How to separate build settings and sources by platform type?

[Seonny]

I'd like to make multiplatform target for iOS and watchOS like "platform: [iOS, watchOS]"
watchOS has different sources and settings from iOS's.
How can I handle this ?
I'm using 2.25.0 XcodeGen

[Vasily Anisimov]

Same question.

Made workaround for now:

settings:
  FRAMEWORK_SEARCH_PATHS: <this_is_base_settings>
  HEADER_SEARCH_PATHS: <this_is_base_settings>
  FRAMEWORK_SEARCH_PATHS[sdk=macosx*]: <this_is_macOS_settings>
  HEADER_SEARCH_PATHS[sdk=macosx*]: <this_is_macOS_settings>