xref: /freebsd/contrib/libarchive/libarchive/archive_endian.h (revision b9128a37faafede823eb456aa65a11ac69997284)
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  * Borrowed from FreeBSD's <sys/endian.h>
27  */
28 
29 #ifndef ARCHIVE_ENDIAN_H_INCLUDED
30 #define ARCHIVE_ENDIAN_H_INCLUDED
31 
32 /* Note:  This is a purely internal header! */
33 /* Do not use this outside of libarchive internal code! */
34 
35 #ifndef __LIBARCHIVE_BUILD
36 #error This header is only to be used internally to libarchive.
37 #endif
38 
39 /*
40  * Disabling inline keyword for compilers known to choke on it:
41  * - Watcom C++ in C code.  (For any version?)
42  * - SGI MIPSpro
43  * - Microsoft Visual C++ 6.0 (supposedly newer versions too)
44  * - IBM VisualAge 6 (XL v6)
45  * - Sun WorkShop C (SunPro) before 5.9
46  */
47 #if defined(__WATCOMC__) || defined(__sgi) || defined(__hpux) || defined(__BORLANDC__)
48 #define	inline
49 #elif defined(__IBMC__) && __IBMC__ < 700
50 #define	inline
51 #elif defined(__SUNPRO_C) && __SUNPRO_C < 0x590
52 #define inline
53 #elif defined(_MSC_VER) || defined(__osf__)
54 #define inline __inline
55 #endif
56 
57 /* Alignment-agnostic encode/decode bytestream to/from little/big endian. */
58 
59 static inline uint16_t
60 archive_be16dec(const void *pp)
61 {
62 	unsigned char const *p = (unsigned char const *)pp;
63 
64 	/* Store into unsigned temporaries before left shifting, to avoid
65 	promotion to signed int and then left shifting into the sign bit,
66 	which is undefined behaviour. */
67 	unsigned int p1 = p[1];
68 	unsigned int p0 = p[0];
69 
70 	return ((p0 << 8) | p1);
71 }
72 
73 static inline uint32_t
74 archive_be32dec(const void *pp)
75 {
76 	unsigned char const *p = (unsigned char const *)pp;
77 
78 	/* Store into unsigned temporaries before left shifting, to avoid
79 	promotion to signed int and then left shifting into the sign bit,
80 	which is undefined behaviour. */
81 	unsigned int p3 = p[3];
82 	unsigned int p2 = p[2];
83 	unsigned int p1 = p[1];
84 	unsigned int p0 = p[0];
85 
86 	return ((p0 << 24) | (p1 << 16) | (p2 << 8) | p3);
87 }
88 
89 static inline uint64_t
90 archive_be64dec(const void *pp)
91 {
92 	unsigned char const *p = (unsigned char const *)pp;
93 
94 	return (((uint64_t)archive_be32dec(p) << 32) | archive_be32dec(p + 4));
95 }
96 
97 static inline uint16_t
98 archive_le16dec(const void *pp)
99 {
100 	unsigned char const *p = (unsigned char const *)pp;
101 
102 	/* Store into unsigned temporaries before left shifting, to avoid
103 	promotion to signed int and then left shifting into the sign bit,
104 	which is undefined behaviour. */
105 	unsigned int p1 = p[1];
106 	unsigned int p0 = p[0];
107 
108 	return ((p1 << 8) | p0);
109 }
110 
111 static inline uint32_t
112 archive_le32dec(const void *pp)
113 {
114 	unsigned char const *p = (unsigned char const *)pp;
115 
116 	/* Store into unsigned temporaries before left shifting, to avoid
117 	promotion to signed int and then left shifting into the sign bit,
118 	which is undefined behaviour. */
119 	unsigned int p3 = p[3];
120 	unsigned int p2 = p[2];
121 	unsigned int p1 = p[1];
122 	unsigned int p0 = p[0];
123 
124 	return ((p3 << 24) | (p2 << 16) | (p1 << 8) | p0);
125 }
126 
127 static inline uint64_t
128 archive_le64dec(const void *pp)
129 {
130 	unsigned char const *p = (unsigned char const *)pp;
131 
132 	return (((uint64_t)archive_le32dec(p + 4) << 32) | archive_le32dec(p));
133 }
134 
135 static inline void
136 archive_be16enc(void *pp, uint16_t u)
137 {
138 	unsigned char *p = (unsigned char *)pp;
139 
140 	p[0] = (u >> 8) & 0xff;
141 	p[1] = u & 0xff;
142 }
143 
144 static inline void
145 archive_be32enc(void *pp, uint32_t u)
146 {
147 	unsigned char *p = (unsigned char *)pp;
148 
149 	p[0] = (u >> 24) & 0xff;
150 	p[1] = (u >> 16) & 0xff;
151 	p[2] = (u >> 8) & 0xff;
152 	p[3] = u & 0xff;
153 }
154 
155 static inline void
156 archive_be64enc(void *pp, uint64_t u)
157 {
158 	unsigned char *p = (unsigned char *)pp;
159 
160 	archive_be32enc(p, (uint32_t)(u >> 32));
161 	archive_be32enc(p + 4, (uint32_t)(u & 0xffffffff));
162 }
163 
164 static inline void
165 archive_le16enc(void *pp, uint16_t u)
166 {
167 	unsigned char *p = (unsigned char *)pp;
168 
169 	p[0] = u & 0xff;
170 	p[1] = (u >> 8) & 0xff;
171 }
172 
173 static inline void
174 archive_le32enc(void *pp, uint32_t u)
175 {
176 	unsigned char *p = (unsigned char *)pp;
177 
178 	p[0] = u & 0xff;
179 	p[1] = (u >> 8) & 0xff;
180 	p[2] = (u >> 16) & 0xff;
181 	p[3] = (u >> 24) & 0xff;
182 }
183 
184 static inline void
185 archive_le64enc(void *pp, uint64_t u)
186 {
187 	unsigned char *p = (unsigned char *)pp;
188 
189 	archive_le32enc(p, (uint32_t)(u & 0xffffffff));
190 	archive_le32enc(p + 4, (uint32_t)(u >> 32));
191 }
192 
193 #endif
194