rednaxelafx opened a new pull request #29602: URL: https://github.com/apache/spark/pull/29602
### What changes were proposed in this pull request? Use `CodeGenerator.typeName()` instead of `Class.getCanonicalName()` in `CodegenContext.addReferenceObj()` for getting the runtime class name for an object. ### Why are the changes needed? https://github.com/apache/spark/pull/29439 fixed a bug in `CodegenContext.addReferenceObj()` for `Array[Byte]` (i.e. Spark SQL's `BinaryType`) objects, but unfortunately it introduced a regression for some nested Scala types. For example, for `implicitly[Ordering[UTF8String]]`, after that PR `CodegenContext.addReferenceObj()` would return `((null) references[0] /* ... */)`. The actual type for `implicitly[Ordering[UTF8String]]` is `scala.math.LowPriorityOrderingImplicits$$anon$3` in Scala 2.12.10, and `Class.getCanonicalName()` returns `null` for that class. On the other hand, `Class.getName()` is safe to use for all non-array types, and Janino will happily accept the type name returned from `Class.getName()` for nested types. `CodeGenerator.typeName()` happens to do the right thing by correctly handling arrays and otherwise use `Class.getName()`. So it's a better alternative than `Class.getCanonicalName()`. Side note: rule of thumb for using Java reflection in Spark: it may be tempting to use `Class.getCanonicalName()`, but for functions that may need to handle Scala types, please avoid it due to potential issues with nested Scala types. Instead, use `Class.getName()` or utility functions in `org.apache.spark.util.Utils` (e.g. `Utils.getSimpleName()` or `Utils.getFormattedClassName()` etc). ### Does this PR introduce _any_ user-facing change? No. ### How was this patch tested? Added new unit test case for the regression case in `CodeGenerationSuite`. ---------------------------------------------------------------- This is an automated message from the Apache Git Service. To respond to the message, please log on to GitHub and use the URL above to go to the specific comment. For queries about this service, please contact Infrastructure at: [email protected] --------------------------------------------------------------------- To unsubscribe, e-mail: [email protected] For additional commands, e-mail: [email protected]
