When a `.moc` file is included in a source file and that source passed
to `qt_wrap_cpp`, Users should add the generated `.moc`s path to the
target's include path. Since we don't share anything about the output
path of generated files by `qt_wrap_cpp`, it makes sense to add in
inside `qt_wrap_cpp`. And also, the generated `.moc` file is added
to target's source to complete the dependency graph. Otherwise, Users
need to get output variable and pass it to target's sources.
* Update docs
* Add test
[ChangeLog][Build System] qt_wrap_cpp will accept .cpp files from now
on. When .cpp a file is passed to qt_wrap_cpp, TARGET parameter
becomes required. Generated .moc files are added to target's sources
inside qt_wrap_cpp. That's why the output parameter will not contain
generated .moc files.
Fixes: QTBUG-113402
Change-Id: I54dd2b1ff8e5c9ba457b1eb4f73b0a8190d9c659
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>