OpenTTD/endian_check.c

53 lines
1.6 KiB
C

/* $Id$ */
#include <stdio.h>
// This pretty simple file checks if the system is LITTLE_ENDIAN or BIG_ENDIAN
// it does that by putting a 1 and a 0 in an array, and read it out as one
// number. If it is 1, it is LITTLE_ENDIAN, if it is 256, it is BIG_ENDIAN
//
// After that it outputs the contents of an include files (endian.h)
// that says or TTD_LITTLE_ENDIAN, or TTD_BIG_ENDIAN. Makefile takes
// care of the real writing to the file.
int main (int argc, char *argv[]) {
unsigned char EndianTest[2] = { 1, 0 };
int force_BE = 0, force_LE = 0, force_PREPROCESSOR = 0;
if (argc > 1 && strcmp(argv[1], "BE") == 0)
force_BE = 1;
if (argc > 1 && strcmp(argv[1], "LE") == 0)
force_LE = 1;
if (argc > 1 && strcmp(argv[1], "PREPROCESSOR") == 0)
force_PREPROCESSOR = 1;
printf("#ifndef ENDIAN_H\n#define ENDIAN_H\n");
if (force_LE == 1) {
printf("#define TTD_LITTLE_ENDIAN\n");
} else {
if (force_BE == 1) {
printf("#define TTD_BIG_ENDIAN\n");
} else {
if (force_PREPROCESSOR == 1) {
// adding support for universal binaries on OSX
// Universal binaries supports both PPC and x86
// If a compiler for OSX gets this setting, it will always pick the correct endian and no test is needed
printf("#ifdef __BIG_ENDIAN__\n");
printf("#define TTD_BIG_ENDIAN\n");
printf("#else\n");
printf("#define TTD_LITTLE_ENDIAN\n");
printf("#endif\n");
} else {
if ( *(short *) EndianTest == 1 )
printf("#define TTD_LITTLE_ENDIAN\n");
else
printf("#define TTD_BIG_ENDIAN\n");
}
}
}
printf("#endif\n");
return 0;
}