When determining the endiandness of the target architecture we're building for a small program is compiled, which in an obfuscated way declares two strings. Then, we look which string is in correct order (using strings binary) and deduct the endiandness. But using the strings binary is problematic, because it's part of toolchain (strings is just a symlink to x86_64-pc-linux-gnu-strings or llvm-strings). And when (cross-)compiling, it requires users to set the symlink to the correct toolchain.
Fortunately, we have a better alternative anyways. We can mimic what compiler.h is already doing: comparing __BYTE_ORDER__ against values for little/big endiandness. Bug: https://bugs.gentoo.org/876933 Signed-off-by: Michal Privoznik <mpriv...@redhat.com> --- v2 of: https://lists.gnu.org/archive/html/qemu-devel/2022-10/msg02054.html diff to v1: - Fixed reversed logic - Ditched custom compiler macros in favor of __BYTE_ORDER__ configure | 33 +++++++++++++++++---------------- 1 file changed, 17 insertions(+), 16 deletions(-) diff --git a/configure b/configure index 45ee6f4eb3..2ac26c6978 100755 --- a/configure +++ b/configure @@ -1423,30 +1423,31 @@ if test "$tcg" = "enabled"; then git_submodules="$git_submodules tests/fp/berkeley-softfloat-3" fi -# --- +########################################## # big/little endian test cat > $TMPC << EOF -#include <stdio.h> -short big_endian[] = { 0x4269, 0x4765, 0x4e64, 0x4961, 0x4e00, 0, }; -short little_endian[] = { 0x694c, 0x7454, 0x654c, 0x6e45, 0x6944, 0x6e41, 0, }; -int main(int argc, char *argv[]) -{ - return printf("%s %s\n", (char *)big_endian, (char *)little_endian); -} +#if __BYTE_ORDER__ == __ORDER_LITTLE_ENDIAN__ +# error LITTLE +#endif +int main(void) { return 0; } EOF if compile_prog ; then - if strings -a $TMPE | grep -q BiGeNdIaN ; then - bigendian="yes" - elif strings -a $TMPE | grep -q LiTtLeEnDiAn ; then - bigendian="no" - else - echo big/little test failed - exit 1 - fi + bigendian="yes" else + cat > $TMPC << EOF +#if __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__ +# error BIG +#endif +int main(void) { return 0; } +EOF + + if compile_prog ; then + bigendian="no" + else echo big/little test failed exit 1 + fi fi ########################################## -- 2.35.1
