Compile options in Ant javac task

Recently I was tasked to migrate a code base from JDK 1.4 to 1.6. As part of this work, I need to take care of deprecated methods and unchecked types in collections. To verify, I turned on the options in ANT javac task as below. Note the use of deprecation="on" and <compilerarg value="-Xlint:unchecked"/>.

        <javac destdir="${build.dir}" source="1.6" target="1.6" debug="true"
               deprecation="on" failonerror="true">
            <src path="${src.dir}"/>
            <classpath refid="master-classpath"/>
            <compilerarg value="-Xlint:unchecked"/>
        </javac>