freebsd-dev/crypto/heimdal/cf/krb-bigendian.m4
2004-04-03 21:22:55 +00:00

63 lines
1.9 KiB
Plaintext

dnl
dnl $Id: krb-bigendian.m4,v 1.8.6.1 2004/04/01 07:27:33 joda Exp $
dnl
dnl check if this computer is little or big-endian
dnl if we can figure it out at compile-time then don't define the cpp symbol
dnl otherwise test for it and define it. also allow options for overriding
dnl it when cross-compiling
AC_DEFUN([KRB_C_BIGENDIAN], [
AC_ARG_ENABLE(bigendian,
AC_HELP_STRING([--enable-bigendian],[the target is big endian]),
krb_cv_c_bigendian=yes)
AC_ARG_ENABLE(littleendian,
AC_HELP_STRING([--enable-littleendian],[the target is little endian]),
krb_cv_c_bigendian=no)
AC_CACHE_CHECK(whether byte order is known at compile time,
krb_cv_c_bigendian_compile,
[AC_TRY_COMPILE([
#include <sys/types.h>
#include <sys/param.h>],[
#if !BYTE_ORDER || !BIG_ENDIAN || !LITTLE_ENDIAN
bogus endian macros
#endif], krb_cv_c_bigendian_compile=yes, krb_cv_c_bigendian_compile=no)])
AC_CACHE_CHECK(whether byte ordering is bigendian, krb_cv_c_bigendian,[
if test "$krb_cv_c_bigendian_compile" = "yes"; then
AC_TRY_COMPILE([
#include <sys/types.h>
#include <sys/param.h>],[
#if BYTE_ORDER != BIG_ENDIAN
not big endian
#endif], krb_cv_c_bigendian=yes, krb_cv_c_bigendian=no)
else
AC_TRY_RUN([main () {
/* Are we little or big endian? From Harbison&Steele. */
union
{
long l;
char c[sizeof (long)];
} u;
u.l = 1;
exit (u.c[sizeof (long) - 1] == 1);
}], krb_cv_c_bigendian=no, krb_cv_c_bigendian=yes,
AC_MSG_ERROR([specify either --enable-bigendian or --enable-littleendian]))
fi
])
if test "$krb_cv_c_bigendian" = "yes"; then
AC_DEFINE(WORDS_BIGENDIAN, 1, [define if target is big endian])dnl
fi
if test "$krb_cv_c_bigendian_compile" = "yes"; then
AC_DEFINE(ENDIANESS_IN_SYS_PARAM_H, 1, [define if sys/param.h defines the endiness])dnl
fi
AH_BOTTOM([
#if ENDIANESS_IN_SYS_PARAM_H
# include <sys/types.h>
# include <sys/param.h>
# if BYTE_ORDER == BIG_ENDIAN
# define WORDS_BIGENDIAN 1
# endif
#endif
])
])