vendor/clang/clang-trunk-r301939

11 files changed, 579 insertions, 485 deletions

diff --git a/lib/Frontend/ASTUnit.cpp b/lib/Frontend/ASTUnit.cpp
index 2acdc6494f85..32ee9d3e9961 100644
--- a/lib/Frontend/ASTUnit.cpp
+++ b/lib/Frontend/ASTUnit.cpp
@@ -1076,9 +1076,11 @@ bool ASTUnit::Parse(std::shared_ptr<PCHContainerOperations> PCHContainerOps,
   
   assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
          "Invocation must have exactly one source file!");
-  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_AST &&
+  assert(Clang->getFrontendOpts().Inputs[0].getKind().getFormat() ==
+             InputKind::Source &&
          "FIXME: AST inputs not yet supported here!");
-  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_LLVM_IR &&
+  assert(Clang->getFrontendOpts().Inputs[0].getKind().getLanguage() !=
+             InputKind::LLVM_IR &&
          "IR inputs not support here!");
 
   // Configure the various subsystems.
@@ -1552,9 +1554,11 @@ ASTUnit::getMainBufferWithPrecompiledPreamble(
   
   assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
          "Invocation must have exactly one source file!");
-  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_AST &&
+  assert(Clang->getFrontendOpts().Inputs[0].getKind().getFormat() ==
+             InputKind::Source &&
          "FIXME: AST inputs not yet supported here!");
-  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_LLVM_IR &&
+  assert(Clang->getFrontendOpts().Inputs[0].getKind().getLanguage() !=
+             InputKind::LLVM_IR &&
          "IR inputs not support here!");
   
   // Clear out old caches and data.
@@ -1810,10 +1814,12 @@ ASTUnit *ASTUnit::LoadFromCompilerInvocationAction(
   
   assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
          "Invocation must have exactly one source file!");
-  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_AST &&
+  assert(Clang->getFrontendOpts().Inputs[0].getKind().getFormat() ==
+             InputKind::Source &&
          "FIXME: AST inputs not yet supported here!");
-  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_LLVM_IR &&
-         "IR inputs not supported here!");
+  assert(Clang->getFrontendOpts().Inputs[0].getKind().getLanguage() !=
+             InputKind::LLVM_IR &&
+         "IR inputs not support here!");
 
   // Configure the various subsystems.
   AST->TheSema.reset();
@@ -2399,11 +2405,12 @@ void ASTUnit::CodeComplete(
   
   assert(Clang->getFrontendOpts().Inputs.size() == 1 &&
          "Invocation must have exactly one source file!");
-  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_AST &&
+  assert(Clang->getFrontendOpts().Inputs[0].getKind().getFormat() ==
+             InputKind::Source &&
          "FIXME: AST inputs not yet supported here!");
-  assert(Clang->getFrontendOpts().Inputs[0].getKind() != IK_LLVM_IR &&
+  assert(Clang->getFrontendOpts().Inputs[0].getKind().getLanguage() !=
+             InputKind::LLVM_IR &&
          "IR inputs not support here!");
-
   
   // Use the source and file managers that we were given.
   Clang->setFileManager(&FileMgr);
diff --git a/lib/Frontend/CompilerInstance.cpp b/lib/Frontend/CompilerInstance.cpp
index 8b4b16920668..a7b5fa7dfd29 100644
--- a/lib/Frontend/CompilerInstance.cpp
+++ b/lib/Frontend/CompilerInstance.cpp
@@ -858,7 +858,8 @@ bool CompilerInstance::InitializeSourceManager(
                             /*SearchPath=*/nullptr,
                             /*RelativePath=*/nullptr,
                             /*RequestingModule=*/nullptr,
-                            /*SuggestedModule=*/nullptr, /*SkipCache=*/true);
+                            /*SuggestedModule=*/nullptr, /*IsMapped=*/nullptr,
+                            /*SkipCache=*/true);
       // Also add the header to /showIncludes output.
       if (File)
         DepOpts.ShowIncludesPretendHeader = File->getName();
@@ -1015,14 +1016,14 @@ bool CompilerInstance::ExecuteAction(FrontendAction &Act) {
 
 /// \brief Determine the appropriate source input kind based on language
 /// options.
-static InputKind getSourceInputKindFromOptions(const LangOptions &LangOpts) {
+static InputKind::Language getLanguageFromOptions(const LangOptions &LangOpts) {
   if (LangOpts.OpenCL)
-    return IK_OpenCL;
+    return InputKind::OpenCL;
   if (LangOpts.CUDA)
-    return IK_CUDA;
+    return InputKind::CUDA;
   if (LangOpts.ObjC1)
-    return LangOpts.CPlusPlus? IK_ObjCXX : IK_ObjC;
-  return LangOpts.CPlusPlus? IK_CXX : IK_C;
+    return LangOpts.CPlusPlus ? InputKind::ObjCXX : InputKind::ObjC;
+  return LangOpts.CPlusPlus ? InputKind::CXX : InputKind::C;
 }
 
 /// \brief Compile a module file for the given module, using the options 
@@ -1079,10 +1080,13 @@ static bool compileModuleImpl(CompilerInstance &ImportingInstance,
   FrontendOpts.DisableFree = false;
   FrontendOpts.GenerateGlobalModuleIndex = false;
   FrontendOpts.BuildingImplicitModule = true;
+  FrontendOpts.OriginalModuleMap =
+      ModMap.getModuleMapFileForUniquing(Module)->getName();
   // Force implicitly-built modules to hash the content of the module file.
   HSOpts.ModulesHashContent = true;
   FrontendOpts.Inputs.clear();
-  InputKind IK = getSourceInputKindFromOptions(*Invocation->getLangOpts());
+  InputKind IK(getLanguageFromOptions(*Invocation->getLangOpts()),
+               InputKind::ModuleMap);
 
   // Don't free the remapped file buffers; they are owned by our caller.
   PPOpts.RetainRemappedFileBuffers = true;
@@ -1127,11 +1131,12 @@ static bool compileModuleImpl(CompilerInstance &ImportingInstance,
   if (const FileEntry *ModuleMapFile =
           ModMap.getContainingModuleMapFile(Module)) {
     // Use the module map where this module resides.
-    FrontendOpts.Inputs.emplace_back(ModuleMapFile->getName(), IK);
+    FrontendOpts.Inputs.emplace_back(ModuleMapFile->getName(), IK,
+                                     +Module->IsSystem);
   } else {
     SmallString<128> FakeModuleMapFile(Module->Directory->getName());
     llvm::sys::path::append(FakeModuleMapFile, "__inferred_module.map");
-    FrontendOpts.Inputs.emplace_back(FakeModuleMapFile, IK);
+    FrontendOpts.Inputs.emplace_back(FakeModuleMapFile, IK, +Module->IsSystem);
 
     llvm::raw_string_ostream OS(InferredModuleMapContent);
     Module->print(OS);
@@ -1144,11 +1149,6 @@ static bool compileModuleImpl(CompilerInstance &ImportingInstance,
     SourceMgr.overrideFileContents(ModuleMapFile, std::move(ModuleMapBuffer));
   }
 
-  // Construct a module-generating action. Passing through the module map is
-  // safe because the FileManager is shared between the compiler instances.
-  GenerateModuleFromModuleMapAction CreateModuleAction(
-      ModMap.getModuleMapFileForUniquing(Module), Module->IsSystem);
-
   ImportingInstance.getDiagnostics().Report(ImportLoc,
                                             diag::remark_module_build)
     << Module->Name << ModuleFileName;
@@ -1157,8 +1157,12 @@ static bool compileModuleImpl(CompilerInstance &ImportingInstance,
   // thread so that we get a stack large enough.
   const unsigned ThreadStackSize = 8 << 20;
   llvm::CrashRecoveryContext CRC;
-  CRC.RunSafelyOnThread([&]() { Instance.ExecuteAction(CreateModuleAction); },
-                        ThreadStackSize);
+  CRC.RunSafelyOnThread(
+      [&]() {
+        GenerateModuleFromModuleMapAction Action;
+        Instance.ExecuteAction(Action);
+      },
+      ThreadStackSize);
 
   ImportingInstance.getDiagnostics().Report(ImportLoc,
                                             diag::remark_module_build_done)
diff --git a/lib/Frontend/CompilerInvocation.cpp b/lib/Frontend/CompilerInvocation.cpp
index 8cdb8298ee9e..d3ebf48315e2 100644
--- a/lib/Frontend/CompilerInvocation.cpp
+++ b/lib/Frontend/CompilerInvocation.cpp
@@ -81,7 +81,7 @@ using namespace llvm::opt;
 static unsigned getOptimizationLevel(ArgList &Args, InputKind IK,
                                      DiagnosticsEngine &Diags) {
   unsigned DefaultOpt = 0;
-  if (IK == IK_OpenCL && !Args.hasArg(OPT_cl_opt_disable))
+  if (IK.getLanguage() == InputKind::OpenCL && !Args.hasArg(OPT_cl_opt_disable))
     DefaultOpt = 2;
 
   if (Arg *A = Args.getLastArg(options::OPT_O_Group)) {
@@ -652,7 +652,7 @@ static bool ParseCodeGenArgs(CodeGenOptions &Opts, ArgList &Args, InputKind IK,
   Opts.EmitSummaryIndex = A && A->containsValue("thin");
   Opts.LTOUnit = Args.hasFlag(OPT_flto_unit, OPT_fno_lto_unit, false);
   if (Arg *A = Args.getLastArg(OPT_fthinlto_index_EQ)) {
-    if (IK != IK_LLVM_IR)
+    if (IK.getLanguage() != InputKind::LLVM_IR)
       Diags.Report(diag::err_drv_argument_only_allowed_with)
           << A->getAsString(Args) << "-x ir";
     Opts.ThinLTOIndexFile = Args.getLastArgValue(OPT_fthinlto_index_EQ);
@@ -1347,42 +1347,54 @@ static InputKind ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
       << "ARC migration" << "ObjC migration";
   }
 
-  InputKind DashX = IK_None;
+  InputKind DashX(InputKind::Unknown);
   if (const Arg *A = Args.getLastArg(OPT_x)) {
-    DashX = llvm::StringSwitch<InputKind>(A->getValue())
-      .Case("c", IK_C)
-      .Case("cl", IK_OpenCL)
-      .Case("cuda", IK_CUDA)
-      .Case("c++", IK_CXX)
-      .Case("objective-c", IK_ObjC)
-      .Case("objective-c++", IK_ObjCXX)
-      .Case("cpp-output", IK_PreprocessedC)
-      .Case("assembler-with-cpp", IK_Asm)
-      .Case("c++-cpp-output", IK_PreprocessedCXX)
-      .Case("cuda-cpp-output", IK_PreprocessedCuda)
-      .Case("objective-c-cpp-output", IK_PreprocessedObjC)
-      .Case("objc-cpp-output", IK_PreprocessedObjC)
-      .Case("objective-c++-cpp-output", IK_PreprocessedObjCXX)
-      .Case("objc++-cpp-output", IK_PreprocessedObjCXX)
-      .Case("c-header", IK_C)
-      .Case("cl-header", IK_OpenCL)
-      .Case("objective-c-header", IK_ObjC)
-      .Case("c++-header", IK_CXX)
-      .Case("objective-c++-header", IK_ObjCXX)
-      .Cases("ast", "pcm", IK_AST)
-      .Case("ir", IK_LLVM_IR)
-      .Case("renderscript", IK_RenderScript)
-      .Default(IK_None);
-    if (DashX == IK_None)
+    StringRef XValue = A->getValue();
+
+    // Parse suffixes: '<lang>(-header|[-module-map][-cpp-output])'.
+    // FIXME: Supporting '<lang>-header-cpp-output' would be useful.
+    bool Preprocessed = XValue.consume_back("-cpp-output");
+    bool ModuleMap = XValue.consume_back("-module-map");
+    IsHeaderFile =
+        !Preprocessed && !ModuleMap && XValue.consume_back("-header");
+
+    // Principal languages.
+    DashX = llvm::StringSwitch<InputKind>(XValue)
+                .Case("c", InputKind::C)
+                .Case("cl", InputKind::OpenCL)
+                .Case("cuda", InputKind::CUDA)
+                .Case("c++", InputKind::CXX)
+                .Case("objective-c", InputKind::ObjC)
+                .Case("objective-c++", InputKind::ObjCXX)
+                .Case("renderscript", InputKind::RenderScript)
+                .Default(InputKind::Unknown);
+
+    // "objc[++]-cpp-output" is an acceptable synonym for
+    // "objective-c[++]-cpp-output".
+    if (DashX.isUnknown() && Preprocessed && !IsHeaderFile && !ModuleMap)
+      DashX = llvm::StringSwitch<InputKind>(XValue)
+                  .Case("objc", InputKind::ObjC)
+                  .Case("objc++", InputKind::ObjCXX)
+                  .Default(InputKind::Unknown);
+
+    // Some special cases cannot be combined with suffixes.
+    if (DashX.isUnknown() && !Preprocessed && !ModuleMap && !IsHeaderFile)
+      DashX = llvm::StringSwitch<InputKind>(XValue)
+                  .Case("cpp-output", InputKind(InputKind::C).getPreprocessed())
+                  .Case("assembler-with-cpp", InputKind::Asm)
+                  .Cases("ast", "pcm",
+                         InputKind(InputKind::Unknown, InputKind::Precompiled))
+                  .Case("ir", InputKind::LLVM_IR)
+                  .Default(InputKind::Unknown);
+
+    if (DashX.isUnknown())
       Diags.Report(diag::err_drv_invalid_value)
         << A->getAsString(Args) << A->getValue();
-    IsHeaderFile = llvm::StringSwitch<bool>(A->getValue())
-      .Case("c-header", true)
-      .Case("cl-header", true)
-      .Case("objective-c-header", true)
-      .Case("c++-header", true)
-      .Case("objective-c++-header", true)
-      .Default(false);
+
+    if (Preprocessed)
+      DashX = DashX.getPreprocessed();
+    if (ModuleMap)
+      DashX = DashX.withFormat(InputKind::ModuleMap);
   }
 
   // '-' is the default input if none is given.
@@ -1392,13 +1404,22 @@ static InputKind ParseFrontendArgs(FrontendOptions &Opts, ArgList &Args,
     Inputs.push_back("-");
   for (unsigned i = 0, e = Inputs.size(); i != e; ++i) {
     InputKind IK = DashX;
-    if (IK == IK_None) {
+    if (IK.isUnknown()) {
       IK = FrontendOptions::getInputKindForExtension(
         StringRef(Inputs[i]).rsplit('.').second);
+      // FIXME: Warn on this?
+      if (IK.isUnknown())
+        IK = InputKind::C;
       // FIXME: Remove this hack.
       if (i == 0)
         DashX = IK;
     }
+
+    // The -emit-module action implicitly takes a module map.
+    if (Opts.ProgramAction == frontend::GenerateModule &&
+        IK.getFormat() == InputKind::Source)
+      IK = IK.withFormat(InputKind::ModuleMap);
+
     Opts.Inputs.emplace_back(std::move(Inputs[i]), IK);
   }
 
@@ -1564,53 +1585,48 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
   // 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.
-  if (IK == IK_Asm) {
+  //
+  // 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() == InputKind::Asm) {
     Opts.AsmPreprocessor = 1;
-  } else if (IK == IK_ObjC ||
-             IK == IK_ObjCXX ||
-             IK == IK_PreprocessedObjC ||
-             IK == IK_PreprocessedObjCXX) {
+  } else if (IK.isObjectiveC()) {
     Opts.ObjC1 = Opts.ObjC2 = 1;
   }
 
   if (LangStd == LangStandard::lang_unspecified) {
     // Based on the base language, pick one.
-    switch (IK) {
-    case IK_None:
-    case IK_AST:
-    case IK_LLVM_IR:
+    switch (IK.getLanguage()) {
+    case InputKind::Unknown:
+    case InputKind::LLVM_IR:
       llvm_unreachable("Invalid input kind!");
-    case IK_OpenCL:
-      LangStd = LangStandard::lang_opencl;
+    case InputKind::OpenCL:
+      LangStd = LangStandard::lang_opencl10;
       break;
-    case IK_CUDA:
-    case IK_PreprocessedCuda:
+    case InputKind::CUDA:
       LangStd = LangStandard::lang_cuda;
       break;
-    case IK_Asm:
-    case IK_C:
-    case IK_PreprocessedC:
+    case InputKind::Asm:
+    case InputKind::C:
       // The PS4 uses C99 as the default C standard.
       if (T.isPS4())
         LangStd = LangStandard::lang_gnu99;
       else
         LangStd = LangStandard::lang_gnu11;
       break;
-    case IK_ObjC:
-    case IK_PreprocessedObjC:
+    case InputKind::ObjC:
       LangStd = LangStandard::lang_gnu11;
       break;
-    case IK_CXX:
-    case IK_PreprocessedCXX:
-    case IK_ObjCXX:
-    case IK_PreprocessedObjCXX:
+    case InputKind::CXX:
+    case InputKind::ObjCXX:
       // The PS4 uses C++11 as the default C++ standard.
       if (T.isPS4())
         LangStd = LangStandard::lang_gnucxx11;
       else
         LangStd = LangStandard::lang_gnucxx98;
       break;
-    case IK_RenderScript:
+    case InputKind::RenderScript:
       LangStd = LangStandard::lang_c99;
       break;
     }
@@ -1626,13 +1642,13 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
   Opts.CPlusPlus1z = Std.isCPlusPlus1z();
   Opts.Digraphs = Std.hasDigraphs();
   Opts.GNUMode = Std.isGNUMode();
-  Opts.GNUInline = Std.isC89();
+  Opts.GNUInline = !Opts.C99 && !Opts.CPlusPlus;
   Opts.HexFloats = Std.hasHexFloats();
   Opts.ImplicitInt = Std.hasImplicitInt();
 
   // Set OpenCL Version.
-  Opts.OpenCL = Std.isOpenCL() || IK == IK_OpenCL;
-  if (LangStd == LangStandard::lang_opencl)
+  Opts.OpenCL = Std.isOpenCL();
+  if (LangStd == LangStandard::lang_opencl10)
     Opts.OpenCLVersion = 100;
   else if (LangStd == LangStandard::lang_opencl11)
     Opts.OpenCLVersion = 110;
@@ -1655,13 +1671,12 @@ void CompilerInvocation::setLangDefaults(LangOptions &Opts, InputKind IK,
     }
   }
 
-  Opts.CUDA = IK == IK_CUDA || IK == IK_PreprocessedCuda ||
-              LangStd == LangStandard::lang_cuda;
+  Opts.CUDA = IK.getLanguage() == InputKind::CUDA;
   if (Opts.CUDA)
     // Set default FP_CONTRACT to FAST.
     Opts.setDefaultFPContractMode(LangOptions::FPC_Fast);
 
-  Opts.RenderScript = IK == IK_RenderScript;
+  Opts.RenderScript = IK.getLanguage() == InputKind::RenderScript;
   if (Opts.RenderScript) {
     Opts.NativeHalfType = 1;
     Opts.NativeHalfArgsAndReturns = 1;
@@ -1705,58 +1720,65 @@ static Visibility parseVisibility(Arg *arg, ArgList &args,
 /// Check if input file kind and language standard are compatible.
 static bool IsInputCompatibleWithStandard(InputKind IK,
                                           const LangStandard &S) {
-  switch (IK) {
-  case IK_C:
-  case IK_ObjC:
-  case IK_PreprocessedC:
-  case IK_PreprocessedObjC:
-    if (S.isC89() || S.isC99())
-      return true;
-    break;
-  case IK_CXX:
-  case IK_ObjCXX:
-  case IK_PreprocessedCXX:
-  case IK_PreprocessedObjCXX:
-    if (S.isCPlusPlus())
-      return true;
-    break;
-  case IK_OpenCL:
-    if (S.isOpenCL())
-      return true;
-    break;
-  case IK_CUDA:
-  case IK_PreprocessedCuda:
-    if (S.isCPlusPlus())
-      return true;
-    break;
-  default:
-    // For other inputs, accept (and ignore) all -std= values.
+  switch (IK.getLanguage()) {
+  case InputKind::Unknown:
+  case InputKind::LLVM_IR:
+    llvm_unreachable("should not parse language flags for this input");
+
+  case InputKind::C:
+  case InputKind::ObjC:
+  case InputKind::RenderScript:
+    return S.getLanguage() == InputKind::C;
+
+  case InputKind::OpenCL:
+    return S.getLanguage() == InputKind::OpenCL;
+
+  case InputKind::CXX:
+  case InputKind::ObjCXX:
+    return S.getLanguage() == InputKind::CXX;
+
+  case InputKind::CUDA:
+    // FIXME: What -std= values should be permitted for CUDA compilations?
+    return S.getLanguage() == InputKind::CUDA ||
+           S.getLanguage() == InputKind::CXX;
+
+  case InputKind::Asm:
+    // Accept (and ignore) all -std= values.
+    // FIXME: The -std= value is not ignored; it affects the tokenization
+    // and preprocessing rules if we're preprocessing this asm input.
     return true;
   }
-  return false;
+
+  llvm_unreachable("unexpected input language");
 }
 
 /// Get language name for given input kind.
 static const StringRef GetInputKindName(InputKind IK) {
-  switch (IK) {
-  case IK_C:
-  case IK_ObjC:
-  case IK_PreprocessedC:
-  case IK_PreprocessedObjC:
-    return "C/ObjC";
-  case IK_CXX:
-  case IK_ObjCXX:
-  case IK_PreprocessedCXX:
-  case IK_PreprocessedObjCXX:
-    return "C++/ObjC++";
-  case IK_OpenCL:
+  switch (IK.getLanguage()) {
+  case InputKind::C:
+    return "C";
+  case InputKind::ObjC:
+    return "Objective-C";
+  case InputKind::CXX:
+    return "C++";
+  case InputKind::ObjCXX:
+    return "Objective-C++";
+  case InputKind::OpenCL:
     return "OpenCL";
-  case IK_CUDA:
-  case IK_PreprocessedCuda:
+  case InputKind::CUDA:
     return "CUDA";
-  default:
-    llvm_unreachable("Cannot decide on name for InputKind!");
+  case InputKind::RenderScript:
+    return "RenderScript";
+
+  case InputKind::Asm:
+    return "Asm";
+  case InputKind::LLVM_IR:
+    return "LLVM IR";
+
+  case InputKind::Unknown:
+    break;
   }
+  llvm_unreachable("unknown input language");
 }
 
 static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
@@ -1767,7 +1789,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   LangStandard::Kind LangStd = LangStandard::lang_unspecified;
   if (const Arg *A = Args.getLastArg(OPT_std_EQ)) {
     LangStd = llvm::StringSwitch<LangStandard::Kind>(A->getValue())
-#define LANGSTANDARD(id, name, desc, features) \
+#define LANGSTANDARD(id, name, lang, desc, features) \
       .Case(name, LangStandard::lang_##id)
 #define LANGSTANDARD_ALIAS(id, alias) \
       .Case(alias, LangStandard::lang_##id)
@@ -1783,8 +1805,20 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
         const LangStandard &Std = LangStandard::getLangStandardForKind(
           static_cast<LangStandard::Kind>(KindValue));
         if (IsInputCompatibleWithStandard(IK, Std)) {
-          Diags.Report(diag::note_drv_use_standard)
-            << Std.getName() << Std.getDescription();
+          auto Diag = Diags.Report(diag::note_drv_use_standard);
+          Diag << Std.getName() << Std.getDescription();
+          unsigned NumAliases = 0;
+#define LANGSTANDARD(id, name, lang, desc, features)
+#define LANGSTANDARD_ALIAS(id, alias) \
+          if (KindValue == LangStandard::lang_##id) ++NumAliases;
+#define LANGSTANDARD_ALIAS_DEPR(id, alias)
+#include "clang/Frontend/LangStandards.def"
+          Diag << NumAliases;
+#define LANGSTANDARD(id, name, lang, desc, features)
+#define LANGSTANDARD_ALIAS(id, alias) \
+          if (KindValue == LangStandard::lang_##id) Diag << alias;
+#define LANGSTANDARD_ALIAS_DEPR(id, alias)
+#include "clang/Frontend/LangStandards.def"
         }
       }
     } else {
@@ -1803,7 +1837,7 @@ static void ParseLangArgs(LangOptions &Opts, ArgList &Args, InputKind IK,
   if (const Arg *A = Args.getLastArg(OPT_cl_std_EQ)) {
     LangStandard::Kind OpenCLLangStd
       = llvm::StringSwitch<LangStandard::Kind>(A->getValue())
-        .Cases("cl", "CL", LangStandard::lang_opencl)
+        .Cases("cl", "CL", LangStandard::lang_opencl10)
         .Cases("cl1.1", "CL1.1", LangStandard::lang_opencl11)
         .Cases("cl1.2", "CL1.2", LangStandard::lang_opencl12)
         .Cases("cl2.0", "CL2.0", LangStandard::lang_opencl20)
@@ -2533,7 +2567,8 @@ bool CompilerInvocation::CreateFromArgs(CompilerInvocation &Res,
                               Res.getTargetOpts());
   ParseHeaderSearchArgs(Res.getHeaderSearchOpts(), Args,
                         Res.getFileSystemOpts().WorkingDir);
-  if (DashX == IK_AST || DashX == IK_LLVM_IR) {
+  if (DashX.getFormat() == InputKind::Precompiled ||
+      DashX.getLanguage() == InputKind::LLVM_IR) {
     // ObjCAAutoRefCount and Sanitize LangOpts are used to setup the
     // PassManager in BackendUtil.cpp. They need to be initializd no matter
     // what the input type is.
@@ -2547,8 +2582,9 @@ bool CompilerInvocation::CreateFromArgs(CompilerInvocation &Res,
                         Diags, LangOpts.Sanitize);
   } else {
     // Other LangOpts are only initialzed when the input is not AST or LLVM IR.
+    // FIXME: Should we really be calling this for an InputKind::Asm input?
     ParseLangArgs(LangOpts, Args, DashX, Res.getTargetOpts(),
-      Res.getPreprocessorOpts(), Diags);
+                  Res.getPreprocessorOpts(), Diags);
     if (Res.getFrontendOpts().ProgramAction == frontend::RewriteObjC)
       LangOpts.ObjCExceptions = 1;
   }
diff --git a/lib/Frontend/FrontendAction.cpp b/lib/Frontend/FrontendAction.cpp
index 0dd07d9f817b..d26b6937b851 100644
--- a/lib/Frontend/FrontendAction.cpp
+++ b/lib/Frontend/FrontendAction.cpp
@@ -224,6 +224,231 @@ static bool ReadOriginalFileName(CompilerInstance &CI, std::string &InputFile)
   return true;
 }
 
+static SmallVectorImpl<char> &
+operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
+  Includes.append(RHS.begin(), RHS.end());
+  return Includes;
+}
+
+static void addHeaderInclude(StringRef HeaderName,
+                             SmallVectorImpl<char> &Includes,
+                             const LangOptions &LangOpts,
+                             bool IsExternC) {
+  if (IsExternC && LangOpts.CPlusPlus)
+    Includes += "extern \"C\" {\n";
+  if (LangOpts.ObjC1)
+    Includes += "#import \"";
+  else
+    Includes += "#include \"";
+
+  Includes += HeaderName;
+
+  Includes += "\"\n";
+  if (IsExternC && LangOpts.CPlusPlus)
+    Includes += "}\n";
+}
+
+/// \brief Collect the set of header includes needed to construct the given 
+/// module and update the TopHeaders file set of the module.
+///
+/// \param Module The module we're collecting includes from.
+///
+/// \param Includes Will be augmented with the set of \#includes or \#imports
+/// needed to load all of the named headers.
+static std::error_code
+collectModuleHeaderIncludes(const LangOptions &LangOpts, FileManager &FileMgr,
+                            ModuleMap &ModMap, clang::Module *Module,
+                            SmallVectorImpl<char> &Includes) {
+  // Don't collect any headers for unavailable modules.
+  if (!Module->isAvailable())
+    return std::error_code();
+
+  // Add includes for each of these headers.
+  for (auto HK : {Module::HK_Normal, Module::HK_Private}) {
+    for (Module::Header &H : Module->Headers[HK]) {
+      Module->addTopHeader(H.Entry);
+      // Use the path as specified in the module map file. We'll look for this
+      // file relative to the module build directory (the directory containing
+      // the module map file) so this will find the same file that we found
+      // while parsing the module map.
+      addHeaderInclude(H.NameAsWritten, Includes, LangOpts, Module->IsExternC);
+    }
+  }
+  // Note that Module->PrivateHeaders will not be a TopHeader.
+
+  if (Module::Header UmbrellaHeader = Module->getUmbrellaHeader()) {
+    Module->addTopHeader(UmbrellaHeader.Entry);
+    if (Module->Parent)
+      // Include the umbrella header for submodules.
+      addHeaderInclude(UmbrellaHeader.NameAsWritten, Includes, LangOpts,
+                       Module->IsExternC);
+  } else if (Module::DirectoryName UmbrellaDir = Module->getUmbrellaDir()) {
+    // Add all of the headers we find in this subdirectory.
+    std::error_code EC;
+    SmallString<128> DirNative;
+    llvm::sys::path::native(UmbrellaDir.Entry->getName(), DirNative);
+
+    vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
+    for (vfs::recursive_directory_iterator Dir(FS, DirNative, EC), End;
+         Dir != End && !EC; Dir.increment(EC)) {
+      // Check whether this entry has an extension typically associated with 
+      // headers.
+      if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->getName()))
+          .Cases(".h", ".H", ".hh", ".hpp", true)
+          .Default(false))
+        continue;
+
+      const FileEntry *Header = FileMgr.getFile(Dir->getName());
+      // FIXME: This shouldn't happen unless there is a file system race. Is
+      // that worth diagnosing?
+      if (!Header)
+        continue;
+
+      // If this header is marked 'unavailable' in this module, don't include 
+      // it.
+      if (ModMap.isHeaderUnavailableInModule(Header, Module))
+        continue;
+
+      // Compute the relative path from the directory to this file.
+      SmallVector<StringRef, 16> Components;
+      auto PathIt = llvm::sys::path::rbegin(Dir->getName());
+      for (int I = 0; I != Dir.level() + 1; ++I, ++PathIt)
+        Components.push_back(*PathIt);
+      SmallString<128> RelativeHeader(UmbrellaDir.NameAsWritten);
+      for (auto It = Components.rbegin(), End = Components.rend(); It != End;
+           ++It)
+        llvm::sys::path::append(RelativeHeader, *It);
+
+      // Include this header as part of the umbrella directory.
+      Module->addTopHeader(Header);
+      addHeaderInclude(RelativeHeader, Includes, LangOpts, Module->IsExternC);
+    }
+
+    if (EC)
+      return EC;
+  }
+
+  // Recurse into submodules.
+  for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
+                                      SubEnd = Module->submodule_end();
+       Sub != SubEnd; ++Sub)
+    if (std::error_code Err = collectModuleHeaderIncludes(
+            LangOpts, FileMgr, ModMap, *Sub, Includes))
+      return Err;
+
+  return std::error_code();
+}
+
+/// Parse a module map and compute the corresponding real input buffer that
+/// should be used to build the module described by that module map and the
+/// current module name.
+static std::unique_ptr<llvm::MemoryBuffer>
+getInputBufferForModuleMap(CompilerInstance &CI, StringRef Filename,
+                           bool IsSystem) {
+  // Find the module map file.
+  const FileEntry *ModuleMap =
+      CI.getFileManager().getFile(Filename, /*openFile*/true);
+  if (!ModuleMap)  {
+    CI.getDiagnostics().Report(diag::err_module_map_not_found)
+      << Filename;
+    return nullptr;
+  }
+
+  // Find the module map file from which it was generated, if different.
+  const FileEntry *OriginalModuleMap = ModuleMap;
+  StringRef OriginalModuleMapName = CI.getFrontendOpts().OriginalModuleMap;
+  if (!OriginalModuleMapName.empty()) {
+    OriginalModuleMap = CI.getFileManager().getFile(OriginalModuleMapName,
+                                                    /*openFile*/ true);
+    if (!OriginalModuleMap) {
+      CI.getDiagnostics().Report(diag::err_module_map_not_found)
+        << OriginalModuleMapName;
+      return nullptr;
+    }
+  }
+  
+  // Parse the module map file.
+  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
+  if (HS.loadModuleMapFile(ModuleMap, IsSystem))
+    return nullptr;
+  
+  if (CI.getLangOpts().CurrentModule.empty()) {
+    CI.getDiagnostics().Report(diag::err_missing_module_name);
+    
+    // FIXME: Eventually, we could consider asking whether there was just
+    // a single module described in the module map, and use that as a 
+    // default. Then it would be fairly trivial to just "compile" a module
+    // map with a single module (the common case).
+    return nullptr;
+  }
+
+  // If we're being run from the command-line, the module build stack will not
+  // have been filled in yet, so complete it now in order to allow us to detect
+  // module cycles.
+  SourceManager &SourceMgr = CI.getSourceManager();
+  if (SourceMgr.getModuleBuildStack().empty())
+    SourceMgr.pushModuleBuildStack(CI.getLangOpts().CurrentModule,
+                                   FullSourceLoc(SourceLocation(), SourceMgr));
+
+  // Dig out the module definition.
+  Module *M = HS.lookupModule(CI.getLangOpts().CurrentModule,
+                              /*AllowSearch=*/false);
+  if (!M) {
+    CI.getDiagnostics().Report(diag::err_missing_module)
+      << CI.getLangOpts().CurrentModule << Filename;
+    
+    return nullptr;
+  }
+
+  // Check whether we can build this module at all.
+  clang::Module::Requirement Requirement;
+  clang::Module::UnresolvedHeaderDirective MissingHeader;
+  if (!M->isAvailable(CI.getLangOpts(), CI.getTarget(), Requirement,
+                      MissingHeader)) {
+    if (MissingHeader.FileNameLoc.isValid()) {
+      CI.getDiagnostics().Report(MissingHeader.FileNameLoc,
+                                 diag::err_module_header_missing)
+        << MissingHeader.IsUmbrella << MissingHeader.FileName;
+    } else {
+      CI.getDiagnostics().Report(diag::err_module_unavailable)
+        << M->getFullModuleName() << Requirement.second << Requirement.first;
+    }
+
+    return nullptr;
+  }
+
+  if (OriginalModuleMap != ModuleMap) {
+    M->IsInferred = true;
+    HS.getModuleMap().setInferredModuleAllowedBy(M, OriginalModuleMap);
+  }
+
+  FileManager &FileMgr = CI.getFileManager();
+
+  // Collect the set of #includes we need to build the module.
+  SmallString<256> HeaderContents;
+  std::error_code Err = std::error_code();
+  if (Module::Header UmbrellaHeader = M->getUmbrellaHeader())
+    addHeaderInclude(UmbrellaHeader.NameAsWritten, HeaderContents,
+                     CI.getLangOpts(), M->IsExternC);
+  Err = collectModuleHeaderIncludes(
+      CI.getLangOpts(), FileMgr,
+      CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(), M,
+      HeaderContents);
+
+  if (Err) {
+    CI.getDiagnostics().Report(diag::err_module_cannot_create_includes)
+      << M->getFullModuleName() << Err.message();
+    return nullptr;
+  }
+
+  // Inform the preprocessor that includes from within the input buffer should
+  // be resolved relative to the build directory of the module map file.
+  CI.getPreprocessor().setMainFileDir(M->Directory);
+
+  return llvm::MemoryBuffer::getMemBufferCopy(
+      HeaderContents, Module::getModuleInputBufferName());
+}
+
 bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
                                      const FrontendInputFile &Input) {
   assert(!Instance && "Already processing a source file!");
@@ -232,13 +457,15 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
   setCompilerInstance(&CI);
 
   StringRef InputFile = Input.getFile();
+  FrontendInputFile FileToProcess = Input;
   bool HasBegunSourceFile = false;
   if (!BeginInvocation(CI))
     goto failure;
 
   // AST files follow a very different path, since they share objects via the
   // AST unit.
-  if (Input.getKind() == IK_AST) {
+  if (Input.getKind().getFormat() == InputKind::Precompiled) {
+    // FIXME: We should not be asserting on bad command-line arguments.
     assert(!usesPreprocessorOnly() &&
            "Attempt to pass AST file to preprocessor only action!");
     assert(hasASTFileSupport() &&
@@ -296,8 +523,19 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
   if (!CI.hasSourceManager())
     CI.createSourceManager(CI.getFileManager());
 
+  // Set up embedding for any specified files. Do this before we load any
+  // source files, including the primary module map for the compilation.
+  for (const auto &F : CI.getFrontendOpts().ModulesEmbedFiles) {
+    if (const auto *FE = CI.getFileManager().getFile(F, /*openFile*/true))
+      CI.getSourceManager().setFileIsTransient(FE);
+    else
+      CI.getDiagnostics().Report(diag::err_modules_embed_file_not_found) << F;
+  }
+  if (CI.getFrontendOpts().ModulesEmbedAllFiles)
+    CI.getSourceManager().setAllFilesAreTransient(true);
+
   // IR files bypass the rest of initialization.
-  if (Input.getKind() == IK_LLVM_IR) {
+  if (Input.getKind().getLanguage() == InputKind::LLVM_IR) {
     assert(hasIRSupport() &&
            "This action does not have IR file support!");
 
@@ -359,13 +597,34 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
                                            &CI.getPreprocessor());
   HasBegunSourceFile = true;
 
+  // For module map files, we first parse the module map and synthesize a
+  // "<module-includes>" buffer before more conventional processing.
+  if (Input.getKind().getFormat() == InputKind::ModuleMap) {
+    CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleMap);
+
+    auto Buffer = getInputBufferForModuleMap(CI, InputFile, Input.isSystem());
+    if (!Buffer)
+      goto failure;
+
+    Module *CurrentModule =
+        CI.getPreprocessor().getHeaderSearchInfo().lookupModule(
+            CI.getLangOpts().CurrentModule,
+            /*AllowSearch=*/false);
+    assert(CurrentModule && "no module info for current module");
+
+    // The input that we end up processing is the generated buffer, not the
+    // module map file itself.
+    FileToProcess = FrontendInputFile(
+        Buffer.release(), Input.getKind().withFormat(InputKind::Source),
+        CurrentModule->IsSystem);
+  }
+
   // Initialize the action.
   if (!BeginSourceFileAction(CI, InputFile))
     goto failure;
 
-  // Initialize the main file entry. It is important that this occurs after
-  // BeginSourceFileAction, which may change CurrentInput during module builds.
-  if (!CI.InitializeSourceManager(CurrentInput))
+  // Initialize the main file entry.
+  if (!CI.InitializeSourceManager(FileToProcess))
     goto failure;
 
   // Create the AST context and consumer unless this is a preprocessor only
@@ -497,6 +756,7 @@ bool FrontendAction::BeginSourceFile(CompilerInstance &CI,
   if (HasBegunSourceFile)
     CI.getDiagnosticClient().EndSourceFile();
   CI.clearOutputFiles(/*EraseFiles=*/true);
+  CI.getLangOpts().setCompilingModule(LangOptions::CMK_None);
   setCurrentInput(FrontendInputFile());
   setCompilerInstance(nullptr);
   return false;
@@ -579,6 +839,7 @@ void FrontendAction::EndSourceFile() {
 
   setCompilerInstance(nullptr);
   setCurrentInput(FrontendInputFile());
+  CI.getLangOpts().setCompilingModule(LangOptions::CMK_None);
 }
 
 bool FrontendAction::shouldEraseOutputFiles() {
diff --git a/lib/Frontend/FrontendActions.cpp b/lib/Frontend/FrontendActions.cpp
index e818038b1354..dd7c12f60f0e 100644
--- a/lib/Frontend/FrontendActions.cpp
+++ b/lib/Frontend/FrontendActions.cpp
@@ -164,242 +164,9 @@ GenerateModuleAction::CreateASTConsumer(CompilerInstance &CI,
   return llvm::make_unique<MultiplexConsumer>(std::move(Consumers));
 }
 
-bool GenerateModuleAction::BeginSourceFileAction(CompilerInstance &CI, 
-                                                 StringRef Filename) {
-  // Set up embedding for any specified files. Do this before we load any
-  // source files, including the primary module map for the compilation.
-  for (const auto &F : CI.getFrontendOpts().ModulesEmbedFiles) {
-    if (const auto *FE = CI.getFileManager().getFile(F, /*openFile*/true))
-      CI.getSourceManager().setFileIsTransient(FE);
-    else
-      CI.getDiagnostics().Report(diag::err_modules_embed_file_not_found) << F;
-  }
-  if (CI.getFrontendOpts().ModulesEmbedAllFiles)
-    CI.getSourceManager().setAllFilesAreTransient(true);
-
-  return true;
-}
-
-
-static SmallVectorImpl<char> &
-operator+=(SmallVectorImpl<char> &Includes, StringRef RHS) {
-  Includes.append(RHS.begin(), RHS.end());
-  return Includes;
-}
-
-static void addHeaderInclude(StringRef HeaderName,
-                             SmallVectorImpl<char> &Includes,
-                             const LangOptions &LangOpts,
-                             bool IsExternC) {
-  if (IsExternC && LangOpts.CPlusPlus)
-    Includes += "extern \"C\" {\n";
-  if (LangOpts.ObjC1)
-    Includes += "#import \"";
-  else
-    Includes += "#include \"";
-
-  Includes += HeaderName;
-
-  Includes += "\"\n";
-  if (IsExternC && LangOpts.CPlusPlus)
-    Includes += "}\n";
-}
-
-/// \brief Collect the set of header includes needed to construct the given 
-/// module and update the TopHeaders file set of the module.
-///
-/// \param Module The module we're collecting includes from.
-///
-/// \param Includes Will be augmented with the set of \#includes or \#imports
-/// needed to load all of the named headers.
-static std::error_code
-collectModuleHeaderIncludes(const LangOptions &LangOpts, FileManager &FileMgr,
-                            ModuleMap &ModMap, clang::Module *Module,
-                            SmallVectorImpl<char> &Includes) {
-  // Don't collect any headers for unavailable modules.
-  if (!Module->isAvailable())
-    return std::error_code();
-
-  // Add includes for each of these headers.
-  for (auto HK : {Module::HK_Normal, Module::HK_Private}) {
-    for (Module::Header &H : Module->Headers[HK]) {
-      Module->addTopHeader(H.Entry);
-      // Use the path as specified in the module map file. We'll look for this
-      // file relative to the module build directory (the directory containing
-      // the module map file) so this will find the same file that we found
-      // while parsing the module map.
-      addHeaderInclude(H.NameAsWritten, Includes, LangOpts, Module->IsExternC);
-    }
-  }
-  // Note that Module->PrivateHeaders will not be a TopHeader.
-
-  if (Module::Header UmbrellaHeader = Module->getUmbrellaHeader()) {
-    Module->addTopHeader(UmbrellaHeader.Entry);
-    if (Module->Parent)
-      // Include the umbrella header for submodules.
-      addHeaderInclude(UmbrellaHeader.NameAsWritten, Includes, LangOpts,
-                       Module->IsExternC);
-  } else if (Module::DirectoryName UmbrellaDir = Module->getUmbrellaDir()) {
-    // Add all of the headers we find in this subdirectory.
-    std::error_code EC;
-    SmallString<128> DirNative;
-    llvm::sys::path::native(UmbrellaDir.Entry->getName(), DirNative);
-
-    vfs::FileSystem &FS = *FileMgr.getVirtualFileSystem();
-    for (vfs::recursive_directory_iterator Dir(FS, DirNative, EC), End;
-         Dir != End && !EC; Dir.increment(EC)) {
-      // Check whether this entry has an extension typically associated with 
-      // headers.
-      if (!llvm::StringSwitch<bool>(llvm::sys::path::extension(Dir->getName()))
-          .Cases(".h", ".H", ".hh", ".hpp", true)
-          .Default(false))
-        continue;
-
-      const FileEntry *Header = FileMgr.getFile(Dir->getName());
-      // FIXME: This shouldn't happen unless there is a file system race. Is
-      // that worth diagnosing?
-      if (!Header)
-        continue;
-
-      // If this header is marked 'unavailable' in this module, don't include 
-      // it.
-      if (ModMap.isHeaderUnavailableInModule(Header, Module))
-        continue;
-
-      // Compute the relative path from the directory to this file.
-      SmallVector<StringRef, 16> Components;
-      auto PathIt = llvm::sys::path::rbegin(Dir->getName());
-      for (int I = 0; I != Dir.level() + 1; ++I, ++PathIt)
-        Components.push_back(*PathIt);
-      SmallString<128> RelativeHeader(UmbrellaDir.NameAsWritten);
-      for (auto It = Components.rbegin(), End = Components.rend(); It != End;
-           ++It)
-        llvm::sys::path::append(RelativeHeader, *It);
-
-      // Include this header as part of the umbrella directory.
-      Module->addTopHeader(Header);
-      addHeaderInclude(RelativeHeader, Includes, LangOpts, Module->IsExternC);
-    }
-
-    if (EC)
-      return EC;
-  }
-
-  // Recurse into submodules.
-  for (clang::Module::submodule_iterator Sub = Module->submodule_begin(),
-                                      SubEnd = Module->submodule_end();
-       Sub != SubEnd; ++Sub)
-    if (std::error_code Err = collectModuleHeaderIncludes(
-            LangOpts, FileMgr, ModMap, *Sub, Includes))
-      return Err;
-
-  return std::error_code();
-}
-
 bool GenerateModuleFromModuleMapAction::BeginSourceFileAction(
     CompilerInstance &CI, StringRef Filename) {
-  CI.getLangOpts().setCompilingModule(LangOptions::CMK_ModuleMap);
-
-  if (!GenerateModuleAction::BeginSourceFileAction(CI, Filename))
-    return false;
-
-  // Find the module map file.
-  const FileEntry *ModuleMap =
-      CI.getFileManager().getFile(Filename, /*openFile*/true);
-  if (!ModuleMap)  {
-    CI.getDiagnostics().Report(diag::err_module_map_not_found)
-      << Filename;
-    return false;
-  }
-  
-  // Parse the module map file.
-  HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
-  if (HS.loadModuleMapFile(ModuleMap, IsSystem))
-    return false;
-  
-  if (CI.getLangOpts().CurrentModule.empty()) {
-    CI.getDiagnostics().Report(diag::err_missing_module_name);
-    
-    // FIXME: Eventually, we could consider asking whether there was just
-    // a single module described in the module map, and use that as a 
-    // default. Then it would be fairly trivial to just "compile" a module
-    // map with a single module (the common case).
-    return false;
-  }
-
-  // If we're being run from the command-line, the module build stack will not
-  // have been filled in yet, so complete it now in order to allow us to detect
-  // module cycles.
-  SourceManager &SourceMgr = CI.getSourceManager();
-  if (SourceMgr.getModuleBuildStack().empty())
-    SourceMgr.pushModuleBuildStack(CI.getLangOpts().CurrentModule,
-                                   FullSourceLoc(SourceLocation(), SourceMgr));
-
-  // Dig out the module definition.
-  Module = HS.lookupModule(CI.getLangOpts().CurrentModule, 
-                           /*AllowSearch=*/false);
-  if (!Module) {
-    CI.getDiagnostics().Report(diag::err_missing_module)
-      << CI.getLangOpts().CurrentModule << Filename;
-    
-    return false;
-  }
-
-  // Check whether we can build this module at all.
-  clang::Module::Requirement Requirement;
-  clang::Module::UnresolvedHeaderDirective MissingHeader;
-  if (!Module->isAvailable(CI.getLangOpts(), CI.getTarget(), Requirement,
-                           MissingHeader)) {
-    if (MissingHeader.FileNameLoc.isValid()) {
-      CI.getDiagnostics().Report(MissingHeader.FileNameLoc,
-                                 diag::err_module_header_missing)
-        << MissingHeader.IsUmbrella << MissingHeader.FileName;
-    } else {
-      CI.getDiagnostics().Report(diag::err_module_unavailable)
-        << Module->getFullModuleName()
-        << Requirement.second << Requirement.first;
-    }
-
-    return false;
-  }
-
-  if (ModuleMapForUniquing && ModuleMapForUniquing != ModuleMap) {
-    Module->IsInferred = true;
-    HS.getModuleMap().setInferredModuleAllowedBy(Module, ModuleMapForUniquing);
-  } else {
-    ModuleMapForUniquing = ModuleMap;
-  }
-
-  FileManager &FileMgr = CI.getFileManager();
-
-  // Collect the set of #includes we need to build the module.
-  SmallString<256> HeaderContents;
-  std::error_code Err = std::error_code();
-  if (Module::Header UmbrellaHeader = Module->getUmbrellaHeader())
-    addHeaderInclude(UmbrellaHeader.NameAsWritten, HeaderContents,
-                     CI.getLangOpts(), Module->IsExternC);
-  Err = collectModuleHeaderIncludes(
-        CI.getLangOpts(), FileMgr,
-        CI.getPreprocessor().getHeaderSearchInfo().getModuleMap(), Module,
-        HeaderContents);
-
-  if (Err) {
-    CI.getDiagnostics().Report(diag::err_module_cannot_create_includes)
-      << Module->getFullModuleName() << Err.message();
-    return false;
-  }
-
-  // Inform the preprocessor that includes from within the input buffer should
-  // be resolved relative to the build directory of the module map file.
-  CI.getPreprocessor().setMainFileDir(Module->Directory);
-
-  std::unique_ptr<llvm::MemoryBuffer> InputBuffer =
-      llvm::MemoryBuffer::getMemBufferCopy(HeaderContents,
-                                           Module::getModuleInputBufferName());
-  // Ownership of InputBuffer will be transferred to the SourceManager.
-  setCurrentInput(FrontendInputFile(InputBuffer.release(), getCurrentFileKind(),
-                                    Module->IsSystem));
-  return true;
+  return GenerateModuleAction::BeginSourceFileAction(CI, Filename);
 }
 
 std::unique_ptr<raw_pwrite_stream>
@@ -408,10 +175,13 @@ GenerateModuleFromModuleMapAction::CreateOutputFile(CompilerInstance &CI,
   // If no output file was provided, figure out where this module would go
   // in the module cache.
   if (CI.getFrontendOpts().OutputFile.empty()) {
+    StringRef ModuleMapFile = CI.getFrontendOpts().OriginalModuleMap;
+    if (ModuleMapFile.empty())
+      ModuleMapFile = InFile;
+
     HeaderSearch &HS = CI.getPreprocessor().getHeaderSearchInfo();
     CI.getFrontendOpts().OutputFile =
-        HS.getModuleFileName(CI.getLangOpts().CurrentModule,
-                             ModuleMapForUniquing->getName(),
+        HS.getModuleFileName(CI.getLangOpts().CurrentModule, ModuleMapFile,
                              /*UsePrebuiltPath=*/false);
   }
 
@@ -777,29 +547,27 @@ void PrintPreprocessedAction::ExecuteAction() {
 }
 
 void PrintPreambleAction::ExecuteAction() {
-  switch (getCurrentFileKind()) {
-  case IK_C:
-  case IK_CXX:
-  case IK_ObjC:
-  case IK_ObjCXX:
-  case IK_OpenCL:
-  case IK_CUDA:
+  switch (getCurrentFileKind().getLanguage()) {
+  case InputKind::C:
+  case InputKind::CXX:
+  case InputKind::ObjC:
+  case InputKind::ObjCXX:
+  case InputKind::OpenCL:
+  case InputKind::CUDA:
     break;
       
-  case IK_None:
-  case IK_Asm:
-  case IK_PreprocessedC:
-  case IK_PreprocessedCuda:
-  case IK_PreprocessedCXX:
-  case IK_PreprocessedObjC:
-  case IK_PreprocessedObjCXX:
-  case IK_AST:
-  case IK_LLVM_IR:
-  case IK_RenderScript:
+  case InputKind::Unknown:
+  case InputKind::Asm:
+  case InputKind::LLVM_IR:
+  case InputKind::RenderScript:
     // We can't do anything with these.
     return;
   }
 
+  // We don't expect to find any #include directives in a preprocessed input.
+  if (getCurrentFileKind().isPreprocessed())
+    return;
+
   CompilerInstance &CI = getCompilerInstance();
   auto Buffer = CI.getFileManager().getBufferForFile(getCurrentFile());
   if (Buffer) {
diff --git a/lib/Frontend/FrontendOptions.cpp b/lib/Frontend/FrontendOptions.cpp
index 6a82084aff1b..dca434588fb1 100644
--- a/lib/Frontend/FrontendOptions.cpp
+++ b/lib/Frontend/FrontendOptions.cpp
@@ -13,22 +13,22 @@ using namespace clang;
 
 InputKind FrontendOptions::getInputKindForExtension(StringRef Extension) {
   return llvm::StringSwitch<InputKind>(Extension)
-    .Cases("ast", "pcm", IK_AST)
-    .Case("c", IK_C)
-    .Cases("S", "s", IK_Asm)
-    .Case("i", IK_PreprocessedC)
-    .Case("ii", IK_PreprocessedCXX)
-    .Case("cui", IK_PreprocessedCuda)
-    .Case("m", IK_ObjC)
-    .Case("mi", IK_PreprocessedObjC)
-    .Cases("mm", "M", IK_ObjCXX)
-    .Case("mii", IK_PreprocessedObjCXX)
-    .Cases("C", "cc", "cp", IK_CXX)
-    .Cases("cpp", "CPP", "c++", "cxx", "hpp", IK_CXX)
-    .Case("cppm", IK_CXX)
-    .Case("iim", IK_PreprocessedCXX)
-    .Case("cl", IK_OpenCL)
-    .Case("cu", IK_CUDA)
-    .Cases("ll", "bc", IK_LLVM_IR)
-    .Default(IK_C);
+    .Cases("ast", "pcm", InputKind(InputKind::Unknown, InputKind::Precompiled))
+    .Case("c", InputKind::C)
+    .Cases("S", "s", InputKind::Asm)
+    .Case("i", InputKind(InputKind::C).getPreprocessed())
+    .Case("ii", InputKind(InputKind::CXX).getPreprocessed())
+    .Case("cui", InputKind(InputKind::CUDA).getPreprocessed())
+    .Case("m", InputKind::ObjC)
+    .Case("mi", InputKind(InputKind::ObjC).getPreprocessed())
+    .Cases("mm", "M", InputKind::ObjCXX)
+    .Case("mii", InputKind(InputKind::ObjCXX).getPreprocessed())
+    .Cases("C", "cc", "cp", InputKind::CXX)
+    .Cases("cpp", "CPP", "c++", "cxx", "hpp", InputKind::CXX)
+    .Case("cppm", InputKind::CXX)
+    .Case("iim", InputKind(InputKind::CXX).getPreprocessed())
+    .Case("cl", InputKind::OpenCL)
+    .Case("cu", InputKind::CUDA)
+    .Cases("ll", "bc", InputKind::LLVM_IR)
+    .Default(InputKind::Unknown);
 }
diff --git a/lib/Frontend/InitPreprocessor.cpp b/lib/Frontend/InitPreprocessor.cpp
index 0dd04e8a8fff..9257dcae84cd 100644
--- a/lib/Frontend/InitPreprocessor.cpp
+++ b/lib/Frontend/InitPreprocessor.cpp
@@ -1041,6 +1041,8 @@ void clang::InitializePreprocessor(
 
   // Install things like __POWERPC__, __GNUC__, etc into the macro table.
   if (InitOpts.UsePredefines) {
+    // FIXME: This will create multiple definitions for most of the predefined
+    // macros. This is not the right way to handle this.
     if (LangOpts.CUDA && PP.getAuxTargetInfo())
       InitializePredefinedMacros(*PP.getAuxTargetInfo(), LangOpts, FEOpts,
                                  Builder);
diff --git a/lib/Frontend/LangStandards.cpp b/lib/Frontend/LangStandards.cpp
index f133327f4298..47023e58fa0b 100644
--- a/lib/Frontend/LangStandards.cpp
+++ b/lib/Frontend/LangStandards.cpp
@@ -13,15 +13,15 @@
 using namespace clang;
 using namespace clang::frontend;
 
-#define LANGSTANDARD(id, name, desc, features) \
-  static const LangStandard Lang_##id = { name, desc, features };
+#define LANGSTANDARD(id, name, lang, desc, features) \
+static const LangStandard Lang_##id = { name, desc, features, InputKind::lang };
 #include "clang/Frontend/LangStandards.def"
 
 const LangStandard &LangStandard::getLangStandardForKind(Kind K) {
   switch (K) {
   case lang_unspecified:
     llvm::report_fatal_error("getLangStandardForKind() on unspecified kind");
-#define LANGSTANDARD(id, name, desc, features) \
+#define LANGSTANDARD(id, name, lang, desc, features) \
     case lang_##id: return Lang_##id;
 #include "clang/Frontend/LangStandards.def"
   }
@@ -30,7 +30,7 @@ const LangStandard &LangStandard::getLangStandardForKind(Kind K) {
 
 const LangStandard *LangStandard::getLangStandardForName(StringRef Name) {
   Kind K = llvm::StringSwitch<Kind>(Name)
-#define LANGSTANDARD(id, name, desc, features) \
+#define LANGSTANDARD(id, name, lang, desc, features) \
     .Case(name, lang_##id)
 #include "clang/Frontend/LangStandards.def"
     .Default(lang_unspecified);
diff --git a/lib/Frontend/PrintPreprocessedOutput.cpp b/lib/Frontend/PrintPreprocessedOutput.cpp
index d48b952ef203..ffedf3cac847 100644
--- a/lib/Frontend/PrintPreprocessedOutput.cpp
+++ b/lib/Frontend/PrintPreprocessedOutput.cpp
@@ -172,7 +172,8 @@ public:
 
   /// MacroUndefined - This hook is called whenever a macro #undef is seen.
   void MacroUndefined(const Token &MacroNameTok,
-                      const MacroDefinition &MD) override;
+                      const MacroDefinition &MD,
+                      const MacroDirective *Undef) override;
 };
 }  // end anonymous namespace
 
@@ -323,43 +324,50 @@ void PrintPPOutputPPCallbacks::InclusionDirective(SourceLocation HashLoc,
                                                   StringRef SearchPath,
                                                   StringRef RelativePath,
                                                   const Module *Imported) {
-  if (Imported) {
-    // When preprocessing, turn implicit imports into @imports.
-    // FIXME: This is a stop-gap until a more comprehensive "preprocessing with
-    // modules" solution is introduced.
+  // In -dI mode, dump #include directives prior to dumping their content or
+  // interpretation.
+  if (DumpIncludeDirectives) {
     startNewLineIfNeeded();
     MoveToLine(HashLoc);
-    if (PP.getLangOpts().ObjC2) {
-      OS << "@import " << Imported->getFullModuleName() << ";"
-         << " /* clang -E: implicit import for \"" << File->getName()
-         << "\" */";
-    } else {
-      const std::string TokenText = PP.getSpelling(IncludeTok);
-      assert(!TokenText.empty());
-      OS << "#" << TokenText << " "
-         << (IsAngled ? '<' : '"')
-         << FileName
-         << (IsAngled ? '>' : '"')
-         << " /* clang -E: implicit import for module "
-         << Imported->getFullModuleName() << " */";
-    }
-    // Since we want a newline after the @import, but not a #<line>, start a new
-    // line immediately.
-    EmittedTokensOnThisLine = true;
+    const std::string TokenText = PP.getSpelling(IncludeTok);
+    assert(!TokenText.empty());
+    OS << "#" << TokenText << " "
+       << (IsAngled ? '<' : '"') << FileName << (IsAngled ? '>' : '"')
+       << " /* clang -E -dI */";
+    setEmittedDirectiveOnThisLine();
     startNewLineIfNeeded();
-  } else {
-    // Not a module import; it's a more vanilla inclusion of some file using one
-    // of: #include, #import, #include_next, #include_macros.
-    if (DumpIncludeDirectives) {
+  }
+
+  // When preprocessing, turn implicit imports into module import pragmas.
+  if (Imported) {
+    switch (IncludeTok.getIdentifierInfo()->getPPKeywordID()) {
+    case tok::pp_include:
+    case tok::pp_import:
+    case tok::pp_include_next:
       startNewLineIfNeeded();
       MoveToLine(HashLoc);
-      const std::string TokenText = PP.getSpelling(IncludeTok);
-      assert(!TokenText.empty());
-      OS << "#" << TokenText << " "
+      OS << "#pragma clang module import " << Imported->getFullModuleName()
+         << " /* clang -E: implicit import for "
+         << "#" << PP.getSpelling(IncludeTok) << " "
          << (IsAngled ? '<' : '"') << FileName << (IsAngled ? '>' : '"')
-         << " /* clang -E -dI */";
-      setEmittedDirectiveOnThisLine();
+         << " */";
+      // Since we want a newline after the pragma, but not a #<line>, start a
+      // new line immediately.
+      EmittedTokensOnThisLine = true;
       startNewLineIfNeeded();
+      break;
+
+    case tok::pp___include_macros:
+      // #__include_macros has no effect on a user of a preprocessed source
+      // file; the only effect is on preprocessing.
+      //
+      // FIXME: That's not *quite* true: it causes the module in question to
+      // be loaded, which can affect downstream diagnostics.
+      break;
+
+    default:
+      llvm_unreachable("unknown include directive kind");
+      break;
     }
   }
 }
@@ -389,7 +397,8 @@ void PrintPPOutputPPCallbacks::MacroDefined(const Token &MacroNameTok,
 }
 
 void PrintPPOutputPPCallbacks::MacroUndefined(const Token &MacroNameTok,
-                                              const MacroDefinition &MD) {
+                                              const MacroDefinition &MD,
+                                              const MacroDirective *Undef) {
   // Only print out macro definitions in -dD mode.
   if (!DumpDefines) return;
 
@@ -773,26 +782,33 @@ void clang::DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
 
   // Expand macros in pragmas with -fms-extensions.  The assumption is that
   // the majority of pragmas in such a file will be Microsoft pragmas.
-  PP.AddPragmaHandler(new UnknownPragmaHandler(
-      "#pragma", Callbacks,
+  // Remember the handlers we will add so that we can remove them later.
+  std::unique_ptr<UnknownPragmaHandler> MicrosoftExtHandler(
+      new UnknownPragmaHandler(
+          "#pragma", Callbacks,
+          /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));
+
+  std::unique_ptr<UnknownPragmaHandler> GCCHandler(new UnknownPragmaHandler(
+      "#pragma GCC", Callbacks,
       /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));
-  PP.AddPragmaHandler(
-      "GCC", new UnknownPragmaHandler(
-                 "#pragma GCC", Callbacks,
-                 /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));
-  PP.AddPragmaHandler(
-      "clang", new UnknownPragmaHandler(
-                   "#pragma clang", Callbacks,
-                   /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));
+
+  std::unique_ptr<UnknownPragmaHandler> ClangHandler(new UnknownPragmaHandler(
+      "#pragma clang", Callbacks,
+      /*RequireTokenExpansion=*/PP.getLangOpts().MicrosoftExt));
+
+  PP.AddPragmaHandler(MicrosoftExtHandler.get());
+  PP.AddPragmaHandler("GCC", GCCHandler.get());
+  PP.AddPragmaHandler("clang", ClangHandler.get());
 
   // The tokens after pragma omp need to be expanded.
   //
   //  OpenMP [2.1, Directive format]
   //  Preprocessing tokens following the #pragma omp are subject to macro
   //  replacement.
-  PP.AddPragmaHandler("omp",
-                      new UnknownPragmaHandler("#pragma omp", Callbacks,
-                                               /*RequireTokenExpansion=*/true));
+  std::unique_ptr<UnknownPragmaHandler> OpenMPHandler(
+      new UnknownPragmaHandler("#pragma omp", Callbacks,
+                               /*RequireTokenExpansion=*/true));
+  PP.AddPragmaHandler("omp", OpenMPHandler.get());
 
   PP.addPPCallbacks(std::unique_ptr<PPCallbacks>(Callbacks));
 
@@ -820,4 +836,11 @@ void clang::DoPrintPreprocessedInput(Preprocessor &PP, raw_ostream *OS,
   // Read all the preprocessed tokens, printing them out to the stream.
   PrintPreprocessedTokens(PP, Tok, Callbacks, *OS);
   *OS << '\n';
+
+  // Remove the handlers we just added to leave the preprocessor in a sane state
+  // so that it can be reused (for example by a clang::Parser instance).
+  PP.RemovePragmaHandler(MicrosoftExtHandler.get());
+  PP.RemovePragmaHandler("GCC", GCCHandler.get());
+  PP.RemovePragmaHandler("clang", ClangHandler.get());
+  PP.RemovePragmaHandler("omp", OpenMPHandler.get());
 }
diff --git a/lib/Frontend/Rewrite/InclusionRewriter.cpp b/lib/Frontend/Rewrite/InclusionRewriter.cpp
index d953da2e4fd2..ee61f76d029d 100644
--- a/lib/Frontend/Rewrite/InclusionRewriter.cpp
+++ b/lib/Frontend/Rewrite/InclusionRewriter.cpp
@@ -52,7 +52,7 @@ class InclusionRewriter : public PPCallbacks {
 public:
   InclusionRewriter(Preprocessor &PP, raw_ostream &OS, bool ShowLineMarkers,
                     bool UseLineDirectives);
-  bool Process(FileID FileId, SrcMgr::CharacteristicKind FileType);
+  void Process(FileID FileId, SrcMgr::CharacteristicKind FileType);
   void setPredefinesBuffer(const llvm::MemoryBuffer *Buf) {
     PredefinesBuffer = Buf;
   }
@@ -132,7 +132,7 @@ void InclusionRewriter::WriteLineInfo(StringRef Filename, int Line,
 }
 
 void InclusionRewriter::WriteImplicitModuleImport(const Module *Mod) {
-  OS << "@import " << Mod->getFullModuleName() << ";"
+  OS << "#pragma clang module import " << Mod->getFullModuleName()
      << " /* clang -frewrite-includes: implicit import */" << MainEOL;
 }
 
@@ -392,7 +392,7 @@ bool InclusionRewriter::HandleHasInclude(
   // FIXME: Why don't we call PP.LookupFile here?
   const FileEntry *File = PP.getHeaderSearchInfo().LookupFile(
       Filename, SourceLocation(), isAngled, nullptr, CurDir, Includers, nullptr,
-      nullptr, nullptr, nullptr, false);
+      nullptr, nullptr, nullptr, nullptr);
 
   FileExists = File != nullptr;
   return true;
@@ -400,9 +400,8 @@ bool InclusionRewriter::HandleHasInclude(
 
 /// Use a raw lexer to analyze \p FileId, incrementally copying parts of it
 /// and including content of included files recursively.
-bool InclusionRewriter::Process(FileID FileId,
-                                SrcMgr::CharacteristicKind FileType)
-{
+void InclusionRewriter::Process(FileID FileId,
+                                SrcMgr::CharacteristicKind FileType) {
   bool Invalid;
   const MemoryBuffer &FromFile = *SM.getBuffer(FileId, &Invalid);
   assert(!Invalid && "Attempting to process invalid inclusion");
@@ -419,7 +418,7 @@ bool InclusionRewriter::Process(FileID FileId,
     WriteLineInfo(FileName, 1, FileType, " 1");
 
   if (SM.getFileIDSize(FileId) == 0)
-    return false;
+    return;
 
   // The next byte to be copied from the source file, which may be non-zero if
   // the lexer handled a BOM.
@@ -450,19 +449,14 @@ bool InclusionRewriter::Process(FileID FileId,
               WriteLineInfo(FileName, Line - 1, FileType, "");
             StringRef LineInfoExtra;
             SourceLocation Loc = HashToken.getLocation();
-            if (const Module *Mod = PP.getLangOpts().ObjC2
-                                        ? FindModuleAtLocation(Loc)
-                                        : nullptr)
+            if (const Module *Mod = FindModuleAtLocation(Loc))
               WriteImplicitModuleImport(Mod);
             else if (const IncludedFile *Inc = FindIncludeAtLocation(Loc)) {
-              // include and recursively process the file
-              if (Process(Inc->Id, Inc->FileType)) {
-                // and set lineinfo back to this file, if the nested one was
-                // actually included
-                // `2' indicates returning to a file (after having included
-                // another file.
-                LineInfoExtra = " 2";
-              }
+              // Include and recursively process the file.
+              Process(Inc->Id, Inc->FileType);
+              // Add line marker to indicate we're returning from an included
+              // file.
+              LineInfoExtra = " 2";
             }
             // fix up lineinfo (since commented out directive changed line
             // numbers) for inclusions that were skipped due to header guards
@@ -571,7 +565,6 @@ bool InclusionRewriter::Process(FileID FileId,
   OutputContentUpTo(FromFile, NextToWrite,
                     SM.getFileOffset(SM.getLocForEndOfFile(FileId)), LocalEOL,
                     Line, /*EnsureNewline=*/true);
-  return true;
 }
 
 /// InclusionRewriterInInput - Implement -frewrite-includes mode.
diff --git a/lib/Frontend/VerifyDiagnosticConsumer.cpp b/lib/Frontend/VerifyDiagnosticConsumer.cpp
index ae16ea177ffe..427d15ed703a 100644
--- a/lib/Frontend/VerifyDiagnosticConsumer.cpp
+++ b/lib/Frontend/VerifyDiagnosticConsumer.cpp
@@ -400,7 +400,7 @@ static bool ParseDirective(StringRef S, ExpectedData *ED, SourceManager &SM,
         const DirectoryLookup *CurDir;
         const FileEntry *FE =
             PP->LookupFile(Pos, Filename, false, nullptr, nullptr, CurDir,
-                           nullptr, nullptr, nullptr);
+                           nullptr, nullptr, nullptr, nullptr);
         if (!FE) {
           Diags.Report(Pos.getLocWithOffset(PH.C-PH.Begin),
                        diag::err_verify_missing_file) << Filename << KindStr;