diff --git a/clang/include/clang/Basic/LangOptions.h b/clang/include/clang/Basic/LangOptions.h
--- a/clang/include/clang/Basic/LangOptions.h
+++ b/clang/include/clang/Basic/LangOptions.h
@@ -508,6 +508,18 @@
   void remapPathPrefix(SmallString<256> &Path) const;
 };
 
+/// s 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 - The affected list of included files.
+/// \param LangStd - The input language standard.
+void setLangDefaults(LangOptions &Opts, Language Lang, const llvm::Triple &T,
+                     std::vector<std::string> &Includes,
+                     LangStandard::Kind LangStd);
+
 /// Floating point control options
 class FPOptionsOverride;
 class FPOptions {
diff --git a/clang/include/clang/Frontend/CompilerInvocation.h b/clang/include/clang/Frontend/CompilerInvocation.h
--- a/clang/include/clang/Frontend/CompilerInvocation.h
+++ b/clang/include/clang/Frontend/CompilerInvocation.h
@@ -219,14 +219,7 @@
   /// 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.
+  /// This is deprecated. Please use `clang::setLangDefaults` instead.
   static void
   setLangDefaults(LangOptions &Opts, InputKind IK, const llvm::Triple &T,
                   std::vector<std::string> &Includes,
diff --git a/clang/lib/Basic/LangOptions.cpp b/clang/lib/Basic/LangOptions.cpp
--- a/clang/lib/Basic/LangOptions.cpp
+++ b/clang/lib/Basic/LangOptions.cpp
@@ -11,6 +11,7 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Basic/LangOptions.h"
+#include "clang/Basic/LangStandard.h"
 #include "llvm/ADT/SmallString.h"
 #include "llvm/Support/Path.h"
 
@@ -83,6 +84,155 @@
   return result;
 }
 
+void clang::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) {
+    // Based on the base language, pick one.
+    switch (Lang) {
+    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;
+    }
+  }
+
+  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();
+
+  // 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;
+
+  // 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) {
+    // Allow fuse across statements disregarding pragmas.
+    Opts.setDefaultFPContractMode(LangOptions::FPM_Fast);
+  }
+
+  Opts.RenderScript = Lang == Language::RenderScript;
+
+  // OpenCL and C++ both have bool, true, false keywords.
+  Opts.Bool = Opts.OpenCL || Opts.CPlusPlus;
+
+  // OpenCL has half keyword
+  Opts.Half = Opts.OpenCL;
+}
+
 LLVM_DUMP_METHOD void FPOptions::dump() {
 #define OPTION(NAME, TYPE, WIDTH, PREVIOUS)                                    \
   llvm::errs() << "\n " #NAME " " << get##NAME();
diff --git a/clang/lib/Frontend/CompilerInvocation.cpp b/clang/lib/Frontend/CompilerInvocation.cpp
--- a/clang/lib/Frontend/CompilerInvocation.cpp
+++ b/clang/lib/Frontend/CompilerInvocation.cpp
@@ -3111,149 +3111,7 @@
                                          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;
-    }
-  }
-
-  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();
-
-  // 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;
-
-  // 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) {
-    // Allow fuse across statements disregarding pragmas.
-    Opts.setDefaultFPContractMode(LangOptions::FPM_Fast);
-  }
-
-  Opts.RenderScript = IK.getLanguage() == Language::RenderScript;
-
-  // OpenCL and C++ both have bool, true, false keywords.
-  Opts.Bool = Opts.OpenCL || Opts.CPlusPlus;
-
-  // OpenCL has half keyword
-  Opts.Half = Opts.OpenCL;
+  clang::setLangDefaults(Opts, IK.getLanguage(), T, Includes, LangStd);
 }
 
 /// Check if input file kind and language standard are compatible.
@@ -3685,7 +3543,7 @@
   Opts.IncludeDefaultHeader = Args.hasArg(OPT_finclude_default_header);
   Opts.DeclareOpenCLBuiltins = Args.hasArg(OPT_fdeclare_opencl_builtins);
 
-  CompilerInvocation::setLangDefaults(Opts, IK, T, Includes, LangStd);
+  clang::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.