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configure: Avoid using strings binary

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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 <mprivozn@redhat.com>
Message-Id: <d6d9c7043cfe6d976d96694f2b4ecf85cf3206f1.1665732504.git.mprivozn@redhat.com>
Cc: qemu-stable@nongnu.org
Signed-off-by: Paolo Bonzini <pbonzini@redhat.com>
This commit is contained in:
Michal Privoznik 2022-10-14 09:30:15 +02:00 committed by Paolo Bonzini
parent ec19444a53
commit 33ab5f2491
1 changed files with 18 additions and 17 deletions
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35
configure vendored
View file

@ -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 defined(__BYTE_ORDER__) && __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
if ! compile_prog ; then
bigendian="no"
else
cat > $TMPC << EOF
#if defined(__BYTE_ORDER__) && __BYTE_ORDER__ == __ORDER_BIG_ENDIAN__
# error BIG
#endif
int main(void) { return 0; }
EOF
if ! compile_prog ; then
bigendian="yes"
else
echo big/little test failed
exit 1
fi
fi
##########################################