1 files changed, 49 insertions, 14 deletions

diff --git a/Source/cmGeneratorTarget.cxx b/Source/cmGeneratorTarget.cxx
index 949d9d9..d38e9e1 100644
--- a/Source/cmGeneratorTarget.cxx
+++ b/Source/cmGeneratorTarget.cxx
@@ -1569,6 +1569,8 @@ void cmGeneratorTarget::ComputeKindedSources(KindedSources& files,
       kind = SourceKindCustomCommand;
     } else if (this->Target->GetType() == cmStateEnums::UTILITY) {
       kind = SourceKindExtra;
+    } else if (this->IsSourceFilePartOfUnityBatch(sf->ResolveFullPath())) {
+      kind = SourceKindUnityBatched;
     } else if (sf->GetPropertyAsBool("HEADER_FILE_ONLY")) {
       kind = SourceKindHeader;
     } else if (sf->GetPropertyAsBool("EXTERNAL_OBJECT")) {
@@ -3334,9 +3336,11 @@ std::vector<BT<std::string>> cmGeneratorTarget::GetPrecompileHeaders(
 std::string cmGeneratorTarget::GetPchHeader(const std::string& config,
                                             const std::string& language) const
 {
-  if (language != "C" && language != "CXX") {
+  if (language != "C" && language != "CXX" && language != "OBJC" &&
+      language != "OBJCXX") {
     return std::string();
   }
+
   if (this->GetPropertyAsBool("DISABLE_PRECOMPILE_HEADERS")) {
     return std::string();
   }
@@ -3358,17 +3362,18 @@ std::string cmGeneratorTarget::GetPchHeader(const std::string& config,
         this->GetGlobalGenerator()->FindGeneratorTarget(pchReuseFrom);
     }
 
-    if (this->GetGlobalGenerator()->IsMultiConfig()) {
-      filename = cmStrCat(
-        generatorTarget->LocalGenerator->GetCurrentBinaryDirectory(), "/");
-    } else {
-      // For GCC we need to have the header file .h[xx]
-      // next to the .h[xx].gch file
-      filename = generatorTarget->ObjectDirectory;
-    }
+    filename = cmStrCat(
+      generatorTarget->LocalGenerator->GetCurrentBinaryDirectory(), "/");
+
+    const std::map<std::string, std::string> languageToExtension = {
+      { "C", ".h" },
+      { "CXX", ".hxx" },
+      { "OBJC", ".objc.h" },
+      { "OBJCXX", ".objcxx.hxx" }
+    };
 
     filename = cmStrCat(filename, "CMakeFiles/", generatorTarget->GetName(),
-                        ".dir/cmake_pch", ((language == "C") ? ".h" : ".hxx"));
+                        ".dir/cmake_pch", languageToExtension.at(language));
 
     const std::string filename_tmp = cmStrCat(filename, ".tmp");
     if (!pchReuseFrom) {
@@ -3418,7 +3423,8 @@ std::string cmGeneratorTarget::GetPchHeader(const std::string& config,
 std::string cmGeneratorTarget::GetPchSource(const std::string& config,
                                             const std::string& language) const
 {
-  if (language != "C" && language != "CXX") {
+  if (language != "C" && language != "CXX" && language != "OBJC" &&
+      language != "OBJCXX") {
     return std::string();
   }
   const auto inserted =
@@ -3444,9 +3450,20 @@ std::string cmGeneratorTarget::GetPchSource(const std::string& config,
 
     // For GCC the source extension will be tranformed into .h[xx].gch
     if (!this->Makefile->IsOn("CMAKE_LINK_PCH")) {
-      filename += ((language == "C") ? ".h.c" : ".hxx.cxx");
+      const std::map<std::string, std::string> languageToExtension = {
+        { "C", ".h.c" },
+        { "CXX", ".hxx.cxx" },
+        { "OBJC", ".objc.h.m" },
+        { "OBJCXX", ".objcxx.hxx.mm" }
+      };
+
+      filename += languageToExtension.at(language);
     } else {
-      filename += ((language == "C") ? ".c" : ".cxx");
+      const std::map<std::string, std::string> languageToExtension = {
+        { "C", ".c" }, { "CXX", ".cxx" }, { "OBJC", ".m" }, { "OBJCXX", ".mm" }
+      };
+
+      filename += languageToExtension.at(language);
     }
 
     const std::string filename_tmp = cmStrCat(filename, ".tmp");
@@ -3464,7 +3481,8 @@ std::string cmGeneratorTarget::GetPchSource(const std::string& config,
 std::string cmGeneratorTarget::GetPchFileObject(const std::string& config,
                                                 const std::string& language)
 {
-  if (language != "C" && language != "CXX") {
+  if (language != "C" && language != "CXX" && language != "OBJC" &&
+      language != "OBJCXX") {
     return std::string();
   }
   const auto inserted =
@@ -3572,6 +3590,23 @@ std::string cmGeneratorTarget::GetPchUseCompileOptions(
   return inserted.first->second;
 }
 
+void cmGeneratorTarget::AddSourceFileToUnityBatch(
+  const std::string& sourceFilename)
+{
+  this->UnityBatchedSourceFiles.insert(sourceFilename);
+}
+
+bool cmGeneratorTarget::IsSourceFilePartOfUnityBatch(
+  const std::string& sourceFilename) const
+{
+  if (!this->GetPropertyAsBool("UNITY_BUILD")) {
+    return false;
+  }
+
+  return this->UnityBatchedSourceFiles.find(sourceFilename) !=
+    this->UnityBatchedSourceFiles.end();
+}
+
 void cmGeneratorTarget::GetLinkOptions(std::vector<std::string>& result,
                                        const std::string& config,
                                        const std::string& language) const