LGTM.com - false positive - Java implicit cast in compound assignment for constants

[Marcono1234]

Description of the false positive
The query java/implicit-cast-in-compound-assignment incorrectly flags compound statements with numeric literals within the value range of the target type. E.g.:

byte b = 1;
b *= 10; // Incorrectly flagged even though it is safe

Side note: Literals which exceed the value range should probably be even flagged as error (instead of warning):

byte b = 1;
b += 0xFF; // Exceeds 127, but is still in unsigned value range, might be intended: Ok
b += 256; // Very likely not intended: Error

Also why doesn't java/implicit-cast-in-compound-assignment cover all (arithmetic) compound assignments instead of only addition and multiplication?

URL to the alert on the project page on LGTM.com
https://lgtm.com/projects/g/apache/hive/snapshot/48856d424acd0be5fd4e911bbdabd9483a6fb39e/files/ql/src/java/org/apache/hadoop/hive/ql/udf/generic/GenericUDFMaskFirstN.java?sort=name&dir=ASC&mode=heatmap#x348d57efee59c05:1

[aschackmull]

Thank you for your report. You are correct that this query can be improved. We will look into it, but we cannot guarantee to prioritise this particular query very highly at the moment.