📄 accross.m4
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AC_DEFUN([AC_COMPILE_CHECK_SIZEOF],[changequote(<<, >>)dnldnl The name to #define.define(<<AC_TYPE_NAME>>, translit(sizeof_$1, [a-z *], [A-Z_P]))dnldnl The cache variable name.define(<<AC_CV_NAME>>, translit(ac_cv_sizeof_$1, [ *], [_p]))dnlchangequote([, ])dnlAC_MSG_CHECKING(size of $1)AC_CACHE_VAL(AC_CV_NAME,[for ac_size in 4 8 1 2 16 12 $2 ; do # List sizes in rough order of prevalence. AC_TRY_COMPILE([#include "confdefs.h"#include <sys/types.h>$2], [switch (0) case 0: case (sizeof ($1) == $ac_size):;], AC_CV_NAME=$ac_size) if test x$AC_CV_NAME != x ; then break; fidone])if test x$AC_CV_NAME = x ; then AC_MSG_ERROR([cannot determine a size for $1])fiAC_MSG_RESULT($AC_CV_NAME)AC_DEFINE_UNQUOTED(AC_TYPE_NAME, $AC_CV_NAME, [The number of bytes in type $1])undefine([AC_TYPE_NAME])dnlundefine([AC_CV_NAME])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; thenAC_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; thenAC_MSG_CHECKING(to probe for byte ordering)[cat >conftest.c <<EOFshort 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} ${CFLAGS} -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 $ac_n 'guessing bigendian ... ' >&AC_FD_MSG fi fiAC_MSG_RESULT($ac_cv_c_bigendian)fiif test $ac_cv_c_bigendian = yes; then AC_DEFINE(WORDS_BIGENDIAN, 1, [whether byteorder is bigendian]) AC_DEFINE(HOST_WORDS_BIG_ENDIAN, 1, [Define if the host machine stores words of multi-word integers in big-endian order.]) BYTEORDER=4321else BYTEORDER=1234fiAC_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])
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