src/puresize.h

   1 /* How much read-only Lisp storage a dumped Emacs needs.
   2    Copyright (C) 1993, 2001-2018 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 (at
   9 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 <https://www.gnu.org/licenses/>.  */
  18
  19 #ifndef EMACS_PURESIZE_H
  20 #define EMACS_PURESIZE_H
  21
  22 #include "lisp.h"
  23
  24 INLINE_HEADER_BEGIN
  25
  26 /* Define PURESIZE, the number of bytes of pure Lisp code to leave space for.
  27
  28    At one point, this was defined in config.h, meaning that changing
  29    PURESIZE would make Make recompile all of Emacs.  But only a few
  30    files actually use PURESIZE, so we split it out to its own .h file.
  31
  32    Make sure to include this file after config.h, since that tells us
  33    whether we are running X windows, which tells us how much pure
  34    storage to allocate.  */
  35
  36 /* First define a measure of the amount of data we have.  */
  37
  38 /* A system configuration file may set this to request a certain extra
  39    amount of storage.  This is a lot more update-robust that defining
  40    BASE_PURESIZE or even PURESIZE directly.  */
  41 #ifndef SYSTEM_PURESIZE_EXTRA
  42 #define SYSTEM_PURESIZE_EXTRA 0
  43 #endif
  44
  45 #ifndef SITELOAD_PURESIZE_EXTRA
  46 #define SITELOAD_PURESIZE_EXTRA 0
  47 #endif
  48
  49 #ifndef BASE_PURESIZE
  50 #define BASE_PURESIZE (1900000 + SYSTEM_PURESIZE_EXTRA + SITELOAD_PURESIZE_EXTRA)
  51 #endif
  52
  53 /* Increase BASE_PURESIZE by a ratio depending on the machine's word size.  */
  54 #ifndef PURESIZE_RATIO
  55 #if EMACS_INT_MAX >> 31 != 0
  56 #if PTRDIFF_MAX >> 31 != 0
  57 #define PURESIZE_RATIO 10 / 6   /* Don't surround with `()'.  */
  58 #else
  59 #define PURESIZE_RATIO 8 / 6    /* Don't surround with `()'.  */
  60 #endif
  61 #else
  62 #define PURESIZE_RATIO 1
  63 #endif
  64 #endif
  65
  66 #ifdef ENABLE_CHECKING
  67 /* ENABLE_CHECKING somehow increases the purespace used, probably because
  68    it tends to cause some macro arguments to be evaluated twice.  This is
  69    a bug, but it's difficult to track it down.  */
  70 #define PURESIZE_CHECKING_RATIO 12 / 10 /* Don't surround with `()'.  */
  71 #else
  72 #define PURESIZE_CHECKING_RATIO 1
  73 #endif
  74
  75 /* This is the actual size in bytes to allocate.  */
  76 #ifndef PURESIZE
  77 #define PURESIZE  (BASE_PURESIZE * PURESIZE_RATIO * PURESIZE_CHECKING_RATIO)
  78 #endif
  79
  80 extern _Noreturn void pure_write_error (Lisp_Object);
  81
  82 extern EMACS_INT pure[];
  83
  84 /* The puresize_h_* macros are private to this include file.  */
  85
  86 /* True if PTR is pure.  */
  87
  88 #define puresize_h_PURE_P(ptr) \
  89   ((uintptr_t) (ptr) - (uintptr_t) pure <= PURESIZE)
  90
  91 INLINE bool
  92 PURE_P (void *ptr)
  93 {
  94   return puresize_h_PURE_P (ptr);
  95 }
  96
  97 /* Signal an error if OBJ is pure.  PTR is OBJ untagged.  */
  98
  99 #define puresize_h_CHECK_IMPURE(obj, ptr) \
 100   (PURE_P (ptr) ? pure_write_error (obj) : (void) 0)
 101
 102 INLINE void
 103 CHECK_IMPURE (Lisp_Object obj, void *ptr)
 104 {
 105   puresize_h_CHECK_IMPURE (obj, ptr);
 106 }
 107
 108 #if DEFINE_KEY_OPS_AS_MACROS
 109 # define PURE_P(ptr) puresize_h_PURE_P (ptr)
 110 # define CHECK_IMPURE(obj, ptr) puresize_h_CHECK_IMPURE (obj, ptr)
 111 #endif
 112
 113 INLINE_HEADER_END
 114
 115 #endif /* EMACS_PURESIZE_H */