codegen: Fix critical on symbols without source reference

diff --git a/codegen/valaccodebasemodule.vala b/codegen/valaccodebasemodule.vala
index fb52bf8ea5f53ebd0589bb041bae494745ed3618..5c0695698e7eddac87bef02bfd1e0229220464c0 100644 (file)
--- a/codegen/valaccodebasemodule.vala
+++ b/codegen/valaccodebasemodule.vala
@@ -486,7 +486,9 @@ public class Vala.CCodeBaseModule : CodeGenerator {
                if (decl_space.add_declaration (name)) {
                        return true;
                }
-               sym.source_reference.file.used = true;
+               if (sym.source_reference != null) {
+                       sym.source_reference.file.used = true;
+               }
                if (sym.external_package || (!decl_space.is_header && CodeContext.get ().use_header && !sym.is_internal_symbol ())) {
                        // add appropriate include file
                        foreach (string header_filename in sym.get_cheader_filenames ()) {