Tests: Add support for testing Qt6

The minimum CMake version for Qt6 is 3.16, so all the calls to
cmake_minimum_required() are updated here to enforce that
minimum. This will avoid any CMake version-related warnings
from Qt.

Avoid hard-coding Qt5 where the tests could now be using
Qt5 or Qt6.

Fixes: #22188

6 files changed, 44 insertions, 31 deletions

diff --git a/Tests/RunCMake/Ninja/Qt5AutoMocDeps.cmake b/Tests/RunCMake/Ninja/Qt5AutoMocDeps.cmake
deleted file mode 100644
index 46b840f..0000000
--- a/Tests/RunCMake/Ninja/Qt5AutoMocDeps.cmake
+++ /dev/null
@@ -1,21 +0,0 @@
-enable_language(CXX)
-
-find_package(Qt5Core REQUIRED)
-
-set(CMAKE_AUTOMOC ON)
-
-add_library(simple_lib SHARED simple_lib.cpp)
-add_executable(app_with_qt app.cpp app_qt.cpp)
-target_link_libraries(app_with_qt PRIVATE simple_lib Qt5::Core)
-
-if(Qt5Widgets_DIR)
-  find_package(Qt5Widgets REQUIRED)
-  qt5_wrap_ui(_headers MyWindow.ui)
-  add_executable(app_with_widget app.cpp MyWindow.cpp ${_headers})
-  target_link_libraries(app_with_widget PRIVATE Qt5::Widgets)
-  target_include_directories(app_with_widget PRIVATE "${CMAKE_BINARY_DIR}")
-endif()
-
-add_subdirectory(QtSubDir1)
-add_subdirectory(QtSubDir2)
-add_subdirectory(QtSubDir3)
diff --git a/Tests/RunCMake/Ninja/QtAutoMocDeps.cmake b/Tests/RunCMake/Ninja/QtAutoMocDeps.cmake
new file mode 100644
index 0000000..c441169
--- /dev/null
+++ b/Tests/RunCMake/Ninja/QtAutoMocDeps.cmake
@@ -0,0 +1,27 @@
+enable_language(CXX)
+
+set(QtX Qt${with_qt_version})
+
+find_package(${QtX} REQUIRED COMPONENTS Core)
+
+set(CMAKE_AUTOMOC ON)
+
+add_library(simple_lib SHARED simple_lib.cpp)
+add_executable(app_with_qt app.cpp app_qt.cpp)
+target_link_libraries(app_with_qt PRIVATE simple_lib ${QtX}::Core)
+
+if(${QtX}Widgets_DIR)
+  find_package(${QtX} REQUIRED COMPONENTS Widgets)
+  if(with_qt_version STREQUAL 5)
+    qt5_wrap_ui(_headers MyWindow.ui)
+  else()
+    qt_wrap_ui(_headers MyWindow.ui)
+  endif()
+  add_executable(app_with_widget app.cpp MyWindow.cpp ${_headers})
+  target_link_libraries(app_with_widget PRIVATE ${QtX}::Widgets)
+  target_include_directories(app_with_widget PRIVATE "${CMAKE_BINARY_DIR}")
+endif()
+
+add_subdirectory(QtSubDir1)
+add_subdirectory(QtSubDir2)
+add_subdirectory(QtSubDir3)
diff --git a/Tests/RunCMake/Ninja/QtSubDir1/CMakeLists.txt b/Tests/RunCMake/Ninja/QtSubDir1/CMakeLists.txt
index 64016b6..3a12dcd 100644
--- a/Tests/RunCMake/Ninja/QtSubDir1/CMakeLists.txt
+++ b/Tests/RunCMake/Ninja/QtSubDir1/CMakeLists.txt
@@ -1,4 +1,4 @@
 cmake_policy(SET CMP0116 OLD)
 
 add_executable(sub_exe_1 ../app.cpp)
-target_link_libraries(sub_exe_1 PRIVATE Qt5::Core)
+target_link_libraries(sub_exe_1 PRIVATE ${QtX}::Core)
diff --git a/Tests/RunCMake/Ninja/QtSubDir2/CMakeLists.txt b/Tests/RunCMake/Ninja/QtSubDir2/CMakeLists.txt
index 3176426..a2f77e4 100644
--- a/Tests/RunCMake/Ninja/QtSubDir2/CMakeLists.txt
+++ b/Tests/RunCMake/Ninja/QtSubDir2/CMakeLists.txt
@@ -1,4 +1,4 @@
 cmake_policy(SET CMP0116 NEW)
 
 add_executable(sub_exe_2 ../app.cpp)
-target_link_libraries(sub_exe_2 PRIVATE Qt5::Core)
+target_link_libraries(sub_exe_2 PRIVATE ${QtX}::Core)
diff --git a/Tests/RunCMake/Ninja/QtSubDir3/CMakeLists.txt b/Tests/RunCMake/Ninja/QtSubDir3/CMakeLists.txt
index d38cfe0..70644fa 100644
--- a/Tests/RunCMake/Ninja/QtSubDir3/CMakeLists.txt
+++ b/Tests/RunCMake/Ninja/QtSubDir3/CMakeLists.txt
@@ -1,2 +1,2 @@
 add_executable(sub_exe_3 ../app.cpp)
-target_link_libraries(sub_exe_3 PRIVATE Qt5::Core)
+target_link_libraries(sub_exe_3 PRIVATE ${QtX}::Core)
diff --git a/Tests/RunCMake/Ninja/RunCMakeTest.cmake b/Tests/RunCMake/Ninja/RunCMakeTest.cmake
index 3f239b9..2a5b556 100644
--- a/Tests/RunCMake/Ninja/RunCMakeTest.cmake
+++ b/Tests/RunCMake/Ninja/RunCMakeTest.cmake
@@ -319,12 +319,17 @@ function (run_ChangeBuildType)
 endfunction()
 run_ChangeBuildType()
 
-function(run_Qt5AutoMocDeps)
-  if(CMake_TEST_Qt5 AND CMAKE_TEST_Qt5Core_Version VERSION_GREATER_EQUAL 5.15.0)
-    set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/Qt5AutoMocDeps-build)
-    set(RunCMake_TEST_OPTIONS "-DQt5Core_DIR=${Qt5Core_DIR}" "-DQt5Widgets_DIR=${Qt5Widgets_DIR}")
-    run_cmake(Qt5AutoMocDeps)
-    unset(RunCMake_TEST_OPTIONS)
+function(run_QtAutoMocDeps)
+  set(QtX Qt${CMake_TEST_Qt_version})
+  if(CMake_TEST_${QtX}Core_Version VERSION_GREATER_EQUAL 5.15.0)
+    set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/QtAutoMocDeps-build)
+    run_cmake_with_options(QtAutoMocDeps
+      "-Dwith_qt_version=${CMake_TEST_Qt_version}"
+      "-D${QtX}_DIR=${${QtX}_DIR}"
+      "-D${QtX}Core_DIR=${${QtX}Core_DIR}"
+      "-D${QtX}Widgets_DIR=${${QtX}Widgets_DIR}"
+      "-DCMAKE_PREFIX_PATH:STRING=${CMAKE_PREFIX_PATH}"
+    )
     # Build the project.
     run_ninja("${RunCMake_TEST_BINARY_DIR}")
     # Touch just the library source file, which shouldn't cause a rerun of AUTOMOC
@@ -352,4 +357,6 @@ function(run_Qt5AutoMocDeps)
     run_ninja("${RunCMake_TEST_BINARY_DIR}")
   endif()
 endfunction()
-run_Qt5AutoMocDeps()
+if(CMake_TEST_Qt_version)
+  run_QtAutoMocDeps()
+endif()