CMake: Record the precise package name where Private modules live

Previously if a target depended on CorePrivate, we would write a
_qt_internal_find_qt_dependencies(... Qt6CorePrivate) call into a
FooDependencies.cmake file.
That find_qt_deps call would remove the 'Private' suffix and would run
find_dependency with NAMES set to both the altered and non-altered
names.
This would find the relevant package but it would set the wrong
_FOUND variable name, e.g it would set Qt6CorePrivate_FOUND instead
of Qt6Core_FOUND.
This in turn could cause multiple lookups of the Qt6Core package
during dependency handling because the correct _FOUND var would not be
set.

Instead of always looking for the Qt6CorePrivate package, make sure
we look for an appropriately named package for all Privates modules,
because we have the necessary info to determine the correct name.

Note that INTERNAL modules will still be looked up via a Private
suffixed package name because that's how the package name is chosen
for them.

Remove the code that accounted for Private modules in
qt_internal_remove_qt_dependency_duplicates because it's not needed
anymore.

Warn when a package name can't be queried from a target's property
because the target might not exist yet.

Add a TODO comment for the code that searches with two NAMES.
We can't remove it right now, because it might break user projects
that use stale Dependencies.cmake files.

The dbus subdirectory is added before the tools subdirectory
to ensure that the new package name extraction does not error out, due
to trying to access a target that does not yet exist.

Amends 425ff34aa10a02524f2d52f544dc00b539ef9a26

Pick-to: 6.4
Task-number: QTBUG-104998
Change-Id: Ib34ae5ed92f68b4265518c2b8802daeb1a3a04d6
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>

1 files changed, 3 insertions, 1 deletions

diff --git a/src/CMakeLists.txt b/src/CMakeLists.txt
index 1c36da6022..0e10078bf4 100644
--- a/src/CMakeLists.txt
+++ b/src/CMakeLists.txt
@@ -58,11 +58,13 @@ endif()
 if (QT_FEATURE_xml)
     add_subdirectory(xml)
 endif()
-add_subdirectory(tools)
 
 if (QT_FEATURE_dbus)
     add_subdirectory(dbus)
 endif()
+
+add_subdirectory(tools)
+
 if(QT_FEATURE_gui)
     add_subdirectory(gui)