[clang] NFC, move the utility function CompilerInvocation::setLangDefaults to LangOptions.h

[hokein]

Summary

The function will be moved from clangFrontend to clangBasic, which
allows tools (clang pseudoparser)which don't depend on clangFrontend to use
this function.

[hokein]

in case you missed that, friendly ping :)

[dexonsmith]

This makes sense to me! A few comments inline.

Also, the description doesn't talk about timeline for removing the wrapper. Ideally we wouldn't leave behind the wrapper behind... just long enough that you can migrate the callers and delete the old function in separate incremental commit(s) (or if there are very few callers, all in this commit would be fine, but I'm guessing that's not the case here). Or were you thinking something else?

clang/include/clang/Basic/LangOptions.h

561

Looks like a copy/paste typo in the first word.

569–571

I think this would be cleaner as:

class LangOpts {
// ...
  void setDefaults(Language Lang, const llvm::Triple &T, ...);
};

Or setLangDefaults or setDefaultsFor (I don't care about the name, just feel like it makes more sense as a member function if we're updating all the callers anyway).

Also, you should include a default for LangStd or it'll be hard to migrate over callers.

clang/include/clang/Frontend/CompilerInvocation.h

221–222

I think you should inline the new one-liner implementation into the header, documenting what people should do instead.

221–222

I suggest having this comment phrased to explain what it does before saying what people should do. Something like:

/// Forwards to [...].
///
/// TODO: Remove this wrapper once all callers have been updated.

[sammccall]

+1 to Duncan's comments, and a couple of nits while here.
Otherwise LG, will be nice to use this without pulling in the grab-bag that is Frontend.

In D121375#3428123, @dexonsmith wrote:

Also, the description doesn't talk about timeline for removing the wrapper. Ideally we wouldn't leave behind the wrapper behind... just long enough that you can migrate the callers and delete the old function in separate incremental commit(s) (or if there are very few callers, all in this commit would be fine, but I'm guessing that's not the case here). Or were you thinking something else?

I only see one usage in-tree (and one more in clspv). And migration is very easy. I think you should do it all in this commit.

clang/include/clang/Basic/LangOptions.h

567

while here: this param is non-obvious and this comment doesn't clarify much.
Maybe "If the language requires extra headers to be implicitly included, they will be appended to this list"

569–571

I kind of like the idea that this logic is "layered above" the langopts struct itself. On the other hand making it a member makes it more discoverable and less surprising that LangOptions is actually an inout param (e.g. IncludeDefaultHeader). Either way is fine with me.

clang/lib/Basic/LangOptions.cpp

221

Pull this out into a separate function getDefaultLangStandard(Language, const Triple&)? (No need to expose it unless you want to, though I think it'll be helpful in future).

It seems bizarre that this depends on the triple, but obviously don't want to change that now

[dexonsmith]

In D121375#3429023, @sammccall wrote:

I only see one usage in-tree (and one more in clspv). And migration is very easy. I think you should do it all in this commit.

Nice, agreed, no need to split up.

clang/include/clang/Basic/LangOptions.h

569–571

I kind of like the idea that this logic is "layered above" the langopts struct itself.

@sammccall, I'm curious if you have reasoning for the preference to layer it above; is it because it takes the Triple, or is it something more general? (If it's because of the triple, I agree that makes the layering a bit odd.)

On the other hand making it a member makes it more discoverable and less surprising that LangOptions is actually an inout param (e.g. IncludeDefaultHeader).

Maybe it's better to return by value in either case to remove the inout, since it seems unnecessary:

class LangOpts {
// ...
  static LangOpts getDefaults(Language Lang, const llvm::Triple &T, ...);
};

If you still prefer a free function, I'd be happy enough with something like this:

namespace clang {
LangOpts getLangDefaults(Language Lang, const llvm::Triple &T, ...);
}

(I'm probably almost indifferent at this point, after thinking about the triple, ...)

[sammccall]

clang/include/clang/Basic/LangOptions.h

569–571

@sammccall, I'm curious if you have reasoning for the preference to layer it above; is it because it takes the Triple, or is it something more general?

It's more about compiler defaults being an application-level concern where LangOptions is more of a dumb struct. But that's also an argument for keeping it in Frontend, and we don't want that for practical reasons (it's nice to use the lexer on real code without Frontend!). So I'm not sure I have a coherent argument here, I'm happy with any option.

Return by value sounds great, unfortunately the existing code in Frontend calls this in the *middle* of initializing LangOpts from various sources, so it would imply some bigger/riskier changes I guess.

[dexonsmith]

clang/include/clang/Basic/LangOptions.h

569–571

Return by value sounds great, unfortunately the existing code in Frontend calls this in the *middle* of initializing LangOpts from various sources, so it would imply some bigger/riskier changes I guess.

Looking more closely, you're right that initialization is pretty twisty; I don't think it's worth the risk for now.

In which case, I like the member function approach, even though it makes LangOpts a little less dumb. Something like LangOpts::setLangDefaults(), I guess. @hokein, if you'd strongly prefer a free function (what you already have) I'd be fine with that too.

[hokein]

address comments;
move to LangOpts::setLangDefaults;
pull out a getNameKind in LangStandard;
remove the old API in CompilerInvocation;

[hokein]

Thanks for all comments!

clang/include/clang/Basic/LangOptions.h

569–571

Personally, I don't have a strong opinion, I'm fine with either. Change to a method of LangOpts.

clang/lib/Basic/LangOptions.cpp

221

I think this is a good idea, there is a similar getLangKind method in LangStandard. Moved it to LangStandard.

[sammccall]

clang/include/clang/Basic/LangStandard.h

141

this makes it sound like a simple getter/lookup, which it absolutely is not!

getDefaultLanguageStandard? And separate it out from the simple getters?

(The meaningless distinction in the other function names between "standard" and "kind", and the "lang" abbreviation are both pretty unfortunate here, we don't need to fix them but let's not propagate them further)

[dexonsmith]

LGTM once @sammccall 's new comments are addressed!

[hokein]

getDefaultLanguageStandard.

clang/include/clang/Basic/LangOptions.h

public:
   /// The default stream kind used for HIP kernel launching.
   GPUDefaultStreamKind GPUDefaultStream;
 
   /// The seed used by the randomize structure layout feature.
   std::string RandstructSeed;
 
   LangOptions();
 
+  /// Set language defaults for the given input language and
+  /// language standard in the given LangOptions object.
+  ///
+  /// \param Opts - The LangOptions object to set up.
+  /// \param Lang - The input language.
+  /// \param T - The target triple.
+  /// \param Includes - If the language requires extra headers to be implicitly
+  ///                   included, they will be appended to this list.
+  /// \param LangStd - The input language standard.
+  static void
+  setLangDefaults(LangOptions &Opts, Language Lang, const llvm::Triple &T,
+                  std::vector<std::string> &Includes,
+                  LangStandard::Kind LangStd = LangStandard::lang_unspecified);
+
   // Define accessors/mutators for language options of enumeration type.
 #define LANGOPT(Name, Bits, Default, Description)
 #define ENUM_LANGOPT(Name, Type, Bits, Default, Description) \
   Type get##Name() const { return static_cast<Type>(Name); } \
   void set##Name(Type Value) { Name = static_cast<unsigned>(Value); }
 #include "clang/Basic/LangOptions.def"
 
   /// Are we compiling a module interface (.cppm or module map)?
#include "clang/Basic/LangOptions.def"
   }
 
   bool isSYCL() const { return SYCLIsDevice || SYCLIsHost; }
 
   /// Remap path prefix according to -fmacro-prefix-path option.
   void remapPathPrefix(SmallString<256> &Path) const;
 };
 
 /// Floating point control options
 class FPOptionsOverride;
 class FPOptions {
 public:
   // We start by defining the layout.
   using storage_type = uint16_t;
 
   using RoundingMode = llvm::RoundingMode;
 
   static constexpr unsigned StorageBitSize = 8 * sizeof(storage_type);
 
   // Define a fake option named "First" so that we have a PREVIOUS even for the
   // real first option.
   static constexpr storage_type FirstShift = 0, FirstWidth = 0;
 #define OPTION(NAME, TYPE, WIDTH, PREVIOUS)                                    \
   static constexpr storage_type NAME##Shift =                                  \
       PREVIOUS##Shift + PREVIOUS##Width;                                       \
   static constexpr storage_type NAME##Width = WIDTH;                           \
   static constexpr storage_type NAME##Mask = ((1 << NAME##Width) - 1)          \

clang/include/clang/Basic/LangStandard.h

 //===--- LangStandard.h -----------------------------------------*- C++ -*-===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #ifndef LLVM_CLANG_BASIC_LANGSTANDARD_H
 #define LLVM_CLANG_BASIC_LANGSTANDARD_H
 
 #include "clang/Basic/LLVM.h"
 #include "llvm/ADT/StringRef.h"
 
+namespace llvm {
+class Triple;
+}
+
 namespace clang {
 
 /// The language for the input, used to select and validate the language
 /// standard and possible actions.
 enum class Language : uint8_t {
   Unknown,
 
   /// Assembly: we accept this only so that we can preprocess it.
public:
 
   /// hasImplicitInt - Language allows variables to be typed as int implicitly.
   bool hasImplicitInt() const { return Flags & ImplicitInt; }
 
   /// isOpenCL - Language is a OpenCL variant.
   bool isOpenCL() const { return Flags & OpenCL; }
 
   static Kind getLangKind(StringRef Name);
+
   static const LangStandard &getLangStandardForKind(Kind K);
   static const LangStandard *getLangStandardForName(StringRef Name);
 };
 
+LangStandard::Kind getDefaultLanguageStandard(clang::Language Lang,
+                                              const llvm::Triple &T);
+
 }  // end namespace clang
 
 #endif

clang/include/clang/Frontend/CompilerInvocation.h

public:
   /// reside, relative to the compiler binary (found by the passed in
   /// arguments).
   ///
   /// \param Argv0 - The program path (from argv[0]), for finding the builtin
   /// compiler path.
   /// \param MainAddr - The address of main (or some other function in the main
   /// executable), for finding the builtin compiler path.
   static std::string GetResourcesPath(const char *Argv0, void *MainAddr);
 
-  /// Set language defaults for the given input language and
-  /// language standard in the given LangOptions object.
-  ///
-  /// \param Opts - The LangOptions object to set up.
-  /// \param IK - The input language.
-  /// \param T - The target triple.
-  /// \param Includes - The affected list of included files.
-  /// \param LangStd - The input language standard.
-  static void
-  setLangDefaults(LangOptions &Opts, InputKind IK, const llvm::Triple &T,
-                  std::vector<std::string> &Includes,
-                  LangStandard::Kind LangStd = LangStandard::lang_unspecified);
-
   /// Retrieve a module hash string that is suitable for uniquely
   /// identifying the conditions under which the module was built.
   std::string getModuleHash() const;
 
   using StringAllocator = llvm::function_ref<const char *(const llvm::Twine &)>;
   /// Generate a cc1-compatible command line arguments from this instance.
   ///
   /// \param [out] Args - The generated arguments. Note that the caller is
   /// responsible for inserting the path to the clang executable and "-cc1" if

clang/lib/Basic/LangOptions.cpp

std::string LangOptions::getOpenCLVersionString() const {
   {
     llvm::raw_string_ostream Out(Result);
     Out << (OpenCLCPlusPlus ? "C++ for OpenCL" : "OpenCL C") << " version "
         << getOpenCLVersionTuple().getAsString();
   }
   return Result;
 }
 
+void LangOptions::setLangDefaults(LangOptions &Opts, Language Lang,
+                                  const llvm::Triple &T,
+                                  std::vector<std::string> &Includes,
+                                  LangStandard::Kind LangStd) {
+  // Set some properties which depend solely on the input kind; it would be nice
+  // to move these to the language standard, and have the driver resolve the
+  // input kind + language standard.
+  //
+  // FIXME: Perhaps a better model would be for a single source file to have
+  // multiple language standards (C / C++ std, ObjC std, OpenCL std, OpenMP std)
+  // simultaneously active?
+  if (Lang == Language::Asm) {
+    Opts.AsmPreprocessor = 1;
+  } else if (Lang == Language::ObjC || Lang == Language::ObjCXX) {
+    Opts.ObjC = 1;
+  }
+
+  if (LangStd == LangStandard::lang_unspecified)
+    LangStd = getDefaultLanguageStandard(Lang, T);
+  const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
+  Opts.LangStd = LangStd;
+  Opts.LineComment = Std.hasLineComments();
+  Opts.C99 = Std.isC99();
+  Opts.C11 = Std.isC11();
+  Opts.C17 = Std.isC17();
+  Opts.C2x = Std.isC2x();
+  Opts.CPlusPlus = Std.isCPlusPlus();
+  Opts.CPlusPlus11 = Std.isCPlusPlus11();
+  Opts.CPlusPlus14 = Std.isCPlusPlus14();
+  Opts.CPlusPlus17 = Std.isCPlusPlus17();
+  Opts.CPlusPlus20 = Std.isCPlusPlus20();
+  Opts.CPlusPlus2b = Std.isCPlusPlus2b();
+  Opts.GNUMode = Std.isGNUMode();
+  Opts.GNUCVersion = 0;
+  Opts.HexFloats = Std.hasHexFloats();
+  Opts.ImplicitInt = Std.hasImplicitInt();
+
+  Opts.HLSL = Lang == Language::HLSL;
+
+  // Set OpenCL Version.
+  Opts.OpenCL = Std.isOpenCL();
+  if (LangStd == LangStandard::lang_opencl10)
+    Opts.OpenCLVersion = 100;
+  else if (LangStd == LangStandard::lang_opencl11)
+    Opts.OpenCLVersion = 110;
+  else if (LangStd == LangStandard::lang_opencl12)
+    Opts.OpenCLVersion = 120;
+  else if (LangStd == LangStandard::lang_opencl20)
+    Opts.OpenCLVersion = 200;
+  else if (LangStd == LangStandard::lang_opencl30)
+    Opts.OpenCLVersion = 300;
+  else if (LangStd == LangStandard::lang_openclcpp10)
+    Opts.OpenCLCPlusPlusVersion = 100;
+  else if (LangStd == LangStandard::lang_openclcpp2021)
+    Opts.OpenCLCPlusPlusVersion = 202100;
+  else if (LangStd == LangStandard::lang_hlsl2015)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2015;
+  else if (LangStd == LangStandard::lang_hlsl2016)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2016;
+  else if (LangStd == LangStandard::lang_hlsl2017)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2017;
+  else if (LangStd == LangStandard::lang_hlsl2018)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2018;
+  else if (LangStd == LangStandard::lang_hlsl2021)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2021;
+  else if (LangStd == LangStandard::lang_hlsl202x)
+    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_202x;
+
+  // OpenCL has some additional defaults.
+  if (Opts.OpenCL) {
+    Opts.AltiVec = 0;
+    Opts.ZVector = 0;
+    Opts.setDefaultFPContractMode(LangOptions::FPM_On);
+    Opts.OpenCLCPlusPlus = Opts.CPlusPlus;
+    Opts.OpenCLPipes = Opts.getOpenCLCompatibleVersion() == 200;
+    Opts.OpenCLGenericAddressSpace = Opts.getOpenCLCompatibleVersion() == 200;
+
+    // Include default header file for OpenCL.
+    if (Opts.IncludeDefaultHeader) {
+      if (Opts.DeclareOpenCLBuiltins) {
+        // Only include base header file for builtin types and constants.
+        Includes.push_back("opencl-c-base.h");
+      } else {
+        Includes.push_back("opencl-c.h");
+      }
+    }
+  }
+
+  Opts.HIP = Lang == Language::HIP;
+  Opts.CUDA = Lang == Language::CUDA || Opts.HIP;
+  if (Opts.HIP) {
+    // HIP toolchain does not support 'Fast' FPOpFusion in backends since it
+    // fuses multiplication/addition instructions without contract flag from
+    // device library functions in LLVM bitcode, which causes accuracy loss in
+    // certain math functions, e.g. tan(-1e20) becomes -0.933 instead of 0.8446.
+    // For device library functions in bitcode to work, 'Strict' or 'Standard'
+    // FPOpFusion options in backends is needed. Therefore 'fast-honor-pragmas'
+    // FP contract option is used to allow fuse across statements in frontend
+    // whereas respecting contract flag in backend.
+    Opts.setDefaultFPContractMode(LangOptions::FPM_FastHonorPragmas);
+  } else if (Opts.CUDA) {
+    if (T.isSPIRV()) {
+      // Emit OpenCL version metadata in LLVM IR when targeting SPIR-V.
+      Opts.OpenCLVersion = 200;
+    }
+    // Allow fuse across statements disregarding pragmas.
+    Opts.setDefaultFPContractMode(LangOptions::FPM_Fast);
+  }
+
+  Opts.RenderScript = Lang == Language::RenderScript;
+
+  // OpenCL, C++ and C2x have bool, true, false keywords.
+  Opts.Bool = Opts.OpenCL || Opts.CPlusPlus || Opts.C2x;
+
+  // OpenCL has half keyword
+  Opts.Half = Opts.OpenCL;
+}
+
 FPOptions FPOptions::defaultWithoutTrailingStorage(const LangOptions &LO) {
   FPOptions result(LO);
   return result;
 }
 
 LLVM_DUMP_METHOD void FPOptions::dump() {
 #define OPTION(NAME, TYPE, WIDTH, PREVIOUS)                                    \
   llvm::errs() << "\n " #NAME " " << get##NAME();
 #include "clang/Basic/FPOptions.def"
   llvm::errs() << "\n";
 }
 
 LLVM_DUMP_METHOD void FPOptionsOverride::dump() {
 #define OPTION(NAME, TYPE, WIDTH, PREVIOUS)                                    \
   if (has##NAME##Override())                                                   \
     llvm::errs() << "\n " #NAME " Override is " << get##NAME##Override();
 #include "clang/Basic/FPOptions.def"
   llvm::errs() << "\n";
 }

clang/lib/Basic/LangStandards.cpp

 //===--- LangStandards.cpp - Language Standard Definitions ----------------===//
 //
 // Part of the LLVM Project, under the Apache License v2.0 with LLVM Exceptions.
 // See https://llvm.org/LICENSE.txt for license information.
 // SPDX-License-Identifier: Apache-2.0 WITH LLVM-exception
 //
 //===----------------------------------------------------------------------===//
 
 #include "clang/Basic/LangStandard.h"
 #include "llvm/ADT/StringSwitch.h"
+#include "llvm/ADT/Triple.h"
 #include "llvm/Support/ErrorHandling.h"
 using namespace clang;
 
 #define LANGSTANDARD(id, name, lang, desc, features)                           \
   static const LangStandard Lang_##id = {name, desc, features, Language::lang};
 #include "clang/Basic/LangStandards.def"
 
 const LangStandard &LangStandard::getLangStandardForKind(Kind K) {

 const LangStandard *LangStandard::getLangStandardForName(StringRef Name) {
   Kind K = getLangKind(Name);
   if (K == lang_unspecified)
     return nullptr;
 
   return &getLangStandardForKind(K);
 }
 
-
+LangStandard::Kind clang::getDefaultLanguageStandard(clang::Language Lang,
+                                                     const llvm::Triple &T) {
+  switch (Lang) {
+  case Language::Unknown:
+  case Language::LLVM_IR:
+    llvm_unreachable("Invalid input kind!");
+  case Language::OpenCL:
+    return LangStandard::lang_opencl12;
+  case Language::OpenCLCXX:
+    return LangStandard::lang_openclcpp10;
+  case Language::CUDA:
+    return LangStandard::lang_cuda;
+  case Language::Asm:
+  case Language::C:
+#if defined(CLANG_DEFAULT_STD_C)
+    return CLANG_DEFAULT_STD_C;
+#else
+    // The PS4 uses C99 as the default C standard.
+    if (T.isPS4())
+      return LangStandard::lang_gnu99;
+    return LangStandard::lang_gnu17;
+#endif
+  case Language::ObjC:
+#if defined(CLANG_DEFAULT_STD_C)
+    return CLANG_DEFAULT_STD_C;
+#else
+    return LangStandard::lang_gnu11;
+#endif
+  case Language::CXX:
+  case Language::ObjCXX:
+#if defined(CLANG_DEFAULT_STD_CXX)
+    return CLANG_DEFAULT_STD_CXX;
+#else
+    return LangStandard::lang_gnucxx14;
+#endif
+  case Language::RenderScript:
+    return LangStandard::lang_c99;
+  case Language::HIP:
+    return LangStandard::lang_hip;
+  case Language::HLSL:
+    return LangStandard::lang_hlsl2021;
+  }
+  llvm_unreachable("unhandled Language kind!");
+}

clang/lib/Frontend/CompilerInvocation.cpp

Opts.AddSystemHeaderPrefix(
         A->getValue(), A->getOption().matches(OPT_system_header_prefix));
 
   for (const auto *A : Args.filtered(OPT_ivfsoverlay))
     Opts.AddVFSOverlayFile(A->getValue());
 
   return Diags.getNumErrors() == NumErrorsBefore;
 }
 
-void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
-                                         const llvm::Triple &T,
-                                         std::vector<std::string> &Includes,
-                                         LangStandard::Kind LangStd) {
-  // Set some properties which depend solely on the input kind; it would be nice
-  // to move these to the language standard, and have the driver resolve the
-  // input kind + language standard.
-  //
-  // FIXME: Perhaps a better model would be for a single source file to have
-  // multiple language standards (C / C++ std, ObjC std, OpenCL std, OpenMP std)
-  // simultaneously active?
-  if (IK.getLanguage() == Language::Asm) {
-    Opts.AsmPreprocessor = 1;
-  } else if (IK.isObjectiveC()) {
-    Opts.ObjC = 1;
-  }
-
-  if (LangStd == LangStandard::lang_unspecified) {
-    // Based on the base language, pick one.
-    switch (IK.getLanguage()) {
-    case Language::Unknown:
-    case Language::LLVM_IR:
-      llvm_unreachable("Invalid input kind!");
-    case Language::OpenCL:
-      LangStd = LangStandard::lang_opencl12;
-      break;
-    case Language::OpenCLCXX:
-      LangStd = LangStandard::lang_openclcpp10;
-      break;
-    case Language::CUDA:
-      LangStd = LangStandard::lang_cuda;
-      break;
-    case Language::Asm:
-    case Language::C:
-#if defined(CLANG_DEFAULT_STD_C)
-      LangStd = CLANG_DEFAULT_STD_C;
-#else
-      // The PS4 uses C99 as the default C standard.
-      if (T.isPS4())
-        LangStd = LangStandard::lang_gnu99;
-      else
-        LangStd = LangStandard::lang_gnu17;
-#endif
-      break;
-    case Language::ObjC:
-#if defined(CLANG_DEFAULT_STD_C)
-      LangStd = CLANG_DEFAULT_STD_C;
-#else
-      LangStd = LangStandard::lang_gnu11;
-#endif
-      break;
-    case Language::CXX:
-    case Language::ObjCXX:
-#if defined(CLANG_DEFAULT_STD_CXX)
-      LangStd = CLANG_DEFAULT_STD_CXX;
-#else
-      LangStd = LangStandard::lang_gnucxx14;
-#endif
-      break;
-    case Language::RenderScript:
-      LangStd = LangStandard::lang_c99;
-      break;
-    case Language::HIP:
-      LangStd = LangStandard::lang_hip;
-      break;
-    case Language::HLSL:
-      LangStd = LangStandard::lang_hlsl2021;
-      break;
-    }
-  }
-
-  const LangStandard &Std = LangStandard::getLangStandardForKind(LangStd);
-  Opts.LangStd = LangStd;
-  Opts.LineComment = Std.hasLineComments();
-  Opts.C99 = Std.isC99();
-  Opts.C11 = Std.isC11();
-  Opts.C17 = Std.isC17();
-  Opts.C2x = Std.isC2x();
-  Opts.CPlusPlus = Std.isCPlusPlus();
-  Opts.CPlusPlus11 = Std.isCPlusPlus11();
-  Opts.CPlusPlus14 = Std.isCPlusPlus14();
-  Opts.CPlusPlus17 = Std.isCPlusPlus17();
-  Opts.CPlusPlus20 = Std.isCPlusPlus20();
-  Opts.CPlusPlus2b = Std.isCPlusPlus2b();
-  Opts.GNUMode = Std.isGNUMode();
-  Opts.GNUCVersion = 0;
-  Opts.HexFloats = Std.hasHexFloats();
-  Opts.ImplicitInt = Std.hasImplicitInt();
-  Opts.WChar = Std.isCPlusPlus();
-  Opts.Digraphs = Std.hasDigraphs();
-
-  Opts.HLSL = IK.getLanguage() == Language::HLSL;
-
-  // Set OpenCL Version.
-  Opts.OpenCL = Std.isOpenCL();
-  if (LangStd == LangStandard::lang_opencl10)
-    Opts.OpenCLVersion = 100;
-  else if (LangStd == LangStandard::lang_opencl11)
-    Opts.OpenCLVersion = 110;
-  else if (LangStd == LangStandard::lang_opencl12)
-    Opts.OpenCLVersion = 120;
-  else if (LangStd == LangStandard::lang_opencl20)
-    Opts.OpenCLVersion = 200;
-  else if (LangStd == LangStandard::lang_opencl30)
-    Opts.OpenCLVersion = 300;
-  else if (LangStd == LangStandard::lang_openclcpp10)
-    Opts.OpenCLCPlusPlusVersion = 100;
-  else if (LangStd == LangStandard::lang_openclcpp2021)
-    Opts.OpenCLCPlusPlusVersion = 202100;
-  else if (LangStd == LangStandard::lang_hlsl2015)
-    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2015;
-  else if (LangStd == LangStandard::lang_hlsl2016)
-    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2016;
-  else if (LangStd == LangStandard::lang_hlsl2017)
-    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2017;
-  else if (LangStd == LangStandard::lang_hlsl2018)
-    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2018;
-  else if (LangStd == LangStandard::lang_hlsl2021)
-    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_2021;
-  else if (LangStd == LangStandard::lang_hlsl202x)
-    Opts.HLSLVersion = (unsigned)LangOptions::HLSL_202x;
-
-  // OpenCL has some additional defaults.
-  if (Opts.OpenCL) {
-    Opts.AltiVec = 0;
-    Opts.ZVector = 0;
-    Opts.setDefaultFPContractMode(LangOptions::FPM_On);
-    Opts.OpenCLCPlusPlus = Opts.CPlusPlus;
-    Opts.OpenCLPipes = Opts.getOpenCLCompatibleVersion() == 200;
-    Opts.OpenCLGenericAddressSpace = Opts.getOpenCLCompatibleVersion() == 200;
-
-    // Include default header file for OpenCL.
-    if (Opts.IncludeDefaultHeader) {
-      if (Opts.DeclareOpenCLBuiltins) {
-        // Only include base header file for builtin types and constants.
-        Includes.push_back("opencl-c-base.h");
-      } else {
-        Includes.push_back("opencl-c.h");
-      }
-    }
-  }
-
-  Opts.HIP = IK.getLanguage() == Language::HIP;
-  Opts.CUDA = IK.getLanguage() == Language::CUDA || Opts.HIP;
-  if (Opts.HIP) {
-    // HIP toolchain does not support 'Fast' FPOpFusion in backends since it
-    // fuses multiplication/addition instructions without contract flag from
-    // device library functions in LLVM bitcode, which causes accuracy loss in
-    // certain math functions, e.g. tan(-1e20) becomes -0.933 instead of 0.8446.
-    // For device library functions in bitcode to work, 'Strict' or 'Standard'
-    // FPOpFusion options in backends is needed. Therefore 'fast-honor-pragmas'
-    // FP contract option is used to allow fuse across statements in frontend
-    // whereas respecting contract flag in backend.
-    Opts.setDefaultFPContractMode(LangOptions::FPM_FastHonorPragmas);
-  } else if (Opts.CUDA) {
-    if (T.isSPIRV()) {
-      // Emit OpenCL version metadata in LLVM IR when targeting SPIR-V.
-      Opts.OpenCLVersion = 200;
-    }
-    // Allow fuse across statements disregarding pragmas.
-    Opts.setDefaultFPContractMode(LangOptions::FPM_Fast);
-  }
-
-  Opts.RenderScript = IK.getLanguage() == Language::RenderScript;
-
-  // OpenCL, C++ and C2x have bool, true, false keywords.
-  Opts.Bool = Opts.OpenCL || Opts.CPlusPlus || Opts.C2x;
-
-  // OpenCL has half keyword
-  Opts.Half = Opts.OpenCL;
-}
-
 /// Check if input file kind and language standard are compatible.
 static bool IsInputCompatibleWithStandard(InputKind IK,
                                           const LangStandard &S) {
   switch (IK.getLanguage()) {
   case Language::Unknown:
   case Language::LLVM_IR:
     llvm_unreachable("should not parse language flags for this input");
 
if (const Arg *A = Args.getLastArg(OPT_cl_std_EQ)) {
     else
       LangStd = OpenCLLangStd;
   }
 
   // These need to be parsed now. They are used to set OpenCL defaults.
   Opts.IncludeDefaultHeader = Args.hasArg(OPT_finclude_default_header);
   Opts.DeclareOpenCLBuiltins = Args.hasArg(OPT_fdeclare_opencl_builtins);
 
-  CompilerInvocation::setLangDefaults(Opts, IK, T, Includes, LangStd);
+  LangOptions::setLangDefaults(Opts, IK.getLanguage(), T, Includes, LangStd);
 
   // The key paths of codegen options defined in Options.td start with
   // "LangOpts->". Let's provide the expected variable name and type.
   LangOptions *LangOpts = &Opts;
 
 #define LANG_OPTION_WITH_MARSHALLING(                                          \
     PREFIX_TYPE, NAME, ID, KIND, GROUP, ALIAS, ALIASARGS, FLAGS, PARAM,        \
     HELPTEXT, METAVAR, VALUES, SPELLING, SHOULD_PARSE, ALWAYS_EMIT, KEYPATH,   \