Mercurial > hg > xemacs-beta

comparison src/strcpy.c @ 428:3ecd8885ac67 r21-2-22

Find changesets by keywords (author, files, the commit message), revision number or hash, or revset expression.
Import from CVS: tag r21-2-22
author cvs
date Mon, 13 Aug 2007 11:28:15 +0200
parents
children abe6d1db359e
comparison
equal deleted inserted replaced
427:0a0253eac470 428:3ecd8885ac67
1 /* This file is part of XEmacs.
2
3 XEmacs is free software; you can redistribute it and/or modify it
4 under the terms of the GNU General Public License as published by the
5 Free Software Foundation; either version 2, or (at your option) any
6 later version.
7
8 XEmacs is distributed in the hope that it will be useful, but WITHOUT
9 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or
10 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License
11 for more details.
12
13 You should have received a copy of the GNU General Public License
14 along with XEmacs; see the file COPYING. If not, write to
15 the Free Software Foundation, Inc., 59 Temple Place - Suite 330,
16 Boston, MA 02111-1307, USA. */
17
18 /* Synched up with: Not in FSF. */
19
20 /* In SunOS 4.1.1 the strcpy function references memory past the last byte of
21 the string! This will core dump if the memory following the last byte is
22 not mapped.
23
24 Here are correct versions by hbs@lucid.com.
25 */
26
27 # include <config.h>
28 # ifndef REGISTER /* Strictly enforced in 20.3 */
29 # define REGISTER
30 # endif
31
32 #define ALIGNED(x) (!(((unsigned long) (x)) & (sizeof (unsigned long) - 1)))
33
34 #define MAGIC 0x7efefeff
35 #define HIGH_BIT_P(c) ((c) & hi_bit)
36 #define HAS_ZERO(c) (((((c) + magic) ^ (c)) & not_magic) != not_magic)
37
38 /* CONST IS LOSING, but const is part of the interface of strcpy */
39 char *
40 strcpy (char *to, const char *from)
41 {
42 char *return_value = to;
43 if (to == from)
44 return to;
45 else if (ALIGNED (to) && ALIGNED (from))
46 {
47 unsigned long *to1 = (unsigned long *) to;
48 const unsigned long *from1 = (const unsigned long *) from;
49 unsigned long c;
50 unsigned long magic = MAGIC;
51 unsigned long not_magic = ~magic;
52 /* unsigned long hi_bit = 0x80000000; */
53
54 while ((c = *from1) != 0)
55 {
56 if (HAS_ZERO(c))
57 {
58 to = (char *) to1;
59 from = (CONST char *) from1;
60 goto slow_loop;
61 }
62 else
63 {
64 *to1 = c;
65 to1++;
66 from1++;
67 }
68 }
69
70 to = (char *) to1;
71 *to = (char) 0;
72 return return_value;
73 }
74 else
75 {
76 char c;
77
78 slow_loop:
79
80 while ((c = *from) != 0)
81 {
82 *to = c;
83 to++;
84 from++;
85 }
86 *to = (char) 0;
87 }
88 return return_value;
89 }