Remove LLVM 8.0.1 files.

1 files changed, 0 insertions, 1825 deletions

diff --git a/gnu/llvm/tools/clang/lib/Lex/PPMacroExpansion.cpp b/gnu/llvm/tools/clang/lib/Lex/PPMacroExpansion.cpp
deleted file mode 100644
index c70ff46ec90..00000000000
--- a/gnu/llvm/tools/clang/lib/Lex/PPMacroExpansion.cpp
+++ /dev/null
@@ -1,1825 +0,0 @@
-//===--- MacroExpansion.cpp - Top level Macro Expansion -------------------===//
-//
-//                     The LLVM Compiler Infrastructure
-//
-// This file is distributed under the University of Illinois Open Source
-// License. See LICENSE.TXT for details.
-//
-//===----------------------------------------------------------------------===//
-//
-// This file implements the top level handling of macro expansion for the
-// preprocessor.
-//
-//===----------------------------------------------------------------------===//
-
-#include "clang/Basic/Attributes.h"
-#include "clang/Basic/FileManager.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/HeaderSearch.h"
-#include "clang/Lex/LexDiagnostic.h"
-#include "clang/Lex/MacroArgs.h"
-#include "clang/Lex/MacroInfo.h"
-#include "clang/Lex/Preprocessor.h"
-#include "clang/Lex/PreprocessorLexer.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/Support/Casting.h"
-#include "llvm/Support/ErrorHandling.h"
-#include "llvm/Support/Format.h"
-#include "llvm/Support/raw_ostream.h"
-#include <algorithm>
-#include <cassert>
-#include <cstddef>
-#include <cstring>
-#include <ctime>
-#include <string>
-#include <tuple>
-#include <utility>
-
-using namespace clang;
-
-MacroDirective *
-Preprocessor::getLocalMacroDirectiveHistory(const IdentifierInfo *II) const {
-  if (!II->hadMacroDefinition())
-    return nullptr;
-  auto Pos = CurSubmoduleState->Macros.find(II);
-  return Pos == CurSubmoduleState->Macros.end() ? nullptr
-                                                : Pos->second.getLatest();
-}
-
-void Preprocessor::appendMacroDirective(IdentifierInfo *II, MacroDirective *MD){
-  assert(MD && "MacroDirective should be non-zero!");
-  assert(!MD->getPrevious() && "Already attached to a MacroDirective history.");
-
-  MacroState &StoredMD = CurSubmoduleState->Macros[II];
-  auto *OldMD = StoredMD.getLatest();
-  MD->setPrevious(OldMD);
-  StoredMD.setLatest(MD);
-  StoredMD.overrideActiveModuleMacros(*this, II);
-
-  if (needModuleMacros()) {
-    // Track that we created a new macro directive, so we know we should
-    // consider building a ModuleMacro for it when we get to the end of
-    // the module.
-    PendingModuleMacroNames.push_back(II);
-  }
-
-  // Set up the identifier as having associated macro history.
-  II->setHasMacroDefinition(true);
-  if (!MD->isDefined() && LeafModuleMacros.find(II) == LeafModuleMacros.end())
-    II->setHasMacroDefinition(false);
-  if (II->isFromAST())
-    II->setChangedSinceDeserialization();
-}
-
-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];
-
-  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())
-    II->setHasMacroDefinition(false);
-}
-
-ModuleMacro *Preprocessor::addModuleMacro(Module *Mod, IdentifierInfo *II,
-                                          MacroInfo *Macro,
-                                          ArrayRef<ModuleMacro *> Overrides,
-                                          bool &New) {
-  llvm::FoldingSetNodeID ID;
-  ModuleMacro::Profile(ID, Mod, II);
-
-  void *InsertPos;
-  if (auto *MM = ModuleMacros.FindNodeOrInsertPos(ID, InsertPos)) {
-    New = false;
-    return MM;
-  }
-
-  auto *MM = ModuleMacro::create(*this, Mod, II, Macro, Overrides);
-  ModuleMacros.InsertNode(MM, InsertPos);
-
-  // Each overridden macro is now overridden by one more macro.
-  bool HidAny = false;
-  for (auto *O : Overrides) {
-    HidAny |= (O->NumOverriddenBy == 0);
-    ++O->NumOverriddenBy;
-  }
-
-  // If we were the first overrider for any macro, it's no longer a leaf.
-  auto &LeafMacros = LeafModuleMacros[II];
-  if (HidAny) {
-    LeafMacros.erase(std::remove_if(LeafMacros.begin(), LeafMacros.end(),
-                                    [](ModuleMacro *MM) {
-                                      return MM->NumOverriddenBy != 0;
-                                    }),
-                     LeafMacros.end());
-  }
-
-  // The new macro is always a leaf macro.
-  LeafMacros.push_back(MM);
-  // The identifier now has defined macros (that may or may not be visible).
-  II->setHasMacroDefinition(true);
-
-  New = true;
-  return MM;
-}
-
-ModuleMacro *Preprocessor::getModuleMacro(Module *Mod, IdentifierInfo *II) {
-  llvm::FoldingSetNodeID ID;
-  ModuleMacro::Profile(ID, Mod, II);
-
-  void *InsertPos;
-  return ModuleMacros.FindNodeOrInsertPos(ID, InsertPos);
-}
-
-void Preprocessor::updateModuleMacroInfo(const IdentifierInfo *II,
-                                         ModuleMacroInfo &Info) {
-  assert(Info.ActiveModuleMacrosGeneration !=
-             CurSubmoduleState->VisibleModules.getGeneration() &&
-         "don't need to update this macro name info");
-  Info.ActiveModuleMacrosGeneration =
-      CurSubmoduleState->VisibleModules.getGeneration();
-
-  auto Leaf = LeafModuleMacros.find(II);
-  if (Leaf == LeafModuleMacros.end()) {
-    // No imported macros at all: nothing to do.
-    return;
-  }
-
-  Info.ActiveModuleMacros.clear();
-
-  // Every macro that's locally overridden is overridden by a visible macro.
-  llvm::DenseMap<ModuleMacro *, int> NumHiddenOverrides;
-  for (auto *O : Info.OverriddenMacros)
-    NumHiddenOverrides[O] = -1;
-
-  // Collect all macros that are not overridden by a visible macro.
-  llvm::SmallVector<ModuleMacro *, 16> Worklist;
-  for (auto *LeafMM : Leaf->second) {
-    assert(LeafMM->getNumOverridingMacros() == 0 && "leaf macro overridden");
-    if (NumHiddenOverrides.lookup(LeafMM) == 0)
-      Worklist.push_back(LeafMM);
-  }
-  while (!Worklist.empty()) {
-    auto *MM = Worklist.pop_back_val();
-    if (CurSubmoduleState->VisibleModules.isVisible(MM->getOwningModule())) {
-      // We only care about collecting definitions; undefinitions only act
-      // to override other definitions.
-      if (MM->getMacroInfo())
-        Info.ActiveModuleMacros.push_back(MM);
-    } else {
-      for (auto *O : MM->overrides())
-        if ((unsigned)++NumHiddenOverrides[O] == O->getNumOverridingMacros())
-          Worklist.push_back(O);
-    }
-  }
-  // Our reverse postorder walk found the macros in reverse order.
-  std::reverse(Info.ActiveModuleMacros.begin(), Info.ActiveModuleMacros.end());
-
-  // Determine whether the macro name is ambiguous.
-  MacroInfo *MI = nullptr;
-  bool IsSystemMacro = true;
-  bool IsAmbiguous = false;
-  if (auto *MD = Info.MD) {
-    while (MD && isa<VisibilityMacroDirective>(MD))
-      MD = MD->getPrevious();
-    if (auto *DMD = dyn_cast_or_null<DefMacroDirective>(MD)) {
-      MI = DMD->getInfo();
-      IsSystemMacro &= SourceMgr.isInSystemHeader(DMD->getLocation());
-    }
-  }
-  for (auto *Active : Info.ActiveModuleMacros) {
-    auto *NewMI = Active->getMacroInfo();
-
-    // Before marking the macro as ambiguous, check if this is a case where
-    // both macros are in system headers. If so, we trust that the system
-    // did not get it wrong. This also handles cases where Clang's own
-    // headers have a different spelling of certain system macros:
-    //   #define LONG_MAX __LONG_MAX__ (clang's limits.h)
-    //   #define LONG_MAX 0x7fffffffffffffffL (system's limits.h)
-    //
-    // FIXME: Remove the defined-in-system-headers check. clang's limits.h
-    // overrides the system limits.h's macros, so there's no conflict here.
-    if (MI && NewMI != MI &&
-        !MI->isIdenticalTo(*NewMI, *this, /*Syntactically=*/true))
-      IsAmbiguous = true;
-    IsSystemMacro &= Active->getOwningModule()->IsSystem ||
-                     SourceMgr.isInSystemHeader(NewMI->getDefinitionLoc());
-    MI = NewMI;
-  }
-  Info.IsAmbiguous = IsAmbiguous && !IsSystemMacro;
-}
-
-void Preprocessor::dumpMacroInfo(const IdentifierInfo *II) {
-  ArrayRef<ModuleMacro*> Leaf;
-  auto LeafIt = LeafModuleMacros.find(II);
-  if (LeafIt != LeafModuleMacros.end())
-    Leaf = LeafIt->second;
-  const MacroState *State = nullptr;
-  auto Pos = CurSubmoduleState->Macros.find(II);
-  if (Pos != CurSubmoduleState->Macros.end())
-    State = &Pos->second;
-
-  llvm::errs() << "MacroState " << State << " " << II->getNameStart();
-  if (State && State->isAmbiguous(*this, II))
-    llvm::errs() << " ambiguous";
-  if (State && !State->getOverriddenMacros().empty()) {
-    llvm::errs() << " overrides";
-    for (auto *O : State->getOverriddenMacros())
-      llvm::errs() << " " << O->getOwningModule()->getFullModuleName();
-  }
-  llvm::errs() << "\n";
-
-  // Dump local macro directives.
-  for (auto *MD = State ? State->getLatest() : nullptr; MD;
-       MD = MD->getPrevious()) {
-    llvm::errs() << " ";
-    MD->dump();
-  }
-
-  // Dump module macros.
-  llvm::DenseSet<ModuleMacro*> Active;
-  for (auto *MM : State ? State->getActiveModuleMacros(*this, II) : None)
-    Active.insert(MM);
-  llvm::DenseSet<ModuleMacro*> Visited;
-  llvm::SmallVector<ModuleMacro *, 16> Worklist(Leaf.begin(), Leaf.end());
-  while (!Worklist.empty()) {
-    auto *MM = Worklist.pop_back_val();
-    llvm::errs() << " ModuleMacro " << MM << " "
-                 << MM->getOwningModule()->getFullModuleName();
-    if (!MM->getMacroInfo())
-      llvm::errs() << " undef";
-
-    if (Active.count(MM))
-      llvm::errs() << " active";
-    else if (!CurSubmoduleState->VisibleModules.isVisible(
-                 MM->getOwningModule()))
-      llvm::errs() << " hidden";
-    else if (MM->getMacroInfo())
-      llvm::errs() << " overridden";
-
-    if (!MM->overrides().empty()) {
-      llvm::errs() << " overrides";
-      for (auto *O : MM->overrides()) {
-        llvm::errs() << " " << O->getOwningModule()->getFullModuleName();
-        if (Visited.insert(O).second)
-          Worklist.push_back(O);
-      }
-    }
-    llvm::errs() << "\n";
-    if (auto *MI = MM->getMacroInfo()) {
-      llvm::errs() << "  ";
-      MI->dump();
-      llvm::errs() << "\n";
-    }
-  }
-}
-
-/// RegisterBuiltinMacro - Register the specified identifier in the identifier
-/// table and mark it as a builtin macro to be expanded.
-static IdentifierInfo *RegisterBuiltinMacro(Preprocessor &PP, const char *Name){
-  // Get the identifier.
-  IdentifierInfo *Id = PP.getIdentifierInfo(Name);
-
-  // Mark it as being a macro that is builtin.
-  MacroInfo *MI = PP.AllocateMacroInfo(SourceLocation());
-  MI->setIsBuiltinMacro();
-  PP.appendDefMacroDirective(Id, MI);
-  return Id;
-}
-
-/// RegisterBuiltinMacros - Register builtin macros, such as __LINE__ with the
-/// identifier table.
-void Preprocessor::RegisterBuiltinMacros() {
-  Ident__LINE__ = RegisterBuiltinMacro(*this, "__LINE__");
-  Ident__FILE__ = RegisterBuiltinMacro(*this, "__FILE__");
-  Ident__DATE__ = RegisterBuiltinMacro(*this, "__DATE__");
-  Ident__TIME__ = RegisterBuiltinMacro(*this, "__TIME__");
-  Ident__COUNTER__ = RegisterBuiltinMacro(*this, "__COUNTER__");
-  Ident_Pragma  = RegisterBuiltinMacro(*this, "_Pragma");
-
-  // C++ Standing Document Extensions.
-  if (LangOpts.CPlusPlus)
-    Ident__has_cpp_attribute =
-        RegisterBuiltinMacro(*this, "__has_cpp_attribute");
-  else
-    Ident__has_cpp_attribute = nullptr;
-
-  // GCC Extensions.
-  Ident__BASE_FILE__     = RegisterBuiltinMacro(*this, "__BASE_FILE__");
-  Ident__INCLUDE_LEVEL__ = RegisterBuiltinMacro(*this, "__INCLUDE_LEVEL__");
-  Ident__TIMESTAMP__     = RegisterBuiltinMacro(*this, "__TIMESTAMP__");
-
-  // Microsoft Extensions.
-  if (LangOpts.MicrosoftExt) {
-    Ident__identifier = RegisterBuiltinMacro(*this, "__identifier");
-    Ident__pragma = RegisterBuiltinMacro(*this, "__pragma");
-  } else {
-    Ident__identifier = nullptr;
-    Ident__pragma = nullptr;
-  }
-
-  // Clang Extensions.
-  Ident__has_feature      = RegisterBuiltinMacro(*this, "__has_feature");
-  Ident__has_extension    = RegisterBuiltinMacro(*this, "__has_extension");
-  Ident__has_builtin      = RegisterBuiltinMacro(*this, "__has_builtin");
-  Ident__has_attribute    = RegisterBuiltinMacro(*this, "__has_attribute");
-  Ident__has_c_attribute  = RegisterBuiltinMacro(*this, "__has_c_attribute");
-  Ident__has_declspec = RegisterBuiltinMacro(*this, "__has_declspec_attribute");
-  Ident__has_include      = RegisterBuiltinMacro(*this, "__has_include");
-  Ident__has_include_next = RegisterBuiltinMacro(*this, "__has_include_next");
-  Ident__has_warning      = RegisterBuiltinMacro(*this, "__has_warning");
-  Ident__is_identifier    = RegisterBuiltinMacro(*this, "__is_identifier");
-  Ident__is_target_arch   = RegisterBuiltinMacro(*this, "__is_target_arch");
-  Ident__is_target_vendor = RegisterBuiltinMacro(*this, "__is_target_vendor");
-  Ident__is_target_os     = RegisterBuiltinMacro(*this, "__is_target_os");
-  Ident__is_target_environment =
-      RegisterBuiltinMacro(*this, "__is_target_environment");
-
-  // Modules.
-  Ident__building_module  = RegisterBuiltinMacro(*this, "__building_module");
-  if (!LangOpts.CurrentModule.empty())
-    Ident__MODULE__ = RegisterBuiltinMacro(*this, "__MODULE__");
-  else
-    Ident__MODULE__ = nullptr;
-}
-
-/// isTrivialSingleTokenExpansion - Return true if MI, which has a single token
-/// in its expansion, currently expands to that token literally.
-static bool isTrivialSingleTokenExpansion(const MacroInfo *MI,
-                                          const IdentifierInfo *MacroIdent,
-                                          Preprocessor &PP) {
-  IdentifierInfo *II = MI->getReplacementToken(0).getIdentifierInfo();
-
-  // If the token isn't an identifier, it's always literally expanded.
-  if (!II) return true;
-
-  // If the information about this identifier is out of date, update it from
-  // the external source.
-  if (II->isOutOfDate())
-    PP.getExternalSource()->updateOutOfDateIdentifier(*II);
-
-  // If the identifier is a macro, and if that macro is enabled, it may be
-  // expanded so it's not a trivial expansion.
-  if (auto *ExpansionMI = PP.getMacroInfo(II))
-    if (ExpansionMI->isEnabled() &&
-        // Fast expanding "#define X X" is ok, because X would be disabled.
-        II != MacroIdent)
-      return false;
-
-  // If this is an object-like macro invocation, it is safe to trivially expand
-  // it.
-  if (MI->isObjectLike()) return true;
-
-  // 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->param_begin(), MI->param_end(), II) == MI->param_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.
-bool Preprocessor::isNextPPTokenLParen() {
-  // Do some quick tests for rejection cases.
-  unsigned Val;
-  if (CurLexer)
-    Val = CurLexer->isNextPPTokenLParen();
-  else
-    Val = CurTokenLexer->isNextTokenLParen();
-
-  if (Val == 2) {
-    // We have run off the end.  If it's a source file we don't
-    // examine enclosing ones (C99 5.1.1.2p4).  Otherwise walk up the
-    // macro stack.
-    if (CurPPLexer)
-      return false;
-    for (const IncludeStackInfo &Entry : llvm::reverse(IncludeMacroStack)) {
-      if (Entry.TheLexer)
-        Val = Entry.TheLexer->isNextPPTokenLParen();
-      else
-        Val = Entry.TheTokenLexer->isNextTokenLParen();
-
-      if (Val != 2)
-        break;
-
-      // Ran off the end of a source file?
-      if (Entry.ThePPLexer)
-        return false;
-    }
-  }
-
-  // Okay, if we know that the token is a '(', lex it and return.  Otherwise we
-  // have found something that isn't a '(' or we found the end of the
-  // translation unit.  In either case, return false.
-  return Val == 1;
-}
-
-/// HandleMacroExpandedIdentifier - If an identifier token is read that is to be
-/// expanded as a macro, handle it and return the next token as 'Identifier'.
-bool Preprocessor::HandleMacroExpandedIdentifier(Token &Identifier,
-                                                 const MacroDefinition &M) {
-  MacroInfo *MI = M.getMacroInfo();
-
-  // If this is a macro expansion in the "#if !defined(x)" line for the file,
-  // then the macro could expand to different things in other contexts, we need
-  // to disable the optimization in this case.
-  if (CurPPLexer) CurPPLexer->MIOpt.ExpandedMacro();
-
-  // If this is a builtin macro, like __LINE__ or _Pragma, handle it specially.
-  if (MI->isBuiltinMacro()) {
-    if (Callbacks)
-      Callbacks->MacroExpands(Identifier, M, Identifier.getLocation(),
-                              /*Args=*/nullptr);
-    ExpandBuiltinMacro(Identifier);
-    return true;
-  }
-
-  /// Args - If this is a function-like macro expansion, this contains,
-  /// for each macro argument, the list of tokens that were provided to the
-  /// invocation.
-  MacroArgs *Args = nullptr;
-
-  // Remember where the end of the expansion occurred.  For an object-like
-  // macro, this is the identifier.  For a function-like macro, this is the ')'.
-  SourceLocation ExpansionEnd = Identifier.getLocation();
-
-  // If this is a function-like macro, read the arguments.
-  if (MI->isFunctionLike()) {
-    // Remember that we are now parsing the arguments to a macro invocation.
-    // Preprocessor directives used inside macro arguments are not portable, and
-    // this enables the warning.
-    InMacroArgs = true;
-    Args = ReadMacroCallArgumentList(Identifier, MI, ExpansionEnd);
-
-    // Finished parsing args.
-    InMacroArgs = false;
-
-    // If there was an error parsing the arguments, bail out.
-    if (!Args) return true;
-
-    ++NumFnMacroExpanded;
-  } else {
-    ++NumMacroExpanded;
-  }
-
-  // Notice that this macro has been used.
-  markMacroAsUsed(MI);
-
-  // Remember where the token is expanded.
-  SourceLocation ExpandLoc = Identifier.getLocation();
-  SourceRange ExpansionRange(ExpandLoc, ExpansionEnd);
-
-  if (Callbacks) {
-    if (InMacroArgs) {
-      // We can have macro expansion inside a conditional directive while
-      // reading the function macro arguments. To ensure, in that case, that
-      // MacroExpands callbacks still happen in source order, queue this
-      // callback to have it happen after the function macro callback.
-      DelayedMacroExpandsCallbacks.push_back(
-          MacroExpandsInfo(Identifier, M, ExpansionRange));
-    } else {
-      Callbacks->MacroExpands(Identifier, M, ExpansionRange, Args);
-      if (!DelayedMacroExpandsCallbacks.empty()) {
-        for (const MacroExpandsInfo &Info : DelayedMacroExpandsCallbacks) {
-          // FIXME: We lose macro args info with delayed callback.
-          Callbacks->MacroExpands(Info.Tok, Info.MD, Info.Range,
-                                  /*Args=*/nullptr);
-        }
-        DelayedMacroExpandsCallbacks.clear();
-      }
-    }
-  }
-
-  // If the macro definition is ambiguous, complain.
-  if (M.isAmbiguous()) {
-    Diag(Identifier, diag::warn_pp_ambiguous_macro)
-      << Identifier.getIdentifierInfo();
-    Diag(MI->getDefinitionLoc(), diag::note_pp_ambiguous_macro_chosen)
-      << Identifier.getIdentifierInfo();
-    M.forAllDefinitions([&](const MacroInfo *OtherMI) {
-      if (OtherMI != MI)
-        Diag(OtherMI->getDefinitionLoc(), diag::note_pp_ambiguous_macro_other)
-          << Identifier.getIdentifierInfo();
-    });
-  }
-
-  // If we started lexing a macro, enter the macro expansion body.
-
-  // If this macro expands to no tokens, don't bother to push it onto the
-  // expansion stack, only to take it right back off.
-  if (MI->getNumTokens() == 0) {
-    // No need for arg info.
-    if (Args) Args->destroy(*this);
-
-    // Propagate whitespace info as if we had pushed, then popped,
-    // a macro context.
-    Identifier.setFlag(Token::LeadingEmptyMacro);
-    PropagateLineStartLeadingSpaceInfo(Identifier);
-    ++NumFastMacroExpanded;
-    return false;
-  } else if (MI->getNumTokens() == 1 &&
-             isTrivialSingleTokenExpansion(MI, Identifier.getIdentifierInfo(),
-                                           *this)) {
-    // Otherwise, if this macro expands into a single trivially-expanded
-    // token: expand it now.  This handles common cases like
-    // "#define VAL 42".
-
-    // No need for arg info.
-    if (Args) Args->destroy(*this);
-
-    // Propagate the isAtStartOfLine/hasLeadingSpace markers of the macro
-    // identifier to the expanded token.
-    bool isAtStartOfLine = Identifier.isAtStartOfLine();
-    bool hasLeadingSpace = Identifier.hasLeadingSpace();
-
-    // Replace the result token.
-    Identifier = MI->getReplacementToken(0);
-
-    // Restore the StartOfLine/LeadingSpace markers.
-    Identifier.setFlagValue(Token::StartOfLine , isAtStartOfLine);
-    Identifier.setFlagValue(Token::LeadingSpace, hasLeadingSpace);
-
-    // Update the tokens location to include both its expansion and physical
-    // locations.
-    SourceLocation Loc =
-      SourceMgr.createExpansionLoc(Identifier.getLocation(), ExpandLoc,
-                                   ExpansionEnd,Identifier.getLength());
-    Identifier.setLocation(Loc);
-
-    // If this is a disabled macro or #define X X, we must mark the result as
-    // unexpandable.
-    if (IdentifierInfo *NewII = Identifier.getIdentifierInfo()) {
-      if (MacroInfo *NewMI = getMacroInfo(NewII))
-        if (!NewMI->isEnabled() || NewMI == MI) {
-          Identifier.setFlag(Token::DisableExpand);
-          // Don't warn for "#define X X" like "#define bool bool" from
-          // stdbool.h.
-          if (NewMI != MI || MI->isFunctionLike())
-            Diag(Identifier, diag::pp_disabled_macro_expansion);
-        }
-    }
-
-    // Since this is not an identifier token, it can't be macro expanded, so
-    // we're done.
-    ++NumFastMacroExpanded;
-    return true;
-  }
-
-  // Start expanding the macro.
-  EnterMacro(Identifier, ExpansionEnd, MI, Args);
-  return false;
-}
-
-enum Bracket {
-  Brace,
-  Paren
-};
-
-/// CheckMatchedBrackets - Returns true if the braces and parentheses in the
-/// token vector are properly nested.
-static bool CheckMatchedBrackets(const SmallVectorImpl<Token> &Tokens) {
-  SmallVector<Bracket, 8> Brackets;
-  for (SmallVectorImpl<Token>::const_iterator I = Tokens.begin(),
-                                              E = Tokens.end();
-       I != E; ++I) {
-    if (I->is(tok::l_paren)) {
-      Brackets.push_back(Paren);
-    } else if (I->is(tok::r_paren)) {
-      if (Brackets.empty() || Brackets.back() == Brace)
-        return false;
-      Brackets.pop_back();
-    } else if (I->is(tok::l_brace)) {
-      Brackets.push_back(Brace);
-    } else if (I->is(tok::r_brace)) {
-      if (Brackets.empty() || Brackets.back() == Paren)
-        return false;
-      Brackets.pop_back();
-    }
-  }
-  return Brackets.empty();
-}
-
-/// GenerateNewArgTokens - Returns true if OldTokens can be converted to a new
-/// vector of tokens in NewTokens.  The new number of arguments will be placed
-/// in NumArgs and the ranges which need to surrounded in parentheses will be
-/// in ParenHints.
-/// Returns false if the token stream cannot be changed.  If this is because
-/// of an initializer list starting a macro argument, the range of those
-/// initializer lists will be place in InitLists.
-static bool GenerateNewArgTokens(Preprocessor &PP,
-                                 SmallVectorImpl<Token> &OldTokens,
-                                 SmallVectorImpl<Token> &NewTokens,
-                                 unsigned &NumArgs,
-                                 SmallVectorImpl<SourceRange> &ParenHints,
-                                 SmallVectorImpl<SourceRange> &InitLists) {
-  if (!CheckMatchedBrackets(OldTokens))
-    return false;
-
-  // Once it is known that the brackets are matched, only a simple count of the
-  // braces is needed.
-  unsigned Braces = 0;
-
-  // First token of a new macro argument.
-  SmallVectorImpl<Token>::iterator ArgStartIterator = OldTokens.begin();
-
-  // First closing brace in a new macro argument.  Used to generate
-  // SourceRanges for InitLists.
-  SmallVectorImpl<Token>::iterator ClosingBrace = OldTokens.end();
-  NumArgs = 0;
-  Token TempToken;
-  // Set to true when a macro separator token is found inside a braced list.
-  // If true, the fixed argument spans multiple old arguments and ParenHints
-  // will be updated.
-  bool FoundSeparatorToken = false;
-  for (SmallVectorImpl<Token>::iterator I = OldTokens.begin(),
-                                        E = OldTokens.end();
-       I != E; ++I) {
-    if (I->is(tok::l_brace)) {
-      ++Braces;
-    } else if (I->is(tok::r_brace)) {
-      --Braces;
-      if (Braces == 0 && ClosingBrace == E && FoundSeparatorToken)
-        ClosingBrace = I;
-    } else if (I->is(tok::eof)) {
-      // EOF token is used to separate macro arguments
-      if (Braces != 0) {
-        // Assume comma separator is actually braced list separator and change
-        // it back to a comma.
-        FoundSeparatorToken = true;
-        I->setKind(tok::comma);
-        I->setLength(1);
-      } else { // Braces == 0
-        // Separator token still separates arguments.
-        ++NumArgs;
-
-        // If the argument starts with a brace, it can't be fixed with
-        // parentheses.  A different diagnostic will be given.
-        if (FoundSeparatorToken && ArgStartIterator->is(tok::l_brace)) {
-          InitLists.push_back(
-              SourceRange(ArgStartIterator->getLocation(),
-                          PP.getLocForEndOfToken(ClosingBrace->getLocation())));
-          ClosingBrace = E;
-        }
-
-        // Add left paren
-        if (FoundSeparatorToken) {
-          TempToken.startToken();
-          TempToken.setKind(tok::l_paren);
-          TempToken.setLocation(ArgStartIterator->getLocation());
-          TempToken.setLength(0);
-          NewTokens.push_back(TempToken);
-        }
-
-        // Copy over argument tokens
-        NewTokens.insert(NewTokens.end(), ArgStartIterator, I);
-
-        // Add right paren and store the paren locations in ParenHints
-        if (FoundSeparatorToken) {
-          SourceLocation Loc = PP.getLocForEndOfToken((I - 1)->getLocation());
-          TempToken.startToken();
-          TempToken.setKind(tok::r_paren);
-          TempToken.setLocation(Loc);
-          TempToken.setLength(0);
-          NewTokens.push_back(TempToken);
-          ParenHints.push_back(SourceRange(ArgStartIterator->getLocation(),
-                                           Loc));
-        }
-
-        // Copy separator token
-        NewTokens.push_back(*I);
-
-        // Reset values
-        ArgStartIterator = I + 1;
-        FoundSeparatorToken = false;
-      }
-    }
-  }
-
-  return !ParenHints.empty() && InitLists.empty();
-}
-
-/// ReadFunctionLikeMacroArgs - After reading "MACRO" and knowing that the next
-/// token is the '(' of the macro, this method is invoked to read all of the
-/// actual arguments specified for the macro invocation.  This returns null on
-/// error.
-MacroArgs *Preprocessor::ReadMacroCallArgumentList(Token &MacroName,
-                                                   MacroInfo *MI,
-                                                   SourceLocation &MacroEnd) {
-  // The number of fixed arguments to parse.
-  unsigned NumFixedArgsLeft = MI->getNumParams();
-  bool isVariadic = MI->isVariadic();
-
-  // Outer loop, while there are more arguments, keep reading them.
-  Token Tok;
-
-  // Read arguments as unexpanded tokens.  This avoids issues, e.g., where
-  // an argument value in a macro could expand to ',' or '(' or ')'.
-  LexUnexpandedToken(Tok);
-  assert(Tok.is(tok::l_paren) && "Error computing l-paren-ness?");
-
-  // ArgTokens - Build up a list of tokens that make up each argument.  Each
-  // argument is separated by an EOF token.  Use a SmallVector so we can avoid
-  // heap allocations in the common case.
-  SmallVector<Token, 64> ArgTokens;
-  bool ContainsCodeCompletionTok = false;
-  bool FoundElidedComma = false;
-
-  SourceLocation TooManyArgsLoc;
-
-  unsigned NumActuals = 0;
-  while (Tok.isNot(tok::r_paren)) {
-    if (ContainsCodeCompletionTok && Tok.isOneOf(tok::eof, tok::eod))
-      break;
-
-    assert(Tok.isOneOf(tok::l_paren, tok::comma) &&
-           "only expect argument separators here");
-
-    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 (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);
-
-      if (Tok.isOneOf(tok::eof, tok::eod)) { // "#if f(<eof>" & "#if f(\n"
-        if (!ContainsCodeCompletionTok) {
-          Diag(MacroName, diag::err_unterm_macro_invoc);
-          Diag(MI->getDefinitionLoc(), diag::note_macro_here)
-            << MacroName.getIdentifierInfo();
-          // Do not lose the EOF/EOD.  Return it to the client.
-          MacroName = Tok;
-          return nullptr;
-        }
-        // Do not lose the EOF/EOD.
-        auto Toks = llvm::make_unique<Token[]>(1);
-        Toks[0] = Tok;
-        EnterTokenStream(std::move(Toks), 1, true);
-        break;
-      } else if (Tok.is(tok::r_paren)) {
-        // If we found the ) token, the macro arg list is done.
-        if (NumParens-- == 0) {
-          MacroEnd = Tok.getLocation();
-          if (!ArgTokens.empty() &&
-              ArgTokens.back().commaAfterElided()) {
-            FoundElidedComma = true;
-          }
-          break;
-        }
-      } else if (Tok.is(tok::l_paren)) {
-        ++NumParens;
-      } else if (Tok.is(tok::comma) && NumParens == 0 &&
-                 !(Tok.getFlags() & Token::IgnoredComma)) {
-        // In Microsoft-compatibility mode, single commas from nested macro
-        // expansions should not be considered as argument separators. We test
-        // for this with the IgnoredComma token flag above.
-
-        // Comma ends this argument if there are more fixed arguments expected.
-        // However, if this is a variadic macro, and this is part of the
-        // variadic part, then the comma is just an argument token.
-        if (!isVariadic) break;
-        if (NumFixedArgsLeft > 1)
-          break;
-      } else if (Tok.is(tok::comment) && !KeepMacroComments) {
-        // If this is a comment token in the argument list and we're just in
-        // -C mode (not -CC mode), discard the comment.
-        continue;
-      } else if (!Tok.isAnnotation() && Tok.getIdentifierInfo() != nullptr) {
-        // Reading macro arguments can cause macros that we are currently
-        // expanding from to be popped off the expansion stack.  Doing so causes
-        // them to be reenabled for expansion.  Here we record whether any
-        // identifiers we lex as macro arguments correspond to disabled macros.
-        // If so, we mark the token as noexpand.  This is a subtle aspect of
-        // C99 6.10.3.4p2.
-        if (MacroInfo *MI = getMacroInfo(Tok.getIdentifierInfo()))
-          if (!MI->isEnabled())
-            Tok.setFlag(Token::DisableExpand);
-      } else if (Tok.is(tok::code_completion)) {
-        ContainsCodeCompletionTok = true;
-        if (CodeComplete)
-          CodeComplete->CodeCompleteMacroArgument(MacroName.getIdentifierInfo(),
-                                                  MI, NumActuals);
-        // Don't mark that we reached the code-completion point because the
-        // parser is going to handle the token and there will be another
-        // code-completion callback.
-      }
-
-      ArgTokens.push_back(Tok);
-    }
-
-    // If this was an empty argument list foo(), don't add this as an empty
-    // argument.
-    if (ArgTokens.empty() && Tok.getKind() == tok::r_paren)
-      break;
-
-    // If this is not a variadic macro, and too many args were specified, emit
-    // an error.
-    if (!isVariadic && NumFixedArgsLeft == 0 && TooManyArgsLoc.isInvalid()) {
-      if (ArgTokens.size() != ArgTokenStart)
-        TooManyArgsLoc = ArgTokens[ArgTokenStart].getLocation();
-      else
-        TooManyArgsLoc = ArgStartLoc;
-    }
-
-    // Empty arguments are standard in C99 and C++0x, and are supported as an
-    // extension in other modes.
-    if (ArgTokens.size() == ArgTokenStart && !LangOpts.C99)
-      Diag(Tok, LangOpts.CPlusPlus11 ?
-           diag::warn_cxx98_compat_empty_fnmacro_arg :
-           diag::ext_empty_fnmacro_arg);
-
-    // Add a marker EOF token to the end of the token list for this argument.
-    Token EOFTok;
-    EOFTok.startToken();
-    EOFTok.setKind(tok::eof);
-    EOFTok.setLocation(Tok.getLocation());
-    EOFTok.setLength(0);
-    ArgTokens.push_back(EOFTok);
-    ++NumActuals;
-    if (!ContainsCodeCompletionTok && NumFixedArgsLeft != 0)
-      --NumFixedArgsLeft;
-  }
-
-  // Okay, we either found the r_paren.  Check to see if we parsed too few
-  // arguments.
-  unsigned MinArgsExpected = MI->getNumParams();
-
-  // If this is not a variadic macro, and too many args were specified, emit
-  // an error.
-  if (!isVariadic && NumActuals > MinArgsExpected &&
-      !ContainsCodeCompletionTok) {
-    // Emit the diagnostic at the macro name in case there is a missing ).
-    // Emitting it at the , could be far away from the macro name.
-    Diag(TooManyArgsLoc, diag::err_too_many_args_in_macro_invoc);
-    Diag(MI->getDefinitionLoc(), diag::note_macro_here)
-      << MacroName.getIdentifierInfo();
-
-    // Commas from braced initializer lists will be treated as argument
-    // separators inside macros.  Attempt to correct for this with parentheses.
-    // TODO: See if this can be generalized to angle brackets for templates
-    // inside macro arguments.
-
-    SmallVector<Token, 4> FixedArgTokens;
-    unsigned FixedNumArgs = 0;
-    SmallVector<SourceRange, 4> ParenHints, InitLists;
-    if (!GenerateNewArgTokens(*this, ArgTokens, FixedArgTokens, FixedNumArgs,
-                              ParenHints, InitLists)) {
-      if (!InitLists.empty()) {
-        DiagnosticBuilder DB =
-            Diag(MacroName,
-                 diag::note_init_list_at_beginning_of_macro_argument);
-        for (SourceRange Range : InitLists)
-          DB << Range;
-      }
-      return nullptr;
-    }
-    if (FixedNumArgs != MinArgsExpected)
-      return nullptr;
-
-    DiagnosticBuilder DB = Diag(MacroName, diag::note_suggest_parens_for_macro);
-    for (SourceRange ParenLocation : ParenHints) {
-      DB << FixItHint::CreateInsertion(ParenLocation.getBegin(), "(");
-      DB << FixItHint::CreateInsertion(ParenLocation.getEnd(), ")");
-    }
-    ArgTokens.swap(FixedArgTokens);
-    NumActuals = FixedNumArgs;
-  }
-
-  // See MacroArgs instance var for description of this.
-  bool isVarargsElided = false;
-
-  if (ContainsCodeCompletionTok) {
-    // Recover from not-fully-formed macro invocation during code-completion.
-    Token EOFTok;
-    EOFTok.startToken();
-    EOFTok.setKind(tok::eof);
-    EOFTok.setLocation(Tok.getLocation());
-    EOFTok.setLength(0);
-    for (; NumActuals < MinArgsExpected; ++NumActuals)
-      ArgTokens.push_back(EOFTok);
-  }
-
-  if (NumActuals < MinArgsExpected) {
-    // There are several cases where too few arguments is ok, handle them now.
-    if (NumActuals == 0 && MinArgsExpected == 1) {
-      // #define A(X)  or  #define A(...)   ---> A()
-
-      // If there is exactly one argument, and that argument is missing,
-      // then we have an empty "()" argument empty list.  This is fine, even if
-      // the macro expects one argument (the argument is just empty).
-      isVarargsElided = MI->isVariadic();
-    } else if ((FoundElidedComma || MI->isVariadic()) &&
-               (NumActuals+1 == MinArgsExpected ||  // A(x, ...) -> A(X)
-                (NumActuals == 0 && MinArgsExpected == 2))) {// A(x,...) -> A()
-      // Varargs where the named vararg parameter is missing: OK as extension.
-      //   #define A(x, ...)
-      //   A("blah")
-      //
-      // If the macro contains the comma pasting extension, the diagnostic
-      // is suppressed; we know we'll get another diagnostic later.
-      if (!MI->hasCommaPasting()) {
-        Diag(Tok, diag::ext_missing_varargs_arg);
-        Diag(MI->getDefinitionLoc(), diag::note_macro_here)
-          << MacroName.getIdentifierInfo();
-      }
-
-      // Remember this occurred, allowing us to elide the comma when used for
-      // cases like:
-      //   #define A(x, foo...) blah(a, ## foo)
-      //   #define B(x, ...) blah(a, ## __VA_ARGS__)
-      //   #define C(...) blah(a, ## __VA_ARGS__)
-      //  A(x) B(x) C()
-      isVarargsElided = true;
-    } else if (!ContainsCodeCompletionTok) {
-      // Otherwise, emit the error.
-      Diag(Tok, diag::err_too_few_args_in_macro_invoc);
-      Diag(MI->getDefinitionLoc(), diag::note_macro_here)
-        << MacroName.getIdentifierInfo();
-      return nullptr;
-    }
-
-    // Add a marker EOF token to the end of the token list for this argument.
-    SourceLocation EndLoc = Tok.getLocation();
-    Tok.startToken();
-    Tok.setKind(tok::eof);
-    Tok.setLocation(EndLoc);
-    Tok.setLength(0);
-    ArgTokens.push_back(Tok);
-
-    // If we expect two arguments, add both as empty.
-    if (NumActuals == 0 && MinArgsExpected == 2)
-      ArgTokens.push_back(Tok);
-
-  } else if (NumActuals > MinArgsExpected && !MI->isVariadic() &&
-             !ContainsCodeCompletionTok) {
-    // Emit the diagnostic at the macro name in case there is a missing ).
-    // Emitting it at the , could be far away from the macro name.
-    Diag(MacroName, diag::err_too_many_args_in_macro_invoc);
-    Diag(MI->getDefinitionLoc(), diag::note_macro_here)
-      << MacroName.getIdentifierInfo();
-    return nullptr;
-  }
-
-  return MacroArgs::create(MI, ArgTokens, isVarargsElided, *this);
-}
-
-/// Keeps macro expanded tokens for TokenLexers.
-//
-/// Works like a stack; a TokenLexer adds the macro expanded tokens that is
-/// going to lex in the cache and when it finishes the tokens are removed
-/// from the end of the cache.
-Token *Preprocessor::cacheMacroExpandedTokens(TokenLexer *tokLexer,
-                                              ArrayRef<Token> tokens) {
-  assert(tokLexer);
-  if (tokens.empty())
-    return nullptr;
-
-  size_t newIndex = MacroExpandedTokens.size();
-  bool cacheNeedsToGrow = tokens.size() >
-                      MacroExpandedTokens.capacity()-MacroExpandedTokens.size();
-  MacroExpandedTokens.append(tokens.begin(), tokens.end());
-
-  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 (const auto &Lexer : MacroExpandingLexersStack) {
-      TokenLexer *prevLexer;
-      size_t tokIndex;
-      std::tie(prevLexer, tokIndex) = Lexer;
-      prevLexer->Tokens = MacroExpandedTokens.data() + tokIndex;
-    }
-  }
-
-  MacroExpandingLexersStack.push_back(std::make_pair(tokLexer, newIndex));
-  return MacroExpandedTokens.data() + newIndex;
-}
-
-void Preprocessor::removeCachedMacroExpandedTokensOfLastLexer() {
-  assert(!MacroExpandingLexersStack.empty());
-  size_t tokIndex = MacroExpandingLexersStack.back().second;
-  assert(tokIndex < MacroExpandedTokens.size());
-  // Pop the cached macro expanded tokens from the end.
-  MacroExpandedTokens.resize(tokIndex);
-  MacroExpandingLexersStack.pop_back();
-}
-
-/// ComputeDATE_TIME - Compute the current time, enter it into the specified
-/// scratch buffer, then return DATELoc/TIMELoc locations with the position of
-/// the identifier tokens inserted.
-static void ComputeDATE_TIME(SourceLocation &DATELoc, SourceLocation &TIMELoc,
-                             Preprocessor &PP) {
-  time_t TT = time(nullptr);
-  struct tm *TM = localtime(&TT);
-
-  static const char * const Months[] = {
-    "Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"
-  };
-
-  {
-    SmallString<32> TmpBuffer;
-    llvm::raw_svector_ostream TmpStream(TmpBuffer);
-    TmpStream << llvm::format("\"%s %2d %4d\"", Months[TM->tm_mon],
-                              TM->tm_mday, TM->tm_year + 1900);
-    Token TmpTok;
-    TmpTok.startToken();
-    PP.CreateString(TmpStream.str(), TmpTok);
-    DATELoc = TmpTok.getLocation();
-  }
-
-  {
-    SmallString<32> TmpBuffer;
-    llvm::raw_svector_ostream TmpStream(TmpBuffer);
-    TmpStream << llvm::format("\"%02d:%02d:%02d\"",
-                              TM->tm_hour, TM->tm_min, TM->tm_sec);
-    Token TmpTok;
-    TmpTok.startToken();
-    PP.CreateString(TmpStream.str(), TmpTok);
-    TIMELoc = TmpTok.getLocation();
-  }
-}
-
-/// 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) {
-  const LangOptions &LangOpts = PP.getLangOpts();
-
-  // Normalize the feature name, __foo__ becomes foo.
-  if (Feature.startswith("__") && Feature.endswith("__") && Feature.size() >= 4)
-    Feature = Feature.substr(2, Feature.size() - 4);
-
-#define FEATURE(Name, Predicate) .Case(#Name, Predicate)
-  return llvm::StringSwitch<bool>(Feature)
-#include "clang/Basic/Features.def"
-      .Default(false);
-#undef FEATURE
-}
-
-/// HasExtension - Return true if we recognize and implement the feature
-/// specified by the identifier, either as an extension or a standard language
-/// feature.
-static bool HasExtension(const Preprocessor &PP, StringRef Extension) {
-  if (HasFeature(PP, Extension))
-    return true;
-
-  // If the use of an extension results in an error diagnostic, extensions are
-  // effectively unavailable, so just return false here.
-  if (PP.getDiagnostics().getExtensionHandlingBehavior() >=
-      diag::Severity::Error)
-    return false;
-
-  const LangOptions &LangOpts = PP.getLangOpts();
-
-  // Normalize the extension name, __foo__ becomes foo.
-  if (Extension.startswith("__") && Extension.endswith("__") &&
-      Extension.size() >= 4)
-    Extension = Extension.substr(2, Extension.size() - 4);
-
-    // Because we inherit the feature list from HasFeature, this string switch
-    // must be less restrictive than HasFeature's.
-#define EXTENSION(Name, Predicate) .Case(#Name, Predicate)
-  return llvm::StringSwitch<bool>(Extension)
-#include "clang/Basic/Features.def"
-      .Default(false);
-#undef EXTENSION
-}
-
-/// EvaluateHasIncludeCommon - Process a '__has_include("path")'
-/// or '__has_include_next("path")' expression.
-/// Returns true if successful.
-static bool EvaluateHasIncludeCommon(Token &Tok,
-                                     IdentifierInfo *II, Preprocessor &PP,
-                                     const DirectoryLookup *LookupFrom,
-                                     const FileEntry *LookupFromFile) {
-  // Save the location of the current token.  If a '(' is later found, use
-  // that location.  If not, use the end of this location instead.
-  SourceLocation LParenLoc = Tok.getLocation();
-
-  // These expressions are only allowed within a preprocessor directive.
-  if (!PP.isParsingIfOrElifDirective()) {
-    PP.Diag(LParenLoc, diag::err_pp_directive_required) << II;
-    // Return a valid identifier token.
-    assert(Tok.is(tok::identifier));
-    Tok.setIdentifierInfo(II);
-    return false;
-  }
-
-  // Get '('.
-  PP.LexNonComment(Tok);
-
-  // Ensure we have a '('.
-  if (Tok.isNot(tok::l_paren)) {
-    // No '(', use end of last token.
-    LParenLoc = PP.getLocForEndOfToken(LParenLoc);
-    PP.Diag(LParenLoc, diag::err_pp_expected_after) << II << tok::l_paren;
-    // If the next token looks like a filename or the start of one,
-    // assume it is and process it as such.
-    if (!Tok.is(tok::angle_string_literal) && !Tok.is(tok::string_literal) &&
-        !Tok.is(tok::less))
-      return false;
-  } else {
-    // Save '(' location for possible missing ')' message.
-    LParenLoc = Tok.getLocation();
-
-    if (PP.getCurrentLexer()) {
-      // Get the file name.
-      PP.getCurrentLexer()->LexIncludeFilename(Tok);
-    } else {
-      // We're in a macro, so we can't use LexIncludeFilename; just
-      // grab the next token.
-      PP.Lex(Tok);
-    }
-  }
-
-  // Reserve a buffer to get the spelling.
-  SmallString<128> FilenameBuffer;
-  StringRef Filename;
-  SourceLocation EndLoc;
-
-  switch (Tok.getKind()) {
-  case tok::eod:
-    // If the token kind is EOD, the error has already been diagnosed.
-    return false;
-
-  case tok::angle_string_literal:
-  case tok::string_literal: {
-    bool Invalid = false;
-    Filename = PP.getSpelling(Tok, FilenameBuffer, &Invalid);
-    if (Invalid)
-      return false;
-    break;
-  }
-
-  case tok::less:
-    // This could be a <foo/bar.h> file coming from a macro expansion.  In this
-    // case, glue the tokens together into FilenameBuffer and interpret those.
-    FilenameBuffer.push_back('<');
-    if (PP.ConcatenateIncludeName(FilenameBuffer, EndLoc)) {
-      // Let the caller know a <eod> was found by changing the Token kind.
-      Tok.setKind(tok::eod);
-      return false;   // Found <eod> but no ">"?  Diagnostic already emitted.
-    }
-    Filename = FilenameBuffer;
-    break;
-  default:
-    PP.Diag(Tok.getLocation(), diag::err_pp_expects_filename);
-    return false;
-  }
-
-  SourceLocation FilenameLoc = Tok.getLocation();
-
-  // Get ')'.
-  PP.LexNonComment(Tok);
-
-  // Ensure we have a trailing ).
-  if (Tok.isNot(tok::r_paren)) {
-    PP.Diag(PP.getLocForEndOfToken(FilenameLoc), diag::err_pp_expected_after)
-        << II << tok::r_paren;
-    PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren;
-    return false;
-  }
-
-  bool isAngled = PP.GetIncludeFilenameSpelling(Tok.getLocation(), Filename);
-  // If GetIncludeFilenameSpelling set the start ptr to null, there was an
-  // error.
-  if (Filename.empty())
-    return false;
-
-  // Search include directories.
-  const DirectoryLookup *CurDir;
-  const FileEntry *File =
-      PP.LookupFile(FilenameLoc, Filename, isAngled, LookupFrom, LookupFromFile,
-                    CurDir, nullptr, nullptr, nullptr, nullptr);
-
-  if (PPCallbacks *Callbacks = PP.getPPCallbacks()) {
-    SrcMgr::CharacteristicKind FileType = SrcMgr::C_User;
-    if (File)
-      FileType = PP.getHeaderSearchInfo().getFileDirFlavor(File);
-    Callbacks->HasInclude(FilenameLoc, Filename, isAngled, File, FileType);
-  }
-
-  // Get the result value.  A result of true means the file exists.
-  return File != nullptr;
-}
-
-/// EvaluateHasInclude - Process a '__has_include("path")' expression.
-/// Returns true if successful.
-static bool EvaluateHasInclude(Token &Tok, IdentifierInfo *II,
-                               Preprocessor &PP) {
-  return EvaluateHasIncludeCommon(Tok, II, PP, nullptr, nullptr);
-}
-
-/// EvaluateHasIncludeNext - Process '__has_include_next("path")' expression.
-/// Returns true if successful.
-static bool EvaluateHasIncludeNext(Token &Tok,
-                                   IdentifierInfo *II, Preprocessor &PP) {
-  // __has_include_next is like __has_include, except that we start
-  // searching after the current found directory.  If we can't do this,
-  // issue a diagnostic.
-  // FIXME: Factor out duplication with
-  // Preprocessor::HandleIncludeNextDirective.
-  const DirectoryLookup *Lookup = PP.GetCurDirLookup();
-  const FileEntry *LookupFromFile = nullptr;
-  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.getCurrentLexerSubmodule()) {
-    // Start looking up in the directory *after* the one in which the current
-    // file would be found, if any.
-    assert(PP.getCurrentLexer() && "#include_next directive in macro?");
-    LookupFromFile = PP.getCurrentLexer()->getFileEntry();
-    Lookup = nullptr;
-  } else if (!Lookup) {
-    PP.Diag(Tok, diag::pp_include_next_absolute_path);
-  } else {
-    // Start looking up in the next directory.
-    ++Lookup;
-  }
-
-  return EvaluateHasIncludeCommon(Tok, II, PP, Lookup, LookupFromFile);
-}
-
-/// Process single-argument builtin feature-like macros that return
-/// integer values.
-static void EvaluateFeatureLikeBuiltinMacro(llvm::raw_svector_ostream& OS,
-                                            Token &Tok, IdentifierInfo *II,
-                                            Preprocessor &PP,
-                                            llvm::function_ref<
-                                              int(Token &Tok,
-                                                  bool &HasLexedNextTok)> Op) {
-  // Parse the initial '('.
-  PP.LexUnexpandedToken(Tok);
-  if (Tok.isNot(tok::l_paren)) {
-    PP.Diag(Tok.getLocation(), diag::err_pp_expected_after) << II
-                                                            << tok::l_paren;
-
-    // Provide a dummy '0' value on output stream to elide further errors.
-    if (!Tok.isOneOf(tok::eof, tok::eod)) {
-      OS << 0;
-      Tok.setKind(tok::numeric_constant);
-    }
-    return;
-  }
-
-  unsigned ParenDepth = 1;
-  SourceLocation LParenLoc = Tok.getLocation();
-  llvm::Optional<int> Result;
-
-  Token ResultTok;
-  bool SuppressDiagnostic = false;
-  while (true) {
-    // Parse next token.
-    PP.LexUnexpandedToken(Tok);
-
-already_lexed:
-    switch (Tok.getKind()) {
-      case tok::eof:
-      case tok::eod:
-        // Don't provide even a dummy value if the eod or eof marker is
-        // reached.  Simply provide a diagnostic.
-        PP.Diag(Tok.getLocation(), diag::err_unterm_macro_invoc);
-        return;
-
-      case tok::comma:
-        if (!SuppressDiagnostic) {
-          PP.Diag(Tok.getLocation(), diag::err_too_many_args_in_macro_invoc);
-          SuppressDiagnostic = true;
-        }
-        continue;
-
-      case tok::l_paren:
-        ++ParenDepth;
-        if (Result.hasValue())
-          break;
-        if (!SuppressDiagnostic) {
-          PP.Diag(Tok.getLocation(), diag::err_pp_nested_paren) << II;
-          SuppressDiagnostic = true;
-        }
-        continue;
-
-      case tok::r_paren:
-        if (--ParenDepth > 0)
-          continue;
-
-        // The last ')' has been reached; return the value if one found or
-        // a diagnostic and a dummy value.
-        if (Result.hasValue())
-          OS << Result.getValue();
-        else {
-          OS << 0;
-          if (!SuppressDiagnostic)
-            PP.Diag(Tok.getLocation(), diag::err_too_few_args_in_macro_invoc);
-        }
-        Tok.setKind(tok::numeric_constant);
-        return;
-
-      default: {
-        // Parse the macro argument, if one not found so far.
-        if (Result.hasValue())
-          break;
-
-        bool HasLexedNextToken = false;
-        Result = Op(Tok, HasLexedNextToken);
-        ResultTok = Tok;
-        if (HasLexedNextToken)
-          goto already_lexed;
-        continue;
-      }
-    }
-
-    // Diagnose missing ')'.
-    if (!SuppressDiagnostic) {
-      if (auto Diag = PP.Diag(Tok.getLocation(), diag::err_pp_expected_after)) {
-        if (IdentifierInfo *LastII = ResultTok.getIdentifierInfo())
-          Diag << LastII;
-        else
-          Diag << ResultTok.getKind();
-        Diag << tok::r_paren << ResultTok.getLocation();
-      }
-      PP.Diag(LParenLoc, diag::note_matching) << tok::l_paren;
-      SuppressDiagnostic = true;
-    }
-  }
-}
-
-/// Helper function to return the IdentifierInfo structure of a Token
-/// or generate a diagnostic if none available.
-static IdentifierInfo *ExpectFeatureIdentifierInfo(Token &Tok,
-                                                   Preprocessor &PP,
-                                                   signed DiagID) {
-  IdentifierInfo *II;
-  if (!Tok.isAnnotation() && (II = Tok.getIdentifierInfo()))
-    return II;
-
-  PP.Diag(Tok.getLocation(), DiagID);
-  return nullptr;
-}
-
-/// Implements the __is_target_arch builtin macro.
-static bool isTargetArch(const TargetInfo &TI, const IdentifierInfo *II) {
-  std::string ArchName = II->getName().lower() + "--";
-  llvm::Triple Arch(ArchName);
-  const llvm::Triple &TT = TI.getTriple();
-  if (TT.isThumb()) {
-    // arm matches thumb or thumbv7. armv7 matches thumbv7.
-    if ((Arch.getSubArch() == llvm::Triple::NoSubArch ||
-         Arch.getSubArch() == TT.getSubArch()) &&
-        ((TT.getArch() == llvm::Triple::thumb &&
-          Arch.getArch() == llvm::Triple::arm) ||
-         (TT.getArch() == llvm::Triple::thumbeb &&
-          Arch.getArch() == llvm::Triple::armeb)))
-      return true;
-  }
-  // Check the parsed arch when it has no sub arch to allow Clang to
-  // match thumb to thumbv7 but to prohibit matching thumbv6 to thumbv7.
-  return (Arch.getSubArch() == llvm::Triple::NoSubArch ||
-          Arch.getSubArch() == TT.getSubArch()) &&
-         Arch.getArch() == TT.getArch();
-}
-
-/// Implements the __is_target_vendor builtin macro.
-static bool isTargetVendor(const TargetInfo &TI, const IdentifierInfo *II) {
-  StringRef VendorName = TI.getTriple().getVendorName();
-  if (VendorName.empty())
-    VendorName = "unknown";
-  return VendorName.equals_lower(II->getName());
-}
-
-/// Implements the __is_target_os builtin macro.
-static bool isTargetOS(const TargetInfo &TI, const IdentifierInfo *II) {
-  std::string OSName =
-      (llvm::Twine("unknown-unknown-") + II->getName().lower()).str();
-  llvm::Triple OS(OSName);
-  if (OS.getOS() == llvm::Triple::Darwin) {
-    // Darwin matches macos, ios, etc.
-    return TI.getTriple().isOSDarwin();
-  }
-  return TI.getTriple().getOS() == OS.getOS();
-}
-
-/// Implements the __is_target_environment builtin macro.
-static bool isTargetEnvironment(const TargetInfo &TI,
-                                const IdentifierInfo *II) {
-  std::string EnvName = (llvm::Twine("---") + II->getName().lower()).str();
-  llvm::Triple Env(EnvName);
-  return TI.getTriple().getEnvironment() == Env.getEnvironment();
-}
-
-/// ExpandBuiltinMacro - If an identifier token is read that is to be expanded
-/// as a builtin macro, handle it and return the next token as 'Tok'.
-void Preprocessor::ExpandBuiltinMacro(Token &Tok) {
-  // Figure out which token this is.
-  IdentifierInfo *II = Tok.getIdentifierInfo();
-  assert(II && "Can't be a macro without id info!");
-
-  // If this is an _Pragma or Microsoft __pragma directive, expand it,
-  // invoke the pragma handler, then lex the token after it.
-  if (II == Ident_Pragma)
-    return Handle_Pragma(Tok);
-  else if (II == Ident__pragma) // in non-MS mode this is null
-    return HandleMicrosoft__pragma(Tok);
-
-  ++NumBuiltinMacroExpanded;
-
-  SmallString<128> TmpBuffer;
-  llvm::raw_svector_ostream OS(TmpBuffer);
-
-  // Set up the return result.
-  Tok.setIdentifierInfo(nullptr);
-  Tok.clearFlag(Token::NeedsCleaning);
-
-  if (II == Ident__LINE__) {
-    // C99 6.10.8: "__LINE__: The presumed line number (within the current
-    // source file) of the current source line (an integer constant)".  This can
-    // be affected by #line.
-    SourceLocation Loc = Tok.getLocation();
-
-    // Advance to the location of the first _, this might not be the first byte
-    // of the token if it starts with an escaped newline.
-    Loc = AdvanceToTokenCharacter(Loc, 0);
-
-    // One wrinkle here is that GCC expands __LINE__ to location of the *end* of
-    // a macro expansion.  This doesn't matter for object-like macros, but
-    // can matter for a function-like macro that expands to contain __LINE__.
-    // Skip down through expansion points until we find a file loc for the
-    // end of the expansion history.
-    Loc = SourceMgr.getExpansionRange(Loc).getEnd();
-    PresumedLoc PLoc = SourceMgr.getPresumedLoc(Loc);
-
-    // __LINE__ expands to a simple numeric value.
-    OS << (PLoc.isValid()? PLoc.getLine() : 1);
-    Tok.setKind(tok::numeric_constant);
-  } else if (II == Ident__FILE__ || II == Ident__BASE_FILE__) {
-    // C99 6.10.8: "__FILE__: The presumed name of the current source file (a
-    // character string literal)". This can be affected by #line.
-    PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());
-
-    // __BASE_FILE__ is a GNU extension that returns the top of the presumed
-    // #include stack instead of the current file.
-    if (II == Ident__BASE_FILE__ && PLoc.isValid()) {
-      SourceLocation NextLoc = PLoc.getIncludeLoc();
-      while (NextLoc.isValid()) {
-        PLoc = SourceMgr.getPresumedLoc(NextLoc);
-        if (PLoc.isInvalid())
-          break;
-
-        NextLoc = PLoc.getIncludeLoc();
-      }
-    }
-
-    // Escape this filename.  Turn '\' -> '\\' '"' -> '\"'
-    SmallString<128> FN;
-    if (PLoc.isValid()) {
-      FN += PLoc.getFilename();
-      Lexer::Stringify(FN);
-      OS << '"' << FN << '"';
-    }
-    Tok.setKind(tok::string_literal);
-  } else if (II == Ident__DATE__) {
-    Diag(Tok.getLocation(), diag::warn_pp_date_time);
-    if (!DATELoc.isValid())
-      ComputeDATE_TIME(DATELoc, TIMELoc, *this);
-    Tok.setKind(tok::string_literal);
-    Tok.setLength(strlen("\"Mmm dd yyyy\""));
-    Tok.setLocation(SourceMgr.createExpansionLoc(DATELoc, Tok.getLocation(),
-                                                 Tok.getLocation(),
-                                                 Tok.getLength()));
-    return;
-  } else if (II == Ident__TIME__) {
-    Diag(Tok.getLocation(), diag::warn_pp_date_time);
-    if (!TIMELoc.isValid())
-      ComputeDATE_TIME(DATELoc, TIMELoc, *this);
-    Tok.setKind(tok::string_literal);
-    Tok.setLength(strlen("\"hh:mm:ss\""));
-    Tok.setLocation(SourceMgr.createExpansionLoc(TIMELoc, Tok.getLocation(),
-                                                 Tok.getLocation(),
-                                                 Tok.getLength()));
-    return;
-  } else if (II == Ident__INCLUDE_LEVEL__) {
-    // Compute the presumed include depth of this token.  This can be affected
-    // by GNU line markers.
-    unsigned Depth = 0;
-
-    PresumedLoc PLoc = SourceMgr.getPresumedLoc(Tok.getLocation());
-    if (PLoc.isValid()) {
-      PLoc = SourceMgr.getPresumedLoc(PLoc.getIncludeLoc());
-      for (; PLoc.isValid(); ++Depth)
-        PLoc = SourceMgr.getPresumedLoc(PLoc.getIncludeLoc());
-    }
-
-    // __INCLUDE_LEVEL__ expands to a simple numeric value.
-    OS << Depth;
-    Tok.setKind(tok::numeric_constant);
-  } else if (II == Ident__TIMESTAMP__) {
-    Diag(Tok.getLocation(), diag::warn_pp_date_time);
-    // MSVC, ICC, GCC, VisualAge C++ extension.  The generated string should be
-    // of the form "Ddd Mmm dd hh::mm::ss yyyy", which is returned by asctime.
-
-    // Get the file that we are lexing out of.  If we're currently lexing from
-    // a macro, dig into the include stack.
-    const FileEntry *CurFile = nullptr;
-    PreprocessorLexer *TheLexer = getCurrentFileLexer();
-
-    if (TheLexer)
-      CurFile = SourceMgr.getFileEntryForID(TheLexer->getFileID());
-
-    const char *Result;
-    if (CurFile) {
-      time_t TT = CurFile->getModificationTime();
-      struct tm *TM = localtime(&TT);
-      Result = asctime(TM);
-    } else {
-      Result = "??? ??? ?? ??:??:?? ????\n";
-    }
-    // Surround the string with " and strip the trailing newline.
-    OS << '"' << StringRef(Result).drop_back() << '"';
-    Tok.setKind(tok::string_literal);
-  } else if (II == Ident__COUNTER__) {
-    // __COUNTER__ expands to a simple numeric value.
-    OS << CounterValue++;
-    Tok.setKind(tok::numeric_constant);
-  } else if (II == Ident__has_feature) {
-    EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
-      [this](Token &Tok, bool &HasLexedNextToken) -> int {
-        IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
-                                           diag::err_feature_check_malformed);
-        return II && HasFeature(*this, II->getName());
-      });
-  } else if (II == Ident__has_extension) {
-    EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
-      [this](Token &Tok, bool &HasLexedNextToken) -> int {
-        IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
-                                           diag::err_feature_check_malformed);
-        return II && HasExtension(*this, II->getName());
-      });
-  } else if (II == Ident__has_builtin) {
-    EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
-      [this](Token &Tok, bool &HasLexedNextToken) -> int {
-        IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
-                                           diag::err_feature_check_malformed);
-        const LangOptions &LangOpts = getLangOpts();
-        if (!II)
-          return false;
-        else if (II->getBuiltinID() != 0) {
-          switch (II->getBuiltinID()) {
-          case Builtin::BI__builtin_operator_new:
-          case Builtin::BI__builtin_operator_delete:
-            // denotes date of behavior change to support calling arbitrary
-            // usual allocation and deallocation functions. Required by libc++
-            return 201802;
-          default:
-            return true;
-          }
-          return true;
-        } else {
-          return llvm::StringSwitch<bool>(II->getName())
-                      .Case("__make_integer_seq", LangOpts.CPlusPlus)
-                      .Case("__type_pack_element", LangOpts.CPlusPlus)
-                      .Case("__builtin_available", true)
-                      .Case("__is_target_arch", true)
-                      .Case("__is_target_vendor", true)
-                      .Case("__is_target_os", true)
-                      .Case("__is_target_environment", true)
-                      .Default(false);
-        }
-      });
-  } else if (II == Ident__is_identifier) {
-    EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
-      [](Token &Tok, bool &HasLexedNextToken) -> int {
-        return Tok.is(tok::identifier);
-      });
-  } else if (II == Ident__has_attribute) {
-    EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
-      [this](Token &Tok, bool &HasLexedNextToken) -> int {
-        IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
-                                           diag::err_feature_check_malformed);
-        return II ? hasAttribute(AttrSyntax::GNU, nullptr, II,
-                                 getTargetInfo(), getLangOpts()) : 0;
-      });
-  } else if (II == Ident__has_declspec) {
-    EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
-      [this](Token &Tok, bool &HasLexedNextToken) -> int {
-        IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
-                                           diag::err_feature_check_malformed);
-        return II ? hasAttribute(AttrSyntax::Declspec, nullptr, II,
-                                 getTargetInfo(), getLangOpts()) : 0;
-      });
-  } else if (II == Ident__has_cpp_attribute ||
-             II == Ident__has_c_attribute) {
-    bool IsCXX = II == Ident__has_cpp_attribute;
-    EvaluateFeatureLikeBuiltinMacro(
-        OS, Tok, II, *this, [&](Token &Tok, bool &HasLexedNextToken) -> int {
-          IdentifierInfo *ScopeII = nullptr;
-          IdentifierInfo *II = ExpectFeatureIdentifierInfo(
-              Tok, *this, diag::err_feature_check_malformed);
-          if (!II)
-            return false;
-
-          // It is possible to receive a scope token.  Read the "::", if it is
-          // available, and the subsequent identifier.
-          LexUnexpandedToken(Tok);
-          if (Tok.isNot(tok::coloncolon))
-            HasLexedNextToken = true;
-          else {
-            ScopeII = II;
-            LexUnexpandedToken(Tok);
-            II = ExpectFeatureIdentifierInfo(Tok, *this,
-                                             diag::err_feature_check_malformed);
-          }
-
-          AttrSyntax Syntax = IsCXX ? AttrSyntax::CXX : AttrSyntax::C;
-          return II ? hasAttribute(Syntax, ScopeII, II, getTargetInfo(),
-                                   getLangOpts())
-                    : 0;
-        });
-  } else if (II == Ident__has_include ||
-             II == Ident__has_include_next) {
-    // The argument to these two builtins should be a parenthesized
-    // file name string literal using angle brackets (<>) or
-    // double-quotes ("").
-    bool Value;
-    if (II == Ident__has_include)
-      Value = EvaluateHasInclude(Tok, II, *this);
-    else
-      Value = EvaluateHasIncludeNext(Tok, II, *this);
-
-    if (Tok.isNot(tok::r_paren))
-      return;
-    OS << (int)Value;
-    Tok.setKind(tok::numeric_constant);
-  } else if (II == Ident__has_warning) {
-    // The argument should be a parenthesized string literal.
-    EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
-      [this](Token &Tok, bool &HasLexedNextToken) -> int {
-        std::string WarningName;
-        SourceLocation StrStartLoc = Tok.getLocation();
-
-        HasLexedNextToken = Tok.is(tok::string_literal);
-        if (!FinishLexStringLiteral(Tok, WarningName, "'__has_warning'",
-                                    /*MacroExpansion=*/false))
-          return false;
-
-        // FIXME: Should we accept "-R..." flags here, or should that be
-        // handled by a separate __has_remark?
-        if (WarningName.size() < 3 || WarningName[0] != '-' ||
-            WarningName[1] != 'W') {
-          Diag(StrStartLoc, diag::warn_has_warning_invalid_option);
-          return false;
-        }
-
-        // Finally, check if the warning flags maps to a diagnostic group.
-        // We construct a SmallVector here to talk to getDiagnosticIDs().
-        // Although we don't use the result, this isn't a hot path, and not
-        // worth special casing.
-        SmallVector<diag::kind, 10> Diags;
-        return !getDiagnostics().getDiagnosticIDs()->
-                getDiagnosticsInGroup(diag::Flavor::WarningOrError,
-                                      WarningName.substr(2), Diags);
-      });
-  } else if (II == Ident__building_module) {
-    // The argument to this builtin should be an identifier. The
-    // builtin evaluates to 1 when that identifier names the module we are
-    // currently building.
-    EvaluateFeatureLikeBuiltinMacro(OS, Tok, II, *this,
-      [this](Token &Tok, bool &HasLexedNextToken) -> int {
-        IdentifierInfo *II = ExpectFeatureIdentifierInfo(Tok, *this,
-                                       diag::err_expected_id_building_module);
-        return getLangOpts().isCompilingModule() && II &&
-               (II->getName() == getLangOpts().CurrentModule);
-      });
-  } else if (II == Ident__MODULE__) {
-    // The current module as an identifier.
-    OS << getLangOpts().CurrentModule;
-    IdentifierInfo *ModuleII = getIdentifierInfo(getLangOpts().CurrentModule);
-    Tok.setIdentifierInfo(ModuleII);
-    Tok.setKind(ModuleII->getTokenID());
-  } else if (II == Ident__identifier) {
-    SourceLocation Loc = Tok.getLocation();
-
-    // We're expecting '__identifier' '(' identifier ')'. Try to recover
-    // if the parens are missing.
-    LexNonComment(Tok);
-    if (Tok.isNot(tok::l_paren)) {
-      // No '(', use end of last token.
-      Diag(getLocForEndOfToken(Loc), diag::err_pp_expected_after)
-        << II << tok::l_paren;
-      // If the next token isn't valid as our argument, we can't recover.
-      if (!Tok.isAnnotation() && Tok.getIdentifierInfo())
-        Tok.setKind(tok::identifier);
-      return;
-    }
-
-    SourceLocation LParenLoc = Tok.getLocation();
-    LexNonComment(Tok);
-
-    if (!Tok.isAnnotation() && Tok.getIdentifierInfo())
-      Tok.setKind(tok::identifier);
-    else {
-      Diag(Tok.getLocation(), diag::err_pp_identifier_arg_not_identifier)
-        << Tok.getKind();
-      // Don't walk past anything that's not a real token.
-      if (Tok.isOneOf(tok::eof, tok::eod) || Tok.isAnnotation())
-        return;
-    }
-
-    // Discard the ')', preserving 'Tok' as our result.
-    Token RParen;
-    LexNonComment(RParen);
-    if (RParen.isNot(tok::r_paren)) {
-      Diag(getLocForEndOfToken(Tok.getLocation()), diag::err_pp_expected_after)
-        << Tok.getKind() << tok::r_paren;
-      Diag(LParenLoc, diag::note_matching) << tok::l_paren;
-    }
-    return;
-  } else if (II == Ident__is_target_arch) {
-    EvaluateFeatureLikeBuiltinMacro(
-        OS, Tok, II, *this, [this](Token &Tok, bool &HasLexedNextToken) -> int {
-          IdentifierInfo *II = ExpectFeatureIdentifierInfo(
-              Tok, *this, diag::err_feature_check_malformed);
-          return II && isTargetArch(getTargetInfo(), II);
-        });
-  } else if (II == Ident__is_target_vendor) {
-    EvaluateFeatureLikeBuiltinMacro(
-        OS, Tok, II, *this, [this](Token &Tok, bool &HasLexedNextToken) -> int {
-          IdentifierInfo *II = ExpectFeatureIdentifierInfo(
-              Tok, *this, diag::err_feature_check_malformed);
-          return II && isTargetVendor(getTargetInfo(), II);
-        });
-  } else if (II == Ident__is_target_os) {
-    EvaluateFeatureLikeBuiltinMacro(
-        OS, Tok, II, *this, [this](Token &Tok, bool &HasLexedNextToken) -> int {
-          IdentifierInfo *II = ExpectFeatureIdentifierInfo(
-              Tok, *this, diag::err_feature_check_malformed);
-          return II && isTargetOS(getTargetInfo(), II);
-        });
-  } else if (II == Ident__is_target_environment) {
-    EvaluateFeatureLikeBuiltinMacro(
-        OS, Tok, II, *this, [this](Token &Tok, bool &HasLexedNextToken) -> int {
-          IdentifierInfo *II = ExpectFeatureIdentifierInfo(
-              Tok, *this, diag::err_feature_check_malformed);
-          return II && isTargetEnvironment(getTargetInfo(), II);
-        });
-  } else {
-    llvm_unreachable("Unknown identifier!");
-  }
-  CreateString(OS.str(), Tok, Tok.getLocation(), Tok.getLocation());
-}
-
-void Preprocessor::markMacroAsUsed(MacroInfo *MI) {
-  // If the 'used' status changed, and the macro requires 'unused' warning,
-  // remove its SourceLocation from the warn-for-unused-macro locations.
-  if (MI->isWarnIfUnused() && !MI->isUsed())
-    WarnUnusedMacroLocs.erase(MI->getDefinitionLoc());
-  MI->setIsUsed(true);
-}