C++ SourceColumnMap::byteToContainingColumn方法代码示例

static std::string buildFixItInsertionLine(unsigned LineNo,
                                           const SourceColumnMap &map,
                                           ArrayRef<FixItHint> Hints,
                                           const SourceManager &SM,
                                           const DiagnosticOptions *DiagOpts) {
  std::string FixItInsertionLine;
  if (Hints.empty() || !DiagOpts->ShowFixits)
    return FixItInsertionLine;
  unsigned PrevHintEndCol = 0;

  for (ArrayRef<FixItHint>::iterator I = Hints.begin(), E = Hints.end();
       I != E; ++I) {
    if (!I->CodeToInsert.empty()) {
      // We have an insertion hint. Determine whether the inserted
      // code contains no newlines and is on the same line as the caret.
      std::pair<FileID, unsigned> HintLocInfo
        = SM.getDecomposedExpansionLoc(I->RemoveRange.getBegin());
      if (LineNo == SM.getLineNumber(HintLocInfo.first, HintLocInfo.second) &&
          StringRef(I->CodeToInsert).find_first_of("\n\r") == StringRef::npos) {
        // Insert the new code into the line just below the code
        // that the user wrote.
        // Note: When modifying this function, be very careful about what is a
        // "column" (printed width, platform-dependent) and what is a
        // "byte offset" (SourceManager "column").
        unsigned HintByteOffset
          = SM.getColumnNumber(HintLocInfo.first, HintLocInfo.second) - 1;

        // The hint must start inside the source or right at the end
        assert(HintByteOffset < static_cast<unsigned>(map.bytes())+1);
        unsigned HintCol = map.byteToContainingColumn(HintByteOffset);

        // If we inserted a long previous hint, push this one forwards, and add
        // an extra space to show that this is not part of the previous
        // completion. This is sort of the best we can do when two hints appear
        // to overlap.
        //
        // Note that if this hint is located immediately after the previous
        // hint, no space will be added, since the location is more important.
        if (HintCol < PrevHintEndCol)
          HintCol = PrevHintEndCol + 1;

        // FIXME: This function handles multibyte characters in the source, but
        // not in the fixits. This assertion is intended to catch unintended
        // use of multibyte characters in fixits. If we decide to do this, we'll
        // have to track separate byte widths for the source and fixit lines.
        assert((size_t)llvm::sys::locale::columnWidth(I->CodeToInsert) ==
               I->CodeToInsert.size());

        // This relies on one byte per column in our fixit hints.
        // This should NOT use HintByteOffset, because the source might have
        // Unicode characters in earlier columns.
        unsigned LastColumnModified = HintCol + I->CodeToInsert.size();
        if (LastColumnModified > FixItInsertionLine.size())
          FixItInsertionLine.resize(LastColumnModified, ' ');

        std::copy(I->CodeToInsert.begin(), I->CodeToInsert.end(),
                  FixItInsertionLine.begin() + HintCol);

        PrevHintEndCol = LastColumnModified;
      } else {
        FixItInsertionLine.clear();
        break;
      }
    }
  }

  expandTabs(FixItInsertionLine, DiagOpts->TabStop);

  return FixItInsertionLine;
}

/// \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.........

/// \brief Highlight a SourceRange (with ~'s) for any characters on LineNo.
static void highlightRange(const CharSourceRange &R,
                           unsigned LineNo, FileID FID,
                           const SourceColumnMap &map,
                           std::string &CaretLine,
                           const SourceManager &SM,
                           const LangOptions &LangOpts) {
  if (!R.isValid()) return;

  SourceLocation Begin = R.getBegin();
  SourceLocation End = R.getEnd();

  unsigned StartLineNo = SM.getExpansionLineNumber(Begin);
  if (StartLineNo > LineNo || SM.getFileID(Begin) != FID)
    return;  // No intersection.

  unsigned EndLineNo = SM.getExpansionLineNumber(End);
  if (EndLineNo < LineNo || SM.getFileID(End) != FID)
    return;  // No intersection.

  // Compute the column number of the start.
  unsigned StartColNo = 0;
  if (StartLineNo == LineNo) {
    StartColNo = SM.getExpansionColumnNumber(Begin);
    if (StartColNo) --StartColNo;  // Zero base the col #.
  }

  // Compute the column number of the end.
  unsigned EndColNo = map.getSourceLine().size();
  if (EndLineNo == LineNo) {
    EndColNo = SM.getExpansionColumnNumber(End);
    if (EndColNo) {
      --EndColNo;  // Zero base the col #.

      // Add in the length of the token, so that we cover multi-char tokens if
      // this is a token range.
      if (R.isTokenRange())
        EndColNo += Lexer::MeasureTokenLength(End, SM, LangOpts);
    } else {
      EndColNo = CaretLine.size();
    }
  }

  assert(StartColNo <= EndColNo && "Invalid range!");

  // Check that a token range does not highlight only whitespace.
  if (R.isTokenRange()) {
    // Pick the first non-whitespace column.
    while (StartColNo < map.getSourceLine().size() &&
           (map.getSourceLine()[StartColNo] == ' ' ||
            map.getSourceLine()[StartColNo] == '\t'))
      StartColNo = map.startOfNextColumn(StartColNo);

    // Pick the last non-whitespace column.
    if (EndColNo > map.getSourceLine().size())
      EndColNo = map.getSourceLine().size();
    while (EndColNo-1 &&
           (map.getSourceLine()[EndColNo-1] == ' ' ||
            map.getSourceLine()[EndColNo-1] == '\t'))
      EndColNo = map.startOfPreviousColumn(EndColNo);

    // If the start/end passed each other, then we are trying to highlight a
    // range that just exists in whitespace, which must be some sort of other
    // bug.
    assert(StartColNo <= EndColNo && "Trying to highlight whitespace??");
  }

  assert(StartColNo <= map.getSourceLine().size() && "Invalid range!");
  assert(EndColNo <= map.getSourceLine().size() && "Invalid range!");

  // Fill the range with ~'s.
  StartColNo = map.byteToContainingColumn(StartColNo);
  EndColNo = map.byteToContainingColumn(EndColNo);

  assert(StartColNo <= EndColNo && "Invalid range!");
  if (CaretLine.size() < EndColNo)
    CaretLine.resize(EndColNo,' ');
  std::fill(CaretLine.begin()+StartColNo,CaretLine.begin()+EndColNo,'~');
}

/// 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(
    FullSourceLoc Loc, DiagnosticsEngine::Level Level,
    SmallVectorImpl<CharSourceRange> &Ranges, ArrayRef<FixItHint> Hints) {
  assert(Loc.isValid() && "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 = Loc.getDecomposedLoc();
  FileID FID = LocInfo.first;
  const SourceManager &SM = Loc.getManager();

  // Get information about the buffer it points into.
  bool Invalid = false;
  StringRef BufData = Loc.getBufferData(&Invalid);
  if (Invalid)
    return;

  unsigned CaretLineNo = Loc.getLineNumber();
  unsigned CaretColNo = Loc.getColumnNumber();

  // Arbitrarily stop showing snippets when the line is too long.
  static const size_t MaxLineLengthToPrint = 4096;
  if (CaretColNo > MaxLineLengthToPrint)
    return;

  // Find the set of lines to include.
  const unsigned MaxLines = DiagOpts->SnippetLineLimit;
  std::pair<unsigned, unsigned> Lines = {CaretLineNo, CaretLineNo};
  for (SmallVectorImpl<CharSourceRange>::iterator I = Ranges.begin(),
                                                  E = Ranges.end();
       I != E; ++I)
    if (auto OptionalRange = findLinesForRange(*I, FID, SM))
      Lines = maybeAddRange(Lines, *OptionalRange, MaxLines);

  for (unsigned LineNo = Lines.first; LineNo != Lines.second + 1; ++LineNo) {
    const char *BufStart = BufData.data();
    const char *BufEnd = BufStart + BufData.size();

    // Rewind from the current position to the start of the line.
    const char *LineStart =
        BufStart +
        SM.getDecomposedLoc(SM.translateLineCol(FID, LineNo, 1)).second;
    if (LineStart == BufEnd)
      break;

    // Compute the line end.
    const char *LineEnd = LineStart;
    while (*LineEnd != '\n' && *LineEnd != '\r' && LineEnd != BufEnd)
      ++LineEnd;

    // Arbitrarily stop showing snippets when the line is too long.
    // FIXME: Don't print any lines in this case.
    if (size_t(LineEnd - LineStart) > MaxLineLengthToPrint)
      return;

    // Trim trailing null-bytes.
    StringRef Line(LineStart, LineEnd - LineStart);
    while (!Line.empty() && Line.back() == '\0' &&
           (LineNo != CaretLineNo || Line.size() > CaretColNo))
      Line = Line.drop_back();

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

    // Build the byte to column map.
    const SourceColumnMap sourceColMap(SourceLine, DiagOpts->TabStop);

    // Create a line for the caret that is filled with spaces that is the same
    // number of columns as the line of source code.
    std::string CaretLine(sourceColMap.columns(), ' ');

    // 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.
    if (CaretLineNo == LineNo) {
      CaretColNo = sourceColMap.byteToContainingColumn(CaretColNo - 1);
      if (CaretLine.size() < CaretColNo + 1)
//.........这里部分代码省略.........