1;;; cmacexp.el --- expand C macros in a region 2 3;; Copyright (C) 1992, 1994 Free Software Foundation, Inc. 4 5;; Author: Francesco Potorti` <pot@cnuce.cnr.it> 6;; Version: $Id: cmacexp.el,v 1.14 1994/05/03 22:17:03 kwzh Exp $ 7;; Adapted-By: ESR 8;; Keywords: c 9 10;; This file is part of GNU Emacs. 11 12;; GNU Emacs is free software; you can redistribute it and/or modify 13;; it under the terms of the GNU General Public License as published by 14;; the Free Software Foundation; either version 2, or (at your option) 15;; any later version. 16 17;; GNU Emacs is distributed in the hope that it will be useful, 18;; but WITHOUT ANY WARRANTY; without even the implied warranty of 19;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 20;; GNU General Public License for more details. 21 22;; You should have received a copy of the GNU General Public License 23;; along with GNU Emacs; see the file COPYING. If not, write to 24;; the Free Software Foundation, 675 Mass Ave, Cambridge, MA 02139, USA. 25 26;; USAGE ============================================================= 27 28;; In C mode C-C C-e is bound to c-macro-expand. The result of the 29;; expansion is put in a separate buffer. A user option allows the 30;; window displaying the buffer to be optimally sized. 31;; 32;; When called with a C-u prefix, c-macro-expand replaces the selected 33;; region with the expansion. Both the preprocessor name and the 34;; initial flag can be set by the user. If c-macro-prompt-flag is set 35;; to a non-nil value the user is offered to change the options to the 36;; preprocessor each time c-macro-expand is invoked. Preprocessor 37;; arguments default to the last ones entered. If c-macro-prompt-flag 38;; is nil, one must use M-x set-variable to set a different value for 39;; c-macro-cppflags. 40 41;; A c-macro-expansion function is provided for non-interactive use. 42 43;; INSTALLATION ====================================================== 44 45;; Put the following in your ~/.emacs file. 46 47;; If you want the *Macroexpansion* window to be not higher than 48;; necessary: 49;;(setq c-macro-shrink-window-flag t) 50;; 51;; If you use a preprocessor other than /lib/cpp (be careful to set a 52;; -C option or equivalent in order to make the preprocessor not to 53;; strip the comments): 54;;(setq c-macro-preprocessor "gpp -C") 55;; 56;; If you often use a particular set of flags: 57;;(setq c-macro-cppflags "-I /usr/include/local -DDEBUG" 58;; 59;; If you want the "Preprocessor arguments: " prompt: 60;;(setq c-macro-prompt-flag t) 61 62;; BUG REPORTS ======================================================= 63 64;; Please report bugs, suggestions, complaints and so on to 65;; pot@cnuce.cnr.it (Francesco Potorti`). 66 67;; IMPROVEMENTS OVER emacs 18.xx cmacexp.el ========================== 68 69;; - A lot of user visible changes. See above. 70;; - #line directives are inserted, so __LINE__ and __FILE__ are 71;; correctly expanded. Works even with START inside a string, a 72;; comment or a region #ifdef'd away by cpp. cpp is invoked with -C, 73;; making comments visible in the expansion. 74;; - All work is done in core memory, no need for temporary files. 75 76;; ACKNOWLEDGEMENTS ================================================== 77 78;; A lot of thanks to Don Maszle who did a great work of testing, bug 79;; reporting and suggestion of new features. This work has been 80;; partially inspired by Don Maszle and Jonathan Segal's. 81 82;; BUGS ============================================================== 83 84;; If the start point of the region is inside a macro definition the 85;; macro expansion is often inaccurate. 86 87 88(provide 'cmacexp) 89 90(defvar c-macro-shrink-window-flag nil 91 "*Non-nil means shrink the *Macroexpansion* window to fit its contents.") 92 93(defvar c-macro-prompt-flag nil 94 "*Non-nil makes `c-macro-expand' prompt for preprocessor arguments.") 95 96(defvar c-macro-preprocessor "/lib/cpp -C" 97 "The preprocessor used by the cmacexp package. 98 99If you change this, be sure to preserve the -C (don't strip comments) 100option, or to set an equivalent one.") 101 102(defvar c-macro-cppflags "" 103 "*Preprocessor flags used by c-macro-expand.") 104 105(defconst c-macro-buffer-name "*Macroexpansion*") 106 107(defun c-macro-expand (start end subst) 108 "Expand C macros in the region, using the C preprocessor. 109Normally display output in temp buffer, but 110prefix arg means replace the region with it. 111 112`c-macro-preprocessor' specifies the preprocessor to use. 113Prompt for arguments to the preprocessor \(e.g. `-DDEBUG -I ./include') 114if the user option `c-macro-prompt-flag' is non-nil. 115 116Noninteractive args are START, END, SUBST. 117For use inside Lisp programs, see also `c-macro-expansion'." 118 119 (interactive "r\nP") 120 (let ((inbuf (current-buffer)) 121 (displaybuf (if subst 122 (get-buffer c-macro-buffer-name) 123 (get-buffer-create c-macro-buffer-name))) 124 (expansion "")) 125 ;; Build the command string. 126 (if c-macro-prompt-flag 127 (setq c-macro-cppflags 128 (read-string "Preprocessor arguments: " 129 c-macro-cppflags))) 130 ;; Decide where to display output. 131 (if (and subst 132 (and buffer-read-only (not inhibit-read-only)) 133 (not (eq inbuf displaybuf))) 134 (progn 135 (message 136 "Buffer is read only: displaying expansion in alternate window") 137 (sit-for 2) 138 (setq subst nil) 139 (or displaybuf 140 (setq displaybuf (get-buffer-create c-macro-buffer-name))))) 141 ;; Expand the macro and output it. 142 (setq expansion (c-macro-expansion start end 143 (concat c-macro-preprocessor " " 144 c-macro-cppflags) t)) 145 (if subst 146 (let ((exchange (= (point) start))) 147 (delete-region start end) 148 (insert expansion) 149 (if exchange 150 (exchange-point-and-mark))) 151 (set-buffer displaybuf) 152 (setq buffer-read-only nil) 153 (buffer-flush-undo displaybuf) 154 (erase-buffer) 155 (insert expansion) 156 (set-buffer-modified-p nil) 157 (if (string= "" expansion) 158 (message "Null expansion") 159 (c-macro-display-buffer)) 160 (setq buffer-read-only t) 161 (setq buffer-auto-save-file-name nil) 162 (bury-buffer displaybuf)))) 163 164 165;; Display the current buffer in a window which is either just large 166;; enough to contain the entire buffer, or half the size of the 167;; screen, whichever is smaller. Do not select the new 168;; window. 169;; 170;; Several factors influence window resizing so that the window is 171;; sized optimally if it is created anew, and so that it is messed 172;; with minimally if it has been created by the user. If the window 173;; chosen for display exists already but contains something else, the 174;; window is not re-sized. If the window already contains the current 175;; buffer, it is never shrunk, but possibly expanded. Finally, if the 176;; variable c-macro-shrink-window-flag is nil the window size is *never* 177;; changed. 178(defun c-macro-display-buffer () 179 (goto-char (point-min)) 180 (c-mode) 181 (let ((oldwinheight (window-height)) 182 (alreadythere ;the window was already there 183 (get-buffer-window (current-buffer))) 184 (popped nil)) ;the window popped changing the layout 185 (or alreadythere 186 (progn 187 (display-buffer (current-buffer) t) 188 (setq popped (/= oldwinheight (window-height))))) 189 (if (and c-macro-shrink-window-flag ;user wants fancy shrinking :\) 190 (or alreadythere popped)) 191 ;; Enlarge up to half screen, or shrink properly. 192 (let ((oldwin (selected-window)) 193 (minheight 0) 194 (maxheight 0)) 195 (save-excursion 196 (select-window (get-buffer-window (current-buffer))) 197 (setq minheight (if alreadythere 198 (window-height) 199 window-min-height)) 200 (setq maxheight (/ (screen-height) 2)) 201 (enlarge-window (- (min maxheight 202 (max minheight 203 (+ 2 (vertical-motion (point-max))))) 204 (window-height))) 205 (goto-char (point-min)) 206 (select-window oldwin)))))) 207 208 209(defun c-macro-expansion (start end cppcommand &optional display) 210 "Run a preprocessor on region and return the output as a string. 211Expand the region between START and END in the current buffer using 212the shell command CPPCOMMAND (e.g. \"/lib/cpp -C -DDEBUG\"). 213Be sure to use a -C (don't strip comments) or equivalent option. 214Optional arg DISPLAY non-nil means show messages in the echo area." 215 216;; Copy the current buffer's contents to a temporary hidden buffer. 217;; Delete from END to end of buffer. Insert a preprocessor #line 218;; directive at START and after each #endif following START that are 219;; not inside a comment or a string. Put all the strings thus 220;; inserted (without the "line" substring) in a list named linelist. 221;; If START is inside a comment, prepend "*/" and append "/*" to the 222;; #line directive. If inside a string, prepend and append "\"". 223;; Preprocess the buffer contents, then look for all the lines stored 224;; in linelist starting from end of buffer. The last line so found is 225;; where START was, so return the substring from point to end of 226;; buffer. 227 (let ((inbuf (current-buffer)) 228 (outbuf (get-buffer-create " *C Macro Expansion*")) 229 (filename (if (and buffer-file-name 230 (string-match (regexp-quote default-directory) 231 buffer-file-name)) 232 (substring buffer-file-name (match-end 0)) 233 (buffer-name))) 234 (mymsg (format "Invoking %s%s%s on region..." 235 c-macro-preprocessor 236 (if (string= "" c-macro-cppflags) "" " ") 237 c-macro-cppflags)) 238 (uniquestring "???!!!???!!! start of c-macro expansion ???!!!???!!!") 239 (startlinenum 0) 240 (linenum 0) 241 (startstat ()) 242 (startmarker "")) 243 (unwind-protect 244 (save-excursion 245 (save-restriction 246 (widen) 247 (set-buffer outbuf) 248 (setq buffer-read-only nil) 249 (erase-buffer) 250 (set-syntax-table c-mode-syntax-table) 251 (insert-buffer-substring inbuf 1 end)) 252 253 ;; We have copied inbuf to outbuf. Point is at end of 254 ;; outbuf. Insert a space at the end, so cpp can correctly 255 ;; parse a token ending at END. 256 (insert " ") 257 258 ;; Save sexp status and line number at START. 259 (setq startstat (parse-partial-sexp 1 start)) 260 (setq startlinenum (+ (count-lines 1 (point)) 261 (if (bolp) 1 0))) 262 263 ;; Now we insert the #line directives after all #endif or 264 ;; #else following START going backward, so the lines we 265 ;; insert don't change the line numbers. 266 ;(switch-to-buffer outbuf) (debug) ;debugging instructions 267 (goto-char (point-max)) 268 (while (re-search-backward "\n#\\(endif\\|else\\)\\>" start 'move) 269 (if (equal (nthcdr 3 (parse-partial-sexp start (point) 270 nil nil startstat)) 271 '(nil nil nil 0 nil)) ;neither in string nor in 272 ;comment nor after quote 273 (progn 274 (goto-char (match-end 0)) 275 (setq linenum (+ startlinenum 276 (count-lines start (point)))) 277 (insert (format "\n#line %d \"%s\"\n" linenum filename)) 278 (goto-char (match-beginning 0))))) 279 280 ;; Now we are at START. Insert the first #line directive. 281 ;; This must work even inside a string or comment, or after a 282 ;; quote. 283 (let* ((startinstring (nth 3 startstat)) 284 (startincomment (nth 4 startstat)) 285 (startafterquote (nth 5 startstat)) 286 (startinbcomment (nth 7 startstat))) 287 (insert (if startafterquote " " "") 288 (cond (startinstring 289 (char-to-string startinstring)) 290 (startincomment "*/") 291 ("")) 292 (format "\n#line %d \"%s\"\n" startlinenum filename) 293 (setq startmarker 294 (concat uniquestring 295 (cond (startinstring 296 (char-to-string startinstring)) 297 (startincomment "/*") 298 (startinbcomment "//")) 299 (if startafterquote "\\"))))) 300 301 ;; Call the preprocessor. 302 (if display (message mymsg)) 303 (call-process-region 1 (point-max) "sh" t t nil "-c" 304 (concat cppcommand " 2>/dev/null")) 305 (if display (message (concat mymsg "done"))) 306 307 ;; Find and delete the mark of the start of the expansion. 308 ;; Look for `# nn "file.c"' lines and delete them. 309 (goto-char (point-min)) 310 (search-forward startmarker) 311 (delete-region 1 (point)) 312 (while (re-search-forward (concat "^# [0-9]+ \"" 313 (regexp-quote filename) 314 "\"") nil t) 315 (beginning-of-line) 316 (let ((beg (point))) 317 (forward-line 1) 318 (delete-region beg (point)))) 319 320 ;; Compute the return value, keeping in account the space 321 ;; inserted at the end of the buffer. 322 (buffer-substring 1 (max 1 (- (point-max) 1)))) 323 324 ;; Cleanup. 325 (kill-buffer outbuf)))) 326 327;;; cmacexp.el ends here 328