Emulate MSVC's preprocessor macro argument separator behavior by not considering commas from nested macro expansions as argument separators. Fixes parsing of VS 2012 headers.

git-svn-id: https://llvm.org/svn/llvm-project/cfe/trunk@163022 91177308-0d34-0410-b5e6-96231b3b80d8

4 files changed, 1192 insertions, 1174 deletions

diff --git a/include/clang/Lex/Token.h b/include/clang/Lex/Token.h
index 9c5a023f30..e422c67053 100644
--- a/include/clang/Lex/Token.h
+++ b/include/clang/Lex/Token.h
@@ -76,7 +76,8 @@ public:
     DisableExpand = 0x04,  // This identifier may never be macro expanded.
     NeedsCleaning = 0x08,   // Contained an escaped newline or trigraph.
     LeadingEmptyMacro = 0x10, // Empty macro exists before this token.
-    HasUDSuffix = 0x20     // This string or character literal has a ud-suffix.
+    HasUDSuffix = 0x20, // This string or character literal has a ud-suffix.
+    IgnoredComma = 0x40 // Flags ignored commas from nested macro expansions.
   };
 
   tok::TokenKind getKind() const { return (tok::TokenKind)Kind; }
diff --git a/lib/Lex/PPMacroExpansion.cpp b/lib/Lex/PPMacroExpansion.cpp
index 524f3ab82c..a99a52f861 100644
--- a/lib/Lex/PPMacroExpansion.cpp
+++ b/lib/Lex/PPMacroExpansion.cpp
@@ -1,1173 +1,1177 @@
-//===--- 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 expasion for the
-// preprocessor.
-//
-//===----------------------------------------------------------------------===//
-
-#include "clang/Lex/Preprocessor.h"
-#include "MacroArgs.h"
-#include "clang/Lex/MacroInfo.h"
-#include "clang/Basic/SourceManager.h"
-#include "clang/Basic/FileManager.h"
-#include "clang/Basic/TargetInfo.h"
-#include "clang/Lex/LexDiagnostic.h"
-#include "clang/Lex/CodeCompletionHandler.h"
-#include "clang/Lex/ExternalPreprocessorSource.h"
-#include "clang/Lex/LiteralSupport.h"
-#include "llvm/ADT/StringSwitch.h"
-#include "llvm/ADT/STLExtras.h"
-#include "llvm/Config/llvm-config.h"
-#include "llvm/Support/raw_ostream.h"
-#include "llvm/Support/ErrorHandling.h"
-#include <cstdio>
-#include <ctime>
-using namespace clang;
-
-MacroInfo *Preprocessor::getInfoForMacro(IdentifierInfo *II) const {
-  assert(II->hasMacroDefinition() && "Identifier is not a macro!");
-
-  macro_iterator Pos = Macros.find(II);
-  if (Pos == Macros.end()) {
-    // Load this macro from the external source.
-    getExternalSource()->LoadMacroDefinition(II);
-    Pos = Macros.find(II);
-  }
-  assert(Pos != Macros.end() && "Identifier macro info is missing!");
-  assert(Pos->second->getUndefLoc().isInvalid() && "Macro is undefined!");
-  return Pos->second;
-}
-
-/// setMacroInfo - Specify a macro for this identifier.
-///
-void Preprocessor::setMacroInfo(IdentifierInfo *II, MacroInfo *MI,
-                                bool LoadedFromAST) {
-  assert(MI && "MacroInfo should be non-zero!");
-  MI->setPreviousDefinition(Macros[II]);
-  Macros[II] = MI;
-  II->setHasMacroDefinition(true);
-  if (II->isFromAST() && !LoadedFromAST)
-    II->setChangedSinceDeserialization();
-}
-
-/// \brief Undefine a macro for this identifier.
-void Preprocessor::clearMacroInfo(IdentifierInfo *II) {
-  assert(II->hasMacroDefinition() && "Macro is not defined!");
-  assert(Macros[II]->getUndefLoc().isValid() && "Macro is still defined!");
-  II->setHasMacroDefinition(false);
-  if (II->isFromAST())
-    II->setChangedSinceDeserialization();
-}
-
-/// 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.setMacroInfo(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");
-
-  // GCC Extensions.
-  Ident__BASE_FILE__     = RegisterBuiltinMacro(*this, "__BASE_FILE__");
-  Ident__INCLUDE_LEVEL__ = RegisterBuiltinMacro(*this, "__INCLUDE_LEVEL__");
-  Ident__TIMESTAMP__     = RegisterBuiltinMacro(*this, "__TIMESTAMP__");
-
-  // 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_include      = RegisterBuiltinMacro(*this, "__has_include");
-  Ident__has_include_next = RegisterBuiltinMacro(*this, "__has_include_next");
-  Ident__has_warning      = RegisterBuiltinMacro(*this, "__has_warning");
-
-  // Microsoft Extensions.
-  if (LangOpts.MicrosoftExt) 
-    Ident__pragma = RegisterBuiltinMacro(*this, "__pragma");
-  else
-    Ident__pragma = 0;
-}
-
-/// 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 == 0) 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 (II->hasMacroDefinition() && PP.getMacroInfo(II)->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.
-  for (MacroInfo::arg_iterator I = MI->arg_begin(), E = MI->arg_end();
-       I != E; ++I)
-    if (*I == II)
-      return false;   // Identifier is a macro argument.
-
-  return true;
-}
-
-
-/// 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 if (CurPTHLexer)
-    Val = CurPTHLexer->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 (unsigned i = IncludeMacroStack.size(); i != 0; --i) {
-      IncludeStackInfo &Entry = IncludeMacroStack[i-1];
-      if (Entry.TheLexer)
-        Val = Entry.TheLexer->isNextPPTokenLParen();
-      else if (Entry.ThePTHLexer)
-        Val = Entry.ThePTHLexer->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,
-                                                 MacroInfo *MI) {
-  // 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, MI,
-                                           Identifier.getLocation());
-    ExpandBuiltinMacro(Identifier);
-    return false;
-  }
-
-  /// 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 = 0;
-
-  // 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()) {
-    // C99 6.10.3p10: If the preprocessing token immediately after the macro
-    // name isn't a '(', this macro should not be expanded.
-    if (!isNextPPTokenLParen())
-      return true;
-
-    // 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 = ReadFunctionLikeMacroArgs(Identifier, MI, ExpansionEnd);
-
-    // Finished parsing args.
-    InMacroArgs = false;
-
-    // If there was an error parsing the arguments, bail out.
-    if (Args == 0) return false;
-
-    ++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, MI, ExpansionRange));
-    } else {
-      Callbacks->MacroExpands(Identifier, MI, ExpansionRange);
-      if (!DelayedMacroExpandsCallbacks.empty()) {
-        for (unsigned i=0, e = DelayedMacroExpandsCallbacks.size(); i!=e; ++i) {
-          MacroExpandsInfo &Info = DelayedMacroExpandsCallbacks[i];
-          Callbacks->MacroExpands(Info.Tok, Info.MI, Info.Range);
-        }
-        DelayedMacroExpandsCallbacks.clear();
-      }
-    }
-  }
-  
-  // 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);
-
-    // Ignore this macro use, just return the next token in the current
-    // buffer.
-    bool HadLeadingSpace = Identifier.hasLeadingSpace();
-    bool IsAtStartOfLine = Identifier.isAtStartOfLine();
-
-    Lex(Identifier);
-
-    // If the identifier isn't on some OTHER line, inherit the leading
-    // whitespace/first-on-a-line property of this token.  This handles
-    // stuff like "! XX," -> "! ," and "   XX," -> "    ,", when XX is
-    // empty.
-    if (!Identifier.isAtStartOfLine()) {
-      if (IsAtStartOfLine) Identifier.setFlag(Token::StartOfLine);
-      if (HadLeadingSpace) Identifier.setFlag(Token::LeadingSpace);
-    }
-    Identifier.setFlag(Token::LeadingEmptyMacro);
-    ++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);
-          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 false;
-  }
-
-  // Start expanding the macro.
-  EnterMacro(Identifier, ExpansionEnd, MI, Args);
-
-  // Now that the macro is at the top of the include stack, ask the
-  // preprocessor to read the next token from it.
-  Lex(Identifier);
-  return false;
-}
-
-/// 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::ReadFunctionLikeMacroArgs(Token &MacroName,
-                                                   MacroInfo *MI,
-                                                   SourceLocation &MacroEnd) {
-  // The number of fixed arguments to parse.
-  unsigned NumFixedArgsLeft = MI->getNumArgs();
-  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;
-
-  unsigned NumActuals = 0;
-  while (Tok.isNot(tok::r_paren)) {
-    assert((Tok.is(tok::l_paren) || Tok.is(tok::comma)) &&
-           "only expect argument separators here");
-
-    unsigned 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) {
-      // 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.is(tok::eof) || Tok.is(tok::eod)) { // "#if f(<eof>" & "#if f(\n"
-        Diag(MacroName, diag::err_unterm_macro_invoc);
-        // Do not lose the EOF/EOD.  Return it to the client.
-        MacroName = Tok;
-        return 0;
-      } else if (Tok.is(tok::r_paren)) {
-        // If we found the ) token, the macro arg list is done.
-        if (NumParens-- == 0) {
-          MacroEnd = Tok.getLocation();
-          break;
-        }
-      } else if (Tok.is(tok::l_paren)) {
-        ++NumParens;
-      } else if (Tok.is(tok::comma) && NumParens == 0) {
-        // 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.getIdentifierInfo() != 0) {
-        // 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)) {
-        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) {
-      if (ArgTokens.size() != ArgTokenStart)
-        ArgStartLoc = ArgTokens[ArgTokenStart].getLocation();
-
-      // 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(ArgStartLoc, diag::err_too_many_args_in_macro_invoc);
-      return 0;
-    }
-
-    // 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.CPlusPlus0x ?
-           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;
-    assert(NumFixedArgsLeft != 0 && "Too many arguments parsed");
-    --NumFixedArgsLeft;
-  }
-
-  // Okay, we either found the r_paren.  Check to see if we parsed too few
-  // arguments.
-  unsigned MinArgsExpected = MI->getNumArgs();
-
-  // See MacroArgs instance var for description of this.
-  bool isVarargsElided = false;
-
-  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 (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")
-      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 {
-      // Otherwise, emit the error.
-      Diag(Tok, diag::err_too_few_args_in_macro_invoc);
-      return 0;
-    }
-
-    // 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()) {
-    // 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);
-    return 0;
-  }
-
-  return MacroArgs::create(MI, ArgTokens, isVarargsElided, *this);
-}
-
-/// \brief 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 0;
-
-  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 (unsigned i = 0, e = MacroExpandingLexersStack.size(); i != e; ++i) {
-      TokenLexer *prevLexer;
-      size_t tokIndex;
-      llvm::tie(prevLexer, tokIndex) = MacroExpandingLexersStack[i];
-      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(0);
-  struct tm *TM = localtime(&TT);
-
-  static const char * const Months[] = {
-    "Jan","Feb","Mar","Apr","May","Jun","Jul","Aug","Sep","Oct","Nov","Dec"
-  };
-
-  char TmpBuffer[32];
-#ifdef LLVM_ON_WIN32
-  sprintf(TmpBuffer, "\"%s %2d %4d\"", Months[TM->tm_mon], TM->tm_mday,
-          TM->tm_year+1900);
-#else
-  snprintf(TmpBuffer, sizeof(TmpBuffer), "\"%s %2d %4d\"", Months[TM->tm_mon], TM->tm_mday,
-          TM->tm_year+1900);
-#endif
-
-  Token TmpTok;
-  TmpTok.startToken();
-  PP.CreateString(TmpBuffer, strlen(TmpBuffer), TmpTok);
-  DATELoc = TmpTok.getLocation();
-
-#ifdef LLVM_ON_WIN32
-  sprintf(TmpBuffer, "\"%02d:%02d:%02d\"", TM->tm_hour, TM->tm_min, TM->tm_sec);
-#else
-  snprintf(TmpBuffer, sizeof(TmpBuffer), "\"%02d:%02d:%02d\"", TM->tm_hour, TM->tm_min, TM->tm_sec);
-#endif
-  PP.CreateString(TmpBuffer, strlen(TmpBuffer), 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, const IdentifierInfo *II) {
-  const LangOptions &LangOpts = PP.getLangOpts();
-  StringRef Feature = II->getName();
-
-  // Normalize the feature name, __foo__ becomes foo.
-  if (Feature.startswith("__") && Feature.endswith("__") && Feature.size() >= 4)
-    Feature = Feature.substr(2, Feature.size() - 4);
-
-  return llvm::StringSwitch<bool>(Feature)
-           .Case("address_sanitizer", LangOpts.AddressSanitizer)
-           .Case("attribute_analyzer_noreturn", true)
-           .Case("attribute_availability", true)
-           .Case("attribute_availability_with_message", true)
-           .Case("attribute_cf_returns_not_retained", true)
-           .Case("attribute_cf_returns_retained", true)
-           .Case("attribute_deprecated_with_message", true)
-           .Case("attribute_ext_vector_type", true)
-           .Case("attribute_ns_returns_not_retained", true)
-           .Case("attribute_ns_returns_retained", true)
-           .Case("attribute_ns_consumes_self", true)
-           .Case("attribute_ns_consumed", true)
-           .Case("attribute_cf_consumed", true)
-           .Case("attribute_objc_ivar_unused", true)
-           .Case("attribute_objc_method_family", true)
-           .Case("attribute_overloadable", true)
-           .Case("attribute_unavailable_with_message", true)
-           .Case("attribute_unused_on_fields", true)
-           .Case("blocks", LangOpts.Blocks)
-           .Case("cxx_exceptions", LangOpts.Exceptions)
-           .Case("cxx_rtti", LangOpts.RTTI)
-           .Case("enumerator_attributes", true)
-           // Objective-C features
-           .Case("objc_arr", LangOpts.ObjCAutoRefCount) // FIXME: REMOVE?
-           .Case("objc_arc", LangOpts.ObjCAutoRefCount)
-           .Case("objc_arc_weak", LangOpts.ObjCARCWeak)
-           .Case("objc_default_synthesize_properties", LangOpts.ObjC2)
-           .Case("objc_fixed_enum", LangOpts.ObjC2)
-           .Case("objc_instancetype", LangOpts.ObjC2)
-           .Case("objc_modules", LangOpts.ObjC2 && LangOpts.Modules)
-           .Case("objc_nonfragile_abi", LangOpts.ObjCRuntime.isNonFragile())
-           .Case("objc_weak_class", LangOpts.ObjCRuntime.hasWeakClassImport())
-           .Case("ownership_holds", true)
-           .Case("ownership_returns", true)
-           .Case("ownership_takes", true)
-           .Case("objc_bool", true)
-           .Case("objc_subscripting", LangOpts.ObjCRuntime.isNonFragile())
-           .Case("objc_array_literals", LangOpts.ObjC2)
-           .Case("objc_dictionary_literals", LangOpts.ObjC2)
-           .Case("objc_boxed_expressions", LangOpts.ObjC2)
-           .Case("arc_cf_code_audited", true)
-           // C11 features
-           .Case("c_alignas", LangOpts.C11)
-           .Case("c_atomic", LangOpts.C11)
-           .Case("c_generic_selections", LangOpts.C11)
-           .Case("c_static_assert", LangOpts.C11)
-           // C++11 features
-           .Case("cxx_access_control_sfinae", LangOpts.CPlusPlus0x)
-           .Case("cxx_alias_templates", LangOpts.CPlusPlus0x)
-           .Case("cxx_alignas", LangOpts.CPlusPlus0x)
-           .Case("cxx_atomic", LangOpts.CPlusPlus0x)
-           .Case("cxx_attributes", LangOpts.CPlusPlus0x)
-           .Case("cxx_auto_type", LangOpts.CPlusPlus0x)
-           .Case("cxx_constexpr", LangOpts.CPlusPlus0x)
-           .Case("cxx_decltype", LangOpts.CPlusPlus0x)
-           .Case("cxx_decltype_incomplete_return_types", LangOpts.CPlusPlus0x)
-           .Case("cxx_default_function_template_args", LangOpts.CPlusPlus0x)
-           .Case("cxx_defaulted_functions", LangOpts.CPlusPlus0x)
-           .Case("cxx_delegating_constructors", LangOpts.CPlusPlus0x)
-           .Case("cxx_deleted_functions", LangOpts.CPlusPlus0x)
-           .Case("cxx_explicit_conversions", LangOpts.CPlusPlus0x)
-           .Case("cxx_generalized_initializers", LangOpts.CPlusPlus0x)
-           .Case("cxx_implicit_moves", LangOpts.CPlusPlus0x)
-         //.Case("cxx_inheriting_constructors", false)
-           .Case("cxx_inline_namespaces", LangOpts.CPlusPlus0x)
-           .Case("cxx_lambdas", LangOpts.CPlusPlus0x)
-           .Case("cxx_local_type_template_args", LangOpts.CPlusPlus0x)
-           .Case("cxx_nonstatic_member_init", LangOpts.CPlusPlus0x)
-           .Case("cxx_noexcept", LangOpts.CPlusPlus0x)
-           .Case("cxx_nullptr", LangOpts.CPlusPlus0x)
-           .Case("cxx_override_control", LangOpts.CPlusPlus0x)
-           .Case("cxx_range_for", LangOpts.CPlusPlus0x)
-           .Case("cxx_raw_string_literals", LangOpts.CPlusPlus0x)
-           .Case("cxx_reference_qualified_functions", LangOpts.CPlusPlus0x)
-           .Case("cxx_rvalue_references", LangOpts.CPlusPlus0x)
-           .Case("cxx_strong_enums", LangOpts.CPlusPlus0x)
-           .Case("cxx_static_assert", LangOpts.CPlusPlus0x)
-           .Case("cxx_trailing_return", LangOpts.CPlusPlus0x)
-           .Case("cxx_unicode_literals", LangOpts.CPlusPlus0x)
-           .Case("cxx_unrestricted_unions", LangOpts.CPlusPlus0x)
-           .Case("cxx_user_literals", LangOpts.CPlusPlus0x)
-           .Case("cxx_variadic_templates", LangOpts.CPlusPlus0x)
-           // Type traits
-           .Case("has_nothrow_assign", LangOpts.CPlusPlus)
-           .Case("has_nothrow_copy", LangOpts.CPlusPlus)
-           .Case("has_nothrow_constructor", LangOpts.CPlusPlus)
-           .Case("has_trivial_assign", LangOpts.CPlusPlus)
-           .Case("has_trivial_copy", LangOpts.CPlusPlus)
-           .Case("has_trivial_constructor", LangOpts.CPlusPlus)
-           .Case("has_trivial_destructor", LangOpts.CPlusPlus)
-           .Case("has_virtual_destructor", LangOpts.CPlusPlus)
-           .Case("is_abstract", LangOpts.CPlusPlus)
-           .Case("is_base_of", LangOpts.CPlusPlus)
-           .Case("is_class", LangOpts.CPlusPlus)
-           .Case("is_convertible_to", LangOpts.CPlusPlus)
-            // __is_empty is available only if the horrible
-            // "struct __is_empty" parsing hack hasn't been needed in this
-            // translation unit. If it has, __is_empty reverts to a normal
-            // identifier and __has_feature(is_empty) evaluates false.
-           .Case("is_empty", LangOpts.CPlusPlus)
-           .Case("is_enum", LangOpts.CPlusPlus)
-           .Case("is_final", LangOpts.CPlusPlus)
-           .Case("is_literal", LangOpts.CPlusPlus)
-           .Case("is_standard_layout", LangOpts.CPlusPlus)
-           .Case("is_pod", LangOpts.CPlusPlus)
-           .Case("is_polymorphic", LangOpts.CPlusPlus)
-           .Case("is_trivial", LangOpts.CPlusPlus)
-           .Case("is_trivially_assignable", LangOpts.CPlusPlus)
-           .Case("is_trivially_constructible", LangOpts.CPlusPlus)
-           .Case("is_trivially_copyable", LangOpts.CPlusPlus)
-           .Case("is_union", LangOpts.CPlusPlus)
-           .Case("modules", LangOpts.Modules)
-           .Case("tls", PP.getTargetInfo().isTLSSupported())
-           .Case("underlying_type", LangOpts.CPlusPlus)
-           .Default(false);
-}
-
-/// 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, const IdentifierInfo *II) {
-  if (HasFeature(PP, II))
-    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() ==
-      DiagnosticsEngine::Ext_Error)
-    return false;
-
-  const LangOptions &LangOpts = PP.getLangOpts();
-  StringRef Extension = II->getName();
-
-  // 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.
-  return llvm::StringSwitch<bool>(Extension)
-           // C11 features supported by other languages as extensions.
-           .Case("c_alignas", true)
-           .Case("c_atomic", true)
-           .Case("c_generic_selections", true)
-           .Case("c_static_assert", true)
-           // C++0x features supported by other languages as extensions.
-           .Case("cxx_atomic", LangOpts.CPlusPlus)
-           .Case("cxx_deleted_functions", LangOpts.CPlusPlus)
-           .Case("cxx_explicit_conversions", LangOpts.CPlusPlus)
-           .Case("cxx_inline_namespaces", LangOpts.CPlusPlus)
-           .Case("cxx_local_type_template_args", LangOpts.CPlusPlus)
-           .Case("cxx_nonstatic_member_init", LangOpts.CPlusPlus)
-           .Case("cxx_override_control", LangOpts.CPlusPlus)
-           .Case("cxx_range_for", LangOpts.CPlusPlus)
-           .Case("cxx_reference_qualified_functions", LangOpts.CPlusPlus)
-           .Case("cxx_rvalue_references", LangOpts.CPlusPlus)
-           .Default(false);
-}
-
-/// HasAttribute -  Return true if we recognize and implement the attribute
-/// specified by the given identifier.
-static bool HasAttribute(const IdentifierInfo *II) {
-  StringRef Name = II->getName();
-  // Normalize the attribute name, __foo__ becomes foo.
-  if (Name.startswith("__") && Name.endswith("__") && Name.size() >= 4)
-    Name = Name.substr(2, Name.size() - 4);
-
-  // FIXME: Do we need to handle namespaces here?
-  return llvm::StringSwitch<bool>(Name)
-#include "clang/Lex/AttrSpellings.inc"
-        .Default(false);
-}
-
-/// 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) {
-  SourceLocation LParenLoc;
-
-  // Get '('.
-  PP.LexNonComment(Tok);
-
-  // Ensure we have a '('.
-  if (Tok.isNot(tok::l_paren)) {
-    PP.Diag(Tok.getLocation(), diag::err_pp_missing_lparen) << II->getName();
-    return false;
-  }
-
-  // Save '(' location for possible missing ')' message.
-  LParenLoc = Tok.getLocation();
-
-  // Get the file name.
-  PP.getCurrentLexer()->LexIncludeFilename(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))
-      return false;   // Found <eod> but no ">"?  Diagnostic already emitted.
-    Filename = FilenameBuffer.str();
-    break;
-  default:
-    PP.Diag(Tok.getLocation(), diag::err_pp_expects_filename);
-    return false;
-  }
-
-  // Get ')'.
-  PP.LexNonComment(Tok);
-
-  // Ensure we have a trailing ).
-  if (Tok.isNot(tok::r_paren)) {
-    PP.Diag(Tok.getLocation(), diag::err_pp_missing_rparen) << II->getName();
-    PP.Diag(LParenLoc, diag::note_matching) << "(";
-    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;
-
-  //