[SPARK-31102][SQL][3.0] Spark-sql fails to parse when contains comment

sql/catalyst/src/main/antlr4/org/apache/spark/sql/catalyst/parser/SqlBase.g4

@@ -1784,7 +1784,7 @@ fragment LETTER
     ;
 
 SIMPLE_COMMENT
-    : '--' ~[\r\n]* '\r'? '\n'? -> channel(HIDDEN)
+    : '--' ('\\\n' | ~[\r\n])* '\r'? '\n'? -> channel(HIDDEN)
     ;
 
 BRACKETED_EMPTY_COMMENT

sql/catalyst/src/test/scala/org/apache/spark/sql/catalyst/parser/PlanParserSuite.scala

@@ -55,6 +55,16 @@ class PlanParserSuite extends AnalysisTest {
     With(plan, ctes)
   }
 
+  test("single comment case one") {
+    val plan = table("a").select(star())
+    assertEqual("-- single comment\nSELECT * FROM a", plan)
+  }
+
+  test("single comment case two") {
+    val plan = table("a").select(star())
+    assertEqual("-- single comment\\\nwith line continuity\nSELECT * FROM a", plan)
+  }
+
   test("case insensitive") {
     val plan = table("a").select(star())
     assertEqual("sELEct * FroM a", plan)

sql/hive-thriftserver/src/main/scala/org/apache/spark/sql/hive/thriftserver/SparkSQLCLIDriver.scala

@@ -524,7 +524,6 @@ private[hive] class SparkSQLCLIDriver extends CliDriver with Logging {
     var insideComment = false
     var escape = false
     var beginIndex = 0
-    var endIndex = line.length
     val ret = new JArrayList[String]
 
     for (index <- 0 until line.length) {
@@ -552,8 +551,6 @@ private[hive] class SparkSQLCLIDriver extends CliDriver with Logging {
         } else if (hasNext && line.charAt(index + 1) == '-') {
           // ignore quotes and ;
           insideComment = true
-          // ignore eol
-          endIndex = index
         }
       } else if (line.charAt(index) == ';') {
         if (insideSingleQuote || insideDoubleQuote || insideComment) {
@@ -563,8 +560,11 @@ private[hive] class SparkSQLCLIDriver extends CliDriver with Logging {
           ret.add(line.substring(beginIndex, index))
           beginIndex = index + 1
         }
-      } else {
-        // nothing to do
+      } else if (line.charAt(index) == '\n') {
+        // with a new line the inline comment should end.
+        if (!escape) {
+          insideComment = false
+        }
       }
       // set the escape
       if (escape) {
@@ -573,7 +573,7 @@ private[hive] class SparkSQLCLIDriver extends CliDriver with Logging {
         escape = true
       }
     }
-    ret.add(line.substring(beginIndex, endIndex))
+    ret.add(line.substring(beginIndex))
     ret
   }
 }

sql/hive-thriftserver/src/test/scala/org/apache/spark/sql/hive/thriftserver/CliSuite.scala

@@ -508,18 +508,20 @@ class CliSuite extends SparkFunSuite with BeforeAndAfterAll with Logging {
     )
   }
 
-  test("SPARK-30049 Should not complain for quotes in commented with multi-lines") {
+  test("SPARK-31102 spark-sql fails to parse when contains comment") {
     runCliWithin(1.minute)(
-      """SELECT concat('test', 'comment') -- someone's comment here \\
-        | comment continues here with single ' quote \\
-        | extra ' \\
-        |;""".stripMargin -> "testcomment"
+      """SELECT concat('test', 'comment'),
+        |    -- someone's comment here
+        | 2;""".stripMargin -> "testcomment"
     )
+  }
+
+  test("SPARK-30049 Should not complain for quotes in commented with multi-lines") {
     runCliWithin(1.minute)(
-      """SELECT concat('test', 'comment') -- someone's comment here \\
-        |   comment continues here with single ' quote \\
-        |   extra ' \\
-        |   ;""".stripMargin -> "testcomment"
+      """SELECT concat('test', 'comment') -- someone's comment here \
+        | comment continues here with single ' quote \
+        | extra ' \
+        |;""".stripMargin -> "testcomment"
     )
   }