On Tue, Sep 27, 2022 at 1:59 PM Paolo Bonzini <pbonz...@redhat.com> wrote:
>
> The test is slightly weaker than before, because it does not
> call an extern "C" function from a C source file. However,
> in practice what we seek to detect is ABI compatibility of the
> various sanitizer flags, and for that it is enough to compile
> anything with CC and link it with CXX.
>
> Signed-off-by: Paolo Bonzini <pbonz...@redhat.com>
Reviewed-by: Marc-André Lureau <marcandre.lur...@redhat.com>
> ---
> configure | 57 --------------------------------------------------
> meson.build | 37 ++++++++++++++++++++++----------
> scripts/main.c | 1 +
> 3 files changed, 27 insertions(+), 68 deletions(-)
> create mode 100644 scripts/main.c
>
> diff --git a/configure b/configure
> index 680d96d09f..0a6f57c371 100755
> --- a/configure
> +++ b/configure
> @@ -75,7 +75,6 @@ fi
> TMPB="qemu-conf"
> TMPC="${TMPDIR1}/${TMPB}.c"
> TMPO="${TMPDIR1}/${TMPB}.o"
> -TMPCXX="${TMPDIR1}/${TMPB}.cxx"
> TMPM="${TMPDIR1}/${TMPB}.m"
> TMPE="${TMPDIR1}/${TMPB}.exe"
>
> @@ -158,10 +157,6 @@ do_cc() {
> do_compiler_werror "$cc" $CPU_CFLAGS "$@"
> }
>
> -do_cxx() {
> - do_compiler_werror "$cxx" $CPU_CFLAGS "$@"
> -}
> -
> do_objc() {
> do_compiler_werror "$objcc" $CPU_CFLAGS "$@"
> }
> @@ -171,24 +166,6 @@ add_to() {
> eval $1=\${$1:+\"\$$1 \"}\$2
> }
>
> -update_cxxflags() {
> - # Set QEMU_CXXFLAGS from QEMU_CFLAGS by filtering out those
> - # options which some versions of GCC's C++ compiler complain about
> - # because they only make sense for C programs.
> - QEMU_CXXFLAGS="-D__STDC_LIMIT_MACROS -D__STDC_CONSTANT_MACROS
> -D__STDC_FORMAT_MACROS"
> - CONFIGURE_CXXFLAGS=$(echo "$CONFIGURE_CFLAGS" | sed
> s/-std=gnu11/-std=gnu++11/)
> - for arg in $QEMU_CFLAGS; do
> - case $arg in
> - -Wstrict-prototypes|-Wmissing-prototypes|-Wnested-externs|\
> - -Wold-style-declaration|-Wold-style-definition|-Wredundant-decls)
> - ;;
> - *)
> - QEMU_CXXFLAGS=${QEMU_CXXFLAGS:+$QEMU_CXXFLAGS }$arg
> - ;;
> - esac
> - done
> -}
> -
> compile_object() {
> local_cflags="$1"
> do_cc $CFLAGS $EXTRA_CFLAGS $CONFIGURE_CFLAGS $QEMU_CFLAGS $local_cflags
> -c -o $TMPO $TMPC
> @@ -2371,38 +2348,6 @@ fi
> #######################################
> # generate config-host.mak
>
> -# Check that the C++ compiler exists and works with the C compiler.
> -# All the QEMU_CXXFLAGS are based on QEMU_CFLAGS. Keep this at the end to
> don't miss any other that could be added.
> -if has $cxx; then
> - cat > $TMPC <<EOF
> -int c_function(void);
> -int main(void) { return c_function(); }
> -EOF
> -
> - compile_object
> -
> - cat > $TMPCXX <<EOF
> -extern "C" {
> - int c_function(void);
> -}
> -int c_function(void) { return 42; }
> -EOF
> -
> - update_cxxflags
> -
> - 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 $cc"
> - echo "Disabling C++ specific optional code"
> - cxx=
> - fi
> -else
> - echo "No C++ compiler available; disabling C++ specific optional code"
> - cxx=
> -fi
> -
> if ! (GIT="$git" "$source_path/scripts/git-submodule.sh"
> "$git_submodules_action" "$git_submodules"); then
> exit 1
> fi
> @@ -2486,7 +2431,6 @@ echo "MESON=$meson" >> $config_host_mak
> echo "NINJA=$ninja" >> $config_host_mak
> echo "CC=$cc" >> $config_host_mak
> echo "QEMU_CFLAGS=$QEMU_CFLAGS" >> $config_host_mak
> -echo "QEMU_CXXFLAGS=$QEMU_CXXFLAGS" >> $config_host_mak
> echo "QEMU_OBJCFLAGS=$QEMU_OBJCFLAGS" >> $config_host_mak
> echo "GLIB_CFLAGS=$glib_cflags" >> $config_host_mak
> echo "GLIB_LIBS=$glib_libs" >> $config_host_mak
> @@ -2608,7 +2552,6 @@ if test "$skip_meson" = no; then
> echo "${a}-softmmu = '$c'" >> $cross
> done
>
> - test -z "$cxx" && echo "link_language = 'c'" >> $cross
> echo "[built-in options]" >> $cross
> echo "c_args = [$(meson_quote $CFLAGS $EXTRA_CFLAGS)]" >> $cross
> echo "cpp_args = [$(meson_quote $CXXFLAGS $EXTRA_CXXFLAGS)]" >> $cross
> diff --git a/meson.build b/meson.build
> index e1700d1d55..f57a60ac4c 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -180,7 +180,6 @@ endif
> ##################
>
> qemu_cflags = config_host['QEMU_CFLAGS'].split()
> -qemu_cxxflags = config_host['QEMU_CXXFLAGS'].split()
> qemu_objcflags = config_host['QEMU_OBJCFLAGS'].split()
> qemu_ldflags = config_host['QEMU_LDFLAGS'].split()
>
> @@ -194,7 +193,6 @@ endif
>
> if get_option('gprof')
> qemu_cflags += ['-p']
> - qemu_cxxflags += ['-p']
> qemu_objcflags += ['-p']
> qemu_ldflags += ['-p']
> endif
> @@ -240,8 +238,33 @@ if get_option('fuzzing')
> endif
>
> add_global_arguments(qemu_cflags, native: false, language: ['c'])
> -add_global_arguments(qemu_cxxflags, native: false, language: ['cpp'])
> add_global_arguments(qemu_objcflags, native: false, language: ['objc'])
> +
> +# Check that the C++ compiler exists and works with the C compiler.
> +link_language = 'c'
> +linker = cc
> +qemu_cxxflags = []
> +if add_languages('cpp', required: false, native: false)
> + cxx = meson.get_compiler('cpp')
> + add_global_arguments(['-D__STDC_LIMIT_MACROS', '-D__STDC_CONSTANT_MACROS',
> '-D__STDC_FORMAT_MACROS'],
> + native: false, language: 'cpp')
> + foreach k: qemu_cflags
> + if k not in ['-Wstrict-prototypes', '-Wmissing-prototypes',
> '-Wnested-externs',
> + '-Wold-style-declaration', '-Wold-style-definition',
> '-Wredundant-decls']
> + qemu_cxxflags += [k]
> + endif
> + endforeach
> + add_global_arguments(qemu_cxxflags, native: false, language: 'cpp')
> +
> + if cxx.links(files('scripts/main.c'), args: qemu_cflags)
> + link_language = 'cpp'
> + linker = cxx
> + else
> + message('C++ compiler does not work with C compiler')
> + message('Disabling C++-specific optional code')
> + endif
> +endif
> +
> add_global_link_arguments(qemu_ldflags, native: false, language: ['c',
> 'cpp', 'objc'])
>
> if targetos == 'linux'
> @@ -255,14 +278,6 @@ add_project_arguments('-iquote', '.',
> '-iquote', meson.current_source_dir() / 'include',
> language: ['c', 'cpp', 'objc'])
>
> -link_language = meson.get_external_property('link_language', 'cpp')
> -if link_language == 'cpp'
> - add_languages('cpp', required: true, native: false)
> - cxx = meson.get_compiler('cpp')
> - linker = cxx
> -else
> - linker = cc
> -endif
> if host_machine.system() == 'darwin'
> add_languages('objc', required: false, native: false)
> endif
> diff --git a/scripts/main.c b/scripts/main.c
> new file mode 100644
> index 0000000000..b552c8e4ed
> --- /dev/null
> +++ b/scripts/main.c
> @@ -0,0 +1 @@
> +int main(void) {}
> --
> 2.37.3
>
