pa_endianness.h

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00001 #ifndef PA_ENDIANNESS_H
00002 #define PA_ENDIANNESS_H
00003 /*
00004  * $Id: pa_endianness.h 1216 2007-06-10 09:26:00Z aknudsen $
00005  * Portable Audio I/O Library current platform endianness macros
00006  *
00007  * Based on the Open Source API proposed by Ross Bencina
00008  * Copyright (c) 1999-2002 Phil Burk, Ross Bencina
00009  *
00010  * Permission is hereby granted, free of charge, to any person obtaining
00011  * a copy of this software and associated documentation files
00012  * (the "Software"), to deal in the Software without restriction,
00013  * including without limitation the rights to use, copy, modify, merge,
00014  * publish, distribute, sublicense, and/or sell copies of the Software,
00015  * and to permit persons to whom the Software is furnished to do so,
00016  * subject to the following conditions:
00017  *
00018  * The above copyright notice and this permission notice shall be
00019  * included in all copies or substantial portions of the Software.
00020  *
00021  * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
00022  * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
00023  * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT.
00024  * IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR
00025  * ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION OF
00026  * CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
00027  * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE.
00028  */
00029 
00030 /*
00031  * The text above constitutes the entire PortAudio license; however, 
00032  * the PortAudio community also makes the following non-binding requests:
00033  *
00034  * Any person wishing to distribute modifications to the Software is
00035  * requested to send the modifications to the original developer so that
00036  * they can be incorporated into the canonical version. It is also 
00037  * requested that these non-binding requests be included along with the 
00038  * license above.
00039  */
00040 
00061 #ifdef __cplusplus
00062 extern "C"
00063 {
00064 #endif /* __cplusplus */
00065 
00066 /* If this is an apple, we need to do detect endianness this way */
00067 #if defined(__APPLE__)
00068     /* we need to do some endian detection that is sensitive to harware arch */
00069     #if defined(__LITTLE_ENDIAN__)
00070        #if !defined( PA_LITTLE_ENDIAN )
00071           #define PA_LITTLE_ENDIAN
00072        #endif
00073        #if defined( PA_BIG_ENDIAN )
00074           #undef PA_BIG_ENDIAN
00075        #endif
00076     #else
00077        #if !defined( PA_BIG_ENDIAN )
00078           #define PA_BIG_ENDIAN
00079        #endif
00080        #if defined( PA_LITTLE_ENDIAN )
00081           #undef PA_LITTLE_ENDIAN
00082        #endif
00083     #endif
00084 #else
00085     /* this is not an apple, so first check the existing defines, and, failing that,
00086        detect well-known architechtures. */
00087 
00088     #if defined(PA_LITTLE_ENDIAN) || defined(PA_BIG_ENDIAN)
00089         /* endianness define has been set externally, such as by autoconf */
00090 
00091         #if defined(PA_LITTLE_ENDIAN) && defined(PA_BIG_ENDIAN)
00092         #error both PA_LITTLE_ENDIAN and PA_BIG_ENDIAN have been defined externally to pa_endianness.h - only one endianness at a time please
00093         #endif
00094 
00095     #else
00096         /* endianness define has not been set externally */
00097 
00098         /* set PA_LITTLE_ENDIAN or PA_BIG_ENDIAN by testing well known platform specific defines */
00099 
00100         #if defined(WIN32) || defined(_WIN32) || defined(__WIN32__) || defined(__NT__) || defined(LITTLE_ENDIAN) || defined(__i386) || defined(_M_IX86) || defined(__x86_64__)
00101             #define PA_LITTLE_ENDIAN /* win32, assume intel byte order */
00102         #else
00103             #define PA_BIG_ENDIAN
00104         #endif
00105     #endif
00106 
00107     #if !defined(PA_LITTLE_ENDIAN) && !defined(PA_BIG_ENDIAN)
00108         /*
00109          If the following error is raised, you either need to modify the code above
00110          to automatically determine the endianness from other symbols defined on your
00111          platform, or define either PA_LITTLE_ENDIAN or PA_BIG_ENDIAN externally.
00112         */
00113         #error pa_endianness.h was unable to automatically determine the endianness of the target platform
00114     #endif
00115 
00116 #endif
00117 
00118 
00119 /* PA_VALIDATE_ENDIANNESS compares the compile time and runtime endianness,
00120  and raises an assertion if they don't match. <assert.h> must be included in
00121  the context in which this macro is used.
00122 */
00123 #if defined(PA_LITTLE_ENDIAN)
00124     #define PA_VALIDATE_ENDIANNESS \
00125     { \
00126         const long nativeOne = 1; \
00127         assert( "PortAudio: compile time and runtime endianness don't match" && (((char *)&nativeOne)[0]) == 1 ); \
00128     }
00129 #elif defined(PA_BIG_ENDIAN)
00130     #define PA_VALIDATE_ENDIANNESS \
00131     { \
00132         const long nativeOne = 1; \
00133         assert( "PortAudio: compile time and runtime endianness don't match" && (((char *)&nativeOne)[0]) == 0 ); \
00134     }
00135 #endif
00136 
00137 
00138 #ifdef __cplusplus
00139 }
00140 #endif /* __cplusplus */
00141 #endif /* PA_ENDIANNESS_H */

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