AutoMoc: Configure AutoMoc after generated sources (PCH, Unity)

Fixes: #20119

Source/cmGlobalGenerator.cxx

@@ -1426,13 +1426,13 @@ bool cmGlobalGenerator::Compute()
   // so create the map from project name to vector of local generators
   this->FillProjectMap();
 
-  // Iterate through all targets and set up AUTOMOC, AUTOUIC and AUTORCC
-  if (!this->QtAutoGen()) {
+  // Add automatically generated sources (e.g. unity build).
+  if (!this->AddAutomaticSources()) {
     return false;
   }
 
-  // Add automatically generated sources (e.g. unity build).
-  if (!this->AddAutomaticSources()) {
+  // Iterate through all targets and set up AUTOMOC, AUTOUIC and AUTORCC
+  if (!this->QtAutoGen()) {
     return false;
   }
 

Source/cmLocalGenerator.cxx

@@ -2750,9 +2750,14 @@ void cmLocalGenerator::AddPchDependencies(cmGeneratorTarget* target)
           // Add pchHeader to source files, which will
           // be grouped as "Precompile Header File"
           auto pchHeader_sf = this->Makefile->GetOrCreateSource(
-            pchHeader, false, cmSourceFileLocationKind::Known);
+            pchHeader, true, cmSourceFileLocationKind::Known);
           std::string err;
           pchHeader_sf->ResolveFullPath(&err);
+
+          // The pch file is generated, but mark it as not generated
+          // so that a clean operation will not remove it from disk
+          pchHeader_sf->SetProperty("GENERATED", "0");
+
           target->AddSource(pchHeader);
         }
       }
@@ -2767,6 +2772,7 @@ inline void RegisterUnitySources(cmGeneratorTarget* target, cmSourceFile* sf,
 {
   target->AddSourceFileToUnityBatch(sf->ResolveFullPath());
   sf->SetProperty("UNITY_SOURCE_FILE", filename.c_str());
+  sf->SetProperty("SKIP_AUTOGEN", "ON");
 }
 
 inline void IncludeFileInUnitySources(cmGeneratedFileStream& unity_file,