gitlab-ci: test C++ modules using GCC

.gitlab-ci.yml

@@ -275,6 +275,26 @@ t:hip4.2-radeon:
     variables:
         CMAKE_CI_NO_MR: "true"
 
+t:linux-gcc-cxx-modules-ninja:
+    extends:
+        - .gcc_cxx_modules_ninja
+        - .cmake_test_linux_release
+        - .linux_builder_tags
+        - .run_dependent
+        - .needs_centos6_x86_64
+    variables:
+        CMAKE_CI_JOB_NIGHTLY: "true"
+
+t:linux-gcc-cxx-modules-ninja-multi:
+    extends:
+        - .gcc_cxx_modules_ninja_multi
+        - .cmake_test_linux_release
+        - .linux_builder_tags
+        - .run_dependent
+        - .needs_centos6_x86_64
+    variables:
+        CMAKE_CI_JOB_NIGHTLY: "true"
+
 b:fedora36-ninja:
     extends:
         - .fedora36_ninja

.gitlab/ci/configure_linux_gcc_cxx_modules_ninja.cmake

@@ -0,0 +1,4 @@
+set(CMake_TEST_MODULE_COMPILATION "named,partitions,internal_partitions" CACHE STRING "")
+set(CMake_TEST_MODULE_COMPILATION_RULES "${CMAKE_CURRENT_LIST_DIR}/cxx_modules_rules_gcc.cmake" CACHE STRING "")
+
+include("${CMAKE_CURRENT_LIST_DIR}/configure_external_test.cmake")

.gitlab/ci/configure_linux_gcc_cxx_modules_ninja_multi.cmake

@@ -0,0 +1,4 @@
+set(CMake_TEST_MODULE_COMPILATION "named,partitions,internal_partitions" CACHE STRING "")
+set(CMake_TEST_MODULE_COMPILATION_RULES "${CMAKE_CURRENT_LIST_DIR}/cxx_modules_rules_gcc.cmake" CACHE STRING "")
+
+include("${CMAKE_CURRENT_LIST_DIR}/configure_external_test.cmake")

.gitlab/ci/cxx_modules_rules_gcc.cmake

@@ -0,0 +1,10 @@
+set(CMake_TEST_CXXModules_UUID "a246741c-d067-4019-a8fb-3d16b0c9d1d3")
+
+set(CMAKE_EXPERIMENTAL_CXX_MODULE_DYNDEP 1)
+string(CONCAT CMAKE_EXPERIMENTAL_CXX_SCANDEP_SOURCE
+  "<CMAKE_CXX_COMPILER> <DEFINES> <INCLUDES> <FLAGS> -E -x c++ <SOURCE>"
+  " -MT <DYNDEP_FILE> -MD -MF <DEP_FILE>"
+  " -fmodules-ts -fdep-file=<DYNDEP_FILE> -fdep-output=<OBJECT> -fdep-format=trtbd"
+  " -o <PREPROCESSED_SOURCE>")
+set(CMAKE_EXPERIMENTAL_CXX_MODULE_MAP_FORMAT "gcc")
+set(CMAKE_EXPERIMENTAL_CXX_MODULE_MAP_FLAG "-fmodules-ts -fmodule-mapper=<MODULE_MAP_FILE> -fdep-format=trtbd -x c++")

.gitlab/os-linux.yml

@@ -299,6 +299,30 @@
         CMAKE_CONFIGURATION: hip4.2_radeon
         CMAKE_GENERATOR: "Ninja Multi-Config"
 
+### C++ modules
+
+.gcc_cxx_modules_x86_64:
+    image: "kitware/cmake:ci-gcc_cxx_modules-x86_64-2022-06-14"
+
+    variables:
+        GIT_CLONE_PATH: "$CI_BUILDS_DIR/cmake ci"
+        CMAKE_ARCH: x86_64
+        CC: "/opt/gcc-p1689/bin/gcc"
+        CXX: "/opt/gcc-p1689/bin/g++"
+
+.gcc_cxx_modules_ninja:
+    extends: .gcc_cxx_modules_x86_64
+
+    variables:
+        CMAKE_CONFIGURATION: linux_gcc_cxx_modules_ninja
+
+.gcc_cxx_modules_ninja_multi:
+    extends: .gcc_cxx_modules_x86_64
+
+    variables:
+        CMAKE_CONFIGURATION: linux_gcc_cxx_modules_ninja_multi
+        CMAKE_GENERATOR: "Ninja Multi-Config"
+
 ## Tags
 
 .linux_builder_tags: