Fixes ABI breakage in Eldbus for use with C++ Eldbus

Summary:
This fixes the breakage when Eldbus_Service_Interface_Desc added a
wrongfully methods2 field to a class that is allocated by the user.

This patch adds the respective eldbus_service_interface_register2 and
eldbus_service_interface_fallback_register2 for registration of
Eldbus_Service_Interface_Desc2 which is now versioned. So future the
functions can be backwards compatible and the struct be forward
compatible and leaves the Eldbus_Service_Interface_Desc and
eldbus_service_interface_register and
eldbus_service_interface_fallback_register intact as it was in EFL
1.10.

This fixes T1408

Reviewers: cedric, stefan_schmidt, raster

Reviewed By: raster

Subscribers: cedric

Maniphest Tasks: T1408

Differential Revision: https://phab.enlightenment.org/D1188

src/bindings/eldbus_cxx/eldbus_service.hh

@@ -364,13 +364,13 @@ service_interface service_interface_register(connection& c, const char* path
     (
      _create_methods_specification(std::make_tuple(args...))
     );
-  Eldbus_Service_Interface_Desc description =
+  Eldbus_Service_Interface_Desc2 description =
     {
-      interface, 0, 0, 0, 0, 0, &(*methods)[0]
+      {interface, 0, 0, 0, 0, 0}, ELDBUS_INTERFACE_DESCRIPTOR_VERSION, &(*methods)[0]
     };
 
   Eldbus_Service_Interface* iface
-    = ::eldbus_service_interface_register(c.native_handle(), path, &description);
+    = ::eldbus_service_interface_register2(c.native_handle(), path, &description);
   return service_interface(iface);
 }
 

src/lib/eldbus/eldbus_service.c

@@ -928,7 +928,7 @@ fail_signature:
 }
 
 static Eldbus_Service_Interface *
-_eldbus_service_interface_register(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc *desc, Eina_Bool fallback)
+_eldbus_service_interface_register(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc *desc, Eina_Bool fallback, unsigned int version)
 {
    Eldbus_Service_Object *obj;
    Eldbus_Service_Interface *iface;
@@ -966,8 +966,12 @@ _eldbus_service_interface_register(Eldbus_Connection *conn, const char *path, co
    for (method = desc->methods; method && method->member; method++)
      _eldbus_service_method_add(iface, method);
 
-   for (method2 = desc->methods2; method2 && method2->method.member; method2++)
-     _eldbus_service_method_add(iface, &method2->method);
+   if(version >= 2)
+     {
+        Eldbus_Service_Interface_Desc2* desc2 = (void*)desc;
+        for (method2 = desc2->methods2; method2 && method2->method.member; method2++)
+           _eldbus_service_method_add(iface, &method2->method);
+     }
    
    iface->signals = desc->signals;
    iface->sign_of_signals = signatures;
@@ -992,13 +996,25 @@ fail:
 EAPI Eldbus_Service_Interface *
 eldbus_service_interface_register(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc *desc)
 {
-   return _eldbus_service_interface_register(conn, path, desc, EINA_FALSE);
+   return _eldbus_service_interface_register(conn, path, desc, EINA_FALSE, 1u);
+}
+
+EAPI Eldbus_Service_Interface *
+eldbus_service_interface_register2(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc2 *desc)
+{
+   return _eldbus_service_interface_register(conn, path, &desc->description, EINA_FALSE, desc->version);
 }
 
 EAPI Eldbus_Service_Interface *
 eldbus_service_interface_fallback_register(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc *desc)
 {
-   return _eldbus_service_interface_register(conn, path, desc, EINA_TRUE);
+   return _eldbus_service_interface_register(conn, path, desc, EINA_TRUE, 1u);
+}
+
+EAPI Eldbus_Service_Interface *
+eldbus_service_interface_fallback_register2(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc2 *desc)
+{
+   return _eldbus_service_interface_register(conn, path, &desc->description, EINA_TRUE, desc->version);
 }
 
 static Eina_Bool

src/lib/eldbus/eldbus_service.h

@@ -15,6 +15,8 @@
 
 #define ELDBUS_PROPERTY_FLAG_DEPRECATED 1
 
+#define ELDBUS_INTERFACE_DESCRIPTOR_VERSION 2
+
 typedef struct _Eldbus_Arg_Info
 {
    const char *signature;
@@ -105,9 +107,15 @@ typedef struct _Eldbus_Service_Interface_Desc
    const Eldbus_Property *properties; /**< array of property that this interface have, the last item of array should be filled with NULL  */
    const Eldbus_Property_Get_Cb default_get; /**< default get function, if a property don't have a get function this will be used */
    const Eldbus_Property_Set_Cb default_set; /**< default set function, if a property don't have a set function this will be used */
-  const Eldbus_Method2 *methods2; /**< array of the methods that should be registered in this interface, the last item of array should be filled with NULL @since 1.11 */
 } Eldbus_Service_Interface_Desc;
 
+typedef struct _Eldbus_Service_Interface_Desc2
+{
+  Eldbus_Service_Interface_Desc description;
+  int version; /**< version of the interface descriptor. Must be initialized with ELDBUS_INTERFACE_DESCRIPTOR_VERSION @since 1.11 >*/
+  const Eldbus_Method2 *methods2; /**< array of the methods that should be registered in this interface, the last item of array should be filled with NULL @since 1.11 */
+} Eldbus_Service_Interface_Desc2;
+
 /**
  * @brief Register an interface in the given path and connection.
  *
@@ -134,6 +142,42 @@ EAPI Eldbus_Service_Interface *eldbus_service_interface_register(Eldbus_Connecti
 EAPI Eldbus_Service_Interface *
 eldbus_service_interface_fallback_register(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc *desc) EINA_ARG_NONNULL(1, 2, 3);
 
+/**
+ * @brief Register an interface in the given path and connection. This
+ * extended register function allows the registration of stateful methods, with void* data.
+ *
+ * Note: Use eldbus_service_interface_unregister() to unregister a interface.
+ *
+ * @param conn where the interface should listen
+ * @param path object path
+ * @param desc description of interface
+ *
+ * @since 1.11
+ *
+ * @return Interface
+ */
+EAPI Eldbus_Service_Interface *eldbus_service_interface_register2(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc2 *desc) EINA_ARG_NONNULL(1, 2, 3);
+
+/**
+ * @brief Register a fallback interface handler for a given subsection
+ * of the object hierarchy.  This extended register function allows
+ * the registration of stateful methods, with void* data.
+ *
+ * Note: Use eldbus_service_interface_unregister() to unregister a interface.
+ *
+ * @param conn where the interface should listen
+ * @param path a '/' delimited string of path elements
+ * @param desc description of interface
+ * @see eldbus_service_interface_unregister()
+ *
+ * @since 1.11
+ *
+ * @return Interface
+ */
+EAPI Eldbus_Service_Interface *
+eldbus_service_interface_fallback_register2(Eldbus_Connection *conn, const char *path, const Eldbus_Service_Interface_Desc2 *desc) EINA_ARG_NONNULL(1, 2, 3);
+
+
 /**
  * @brief Unregister a interface.
  * Note: This doesn't unregister the object path if interface count reaches 0.