meson: obtain dbus directories from pkg-config

meson.build

@@ -191,21 +191,6 @@ if docdir == ''
         docdir = datadir / 'doc/systemd'
 endif
 
-dbuspolicydir = get_option('dbuspolicydir')
-if dbuspolicydir == ''
-        dbuspolicydir = datadir / 'dbus-1/system.d'
-endif
-
-dbussessionservicedir = get_option('dbussessionservicedir')
-if dbussessionservicedir == ''
-        dbussessionservicedir = datadir / 'dbus-1/services'
-endif
-
-dbussystemservicedir = get_option('dbussystemservicedir')
-if dbussystemservicedir == ''
-        dbussystemservicedir = datadir / 'dbus-1/system-services'
-endif
-
 pamlibdir = get_option('pamlibdir')
 if pamlibdir == ''
         pamlibdir = rootlibdir / 'security'
@@ -1473,6 +1458,59 @@ else
 endif
 conf.set10('HAVE_DBUS', have)
 
+dbusdatadir = datadir / 'dbus-1'
+if conf.get('HAVE_DBUS') == 1
+        dbusdatadir = libdbus.get_variable(pkgconfig: 'datadir', default_value: datadir) / 'dbus-1'
+endif
+
+dbuspolicydir = get_option('dbuspolicydir')
+if dbuspolicydir == ''
+        dbuspolicydir = dbusdatadir / 'system.d'
+endif
+
+dbussessionservicedir = get_option('dbussessionservicedir')
+if dbussessionservicedir == ''
+        dbussessionservicedir = dbusdatadir / 'services'
+        if conf.get('HAVE_DBUS') == 1
+                dbussessionservicedir = libdbus.get_variable(pkgconfig: 'session_bus_services_dir', default_value: dbussessionservicedir)
+        endif
+endif
+
+dbussystemservicedir = get_option('dbussystemservicedir')
+if dbussystemservicedir == ''
+        dbussystemservicedir = dbusdatadir / 'system-services'
+        if conf.get('HAVE_DBUS') == 1
+                dbussystemservicedir = libdbus.get_variable(pkgconfig: 'system_bus_services_dir', default_value: dbussystemservicedir)
+        endif
+endif
+
+dbus_interfaces_dir = get_option('dbus-interfaces-dir')
+if dbus_interfaces_dir == '' or dbus_interfaces_dir == 'yes'
+        if meson.is_cross_build() and dbus_interfaces_dir != 'yes'
+                dbus_interfaces_dir = 'no'
+                warning('Exporting D-Bus interface XML files is disabled during cross build. Pass path or "yes" to force enable.')
+        else
+                dbus_interfaces_dir = dbusdatadir / 'interfaces'
+                if conf.get('HAVE_DBUS') == 1
+                        dbus_interfaces_dir = libdbus.get_variable(pkgconfig: 'interfaces_dir', default_value: dbus_interfaces_dir)
+                endif
+        endif
+endif
+if dbus_interfaces_dir == dbusdatadir / 'interfaces' or dbus_interfaces_dir == 'no'
+        dbus_interfaces_dir_name = 'interfaces'
+        dbus_interfaces_dir_parent = dbusdatadir
+else
+        elements = dbus_interfaces_dir.split('/')
+        dbus_interfaces_dir_name = elements[-1]
+        dbus_interfaces_dir_parent = '/'
+        foreach elem : elements
+                if elem == dbus_interfaces_dir_name and dbus_interfaces_dir == dbus_interfaces_dir_parent / dbus_interfaces_dir_name
+                        break
+                endif
+                dbus_interfaces_dir_parent = dbus_interfaces_dir_parent / elem
+        endforeach
+endif
+
 # We support one or the other. If gcrypt is available, we assume it's there to
 # be used, and use it in preference.
 opt = get_option('cryptolib')
@@ -1731,17 +1769,6 @@ public_programs = []
 
 # D-Bus introspection XML export
 dbus_programs = []
-dbus_interfaces_dir = get_option('dbus-interfaces-dir')
-if dbus_interfaces_dir == ''
-        if not meson.is_cross_build()
-                dbus_interfaces_dir = datadir / 'dbus-1'
-        else
-                message('D-Bus interfaces export is disabled during cross build. Pass path or yes to force enable.')
-                dbus_interfaces_dir = 'no'
-        endif
-elif dbus_interfaces_dir == 'yes'
-        dbus_interfaces_dir = datadir / 'dbus-1'
-endif
 
 basic_includes = include_directories(
         'src/basic',
@@ -3876,9 +3903,9 @@ alias_target('update-man-rules', update_man_rules)
 
 custom_target(
         'export-dbus-interfaces',
-        output : 'interfaces',
+        output : dbus_interfaces_dir_name,
         install : dbus_interfaces_dir != 'no',
-        install_dir : dbus_interfaces_dir,
+        install_dir : dbus_interfaces_dir_parent,
         command : [export_dbus_interfaces_py, '@OUTPUT@', dbus_programs])
 
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