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 1.2 2001/10/01 20:03:13 fdrake 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

])