C++ FileOffset::getOffset方法代码示例

StringRef EditedSource::getSourceText(FileOffset BeginOffs, FileOffset EndOffs,
                                      bool &Invalid) {
  assert(BeginOffs.getFID() == EndOffs.getFID());
  assert(BeginOffs <= EndOffs);
  SourceLocation BLoc = SourceMgr.getLocForStartOfFile(BeginOffs.getFID());
  BLoc = BLoc.getLocWithOffset(BeginOffs.getOffset());
  assert(BLoc.isFileID());
  SourceLocation
    ELoc = BLoc.getLocWithOffset(EndOffs.getOffset() - BeginOffs.getOffset());
  return Lexer::getSourceText(CharSourceRange::getCharRange(BLoc, ELoc),
                              SourceMgr, LangOpts, &Invalid);
}

static void applyRewrite(EditsReceiver &receiver,
                         StringRef text, FileOffset offs, unsigned len,
                         const SourceManager &SM, const LangOptions &LangOpts) {
  assert(!offs.getFID().isInvalid());
  SourceLocation Loc = SM.getLocForStartOfFile(offs.getFID());
  Loc = Loc.getLocWithOffset(offs.getOffset());
  assert(Loc.isFileID());

  if (text.empty())
    adjustRemoval(SM, LangOpts, Loc, offs, len, text);

  CharSourceRange range = CharSourceRange::getCharRange(Loc,
                                                     Loc.getLocWithOffset(len));

  if (text.empty()) {
    assert(len);
    receiver.remove(range);
    return;
  }

  if (len)
    receiver.replace(range, text);
  else
    receiver.insert(Loc, text);
}

/// \brief Check the range that we are going to remove and:
/// -Remove any trailing whitespace if possible.
/// -Insert a space if removing the range is going to mess up the source tokens.
static void adjustRemoval(const SourceManager &SM, const LangOptions &LangOpts,
                          SourceLocation Loc, FileOffset offs,
                          unsigned &len, StringRef &text) {
  assert(len && text.empty());
  SourceLocation BeginTokLoc = Lexer::GetBeginningOfToken(Loc, SM, LangOpts);
  if (BeginTokLoc != Loc)
    return; // the range is not at the beginning of a token, keep the range.

  bool Invalid = false;
  StringRef buffer = SM.getBufferData(offs.getFID(), &Invalid);
  if (Invalid)
    return;

  unsigned begin = offs.getOffset();
  unsigned end = begin + len;

  // Do not try to extend the removal if we're at the end of the buffer already.
  if (end == buffer.size())
    return;

  assert(begin < buffer.size() && end < buffer.size() && "Invalid range!");

  // FIXME: Remove newline.

  if (begin == 0) {
    if (buffer[end] == ' ')
      ++len;
    return;
  }

  if (buffer[end] == ' ') {
    assert((end + 1 != buffer.size() || buffer.data()[end + 1] == 0) &&
           "buffer not zero-terminated!");
    if (canRemoveWhitespace(/*left=*/buffer[begin-1],
                            /*beforeWSpace=*/buffer[end-1],
                            /*right=*/buffer.data()[end + 1], // zero-terminated
                            LangOpts))
      ++len;
    return;
  }

  if (!canBeJoined(buffer[begin-1], buffer[end], LangOpts))
    text = " ";
}

/// \brief Check the range that we are going to remove and:
/// -Remove any trailing whitespace if possible.
/// -Insert a space if removing the range is going to mess up the source tokens.
static void adjustRemoval(const SourceManager &SM, const LangOptions &LangOpts,
                          SourceLocation Loc, FileOffset offs,
                          unsigned &len, StringRef &text) {
  assert(len && text.empty());
  SourceLocation BeginTokLoc = Lexer::GetBeginningOfToken(Loc, SM, LangOpts);
  if (BeginTokLoc != Loc)
    return; // the range is not at the beginning of a token, keep the range.

  bool Invalid = false;
  StringRef buffer = SM.getBufferData(offs.getFID(), &Invalid);
  if (Invalid)
    return;

  unsigned begin = offs.getOffset();
  unsigned end = begin + len;

  // FIXME: Remove newline.

  if (begin == 0) {
    if (buffer[end] == ' ')
      ++len;
    return;
  }

  if (buffer[end] == ' ') {
    if (canRemoveWhitespace(/*left=*/buffer[begin-1],
                            /*beforeWSpace=*/buffer[end-1],
                            /*right=*/buffer[end+1],
                            LangOpts))
      ++len;
    return;
  }

  if (!canBeJoined(buffer[begin-1], buffer[end], LangOpts))
    text = " ";
}

void EditedSource::commitRemove(SourceLocation OrigLoc,
                                FileOffset BeginOffs, unsigned Len) {
  if (Len == 0)
    return;

  FileOffset EndOffs = BeginOffs.getWithOffset(Len);
  FileEditsTy::iterator I = FileEdits.upper_bound(BeginOffs);
  if (I != FileEdits.begin())
    --I;

  for (; I != FileEdits.end(); ++I) {
    FileEdit &FA = I->second;
    FileOffset B = I->first;
    FileOffset E = B.getWithOffset(FA.RemoveLen);

    if (BeginOffs < E)
      break;
  }

  FileOffset TopBegin, TopEnd;
  FileEdit *TopFA = nullptr;

  if (I == FileEdits.end()) {
    FileEditsTy::iterator
      NewI = FileEdits.insert(I, std::make_pair(BeginOffs, FileEdit()));
    NewI->second.RemoveLen = Len;
    return;
  }

  FileEdit &FA = I->second;
  FileOffset B = I->first;
  FileOffset E = B.getWithOffset(FA.RemoveLen);
  if (BeginOffs < B) {
    FileEditsTy::iterator
      NewI = FileEdits.insert(I, std::make_pair(BeginOffs, FileEdit()));
    TopBegin = BeginOffs;
    TopEnd = EndOffs;
    TopFA = &NewI->second;
    TopFA->RemoveLen = Len;
  } else {
    TopBegin = B;
    TopEnd = E;
    TopFA = &I->second;
    if (TopEnd >= EndOffs)
      return;
    unsigned diff = EndOffs.getOffset() - TopEnd.getOffset();
    TopEnd = EndOffs;
    TopFA->RemoveLen += diff;
    if (B == BeginOffs)
      TopFA->Text = StringRef();
    ++I;
  }

  while (I != FileEdits.end()) {
    FileEdit &FA = I->second;
    FileOffset B = I->first;
    FileOffset E = B.getWithOffset(FA.RemoveLen);

    if (B >= TopEnd)
      break;

    if (E <= TopEnd) {
      FileEdits.erase(I++);
      continue;
    }

    if (B < TopEnd) {
      unsigned diff = E.getOffset() - TopEnd.getOffset();
      TopEnd = E;
      TopFA->RemoveLen += diff;
      FileEdits.erase(I);
    }

    break;
  }
}