C++ PresumedLoc::getIncludeLoc方法代码示例

/// \brief Helper to recursivly walk up the include stack and print each layer
/// on the way back down.
void DiagnosticRenderer::emitIncludeStackRecursively(SourceLocation Loc,
                                                     const SourceManager &SM) {
  if (Loc.isInvalid()) {
    emitModuleBuildStack(SM);
    return;
  }
  
  PresumedLoc PLoc = SM.getPresumedLoc(Loc, DiagOpts->ShowPresumedLoc);
  if (PLoc.isInvalid())
    return;

  // If this source location was imported from a module, print the module
  // import stack rather than the 
  // FIXME: We want submodule granularity here.
  std::pair<SourceLocation, StringRef> Imported = SM.getModuleImportLoc(Loc);
  if (!Imported.second.empty()) {
    // This location was imported by a module. Emit the module import stack.
    emitImportStackRecursively(Imported.first, Imported.second, SM);
    return;
  }

  // Emit the other include frames first.
  emitIncludeStackRecursively(PLoc.getIncludeLoc(), SM);
  
  // Emit the inclusion text/note.
  emitIncludeLocation(Loc, PLoc, SM);
}

/// \brief Helper to recursivly walk up the include stack and print each layer
/// on the way back down.
void DiagnosticRenderer::emitIncludeStackRecursively(SourceLocation Loc,
                                                     const SourceManager &SM) {
  
  PresumedLoc PLoc = SM.getPresumedLoc(Loc, DiagOpts->ShowPresumedLoc);
  if (PLoc.isInvalid())
    return;

  // Emit the other include frames first.
  emitIncludeStackRecursively(PLoc.getIncludeLoc(), SM);
  
  // Emit the inclusion text/note.
  emitIncludeLocation(Loc, PLoc, SM);
}

void TextDiagnosticPrinter::
PrintIncludeStack(SourceLocation Loc, const SourceManager &SM) {
  if (Loc.isInvalid()) return;

  PresumedLoc PLoc = SM.getPresumedLoc(Loc);

  // Print out the other include frames first.
  PrintIncludeStack(PLoc.getIncludeLoc(), SM);

  if (DiagOpts->ShowLocation)
    OS << "In file included from " << PLoc.getFilename()
       << ':' << PLoc.getLine() << ":\n";
  else
    OS << "In included file:\n";
}

static void getInclusions(const SrcMgr::SLocEntry &(SourceManager::*Getter)(unsigned, bool*) const, unsigned n,
                          CXTranslationUnit TU, CXInclusionVisitor CB,
                          CXClientData clientData)
{
  ASTUnit *CXXUnit = cxtu::getASTUnit(TU);
  SourceManager &SM = CXXUnit->getSourceManager();
  ASTContext &Ctx = CXXUnit->getASTContext();
  SmallVector<CXSourceLocation, 10> InclusionStack;
  const bool HasPreamble = SM.getPreambleFileID().isValid();

  for (unsigned i = 0 ; i < n ; ++i) {
    bool Invalid = false;
    const SrcMgr::SLocEntry &SL = (SM.*Getter)(i, &Invalid);

    if (!SL.isFile() || Invalid)
      continue;

    const SrcMgr::FileInfo &FI = SL.getFile();
    if (!FI.getContentCache()->OrigEntry)
      continue;

    // If this is the main file, and there is a preamble, skip this SLoc. The
    // inclusions of the preamble already showed it.
    SourceLocation L = FI.getIncludeLoc();
    if (HasPreamble && CXXUnit->isInMainFileID(L))
      continue;

    // Build the inclusion stack.
    InclusionStack.clear();
    while (L.isValid()) {
      PresumedLoc PLoc = SM.getPresumedLoc(L);
      InclusionStack.push_back(cxloc::translateSourceLocation(Ctx, L));
      L = PLoc.isValid()? PLoc.getIncludeLoc() : SourceLocation();
    }

    // If there is a preamble, the last entry is the "inclusion" of that
    // preamble into the main file, which has the bogus entry of main.c:1:1
    if (HasPreamble && !InclusionStack.empty())
      InclusionStack.pop_back();

    // Callback to the client.
    // FIXME: We should have a function to construct CXFiles.
    CB(static_cast<CXFile>(
         const_cast<FileEntry *>(FI.getContentCache()->OrigEntry)),
       InclusionStack.data(), InclusionStack.size(), clientData);
  }
}

/// \brief Helper to recursivly walk up the include stack and print each layer
/// on the way back down.
void TextDiagnostic::emitIncludeStackRecursively(SourceLocation Loc) {
    if (Loc.isInvalid())
        return;

    PresumedLoc PLoc = SM.getPresumedLoc(Loc);
    if (PLoc.isInvalid())
        return;

    // Emit the other include frames first.
    emitIncludeStackRecursively(PLoc.getIncludeLoc());

    if (DiagOpts.ShowLocation)
        OS << "In file included from " << PLoc.getFilename()
           << ':' << PLoc.getLine() << ":\n";
    else
        OS << "In included file:\n";
}

void TextDiagnostic::emitDiagnostic(SourceLocation Loc,
                                    DiagnosticsEngine::Level Level,
                                    StringRef Message,
                                    ArrayRef<CharSourceRange> Ranges,
                                    ArrayRef<FixItHint> FixItHints) {
    PresumedLoc PLoc = getDiagnosticPresumedLoc(SM, Loc);

    // First, if this diagnostic is not in the main file, print out the
    // "included from" lines.
    emitIncludeStack(PLoc.getIncludeLoc(), Level);

    uint64_t StartOfLocationInfo = OS.tell();

    // Next emit the location of this particular diagnostic.
    emitDiagnosticLoc(Loc, PLoc, Level, Ranges);

    if (DiagOpts.ShowColors)
        OS.resetColor();

    printDiagnosticLevel(OS, Level, DiagOpts.ShowColors);
    printDiagnosticMessage(OS, Level, Message,
                           OS.tell() - StartOfLocationInfo,
                           DiagOpts.MessageLength, DiagOpts.ShowColors);

    // Only recurse if we have a valid location.
    if (Loc.isValid()) {
        // Get the ranges into a local array we can hack on.
        SmallVector<CharSourceRange, 20> MutableRanges(Ranges.begin(),
                Ranges.end());

        for (ArrayRef<FixItHint>::const_iterator I = FixItHints.begin(),
                E = FixItHints.end();
                I != E; ++I)
            if (I->RemoveRange.isValid())
                MutableRanges.push_back(I->RemoveRange);

        unsigned MacroDepth = 0;
        emitMacroExpansionsAndCarets(Loc, Level, MutableRanges, FixItHints,
                                     MacroDepth);
    }

    LastLoc = Loc;
    LastLevel = Level;
}

void clang_getInclusions(CXTranslationUnit TU, CXInclusionVisitor CB,
                         CXClientData clientData) {
  
  ASTUnit *CXXUnit = static_cast<ASTUnit *>(TU);
  SourceManager &SM = CXXUnit->getSourceManager();
  ASTContext &Ctx = CXXUnit->getASTContext();

  llvm::SmallVector<CXSourceLocation, 10> InclusionStack;
  unsigned i = SM.sloc_loaded_entry_size();
  unsigned n =  SM.sloc_entry_size();

  // In the case where all the SLocEntries are in an external source, traverse
  // those SLocEntries as well.  This is the case where we are looking
  // at the inclusion stack of an AST/PCH file.
  if (i >= n)
    i = 0;
  
  for ( ; i < n ; ++i) {

    const SrcMgr::SLocEntry &SL = SM.getSLocEntry(i);
    
    if (!SL.isFile())
      continue;

    const SrcMgr::FileInfo &FI = SL.getFile();
    if (!FI.getContentCache()->Entry)
      continue;
    
    // Build the inclusion stack.
    SourceLocation L = FI.getIncludeLoc();
    InclusionStack.clear();
    while (L.isValid()) {
      PresumedLoc PLoc = SM.getPresumedLoc(L);
      InclusionStack.push_back(cxloc::translateSourceLocation(Ctx, L));
      L = PLoc.getIncludeLoc();
    }
            
    // Callback to the client.
    // FIXME: We should have a function to construct CXFiles.
    CB((CXFile) FI.getContentCache()->Entry, 
       InclusionStack.data(), InclusionStack.size(), clientData);
  }    
}

/// \brief Prints an include stack when appropriate for a particular
/// diagnostic level and location.
///
/// This routine handles all the logic of suppressing particular include
/// stacks (such as those for notes) and duplicate include stacks when
/// repeated warnings occur within the same file. It also handles the logic
/// of customizing the formatting and display of the include stack.
///
/// \param Loc   The diagnostic location.
/// \param PLoc  The presumed location of the diagnostic location.
/// \param Level The diagnostic level of the message this stack pertains to.
void DiagnosticRenderer::emitIncludeStack(SourceLocation Loc,
                                          PresumedLoc PLoc,
                                          DiagnosticsEngine::Level Level,
                                          const SourceManager &SM) {
  SourceLocation IncludeLoc = PLoc.getIncludeLoc();

  // Skip redundant include stacks altogether.
  if (LastIncludeLoc == IncludeLoc)
    return;
  
  LastIncludeLoc = IncludeLoc;
  
  if (!DiagOpts->ShowNoteIncludeStack && Level == DiagnosticsEngine::Note)
    return;

  if (!IncludeLoc.isValid()){
	  // TODO: Should ERROR
  }
  emitIncludeStackRecursively(IncludeLoc, SM);
}

/// \brief Prints an include stack when appropriate for a particular
/// diagnostic level and location.
///
/// This routine handles all the logic of suppressing particular include
/// stacks (such as those for notes) and duplicate include stacks when
/// repeated warnings occur within the same file. It also handles the logic
/// of customizing the formatting and display of the include stack.
///
/// \param Loc   The diagnostic location.
/// \param PLoc  The presumed location of the diagnostic location.
/// \param Level The diagnostic level of the message this stack pertains to.
void DiagnosticRenderer::emitIncludeStack(SourceLocation Loc,
                                          PresumedLoc PLoc,
                                          DiagnosticsEngine::Level Level,
                                          const SourceManager &SM) {
  SourceLocation IncludeLoc =
      PLoc.isInvalid() ? SourceLocation() : PLoc.getIncludeLoc();

  // Skip redundant include stacks altogether.
  if (LastIncludeLoc == IncludeLoc)
    return;
  
  LastIncludeLoc = IncludeLoc;
  
  if (!DiagOpts->ShowNoteIncludeStack && Level == DiagnosticsEngine::Note)
    return;

  if (IncludeLoc.isValid())
    emitIncludeStackRecursively(IncludeLoc, SM);
  else {
    emitModuleBuildStack(SM);
    emitImportStack(Loc, SM);
  }
}

/// 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;

  llvm::SmallString<128> TmpBuffer;
  llvm::raw_svector_ostream OS(TmpBuffer);

  // Set up the return result.
  Tok.setIdentifierInfo(0);
  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).second;
    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 '\' -> '\\' '"' -> '\"'
    llvm::SmallString<128> FN;
    if (PLoc.isValid()) {
      FN += PLoc.getFilename();
      Lexer::Stringify(FN);
      OS << '"' << FN.str() << '"';
    }
    Tok.setKind(tok::string_literal);
  } else if (II == Ident__DATE__) {
    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__) {
    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());
    }

//.........这里部分代码省略.........

void TextDiagnosticPrinter::HandleDiagnostic(Diagnostic::Level Level,
                                             const DiagnosticInfo &Info) {
  // Keeps track of the the starting position of the location
  // information (e.g., "foo.c:10:4:") that precedes the error
  // message. We use this information to determine how long the
  // file+line+column number prefix is.
  uint64_t StartOfLocationInfo = OS.tell();

  if (!Prefix.empty())
    OS << Prefix << ": ";

  // If the location is specified, print out a file/line/col and include trace
  // if enabled.
  if (Info.getLocation().isValid()) {
    const SourceManager &SM = Info.getLocation().getManager();
    PresumedLoc PLoc = SM.getPresumedLoc(Info.getLocation());
    unsigned LineNo = PLoc.getLine();

    // First, if this diagnostic is not in the main file, print out the
    // "included from" lines.
    if (LastWarningLoc != PLoc.getIncludeLoc()) {
      LastWarningLoc = PLoc.getIncludeLoc();
      PrintIncludeStack(LastWarningLoc, SM);
      StartOfLocationInfo = OS.tell();
    }

    // Compute the column number.
    if (DiagOpts->ShowLocation) {
      if (DiagOpts->ShowColors)
        OS.changeColor(savedColor, true);
      
      // Emit a Visual Studio compatible line number syntax.
      if (LangOpts && LangOpts->Microsoft) {
        OS << PLoc.getFilename() << '(' << LineNo << ')';
        OS << " : ";
      } else {
        OS << PLoc.getFilename() << ':' << LineNo << ':';
        if (DiagOpts->ShowColumn)
          if (unsigned ColNo = PLoc.getColumn())
            OS << ColNo << ':';
      }
      if (DiagOpts->ShowSourceRanges && Info.getNumRanges()) {
        FileID CaretFileID =
          SM.getFileID(SM.getInstantiationLoc(Info.getLocation()));
        bool PrintedRange = false;

        for (unsigned i = 0, e = Info.getNumRanges(); i != e; ++i) {
          // Ignore invalid ranges.
          if (!Info.getRange(i).isValid()) continue;

          SourceLocation B = Info.getRange(i).getBegin();
          SourceLocation E = Info.getRange(i).getEnd();
          B = SM.getInstantiationLoc(B);
          E = SM.getInstantiationLoc(E);

          // If the End location and the start location are the same and are a
          // macro location, then the range was something that came from a macro
          // expansion or _Pragma.  If this is an object-like macro, the best we
          // can do is to highlight the range.  If this is a function-like
          // macro, we'd also like to highlight the arguments.
          if (B == E && Info.getRange(i).getEnd().isMacroID())
            E = SM.getInstantiationRange(Info.getRange(i).getEnd()).second;

          std::pair<FileID, unsigned> BInfo = SM.getDecomposedLoc(B);
          std::pair<FileID, unsigned> EInfo = SM.getDecomposedLoc(E);

          // If the start or end of the range is in another file, just discard
          // it.
          if (BInfo.first != CaretFileID || EInfo.first != CaretFileID)
            continue;

          // Add in the length of the token, so that we cover multi-char tokens.
          unsigned TokSize = Lexer::MeasureTokenLength(E, SM, *LangOpts);

          OS << '{' << SM.getLineNumber(BInfo.first, BInfo.second) << ':'
             << SM.getColumnNumber(BInfo.first, BInfo.second) << '-'
             << SM.getLineNumber(EInfo.first, EInfo.second) << ':'
             << (SM.getColumnNumber(EInfo.first, EInfo.second)+TokSize) << '}';
          PrintedRange = true;
        }

        if (PrintedRange)
          OS << ':';
      }
      OS << ' ';
      if (DiagOpts->ShowColors)
        OS.resetColor();
    }
  }

  if (DiagOpts->ShowColors) {
    // Print diagnostic category in bold and color
    switch (Level) {
    case Diagnostic::Ignored: assert(0 && "Invalid diagnostic type");
    case Diagnostic::Note:    OS.changeColor(noteColor, true); break;
    case Diagnostic::Warning: OS.changeColor(warningColor, true); break;
    case Diagnostic::Error:   OS.changeColor(errorColor, true); break;
    case Diagnostic::Fatal:   OS.changeColor(fatalColor, true); break;
    }
  }
//.........这里部分代码省略.........

void TextDiagnosticPrinter::EmitCaretDiagnostic(SourceLocation Loc,
                                                SourceRange *Ranges,
                                                unsigned NumRanges,
                                                SourceManager &SM,
                                          const CodeModificationHint *Hints,
                                                unsigned NumHints,
                                                unsigned Columns) {
  assert(LangOpts && "Unexpected diagnostic outside source file processing");
  assert(!Loc.isInvalid() && "must have a valid source location here");

  // If this is a macro ID, first emit information about where this was
  // instantiated (recursively) then emit information about where the token was
  // spelled from.
  if (!Loc.isFileID()) {
    SourceLocation OneLevelUp = SM.getImmediateInstantiationRange(Loc).first;
    // FIXME: Map ranges?
    EmitCaretDiagnostic(OneLevelUp, Ranges, NumRanges, SM, 0, 0, Columns);

    // Map the location.
    Loc = SM.getImmediateSpellingLoc(Loc);

    // Map the ranges.
    for (unsigned i = 0; i != NumRanges; ++i) {
      SourceLocation S = Ranges[i].getBegin(), E = Ranges[i].getEnd();
      if (S.isMacroID()) S = SM.getImmediateSpellingLoc(S);
      if (E.isMacroID()) E = SM.getImmediateSpellingLoc(E);
      Ranges[i] = SourceRange(S, E);
    }
    
    // Get the pretty name, according to #line directives etc.
    PresumedLoc PLoc = SM.getPresumedLoc(Loc);
    
    // If this diagnostic is not in the main file, print out the "included from"
    // lines.
    if (LastWarningLoc != PLoc.getIncludeLoc()) {
      LastWarningLoc = PLoc.getIncludeLoc();
      PrintIncludeStack(LastWarningLoc, SM);
    }

    if (DiagOpts->ShowLocation) {
      // Emit the file/line/column that this expansion came from.
      OS << PLoc.getFilename() << ':' << PLoc.getLine() << ':';
      if (DiagOpts->ShowColumn)
        OS << PLoc.getColumn() << ':';
      OS << ' ';
    }
    OS << "note: instantiated from:\n";

    EmitCaretDiagnostic(Loc, Ranges, NumRanges, SM, Hints, NumHints, Columns);
    return;
  }

  // Decompose the location into a FID/Offset pair.
  std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(Loc);
  FileID FID = LocInfo.first;
  unsigned FileOffset = LocInfo.second;

  // Get information about the buffer it points into.
  std::pair<const char*, const char*> BufferInfo = SM.getBufferData(FID);
  const char *BufStart = BufferInfo.first;

  unsigned ColNo = SM.getColumnNumber(FID, FileOffset);
  unsigned CaretEndColNo
    = ColNo + Lexer::MeasureTokenLength(Loc, SM, *LangOpts);

  // Rewind from the current position to the start of the line.
  const char *TokPtr = BufStart+FileOffset;
  const char *LineStart = TokPtr-ColNo+1; // Column # is 1-based.


  // Compute the line end.  Scan forward from the error position to the end of
  // the line.
  const char *LineEnd = TokPtr;
  while (*LineEnd != '\n' && *LineEnd != '\r' && *LineEnd != '\0')
    ++LineEnd;

  // FIXME: This shouldn't be necessary, but the CaretEndColNo can extend past
  // the source line length as currently being computed. See
  // test/Misc/message-length.c.
  CaretEndColNo = std::min(CaretEndColNo, unsigned(LineEnd - LineStart));

  // Copy the line of code into an std::string for ease of manipulation.
  std::string SourceLine(LineStart, LineEnd);

  // Create a line for the caret that is filled with spaces that is the same
  // length as the line of source code.
  std::string CaretLine(LineEnd-LineStart, ' ');

  // Highlight all of the characters covered by Ranges with ~ characters.
  if (NumRanges) {
    unsigned LineNo = SM.getLineNumber(FID, FileOffset);

    for (unsigned i = 0, e = NumRanges; i != e; ++i)
      HighlightRange(Ranges[i], SM, LineNo, FID, CaretLine, SourceLine);
  }

  // Next, insert the caret itself.
  if (ColNo-1 < CaretLine.size())
    CaretLine[ColNo-1] = '^';
  else
//.........这里部分代码省略.........

/// 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!");


  ++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__) {
//.........这里部分代码省略.........