feat(test): run tests and update build result

Although the project's language is now `CXX`,
the setup of the C++ environment is as was before.
I.e.,
- The environment of the build test can only be set globally
  (through CMake defaults, the environment, etc.).
- The environment of this project should match that of the build test.
  It doesn't attempt to propagate any aspect explicitly.

Author: JohelEGP

regression-tests/CMakeLists.txt

@@ -1,5 +1,5 @@
 cmake_minimum_required(VERSION 3.23)
-project(cppfront-regression-tests LANGUAGES NONE)
+project(cppfront-regression-tests LANGUAGES CXX)
 
 option(CPPFRONT_DEVELOPING "Test results are updated.")
 
@@ -10,7 +10,31 @@ find_package(cppfront REQUIRED)
 
 set(REGRESSION_TESTS_DIR "${CMAKE_CURRENT_LIST_DIR}/../cppfront/regression-tests")
 
+if (CPPFRONT_DEVELOPING)
+    if (CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+        set(compiler_id "gcc")
+    elseif (CMAKE_CXX_COMPILER_ID STREQUAL "AppleClang")
+        set(compiler_id "apple-clang")
+    else ()
+        string(TOLOWER "${CMAKE_CXX_COMPILER_ID}" compiler_id)
+    endif ()
+    string(REGEX MATCH "[0-9]+" compiler_major_version "${CMAKE_CXX_COMPILER_VERSION}")
+
+    set(TEST_RESULTS_BUILD_DIR "${REGRESSION_TESTS_DIR}/test-results/${compiler_id}-${compiler_major_version}")
+    file(MAKE_DIRECTORY "${TEST_RESULTS_BUILD_DIR}")
+
+    set(compiler_version_command "${CMAKE_CXX_COMPILER}" "--version")
+    if (CMAKE_CXX_COMPILER_ID MATCHES "AppleClang")
+        set(compiler_id "clang")
+    endif ()
+    execute_process(
+        COMMAND ${compiler_version_command}
+        OUTPUT_FILE "${TEST_RESULTS_BUILD_DIR}/${compiler_id}-version.output"
+    )
+endif ()
+
 configure_file("cmake/ExecuteWithRedirection.cmake" "ExecuteWithRedirection.cmake" COPYONLY)
+configure_file("cmake/ExecuteTestCase.cmake.in" "ExecuteTestCase.cmake" @ONLY)
 
 function(cppfront_command_tests)
     cmake_parse_arguments(PARSE_ARGV 0 ARG "" "SOURCE;EXPECTED_FILE" "EXTRA_FLAGS")
@@ -106,6 +130,7 @@ function(cppfront_build_tests)
 
     configure_file("${REGRESSION_TESTS_DIR}/${ARG_SOURCE}" "${test_dir}/${ARG_SOURCE}" COPYONLY)
     configure_file("cmake/CMakeLists.txt.in" "${test_dir}/CMakeLists.txt" @ONLY)
+    configure_file("cmake/test-case-config.cmake.in" "${test_dir}/test-case-config.cmake.in" COPYONLY)
 
     add_test(
         NAME "build/${test_name}"
@@ -119,8 +144,48 @@ function(cppfront_build_tests)
         "-Dcppfront_DIR=${cppfront_DIR}"
         "-Dcppfront-exe_DIR=${cppfront-exe_DIR}"
         "-DCPPFRONT_FLAGS=${ARG_EXTRA_FLAGS}"
+        # There's `CMAKE_CXX_LINKER_LAUNCHER`, too. So far, it's not needed.
+        "-DCMAKE_CXX_COMPILER_LAUNCHER=${CMAKE_COMMAND};-D;OUTPUT_FILE=${gen_cpp_src}.output;-P;../../ExecuteWithRedirection.cmake;--"
+    )
+    set_tests_properties(
+        "build/${test_name}"
+        PROPERTIES
+        DEPENDS "${build_test_depends};codegen/check/${test_name}"
+        FIXTURES_SETUP "build/${test_name}"
     )
-    set_tests_properties("build/${test_name}" PROPERTIES DEPENDS "${build_test_depends};codegen/check/${test_name}")
+
+    if (CPPFRONT_DEVELOPING)
+        add_test(
+            NAME "build/execute/${test_name}"
+            COMMAND
+            "${CMAKE_COMMAND}"
+            -D "OUTPUT_FILE=${test_dir}/${gen_cpp_src}.execution"
+            -P "../ExecuteTestCase.cmake"
+            WORKING_DIRECTORY "${test_dir}"
+        )
+        set_tests_properties(
+            "build/execute/${test_name}"
+            PROPERTIES
+            FIXTURES_REQUIRED "build/${test_name}"
+            FIXTURES_SETUP "build/execute/${test_name}"
+            RESOURCE_LOCK "test.exe")
+
+        add_test(
+            NAME "build/update/${test_name}"
+            COMMAND
+            "${CMAKE_COMMAND}"
+            -E copy_if_different
+            "build/${gen_cpp_src}.output"
+            "${gen_cpp_src}.execution"
+            "${TEST_RESULTS_BUILD_DIR}"
+            WORKING_DIRECTORY "${test_dir}"
+        )
+        set_tests_properties(
+            "build/update/${test_name}"
+            PROPERTIES
+            FIXTURES_CLEANUP "build/${test_name};build/execute/${test_name}"
+        )
+    endif ()
 endfunction()
 
 function(cppfront_tests)

regression-tests/cmake/CMakeLists.txt.in

@@ -13,3 +13,30 @@ target_compile_options(
     PRIVATE
     "$<$<CXX_COMPILER_ID:MSVC>:/experimental:module>"
 )
+
+include(GNUInstallDirs)
+include(CMakePackageConfigHelpers)
+
+set(TEST_CASE_INSTALL_CMAKEDIR "${CMAKE_INSTALL_DATADIR}/cmake/test-case")
+
+install(
+    TARGETS test-case
+    EXPORT test-case-targets
+)
+
+install(
+    EXPORT test-case-targets
+    DESTINATION "${TEST_CASE_INSTALL_CMAKEDIR}"
+)
+
+configure_package_config_file(
+    "test-case-config.cmake.in"
+    "test-case-config.cmake"
+    INSTALL_DESTINATION "${TEST_CASE_INSTALL_CMAKEDIR}"
+    PATH_VARS CMAKE_INSTALL_BINDIR
+)
+
+install(
+    FILES "${CMAKE_CURRENT_BINARY_DIR}/test-case-config.cmake"
+    DESTINATION "${TEST_CASE_INSTALL_CMAKEDIR}"
+)

regression-tests/cmake/ExecuteTestCase.cmake.in

@@ -0,0 +1,23 @@
+execute_process(
+    COMMAND "${CMAKE_COMMAND}" --install "build" --prefix "_local"
+    COMMAND_ERROR_IS_FATAL ANY
+)
+find_package(test-case REQUIRED PATHS "${CMAKE_CURRENT_BINARY_DIR}/_local" NO_DEFAULT_PATH)
+execute_process(
+    COMMAND
+    "${CMAKE_COMMAND}"
+    -E copy
+    "${TEST_CASE_EXECUTABLE}"
+    "@TEST_RESULTS_BUILD_DIR@/test.exe"
+)
+execute_process(
+    COMMAND
+    "${CMAKE_COMMAND}"
+    -D "OUTPUT_FILE=${OUTPUT_FILE}"
+    -P "@CMAKE_CURRENT_BINARY_DIR@/ExecuteWithRedirection.cmake"
+    --
+    "./test.exe"
+    COMMAND_ERROR_IS_FATAL ANY
+    WORKING_DIRECTORY "@TEST_RESULTS_BUILD_DIR@"
+)
+execute_process(COMMAND "${CMAKE_COMMAND}" -E rm "@TEST_RESULTS_BUILD_DIR@/test.exe")

regression-tests/cmake/test-case-config.cmake.in

@@ -0,0 +1,7 @@
+cmake_minimum_required(VERSION 3.23)
+@PACKAGE_INIT@
+
+set_and_check(
+    TEST_CASE_EXECUTABLE
+    "@PACKAGE_CMAKE_INSTALL_BINDIR@/test-case@CMAKE_EXECUTABLE_SUFFIX@"
+)