82 lines
2.9 KiB
Plaintext
82 lines
2.9 KiB
Plaintext
|
dnl @synopsis AC_C_BIGENDIAN_CROSS
|
||
|
|
dnl
|
||
|
|
dnl Check endianess even when crosscompiling
|
||
|
|
dnl (partially based on the original AC_C_BIGENDIAN).
|
||
|
|
dnl
|
||
|
|
dnl The implementation will create a binary, and instead of running
|
||
|
|
dnl the binary it will be grep'ed for some symbols that will look
|
||
|
|
dnl different for different endianess of the binary.
|
||
|
|
dnl
|
||
|
|
dnl @version $Id: ac_c_bigendian_cross.m4,v 1.1.1.1 2006/11/25 18:35:44 matthieu Exp $
|
||
|
|
dnl @author Guido Draheim <guidod@gmx.de>
|
||
|
|
dnl
|
||
|
|
AC_DEFUN([AC_C_BIGENDIAN_CROSS],
|
||
|
|
[AC_CACHE_CHECK(whether byte ordering is bigendian, ac_cv_c_bigendian,
|
||
|
|
[ac_cv_c_bigendian=unknown
|
||
|
|
# See if sys/param.h defines the BYTE_ORDER macro.
|
||
|
|
AC_TRY_COMPILE([#include <sys/types.h>
|
||
|
|
#include <sys/param.h>], [
|
||
|
|
#if !BYTE_ORDER || !BIG_ENDIAN || !LITTLE_ENDIAN
|
||
|
|
bogus endian macros
|
||
|
|
#endif], [# It does; now see whether it defined to BIG_ENDIAN or not.
|
||
|
|
AC_TRY_COMPILE([#include <sys/types.h>
|
||
|
|
#include <sys/param.h>], [
|
||
|
|
#if BYTE_ORDER != BIG_ENDIAN
|
||
|
|
not big endian
|
||
|
|
#endif], ac_cv_c_bigendian=yes, ac_cv_c_bigendian=no)])
|
||
|
|
if test $ac_cv_c_bigendian = unknown; then
|
||
|
|
AC_TRY_RUN([main () {
|
||
|
|
/* Are we little or big endian? From Harbison&Steele. */
|
||
|
|
union
|
||
|
|
{
|
||
|
|
long l;
|
||
|
|
char c[sizeof (long)];
|
||
|
|
} u;
|
||
|
|
u.l = 1;
|
||
|
|
exit (u.c[sizeof (long) - 1] == 1);
|
||
|
|
}], ac_cv_c_bigendian=no, ac_cv_c_bigendian=yes,
|
||
|
|
[ echo $ac_n "cross-compiling... " 2>&AC_FD_MSG ])
|
||
|
|
fi])
|
||
|
|
if test $ac_cv_c_bigendian = unknown; then
|
||
|
|
AC_MSG_CHECKING(to probe for byte ordering)
|
||
|
|
[
|
||
|
|
cat >conftest.c <<EOF
|
||
|
|
short ascii_mm[] = { 0x4249, 0x4765, 0x6E44, 0x6961, 0x6E53, 0x7953, 0 };
|
||
|
|
short ascii_ii[] = { 0x694C, 0x5454, 0x656C, 0x6E45, 0x6944, 0x6E61, 0 };
|
||
|
|
void _ascii() { char* s = (char*) ascii_mm; s = (char*) ascii_ii; }
|
||
|
|
short ebcdic_ii[] = { 0x89D3, 0xE3E3, 0x8593, 0x95C5, 0x89C4, 0x9581, 0 };
|
||
|
|
short ebcdic_mm[] = { 0xC2C9, 0xC785, 0x95C4, 0x8981, 0x95E2, 0xA8E2, 0 };
|
||
|
|
void _ebcdic() { char* s = (char*) ebcdic_mm; s = (char*) ebcdic_ii; }
|
||
|
|
int main() { _ascii (); _ebcdic (); return 0; }
|
||
|
|
EOF
|
||
|
|
] if test -f conftest.c ; then
|
||
|
|
if ${CC-cc} -c conftest.c -o conftest.o && test -f conftest.o ; then
|
||
|
|
if test `grep -l BIGenDianSyS conftest.o` ; then
|
||
|
|
echo $ac_n ' big endian probe OK, ' 1>&AC_FD_MSG
|
||
|
|
ac_cv_c_bigendian=yes
|
||
|
|
fi
|
||
|
|
if test `grep -l LiTTleEnDian conftest.o` ; then
|
||
|
|
echo $ac_n ' little endian probe OK, ' 1>&AC_FD_MSG
|
||
|
|
if test $ac_cv_c_bigendian = yes ; then
|
||
|
|
ac_cv_c_bigendian=unknown;
|
||
|
|
else
|
||
|
|
ac_cv_c_bigendian=no
|
||
|
|
fi
|
||
|
|
fi
|
||
|
|
echo $ac_n 'guessing bigendian ... ' >&AC_FD_MSG
|
||
|
|
fi
|
||
|
|
fi
|
||
|
|
AC_MSG_RESULT($ac_cv_c_bigendian)
|
||
|
|
fi
|
||
|
|
if test $ac_cv_c_bigendian = yes; then
|
||
|
|
AC_DEFINE(WORDS_BIGENDIAN, 1, [whether byteorder is bigendian])
|
||
|
|
BYTEORDER=4321
|
||
|
|
else
|
||
|
|
BYTEORDER=1234
|
||
|
|
fi
|
||
|
|
AC_DEFINE_UNQUOTED(BYTEORDER, $BYTEORDER, [1234 = LIL_ENDIAN, 4321 = BIGENDIAN])
|
||
|
|
if test $ac_cv_c_bigendian = unknown; then
|
||
|
|
AC_MSG_ERROR(unknown endianess - sorry, please pre-set ac_cv_c_bigendian)
|
||
|
|
fi
|
||
|
|
])
|