[PATCH-for-5.2 v2 1/4] meson: move vhost_user_blk_server to meson.build

["Philippe Mathieu-Daudé" <philmd@redhat.com>]

From: Stefan Hajnoczi <stefanha@redhat.com>

The --enable/disable-vhost-user-blk-server options were implemented in
./configure. There has been confusion about them and part of the problem
is that the shell syntax used for setting the default value is not easy
to read. Move the option over to meson where the conditions are easier
to understand:

  have_vhost_user_blk_server = (targetos == 'linux')

  if get_option('vhost_user_blk_server').enabled()
      if targetos != 'linux'
          error('vhost_user_blk_server requires linux')
      endif
  elif get_option('vhost_user_blk_server').disabled() or not have_system
      have_vhost_user_blk_server = false
  endif

This patch does not change behavior.

Signed-off-by: Stefan Hajnoczi <stefanha@redhat.com>
Tested-by: Philippe Mathieu-Daudé <philmd@redhat.com>
Message-Id: <20201110171121.1265142-2-stefanha@redhat.com>
Signed-off-by: Philippe Mathieu-Daudé <philmd@redhat.com>
---
 configure                | 16 ++++------------
 meson.build              | 12 ++++++++++++
 block/export/meson.build |  5 ++++-
 meson_options.txt        |  2 ++
 4 files changed, 22 insertions(+), 13 deletions(-)

diff --git a/configure b/configure
index 4cef321d9dc..516f28a0888 100755
--- a/configure
+++ b/configure
@@ -329,7 +329,7 @@ vhost_crypto=""
 vhost_scsi=""
 vhost_vsock=""
 vhost_user=""
-vhost_user_blk_server=""
+vhost_user_blk_server="auto"
 vhost_user_fs=""
 kvm="auto"
 hax="auto"
@@ -1247,9 +1247,9 @@ for opt do
   ;;
   --enable-vhost-vsock) vhost_vsock="yes"
   ;;
-  --disable-vhost-user-blk-server) vhost_user_blk_server="no"
+  --disable-vhost-user-blk-server) vhost_user_blk_server="disabled"
   ;;
-  --enable-vhost-user-blk-server) vhost_user_blk_server="yes"
+  --enable-vhost-user-blk-server) vhost_user_blk_server="enabled"
   ;;
   --disable-vhost-user-fs) vhost_user_fs="no"
   ;;
@@ -2390,12 +2390,6 @@ if test "$vhost_net" = ""; then
   test "$vhost_kernel" = "yes" && vhost_net=yes
 fi
 
-# libvhost-user is Linux-only
-test "$vhost_user_blk_server" = "" && vhost_user_blk_server=$linux
-if test "$vhost_user_blk_server" = "yes" && test "$linux" = "no"; then
-  error_exit "--enable-vhost-user-blk-server is only available on Linux"
-fi
-
 ##########################################
 # pkg-config probe
 
@@ -6289,9 +6283,6 @@ fi
 if test "$vhost_vdpa" = "yes" ; then
   echo "CONFIG_VHOST_VDPA=y" >> $config_host_mak
 fi
-if test "$vhost_user_blk_server" = "yes" ; then
-  echo "CONFIG_VHOST_USER_BLK_SERVER=y" >> $config_host_mak
-fi
 if test "$vhost_user_fs" = "yes" ; then
   echo "CONFIG_VHOST_USER_FS=y" >> $config_host_mak
 fi
@@ -7012,6 +7003,7 @@ NINJA=$ninja $meson setup \
         -Dcapstone=$capstone -Dslirp=$slirp -Dfdt=$fdt \
         -Diconv=$iconv -Dcurses=$curses -Dlibudev=$libudev\
         -Ddocs=$docs -Dsphinx_build=$sphinx_build -Dinstall_blobs=$blobs \
+        -Dvhost_user_blk_server=$vhost_user_blk_server \
         $cross_arg \
         "$PWD" "$source_path"
 
diff --git a/meson.build b/meson.build
index b4736203219..4b789f18c17 100644
--- a/meson.build
+++ b/meson.build
@@ -751,6 +751,16 @@
 
 has_statx = cc.links(statx_test)
 
+have_vhost_user_blk_server = (targetos == 'linux')
+
+if get_option('vhost_user_blk_server').enabled()
+    if targetos != 'linux'
+        error('vhost_user_blk_server requires linux')
+    endif
+elif get_option('vhost_user_blk_server').disabled() or not have_system
+    have_vhost_user_blk_server = false
+endif
+
 #################
 # config-host.h #
 #################
@@ -775,6 +785,7 @@
 config_host_data.set('CONFIG_CURSES', curses.found())
 config_host_data.set('CONFIG_SDL', sdl.found())
 config_host_data.set('CONFIG_SDL_IMAGE', sdl_image.found())
+config_host_data.set('CONFIG_VHOST_USER_BLK_SERVER', have_vhost_user_blk_server)
 config_host_data.set('CONFIG_VNC', vnc.found())
 config_host_data.set('CONFIG_VNC_JPEG', jpeg.found())
 config_host_data.set('CONFIG_VNC_PNG', png.found())
@@ -2103,6 +2114,7 @@
 summary_info += {'vhost-scsi support': config_host.has_key('CONFIG_VHOST_SCSI')}
 summary_info += {'vhost-vsock support': config_host.has_key('CONFIG_VHOST_VSOCK')}
 summary_info += {'vhost-user support': config_host.has_key('CONFIG_VHOST_KERNEL')}
+summary_info += {'vhost-user-blk server support': have_vhost_user_blk_server}
 summary_info += {'vhost-user-fs support': config_host.has_key('CONFIG_VHOST_USER_FS')}
 summary_info += {'vhost-vdpa support': config_host.has_key('CONFIG_VHOST_VDPA')}
 summary_info += {'Trace backends':    config_host['TRACE_BACKENDS']}
diff --git a/block/export/meson.build b/block/export/meson.build
index 19526435d84..135b356775b 100644
--- a/block/export/meson.build
+++ b/block/export/meson.build
@@ -1,2 +1,5 @@
 blockdev_ss.add(files('export.c'))
-blockdev_ss.add(when: 'CONFIG_VHOST_USER_BLK_SERVER', if_true: files('vhost-user-blk-server.c'))
+
+if have_vhost_user_blk_server
+    blockdev_ss.add(files('vhost-user-blk-server.c'))
+endif
diff --git a/meson_options.txt b/meson_options.txt
index b4f18018752..f6f64785fe7 100644
--- a/meson_options.txt
+++ b/meson_options.txt
@@ -64,6 +64,8 @@ option('xkbcommon', type : 'feature', value : 'auto',
        description: 'xkbcommon support')
 option('virtiofsd', type: 'feature', value: 'auto',
        description: 'build virtiofs daemon (virtiofsd)')
+option('vhost_user_blk_server', type: 'feature', value: 'auto',
+       description: 'build vhost-user-blk server')
 
 option('capstone', type: 'combo', value: 'auto',
        choices: ['disabled', 'enabled', 'auto', 'system', 'internal'],
-- 
2.26.2