projects / wxWidgets.git / blame
| Commit | Line | Data |
|---|---|---|
| 5e9f2524 VS |
1 | dnl @synopsis AC_C_BIGENDIAN_CROSS |
| 2 | dnl | |
| 3 | dnl Check endianess even when crosscompiling | |
| 4 | dnl (partially based on the original AC_C_BIGENDIAN). | |
| 5 | dnl | |
| 6 | dnl The implementation will create a binary, and instead of running | |
| 7 | dnl the binary it will be grep'ed for some symbols that will look | |
| 8 | dnl different for different endianess of the binary. | |
| 9 | dnl | |
| 10 | dnl @version $Id$ | |
| 11 | dnl @author Guido Draheim <guidod@gmx.de> | |
| 12 | dnl | |
| 13 | AC_DEFUN([AC_C_BIGENDIAN_CROSS], | |
| 14 | [AC_CACHE_CHECK(whether byte ordering is bigendian, ac_cv_c_bigendian, | |
| 15 | [ac_cv_c_bigendian=unknown | |
| 16 | # See if sys/param.h defines the BYTE_ORDER macro. | |
| 17 | AC_TRY_COMPILE([#include <sys/types.h> | |
| 18 | #include <sys/param.h>], [ | |
| 19 | #if !BYTE_ORDER || !BIG_ENDIAN || !LITTLE_ENDIAN | |
| 20 | bogus endian macros | |
| 21 | #endif], [# It does; now see whether it defined to BIG_ENDIAN or not. | |
| 22 | AC_TRY_COMPILE([#include <sys/types.h> | |
| 23 | #include <sys/param.h>], [ | |
| 24 | #if BYTE_ORDER != BIG_ENDIAN | |
| 25 | not big endian | |
| 26 | #endif], ac_cv_c_bigendian=yes, ac_cv_c_bigendian=no)]) | |
| 27 | if test $ac_cv_c_bigendian = unknown; then | |
| 28 | AC_TRY_RUN([main () { | |
| 29 | /* Are we little or big endian? From Harbison&Steele. */ | |
| 30 | union | |
| 31 | { | |
| 32 | long l; | |
| 33 | char c[sizeof (long)]; | |
| 34 | } u; | |
| 35 | u.l = 1; | |
| 36 | exit (u.c[sizeof (long) - 1] == 1); | |
| 37 | }], ac_cv_c_bigendian=no, ac_cv_c_bigendian=yes, | |
| 38 | [ echo $ac_n "cross-compiling... " 2>&AC_FD_MSG ]) | |
| 39 | fi]) | |
| 40 | if test $ac_cv_c_bigendian = unknown; then | |
| 41 | AC_MSG_CHECKING(to probe for byte ordering) | |
| 42 | [ | |
| 43 | cat >conftest.c <<EOF | |
| 44 | short ascii_mm[] = { 0x4249, 0x4765, 0x6E44, 0x6961, 0x6E53, 0x7953, 0 }; | |
| 45 | short ascii_ii[] = { 0x694C, 0x5454, 0x656C, 0x6E45, 0x6944, 0x6E61, 0 }; | |
| 46 | void _ascii() { char* s = (char*) ascii_mm; s = (char*) ascii_ii; } | |
| 47 | short ebcdic_ii[] = { 0x89D3, 0xE3E3, 0x8593, 0x95C5, 0x89C4, 0x9581, 0 }; | |
| 48 | short ebcdic_mm[] = { 0xC2C9, 0xC785, 0x95C4, 0x8981, 0x95E2, 0xA8E2, 0 }; | |
| 49 | void _ebcdic() { char* s = (char*) ebcdic_mm; s = (char*) ebcdic_ii; } | |
| 50 | int main() { _ascii (); _ebcdic (); return 0; } | |
| 51 | EOF | |
| 52 | ] if test -f conftest.c ; then | |
| 53 | if ${CC-cc} -c conftest.c -o conftest.o && test -f conftest.o ; then | |
| 54 | if test `grep -l BIGenDianSyS conftest.o` ; then | |
| 55 | echo $ac_n ' big endian probe OK, ' 1>&AC_FD_MSG | |
| 56 | ac_cv_c_bigendian=yes | |
| 57 | fi | |
| 58 | if test `grep -l LiTTleEnDian conftest.o` ; then | |
| 59 | echo $ac_n ' little endian probe OK, ' 1>&AC_FD_MSG | |
| 60 | if test $ac_cv_c_bigendian = yes ; then | |
| 61 | ac_cv_c_bigendian=unknown; | |
| 62 | else | |
| 63 | ac_cv_c_bigendian=no | |
| 64 | fi | |
| 65 | fi | |
| 66 | echo $ac_n 'guessing bigendian ... ' >&AC_FD_MSG | |
| 67 | fi | |
| 68 | fi | |
| 69 | AC_MSG_RESULT($ac_cv_c_bigendian) | |
| 70 | fi | |
| 71 | if test $ac_cv_c_bigendian = yes; then | |
| 72 | AC_DEFINE(WORDS_BIGENDIAN, 1, [whether byteorder is bigendian]) | |
| 73 | BYTEORDER=4321 | |
| 74 | else | |
| 75 | BYTEORDER=1234 | |
| 76 | fi | |
| 77 | AC_DEFINE_UNQUOTED(BYTEORDER, $BYTEORDER, [1234 = LIL_ENDIAN, 4321 = BIGENDIAN]) | |
| 78 | if test $ac_cv_c_bigendian = unknown; then | |
| 79 | AC_MSG_ERROR(unknown endianess - sorry, please pre-set ac_cv_c_bigendian) | |
| 80 | fi | |
| 81 | ]) |