There are a number of things you can filter from reporting warnings on:

• excludeCategory
• pattern
  • Type: String

• excludeFile
• pattern
  • Type: String

• excludeModule
• pattern
  • Type: String

• excludePackage
• pattern
  • Type: String

• excludeType
• pattern
  • Type: String

None of those appears to allow you to just specify a path/directory under which everything should be filtered, for the gcc4 format for example.

I tried to use an Ant-style directory/*** but that was rejected as having one too many {}'s. I'm not sure that Module or Package will match an arbitrary path either though.

It seems that this plugin is missing that ability.