[vala/staging: 4/10] codegen: Only emit declaration of *_register_type if needed

[Rico Tzschichholz <ricotz src gnome org>]

commit 5d7b6a1e59dc330b2bdcf0ff8ff38a85adda8edc
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Sat Feb 23 20:19:31 2019 +0100

    codegen: Only emit declaration of *_register_type if needed
    
    This allows to add a test case for ModuleInit with -Werror=redundant-decls

 codegen/valaccodemethodmodule.vala | 11 +++++++----
 1 file changed, 7 insertions(+), 4 deletions(-)
---
diff --git a/codegen/valaccodemethodmodule.vala b/codegen/valaccodemethodmodule.vala
index 4adf1f4b3..bc7a3b2a1 100644
--- a/codegen/valaccodemethodmodule.vala
+++ b/codegen/valaccodemethodmodule.vala
@@ -289,10 +289,13 @@ public abstract class Vala.CCodeMethodModule : CCodeStructModule {
                }
 
                // Add function prototypes for required register-type-calls which are likely external
-               var register_func = new CCodeFunction ("%s_register_type".printf (get_ccode_lower_case_name 
(type_symbol, null)), "GType");
-               register_func.add_parameter (new CCodeParameter ("module", "GTypeModule *"));
-               register_func.is_declaration = true;
-               cfile.add_function_declaration (register_func);
+               if (type_symbol.source_reference.file != cfile.file) {
+                       // TODO Duplicated source with TypeRegisterFunction.init_from_type()
+                       var register_func = new CCodeFunction ("%s_register_type".printf 
(get_ccode_lower_case_name (type_symbol, null)), "GType");
+                       register_func.add_parameter (new CCodeParameter ("module", "GTypeModule *"));
+                       register_func.is_declaration = true;
+                       cfile.add_function_declaration (register_func);
+               }
 
                var register_call = new CCodeFunctionCall (new CCodeIdentifier ("%s_register_type".printf 
(get_ccode_lower_case_name (type_symbol, null))));
                register_call.add_argument (new CCodeIdentifier (module_init_param_name));