Add @Options annotation

Support using @Option annotations from other objects during command
line parsing so that options can be shared by different classes
using composition instead of inheritance.

Change-Id: I949ae8387847057301e22bd2b2be77d1dc3c25aa

gerrit-server/src/main/java/com/google/gerrit/server/DynamicOptions.java

@@ -138,7 +138,7 @@ public class DynamicOptions {
 
   public void parseDynamicBeans(CmdLineParser clp) {
     for (Entry<String, DynamicBean> e : beansByPlugin.entrySet()) {
-      clp.parseWithPrefix(e.getKey(), e.getValue());
+      clp.parseWithPrefix("--" + e.getKey(), e.getValue());
     }
   }
 

gerrit-util-cli/src/main/java/com/google/gerrit/util/cli/CmdLineParser.java

@@ -48,9 +48,11 @@ import java.lang.reflect.Field;
 import java.lang.reflect.Method;
 import java.util.ArrayList;
 import java.util.HashMap;
+import java.util.HashSet;
 import java.util.List;
 import java.util.Map;
 import java.util.ResourceBundle;
+import java.util.Set;
 import org.kohsuke.args4j.Argument;
 import org.kohsuke.args4j.CmdLineException;
 import org.kohsuke.args4j.IllegalAnnotationError;
@@ -381,7 +383,7 @@ public class CmdLineParser {
     }
 
     private static String getPrefixedName(String prefix, String name) {
-      return "--" + prefix + name;
+      return prefix + name;
     }
   }
 
@@ -393,11 +395,19 @@ public class CmdLineParser {
 
     MyParser(Object bean) {
       super(bean);
+      parseAdditionalOptions("", bean, new HashSet<>());
       ensureOptionsInitialized();
     }
 
     // NOTE: Argument annotations on bean are ignored.
     public void parseWithPrefix(String prefix, Object bean) {
+      parseWithPrefix(prefix, bean, new HashSet<>());
+    }
+
+    private void parseWithPrefix(String prefix, Object bean, Set<Object> parsedBeans) {
+      if (!parsedBeans.add(bean)) {
+        return;
+      }
       // recursively process all the methods/fields.
       for (Class<?> c = bean.getClass(); c != null; c = c.getSuperclass()) {
         for (Method m : c.getDeclaredMethods()) {
@@ -411,6 +421,31 @@ public class CmdLineParser {
           if (o != null) {
             addOption(Setters.create(f, bean), new PrefixedOption(prefix, o));
           }
+          if (f.isAnnotationPresent(Options.class)) {
+            try {
+              parseWithPrefix(
+                  prefix + f.getAnnotation(Options.class).prefix(), f.get(bean), parsedBeans);
+            } catch (IllegalAccessException e) {
+              throw new IllegalAnnotationError(e);
+            }
+          }
+        }
+      }
+    }
+
+    private void parseAdditionalOptions(String prefix, Object bean, Set<Object> parsedBeans) {
+      for (Class c = bean.getClass(); c != null; c = c.getSuperclass()) {
+        for (Field f : c.getDeclaredFields()) {
+          if (f.isAnnotationPresent(Options.class)) {
+            Object additionalBean = null;
+            try {
+              additionalBean = f.get(bean);
+            } catch (IllegalAccessException e) {
+              throw new IllegalAnnotationError(e);
+            }
+            parseWithPrefix(
+                prefix + f.getAnnotation(Options.class).prefix(), additionalBean, parsedBeans);
+          }
         }
       }
     }

gerrit-util-cli/src/main/java/com/google/gerrit/util/cli/Options.java

@@ -0,0 +1,33 @@
+// Copyright (C) 2017 The Android Open Source Project
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package com.google.gerrit.util.cli;
+
+import static java.lang.annotation.ElementType.FIELD;
+import static java.lang.annotation.RetentionPolicy.RUNTIME;
+
+import java.lang.annotation.Retention;
+import java.lang.annotation.Target;
+
+/**
+ * Marks a field that refers to a class with @Option annotations
+ *
+ * <p>Any @Option annotations found on the referred class will be handled as if they were found on
+ * the referring class.
+ */
+@Retention(RUNTIME)
+@Target({FIELD})
+public @interface Options {
+  String prefix() default "";
+}