mirror of
https://gitlab.com/mbunkus/mkvtoolnix.git
synced 2024-12-27 05:14:47 +00:00
60 lines
2.0 KiB
Plaintext
60 lines
2.0 KiB
Plaintext
dnl Stolen from VideoLAN Client, http://www.videolan.org/
|
|
dnl
|
|
dnl Endianness check, AC_C_BIGENDIAN doesn't work if we are cross-compiling
|
|
dnl
|
|
dnl We give the user the opportunity to specify
|
|
dnl --with-words=big or --with-words=little ; otherwise, try to guess
|
|
dnl
|
|
AC_ARG_WITH(words,
|
|
AC_HELP_STRING([--with-words=endianness],[set endianness (big or little)]))
|
|
case "${with_words}" in
|
|
big)
|
|
ac_cv_c_bigendian=yes
|
|
;;
|
|
little)
|
|
ac_cv_c_bigendian=no
|
|
;;
|
|
*)
|
|
dnl Try to guess endianness by matching patterns on a compiled
|
|
dnl binary, by looking for an ASCII or EBCDIC string
|
|
AC_CACHE_CHECK([whether the byte order is big-endian],
|
|
[ac_cv_c_bigendian],
|
|
[ac_cv_c_bigendian="unknown"
|
|
[cat >conftest.c <<EOF
|
|
short am[] = { 0x4249, 0x4765, 0x6e44, 0x6961, 0x6e53, 0x7953, 0 };
|
|
short ai[] = { 0x694c, 0x5454, 0x656c, 0x6e45, 0x6944, 0x6e61, 0 };
|
|
void _a(void) { char*s = (char*)am; s = (char *)ai; }
|
|
short ei[] = { 0x89D3, 0xe3e3, 0x8593, 0x95c5, 0x89c4, 0x9581, 0 };
|
|
short em[] = { 0xc2c9, 0xc785, 0x95c4, 0x8981, 0x95e2, 0xa8e2, 0 };
|
|
void _e(void) { char*s = (char*)em; s = (char*)ei; }
|
|
int main(void) { _a(); _e(); return 0; }
|
|
EOF
|
|
]
|
|
if test -f conftest.c
|
|
then
|
|
if ${CC-cc} -c conftest.c -o conftest.o >>config.log 2>&1 \
|
|
&& test -f conftest.o
|
|
then
|
|
if test "`"$STRINGS" conftest.o | grep BIGenDianSyS`"
|
|
then
|
|
ac_cv_c_bigendian="yes"
|
|
fi
|
|
if test "`"$STRINGS" conftest.o | grep LiTTleEnDian`"
|
|
then
|
|
ac_cv_c_bigendian="no"
|
|
fi
|
|
fi
|
|
fi
|
|
])
|
|
if test "${ac_cv_c_bigendian}" = "unknown"
|
|
then
|
|
AC_MSG_ERROR([Could not guess endianness, please use --with-words])
|
|
fi
|
|
;;
|
|
esac
|
|
dnl Now we know what to use for endianness, just put it in the header
|
|
if test "${ac_cv_c_bigendian}" = "yes"
|
|
then
|
|
AC_DEFINE(WORDS_BIGENDIAN, 1, big endian system)
|
|
fi
|