Merge topic 'fix-mod-manifest-nested-dirs' into release-4.4

539b097bd8 CPS/c++modules: Use file system root as base directory for module manifests

Acked-by: Kitware Robot <kwrobot@kitware.com>
Tested-by: buildbot <buildbot@kitware.com>
Merge-request: !12326

Source/cmCxxModuleMetadata.cxx

@@ -464,13 +464,19 @@ MetaDataProperties CollectMetaProperties(cmCxxModuleMetadata const& meta)
 
   props.MetadataDir = cmSystemTools::GetFilenamePath(meta.MetadataFilePath);
 
+#ifndef _WIN32
+  props.BaseDirs.insert("/");
+#endif
+
   for (auto const& module : meta.Modules) {
     std::string sourcePath = props.NormalizePath(module.SourcePath);
     props.Sources.insert(sourcePath);
 
-    // Module metadata files can reference files in different roots,
-    // just use the immediate parent directory as a base directory
-    props.BaseDirs.insert(cmSystemTools::GetFilenamePath(sourcePath));
+#ifdef _WIN32
+    std::string root;
+    cmSystemTools::SplitPathRootComponent(sourcePath, &root);
+    props.BaseDirs.insert(root);
+#endif
 
     if (module.LocalArguments) {
       for (auto const& incDir : module.LocalArguments->IncludeDirectories) {

Tests/RunCMake/CXXModulesCompile/RunCMakeTest.cmake

@@ -335,6 +335,7 @@ endfunction ()
 
 # Tests which install BMIs
 if ("export_bmi" IN_LIST CMake_TEST_MODULE_COMPILATION)
+  run_cxx_module_test(exp-nested-dirs-build)
   run_cxx_module_test(exp-iface-no-props-build)
   run_cxx_module_test(exp-iface-build)
   run_cxx_module_test(exp-incdirs-build)

Tests/RunCMake/CXXModulesCompile/exp-nested-dirs-build/CMakeLists.txt

@@ -0,0 +1,50 @@
+cmake_minimum_required(VERSION 3.24...3.28)
+project(cxx_modules_nested_dirs CXX)
+
+include("${CMAKE_SOURCE_DIR}/../cxx-modules-rules.cmake")
+
+add_library(export_nested_dirs STATIC)
+target_sources(export_nested_dirs
+  PUBLIC
+    FILE_SET modules TYPE CXX_MODULES
+      BASE_DIRS
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+      FILES
+        nested/alpha.cxx
+        nested/sub/beta.cxx
+  )
+target_compile_features(export_nested_dirs PUBLIC cxx_std_20)
+
+install(TARGETS export_nested_dirs
+  EXPORT CXXModules
+  FILE_SET modules DESTINATION "lib/cxx/miu")
+export(EXPORT CXXModules
+  NAMESPACE CXXModules::
+  FILE "${CMAKE_CURRENT_BINARY_DIR}/export_nested_dirs-targets.cmake"
+  CXX_MODULES_DIRECTORY "export_nested_dirs-cxx-modules")
+export(PACKAGE_INFO export_nested_dirs_cps
+  EXPORT CXXModules
+  CXX_MODULES_DIRECTORY "export_nested_dirs-cxx-modules-cps")
+file(WRITE "${CMAKE_CURRENT_BINARY_DIR}/export_nested_dirs-config.cmake"
+  "include(\"\${CMAKE_CURRENT_LIST_DIR}/export_nested_dirs-targets.cmake\")
+set(\${CMAKE_FIND_PACKAGE_NAME}_FOUND 1)
+")
+
+set(generator
+  -G "${CMAKE_GENERATOR}")
+if (CMAKE_GENERATOR_TOOLSET)
+  list(APPEND generator
+    -T "${CMAKE_GENERATOR_TOOLSET}")
+endif ()
+if (CMAKE_GENERATOR_PLATFORM)
+  list(APPEND generator
+    -A "${CMAKE_GENERATOR_PLATFORM}")
+endif ()
+
+add_test(NAME export_nested_dirs_build
+  COMMAND
+    "${CMAKE_COMMAND}"
+    "-DCMAKE_PREFIX_PATH=${CMAKE_CURRENT_BINARY_DIR}"
+    ${generator}
+    -S "${CMAKE_CURRENT_SOURCE_DIR}/test"
+    -B "${CMAKE_CURRENT_BINARY_DIR}/test")

Tests/RunCMake/CXXModulesCompile/exp-nested-dirs-build/nested/alpha.cxx

@@ -0,0 +1,6 @@
+export module nested_alpha;
+
+export int from_alpha()
+{
+  return 1;
+}

Tests/RunCMake/CXXModulesCompile/exp-nested-dirs-build/nested/sub/beta.cxx

@@ -0,0 +1,6 @@
+export module nested_sub_beta;
+
+export int from_beta()
+{
+  return 2;
+}

Tests/RunCMake/CXXModulesCompile/exp-nested-dirs-build/test/CMakeLists.txt

@@ -0,0 +1,5 @@
+cmake_minimum_required(VERSION 3.28)
+project(cxx_modules_library NONE)
+
+find_package(export_nested_dirs REQUIRED)
+find_package(export_nested_dirs_cps REQUIRED)