c++modules: Fix scanning with spaces in subdirectory name

If the path to a subdirectory inside the project has a space,
C++ module dependency scanning paths need quoting.

Fixes: #27647

Source/cmCxxModuleMapper.cxx

@@ -148,15 +148,15 @@ std::string CxxModuleMapContentClang(CxxModuleLocations const& loc,
       // extension.
       mm << "-x c++-module\n";
 
-      mm << "-fmodule-output=" << bmi_loc.Location() << '\n';
+      mm << "-fmodule-output=\"" << bmi_loc.Location() << "\"\n";
       break;
     }
   }
 
   auto all_usages = GetTransitiveUsages(loc, obj.Requires, usages);
   for (auto const& usage : all_usages) {
-    mm << "-fmodule-file=" << usage.LogicalName << '=' << usage.Location
-       << '\n';
+    mm << "-fmodule-file=\"" << usage.LogicalName << '=' << usage.Location
+       << "\"\n";
   }
 
   return mm.str();
@@ -229,7 +229,7 @@ std::string CxxModuleMapContentMsvc(CxxModuleLocations const& loc,
 
     auto bmi_loc = loc.BmiGeneratorPathForModule(p.LogicalName);
     if (bmi_loc.IsKnown()) {
-      mm << "-ifcOutput " << bmi_loc.Location() << '\n';
+      mm << "-ifcOutput \"" << bmi_loc.Location() << "\"\n";
     }
   }
 
@@ -237,7 +237,8 @@ std::string CxxModuleMapContentMsvc(CxxModuleLocations const& loc,
   for (auto const& usage : all_usages) {
     auto flag = flag_for_method(usage.Method);
 
-    mm << flag << ' ' << usage.LogicalName << '=' << usage.Location << '\n';
+    mm << flag << " \"" << usage.LogicalName << '=' << usage.Location
+       << "\"\n";
   }
 
   return mm.str();

Source/cmNinjaTargetGenerator.cxx

@@ -1351,11 +1351,13 @@ cmNinjaBuild GetScanBuildStatement(std::string const& ruleName,
 
   // Tell dependency scanner the object file that will result from
   // compiling the source.
-  scanBuild.Variables["OBJ_FILE"] = objectFileName;
+  scanBuild.Variables["OBJ_FILE"] =
+    tg->ConvertToOutputFormatForShell(objectFileName);
 
   // Tell dependency scanner where to store dyndep intermediate results.
   std::string ddiFileName = cmStrCat(objectFileName, ".ddi");
-  scanBuild.Variables["DYNDEP_INTERMEDIATE_FILE"] = ddiFileName;
+  scanBuild.Variables["DYNDEP_INTERMEDIATE_FILE"] =
+    tg->ConvertToOutputFormatForShell(ddiFileName);
   scanBuild.RspFile = cmStrCat(ddiFileName, ".rsp");
 
   // Outputs of the scan/preprocessor build statement.
@@ -1364,7 +1366,8 @@ cmNinjaBuild GetScanBuildStatement(std::string const& ruleName,
     scanBuild.ImplicitOuts.push_back(ddiFileName);
   } else {
     scanBuild.Outputs.push_back(ddiFileName);
-    scanBuild.Variables["PREPROCESSED_OUTPUT_FILE"] = ppFileName;
+    scanBuild.Variables["PREPROCESSED_OUTPUT_FILE"] =
+      tg->ConvertToOutputFormatForShell(ppFileName);
     if (!compilationPreprocesses) {
       // Compilation does not preprocess and we are not compiling an
       // already-preprocessed source.  Make compilation depend on the scan
@@ -1650,7 +1653,8 @@ void cmNinjaTargetGenerator::WriteObjectBuildStatement(
       // `cmNinjaTargetGenerator::ExportObjectCompileCommand` to expect the
       // corresponding file path.
       std::string ddModmapFile = cmStrCat(objectFileName, ".modmap");
-      vars["DYNDEP_MODULE_MAP_FILE"] = ddModmapFile;
+      vars["DYNDEP_MODULE_MAP_FILE"] =
+        this->ConvertToOutputFormatForShell(ddModmapFile);
       objBuild.ImplicitDeps.push_back(ddModmapFile);
       scanningFiles.ModuleMapFile = std::move(ddModmapFile);
     }
@@ -1877,7 +1881,8 @@ void cmNinjaTargetGenerator::WriteCxxModuleBmiBuildStatement(
 
     if (!modmapFormat.empty()) {
       std::string ddModmapFile = cmStrCat(bmiFileName, ".modmap");
-      vars["DYNDEP_MODULE_MAP_FILE"] = ddModmapFile;
+      vars["DYNDEP_MODULE_MAP_FILE"] =
+        this->ConvertToOutputFormatForShell(ddModmapFile);
       scanningFiles.ModuleMapFile = std::move(ddModmapFile);
     }
 

Tests/RunCMake/CXXModulesCompile/Inspect.cmake

@@ -13,6 +13,7 @@ endif ()
 string(APPEND info "\
 set(CMAKE_CXX_COMPILE_FEATURES \"${CMAKE_CXX_COMPILE_FEATURES}\")
 set(CMAKE_MAKE_PROGRAM \"${CMAKE_MAKE_PROGRAM}\")
+set(CMAKE_CXX_COMPILER_ID \"${CMAKE_CXX_COMPILER_ID}\")
 set(CMAKE_CXX_COMPILER_VERSION \"${CMAKE_CXX_COMPILER_VERSION}\")
 set(CMAKE_CXX_OUTPUT_EXTENSION \"${CMAKE_CXX_OUTPUT_EXTENSION}\")
 set(CMAKE_CXX20_STANDARD_COMPILE_OPTION \"${CMAKE_CXX20_STANDARD_COMPILE_OPTION}\")

Tests/RunCMake/CXXModulesCompile/RunCMakeTest.cmake

@@ -157,6 +157,10 @@ run_cxx_module_test(scan-with-pch)
 # Tests which use named modules.
 if ("named" IN_LIST CMake_TEST_MODULE_COMPILATION)
   run_cxx_module_test(simple)
+  # FIXME(GCC): `g++ -c "with space.cpp" -M -fdeps-format=p1689r5` fails.
+  if (NOT CMAKE_CXX_COMPILER_ID STREQUAL "GNU")
+    run_cxx_module_test(subdir)
+  endif ()
   run_cxx_module_test(file-sets-with-dot)
   run_cxx_module_test(vs-without-flags)
   run_cxx_module_test(library library-static -DBUILD_SHARED_LIBS=OFF)

Tests/RunCMake/CXXModulesCompile/subdir/CMakeLists.txt

@@ -0,0 +1,6 @@
+cmake_minimum_required(VERSION 3.24...3.28)
+project(cxx_modules_simple CXX)
+
+include("${CMAKE_SOURCE_DIR}/../cxx-modules-rules.cmake")
+
+add_subdirectory("with space")

Tests/RunCMake/CXXModulesCompile/subdir/with space/CMakeLists.txt

@@ -0,0 +1,13 @@
+add_executable(simple)
+target_sources(simple
+  PRIVATE
+    main.cxx
+  PRIVATE
+    FILE_SET CXX_MODULES
+      BASE_DIRS
+        "${CMAKE_CURRENT_SOURCE_DIR}"
+      FILES
+        importable.cxx)
+target_compile_features(simple PUBLIC cxx_std_20)
+
+add_test(NAME simple COMMAND simple)

Tests/RunCMake/CXXModulesCompile/subdir/with space/importable.cxx

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

Tests/RunCMake/CXXModulesCompile/subdir/with space/main.cxx

@@ -0,0 +1,6 @@
+import importable;
+
+int main(int argc, char* argv[])
+{
+  return from_import();
+}