1;;; cmacexp.el --- expand C macros in a region 2 3;; Copyright (C) 1992, 1994, 1996, 2000, 2001, 2002, 2003, 2004, 2005, 2006, 2007 4;; Free Software Foundation, Inc. 5 6;; Author: Francesco Potorti` <pot@gnu.org> 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 the 24;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor, 25;; Boston, MA 02110-1301, USA. 26 27;;; Commentary: 28 29;; USAGE ============================================================= 30 31;; In C mode C-C C-e is bound to c-macro-expand. The result of the 32;; expansion is put in a separate buffer. A user option allows the 33;; window displaying the buffer to be optimally sized. 34;; 35;; When called with a C-u prefix, c-macro-expand replaces the selected 36;; region with the expansion. Both the preprocessor name and the 37;; initial flag can be set by the user. If c-macro-prompt-flag is set 38;; to a non-nil value the user is offered to change the options to the 39;; preprocessor each time c-macro-expand is invoked. Preprocessor 40;; arguments default to the last ones entered. If c-macro-prompt-flag 41;; is nil, one must use M-x set-variable to set a different value for 42;; c-macro-cppflags. 43 44;; A c-macro-expansion function is provided for non-interactive use. 45 46;; INSTALLATION ====================================================== 47 48;; Put the following in your ~/.emacs file. 49 50;; If you want the *Macroexpansion* window to be not higher than 51;; necessary: 52;;(setq c-macro-shrink-window-flag t) 53;; 54;; If you use a preprocessor other than /lib/cpp (be careful to set a 55;; -C option or equivalent in order to make the preprocessor not to 56;; strip the comments): 57;;(setq c-macro-preprocessor "gpp -C") 58;; 59;; If you often use a particular set of flags: 60;;(setq c-macro-cppflags "-I /usr/include/local -DDEBUG" 61;; 62;; If you want the "Preprocessor arguments: " prompt: 63;;(setq c-macro-prompt-flag t) 64 65;; BUG REPORTS ======================================================= 66 67;; Please report bugs, suggestions, complaints and so on to 68;; pot@gnu.org (Francesco Potorti`). 69 70;; IMPROVEMENTS OVER emacs 18.xx cmacexp.el ========================== 71 72;; - A lot of user and programmer visible changes. See above. 73;; - #line directives are inserted, so __LINE__ and __FILE__ are 74;; correctly expanded. Works even with START inside a string, a 75;; comment or a region #ifdef'd away by cpp. cpp is invoked with -C, 76;; making comments visible in the expansion. 77;; - All work is done in core memory, no need for temporary files. 78 79;; ACKNOWLEDGEMENTS ================================================== 80 81;; A lot of thanks to Don Maszle who did a great work of testing, bug 82;; reporting and suggestion of new features. This work has been 83;; partially inspired by Don Maszle and Jonathan Segal's. 84 85;; BUGS ============================================================== 86 87;; If the start point of the region is inside a macro definition the 88;; macro expansion is often inaccurate. 89 90;;; Code: 91 92(require 'cc-mode) 93 94(provide 'cmacexp) 95 96(defvar msdos-shells) 97 98 99(defgroup c-macro nil 100 "Expand C macros in a region." 101 :group 'c) 102 103 104(defcustom c-macro-shrink-window-flag nil 105 "*Non-nil means shrink the *Macroexpansion* window to fit its contents." 106 :type 'boolean 107 :group 'c-macro) 108 109(defcustom c-macro-prompt-flag nil 110 "*Non-nil makes `c-macro-expand' prompt for preprocessor arguments." 111 :type 'boolean 112 :group 'c-macro) 113 114(defcustom c-macro-preprocessor 115 (cond ;; Solaris has it in an unusual place. 116 ((and (string-match "^[^-]*-[^-]*-\\(solaris\\|sunos5\\)" 117 system-configuration) 118 (file-exists-p "/opt/SUNWspro/SC3.0.1/bin/acomp")) 119 "/opt/SUNWspro/SC3.0.1/bin/acomp -C -E") 120 ((locate-file "/usr/ccs/lib/cpp" 121 '("/") exec-suffixes 'file-executable-p) 122 "/usr/ccs/lib/cpp -C") 123 ((locate-file "/lib/cpp" 124 '("/") exec-suffixes 'file-executable-p) 125 "/lib/cpp -C") 126 ;; On some systems, we cannot rely on standard directories to 127 ;; find CPP. In fact, we cannot rely on having cpp, either, 128 ;; in some GCC versions. 129 ((locate-file "cpp" exec-path exec-suffixes 'file-executable-p) 130 "cpp -C") 131 (t "gcc -E -C -o - -")) 132 "The preprocessor used by the cmacexp package. 133 134If you change this, be sure to preserve the `-C' (don't strip comments) 135option, or to set an equivalent one." 136 :type 'string 137 :group 'c-macro) 138 139(defcustom c-macro-cppflags "" 140 "*Preprocessor flags used by `c-macro-expand'." 141 :type 'string 142 :group 'c-macro) 143 144(defconst c-macro-buffer-name "*Macroexpansion*") 145 146;;;###autoload 147(defun c-macro-expand (start end subst) 148 "Expand C macros in the region, using the C preprocessor. 149Normally display output in temp buffer, but 150prefix arg means replace the region with it. 151 152`c-macro-preprocessor' specifies the preprocessor to use. 153Tf the user option `c-macro-prompt-flag' is non-nil 154prompt for arguments to the preprocessor \(e.g. `-DDEBUG -I ./include'), 155otherwise use `c-macro-cppflags'. 156 157Noninteractive args are START, END, SUBST. 158For use inside Lisp programs, see also `c-macro-expansion'." 159 160 (interactive "r\nP") 161 (let ((inbuf (current-buffer)) 162 (displaybuf (if subst 163 (get-buffer c-macro-buffer-name) 164 (get-buffer-create c-macro-buffer-name))) 165 (expansion "")) 166 ;; Build the command string. 167 (if c-macro-prompt-flag 168 (setq c-macro-cppflags 169 (read-string "Preprocessor arguments: " 170 c-macro-cppflags))) 171 ;; Decide where to display output. 172 (if (and subst 173 (and buffer-read-only (not inhibit-read-only)) 174 (not (eq inbuf displaybuf))) 175 (progn 176 (message 177 "Buffer is read only: displaying expansion in alternate window") 178 (sit-for 2) 179 (setq subst nil) 180 (or displaybuf 181 (setq displaybuf (get-buffer-create c-macro-buffer-name))))) 182 ;; Expand the macro and output it. 183 (setq expansion (c-macro-expansion start end 184 (concat c-macro-preprocessor " " 185 c-macro-cppflags) t)) 186 (if subst 187 (let ((exchange (= (point) start))) 188 (delete-region start end) 189 (insert expansion) 190 (if exchange 191 (exchange-point-and-mark))) 192 (set-buffer displaybuf) 193 (setq buffer-read-only nil) 194 (buffer-disable-undo displaybuf) 195 (erase-buffer) 196 (insert expansion) 197 (set-buffer-modified-p nil) 198 (if (string= "" expansion) 199 (message "Null expansion") 200 (c-macro-display-buffer)) 201 (setq buffer-read-only t) 202 (setq buffer-auto-save-file-name nil) 203 (bury-buffer displaybuf)))) 204 205 206;; Display the current buffer in a window which is either just large 207;; enough to contain the entire buffer, or half the size of the 208;; screen, whichever is smaller. Do not select the new 209;; window. 210;; 211;; Several factors influence window resizing so that the window is 212;; sized optimally if it is created anew, and so that it is messed 213;; with minimally if it has been created by the user. If the window 214;; chosen for display exists already but contains something else, the 215;; window is not re-sized. If the window already contains the current 216;; buffer, it is never shrunk, but possibly expanded. Finally, if the 217;; variable c-macro-shrink-window-flag is nil the window size is *never* 218;; changed. 219(defun c-macro-display-buffer () 220 (goto-char (point-min)) 221 (c-mode) 222 (let ((oldwinheight (window-height)) 223 (alreadythere ;the window was already there 224 (get-buffer-window (current-buffer))) 225 (popped nil)) ;the window popped changing the layout 226 (or alreadythere 227 (progn 228 (display-buffer (current-buffer) t) 229 (setq popped (/= oldwinheight (window-height))))) 230 (if (and c-macro-shrink-window-flag ;user wants fancy shrinking :\) 231 (or alreadythere popped)) 232 ;; Enlarge up to half screen, or shrink properly. 233 (let ((oldwin (selected-window)) 234 (minheight 0) 235 (maxheight 0)) 236 (save-excursion 237 (select-window (get-buffer-window (current-buffer))) 238 (setq minheight (if alreadythere 239 (window-height) 240 window-min-height)) 241 (setq maxheight (/ (frame-height) 2)) 242 (enlarge-window (- (min maxheight 243 (max minheight 244 (+ 2 (vertical-motion (point-max))))) 245 (window-height))) 246 (goto-char (point-min)) 247 (select-window oldwin)))))) 248 249 250(defun c-macro-expansion (start end cppcommand &optional display) 251 "Run a preprocessor on region and return the output as a string. 252Expand the region between START and END in the current buffer using 253the shell command CPPCOMMAND (e.g. \"/lib/cpp -C -DDEBUG\"). 254Be sure to use a -C (don't strip comments) or equivalent option. 255Optional arg DISPLAY non-nil means show messages in the echo area." 256 257;; Copy the current buffer's contents to a temporary hidden buffer. 258;; Delete from END to end of buffer. Insert a preprocessor #line 259;; directive at START and after each #endif following START that are 260;; not inside a comment or a string. Put all the strings thus 261;; inserted (without the "line" substring) in a list named linelist. 262;; If START is inside a comment, prepend "*/" and append "/*" to the 263;; #line directive. If inside a string, prepend and append "\"". 264;; Preprocess the buffer contents, then look for all the lines stored 265;; in linelist starting from end of buffer. The last line so found is 266;; where START was, so return the substring from point to end of 267;; buffer. 268 (let ((inbuf (current-buffer)) 269 (outbuf (get-buffer-create " *C Macro Expansion*")) 270 (filename (if (and buffer-file-name 271 (string-match (regexp-quote default-directory) 272 buffer-file-name)) 273 (substring buffer-file-name (match-end 0)) 274 (buffer-name))) 275 (mymsg (format "Invoking %s%s%s on region..." 276 c-macro-preprocessor 277 (if (string= "" c-macro-cppflags) "" " ") 278 c-macro-cppflags)) 279 (uniquestring "??? !!! ??? start of c-macro expansion ??? !!! ???") 280 (startlinenum 0) 281 (linenum 0) 282 (startstat ()) 283 (startmarker "") 284 (exit-status 0) 285 (tempname (make-temp-file 286 (expand-file-name "cmacexp" 287 (or small-temporary-file-directory 288 temporary-file-directory))))) 289 (unwind-protect 290 (save-excursion 291 (save-restriction 292 (widen) 293 (let ((in-syntax-table (syntax-table))) 294 (set-buffer outbuf) 295 (setq buffer-read-only nil) 296 (erase-buffer) 297 (set-syntax-table in-syntax-table)) 298 (insert-buffer-substring inbuf 1 end)) 299 300 ;; We have copied inbuf to outbuf. Point is at end of 301 ;; outbuf. Inset a newline at the end, so cpp can correctly 302 ;; parse a token ending at END. 303 (insert "\n") 304 305 ;; Save sexp status and line number at START. 306 (setq startstat (parse-partial-sexp 1 start)) 307 (setq startlinenum (+ (count-lines 1 (point)) 308 (if (bolp) 1 0))) 309 310 ;; Now we insert the #line directives after all #endif or 311 ;; #else following START going backward, so the lines we 312 ;; insert don't change the line numbers. 313 ;(switch-to-buffer outbuf) (debug) ;debugging instructions 314 (goto-char (point-max)) 315 (while (re-search-backward "\n#\\(endif\\|else\\)\\>" start 'move) 316 (if (equal (nthcdr 3 (parse-partial-sexp start (point) 317 nil nil startstat)) 318 '(nil nil nil 0 nil)) ;neither in string nor in 319 ;comment nor after quote 320 (progn 321 (goto-char (match-end 0)) 322 (setq linenum (+ startlinenum 323 (count-lines start (point)))) 324 (insert (format "\n#line %d \"%s\"\n" linenum filename)) 325 (goto-char (match-beginning 0))))) 326 327 ;; Now we are at START. Insert the first #line directive. 328 ;; This must work even inside a string or comment, or after a 329 ;; quote. 330 (let* ((startinstring (nth 3 startstat)) 331 (startincomment (nth 4 startstat)) 332 (startafterquote (nth 5 startstat)) 333 (startinbcomment (nth 7 startstat))) 334 (insert (if startafterquote " " "") 335 (cond (startinstring 336 (char-to-string startinstring)) 337 (startincomment "*/") 338 ("")) 339 (setq startmarker 340 (concat "\n" uniquestring 341 (cond (startinstring 342 (char-to-string startinstring)) 343 (startincomment "/*") 344 (startinbcomment "//")) 345 (if startafterquote "\\"))) 346 (format "\n#line %d \"%s\"\n" startlinenum filename))) 347 348 ;; Call the preprocessor. 349 (if display (message "%s" mymsg)) 350 (setq exit-status 351 (call-process-region 1 (point-max) 352 shell-file-name 353 t (list t tempname) nil "-c" 354 cppcommand)) 355 (if display (message "%s" (concat mymsg "done"))) 356 (if (= (buffer-size) 0) 357 ;; Empty output is normal after a fatal error. 358 (insert "\nPreprocessor produced no output\n") 359 ;; Find and delete the mark of the start of the expansion. 360 ;; Look for `# nn "file.c"' lines and delete them. 361 (goto-char (point-min)) 362 (search-forward startmarker) 363 (delete-region 1 (point))) 364 (while (re-search-forward (concat "^# [0-9]+ \"" 365 (regexp-quote filename) 366 "\"") nil t) 367 (beginning-of-line) 368 (let ((beg (point))) 369 (forward-line 1) 370 (delete-region beg (point)))) 371 372 ;; If CPP got errors, show them at the beginning. 373 ;; MS-DOS shells don't return the exit code of their children. 374 ;; Look at the size of the error message file instead, but 375 ;; don't punish those MS-DOS users who have a shell that does 376 ;; return an error code. 377 (or (and (or (not (boundp 'msdos-shells)) 378 (not (member (file-name-nondirectory shell-file-name) 379 msdos-shells))) 380 (eq exit-status 0)) 381 (zerop (nth 7 (file-attributes (expand-file-name tempname)))) 382 (progn 383 (goto-char (point-min)) 384 ;; Put the messages inside a comment, so they won't get in 385 ;; the way of font-lock, highlighting etc. 386 (insert 387 (format "/* Preprocessor terminated with status %s\n\n Messages from `%s\':\n\n" 388 exit-status cppcommand)) 389 (goto-char (+ (point) 390 (nth 1 (insert-file-contents tempname)))) 391 (insert "\n\n*/\n"))) 392 (delete-file tempname) 393 394 ;; Compute the return value, keeping in account the space 395 ;; inserted at the end of the buffer. 396 (buffer-substring 1 (max 1 (- (point-max) 1)))) 397 398 ;; Cleanup. 399 (kill-buffer outbuf)))) 400 401;;; arch-tag: 4f20253c-71ef-4e6d-a774-19087060910e 402;;; cmacexp.el ends here 403