CMake: Generate qdevice.pri when cross-building

This adds the CMake equivalent to the classical -device-option key=value
configure argument:
-DQT_QMAKE_DEVICE_OPTIONS=key1=value1[;keyN=valueN]
The keys and values get dumped verbatim into qdevice.pri.

This patch also ports the machineTuple configure test. Its result is
written into qdevice.pri as value for the GCC_MACHINE_DUMP variable.

Change-Id: I29f2323fd87639fafaed99ec7446c7ee75504705
Reviewed-by: Alexandru Croitor <alexandru.croitor@qt.io>

cmake/QtBaseGlobalTargets.cmake

@@ -293,6 +293,7 @@ qt_feature_module_end(GlobalConfig OUT_VAR_PREFIX "__GlobalConfig_")
 
 qt_generate_global_config_pri_file()
 qt_generate_global_module_pri_file()
+qt_generate_global_device_pri_file()
 qt_generate_qmake_wrapper_for_target()
 
 add_library(Qt::GlobalConfig ALIAS GlobalConfig)

cmake/QtBuild.cmake

@@ -1244,6 +1244,28 @@ QT_PATCH_VERSION = ${PROJECT_VERSION_PATCH}
     qt_install(FILES "${qconfig_pri_target_path}" DESTINATION ${INSTALL_MKSPECSDIR})
 endfunction()
 
+# Creates mkspecs/qdevice.pri which contains target device information for cross-builds.
+# The content of QT_QMAKE_DEVICE_OPTIONS is written verbatim into qdevice.pri.
+function(qt_generate_global_device_pri_file)
+    if(NOT CMAKE_CROSSCOMPILING)
+        return()
+    endif()
+
+    qt_path_join(qdevice_pri_target_path ${PROJECT_BINARY_DIR} ${INSTALL_MKSPECSDIR} "qdevice.pri")
+
+    set(content "")
+    foreach(opt ${QT_QMAKE_DEVICE_OPTIONS})
+        string(APPEND content "${opt}\n")
+    endforeach()
+
+    if(TEST_machine_tuple)
+        string(APPEND content "GCC_MACHINE_DUMP = ${TEST_machine_tuple}\n")
+    endif()
+
+    file(GENERATE OUTPUT "${qdevice_pri_target_path}" CONTENT "${content}")
+    qt_install(FILES "${qdevice_pri_target_path}" DESTINATION ${INSTALL_MKSPECSDIR})
+endfunction()
+
 function(qt_get_build_parts out_var)
     set(parts "libs")
 

cmake/QtFeature.cmake

@@ -858,6 +858,25 @@ function(qt_config_compile_test_x86simd extension label)
     set(TEST_subarch_${extension} "${TEST_X86SIMD_${extension}}" CACHE INTERNAL "${label}")
 endfunction()
 
+function(qt_config_compile_test_machine_tuple label)
+    if(DEFINED TEST_MACHINE_TUPLE OR NOT (GCC OR CLANG))
+        return()
+    endif()
+
+    message(STATUS "Performing Test ${label}")
+    execute_process(COMMAND "${CMAKE_CXX_COMPILER}" -dumpmachine
+        OUTPUT_VARIABLE output
+        OUTPUT_STRIP_TRAILING_WHITESPACE
+        RESULT_VARIABLE exit_code)
+    if(exit_code EQUAL 0)
+        set(status_label "Success")
+    else()
+        set(status_label "Failed")
+    endif()
+    message(STATUS "Performing Test ${label} - ${status_label}")
+    set(TEST_machine_tuple "${output}" CACHE INTERNAL "${label}")
+endfunction()
+
 function(qt_make_features_available target)
     if(NOT "${target}" MATCHES "^${QT_CMAKE_EXPORT_NAMESPACE}::[a-zA-Z0-9_-]*$")
         message(FATAL_ERROR "${target} does not match ${QT_CMAKE_EXPORT_NAMESPACE}::[a-zA-Z0-9_-]*. INVALID NAME.")

configure.cmake

@@ -14,6 +14,9 @@ qt_find_package(Libudev PROVIDED_TARGETS PkgConfig::Libudev MODULE_NAME global Q
 
 #### Tests
 
+# machineTuple
+qt_config_compile_test_machine_tuple("machine tuple")
+
 # cxx14
 qt_config_compile_test(cxx14
     LABEL "C++14 support"

util/cmake/configurejson2cmake.py

@@ -819,6 +819,15 @@ def parseTest(ctx, test, data, cm_fh):
         cm_fh.write(f'qt_config_compile_test_x86simd({test} "{label}")\n')
         cm_fh.write("\n")
 
+    elif data["type"] == "machineTuple":
+        knownTests.add(test)
+
+        label = data["label"]
+
+        cm_fh.write(f"# {test}\n")
+        cm_fh.write(f'qt_config_compile_test_machine_tuple("{label}")\n')
+        cm_fh.write("\n")
+
     #    "features": {
     #        "android-style-assets": {
     #            "label": "Android Style Assets",