2 files changed, 15 insertions, 5 deletions
diff --git a/Source/cmGlobalGenerator.cxx b/Source/cmGlobalGenerator.cxx
index c2b972d..493d32d 100644
--- a/Source/cmGlobalGenerator.cxx
+++ b/Source/cmGlobalGenerator.cxx
@@ -1543,10 +1543,7 @@ bool cmGlobalGenerator::Compute()
   // so create the map from project name to vector of local generators
   this->FillProjectMap();
 
-  // Add automatically generated sources (e.g. unity build).
-  if (!this->AddAutomaticSources()) {
-    return false;
-  }
+  this->CreateFileGenerateOutputs();
 
   // Iterate through all targets and add verification targets for header sets
   if (!this->AddHeaderSetVerification()) {
@@ -1587,6 +1584,14 @@ bool cmGlobalGenerator::Compute()
     }
   }
 
+  // Add automatically generated sources (e.g. unity build).
+  // Add unity sources after computing compile features.  Unity sources do
+  // not change the set of languages or features, but we need to know them
+  // to filter out sources that are scanned for C++ module dependencies.
+  if (!this->AddAutomaticSources()) {
+    return false;
+  }
+
   for (const auto& localGen : this->LocalGenerators) {
     cmMakefile* mf = localGen->GetMakefile();
     for (const auto& g : mf->GetInstallGenerators()) {
@@ -1853,11 +1858,15 @@ bool cmGlobalGenerator::AddHeaderSetVerification()
   return true;
 }
 
-bool cmGlobalGenerator::AddAutomaticSources()
+void cmGlobalGenerator::CreateFileGenerateOutputs()
 {
   for (const auto& lg : this->LocalGenerators) {
     lg->CreateEvaluationFileOutputs();
   }
+}
+
+bool cmGlobalGenerator::AddAutomaticSources()
+{
   for (const auto& lg : this->LocalGenerators) {
     for (const auto& gt : lg->GetGeneratorTargets()) {
       if (!gt->CanCompileSources()) {
diff --git a/Source/cmGlobalGenerator.h b/Source/cmGlobalGenerator.h
index aa54f69..bc80547 100644
--- a/Source/cmGlobalGenerator.h
+++ b/Source/cmGlobalGenerator.h
@@ -676,6 +676,7 @@ protected:
 
   bool AddHeaderSetVerification();
 
+  void CreateFileGenerateOutputs();
   bool AddAutomaticSources();
 
   std::string SelectMakeProgram(const std::string& makeProgram,