Warn when no relevant methods are found

compiler/preloader/instrumentation/src/org/jetbrains/jet/preloading/instrumentation/InterceptionInstrumenter.java

@@ -57,7 +57,7 @@ public class InterceptionInstrumenter {
     }
 
     private void addHandlerClass(Class<?> handlerClass) {
-        for (Field field : handlerClass.getFields()) {
+        for (final Field field : handlerClass.getFields()) {
             MethodInterceptor annotation = field.getAnnotation(MethodInterceptor.class);
             if (annotation == null) continue;
 
@@ -74,7 +74,7 @@ public class InterceptionInstrumenter {
                     throw new IllegalArgumentException("Interceptor is null: " + field);
                 }
 
-                Class<?> interceptorClass = interceptor.getClass();
+                final Class<?> interceptorClass = interceptor.getClass();
 
                 FieldData fieldData = getFieldData(field, interceptorClass);
 
@@ -109,6 +109,15 @@ public class InterceptionInstrumenter {
                     }
                 }
 
+                if (enterData.isEmpty() && normalReturnData.isEmpty() && exceptionData.isEmpty()) {
+                    dumpTasks.add(new DumpAction() {
+                        @Override
+                        public void dump(PrintStream out) {
+                            out.println("WARNING: No relevant methods found in " + field + " of type " + interceptorClass.getCanonicalName());
+                        }
+                    });
+                }
+
                 String nameFromAnnotation = annotation.methodName();
                 String methodName = nameFromAnnotation.isEmpty() ? field.getName() : nameFromAnnotation;
                 MethodInstrumenter instrumenter = new MethodInstrumenter(