mkspecs/features/qt.prf adds a dependency on the system threading
library if the Qt Core thread feature is enabled. Because qt.prf is
loaded by any public or internal Qt project, it's essentially a public
dependency for any Qt consumer.
To mimic that in CMake, we check if the thread feature is enabled, and
and set the Threads::Threads library as a dependency of Qt6::Platform,
which is a public target used by all Qt modules and plugins and Qt
consumers.
We also need to create a Qt6Dependencies.cmake file so we
find_package(Threads) every time find_package(Qt6) is called.
For the .prl files to be usable, we have to filter out some
CMake implementation specific directory separator tokens
'CMAKE_DIRECTORY_ID_SEP' aka '::@', which are added because we call
target_link_libraries() with a target created in a different scope
(I think).
As a result of this change, we shouldn't have to hardcode
Threads::Threads in other projects, because it's now a global public
dependency.
Task-number: QTBUG-85801
Task-number: QTBUG-85877
Change-Id: Ib5d662c43b28e63f7da49d3bd77d0ad751220b31
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Cristian Adam <cristian.adam@qt.io>
92ee9bd6b8