Re: [RFC PATCH v3 1/7] configure: Allow passing extra Objective C compiler flags

From: Roman Bolshakov <roman@roolebo.dev>
To: "Philippe Mathieu-Daudé" <f4bug@amsat.org>
Cc: "Peter Maydell" <peter.maydell@linaro.org>,
	"Thomas Huth" <thuth@redhat.com>,
	"Daniel P . Berrangé" <berrange@redhat.com>,
	"Christian Schoenebeck" <qemu_oss@crudebyte.com>,
	qemu-devel@nongnu.org, "Cameron Esfahani" <dirty@apple.com>,
	"Roman Bolshakov" <r.bolshakov@yadro.com>,
	"Alexander Graf" <agraf@csgraf.de>,
	"Gerd Hoffmann" <kraxel@redhat.com>,
	"Akihiko Odaki" <akihiko.odaki@gmail.com>,
	"Alex Bennée" <alex.bennee@linaro.org>,
	"Wainer dos Santos Moschetta" <wainersm@redhat.com>
Subject: Re: [RFC PATCH v3 1/7] configure: Allow passing extra Objective C compiler flags
Date: Tue, 11 Jan 2022 20:16:45 +0300	[thread overview]
Message-ID: <Yd27fVx1iHyvA9ng@roolebo.dev> (raw)
In-Reply-To: <20220110131001.614319-2-f4bug@amsat.org>

On Mon, Jan 10, 2022 at 02:09:55PM +0100, Philippe Mathieu-Daudé wrote:
> We can pass C/CPP/LD flags via CFLAGS/CXXFLAGS/LDFLAGS environment
> variables, or via configure --extra-cflags / --extra-cxxflags /
> --extra-ldflags options. Provide similar behavior for Objective C:
> use existing flags from $OBJCFLAGS, or passed via --extra-objcflags.
> 
> Signed-off-by: Philippe Mathieu-Daudé <f4bug@amsat.org>
> ---
>  configure   | 8 ++++++++
>  meson.build | 5 +++++
>  2 files changed, 13 insertions(+)
> 
> diff --git a/configure b/configure
> index 0c57a063c66..adb42d8beb1 100755
> --- a/configure
> +++ b/configure
> @@ -288,6 +288,7 @@ done
>  
>  EXTRA_CFLAGS=""
>  EXTRA_CXXFLAGS=""
> +EXTRA_OBJCFLAGS=""
>  EXTRA_LDFLAGS=""
>  
>  xen_ctrl_version="$default_feature"
> @@ -400,9 +401,12 @@ for opt do
>    --extra-cflags=*)
>      EXTRA_CFLAGS="$EXTRA_CFLAGS $optarg"
>      EXTRA_CXXFLAGS="$EXTRA_CXXFLAGS $optarg"
> +    EXTRA_OBJCFLAGS="$EXTRA_OBJCFLAGS $optarg"
>      ;;
>    --extra-cxxflags=*) EXTRA_CXXFLAGS="$EXTRA_CXXFLAGS $optarg"
>    ;;
> +  --extra-objcflags=*) EXTRA_OBJCFLAGS="$EXTRA_OBJCFLAGS $optarg"
> +  ;;
>    --extra-ldflags=*) EXTRA_LDFLAGS="$EXTRA_LDFLAGS $optarg"
>    ;;
>    --enable-debug-info) debug_info="yes"
> @@ -781,6 +785,8 @@ for opt do
>    ;;
>    --extra-cxxflags=*)
>    ;;
> +  --extra-objcflags=*)
> +  ;;
>    --extra-ldflags=*)
>    ;;
>    --enable-debug-info)
> @@ -1318,6 +1324,7 @@ Advanced options (experts only):
>    --objcc=OBJCC            use Objective-C compiler OBJCC [$objcc]
>    --extra-cflags=CFLAGS    append extra C compiler flags CFLAGS
>    --extra-cxxflags=CXXFLAGS append extra C++ compiler flags CXXFLAGS
> +  --extra-objcflags=OBJCFLAGS append extra Objective C compiler flags OBJCFLAGS
>    --extra-ldflags=LDFLAGS  append extra linker flags LDFLAGS
>    --cross-cc-ARCH=CC       use compiler when building ARCH guest test cases
>    --cross-cc-flags-ARCH=   use compiler flags when building ARCH guest tests
> @@ -3843,6 +3850,7 @@ if test "$skip_meson" = no; then
>    echo "[built-in options]" >> $cross
>    echo "c_args = [$(meson_quote $CFLAGS $EXTRA_CFLAGS)]" >> $cross
>    echo "cpp_args = [$(meson_quote $CXXFLAGS $EXTRA_CXXFLAGS)]" >> $cross
> +  test -n "$objcc" && echo "objc_args = [$(meson_quote $OBJCFLAGS $EXTRA_OBJCFLAGS)]" >> $cross
>    echo "c_link_args = [$(meson_quote $CFLAGS $LDFLAGS $EXTRA_CFLAGS $EXTRA_LDFLAGS)]" >> $cross
>    echo "cpp_link_args = [$(meson_quote $CXXFLAGS $LDFLAGS $EXTRA_CXXFLAGS $EXTRA_LDFLAGS)]" >> $cross
>    echo "[binaries]" >> $cross
> diff --git a/meson.build b/meson.build
> index 0e52f54b100..a21305d62c1 100644
> --- a/meson.build
> +++ b/meson.build
> @@ -3286,6 +3286,11 @@
>                                                 + ['-O' + get_option('optimization')]
>                                                 + (get_option('debug') ? ['-g'] : []))}
>  endif
> +if targetos == 'darwin'
> +  summary_info += {'OBJCFLAGS':       ' '.join(get_option('objc_args')
> +                                               + ['-O' + get_option('optimization')]
> +                                               + (get_option('debug') ? ['-g'] : []))}

Hi Philippe,

You need to add something like below to actually use the flags in build:

add_global_arguments(config_host['QEMU_OBJCFLAGS'].split(),
                     native: false, language: 'objc')

Regards,
Roman

> +endif
>  link_args = get_option(link_language + '_link_args')
>  if link_args.length() > 0
>    summary_info += {'LDFLAGS':         ' '.join(link_args)}
> -- 
> 2.33.1