xref: /freebsd/contrib/libarchive/libarchive/archive_endian.h (revision 389e4940069316fe667ffa263fa7d6390d0a960f)
1 /*-
2  * Copyright (c) 2002 Thomas Moestl <tmm@FreeBSD.org>
3  * All rights reserved.
4  *
5  * Redistribution and use in source and binary forms, with or without
6  * modification, are permitted provided that the following conditions
7  * are met:
8  * 1. Redistributions of source code must retain the above copyright
9  *    notice, this list of conditions and the following disclaimer.
10  * 2. Redistributions in binary form must reproduce the above copyright
11  *    notice, this list of conditions and the following disclaimer in the
12  *    documentation and/or other materials provided with the distribution.
13  *
14  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
15  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
16  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
17  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
18  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
19  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
20  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
21  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
22  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
23  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
24  * SUCH DAMAGE.
25  *
26  * $FreeBSD$
27  *
28  * Borrowed from FreeBSD's <sys/endian.h>
29  */
30 
31 #ifndef __LIBARCHIVE_BUILD
32 #error This header is only to be used internally to libarchive.
33 #endif
34 
35 /* Note:  This is a purely internal header! */
36 /* Do not use this outside of libarchive internal code! */
37 
38 #ifndef ARCHIVE_ENDIAN_H_INCLUDED
39 #define ARCHIVE_ENDIAN_H_INCLUDED
40 
41 
42 /*
43  * Disabling inline keyword for compilers known to choke on it:
44  * - Watcom C++ in C code.  (For any version?)
45  * - SGI MIPSpro
46  * - Microsoft Visual C++ 6.0 (supposedly newer versions too)
47  * - IBM VisualAge 6 (XL v6)
48  * - Sun WorkShop C (SunPro) before 5.9
49  */
50 #if defined(__WATCOMC__) || defined(__sgi) || defined(__hpux) || defined(__BORLANDC__)
51 #define	inline
52 #elif defined(__IBMC__) && __IBMC__ < 700
53 #define	inline
54 #elif defined(__SUNPRO_C) && __SUNPRO_C < 0x590
55 #define inline
56 #elif defined(_MSC_VER) || defined(__osf__)
57 #define inline __inline
58 #endif
59 
60 /* Alignment-agnostic encode/decode bytestream to/from little/big endian. */
61 
62 static inline uint16_t
63 archive_be16dec(const void *pp)
64 {
65 	unsigned char const *p = (unsigned char const *)pp;
66 
67 	/* Store into unsigned temporaries before left shifting, to avoid
68 	promotion to signed int and then left shifting into the sign bit,
69 	which is undefined behaviour. */
70 	unsigned int p1 = p[1];
71 	unsigned int p0 = p[0];
72 
73 	return ((p0 << 8) | p1);
74 }
75 
76 static inline uint32_t
77 archive_be32dec(const void *pp)
78 {
79 	unsigned char const *p = (unsigned char const *)pp;
80 
81 	/* Store into unsigned temporaries before left shifting, to avoid
82 	promotion to signed int and then left shifting into the sign bit,
83 	which is undefined behaviour. */
84 	unsigned int p3 = p[3];
85 	unsigned int p2 = p[2];
86 	unsigned int p1 = p[1];
87 	unsigned int p0 = p[0];
88 
89 	return ((p0 << 24) | (p1 << 16) | (p2 << 8) | p3);
90 }
91 
92 static inline uint64_t
93 archive_be64dec(const void *pp)
94 {
95 	unsigned char const *p = (unsigned char const *)pp;
96 
97 	return (((uint64_t)archive_be32dec(p) << 32) | archive_be32dec(p + 4));
98 }
99 
100 static inline uint16_t
101 archive_le16dec(const void *pp)
102 {
103 	unsigned char const *p = (unsigned char const *)pp;
104 
105 	/* Store into unsigned temporaries before left shifting, to avoid
106 	promotion to signed int and then left shifting into the sign bit,
107 	which is undefined behaviour. */
108 	unsigned int p1 = p[1];
109 	unsigned int p0 = p[0];
110 
111 	return ((p1 << 8) | p0);
112 }
113 
114 static inline uint32_t
115 archive_le32dec(const void *pp)
116 {
117 	unsigned char const *p = (unsigned char const *)pp;
118 
119 	/* Store into unsigned temporaries before left shifting, to avoid
120 	promotion to signed int and then left shifting into the sign bit,
121 	which is undefined behaviour. */
122 	unsigned int p3 = p[3];
123 	unsigned int p2 = p[2];
124 	unsigned int p1 = p[1];
125 	unsigned int p0 = p[0];
126 
127 	return ((p3 << 24) | (p2 << 16) | (p1 << 8) | p0);
128 }
129 
130 static inline uint64_t
131 archive_le64dec(const void *pp)
132 {
133 	unsigned char const *p = (unsigned char const *)pp;
134 
135 	return (((uint64_t)archive_le32dec(p + 4) << 32) | archive_le32dec(p));
136 }
137 
138 static inline void
139 archive_be16enc(void *pp, uint16_t u)
140 {
141 	unsigned char *p = (unsigned char *)pp;
142 
143 	p[0] = (u >> 8) & 0xff;
144 	p[1] = u & 0xff;
145 }
146 
147 static inline void
148 archive_be32enc(void *pp, uint32_t u)
149 {
150 	unsigned char *p = (unsigned char *)pp;
151 
152 	p[0] = (u >> 24) & 0xff;
153 	p[1] = (u >> 16) & 0xff;
154 	p[2] = (u >> 8) & 0xff;
155 	p[3] = u & 0xff;
156 }
157 
158 static inline void
159 archive_be64enc(void *pp, uint64_t u)
160 {
161 	unsigned char *p = (unsigned char *)pp;
162 
163 	archive_be32enc(p, (uint32_t)(u >> 32));
164 	archive_be32enc(p + 4, (uint32_t)(u & 0xffffffff));
165 }
166 
167 static inline void
168 archive_le16enc(void *pp, uint16_t u)
169 {
170 	unsigned char *p = (unsigned char *)pp;
171 
172 	p[0] = u & 0xff;
173 	p[1] = (u >> 8) & 0xff;
174 }
175 
176 static inline void
177 archive_le32enc(void *pp, uint32_t u)
178 {
179 	unsigned char *p = (unsigned char *)pp;
180 
181 	p[0] = u & 0xff;
182 	p[1] = (u >> 8) & 0xff;
183 	p[2] = (u >> 16) & 0xff;
184 	p[3] = (u >> 24) & 0xff;
185 }
186 
187 static inline void
188 archive_le64enc(void *pp, uint64_t u)
189 {
190 	unsigned char *p = (unsigned char *)pp;
191 
192 	archive_le32enc(p, (uint32_t)(u & 0xffffffff));
193 	archive_le32enc(p + 4, (uint32_t)(u >> 32));
194 }
195 
196 #endif
197