Autogen: Add AUTOGEN_USE_SYSTEM_INCLUDE target property

`AUTOGEN_USE_SYSTEM_INCLUDE` was added. `AUTOGEN_USE_SYSTEM_INCLUDE`
is a boolean property that can be set on a target to indicate that the
autogen target include directory should be added as a system include
directory or normal include directory to the target.

Source/cmGeneratorTarget.cxx

@@ -731,6 +731,29 @@ void cmGeneratorTarget::AddIncludeDirectory(const std::string& src,
       BT<std::string>(src, this->Makefile->GetBacktrace()), true));
 }
 
+void cmGeneratorTarget::AddSystemIncludeDirectory(std::string const& inc,
+                                                  std::string const& lang)
+{
+  std::string config_upper;
+  auto const& configs =
+    this->Makefile->GetGeneratorConfigs(cmMakefile::IncludeEmptyConfig);
+
+  for (auto const& config : configs) {
+    std::string inc_with_config = inc;
+    if (!config.empty()) {
+      cmSystemTools::ReplaceString(inc_with_config, "$<CONFIG>", config);
+      config_upper = cmSystemTools::UpperCase(config);
+    }
+    auto const& key = cmStrCat(config_upper, "/", lang);
+    this->Target->AddSystemIncludeDirectories({ inc_with_config });
+    this->SystemIncludesCache[key].emplace_back(inc_with_config);
+
+    // SystemIncludesCache should be sorted so that binary search can be used
+    std::sort(this->SystemIncludesCache[key].begin(),
+              this->SystemIncludesCache[key].end());
+  }
+}
+
 std::vector<cmSourceFile*> const* cmGeneratorTarget::GetSourceDepends(
   cmSourceFile const* sf) const
 {

Source/cmGeneratorTarget.h

@@ -912,6 +912,8 @@ public:
   std::vector<std::string> GetGeneratedISPCObjects(
     std::string const& config) const;
 
+  void AddSystemIncludeDirectory(std::string const& inc,
+                                 std::string const& lang);
   bool AddHeaderSetVerification();
   std::string GenerateHeaderSetVerificationFile(
     cmSourceFile& source, const std::string& dir,

Source/cmQtAutoGenInitializer.cxx

@@ -576,7 +576,20 @@ bool cmQtAutoGenInitializer::InitCustomTargets()
 
   // Add autogen include directory to the origin target INCLUDE_DIRECTORIES
   if (this->MocOrUicEnabled() || (this->Rcc.Enabled && this->MultiConfig)) {
-    this->GenTarget->AddIncludeDirectory(this->Dir.IncludeGenExp, true);
+    auto addBefore = false;
+    auto const& value =
+      this->GenTarget->GetProperty("AUTOGEN_USE_SYSTEM_INCLUDE");
+    if (value.IsSet()) {
+      if (cmIsOn(value)) {
+        this->GenTarget->AddSystemIncludeDirectory(this->Dir.IncludeGenExp,
+                                                   "CXX");
+      } else {
+        addBefore = true;
+      }
+    } else {
+      addBefore = true;
+    }
+    this->GenTarget->AddIncludeDirectory(this->Dir.IncludeGenExp, addBefore);
   }
 
   // Scan files

Source/cmTarget.cxx

@@ -546,6 +546,7 @@ TargetProperty const StaticTargetProperties[] = {
   // -- Autogen
   { "AUTOGEN_ORIGIN_DEPENDS"_s, IC::CanCompileSources },
   { "AUTOGEN_PARALLEL"_s, IC::CanCompileSources },
+  { "AUTOGEN_USE_SYSTEM_INCLUDE"_s, IC::CanCompileSources },
   // -- moc
   { "AUTOMOC_DEPEND_FILTERS"_s, IC::CanCompileSources },
   // -- C++