diff options
Diffstat (limited to 'expat/conftools/ac_c_bigendian_cross.m4')
| -rw-r--r-- | expat/conftools/ac_c_bigendian_cross.m4 | 81 |
1 files changed, 81 insertions, 0 deletions
diff --git a/expat/conftools/ac_c_bigendian_cross.m4 b/expat/conftools/ac_c_bigendian_cross.m4 new file mode 100644 index 000000000..8ed3edb24 --- /dev/null +++ b/expat/conftools/ac_c_bigendian_cross.m4 @@ -0,0 +1,81 @@ +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 +]) |