[LLVM16] Minor compilation fixes: Optionals

Porting IGC code to LLVM16

Once changes related to Source/IGC/CMFE/AdaptorCM/Frontend.h file are merged
the return type of makeFEWrapper() will be changed from LLVM::Optional to std::optional.
Due to this change the IGCLLVM::makeOptional() call no longer valid and can be removed.

(cherry picked from commit 8ff0a49)

Author: bokrzesi

IGC/AdaptorOCL/ocl_igc_interface/impl/fcl_ocl_translation_ctx_impl.cpp

@@ -551,6 +551,7 @@ OclTranslationOutputBase* CIF_PIMPL(FclOclTranslationCtx)::TranslateCM(
     };
     auto MaybeFE =
         IGC::AdaptorCM::Frontend::makeFEWrapper(ErrFn, getCMFEWrapperDir());
+
     if (!MaybeFE)
         return outputInterface;
 

IGC/CMFE/AdaptorCM/Frontend.h

@@ -11,7 +11,6 @@ SPDX-License-Identifier: MIT
 
 #include "Interface.h"
 
-#include <llvm/ADT/Optional.h>
 #include <llvm/ADT/StringExtras.h>
 #include <llvm/ADT/StringRef.h>
 #include <llvm/ADT/Twine.h>
@@ -20,6 +19,7 @@ SPDX-License-Identifier: MIT
 #include <llvm/Support/Process.h>
 
 #include <memory>
+#include <optional>
 #include <sstream>
 
 namespace IGC {
@@ -117,8 +117,8 @@ template <typename Fn> class FEWrapper {
     constexpr auto CustomPathEnv = "CM_FE_DIR";
 
     std::string LibDir;
-    if (auto EnvDir = llvm::sys::Process::GetEnv(CustomPathEnv))
-      LibDir = EnvDir.getValue();
+    if (const char *EnvDir = std::getenv(CustomPathEnv))
+      LibDir = std::string(EnvDir);
     else
       LibDir = DefaultDir;
 
@@ -145,7 +145,7 @@ template <typename Fn> class FEWrapper {
       : ErrHandler(std::forward<ErrFn>(ErrH)), Lib(loadLibrary(DefaultPath)) {}
 
   template <typename ErrFn, typename ErrFnTy>
-  friend llvm::Optional<FEWrapper<ErrFnTy>>
+  friend std::optional<FEWrapper<ErrFnTy>>
   makeFEWrapper(ErrFn &&ErrH, const std::string &DefaultDir);
 
 public:
@@ -212,16 +212,15 @@ template <typename Fn> class FEWrapper {
 // absolute path to directory with FE wrapper. Defaults to empty string
 // that is expanded to plain FE wrapper name.
 // Return Optional as it can fail during loading.
-template <typename ErrFn,
-          typename ErrFnTy = typename std::decay<ErrFn>::type>
-inline llvm::Optional<FEWrapper<ErrFnTy>>
+template <typename ErrFn, typename ErrFnTy = typename std::decay<ErrFn>::type>
+inline std::optional<FEWrapper<ErrFnTy>>
 makeFEWrapper(ErrFn &&ErrH, const std::string &DefaultDir = std::string{}) {
   FEWrapper<ErrFnTy> IFace{std::forward<ErrFn>(ErrH), DefaultDir};
 
   if (!IFace.Lib.isValid())
-    return llvm::None;
+    return std::nullopt;
   if (!IFace.isCompatibleABI())
-    return llvm::None;
+    return std::nullopt;
   return IFace;
 }
 

IGC/CMFE/AdaptorCM/Interface.h

@@ -83,7 +83,7 @@ struct IDriverInvocation {
 };
 
 // this number should be increased whenever the public interface changes
-static const int InterfaceVersion = 10;
+static const int InterfaceVersion = 11;
 
 } // namespace ClangFE
 } // namespace CM