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