Requiring users to do find_package(Qt6FooPrivate) to use private modules
turned out to be a too invasive change for Qt 6.9. We turn off this
behavior and restrict it to the dev branch.
[ChangeLog][CMake] The requirement to do find_package(Qt6FooPrivate) in
user projects was postponed to a later Qt version.
Task-number: QTBUG-87776
Change-Id: Ifbf676288587ae5fabe100bf3bd93b220ddbc5ac
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
[ChangeLog][CMake] CMake packages of public Qt modules don't provide the
targets of their private counterparts anymore. User projects must now
call find_package(Qt6 COMPONENTS FooPrivate) to make use of the
Qt6::FooPrivate target. User projects that rely on the old behavior can
set the CMake variable QT_FIND_PRIVATE_MODULES to ON.
For user projects, the warning message we know from QMake is displayed.
The warning can be disabled by setting the CMake variable
QT_NO_PRIVATE_MODULE_WARNING to ON.
Within Qt itself, find_package(Qt6Foo) will still
find_package(Qt6FooPrivate).
For static Qt builds, we need to wrap usage of private Qt modules in
$<BUILD_INTERFACE> or $<BUILD_LOCAL_INTERFACE> (if CMake's version is >=
3.26). Static builds with CMake < 3.26 will always load the private
modules if the Qt6FooConfig.cmake from Qt's build tree is loaded. This
is the case in non-prefix builds and (in the future) when building
examples as external project.
This amends commit fbbf4ace0188b9718b6d7808021c0b887fd52d9f.
Task-number: QTBUG-87776
Change-Id: I78e95248f2b3fa73c3005c61df2fe4f71ad8eeb8
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
(cherry picked from commit ad7b94e163ac5c3959a7e38d7f48536be288a187)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
[ChangeLog][CMake] Private Qt modules have been split off into separate
Qt6FooPrivate CMake config packages. A call to find_package(Qt6Foo) will
now implicitly find_package(Qt6FooPrivate). It's not an error if
Qt6FooPrivate isn't available as it may be the case on certain Linux
distros that split their Qt module packages into private and public
parts.
For every public module Qt6Foo that has an associated Qt6FooPrivate
module, create a separate Qt6FooPrivate CMake config package.
Let Qt6FooPrivate find Qt6Foo. This is a required dependency.
Let Qt6Foo find Qt6FooPrivate if it's available. A message of log level
VERBOSE is issued if Qt6FooPrivate is not found.
Implementation notes: In QtModuleConfig.cmake.in, we pull in the private
module. This is not part of the *Dependencies.cmake file, because
1. The Qt6FooPrivate package references the Qt6::Foo target, therefore
it must be available. And Qt6FooDependencies.cmake is loaded before
creating targets.
2. The dependency needs to be optional, and we don't have facilities for
optional dependencies in Qt6FooDependencies yet.
3. We'd have to avoid recursion, because of the Qt6FooPrivate -> Qt6Foo
dependency.
Fixes: QTBUG-87776
Change-Id: I8f23f07da7ca76486f87b759e197174c11e13534
Reviewed-by: Alexey Edelev <alexey.edelev@qt.io>
(cherry picked from commit fbbf4ace0188b9718b6d7808021c0b887fd52d9f)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>
