code.delx.au - gnu-emacs/blob - lisp/progmodes/cc-defs.el

   1 ;;; cc-defs.el --- definitions for CC Mode
   2
   3 ;; Copyright (C) 1985,87,92,93,94,95,96,97,98 Free Software Foundation, Inc.
   4
   5 ;; Authors:    1992-1997 Barry A. Warsaw
   6 ;;             1987 Dave Detlefs and Stewart Clamen
   7 ;;             1985 Richard M. Stallman
   8 ;; Maintainer: cc-mode-help@python.org
   9 ;; Created:    22-Apr-1997 (split from cc-mode.el)
  10 ;; Version:    See cc-mode.el
  11 ;; Keywords:   c languages oop
  12
  13 ;; This file is part of GNU Emacs.
  14
  15 ;; GNU Emacs is free software; you can redistribute it and/or modify
  16 ;; it under the terms of the GNU General Public License as published by
  17 ;; the Free Software Foundation; either version 2, or (at your option)
  18 ;; any later version.
  19
  20 ;; GNU Emacs is distributed in the hope that it will be useful,
  21 ;; but WITHOUT ANY WARRANTY; without even the implied warranty of
  22 ;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  23 ;; GNU General Public License for more details.
  24
  25 ;; You should have received a copy of the GNU General Public License
  26 ;; along with GNU Emacs; see the file COPYING.  If not, write to the
  27 ;; Free Software Foundation, Inc., 59 Temple Place - Suite 330,
  28 ;; Boston, MA 02111-1307, USA.
  29
  30 \f
  31 ;; Figure out what features this Emacs has
  32 ;;;###autoload
  33 (defconst c-emacs-features
  34   (let ((infodock-p (boundp 'infodock-version))
  35         (comments
  36          ;; XEmacs 19 and beyond use 8-bit modify-syntax-entry flags.
  37          ;; Emacs 19 uses a 1-bit flag.  We will have to set up our
  38          ;; syntax tables differently to handle this.
  39          (let ((table (copy-syntax-table))
  40                entry)
  41            (modify-syntax-entry ?a ". 12345678" table)
  42            (cond
  43             ;; XEmacs 19, and beyond Emacs 19.34
  44             ((arrayp table)
  45              (setq entry (aref table ?a))
  46              ;; In Emacs, table entries are cons cells
  47              (if (consp entry) (setq entry (car entry))))
  48             ;; XEmacs 20
  49             ((fboundp 'get-char-table) (setq entry (get-char-table ?a table)))
  50             ;; before and including Emacs 19.34
  51             ((and (fboundp 'char-table-p)
  52                   (char-table-p table))
  53              (setq entry (car (char-table-range table [?a]))))
  54             ;; incompatible
  55             (t (error "CC Mode is incompatible with this version of Emacs")))
  56            (if (= (logand (lsh entry -16) 255) 255)
  57                '8-bit
  58              '1-bit))))
  59     (if infodock-p
  60         (list comments 'infodock)
  61       (list comments)))
  62   "A list of features extant in the Emacs you are using.
  63 There are many flavors of Emacs out there, each with different
  64 features supporting those needed by CC Mode.  Here's the current
  65 supported list, along with the values for this variable:
  66
  67  XEmacs 19:                  (8-bit)
  68  XEmacs 20:                  (8-bit)
  69  Emacs 19:                   (1-bit)
  70
  71 Infodock (based on XEmacs) has an additional symbol on this list:
  72 'infodock.")
  73
  74
  75 \f
  76 (defsubst c-point (position)
  77   ;; Returns the value of point at certain commonly referenced POSITIONs.
  78   ;; POSITION can be one of the following symbols:
  79   ;;
  80   ;; bol  -- beginning of line
  81   ;; eol  -- end of line
  82   ;; bod  -- beginning of defun
  83   ;; boi  -- back to indentation
  84   ;; ionl -- indentation of next line
  85   ;; iopl -- indentation of previous line
  86   ;; bonl -- beginning of next line
  87   ;; bopl -- beginning of previous line
  88   ;;
  89   ;; This function does not modify point or mark.
  90   (let ((here (point)))
  91     (cond
  92      ((eq position 'bol)  (beginning-of-line))
  93      ((eq position 'eol)  (end-of-line))
  94      ((eq position 'boi)  (back-to-indentation))
  95      ((eq position 'bonl) (forward-line 1))
  96      ((eq position 'bopl) (forward-line -1))
  97      ((eq position 'iopl)
  98       (forward-line -1)
  99       (back-to-indentation))
 100      ((eq position 'ionl)
 101       (forward-line 1)
 102       (back-to-indentation))
 103      ((eq position 'bod)
 104       (if (and (fboundp 'buffer-syntactic-context-depth)
 105                c-enable-xemacs-performance-kludge-p)
 106           ;; XEmacs only.  This can improve the performance of
 107           ;; c-parse-state to between 3 and 60 times faster when
 108           ;; braces are hung.  It can cause c-parse-state to be
 109           ;; slightly slower when braces are not hung, but general
 110           ;; editing appears to be still about as fast.
 111           (let (pos)
 112             (while (not pos)
 113               (save-restriction
 114                 (widen)
 115                 (setq pos (scan-lists (point) -1
 116                                       (buffer-syntactic-context-depth)
 117                                       nil t)))
 118               (cond
 119                ((bobp) (setq pos (point-min)))
 120                ((not pos)
 121                 (let ((distance (skip-chars-backward "^{")))
 122                   ;; unbalanced parenthesis, while illegal C code,
 123                   ;; shouldn't cause an infloop!  See unbal.c
 124                   (when (zerop distance)
 125                     ;; Punt!
 126                     (beginning-of-defun)
 127                     (setq pos (point)))))
 128                ((= pos 0))
 129                ((not (eq (char-after pos) ?{))
 130                 (goto-char pos)
 131                 (setq pos nil))
 132                ))
 133             (goto-char pos))
 134         ;; Emacs, which doesn't have buffer-syntactic-context-depth
 135         ;;
 136         ;; NOTE: This should be the only explicit use of
 137         ;; beginning-of-defun in CC Mode.  Eventually something better
 138         ;; than b-o-d will be available and this should be the only
 139         ;; place the code needs to change.  Everything else should use
 140         ;; (goto-char (c-point 'bod))
 141         (beginning-of-defun)
 142         ;; if defun-prompt-regexp is non-nil, b-o-d won't leave us at
 143         ;; the open brace.
 144         (and defun-prompt-regexp
 145              (looking-at defun-prompt-regexp)
 146              (goto-char (match-end 0)))
 147         ))
 148      (t (error "unknown buffer position requested: %s" position))
 149      )
 150     (prog1
 151         (point)
 152       (goto-char here))))
 153
 154 (defmacro c-safe (&rest body)
 155   ;; safely execute BODY, return nil if an error occurred
 156   (` (condition-case nil
 157          (progn (,@ body))
 158        (error nil))))
 159
 160 (defmacro c-add-syntax (symbol &optional relpos)
 161   ;; a simple macro to append the syntax in symbol to the syntax list.
 162   ;; try to increase performance by using this macro
 163   (` (setq syntax (cons (cons (, symbol) (, relpos)) syntax))))
 164
 165 (defsubst c-auto-newline ()
 166   ;; if auto-newline feature is turned on, insert a newline character
 167   ;; and return t, otherwise return nil.
 168   (and c-auto-newline
 169        (not (c-in-literal))
 170        (not (newline))))
 171
 172 (defsubst c-intersect-lists (list alist)
 173   ;; return the element of ALIST that matches the first element found
 174   ;; in LIST.  Uses assq.
 175   (let (match)
 176     (while (and list
 177                 (not (setq match (assq (car list) alist))))
 178       (setq list (cdr list)))
 179     match))
 180
 181 (defsubst c-lookup-lists (list alist1 alist2)
 182   ;; first, find the first entry from LIST that is present in ALIST1,
 183   ;; then find the entry in ALIST2 for that entry.
 184   (assq (car (c-intersect-lists list alist1)) alist2))
 185
 186 (defsubst c-langelem-col (langelem &optional preserve-point)
 187   ;; convenience routine to return the column of langelem's relpos.
 188   ;; Leaves point at the relpos unless preserve-point is non-nil.
 189   (let ((here (point)))
 190     (goto-char (cdr langelem))
 191     (prog1 (current-column)
 192       (if preserve-point
 193           (goto-char here))
 194       )))
 195
 196 (defsubst c-update-modeline ()
 197   ;; set the c-auto-hungry-string for the correct designation on the modeline
 198   (setq c-auto-hungry-string
 199         (if c-auto-newline
 200             (if c-hungry-delete-key "/ah" "/a")
 201           (if c-hungry-delete-key "/h" nil)))
 202   (force-mode-line-update))
 203
 204 (defsubst c-keep-region-active ()
 205   ;; Do whatever is necessary to keep the region active in XEmacs.
 206   ;; Ignore byte-compiler warnings you might see.  This is not needed
 207   ;; for Emacs.
 208   (and (boundp 'zmacs-region-stays)
 209        (setq zmacs-region-stays t)))
 210
 211 \f
 212 (provide 'cc-defs)
 213 ;;; cc-defs.el ends here