Vendor import of clang trunk r256633:vendor/clang/clang-trunk-r256633

https://llvm.org/svn/llvm-project/cfe/trunk@256633

13 files changed, 508 insertions, 268 deletions

diff --git a/lib/Lex/HeaderSearch.cpp b/lib/Lex/HeaderSearch.cpp
index 983dc18b57af..8a686a7f3d74 100644
--- a/lib/Lex/HeaderSearch.cpp
+++ b/lib/Lex/HeaderSearch.cpp
@@ -127,11 +127,12 @@ std::string HeaderSearch::getModuleFileName(Module *Module) {
 
 std::string HeaderSearch::getModuleFileName(StringRef ModuleName,
                                             StringRef ModuleMapPath) {
-  // If we don't have a module cache path, we can't do anything.
-  if (ModuleCachePath.empty()) 
+  // If we don't have a module cache path or aren't supposed to use one, we
+  // can't do anything.
+  if (getModuleCachePath().empty())
     return std::string();
 
-  SmallString<256> Result(ModuleCachePath);
+  SmallString<256> Result(getModuleCachePath());
   llvm::sys::fs::make_absolute(Result);
 
   if (HSOpts->DisableModuleHash) {
@@ -153,7 +154,7 @@ std::string HeaderSearch::getModuleFileName(StringRef ModuleName,
 
     llvm::hash_code Hash =
       llvm::hash_combine(DirName.lower(), FileName.lower(),
-                         HSOpts->ModuleFormat);
+                         HSOpts->ModuleFormat, HSOpts->UseDebugInfo);
 
     SmallString<128> HashStr;
     llvm::APInt(64, size_t(Hash)).toStringUnsigned(HashStr, /*Radix*/36);
@@ -249,31 +250,22 @@ const char *DirectoryLookup::getName() const {
   return getHeaderMap()->getFileName();
 }
 
-static const FileEntry *
-getFileAndSuggestModule(HeaderSearch &HS, StringRef FileName,
-                        const DirectoryEntry *Dir, bool IsSystemHeaderDir,
-                        ModuleMap::KnownHeader *SuggestedModule) {
+const FileEntry *HeaderSearch::getFileAndSuggestModule(
+    StringRef FileName, const DirectoryEntry *Dir, bool IsSystemHeaderDir,
+    Module *RequestingModule, ModuleMap::KnownHeader *SuggestedModule) {
   // If we have a module map that might map this header, load it and
   // check whether we'll have a suggestion for a module.
-  HS.hasModuleMap(FileName, Dir, IsSystemHeaderDir);
-  if (SuggestedModule) {
-    const FileEntry *File = HS.getFileMgr().getFile(FileName,
-                                                    /*OpenFile=*/false);
-    if (File) {
-      // If there is a module that corresponds to this header, suggest it.
-      *SuggestedModule = HS.findModuleForHeader(File);
-
-      // FIXME: This appears to be a no-op. We loaded the module map for this
-      // directory at the start of this function.
-      if (!SuggestedModule->getModule() &&
-          HS.hasModuleMap(FileName, Dir, IsSystemHeaderDir))
-        *SuggestedModule = HS.findModuleForHeader(File);
-    }
+  const FileEntry *File = getFileMgr().getFile(FileName, /*OpenFile=*/true);
+  if (!File)
+    return nullptr;
 
-    return File;
-  }
+  // If there is a module that corresponds to this header, suggest it.
+  if (!findUsableModuleForHeader(File, Dir ? Dir : File->getDir(),
+                                 RequestingModule, SuggestedModule,
+                                 IsSystemHeaderDir))
+    return nullptr;
 
-  return HS.getFileMgr().getFile(FileName, /*openFile=*/true);
+  return File;
 }
 
 /// LookupFile - Lookup the specified file in this search path, returning it
@@ -283,6 +275,7 @@ const FileEntry *DirectoryLookup::LookupFile(
     HeaderSearch &HS,
     SmallVectorImpl<char> *SearchPath,
     SmallVectorImpl<char> *RelativePath,
+    Module *RequestingModule,
     ModuleMap::KnownHeader *SuggestedModule,
     bool &InUserSpecifiedSystemFramework,
     bool &HasBeenMapped,
@@ -305,14 +298,15 @@ const FileEntry *DirectoryLookup::LookupFile(
       RelativePath->append(Filename.begin(), Filename.end());
     }
 
-    return getFileAndSuggestModule(HS, TmpDir, getDir(),
-                                   isSystemHeaderDirectory(),
-                                   SuggestedModule);
+    return HS.getFileAndSuggestModule(TmpDir, getDir(),
+                                      isSystemHeaderDirectory(),
+                                      RequestingModule, SuggestedModule);
   }
 
   if (isFramework())
     return DoFrameworkLookup(Filename, HS, SearchPath, RelativePath,
-                             SuggestedModule, InUserSpecifiedSystemFramework);
+                             RequestingModule, SuggestedModule,
+                             InUserSpecifiedSystemFramework);
 
   assert(isHeaderMap() && "Unknown directory lookup");
   const HeaderMap *HM = getHeaderMap();
@@ -404,13 +398,10 @@ getTopFrameworkDir(FileManager &FileMgr, StringRef DirName,
 /// DoFrameworkLookup - Do a lookup of the specified file in the current
 /// DirectoryLookup, which is a framework directory.
 const FileEntry *DirectoryLookup::DoFrameworkLookup(
-    StringRef Filename,
-    HeaderSearch &HS,
-    SmallVectorImpl<char> *SearchPath,
-    SmallVectorImpl<char> *RelativePath,
+    StringRef Filename, HeaderSearch &HS, SmallVectorImpl<char> *SearchPath,
+    SmallVectorImpl<char> *RelativePath, Module *RequestingModule,
     ModuleMap::KnownHeader *SuggestedModule,
-    bool &InUserSpecifiedSystemFramework) const
-{
+    bool &InUserSpecifiedSystemFramework) const {
   FileManager &FileMgr = HS.getFileMgr();
 
   // Framework names must have a '/' in the filename.
@@ -522,27 +513,15 @@ const FileEntry *DirectoryLookup::DoFrameworkLookup(
         break;
     } while (true);
 
+    bool IsSystem = getDirCharacteristic() != SrcMgr::C_User;
     if (FoundFramework) {
-      // Find the top-level framework based on this framework.
-      SmallVector<std::string, 4> SubmodulePath;
-      const DirectoryEntry *TopFrameworkDir
-        = ::getTopFrameworkDir(FileMgr, FrameworkPath, SubmodulePath);
-
-      // Determine the name of the top-level framework.
-      StringRef ModuleName = llvm::sys::path::stem(TopFrameworkDir->getName());
-
-      // Load this framework module. If that succeeds, find the suggested module
-      // for this header, if any.
-      bool IsSystem = getDirCharacteristic() != SrcMgr::C_User;
-      HS.loadFrameworkModule(ModuleName, TopFrameworkDir, IsSystem);
-
-      // FIXME: This can find a module not part of ModuleName, which is
-      // important so that we're consistent about whether this header
-      // corresponds to a module. Possibly we should lock down framework modules
-      // so that this is not possible.
-      *SuggestedModule = HS.findModuleForHeader(FE);
+      if (!HS.findUsableModuleForFrameworkHeader(
+              FE, FrameworkPath, RequestingModule, SuggestedModule, IsSystem))
+        return nullptr;
     } else {
-      *SuggestedModule = HS.findModuleForHeader(FE);
+      if (!HS.findUsableModuleForHeader(FE, getDir(), RequestingModule,
+                                        SuggestedModule, IsSystem))
+        return nullptr;
     }
   }
   return FE;
@@ -588,7 +567,8 @@ const FileEntry *HeaderSearch::LookupFile(
     const DirectoryLookup *FromDir, const DirectoryLookup *&CurDir,
     ArrayRef<std::pair<const FileEntry *, const DirectoryEntry *>> Includers,
     SmallVectorImpl<char> *SearchPath, SmallVectorImpl<char> *RelativePath,
-    ModuleMap::KnownHeader *SuggestedModule, bool SkipCache) {
+    Module *RequestingModule, ModuleMap::KnownHeader *SuggestedModule,
+    bool SkipCache) {
   if (SuggestedModule)
     *SuggestedModule = ModuleMap::KnownHeader();
     
@@ -606,13 +586,9 @@ const FileEntry *HeaderSearch::LookupFile(
       RelativePath->append(Filename.begin(), Filename.end());
     }
     // Otherwise, just return the file.
-    const FileEntry *File = FileMgr.getFile(Filename, /*openFile=*/true);
-    if (File && SuggestedModule) {
-      // If there is a module that corresponds to this header, suggest it.
-      hasModuleMap(Filename, File->getDir(), /*SystemHeaderDir*/false);
-      *SuggestedModule = findModuleForHeader(File);
-    }
-    return File;
+    return getFileAndSuggestModule(Filename, nullptr,
+                                   /*IsSystemHeaderDir*/false,
+                                   RequestingModule, SuggestedModule);
   }
 
   // This is the header that MSVC's header search would have found.
@@ -646,8 +622,8 @@ const FileEntry *HeaderSearch::LookupFile(
       bool IncluderIsSystemHeader =
           Includer && getFileInfo(Includer).DirInfo != SrcMgr::C_User;
       if (const FileEntry *FE = getFileAndSuggestModule(
-              *this, TmpDir, IncluderAndDir.second,
-              IncluderIsSystemHeader, SuggestedModule)) {
+              TmpDir, IncluderAndDir.second, IncluderIsSystemHeader,
+              RequestingModule, SuggestedModule)) {
         if (!Includer) {
           assert(First && "only first includer can have no file");
           return FE;
@@ -736,10 +712,10 @@ const FileEntry *HeaderSearch::LookupFile(
   for (; i != SearchDirs.size(); ++i) {
     bool InUserSpecifiedSystemFramework = false;
     bool HasBeenMapped = false;
-    const FileEntry *FE =
-      SearchDirs[i].LookupFile(Filename, *this, SearchPath, RelativePath,
-                               SuggestedModule, InUserSpecifiedSystemFramework,
-                               HasBeenMapped, MappedName);
+    const FileEntry *FE = SearchDirs[i].LookupFile(
+        Filename, *this, SearchPath, RelativePath, RequestingModule,
+        SuggestedModule, InUserSpecifiedSystemFramework, HasBeenMapped,
+        MappedName);
     if (HasBeenMapped) {
       CacheLookup.MappedName =
           copyString(Filename, LookupFileCache.getAllocator());
@@ -803,9 +779,10 @@ const FileEntry *HeaderSearch::LookupFile(
       ScratchFilename += '/';
       ScratchFilename += Filename;
 
-      const FileEntry *FE = LookupFile(
-          ScratchFilename, IncludeLoc, /*isAngled=*/true, FromDir, CurDir,
-          Includers.front(), SearchPath, RelativePath, SuggestedModule);
+      const FileEntry *FE =
+          LookupFile(ScratchFilename, IncludeLoc, /*isAngled=*/true, FromDir,
+                     CurDir, Includers.front(), SearchPath, RelativePath,
+                     RequestingModule, SuggestedModule);
 
       if (checkMSVCHeaderSearch(Diags, MSFE, FE, IncludeLoc)) {
         if (SuggestedModule)
@@ -841,6 +818,7 @@ LookupSubframeworkHeader(StringRef Filename,
                          const FileEntry *ContextFileEnt,
                          SmallVectorImpl<char> *SearchPath,
                          SmallVectorImpl<char> *RelativePath,
+                         Module *RequestingModule,
                          ModuleMap::KnownHeader *SuggestedModule) {
   assert(ContextFileEnt && "No context file?");
 
@@ -932,24 +910,10 @@ LookupSubframeworkHeader(StringRef Filename,
   unsigned DirInfo = getFileInfo(ContextFileEnt).DirInfo;
   getFileInfo(FE).DirInfo = DirInfo;
 
-  // If we're supposed to suggest a module, look for one now.
-  if (SuggestedModule) {
-    // Find the top-level framework based on this framework.
-    FrameworkName.pop_back(); // remove the trailing '/'
-    SmallVector<std::string, 4> SubmodulePath;
-    const DirectoryEntry *TopFrameworkDir
-      = ::getTopFrameworkDir(FileMgr, FrameworkName, SubmodulePath);
-    
-    // Determine the name of the top-level framework.
-    StringRef ModuleName = llvm::sys::path::stem(TopFrameworkDir->getName());
-
-    // Load this framework module. If that succeeds, find the suggested module
-    // for this header, if any.
-    bool IsSystem = false;
-    if (loadFrameworkModule(ModuleName, TopFrameworkDir, IsSystem)) {
-      *SuggestedModule = findModuleForHeader(FE);
-    }
-  }
+  FrameworkName.pop_back(); // remove the trailing '/'
+  if (!findUsableModuleForFrameworkHeader(FE, FrameworkName, RequestingModule,
+                                          SuggestedModule, /*IsSystem*/ false))
+    return nullptr;
 
   return FE;
 }
@@ -962,77 +926,112 @@ LookupSubframeworkHeader(StringRef Filename,
 /// header file info (\p HFI)
 static void mergeHeaderFileInfo(HeaderFileInfo &HFI, 
                                 const HeaderFileInfo &OtherHFI) {
+  assert(OtherHFI.External && "expected to merge external HFI");
+
   HFI.isImport |= OtherHFI.isImport;
   HFI.isPragmaOnce |= OtherHFI.isPragmaOnce;
   HFI.isModuleHeader |= OtherHFI.isModuleHeader;
   HFI.NumIncludes += OtherHFI.NumIncludes;
-  
+
   if (!HFI.ControllingMacro && !HFI.ControllingMacroID) {
     HFI.ControllingMacro = OtherHFI.ControllingMacro;
     HFI.ControllingMacroID = OtherHFI.ControllingMacroID;
   }
-  
-  if (OtherHFI.External) {
-    HFI.DirInfo = OtherHFI.DirInfo;
-    HFI.External = OtherHFI.External;
-    HFI.IndexHeaderMapHeader = OtherHFI.IndexHeaderMapHeader;
-  }
+
+  HFI.DirInfo = OtherHFI.DirInfo;
+  HFI.External = (!HFI.IsValid || HFI.External);
+  HFI.IsValid = true;
+  HFI.IndexHeaderMapHeader = OtherHFI.IndexHeaderMapHeader;
 
   if (HFI.Framework.empty())
     HFI.Framework = OtherHFI.Framework;
-  
-  HFI.Resolved = true;
 }
                                 
 /// getFileInfo - Return the HeaderFileInfo structure for the specified
 /// FileEntry.
 HeaderFileInfo &HeaderSearch::getFileInfo(const FileEntry *FE) {
   if (FE->getUID() >= FileInfo.size())
-    FileInfo.resize(FE->getUID()+1);
-  
-  HeaderFileInfo &HFI = FileInfo[FE->getUID()];
-  if (ExternalSource && !HFI.Resolved)
-    mergeHeaderFileInfo(HFI, ExternalSource->GetHeaderFileInfo(FE));
-  HFI.IsValid = 1;
-  return HFI;
+    FileInfo.resize(FE->getUID() + 1);
+
+  HeaderFileInfo *HFI = &FileInfo[FE->getUID()];
+  // FIXME: Use a generation count to check whether this is really up to date.
+  if (ExternalSource && !HFI->Resolved) {
+    HFI->Resolved = true;
+    auto ExternalHFI = ExternalSource->GetHeaderFileInfo(FE);
+
+    HFI = &FileInfo[FE->getUID()];
+    if (ExternalHFI.External)
+      mergeHeaderFileInfo(*HFI, ExternalHFI);
+  }
+
+  HFI->IsValid = true;
+  // We have local information about this header file, so it's no longer
+  // strictly external.
+  HFI->External = false;
+  return *HFI;
 }
 
-bool HeaderSearch::tryGetFileInfo(const FileEntry *FE,
-                                  HeaderFileInfo &Result) const {
-  if (FE->getUID() >= FileInfo.size())
-    return false;
-  const HeaderFileInfo &HFI = FileInfo[FE->getUID()];
-  if (HFI.IsValid) {
-    Result = HFI;
-    return true;
+const HeaderFileInfo *
+HeaderSearch::getExistingFileInfo(const FileEntry *FE,
+                                  bool WantExternal) const {
+  // If we have an external source, ensure we have the latest information.
+  // FIXME: Use a generation count to check whether this is really up to date.
+  HeaderFileInfo *HFI;
+  if (ExternalSource) {
+    if (FE->getUID() >= FileInfo.size()) {
+      if (!WantExternal)
+        return nullptr;
+      FileInfo.resize(FE->getUID() + 1);
+    }
+
+    HFI = &FileInfo[FE->getUID()];
+    if (!WantExternal && (!HFI->IsValid || HFI->External))
+      return nullptr;
+    if (!HFI->Resolved) {
+      HFI->Resolved = true;
+      auto ExternalHFI = ExternalSource->GetHeaderFileInfo(FE);
+
+      HFI = &FileInfo[FE->getUID()];
+      if (ExternalHFI.External)
+        mergeHeaderFileInfo(*HFI, ExternalHFI);
+    }
+  } else if (FE->getUID() >= FileInfo.size()) {
+    return nullptr;
+  } else {
+    HFI = &FileInfo[FE->getUID()];
   }
-  return false;
+
+  if (!HFI->IsValid || (HFI->External && !WantExternal))
+    return nullptr;
+
+  return HFI;
 }
 
 bool HeaderSearch::isFileMultipleIncludeGuarded(const FileEntry *File) {
   // Check if we've ever seen this file as a header.
-  if (File->getUID() >= FileInfo.size())
-    return false;
-
-  // Resolve header file info from the external source, if needed.
-  HeaderFileInfo &HFI = FileInfo[File->getUID()];
-  if (ExternalSource && !HFI.Resolved)
-    mergeHeaderFileInfo(HFI, ExternalSource->GetHeaderFileInfo(File));
-
-  return HFI.isPragmaOnce || HFI.isImport ||
-      HFI.ControllingMacro || HFI.ControllingMacroID;
+  if (auto *HFI = getExistingFileInfo(File))
+    return HFI->isPragmaOnce || HFI->isImport || HFI->ControllingMacro ||
+           HFI->ControllingMacroID;
+  return false;
 }
 
 void HeaderSearch::MarkFileModuleHeader(const FileEntry *FE,
                                         ModuleMap::ModuleHeaderRole Role,
                                         bool isCompilingModuleHeader) {
-  if (FE->getUID() >= FileInfo.size())
-    FileInfo.resize(FE->getUID()+1);
+  bool isModularHeader = !(Role & ModuleMap::TextualHeader);
+
+  // Don't mark the file info as non-external if there's nothing to change.
+  if (!isCompilingModuleHeader) {
+    if (!isModularHeader)
+      return;
+    auto *HFI = getExistingFileInfo(FE);
+    if (HFI && HFI->isModuleHeader)
+      return;
+  }
 
-  HeaderFileInfo &HFI = FileInfo[FE->getUID()];
-  HFI.isModuleHeader = true;
+  auto &HFI = getFileInfo(FE);
+  HFI.isModuleHeader |= isModularHeader;
   HFI.isCompilingModuleHeader |= isCompilingModuleHeader;
-  HFI.setHeaderRole(Role);
 }
 
 bool HeaderSearch::ShouldEnterIncludeFile(Preprocessor &PP,
@@ -1142,11 +1141,48 @@ HeaderSearch::findModuleForHeader(const FileEntry *File) const {
   if (ExternalSource) {
     // Make sure the external source has handled header info about this file,
     // which includes whether the file is part of a module.
-    (void)getFileInfo(File);
+    (void)getExistingFileInfo(File);
   }
   return ModMap.findModuleForHeader(File);
 }
 
+bool HeaderSearch::findUsableModuleForHeader(
+    const FileEntry *File, const DirectoryEntry *Root, Module *RequestingModule,
+    ModuleMap::KnownHeader *SuggestedModule, bool IsSystemHeaderDir) {
+  if (File && SuggestedModule) {
+    // If there is a module that corresponds to this header, suggest it.
+    hasModuleMap(File->getName(), Root, IsSystemHeaderDir);
+    *SuggestedModule = findModuleForHeader(File);
+  }
+  return true;
+}
+
+bool HeaderSearch::findUsableModuleForFrameworkHeader(
+    const FileEntry *File, StringRef FrameworkName, Module *RequestingModule,
+    ModuleMap::KnownHeader *SuggestedModule, bool IsSystemFramework) {
+  // If we're supposed to suggest a module, look for one now.
+  if (SuggestedModule) {
+    // Find the top-level framework based on this framework.
+    SmallVector<std::string, 4> SubmodulePath;
+    const DirectoryEntry *TopFrameworkDir
+      = ::getTopFrameworkDir(FileMgr, FrameworkName, SubmodulePath);
+    
+    // Determine the name of the top-level framework.
+    StringRef ModuleName = llvm::sys::path::stem(TopFrameworkDir->getName());
+
+    // Load this framework module. If that succeeds, find the suggested module
+    // for this header, if any.
+    loadFrameworkModule(ModuleName, TopFrameworkDir, IsSystemFramework);
+
+    // FIXME: This can find a module not part of ModuleName, which is
+    // important so that we're consistent about whether this header
+    // corresponds to a module. Possibly we should lock down framework modules
+    // so that this is not possible.
+    *SuggestedModule = findModuleForHeader(File);
+  }
+  return true;
+}
+
 static const FileEntry *getPrivateModuleMap(const FileEntry *File,
                                             FileManager &FileMgr) {
   StringRef Filename = llvm::sys::path::filename(File->getName());
diff --git a/lib/Lex/Lexer.cpp b/lib/Lex/Lexer.cpp
index 4007914b6c08..27b0feb48270 100644
--- a/lib/Lex/Lexer.cpp
+++ b/lib/Lex/Lexer.cpp
@@ -235,7 +235,7 @@ static size_t getSpellingSlow(const Token &Tok, const char *BufPtr,
   size_t Length = 0;
   const char *BufEnd = BufPtr + Tok.getLength();
 
-  if (Tok.is(tok::string_literal)) {
+  if (tok::isStringLiteral(Tok.getKind())) {
     // Munch the encoding-prefix and opening double-quote.
     while (BufPtr < BufEnd) {
       unsigned Size;
@@ -1354,7 +1354,9 @@ void Lexer::SkipBytes(unsigned Bytes, bool StartOfLine) {
 }
 
 static bool isAllowedIDChar(uint32_t C, const LangOptions &LangOpts) {
-  if (LangOpts.CPlusPlus11 || LangOpts.C11) {
+  if (LangOpts.AsmPreprocessor) {
+    return false;
+  } else if (LangOpts.CPlusPlus11 || LangOpts.C11) {
     static const llvm::sys::UnicodeCharSet C11AllowedIDChars(
         C11AllowedIDCharRanges);
     return C11AllowedIDChars.contains(C);
@@ -1371,7 +1373,9 @@ static bool isAllowedIDChar(uint32_t C, const LangOptions &LangOpts) {
 
 static bool isAllowedInitiallyIDChar(uint32_t C, const LangOptions &LangOpts) {
   assert(isAllowedIDChar(C, LangOpts));
-  if (LangOpts.CPlusPlus11 || LangOpts.C11) {
+  if (LangOpts.AsmPreprocessor) {
+    return false;
+  } else if (LangOpts.CPlusPlus11 || LangOpts.C11) {
     static const llvm::sys::UnicodeCharSet C11DisallowedInitialIDChars(
         C11DisallowedInitialIDCharRanges);
     return !C11DisallowedInitialIDChars.contains(C);
@@ -1732,7 +1736,7 @@ bool Lexer::LexStringLiteral(Token &Result, const char *CurPtr,
     if (C == '\n' || C == '\r' ||             // Newline.
         (C == 0 && CurPtr-1 == BufferEnd)) {  // End of file.
       if (!isLexingRawMode() && !LangOpts.AsmPreprocessor)
-        Diag(BufferPtr, diag::ext_unterminated_string);
+        Diag(BufferPtr, diag::ext_unterminated_char_or_string) << 1;
       FormTokenWithChars(Result, CurPtr-1, tok::unknown);
       return true;
     }
@@ -1756,7 +1760,7 @@ bool Lexer::LexStringLiteral(Token &Result, const char *CurPtr,
 
   // If a nul character existed in the string, warn about it.
   if (NulCharacter && !isLexingRawMode())
-    Diag(NulCharacter, diag::null_in_string);
+    Diag(NulCharacter, diag::null_in_char_or_string) << 1;
 
   // Update the location of the token as well as the BufferPtr instance var.
   const char *TokStart = BufferPtr;
@@ -1872,7 +1876,7 @@ bool Lexer::LexAngledStringLiteral(Token &Result, const char *CurPtr) {
 
   // If a nul character existed in the string, warn about it.
   if (NulCharacter && !isLexingRawMode())
-    Diag(NulCharacter, diag::null_in_string);
+    Diag(NulCharacter, diag::null_in_char_or_string) << 1;
 
   // Update the location of token as well as BufferPtr.
   const char *TokStart = BufferPtr;
@@ -1914,7 +1918,7 @@ bool Lexer::LexCharConstant(Token &Result, const char *CurPtr,
     if (C == '\n' || C == '\r' ||             // Newline.
         (C == 0 && CurPtr-1 == BufferEnd)) {  // End of file.
       if (!isLexingRawMode() && !LangOpts.AsmPreprocessor)
-        Diag(BufferPtr, diag::ext_unterminated_char);
+        Diag(BufferPtr, diag::ext_unterminated_char_or_string) << 0;
       FormTokenWithChars(Result, CurPtr-1, tok::unknown);
       return true;
     }
@@ -1938,7 +1942,7 @@ bool Lexer::LexCharConstant(Token &Result, const char *CurPtr,
 
   // If a nul character existed in the character, warn about it.
   if (NulCharacter && !isLexingRawMode())
-    Diag(NulCharacter, diag::null_in_char);
+    Diag(NulCharacter, diag::null_in_char_or_string) << 0;
 
   // Update the location of token as well as BufferPtr.
   const char *TokStart = BufferPtr;
@@ -2956,8 +2960,11 @@ LexNextToken:
       
   case 26:  // DOS & CP/M EOF: "^Z".
     // If we're in Microsoft extensions mode, treat this as end of file.
-    if (LangOpts.MicrosoftExt)
+    if (LangOpts.MicrosoftExt) {
+      if (!isLexingRawMode())
+        Diag(CurPtr-1, diag::ext_ctrl_z_eof_microsoft);
       return LexEndOfFile(Result, CurPtr-1);
+    }
 
     // If Microsoft extensions are disabled, this is just random garbage.
     Kind = tok::unknown;
diff --git a/lib/Lex/LiteralSupport.cpp b/lib/Lex/LiteralSupport.cpp
index aed91648799b..1e7858af8948 100644
--- a/lib/Lex/LiteralSupport.cpp
+++ b/lib/Lex/LiteralSupport.cpp
@@ -159,7 +159,7 @@ static unsigned ProcessCharEscape(const char *ThisTokBegin,
     // Check for overflow.
     if (Overflow && Diags)   // Too many digits to fit in
       Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
-           diag::err_hex_escape_too_large);
+           diag::err_escape_too_large) << 0;
     break;
   }
   case '0': case '1': case '2': case '3':
@@ -182,7 +182,7 @@ static unsigned ProcessCharEscape(const char *ThisTokBegin,
     if (CharWidth != 32 && (ResultChar >> CharWidth) != 0) {
       if (Diags)
         Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
-             diag::err_octal_escape_too_large);
+             diag::err_escape_too_large) << 1;
       ResultChar &= ~0U >> (32-CharWidth);
     }
     break;
@@ -538,7 +538,7 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
       // Done.
     } else if (isHexDigit(*s) && !(*s == 'e' || *s == 'E')) {
       PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin),
-              diag::err_invalid_decimal_digit) << StringRef(s, 1);
+              diag::err_invalid_digit) << StringRef(s, 1) << 0;
       hadError = true;
       return;
     } else if (*s == '.') {
@@ -613,7 +613,7 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
           break;
 
         if (!isFPConstant) {
-          // Allow i8, i16, i32, i64, and i128.
+          // Allow i8, i16, i32, and i64.
           switch (s[1]) {
           case '8':
             s += 2; // i8 suffix
@@ -623,9 +623,6 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
             if (s[2] == '6') {
               s += 3; // i16 suffix
               MicrosoftInteger = 16;
-            } else if (s[2] == '2' && s[3] == '8') {
-              s += 4; // i128 suffix
-              MicrosoftInteger = 128;
             }
             break;
           case '3':
@@ -683,9 +680,8 @@ NumericLiteralParser::NumericLiteralParser(StringRef TokSpelling,
 
     // Report an error if there are any.
     PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, SuffixBegin - ThisTokBegin),
-            isFPConstant ? diag::err_invalid_suffix_float_constant :
-                           diag::err_invalid_suffix_integer_constant)
-      << StringRef(SuffixBegin, ThisTokEnd-SuffixBegin);
+            diag::err_invalid_suffix_constant)
+      << StringRef(SuffixBegin, ThisTokEnd-SuffixBegin) << isFPConstant;
     hadError = true;
     return;
   }
@@ -770,7 +766,7 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
 
     if (noSignificand) {
       PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s - ThisTokBegin),
-        diag::err_hexconstant_requires_digits);
+        diag::err_hexconstant_requires) << 1;
       hadError = true;
       return;
     }
@@ -797,7 +793,7 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
         PP.Diag(TokLoc, diag::ext_hexconstant_invalid);
     } else if (saw_period) {
       PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
-              diag::err_hexconstant_requires_exponent);
+              diag::err_hexconstant_requires) << 0;
       hadError = true;
     }
     return;
@@ -821,7 +817,7 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
       // Done.
     } else if (isHexDigit(*s)) {
       PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
-              diag::err_invalid_binary_digit) << StringRef(s, 1);
+              diag::err_invalid_digit) << StringRef(s, 1) << 2;
       hadError = true;
     }
     // Other suffixes will be diagnosed by the caller.
@@ -851,7 +847,7 @@ void NumericLiteralParser::ParseNumberStartingWithZero(SourceLocation TokLoc) {
   // the code is using an incorrect base.
   if (isHexDigit(*s) && *s != 'e' && *s != 'E') {
     PP.Diag(PP.AdvanceToTokenCharacter(TokLoc, s-ThisTokBegin),
-            diag::err_invalid_octal_digit) << StringRef(s, 1);
+            diag::err_invalid_digit) << StringRef(s, 1) << 1;
     hadError = true;
     return;
   }
@@ -1420,10 +1416,23 @@ void StringLiteralParser::init(ArrayRef<Token> StringToks){
       ThisTokEnd -= ThisTokBuf - Prefix;
       assert(ThisTokEnd >= ThisTokBuf && "malformed raw string literal");
 
-      // Copy the string over
-      if (CopyStringFragment(StringToks[i], ThisTokBegin,
-                             StringRef(ThisTokBuf, ThisTokEnd - ThisTokBuf)))
-        hadError = true;
+      // C++14 [lex.string]p4: A source-file new-line in a raw string literal
+      // results in a new-line in the resulting execution string-literal.
+      StringRef RemainingTokenSpan(ThisTokBuf, ThisTokEnd - ThisTokBuf);
+      while (!RemainingTokenSpan.empty()) {
+        // Split the string literal on \r\n boundaries.
+        size_t CRLFPos = RemainingTokenSpan.find("\r\n");
+        StringRef BeforeCRLF = RemainingTokenSpan.substr(0, CRLFPos);
+        StringRef AfterCRLF = RemainingTokenSpan.substr(CRLFPos);
+
+        // Copy everything before the \r\n sequence into the string literal.
+        if (CopyStringFragment(StringToks[i], ThisTokBegin, BeforeCRLF))
+          hadError = true;
+
+        // Point into the \n inside the \r\n sequence and operate on the
+        // remaining portion of the literal.
+        RemainingTokenSpan = AfterCRLF.substr(1);
+      }
     } else {
       if (ThisTokBuf[0] != '"') {
         // The file may have come from PCH and then changed after loading the
diff --git a/lib/Lex/MacroInfo.cpp b/lib/Lex/MacroInfo.cpp
index 109b6c12b89b..0b4292fbeae5 100644
--- a/lib/Lex/MacroInfo.cpp
+++ b/lib/Lex/MacroInfo.cpp
@@ -154,16 +154,20 @@ void MacroInfo::dump() const {
     Out << ")";
   }
 
+  bool First = true;
   for (const Token &Tok : ReplacementTokens) {
-    Out << " ";
+    // Leading space is semantically meaningful in a macro definition,
+    // so preserve it in the dump output.
+    if (First || Tok.hasLeadingSpace())
+      Out << " ";
+    First = false;
+
     if (const char *Punc = tok::getPunctuatorSpelling(Tok.getKind()))
       Out << Punc;
-    else if (const char *Kwd = tok::getKeywordSpelling(Tok.getKind()))
-      Out << Kwd;
-    else if (Tok.is(tok::identifier))
-      Out << Tok.getIdentifierInfo()->getName();
     else if (Tok.isLiteral() && Tok.getLiteralData())
       Out << StringRef(Tok.getLiteralData(), Tok.getLength());
+    else if (auto *II = Tok.getIdentifierInfo())
+      Out << II->getName();
     else
       Out << Tok.getName();
   }
diff --git a/lib/Lex/ModuleMap.cpp b/lib/Lex/ModuleMap.cpp
index 96d3e4b8fe65..a7524028a229 100644
--- a/lib/Lex/ModuleMap.cpp
+++ b/lib/Lex/ModuleMap.cpp
@@ -231,11 +231,9 @@ static bool violatesPrivateInclude(Module *RequestingModule,
     assert((!IsPrivateRole || IsPrivate) && "inconsistent headers and roles");
   }
 #endif
-  return IsPrivateRole &&
-         // FIXME: Should we map RequestingModule to its top-level module here
-         //        too? This check is redundant with the isSubModuleOf check in
-         //        diagnoseHeaderInclusion.
-         RequestedModule->getTopLevelModule() != RequestingModule;
+  return IsPrivateRole && (!RequestingModule ||
+                           RequestedModule->getTopLevelModule() !=
+                               RequestingModule->getTopLevelModule());
 }
 
 static Module *getTopLevelOrNull(Module *M) {
@@ -261,11 +259,6 @@ void ModuleMap::diagnoseHeaderInclusion(Module *RequestingModule,
   HeadersMap::iterator Known = findKnownHeader(File);
   if (Known != Headers.end()) {
     for (const KnownHeader &Header : Known->second) {
-      // If 'File' is part of 'RequestingModule' we can definitely include it.
-      if (Header.getModule() &&
-          Header.getModule()->isSubModuleOf(RequestingModule))
-        return;
-
       // Remember private headers for later printing of a diagnostic.
       if (violatesPrivateInclude(RequestingModule, File, Header.getRole(),
                                  Header.getModule())) {
@@ -320,6 +313,10 @@ void ModuleMap::diagnoseHeaderInclusion(Module *RequestingModule,
 
 static bool isBetterKnownHeader(const ModuleMap::KnownHeader &New,
                                 const ModuleMap::KnownHeader &Old) {
+  // Prefer available modules.
+  if (New.getModule()->isAvailable() && !Old.getModule()->isAvailable())
+    return true;
+
   // Prefer a public header over a private header.
   if ((New.getRole() & ModuleMap::PrivateHeader) !=
       (Old.getRole() & ModuleMap::PrivateHeader))
@@ -349,15 +346,19 @@ ModuleMap::KnownHeader ModuleMap::findModuleForHeader(const FileEntry *File) {
       // Prefer a header from the current module over all others.
       if (H.getModule()->getTopLevelModule() == CompilingModule)
         return MakeResult(H);
-      // Cannot use a module if it is unavailable.
-      if (!H.getModule()->isAvailable())
-        continue;
       if (!Result || isBetterKnownHeader(H, Result))
         Result = H;
     }
     return MakeResult(Result);
   }
 
+  return MakeResult(findOrCreateModuleForHeaderInUmbrellaDir(File));
+}
+
+ModuleMap::KnownHeader
+ModuleMap::findOrCreateModuleForHeaderInUmbrellaDir(const FileEntry *File) {
+  assert(!Headers.count(File) && "already have a module for this header");
+
   SmallVector<const DirectoryEntry *, 2> SkippedDirs;
   KnownHeader H = findHeaderInUmbrellaDirs(File, SkippedDirs);
   if (H) {
@@ -418,19 +419,22 @@ ModuleMap::KnownHeader ModuleMap::findModuleForHeader(const FileEntry *File) {
         UmbrellaDirs[SkippedDirs[I]] = Result;
     }
 
-    Headers[File].push_back(KnownHeader(Result, NormalHeader));
-
-    // If a header corresponds to an unavailable module, don't report
-    // that it maps to anything.
-    if (!Result->isAvailable())
-      return KnownHeader();
-
-    return MakeResult(Headers[File].back());
+    KnownHeader Header(Result, NormalHeader);
+    Headers[File].push_back(Header);
+    return Header;
   }
 
   return KnownHeader();
 }
 
+ArrayRef<ModuleMap::KnownHeader>
+ModuleMap::findAllModulesForHeader(const FileEntry *File) const {
+  auto It = Headers.find(File);
+  if (It == Headers.end())
+    return None;
+  return It->second;
+}
+
 bool ModuleMap::isHeaderInUnavailableModule(const FileEntry *Header) const {
   return isHeaderUnavailableInModule(Header, nullptr);
 }
@@ -577,9 +581,18 @@ static void inferFrameworkLink(Module *Mod, const DirectoryEntry *FrameworkDir,
   SmallString<128> LibName;
   LibName += FrameworkDir->getName();
   llvm::sys::path::append(LibName, Mod->Name);
-  if (FileMgr.getFile(LibName)) {
-    Mod->LinkLibraries.push_back(Module::LinkLibrary(Mod->Name,
-                                                     /*IsFramework=*/true));
+
+  // The library name of a framework has more than one possible extension since
+  // the introduction of the text-based dynamic library format. We need to check
+  // for both before we give up.
+  static const char *frameworkExtensions[] = {"", ".tbd"};
+  for (const auto *extension : frameworkExtensions) {
+    llvm::sys::path::replace_extension(LibName, extension);
+    if (FileMgr.getFile(LibName)) {
+      Mod->LinkLibraries.push_back(Module::LinkLibrary(Mod->Name,
+                                                       /*IsFramework=*/true));
+      return;
+    }
   }
 }
 
@@ -785,15 +798,27 @@ static Module::HeaderKind headerRoleToKind(ModuleMap::ModuleHeaderRole Role) {
 }
 
 void ModuleMap::addHeader(Module *Mod, Module::Header Header,
-                          ModuleHeaderRole Role) {
-  if (!(Role & TextualHeader)) {
-    bool isCompilingModuleHeader = Mod->getTopLevelModule() == CompilingModule;
+                          ModuleHeaderRole Role, bool Imported) {
+  KnownHeader KH(Mod, Role);
+
+  // Only add each header to the headers list once.
+  // FIXME: Should we diagnose if a header is listed twice in the
+  // same module definition?
+  auto &HeaderList = Headers[Header.Entry];
+  for (auto H : HeaderList)
+    if (H == KH)
+      return;
+
+  HeaderList.push_back(KH);
+  Mod->Headers[headerRoleToKind(Role)].push_back(std::move(Header));
+
+  bool isCompilingModuleHeader = Mod->getTopLevelModule() == CompilingModule;
+  if (!Imported || isCompilingModuleHeader) {
+    // When we import HeaderFileInfo, the external source is expected to
+    // set the isModuleHeader flag itself.
     HeaderInfo.MarkFileModuleHeader(Header.Entry, Role,
                                     isCompilingModuleHeader);
   }
-  Headers[Header.Entry].push_back(KnownHeader(Mod, Role));
-
-  Mod->Headers[headerRoleToKind(Role)].push_back(std::move(Header));
 }
 
 void ModuleMap::excludeHeader(Module *Mod, Module::Header Header) {
@@ -1015,7 +1040,17 @@ namespace clang {
     
     /// \brief The active module.
     Module *ActiveModule;
-    
+
+    /// \brief Whether a module uses the 'requires excluded' hack to mark its
+    /// contents as 'textual'.
+    ///
+    /// On older Darwin SDK versions, 'requires excluded' is used to mark the
+    /// contents of the Darwin.C.excluded (assert.h) and Tcl.Private modules as
+    /// non-modular headers.  For backwards compatibility, we continue to
+    /// support this idiom for just these modules, and map the headers to
+    /// 'textual' to match the original intent.
+    llvm::SmallPtrSet<Module *, 2> UsesRequiresExcludedHack;
+
     /// \brief Consume the current token and return its location.
     SourceLocation consumeToken();
     
@@ -1570,6 +1605,38 @@ void ModuleMapParser::parseExternModuleDecl() {
             : File->getDir(), ExternLoc);
 }
 
+/// Whether to add the requirement \p Feature to the module \p M.
+///
+/// This preserves backwards compatibility for two hacks in the Darwin system
+/// module map files:
+///
+/// 1. The use of 'requires excluded' to make headers non-modular, which
+///    should really be mapped to 'textual' now that we have this feature.  We
+///    drop the 'excluded' requirement, and set \p IsRequiresExcludedHack to
+///    true.  Later, this bit will be used to map all the headers inside this
+///    module to 'textual'.
+///
+///    This affects Darwin.C.excluded (for assert.h) and Tcl.Private.
+///
+/// 2. Removes a bogus cplusplus requirement from IOKit.avc.  This requirement
+///    was never correct and causes issues now that we check it, so drop it.
+static bool shouldAddRequirement(Module *M, StringRef Feature,
+                                 bool &IsRequiresExcludedHack) {
+  static const StringRef DarwinCExcluded[] = {"Darwin", "C", "excluded"};
+  static const StringRef TclPrivate[] = {"Tcl", "Private"};
+  static const StringRef IOKitAVC[] = {"IOKit", "avc"};
+
+  if (Feature == "excluded" && (M->fullModuleNameIs(DarwinCExcluded) ||
+                                M->fullModuleNameIs(TclPrivate))) {
+    IsRequiresExcludedHack = true;
+    return false;
+  } else if (Feature == "cplusplus" && M->fullModuleNameIs(IOKitAVC)) {
+    return false;
+  }
+
+  return true;
+}
+
 /// \brief Parse a requires declaration.
 ///
 ///   requires-declaration:
@@ -1605,9 +1672,18 @@ void ModuleMapParser::parseRequiresDecl() {
     std::string Feature = Tok.getString();
     consumeToken();
 
-    // Add this feature.
-    ActiveModule->addRequirement(Feature, RequiredState,
-                                 Map.LangOpts, *Map.Target);
+    bool IsRequiresExcludedHack = false;
+    bool ShouldAddRequirement =
+        shouldAddRequirement(ActiveModule, Feature, IsRequiresExcludedHack);
+
+    if (IsRequiresExcludedHack)
+      UsesRequiresExcludedHack.insert(ActiveModule);
+
+    if (ShouldAddRequirement) {
+      // Add this feature.
+      ActiveModule->addRequirement(Feature, RequiredState, Map.LangOpts,
+                                   *Map.Target);
+    }
 
     if (!Tok.is(MMToken::Comma))
       break;
@@ -1657,9 +1733,16 @@ void ModuleMapParser::parseHeaderDecl(MMToken::TokenKind LeadingToken,
       consumeToken();
     }
   }
+
   if (LeadingToken == MMToken::TextualKeyword)
     Role = ModuleMap::ModuleHeaderRole(Role | ModuleMap::TextualHeader);
 
+  if (UsesRequiresExcludedHack.count(ActiveModule)) {
+    // Mark this header 'textual' (see doc comment for
+    // Module::UsesRequiresExcludedHack).
+    Role = ModuleMap::ModuleHeaderRole(Role | ModuleMap::TextualHeader);
+  }
+
   if (LeadingToken != MMToken::HeaderKeyword) {
     if (!Tok.is(MMToken::HeaderKeyword)) {
       Diags.Report(Tok.getLocation(), diag::err_mmap_expected_header)
@@ -1797,6 +1880,11 @@ void ModuleMapParser::parseHeaderDecl(MMToken::TokenKind LeadingToken,
   }
 }
 
+static int compareModuleHeaders(const Module::Header *A,
+                                const Module::Header *B) {
+  return A->NameAsWritten.compare(B->NameAsWritten);
+}
+
 /// \brief Parse an umbrella directory declaration.
 ///
 ///   umbrella-dir-declaration:
@@ -1838,14 +1926,38 @@ void ModuleMapParser::parseUmbrellaDirDecl(SourceLocation UmbrellaLoc) {
     HadError = true;
     return;
   }
-  
+
+  if (UsesRequiresExcludedHack.count(ActiveModule)) {
+    // Mark this header 'textual' (see doc comment for
+    // ModuleMapParser::UsesRequiresExcludedHack). Although iterating over the
+    // directory is relatively expensive, in practice this only applies to the
+    // uncommonly used Tcl module on Darwin platforms.
+    std::error_code EC;
+    SmallVector<Module::Header, 6> Headers;
+    for (llvm::sys::fs::recursive_directory_iterator I(Dir->getName(), EC), E;
+         I != E && !EC; I.increment(EC)) {
+      if (const FileEntry *FE = SourceMgr.getFileManager().getFile(I->path())) {
+
+        Module::Header Header = {I->path(), FE};
+        Headers.push_back(std::move(Header));
+      }
+    }
+
+    // Sort header paths so that the pcm doesn't depend on iteration order.
+    llvm::array_pod_sort(Headers.begin(), Headers.end(), compareModuleHeaders);
+
+    for (auto &Header : Headers)
+      Map.addHeader(ActiveModule, std::move(Header), ModuleMap::TextualHeader);
+    return;
+  }
+
   if (Module *OwningModule = Map.UmbrellaDirs[Dir]) {
     Diags.Report(UmbrellaLoc, diag::err_mmap_umbrella_clash)
       << OwningModule->getFullModuleName();
     HadError = true;
     return;
-  } 
-  
+  }
+
   // Record this umbrella directory.
   Map.setUmbrellaDir(ActiveModule, Dir, DirName);
 }
@@ -2335,9 +2447,14 @@ bool ModuleMap::parseModuleMapFile(const FileEntry *File, bool IsSystem,
 
   // Parse this module map file.
   Lexer L(ID, SourceMgr.getBuffer(ID), SourceMgr, MMapLangOpts);
+  SourceLocation Start = L.getSourceLocation();
   ModuleMapParser Parser(L, SourceMgr, Target, Diags, *this, File, Dir,
                          BuiltinIncludeDir, IsSystem);
   bool Result = Parser.parseModuleMapFile();
   ParsedModuleMap[File] = Result;
+
+  // Notify callbacks that we parsed it.
+  for (const auto &Cb : Callbacks)
+    Cb->moduleMapFileRead(Start, *File, IsSystem);
   return Result;
 }
diff --git a/lib/Lex/PPDirectives.cpp b/lib/Lex/PPDirectives.cpp
index ce64538de41b..c02a0cb8d302 100644
--- a/lib/Lex/PPDirectives.cpp
+++ b/lib/Lex/PPDirectives.cpp
@@ -611,6 +611,8 @@ const FileEntry *Preprocessor::LookupFile(
     SmallVectorImpl<char> *RelativePath,
     ModuleMap::KnownHeader *SuggestedModule,
     bool SkipCache) {
+  Module *RequestingModule = getModuleForLocation(FilenameLoc); 
+
   // If the header lookup mechanism may be relative to the current inclusion
   // stack, record the parent #includes.
   SmallVector<std::pair<const FileEntry *, const DirectoryEntry *>, 16>
@@ -648,8 +650,7 @@ const FileEntry *Preprocessor::LookupFile(
       for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) {
         IncludeStackInfo &ISEntry = IncludeMacroStack[e - i - 1];
         if (IsFileLexer(ISEntry))
-          if ((FileEnt = SourceMgr.getFileEntryForID(
-                   ISEntry.ThePPLexer->getFileID())))
+          if ((FileEnt = ISEntry.ThePPLexer->getFileEntry()))
             Includers.push_back(std::make_pair(FileEnt, FileEnt->getDir()));
       }
     }
@@ -664,8 +665,8 @@ const FileEntry *Preprocessor::LookupFile(
     const DirectoryLookup *TmpFromDir = nullptr;
     while (const FileEntry *FE = HeaderInfo.LookupFile(
                Filename, FilenameLoc, isAngled, TmpFromDir, TmpCurDir,
-               Includers, SearchPath, RelativePath, SuggestedModule,
-               SkipCache)) {
+               Includers, SearchPath, RelativePath, RequestingModule,
+               SuggestedModule, SkipCache)) {
       // Keep looking as if this file did a #include_next.
       TmpFromDir = TmpCurDir;
       ++TmpFromDir;
@@ -681,11 +682,11 @@ const FileEntry *Preprocessor::LookupFile(
   // Do a standard file entry lookup.
   const FileEntry *FE = HeaderInfo.LookupFile(
       Filename, FilenameLoc, isAngled, FromDir, CurDir, Includers, SearchPath,
-      RelativePath, SuggestedModule, SkipCache);
+      RelativePath, RequestingModule, SuggestedModule, SkipCache);
   if (FE) {
     if (SuggestedModule && !LangOpts.AsmPreprocessor)
       HeaderInfo.getModuleMap().diagnoseHeaderInclusion(
-          getModuleForLocation(FilenameLoc), FilenameLoc, Filename, FE);
+          RequestingModule, FilenameLoc, Filename, FE);
     return FE;
   }
 
@@ -694,13 +695,14 @@ const FileEntry *Preprocessor::LookupFile(
   // to one of the headers on the #include stack.  Walk the list of the current
   // headers on the #include stack and pass them to HeaderInfo.
   if (IsFileLexer()) {
-    if ((CurFileEnt = SourceMgr.getFileEntryForID(CurPPLexer->getFileID()))) {
+    if ((CurFileEnt = CurPPLexer->getFileEntry())) {
       if ((FE = HeaderInfo.LookupSubframeworkHeader(Filename, CurFileEnt,
                                                     SearchPath, RelativePath,
+                                                    RequestingModule,
                                                     SuggestedModule))) {
         if (SuggestedModule && !LangOpts.AsmPreprocessor)
           HeaderInfo.getModuleMap().diagnoseHeaderInclusion(
-              getModuleForLocation(FilenameLoc), FilenameLoc, Filename, FE);
+              RequestingModule, FilenameLoc, Filename, FE);
         return FE;
       }
     }
@@ -709,14 +711,13 @@ const FileEntry *Preprocessor::LookupFile(
   for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) {
     IncludeStackInfo &ISEntry = IncludeMacroStack[e-i-1];
     if (IsFileLexer(ISEntry)) {
-      if ((CurFileEnt =
-           SourceMgr.getFileEntryForID(ISEntry.ThePPLexer->getFileID()))) {
+      if ((CurFileEnt = ISEntry.ThePPLexer->getFileEntry())) {
         if ((FE = HeaderInfo.LookupSubframeworkHeader(
                 Filename, CurFileEnt, SearchPath, RelativePath,
-                SuggestedModule))) {
+                RequestingModule, SuggestedModule))) {
           if (SuggestedModule && !LangOpts.AsmPreprocessor)
             HeaderInfo.getModuleMap().diagnoseHeaderInclusion(
-                getModuleForLocation(FilenameLoc), FilenameLoc, Filename, FE);
+                RequestingModule, FilenameLoc, Filename, FE);
           return FE;
         }
       }
@@ -1674,6 +1675,29 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
           getLangOpts().CurrentModule &&
       SuggestedModule.getModule()->getTopLevelModuleName() !=
           getLangOpts().ImplementationOfModule) {
+
+    // If this include corresponds to a module but that module is
+    // unavailable, diagnose the situation and bail out.
+    if (!SuggestedModule.getModule()->isAvailable()) {
+      clang::Module::Requirement Requirement;
+      clang::Module::UnresolvedHeaderDirective MissingHeader;
+      Module *M = SuggestedModule.getModule();
+      // Identify the cause.
+      (void)M->isAvailable(getLangOpts(), getTargetInfo(), Requirement,
+                           MissingHeader);
+      if (MissingHeader.FileNameLoc.isValid()) {
+        Diag(MissingHeader.FileNameLoc, diag::err_module_header_missing)
+            << MissingHeader.IsUmbrella << MissingHeader.FileName;
+      } else {
+        Diag(M->DefinitionLoc, diag::err_module_unavailable)
+            << M->getFullModuleName() << Requirement.second << Requirement.first;
+      }
+      Diag(FilenameTok.getLocation(),
+           diag::note_implicit_top_level_module_import_here)
+          << M->getTopLevelModuleName();
+      return;
+    }
+
     // Compute the module access path corresponding to this module.
     // FIXME: Should we have a second loadModule() overload to avoid this
     // extra lookup step?
@@ -1776,7 +1800,7 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
   if (IncludePos.isMacroID())
     IncludePos = SourceMgr.getExpansionRange(IncludePos).second;
   FileID FID = SourceMgr.createFileID(File, IncludePos, FileCharacter);
-  assert(!FID.isInvalid() && "Expected valid file ID");
+  assert(FID.isValid() && "Expected valid file ID");
 
   // If all is good, enter the new file!
   if (EnterSourceFile(FID, CurDir, FilenameTok.getLocation()))
@@ -1925,7 +1949,7 @@ bool Preprocessor::ReadMacroDefinitionArgList(MacroInfo *MI, Token &Tok) {
       // Add the __VA_ARGS__ identifier as an argument.
       Arguments.push_back(Ident__VA_ARGS__);
       MI->setIsC99Varargs();
-      MI->setArgumentList(&Arguments[0], Arguments.size(), BP);
+      MI->setArgumentList(Arguments, BP);
       return false;
     case tok::eod:  // #define X(
       Diag(Tok, diag::err_pp_missing_rparen_in_macro_def);
@@ -1959,7 +1983,7 @@ bool Preprocessor::ReadMacroDefinitionArgList(MacroInfo *MI, Token &Tok) {
         Diag(Tok, diag::err_pp_expected_comma_in_arg_list);
         return true;
       case tok::r_paren: // #define X(A)
-        MI->setArgumentList(&Arguments[0], Arguments.size(), BP);
+        MI->setArgumentList(Arguments, BP);
         return false;
       case tok::comma:  // #define X(A,
         break;
@@ -1975,7 +1999,7 @@ bool Preprocessor::ReadMacroDefinitionArgList(MacroInfo *MI, Token &Tok) {
         }
 
         MI->setIsGNUVarargs();
-        MI->setArgumentList(&Arguments[0], Arguments.size(), BP);
+        MI->setArgumentList(Arguments, BP);
         return false;
       }
     }
@@ -2019,13 +2043,9 @@ static bool isConfigurationPattern(Token &MacroName, MacroInfo *MI,
   }
 
   // #define inline
-  if (MacroName.isOneOf(tok::kw_extern, tok::kw_inline, tok::kw_static,
-                        tok::kw_const) &&
-      MI->getNumTokens() == 0) {
-    return true;
-  }
-
-  return false;
+  return MacroName.isOneOf(tok::kw_extern, tok::kw_inline, tok::kw_static,
+                           tok::kw_const) &&
+         MI->getNumTokens() == 0;
 }
 
 /// HandleDefineDirective - Implements \#define.  This consumes the entire macro
@@ -2240,6 +2260,30 @@ void Preprocessor::HandleDefineDirective(Token &DefineTok,
   // Finally, if this identifier already had a macro defined for it, verify that
   // the macro bodies are identical, and issue diagnostics if they are not.
   if (const MacroInfo *OtherMI=getMacroInfo(MacroNameTok.getIdentifierInfo())) {
+    // In Objective-C, ignore attempts to directly redefine the builtin
+    // definitions of the ownership qualifiers.  It's still possible to
+    // #undef them.
+    auto isObjCProtectedMacro = [](const IdentifierInfo *II) -> bool {
+      return II->isStr("__strong") ||
+             II->isStr("__weak") ||
+             II->isStr("__unsafe_unretained") ||
+             II->isStr("__autoreleasing");
+    };
+   if (getLangOpts().ObjC1 &&
+        SourceMgr.getFileID(OtherMI->getDefinitionLoc())
+          == getPredefinesFileID() &&
+        isObjCProtectedMacro(MacroNameTok.getIdentifierInfo())) {
+      // Warn if it changes the tokens.
+      if ((!getDiagnostics().getSuppressSystemWarnings() ||
+           !SourceMgr.isInSystemHeader(DefineTok.getLocation())) &&
+          !MI->isIdenticalTo(*OtherMI, *this,
+                             /*Syntactic=*/LangOpts.MicrosoftExt)) {
+        Diag(MI->getDefinitionLoc(), diag::warn_pp_objc_macro_redef_ignored);
+      }
+      assert(!OtherMI->isWarnIfUnused());
+      return;
+    }
+
     // It is very common for system headers to have tons of macro redefinitions
     // and for warnings to be disabled in system headers.  If this is the case,
     // then don't bother calling MacroInfo::isIdenticalTo.
diff --git a/lib/Lex/PPExpressions.cpp b/lib/Lex/PPExpressions.cpp
index 44513023395d..c40598c06756 100644
--- a/lib/Lex/PPExpressions.cpp
+++ b/lib/Lex/PPExpressions.cpp
@@ -42,7 +42,7 @@ public:
   unsigned getBitWidth() const { return Val.getBitWidth(); }
   bool isUnsigned() const { return Val.isUnsigned(); }
 
-  const SourceRange &getRange() const { return Range; }
+  SourceRange getRange() const { return Range; }
 
   void setRange(SourceLocation L) { Range.setBegin(L); Range.setEnd(L); }
   void setRange(SourceLocation B, SourceLocation E) {
@@ -549,12 +549,12 @@ static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
       // value was negative, warn about it.
       if (ValueLive && Res.isUnsigned()) {
         if (!LHS.isUnsigned() && LHS.Val.isNegative())
-          PP.Diag(OpLoc, diag::warn_pp_convert_lhs_to_positive)
+          PP.Diag(OpLoc, diag::warn_pp_convert_to_positive) << 0
             << LHS.Val.toString(10, true) + " to " +
                LHS.Val.toString(10, false)
             << LHS.getRange() << RHS.getRange();
         if (!RHS.isUnsigned() && RHS.Val.isNegative())
-          PP.Diag(OpLoc, diag::warn_pp_convert_rhs_to_positive)
+          PP.Diag(OpLoc, diag::warn_pp_convert_to_positive) << 1
             << RHS.Val.toString(10, true) + " to " +
                RHS.Val.toString(10, false)
             << LHS.getRange() << RHS.getRange();
diff --git a/lib/Lex/PPLexerChange.cpp b/lib/Lex/PPLexerChange.cpp
index c231e18eecc3..2f09841c5b5d 100644
--- a/lib/Lex/PPLexerChange.cpp
+++ b/lib/Lex/PPLexerChange.cpp
@@ -18,6 +18,7 @@
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/MacroInfo.h"
+#include "clang/Lex/PTHManager.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/MemoryBuffer.h"
@@ -120,7 +121,7 @@ void Preprocessor::EnterSourceFileWithLexer(Lexer *TheLexer,
   CurSubmodule = nullptr;
   if (CurLexerKind != CLK_LexAfterModuleImport)
     CurLexerKind = CLK_Lexer;
-  
+
   // Notify the client, if desired, that we are in a new source file.
   if (Callbacks && !CurLexer->Is_PragmaLexer) {
     SrcMgr::CharacteristicKind FileType =
@@ -300,8 +301,7 @@ bool Preprocessor::HandleEndOfFile(Token &Result, bool isEndOfMacro) {
     if (const IdentifierInfo *ControllingMacro =
           CurPPLexer->MIOpt.GetControllingMacroAtEndOfFile()) {
       // Okay, this has a controlling macro, remember in HeaderFileInfo.
-      if (const FileEntry *FE =
-            SourceMgr.getFileEntryForID(CurPPLexer->getFileID())) {
+      if (const FileEntry *FE = CurPPLexer->getFileEntry()) {
         HeaderInfo.SetFileControllingMacro(FE, ControllingMacro);
         if (MacroInfo *MI =
               getMacroInfo(const_cast<IdentifierInfo*>(ControllingMacro))) {
@@ -561,7 +561,6 @@ void Preprocessor::RemoveTopOfLexerStack() {
 void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) {
   assert(CurTokenLexer && !CurPPLexer &&
          "Pasted comment can only be formed from macro");
-
   // We handle this by scanning for the closest real lexer, switching it to
   // raw mode and preprocessor mode.  This will cause it to return \n as an
   // explicit EOD token.
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 64ce8c918258..18348df0a39e 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -145,8 +145,12 @@ void Preprocessor::updateModuleMacroInfo(const IdentifierInfo *II,
     NumHiddenOverrides[O] = -1;
 
   // Collect all macros that are not overridden by a visible macro.
-  llvm::SmallVector<ModuleMacro *, 16> Worklist(Leaf->second.begin(),
-                                                Leaf->second.end());
+  llvm::SmallVector<ModuleMacro *, 16> Worklist;
+  for (auto *LeafMM : Leaf->second) {
+    assert(LeafMM->getNumOverridingMacros() == 0 && "leaf macro overridden");
+    if (NumHiddenOverrides.lookup(LeafMM) == 0)
+      Worklist.push_back(LeafMM);
+  }
   while (!Worklist.empty()) {
     auto *MM = Worklist.pop_back_val();
     if (CurSubmoduleState->VisibleModules.isVisible(MM->getOwningModule())) {
@@ -593,9 +597,7 @@ static bool CheckMatchedBrackets(const SmallVectorImpl<Token> &Tokens) {
       Brackets.pop_back();
     }
   }
-  if (!Brackets.empty())
-    return false;
-  return true;
+  return Brackets.empty();
 }
 
 /// GenerateNewArgTokens - Returns true if OldTokens can be converted to a new
@@ -867,7 +869,7 @@ MacroArgs *Preprocessor::ReadFunctionLikeMacroArgs(Token &MacroName,
         DiagnosticBuilder DB =
             Diag(MacroName,
                  diag::note_init_list_at_beginning_of_macro_argument);
-        for (const SourceRange &Range : InitLists)
+        for (SourceRange Range : InitLists)
           DB << Range;
       }
       return nullptr;
@@ -876,7 +878,7 @@ MacroArgs *Preprocessor::ReadFunctionLikeMacroArgs(Token &MacroName,
       return nullptr;
 
     DiagnosticBuilder DB = Diag(MacroName, diag::note_suggest_parens_for_macro);
-    for (const SourceRange &ParenLocation : ParenHints) {
+    for (SourceRange ParenLocation : ParenHints) {
       DB << FixItHint::CreateInsertion(ParenLocation.getBegin(), "(");
       DB << FixItHint::CreateInsertion(ParenLocation.getEnd(), ")");
     }
@@ -1057,6 +1059,9 @@ static bool HasFeature(const Preprocessor &PP, const IdentifierInfo *II) {
       .Case("attribute_availability", true)
       .Case("attribute_availability_with_message", true)
       .Case("attribute_availability_app_extension", true)
+      .Case("attribute_availability_with_version_underscores", true)
+      .Case("attribute_availability_tvos", true)
+      .Case("attribute_availability_watchos", true)
       .Case("attribute_cf_returns_not_retained", true)
       .Case("attribute_cf_returns_retained", true)
       .Case("attribute_cf_returns_on_parameters", true)
@@ -1075,7 +1080,7 @@ static bool HasFeature(const Preprocessor &PP, const IdentifierInfo *II) {
       .Case("blocks", LangOpts.Blocks)
       .Case("c_thread_safety_attributes", true)
       .Case("cxx_exceptions", LangOpts.CXXExceptions)
-      .Case("cxx_rtti", LangOpts.RTTI)
+      .Case("cxx_rtti", LangOpts.RTTI && LangOpts.RTTIData)
       .Case("enumerator_attributes", true)
       .Case("nullability", true)
       .Case("memory_sanitizer", LangOpts.Sanitize.has(SanitizerKind::Memory))
@@ -1084,7 +1089,7 @@ static bool HasFeature(const Preprocessor &PP, const IdentifierInfo *II) {
       // Objective-C features
       .Case("objc_arr", LangOpts.ObjCAutoRefCount) // FIXME: REMOVE?
       .Case("objc_arc", LangOpts.ObjCAutoRefCount)
-      .Case("objc_arc_weak", LangOpts.ObjCARCWeak)
+      .Case("objc_arc_weak", LangOpts.ObjCWeak)
       .Case("objc_default_synthesize_properties", LangOpts.ObjC2)
       .Case("objc_fixed_enum", LangOpts.ObjC2)
       .Case("objc_instancetype", LangOpts.ObjC2)
@@ -1629,16 +1634,23 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
       Value = FeatureII->getTokenID() == tok::identifier;
     else if (II == Ident__has_builtin) {
       // Check for a builtin is trivial.
-      Value = FeatureII->getBuiltinID() != 0;
+      if (FeatureII->getBuiltinID() != 0) {
+        Value = true;
+      } else {
+        StringRef Feature = FeatureII->getName();
+        Value = llvm::StringSwitch<bool>(Feature)
+                    .Case("__make_integer_seq", getLangOpts().CPlusPlus)
+                    .Default(false);
+      }
     } else if (II == Ident__has_attribute)
       Value = hasAttribute(AttrSyntax::GNU, nullptr, FeatureII,
-                           getTargetInfo().getTriple(), getLangOpts());
+                           getTargetInfo(), getLangOpts());
     else if (II == Ident__has_cpp_attribute)
       Value = hasAttribute(AttrSyntax::CXX, ScopeII, FeatureII,
-                           getTargetInfo().getTriple(), getLangOpts());
+                           getTargetInfo(), getLangOpts());
     else if (II == Ident__has_declspec)
       Value = hasAttribute(AttrSyntax::Declspec, nullptr, FeatureII,
-                           getTargetInfo().getTriple(), getLangOpts());
+                           getTargetInfo(), getLangOpts());
     else if (II == Ident__has_extension)
       Value = HasExtension(*this, FeatureII);
     else {
diff --git a/lib/Lex/Pragma.cpp b/lib/Lex/Pragma.cpp
index 5eb665549e86..3134790ccb90 100644
--- a/lib/Lex/Pragma.cpp
+++ b/lib/Lex/Pragma.cpp
@@ -38,7 +38,7 @@ PragmaHandler::~PragmaHandler() {
 // EmptyPragmaHandler Implementation.
 //===----------------------------------------------------------------------===//
 
-EmptyPragmaHandler::EmptyPragmaHandler() {}
+EmptyPragmaHandler::EmptyPragmaHandler(StringRef Name) : PragmaHandler(Name) {}
 
 void EmptyPragmaHandler::HandlePragma(Preprocessor &PP, 
                                       PragmaIntroducerKind Introducer,
@@ -191,9 +191,13 @@ void Preprocessor::Handle_Pragma(Token &Tok) {
   Lex(Tok);
   if (!tok::isStringLiteral(Tok.getKind())) {
     Diag(PragmaLoc, diag::err__Pragma_malformed);
-    // Skip this token, and the ')', if present.
+    // Skip bad tokens, and the ')', if present.
     if (Tok.isNot(tok::r_paren) && Tok.isNot(tok::eof))
       Lex(Tok);
+    while (Tok.isNot(tok::r_paren) &&
+           !Tok.isAtStartOfLine() &&
+           Tok.isNot(tok::eof))
+      Lex(Tok);
     if (Tok.is(tok::r_paren))
       Lex(Tok);
     return _PragmaLexing.failed();
diff --git a/lib/Lex/PreprocessingRecord.cpp b/lib/Lex/PreprocessingRecord.cpp
index a423041a2d95..32e6de69f0db 100644
--- a/lib/Lex/PreprocessingRecord.cpp
+++ b/lib/Lex/PreprocessingRecord.cpp
@@ -66,7 +66,7 @@ PreprocessingRecord::getPreprocessedEntitiesInRange(SourceRange Range) {
 
 static bool isPreprocessedEntityIfInFileID(PreprocessedEntity *PPE, FileID FID,
                                            SourceManager &SM) {
-  assert(!FID.isInvalid());
+  assert(FID.isValid());
   if (!PPE)
     return false;
 
diff --git a/lib/Lex/Preprocessor.cpp b/lib/Lex/Preprocessor.cpp
index e2db638a33d0..142d9ce09049 100644
--- a/lib/Lex/Preprocessor.cpp
+++ b/lib/Lex/Preprocessor.cpp
@@ -38,6 +38,7 @@
 #include "clang/Lex/MacroArgs.h"
 #include "clang/Lex/MacroInfo.h"
 #include "clang/Lex/ModuleLoader.h"
+#include "clang/Lex/PTHManager.h"
 #include "clang/Lex/Pragma.h"
 #include "clang/Lex/PreprocessingRecord.h"
 #include "clang/Lex/PreprocessorOptions.h"
@@ -62,20 +63,19 @@ Preprocessor::Preprocessor(IntrusiveRefCntPtr<PreprocessorOptions> PPOpts,
                            IdentifierInfoLookup *IILookup, bool OwnsHeaders,
                            TranslationUnitKind TUKind)
     : PPOpts(PPOpts), Diags(&diags), LangOpts(opts), Target(nullptr),
-      FileMgr(Headers.getFileMgr()), SourceMgr(SM),
-      ScratchBuf(new ScratchBuffer(SourceMgr)),HeaderInfo(Headers),
+      AuxTarget(nullptr), FileMgr(Headers.getFileMgr()), SourceMgr(SM),
+      ScratchBuf(new ScratchBuffer(SourceMgr)), HeaderInfo(Headers),
       TheModuleLoader(TheModuleLoader), ExternalSource(nullptr),
       Identifiers(opts, IILookup),
       PragmaHandlers(new PragmaNamespace(StringRef())),
-      IncrementalProcessing(false), TUKind(TUKind),
-      CodeComplete(nullptr), CodeCompletionFile(nullptr),
-      CodeCompletionOffset(0), LastTokenWasAt(false),
-      ModuleImportExpectsIdentifier(false), CodeCompletionReached(0),
-      MainFileDir(nullptr), SkipMainFilePreamble(0, true), CurPPLexer(nullptr),
-      CurDirLookup(nullptr), CurLexerKind(CLK_Lexer), CurSubmodule(nullptr),
-      Callbacks(nullptr), CurSubmoduleState(&NullSubmoduleState),
-      MacroArgCache(nullptr), Record(nullptr),
-      MIChainHead(nullptr), DeserialMIChainHead(nullptr) {
+      IncrementalProcessing(false), TUKind(TUKind), CodeComplete(nullptr),
+      CodeCompletionFile(nullptr), CodeCompletionOffset(0),
+      LastTokenWasAt(false), ModuleImportExpectsIdentifier(false),
+      CodeCompletionReached(0), MainFileDir(nullptr),
+      SkipMainFilePreamble(0, true), CurPPLexer(nullptr), CurDirLookup(nullptr),
+      CurLexerKind(CLK_Lexer), CurSubmodule(nullptr), Callbacks(nullptr),
+      CurSubmoduleState(&NullSubmoduleState), MacroArgCache(nullptr),
+      Record(nullptr), MIChainHead(nullptr), DeserialMIChainHead(nullptr) {
   OwnsHeaderSearch = OwnsHeaders;
   
   CounterValue = 0; // __COUNTER__ starts at 0.
@@ -170,13 +170,18 @@ Preprocessor::~Preprocessor() {
     delete &HeaderInfo;
 }
 
-void Preprocessor::Initialize(const TargetInfo &Target) {
+void Preprocessor::Initialize(const TargetInfo &Target,
+                              const TargetInfo *AuxTarget) {
   assert((!this->Target || this->Target == &Target) &&
          "Invalid override of target information");
   this->Target = &Target;
-  
+
+  assert((!this->AuxTarget || this->AuxTarget == AuxTarget) &&
+         "Invalid override of aux target information.");
+  this->AuxTarget = AuxTarget;
+
   // Initialize information about built-ins.
-  BuiltinInfo.InitializeTarget(Target);
+  BuiltinInfo.InitializeTarget(Target, AuxTarget);
   HeaderInfo.setTarget(Target);
 }
 
@@ -515,7 +520,7 @@ void Preprocessor::EnterMainSourceFile() {
     llvm::MemoryBuffer::getMemBufferCopy(Predefines, "<built-in>");
   assert(SB && "Cannot create predefined source buffer");
   FileID FID = SourceMgr.createFileID(std::move(SB));
-  assert(!FID.isInvalid() && "Could not create FileID for predefines?");
+  assert(FID.isValid() && "Could not create FileID for predefines?");
   setPredefinesFileID(FID);
 
   // Start parsing the predefines.
@@ -712,7 +717,7 @@ bool Preprocessor::HandleIdentifier(Token &Identifier) {
 }
 
 void Preprocessor::Lex(Token &Result) {
-  // We loop here until a lex function retuns a token; this avoids recursion.
+  // We loop here until a lex function returns a token; this avoids recursion.
   bool ReturnedToken;
   do {
     switch (CurLexerKind) {
diff --git a/lib/Lex/TokenLexer.cpp b/lib/Lex/TokenLexer.cpp
index e7512fa2831a..c42966928e52 100644
--- a/lib/Lex/TokenLexer.cpp
+++ b/lib/Lex/TokenLexer.cpp
@@ -624,21 +624,22 @@ bool TokenLexer::PasteTokens(Token &Tok) {
       // error.  This occurs with "x ## +"  and other stuff.  Return with Tok
       // unmodified and with RHS as the next token to lex.
       if (isInvalid) {
+        // Explicitly convert the token location to have proper expansion
+        // information so that the user knows where it came from.
+        SourceManager &SM = PP.getSourceManager();
+        SourceLocation Loc =
+          SM.createExpansionLoc(PasteOpLoc, ExpandLocStart, ExpandLocEnd, 2);
+
         // Test for the Microsoft extension of /##/ turning into // here on the
         // error path.
         if (PP.getLangOpts().MicrosoftExt && Tok.is(tok::slash) &&
             RHS.is(tok::slash)) {
-          HandleMicrosoftCommentPaste(Tok);
+          HandleMicrosoftCommentPaste(Tok, Loc);
           return true;
         }
 
         // Do not emit the error when preprocessing assembler code.
         if (!PP.getLangOpts().AsmPreprocessor) {
-          // Explicitly convert the token location to have proper expansion
-          // information so that the user knows where it came from.
-          SourceManager &SM = PP.getSourceManager();
-          SourceLocation Loc =
-            SM.createExpansionLoc(PasteOpLoc, ExpandLocStart, ExpandLocEnd, 2);
           // If we're in microsoft extensions mode, downgrade this from a hard
           // error to an extension that defaults to an error.  This allows
           // disabling it.
@@ -719,7 +720,9 @@ bool TokenLexer::isParsingPreprocessorDirective() const {
 /// macro, other active macros, and anything left on the current physical
 /// source line of the expanded buffer.  Handle this by returning the
 /// first token on the next line.
-void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok) {
+void TokenLexer::HandleMicrosoftCommentPaste(Token &Tok, SourceLocation OpLoc) {
+  PP.Diag(OpLoc, diag::ext_comment_paste_microsoft);
+
   // We 'comment out' the rest of this macro by just ignoring the rest of the
   // tokens that have not been lexed yet, if any.