When I tried to scan warnings from a separate file (using the "File pattern"
field) specifying what types of warnings I wanted to see in the "Warnings to
include" field, the plugin actually ignored those types of warnings. After that,
I tried to specified types of warnings I didn't want to see in the "Warnings to
ignore" field, and it did absolutely nothing (all the warnings appeared).

Using the "scan console" or "scan build log" option works well with "Warnings to
include/ignore" option (I checked). But it seems that using "File pattern"
option, the "Warning to include" option will do the job of the "Warning to
ignore" option, and the "Warning to ignore" option will do nothing.