[vala/wip/issue548: 28/34] vala: Add Method.compatible_no_error()

[Rico Tzschichholz <ricotz src gnome org>]

commit d9c150c7ac267f3ef36a2b9f5c35913387788066
Author: Rico Tzschichholz <ricotz ubuntu com>
Date:   Tue Dec 18 21:19:35 2018 +0100

    vala: Add Method.compatible_no_error()

 vala/valamethod.vala | 19 +++++++++++++++++--
 1 file changed, 17 insertions(+), 2 deletions(-)
---
diff --git a/vala/valamethod.vala b/vala/valamethod.vala
index 18f043f07..294f7b397 100644
--- a/vala/valamethod.vala
+++ b/vala/valamethod.vala
@@ -310,6 +310,21 @@ public class Vala.Method : Subroutine, Callable {
         * @return true if the specified method is compatible to this method
         */
        public bool compatible (Method base_method, out string? invalid_match) {
+               return compatible_internal (base_method, out invalid_match, this);
+       }
+
+       /**
+        * Checks whether the parameters and return type of this method are
+        * compatible with the specified method
+        *
+        * @param base_method a method
+        * @return true if the specified method is compatible to this method
+        */
+       public bool compatible_no_error (Method base_method) {
+               return compatible_internal (base_method, null, null);
+       }
+
+       bool compatible_internal (Method base_method, out string? invalid_match, CodeNode? node_reference) {
                // method is always compatible to itself
                if (this == base_method) {
                        invalid_match = null;
@@ -349,7 +364,7 @@ public class Vala.Method : Subroutine, Callable {
                        }
                }
 
-               var actual_base_type = base_method.return_type.get_actual_type (object_type, 
method_type_args, this);
+               var actual_base_type = base_method.return_type.get_actual_type (object_type, 
method_type_args, node_reference);
                if (!return_type.equals (actual_base_type)) {
                        invalid_match = "Base method expected return type `%s', but `%s' was provided".printf 
(actual_base_type.to_prototype_string (), return_type.to_prototype_string ());
                        return false;
@@ -375,7 +390,7 @@ public class Vala.Method : Subroutine, Callable {
                                        return false;
                                }
 
-                               actual_base_type = base_param.variable_type.get_actual_type (object_type, 
method_type_args, this);
+                               actual_base_type = base_param.variable_type.get_actual_type (object_type, 
method_type_args, node_reference);
                                if (!actual_base_type.equals (param.variable_type)) {
                                        invalid_match = "incompatible type of parameter %d".printf 
(param_index);
                                        return false;