fix bugs

Author: Davies Liu

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/codegen/CodeGenerator.scala

@@ -160,6 +160,7 @@ class CodegenContext {
     * The map from a variable name to it's next ID.
     */
   private val freshNameIds = new mutable.HashMap[String, Int]
+  freshNameIds += INPUT_ROW -> 1
 
   /**
     * A prefix used to generate fresh name.

sql/catalyst/src/main/scala/org/apache/spark/sql/catalyst/expressions/complexTypeExtractors.scala

@@ -173,22 +173,26 @@ case class GetArrayStructFields(
   override def genCode(ctx: CodegenContext, ev: ExprCode): String = {
     val arrayClass = classOf[GenericArrayData].getName
     nullSafeCodeGen(ctx, ev, eval => {
+      val n = ctx.freshName("n")
+      val values = ctx.freshName("values")
+      val j = ctx.freshName("j")
+      val row = ctx.freshName("row")
       s"""
-        final int n = $eval.numElements();
-        final Object[] values = new Object[n];
-        for (int j = 0; j < n; j++) {
-          if ($eval.isNullAt(j)) {
-            values[j] = null;
+        final int $n = $eval.numElements();
+        final Object[] $values = new Object[$n];
+        for (int $j = 0; $j < $n; $j++) {
+          if ($eval.isNullAt($j)) {
+            $values[$j] = null;
           } else {
-            final InternalRow row = $eval.getStruct(j, $numFields);
-            if (row.isNullAt($ordinal)) {
-              values[j] = null;
+            final InternalRow $row = $eval.getStruct($j, $numFields);
+            if ($row.isNullAt($ordinal)) {
+              $values[$j] = null;
             } else {
-              values[j] = ${ctx.getValue("row", field.dataType, ordinal.toString)};
+              $values[$j] = ${ctx.getValue(row, field.dataType, ordinal.toString)};
             }
           }
         }
-        ${ev.value} = new $arrayClass(values);
+        ${ev.value} = new $arrayClass($values);
       """
     })
   }
@@ -227,12 +231,13 @@ case class GetArrayItem(child: Expression, ordinal: Expression)
 
   override def genCode(ctx: CodegenContext, ev: ExprCode): String = {
     nullSafeCodeGen(ctx, ev, (eval1, eval2) => {
+      val index = ctx.freshName("index")
       s"""
-        final int index = (int) $eval2;
-        if (index >= $eval1.numElements() || index < 0 || $eval1.isNullAt(index)) {
+        final int $index = (int) $eval2;
+        if ($index >= $eval1.numElements() || $index < 0 || $eval1.isNullAt($index)) {
           ${ev.isNull} = true;
         } else {
-          ${ev.value} = ${ctx.getValue(eval1, dataType, "index")};
+          ${ev.value} = ${ctx.getValue(eval1, dataType, index)};
         }
       """
     })