[SPARK-33100][SQL] Ignore a semicolon inside a bracketed comment in spark-sql

### What changes were proposed in this pull request?
Now the spark-sql does not support parse the sql statements with bracketed comments.
For the sql statements:
```
/* SELECT 'test'; */
SELECT 'test';
```
Would be split to two statements:
The first one: `/* SELECT 'test'`
The second one: `*/ SELECT 'test'`

Then it would throw an exception because the first one is illegal.
In this PR, we ignore the content in bracketed comments while splitting the sql statements.
Besides, we ignore the comment without any content.

### Why are the changes needed?
Spark-sql might split the statements inside bracketed comments and it is not correct.

### Does this PR introduce _any_ user-facing change?
No.

### How was this patch tested?
Added UT.

Closes #29982 from turboFei/SPARK-33110.

Lead-authored-by: fwang12 <[email protected]>
Co-authored-by: turbofei <[email protected]>
Signed-off-by: Takeshi Yamamuro <[email protected]>
(cherry picked from commit a071826)
Signed-off-by: Takeshi Yamamuro <[email protected]>

Author: turboFei

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

@@ -522,14 +522,22 @@ private[hive] class SparkSQLCLIDriver extends CliDriver with Logging {
   // Note: [SPARK-31595] if there is a `'` in a double quoted string, or a `"` in a single quoted
   // string, the origin implementation from Hive will not drop the trailing semicolon as expected,
   // hence we refined this function a little bit.
+  // Note: [SPARK-33100] Ignore a semicolon inside a bracketed comment in spark-sql.
   private def splitSemiColon(line: String): JList[String] = {
     var insideSingleQuote = false
     var insideDoubleQuote = false
-    var insideComment = false
+    var insideSimpleComment = false
+    var bracketedCommentLevel = 0
     var escape = false
     var beginIndex = 0
+    var includingStatement = false
     val ret = new JArrayList[String]
 
+    def insideBracketedComment: Boolean = bracketedCommentLevel > 0
+    def insideComment: Boolean = insideSimpleComment || insideBracketedComment
+    def statementBegin(index: Int): Boolean = includingStatement || (!insideComment &&
+      index > beginIndex && !s"${line.charAt(index)}".trim.isEmpty)
+
     for (index <- 0 until line.length) {
       if (line.charAt(index) == '\'' && !insideComment) {
         // take a look to see if it is escaped
@@ -553,21 +561,33 @@ private[hive] class SparkSQLCLIDriver extends CliDriver with Logging {
           // Sample query: select "quoted value --"
           //                                    ^^ avoids starting a comment if it's inside quotes.
         } else if (hasNext && line.charAt(index + 1) == '-') {
-          // ignore quotes and ;
-          insideComment = true
+          // ignore quotes and ; in simple comment
+          insideSimpleComment = true
         }
       } else if (line.charAt(index) == ';') {
         if (insideSingleQuote || insideDoubleQuote || insideComment) {
           // do not split
         } else {
-          // split, do not include ; itself
-          ret.add(line.substring(beginIndex, index))
+          if (includingStatement) {
+            // split, do not include ; itself
+            ret.add(line.substring(beginIndex, index))
+          }
           beginIndex = index + 1
+          includingStatement = false
         }
       } else if (line.charAt(index) == '\n') {
-        // with a new line the inline comment should end.
+        // with a new line the inline simple comment should end.
         if (!escape) {
-          insideComment = false
+          insideSimpleComment = false
+        }
+      } else if (line.charAt(index) == '/' && !insideSimpleComment) {
+        val hasNext = index + 1 < line.length
+        if (insideSingleQuote || insideDoubleQuote) {
+          // Ignores '/' in any case of quotes
+        } else if (insideBracketedComment && line.charAt(index - 1) == '*' ) {
+          bracketedCommentLevel -= 1
+        } else if (hasNext && !insideBracketedComment && line.charAt(index + 1) == '*') {
+          bracketedCommentLevel += 1
         }
       }
       // set the escape
@@ -576,8 +596,12 @@ private[hive] class SparkSQLCLIDriver extends CliDriver with Logging {
       } else if (line.charAt(index) == '\\') {
         escape = true
       }
+
+      includingStatement = statementBegin(index)
+    }
+    if (includingStatement) {
+      ret.add(line.substring(beginIndex))
     }
-    ret.add(line.substring(beginIndex))
     ret
   }
 }

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

@@ -571,4 +571,27 @@ class CliSuite extends SparkFunSuite with BeforeAndAfterAll with Logging {
     // the date formatter for `java.sql.LocalDate` must output negative years with sign.
     runCliWithin(1.minute)("SELECT MAKE_DATE(-44, 3, 15);" -> "-0044-03-15")
   }
+
+  test("SPARK-33100: Ignore a semicolon inside a bracketed comment in spark-sql") {
+    runCliWithin(4.minute)(
+      "/* SELECT 'test';*/ SELECT 'test';" -> "test",
+      ";;/* SELECT 'test';*/ SELECT 'test';" -> "test",
+      "/* SELECT 'test';*/;; SELECT 'test';" -> "test",
+      "SELECT 'test'; -- SELECT 'test';" -> "",
+      "SELECT 'test'; /* SELECT 'test';*/;" -> "",
+      "/*$meta chars{^\\;}*/ SELECT 'test';" -> "test",
+      "/*\nmulti-line\n*/ SELECT 'test';" -> "test",
+      "/*/* multi-level bracketed*/ SELECT 'test';" -> "test"
+    )
+  }
+
+  test("SPARK-33100: test sql statements with hint in bracketed comment") {
+    runCliWithin(2.minute)(
+      "CREATE TEMPORARY VIEW t1 AS SELECT * FROM VALUES(1, 2) AS t1(k, v);" -> "",
+      "CREATE TEMPORARY VIEW t2 AS SELECT * FROM VALUES(2, 1) AS t2(k, v);" -> "",
+      "EXPLAIN SELECT /*+ MERGEJOIN(t1) */ t1.* FROM t1 JOIN t2 ON t1.k = t2.v;" -> "SortMergeJoin",
+      "EXPLAIN SELECT /* + MERGEJOIN(t1) */ t1.* FROM t1 JOIN t2 ON t1.k = t2.v;"
+        -> "BroadcastHashJoin"
+    )
+  }
 }