Merge topic 'clang-cl-vfs'

20ebaed972 Clang: Add support for passing VFS arguments
d993ebd4ca clang-cl: Add '--' before source file
a94672b919 cmake: Change cmake_llvm_rc separator from -- to ++ to avoid conflict

Acked-by: Kitware Robot <kwrobot@kitware.com>
Merge-request: !5087

2 files changed, 27 insertions, 6 deletions

diff --git a/Source/cmLocalGenerator.cxx b/Source/cmLocalGenerator.cxx
index 7e35fe7..2380cce 100644
--- a/Source/cmLocalGenerator.cxx
+++ b/Source/cmLocalGenerator.cxx
@@ -1938,6 +1938,9 @@ void cmLocalGenerator::AddLanguageFlags(std::string& flags,
   this->AddConfigVariableFlags(flags, cmStrCat("CMAKE_", lang, "_FLAGS"),
                                config);
 
+  std::string const& compiler = this->Makefile->GetSafeDefinition(
+    cmStrCat("CMAKE_", lang, "_COMPILER_ID"));
+
   if (lang == "Swift") {
     if (cmProp v = target->GetProperty("Swift_LANGUAGE_VERSION")) {
       if (cmSystemTools::VersionCompare(
@@ -1951,9 +1954,6 @@ void cmLocalGenerator::AddLanguageFlags(std::string& flags,
     target->AddCUDAArchitectureFlags(flags);
     target->AddCUDAToolkitFlags(flags);
 
-    std::string const& compiler =
-      this->Makefile->GetSafeDefinition("CMAKE_CUDA_COMPILER_ID");
-
     if (compiler == "Clang") {
       bool separable = target->GetPropertyAsBool("CUDA_SEPARABLE_COMPILATION");
 
@@ -1965,7 +1965,24 @@ void cmLocalGenerator::AddLanguageFlags(std::string& flags,
       }
     }
   }
-
+  // Add VFS Overlay for Clang compiliers
+  if (compiler == "Clang") {
+    if (const char* vfsOverlay =
+          this->Makefile->GetDefinition("CMAKE_CLANG_VFS_OVERLAY")) {
+      std::string const& compilerSimulateId =
+        this->Makefile->GetSafeDefinition(
+          cmStrCat("CMAKE_", lang, "_SIMULATE_ID"));
+      if (compilerSimulateId == "MSVC") {
+        this->AppendCompileOptions(
+          flags,
+          std::vector<std::string>{ "-Xclang", "-ivfsoverlay", "-Xclang",
+                                    vfsOverlay });
+      } else {
+        this->AppendCompileOptions(
+          flags, std::vector<std::string>{ "-ivfsoverlay", vfsOverlay });
+      }
+    }
+  }
   // Add MSVC runtime library flags.  This is activated by the presence
   // of a default selection whether or not it is overridden by a property.
   cmProp msvcRuntimeLibraryDefault =
diff --git a/Source/cmcmd.cxx b/Source/cmcmd.cxx
index 1a5fea1..a1c6771 100644
--- a/Source/cmcmd.cxx
+++ b/Source/cmcmd.cxx
@@ -1772,7 +1772,7 @@ int cmcmd::RunLLVMRC(std::vector<std::string> const& args)
   //   args[2] == source_file_path
   //   args[3] == intermediate_file
   //   args[4..n] == preprocess+args
-  //   args[n+1] == --
+  //   args[n+1] == ++
   //   args[n+2...] == llvm-rc+args
   if (args.size() < 3) {
     std::cerr << "Invalid cmake_llvm_rc arguments";
@@ -1784,7 +1784,11 @@ int cmcmd::RunLLVMRC(std::vector<std::string> const& args)
   std::vector<std::string> resource_compile;
   std::vector<std::string>* pArgTgt = &preprocess;
   for (std::string const& arg : cmMakeRange(args).advance(4)) {
-    if (arg == "--") {
+    // We use ++ as seperator between the preprocessing step definition and the
+    // rc compilation step becase we need to prepend a -- to seperate the
+    // source file properly from other options when using clang-cl for
+    // preprocessing.
+    if (arg == "++") {
       pArgTgt = &resource_compile;
     } else {
       if (arg.find("SOURCE_DIR") != std::string::npos) {