1 // SPDX-License-Identifier: BSD-3-Clause
2 /*
3  * Copyright (c) 1994-2009  Red Hat, Inc.
4  * All rights reserved.
5  *
6  * Redistribution and use in source and binary forms, with or without
7  * modification, are permitted provided that the following conditions are met:
8  *
9  * 1. Redistributions of source code must retain the above copyright notice,
10  * this list of conditions and the following disclaimer.
11  *
12  * 2. Redistributions in binary form must reproduce the above copyright notice,
13  * this list of conditions and the following disclaimer in the documentation
14  * and/or other materials provided with the distribution.
15  *
16  * 3. Neither the name of the copyright holder nor the names of its
17  * contributors may be used to endorse or promote products derived from this
18  * software without specific prior written permission.
19  *
20  * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS"
21  * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
22  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
23  * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT HOLDER OR CONTRIBUTORS BE
24  * LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
25  * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
26  * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
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28  * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
29  * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
30  * POSSIBILITY OF SUCH DAMAGE.
31  */
32 
33 /*
34 FUNCTION
35 	<<strcpy>>---copy string
36 
37 INDEX
38 	strcpy
39 
40 ANSI_SYNOPSIS
41 	#include <string.h>
42 	char *strcpy(char *<[dst]>, const char *<[src]>);
43 
44 TRAD_SYNOPSIS
45 	#include <string.h>
46 	char *strcpy(<[dst]>, <[src]>)
47 	char *<[dst]>;
48 	char *<[src]>;
49 
50 DESCRIPTION
51 	<<strcpy>> copies the string pointed to by <[src]>
52 	(including the terminating null character) to the array
53 	pointed to by <[dst]>.
54 
55 RETURNS
56 	This function returns the initial value of <[dst]>.
57 
58 PORTABILITY
59 <<strcpy>> is ANSI C.
60 
61 <<strcpy>> requires no supporting OS subroutines.
62 
63 QUICKREF
64 	strcpy ansi pure
65 */
66 
67 #include "_ansi.h"
68 #include <string.h>
69 #include <limits.h>
70 
71 /*SUPPRESS 560*/
72 /*SUPPRESS 530*/
73 
74 /* Nonzero if either X or Y is not aligned on a "long" boundary.  */
75 #define UNALIGNED(X, Y) \
76   (((long)X & (sizeof (long) - 1)) | ((long)Y & (sizeof (long) - 1)))
77 
78 #if LONG_MAX == 2147483647L
79 #define DETECTNULL(X) (((X) - 0x01010101) & ~(X) & 0x80808080)
80 #else
81 #if LONG_MAX == 9223372036854775807L
82 /* Nonzero if X (a long int) contains a NULL byte. */
83 #define DETECTNULL(X) (((X) - 0x0101010101010101) & ~(X) & 0x8080808080808080)
84 #else
85 #error long int is not a 32bit or 64bit type.
86 #endif
87 #endif
88 
89 #ifndef DETECTNULL
90 #error long int is not a 32bit or 64bit byte
91 #endif
92 
93 char*
94 _DEFUN (strcpy, (dst0, src0),
95 	char *dst0 _AND
96 	_CONST char *src0)
97 {
98 #if defined(PREFER_SIZE_OVER_SPEED) || defined(__OPTIMIZE_SIZE__)
99   char *s = dst0;
100 
101   while (*dst0++ = *src0++)
102     ;
103 
104   return s;
105 #else
106   char *dst = dst0;
107   _CONST char *src = src0;
108   long *aligned_dst;
109   _CONST long *aligned_src;
110 
111   /* If SRC or DEST is unaligned, then copy bytes.  */
112   if (!UNALIGNED (src, dst))
113     {
114       aligned_dst = (long*)dst;
115       aligned_src = (long*)src;
116 
117       /* SRC and DEST are both "long int" aligned, try to do "long int"
118          sized copies.  */
119       while (!DETECTNULL(*aligned_src))
120         {
121           *aligned_dst++ = *aligned_src++;
122         }
123 
124       dst = (char*)aligned_dst;
125       src = (char*)aligned_src;
126     }
127 
128   while ((*dst++ = *src++))
129     ;
130   return dst0;
131 #endif /* not PREFER_SIZE_OVER_SPEED */
132 }
133