Reporting unused parameters

injector-generator/src/org/jetbrains/jet/di/Dependencies.java

@@ -34,6 +34,7 @@ public class Dependencies {
 
     private final Set<Field> allFields = Sets.newLinkedHashSet();
     private final Set<Field> satisfied = Sets.newHashSet();
+    private final Set<Field> used = Sets.newHashSet();
     private final Multimap<DiType, Field> typeToFields = HashMultimap.create();
 
     private final Set<Field> newFields = Sets.newLinkedHashSet();
@@ -85,6 +86,7 @@ public class Dependencies {
                     field + ": " + method + ": " + allFields,
                     neededFor.prepend(field)
             );
+            used.add(dependency);
 
             field.getDependencies().add(new SetterDependency(field, method.getName(), dependency));
         }
@@ -152,6 +154,7 @@ public class Dependencies {
                     "constructor: " + constructor + ", parameter: " + parameterType,
                     neededFor.prepend(field)
             );
+            used.add(fieldForParameter);
             dependency.getConstructorArguments().add(fieldForParameter);
         }
 
@@ -165,6 +168,11 @@ public class Dependencies {
         return newFields;
     }
 
+    @NotNull
+    public Set<Field> getUsedFields() {
+        return used;
+    }
+
     private interface ImmutableStack<T> {
         @NotNull
         ImmutableStack<T> prepend(T t);

injector-generator/src/org/jetbrains/jet/di/DependencyInjectorGenerator.java

@@ -53,7 +53,7 @@ public class DependencyInjectorGenerator {
         File file = new File(outputFileName);
 
         fields.addAll(dependencies.satisfyDependencies());
-
+        reportUnusedParameters(injectorPackageName, injectorClassName);
 
         StringBuilder preamble = new StringBuilder();
         generatePreamble(injectorPackageName, new Printer(preamble));
@@ -92,6 +92,15 @@ public class DependencyInjectorGenerator {
         GeneratorsFileUtil.writeFileIfContentChanged(file, text.toString());
     }
 
+    private void reportUnusedParameters(String injectorPackageName, String injectorClassName) {
+        Sets.SetView<Field> unusedParameters = Sets.difference(backsParameter, dependencies.getUsedFields());
+        for (Field parameter : unusedParameters) {
+            if (!parameter.isPublic()) {
+                System.err.println("Unused parameter: " + parameter + " for " + injectorPackageName + "." + injectorClassName);
+            }
+        }
+    }
+
     private void generatePreamble(String injectorPackageName, Printer p) throws IOException {
         String copyright = "injector-generator/copyright.txt";
         p.println(FileUtil.loadFile(new File(copyright)));