pa_endianness.h (5465B)
1 #ifndef PA_ENDIANNESS_H 2 #define PA_ENDIANNESS_H 3 /* 4 * $Id$ 5 * Portable Audio I/O Library current platform endianness macros 6 * 7 * Based on the Open Source API proposed by Ross Bencina 8 * Copyright (c) 1999-2002 Phil Burk, Ross Bencina 9 * 10 * Permission is hereby granted, free of charge, to any person obtaining 11 * a copy of this software and associated documentation files 12 * (the "Software"), to deal in the Software without restriction, 13 * including without limitation the rights to use, copy, modify, merge, 14 * publish, distribute, sublicense, and/or sell copies of the Software, 15 * and to permit persons to whom the Software is furnished to do so, 16 * subject to the following conditions: 17 * 18 * The above copyright notice and this permission notice shall be 19 * included in all copies or substantial portions of the Software. 20 * 21 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, 22 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF 23 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. 24 * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR 25 * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF 26 * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION 27 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE. 28 */ 29 30 /* 31 * The text above constitutes the entire PortAudio license; however, 32 * the PortAudio community also makes the following non-binding requests: 33 * 34 * Any person wishing to distribute modifications to the Software is 35 * requested to send the modifications to the original developer so that 36 * they can be incorporated into the canonical version. It is also 37 * requested that these non-binding requests be included along with the 38 * license above. 39 */ 40 41 /** @file 42 @ingroup common_src 43 44 @brief Configure endianness symbols for the target processor. 45 46 Arrange for either the PA_LITTLE_ENDIAN or PA_BIG_ENDIAN preprocessor symbols 47 to be defined. The one that is defined reflects the endianness of the target 48 platform and may be used to implement conditional compilation of byte-order 49 dependent code. 50 51 If either PA_LITTLE_ENDIAN or PA_BIG_ENDIAN is defined already, then no attempt 52 is made to override that setting. This may be useful if you have a better way 53 of determining the platform's endianness. The autoconf mechanism uses this for 54 example. 55 56 A PA_VALIDATE_ENDIANNESS macro is provided to compare the compile time 57 and runtime endiannes and raise an assertion if they don't match. 58 */ 59 60 61 #ifdef __cplusplus 62 extern "C" 63 { 64 #endif /* __cplusplus */ 65 66 /* If this is an apple, we need to do detect endianness this way */ 67 #if defined(__APPLE__) 68 /* we need to do some endian detection that is sensitive to harware arch */ 69 #if defined(__LITTLE_ENDIAN__) 70 #if !defined( PA_LITTLE_ENDIAN ) 71 #define PA_LITTLE_ENDIAN 72 #endif 73 #if defined( PA_BIG_ENDIAN ) 74 #undef PA_BIG_ENDIAN 75 #endif 76 #else 77 #if !defined( PA_BIG_ENDIAN ) 78 #define PA_BIG_ENDIAN 79 #endif 80 #if defined( PA_LITTLE_ENDIAN ) 81 #undef PA_LITTLE_ENDIAN 82 #endif 83 #endif 84 #else 85 /* this is not an apple, so first check the existing defines, and, failing that, 86 detect well-known architechtures. */ 87 88 #if defined(PA_LITTLE_ENDIAN) || defined(PA_BIG_ENDIAN) 89 /* endianness define has been set externally, such as by autoconf */ 90 91 #if defined(PA_LITTLE_ENDIAN) && defined(PA_BIG_ENDIAN) 92 #error both PA_LITTLE_ENDIAN and PA_BIG_ENDIAN have been defined externally to pa_endianness.h - only one endianness at a time please 93 #endif 94 95 #else 96 /* endianness define has not been set externally */ 97 98 /* set PA_LITTLE_ENDIAN or PA_BIG_ENDIAN by testing well known platform specific defines */ 99 100 #if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || defined(LITTLE_ENDIAN) || defined(__i386) || defined(_M_IX86) || defined(__x86_64__) 101 #define PA_LITTLE_ENDIAN /* win32, assume intel byte order */ 102 #else 103 #define PA_BIG_ENDIAN 104 #endif 105 #endif 106 107 #if !defined(PA_LITTLE_ENDIAN) && !defined(PA_BIG_ENDIAN) 108 /* 109 If the following error is raised, you either need to modify the code above 110 to automatically determine the endianness from other symbols defined on your 111 platform, or define either PA_LITTLE_ENDIAN or PA_BIG_ENDIAN externally. 112 */ 113 #error pa_endianness.h was unable to automatically determine the endianness of the target platform 114 #endif 115 116 #endif 117 118 119 /* PA_VALIDATE_ENDIANNESS compares the compile time and runtime endianness, 120 and raises an assertion if they don't match. <assert.h> must be included in 121 the context in which this macro is used. 122 */ 123 #if defined(NDEBUG) 124 #define PA_VALIDATE_ENDIANNESS 125 #else 126 #if defined(PA_LITTLE_ENDIAN) 127 #define PA_VALIDATE_ENDIANNESS \ 128 { \ 129 const long nativeOne = 1; \ 130 assert( "PortAudio: compile time and runtime endianness don't match" && (((char *)&nativeOne)[0]) == 1 ); \ 131 } 132 #elif defined(PA_BIG_ENDIAN) 133 #define PA_VALIDATE_ENDIANNESS \ 134 { \ 135 const long nativeOne = 1; \ 136 assert( "PortAudio: compile time and runtime endianness don't match" && (((char *)&nativeOne)[0]) == 0 ); \ 137 } 138 #endif 139 #endif 140 141 142 #ifdef __cplusplus 143 } 144 #endif /* __cplusplus */ 145 #endif /* PA_ENDIANNESS_H */