6 files changed, 36 insertions, 8 deletions
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index 8dfc0ce..0e782f2 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1566,13 +1566,24 @@ bool cmGlobalGenerator::AddAutomaticSources()
   for (cmLocalGenerator* lg : this->LocalGenerators) {
     lg->CreateEvaluationFileOutputs();
     for (const auto& gt : lg->GetGeneratorTargets()) {
-      if (gt->GetType() == cmStateEnums::INTERFACE_LIBRARY) {
+      if (gt->GetType() == cmStateEnums::INTERFACE_LIBRARY ||
+          gt->GetType() == cmStateEnums::UTILITY ||
+          gt->GetType() == cmStateEnums::GLOBAL_TARGET) {
         continue;
       }
       lg->AddUnityBuild(gt.get());
       lg->AddPchDependencies(gt.get());
     }
   }
+  // The above transformations may have changed the classification of sources.
+  // Clear the source list and classification cache (KindedSources) of all
+  // targets so that it will be recomputed correctly by the generators later
+  // now that the above transformations are done for all targets.
+  for (cmLocalGenerator* lg : this->LocalGenerators) {
+    for (const auto& gt : lg->GetGeneratorTargets()) {
+      gt->ClearSourcesCache();
+    }
+  }
   return true;
 }
 
diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index fa997f4..c58603f 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -2393,6 +2393,7 @@ void cmLocalGenerator::AddPchDependencies(cmGeneratorTarget* target)
   }
   const std::string buildType = cmSystemTools::UpperCase(config);
 
+  // FIXME: Refactor collection of sources to not evaluate object libraries.
   std::vector<cmSourceFile*> sources;
   target->GetSourceFiles(sources, buildType);
 
@@ -2565,6 +2566,7 @@ void cmLocalGenerator::AddUnityBuild(cmGeneratorTarget* target)
     cmStrCat(this->GetCurrentBinaryDirectory(), "/CMakeFiles/",
              target->GetName(), ".dir/Unity/");
 
+  // FIXME: Refactor collection of sources to not evaluate object libraries.
   std::vector<cmSourceFile*> sources;
   target->GetSourceFiles(sources, buildType);
 
@@ -2614,12 +2616,7 @@ void cmLocalGenerator::AddUnityBuild(cmGeneratorTarget* target)
         for (; begin != end; ++begin) {
           cmSourceFile* sf = filtered_sources[begin];
 
-          // Only in Visual Studio generator we keep the source files
-          // for explicit processing.
-          if (!this->GetGlobalGenerator()->IsMultiConfig() ||
-              this->GetGlobalGenerator()->IsXcode()) {
-            target->AddSourceFileToUnityBatch(sf->ResolveFullPath());
-          }
+          target->AddSourceFileToUnityBatch(sf->ResolveFullPath());
           sf->SetProperty("UNITY_SOURCE_FILE", filename.c_str());
 
           if (beforeInclude) {
diff --git a/Source/cmVisualStudio10TargetGenerator.cxx b/Source/cmVisualStudio10TargetGenerator.cxx
index 5ffa576..8fc40a79 100644
--- a/Source/cmVisualStudio10TargetGenerator.cxx
+++ b/Source/cmVisualStudio10TargetGenerator.cxx
@@ -2160,7 +2160,6 @@ void cmVisualStudio10TargetGenerator::WriteAllSources(Elem& e0)
         this->WriteExtraSource(e1, si.Source);
         break;
       case cmGeneratorTarget::SourceKindHeader:
-      case cmGeneratorTarget::SourceKindUnityBatched:
         this->WriteHeaderSource(e1, si.Source);
         break;
       case cmGeneratorTarget::SourceKindIDL:
@@ -2172,6 +2171,7 @@ void cmVisualStudio10TargetGenerator::WriteAllSources(Elem& e0)
       case cmGeneratorTarget::SourceKindModuleDefinition:
         tool = "None";
         break;
+      case cmGeneratorTarget::SourceKindUnityBatched:
       case cmGeneratorTarget::SourceKindObjectSource: {
         const std::string& lang = si.Source->GetLanguage();
         if (lang == "C" || lang == "CXX") {
diff --git a/Tests/RunCMake/ObjectLibrary/OwnSources-stderr.txt b/Tests/RunCMake/ObjectLibrary/OwnSources-stderr.txt
index 208f3c9..cb1a2e5 100644
--- a/Tests/RunCMake/ObjectLibrary/OwnSources-stderr.txt
+++ b/Tests/RunCMake/ObjectLibrary/OwnSources-stderr.txt
@@ -4,4 +4,10 @@
 Call Stack \(most recent call first\):
   CMakeLists.txt:[0-9]+ \(include\)
 +
+CMake Error at OwnSources.cmake:[0-9]+ \(add_library\):
+  The SOURCES of "A" use a generator expression that depends on the SOURCES
+  themselves.
+Call Stack \(most recent call first\):
+  CMakeLists.txt:[0-9]+ \(include\)
++
 CMake Generate step failed\.  Build files cannot be regenerated correctly\.$
diff --git a/Tests/RunCMake/UnityBuild/RunCMakeTest.cmake b/Tests/RunCMake/UnityBuild/RunCMakeTest.cmake
index 8e484d0..24daa64 100644
--- a/Tests/RunCMake/UnityBuild/RunCMakeTest.cmake
+++ b/Tests/RunCMake/UnityBuild/RunCMakeTest.cmake
@@ -21,3 +21,4 @@ function(run_test name)
 endfunction()
 
 run_test(unitybuild_runtest)
+run_test(unitybuild_object_library)
diff --git a/Tests/RunCMake/UnityBuild/unitybuild_object_library.cmake b/Tests/RunCMake/UnityBuild/unitybuild_object_library.cmake
new file mode 100644
index 0000000..b400517
--- /dev/null
+++ b/Tests/RunCMake/UnityBuild/unitybuild_object_library.cmake
@@ -0,0 +1,13 @@
+project(unitybuild_object_library C)
+
+set(CMAKE_UNITY_BUILD ON) # This tests that the variable works in addition to the property
+
+add_library(lib OBJECT func.c)
+
+add_library(other-lib STATIC func.c)
+
+add_executable(main main.c)
+target_link_libraries(main PRIVATE lib)
+
+enable_testing()
+add_test(NAME main COMMAND main)