Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release:

MFC r309142 (by emaste):

Add WITH_LLD_AS_LD build knob

If set it installs LLD as /usr/bin/ld.  LLD (as of version 3.9) is not
capable of linking the world and kernel, but can self-host and link many
substantial applications. GNU ld continues to be used for the world and
kernel build, regardless of how this knob is set.

It is on by default for arm64, and off for all other CPU architectures.

Sponsored by:	The FreeBSD Foundation

MFC r310840:

Reapply 310775, now it also builds correctly if lldb is disabled:

Move llvm-objdump from CLANG_EXTRAS to installed by default

We currently install three tools from binutils 2.17.50: as, ld, and
objdump. Work is underway to migrate to a permissively-licensed
tool-chain, with one goal being the retirement of binutils 2.17.50.

LLVM's llvm-objdump is intended to be compatible with GNU objdump
although it is currently missing some options and may have formatting
differences. Enable it by default for testing and further investigation.
It may later be changed to install as /usr/bin/objdump, it becomes a
fully viable replacement.

Reviewed by:	emaste
Differential Revision:	https://reviews.freebsd.org/D8879

MFC r312855 (by emaste):

Rename LLD_AS_LD to LLD_IS_LD, for consistency with CLANG_IS_CC

Reported by:	Dan McGregor <dan.mcgregor usask.ca>

MFC r313559 | glebius | 2017-02-10 18:34:48 +0100 (Fri, 10 Feb 2017) | 5 lines

Don't check struct rtentry on FreeBSD, it is an internal kernel structure.
On other systems it may be API structure for SIOCADDRT/SIOCDELRT.

Reviewed by:	emaste, dim

MFC r314152 (by jkim):

Remove an assembler flag, which is redundant since r309124.  The upstream
took care of it by introducing a macro NO_EXEC_STACK_DIRECTIVE.

http://llvm.org/viewvc/llvm-project?rev=273500&view=rev

Reviewed by:	dim

MFC r314564:

Upgrade our copies of clang, llvm, lld, lldb, compiler-rt and libc++ to
4.0.0 (branches/release_40 296509).  The release will follow soon.

Please note that from 3.5.0 onwards, clang, llvm and lldb require C++11
support to build; see UPDATING for more information.

Also note that as of 4.0.0, lld should be able to link the base system
on amd64 and aarch64.  See the WITH_LLD_IS_LLD setting in src.conf(5).
Though please be aware that this is work in progress.

Release notes for llvm, clang and lld will be available here:
<http://releases.llvm.org/4.0.0/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/clang/docs/ReleaseNotes.html>
<http://releases.llvm.org/4.0.0/tools/lld/docs/ReleaseNotes.html>

Thanks to Ed Maste, Jan Beich, Antoine Brodin and Eric Fiselier for
their help.

Relnotes:	yes
Exp-run:	antoine
PR:		215969, 216008

MFC r314708:

For now, revert r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

This commit is the cause of excessive compile times on skein_block.c
(and possibly other files) during kernel builds on amd64.

We never saw the problematic behavior described in this upstream commit,
so for now it is better to revert it.  An upstream bug has been filed
here: https://bugs.llvm.org/show_bug.cgi?id=32142

Reported by:	mjg

MFC r314795:

Reapply r287232 from upstream llvm trunk (by Daniil Fukalov):

  [SCEV] limit recursion depth of CompareSCEVComplexity

  Summary:
  CompareSCEVComplexity goes too deep (50+ on a quite a big unrolled
  loop) and runs almost infinite time.

  Added cache of "equal" SCEV pairs to earlier cutoff of further
  estimation. Recursion depth limit was also introduced as a parameter.

  Reviewers: sanjoy

  Subscribers: mzolotukhin, tstellarAMD, llvm-commits

  Differential Revision: https://reviews.llvm.org/D26389

Pull in r296992 from upstream llvm trunk (by Sanjoy Das):

  [SCEV] Decrease the recursion threshold for CompareValueComplexity

  Fixes PR32142.

  r287232 accidentally increased the recursion threshold for
  CompareValueComplexity from 2 to 32.  This change reverses that
  change by introducing a separate flag for CompareValueComplexity's
  threshold.

The latter revision fixes the excessive compile times for skein_block.c.

MFC r314907 | mmel | 2017-03-08 12:40:27 +0100 (Wed, 08 Mar 2017) | 7 lines

Unbreak ARMv6 world.

The new compiler_rt library imported with clang 4.0.0 have several fatal
issues (non-functional __udivsi3 for example) with ARM specific instrict
functions. As temporary workaround, until upstream solve these problems,
disable all thumb[1][2] related feature.

MFC r315016:

Update clang, llvm, lld, lldb, compiler-rt and libc++ to 4.0.0 release.
We were already very close to the last release candidate, so this is a
pretty minor update.

Relnotes:	yes

MFC r316005:

Revert r314907, and pull in r298713 from upstream compiler-rt trunk (by
Weiming Zhao):

  builtins: Select correct code fragments when compiling for Thumb1/Thum2/ARM ISA.

  Summary:
  Value of __ARM_ARCH_ISA_THUMB isn't based on the actual compilation
  mode (-mthumb, -marm), it reflect's capability of given CPU.

  Due to this:
   - use  __tbumb__ and __thumb2__ insteand of __ARM_ARCH_ISA_THUMB
   - use '.thumb' directive consistently  in all affected files
   - decorate all thumb functions using
     DEFINE_COMPILERRT_THUMB_FUNCTION()

  ---------
  Note: This patch doesn't fix broken Thumb1 variant of __udivsi3 !

  Reviewers: weimingz, rengolin, compnerd

  Subscribers: aemerson, dim

  Differential Revision: https://reviews.llvm.org/D30938

Discussed with:	mmel

17 files changed, 629 insertions, 249 deletions

diff --git a/contrib/llvm/tools/clang/lib/Lex/HeaderMap.cpp b/contrib/llvm/tools/clang/lib/Lex/HeaderMap.cpp
index 4cace5b..24a14b6 100644
--- a/contrib/llvm/tools/clang/lib/Lex/HeaderMap.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/HeaderMap.cpp
@@ -106,7 +106,7 @@ bool HeaderMapImpl::checkHeader(const llvm::MemoryBuffer &File,
 
 
 /// getFileName - Return the filename of the headermap.
-const char *HeaderMapImpl::getFileName() const {
+StringRef HeaderMapImpl::getFileName() const {
   return FileBuffer->getBufferIdentifier();
 }
 
diff --git a/contrib/llvm/tools/clang/lib/Lex/HeaderSearch.cpp b/contrib/llvm/tools/clang/lib/Lex/HeaderSearch.cpp
index e5cc30e..c667f4b 100644
--- a/contrib/llvm/tools/clang/lib/Lex/HeaderSearch.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/HeaderSearch.cpp
@@ -26,7 +26,6 @@
 #include "llvm/Support/Capacity.h"
 #include "llvm/Support/FileSystem.h"
 #include "llvm/Support/Path.h"
-#include "llvm/Support/raw_ostream.h"
 #include <cstdio>
 #include <utility>
 #if defined(LLVM_ON_UNIX)
@@ -37,9 +36,12 @@ using namespace clang;
 const IdentifierInfo *
 HeaderFileInfo::getControllingMacro(ExternalPreprocessorSource *External) {
   if (ControllingMacro) {
-    if (ControllingMacro->isOutOfDate())
+    if (ControllingMacro->isOutOfDate()) {
+      assert(External && "We must have an external source if we have a "
+                         "controlling macro that is out of date.");
       External->updateOutOfDateIdentifier(
           *const_cast<IdentifierInfo *>(ControllingMacro));
+    }
     return ControllingMacro;
   }
 
@@ -52,7 +54,7 @@ HeaderFileInfo::getControllingMacro(ExternalPreprocessorSource *External) {
 
 ExternalHeaderFileInfoSource::~ExternalHeaderFileInfoSource() {}
 
-HeaderSearch::HeaderSearch(IntrusiveRefCntPtr<HeaderSearchOptions> HSOpts,
+HeaderSearch::HeaderSearch(std::shared_ptr<HeaderSearchOptions> HSOpts,
                            SourceManager &SourceMgr, DiagnosticsEngine &Diags,
                            const LangOptions &LangOpts,
                            const TargetInfo *Target)
@@ -119,14 +121,39 @@ const HeaderMap *HeaderSearch::CreateHeaderMap(const FileEntry *FE) {
   return nullptr;
 }
 
+/// \brief Get filenames for all registered header maps.
+void HeaderSearch::getHeaderMapFileNames(
+    SmallVectorImpl<std::string> &Names) const {
+  for (auto &HM : HeaderMaps)
+    Names.push_back(HM.first->getName());
+}
+
 std::string HeaderSearch::getModuleFileName(Module *Module) {
   const FileEntry *ModuleMap =
       getModuleMap().getModuleMapFileForUniquing(Module);
-  return getModuleFileName(Module->Name, ModuleMap->getName());
+  return getModuleFileName(Module->Name, ModuleMap->getName(),
+                           /*UsePrebuiltPath*/false);
 }
 
 std::string HeaderSearch::getModuleFileName(StringRef ModuleName,
-                                            StringRef ModuleMapPath) {
+                                            StringRef ModuleMapPath,
+                                            bool UsePrebuiltPath) {
+  if (UsePrebuiltPath) {
+    if (HSOpts->PrebuiltModulePaths.empty())
+      return std::string();
+
+    // Go though each prebuilt module path and try to find the pcm file.
+    for (const std::string &Dir : HSOpts->PrebuiltModulePaths) {
+      SmallString<256> Result(Dir);
+      llvm::sys::fs::make_absolute(Result);
+
+      llvm::sys::path::append(Result, ModuleName + ".pcm");
+      if (getFileMgr().getFile(Result.str()))
+        return Result.str().str();
+    }
+    return std::string();
+  }
+
   // If we don't have a module cache path or aren't supposed to use one, we
   // can't do anything.
   if (getModuleCachePath().empty())
@@ -167,16 +194,36 @@ Module *HeaderSearch::lookupModule(StringRef ModuleName, bool AllowSearch) {
   Module *Module = ModMap.findModule(ModuleName);
   if (Module || !AllowSearch || !HSOpts->ImplicitModuleMaps)
     return Module;
-  
+
+  StringRef SearchName = ModuleName;
+  Module = lookupModule(ModuleName, SearchName);
+
+  // The facility for "private modules" -- adjacent, optional module maps named
+  // module.private.modulemap that are supposed to define private submodules --
+  // is sometimes misused by frameworks that name their associated private
+  // module FooPrivate, rather than as a submodule named Foo.Private as
+  // intended. Here we compensate for such cases by looking in directories named
+  // Foo.framework, when we previously looked and failed to find a
+  // FooPrivate.framework.
+  if (!Module && SearchName.consume_back("Private"))
+    Module = lookupModule(ModuleName, SearchName);
+  return Module;
+}
+
+Module *HeaderSearch::lookupModule(StringRef ModuleName, StringRef SearchName) {
+  Module *Module = nullptr;
+
   // Look through the various header search paths to load any available module
   // maps, searching for a module map that describes this module.
   for (unsigned Idx = 0, N = SearchDirs.size(); Idx != N; ++Idx) {
     if (SearchDirs[Idx].isFramework()) {
-      // Search for or infer a module map for a framework.
+      // Search for or infer a module map for a framework. Here we use
+      // SearchName rather than ModuleName, to permit finding private modules
+      // named FooPrivate in buggy frameworks named Foo.
       SmallString<128> FrameworkDirName;
       FrameworkDirName += SearchDirs[Idx].getFrameworkDir()->getName();
-      llvm::sys::path::append(FrameworkDirName, ModuleName + ".framework");
-      if (const DirectoryEntry *FrameworkDir 
+      llvm::sys::path::append(FrameworkDirName, SearchName + ".framework");
+      if (const DirectoryEntry *FrameworkDir
             = FileMgr.getDirectory(FrameworkDirName)) {
         bool IsSystem
           = SearchDirs[Idx].getDirCharacteristic() != SrcMgr::C_User;
@@ -240,7 +287,7 @@ Module *HeaderSearch::lookupModule(StringRef ModuleName, bool AllowSearch) {
 
 /// getName - Return the directory or filename corresponding to this lookup
 /// object.
-const char *DirectoryLookup::getName() const {
+StringRef DirectoryLookup::getName() const {
   if (isNormalDir())
     return getDir()->getName();
   if (isFramework())
@@ -396,6 +443,12 @@ getTopFrameworkDir(FileManager &FileMgr, StringRef DirName,
   return TopFrameworkDir;
 }
 
+static bool needModuleLookup(Module *RequestingModule,
+                             bool HasSuggestedModule) {
+  return HasSuggestedModule ||
+         (RequestingModule && RequestingModule->NoUndeclaredIncludes);
+}
+
 /// DoFrameworkLookup - Do a lookup of the specified file in the current
 /// DirectoryLookup, which is a framework directory.
 const FileEntry *DirectoryLookup::DoFrameworkLookup(
@@ -491,7 +544,7 @@ const FileEntry *DirectoryLookup::DoFrameworkLookup(
   }
 
   // If we found the header and are allowed to suggest a module, do so now.
-  if (FE && SuggestedModule) {
+  if (FE && needModuleLookup(RequestingModule, SuggestedModule)) {
     // Find the framework in which this header occurs.
     StringRef FrameworkPath = FE->getDir()->getName();
     bool FoundFramework = false;
@@ -830,17 +883,19 @@ LookupSubframeworkHeader(StringRef Filename,
   if (SlashPos == StringRef::npos) return nullptr;
 
   // Look up the base framework name of the ContextFileEnt.
-  const char *ContextName = ContextFileEnt->getName();
+  StringRef ContextName = ContextFileEnt->getName();
 
   // If the context info wasn't a framework, couldn't be a subframework.
   const unsigned DotFrameworkLen = 10;
-  const char *FrameworkPos = strstr(ContextName, ".framework");
-  if (FrameworkPos == nullptr ||
-      (FrameworkPos[DotFrameworkLen] != '/' && 
-       FrameworkPos[DotFrameworkLen] != '\\'))
+  auto FrameworkPos = ContextName.find(".framework");
+  if (FrameworkPos == StringRef::npos ||
+      (ContextName[FrameworkPos + DotFrameworkLen] != '/' &&
+       ContextName[FrameworkPos + DotFrameworkLen] != '\\'))
     return nullptr;
 
-  SmallString<1024> FrameworkName(ContextName, FrameworkPos+DotFrameworkLen+1);
+  SmallString<1024> FrameworkName(ContextName.data(), ContextName.data() +
+                                                          FrameworkPos +
+                                                          DotFrameworkLen + 1);
 
   // Append Frameworks/HIToolbox.framework/
   FrameworkName += "Frameworks/";
@@ -1037,13 +1092,51 @@ void HeaderSearch::MarkFileModuleHeader(const FileEntry *FE,
 }
 
 bool HeaderSearch::ShouldEnterIncludeFile(Preprocessor &PP,
-                                          const FileEntry *File,
-                                          bool isImport, Module *M) {
+                                          const FileEntry *File, bool isImport,
+                                          bool ModulesEnabled, Module *M) {
   ++NumIncluded; // Count # of attempted #includes.
 
   // Get information about this file.
   HeaderFileInfo &FileInfo = getFileInfo(File);
 
+  // FIXME: this is a workaround for the lack of proper modules-aware support
+  // for #import / #pragma once
+  auto TryEnterImported = [&](void) -> bool {
+    if (!ModulesEnabled)
+      return false;
+    // Modules with builtins are special; multiple modules use builtins as
+    // modular headers, example:
+    //
+    //    module stddef { header "stddef.h" export * }
+    //
+    // After module map parsing, this expands to:
+    //
+    //    module stddef {
+    //      header "/path_to_builtin_dirs/stddef.h"
+    //      textual "stddef.h"
+    //    }
+    //
+    // It's common that libc++ and system modules will both define such
+    // submodules. Make sure cached results for a builtin header won't
+    // prevent other builtin modules to potentially enter the builtin header.
+    // Note that builtins are header guarded and the decision to actually
+    // enter them is postponed to the controlling macros logic below.
+    bool TryEnterHdr = false;
+    if (FileInfo.isCompilingModuleHeader && FileInfo.isModuleHeader)
+      TryEnterHdr = File->getDir() == ModMap.getBuiltinDir() &&
+                    ModuleMap::isBuiltinHeader(
+                        llvm::sys::path::filename(File->getName()));
+
+    // Textual headers can be #imported from different modules. Since ObjC
+    // headers find in the wild might rely only on #import and do not contain
+    // controlling macros, be conservative and only try to enter textual headers
+    // if such macro is present.
+    if (!FileInfo.isModuleHeader &&
+        FileInfo.getControllingMacro(ExternalLookup))
+      TryEnterHdr = true;
+    return TryEnterHdr;
+  };
+
   // If this is a #import directive, check that we have not already imported
   // this header.
   if (isImport) {
@@ -1051,11 +1144,12 @@ bool HeaderSearch::ShouldEnterIncludeFile(Preprocessor &PP,
     FileInfo.isImport = true;
 
     // Has this already been #import'ed or #include'd?
-    if (FileInfo.NumIncludes) return false;
+    if (FileInfo.NumIncludes && !TryEnterImported())
+      return false;
   } else {
     // Otherwise, if this is a #include of a file that was previously #import'd
     // or if this is the second #include of a #pragma once file, ignore it.
-    if (FileInfo.isImport)
+    if (FileInfo.isImport && !TryEnterImported())
       return false;
   }
 
@@ -1139,22 +1233,45 @@ bool HeaderSearch::hasModuleMap(StringRef FileName,
 }
 
 ModuleMap::KnownHeader
-HeaderSearch::findModuleForHeader(const FileEntry *File) const {
+HeaderSearch::findModuleForHeader(const FileEntry *File,
+                                  bool AllowTextual) 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)getExistingFileInfo(File);
   }
-  return ModMap.findModuleForHeader(File);
+  return ModMap.findModuleForHeader(File, AllowTextual);
+}
+
+static bool suggestModule(HeaderSearch &HS, const FileEntry *File,
+                          Module *RequestingModule,
+                          ModuleMap::KnownHeader *SuggestedModule) {
+  ModuleMap::KnownHeader Module =
+      HS.findModuleForHeader(File, /*AllowTextual*/true);
+  if (SuggestedModule)
+    *SuggestedModule = (Module.getRole() & ModuleMap::TextualHeader)
+                           ? ModuleMap::KnownHeader()
+                           : Module;
+
+  // If this module specifies [no_undeclared_includes], we cannot find any
+  // file that's in a non-dependency module.
+  if (RequestingModule && Module && RequestingModule->NoUndeclaredIncludes) {
+    HS.getModuleMap().resolveUses(RequestingModule, /*Complain*/false);
+    if (!RequestingModule->directlyUses(Module.getModule())) {
+      return false;
+    }
+  }
+
+  return true;
 }
 
 bool HeaderSearch::findUsableModuleForHeader(
     const FileEntry *File, const DirectoryEntry *Root, Module *RequestingModule,
     ModuleMap::KnownHeader *SuggestedModule, bool IsSystemHeaderDir) {
-  if (File && SuggestedModule) {
+  if (File && needModuleLookup(RequestingModule, SuggestedModule)) {
     // If there is a module that corresponds to this header, suggest it.
     hasModuleMap(File->getName(), Root, IsSystemHeaderDir);
-    *SuggestedModule = findModuleForHeader(File);
+    return suggestModule(*this, File, RequestingModule, SuggestedModule);
   }
   return true;
 }
@@ -1163,7 +1280,7 @@ 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) {
+  if (needModuleLookup(RequestingModule, SuggestedModule)) {
     // Find the top-level framework based on this framework.
     SmallVector<std::string, 4> SubmodulePath;
     const DirectoryEntry *TopFrameworkDir
@@ -1180,7 +1297,7 @@ bool HeaderSearch::findUsableModuleForFrameworkHeader(
     // 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 suggestModule(*this, File, RequestingModule, SuggestedModule);
   }
   return true;
 }
@@ -1432,7 +1549,7 @@ std::string HeaderSearch::suggestPathToFileForDiagnostics(const FileEntry *File,
   // FIXME: We assume that the path name currently cached in the FileEntry is
   // the most appropriate one for this analysis (and that it's spelled the same
   // way as the corresponding header search path).
-  const char *Name = File->getName();
+  StringRef Name = File->getName();
 
   unsigned BestPrefixLength = 0;
   unsigned BestSearchDir;
@@ -1442,7 +1559,7 @@ std::string HeaderSearch::suggestPathToFileForDiagnostics(const FileEntry *File,
     if (!SearchDirs[I].isNormalDir())
       continue;
 
-    const char *Dir = SearchDirs[I].getDir()->getName();
+    StringRef Dir = SearchDirs[I].getDir()->getName();
     for (auto NI = llvm::sys::path::begin(Name),
               NE = llvm::sys::path::end(Name),
               DI = llvm::sys::path::begin(Dir),
@@ -1475,5 +1592,5 @@ std::string HeaderSearch::suggestPathToFileForDiagnostics(const FileEntry *File,
 
   if (IsSystem)
     *IsSystem = BestPrefixLength ? BestSearchDir >= SystemDirIdx : false;
-  return Name + BestPrefixLength;
+  return Name.drop_front(BestPrefixLength);
 }
diff --git a/contrib/llvm/tools/clang/lib/Lex/Lexer.cpp b/contrib/llvm/tools/clang/lib/Lex/Lexer.cpp
index 9c2a016..6025a66 100644
--- a/contrib/llvm/tools/clang/lib/Lex/Lexer.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/Lexer.cpp
@@ -14,18 +14,27 @@
 #include "clang/Lex/Lexer.h"
 #include "UnicodeCharSets.h"
 #include "clang/Basic/CharInfo.h"
+#include "clang/Basic/IdentifierTable.h"
 #include "clang/Basic/SourceManager.h"
-#include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/LiteralSupport.h"
 #include "clang/Lex/Preprocessor.h"
-#include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/Compiler.h"
 #include "llvm/Support/ConvertUTF.h"
+#include "llvm/Support/MathExtras.h"
 #include "llvm/Support/MemoryBuffer.h"
+#include "llvm/Support/UnicodeCharRanges.h"
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdint>
 #include <cstring>
+#include <string>
+#include <tuple>
+#include <utility>
+
 using namespace clang;
 
 //===----------------------------------------------------------------------===//
@@ -45,7 +54,6 @@ tok::ObjCKeywordKind Token::getObjCKeywordID() const {
   return specId ? specId->getObjCKeywordID() : tok::objc_not_keyword;
 }
 
-
 //===----------------------------------------------------------------------===//
 // Lexer Class Implementation
 //===----------------------------------------------------------------------===//
@@ -196,7 +204,6 @@ Lexer *Lexer::Create_PragmaLexer(SourceLocation SpellingLoc,
   return L;
 }
 
-
 /// Stringify - Convert the specified string into a C string, with surrounding
 /// ""'s, and with escaped \ and " characters.
 std::string Lexer::Stringify(StringRef Str, bool Charify) {
@@ -398,7 +405,6 @@ unsigned Lexer::getSpelling(const Token &Tok, const char *&Buffer,
   return getSpellingSlow(Tok, TokStart, LangOpts, const_cast<char*>(Buffer));
 }
 
-
 /// MeasureTokenLength - Relex the token at the specified location and return
 /// its length in bytes in the input file.  If the token needs cleaning (e.g.
 /// includes a trigraph or an escaped newline) then this count includes bytes
@@ -526,13 +532,15 @@ SourceLocation Lexer::GetBeginningOfToken(SourceLocation Loc,
 }
 
 namespace {
+
   enum PreambleDirectiveKind {
     PDK_Skipped,
     PDK_StartIf,
     PDK_EndIf,
     PDK_Unknown
   };
-}
+
+} // end anonymous namespace
 
 std::pair<unsigned, bool> Lexer::ComputePreamble(StringRef Buffer,
                                                  const LangOptions &LangOpts,
@@ -694,7 +702,6 @@ std::pair<unsigned, bool> Lexer::ComputePreamble(StringRef Buffer,
                                : TheTok.isAtStartOfLine());
 }
 
-
 /// AdvanceToTokenCharacter - Given a location that specifies the start of a
 /// token, return a new location that specifies a character within the token.
 SourceLocation Lexer::AdvanceToTokenCharacter(SourceLocation TokStart,
@@ -961,7 +968,7 @@ StringRef Lexer::getImmediateMacroName(SourceLocation Loc,
   assert(Loc.isMacroID() && "Only reasonble to call this on macros");
 
   // Find the location of the immediate macro expansion.
-  while (1) {
+  while (true) {
     FileID FID = SM.getFileID(Loc);
     const SrcMgr::SLocEntry *E = &SM.getSLocEntry(FID);
     const SrcMgr::ExpansionInfo &Expansion = E->getExpansion();
@@ -1031,7 +1038,6 @@ bool Lexer::isIdentifierBodyChar(char c, const LangOptions &LangOpts) {
   return isIdentifierBody(c, LangOpts.DollarIdents);
 }
 
-
 //===----------------------------------------------------------------------===//
 // Diagnostics forwarding code.
 //===----------------------------------------------------------------------===//
@@ -1157,7 +1163,7 @@ unsigned Lexer::getEscapedNewLineSize(const char *Ptr) {
 /// them), skip over them and return the first non-escaped-newline found,
 /// otherwise return P.
 const char *Lexer::SkipEscapedNewLines(const char *P) {
-  while (1) {
+  while (true) {
     const char *AfterEscape;
     if (*P == '\\') {
       AfterEscape = P+1;
@@ -1310,7 +1316,6 @@ Slash:
   return *Ptr;
 }
 
-
 /// getCharAndSizeSlowNoWarn - Handle the slow/uncommon case of the
 /// getCharAndSizeNoWarn method.  Here we know that we can accumulate into Size,
 /// and that we have already incremented Ptr by Size bytes.
@@ -1480,13 +1485,13 @@ bool Lexer::tryConsumeIdentifierUCN(const char *&CurPtr, unsigned Size,
 
 bool Lexer::tryConsumeIdentifierUTF8Char(const char *&CurPtr) {
   const char *UnicodePtr = CurPtr;
-  UTF32 CodePoint;
-  ConversionResult Result =
-      llvm::convertUTF8Sequence((const UTF8 **)&UnicodePtr,
-                                (const UTF8 *)BufferEnd,
+  llvm::UTF32 CodePoint;
+  llvm::ConversionResult Result =
+      llvm::convertUTF8Sequence((const llvm::UTF8 **)&UnicodePtr,
+                                (const llvm::UTF8 *)BufferEnd,
                                 &CodePoint,
-                                strictConversion);
-  if (Result != conversionOK ||
+                                llvm::strictConversion);
+  if (Result != llvm::conversionOK ||
       !isAllowedIDChar(static_cast<uint32_t>(CodePoint), LangOpts))
     return false;
 
@@ -1533,14 +1538,22 @@ FinishIdentifier:
     // preprocessor, which may macro expand it or something.
     if (II->isHandleIdentifierCase())
       return PP->HandleIdentifier(Result);
-    
+
+    if (II->getTokenID() == tok::identifier && isCodeCompletionPoint(CurPtr)
+        && II->getPPKeywordID() == tok::pp_not_keyword
+        && II->getObjCKeywordID() == tok::objc_not_keyword) {
+      // Return the code-completion token.
+      Result.setKind(tok::code_completion);
+      cutOffLexing();
+      return true;
+    }
     return true;
   }
 
   // Otherwise, $,\,? in identifier found.  Enter slower path.
 
   C = getCharAndSize(CurPtr, Size);
-  while (1) {
+  while (true) {
     if (C == '$') {
       // If we hit a $ and they are not supported in identifiers, we are done.
       if (!LangOpts.DollarIdents) goto FinishIdentifier;
@@ -1700,9 +1713,9 @@ const char *Lexer::LexUDSuffix(Token &Result, const char *CurPtr,
                                          getLangOpts());
         if (!isIdentifierBody(Next)) {
           // End of suffix. Check whether this is on the whitelist.
-          IsUDSuffix = (Chars == 1 && Buffer[0] == 's') ||
-                       NumericLiteralParser::isValidUDSuffix(
-                           getLangOpts(), StringRef(Buffer, Chars));
+          const StringRef CompleteSuffix(Buffer, Chars);
+          IsUDSuffix = StringLiteralParser::isValidUDSuffix(getLangOpts(),
+                                                            CompleteSuffix);
           break;
         }
 
@@ -1829,7 +1842,7 @@ bool Lexer::LexRawStringLiteral(Token &Result, const char *CurPtr,
     // Search for the next '"' in hopes of salvaging the lexer. Unfortunately,
     // it's possible the '"' was intended to be part of the raw string, but
     // there's not much we can do about that.
-    while (1) {
+    while (true) {
       char C = *CurPtr++;
 
       if (C == '"')
@@ -1848,7 +1861,7 @@ bool Lexer::LexRawStringLiteral(Token &Result, const char *CurPtr,
   const char *Prefix = CurPtr;
   CurPtr += PrefixLen + 1; // skip over prefix and '('
 
-  while (1) {
+  while (true) {
     char C = *CurPtr++;
 
     if (C == ')') {
@@ -1913,7 +1926,6 @@ bool Lexer::LexAngledStringLiteral(Token &Result, const char *CurPtr) {
   return true;
 }
 
-
 /// LexCharConstant - Lex the remainder of a character constant, after having
 /// lexed either ' or L' or u8' or u' or U'.
 bool Lexer::LexCharConstant(Token &Result, const char *CurPtr,
@@ -1992,7 +2004,7 @@ bool Lexer::SkipWhitespace(Token &Result, const char *CurPtr,
   unsigned char Char = *CurPtr;
 
   // Skip consecutive spaces efficiently.
-  while (1) {
+  while (true) {
     // Skip horizontal whitespace very aggressively.
     while (isHorizontalWhitespace(Char))
       Char = *++CurPtr;
@@ -2315,7 +2327,7 @@ bool Lexer::SkipBlockComment(Token &Result, const char *CurPtr,
   if (C == '/')
     C = *CurPtr++;
 
-  while (1) {
+  while (true) {
     // Skip over all non-interesting characters until we find end of buffer or a
     // (probably ending) '/' character.
     if (CurPtr + 24 < BufferEnd &&
@@ -2456,7 +2468,7 @@ void Lexer::ReadToEndOfLine(SmallVectorImpl<char> *Result) {
 
   // CurPtr - Cache BufferPtr in an automatic variable.
   const char *CurPtr = BufferPtr;
-  while (1) {
+  while (true) {
     char Char = getAndAdvanceChar(CurPtr, Tmp);
     switch (Char) {
     default:
@@ -2669,7 +2681,6 @@ bool Lexer::IsStartOfConflictMarker(const char *CurPtr) {
   return false;
 }
 
-
 /// HandleEndOfConflictMarker - If this is a '====' or '||||' or '>>>>', or if
 /// it is '<<<<' and the conflict marker started with a '>>>>' marker, then it
 /// is the end of a conflict marker.  Handle it by ignoring up until the end of
@@ -3498,7 +3509,6 @@ LexNextToken:
         CurPtr = ConsumeChar(CurPtr, SizeTmp, Result);
         Kind = tok::greatergreater;
       }
-      
     } else {
       Kind = tok::greater;
     }
@@ -3615,17 +3625,17 @@ LexNextToken:
       break;
     }
 
-    UTF32 CodePoint;
+    llvm::UTF32 CodePoint;
 
     // We can't just reset CurPtr to BufferPtr because BufferPtr may point to
     // an escaped newline.
     --CurPtr;
-    ConversionResult Status =
-        llvm::convertUTF8Sequence((const UTF8 **)&CurPtr,
-                                  (const UTF8 *)BufferEnd,
+    llvm::ConversionResult Status =
+        llvm::convertUTF8Sequence((const llvm::UTF8 **)&CurPtr,
+                                  (const llvm::UTF8 *)BufferEnd,
                                   &CodePoint,
-                                  strictConversion);
-    if (Status == conversionOK) {
+                                  llvm::strictConversion);
+    if (Status == llvm::conversionOK) {
       if (CheckUnicodeWhitespace(Result, CodePoint, CurPtr)) {
         if (SkipWhitespace(Result, CurPtr, TokAtPhysicalStartOfLine))
           return true; // KeepWhitespaceMode
diff --git a/contrib/llvm/tools/clang/lib/Lex/LiteralSupport.cpp b/contrib/llvm/tools/clang/lib/Lex/LiteralSupport.cpp
index e68b82f..fbfd3fe 100644
--- a/contrib/llvm/tools/clang/lib/Lex/LiteralSupport.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/LiteralSupport.cpp
@@ -14,12 +14,25 @@
 
 #include "clang/Lex/LiteralSupport.h"
 #include "clang/Basic/CharInfo.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/LexDiagnostic.h"
+#include "clang/Lex/Lexer.h"
 #include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/Token.h"
+#include "llvm/ADT/APInt.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/ConvertUTF.h"
 #include "llvm/Support/ErrorHandling.h"
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstdint> 
+#include <cstring>
+#include <string>
 
 using namespace clang;
 
@@ -134,7 +147,7 @@ static unsigned ProcessCharEscape(const char *ThisTokBegin,
       if (Diags)
         Diag(Diags, Features, Loc, ThisTokBegin, EscapeBegin, ThisTokBuf,
              diag::err_hex_escape_no_digits) << "x";
-      HadError = 1;
+      HadError = true;
       break;
     }
 
@@ -389,7 +402,7 @@ static void EncodeUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
   if (CharByteWidth == 4) {
     // FIXME: Make the type of the result buffer correct instead of
     // using reinterpret_cast.
-    UTF32 *ResultPtr = reinterpret_cast<UTF32*>(ResultBuf);
+    llvm::UTF32 *ResultPtr = reinterpret_cast<llvm::UTF32*>(ResultBuf);
     *ResultPtr = UcnVal;
     ResultBuf += 4;
     return;
@@ -398,7 +411,7 @@ static void EncodeUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
   if (CharByteWidth == 2) {
     // FIXME: Make the type of the result buffer correct instead of
     // using reinterpret_cast.
-    UTF16 *ResultPtr = reinterpret_cast<UTF16*>(ResultBuf);
+    llvm::UTF16 *ResultPtr = reinterpret_cast<llvm::UTF16*>(ResultBuf);
 
     if (UcnVal <= (UTF32)0xFFFF) {
       *ResultPtr = UcnVal;
@@ -452,7 +465,6 @@ static void EncodeUCNEscape(const char *ThisTokBegin, const char *&ThisTokBuf,
   ResultBuf += bytesToWrite;
 }
 
-
 ///       integer-constant: [C99 6.4.4.1]
 ///         decimal-constant integer-suffix
 ///         octal-constant integer-suffix
@@ -985,7 +997,6 @@ NumericLiteralParser::GetFloatValue(llvm::APFloat &Result) {
   return Result.convertFromString(Str, APFloat::rmNearestTiesToEven);
 }
 
-
 /// \verbatim
 ///       user-defined-character-literal: [C++11 lex.ext]
 ///         character-literal ud-suffix
@@ -1103,11 +1114,11 @@ CharLiteralParser::CharLiteralParser(const char *begin, const char *end,
 
       char const *tmp_in_start = start;
       uint32_t *tmp_out_start = buffer_begin;
-      ConversionResult res =
-          ConvertUTF8toUTF32(reinterpret_cast<UTF8 const **>(&start),
-                             reinterpret_cast<UTF8 const *>(begin),
-                             &buffer_begin, buffer_end, strictConversion);
-      if (res != conversionOK) {
+      llvm::ConversionResult res =
+          llvm::ConvertUTF8toUTF32(reinterpret_cast<llvm::UTF8 const **>(&start),
+                             reinterpret_cast<llvm::UTF8 const *>(begin),
+                             &buffer_begin, buffer_end, llvm::strictConversion);
+      if (res != llvm::conversionOK) {
         // If we see bad encoding for unprefixed character literals, warn and
         // simply copy the byte values, for compatibility with gcc and
         // older versions of clang.
@@ -1499,13 +1510,13 @@ void StringLiteralParser::init(ArrayRef<Token> StringToks){
         if (CharByteWidth == 4) {
           // FIXME: Make the type of the result buffer correct instead of
           // using reinterpret_cast.
-          UTF32 *ResultWidePtr = reinterpret_cast<UTF32*>(ResultPtr);
+          llvm::UTF32 *ResultWidePtr = reinterpret_cast<llvm::UTF32*>(ResultPtr);
           *ResultWidePtr = ResultChar;
           ResultPtr += 4;
         } else if (CharByteWidth == 2) {
           // FIXME: Make the type of the result buffer correct instead of
           // using reinterpret_cast.
-          UTF16 *ResultWidePtr = reinterpret_cast<UTF16*>(ResultPtr);
+          llvm::UTF16 *ResultWidePtr = reinterpret_cast<llvm::UTF16*>(ResultPtr);
           *ResultWidePtr = ResultChar & 0xFFFF;
           ResultPtr += 2;
         } else {
@@ -1520,12 +1531,12 @@ void StringLiteralParser::init(ArrayRef<Token> StringToks){
     if (CharByteWidth == 4) {
       // FIXME: Make the type of the result buffer correct instead of
       // using reinterpret_cast.
-      UTF32 *ResultWidePtr = reinterpret_cast<UTF32*>(ResultBuf.data());
+      llvm::UTF32 *ResultWidePtr = reinterpret_cast<llvm::UTF32*>(ResultBuf.data());
       ResultWidePtr[0] = GetNumStringChars() - 1;
     } else if (CharByteWidth == 2) {
       // FIXME: Make the type of the result buffer correct instead of
       // using reinterpret_cast.
-      UTF16 *ResultWidePtr = reinterpret_cast<UTF16*>(ResultBuf.data());
+      llvm::UTF16 *ResultWidePtr = reinterpret_cast<llvm::UTF16*>(ResultBuf.data());
       ResultWidePtr[0] = GetNumStringChars() - 1;
     } else {
       assert(CharByteWidth == 1 && "Unexpected char width");
@@ -1559,7 +1570,7 @@ void StringLiteralParser::init(ArrayRef<Token> StringToks){
 static const char *resyncUTF8(const char *Err, const char *End) {
   if (Err == End)
     return End;
-  End = Err + std::min<unsigned>(getNumBytesForUTF8(*Err), End-Err);
+  End = Err + std::min<unsigned>(llvm::getNumBytesForUTF8(*Err), End-Err);
   while (++Err != End && (*Err & 0xC0) == 0x80)
     ;
   return Err;
@@ -1571,7 +1582,7 @@ static const char *resyncUTF8(const char *Err, const char *End) {
 bool StringLiteralParser::CopyStringFragment(const Token &Tok,
                                              const char *TokBegin,
                                              StringRef Fragment) {
-  const UTF8 *ErrorPtrTmp;
+  const llvm::UTF8 *ErrorPtrTmp;
   if (ConvertUTF8toWide(CharByteWidth, Fragment, ResultPtr, ErrorPtrTmp))
     return false;
 
@@ -1697,3 +1708,12 @@ unsigned StringLiteralParser::getOffsetOfStringByte(const Token &Tok,
 
   return SpellingPtr-SpellingStart;
 }
+
+/// Determine whether a suffix is a valid ud-suffix. We avoid treating reserved
+/// suffixes as ud-suffixes, because the diagnostic experience is better if we
+/// treat it as an invalid suffix.
+bool StringLiteralParser::isValidUDSuffix(const LangOptions &LangOpts,
+                                          StringRef Suffix) {
+  return NumericLiteralParser::isValidUDSuffix(LangOpts, Suffix) ||
+         Suffix == "sv";
+}
diff --git a/contrib/llvm/tools/clang/lib/Lex/MacroInfo.cpp b/contrib/llvm/tools/clang/lib/Lex/MacroInfo.cpp
index 2ef4387..924613d 100644
--- a/contrib/llvm/tools/clang/lib/Lex/MacroInfo.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/MacroInfo.cpp
@@ -240,6 +240,6 @@ ModuleMacro *ModuleMacro::create(Preprocessor &PP, Module *OwningModule,
                                  ArrayRef<ModuleMacro *> Overrides) {
   void *Mem = PP.getPreprocessorAllocator().Allocate(
       sizeof(ModuleMacro) + sizeof(ModuleMacro *) * Overrides.size(),
-      llvm::alignOf<ModuleMacro>());
+      alignof(ModuleMacro));
   return new (Mem) ModuleMacro(OwningModule, II, Macro, Overrides);
 }
diff --git a/contrib/llvm/tools/clang/lib/Lex/ModuleMap.cpp b/contrib/llvm/tools/clang/lib/Lex/ModuleMap.cpp
index 3e3215d..1488f62 100644
--- a/contrib/llvm/tools/clang/lib/Lex/ModuleMap.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/ModuleMap.cpp
@@ -144,7 +144,7 @@ static StringRef sanitizeFilenameAsIdentifier(StringRef Name,
 /// \brief Determine whether the given file name is the name of a builtin
 /// header, supplied by Clang to replace, override, or augment existing system
 /// headers.
-static bool isBuiltinHeader(StringRef FileName) {
+bool ModuleMap::isBuiltinHeader(StringRef FileName) {
   return llvm::StringSwitch<bool>(FileName)
            .Case("float.h", true)
            .Case("iso646.h", true)
@@ -165,7 +165,7 @@ ModuleMap::findKnownHeader(const FileEntry *File) {
   HeadersMap::iterator Known = Headers.find(File);
   if (HeaderInfo.getHeaderSearchOpts().ImplicitModuleMaps &&
       Known == Headers.end() && File->getDir() == BuiltinIncludeDir &&
-      isBuiltinHeader(llvm::sys::path::filename(File->getName()))) {
+      ModuleMap::isBuiltinHeader(llvm::sys::path::filename(File->getName()))) {
     HeaderInfo.loadTopLevelSystemModules();
     return Headers.find(File);
   }
@@ -297,11 +297,14 @@ void ModuleMap::diagnoseHeaderInclusion(Module *RequestingModule,
   if (LangOpts.ModulesStrictDeclUse) {
     Diags.Report(FilenameLoc, diag::err_undeclared_use_of_module)
         << RequestingModule->getFullModuleName() << Filename;
-  } else if (RequestingModule && RequestingModuleIsModuleInterface) {
+  } else if (RequestingModule && RequestingModuleIsModuleInterface &&
+             LangOpts.isCompilingModule()) {
+    // Do not diagnose when we are not compiling a module. 
     diag::kind DiagID = RequestingModule->getTopLevelModule()->IsFramework ?
         diag::warn_non_modular_include_in_framework_module :
         diag::warn_non_modular_include_in_module;
-    Diags.Report(FilenameLoc, DiagID) << RequestingModule->getFullModuleName();
+    Diags.Report(FilenameLoc, DiagID) << RequestingModule->getFullModuleName()
+        << File->getName();
   }
 }
 
@@ -325,9 +328,10 @@ static bool isBetterKnownHeader(const ModuleMap::KnownHeader &New,
   return false;
 }
 
-ModuleMap::KnownHeader ModuleMap::findModuleForHeader(const FileEntry *File) {
+ModuleMap::KnownHeader ModuleMap::findModuleForHeader(const FileEntry *File,
+                                                      bool AllowTextual) {
   auto MakeResult = [&](ModuleMap::KnownHeader R) -> ModuleMap::KnownHeader {
-    if (R.getRole() & ModuleMap::TextualHeader)
+    if (!AllowTextual && R.getRole() & ModuleMap::TextualHeader)
       return ModuleMap::KnownHeader();
     return R;
   };
@@ -442,9 +446,19 @@ ModuleMap::isHeaderUnavailableInModule(const FileEntry *Header,
              I = Known->second.begin(),
              E = Known->second.end();
          I != E; ++I) {
-      if (I->isAvailable() && (!RequestingModule ||
-                               I->getModule()->isSubModuleOf(RequestingModule)))
+
+      if (I->isAvailable() &&
+          (!RequestingModule ||
+           I->getModule()->isSubModuleOf(RequestingModule))) {
+        // When no requesting module is available, the caller is looking if a
+        // header is part a module by only looking into the module map. This is
+        // done by warn_uncovered_module_header checks; don't consider textual
+        // headers part of it in this mode, otherwise we get misleading warnings
+        // that a umbrella header is not including a textual header.
+        if (!RequestingModule && I->getRole() == ModuleMap::TextualHeader)
+          continue;
         return false;
+      }
     }
     return true;
   }
@@ -558,6 +572,25 @@ ModuleMap::findOrCreateModule(StringRef Name, Module *Parent, bool IsFramework,
   return std::make_pair(Result, true);
 }
 
+Module *ModuleMap::createModuleForInterfaceUnit(SourceLocation Loc,
+                                                StringRef Name) {
+  assert(LangOpts.CurrentModule == Name && "module name mismatch");
+  assert(!Modules[Name] && "redefining existing module");
+
+  auto *Result =
+      new Module(Name, Loc, nullptr, /*IsFramework*/ false,
+                 /*IsExplicit*/ false, NumCreatedModules++);
+  Modules[Name] = SourceModule = Result;
+
+  // Mark the main source file as being within the newly-created module so that
+  // declarations and macros are properly visibility-restricted to it.
+  auto *MainFile = SourceMgr.getFileEntryForID(SourceMgr.getMainFileID());
+  assert(MainFile && "no input file for module interface");
+  Headers[MainFile].push_back(KnownHeader(Result, PrivateHeader));
+
+  return Result;
+}
+
 /// \brief For a framework module, infer the framework against which we
 /// should link.
 static void inferFrameworkLink(Module *Mod, const DirectoryEntry *FrameworkDir,
@@ -573,8 +606,7 @@ static void inferFrameworkLink(Module *Mod, const DirectoryEntry *FrameworkDir,
   // 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) {
+  for (const char *extension : {"", ".tbd"}) {
     llvm::sys::path::replace_extension(LibName, extension);
     if (FileMgr.getFile(LibName)) {
       Mod->LinkLibraries.push_back(Module::LinkLibrary(Mod->Name,
@@ -653,6 +685,8 @@ Module *ModuleMap::inferFrameworkModule(const DirectoryEntry *FrameworkDir,
           Attrs.IsSystem |= inferred->second.Attrs.IsSystem;
           Attrs.IsExternC |= inferred->second.Attrs.IsExternC;
           Attrs.IsExhaustive |= inferred->second.Attrs.IsExhaustive;
+          Attrs.NoUndeclaredIncludes |=
+              inferred->second.Attrs.NoUndeclaredIncludes;
           ModuleMapFile = inferred->second.ModuleMapFile;
         }
       }
@@ -690,6 +724,7 @@ Module *ModuleMap::inferFrameworkModule(const DirectoryEntry *FrameworkDir,
   Result->IsSystem |= Attrs.IsSystem;
   Result->IsExternC |= Attrs.IsExternC;
   Result->ConfigMacrosExhaustive |= Attrs.IsExhaustive;
+  Result->NoUndeclaredIncludes |= Attrs.NoUndeclaredIncludes;
   Result->Directory = FrameworkDir;
 
   // umbrella header "umbrella-header-name"
@@ -802,10 +837,10 @@ void ModuleMap::addHeader(Module *Mod, Module::Header Header,
       return;
 
   HeaderList.push_back(KH);
-  Mod->Headers[headerRoleToKind(Role)].push_back(std::move(Header));
+  Mod->Headers[headerRoleToKind(Role)].push_back(Header);
 
   bool isCompilingModuleHeader =
-      LangOpts.CompilingModule && Mod->getTopLevelModule() == SourceModule;
+      LangOpts.isCompilingModule() && Mod->getTopLevelModule() == SourceModule;
   if (!Imported || isCompilingModuleHeader) {
     // When we import HeaderFileInfo, the external source is expected to
     // set the isModuleHeader flag itself.
@@ -1288,7 +1323,9 @@ namespace {
     /// \brief The 'extern_c' attribute.
     AT_extern_c,
     /// \brief The 'exhaustive' attribute.
-    AT_exhaustive
+    AT_exhaustive,
+    /// \brief The 'no_undeclared_includes' attribute.
+    AT_no_undeclared_includes
   };
 }
 
@@ -1458,8 +1495,47 @@ void ModuleMapParser::parseModuleDecl() {
     ActiveModule->IsSystem = true;
   if (Attrs.IsExternC)
     ActiveModule->IsExternC = true;
+  if (Attrs.NoUndeclaredIncludes ||
+      (!ActiveModule->Parent && ModuleName == "Darwin"))
+    ActiveModule->NoUndeclaredIncludes = true;
   ActiveModule->Directory = Directory;
 
+  if (!ActiveModule->Parent) {
+    StringRef MapFileName(ModuleMapFile->getName());
+    if (MapFileName.endswith("module.private.modulemap") ||
+        MapFileName.endswith("module_private.map")) {
+      // Adding a top-level module from a private modulemap is likely a
+      // user error; we check to see if there's another top-level module
+      // defined in the non-private map in the same dir, and if so emit a
+      // warning.
+      for (auto E = Map.module_begin(); E != Map.module_end(); ++E) {
+        auto const *M = E->getValue();
+        if (!M->Parent &&
+            M->Directory == ActiveModule->Directory &&
+            M->Name != ActiveModule->Name) {
+          Diags.Report(ActiveModule->DefinitionLoc,
+                       diag::warn_mmap_mismatched_top_level_private)
+            << ActiveModule->Name << M->Name;
+          // The pattern we're defending against here is typically due to
+          // a module named FooPrivate which is supposed to be a submodule
+          // called Foo.Private. Emit a fixit in that case.
+          auto D =
+            Diags.Report(ActiveModule->DefinitionLoc,
+                         diag::note_mmap_rename_top_level_private_as_submodule);
+          D << ActiveModule->Name << M->Name;
+          StringRef Bad(ActiveModule->Name);
+          if (Bad.consume_back("Private")) {
+            SmallString<128> Fixed = Bad;
+            Fixed.append(".Private");
+            D << FixItHint::CreateReplacement(ActiveModule->DefinitionLoc,
+                                              Fixed);
+          }
+          break;
+        }
+      }
+    }
+  }
+
   bool Done = false;
   do {
     switch (Tok.Kind) {
@@ -1624,15 +1700,12 @@ void ModuleMapParser::parseExternModuleDecl() {
 ///    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))) {
+  if (Feature == "excluded" &&
+      (M->fullModuleNameIs({"Darwin", "C", "excluded"}) ||
+       M->fullModuleNameIs({"Tcl", "Private"}))) {
     IsRequiresExcludedHack = true;
     return false;
-  } else if (Feature == "cplusplus" && M->fullModuleNameIs(IOKitAVC)) {
+  } else if (Feature == "cplusplus" && M->fullModuleNameIs({"IOKit", "avc"})) {
     return false;
   }
 
@@ -1816,7 +1889,7 @@ void ModuleMapParser::parseHeaderDecl(MMToken::TokenKind LeadingToken,
       // supplied by Clang. Find that builtin header.
       if (ActiveModule->IsSystem && LeadingToken != MMToken::UmbrellaKeyword &&
           BuiltinIncludeDir && BuiltinIncludeDir != Directory &&
-          isBuiltinHeader(Header.FileName)) {
+          ModuleMap::isBuiltinHeader(Header.FileName)) {
         SmallString<128> BuiltinPathName(BuiltinIncludeDir->getName());
         llvm::sys::path::append(BuiltinPathName, Header.FileName);
         BuiltinFile = SourceMgr.getFileManager().getFile(BuiltinPathName);
@@ -1824,13 +1897,7 @@ void ModuleMapParser::parseHeaderDecl(MMToken::TokenKind LeadingToken,
         // If Clang supplies this header but the underlying system does not,
         // just silently swap in our builtin version. Otherwise, we'll end
         // up adding both (later).
-        //
-        // For local visibility, entirely replace the system file with our
-        // one and textually include the system one. We need to pass macros
-        // from our header to the system one if we #include_next it.
-        //
-        // FIXME: Can we do this in all cases?
-        if (BuiltinFile && (!File || Map.LangOpts.ModulesLocalVisibility)) {
+        if (BuiltinFile && !File) {
           File = BuiltinFile;
           RelativePathName = BuiltinPathName;
           BuiltinFile = nullptr;
@@ -1856,15 +1923,20 @@ void ModuleMapParser::parseHeaderDecl(MMToken::TokenKind LeadingToken,
       Module::Header H = {RelativePathName.str(), File};
       Map.excludeHeader(ActiveModule, H);
     } else {
-      // If there is a builtin counterpart to this file, add it now, before
-      // the "real" header, so we build the built-in one first when building
-      // the module.
+      // If there is a builtin counterpart to this file, add it now so it can
+      // wrap the system header.
       if (BuiltinFile) {
         // FIXME: Taking the name from the FileEntry is unstable and can give
         // different results depending on how we've previously named that file
         // in this build.
         Module::Header H = { BuiltinFile->getName(), BuiltinFile };
         Map.addHeader(ActiveModule, H, Role);
+
+        // If we have both a builtin and system version of the file, the
+        // builtin version may want to inject macros into the system header, so
+        // force the system header to be treated as a textual header in this
+        // case.
+        Role = ModuleMap::ModuleHeaderRole(Role | ModuleMap::TextualHeader);
       }
 
       // Record this header.
@@ -2354,6 +2426,7 @@ bool ModuleMapParser::parseOptionalAttributes(Attributes &Attrs) {
       = llvm::StringSwitch<AttributeKind>(Tok.getString())
           .Case("exhaustive", AT_exhaustive)
           .Case("extern_c", AT_extern_c)
+          .Case("no_undeclared_includes", AT_no_undeclared_includes)
           .Case("system", AT_system)
           .Default(AT_unknown);
     switch (Attribute) {
@@ -2373,6 +2446,10 @@ bool ModuleMapParser::parseOptionalAttributes(Attributes &Attrs) {
     case AT_exhaustive:
       Attrs.IsExhaustive = true;
       break;
+
+    case AT_no_undeclared_includes:
+      Attrs.NoUndeclaredIncludes = true;
+      break;
     }
     consumeToken();
 
diff --git a/contrib/llvm/tools/clang/lib/Lex/PPCaching.cpp b/contrib/llvm/tools/clang/lib/Lex/PPCaching.cpp
index 4742aae..45bdce3 100644
--- a/contrib/llvm/tools/clang/lib/Lex/PPCaching.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/PPCaching.cpp
@@ -86,7 +86,7 @@ void Preprocessor::EnterCachingLexMode() {
 const Token &Preprocessor::PeekAhead(unsigned N) {
   assert(CachedLexPos + N > CachedTokens.size() && "Confused caching.");
   ExitCachingLexMode();
-  for (unsigned C = CachedLexPos + N - CachedTokens.size(); C > 0; --C) {
+  for (size_t C = CachedLexPos + N - CachedTokens.size(); C > 0; --C) {
     CachedTokens.push_back(Token());
     Lex(CachedTokens.back());
   }
@@ -105,7 +105,7 @@ void Preprocessor::AnnotatePreviousCachedTokens(const Token &Tok) {
   for (CachedTokensTy::size_type i = CachedLexPos; i != 0; --i) {
     CachedTokensTy::iterator AnnotBegin = CachedTokens.begin() + i-1;
     if (AnnotBegin->getLocation() == Tok.getLocation()) {
-      assert((BacktrackPositions.empty() || BacktrackPositions.back() < i) &&
+      assert((BacktrackPositions.empty() || BacktrackPositions.back() <= i) &&
              "The backtrack pos points inside the annotated tokens!");
       // Replace the cached tokens with the single annotation token.
       if (i < CachedLexPos)
diff --git a/contrib/llvm/tools/clang/lib/Lex/PPDirectives.cpp b/contrib/llvm/tools/clang/lib/Lex/PPDirectives.cpp
index 77f118f..322c580 100644
--- a/contrib/llvm/tools/clang/lib/Lex/PPDirectives.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/PPDirectives.cpp
@@ -12,25 +12,41 @@
 ///
 //===----------------------------------------------------------------------===//
 
-#include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/CharInfo.h"
 #include "clang/Basic/FileManager.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/Module.h"
+#include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
+#include "clang/Basic/TokenKinds.h"
 #include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Lex/HeaderSearch.h"
-#include "clang/Lex/HeaderSearchOptions.h"
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/LiteralSupport.h"
 #include "clang/Lex/MacroInfo.h"
 #include "clang/Lex/ModuleLoader.h"
+#include "clang/Lex/ModuleMap.h"
+#include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Pragma.h"
-#include "llvm/ADT/APInt.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/PTHLexer.h"
+#include "clang/Lex/Token.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/STLExtras.h"
-#include "llvm/ADT/StringExtras.h"
 #include "llvm/ADT/StringSwitch.h"
-#include "llvm/ADT/iterator_range.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/Support/AlignOf.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Path.h"
-#include "llvm/Support/SaveAndRestore.h"
+#include <algorithm>
+#include <cassert>
+#include <cstring>
+#include <new>
+#include <string>
+#include <utility>
 
 using namespace clang;
 
@@ -53,7 +69,7 @@ MacroInfo *Preprocessor::AllocateMacroInfo(SourceLocation L) {
 
 MacroInfo *Preprocessor::AllocateDeserializedMacroInfo(SourceLocation L,
                                                        unsigned SubModuleID) {
-  static_assert(llvm::AlignOf<MacroInfo>::Alignment >= sizeof(SubModuleID),
+  static_assert(alignof(MacroInfo) >= sizeof(SubModuleID),
                 "alignment for MacroInfo is less than the ID");
   DeserializedMacroInfoChain *MIChain =
       BP.Allocate<DeserializedMacroInfoChain>();
@@ -268,7 +284,7 @@ bool Preprocessor::CheckMacroName(Token &MacroNameTok, MacroUse isDefineUndef,
   if (ShadowFlag)
     *ShadowFlag = false;
   if (!SourceMgr.isInSystemHeader(MacroNameLoc) &&
-      (strcmp(SourceMgr.getBufferName(MacroNameLoc), "<built-in>") != 0)) {
+      (SourceMgr.getBufferName(MacroNameLoc) != "<built-in>")) {
     MacroDiag D = MD_NoWarn;
     if (isDefineUndef == MU_Define) {
       D = shouldWarnOnMacroDef(*this, II);
@@ -382,7 +398,7 @@ void Preprocessor::SkipExcludedConditionalBlock(SourceLocation IfTokenLoc,
   // disabling warnings, etc.
   CurPPLexer->LexingRawMode = true;
   Token Tok;
-  while (1) {
+  while (true) {
     CurLexer->Lex(Tok);
 
     if (Tok.is(tok::code_completion)) {
@@ -455,7 +471,7 @@ void Preprocessor::SkipExcludedConditionalBlock(SourceLocation IfTokenLoc,
       Directive = RI;
     } else {
       std::string DirectiveStr = getSpelling(Tok);
-      unsigned IdLen = DirectiveStr.size();
+      size_t IdLen = DirectiveStr.size();
       if (IdLen >= 20) {
         CurPPLexer->ParsingPreprocessorDirective = false;
         // Restore comment saving mode.
@@ -578,7 +594,7 @@ void Preprocessor::SkipExcludedConditionalBlock(SourceLocation IfTokenLoc,
 }
 
 void Preprocessor::PTHSkipExcludedConditionalBlock() {
-  while (1) {
+  while (true) {
     assert(CurPTHLexer);
     assert(CurPTHLexer->LexingRawMode == false);
 
@@ -785,8 +801,7 @@ const FileEntry *Preprocessor::LookupFile(
     // headers included by quoted include directives.
     // See: http://msdn.microsoft.com/en-us/library/36k2cdd4.aspx
     if (LangOpts.MSVCCompat && !isAngled) {
-      for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) {
-        IncludeStackInfo &ISEntry = IncludeMacroStack[e - i - 1];
+      for (IncludeStackInfo &ISEntry : llvm::reverse(IncludeMacroStack)) {
         if (IsFileLexer(ISEntry))
           if ((FileEnt = ISEntry.ThePPLexer->getFileEntry()))
             Includers.push_back(std::make_pair(FileEnt, FileEnt->getDir()));
@@ -849,8 +864,7 @@ const FileEntry *Preprocessor::LookupFile(
     }
   }
 
-  for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) {
-    IncludeStackInfo &ISEntry = IncludeMacroStack[e-i-1];
+  for (IncludeStackInfo &ISEntry : llvm::reverse(IncludeMacroStack)) {
     if (IsFileLexer(ISEntry)) {
       if ((CurFileEnt = ISEntry.ThePPLexer->getFileEntry())) {
         if ((FE = HeaderInfo.LookupSubframeworkHeader(
@@ -998,11 +1012,11 @@ void Preprocessor::HandleDirective(Token &Result) {
     case tok::pp_define:
       return HandleDefineDirective(Result, ImmediatelyAfterTopLevelIfndef);
     case tok::pp_undef:
-      return HandleUndefDirective(Result);
+      return HandleUndefDirective();
 
     // C99 6.10.4 - Line Control.
     case tok::pp_line:
-      return HandleLineDirective(Result);
+      return HandleLineDirective();
 
     // C99 6.10.5 - Error Directive.
     case tok::pp_error:
@@ -1039,7 +1053,7 @@ void Preprocessor::HandleDirective(Token &Result) {
 
     case tok::pp___private_macro:
       if (getLangOpts().Modules)
-        return HandleMacroPrivateDirective(Result);
+        return HandleMacroPrivateDirective();
       break;
     }
     break;
@@ -1137,7 +1151,7 @@ static bool GetLineValue(Token &DigitTok, unsigned &Val,
 ///   # line digit-sequence
 ///   # line digit-sequence "s-char-sequence"
 /// \endverbatim
-void Preprocessor::HandleLineDirective(Token &Tok) {
+void Preprocessor::HandleLineDirective() {
   // Read the line # and string argument.  Per C99 6.10.4p5, these tokens are
   // expanded.
   Token DigitTok;
@@ -1442,7 +1456,7 @@ void Preprocessor::HandleMacroPublicDirective(Token &Tok) {
 }
 
 /// \brief Handle a #private directive.
-void Preprocessor::HandleMacroPrivateDirective(Token &Tok) {
+void Preprocessor::HandleMacroPrivateDirective() {
   Token MacroNameTok;
   ReadMacroName(MacroNameTok, MU_Undef);
 
@@ -1551,7 +1565,7 @@ bool Preprocessor::ConcatenateIncludeName(SmallString<128> &FilenameBuffer,
       FilenameBuffer.push_back(' ');
 
     // Get the spelling of the token, directly into FilenameBuffer if possible.
-    unsigned PreAppendSize = FilenameBuffer.size();
+    size_t PreAppendSize = FilenameBuffer.size();
     FilenameBuffer.resize(PreAppendSize+CurTok.getLength());
 
     const char *BufPtr = &FilenameBuffer[PreAppendSize];
@@ -1602,7 +1616,7 @@ static void diagnoseAutoModuleImport(
   assert(PP.getLangOpts().ObjC2 && "no import syntax available");
 
   SmallString<128> PathString;
-  for (unsigned I = 0, N = Path.size(); I != N; ++I) {
+  for (size_t I = 0, N = Path.size(); I != N; ++I) {
     if (I)
       PathString += '.';
     PathString += Path[I].first->getName();
@@ -1831,7 +1845,8 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
 
       // If the file is still not found, just go with the vanilla diagnostic
       if (!File)
-        Diag(FilenameTok, diag::err_pp_file_not_found) << Filename;
+        Diag(FilenameTok, diag::err_pp_file_not_found) << Filename
+                                                       << FilenameRange;
     }
   }
 
@@ -1851,12 +1866,9 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
     // unavailable, diagnose the situation and bail out.
     // FIXME: Remove this; loadModule does the same check (but produces
     // slightly worse diagnostics).
-    if (!SuggestedModule.getModule()->isAvailable() &&
-        !SuggestedModule.getModule()
-             ->getTopLevelModule()
-             ->HasIncompatibleModuleFile) {
-      clang::Module::Requirement Requirement;
-      clang::Module::UnresolvedHeaderDirective MissingHeader;
+    if (!SuggestedModule.getModule()->isAvailable()) {
+      Module::Requirement Requirement;
+      Module::UnresolvedHeaderDirective MissingHeader;
       Module *M = SuggestedModule.getModule();
       // Identify the cause.
       (void)M->isAvailable(getLangOpts(), getTargetInfo(), Requirement,
@@ -1903,9 +1915,12 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
     else if (Imported.isMissingExpected()) {
       // We failed to find a submodule that we assumed would exist (because it
       // was in the directory of an umbrella header, for instance), but no
-      // actual module exists for it (because the umbrella header is
+      // actual module containing it exists (because the umbrella header is
       // incomplete).  Treat this as a textual inclusion.
       SuggestedModule = ModuleMap::KnownHeader();
+    } else if (Imported.isConfigMismatch()) {
+      // On a configuration mismatch, enter the header textually. We still know
+      // that it's part of the corresponding module.
     } else {
       // We hit an error processing the import. Bail out.
       if (hadModuleLoaderFatalFailure()) {
@@ -1981,10 +1996,13 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
 
   // Ask HeaderInfo if we should enter this #include file.  If not, #including
   // this file will have no effect.
+  bool SkipHeader = false;
   if (ShouldEnter &&
       !HeaderInfo.ShouldEnterIncludeFile(*this, File, isImport,
+                                         getLangOpts().Modules,
                                          SuggestedModule.getModule())) {
     ShouldEnter = false;
+    SkipHeader = true;
     if (Callbacks)
       Callbacks->FileSkipped(*File, FilenameTok, FileCharacter);
   }
@@ -1993,6 +2011,14 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
   if (!ShouldEnter) {
     // If this is a module import, make it visible if needed.
     if (auto *M = SuggestedModule.getModule()) {
+      // When building a pch, -fmodule-name tells the compiler to textually
+      // include headers in the specified module. But it is possible that
+      // ShouldEnter is false because we are skipping the header. In that
+      // case, We are not importing the specified module.
+      if (SkipHeader && getLangOpts().CompilingPCH &&
+          M->getTopLevelModuleName() == getLangOpts().CurrentModule)
+        return;
+
       makeModuleVisible(M, HashLoc);
 
       if (IncludeTok.getIdentifierInfo()->getPPKeywordID() !=
@@ -2017,6 +2043,13 @@ void Preprocessor::HandleIncludeDirective(SourceLocation HashLoc,
 
   // Determine if we're switching to building a new submodule, and which one.
   if (auto *M = SuggestedModule.getModule()) {
+    // When building a pch, -fmodule-name tells the compiler to textually
+    // include headers in the specified module. We are not building the
+    // specified module.
+    if (getLangOpts().CompilingPCH &&
+        M->getTopLevelModuleName() == getLangOpts().CurrentModule)
+      return;
+
     assert(!CurSubmodule && "should not have marked this as a module yet");
     CurSubmodule = M;
 
@@ -2043,7 +2076,11 @@ void Preprocessor::HandleIncludeNextDirective(SourceLocation HashLoc,
   // diagnostic.
   const DirectoryLookup *Lookup = CurDirLookup;
   const FileEntry *LookupFromFile = nullptr;
-  if (isInPrimaryFile()) {
+  if (isInPrimaryFile() && LangOpts.IsHeaderFile) {
+    // If the main file is a header, then it's either for PCH/AST generation,
+    // or libclang opened it. Either way, handle it as a normal include below
+    // and do not complain about include_next.
+  } else if (isInPrimaryFile()) {
     Lookup = nullptr;
     Diag(IncludeNextTok, diag::pp_include_next_in_primary);
   } else if (CurSubmodule) {
@@ -2098,7 +2135,7 @@ void Preprocessor::HandleIncludeMacrosDirective(SourceLocation HashLoc,
   // This directive should only occur in the predefines buffer.  If not, emit an
   // error and reject it.
   SourceLocation Loc = IncludeMacrosTok.getLocation();
-  if (strcmp(SourceMgr.getBufferName(Loc), "<built-in>") != 0) {
+  if (SourceMgr.getBufferName(Loc) != "<built-in>") {
     Diag(IncludeMacrosTok.getLocation(),
          diag::pp_include_macros_out_of_predefines);
     DiscardUntilEndOfDirective();
@@ -2127,7 +2164,7 @@ void Preprocessor::HandleIncludeMacrosDirective(SourceLocation HashLoc,
 bool Preprocessor::ReadMacroDefinitionArgList(MacroInfo *MI, Token &Tok) {
   SmallVector<IdentifierInfo*, 32> Arguments;
 
-  while (1) {
+  while (true) {
     LexUnexpandedToken(Tok);
     switch (Tok.getKind()) {
     case tok::r_paren:
@@ -2536,7 +2573,7 @@ void Preprocessor::HandleDefineDirective(Token &DefineTok,
 
 /// HandleUndefDirective - Implements \#undef.
 ///
-void Preprocessor::HandleUndefDirective(Token &UndefTok) {
+void Preprocessor::HandleUndefDirective() {
   ++NumUndefined;
 
   Token MacroNameTok;
diff --git a/contrib/llvm/tools/clang/lib/Lex/PPExpressions.cpp b/contrib/llvm/tools/clang/lib/Lex/PPExpressions.cpp
index 94075ec..862a471 100644
--- a/contrib/llvm/tools/clang/lib/Lex/PPExpressions.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/PPExpressions.cpp
@@ -17,14 +17,24 @@
 //===----------------------------------------------------------------------===//
 
 #include "clang/Lex/Preprocessor.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/SourceLocation.h"
+#include "clang/Basic/SourceManager.h"
 #include "clang/Basic/TargetInfo.h"
+#include "clang/Basic/TokenKinds.h"
 #include "clang/Lex/CodeCompletionHandler.h"
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/LiteralSupport.h"
 #include "clang/Lex/MacroInfo.h"
+#include "clang/Lex/PPCallbacks.h"
+#include "clang/Lex/Token.h"
 #include "llvm/ADT/APSInt.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/SaveAndRestore.h"
+#include <cassert>
+
 using namespace clang;
 
 namespace {
@@ -34,6 +44,7 @@ namespace {
 class PPValue {
   SourceRange Range;
   IdentifierInfo *II;
+
 public:
   llvm::APSInt Val;
 
@@ -58,7 +69,7 @@ public:
   void setEnd(SourceLocation L) { Range.setEnd(L); }
 };
 
-}
+} // end anonymous namespace
 
 static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
                                      Token &PeekTok, bool ValueLive,
@@ -469,8 +480,6 @@ static bool EvaluateValue(PPValue &Result, Token &PeekTok, DefinedTracker &DT,
   }
 }
 
-
-
 /// getPrecedence - Return the precedence of the specified binary operator
 /// token.  This returns:
 ///   ~0 - Invalid token.
@@ -531,7 +540,7 @@ static bool EvaluateDirectiveSubExpr(PPValue &LHS, unsigned MinPrec,
     return true;
   }
 
-  while (1) {
+  while (true) {
     // If this token has a lower precedence than we are allowed to parse, return
     // it so that higher levels of the recursion can parse it.
     if (PeekPrec < MinPrec)
diff --git a/contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp b/contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp
index e2eceaf..4db17c3 100644
--- a/contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/PPLexerChange.cpp
@@ -40,10 +40,10 @@ bool Preprocessor::isInPrimaryFile() const {
   // If there are any stacked lexers, we're in a #include.
   assert(IsFileLexer(IncludeMacroStack[0]) &&
          "Top level include stack isn't our primary lexer?");
-  for (unsigned i = 1, e = IncludeMacroStack.size(); i != e; ++i)
-    if (IsFileLexer(IncludeMacroStack[i]))
-      return false;
-  return true;
+  return std::none_of(IncludeMacroStack.begin() + 1, IncludeMacroStack.end(),
+                      [this](const IncludeStackInfo &ISI) -> bool {
+    return IsFileLexer(ISI);
+  });
 }
 
 /// getCurrentLexer - Return the current file lexer being lexed from.  Note
@@ -54,8 +54,7 @@ PreprocessorLexer *Preprocessor::getCurrentFileLexer() const {
     return CurPPLexer;
 
   // Look for a stacked lexer.
-  for (unsigned i = IncludeMacroStack.size(); i != 0; --i) {
-    const IncludeStackInfo& ISI = IncludeMacroStack[i-1];
+  for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
     if (IsFileLexer(ISI))
       return ISI.ThePPLexer;
   }
@@ -566,8 +565,7 @@ void Preprocessor::HandleMicrosoftCommentPaste(Token &Tok) {
   // explicit EOD token.
   PreprocessorLexer *FoundLexer = nullptr;
   bool LexerWasInPPMode = false;
-  for (unsigned i = 0, e = IncludeMacroStack.size(); i != e; ++i) {
-    IncludeStackInfo &ISI = *(IncludeMacroStack.end()-i-1);
+  for (const IncludeStackInfo &ISI : llvm::reverse(IncludeMacroStack)) {
     if (ISI.ThePPLexer == nullptr) continue;  // Scan for a real lexer.
 
     // Once we find a real lexer, mark it as raw mode (disabling macro
@@ -685,7 +683,7 @@ bool Preprocessor::needModuleMacros() const {
     return true;
   // Otherwise, we only need module macros if we're actually compiling a module
   // interface.
-  return getLangOpts().CompilingModule;
+  return getLangOpts().isCompilingModule();
 }
 
 void Preprocessor::LeaveSubmodule() {
diff --git a/contrib/llvm/tools/clang/lib/Lex/PPMacroExpansion.cpp b/contrib/llvm/tools/clang/lib/Lex/PPMacroExpansion.cpp
index 2ade6df..de166c7 100644
--- a/contrib/llvm/tools/clang/lib/Lex/PPMacroExpansion.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/PPMacroExpansion.cpp
@@ -12,25 +12,49 @@
 //
 //===----------------------------------------------------------------------===//
 
-#include "clang/Lex/Preprocessor.h"
 #include "clang/Basic/Attributes.h"
 #include "clang/Basic/FileManager.h"
-#include "clang/Basic/SourceManager.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/LLVM.h"
+#include "clang/Basic/LangOptions.h"
+#include "clang/Basic/ObjCRuntime.h"
+#include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/TargetInfo.h"
 #include "clang/Lex/CodeCompletionHandler.h"
+#include "clang/Lex/DirectoryLookup.h"
 #include "clang/Lex/ExternalPreprocessorSource.h"
 #include "clang/Lex/LexDiagnostic.h"
 #include "clang/Lex/MacroArgs.h"
 #include "clang/Lex/MacroInfo.h"
-#include "llvm/ADT/STLExtras.h"
+#include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/PreprocessorLexer.h"
+#include "clang/Lex/PTHLexer.h"
+#include "clang/Lex/Token.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/DenseSet.h"
+#include "llvm/ADT/FoldingSet.h"
+#include "llvm/ADT/None.h"
+#include "llvm/ADT/Optional.h"
 #include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
 #include "llvm/ADT/StringSwitch.h"
 #include "llvm/Config/llvm-config.h"
+#include "llvm/Support/Casting.h"
 #include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/Format.h"
 #include "llvm/Support/raw_ostream.h"
-#include <cstdio>
+#include <algorithm>
+#include <cassert>
+#include <cstddef>
+#include <cstring>
 #include <ctime>
+#include <string>
+#include <tuple>
+#include <utility>
+
 using namespace clang;
 
 MacroDirective *
@@ -68,12 +92,35 @@ void Preprocessor::appendMacroDirective(IdentifierInfo *II, MacroDirective *MD){
 }
 
 void Preprocessor::setLoadedMacroDirective(IdentifierInfo *II,
+                                           MacroDirective *ED,
                                            MacroDirective *MD) {
+  // Normally, when a macro is defined, it goes through appendMacroDirective()
+  // above, which chains a macro to previous defines, undefs, etc.
+  // However, in a pch, the whole macro history up to the end of the pch is
+  // stored, so ASTReader goes through this function instead.
+  // However, built-in macros are already registered in the Preprocessor
+  // ctor, and ASTWriter stops writing the macro chain at built-in macros,
+  // so in that case the chain from the pch needs to be spliced to the existing
+  // built-in.
+
   assert(II && MD);
   MacroState &StoredMD = CurSubmoduleState->Macros[II];
-  assert(!StoredMD.getLatest() &&
-         "the macro history was modified before initializing it from a pch");
-  StoredMD = MD;
+
+  if (auto *OldMD = StoredMD.getLatest()) {
+    // shouldIgnoreMacro() in ASTWriter also stops at macros from the
+    // predefines buffer in module builds. However, in module builds, modules
+    // are loaded completely before predefines are processed, so StoredMD
+    // will be nullptr for them when they're loaded. StoredMD should only be
+    // non-nullptr for builtins read from a pch file.
+    assert(OldMD->getMacroInfo()->isBuiltinMacro() &&
+           "only built-ins should have an entry here");
+    assert(!OldMD->getPrevious() && "builtin should only have a single entry");
+    ED->setPrevious(OldMD);
+    StoredMD.setLatest(MD);
+  } else {
+    StoredMD = MD;
+  }
+
   // Setup the identifier as having associated macro history.
   II->setHasMacroDefinition(true);
   if (!MD->isDefined() && LeafModuleMacros.find(II) == LeafModuleMacros.end())
@@ -286,7 +333,6 @@ static IdentifierInfo *RegisterBuiltinMacro(Preprocessor &PP, const char *Name){
   return Id;
 }
 
-
 /// RegisterBuiltinMacros - Register builtin macros, such as __LINE__ with the
 /// identifier table.
 void Preprocessor::RegisterBuiltinMacros() {
@@ -367,10 +413,8 @@ static bool isTrivialSingleTokenExpansion(const MacroInfo *MI,
   // If this is a function-like macro invocation, it's safe to trivially expand
   // as long as the identifier is not a macro argument.
   return std::find(MI->arg_begin(), MI->arg_end(), II) == MI->arg_end();
-
 }
 
-
 /// isNextPPTokenLParen - Determine whether the next preprocessor token to be
 /// lexed is a '('.  If so, consume the token and return true, if not, this
 /// method should have no observable side-effect on the lexed tokens.
@@ -390,8 +434,7 @@ bool Preprocessor::isNextPPTokenLParen() {
     // macro stack.
     if (CurPPLexer)
       return false;
-    for (unsigned i = IncludeMacroStack.size(); i != 0; --i) {
-      IncludeStackInfo &Entry = IncludeMacroStack[i-1];
+    for (const IncludeStackInfo &Entry : llvm::reverse(IncludeMacroStack)) {
       if (Entry.TheLexer)
         Val = Entry.TheLexer->isNextPPTokenLParen();
       else if (Entry.ThePTHLexer)
@@ -480,8 +523,7 @@ bool Preprocessor::HandleMacroExpandedIdentifier(Token &Identifier,
     } else {
       Callbacks->MacroExpands(Identifier, M, ExpansionRange, Args);
       if (!DelayedMacroExpandsCallbacks.empty()) {
-        for (unsigned i=0, e = DelayedMacroExpandsCallbacks.size(); i!=e; ++i) {
-          MacroExpandsInfo &Info = DelayedMacroExpandsCallbacks[i];
+        for (const MacroExpandsInfo &Info : DelayedMacroExpandsCallbacks) {
           // FIXME: We lose macro args info with delayed callback.
           Callbacks->MacroExpands(Info.Tok, Info.MD, Info.Range,
                                   /*Args=*/nullptr);
@@ -735,14 +777,14 @@ MacroArgs *Preprocessor::ReadFunctionLikeMacroArgs(Token &MacroName,
     assert(Tok.isOneOf(tok::l_paren, tok::comma) &&
            "only expect argument separators here");
 
-    unsigned ArgTokenStart = ArgTokens.size();
+    size_t ArgTokenStart = ArgTokens.size();
     SourceLocation ArgStartLoc = Tok.getLocation();
 
     // C99 6.10.3p11: Keep track of the number of l_parens we have seen.  Note
     // that we already consumed the first one.
     unsigned NumParens = 0;
 
-    while (1) {
+    while (true) {
       // Read arguments as unexpanded tokens.  This avoids issues, e.g., where
       // an argument value in a macro could expand to ',' or '(' or ')'.
       LexUnexpandedToken(Tok);
@@ -987,10 +1029,10 @@ Token *Preprocessor::cacheMacroExpandedTokens(TokenLexer *tokLexer,
   if (cacheNeedsToGrow) {
     // Go through all the TokenLexers whose 'Tokens' pointer points in the
     // buffer and update the pointers to the (potential) new buffer array.
-    for (unsigned i = 0, e = MacroExpandingLexersStack.size(); i != e; ++i) {
+    for (const auto &Lexer : MacroExpandingLexersStack) {
       TokenLexer *prevLexer;
       size_t tokIndex;
-      std::tie(prevLexer, tokIndex) = MacroExpandingLexersStack[i];
+      std::tie(prevLexer, tokIndex) = Lexer;
       prevLexer->Tokens = MacroExpandedTokens.data() + tokIndex;
     }
   }
@@ -1043,7 +1085,6 @@ static void ComputeDATE_TIME(SourceLocation &DATELoc, SourceLocation &TIMELoc,
   }
 }
 
-
 /// HasFeature - Return true if we recognize and implement the feature
 /// specified by the identifier as a standard language feature.
 static bool HasFeature(const Preprocessor &PP, StringRef Feature) {
@@ -1090,6 +1131,7 @@ static bool HasFeature(const Preprocessor &PP, StringRef Feature) {
       .Case("cxx_rtti", LangOpts.RTTI && LangOpts.RTTIData)
       .Case("enumerator_attributes", true)
       .Case("nullability", true)
+      .Case("nullability_on_arrays", true)
       .Case("memory_sanitizer", LangOpts.Sanitize.has(SanitizerKind::Memory))
       .Case("thread_sanitizer", LangOpts.Sanitize.has(SanitizerKind::Thread))
       .Case("dataflow_sanitizer", LangOpts.Sanitize.has(SanitizerKind::DataFlow))
@@ -1141,6 +1183,7 @@ static bool HasFeature(const Preprocessor &PP, StringRef Feature) {
       .Case("cxx_attributes", LangOpts.CPlusPlus11)
       .Case("cxx_auto_type", LangOpts.CPlusPlus11)
       .Case("cxx_constexpr", LangOpts.CPlusPlus11)
+      .Case("cxx_constexpr_string_builtins", LangOpts.CPlusPlus11)
       .Case("cxx_decltype", LangOpts.CPlusPlus11)
       .Case("cxx_decltype_incomplete_return_types", LangOpts.CPlusPlus11)
       .Case("cxx_default_function_template_args", LangOpts.CPlusPlus11)
@@ -1171,7 +1214,7 @@ static bool HasFeature(const Preprocessor &PP, StringRef Feature) {
       .Case("cxx_unrestricted_unions", LangOpts.CPlusPlus11)
       .Case("cxx_user_literals", LangOpts.CPlusPlus11)
       .Case("cxx_variadic_templates", LangOpts.CPlusPlus11)
-      // C++1y features
+      // C++14 features
       .Case("cxx_aggregate_nsdmi", LangOpts.CPlusPlus14)
       .Case("cxx_binary_literals", LangOpts.CPlusPlus14)
       .Case("cxx_contextual_conversions", LangOpts.CPlusPlus14)
@@ -1181,6 +1224,9 @@ static bool HasFeature(const Preprocessor &PP, StringRef Feature) {
       .Case("cxx_relaxed_constexpr", LangOpts.CPlusPlus14)
       .Case("cxx_return_type_deduction", LangOpts.CPlusPlus14)
       .Case("cxx_variable_templates", LangOpts.CPlusPlus14)
+      // NOTE: For features covered by SD-6, it is preferable to provide *only*
+      // the SD-6 macro and not a __has_feature check.
+
       // C++ TSes
       //.Case("cxx_runtime_arrays", LangOpts.CPlusPlusTSArrays)
       //.Case("cxx_concepts", LangOpts.CPlusPlusTSConcepts)
@@ -1264,7 +1310,7 @@ static bool HasExtension(const Preprocessor &PP, StringRef Extension) {
            .Case("cxx_reference_qualified_functions", LangOpts.CPlusPlus)
            .Case("cxx_rvalue_references", LangOpts.CPlusPlus)
            .Case("cxx_variadic_templates", LangOpts.CPlusPlus)
-           // C++1y features supported by other languages as extensions.
+           // C++14 features supported by other languages as extensions.
            .Case("cxx_binary_literals", true)
            .Case("cxx_init_captures", LangOpts.CPlusPlus11)
            .Case("cxx_variable_templates", LangOpts.CPlusPlus)
@@ -1400,7 +1446,11 @@ static bool EvaluateHasIncludeNext(Token &Tok,
   // Preprocessor::HandleIncludeNextDirective.
   const DirectoryLookup *Lookup = PP.GetCurDirLookup();
   const FileEntry *LookupFromFile = nullptr;
-  if (PP.isInPrimaryFile()) {
+  if (PP.isInPrimaryFile() && PP.getLangOpts().IsHeaderFile) {
+    // If the main file is a header, then it's either for PCH/AST generation,
+    // or libclang opened it. Either way, handle it as a normal include below
+    // and do not complain about __has_include_next.
+  } else if (PP.isInPrimaryFile()) {
     Lookup = nullptr;
     PP.Diag(Tok, diag::pp_include_next_in_primary);
   } else if (PP.getCurrentSubmodule()) {
@@ -1796,7 +1846,7 @@ void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
       [this](Token &Tok, bool &HasLexedNextToken) -> int {
         IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
                                        diag::err_expected_id_building_module);
-        return getLangOpts().CompilingModule && II &&
+        return getLangOpts().isCompilingModule() && II &&
                (II->getName() == getLangOpts().CurrentModule);
       });
   } else if (II == Ident__MODULE__) {
diff --git a/contrib/llvm/tools/clang/lib/Lex/PTHLexer.cpp b/contrib/llvm/tools/clang/lib/Lex/PTHLexer.cpp
index 5f63d35..ec806e8 100644
--- a/contrib/llvm/tools/clang/lib/Lex/PTHLexer.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/PTHLexer.cpp
@@ -21,7 +21,6 @@
 #include "clang/Lex/Preprocessor.h"
 #include "clang/Lex/Token.h"
 #include "llvm/ADT/StringExtras.h"
-#include "llvm/ADT/StringMap.h"
 #include "llvm/Support/EndianStream.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include <memory>
@@ -318,7 +317,7 @@ public:
 
 class PTHFileLookupCommonTrait {
 public:
-  typedef std::pair<unsigned char, const char*> internal_key_type;
+  typedef std::pair<unsigned char, StringRef> internal_key_type;
   typedef unsigned hash_value_type;
   typedef unsigned offset_type;
 
@@ -353,7 +352,7 @@ public:
   }
 
   static bool EqualKey(internal_key_type a, internal_key_type b) {
-    return a.first == b.first && strcmp(a.second, b.second) == 0;
+    return a.first == b.first && a.second == b.second;
   }
 
   static PTHFileData ReadData(const internal_key_type& k,
@@ -629,15 +628,15 @@ PTHLexer *PTHManager::CreateLexer(FileID FID) {
 namespace {
 class PTHStatData {
 public:
-  const bool HasData;
   uint64_t Size;
   time_t ModTime;
   llvm::sys::fs::UniqueID UniqueID;
+  const bool HasData;
   bool IsDirectory;
 
   PTHStatData(uint64_t Size, time_t ModTime, llvm::sys::fs::UniqueID UniqueID,
               bool IsDirectory)
-      : HasData(true), Size(Size), ModTime(ModTime), UniqueID(UniqueID),
+      : Size(Size), ModTime(ModTime), UniqueID(UniqueID), HasData(true),
         IsDirectory(IsDirectory) {}
 
   PTHStatData() : HasData(false) {}
@@ -645,10 +644,10 @@ public:
 
 class PTHStatLookupTrait : public PTHFileLookupCommonTrait {
 public:
-  typedef const char* external_key_type;  // const char*
+  typedef StringRef external_key_type; // const char*
   typedef PTHStatData data_type;
 
-  static internal_key_type GetInternalKey(const char *path) {
+  static internal_key_type GetInternalKey(StringRef path) {
     // The key 'kind' doesn't matter here because it is ignored in EqualKey.
     return std::make_pair((unsigned char) 0x0, path);
   }
@@ -656,7 +655,7 @@ public:
   static bool EqualKey(internal_key_type a, internal_key_type b) {
     // When doing 'stat' lookups we don't care about the kind of 'a' and 'b',
     // just the paths.
-    return strcmp(a.second, b.second) == 0;
+    return a.second == b.second;
   }
 
   static data_type ReadData(const internal_key_type& k, const unsigned char* d,
@@ -695,7 +694,7 @@ public:
       : Cache(FL.getNumBuckets(), FL.getNumEntries(), FL.getBuckets(),
               FL.getBase()) {}
 
-  LookupResult getStat(const char *Path, FileData &Data, bool isFile,
+  LookupResult getStat(StringRef Path, FileData &Data, bool isFile,
                        std::unique_ptr<vfs::File> *F,
                        vfs::FileSystem &FS) override {
     // Do the lookup for the file's data in the PTH file.
diff --git a/contrib/llvm/tools/clang/lib/Lex/Pragma.cpp b/contrib/llvm/tools/clang/lib/Lex/Pragma.cpp
index 3bdd31b..100da51 100644
--- a/contrib/llvm/tools/clang/lib/Lex/Pragma.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/Pragma.cpp
@@ -14,21 +14,36 @@
 
 #include "clang/Lex/Pragma.h"
 #include "clang/Basic/FileManager.h"
+#include "clang/Basic/IdentifierTable.h"
+#include "clang/Basic/SourceLocation.h"
 #include "clang/Basic/SourceManager.h"
+#include "clang/Basic/TokenKinds.h"
 #include "clang/Lex/HeaderSearch.h"
 #include "clang/Lex/LexDiagnostic.h"
-#include "clang/Lex/LiteralSupport.h"
 #include "clang/Lex/MacroInfo.h"
+#include "clang/Lex/PPCallbacks.h"
 #include "clang/Lex/Preprocessor.h"
+#include "clang/Lex/PreprocessorLexer.h"
+#include "clang/Lex/PTHLexer.h"
+#include "clang/Lex/Token.h"
+#include "clang/Lex/TokenLexer.h"
+#include "llvm/ADT/ArrayRef.h"
+#include "llvm/ADT/DenseMap.h"
+#include "llvm/ADT/SmallString.h"
+#include "llvm/ADT/SmallVector.h"
 #include "llvm/ADT/STLExtras.h"
 #include "llvm/ADT/StringSwitch.h"
-#include "llvm/ADT/StringExtras.h"
 #include "llvm/Support/CrashRecoveryContext.h"
+#include "llvm/Support/Compiler.h"
 #include "llvm/Support/ErrorHandling.h"
 #include <algorithm>
-using namespace clang;
+#include <cassert>
+#include <cstdint>
+#include <limits>
+#include <string>
+#include <vector>
 
-#include "llvm/Support/raw_ostream.h"
+using namespace clang;
 
 // Out-of-line destructor to provide a home for the class.
 PragmaHandler::~PragmaHandler() {
@@ -123,6 +138,7 @@ void Preprocessor::HandlePragmaDirective(SourceLocation IntroducerLoc,
 }
 
 namespace {
+
 /// \brief Helper class for \see Preprocessor::Handle_Pragma.
 class LexingFor_PragmaRAII {
   Preprocessor &PP;
@@ -157,7 +173,8 @@ public:
     Failed = true;
   }
 };
-}
+
+} // end anonymous namespace
 
 /// Handle_Pragma - Read a _Pragma directive, slice it up, process it, then
 /// return the first token after the directive.  The _Pragma token has just
@@ -264,7 +281,7 @@ void Preprocessor::Handle_Pragma(Token &Tok) {
 
     // Remove escaped quotes and escapes.
     unsigned ResultPos = 1;
-    for (unsigned i = 1, e = StrVal.size() - 1; i != e; ++i) {
+    for (size_t i = 1, e = StrVal.size() - 1; i != e; ++i) {
       // Skip escapes.  \\ -> '\' and \" -> '"'.
       if (StrVal[i] == '\\' && i + 1 < e &&
           (StrVal[i + 1] == '\\' || StrVal[i + 1] == '"'))
@@ -355,8 +372,10 @@ void Preprocessor::HandleMicrosoft__pragma(Token &Tok) {
 ///
 void Preprocessor::HandlePragmaOnce(Token &OnceTok) {
   // Don't honor the 'once' when handling the primary source file, unless
-  // this is a prefix to a TU, which indicates we're generating a PCH file.
-  if (isInPrimaryFile() && TUKind != TU_Prefix) {
+  // this is a prefix to a TU, which indicates we're generating a PCH file, or
+  // when the main file is a header (e.g. when -xc-header is provided on the
+  // commandline).
+  if (isInPrimaryFile() && TUKind != TU_Prefix && !getLangOpts().IsHeaderFile) {
     Diag(OnceTok, diag::pp_pragma_once_in_main_file);
     return;
   }
@@ -374,13 +393,12 @@ void Preprocessor::HandlePragmaMark() {
     CurPTHLexer->DiscardToEndOfLine();
 }
 
-
 /// HandlePragmaPoison - Handle \#pragma GCC poison.  PoisonTok is the 'poison'.
 ///
-void Preprocessor::HandlePragmaPoison(Token &PoisonTok) {
+void Preprocessor::HandlePragmaPoison() {
   Token Tok;
 
-  while (1) {
+  while (true) {
     // Read the next token to poison.  While doing this, pretend that we are
     // skipping while reading the identifier to poison.
     // This avoids errors on code like:
@@ -612,7 +630,7 @@ void Preprocessor::HandlePragmaPopMacro(Token &PopMacroTok) {
 
     // Pop PragmaPushMacroInfo stack.
     iter->second.pop_back();
-    if (iter->second.size() == 0)
+    if (iter->second.empty())
       PragmaPushMacroInfo.erase(iter);
   } else {
     Diag(MessageLoc, diag::warn_pragma_pop_macro_no_push)
@@ -809,6 +827,7 @@ bool Preprocessor::LexOnOffSwitch(tok::OnOffSwitch &Result) {
 }
 
 namespace {
+
 /// PragmaOnceHandler - "\#pragma once" marks the file as atomically included.
 struct PragmaOnceHandler : public PragmaHandler {
   PragmaOnceHandler() : PragmaHandler("once") {}
@@ -823,6 +842,7 @@ struct PragmaOnceHandler : public PragmaHandler {
 /// rest of the line is not lexed.
 struct PragmaMarkHandler : public PragmaHandler {
   PragmaMarkHandler() : PragmaHandler("mark") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &MarkTok) override {
     PP.HandlePragmaMark();
@@ -832,9 +852,10 @@ struct PragmaMarkHandler : public PragmaHandler {
 /// PragmaPoisonHandler - "\#pragma poison x" marks x as not usable.
 struct PragmaPoisonHandler : public PragmaHandler {
   PragmaPoisonHandler() : PragmaHandler("poison") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &PoisonTok) override {
-    PP.HandlePragmaPoison(PoisonTok);
+    PP.HandlePragmaPoison();
   }
 };
 
@@ -842,14 +863,17 @@ struct PragmaPoisonHandler : public PragmaHandler {
 /// as a system header, which silences warnings in it.
 struct PragmaSystemHeaderHandler : public PragmaHandler {
   PragmaSystemHeaderHandler() : PragmaHandler("system_header") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &SHToken) override {
     PP.HandlePragmaSystemHeader(SHToken);
     PP.CheckEndOfDirective("pragma");
   }
 };
+
 struct PragmaDependencyHandler : public PragmaHandler {
   PragmaDependencyHandler() : PragmaHandler("dependency") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &DepToken) override {
     PP.HandlePragmaDependency(DepToken);
@@ -858,6 +882,7 @@ struct PragmaDependencyHandler : public PragmaHandler {
 
 struct PragmaDebugHandler : public PragmaHandler {
   PragmaDebugHandler() : PragmaHandler("__debug") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &DepToken) override {
     Token Tok;
@@ -967,9 +992,11 @@ struct PragmaDebugHandler : public PragmaHandler {
 struct PragmaDiagnosticHandler : public PragmaHandler {
 private:
   const char *Namespace;
+
 public:
   explicit PragmaDiagnosticHandler(const char *NS) :
     PragmaHandler("diagnostic"), Namespace(NS) {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &DiagToken) override {
     SourceLocation DiagLoc = DiagToken.getLocation();
@@ -1142,7 +1169,7 @@ struct PragmaWarningHandler : public PragmaHandler {
         while (Tok.is(tok::numeric_constant)) {
           uint64_t Value;
           if (!PP.parseSimpleIntegerLiteral(Tok, Value) || Value == 0 ||
-              Value > INT_MAX) {
+              Value > std::numeric_limits<int>::max()) {
             PP.Diag(Tok, diag::warn_pragma_warning_expected_number);
             return;
           }
@@ -1267,17 +1294,18 @@ public:
 /// macro on the top of the stack.
 struct PragmaPushMacroHandler : public PragmaHandler {
   PragmaPushMacroHandler() : PragmaHandler("push_macro") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &PushMacroTok) override {
     PP.HandlePragmaPushMacro(PushMacroTok);
   }
 };
 
-
 /// PragmaPopMacroHandler - "\#pragma pop_macro" sets the value of the
 /// macro to the value on the top of the stack.
 struct PragmaPopMacroHandler : public PragmaHandler {
   PragmaPopMacroHandler() : PragmaHandler("pop_macro") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &PopMacroTok) override {
     PP.HandlePragmaPopMacro(PopMacroTok);
@@ -1289,6 +1317,7 @@ struct PragmaPopMacroHandler : public PragmaHandler {
 /// PragmaSTDC_FENV_ACCESSHandler - "\#pragma STDC FENV_ACCESS ...".
 struct PragmaSTDC_FENV_ACCESSHandler : public PragmaHandler {
   PragmaSTDC_FENV_ACCESSHandler() : PragmaHandler("FENV_ACCESS") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &Tok) override {
     tok::OnOffSwitch OOS;
@@ -1303,6 +1332,7 @@ struct PragmaSTDC_FENV_ACCESSHandler : public PragmaHandler {
 struct PragmaSTDC_CX_LIMITED_RANGEHandler : public PragmaHandler {
   PragmaSTDC_CX_LIMITED_RANGEHandler()
     : PragmaHandler("CX_LIMITED_RANGE") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &Tok) override {
     tok::OnOffSwitch OOS;
@@ -1313,6 +1343,7 @@ struct PragmaSTDC_CX_LIMITED_RANGEHandler : public PragmaHandler {
 /// PragmaSTDC_UnknownHandler - "\#pragma STDC ...".
 struct PragmaSTDC_UnknownHandler : public PragmaHandler {
   PragmaSTDC_UnknownHandler() {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &UnknownTok) override {
     // C99 6.10.6p2, unknown forms are not allowed.
@@ -1324,6 +1355,7 @@ struct PragmaSTDC_UnknownHandler : public PragmaHandler {
 ///   \#pragma clang arc_cf_code_audited begin/end
 struct PragmaARCCFCodeAuditedHandler : public PragmaHandler {
   PragmaARCCFCodeAuditedHandler() : PragmaHandler("arc_cf_code_audited") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &NameTok) override {
     SourceLocation Loc = NameTok.getLocation();
@@ -1378,6 +1410,7 @@ struct PragmaARCCFCodeAuditedHandler : public PragmaHandler {
 ///   \#pragma clang assume_nonnull begin/end
 struct PragmaAssumeNonNullHandler : public PragmaHandler {
   PragmaAssumeNonNullHandler() : PragmaHandler("assume_nonnull") {}
+
   void HandlePragma(Preprocessor &PP, PragmaIntroducerKind Introducer,
                     Token &NameTok) override {
     SourceLocation Loc = NameTok.getLocation();
@@ -1451,8 +1484,7 @@ struct PragmaRegionHandler : public PragmaHandler {
   }
 };
 
-}  // end anonymous namespace
-
+} // end anonymous namespace
 
 /// RegisterBuiltinPragmas - Install the standard preprocessor pragmas:
 /// \#pragma GCC poison/system_header/dependency and \#pragma once.
diff --git a/contrib/llvm/tools/clang/lib/Lex/PreprocessingRecord.cpp b/contrib/llvm/tools/clang/lib/Lex/PreprocessingRecord.cpp
index 32e6de6..13e15f3 100644
--- a/contrib/llvm/tools/clang/lib/Lex/PreprocessingRecord.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/PreprocessingRecord.cpp
@@ -21,18 +21,13 @@ using namespace clang;
 
 ExternalPreprocessingRecordSource::~ExternalPreprocessingRecordSource() { }
 
-
 InclusionDirective::InclusionDirective(PreprocessingRecord &PPRec,
-                                       InclusionKind Kind, 
-                                       StringRef FileName, 
+                                       InclusionKind Kind, StringRef FileName,
                                        bool InQuotes, bool ImportedModule,
-                                       const FileEntry *File,
-                                       SourceRange Range)
-  : PreprocessingDirective(InclusionDirectiveKind, Range), 
-    InQuotes(InQuotes), Kind(Kind), ImportedModule(ImportedModule), File(File)
-{ 
-  char *Memory 
-    = (char*)PPRec.Allocate(FileName.size() + 1, llvm::alignOf<char>());
+                                       const FileEntry *File, SourceRange Range)
+    : PreprocessingDirective(InclusionDirectiveKind, Range), InQuotes(InQuotes),
+      Kind(Kind), ImportedModule(ImportedModule), File(File) {
+  char *Memory = (char *)PPRec.Allocate(FileName.size() + 1, alignof(char));
   memcpy(Memory, FileName.data(), FileName.size());
   Memory[FileName.size()] = 0;
   this->FileName = StringRef(Memory, FileName.size());
diff --git a/contrib/llvm/tools/clang/lib/Lex/Preprocessor.cpp b/contrib/llvm/tools/clang/lib/Lex/Preprocessor.cpp
index 78179dd..91319be 100644
--- a/contrib/llvm/tools/clang/lib/Lex/Preprocessor.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/Preprocessor.cpp
@@ -43,23 +43,32 @@
 #include "clang/Lex/PreprocessingRecord.h"
 #include "clang/Lex/PreprocessorOptions.h"
 #include "clang/Lex/ScratchBuffer.h"
-#include "llvm/ADT/APFloat.h"
-#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/APInt.h"
+#include "llvm/ADT/DenseMap.h"
 #include "llvm/ADT/SmallString.h"
-#include "llvm/ADT/StringExtras.h"
+#include "llvm/ADT/SmallVector.h"
+#include "llvm/ADT/STLExtras.h"
+#include "llvm/ADT/StringRef.h"
+#include "llvm/ADT/StringSwitch.h"
 #include "llvm/Support/Capacity.h"
-#include "llvm/Support/ConvertUTF.h"
+#include "llvm/Support/ErrorHandling.h"
 #include "llvm/Support/MemoryBuffer.h"
 #include "llvm/Support/raw_ostream.h"
+#include <algorithm>
+#include <cassert>
+#include <memory>
+#include <string>
 #include <utility>
+#include <vector>
+
 using namespace clang;
 
-template class llvm::Registry<clang::PragmaHandler>;
+LLVM_INSTANTIATE_REGISTRY(PragmaHandlerRegistry)
 
 //===----------------------------------------------------------------------===//
 ExternalPreprocessorSource::~ExternalPreprocessorSource() { }
 
-Preprocessor::Preprocessor(IntrusiveRefCntPtr<PreprocessorOptions> PPOpts,
+Preprocessor::Preprocessor(std::shared_ptr<PreprocessorOptions> PPOpts,
                            DiagnosticsEngine &diags, LangOptions &opts,
                            SourceManager &SM, HeaderSearch &Headers,
                            ModuleLoader &TheModuleLoader,
@@ -74,11 +83,12 @@ Preprocessor::Preprocessor(IntrusiveRefCntPtr<PreprocessorOptions> PPOpts,
       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) {
+      CodeCompletionReached(false), CodeCompletionII(nullptr),
+      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.
@@ -480,7 +490,7 @@ void Preprocessor::CreateString(StringRef Str, Token &Tok,
 }
 
 Module *Preprocessor::getCurrentModule() {
-  if (!getLangOpts().CompilingModule)
+  if (!getLangOpts().isCompilingModule())
     return nullptr;
 
   return getHeaderSearchInfo().lookupModule(getLangOpts().CurrentModule);
@@ -490,7 +500,6 @@ Module *Preprocessor::getCurrentModule() {
 // Preprocessor Initialization Methods
 //===----------------------------------------------------------------------===//
 
-
 /// EnterMainSourceFile - Enter the specified FileID as the main source file,
 /// which implicitly adds the builtin defines etc.
 void Preprocessor::EnterMainSourceFile() {
@@ -618,6 +627,11 @@ static diag::kind getFutureCompatDiagKind(const IdentifierInfo &II,
       "Keyword not known to come from a newer Standard or proposed Standard");
 }
 
+void Preprocessor::updateOutOfDateIdentifier(IdentifierInfo &II) const {
+  assert(II.isOutOfDate() && "not out of date");
+  getExternalSource()->updateOutOfDateIdentifier(II);
+}
+
 /// HandleIdentifier - This callback is invoked when the lexer reads an
 /// identifier.  This callback looks up the identifier in the map and/or
 /// potentially macro expands it or turns it into a named token (like 'for').
@@ -642,7 +656,7 @@ bool Preprocessor::HandleIdentifier(Token &Identifier) {
     if (&II == Ident__VA_ARGS__)
       CurrentIsPoisoned = Ident__VA_ARGS__->isPoisoned();
 
-    ExternalSource->updateOutOfDateIdentifier(II);
+    updateOutOfDateIdentifier(II);
     Identifier.setKind(II.getTokenID());
 
     if (&II == Ident__VA_ARGS__)
@@ -707,9 +721,12 @@ bool Preprocessor::HandleIdentifier(Token &Identifier) {
   // Note that we do not treat 'import' as a contextual
   // keyword when we're in a caching lexer, because caching lexers only get
   // used in contexts where import declarations are disallowed.
-  if (LastTokenWasAt && II.isModulesImport() && !InMacroArgs && 
-      !DisableMacroExpansion &&
-      (getLangOpts().Modules || getLangOpts().DebuggerSupport) && 
+  //
+  // Likewise if this is the C++ Modules TS import keyword.
+  if (((LastTokenWasAt && II.isModulesImport()) ||
+       Identifier.is(tok::kw_import)) &&
+      !InMacroArgs && !DisableMacroExpansion &&
+      (getLangOpts().Modules || getLangOpts().DebuggerSupport) &&
       CurLexerKind != CLK_CachingLexer) {
     ModuleImportLoc = Identifier.getLocation();
     ModuleImportPath.clear();
@@ -744,10 +761,12 @@ void Preprocessor::Lex(Token &Result) {
     }
   } while (!ReturnedToken);
 
+  if (Result.is(tok::code_completion))
+    setCodeCompletionIdentifierInfo(Result.getIdentifierInfo());
+
   LastTokenWasAt = Result.is(tok::at);
 }
 
-
 /// \brief Lex a token following the 'import' contextual keyword.
 ///
 void Preprocessor::LexAfterModuleImport(Token &Result) {
@@ -774,7 +793,8 @@ void Preprocessor::LexAfterModuleImport(Token &Result) {
   }
   
   // If we're expecting a '.' or a ';', and we got a '.', then wait until we
-  // see the next identifier.
+  // see the next identifier. (We can also see a '[[' that begins an
+  // attribute-specifier-seq here under the C++ Modules TS.)
   if (!ModuleImportExpectsIdentifier && Result.getKind() == tok::period) {
     ModuleImportExpectsIdentifier = true;
     CurLexerKind = CLK_LexAfterModuleImport;
@@ -783,6 +803,23 @@ void Preprocessor::LexAfterModuleImport(Token &Result) {
 
   // If we have a non-empty module path, load the named module.
   if (!ModuleImportPath.empty()) {
+    // Under the Modules TS, the dot is just part of the module name, and not
+    // a real hierarachy separator. Flatten such module names now.
+    //
+    // FIXME: Is this the right level to be performing this transformation?
+    std::string FlatModuleName;
+    if (getLangOpts().ModulesTS) {
+      for (auto &Piece : ModuleImportPath) {
+        if (!FlatModuleName.empty())
+          FlatModuleName += ".";
+        FlatModuleName += Piece.first->getName();
+      }
+      SourceLocation FirstPathLoc = ModuleImportPath[0].second;
+      ModuleImportPath.clear();
+      ModuleImportPath.push_back(
+          std::make_pair(getIdentifierInfo(FlatModuleName), FirstPathLoc));
+    }
+
     Module *Imported = nullptr;
     if (getLangOpts().Modules) {
       Imported = TheModuleLoader.loadModule(ModuleImportLoc,
diff --git a/contrib/llvm/tools/clang/lib/Lex/TokenConcatenation.cpp b/contrib/llvm/tools/clang/lib/Lex/TokenConcatenation.cpp
index 27b4eab..d1facd9 100644
--- a/contrib/llvm/tools/clang/lib/Lex/TokenConcatenation.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/TokenConcatenation.cpp
@@ -232,7 +232,7 @@ bool TokenConcatenation::AvoidConcat(const Token &PrevPrevTok,
     // it as an identifier.
     if (!PrevTok.hasUDSuffix())
       return false;
-    // FALL THROUGH.
+    LLVM_FALLTHROUGH;
   case tok::identifier:   // id+id or id+number or id+L"foo".
     // id+'.'... will not append.
     if (Tok.is(tok::numeric_constant))
diff --git a/contrib/llvm/tools/clang/lib/Lex/TokenLexer.cpp b/contrib/llvm/tools/clang/lib/Lex/TokenLexer.cpp
index 994bae6..a53c801 100644
--- a/contrib/llvm/tools/clang/lib/Lex/TokenLexer.cpp
+++ b/contrib/llvm/tools/clang/lib/Lex/TokenLexer.cpp
@@ -275,7 +275,7 @@ void TokenLexer::ExpandFunctionArguments() {
 
       // If the arg token expanded into anything, append it.
       if (ResultArgToks->isNot(tok::eof)) {
-        unsigned FirstResult = ResultToks.size();
+        size_t FirstResult = ResultToks.size();
         unsigned NumToks = MacroArgs::getArgLength(ResultArgToks);
         ResultToks.append(ResultArgToks, ResultArgToks+NumToks);
 
@@ -289,8 +289,8 @@ void TokenLexer::ExpandFunctionArguments() {
 
         // If the '##' came from expanding an argument, turn it into 'unknown'
         // to avoid pasting.
-        for (unsigned i = FirstResult, e = ResultToks.size(); i != e; ++i) {
-          Token &Tok = ResultToks[i];
+        for (Token &Tok : llvm::make_range(ResultToks.begin() + FirstResult,
+                                           ResultToks.end())) {
           if (Tok.is(tok::hashhash))
             Tok.setKind(tok::unknown);
         }
@@ -333,9 +333,8 @@ void TokenLexer::ExpandFunctionArguments() {
 
       // If the '##' came from expanding an argument, turn it into 'unknown'
       // to avoid pasting.
-      for (unsigned i = ResultToks.size() - NumToks, e = ResultToks.size();
-             i != e; ++i) {
-        Token &Tok = ResultToks[i];
+      for (Token &Tok : llvm::make_range(ResultToks.end() - NumToks,
+                                         ResultToks.end())) {
         if (Tok.is(tok::hashhash))
           Tok.setKind(tok::unknown);
       }