;;; cc-defs.el --- compile time definitions for CC Mode

;; Copyright (C) 1985,1987,1992-2001 Free Software Foundation, Inc.

;; Authors:    2000- Martin Stjernholm
;;	       1998-1999 Barry A. Warsaw and Martin Stjernholm
;;             1992-1997 Barry A. Warsaw
;;             1987 Dave Detlefs and Stewart Clamen
;;             1985 Richard M. Stallman
;; Maintainer: bug-cc-mode@gnu.org
;; Created:    22-Apr-1997 (split from cc-mode.el)
;; Version:    See cc-mode.el
;; Keywords:   c languages oop

;; 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., 59 Temple Place - Suite 330,
;; Boston, MA 02111-1307, USA.

;;; Commentary:

;;; Code:

(eval-when-compile
  (let ((load-path
	 (if (and (boundp 'byte-compile-dest-file)
		  (stringp byte-compile-dest-file))
	     (cons (file-name-directory byte-compile-dest-file) load-path)
	   load-path)))
    (require 'cc-bytecomp)))

;; cc-mode-19.el contains compatibility macros that should be used if
;; needed.
(eval-and-compile
  (if (or (not (fboundp 'functionp))
	  (not (condition-case nil
		   (progn (eval '(char-before)) t)
		 (error nil)))
	  (not (condition-case nil
		   (progn (eval '(char-after)) t)
		 (error nil)))
	  (not (fboundp 'when))
	  (not (fboundp 'unless)))
      (cc-load "cc-mode-19")))

;; Silence the compiler.
(cc-bytecomp-defvar c-enable-xemacs-performance-kludge-p) ; In cc-vars.el
(cc-bytecomp-defvar c-buffer-is-cc-mode) ; In cc-vars.el
(cc-bytecomp-defun buffer-syntactic-context-depth) ; XEmacs
(cc-bytecomp-defun region-active-p)	; XEmacs
(cc-bytecomp-defvar zmacs-region-stays)	; XEmacs
(cc-bytecomp-defvar zmacs-regions)	; XEmacs
(cc-bytecomp-defvar mark-active)	; Emacs
(cc-bytecomp-defun scan-lists)		; 5 args in XEmacs, 3 in Emacs
(require 'derived)			; Only necessary in Emacs


;;; Macros.

;;; Helpers for building regexps.
(defmacro c-paren-re (re)
  `(concat "\\(" ,re "\\)"))
(defmacro c-identifier-re (re)
  `(concat "\\<\\(" ,re "\\)\\>[^_]"))

(defmacro c-point (position &optional point)
  ;; Returns the value of certain commonly referenced POSITIONs
  ;; relative to POINT.  The current point is used if POINT isn't
  ;; specified.  POSITION can be one of the following symbols:
  ;; 
  ;; bol  -- beginning of line
  ;; eol  -- end of line
  ;; bod  -- beginning of defun
  ;; eod  -- end of defun
  ;; boi  -- beginning of indentation
  ;; ionl -- indentation of next line
  ;; iopl -- indentation of previous line
  ;; bonl -- beginning of next line
  ;; eonl -- end of next line
  ;; bopl -- beginning of previous line
  ;; eopl -- end of previous line
  ;; 
  ;; If the referenced position doesn't exist, the closest accessible
  ;; point to it is returned.  This function does not modify point or
  ;; mark.
  `(save-excursion
     ,(if point `(goto-char ,point))
     ,(if (and (eq (car-safe position) 'quote)
	       (symbolp (eval position)))
	  (let ((position (eval position)))
	    (cond
	     ((eq position 'bol)  `(beginning-of-line))
	     ((eq position 'eol)  `(end-of-line))
	     ((eq position 'boi)  `(back-to-indentation))
	     ((eq position 'bod)  `(c-beginning-of-defun-1))
	     ((eq position 'bonl) `(forward-line 1))
	     ((eq position 'bopl) `(forward-line -1))
	     ((eq position 'eod)  `(c-end-of-defun-1))
	     ((eq position 'eopl) `(progn
				     (beginning-of-line)
				     (or (bobp) (backward-char))))
	     ((eq position 'eonl) `(progn
				     (forward-line 1)
				     (end-of-line)))
	     ((eq position 'iopl) `(progn
				     (forward-line -1)
				     (back-to-indentation)))
	     ((eq position 'ionl) `(progn
				     (forward-line 1)
				     (back-to-indentation)))
	     (t (error "unknown buffer position requested: %s" position))))
	;;(message "c-point long expansion")
	`(let ((position ,position))
	   (cond
	    ((eq position 'bol)  (beginning-of-line))
	    ((eq position 'eol)  (end-of-line))
	    ((eq position 'boi)  (back-to-indentation))
	    ((eq position 'bod)  (c-beginning-of-defun-1))
	    ((eq position 'bonl) (forward-line 1))
	    ((eq position 'bopl) (forward-line -1))
	    ((eq position 'eod)  (c-end-of-defun-1))
	    ((eq position 'eopl) (progn
				   (beginning-of-line)
				   (or (bobp) (backward-char))))
	    ((eq position 'eonl) (progn
				   (forward-line 1)
				   (end-of-line)))
	    ((eq position 'iopl) (progn
				   (forward-line -1)
				   (back-to-indentation)))
	    ((eq position 'ionl) (progn
				   (forward-line 1)
				   (back-to-indentation)))
	    (t (error "unknown buffer position requested: %s" position)))))
     (point)))

(defmacro c-safe (&rest body)
  ;; safely execute BODY, return nil if an error occurred
  `(condition-case nil
       (progn ,@body)
     (error nil)))
(put 'c-safe 'lisp-indent-function 0)

(defmacro c-forward-sexp (&optional arg)
  ;; like forward-sexp except
  ;;   1. this is much stripped down from the XEmacs version
  ;;   2. this cannot be used as a command, so we're insulated from
  ;;      XEmacs' losing efforts to make forward-sexp more user
  ;;      friendly
  ;;   3. Preserves the semantics most of CC Mode is based on
  (or arg (setq arg 1))
  `(goto-char (or (scan-sexps (point) ,arg)
		  ,(if (numberp arg)
		       (if (> arg 0) `(point-max) `(point-min))
		     `(if (> ,arg 0) (point-max) (point-min))))))

(defmacro c-backward-sexp (&optional arg)
  ;; See c-forward-sexp and reverse directions
  (or arg (setq arg 1))
  `(c-forward-sexp ,(if (numberp arg) (- arg) `(- ,arg))))

;; Wrappers for common scan-lists cases, mainly because it's almost
;; impossible to get a feel for how that function works.
(defmacro c-up-list-forward (pos)
  `(c-safe (scan-lists ,pos 1 1)))
(defmacro c-up-list-backward (pos)
  `(c-safe (scan-lists ,pos -1 1)))
(defmacro c-down-list-forward (pos)
  `(c-safe (scan-lists ,pos 1 -1)))
(defmacro c-down-list-backward (pos)
  `(c-safe (scan-lists ,pos -1 -1)))

(defmacro c-add-syntax (symbol &optional relpos)
  ;; a simple macro to append the syntax in symbol to the syntax list.
  ;; try to increase performance by using this macro
  `(let ((relpos-tmp ,relpos))
     (if relpos-tmp (setq syntactic-relpos relpos-tmp))
     (setq syntax (cons (cons ,symbol relpos-tmp) syntax))))

(defmacro c-benign-error (format &rest args)
  ;; Formats an error message for the echo area and dings, i.e. like
  ;; `error' but doesn't abort.
  `(progn
     (message ,format ,@args)
     (ding)))

(defmacro c-update-modeline ()
  ;; set the c-auto-hungry-string for the correct designation on the modeline
  `(progn
     (setq c-auto-hungry-string
	   (if c-auto-newline
	       (if c-hungry-delete-key "/ah" "/a")
	     (if c-hungry-delete-key "/h" nil)))
     (force-mode-line-update)))

(defmacro c-with-syntax-table (table &rest code)
  ;; Temporarily switches to the specified syntax table in a failsafe
  ;; way to execute code.
  `(let ((c-with-syntax-table-orig-table (syntax-table)))
     (unwind-protect
	 (progn
	   (set-syntax-table ,table)
	   ,@code)
       (set-syntax-table c-with-syntax-table-orig-table))))
(put 'c-with-syntax-table 'lisp-indent-function 1)

(defmacro c-skip-ws-forward (&optional limit)
  "Skip over any whitespace following point.
This function skips over horizontal and vertical whitespace and line
continuations."
  (if limit
      `(let ((-limit- (or ,limit (point-max))))
	 (while (progn
		  ;; skip-syntax-* doesn't count \n as whitespace..
		  (skip-chars-forward " \t\n\r\f" -limit-)
		  (when (and (eq (char-after) ?\\)
			     (< (point) -limit-))
		    (forward-char)
		    (or (eolp)
			(progn (backward-char) nil))))))
    '(while (progn
	      (skip-chars-forward " \t\n\r\f")
	      (when (eq (char-after) ?\\)
		(forward-char)
		(or (eolp)
		    (progn (backward-char) nil)))))))

(defmacro c-skip-ws-backward (&optional limit)
  "Skip over any whitespace preceding point.
This function skips over horizontal and vertical whitespace and line
continuations."
  (if limit
      `(let ((-limit- (or ,limit (point-min))))
	 (while (progn
		  ;; skip-syntax-* doesn't count \n as whitespace..
		  (skip-chars-backward " \t\n\r\f" -limit-)
		  (and (eolp)
		       (eq (char-before) ?\\)
		       (> (point) -limit-)))
	   (backward-char)))
    '(while (progn
	      (skip-chars-backward " \t\n\r\f")
	      (and (eolp)
		   (eq (char-before) ?\\)))
       (backward-char))))

;; Make edebug understand the macros.
(eval-after-load "edebug"
  '(progn
     (def-edebug-spec c-paren-re t)
     (def-edebug-spec c-identifier-re t)
     (def-edebug-spec c-point ([&or symbolp form] &optional form))
     (def-edebug-spec c-safe t)
     (def-edebug-spec c-forward-sexp (&optional [&or numberp form]))
     (def-edebug-spec c-backward-sexp (&optional [&or numberp form]))
     (def-edebug-spec c-up-list-forward t)
     (def-edebug-spec c-up-list-backward t)
     (def-edebug-spec c-down-list-forward t)
     (def-edebug-spec c-down-list-backward t)
     (def-edebug-spec c-add-syntax t)
     (def-edebug-spec c-add-class-syntax t)
     (def-edebug-spec c-benign-error t)
     (def-edebug-spec c-with-syntax-table t)
     (def-edebug-spec c-skip-ws-forward t)
     (def-edebug-spec c-skip-ws-backward t)))

;;; Inline functions.

;; Note: All these after the macros, to be on safe side in avoiding
;; bugs where macros are defined too late.  These bugs often only show
;; when the files are compiled in a certain order within the same
;; session.

(defsubst c-beginning-of-defun-1 ()
  ;; Wrapper around beginning-of-defun.
  ;;
  ;; NOTE: This function should contain the only explicit use of
  ;; beginning-of-defun in CC Mode.  Eventually something better than
  ;; b-o-d will be available and this should be the only place the
  ;; code needs to change.  Everything else should use
  ;; (c-beginning-of-defun-1)
  (if (and (fboundp 'buffer-syntactic-context-depth)
	   c-enable-xemacs-performance-kludge-p)
      ;; XEmacs only.  This can improve the performance of
      ;; c-parse-state to between 3 and 60 times faster when
      ;; braces are hung.  It can also degrade performance by
      ;; about as much when braces are not hung.
      (let (pos)
	(while (not pos)
	  (save-restriction
	    (widen)
	    (setq pos (scan-lists (point) -1
				  (buffer-syntactic-context-depth)
				  nil t)))
	  (cond
	   ((bobp) (setq pos (point-min)))
	   ((not pos)
	    (let ((distance (skip-chars-backward "^{")))
	      ;; unbalanced parenthesis, while illegal C code,
	      ;; shouldn't cause an infloop!  See unbal.c
	      (when (zerop distance)
		;; Punt!
		(beginning-of-defun)
		(setq pos (point)))))
	   ((= pos 0))
	   ((not (eq (char-after pos) ?{))
	    (goto-char pos)
	    (setq pos nil))
	   ))
	(goto-char pos))
    ;; Emacs, which doesn't have buffer-syntactic-context-depth
    (beginning-of-defun))
  ;; if defun-prompt-regexp is non-nil, b-o-d won't leave us at the
  ;; open brace.
  (and defun-prompt-regexp
       (looking-at defun-prompt-regexp)
       (goto-char (match-end 0))))

(defsubst c-end-of-defun-1 ()
  ;; Replacement for end-of-defun that use c-beginning-of-defun-1.
  (let ((start (point)))
    ;; Skip forward into the next defun block. Don't bother to avoid
    ;; comments, literals etc, since beginning-of-defun doesn't do that
    ;; anyway.
    (skip-chars-forward "^}")
    (c-beginning-of-defun-1)
    (if (eq (char-after) ?{)
	(c-forward-sexp))
    (if (< (point) start)
	(goto-char (point-max)))))

(defsubst c-intersect-lists (list alist)
  ;; return the element of ALIST that matches the first element found
  ;; in LIST.  Uses assq.
  (let (match)
    (while (and list
		(not (setq match (assq (car list) alist))))
      (setq list (cdr list)))
    match))

(defsubst c-lookup-lists (list alist1 alist2)
  ;; first, find the first entry from LIST that is present in ALIST1,
  ;; then find the entry in ALIST2 for that entry.
  (assq (car (c-intersect-lists list alist1)) alist2))

(defsubst c-langelem-col (langelem &optional preserve-point)
  ;; convenience routine to return the column of langelem's relpos.
  ;; Leaves point at the relpos unless preserve-point is non-nil.
  (if (cdr langelem)
      (let ((here (point)))
	(goto-char (cdr langelem))
	(prog1 (current-column)
	  (if preserve-point
	      (goto-char here))
	  ))
    0))

(defsubst c-keep-region-active ()
  ;; Do whatever is necessary to keep the region active in XEmacs.
  ;; This is not needed for Emacs.
  (and (boundp 'zmacs-region-stays)
       (setq zmacs-region-stays t)))

(defsubst c-region-is-active-p ()
  ;; Return t when the region is active.  The determination of region
  ;; activeness is different in both Emacs and XEmacs.
  (cond
   ;; XEmacs
   ((and (fboundp 'region-active-p)
	 (boundp 'zmacs-regions)
	 zmacs-regions)
    (region-active-p))
   ;; Emacs
   ((boundp 'mark-active) mark-active)
   ;; fallback; shouldn't get here
   (t (mark t))))

(defsubst c-major-mode-is (mode)
  (eq c-buffer-is-cc-mode mode))


(cc-provide 'cc-defs)

;;; cc-defs.el ends here