Re: [PATCH v2 4/8] configure: Disable out-of-line atomic operations on Aarch64

[Paolo Bonzini <pbonzini@redhat.com>]

On 2/18/22 02:46, Richard Henderson wrote:
>>>>
>>>> I don't have gobjc/g++ installed, so ./configure defaulted to Clang to
>>>> compile these languages, but compiled C files using GCC. At the end the
>>>> Clang linker is used (the default c++ symlink).
> 
> This is another form of compiler mis-configuration.
> If you don't have g++ to go with gcc, use --cxx=false to avoid picking 
> up a different compiler.

This would be the kind of problem that this test is trying to cover:

     if do_cxx $CXXFLAGS $EXTRA_CXXFLAGS $CONFIGURE_CXXFLAGS $QEMU_CXXFLAGS -o $TMPE $TMPCXX $TMPO $QEMU_LDFLAGS; then
         # C++ compiler $cxx works ok with C compiler $cc
         :
     else
         echo "C++ compiler $cxx does not work with C compiler $cc"
         echo "Disabling C++ specific optional code"
         cxx=
     fi

In the past it detected issues with libasan/libtsan incompatibilities.
We should either add a test for atomic operations, or just drop the
test.

Paolo