xref: /freebsd/contrib/libarchive/libarchive/archive_endian.h (revision e0c4386e7e71d93b0edc0c8fa156263fc4a8b0b6)
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 ARCHIVE_ENDIAN_H_INCLUDED
32 #define ARCHIVE_ENDIAN_H_INCLUDED
33 
34 /* Note:  This is a purely internal header! */
35 /* Do not use this outside of libarchive internal code! */
36 
37 #ifndef __LIBARCHIVE_BUILD
38 #error This header is only to be used internally to libarchive.
39 #endif
40 
41 /*
42  * Disabling inline keyword for compilers known to choke on it:
43  * - Watcom C++ in C code.  (For any version?)
44  * - SGI MIPSpro
45  * - Microsoft Visual C++ 6.0 (supposedly newer versions too)
46  * - IBM VisualAge 6 (XL v6)
47  * - Sun WorkShop C (SunPro) before 5.9
48  */
49 #if defined(__WATCOMC__) || defined(__sgi) || defined(__hpux) || defined(__BORLANDC__)
50 #define	inline
51 #elif defined(__IBMC__) && __IBMC__ < 700
52 #define	inline
53 #elif defined(__SUNPRO_C) && __SUNPRO_C < 0x590
54 #define inline
55 #elif defined(_MSC_VER) || defined(__osf__)
56 #define inline __inline
57 #endif
58 
59 /* Alignment-agnostic encode/decode bytestream to/from little/big endian. */
60 
61 static inline uint16_t
62 archive_be16dec(const void *pp)
63 {
64 	unsigned char const *p = (unsigned char const *)pp;
65 
66 	/* Store into unsigned temporaries before left shifting, to avoid
67 	promotion to signed int and then left shifting into the sign bit,
68 	which is undefined behaviour. */
69 	unsigned int p1 = p[1];
70 	unsigned int p0 = p[0];
71 
72 	return ((p0 << 8) | p1);
73 }
74 
75 static inline uint32_t
76 archive_be32dec(const void *pp)
77 {
78 	unsigned char const *p = (unsigned char const *)pp;
79 
80 	/* Store into unsigned temporaries before left shifting, to avoid
81 	promotion to signed int and then left shifting into the sign bit,
82 	which is undefined behaviour. */
83 	unsigned int p3 = p[3];
84 	unsigned int p2 = p[2];
85 	unsigned int p1 = p[1];
86 	unsigned int p0 = p[0];
87 
88 	return ((p0 << 24) | (p1 << 16) | (p2 << 8) | p3);
89 }
90 
91 static inline uint64_t
92 archive_be64dec(const void *pp)
93 {
94 	unsigned char const *p = (unsigned char const *)pp;
95 
96 	return (((uint64_t)archive_be32dec(p) << 32) | archive_be32dec(p + 4));
97 }
98 
99 static inline uint16_t
100 archive_le16dec(const void *pp)
101 {
102 	unsigned char const *p = (unsigned char const *)pp;
103 
104 	/* Store into unsigned temporaries before left shifting, to avoid
105 	promotion to signed int and then left shifting into the sign bit,
106 	which is undefined behaviour. */
107 	unsigned int p1 = p[1];
108 	unsigned int p0 = p[0];
109 
110 	return ((p1 << 8) | p0);
111 }
112 
113 static inline uint32_t
114 archive_le32dec(const void *pp)
115 {
116 	unsigned char const *p = (unsigned char const *)pp;
117 
118 	/* Store into unsigned temporaries before left shifting, to avoid
119 	promotion to signed int and then left shifting into the sign bit,
120 	which is undefined behaviour. */
121 	unsigned int p3 = p[3];
122 	unsigned int p2 = p[2];
123 	unsigned int p1 = p[1];
124 	unsigned int p0 = p[0];
125 
126 	return ((p3 << 24) | (p2 << 16) | (p1 << 8) | p0);
127 }
128 
129 static inline uint64_t
130 archive_le64dec(const void *pp)
131 {
132 	unsigned char const *p = (unsigned char const *)pp;
133 
134 	return (((uint64_t)archive_le32dec(p + 4) << 32) | archive_le32dec(p));
135 }
136 
137 static inline void
138 archive_be16enc(void *pp, uint16_t u)
139 {
140 	unsigned char *p = (unsigned char *)pp;
141 
142 	p[0] = (u >> 8) & 0xff;
143 	p[1] = u & 0xff;
144 }
145 
146 static inline void
147 archive_be32enc(void *pp, uint32_t u)
148 {
149 	unsigned char *p = (unsigned char *)pp;
150 
151 	p[0] = (u >> 24) & 0xff;
152 	p[1] = (u >> 16) & 0xff;
153 	p[2] = (u >> 8) & 0xff;
154 	p[3] = u & 0xff;
155 }
156 
157 static inline void
158 archive_be64enc(void *pp, uint64_t u)
159 {
160 	unsigned char *p = (unsigned char *)pp;
161 
162 	archive_be32enc(p, (uint32_t)(u >> 32));
163 	archive_be32enc(p + 4, (uint32_t)(u & 0xffffffff));
164 }
165 
166 static inline void
167 archive_le16enc(void *pp, uint16_t u)
168 {
169 	unsigned char *p = (unsigned char *)pp;
170 
171 	p[0] = u & 0xff;
172 	p[1] = (u >> 8) & 0xff;
173 }
174 
175 static inline void
176 archive_le32enc(void *pp, uint32_t u)
177 {
178 	unsigned char *p = (unsigned char *)pp;
179 
180 	p[0] = u & 0xff;
181 	p[1] = (u >> 8) & 0xff;
182 	p[2] = (u >> 16) & 0xff;
183 	p[3] = (u >> 24) & 0xff;
184 }
185 
186 static inline void
187 archive_le64enc(void *pp, uint64_t u)
188 {
189 	unsigned char *p = (unsigned char *)pp;
190 
191 	archive_le32enc(p, (uint32_t)(u & 0xffffffff));
192 	archive_le32enc(p + 4, (uint32_t)(u >> 32));
193 }
194 
195 #endif
196