[SPARK-15166][SQL] Move some hive-specific code from SparkSession

## What changes were proposed in this pull request?

This also simplifies the code being moved.

## How was this patch tested?

Existing tests.

Author: Andrew Or <andrew@databricks.com>

Closes #12941 from andrewor14/move-code.

sql/core/src/main/scala/org/apache/spark/sql/SparkSession.scala

@@ -73,19 +73,6 @@ class SparkSession private(
    |  Session-related state  |
    * ----------------------- */
 
-  {
-    val defaultWarehousePath =
-      SQLConf.WAREHOUSE_PATH
-        .defaultValueString
-        .replace("${system:user.dir}", System.getProperty("user.dir"))
-    val warehousePath = sparkContext.conf.get(
-      SQLConf.WAREHOUSE_PATH.key,
-      defaultWarehousePath)
-    sparkContext.conf.set(SQLConf.WAREHOUSE_PATH.key, warehousePath)
-    sparkContext.conf.set("hive.metastore.warehouse.dir", warehousePath)
-    logInfo(s"Setting warehouse location to $warehousePath")
-  }
-
   /**
    * State shared across sessions, including the [[SparkContext]], cached data, listener,
    * and a catalog that interacts with external systems.

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSessionState.scala

@@ -17,8 +17,6 @@
 
 package org.apache.spark.sql.hive
 
-import org.apache.hadoop.hive.conf.HiveConf.ConfVars
-
 import org.apache.spark.sql._
 import org.apache.spark.sql.catalyst.analysis.Analyzer
 import org.apache.spark.sql.execution.SparkPlanner

sql/hive/src/main/scala/org/apache/spark/sql/hive/HiveSharedState.scala

@@ -18,8 +18,9 @@
 package org.apache.spark.sql.hive
 
 import org.apache.spark.SparkContext
-import org.apache.spark.sql.hive.client.{HiveClient, HiveClientImpl}
-import org.apache.spark.sql.internal.SharedState
+import org.apache.spark.internal.Logging
+import org.apache.spark.sql.hive.client.HiveClient
+import org.apache.spark.sql.internal.{SharedState, SQLConf}
 
 
 /**
@@ -27,9 +28,17 @@ import org.apache.spark.sql.internal.SharedState
  * [[org.apache.spark.sql.SparkSession]] backed by Hive.
  */
 private[hive] class HiveSharedState(override val sparkContext: SparkContext)
-  extends SharedState(sparkContext) {
+  extends SharedState(sparkContext) with Logging {
 
-  // TODO: just share the IsolatedClientLoader instead of the client instances themselves
+  // TODO: just share the IsolatedClientLoader instead of the client instance itself
+
+  {
+    // Set the Hive metastore warehouse path to the one we use
+    val tempConf = new SQLConf
+    sparkContext.conf.getAll.foreach { case (k, v) => tempConf.setConfString(k, v) }
+    sparkContext.conf.set("hive.metastore.warehouse.dir", tempConf.warehousePath)
+    logInfo(s"Setting Hive metastore warehouse path to '${tempConf.warehousePath}'")
+  }
 
   /**
    * A Hive client used to interact with the metastore.