[SPARK-16489] Test harness to prevent expression code generation from reusing variable names

• Type: Bug
• Status: Resolved
• Priority: Major
• Resolution: Fixed
• Fix Version/s: 1.6.3, 2.0.0
• Component/s: SQL
• Target Version/s: 2.0.0
• Assignee: Reynold Xin
• Reporter: Reynold Xin
• Created: 12/Jul/16 01:08
• Updated: 13/Jul/16 06:14
• Resolved: 12/Jul/16 17:08

Description

In code generation, it is incorrect for expressions to reuse variable names across different instances of itself. As an example, SPARK-16488 reports a bug in which pmod expression reuses variable name "r".

This patch updates ExpressionEvalHelper test harness to always project two instances of the same expression, which will help us catch variable reuse problems in expression unit tests.

Issue Links

• is related to: SPARK-16488 Codegen variable namespace collision for pmod and partitionBy
• links to: [Github] Pull Request #14146 (rxin)