Commit Graph

9 Commits

Author SHA1 Message Date
Alexandru Croitor
0da123d67b CMake: Bump almost all cmake_minimum_required calls to 3.16
Needed for subsequent change that will check and error out if the
version is lower than 3.16. We do that to ensure all policies
introduced by CMake up to version 3.16 have their behavior set to
NEW.

Pick-to: 6.2
Task-number: QTBUG-95018
Change-Id: Ieaf82c10987dd797d86a3fd4a986a67e72de486a
Reviewed-by: Kai Koehne <kai.koehne@qt.io>
2021-09-22 19:36:49 +02:00
Alexandru Croitor
5161d8d525 CMake: Remove qt6_enable_object_libraries_finalizer_mode
qt6_enable_object_libraries_finalizer_mode is not needed anymore
now that static Qt builds require CMake 3.21 and thus CMake takes
care of placing object library object files at the beginning of
the link line.

Rename qt6_enable_import_plugins_finalizer_mode to a more generic
qt6_set_finalizer_mode that can enable or disable multiple
different modes.

For now the only available mode is "static_plugins" which handles
the behavior of the old function name.

The mode can be enabled by calling

 qt6_set_finalizer_mode(${target} ENABLE MODES "static_plugins")

Note that the function is re-tagged as being in Technical Preview.

Ideally we would not need it at all. But we need to provide some
workaround for the limitations of linking Qt static plugins in CMake
on Linux-y platforms that use bfd ld or ld.gold.

The workaround does not work well with dependencies wrapped in
generator expressions which is why we can't confidently advertise it
as a proper solution.
Our hope is that this can be fixed in future upstream CMake versions
and the function can be removed.
See 6fcc272ac9 for details.

Adjust the tests due to the renamed and removed functions.

Amends 19e789bace
Amends cdbb390c4a
Amends a25027eecb
Amends 6fcc272ac9
Amends a3c430f390

Pick-to: 6.2
Fixes: QTBUG-95169
Task-number: QTBUG-95601
Task-number: QTBUG-95603
Change-Id: I51b85f776ec29fc04fed1a637eba7d1f60609e69
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
2021-08-10 16:51:53 +02:00
Alexandru Croitor
b2f00dfb46 CMake: Rename qt6_add_plugin TYPE option to PLUGIN_TYPE
The intention is to remove TYPE as a keyword completely before 6.2.0
release, but in case if that's not possible due to the large amount
of repositories and examples, just print a deprecation warning for
now and handle both TYPE and PLUGIN_TYPE.

Task-number: QTBUG-95170
Pick-to: 6.2
Change-Id: If0c18345483b9254b0fc21120229fcc2a2fbfbf5
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
2021-08-06 21:08:21 +02:00
Alexey Edelev
e80b010795 Use target_link_options to propagate object libraries
target_link_options are placed by CMake at the beginning of a linker
line. This gives us an opportunity to use the function to propagate
object libraries. This change adds one more check in the root
Config.cmake file. If CMP0099 policy is enabled, CMake enables
propagating of the linking options when linking two static libraries
using the PRIVATE linking visibility, so we can rely on the correct
linking order and expect object libraries to be propagated.

Note that on the platforms where cmake version is higher than 3.16
Qt uses CMP0099 NEW in functions like qt_add_executable. This means
that at the moment of creating an executable target the TARGET_POLICY
genex will also be NEW, so we do not take into the account the user
defined CMP0099.

If the CMP0099 policy is not available for a certain CMake version
we skip the TARGET_POLICY check and simply disable propagation of
the object libraries using target_link_options for both user and Qt
libraries. This is applicable for the CMake versions 3.16 and less.

Linking approaches have the following priorities(from higher to lower)
after this change:
  - target_link_libraries - works if link order matters not or CMake
    version greater equal 3.21.
  - target_link_options - works if CMP0099 is set to NEW by user or
    if the CMake version is greater than or equal to 3.17 and an
    executable is created using Qt functions.
  - object library finalizer - works if CMake version is greater equal
    3.19 or qt6_finalize_target is called explicitly.
  - target_sources - is used when all the other approaches could not
    be used.

Amends a1fd4f51ad
Amends 3329212815

Pick-to: 6.2
Change-Id: I14f88caeb04e357191c840abeab89b03e210b796
Reviewed-by: Qt CI Bot <qt_ci_bot@qt-project.org>
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2021-07-02 15:17:06 +02:00
Alexey Edelev
3329212815 Move the linking logic of the object libraries to a common function
The linking logic of object libraries should be reusable outside of the
resource context. This introduces a
__qt_internal_propagate_object_library function that prepares all the
necessary genexes to link and propagate the object library to the
end-point executable.

Rename resource object finalizer API to make the naming more generic
to object libraries of any kind.

Amends 5fb99e3860

Pick-to: 6.2
Task-number: QTBUG-93002
Task-number: QTBUG-94528
Change-Id: I69d0f34c0dadbd67232de91035aaa53af93d1fa1
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2021-06-18 23:18:26 +02:00
Alexey Edelev
5fb99e3860 Check the impact of static link order for user projects
For user projects we run the static link order check once
'find_package(Qt6 ...)' is called.

If linker can resolve circular dependencies between static libraries
and object files we set the _qt_link_order_matters property of the
Qt::Platform target. This indicates the use of finalizers is not
required and we may rely on CMake-base propagation of resource
libraries and resource object files.

If linker could not resolve circular dependencies depending on
the _qt_resource_objects_finalizer_mode value:
  - Finalizer will be called and collected resource objects will be
    linked to the target directly.
  - Finalizer will be omitted and resource objects will be linked
    using the target_sources function implicitly. This only
    propagates resource one level up if consumer links the static
    library PUBLICly, but all symbols will be resolved correctly
    since object files are placed in the beginning of the linker line.

In the CMake version 3.21 we expect that CMake will take care about
the order of the resource object files in a linker line, it's
expected that all object files are located at the beginning of the
linker line.

TODO: Need to confirm that the CMake 3.21 meets the expectations.

Amends 4e901a2f99

Pick-to: 6.2
Task-number: QTBUG-93002
Task-number: QTBUG-94528
Change-Id: Ia68976df8182d3d3007b90c475c1e3928a305339
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2021-06-16 16:58:45 +02:00
Peng Wenhao
9c32e7dc60 remove cmake compatibility functions for old API
QT_NO_INTERNAL_COMPATIBILITY_FUNCTIONS has been removed

Change-Id: Ic77cdae4e5151e3b0fe05cc6dd5b43bffc24768c
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2021-06-11 01:05:28 +08:00
Alexey Edelev
4e901a2f99 Add the check for linker capabilities to resolve circular dependencies
'ld' only capable to resolve circular dependencies by wrapping the
suspected static libraries and objects using --start/end-group
arguments. We want to detect if linker is 'ld' at configure time to
decide how to link the resource objects if finalizers are not enabled.

The qt_config_compile_test function is extended with an extra argument
since it's required to pass custom cmake flags to the ld-related test.

Pick-to: 6.2
Change-Id: I484fcc99e2886952d8b0232f37e4e6a35d072931
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2021-06-10 15:17:55 +02:00
Alexey Edelev
19e789bace Implement propagation of object files to the end-point executable
This proposal collects all the resource objects to the qt-specific
property of the static libraries. This is done to avoid littering
of other static libraries and put resource object files to the
source part of the linker line when linking the end-point
executable.
The way we link object resource libraries is changed back to the
target_link_libraries approach as we may omit using finalizers
with linkers other than ld. Users may enforce finalizers by calling
the qt6_enable_resource_objects_finalizer_mode function if need.

Refactor tests related to the static resources.

Amends ddaa7150d8

Task-number: QTBUG-93002
Change-Id: I74135e291cd82fb54d1b284b4b4a1e002b1fef98
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>
2021-05-27 14:28:17 +02:00