hideif.el

早期freebsd实现

; pattern to match initial identifier, !, &&, ||, (, or ).
(defconst hif-token-regexp "^\\(!\\|&&\\|||\\|[()]\\|\\w+\\)")
(defconst hif-end-of-comment "\\*/")


(defun hif-tokenize (expr-string)
  "Separate string into a list of tokens"
  (let ((token-list nil)
	(expr-start 0)
	(expr-length (length expr-string)))

    (while (< expr-start expr-length) 
;      (message "expr-start = %d" expr-start) (sit-for 1)
      (cond
	((string-match "^[ \t]+" expr-string expr-start)
	   ; skip whitespace
	 (setq expr-start (match-end 0))
	 ; stick newline in string so ^ matches on the next string-match
	 (aset expr-string (1- expr-start) ?\n)
	 )

	((string-match "^/\\*" expr-string expr-start)
	 (setq expr-start (match-end 0))
	 (aset expr-string (1- expr-start) ?\n)
	 (or
	   (string-match hif-end-of-comment
			 expr-string expr-start) ; eat comment
	   (string-match "$" expr-string expr-start)) ; multi-line comment
	 (setq expr-start (match-end 0))
	 (aset expr-string (1- expr-start) ?\n)
	 )

	((string-match hif-token-regexp expr-string expr-start)
	  (let ((token (substring expr-string expr-start (match-end 0))))
	    (setq expr-start (match-end 0))
	    (aset expr-string (1- expr-start) ?\n)
;	    (message "token: %s" token) (sit-for 1)
	    (setq token-list
		  (cons
		    (cond
		      ((string-equal token "||") 'or)
		      ((string-equal token "&&") 'and)
		      ((string-equal token "!")  'not)
		      ((string-equal token "defined") 'hif-defined)
		      ((string-equal token "(") 'lparen)
		      ((string-equal token ")") 'rparen)
		      (t (intern token)))
		    token-list))
	    ))
	  (t (error "Bad #if expression: %s" expr-string))
	  ))
    (nreverse token-list)
    ))

;;;-----------------------------------------------------------------
;;; Translate C preprocessor #if expressions using recursive descent.
;;; This parser is limited to the operators &&, ||, !, and "defined".

(defun hif-parse-if-exp (token-list)
  "Parse the TOKEN-LIST.  Return translated list in prefix form."
  (hif-nexttoken)
  (prog1
      (hif-expr)
    (if token ; is there still a token?
	(error "Error: unexpected token: %s" token)))
  )

(defun hif-nexttoken ()
  "Pop the next token from token-list into the let variable \"token\"."
  (setq token (car token-list))
  (setq token-list (cdr token-list))
  token
  )

(defun hif-expr ()
  "Parse and expression of the form
       expr : term | expr '||' term."
  (let ((result (hif-term)))
    (while (eq  token 'or)
      (hif-nexttoken)
      (setq result (list 'or result (hif-term))))
  result
  ))

(defun hif-term ()
  "Parse a term of the form
       term : factor | term '&&' factor."
  (let ((result (hif-factor)))
    (while (eq token 'and)
      (hif-nexttoken)
      (setq result (list 'and result (hif-factor))))
    result
    ))

(defun hif-factor ()
  "Parse a factor of the form
       factor : '!' factor | '(' expr ')' | 'defined(' id ')' | id."
  (cond
    ((eq token 'not)
     (hif-nexttoken)
     (list 'not (hif-factor)))

    ((eq token 'lparen)
     (hif-nexttoken)
     (let ((result (hif-expr)))
       (if (not (eq token 'rparen))
	   (error "Bad token in parenthesized expression: %s" token)
	 (hif-nexttoken)
	 result)))

    ((eq token 'hif-defined)
     (hif-nexttoken)
     (if (not (eq token 'lparen))
	 (error "Error: expected \"(\" after \"define\""))
     (hif-nexttoken)
     (let ((ident token))
       (if (memq token '(or and not hif-defined lparen rparen))
	   (error "Error: unexpected token: %s" token))
       (hif-nexttoken)
       (if (not (eq token 'rparen))
	   (error "Error: expected \")\" after identifier"))
       (hif-nexttoken)
       (` (hif-defined (quote (, ident))))
       ))

    (t ; identifier
      (let ((ident token))
	(if (memq ident '(or and))
	    (error "Error: missing identifier"))
	(hif-nexttoken)
	(` (hif-lookup (quote (, ident))))
	))

    ))

;;;----------- end of parser -----------------------


(defun hif-canonicalize ()
  "When at beginning of #ifX, returns a canonical (evaluatable)
       form for the expression."
  (save-excursion
    (let ((negate (looking-at hif-ifndef-regexp)))
      (re-search-forward hif-ifx-regexp)
      (let* ((expr-string
	      (buffer-substring (point)
				(progn (skip-chars-forward "^\n\r") (point))))
	     (expr (hif-infix-to-prefix (hif-tokenize expr-string))))
;	(message "hif-canonicalized: %s" expr)
	(if negate
	    (list 'not expr)
	  expr)))))


(defun hif-find-any-ifX ()
  "Position at beginning of next #if, #ifdef, or #ifndef, including one on
this line."
;  (message "find ifX at %d" (point))
  (prog1
      (re-search-forward hif-ifx-regexp (point-max) t)
    (beginning-of-line)))


(defun hif-find-next-relevant ()
  "Position at beginning of next #ifdef, #ifndef, #else, #endif,
NOT including one on this 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 ()
  "Position at beginning of previous #ifdef, #ifndef, #else, #endif,
NOT including one on this 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 "Missmatched #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 "Missmatched #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)))
      (if (not (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)))
      (if (not (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)))
    (if (not (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)
    (if (eolp)
	(progn
	  (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)

(defun hif-make-range (else-p start end &optional else)
  (list else-p start else end))

(defun hif-range-else-p (range)  (elt range 0))
(defun hif-range-start (range) (elt range 1))
(defun hif-range-else (range) (elt range 2))
(defun hif-range-end (range) (elt range 3))