cxxmodules: compute link information for C++ module-consuming targets

Compute link information for all C++ targets which support
modules instead of just those which may provide modules, as
they may import modules as well. This captures `OBJECT` libraries using modules
which otherwise do not have link steps.

Fixes: #25592

Source/cmComputeLinkInformation.cxx

@@ -553,7 +553,8 @@ bool cmComputeLinkInformation::Compute()
         this->Target->GetType() == cmStateEnums::MODULE_LIBRARY ||
         this->Target->GetType() == cmStateEnums::STATIC_LIBRARY ||
         (this->Target->CanCompileSources() &&
-         (this->Target->HaveCxx20ModuleSources() ||
+         (this->Target->HaveCxxModuleSupport(this->Config) ==
+            cmGeneratorTarget::Cxx20SupportLevel::Supported ||
           this->Target->HaveFortranSources())))) {
     return false;
   }

Tests/RunCMake/CXXModules/RunCMakeTest.cmake

@@ -180,6 +180,7 @@ if ("named" IN_LIST CMake_TEST_MODULE_COMPILATION)
   run_cxx_module_test(non-trivial-collation-order-randomized)
   run_cxx_module_test(duplicate)
   set(RunCMake_CXXModules_NO_TEST 1)
+  run_cxx_module_test(import-from-object)
   run_cxx_module_test(circular)
   run_cxx_module_test(try-compile)
   run_cxx_module_test(try-run)

Tests/RunCMake/CXXModules/examples/import-from-object/CMakeLists.txt

@@ -0,0 +1,16 @@
+cmake_minimum_required(VERSION 3.24...3.28)
+project(cxx_modules_import_from_object CXX)
+
+include("${CMAKE_SOURCE_DIR}/../cxx-modules-rules.cmake")
+
+set(CMAKE_CXX_STANDARD 20)
+
+add_library(a STATIC)
+target_sources(a
+  PUBLIC
+    FILE_SET CXX_MODULES
+      FILES
+        object-a.cxx)
+
+add_library(b OBJECT object-b.cxx)
+target_link_libraries(b PRIVATE a)

Tests/RunCMake/CXXModules/examples/import-from-object/object-a.cxx

@@ -0,0 +1,2 @@
+module;
+export module a;

Tests/RunCMake/CXXModules/examples/import-from-object/object-b.cxx

@@ -0,0 +1 @@
+import a;