; ELSE The else marker (beginning of line)
;;; Only valid if ELSE-P is true.
;;; END The end of the range. (beginning of line)
(defsubst hif-make-range (start end &optional else)
(list start else end))
(defsubst hif-range-start (range) (elt range 0))
(defsubst hif-range-else (range) (elt range 1))
(defsubst hif-range-end (range) (elt range 2))
;;; Find-Range
;;; The workhorse, it delimits the #if region. Reasonably simple:
;;; Skip until an #else or #endif is found, remembering positions. If
;;; an #else was found, skip some more, looking for the true #endif.
(defun hif-find-range ()
"Return a Range structure describing the current #if region.
Point is left unchanged."
;; (message "hif-find-range at %d" (point))
(save-excursion
(beginning-of-line)
(let ((start (point))
(else nil)
(end nil))
;; Part one. Look for either #endif or #else.
;; This loop-and-a-half dedicated to E. Dijkstra.
(while (progn
(hif-find-next-relevant)
(hif-looking-at-ifX)) ; Skip nested ifdef
(hif-ifdef-to-endif))
;; Found either a #else or an #endif.
(cond ((hif-looking-at-else)
(setq else (point)))
(t
(setq end (point)))) ; (save-excursion (end-of-line) (point))
;; If found #else, look for #endif.
(when else
(while (progn
(hif-find-next-relevant)
(hif-looking-at-ifX)) ; Skip nested ifdef
(hif-ifdef-to-endif))
(if (hif-looking-at-else)
(error "Found two elses in a row? Broken!"))
(setq end (point))) ; (save-excursion (end-of-line) (point))
(hif-make-range start end else))))
;;; A bit slimy.
(defun hif-hide-line (point)
"Hide the line containing point. Does nothing if `hide-ifdef-lines' is nil."
(if hide-ifdef-lines
(save-excursion
(goto-char point)
(hide-ifdef-region-internal (line-beginning-position)
(progn (hif-end-of-line) (point))))))
;;; Hif-Possibly-Hide
;;; There are four cases. The #ifX expression is "taken" if it
;;; the hide-ifdef-evaluator returns T. Presumably, this means the code
;;; inside the #ifdef would be included when the program was
;;; compiled.
;;;
;;; Case 1: #ifX taken, and there's an #else.
;;; The #else part must be hidden. The #if (then) part must be
;;; processed for nested #ifX's.
;;; Case 2: #ifX taken, and there's no #else.
;;; The #if part must be processed for nested #ifX's.
;;; Case 3: #ifX not taken, and there's an #else.
;;; The #if part must be hidden. The #else part must be processed
;;; for nested #ifs.
;;; Case 4: #ifX not taken, and there's no #else.
;;; The #ifX part must be hidden.
;;;
;;; Further processing is done by narrowing to the relevant region
;;; and just recursively calling hide-ifdef-guts.
;;;
;;; When hif-possibly-hide returns, point is at the end of the
;;; possibly-hidden range.
(defun hif-recurse-on (start end)
"Call `hide-ifdef-guts' after narrowing to end of START line and END line."
(save-excursion
(save-restriction
(goto-char start)
(end-of-line)
(narrow-to-region (point) end)
(hide-ifdef-guts))))
(defun hif-possibly-hide ()
"Called at #ifX expression, this hides those parts that should be hidden.
It uses the judgement of `hide-ifdef-evaluator'."
;; (message "hif-possibly-hide") (sit-for 1)
(let ((test (hif-canonicalize))
(range (hif-find-range)))
;; (message "test = %s" test) (sit-for 1)
(hif-hide-line (hif-range-end range))
(if (not (hif-not (funcall hide-ifdef-evaluator test)))
(cond ((hif-range-else range) ; case 1
(hif-hide-line (hif-range-else range))
(hide-ifdef-region (hif-range-else range)
(1- (hif-range-end range)))
(hif-recurse-on (hif-range-start range)
(hif-range-else range)))
(t ; case 2
(hif-recurse-on (hif-range-start range)
(hif-range-end range))))
(cond ((hif-range-else range) ; case 3
(hif-hide-line (hif-range-else range))
(hide-ifdef-region (hif-range-start range)
(1- (hif-range-else range)))
(hif-recurse-on (hif-range-else range)
(hif-range-end range)))
(t ; case 4
(hide-ifdef-region (point)
(1- (hif-range-end range))))))
(hif-hide-line (hif-range-start range)) ; Always hide start.
(goto-char (hif-range-end range))
(end-of-line)))
(defun hide-ifdef-guts ()
"Does most of the work of `hide-ifdefs'.
It does not do the work that's pointless to redo on a recursive entry."
;; (message "hide-ifdef-guts")
(save-excursion
(goto-char (point-min))
(while (hif-find-any-ifX)
(hif-possibly-hide))))
;;===%%SF%% hide-ifdef-hiding (End) ===
;;===%%SF%% exports (Start) ===
;;;###autoload
(defcustom hide-ifdef-initially nil
"*Non-nil means call `hide-ifdefs' when Hide-Ifdef mode is first activated."
:type 'boolean
:group 'hide-ifdef)
;;;###autoload
(defcustom hide-ifdef-read-only nil
"*Set to non-nil if you want buffer to be read-only while hiding text."
:type 'boolean
:group 'hide-ifdef)
;;;###autoload
(defcustom hide-ifdef-lines nil
"*Non-nil means hide the #ifX, #else, and #endif lines."
:type 'boolean
:group 'hide-ifdef)
(defun hide-ifdef-toggle-read-only ()
"Toggle `hide-ifdef-read-only'."
(interactive)
(setq hide-ifdef-read-only (not hide-ifdef-read-only))
(message "Hide-Read-Only %s"
(if hide-ifdef-read-only "ON" "OFF"))
(if hide-ifdef-hiding
(setq buffer-read-only (or hide-ifdef-read-only hif-outside-read-only)))
(force-mode-line-update))
(defun hide-ifdef-toggle-outside-read-only ()
"Replacement for `toggle-read-only' within Hide-Ifdef mode."
(interactive)
(setq hif-outside-read-only (not hif-outside-read-only))
(message "Read only %s"
(if hif-outside-read-only "ON" "OFF"))
(setq buffer-read-only
(or (and hide-ifdef-hiding hide-ifdef-read-only)
hif-outside-read-only))
(force-mode-line-update))
(defun hide-ifdef-define (var)
"Define a VAR so that #ifdef VAR would be included."
(interactive "SDefine what? ")
(hif-set-var var 1)
(if hide-ifdef-hiding (hide-ifdefs)))
(defun hide-ifdef-undef (var)
"Undefine a VAR so that #ifdef VAR would not be included."
(interactive "SUndefine what? ")
(hif-set-var var nil)
(if hide-ifdef-hiding (hide-ifdefs)))
(defun hide-ifdefs (&optional nomsg)
"Hide the contents of some #ifdefs.
Assume that defined symbols have been added to `hide-ifdef-env'.
The text hidden is the text that would not be included by the C
preprocessor if it were given the file with those symbols defined.
Turn off hiding by calling `show-ifdefs'."
(interactive)
(message "Hiding...")
(setq hif-outside-read-only buffer-read-only)
(unless hide-ifdef-mode (hide-ifdef-mode 1)) ; turn on hide-ifdef-mode
(if hide-ifdef-hiding
(show-ifdefs)) ; Otherwise, deep confusion.
(setq hide-ifdef-hiding t)
(hide-ifdef-guts)
(setq buffer-read-only (or hide-ifdef-read-only hif-outside-read-only))
(or nomsg
(message "Hiding done")))
(defun show-ifdefs ()
"Cancel the effects of `hide-ifdef': show the contents of all #ifdefs."
(interactive)
(setq buffer-read-only hif-outside-read-only)
(hif-show-all)
(setq hide-ifdef-hiding nil))
(defun hif-find-ifdef-block ()
"Utility for hide and show `ifdef-block'.
Return as (TOP . BOTTOM) the extent of ifdef block."
(let (max-bottom)
(cons (save-excursion
(beginning-of-line)
(unless (or (hif-looking-at-else) (hif-looking-at-ifX))
(up-ifdef))
(prog1 (point)
(hif-ifdef-to-endif)
(setq max-bottom (1- (point)))))
(save-excursion
(beginning-of-line)
(unless (hif-looking-at-endif)
(hif-find-next-relevant))
(while (hif-looking-at-ifX)
(hif-ifdef-to-endif)
(hif-find-next-relevant))
(min max-bottom (1- (point)))))))
(defun hide-ifdef-block ()
"Hide the ifdef block (true or false part) enclosing or before the cursor."
(interactive)
(unless hide-ifdef-mode (hide-ifdef-mode 1))
(let ((top-bottom (hif-find-ifdef-block)))
(hide-ifdef-region (car top-bottom) (cdr top-bottom))
(when hide-ifdef-lines
(hif-hide-line (car top-bottom))
(hif-hide-line (1+ (cdr top-bottom))))
(setq hide-ifdef-hiding t))
(setq buffer-read-only (or hide-ifdef-read-only hif-outside-read-only)))
(defun show-ifdef-block ()
"Show the ifdef block (true or false part) enclosing or before the cursor."
(interactive)
(let ((top-bottom (hif-find-ifdef-block)))
(if hide-ifdef-lines
(hif-show-ifdef-region
(save-excursion
(goto-char (car top-bottom)) (line-beginning-position))
(save-excursion
(goto-char (1+ (cdr top-bottom)))
(hif-end-of-line) (point)))
(hif-show-ifdef-region (1- (car top-bottom)) (cdr top-bottom)))))
;;; definition alist support
(defvar hide-ifdef-define-alist nil
"A global assoc list of pre-defined symbol lists.")
(defun hif-compress-define-list (env)
"Compress the define list ENV into a list of defined symbols only."
(let ((new-defs nil))
(dolist (def env new-defs)
(if (hif-lookup (car def)) (push (car env) new-defs)))))
(defun hide-ifdef-set-define-alist (name)
"Set the association for NAME to `hide-ifdef-env'."
(interactive "SSet define list: ")
(push (cons name (hif-compress-define-list hide-ifdef-env))
hide-ifdef-define-alist))
(defun hide-ifdef-use-define-alist (name)
"Set `hide-ifdef-env' to the define list specified by NAME."
(interactive
(list (completing-read "Use define list: "
(mapcar (lambda (x) (symbol-name (car x)))
hide-ifdef-define-alist)
nil t)))
(if (stringp name) (setq name (intern name)))
(let ((define-list (assoc name hide-ifdef-define-alist)))
(if define-list
(setq hide-ifdef-env
(mapcar (lambda (arg) (cons arg t))
(cdr define-list)))
(error "No define list for %s" name))
(if hide-ifdef-hiding (hide-ifdefs))))
(provide 'hideif)
;; arch-tag: c6381d17-a59a-483a-b945-658f22277981
;;; hideif.el ends here
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