When a CMake release introduces a new policy that affects most Qt
modules, it may be appropriate to make each module aware of that newer
CMake version and use the NEW policy without raising the minimum CMake
version requirement. To reduce the churn associated with making that
change across all Qt modules individually, this change allows it to be
updated in a central place (qtbase), but in a way that allows a Qt
module to override it in its own .cmake.conf file if required (e.g. to
address the issues identified by policy warnings at a later time). The
policies are modified at the start of the call to
qt_build_repo_begin().
For commands defined by the qtbase module, qtbase needs to be in
control of the policy settings at the point where those commands are
defined. The above mechanism should not affect the policy settings for
these commands, so the various *Config.cmake.in files must not specify
policy ranges in a way that a Qt module's .cmake.conf file could
influence.
Starting with CMake 3.12, policies can be specified as a version range
with the cmake_minimum_required() and cmake_policy() commands. All
policies introduced in CMake versions up to the upper limit of that
range will be set to NEW. The actual version of CMake being used only
has to be at least the lower limit of the specified version range.
This change uses cmake_minimum_required() rather than cmake_policy()
due to the latter not halting further processing upon failure.
See the following:
https://gitlab.kitware.com/cmake/cmake/-/issues/21557
Task-number: QTBUG-88700
Pick-to: 6.0
Change-Id: I0a1f2611dd629f847a18186394f500d7f52753bc
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Building a user project in Release configuration against a Qt built with
CMAKE_CONFIGURATION_TYPES=RelWithDebInfo;Debug led to the user project
being linked against the Debug Qt libraries. This is especially painful
with MSVC where debug and release runtimes are incompatible.
We now create *AdditionalTargetInfo.cmake files along the
exported *Targets.cmake files that set the IMPORT_*_<CONFIG> properties
to the values of the release config Qt was built with.
User projects built with an unknown
configuration (CMAKE_BUILD_TYPE=ArbitraryName) will link against a
release Qt. This can be controlled by setting the variable
QT_DEFAULT_IMPORT_CONFIGURATION to, for example, DEBUG in the user
project.
Fixes: QTBUG-86743
Change-Id: I12c4b065a9845c7317f6acddab46b649f2732c9e
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
Add qt_add_3rdparty_library() function as a replacement for qmake's
qt_helper_lib feature.
All 3rdparty libraries will be available under the Qt:: alias when built
through this method so that they can properly register as dependencies
of a Qt module.
This patch also adds Qt3rdPartyLibraryConfig.cmake.in to export the
CMake configuration for static builds and shared libraries.
Change-Id: I52bf3a95ca22fccd9ab54343468847bb1b570c28
Fixes: QTBUG-81969
Reviewed-by: Liang Qi <liang.qi@qt.io>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
