Adapt build system to also support building against Qt6

CMakeLists.txt

@@ -13,7 +13,6 @@ option(INSTALL_SDDM_WAYLAND_SESSION OFF)
 set(CMAKE_CXX_STANDARD 17)
 set(CMAKE_CXX_STANDARD_REQUIRED ON)
 
-find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS Svg Widgets Quick QuickWidgets Concurrent Test Network)
 find_package(ECM ${KF5_MIN_VERSION} REQUIRED NO_MODULE)
 set(CMAKE_MODULE_PATH ${ECM_MODULE_PATH} ${CMAKE_CURRENT_SOURCE_DIR}/cmake)
 
@@ -36,6 +35,7 @@ include(ECMGenerateDBusServiceFile)
 include(ECMFindQmlModule)
 include(ECMGenerateExportHeader)
 
+find_package(Qt${QT_MAJOR_VERSION} ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS Svg Widgets Quick QuickWidgets Concurrent Test Network)
 find_package(KF5 ${KF5_MIN_VERSION} REQUIRED COMPONENTS
                     Plasma Runner Notifications NotifyConfig NewStuff Wallet IdleTime
                     Declarative I18n KCMUtils TextWidgets Crash GlobalAccel DBusAddons Wayland
@@ -89,8 +89,8 @@ set_package_properties(KF5Holidays PROPERTIES DESCRIPTION "Holidays provider for
                        PURPOSE "Needed to for holidays plugin for Plasma Calendar."
                       )
 
-find_package(Phonon4Qt5 4.6.60 REQUIRED NO_MODULE)
-set_package_properties(Phonon4Qt5 PROPERTIES
+find_package(Phonon4Qt${QT_MAJOR_VERSION} 4.6.60 REQUIRED NO_MODULE)
+set_package_properties(Phonon4Qt${QT_MAJOR_VERSION} PROPERTIES
    DESCRIPTION "Qt-based audio library"
    TYPE REQUIRED)
 
@@ -127,15 +127,19 @@ if(PipeWire_FOUND)
   find_package(Libdrm REQUIRED)
 endif()
 
-find_package(QtWaylandScanner REQUIRED)
-find_package(Qt5WaylandClient)
-find_package(Qt5XkbCommonSupport)
+if(QT_MAJOR_VERSION EQUAL "5")
+  find_package(QtWaylandScanner REQUIRED)
+  find_package(Qt5XkbCommonSupport)
+else()
+  find_package(Qt6 REQUIRED CONFIG COMPONENTS WaylandCompositor)
+endif()
+find_package(Qt${QT_MAJOR_VERSION}WaylandClient)
 find_package(PlasmaWaylandProtocols 1.6 REQUIRED)
 find_package(Wayland REQUIRED COMPONENTS Client Server) # Server is used in autotests
 
 if(FONTCONFIG_FOUND)
   # kfontinst
-  find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS PrintSupport)
+  find_package(Qt${QT_MAJOR_VERSION} ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS PrintSupport)
 endif()
 
 if(X11_FOUND)
@@ -145,7 +149,9 @@ if(X11_FOUND)
     message(FATAL_ERROR "\nThe X11 Session Management (SM) development package could not be found.\nPlease install libSM.\n")
   endif(NOT X11_SM_FOUND)
 
-  find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS X11Extras)
+  if (QT_MAJOR_VERSION EQUAL "5")
+    find_package(Qt5 ${QT_MIN_VERSION} CONFIG REQUIRED COMPONENTS X11Extras)
+  endif()
 endif()
 
 if(X11_FOUND AND XCB_XCB_FOUND)
@@ -161,13 +167,13 @@ if(${AppStreamQt_FOUND})
     set(HAVE_APPSTREAMQT true)
 endif()
 
-find_package(PackageKitQt5)
-set_package_properties(PackageKitQt5
+find_package(PackageKitQt${QT_MAJOR_VERSION})
+set_package_properties(PackageKitQt${QT_MAJOR_VERSION}
         PROPERTIES DESCRIPTION "Software Manager integration"
         TYPE OPTIONAL
         PURPOSE "Used to install additional language packages on demand"
         )
-if(PackageKitQt5_FOUND)
+if(PackageKitQt${QT_MAJOR_VERSION}_FOUND)
     set(HAVE_PACKAGEKIT TRUE)
 endif()
 

appmenu/CMakeLists.txt

@@ -20,7 +20,6 @@ pkg_check_modules(XKBCommon REQUIRED IMPORTED_TARGET xkbcommon)
 target_link_libraries(appmenu
     Qt::DBus
     Qt::WaylandClientPrivate
-    Qt::XkbCommonSupportPrivate
     KF5::DBusAddons
     KF5::KIOCore
     KF5::WaylandClient
@@ -29,6 +28,9 @@ target_link_libraries(appmenu
     PkgConfig::XKBCommon
     dbusmenuqt
 )
+if (QT_MAJOR_VERSION EQUAL "5")
+    target_link_libraries(appmenu Qt::XkbCommonSupportPrivate)
+endif()
 
 if (HAVE_X11)
     target_link_libraries(appmenu Qt::X11Extras XCB::XCB)

kcms/formats/CMakeLists.txt

@@ -20,7 +20,9 @@ target_link_libraries(kcm_formats
     KF5::CoreAddons
     KF5::I18n
     KF5::QuickAddons)
-
+if (QT_MAJOR_VERSION EQUAL "6")
+    target_link_libraries(kcm_formats Qt::Core5Compat) # for QTextCodec
+endif()
 
 ########### install files ###############
 install(TARGETS kcm_formats  DESTINATION ${KDE_INSTALL_PLUGINDIR}/plasma/kcms/systemsettings)

kcms/kfontinst/dbus/CMakeLists.txt

@@ -15,6 +15,9 @@ target_link_libraries(fontinst_bin
 set_target_properties(fontinst_helper PROPERTIES OUTPUT_NAME fontinst_helper)
 target_link_libraries(fontinst_helper 
                       Qt::DBus Qt::Xml KF5::AuthCore KF5::KIOCore kfontinst)
+if (QT_MAJOR_VERSION EQUAL "6")
+    target_link_libraries(fontinst_helper Qt::Core5Compat) # for QTextCodec
+endif()
 
 ecm_qt_declare_logging_category(fontinst_bin
     HEADER kfontinst_debug.h

kcms/kfontinst/lib/CMakeLists.txt

@@ -14,6 +14,9 @@ target_link_libraries(kfontinst
     Qt::Gui
     XCB::IMAGE
 )
+if (QT_MAJOR_VERSION EQUAL "6")
+    target_link_libraries(kfontinst PRIVATE Qt::Core5Compat) # for QTextCodec
+endif()
 
 set_target_properties(kfontinst PROPERTIES VERSION ${PROJECT_VERSION} SOVERSION ${PROJECT_VERSION_MAJOR} )
 

kcms/lookandfeel/CMakeLists.txt

@@ -78,7 +78,7 @@ install(FILES kcm_lookandfeel.desktop DESTINATION ${KDE_INSTALL_APPDIR})
 install(FILES lookandfeel.knsrc DESTINATION ${KDE_INSTALL_KNSRCDIR})
 
 if(BUILD_TESTING)
-   find_package(Qt5Test ${QT_MIN_VERSION} CONFIG REQUIRED)
+   find_package(Qt${QT_MAJOR_VERSION}Test ${QT_MIN_VERSION} CONFIG REQUIRED)
    add_subdirectory(autotests)
 endif()
 

libtaskmanager/declarative/CMakeLists.txt

@@ -20,10 +20,15 @@ if(TARGET PkgConfig::PipeWire)
         DESTINATION "${KDE_INSTALL_LOGGINGCATEGORIESDIR}"
     )
 
-    ecm_add_qtwayland_client_protocol(SRCS
-        PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/screencast.xml
-        BASENAME zkde-screencast-unstable-v1
-    )
+    if (QT_MAJOR_VERSION EQUAL "5")
+        ecm_add_qtwayland_client_protocol(SRCS
+            PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/screencast.xml
+            BASENAME zkde-screencast-unstable-v1
+        )
+    else()
+        qt6_generate_wayland_protocol_client_sources(taskmanagerplugin FILES
+            ${PLASMA_WAYLAND_PROTOCOLS_DIR}/screencast.xml)
+    endif()
     target_include_directories(taskmanagerplugin PRIVATE ${Libdrm_INCLUDE_DIR})
 
     target_compile_definitions(taskmanagerplugin PRIVATE -DWITH_PIPEWIRE)

phonon/platform_kde/CMakeLists.txt

@@ -5,7 +5,7 @@ set(kde_PART_SRCS
 )
 
 kcoreaddons_add_plugin(kde SOURCES ${kde_PART_SRCS} INSTALL_NAMESPACE "phonon_platform")
-target_link_libraries(kde ${PHONON_LIBRARY} KF5::CoreAddons KF5::ConfigCore KF5::WidgetsAddons KF5::I18n KF5::KIOCore KF5::Notifications)
+target_link_libraries(kde Phonon::phonon4qt${QT_MAJOR_VERSION} KF5::CoreAddons KF5::ConfigCore KF5::WidgetsAddons KF5::I18n KF5::KIOCore KF5::Notifications)
 
 install(FILES phonon.notifyrc DESTINATION ${KDE_INSTALL_KNOTIFYRCDIR})
 install(FILES phononbackend.desktop DESTINATION ${KDE_INSTALL_KSERVICETYPESDIR})

runners/bookmarks/CMakeLists.txt

@@ -3,7 +3,7 @@
 
 add_definitions(-DTRANSLATION_DOMAIN=\"plasma_runner_bookmarksrunner\")
 
-find_package(Qt5 CONFIG REQUIRED COMPONENTS Sql)
+find_package(Qt${QT_MAJOR_VERSION} CONFIG REQUIRED COMPONENTS Sql)
 
 set(krunner_bookmarks_common_SRCS
     bookmarkmatch.cpp

shell/CMakeLists.txt

@@ -57,18 +57,23 @@ if (TARGET KUserFeedbackCore)
     )
 endif()
 
-ecm_add_qtwayland_client_protocol(plasma_shell_SRCS
-    PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
-    BASENAME kde-primary-output-v1
-)
+add_executable(plasmashell)
+if (QT_MAJOR_VERSION EQUAL "5")
+    ecm_add_qtwayland_client_protocol(plasma_shell_SRCS
+        PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
+        BASENAME kde-primary-output-v1
+    )
+else()
+    qt6_generate_wayland_protocol_client_sources(plasmashell FILES
+        ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
+    )
+endif()
 
 set(krunner_xml ${plasma-workspace_SOURCE_DIR}/krunner/dbus/org.kde.krunner.App.xml)
 qt_add_dbus_interface(plasma_shell_SRCS ${krunner_xml} krunner_interface)
 
 
-add_executable(plasmashell
-    ${plasma_shell_SRCS}
-)
+target_sources(plasmashell PRIVATE ${plasma_shell_SRCS})
 
 target_link_libraries(plasmashell
  Qt::Quick

shell/autotests/mockserver/CMakeLists.txt

@@ -14,26 +14,38 @@ set(SharedClientTest_LIB_SRCS
     primaryoutput.cpp primaryoutput.h
 )
 
-ecm_add_qtwayland_server_protocol(SharedClientTest_LIB_SRCS
-    PROTOCOL ${Wayland_DATADIR}/wayland.xml
-    BASENAME wayland
-)
-
-ecm_add_qtwayland_server_protocol(SharedClientTest_LIB_SRCS
-    PROTOCOL ${WaylandProtocols_DATADIR}/unstable/xdg-output/xdg-output-unstable-v1.xml
-    BASENAME xdg-output-unstable-v1
-)
-
-ecm_add_qtwayland_client_protocol(SharedClientTest_LIB_SRCS
-    PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
-    BASENAME kde-primary-output-v1
-)
-ecm_add_qtwayland_server_protocol(SharedClientTest_LIB_SRCS
-    PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
-    BASENAME kde-primary-output-v1
-)
-
-add_library(SharedClientTest OBJECT ${SharedClientTest_LIB_SRCS})
+add_library(SharedClientTest OBJECT)
+if (QT_MAJOR_VERSION EQUAL "5")
+    ecm_add_qtwayland_server_protocol(SharedClientTest_LIB_SRCS
+        PROTOCOL ${Wayland_DATADIR}/wayland.xml
+        BASENAME wayland
+    )
+
+    ecm_add_qtwayland_server_protocol(SharedClientTest_LIB_SRCS
+        PROTOCOL ${WaylandProtocols_DATADIR}/unstable/xdg-output/xdg-output-unstable-v1.xml
+        BASENAME xdg-output-unstable-v1
+    )
+
+    ecm_add_qtwayland_client_protocol(SharedClientTest_LIB_SRCS
+        PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
+        BASENAME kde-primary-output-v1
+    )
+    ecm_add_qtwayland_server_protocol(SharedClientTest_LIB_SRCS
+        PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
+        BASENAME kde-primary-output-v1
+    )
+else()
+    qt6_generate_wayland_protocol_client_sources(SharedClientTest FILES
+        ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
+    )
+    qt6_generate_wayland_protocol_server_sources(SharedClientTest FILES
+        ${Wayland_DATADIR}/wayland.xml
+        ${WaylandProtocols_DATADIR}/unstable/xdg-output/xdg-output-unstable-v1.xml
+        ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
+    )
+endif()
+
+target_sources(SharedClientTest PRIVATE ${SharedClientTest_LIB_SRCS})
 
 target_link_libraries(SharedClientTest
     PUBLIC

shell/tests/CMakeLists.txt

@@ -7,11 +7,17 @@ set(screenpoolmanualtest_SRCS
     ${CMAKE_CURRENT_BINARY_DIR}/../screenpool-debug.cpp
     ../primaryoutputwatcher.cpp
     )
-ecm_add_qtwayland_client_protocol(screenpoolmanualtest_SRCS
+add_executable(screenpoolmanualtest)
+if (QT_MAJOR_VERSION EQUAL "5")
+    ecm_add_qtwayland_client_protocol(screenpoolmanualtest_SRCS
         PROTOCOL ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml
         BASENAME kde-primary-output-v1
     )
-add_executable(screenpoolmanualtest ${screenpoolmanualtest_SRCS})
+else()
+    qt6_generate_wayland_protocol_client_sources(screenpoolmanualtest FILES
+        ${PLASMA_WAYLAND_PROTOCOLS_DIR}/kde-primary-output-v1.xml)
+endif()
+target_sources(screenpoolmanualtest PRIVATE ${screenpoolmanualtest_SRCS})
 target_link_libraries(screenpoolmanualtest
             Qt::Test
             Qt::Gui