[PATCH v3 01/11] audio: add `audio` build option for meson and Kconfig

[Sergei Heifetz <heifetz@yandex-team.com>]

This patch adds the `audio` option to meson_options.txt. It is
propagated into Kconfig as AUDIO. It is enabled by default.
The corresponding `--disable-audio` and `--enable-audio` options
for `configure` are also added.

For now, this option does nothing. In subsequent patches, it will
gradually disable audio in different places. The final goal is to stop
building sources from `audio/` and `hw/audio/` and other audio-related
files (except for some stubs). Note that this intent is different from
`-audio none`, which mutes audio but still compiles the audio subsystem.

Signed-off-by: Sergei Heifetz <heifetz@yandex-team.com>
Reviewed-by: Marc-André Lureau <marcandre.lureau@redhat.com>
---
 Kconfig.host                  | 3 +++
 meson.build                   | 3 +++
 meson_options.txt             | 3 +++
 scripts/meson-buildoptions.sh | 3 +++
 4 files changed, 12 insertions(+)

diff --git a/Kconfig.host b/Kconfig.host
index 933425c74b4..ec129aa4fc0 100644
--- a/Kconfig.host
+++ b/Kconfig.host
@@ -29,6 +29,9 @@ config IVSHMEM
 config TPM
     bool
 
+config AUDIO
+    bool
+
 config FDT
     bool
 
diff --git a/meson.build b/meson.build
index ed82247111e..d05533488f9 100644
--- a/meson.build
+++ b/meson.build
@@ -68,6 +68,8 @@ foreach target : target_dirs
 endforeach
 have_user = have_linux_user or have_bsd_user
 
+have_audio = get_option('audio').disable_auto_if(not have_system).allowed()
+
 ############
 # Programs #
 ############
@@ -3277,6 +3279,7 @@ disassemblers = {
 have_ivshmem = config_host_data.get('CONFIG_EVENTFD')
 host_kconfig = \
   (get_option('fuzzing') ? ['CONFIG_FUZZ=y'] : []) + \
+  (have_audio ? ['CONFIG_AUDIO=y'] : []) + \
   (have_tpm ? ['CONFIG_TPM=y'] : []) + \
   (pixman.found() ? ['CONFIG_PIXMAN=y'] : []) + \
   (spice.found() ? ['CONFIG_SPICE=y'] : []) + \
diff --git a/meson_options.txt b/meson_options.txt
index 31d5916cfce..d22386b4c15 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -71,6 +71,9 @@ option('malloc_trim', type : 'feature', value : 'auto',
 option('malloc', type : 'combo', choices : ['system', 'tcmalloc', 'jemalloc'],
        value: 'system', description: 'choose memory allocator to use')
 
+option('audio', type: 'feature', value: 'auto',
+       description: 'Audio support')
+
 option('kvm', type: 'feature', value: 'auto',
        description: 'KVM acceleration support')
 option('mshv', type: 'feature', value: 'auto',
diff --git a/scripts/meson-buildoptions.sh b/scripts/meson-buildoptions.sh
index ca5b113119a..05c55d2e70f 100644
--- a/scripts/meson-buildoptions.sh
+++ b/scripts/meson-buildoptions.sh
@@ -96,6 +96,7 @@ meson_options_help() {
   printf "%s\n" '  af-xdp          AF_XDP network backend support'
   printf "%s\n" '  alsa            ALSA sound support'
   printf "%s\n" '  attr            attr/xattr support'
+  printf "%s\n" '  audio           Audio support'
   printf "%s\n" '  auth-pam        PAM access control'
   printf "%s\n" '  blkio           libblkio block device driver'
   printf "%s\n" '  bochs           bochs image format support'
@@ -243,6 +244,8 @@ _meson_option_parse() {
     --disable-asan) printf "%s" -Dasan=false ;;
     --enable-attr) printf "%s" -Dattr=enabled ;;
     --disable-attr) printf "%s" -Dattr=disabled ;;
+    --enable-audio) printf "%s" -Daudio=enabled ;;
+    --disable-audio) printf "%s" -Daudio=disabled ;;
     --audio-drv-list=*) quote_sh "-Daudio_drv_list=$2" ;;
     --enable-auth-pam) printf "%s" -Dauth_pam=enabled ;;
     --disable-auth-pam) printf "%s" -Dauth_pam=disabled ;;
-- 
2.34.1