meson: export the module & config dirs to the C code

This allows loading of config and modules when deployed in
the target system without setting environment variables.

lib/wp/meson.build

@@ -26,7 +26,8 @@ wp_lib = library('wireplumber-' + wireplumber_api_version,
   c_args : [
     '-D_GNU_SOURCE',
     '-DG_LOG_USE_STRUCTURED',
-    '-DG_LOG_DOMAIN="libwireplumber"'
+    '-DG_LOG_DOMAIN="libwireplumber"',
+    '-DWIREPLUMBER_DEFAULT_MODULE_DIR="@0@"'.format(wireplumber_module_dir),
   ],
   install: true,
   include_directories: wp_lib_include_dir,

lib/wp/module.c

@@ -56,9 +56,12 @@ wp_module_class_init (WpModuleClass * klass)
 static const gchar *
 get_module_dir (void)
 {
-  const gchar *module_dir = NULL;
-  if (!module_dir)
+  static const gchar *module_dir = NULL;
+  if (!module_dir) {
     module_dir = g_getenv ("WIREPLUMBER_MODULE_DIR");
+    if (!module_dir)
+      module_dir = WIREPLUMBER_DEFAULT_MODULE_DIR;
+  }
   return module_dir;
 }
 

meson.build

@@ -11,9 +11,17 @@ project('wireplumber', ['c'],
 wireplumber_api_version = '0.1'
 wireplumber_so_version = '0'
 
-modules_install_dir = join_paths(
-  get_option('libdir'), 'wireplumber-' + wireplumber_api_version
-)
+if get_option('libdir').startswith('/')
+  wireplumber_module_dir = join_paths(get_option('libdir'), 'wireplumber-' + wireplumber_api_version)
+else
+  wireplumber_module_dir = join_paths(get_option('prefix'), get_option('libdir'), 'wireplumber-' + wireplumber_api_version)
+endif
+
+if get_option('sysconfdir').startswith('/')
+  wireplumber_config_dir = join_paths(get_option('sysconfdir'), 'wireplumber')
+else
+  wireplumber_config_dir = join_paths(get_option('prefix'), get_option('sysconfdir'), 'wireplumber')
+endif
 
 gobject_dep = dependency('gobject-2.0')
 gmodule_dep = dependency('gmodule-2.0')

modules/meson.build

@@ -14,7 +14,7 @@ shared_library(
   ],
   c_args : [common_c_args, '-DG_LOG_DOMAIN="m-pipewire"'],
   install : true,
-  install_dir : modules_install_dir,
+  install_dir : wireplumber_module_dir,
   dependencies : [wp_dep, pipewire_dep],
 )
 
@@ -25,7 +25,7 @@ shared_library(
   ],
   c_args : [common_c_args, '-DG_LOG_DOMAIN="m-pw-alsa-udev"'],
   install : true,
-  install_dir : modules_install_dir,
+  install_dir : wireplumber_module_dir,
   dependencies : [wp_dep, pipewire_dep],
 )
 
@@ -36,6 +36,6 @@ shared_library(
   ],
   c_args : [common_c_args, '-DG_LOG_DOMAIN="m-pw-audio-softdsp-endpoint"'],
   install : true,
-  install_dir : modules_install_dir,
+  install_dir : wireplumber_module_dir,
   dependencies : [wp_dep, pipewire_dep],
 )

src/main.c

@@ -10,8 +10,6 @@
 #include <gio/gio.h>
 #include <glib-unix.h>
 
-#define WIREPLUMBER_DEFAULT_CONFIG_FILE "wireplumber.conf"
-
 static GOptionEntry entries[] =
 {
   { NULL }

src/meson.build

@@ -2,17 +2,19 @@ wp_sources = [
   'main.c',
 ]
 
+wireplumber_config_file = join_paths(wireplumber_config_dir, 'wireplumber.conf')
+install_data('wireplumber.conf',
+  install_dir: wireplumber_config_dir
+)
+
 executable('wireplumber',
   wp_sources,
   c_args : [
     '-D_GNU_SOURCE',
     '-DG_LOG_USE_STRUCTURED',
-    '-DG_LOG_DOMAIN="wireplumber"'
+    '-DG_LOG_DOMAIN="wireplumber"',
+    '-DWIREPLUMBER_DEFAULT_CONFIG_FILE="@0@"'.format(wireplumber_config_file),
   ],
   install: true,
   dependencies : [gobject_dep, gio_dep, wp_dep],
 )
-
-install_data('wireplumber.conf',
-  install_dir: join_paths(get_option('sysconfdir'), 'wireplumber')
-)