[bpt/emacs.git] / lisp / progmodes / cc-engine.el

;;; cc-engine.el --- core syntax guessing engine for CC mode

;; Copyright (C) 1985,87,92,93,94,95,96,97,98 Free Software Foundation, Inc.

;; Authors:    1998 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.

\f
(eval-when-compile
  (require 'cc-defs))

;; KLUDGE ALERT: c-maybe-labelp is used to pass information between
;; c-crosses-statement-barrier-p and c-beginning-of-statement-1.  A
;; better way should be implemented, but this will at least shut up
;; the byte compiler.
(defvar c-maybe-labelp nil)

;; WARNING WARNING WARNING
;;
;; Be *exceptionally* careful about modifications to this function!
;; Much of CC Mode depends on this Doing The Right Thing.  If you
;; break it you will be sorry.  If you think you know how this works,
;; you probably don't.  No human on Earth does! :-)
;;
;; WARNING WARNING WARNING

(defun c-beginning-of-statement-1 (&optional lim)
  ;; move to the start of the current statement, or the previous
  ;; statement if already at the beginning of one.
  (let ((firstp t)
	(substmt-p t)
	donep c-in-literal-cache saved
	(last-begin (point)))
    ;; first check for bare semicolon
    (if (and (progn (c-backward-syntactic-ws lim)
		    (eq (char-before) ?\;))
	     (c-safe (progn (forward-char -1)
			    (setq saved (point))
			    t))
	     (progn (c-backward-syntactic-ws lim)
		    (memq (char-before) '(?\; ?{ ?:)))
	     )
	(setq last-begin saved)
      (goto-char last-begin)
      (while (not donep)
	;; stop at beginning of buffer
	(if (bobp) (setq donep t)
	  ;; go backwards one balanced expression, but be careful of
	  ;; unbalanced paren being reached
	  (if (not (c-safe (progn (c-backward-sexp 1) t)))
	      (progn
		(if firstp
		    (backward-up-list 1)
		  (goto-char last-begin))
		;; skip over any unary operators, or other special
		;; characters appearing at front of identifier
		(save-excursion
		  (c-backward-syntactic-ws lim)
		  (skip-chars-backward "-+!*&:.~@ \t\n")
		  (if (eq (char-before) ?\()
		      (setq last-begin (point))))
		(goto-char last-begin)
		(setq last-begin (point)
		      donep t)))

	  (setq c-maybe-labelp nil)
	  ;; see if we're in a literal. if not, then this bufpos may be
	  ;; a candidate for stopping
	  (cond
	   ;; CASE 0: did we hit the error condition above?
	   (donep)
	   ;; CASE 1: are we in a literal?
	   ((eq (c-in-literal lim) 'pound)
	    (beginning-of-line))
	   ;; CASE 2: some other kind of literal?
	   ((c-in-literal lim))
	   ;; CASE 3: are we looking at a conditional keyword?
	   ((or (looking-at c-conditional-key)
		(and (eq (char-after) ?\()
		     (save-excursion
		       (c-forward-sexp 1)
		       (c-forward-syntactic-ws)
		       (not (eq (char-after) ?\;)))
		     (let ((here (point))
			   (foundp (progn
				     (c-backward-syntactic-ws lim)
				     (forward-word -1)
				     (and lim
					  (<= lim (point))
					  (not (c-in-literal lim))
					  (not (eq (char-before) ?_))
					  (looking-at c-conditional-key)
					  ))))
		       ;; did we find a conditional?
		       (if (not foundp)
			   (goto-char here))
		       foundp)))
	    ;; are we in the middle of an else-if clause?
	    (if (save-excursion
		  (and (not substmt-p)
		       (c-safe (progn (c-forward-sexp -1) t))
		       (looking-at "\\<else\\>[ \t\n]+\\<if\\>")
		       (not (c-in-literal lim))))
		(progn
		  (c-forward-sexp -1)
		  (c-backward-to-start-of-if lim)))
	    ;; are we sitting at an else clause, that we are not a
	    ;; substatement of?
	    (if (and (not substmt-p)
		     (looking-at "\\<else\\>[^_]"))
		(c-backward-to-start-of-if lim))
	    ;; a finally or a series of catches?
	    (if (not substmt-p)
		(while (looking-at "\\<\\(catch\\|finally\\)\\>[^_]")
		  (c-safe (c-backward-sexp 2))
		  (if (eq (char-after) ?\()
		      (c-safe (c-backward-sexp)))))
	    ;; are we sitting at the while of a do-while?
	    (if (and (looking-at "\\<while\\>[^_]")
		     (c-backward-to-start-of-do lim))
		(setq substmt-p nil))
	    (setq last-begin (point)
		  donep substmt-p))
	   ;; CASE 4: are we looking at a label?
	   ((looking-at c-label-key))
	   ;; CASE 5: is this the first time we're checking?
	   (firstp (setq firstp nil
			 substmt-p (not (c-crosses-statement-barrier-p
					 (point) last-begin))
			 last-begin (point)))
	   ;; CASE 6: have we crossed a statement barrier?
	   ((save-excursion
	      ;; Move over in-expression blocks before checking the
	      ;; barrier
	      (if (or (memq (char-after) '(?\( ?\[))
		      (and (eq (char-after) ?{)
			   (c-looking-at-inexpr-block lim)))
		  (c-forward-sexp 1))
	      (c-crosses-statement-barrier-p (point) last-begin))
	    (setq donep t))
	   ;; CASE 7: ignore labels
	   ((and c-maybe-labelp
		 (or (and c-access-key (looking-at c-access-key))
		     ;; with switch labels, we have to go back further
		     ;; to try to pick up the case or default
		     ;; keyword. Potential bogosity alert: we assume
		     ;; `case' or `default' is first thing on line
		     (let ((here (point)))
		       (beginning-of-line)
		       (c-forward-syntactic-ws)
		       (if (looking-at c-switch-label-key)
			   t
			 (goto-char here)
			 nil))
		     (looking-at c-label-key))))
	   ;; CASE 8: ObjC or Java method def
	   ((and c-method-key
		 (setq last-begin (c-in-method-def-p)))
	    (setq donep t))
	   ;; CASE 9: nothing special
	   (t (setq last-begin (point)))
	   ))))
    (goto-char last-begin)
    ;; We always want to skip over the non-whitespace modifier
    ;; characters that can start a statement.
    (let ((lim (point)))
      (skip-chars-backward "-+!*&~@ \t\n" (c-point 'boi))
      (skip-chars-forward " \t\n" lim))))

(defun c-end-of-statement-1 ()
  (condition-case nil
      (let (beg end found)
	(while (and (not (eobp))
		    (progn
		      (setq beg (point))
		      (c-forward-sexp 1)
		      (setq end (point))
		      (goto-char beg)
		      (setq found nil)
		      (while (and (not found)
				  (re-search-forward "[;{}]" end t))
			(if (not (c-in-literal beg))
			    (setq found t)))
		      (not found)))
	  (goto-char end))
	(re-search-backward "[;{}]")
	(forward-char 1))
    (error
     (let ((beg (point)))
       (c-safe (backward-up-list -1))
       (let ((end (point)))
	 (goto-char beg)
	 (search-forward ";" end 'move)))
     )))

\f
(defun c-crosses-statement-barrier-p (from to)
  ;; Does buffer positions FROM to TO cross a C statement boundary?
  (let ((here (point))
	(lim from)
	crossedp)
    (condition-case ()
	(progn
	  (goto-char from)
	  (while (and (not crossedp)
		      (< (point) to))
	    (skip-chars-forward "^;{}:" (1- to))
	    (if (not (c-in-literal lim))
		(progn
		  (if (memq (char-after) '(?\; ?{ ?}))
		      (setq crossedp t)
		    (if (eq (char-after) ?:)
			(setq c-maybe-labelp t))
		    (forward-char 1))
		  (setq lim (point)))
	      (forward-char 1))))
      (error (setq crossedp nil)))
    (goto-char here)
    crossedp))

\f
;; Skipping of "syntactic whitespace", defined as lexical whitespace,
;; C and C++ style comments, and preprocessor directives.  Search no
;; farther back or forward than optional LIM.  If LIM is omitted,
;; `beginning-of-defun' is used for backward skipping, point-max is
;; used for forward skipping.

(defun c-forward-syntactic-ws (&optional lim)
  ;; Forward skip of syntactic whitespace for Emacs 19.
  (let* ((here (point-max))
	 (hugenum (point-max)))
    (while (/= here (point))
      (setq here (point))
      (forward-comment hugenum)
      ;; skip preprocessor directives
      (when (and (eq (char-after) ?#)
		 (= (c-point 'boi) (point)))
	(while (eq (char-before (c-point 'eol)) ?\\)
	  (forward-line 1))
	(end-of-line))
      )
    (if lim (goto-char (min (point) lim)))))

(defsubst c-beginning-of-macro (&optional lim)
  ;; Go to the beginning of a cpp macro definition.  Leaves point at
  ;; the beginning of the macro and returns t if in a cpp macro
  ;; definition, otherwise returns nil and leaves point unchanged.
  ;; `lim' is currently ignored, but the interface requires it.
  (let ((here (point)))
    (beginning-of-line)
    (while (eq (char-before (1- (point))) ?\\)
      (forward-line -1))
    (back-to-indentation)
    (if (eq (char-after) ?#)
	t
      (goto-char here)
      nil)))

(defun c-backward-syntactic-ws (&optional lim)
  ;; Backward skip over syntactic whitespace for Emacs 19.
  (let* ((here (point-min))
	 (hugenum (- (point-max))))
    (while (/= here (point))
      (setq here (point))
      (forward-comment hugenum)
      (c-beginning-of-macro))
    (if lim (goto-char (max (point) lim)))))

\f
;; Moving by tokens, where a token is defined as all symbols and
;; identifiers which aren't syntactic whitespace (note that "->" is
;; considered to be two tokens).  Point is always either left at the
;; beginning of a token or not moved at all.  COUNT specifies the
;; number of tokens to move; a negative COUNT moves in the opposite
;; direction.  A COUNT of 0 moves to the next token beginning only if
;; not already at one.  If BALANCED is true, move over balanced
;; parens, otherwise move into them.  Also, if BALANCED is true, never
;; move out of an enclosing paren.  LIM sets the limit for the
;; movement and defaults to the point limit.  Returns the number of
;; tokens left to move (positive or negative).  If BALANCED is true, a
;; move over a balanced paren counts as one.  Note that if COUNT is 0
;; and no appropriate token beginning is found, 1 will be returned.
;; Thus, a return value of 0 guarantees that point is at the requested
;; position and a return value less (without signs) than COUNT
;; guarantees that point is at the beginning of some token.

(defun c-forward-token-1 (&optional count balanced lim)
  (or count (setq count 1))
  (if (< count 0)
      (- (c-backward-token-1 (- count) balanced lim))
    (let ((jump-syntax (if balanced
			   '(?w ?_ ?\( ?\) ?\" ?\\ ?/ ?$ ?')
			 '(?w ?_ ?\" ?\\ ?/ ?')))
	  (last (point))
	  (prev (point)))
      (if (/= (point)
	      (progn (c-forward-syntactic-ws) (point)))
	  ;; Skip whitespace.  Count this as a move if we did in fact
	  ;; move and aren't out of bounds.
	  (or (eobp)
	      (and lim (> (point) lim))
	      (setq count (max (1- count) 0))))
      (if (and (= count 0)
	       (or (and (memq (char-syntax (or (char-after) ? )) '(?w ?_))
			(memq (char-syntax (or (char-before) ? )) '(?w ?_)))
		   (eobp)))
	  ;; If count is zero we should jump if in the middle of a
	  ;; token or if there is whitespace between point and the
	  ;; following token beginning.
	  (setq count 1))
      ;; Avoid having the limit tests inside the loop.
      (save-restriction
	(if lim (narrow-to-region (point-min) lim))
	(if (eobp)
	    (goto-char last)
	  (condition-case nil
	      (while (> count 0)
		(setq prev last
		      last (point))
		(if (memq (char-syntax (char-after)) jump-syntax)
		    (goto-char (scan-sexps (point) 1))
		  (forward-char))
		(c-forward-syntactic-ws lim)
		(setq count (1- count)))
	    (error (goto-char last)))
	  (when (eobp)
	    (goto-char prev)
	    (setq count (1+ count)))))
      count)))

(defun c-backward-token-1 (&optional count balanced lim)
  (or count (setq count 1))
  (if (< count 0)
      (- (c-forward-token-1 (- count) balanced lim))
    (let ((jump-syntax (if balanced
			   '(?w ?_ ?\( ?\) ?\" ?\\ ?/ ?$ ?')
			 '(?w ?_ ?\" ?\\ ?/ ?')))
	  last)
      (if (and (= count 0)
	       (or (and (memq (char-syntax (or (char-after) ? )) '(?w ?_))
			(memq (char-syntax (or (char-before) ? )) '(?w ?_)))
		   (/= (point)
		       (save-excursion (c-forward-syntactic-ws) (point)))
		   (eobp)))
	  ;; If count is zero we should jump if in the middle of a
	  ;; token or if there is whitespace between point and the
	  ;; following token beginning.
	  (setq count 1))
      ;; Avoid having the limit tests inside the loop.
      (save-restriction
	(if lim (narrow-to-region lim (point-max)))
	(or (bobp)
	    (progn
	      (condition-case nil
		  (while (progn
			   (setq last (point))
			   (> count 0))
		    (c-backward-syntactic-ws lim)
		    (if (memq (char-syntax (char-before)) jump-syntax)
			(goto-char (scan-sexps (point) -1))
		      (backward-char))
		    (setq count (1- count)))
		(error (goto-char last)))
	      (if (bobp) (goto-char last)))))
      count)))

\f
;; Return `c' if in a C-style comment, `c++' if in a C++ style
;; comment, `string' if in a string literal, `pound' if on a
;; preprocessor line, or nil if not in a comment at all.  Optional LIM
;; is used as the backward limit of the search.  If omitted, or nil,
;; `beginning-of-defun' is used."

(defun c-in-literal (&optional lim)
  ;; Determine if point is in a C++ literal. we cache the last point
  ;; calculated if the cache is enabled
  (if (and (boundp 'c-in-literal-cache)
	   c-in-literal-cache
	   (= (point) (aref c-in-literal-cache 0)))
      (aref c-in-literal-cache 1)
    (let ((rtn (save-excursion
		 (let* ((lim (or lim (c-point 'bod)))
			(state (parse-partial-sexp lim (point))))
		   (cond
		    ((nth 3 state) 'string)
		    ((nth 4 state) (if (nth 7 state) 'c++ 'c))
		    ((c-beginning-of-macro lim) 'pound)
		    (t nil))))))
      ;; cache this result if the cache is enabled
      (and (boundp 'c-in-literal-cache)
	   (setq c-in-literal-cache (vector (point) rtn)))
      rtn)))

;; XEmacs has a built-in function that should make this much quicker.
;; I don't think we even need the cache, which makes our lives more
;; complicated anyway.  In this case, lim is ignored.
(defun c-fast-in-literal (&optional lim)
  (let ((context (buffer-syntactic-context)))
    (cond
     ((eq context 'string) 'string)
     ((eq context 'comment) 'c++)
     ((eq context 'block-comment) 'c)
     ((save-excursion (c-beginning-of-macro lim)) 'pound))))

(if (fboundp 'buffer-syntactic-context)
    (defalias 'c-in-literal 'c-fast-in-literal))

(defun c-literal-limits (&optional lim near)
  ;; Returns a cons of the beginning and end positions of the comment
  ;; or string surrounding point (including both delimiters), or nil
  ;; if point isn't in one.  If LIM is non-nil, it's used as the
  ;; "safe" position to start parsing from.  If NEAR is non-nil, then
  ;; the limits of any literal next to point is returned.  "Next to"
  ;; means there's only [ \t] between point and the literal.  The
  ;; search for such a literal is done first in forward direction.
  ;;
  ;; This is the Emacs 19 version.
  (save-excursion
    (let* ((pos (point))
	   (lim (or lim (c-point 'bod)))
	   (state (parse-partial-sexp lim (point))))
      (cond ((nth 3 state)
	     ;; String.  Search backward for the start.
	     (while (nth 3 state)
	       (search-backward (make-string 1 (nth 3 state)))
	       (setq state (parse-partial-sexp lim (point))))
	     (cons (point) (or (c-safe (c-forward-sexp 1) (point))
			       (point-max))))
	    ((nth 7 state)
	     ;; Line comment.  Search from bol for the comment starter.
	     (beginning-of-line)
	     (setq state (parse-partial-sexp lim (point))
		   lim (point))
	     (while (not (nth 7 state))
	       (search-forward "//")	; Should never fail.
	       (setq state (parse-partial-sexp
			    lim (point) nil nil state)
		     lim (point)))
	     (backward-char 2)
	     (cons (point) (progn (forward-comment 1) (point))))
	    ((nth 4 state)
	     ;; Block comment.  Search backward for the comment starter.
	     (while (nth 4 state)
	       (search-backward "/*")	; Should never fail.
	       (setq state (parse-partial-sexp lim (point))))
	     (cons (point) (progn (forward-comment 1) (point))))
	    ((c-safe (nth 4 (parse-partial-sexp ; Can't use prev state due
			     lim (1+ (point))))) ; to bug in Emacs 19.34.
	     ;; We're standing in a comment starter.
	     (backward-char 2)
	     (cons (point) (progn (forward-comment 1) (point))))
	    (near
	     (goto-char pos)
	     ;; Search forward for a literal.
	     (skip-chars-forward " \t")
	     (cond
	      ((eq (char-syntax (or (char-after) ?\ )) ?\") ; String.
	       (cons (point) (or (c-safe (c-forward-sexp 1) (point))
				 (point-max))))
	      ((looking-at "/[/*]")	; Line or block comment.
	       (cons (point) (progn (forward-comment 1) (point))))
	      (t
	       ;; Search backward.
	       (skip-chars-backward " \t")
	       (let ((end (point)) beg)
		 (cond
		  ((eq (char-syntax (or (char-before) ?\ )) ?\") ; String.
		   (setq beg (c-safe (c-backward-sexp 1) (point))))
		  ((and (c-safe (forward-char -2) t)
			(looking-at "*/"))
		   ;; Block comment.  Due to the nature of line
		   ;; comments, they will always be covered by the
		   ;; normal case above.
		   (goto-char end)
		   (forward-comment -1)
		   ;; If LIM is bogus, beg will be bogus.
		   (setq beg (point))))
		 (if beg (cons beg end))))))
	    ))))

(defun c-literal-limits-fast (&optional lim)
  ;; Like c-literal-limits, but for emacsen whose `parse-partial-sexp'
  ;; returns the pos of the comment start.  FIXME: Add NEAR.
  (save-excursion
    (let ((state (parse-partial-sexp lim (point))))
      (cond ((nth 3 state)		; String.
	     (goto-char (nth 8 state))
	     (cons (point) (or (c-safe (c-forward-sexp 1) (point))
			       (point-max))))
	    ((nth 4 state)		; Comment.
	     (goto-char (nth 8 state))
	     (cons (point) (progn (forward-comment 1) (point))))
	    ((c-safe
	      (nth 4 (parse-partial-sexp ; Works?
		      (point) (1+ (point)) nil nil state)))
	     ;; We're in a comment starter.
	     (backward-char 2)
	     (cons (point) (progn (forward-comment 1) (point))))
	    ))))

(defun c-collect-line-comments (range)
  ;; If the argument is a cons of two buffer positions (such as
  ;; returned by c-literal-limits), and that range contains a C++
  ;; style line comment, then an extended range is returned that
  ;; contains all adjacent line comments (i.e. all comments that
  ;; starts in the same column with no empty lines or non-whitespace
  ;; characters between them).  Otherwise the argument is returned.
  (save-excursion
    (condition-case nil
	(if (and (consp range) (progn
				 (goto-char (car range))
				 (looking-at "//")))
	    (let ((col (current-column))
		  (beg (point))
		  (end (cdr range)))
	      (while (and (not (bobp))
			  (forward-comment -1)
			  (looking-at "//")
			  (= col (current-column)))
		(setq beg (point)))
	      (goto-char end)
	      (while (progn
		       (skip-chars-forward " \t")
		       (and (looking-at "//")
			    (= col (current-column))))
		(forward-comment 1)
		(setq end (point)))
	      (cons beg end))
	  range)
      (error range))))

(defun c-literal-type (range)
  ;; Convenience function that given the result of c-literal-limits,
  ;; returns nil or the type of literal that the range surrounds.
  ;; It's much faster than using c-in-literal and is intended to be
  ;; used when you need both the type of a literal and its limits.
  (if (consp range)
    (save-excursion
      (goto-char (car range))
      (cond ((eq (char-syntax (or (char-after) ?\ )) ?\") 'string)
	    ((looking-at "//") 'c++)
	    (t 'c)))			; Assuming the range is valid.
    range))


\f
;; utilities for moving and querying around syntactic elements
(defvar c-parsing-error nil)

(defun c-parse-state ()
  ;; Finds and records all open parens between some important point
  ;; earlier in the file and point.
  ;;
  ;; if there's a state cache, return it
  (setq c-parsing-error nil)
  (if (boundp 'c-state-cache) c-state-cache
    (let* (at-bob
	   (pos (save-excursion
		  ;; go back 2 bods, but ignore any bogus positions
		  ;; returned by beginning-of-defun (i.e. open paren
		  ;; in column zero)
		  (let ((cnt 2))
		    (while (not (or at-bob (zerop cnt)))
		      (goto-char (c-point 'bod))
		      (if (and
			   (eq (char-after) ?\{)
			   ;; The following catches an obscure special
			   ;; case where the brace is preceded by an
			   ;; open paren.  That can only legally occur
			   ;; with blocks inside expressions and in
			   ;; Pike special brace lists.  Even so, this
			   ;; test is still bogus then, but hopefully
			   ;; good enough.  (We don't want to use
			   ;; up-list here since it might be slow.)
			   (save-excursion
			     (c-backward-syntactic-ws)
			     (not (eq (char-before) ?\())))
			  (setq cnt (1- cnt)))
		      (if (bobp)
			  (setq at-bob t))))
		  (point)))
	   (here (save-excursion
		   ;;(skip-chars-forward " \t}")
		   (point)))
	   (last-bod pos) (last-pos pos)
	   placeholder state sexp-end)
      ;; cache last bod position
      (while (catch 'backup-bod
	       (setq state nil)
	       (while (and pos (< pos here))
		 (setq last-pos pos)
		 (if (and (setq pos (c-safe (scan-lists pos 1 -1)))
			  (<= pos here))
		     (progn
		       (setq sexp-end (c-safe (scan-sexps (1- pos) 1)))
		       (if (and sexp-end
				(<= sexp-end here))
			   ;; we want to record both the start and end
			   ;; of this sexp, but we only want to record
			   ;; the last-most of any of them before here
			   (progn
			     (if (eq (char-after (1- pos)) ?\{)
				 (setq state (cons (cons (1- pos) sexp-end)
						   (if (consp (car state))
						       (cdr state)
						     state))))
			     (setq pos sexp-end))
			 ;; we're contained in this sexp so put pos on
			 ;; front of list
			 (setq state (cons (1- pos) state))))
		   ;; something bad happened. check to see if we
		   ;; crossed an unbalanced close brace. if so, we
		   ;; didn't really find the right `important bufpos'
		   ;; so lets back up and try again
		   (if (and (not pos) (not at-bob)
			    (setq placeholder
				  (c-safe (scan-lists last-pos 1 1)))
			    ;;(char-after (1- placeholder))
			    (<= placeholder here)
			    (eq (char-after (1- placeholder)) ?\}))
		       (while t
			 (setq last-bod (c-safe (scan-lists last-bod -1 1)))
			 (if (not last-bod)
			     (progn
			       ;; bogus, but what can we do here?
			       (setq c-parsing-error (1- placeholder))
			       (throw 'backup-bod nil))
			   (setq at-bob (= last-bod (point-min))
				 pos last-bod)
			   (if (= (char-after last-bod) ?\{)
			       (throw 'backup-bod t)))
			 ))		;end-if
		   ))			;end-while
	       nil))
      state)))

(defun c-whack-state (bufpos state)
  ;; whack off any state information that appears on STATE which lies
  ;; after the bounds of BUFPOS.
  (let (newstate car)
    (while state
      (setq car (car state)
	    state (cdr state))
      (if (consp car)
	  ;; just check the car, because in a balanced brace
	  ;; expression, it must be impossible for the corresponding
	  ;; close brace to be before point, but the open brace to be
	  ;; after.
	  (if (<= bufpos (car car))
	      nil			; whack it off
	    ;; its possible that the open brace is before bufpos, but
	    ;; the close brace is after.  In that case, convert this
	    ;; to a non-cons element.
	    (if (<= bufpos (cdr car))
		(setq newstate (append newstate (list (car car))))
	      ;; we know that both the open and close braces are
	      ;; before bufpos, so we also know that everything else
	      ;; on state is before bufpos, so we can glom up the
	      ;; whole thing and exit.
	      (setq newstate (append newstate (list car) state)
		    state nil)))
	(if (<= bufpos car)
	    nil				; whack it off
	  ;; it's before bufpos, so everything else should too
	  (setq newstate (append newstate (list car) state)
		state nil))))
    newstate))

(defun c-hack-state (bufpos which state)
  ;; Using BUFPOS buffer position, and WHICH (must be 'open or
  ;; 'close), hack the c-parse-state STATE and return the results.
  (if (eq which 'open)
      (let ((car (car state)))
	(if (or (null car)
		(consp car)
		(/= bufpos car))
	    (cons bufpos state)
	  state))
    (if (not (eq which 'close))
	(error "c-hack-state, bad argument: %s" which))
    ;; 'close brace
    (let ((car (car state))
	  (cdr (cdr state)))
      (if (consp car)
	  (setq car (car cdr)
		cdr (cdr cdr)))
      ;; TBD: is this test relevant???
      (if (consp car)
	  state				;on error, don't change
	;; watch out for balanced expr already on cdr of list
	(cons (cons car bufpos)
	      (if (consp (car cdr))
		  (cdr cdr) cdr))
	))))

(defun c-adjust-state (from to shift state)
  ;; Adjust all points in state that lie in the region FROM..TO by
  ;; SHIFT amount.
  (mapcar
   (function
    (lambda (e)
      (if (consp e)
	  (let ((car (car e))
		(cdr (cdr e)))
	    (if (and (<= from car) (< car to))
		(setcar e (+ shift car)))
	    (if (and (<= from cdr) (< cdr to))
		(setcdr e (+ shift cdr))))
	(if (and (<= from e) (< e to))
	    (setq e (+ shift e))))
      e))
   state))

\f
(defun c-beginning-of-inheritance-list (&optional lim)
  ;; Go to the first non-whitespace after the colon that starts a
  ;; multiple inheritance introduction.  Optional LIM is the farthest
  ;; back we should search.
  (let ((lim (or lim (c-point 'bod)))
	(placeholder (progn
		       (back-to-indentation)
		       (point))))
    (c-backward-syntactic-ws lim)
    (while (and (> (point) lim)
		(memq (char-before) '(?, ?:))
		(progn
		  (beginning-of-line)
		  (setq placeholder (point))
		  (skip-chars-forward " \t")
		  (not (looking-at c-class-key))
		  ))
      (c-backward-syntactic-ws lim))
    (goto-char placeholder)
    (skip-chars-forward "^:" (c-point 'eol))))

(defun c-in-method-def-p ()
  ;; Return nil if we aren't in a method definition, otherwise the
  ;; position of the initial [+-].
  (save-excursion
    (beginning-of-line)
    (and c-method-key
	 (looking-at c-method-key)
	 (point))
    ))

(defun c-just-after-func-arglist-p (&optional containing)
  ;; Return t if we are between a function's argument list closing
  ;; paren and its opening brace.  Note that the list close brace
  ;; could be followed by a "const" specifier or a member init hanging
  ;; colon.  Optional CONTAINING is position of containing s-exp open
  ;; brace.  If not supplied, point is used as search start.
  (save-excursion
    (c-backward-syntactic-ws)
    (let ((checkpoint (or containing (point))))
      (goto-char checkpoint)
      ;; could be looking at const specifier
      (if (and (eq (char-before) ?t)
	       (forward-word -1)
	       (looking-at "\\<const\\>"))
	  (c-backward-syntactic-ws)
	;; otherwise, we could be looking at a hanging member init
	;; colon
	(goto-char checkpoint)
	(if (and (eq (char-before) ?:)
		 (progn
		   (forward-char -1)
		   (c-backward-syntactic-ws)
		   (looking-at "[ \t\n]*:\\([^:]+\\|$\\)")))
	    nil
	  (goto-char checkpoint))
	)
      (and (eq (char-before) ?\))
	   ;; check if we are looking at a method def
	   (or (not c-method-key)
	       (progn
		 (c-forward-sexp -1)
		 (forward-char -1)
		 (c-backward-syntactic-ws)
		 (not (or (memq (char-before) '(?- ?+))
			  ;; or a class category
			  (progn
			    (c-forward-sexp -2)
			    (looking-at c-class-key))
			  )))))
      )))

;; defuns to look backwards for things
(defun c-backward-to-start-of-do (&optional lim)
  ;; Move to the start of the last "unbalanced" do expression.
  ;; Optional LIM is the farthest back to search.  If none is found,
  ;; nil is returned and point is left unchanged, otherwise t is returned.
  (let ((do-level 1)
	(case-fold-search nil)
	(lim (or lim (c-point 'bod)))
	(here (point))
	foundp)
    (while (not (zerop do-level))
      ;; we protect this call because trying to execute this when the
      ;; while is not associated with a do will throw an error
      (condition-case nil
	  (progn
	    (c-backward-sexp 1)
	    (cond
	     ;; break infloop for illegal C code
	     ((bobp) (setq do-level 0))
	     ((memq (c-in-literal lim) '(c c++)))
	     ((looking-at "while\\b[^_]")
	      (setq do-level (1+ do-level)))
	     ((looking-at "do\\b[^_]")
	      (if (zerop (setq do-level (1- do-level)))
		  (setq foundp t)))
	     ((<= (point) lim)
	      (setq do-level 0)
	      (goto-char lim))))
	(error
	 (goto-char lim)
	 (setq do-level 0))))
    (if (not foundp)
	(goto-char here))
    foundp))

(defun c-backward-to-start-of-if (&optional lim)
  ;; Move to the start of the last "unbalanced" if and return t.  If
  ;; none is found, and we are looking at an if clause, nil is
  ;; returned.  If none is found and we are looking at an else clause,
  ;; an error is thrown.
  (let ((if-level 1)
	(here (c-point 'bol))
	(case-fold-search nil)
	(lim (or (and (>= (point) lim)
		      lim)
		 (c-point 'bod)))
	(at-if (looking-at "if\\b[^_]")))
    (catch 'orphan-if
      (while (and (not (bobp))
		  (not (zerop if-level)))
	(c-backward-syntactic-ws)
	(condition-case nil
	    (c-backward-sexp 1)
	  (error
	   (if at-if
	       (throw 'orphan-if nil)
	     (error "No matching `if' found for `else' on line %d."
		    (1+ (count-lines 1 here))))))
	(cond
	 ((looking-at "else\\b[^_]")
	  (setq if-level (1+ if-level)))
	 ((looking-at "if\\b[^_]")
	  ;; check for else if... skip over
	  (let ((here (point)))
	    (c-safe (c-forward-sexp -1))
	    (if (looking-at "\\<else\\>[ \t]+\\<if\\>")
		nil
	      (setq if-level (1- if-level))
	      (goto-char here))))
	 ((< (point) lim)
	  (setq if-level 0)
	  (goto-char lim))
	 ))
      t)))

(defun c-skip-conditional ()
  ;; skip forward over conditional at point, including any predicate
  ;; statements in parentheses. No error checking is performed.
  (c-forward-sexp (cond
		   ;; else if()
		   ((looking-at "\\<else\\>[ \t]+\\<if\\>") 3)
		   ;; do, else, try, finally
		   ((looking-at "\\<\\(do\\|else\\|try\\|finally\\)\\>") 1)
		   ;; for, if, while, switch, catch, synchronized
		   (t 2))))

(defun c-skip-case-statement-forward (state &optional lim)
  ;; skip forward over case/default bodies, with optional maximal
  ;; limit. if no next case body is found, nil is returned and point
  ;; is not moved
  (let ((lim (or lim (point-max)))
	(here (point))
	donep foundp bufpos
	(safepos (point))
	(balanced (car state)))
    ;; search until we've passed the limit, or we've found our match
    (while (and (< (point) lim)
		(not donep))
      (setq safepos (point))
      ;; see if we can find a case statement, not in a literal
      (if (and (re-search-forward c-switch-label-key lim 'move)
	       (setq bufpos (match-beginning 0))
	       (not (c-in-literal safepos))
	       (/= bufpos here))
	  ;; if we crossed into a balanced sexp, we know the case is
	  ;; not part of our switch statement, so just bound over the
	  ;; sexp and keep looking.
	  (if (and (consp balanced)
		   (> bufpos (car balanced))
		   (< bufpos (cdr balanced)))
	      (goto-char (cdr balanced))
	    (goto-char bufpos)
	    (setq donep t
		  foundp t))))
    (if (not foundp)
	(goto-char here))
    foundp))

(defun c-search-uplist-for-classkey (brace-state)
  ;; search for the containing class, returning a 2 element vector if
  ;; found. aref 0 contains the bufpos of the boi of the class key
  ;; line, and aref 1 contains the bufpos of the open brace.
  (if (null brace-state)
      ;; no brace-state means we cannot be inside a class
      nil
    (let ((carcache (car brace-state))
	  search-start search-end)
      (if (consp carcache)
	  ;; a cons cell in the first element means that there is some
	  ;; balanced sexp before the current bufpos. this we can
	  ;; ignore. the nth 1 and nth 2 elements define for us the
	  ;; search boundaries
	  (setq search-start (nth 2 brace-state)
		search-end (nth 1 brace-state))
	;; if the car was not a cons cell then nth 0 and nth 1 define
	;; for us the search boundaries
	(setq search-start (nth 1 brace-state)
	      search-end (nth 0 brace-state)))
      ;; search-end cannot be a cons cell
      (and (consp search-end)
	   (error "consp search-end: %s" search-end))
      ;; if search-end is nil, or if the search-end character isn't an
      ;; open brace, we are definitely not in a class
      (if (or (not search-end)
	      (< search-end (point-min))
	      (not (eq (char-after search-end) ?{)))
	  nil
	;; now, we need to look more closely at search-start.  if
	;; search-start is nil, then our start boundary is really
	;; point-min.
	(if (not search-start)
	    (setq search-start (point-min))
	  ;; if search-start is a cons cell, then we can start
	  ;; searching from the end of the balanced sexp just ahead of
	  ;; us
	  (if (consp search-start)
	      (setq search-start (cdr search-start))))
	;; now we can do a quick regexp search from search-start to
	;; search-end and see if we can find a class key.  watch for
	;; class like strings in literals
	(save-excursion
	  (save-restriction
	    (goto-char search-start)
	    (let ((search-key (concat c-class-key "\\|" c-extra-toplevel-key))
		  foundp class match-end)
	      (if c-inexpr-class-key
		  (setq search-key (concat search-key "\\|"
					   c-inexpr-class-key)))
	      (while (and (not foundp)
			  (progn
			    (c-forward-syntactic-ws)
			    (> search-end (point)))
			  (re-search-forward search-key search-end t))
		(setq class (match-beginning 0)
		      match-end (match-end 0))
		(if (c-in-literal search-start)
		    nil			; its in a comment or string, ignore
		  (goto-char class)
		  (skip-chars-forward " \t\n")
		  (setq foundp (vector (c-point 'boi) search-end))
		  (cond
		   ;; check for embedded keywords
		   ((let ((char (char-after (1- class))))
		      (and char
			   (memq (char-syntax char) '(?w ?_))))
		    (goto-char match-end)
		    (setq foundp nil))
		   ;; make sure we're really looking at the start of a
		   ;; class definition, and not a forward decl, return
		   ;; arg, template arg list, or an ObjC or Java method.
		   ((and c-method-key
			 (re-search-forward c-method-key search-end t)
			 (not (c-in-literal class)))
		    (setq foundp nil))
		   ;; Check if this is an anonymous inner class.
		   ((and c-inexpr-class-key
			 (looking-at c-inexpr-class-key))
		    (while (and (= (c-forward-token-1 1 t) 0)
				(looking-at "(\\|\\w\\|\\s_\\|\\.")))
		    (if (eq (point) search-end)
			;; We're done.  Just trap this case in the cond.
			nil
		      ;; False alarm; all conditions aren't satisfied.
		      (setq foundp nil)))
		   ;; Its impossible to define a regexp for this, and
		   ;; nearly so to do it programmatically.
		   ;;
		   ;; ; picks up forward decls
		   ;; = picks up init lists
		   ;; ) picks up return types
		   ;; > picks up templates, but remember that we can
		   ;;   inherit from templates!
		   ((let ((skipchars "^;=)"))
		      ;; try to see if we found the `class' keyword
		      ;; inside a template arg list
		      (save-excursion
			(skip-chars-backward "^<>" search-start)
			(if (eq (char-before) ?<)
			    (setq skipchars (concat skipchars ">"))))
		      (while (progn
			       (skip-chars-forward skipchars search-end)
			       (c-in-literal class))
			(forward-char))
		      (/= (point) search-end))
		    (setq foundp nil))
		   )))
	      foundp))
	  )))))

(defun c-inside-bracelist-p (containing-sexp brace-state)
  ;; return the buffer position of the beginning of the brace list
  ;; statement if we're inside a brace list, otherwise return nil.
  ;; CONTAINING-SEXP is the buffer pos of the innermost containing
  ;; paren. BRACE-STATE is the remainder of the state of enclosing braces
  ;;
  ;; N.B.: This algorithm can potentially get confused by cpp macros
  ;; places in inconvenient locations.  Its a trade-off we make for
  ;; speed.
  (or
   ;; this will pick up enum lists
   (c-safe
    (save-excursion
      (goto-char containing-sexp)
      (c-forward-sexp -1)
      (let (bracepos)
	(if (and (or (looking-at "enum[\t\n ]+")
		     (progn (c-forward-sexp -1)
			    (looking-at "enum[\t\n ]+")))
		 (setq bracepos (c-safe (scan-lists (point) 1 -1)))
		 (not (c-crosses-statement-barrier-p (point)
						     (- bracepos 2))))
	    (point)))))
   ;; this will pick up array/aggregate init lists, even if they are nested.
   (save-excursion
     (let ((class-key
	    ;; Pike can have class definitions anywhere, so we must
	    ;; check for the class key here.
	    (and (c-major-mode-is 'pike-mode)
		 (concat c-class-key "\\|" c-extra-toplevel-key)))
	   bufpos lim braceassignp)
       (while (and (not bufpos)
		   containing-sexp)
	 (if (consp containing-sexp)
	     (setq containing-sexp (car brace-state)
		   brace-state (cdr brace-state))
	   (goto-char containing-sexp)
	   (if (c-looking-at-inexpr-block)
	       ;; We're in an in-expression block of some kind.  Do
	       ;; not check nesting.
	       (setq containing-sexp nil)
	     ;; see if the open brace is preceded by = or [...] in
	     ;; this statement, but watch out for operator=
	     (setq lim (if (consp (car brace-state))
			   (cdr (car brace-state))
			 (car brace-state))
		   braceassignp 'dontknow)
	     (while (and (eq braceassignp 'dontknow)
			 (zerop (c-backward-token-1 1 t lim)))
	       (cond ((eq (char-after) ?\;)
		      (setq braceassignp nil))
		     ((and class-key
			   (looking-at class-key))
		      (setq braceassignp nil))
		     ((eq (char-after) ?=)
		      ;; We've seen a =, but must check earlier tokens so
		      ;; that it isn't something that should be ignored.
		      (setq braceassignp 'maybe)
		      (while (and (eq braceassignp 'maybe)
				  (zerop (c-backward-token-1 1 t lim)))
			(setq braceassignp
			      (cond
			       ;; Check for operator =
			       ((looking-at "operator\\>") nil)
			       ;; Check for `<opchar>= (Pike)
			       ((eq (char-after) ?`) nil)
			       ((looking-at "\\s.") 'maybe)
			       ;; make sure we're not in a C++ template
			       ;; argument assignment
			       ((save-excursion
				  (let ((here (point))
					(pos< (progn
						(skip-chars-backward "^<")
						(point))))
				    (and (c-major-mode-is 'c++-mode)
					 (eq (char-before) ?<)
					 (not (c-crosses-statement-barrier-p
					       here pos<))
					 (not (c-in-literal))
					 )))
				nil)
			       (t t)))))
		     ((eq (char-after) ?\[)
		      ;; In Java, an initialization brace list may
		      ;; follow "new Foo[]", so check for [].  Got to
		      ;; watch out for the C++ "operator[]" defun,
		      ;; though.
		      (setq braceassignp
			    (save-excursion
			      (c-backward-token-1)
			      (not (looking-at "operator\\>")))))
		     ))
	     (if (memq braceassignp '(nil dontknow))
		 (if (eq (char-after) ?\;)
		     ;; Brace lists can't contain a semicolon, so we're done.
		     (setq containing-sexp nil)
		   ;; lets see if we're nested. find the most nested
		   ;; containing brace
		   (setq containing-sexp (car brace-state)
			 brace-state (cdr brace-state)))
	       ;; we've hit the beginning of the aggregate list
	       (c-beginning-of-statement-1
		(c-most-enclosing-brace brace-state))
	       (setq bufpos (point))))
	   ))
       bufpos))
   ))

(defun c-looking-at-special-brace-list (&optional lim)