Add socket and flags references.

libdbus-sys/build_vendored.rs

@@ -17,7 +17,8 @@ const DBUS_VERSION_MAJOR: u32 = 1;
 const DBUS_VERSION_MINOR: u32 = 14;
 const DBUS_VERSION_MICRO: u32 = 4;
 
-// Location of dbus-daemon socket
+// Location of dbus-daemon socket.
+// Systemd Default: https://github.com/systemd/systemd/blob/main/src/libsystemd/sd-bus/bus-internal.h#L20
 const DBUS_SYSTEM_BUS_DEFAULT_ADDRESS: &str = "/run/dbus/system_bus_socket";
 const DBUS_SESSION_SOCKET_DIR: &str = "/tmp";
 const DBUS_MACHINE_UUID_FILE: &str = "/etc/machine-id";
@@ -93,6 +94,8 @@ const UNIX_SOURCES: &'static [&'static str] = &[
 ];
 
 /// Taken directly from the libdbus meson config
+/// Reference: https://github.com/freedesktop/dbus/blob/master/meson.build#L1026
+/// Meson variable: compile_warnings
 const CWARNINGS: &'static [&'static str] = &[
     // These warnings are intentionally disabled:
     //  - missing field initializers being implicitly 0 is a feature,