From 986ffe52eeebb14b94c04a264141cf09ff5530b1 Mon Sep 17 00:00:00 2001
From: yangjie01 <yangjie01@baidu.com>
Date: Thu, 12 Nov 2020 22:00:59 +0800
Subject: [PATCH]  add unused-imports compile arg

---
 .../org/apache/spark/deploy/history/FsHistoryProvider.scala    | 2 +-
 pom.xml                                                        | 3 +++
 2 files changed, 4 insertions(+), 1 deletion(-)

diff --git a/core/src/main/scala/org/apache/spark/deploy/history/FsHistoryProvider.scala b/core/src/main/scala/org/apache/spark/deploy/history/FsHistoryProvider.scala
index e1b0fc5e45d6e..e5341aff8ce66 100644
--- a/core/src/main/scala/org/apache/spark/deploy/history/FsHistoryProvider.scala
+++ b/core/src/main/scala/org/apache/spark/deploy/history/FsHistoryProvider.scala
@@ -21,7 +21,7 @@ import java.io.{File, FileNotFoundException, IOException}
 import java.lang.{Long => JLong}
 import java.nio.file.Files
 import java.util.{Date, NoSuchElementException, ServiceLoader}
-import java.util.concurrent.{ConcurrentHashMap, ExecutorService, Future, TimeUnit}
+import java.util.concurrent.{ConcurrentHashMap, ExecutorService, TimeUnit}
 import java.util.zip.ZipOutputStream
 
 import scala.collection.JavaConverters._
diff --git a/pom.xml b/pom.xml
index 25c6da7100056..19f053d3ecdca 100644
--- a/pom.xml
+++ b/pom.xml
@@ -164,6 +164,7 @@
     <commons.collections.version>3.2.2</commons.collections.version>
     <scala.version>2.12.10</scala.version>
     <scala.binary.version>2.12</scala.binary.version>
+    <scalac.arg.unused-imports>-Ywarn-unused-import</scalac.arg.unused-imports>
     <scalatest-maven-plugin.version>2.0.0</scalatest-maven-plugin.version>
     <scalafmt.parameters>--test</scalafmt.parameters>
     <!-- for now, not running scalafmt as part of default verify pipeline -->
@@ -2537,6 +2538,7 @@
               <arg>-deprecation</arg>
               <arg>-feature</arg>
               <arg>-explaintypes</arg>
+              <arg>${scalac.arg.unused-imports}</arg>
               <arg>-target:jvm-1.8</arg>
             </args>
             <jvmArgs>
@@ -3266,6 +3268,7 @@
       <properties>
         <scala.version>2.13.3</scala.version>
         <scala.binary.version>2.13</scala.binary.version>
+        <scalac.arg.unused-imports>-Wconf:cat=unused-imports:ws</scalac.arg.unused-imports>
       </properties>
       <dependencyManagement>
         <dependencies>