C++ SourceLocation::isFileID方法代码示例

/// If \arg loc is a file ID and points inside the current macro
/// definition, returns the appropriate source location pointing at the
/// macro expansion source location entry, otherwise it returns an invalid
/// SourceLocation.
SourceLocation
TokenLexer::getExpansionLocForMacroDefLoc(SourceLocation loc) const {
  assert(ExpandLocStart.isValid() && MacroExpansionStart.isValid() &&
         "Not appropriate for token streams");
  assert(loc.isValid() && loc.isFileID());

  SourceManager &SM = PP.getSourceManager();
  assert(SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength) &&
         "Expected loc to come from the macro definition");

  unsigned relativeOffset = 0;
  SM.isInSLocAddrSpace(loc, MacroDefStart, MacroDefLength, &relativeOffset);
  return MacroExpansionStart.getLocWithOffset(relativeOffset);
}

// Checks if 'typedef' keyword can be removed - we do it only if
// it is the only declaration in a declaration chain.
static bool CheckRemoval(SourceManager &SM, SourceLocation StartLoc,
                         ASTContext &Context) {
  assert(StartLoc.isFileID() && "StartLoc must not be in a macro");
  std::pair<FileID, unsigned> LocInfo = SM.getDecomposedLoc(StartLoc);
  StringRef File = SM.getBufferData(LocInfo.first);
  const char *TokenBegin = File.data() + LocInfo.second;
  Lexer DeclLexer(SM.getLocForStartOfFile(LocInfo.first), Context.getLangOpts(),
                  File.begin(), TokenBegin, File.end());

  Token Tok;
  int ParenLevel = 0;
  bool FoundTypedef = false;

  while (!DeclLexer.LexFromRawLexer(Tok) && !Tok.is(tok::semi)) {
    switch (Tok.getKind()) {
    case tok::l_brace:
    case tok::r_brace:
      // This might be the `typedef struct {...} T;` case.
      return false;
    case tok::l_paren:
      ParenLevel++;
      break;
    case tok::r_paren:
      ParenLevel--;
      break;
    case tok::comma:
      if (ParenLevel == 0) {
        // If there is comma and we are not between open parenthesis then it is
        // two or more declarations in this chain.
        return false;
      }
      break;
    case tok::raw_identifier:
      if (Tok.getRawIdentifier() == "typedef") {
        FoundTypedef = true;
      }
      break;
    default:
      break;
    }
  }

  // Sanity check against weird macro cases.
  return FoundTypedef;
}

static bool isEmptyARCMTMacroStatement(NullStmt *S,
                                       std::vector<SourceLocation> &MacroLocs,
                                       ASTContext &Ctx) {
  if (!S->hasLeadingEmptyMacro())
    return false;

  SourceLocation SemiLoc = S->getSemiLoc();
  if (SemiLoc.isInvalid() || SemiLoc.isMacroID())
    return false;

  if (MacroLocs.empty())
    return false;

  SourceManager &SM = Ctx.getSourceManager();
  std::vector<SourceLocation>::iterator
    I = std::upper_bound(MacroLocs.begin(), MacroLocs.end(), SemiLoc,
                         BeforeThanCompare<SourceLocation>(SM));
  --I;
  SourceLocation
      AfterMacroLoc = I->getLocWithOffset(getARCMTMacroName().size());
  assert(AfterMacroLoc.isFileID());

  if (AfterMacroLoc == SemiLoc)
    return true;

  int RelOffs = 0;
  if (!SM.isInSameSLocAddrSpace(AfterMacroLoc, SemiLoc, &RelOffs))
    return false;
  if (RelOffs < 0)
    return false;

  // We make the reasonable assumption that a semicolon after 100 characters
  // means that it is not the next token after our macro. If this assumption
  // fails it is not critical, we will just fail to clear out, e.g., an empty
  // 'if'.
  if (RelOffs - getARCMTMacroName().size() > 100)
    return false;

  SourceLocation AfterMacroSemiLoc = findSemiAfterLocation(AfterMacroLoc, Ctx);
  return AfterMacroSemiLoc == SemiLoc;
}

static bool locationsInSameFile(const SourceManager &Sources,
                                SourceLocation Loc1, SourceLocation Loc2) {
  return Loc1.isFileID() && Loc2.isFileID() &&
         Sources.getFileID(Loc1) == Sources.getFileID(Loc2);
}

/// \brief Recursively emit notes for each macro expansion and caret
/// diagnostics where appropriate.
///
/// Walks up the macro expansion stack printing expansion notes, the code
/// snippet, caret, underlines and FixItHint display as appropriate at each
/// level.
///
/// \param Loc The location for this caret.
/// \param Level The diagnostic level currently being emitted.
/// \param Ranges The underlined ranges for this code snippet.
/// \param Hints The FixIt hints active for this diagnostic.
void DiagnosticRenderer::emitMacroExpansions(SourceLocation Loc,
                                             DiagnosticsEngine::Level Level,
                                             ArrayRef<CharSourceRange> Ranges,
                                             ArrayRef<FixItHint> Hints,
                                             const SourceManager &SM) {
  assert(!Loc.isInvalid() && "must have a valid source location here");

  // Produce a stack of macro backtraces.
  SmallVector<SourceLocation, 8> LocationStack;
  unsigned IgnoredEnd = 0;
  while (Loc.isMacroID()) {
    // If this is the expansion of a macro argument, point the caret at the
    // use of the argument in the definition of the macro, not the expansion.
    if (SM.isMacroArgExpansion(Loc))
      LocationStack.push_back(SM.getImmediateExpansionRange(Loc).first);
    else
      LocationStack.push_back(Loc);

    if (checkRangesForMacroArgExpansion(Loc, Ranges, SM))
      IgnoredEnd = LocationStack.size();

    Loc = SM.getImmediateMacroCallerLoc(Loc);

    // Once the location no longer points into a macro, try stepping through
    // the last found location.  This sometimes produces additional useful
    // backtraces.
    if (Loc.isFileID())
      Loc = SM.getImmediateMacroCallerLoc(LocationStack.back());
    assert(!Loc.isInvalid() && "must have a valid source location here");
  }

  LocationStack.erase(LocationStack.begin(),
                      LocationStack.begin() + IgnoredEnd);

  unsigned MacroDepth = LocationStack.size();
  unsigned MacroLimit = DiagOpts->MacroBacktraceLimit;
  if (MacroDepth <= MacroLimit || MacroLimit == 0) {
    for (auto I = LocationStack.rbegin(), E = LocationStack.rend();
         I != E; ++I)
      emitSingleMacroExpansion(*I, Level, Ranges, SM);
    return;
  }

  unsigned MacroStartMessages = MacroLimit / 2;
  unsigned MacroEndMessages = MacroLimit / 2 + MacroLimit % 2;

  for (auto I = LocationStack.rbegin(),
            E = LocationStack.rbegin() + MacroStartMessages;
       I != E; ++I)
    emitSingleMacroExpansion(*I, Level, Ranges, SM);

  SmallString<200> MessageStorage;
  llvm::raw_svector_ostream Message(MessageStorage);
  Message << "(skipping " << (MacroDepth - MacroLimit)
          << " expansions in backtrace; use -fmacro-backtrace-limit=0 to "
             "see all)";
  emitBasicNote(Message.str());

  for (auto I = LocationStack.rend() - MacroEndMessages,
            E = LocationStack.rend();
       I != E; ++I)
    emitSingleMacroExpansion(*I, Level, Ranges, SM);
}

/// \brief Emit a code snippet and caret line.
///
/// This routine emits a single line's code snippet and caret line..
///
/// \param Loc The location for the caret.
/// \param Ranges The underlined ranges for this code snippet.
/// \param Hints The FixIt hints active for this diagnostic.
void TextDiagnostic::emitSnippetAndCaret(
    SourceLocation Loc, DiagnosticsEngine::Level Level,
    SmallVectorImpl<CharSourceRange>& Ranges,
    ArrayRef<FixItHint> Hints,
    const SourceManager &SM) {
  assert(!Loc.isInvalid() && "must have a valid source location here");
  assert(Loc.isFileID() && "must have a file location here");

  // If caret diagnostics are enabled and we have location, we want to
  // emit the caret.  However, we only do this if the location moved
  // from the last diagnostic, if the last diagnostic was a note that
  // was part of a different warning or error diagnostic, or if the
  // diagnostic has ranges.  We don't want to emit the same caret
  // multiple times if one loc has multiple diagnostics.
  if (!DiagOpts->ShowCarets)
    return;
  if (Loc == LastLoc && Ranges.empty() && Hints.empty() &&
      (LastLevel != DiagnosticsEngine::Note || Level == LastLevel))
    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.
  bool Invalid = false;
  const char *BufStart = SM.getBufferData(FID, &Invalid).data();
  if (Invalid)
    return;

  unsigned LineNo = SM.getLineNumber(FID, FileOffset);
  unsigned ColNo = SM.getColumnNumber(FID, FileOffset);

  // 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;

  // 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, ' ');

  const SourceColumnMap sourceColMap(SourceLine, DiagOpts->TabStop);

  // Highlight all of the characters covered by Ranges with ~ characters.
  for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
                                                  E = Ranges.end();
       I != E; ++I)
    highlightRange(*I, LineNo, FID, sourceColMap, CaretLine, SM, LangOpts);

  // Next, insert the caret itself.
  ColNo = sourceColMap.byteToContainingColumn(ColNo-1);
  if (CaretLine.size()<ColNo+1)
    CaretLine.resize(ColNo+1, ' ');
  CaretLine[ColNo] = '^';

  std::string FixItInsertionLine = buildFixItInsertionLine(LineNo,
                                                           sourceColMap,
                                                           Hints, SM,
                                                           DiagOpts.getPtr());

  // If the source line is too long for our terminal, select only the
  // "interesting" source region within that line.
  unsigned Columns = DiagOpts->MessageLength;
  if (Columns)
    selectInterestingSourceRegion(SourceLine, CaretLine, FixItInsertionLine,
                                  Columns, sourceColMap);

  // If we are in -fdiagnostics-print-source-range-info mode, we are trying
  // to produce easily machine parsable output.  Add a space before the
  // source line and the caret to make it trivial to tell the main diagnostic
  // line from what the user is intended to see.
  if (DiagOpts->ShowSourceRanges) {
    SourceLine = ' ' + SourceLine;
    CaretLine = ' ' + CaretLine;
  }

  // Finally, remove any blank spaces from the end of CaretLine.
  while (CaretLine[CaretLine.size()-1] == ' ')
    CaretLine.erase(CaretLine.end()-1);

  // Emit what we have computed.
  emitSnippet(SourceLine);
//.........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.........

void TextDiagnosticPrinter::EmitCaretDiagnostic(SourceLocation Loc,
                                                SourceRange *Ranges,
                                                unsigned NumRanges,
                                                SourceManager &SM,
                                          const CodeModificationHint *Hints,
                                                unsigned NumHints,
                                                unsigned Columns) {
  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);

    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);
    }
    
    if (ShowLocation) {
      std::pair<FileID, unsigned> IInfo = SM.getDecomposedInstantiationLoc(Loc);
      
      // Emit the file/line/column that this expansion came from.
      OS << SM.getBuffer(IInfo.first)->getBufferIdentifier() << ':'
         << SM.getLineNumber(IInfo.first, IInfo.second) << ':';
      if (ShowColumn)
        OS << SM.getColumnNumber(IInfo.first, IInfo.second) << ':';
      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;
  
  // 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
    CaretLine.push_back('^');
  
  // Scan the source line, looking for tabs.  If we find any, manually expand
  // them to 8 characters and update the CaretLine to match.
  for (unsigned i = 0; i != SourceLine.size(); ++i) {
    if (SourceLine[i] != '\t') continue;
    
    // Replace this tab with at least one space.
    SourceLine[i] = ' ';
    
    // Compute the number of spaces we need to insert.
    unsigned NumSpaces = ((i+8)&~7) - (i+1);
    assert(NumSpaces < 8 && "Invalid computation of space amt");
    
//.........这里部分代码省略.........

/// \brief Recursively emit notes for each macro expansion and caret
/// diagnostics where appropriate.
///
/// Walks up the macro expansion stack printing expansion notes, the code
/// snippet, caret, underlines and FixItHint display as appropriate at each
/// level.
///
/// \param Loc The location for this caret.
/// \param Level The diagnostic level currently being emitted.
/// \param Ranges The underlined ranges for this code snippet.
/// \param Hints The FixIt hints active for this diagnostic.
/// \param MacroSkipEnd The depth to stop skipping macro expansions.
/// \param OnMacroInst The current depth of the macro expansion stack.
void TextDiagnostic::emitMacroExpansionsAndCarets(
    SourceLocation Loc,
    DiagnosticsEngine::Level Level,
    SmallVectorImpl<CharSourceRange>& Ranges,
    ArrayRef<FixItHint> Hints,
    unsigned &MacroDepth,
    unsigned OnMacroInst) {
    assert(!Loc.isInvalid() && "must have a valid source location here");

    // If this is a file source location, directly emit the source snippet and
    // caret line. Also record the macro depth reached.
    if (Loc.isFileID()) {
        assert(MacroDepth == 0 && "We shouldn't hit a leaf node twice!");
        MacroDepth = OnMacroInst;
        emitSnippetAndCaret(Loc, Level, Ranges, Hints);
        return;
    }
    // Otherwise recurse through each macro expansion layer.

    // When processing macros, skip over the expansions leading up to
    // a macro argument, and trace the argument's expansion stack instead.
    Loc = skipToMacroArgExpansion(SM, Loc);

    SourceLocation OneLevelUp = getImmediateMacroCallerLoc(SM, Loc);

    // FIXME: Map ranges?
    emitMacroExpansionsAndCarets(OneLevelUp, Level, Ranges, Hints, MacroDepth,
                                 OnMacroInst + 1);

    // Save the original location so we can find the spelling of the macro call.
    SourceLocation MacroLoc = Loc;

    // Map the location.
    Loc = getImmediateMacroCalleeLoc(SM, Loc);

    unsigned MacroSkipStart = 0, MacroSkipEnd = 0;
    if (MacroDepth > DiagOpts.MacroBacktraceLimit) {
        MacroSkipStart = DiagOpts.MacroBacktraceLimit / 2 +
                         DiagOpts.MacroBacktraceLimit % 2;
        MacroSkipEnd = MacroDepth - DiagOpts.MacroBacktraceLimit / 2;
    }

    // Whether to suppress printing this macro expansion.
    bool Suppressed = (OnMacroInst >= MacroSkipStart &&
                       OnMacroInst < MacroSkipEnd);

    // Map the ranges.
    for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
            E = Ranges.end();
            I != E; ++I) {
        SourceLocation Start = I->getBegin(), End = I->getEnd();
        if (Start.isMacroID())
            I->setBegin(getImmediateMacroCalleeLoc(SM, Start));
        if (End.isMacroID())
            I->setEnd(getImmediateMacroCalleeLoc(SM, End));
    }

    if (Suppressed) {
        // Tell the user that we've skipped contexts.
        if (OnMacroInst == MacroSkipStart) {
            // FIXME: Emit this as a real note diagnostic.
            // FIXME: Format an actual diagnostic rather than a hard coded string.
            OS << "note: (skipping " << (MacroSkipEnd - MacroSkipStart)
               << " expansions in backtrace; use -fmacro-backtrace-limit=0 to see "
               "all)\n";
        }
        return;
    }

    llvm::SmallString<100> MessageStorage;
    llvm::raw_svector_ostream Message(MessageStorage);
    Message << "expanded from macro '"
            << getImmediateMacroName(MacroLoc, SM, LangOpts) << "'";
    emitDiagnostic(SM.getSpellingLoc(Loc), DiagnosticsEngine::Note,
                   Message.str(),
                   Ranges, ArrayRef<FixItHint>());
}

void PathDiagnosticConsumer::HandlePathDiagnostic(
    std::unique_ptr<PathDiagnostic> D) {
  if (!D || D->path.empty())
    return;

  // We need to flatten the locations (convert Stmt* to locations) because
  // the referenced statements may be freed by the time the diagnostics
  // are emitted.
  D->flattenLocations();

  // If the PathDiagnosticConsumer does not support diagnostics that
  // cross file boundaries, prune out such diagnostics now.
  if (!supportsCrossFileDiagnostics()) {
    // Verify that the entire path is from the same FileID.
    FileID FID;
    const SourceManager &SMgr = D->path.front()->getLocation().getManager();
    SmallVector<const PathPieces *, 5> WorkList;
    WorkList.push_back(&D->path);
    SmallString<128> buf;
    llvm::raw_svector_ostream warning(buf);
    warning << "warning: Path diagnostic report is not generated. Current "
            << "output format does not support diagnostics that cross file "
            << "boundaries. Refer to --analyzer-output for valid output "
            << "formats\n";

    while (!WorkList.empty()) {
      const PathPieces &path = *WorkList.pop_back_val();

      for (const auto &I : path) {
        const PathDiagnosticPiece *piece = I.get();
        FullSourceLoc L = piece->getLocation().asLocation().getExpansionLoc();

        if (FID.isInvalid()) {
          FID = SMgr.getFileID(L);
        } else if (SMgr.getFileID(L) != FID) {
          llvm::errs() << warning.str();
          return;
        }

        // Check the source ranges.
        ArrayRef<SourceRange> Ranges = piece->getRanges();
        for (const auto &I : Ranges) {
          SourceLocation L = SMgr.getExpansionLoc(I.getBegin());
          if (!L.isFileID() || SMgr.getFileID(L) != FID) {
            llvm::errs() << warning.str();
            return;
          }
          L = SMgr.getExpansionLoc(I.getEnd());
          if (!L.isFileID() || SMgr.getFileID(L) != FID) {
            llvm::errs() << warning.str();
            return;
          }
        }

        if (const auto *call = dyn_cast<PathDiagnosticCallPiece>(piece))
          WorkList.push_back(&call->path);
        else if (const auto *macro = dyn_cast<PathDiagnosticMacroPiece>(piece))
          WorkList.push_back(&macro->subPieces);
      }
    }

    if (FID.isInvalid())
      return; // FIXME: Emit a warning?
  }

  // Profile the node to see if we already have something matching it
  llvm::FoldingSetNodeID profile;
  D->Profile(profile);
  void *InsertPos = nullptr;

  if (PathDiagnostic *orig = Diags.FindNodeOrInsertPos(profile, InsertPos)) {
    // Keep the PathDiagnostic with the shorter path.
    // Note, the enclosing routine is called in deterministic order, so the
    // results will be consistent between runs (no reason to break ties if the
    // size is the same).
    const unsigned orig_size = orig->full_size();
    const unsigned new_size = D->full_size();
    if (orig_size <= new_size)
      return;

    assert(orig != D.get());
    Diags.RemoveNode(orig);
    delete orig;
  }

  Diags.InsertNode(D.release());
}

/// PasteTokens - Tok is the LHS of a ## operator, and CurToken is the ##
/// operator.  Read the ## and RHS, and paste the LHS/RHS together.  If there
/// are more ## after it, chomp them iteratively.  Return the result as Tok.
/// If this returns true, the caller should immediately return the token.
bool TokenLexer::PasteTokens(Token &Tok) {
  SmallString<128> Buffer;
  const char *ResultTokStrPtr = 0;
  SourceLocation StartLoc = Tok.getLocation();
  SourceLocation PasteOpLoc;
  do {
    // Consume the ## operator.
    PasteOpLoc = Tokens[CurToken].getLocation();
    ++CurToken;
    assert(!isAtEnd() && "No token on the RHS of a paste operator!");

    // Get the RHS token.
    const Token &RHS = Tokens[CurToken];

    // Allocate space for the result token.  This is guaranteed to be enough for
    // the two tokens.
    Buffer.resize(Tok.getLength() + RHS.getLength());

    // Get the spelling of the LHS token in Buffer.
    const char *BufPtr = &Buffer[0];
    bool Invalid = false;
    unsigned LHSLen = PP.getSpelling(Tok, BufPtr, &Invalid);
    if (BufPtr != &Buffer[0])   // Really, we want the chars in Buffer!
      memcpy(&Buffer[0], BufPtr, LHSLen);
    if (Invalid)
      return true;
    
    BufPtr = &Buffer[LHSLen];
    unsigned RHSLen = PP.getSpelling(RHS, BufPtr, &Invalid);
    if (Invalid)
      return true;
    if (BufPtr != &Buffer[LHSLen])   // Really, we want the chars in Buffer!
      memcpy(&Buffer[LHSLen], BufPtr, RHSLen);

    // Trim excess space.
    Buffer.resize(LHSLen+RHSLen);

    // Plop the pasted result (including the trailing newline and null) into a
    // scratch buffer where we can lex it.
    Token ResultTokTmp;
    ResultTokTmp.startToken();

    // Claim that the tmp token is a string_literal so that we can get the
    // character pointer back from CreateString in getLiteralData().
    ResultTokTmp.setKind(tok::string_literal);
    PP.CreateString(&Buffer[0], Buffer.size(), ResultTokTmp);
    SourceLocation ResultTokLoc = ResultTokTmp.getLocation();
    ResultTokStrPtr = ResultTokTmp.getLiteralData();

    // Lex the resultant pasted token into Result.
    Token Result;

    if (Tok.isAnyIdentifier() && RHS.isAnyIdentifier()) {
      // Common paste case: identifier+identifier = identifier.  Avoid creating
      // a lexer and other overhead.
      PP.IncrementPasteCounter(true);
      Result.startToken();
      Result.setKind(tok::raw_identifier);
      Result.setRawIdentifierData(ResultTokStrPtr);
      Result.setLocation(ResultTokLoc);
      Result.setLength(LHSLen+RHSLen);
    } else {
      PP.IncrementPasteCounter(false);

      assert(ResultTokLoc.isFileID() &&
             "Should be a raw location into scratch buffer");
      SourceManager &SourceMgr = PP.getSourceManager();
      FileID LocFileID = SourceMgr.getFileID(ResultTokLoc);

      bool Invalid = false;
      const char *ScratchBufStart
        = SourceMgr.getBufferData(LocFileID, &Invalid).data();
      if (Invalid)
        return false;

      // Make a lexer to lex this string from.  Lex just this one token.
      // Make a lexer object so that we lex and expand the paste result.
      Lexer TL(SourceMgr.getLocForStartOfFile(LocFileID),
               PP.getLangOpts(), ScratchBufStart,
               ResultTokStrPtr, ResultTokStrPtr+LHSLen+RHSLen);

      // Lex a token in raw mode.  This way it won't look up identifiers
      // automatically, lexing off the end will return an eof token, and
      // warnings are disabled.  This returns true if the result token is the
      // entire buffer.
      bool isInvalid = !TL.LexFromRawLexer(Result);

      // If we got an EOF token, we didn't form even ONE token.  For example, we
      // did "/ ## /" to get "//".
      isInvalid |= Result.is(tok::eof);

      // If pasting the two tokens didn't form a full new token, this is an
      // error.  This occurs with "x ## +"  and other stuff.  Return with Tok
      // unmodified and with RHS as the next token to lex.
      if (isInvalid) {
        // Test for the Microsoft extension of /##/ turning into // here on the
//.........这里部分代码省略.........

void PathDiagnosticConsumer::HandlePathDiagnostic(PathDiagnostic *D) {
  llvm::OwningPtr<PathDiagnostic> OwningD(D);
  
  if (!D || D->path.empty())
    return;
  
  // We need to flatten the locations (convert Stmt* to locations) because
  // the referenced statements may be freed by the time the diagnostics
  // are emitted.
  D->flattenLocations();

  // If the PathDiagnosticConsumer does not support diagnostics that
  // cross file boundaries, prune out such diagnostics now.
  if (!supportsCrossFileDiagnostics()) {
    // Verify that the entire path is from the same FileID.
    FileID FID;
    const SourceManager &SMgr = (*D->path.begin())->getLocation().getManager();
    llvm::SmallVector<const PathPieces *, 5> WorkList;
    WorkList.push_back(&D->path);

    while (!WorkList.empty()) {
      const PathPieces &path = *WorkList.back();
      WorkList.pop_back();

      for (PathPieces::const_iterator I = path.begin(), E = path.end();
           I != E; ++I) {
        const PathDiagnosticPiece *piece = I->getPtr();
        FullSourceLoc L = piece->getLocation().asLocation().getExpansionLoc();
      
        if (FID.isInvalid()) {
          FID = SMgr.getFileID(L);
        } else if (SMgr.getFileID(L) != FID)
          return; // FIXME: Emit a warning?
      
        // Check the source ranges.
        ArrayRef<SourceRange> Ranges = piece->getRanges();
        for (ArrayRef<SourceRange>::iterator I = Ranges.begin(),
                                             E = Ranges.end(); I != E; ++I) {
          SourceLocation L = SMgr.getExpansionLoc(I->getBegin());
          if (!L.isFileID() || SMgr.getFileID(L) != FID)
            return; // FIXME: Emit a warning?
          L = SMgr.getExpansionLoc(I->getEnd());
          if (!L.isFileID() || SMgr.getFileID(L) != FID)
            return; // FIXME: Emit a warning?
        }
        
        if (const PathDiagnosticCallPiece *call =
            dyn_cast<PathDiagnosticCallPiece>(piece)) {
          WorkList.push_back(&call->path);
        }
        else if (const PathDiagnosticMacroPiece *macro =
                 dyn_cast<PathDiagnosticMacroPiece>(piece)) {
          WorkList.push_back(&macro->subPieces);
        }
      }
    }
    
    if (FID.isInvalid())
      return; // FIXME: Emit a warning?
  }  

  // Profile the node to see if we already have something matching it
  llvm::FoldingSetNodeID profile;
  D->Profile(profile);
  void *InsertPos = 0;

  if (PathDiagnostic *orig = Diags.FindNodeOrInsertPos(profile, InsertPos)) {
    // Keep the PathDiagnostic with the shorter path.
    // Note, the enclosing routine is called in deterministic order, so the
    // results will be consistent between runs (no reason to break ties if the
    // size is the same).
    const unsigned orig_size = orig->full_size();
    const unsigned new_size = D->full_size();
    if (orig_size <= new_size)
      return;

    assert(orig != D);
    Diags.RemoveNode(orig);
    delete orig;
  }
  
  Diags.InsertNode(OwningD.take());
}

bool Preprocessor::isCodeCompletionFile(SourceLocation FileLoc) const {
  return CodeCompletionFile && FileLoc.isFileID() &&
    SourceMgr.getFileEntryForID(SourceMgr.getFileID(FileLoc))
      == CodeCompletionFile;
}