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

4 files changed, 19 insertions, 10 deletions

diff --git a/Tests/RunCMake/NinjaMultiConfig/Qt5-automoc-check-ninja-stdout.txt b/Tests/RunCMake/NinjaMultiConfig/QtX-automoc-check-ninja-stdout.txt
index 85d5fdc..85d5fdc 100644
--- a/Tests/RunCMake/NinjaMultiConfig/Qt5-automoc-check-ninja-stdout.txt
+++ b/Tests/RunCMake/NinjaMultiConfig/QtX-automoc-check-ninja-stdout.txt
diff --git a/Tests/RunCMake/NinjaMultiConfig/Qt5-debug-in-release-graph-build-check.cmake b/Tests/RunCMake/NinjaMultiConfig/QtX-debug-in-release-graph-build-check.cmake
index 2d8df13..2d8df13 100644
--- a/Tests/RunCMake/NinjaMultiConfig/Qt5-debug-in-release-graph-build-check.cmake
+++ b/Tests/RunCMake/NinjaMultiConfig/QtX-debug-in-release-graph-build-check.cmake
diff --git a/Tests/RunCMake/NinjaMultiConfig/Qt5.cmake b/Tests/RunCMake/NinjaMultiConfig/QtX.cmake
index 578256a..130f883 100644
--- a/Tests/RunCMake/NinjaMultiConfig/Qt5.cmake
+++ b/Tests/RunCMake/NinjaMultiConfig/QtX.cmake
@@ -1,18 +1,21 @@
 enable_language(CXX)
 
-find_package(Qt5Core REQUIRED)
+set(QtX Qt${with_qt_version})
+
+find_package(${QtX} REQUIRED COMPONENTS Core)
 
 set(CMAKE_AUTOMOC ON)
 set(CMAKE_AUTOMOC_COMPILER_PREDEFINES OFF)
 
+# Source files are always named qt5.* for simplicity but apply to Qt5 and later
 add_executable(exe qt5.cxx)
-target_link_libraries(exe PRIVATE Qt5::Core)
+target_link_libraries(exe PRIVATE ${QtX}::Core)
 
 include(${CMAKE_CURRENT_LIST_DIR}/Common.cmake)
 generate_output_files(exe)
 
 set(moc_writes_depfiles 0)
-if(Qt5Core_VERSION VERSION_GREATER_EQUAL "5.15.0")
+if(${QtX}Core_VERSION VERSION_GREATER_EQUAL "5.15.0")
   set(moc_writes_depfiles 1)
 endif()
 
diff --git a/Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake b/Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake
index 7c100eb..c7b876c 100644
--- a/Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake
+++ b/Tests/RunCMake/NinjaMultiConfig/RunCMakeTest.cmake
@@ -446,14 +446,20 @@ if(CMake_TEST_CUDA AND NOT CMake_TEST_CUDA STREQUAL "Clang")
   run_ninja(CudaSimple all-clean build-Debug.ninja clean:Debug)
 endif()
 
-if(CMake_TEST_Qt5)
-  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/Qt5-build)
-  set(RunCMake_TEST_OPTIONS "-DCMAKE_CROSS_CONFIGS=all" "-DQt5Core_DIR=${Qt5Core_DIR}")
-  run_cmake_configure(Qt5)
+if(CMake_TEST_Qt_version)
+  set(QtX Qt${CMake_TEST_Qt_version})
+  set(RunCMake_TEST_BINARY_DIR ${RunCMake_BINARY_DIR}/QtX-build)
+  set(RunCMake_TEST_OPTIONS
+    "-DCMAKE_CROSS_CONFIGS=all"
+    "-Dwith_qt_version:STRING=${CMake_TEST_Qt_version}"
+    "-D${QtX}Core_DIR=${${QtX}Core_DIR}"
+    "-DCMAKE_PREFIX_PATH:STRING=${CMAKE_PREFIX_PATH}"
+  )
+  run_cmake_configure(QtX)
   unset(RunCMake_TEST_OPTIONS)
   include(${RunCMake_TEST_BINARY_DIR}/target_files.cmake)
-  run_cmake_build(Qt5 debug-in-release-graph Release exe:Debug)
-  if(CMAKE_TEST_Qt5Core_Version VERSION_GREATER_EQUAL 5.15.0)
-    run_ninja(Qt5 automoc-check build-Debug.ninja -t query exe_autogen/timestamp)
+  run_cmake_build(QtX debug-in-release-graph Release exe:Debug)
+  if(CMake_TEST_${QtX}Core_Version VERSION_GREATER_EQUAL 5.15.0)
+    run_ninja(QtX automoc-check build-Debug.ninja -t query exe_autogen/timestamp)
   endif()
 endif()