src/puresize.h

   1 /* How much read-only Lisp storage a dumped Emacs needs.
   2    Copyright (C) 1993, 2001, 2002, 2003, 2004, 2005,
   3                  2006, 2007, 2008, 2009, 2010, 2011  Free Software Foundation, Inc.
   4
   5 This file is part of GNU Emacs.
   6
   7 GNU Emacs is free software: you can redistribute it and/or modify
   8 it under the terms of the GNU General Public License as published by
   9 the Free Software Foundation, either version 3 of the License, or
  10 (at your option) any later version.
  11
  12 GNU Emacs is distributed in the hope that it will be useful,
  13 but WITHOUT ANY WARRANTY; without even the implied warranty of
  14 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
  15 GNU General Public License for more details.
  16
  17 You should have received a copy of the GNU General Public License
  18 along with GNU Emacs.  If not, see <http://www.gnu.org/licenses/>.  */
  19
  20 /* Define PURESIZE, the number of bytes of pure Lisp code to leave space for.
  21
  22    At one point, this was defined in config.h, meaning that changing
  23    PURESIZE would make Make recompile all of Emacs.  But only a few
  24    files actually use PURESIZE, so we split it out to its own .h file.
  25
  26    Make sure to include this file after config.h, since that tells us
  27    whether we are running X windows, which tells us how much pure
  28    storage to allocate.  */
  29
  30 /* First define a measure of the amount of data we have.  */
  31
  32 /* A system configuration file may set this to request a certain extra
  33    amount of storage.  This is a lot more update-robust that defining
  34    BASE_PURESIZE or even PURESIZE directly.  */
  35 #ifndef SYSTEM_PURESIZE_EXTRA
  36 #define SYSTEM_PURESIZE_EXTRA 0
  37 #endif
  38
  39 #ifndef SITELOAD_PURESIZE_EXTRA
  40 #define SITELOAD_PURESIZE_EXTRA 0
  41 #endif
  42
  43 #ifndef BASE_PURESIZE
  44 #define BASE_PURESIZE (1620000 + SYSTEM_PURESIZE_EXTRA + SITELOAD_PURESIZE_EXTRA)
  45 #endif
  46
  47 /* Increase BASE_PURESIZE by a ratio depending on the machine's word size.  */
  48 #ifndef PURESIZE_RATIO
  49 #if BITS_PER_EMACS_INT > 32
  50 #define PURESIZE_RATIO 10/6     /* Don't surround with `()'. */
  51 #else
  52 #define PURESIZE_RATIO 1
  53 #endif
  54 #endif
  55
  56 #ifdef ENABLE_CHECKING
  57 /* ENABLE_CHECKING somehow increases the purespace used, probably because
  58    it tends to cause some macro arguments to be evaluated twice.  This is
  59    a bug, but it's difficult to track it down.  */
  60 #define PURESIZE_CHECKING_RATIO 12/10   /* Don't surround with `()'. */
  61 #else
  62 #define PURESIZE_CHECKING_RATIO 1
  63 #endif
  64
  65 /* This is the actual size in bytes to allocate.  */
  66 #ifndef PURESIZE
  67 #define PURESIZE  (BASE_PURESIZE * PURESIZE_RATIO * PURESIZE_CHECKING_RATIO)
  68 #endif
  69
  70 /* Signal an error if OBJ is pure.  */
  71 #define CHECK_IMPURE(obj) \
  72   { if (PURE_P (obj))     \
  73       pure_write_error (); }
  74
  75 extern void pure_write_error (void) NO_RETURN;
  76 \f
  77 /* Define PURE_P.  */
  78
  79 #ifdef VIRT_ADDR_VARIES
  80 /* For machines where text and data can go anywhere
  81    in virtual memory.  */
  82
  83 extern EMACS_INT pure[];
  84
  85 #define PURE_P(obj) \
  86  ((PNTR_COMPARISON_TYPE) XPNTR (obj) < (PNTR_COMPARISON_TYPE) ((char *) pure + PURESIZE) \
  87   && (PNTR_COMPARISON_TYPE) XPNTR (obj) >= (PNTR_COMPARISON_TYPE) pure)
  88
  89 #else /* not VIRT_ADDR_VARIES */
  90 /* When PNTR_COMPARISON_TYPE is not the default (unsigned int).  */
  91
  92 extern char my_edata[];
  93
  94 #define PURE_P(obj) \
  95   ((PNTR_COMPARISON_TYPE) XPNTR (obj) < (PNTR_COMPARISON_TYPE) my_edata)
  96
  97 #endif /* VIRT_ADDRESS_VARIES */
  98