Add finalizer to call qt6_import_qml_plugins() automatically

Any target created by a call to qt6_add_executable() that also links to
the Qml target will now automatically call qt6_import_qml_plugins() in
qt6_finalize_executable() for scenarios that need it. This is only
relevant for static builds and only when not doing a top level Qt
superbuild.

The finalizers feature requires CMake 3.18. If using an earlier CMake
version, the project is still responsible for calling
qt6_import_qml_plugins() itself.

Fixes: QTBUG-86669
Change-Id: I0f0b3f700ab6f1240b2373cb4155f52dc8991d2e
Reviewed-by: Joerg Bornemann <joerg.bornemann@qt.io>
(cherry picked from commit c71c48f5125c116f01f615f51f10e4f2877b2b1d)
Reviewed-by: Qt Cherry-pick Bot <cherrypick_bot@qt-project.org>

1 files changed, 11 insertions, 0 deletions

diff --git a/src/qml/Qt6QmlMacros.cmake b/src/qml/Qt6QmlMacros.cmake
index 01ee8fc4d4..2dfd02cbf6 100644
--- a/src/qml/Qt6QmlMacros.cmake
+++ b/src/qml/Qt6QmlMacros.cmake
@@ -1084,10 +1084,21 @@ endfunction()
 
 include(CMakeParseArguments)
 
+# This function is called as a finalizer in qt6_finalize_executable() for any
+# target that links against the Qml library for a statically built Qt.
 function(qt6_import_qml_plugins target)
     if(QT6_IS_SHARED_LIBS_BUILD)
         return()
     endif()
+
+    # Protect against being called multiple times in case we are being called
+    # explicitly before the finalizer is invoked.
+    get_target_property(alreadyImported ${target} _QT_QML_PLUGINS_IMPORTED)
+    if(alreadyImported)
+        return()
+    endif()
+    set_target_properties(${target} PROPERTIES _QT_QML_PLUGINS_IMPORTED TRUE)
+
     set(options)
     set(oneValueArgs "PATH_TO_SCAN")
     set(multiValueArgs)