Explain vc-BACKEND-root in Commentary; nfc.
[emacs.git] / src / puresize.h
blob26435f39a778c3ac324024ed3aa02478f90acf63
1 /* How much read-only Lisp storage a dumped Emacs needs.
2 Copyright (C) 1993, 2001, 2002, 2003, 2004, 2005,
3 2006, 2007, 2008 Free Software Foundation, Inc.
5 This file is part of GNU Emacs.
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, or (at your option)
10 any later version.
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.
17 You should have received a copy of the GNU General Public License
18 along with GNU Emacs; see the file COPYING. If not, write to
19 the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
20 Boston, MA 02110-1301, USA. */
22 /* Define PURESIZE, the number of bytes of pure Lisp code to leave space for.
24 At one point, this was defined in config.h, meaning that changing
25 PURESIZE would make Make recompile all of Emacs. But only a few
26 files actually use PURESIZE, so we split it out to its own .h file.
28 Make sure to include this file after config.h, since that tells us
29 whether we are running X windows, which tells us how much pure
30 storage to allocate. */
32 /* First define a measure of the amount of data we have. */
34 /* A system configuration file may set this to request a certain extra
35 amount of storage. This is a lot more update-robust that defining
36 BASE_PURESIZE or even PURESIZE directly. */
37 #ifndef SYSTEM_PURESIZE_EXTRA
38 #define SYSTEM_PURESIZE_EXTRA 0
39 #endif
41 #ifndef SITELOAD_PURESIZE_EXTRA
42 #define SITELOAD_PURESIZE_EXTRA 0
43 #endif
45 #ifndef BASE_PURESIZE
46 #define BASE_PURESIZE (1190000 + SYSTEM_PURESIZE_EXTRA + SITELOAD_PURESIZE_EXTRA)
47 #endif
49 /* Increase BASE_PURESIZE by a ratio depending on the machine's word size. */
50 #ifndef PURESIZE_RATIO
51 #if BITS_PER_EMACS_INT > 32
52 #define PURESIZE_RATIO 10/6 /* Don't surround with `()'. */
53 #else
54 #define PURESIZE_RATIO 1
55 #endif
56 #endif
58 /* This is the actual size in bytes to allocate. */
59 #ifndef PURESIZE
60 #define PURESIZE (BASE_PURESIZE * PURESIZE_RATIO)
61 #endif
63 /* Signal an error if OBJ is pure. */
64 #define CHECK_IMPURE(obj) \
65 { if (PURE_P (obj)) \
66 pure_write_error (); }
68 extern void pure_write_error P_ ((void)) NO_RETURN;
70 /* Define PURE_P. */
72 #ifdef VIRT_ADDR_VARIES
73 /* For machines where text and data can go anywhere
74 in virtual memory. */
76 extern EMACS_INT pure[];
78 #define PURE_P(obj) \
79 ((PNTR_COMPARISON_TYPE) XPNTR (obj) < (PNTR_COMPARISON_TYPE) ((char *) pure + PURESIZE) \
80 && (PNTR_COMPARISON_TYPE) XPNTR (obj) >= (PNTR_COMPARISON_TYPE) pure)
82 #else /* not VIRT_ADDR_VARIES */
83 #ifdef PNTR_COMPARISON_TYPE
84 /* When PNTR_COMPARISON_TYPE is not the default (unsigned int). */
86 extern char my_edata[];
88 #define PURE_P(obj) \
89 ((PNTR_COMPARISON_TYPE) XPNTR (obj) < (PNTR_COMPARISON_TYPE) my_edata)
91 #else /* not VIRT_ADDRESS_VARIES, not PNTR_COMPARISON_TYPE */
93 extern char my_edata[];
95 #define PURE_P(obj) \
96 (XPNTR (obj) < (unsigned int) my_edata)
98 #endif /* PNTR_COMPARISON_TYPE */
99 #endif /* VIRT_ADDRESS_VARIES */
101 /* arch-tag: fd9b0a91-a70e-4729-a75a-6bb4ca1ce14f
102 (do not change this comment) */