# endian_check.cpp

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    00001 /* $Id: endian_check.cpp 13571 2008-06-18 21:19:04Z smatz $ */
    00002
    00012 #include <stdio.h>
    00013 #include <string.h>
    00014
    00016 enum Endian {
    00017   ENDIAN_LITTLE,
    00018   ENDIAN_BIG
    00019 };
    00020
    00025 static inline void printf_endian(Endian endian)
    00026 {
    00027   printf("#define TTD_ENDIAN %s\n", endian == ENDIAN_LITTLE ? "TTD_LITTLE_ENDIAN" : "TTD_BIG_ENDIAN");
    00028 }
    00029
    00036 int main (int argc, char *argv[])
    00037 {
    00038   unsigned char endian_test[2] = { 1, 0 };
    00039   int force_BE = 0, force_LE = 0, force_PREPROCESSOR = 0;
    00040
    00041   if (argc > 1 && strcmp(argv[1], "BE") == 0) force_BE = 1;
    00042   if (argc > 1 && strcmp(argv[1], "LE") == 0) force_LE = 1;
    00043   if (argc > 1 && strcmp(argv[1], "PREPROCESSOR") == 0) force_PREPROCESSOR = 1;
    00044
    00045   printf("#ifndef ENDIAN_H\n#define ENDIAN_H\n");
    00046
    00047   if (force_LE == 1) {
    00048     printf_endian(ENDIAN_LITTLE);
    00049   } else if (force_BE == 1) {
    00050     printf_endian(ENDIAN_BIG);
    00051   } else if (force_PREPROCESSOR == 1) {
    00052     /* Support for universal binaries on OSX
    00053      * Universal binaries supports both PPC and x86
    00054      * If a compiler for OSX gets this setting, it will always pick the correct endian and no test is needed
    00055      */
    00056     printf("#ifdef __BIG_ENDIAN__\n");
    00057     printf_endian(ENDIAN_BIG);
    00058     printf("#else\n");
    00059     printf_endian(ENDIAN_LITTLE);
    00060     printf("#endif\n");
    00061   } else if (*(short*)endian_test == 1 ) {
    00062     printf_endian(ENDIAN_LITTLE);
    00063   } else {
    00064     printf_endian(ENDIAN_BIG);
    00065   }
    00066   printf("#endif\n");
    00067
    00068   return 0;
    00069 }