;;; cmacexp.el --- expand C macros in a region
;; Copyright (C) 1992, 1994, 1996 Free Software Foundation, Inc.
;; Author: Francesco Potorti` <firstname.lastname@example.org>
;; Version: $Id$
;; Adapted-By: ESR
;; Keywords: c
;; This file is part of XEmacs.
;; XEmacs 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.
;; XEmacs 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 XEmacs; see the file COPYING. If not, write to the Free
;; Software Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA
;; 02111-1307, USA.
;;; Synched up with: FSF 19.34.
;; USAGE =============================================================
;; In C mode C-C C-e is bound to c-macro-expand. The result of the
;; expansion is put in a separate buffer. A user option allows the
;; window displaying the buffer to be optimally sized.
;; When called with a C-u prefix, c-macro-expand replaces the selected
;; region with the expansion. Both the preprocessor name and the
;; initial flag can be set by the user. If c-macro-prompt-flag is set
;; to a non-nil value the user is offered to change the options to the
;; preprocessor each time c-macro-expand is invoked. Preprocessor
;; arguments default to the last ones entered. If c-macro-prompt-flag
;; is nil, one must use M-x set-variable to set a different value for
;; A c-macro-expansion function is provided for non-interactive use.
;; INSTALLATION ======================================================
;; Put the following in your ~/.emacs file.
;; If you want the *Macroexpansion* window to be not higher than
;;(setq c-macro-shrink-window-flag t)
;; If you use a preprocessor other than /lib/cpp (be careful to set a
;; -C option or equivalent in order to make the preprocessor not to
;; strip the comments):
;;(setq c-macro-preprocessor "gpp -C")
;; If you often use a particular set of flags:
;;(setq c-macro-cppflags "-I /usr/include/local -DDEBUG"
;; If you want the "Preprocessor arguments: " prompt:
;;(setq c-macro-prompt-flag t)
;; BUG REPORTS =======================================================
;; Please report bugs, suggestions, complaints and so on to
;; email@example.com (Francesco Potorti`).
;; IMPROVEMENTS OVER emacs 18.xx cmacexp.el ==========================
;; - A lot of user and programmer visible changes. See above.
;; - #line directives are inserted, so __LINE__ and __FILE__ are
;; correctly expanded. Works even with START inside a string, a
;; comment or a region #ifdef'd away by cpp. cpp is invoked with -C,
;; making comments visible in the expansion.
;; - All work is done in core memory, no need for temporary files.
;; ACKNOWLEDGEMENTS ==================================================
;; A lot of thanks to Don Maszle who did a great work of testing, bug
;; reporting and suggestion of new features. This work has been
;; partially inspired by Don Maszle and Jonathan Segal's.
;; BUGS ==============================================================
;; If the start point of the region is inside a macro definition the
;; macro expansion is often inaccurate.
(defgroup c-macro nil
"Expand C macros in a region."
(defcustom c-macro-shrink-window-flag nil
"*Non-nil means shrink the *Macroexpansion* window to fit its contents."
(defcustom c-macro-prompt-flag nil
"*Non-nil makes `c-macro-expand' prompt for preprocessor arguments."
;; Cannot rely on standard directory on MS-DOS to find CPP.
(cond ((eq system-type 'ms-dos) "cpp -C")
;; Solaris has it in an unusual place.
((and (string-match "^[^-]*-[^-]*-\\(solaris\\|sunos5\\)"
"/opt/SUNWspro/SC3.0.1/bin/acomp -C -E")
(t "/lib/cpp -C"))
"The preprocessor used by the cmacexp package.
If you change this, be sure to preserve the `-C' (don't strip comments)
option, or to set an equivalent one."
(defcustom c-macro-cppflags ""
"*Preprocessor flags used by `c-macro-expand'."
(defconst c-macro-buffer-name "*Macroexpansion*")
;; Autoload for XEmacs
(defun c-macro-expand (start end subst)
"Expand C macros in the region, using the C preprocessor.
Normally display output in temp buffer, but
prefix arg means replace the region with it.
`c-macro-preprocessor' specifies the preprocessor to use.
Prompt for arguments to the preprocessor \(e.g. `-DDEBUG -I ./include')
if the user option `c-macro-prompt-flag' is non-nil.
Noninteractive args are START, END, SUBST.
For use inside Lisp programs, see also `c-macro-expansion'."
(let ((inbuf (current-buffer))
(displaybuf (if subst
;; Build the command string.
(read-string "Preprocessor arguments: "
;; Decide where to display output.
(if (and subst
(and buffer-read-only (not inhibit-read-only))
(not (eq inbuf displaybuf)))
"Buffer is read only: displaying expansion in alternate window")
(setq subst nil)
(setq displaybuf (get-buffer-create c-macro-buffer-name)))))
;; Expand the macro and output it.
(setq expansion (c-macro-expansion start end
(concat c-macro-preprocessor " "
(let ((exchange (= (point) start)))
(delete-region start end)
(setq buffer-read-only nil)
(if (string= "" expansion)
(message "Null expansion")
(setq buffer-read-only t)
(setq buffer-auto-save-file-name nil)
;; Display the current buffer in a window which is either just large
;; enough to contain the entire buffer, or half the size of the
;; screen, whichever is smaller. Do not select the new
;; Several factors influence window resizing so that the window is
;; sized optimally if it is created anew, and so that it is messed
;; with minimally if it has been created by the user. If the window
;; chosen for display exists already but contains something else, the
;; window is not re-sized. If the window already contains the current
;; buffer, it is never shrunk, but possibly expanded. Finally, if the
;; variable c-macro-shrink-window-flag is nil the window size is *never*
(defun c-macro-display-buffer ()
(let ((oldwinheight (window-height))
(alreadythere ;the window was already there
(popped nil)) ;the window popped changing the layout
(display-buffer (current-buffer) t)
(setq popped (/= oldwinheight (window-height)))))
(if (and c-macro-shrink-window-flag ;user wants fancy shrinking :\)
(or alreadythere popped))
;; Enlarge up to half screen, or shrink properly.
(let ((oldwin (selected-window))
(select-window (get-buffer-window (current-buffer)))
(setq minheight (if alreadythere
;; XEmacs change
(setq maxheight (/ (screen-height) 2))
(enlarge-window (- (min maxheight
(+ 2 (vertical-motion (point-max)))))
(defun c-macro-expansion (start end cppcommand &optional display)
"Run a preprocessor on region and return the output as a string.
Expand the region between START and END in the current buffer using
the shell command CPPCOMMAND (e.g. \"/lib/cpp -C -DDEBUG\").
Be sure to use a -C (don't strip comments) or equivalent option.
Optional arg DISPLAY non-nil means show messages in the echo area."
;; Copy the current buffer's contents to a temporary hidden buffer.
;; Delete from END to end of buffer. Insert a preprocessor #line
;; directive at START and after each #endif following START that are
;; not inside a comment or a string. Put all the strings thus
;; inserted (without the "line" substring) in a list named linelist.
;; If START is inside a comment, prepend "*/" and append "/*" to the
;; #line directive. If inside a string, prepend and append "\"".
;; Preprocess the buffer contents, then look for all the lines stored
;; in linelist starting from end of buffer. The last line so found is
;; where START was, so return the substring from point to end of
(let ((inbuf (current-buffer))
(outbuf (get-buffer-create " *C Macro Expansion*"))
(filename (if (and buffer-file-name
(string-match (regexp-quote default-directory)
(substring buffer-file-name (match-end 0))
(mymsg (format "Invoking %s%s%s on region..."
(if (string= "" c-macro-cppflags) "" " ")
(uniquestring "??? !!! ??? start of c-macro expansion ??? !!! ???")
(tempname (make-temp-name (concat
(or (getenv "TMPDIR") (getenv "TEMP")
(getenv "TMP") "/tmp")
(let ((in-syntax-table (syntax-table)))
(setq buffer-read-only nil)
(insert-buffer-substring inbuf 1 end))
;; We have copied inbuf to outbuf. Point is at end of
;; outbuf. Inset a newline at the end, so cpp can correctly
;; parse a token ending at END.
;; Save sexp status and line number at START.
(setq startstat (parse-partial-sexp 1 start))
(setq startlinenum (+ (count-lines 1 (point))
(if (bolp) 1 0)))
;; Now we insert the #line directives after all #endif or
;; #else following START going backward, so the lines we
;; insert don't change the line numbers.
;(switch-to-buffer outbuf) (debug) ;debugging instructions
(while (re-search-backward "\n#\\(endif\\|else\\)\\>" start 'move)
(if (equal (nthcdr 3 (parse-partial-sexp start (point)
nil nil startstat))
'(nil nil nil 0 nil)) ;neither in string nor in
;comment nor after quote
(goto-char (match-end 0))
(setq linenum (+ startlinenum
(count-lines start (point))))
(insert (format "\n#line %d \"%s\"\n" linenum filename))
(goto-char (match-beginning 0)))))
;; Now we are at START. Insert the first #line directive.
;; This must work even inside a string or comment, or after a
(let* ((startinstring (nth 3 startstat))
(startincomment (nth 4 startstat))
(startafterquote (nth 5 startstat))
(startinbcomment (nth 7 startstat)))
(insert (if startafterquote " " "")
(concat "\n" uniquestring
(if startafterquote "\\")))
(format "\n#line %d \"%s\"\n" startlinenum filename)))
;; Call the preprocessor.
(if display (message mymsg))
(call-process-region 1 (point-max)
t (list t tempname) nil "-c"
(if display (message (concat mymsg "done")))
(if (= (buffer-size) 0)
;; Empty output is normal after a fatal error.
(insert "\nPreprocessor produced no output\n")
;; Find and delete the mark of the start of the expansion.
;; Look for `# nn "file.c"' lines and delete them.
(delete-region 1 (point)))
(while (re-search-forward (concat "^# [0-9]+ \""
"\"") nil t)
(let ((beg (point)))
(delete-region beg (point))))
;; If CPP got errors, show them at the beginning.
;; MS-DOS shells don't return the exit code of their children.
;; Look at the size of the error message file instead, but
;; don't punish those MS-DOS users who have a shell that does
;; return an error code.
(or (and (or (not (boundp 'msdos-shells))
(not (member (file-name-nondirectory shell-file-name)
(eq exit-status 0))
(zerop (nth 7 (file-attributes (expand-file-name tempname))))
;; Put the messages inside a comment, so they won't get in
;; the way of font-lock, highlighting etc.
(format "/* Preprocessor terminated with status %s\n\n Messages from `%s\':\n\n"
(goto-char (+ (point)
(nth 1 (insert-file-contents tempname))))
;; Compute the return value, keeping in account the space
;; inserted at the end of the buffer.
(buffer-substring 1 (max 1 (- (point-max) 1))))
;;; cmacexp.el ends here