src/lastfile.c

   1 /* Mark end of data space to dump as pure, for GNU Emacs.
   2    Copyright (C) 1985, 2001-2015 Free Software Foundation, Inc.
   3
   4 This file is part of GNU Emacs.
   5
   6 GNU Emacs is free software: you can redistribute it and/or modify
   7 it under the terms of the GNU General Public License as published by
   8 the Free Software Foundation, either version 3 of the License, or
   9 (at your option) any later version.
  10
  11 GNU Emacs is distributed in the hope that it will be useful,
  12 but WITHOUT ANY WARRANTY; without even the implied warranty of
  13 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  14 GNU General Public License for more details.
  15
  16 You should have received a copy of the GNU General Public License
  17 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  18
  19
  20 /* How this works:
  21
  22  Fdump_emacs dumps everything up to my_edata as text space (pure).
  23
  24  The files of Emacs are written so as to have no initialized
  25  data that can ever need to be altered except at the first startup.
  26  This is so that those words can be dumped as shareable text.
  27
  28  It is not possible to exercise such control over library files.
  29  So it is necessary to refrain from making their data areas shared.
  30  Therefore, this file is loaded following all the files of Emacs
  31  but before library files.
  32  As a result, the symbol my_edata indicates the point
  33  in data space between data coming from Emacs and data
  34  coming from libraries.
  35 */
  36
  37 #include <config.h>
  38
  39 #include "lisp.h"
  40
  41 char my_edata[] = "End of Emacs initialized data";
  42
  43 /* Help unexec locate the end of the .bss area used by Emacs (which
  44    isn't always a separate section in NT executables).  */
  45 char my_endbss[1];
  46
  47 /* The Alpha MSVC linker globally segregates all static and public bss
  48    data, so we must take both into account to determine the true extent
  49    of the bss area used by Emacs.  */
  50 static char _my_endbss[1];
  51 char * my_endbss_static = _my_endbss;